clang format

Add optional "ident" argument to systemd sink constructor

.clang-format

@@ -104,5 +104,6 @@ SpacesInSquareBrackets: false
 Standard:        Cpp11
 TabWidth:        8
 UseTab:          Never
+IndentPPDirectives: AfterHash
 ...
 

.clang-tidy

@@ -2,7 +2,7 @@ Checks: 'cppcoreguidelines-*,
 performance-*,
 modernize-*,
 google-*,
-misc-*,
+misc-*
 cert-*,
 readability-*,
 clang-analyzer-*,

.gitignore

@@ -1,4 +1,6 @@
 # Auto generated files
+[Dd]ebug/
+[Rr]elease/
 build/*
 *.slo
 *.lo
@@ -55,6 +57,7 @@ example/*
 
 # generated files
 generated
+version.rc
 
 # Cmake
 CMakeCache.txt
@@ -67,6 +70,8 @@ install_manifest.txt
 /tests/tests.VC.db
 /tests/tests
 /tests/logs/*
+spdlogConfig.cmake
+spdlogConfigVersion.cmake
 
 # idea
 .idea/
@@ -81,3 +86,7 @@ cmake-build-*/
 *.tcl
 *.user
 *.sln
+
+# macos
+*.DS_store
+*.xcodeproj/

.travis.yml

@@ -5,11 +5,11 @@
 sudo: required
 language: cpp
 
-# gcc 4.8
-addons: &gcc48
+# gcc 4.9
+addons: &gcc49
   apt:
     packages:
-      - g++-4.8
+      - g++-4.9
     sources:
       - ubuntu-toolchain-r-test
 
@@ -21,6 +21,24 @@ addons: &gcc7
     sources:
       - ubuntu-toolchain-r-test
 
+
+# gcc 9.0
+addons: &gcc9
+  apt:
+    packages:
+      - g++-9
+    sources:
+      - ubuntu-toolchain-r-test
+      
+# gcc 11.0
+addons: &gcc11
+  apt:
+    packages:
+      - g++-11
+    sources:
+      - ubuntu-toolchain-r-test
+
+
 # Clang 3.5
 addons: &clang35
   apt:
@@ -40,48 +58,73 @@ addons: &clang10
     sources:
       - sourceline: "deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-10 main"
         key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
+        
+addons: &clang12
+  apt:
+    packages:
+      - clang-12
+      - lldb-12
+      - lld-12
+    sources:
+      - sourceline: "deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-12 main"
+        key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"        
 
-
+env:
+  global:
+    - BUILD_EXAMPLE='ON'
+    
 matrix:
   include:
-    # Test gcc-4.8: C++11, Build=Debug/Release
-    - env: GCC_VERSION=4.8 BUILD_TYPE=Debug CPP=11
+    # Test gcc-4.9: C++11, Build=Release
+    - env: GCC_VERSION=4.9 BUILD_TYPE=Release CPP=11 BUILD_EXAMPLE='OFF'
       os: linux
-      addons: *gcc48
-
-    - env: GCC_VERSION=4.8 BUILD_TYPE=Release CPP=11
-      os: linux
-      addons: *gcc48
-
+      addons: *gcc49
+      
+    # Test gcc-7: C++11, Build=Release
     - env: GCC_VERSION=7 BUILD_TYPE=Release CPP=11
       os: linux
       addons: *gcc7
-
-    # Test clang-3.5: C++11, Build=Debug/Release
-    - env: CLANG_VERSION=3.5 BUILD_TYPE=Debug CPP=11
+      
+    # Test gcc-9: C++17, Build=Release
+    - env: GCC_VERSION=9 BUILD_TYPE=Release CPP=17
       os: linux
-      addons: *clang35
+      addons: *gcc9
 
+    # Test gcc-11.0: C++20, Build=Debug
+    - env: GCC_VERSION=11 BUILD_TYPE=Debug CPP=20 ASAN=Off
+      os: linux
+      dist: bionic
+      addons: *gcc11
+      
+    # Test clang-3.5: C++11, Build=Release
     - env: CLANG_VERSION=3.5 BUILD_TYPE=Release CPP=11
       os: linux
       addons: *clang35
 
-      # osx
+    # Text osx
     - env: BUILD_TYPE=Release CPP=11 ASAN=Off TSAN=Off
       os: osx
 
-    # Test clang-10.0: C++11, Build=Debug/Release
-    - env: CLANG_VERSION=10 BUILD_TYPE=Debug CPP=11
-      os: linux
-      dist: bionic
-      addons: *clang10
-
+    # Test clang-10.0: C++11, Build=Release
     - env: CLANG_VERSION=10 BUILD_TYPE=Release CPP=11 ASAN=On
       os: linux
       dist: bionic
       addons: *clang10
-
-
+      
+    # Test clang-10.0: C++17, Build=Debug
+    - env: CLANG_VERSION=10 BUILD_TYPE=Debug CPP=17 ASAN=Off
+      os: linux
+      dist: bionic
+      addons: *clang10
+      
+            
+    # Test clang-12.0: C++17, Build=Debug
+    - env: CLANG_VERSION=12 BUILD_TYPE=Debug CPP=17 ASAN=Off
+      os: linux
+      dist: bionic
+      addons: *clang12
+          
+                        
 before_script:
   - if [ -n "$GCC_VERSION" ]; then export CXX="g++-${GCC_VERSION}" CC="gcc-${GCC_VERSION}"; fi
   - if [ -n "$CLANG_VERSION" ]; then export CXX="clang++-${CLANG_VERSION}" CC="clang-${CLANG_VERSION}"; fi
@@ -99,12 +142,12 @@ script:
       --warn-uninitialized \
       -DCMAKE_BUILD_TYPE=$BUILD_TYPE \
       -DCMAKE_CXX_STANDARD=$CPP \
-      -DSPDLOG_BUILD_EXAMPLE=ON \
-      -DSPDLOG_BUILD_EXAMPLE_HO=ON \
-      -DSPDLOG_ENABLE_WARNINGS=ON \
+      -DSPDLOG_BUILD_EXAMPLE=$BUILD_EXAMPLE \
+      -DSPDLOG_BUILD_EXAMPLE_HO=$BUILD_EXAMPLE \
+      -DSPDLOG_BUILD_WARNINGS=ON \
       -DSPDLOG_BUILD_BENCH=OFF \
       -DSPDLOG_BUILD_TESTS=ON \
-      -DSPDLOG_BUILD_TESTS_HO=OFf \
+      -DSPDLOG_BUILD_TESTS_HO=OFF \
       -DSPDLOG_SANITIZE_ADDRESS=$ASAN 
       
   - make VERBOSE=1 -j2

CMakeLists.txt

@@ -1,14 +1,6 @@
 # Copyright(c) 2019 spdlog authors Distributed under the MIT License (http://opensource.org/licenses/MIT)
 
-cmake_minimum_required(VERSION 3.2)
-
-if(${CMAKE_VERSION} VERSION_LESS 3.11)
-    cmake_policy(VERSION ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION})
-else()
-    cmake_policy(VERSION 3.11)
-endif()
-
-enable_language(C)
+cmake_minimum_required(VERSION 3.10...3.21)
 
 # ---------------------------------------------------------------------------------------
 # Start spdlog project
@@ -38,9 +30,14 @@ if(NOT CMAKE_CXX_STANDARD)
     set(CMAKE_CXX_STANDARD_REQUIRED ON)
 endif()
 
+# make sure __cplusplus is defined when using msvc and enable parallel build
+if(MSVC)
+    string(APPEND CMAKE_CXX_FLAGS " /Zc:__cplusplus /MP")
+endif()
+
 set(CMAKE_CXX_EXTENSIONS OFF)
 
-if(CMAKE_SYSTEM_NAME MATCHES "CYGWIN")
+if(CMAKE_SYSTEM_NAME MATCHES "CYGWIN" OR CMAKE_SYSTEM_NAME MATCHES "MSYS")
     set(CMAKE_CXX_EXTENSIONS ON)
 endif()
 
@@ -83,6 +80,7 @@ option(SPDLOG_BUILD_WARNINGS "Enable compiler warnings" OFF)
 
 # install options
 option(SPDLOG_INSTALL "Generate the install target" ${SPDLOG_MASTER_PROJECT})
+option(SPDLOG_USE_STD_FORMAT "Use std::format instead of fmt library. No compile-time format string checking." OFF)
 option(SPDLOG_FMT_EXTERNAL "Use external fmt library instead of bundled" OFF)
 option(SPDLOG_FMT_EXTERNAL_HO "Use external fmt header-only library instead of bundled" OFF)
 option(SPDLOG_NO_EXCEPTIONS "Compile with -fno-exceptions. Call abort() on any spdlog exceptions" OFF)
@@ -91,14 +89,27 @@ if(SPDLOG_FMT_EXTERNAL AND SPDLOG_FMT_EXTERNAL_HO)
     message(FATAL_ERROR "SPDLOG_FMT_EXTERNAL and SPDLOG_FMT_EXTERNAL_HO are mutually exclusive")
 endif()
 
+if(SPDLOG_USE_STD_FORMAT AND SPDLOG_FMT_EXTERNAL_HO)
+    message(FATAL_ERROR "SPDLOG_USE_STD_FORMAT and SPDLOG_FMT_EXTERNAL_HO are mutually exclusive")
+endif()
+
+if(SPDLOG_USE_STD_FORMAT AND SPDLOG_FMT_EXTERNAL)
+    message(FATAL_ERROR "SPDLOG_USE_STD_FORMAT and SPDLOG_FMT_EXTERNAL are mutually exclusive")
+endif()
+
 # misc tweakme options
 if(WIN32)
     option(SPDLOG_WCHAR_SUPPORT "Support wchar api" OFF)
     option(SPDLOG_WCHAR_FILENAMES "Support wchar filenames" OFF)
+else()
+    set(SPDLOG_WCHAR_SUPPORT OFF CACHE BOOL "non supported option" FORCE)
+    set(SPDLOG_WCHAR_FILENAMES OFF CACHE BOOL "non supported option" FORCE)
 endif()
+
 if(${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
-    option(SPDLOG_CLOCK_COARSE
-           "Use the much faster (but much less accurate) CLOCK_REALTIME_COARSE instead of the regular clock," OFF)
+    option(SPDLOG_CLOCK_COARSE "Use CLOCK_REALTIME_COARSE instead of the regular clock," OFF)
+else()
+    set(SPDLOG_CLOCK_COARSE OFF CACHE BOOL "non supported option" FORCE)
 endif()
 
 option(SPDLOG_PREVENT_CHILD_FD "Prevent from child processes to inherit log file descriptors" OFF)
@@ -108,6 +119,7 @@ option(
     SPDLOG_NO_ATOMIC_LEVELS
     "prevent spdlog from using of std::atomic log levels (use only if your code never modifies log levels concurrently"
     OFF)
+option(SPDLOG_DISABLE_DEFAULT_LOGGER "Disable default logger creation" OFF)
 
 # clang-tidy
 if(${CMAKE_VERSION} VERSION_GREATER "3.5")
@@ -127,22 +139,22 @@ message(STATUS "Build type: " ${CMAKE_BUILD_TYPE})
 # ---------------------------------------------------------------------------------------
 set(SPDLOG_SRCS src/spdlog.cpp src/stdout_sinks.cpp src/color_sinks.cpp src/file_sinks.cpp src/async.cpp src/cfg.cpp)
 
-if(NOT SPDLOG_FMT_EXTERNAL AND NOT SPDLOG_FMT_EXTERNAL_HO)
+if(NOT SPDLOG_USE_STD_FORMAT AND NOT SPDLOG_FMT_EXTERNAL AND NOT SPDLOG_FMT_EXTERNAL_HO)
     list(APPEND SPDLOG_SRCS src/fmt.cpp)
 endif()
 
-if(WIN32 AND SPDLOG_BUILD_SHARED)
-    list(APPEND SPDLOG_SRCS ${CMAKE_CURRENT_BINARY_DIR}/version.rc)
-endif()
-
-if(SPDLOG_BUILD_SHARED)
+if(SPDLOG_BUILD_SHARED OR BUILD_SHARED_LIBS)
+    if(WIN32)
+        configure_file(${CMAKE_CURRENT_SOURCE_DIR}/cmake/version.rc.in ${CMAKE_CURRENT_BINARY_DIR}/version.rc @ONLY)
+        list(APPEND SPDLOG_SRCS ${CMAKE_CURRENT_BINARY_DIR}/version.rc)
+    endif()
     add_library(spdlog SHARED ${SPDLOG_SRCS} ${SPDLOG_ALL_HEADERS})
     target_compile_definitions(spdlog PUBLIC SPDLOG_SHARED_LIB)
-    if(WIN32)
-        target_compile_options(spdlog PUBLIC /wd4251 /wd4275)
-        configure_file(${CMAKE_CURRENT_SOURCE_DIR}/cmake/version.rc.in ${CMAKE_CURRENT_BINARY_DIR}/version.rc @ONLY)
+    if(MSVC)
+        target_compile_options(spdlog PUBLIC $<$<AND:$<CXX_COMPILER_ID:MSVC>,$<NOT:$<COMPILE_LANGUAGE:CUDA>>>:/wd4251
+                                             /wd4275>)
     endif()
-    if(NOT SPDLOG_FMT_EXTERNAL AND NOT SPDLOG_FMT_EXTERNAL_HO)
+    if(NOT SPDLOG_USE_STD_FORMAT AND NOT SPDLOG_FMT_EXTERNAL AND NOT SPDLOG_FMT_EXTERNAL_HO)
         target_compile_definitions(spdlog PRIVATE FMT_EXPORT PUBLIC FMT_SHARED)
     endif()
 else()
@@ -180,7 +192,7 @@ target_link_libraries(spdlog_header_only INTERFACE Threads::Threads)
 # ---------------------------------------------------------------------------------------
 if(SPDLOG_FMT_EXTERNAL OR SPDLOG_FMT_EXTERNAL_HO)
     if(NOT TARGET fmt::fmt)
-        find_package(fmt 5.3.0 REQUIRED)
+        find_package(fmt CONFIG REQUIRED)
     endif()
     target_compile_definitions(spdlog PUBLIC SPDLOG_FMT_EXTERNAL)
     target_compile_definitions(spdlog_header_only INTERFACE SPDLOG_FMT_EXTERNAL)
@@ -197,52 +209,38 @@ if(SPDLOG_FMT_EXTERNAL OR SPDLOG_FMT_EXTERNAL_HO)
     set(PKG_CONFIG_REQUIRES fmt) # add dependency to pkg-config
 endif()
 
+# ---------------------------------------------------------------------------------------
+# Add required libraries for Android CMake build
+# ---------------------------------------------------------------------------------------
+if(ANDROID)
+    target_link_libraries(spdlog PUBLIC log)
+    target_link_libraries(spdlog_header_only INTERFACE log)
+endif()
+
 # ---------------------------------------------------------------------------------------
 # Misc definitions according to tweak options
 # ---------------------------------------------------------------------------------------
-if(SPDLOG_WCHAR_SUPPORT)
-    target_compile_definitions(spdlog PUBLIC SPDLOG_WCHAR_TO_UTF8_SUPPORT)
-    target_compile_definitions(spdlog_header_only INTERFACE SPDLOG_WCHAR_TO_UTF8_SUPPORT)
-endif()
-
-if(SPDLOG_WCHAR_FILENAMES)
-    target_compile_definitions(spdlog PUBLIC SPDLOG_WCHAR_FILENAMES)
-    target_compile_definitions(spdlog_header_only INTERFACE SPDLOG_WCHAR_FILENAMES)
-endif()
-
-if(SPDLOG_NO_EXCEPTIONS)
-    target_compile_definitions(spdlog PUBLIC SPDLOG_NO_EXCEPTIONS)
-
-    target_compile_definitions(spdlog_header_only INTERFACE SPDLOG_NO_EXCEPTIONS)
-
-    if(NOT MSVC)
-        target_compile_options(spdlog PRIVATE -fno-exceptions)
+set(SPDLOG_WCHAR_TO_UTF8_SUPPORT ${SPDLOG_WCHAR_SUPPORT})
+foreach(
+    SPDLOG_OPTION
+    SPDLOG_WCHAR_TO_UTF8_SUPPORT
+    SPDLOG_WCHAR_FILENAMES
+    SPDLOG_NO_EXCEPTIONS
+    SPDLOG_CLOCK_COARSE
+    SPDLOG_PREVENT_CHILD_FD
+    SPDLOG_NO_THREAD_ID
+    SPDLOG_NO_TLS
+    SPDLOG_NO_ATOMIC_LEVELS
+    SPDLOG_DISABLE_DEFAULT_LOGGER
+    SPDLOG_USE_STD_FORMAT)
+    if(${SPDLOG_OPTION})
+        target_compile_definitions(spdlog PUBLIC ${SPDLOG_OPTION})
+        target_compile_definitions(spdlog_header_only INTERFACE ${SPDLOG_OPTION})
     endif()
-endif()
+endforeach()
 
-if(SPDLOG_CLOCK_COARSE)
-    target_compile_definitions(spdlog PRIVATE SPDLOG_CLOCK_COARSE)
-    target_compile_definitions(spdlog_header_only INTERFACE SPDLOG_CLOCK_COARSE)
-endif()
-
-if(SPDLOG_PREVENT_CHILD_FD)
-    target_compile_definitions(spdlog PRIVATE SPDLOG_PREVENT_CHILD_FD)
-    target_compile_definitions(spdlog_header_only INTERFACE SPDLOG_PREVENT_CHILD_FD)
-endif()
-
-if(SPDLOG_NO_THREAD_ID)
-    target_compile_definitions(spdlog PRIVATE SPDLOG_NO_THREAD_ID)
-    target_compile_definitions(spdlog_header_only INTERFACE SPDLOG_NO_THREAD_ID)
-endif()
-
-if(SPDLOG_NO_TLS)
-    target_compile_definitions(spdlog PRIVATE SPDLOG_NO_TLS)
-    target_compile_definitions(spdlog_header_only INTERFACE SPDLOG_NO_TLS)
-endif()
-
-if(SPDLOG_NO_ATOMIC_LEVELS)
-    target_compile_definitions(spdlog PUBLIC SPDLOG_NO_ATOMIC_LEVELS)
-    target_compile_definitions(spdlog_header_only INTERFACE SPDLOG_NO_ATOMIC_LEVELS)
+if(SPDLOG_NO_EXCEPTIONS AND NOT MSVC)
+    target_compile_options(spdlog PRIVATE -fno-exceptions)
 endif()
 
 # ---------------------------------------------------------------------------------------
@@ -292,7 +290,7 @@ if(SPDLOG_INSTALL)
         ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
         RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
 
-    if(NOT SPDLOG_FMT_EXTERNAL AND NOT SPDLOG_FMT_EXTERNAL_HO)
+    if(NOT SPDLOG_USE_STD_FORMAT AND NOT SPDLOG_FMT_EXTERNAL AND NOT SPDLOG_FMT_EXTERNAL_HO)
         install(DIRECTORY include/${PROJECT_NAME}/fmt/bundled/
                 DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/${PROJECT_NAME}/fmt/bundled/")
     endif()
@@ -312,7 +310,8 @@ if(SPDLOG_INSTALL)
     install(EXPORT spdlog DESTINATION ${export_dest_dir} NAMESPACE spdlog:: FILE ${config_targets_file})
 
     include(CMakePackageConfigHelpers)
-    configure_file("${project_config_in}" "${project_config_out}" @ONLY)
+    configure_package_config_file("${project_config_in}" "${project_config_out}"
+        INSTALL_DESTINATION ${export_dest_dir})
 
     write_basic_package_version_file("${version_config_file}" COMPATIBILITY SameMajorVersion)
     install(FILES "${project_config_out}" "${version_config_file}" DESTINATION "${export_dest_dir}")

README.md

@@ -1,10 +1,10 @@
 # spdlog
 
-Very fast, header-only/compiled, C++ logging library. [![Build Status](https://travis-ci.org/gabime/spdlog.svg?branch=v1.x)](https://travis-ci.org/gabime/spdlog)  [![Build status](https://ci.appveyor.com/api/projects/status/d2jnxclg20vd0o50?svg=true)](https://ci.appveyor.com/project/gabime/spdlog) [![Release](https://img.shields.io/github/release/gabime/spdlog.svg)](https://github.com/gabime/spdlog/releases/latest)
+Very fast, header-only/compiled, C++ logging library. [![Build Status](https://app.travis-ci.com/gabime/spdlog.svg?branch=v1.x)](https://app.travis-ci.com/gabime/spdlog)  [![Build status](https://ci.appveyor.com/api/projects/status/d2jnxclg20vd0o50?svg=true&branch=v1.x)](https://ci.appveyor.com/project/gabime/spdlog) [![Release](https://img.shields.io/github/release/gabime/spdlog.svg)](https://github.com/gabime/spdlog/releases/latest)
 
 ## Install 
 #### Header only version
-Copy the source [folder](https://github.com/gabime/spdlog/tree/v1.x/include/spdlog) to your build tree and use a C++11 compiler.
+Copy the include [folder](https://github.com/gabime/spdlog/tree/v1.x/include/spdlog) to your build tree and use a C++11 compiler.
 
 #### Static lib version (recommended - much faster compile times)
 ```console
@@ -22,15 +22,17 @@ $ cmake .. && make -j
  * Android
 
 ## Package managers:
+* Debian: `sudo apt install libspdlog-dev`
 * Homebrew: `brew install spdlog`
 * MacPorts: `sudo port install spdlog`
-* FreeBSD:  `cd /usr/ports/devel/spdlog/ && make install clean`
-* Fedora: `yum install spdlog`
+* FreeBSD:  `pkg install spdlog`
+* Fedora: `dnf install spdlog`
 * Gentoo: `emerge dev-libs/spdlog`
 * Arch Linux: `pacman -S spdlog`
 * vcpkg: `vcpkg install spdlog`
 * conan: `spdlog/[>=1.4.1]`
 * conda: `conda install -c conda-forge spdlog`
+* build2: ```depends: spdlog ^1.8.2```
 
 
 ## Features
@@ -45,8 +47,9 @@ $ cmake .. && make -j
     * Daily log files.
     * Console logging (colors supported).
     * syslog.
-    * Windows debugger (```OutputDebugString(..)```)
-    * Easily extendable with custom log targets  (just implement a single function in the [sink](include/spdlog/sinks/sink.h) interface).
+    * Windows event log.
+    * Windows debugger (```OutputDebugString(..)```).
+    * Easily [extendable](https://github.com/gabime/spdlog/wiki/4.-Sinks#implementing-your-own-sink) with custom log targets.
 * Log filtering - log levels can be modified in runtime as well as in compile time.
 * Support for loading log levels from argv or from environment var.
 * [Backtrace](#backtrace-support) support - store debug messages in a ring buffer and display later on demand.
@@ -56,7 +59,6 @@ $ cmake .. && make -j
 #### Basic usage
 ```c++
 #include "spdlog/spdlog.h"
-#include "spdlog/sinks/basic_file_sink.h"
 
 int main() 
 {
@@ -79,10 +81,6 @@ int main()
     // define SPDLOG_ACTIVE_LEVEL to desired level
     SPDLOG_TRACE("Some trace message with param {}", 42);
     SPDLOG_DEBUG("Some debug message");
-    
-    // Set the default logger to file logger
-    auto file_logger = spdlog::basic_logger_mt("basic_logger", "logs/basic.txt");
-    spdlog::set_default_logger(file_logger);            
 }
 
 ```
@@ -145,8 +143,9 @@ void daily_example()
 ---
 #### Backtrace support
 ```c++
-// Loggers can store in a ring buffer all messages (including debug/trace) and display later on demand.
-// When needed, call dump_backtrace() to see them
+// Debug messages can be stored in a ring buffer instead of being logged immediately.
+// This is useful in order to display debug logs only when really needed (e.g. when error happens).
+// When needed, call dump_backtrace() to see them.
 
 spdlog::enable_backtrace(32); // Store the latest 32 messages in a buffer. Older messages will be dropped.
 // or my_logger->enable_backtrace(32)..
@@ -169,6 +168,20 @@ spdlog::flush_every(std::chrono::seconds(3));
 
 ```
 
+---
+#### Stopwatch
+```c++
+// Stopwatch support for spdlog
+#include "spdlog/stopwatch.h"
+void stopwatch_example()
+{
+    spdlog::stopwatch sw;    
+    spdlog::debug("Elapsed {}", sw);
+    spdlog::debug("Elapsed {:.3}", sw);       
+}
+
+```
+
 ---
 #### Log binary data in hex
 ```c++
@@ -179,6 +192,7 @@ spdlog::flush_every(std::chrono::seconds(3));
 // {:s} - don't separate each byte with space.
 // {:p} - don't print the position on each line start.
 // {:n} - don't split the output to lines.
+// {:a} - show ASCII if :n is not set.
 
 #include "spdlog/fmt/bin_to_hex.h"
 
@@ -359,6 +373,35 @@ $ export SPDLOG_LEVEL=info,mylogger=trace
 $ ./example
 ```
 
+
+---
+#### Log file open/close event handlers
+```c++
+// You can get callbacks from spdlog before/after log file has been opened or closed. 
+// This is useful for cleanup procedures or for adding someting the start/end of the log files.
+void file_events_example()
+{
+    // pass the spdlog::file_event_handlers to file sinks for open/close log file notifications
+    spdlog::file_event_handlers handlers;
+    handlers.before_open = [](spdlog::filename_t filename) { spdlog::info("Before opening {}", filename); };
+    handlers.after_open = [](spdlog::filename_t filename, std::FILE *fstream) { fputs("After opening\n", fstream); };
+    handlers.before_close = [](spdlog::filename_t filename, std::FILE *fstream) { fputs("Before closing\n", fstream); };
+    handlers.after_close = [](spdlog::filename_t filename) { spdlog::info("After closing {}", filename); };
+    auto my_logger = spdlog::basic_logger_st("some_logger", "logs/events-sample.txt", true, handlers);        
+}
+```
+
+---
+#### Replace the Default Logger
+```c++
+void replace_default_logger_example()
+{
+    auto new_logger = spdlog::basic_logger_mt("new_default_logger", "logs/new-default-log.txt", true);
+    spdlog::set_default_logger(new_logger);
+    spdlog::info("new logger log message");
+}
+```
+
 ---
 ## Benchmarks
 
@@ -418,6 +461,6 @@ Documentation can be found in the [wiki](https://github.com/gabime/spdlog/wiki/1
 
 ---
 
-Thanks to [JetBrains](https://www.jetbrains.com/?from=spdlog) for donating licenses to their products to help developing **spdlog** <a href="https://www.jetbrains.com/?from=spdlog"><img src="logos/jetbrains-variant-4.svg" width="94" align="center" /></a>
+Thanks to [JetBrains](https://www.jetbrains.com/?from=spdlog) for donating product licenses to help develop **spdlog** <a href="https://www.jetbrains.com/?from=spdlog"><img src="logos/jetbrains-variant-4.svg" width="94" align="center" /></a>
 
 

appveyor.yml

@@ -4,32 +4,95 @@ environment:
   matrix:
     - GENERATOR: '"Visual Studio 14 2015"'
       BUILD_TYPE: Debug
-      WCHAR: 'OFF'
       BUILD_SHARED: 'OFF'
+      WCHAR: 'OFF'
+      WCHAR_FILES: 'OFF'
+      BUILD_EXAMPLE: 'ON'
+      USE_STD_FORMAT: 'OFF'
+      CXX_STANDARD: 11
     - GENERATOR: '"Visual Studio 14 2015"'
       BUILD_TYPE: Release
-      WCHAR: 'ON'
       BUILD_SHARED: 'OFF'
+      WCHAR: 'ON'
+      WCHAR_FILES: 'OFF'
+      BUILD_EXAMPLE: 'ON'
+      USE_STD_FORMAT: 'OFF'
+      CXX_STANDARD: 11
     - GENERATOR: '"Visual Studio 14 2015 Win64"'
       BUILD_TYPE: Debug
-      WCHAR: 'ON'
       BUILD_SHARED: 'OFF'
+      WCHAR: 'ON'
+      WCHAR_FILES: 'OFF'
+      BUILD_EXAMPLE: 'ON'
+      USE_STD_FORMAT: 'OFF'
+      CXX_STANDARD: 11
     - GENERATOR: '"Visual Studio 14 2015 Win64"'
       BUILD_TYPE: Release
-      WCHAR: 'ON'
       BUILD_SHARED: 'OFF'
+      WCHAR: 'ON'
+      WCHAR_FILES: 'OFF'
+      BUILD_EXAMPLE: 'ON'
+      USE_STD_FORMAT: 'OFF'
+      CXX_STANDARD: 11
     - GENERATOR: '"Visual Studio 15 2017 Win64"'
       BUILD_TYPE: Debug
+      BUILD_SHARED: 'OFF'
       WCHAR: 'ON'
-      BUILD_SHARED: 'OFF'
+      WCHAR_FILES: 'OFF'
+      BUILD_EXAMPLE: 'ON'
+      USE_STD_FORMAT: 'OFF'
+      CXX_STANDARD: 11
     - GENERATOR: '"Visual Studio 15 2017 Win64"'
       BUILD_TYPE: Release
-      WCHAR: 'OFF'
       BUILD_SHARED: 'OFF'
+      WCHAR: 'OFF'
+      WCHAR_FILES: 'OFF'
+      BUILD_EXAMPLE: 'ON'
+      USE_STD_FORMAT: 'OFF'
+      CXX_STANDARD: 11
     - GENERATOR: '"Visual Studio 15 2017 Win64"'
       BUILD_TYPE: Release
-      WCHAR: 'OFF'
       BUILD_SHARED: 'ON'
+      WCHAR: 'OFF'
+      WCHAR_FILES: 'OFF'
+      BUILD_EXAMPLE: 'ON'
+      USE_STD_FORMAT: 'OFF'
+      CXX_STANDARD: 11
+    - GENERATOR: '"Visual Studio 15 2017 Win64"'
+      BUILD_TYPE: Release
+      BUILD_SHARED: 'ON'
+      WCHAR: 'ON'
+      WCHAR_FILES: 'ON'
+      BUILD_EXAMPLE: 'OFF'
+      USE_STD_FORMAT: 'OFF'
+      CXX_STANDARD: 11
+    - GENERATOR: '"Visual Studio 16 2019" -A x64'
+      BUILD_TYPE: Release
+      BUILD_SHARED: 'ON'
+      WCHAR: 'OFF'
+      WCHAR_FILES: 'OFF'
+      BUILD_EXAMPLE: 'OFF'
+      USE_STD_FORMAT: 'OFF'
+      CXX_STANDARD: 17
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+    - GENERATOR: '"Visual Studio 17 2022" -A x64'
+      BUILD_TYPE: Release
+      BUILD_SHARED: 'ON'
+      WCHAR: 'OFF'
+      WCHAR_FILES: 'OFF'
+      BUILD_EXAMPLE: 'OFF'
+      USE_STD_FORMAT: 'ON'
+      CXX_STANDARD: 23 # std::format is only available with /std:c++latest at the moment.
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2022
+    - GENERATOR: '"Visual Studio 17 2022" -A x64'
+      BUILD_TYPE: Release
+      BUILD_SHARED: 'ON'
+      WCHAR: 'ON'
+      WCHAR_FILES: 'ON'
+      BUILD_EXAMPLE: 'OFF'
+      USE_STD_FORMAT: 'ON'
+      CXX_STANDARD: 23 # std::format is only available with /std:c++latest at the moment.
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2022
 build_script:
   - cmd: >-
       set
@@ -40,7 +103,7 @@ build_script:
 
       set PATH=%PATH%;C:\Program Files\Git\usr\bin
 
-      cmake .. -G %GENERATOR% -DCMAKE_BUILD_TYPE=%BUILD_TYPE% -DSPDLOG_WCHAR_SUPPORT=%WCHAR% -DSPDLOG_BUILD_SHARED=%BUILD_SHARED% -DSPDLOG_BUILD_EXAMPLE=ON -DSPDLOG_BUILD_EXAMPLE_HO=ON -DSPDLOG_BUILD_TESTS=ON -DSPDLOG_BUILD_TESTS_HO=OFF -DSPDLOG_ENABLE_WARNINGS=ON
+      cmake -G %GENERATOR% -D CMAKE_BUILD_TYPE=%BUILD_TYPE% -D BUILD_SHARED_LIBS=%BUILD_SHARED% -D SPDLOG_WCHAR_SUPPORT=%WCHAR% -D SPDLOG_WCHAR_FILENAMES=%WCHAR_FILES% -D SPDLOG_BUILD_EXAMPLE=%BUILD_EXAMPLE% -D SPDLOG_BUILD_EXAMPLE_HO=%BUILD_EXAMPLE% -D SPDLOG_BUILD_TESTS=ON -D SPDLOG_BUILD_TESTS_HO=OFF -D SPDLOG_BUILD_WARNINGS=ON -D SPDLOG_USE_STD_FORMAT=%USE_STD_FORMAT% -D CMAKE_CXX_STANDARD=%CXX_STANDARD% ..
 
       cmake --build . --config %BUILD_TYPE%
 

bench/CMakeLists.txt

@@ -1,6 +1,6 @@
 # Copyright(c) 2019 spdlog authors Distributed under the MIT License (http://opensource.org/licenses/MIT)
 
-cmake_minimum_required(VERSION 3.1)
+cmake_minimum_required(VERSION 3.10)
 project(spdlog_bench CXX)
 
 if(NOT TARGET spdlog)
@@ -9,7 +9,23 @@ if(NOT TARGET spdlog)
 endif()
 
 find_package(Threads REQUIRED)
-find_package(benchmark CONFIG REQUIRED)
+find_package(benchmark CONFIG)
+if(NOT benchmark_FOUND)
+    message(STATUS "Using CMake Version ${CMAKE_VERSION}")
+    if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.11.0")
+        # User can fetch googlebenchmark
+        message(STATUS "Downloading GoogleBenchmark")
+        include(FetchContent)
+
+        # disable tests  
+        set(BENCHMARK_ENABLE_TESTING OFF CACHE INTERNAL "")        
+        # Do not build and run googlebenchmark tests
+        FetchContent_Declare(googlebenchmark GIT_REPOSITORY https://github.com/google/benchmark.git GIT_TAG v1.6.0)
+        FetchContent_MakeAvailable(googlebenchmark)
+    else()
+        message(FATAL_ERROR "GoogleBenchmark is missing. Use CMake >= 3.11 or download it")
+    endif()
+endif()
 
 add_executable(bench bench.cpp)
 spdlog_enable_warnings(bench)

bench/async_bench.cpp

@@ -9,7 +9,14 @@
 #include "spdlog/spdlog.h"
 #include "spdlog/async.h"
 #include "spdlog/sinks/basic_file_sink.h"
-#include "spdlog/sinks/stdout_color_sinks.h"
+
+#if defined(SPDLOG_USE_STD_FORMAT)
+#    include <format>
+#elif defined(SPDLOG_FMT_EXTERNAL)
+#    include <fmt/format.h>
+#else
+#    include "spdlog/fmt/bundled/format.h"
+#endif
 
 #include "utils.h"
 #include <atomic>
@@ -27,9 +34,9 @@ using namespace utils;
 void bench_mt(int howmany, std::shared_ptr<spdlog::logger> log, int thread_count);
 
 #ifdef _MSC_VER
-#pragma warning(push)
-#pragma warning(disable : 4996) // disable fopen warning under msvc
-#endif                          // _MSC_VER
+#    pragma warning(push)
+#    pragma warning(disable : 4996) // disable fopen warning under msvc
+#endif                              // _MSC_VER
 
 int count_lines(const char *filename)
 {
@@ -48,18 +55,18 @@ int count_lines(const char *filename)
 
 void verify_file(const char *filename, int expected_count)
 {
-    spdlog::info("Verifying {} to contain {:n} line..", filename, expected_count);
+    spdlog::info("Verifying {} to contain {} line..", filename, expected_count);
     auto count = count_lines(filename);
     if (count != expected_count)
     {
-        spdlog::error("Test failed. {} has {:n} lines instead of {:n}", filename, count, expected_count);
+        spdlog::error("Test failed. {} has {} lines instead of {}", filename, count, expected_count);
         exit(1);
     }
-    spdlog::info("Line count OK ({:n})\n", count);
+    spdlog::info("Line count OK ({})\n", count);
 }
 
 #ifdef _MSC_VER
-#pragma warning(pop)
+#    pragma warning(pop)
 #endif
 
 int main(int argc, char *argv[])
@@ -98,11 +105,11 @@ int main(int argc, char *argv[])
 
         auto slot_size = sizeof(spdlog::details::async_msg);
         spdlog::info("-------------------------------------------------");
-        spdlog::info("Messages     : {:n}", howmany);
-        spdlog::info("Threads      : {:n}", threads);
-        spdlog::info("Queue        : {:n} slots", queue_size);
-        spdlog::info("Queue memory : {:n} x {} = {:n} KB ", queue_size, slot_size, (queue_size * slot_size) / 1024);
-        spdlog::info("Total iters  : {:n}", iters);
+        spdlog::info("Messages     : {:L}", howmany);
+        spdlog::info("Threads      : {:L}", threads);
+        spdlog::info("Queue        : {:L} slots", queue_size);
+        spdlog::info("Queue memory : {:L} x {:L} = {:L} KB ", queue_size, slot_size, (queue_size * slot_size) / 1024);
+        spdlog::info("Total iters  : {:L}", iters);
         spdlog::info("-------------------------------------------------");
 
         const char *filename = "logs/basic_async.log";
@@ -155,7 +162,7 @@ void thread_fun(std::shared_ptr<spdlog::logger> logger, int howmany)
 void bench_mt(int howmany, std::shared_ptr<spdlog::logger> logger, int thread_count)
 {
     using std::chrono::high_resolution_clock;
-    vector<thread> threads;
+    vector<std::thread> threads;
     auto start = high_resolution_clock::now();
 
     int msgs_per_thread = howmany / thread_count;
@@ -175,5 +182,5 @@ void bench_mt(int howmany, std::shared_ptr<spdlog::logger> logger, int thread_co
 
     auto delta = high_resolution_clock::now() - start;
     auto delta_d = duration_cast<duration<double>>(delta).count();
-    spdlog::info("Elapsed: {} secs\t {:n}/sec", delta_d, int(howmany / delta_d));
+    spdlog::info("Elapsed: {} secs\t {:L}/sec", delta_d, int(howmany / delta_d));
 }

bench/bench.cpp

@@ -12,6 +12,14 @@
 #include "spdlog/sinks/null_sink.h"
 #include "spdlog/sinks/rotating_file_sink.h"
 
+#if defined(SPDLOG_USE_STD_FORMAT)
+#    include <format>
+#elif defined(SPDLOG_FMT_EXTERNAL)
+#    include <fmt/locale.h>
+#else
+#    include "spdlog/fmt/bundled/format.h"
+#endif
+
 #include "utils.h"
 #include <atomic>
 #include <cstdlib> // EXIT_FAILURE
@@ -32,7 +40,7 @@ static const int max_threads = 1000;
 void bench_threaded_logging(size_t threads, int iters)
 {
     spdlog::info("**************************************************************");
-    spdlog::info("Multi threaded: {:n} threads, {:n} messages", threads, iters);
+    spdlog::info(spdlog::fmt_lib::format(std::locale("en_US.UTF-8"), "Multi threaded: {:L} threads, {:L} messages", threads, iters));
     spdlog::info("**************************************************************");
 
     auto basic_mt = spdlog::basic_logger_mt("basic_mt", "logs/basic_mt.log", true);
@@ -68,7 +76,7 @@ void bench_threaded_logging(size_t threads, int iters)
 void bench_single_threaded(int iters)
 {
     spdlog::info("**************************************************************");
-    spdlog::info("Single threaded: {:n} messages", iters);
+    spdlog::info(spdlog::fmt_lib::format(std::locale("en_US.UTF-8"), "Single threaded: {} messages", iters));
     spdlog::info("**************************************************************");
 
     auto basic_st = spdlog::basic_logger_st("basic_st", "logs/basic_st.log", true);
@@ -122,7 +130,7 @@ int main(int argc, char *argv[])
 
         if (threads > max_threads)
         {
-            throw std::runtime_error(fmt::format("Number of threads exceeds maximum({}})", max_threads));
+            throw std::runtime_error(spdlog::fmt_lib::format("Number of threads exceeds maximum({})", max_threads));
         }
 
         bench_single_threaded(iters);
@@ -152,7 +160,8 @@ void bench(int howmany, std::shared_ptr<spdlog::logger> log)
     auto delta = high_resolution_clock::now() - start;
     auto delta_d = duration_cast<duration<double>>(delta).count();
 
-    spdlog::info("{:<30} Elapsed: {:0.2f} secs {:>16n}/sec", log->name(), delta_d, int(howmany / delta_d));
+    spdlog::info(spdlog::fmt_lib::format(
+        std::locale("en_US.UTF-8"), "{:<30} Elapsed: {:0.2f} secs {:>16L}/sec", log->name(), delta_d, int(howmany / delta_d)));
     spdlog::drop(log->name());
 }
 
@@ -182,7 +191,8 @@ void bench_mt(int howmany, std::shared_ptr<spdlog::logger> log, size_t thread_co
 
     auto delta = high_resolution_clock::now() - start;
     auto delta_d = duration_cast<duration<double>>(delta).count();
-    spdlog::info("{:<30} Elapsed: {:0.2f} secs {:>16n}/sec", log->name(), delta_d, int(howmany / delta_d));
+    spdlog::info(spdlog::fmt_lib::format(
+        std::locale("en_US.UTF-8"), "{:<30} Elapsed: {:0.2f} secs {:>16L}/sec", log->name(), delta_d, int(howmany / delta_d)));
     spdlog::drop(log->name());
 }
 
@@ -205,7 +215,7 @@ void bench_default_api(int howmany, std::shared_ptr<spdlog::logger> log)
     auto delta_d = duration_cast<duration<double>>(delta).count();
     spdlog::drop(log->name());
     spdlog::set_default_logger(std::move(orig_default));
-    spdlog::info("{:<30} Elapsed: {:0.2f} secs {:>16n}/sec", log->name(), delta_d, int(howmany / delta_d));
+    spdlog::info("{:<30} Elapsed: {:0.2f} secs {:>16}/sec", log->name(), delta_d, int(howmany / delta_d));
 }
 
 void bench_c_string(int howmany, std::shared_ptr<spdlog::logger> log)
@@ -232,7 +242,7 @@ void bench_c_string(int howmany, std::shared_ptr<spdlog::logger> log)
     auto delta_d = duration_cast<duration<double>>(delta).count();
     spdlog::drop(log->name());
     spdlog::set_default_logger(std::move(orig_default));
-    spdlog::info("{:<30} Elapsed: {:0.2f} secs {:>16n}/sec", log->name(), delta_d, int(howmany / delta_d));
+    spdlog::info("{:<30} Elapsed: {:0.2f} secs {:>16}/sec", log->name(), delta_d, int(howmany / delta_d));
 }
 
 */

bench/formatter-bench.cpp

@@ -34,14 +34,14 @@ void bench_formatters()
     for (auto &flag : all_flags)
     {
         auto pattern = std::string("%") + flag;
-        benchmark::RegisterBenchmark(pattern.c_str(), bench_formatter, pattern);
+        benchmark::RegisterBenchmark(pattern.c_str(), &bench_formatter, pattern);
 
         //        pattern = std::string("%16") + flag;
-        //        benchmark::RegisterBenchmark(pattern.c_str(), bench_formatter, pattern);
+        //        benchmark::RegisterBenchmark(pattern.c_str(), &bench_formatter, pattern);
         //
         //        // bench center padding
         //        pattern = std::string("%=16") + flag;
-        //        benchmark::RegisterBenchmark(pattern.c_str(), bench_formatter, pattern);
+        //        benchmark::RegisterBenchmark(pattern.c_str(), &bench_formatter, pattern);
     }
 
     // complex patterns
@@ -52,7 +52,7 @@ void bench_formatters()
     };
     for (auto &pattern : patterns)
     {
-        benchmark::RegisterBenchmark(pattern.c_str(), bench_formatter, pattern)->Iterations(2500000);
+        benchmark::RegisterBenchmark(pattern.c_str(), &bench_formatter, pattern)->Iterations(2500000);
     }
 }
 
@@ -73,7 +73,7 @@ int main(int argc, char *argv[])
     }
     else
     {
-        benchmark::RegisterBenchmark(pattern.c_str(), bench_formatter, pattern);
+        benchmark::RegisterBenchmark(pattern.c_str(), &bench_formatter, pattern);
     }
     benchmark::Initialize(&argc, argv);
     benchmark::RunSpecifiedBenchmarks();

bench/latency.cpp

@@ -39,6 +39,16 @@ void bench_logger(benchmark::State &state, std::shared_ptr<spdlog::logger> logge
     }
 }
 
+void bench_logger_fmt_string(benchmark::State &state, std::shared_ptr<spdlog::logger> logger)
+{
+    int i = 0;
+    for (auto _ : state)
+    {
+        logger->info(FMT_STRING("Hello logger: msg number {}..............."), ++i);
+        ;
+    }
+}
+
 void bench_disabled_macro(benchmark::State &state, std::shared_ptr<spdlog::logger> logger)
 {
     int i = 0;
@@ -88,6 +98,7 @@ int main(int argc, char *argv[])
     auto null_logger_st = std::make_shared<spdlog::logger>("bench", std::make_shared<null_sink_st>());
     benchmark::RegisterBenchmark("null_sink_st (500_bytes c_str)", bench_c_string, std::move(null_logger_st));
     benchmark::RegisterBenchmark("null_sink_st", bench_logger, null_logger_st);
+    benchmark::RegisterBenchmark("null_sink_fmt_string", bench_logger_fmt_string, null_logger_st);
     // with backtrace of 64
     auto tracing_null_logger_st = std::make_shared<spdlog::logger>("bench", std::make_shared<null_sink_st>());
     tracing_null_logger_st->enable_backtrace(64);

cmake/spdlogCPack.cmake

@@ -18,23 +18,37 @@ set(CPACK_PACKAGE_RELOCATABLE ON CACHE BOOL "Build relocatable package")
 
 set(CPACK_RPM_PACKAGE_LICENSE "MIT")
 set(CPACK_RPM_PACKAGE_GROUP "Development/Libraries")
+set(CPACK_DEBIAN_PACKAGE_SECTION "libs")
 set(CPACK_RPM_PACKAGE_URL ${CPACK_PROJECT_URL})
+set(CPACK_DEBIAN_PACKAGE_HOMEPAGE ${CPACK_PROJECT_URL})
 set(CPACK_RPM_PACKAGE_DESCRIPTION "Very fast, header-only/compiled, C++ logging library.")
+set(CPACK_DEBIAN_PACKAGE_DESCRIPTION "Very fast, header-only/compiled, C++ logging library.")
 
 if(CPACK_PACKAGE_NAME)
     set(CPACK_RPM_FILE_NAME "${CPACK_PACKAGE_NAME}-${CPACK_PACKAGE_VERSION}")
+    set(CPACK_DEBIAN_FILE_NAME "${CPACK_PACKAGE_NAME}-${CPACK_PACKAGE_VERSION}")
 else()
     set(CPACK_RPM_FILE_NAME "${PROJECT_NAME}-${CPACK_PACKAGE_VERSION}")
+    set(CPACK_DEBIAN_FILE_NAME "${PROJECT_NAME}-${CPACK_PACKAGE_VERSION}")
+    set(CPACK_RPM_PACKAGE_NAME "${PROJECT_NAME}")
+    set(CPACK_DEBIAN_PACKAGE_NAME "${PROJECT_NAME}")
 endif()
 
 if(CPACK_RPM_PACKAGE_RELEASE)
     set(CPACK_RPM_FILE_NAME "${CPACK_RPM_FILE_NAME}-${CPACK_RPM_PACKAGE_RELEASE}")
 endif()
+if(CPACK_DEBIAN_PACKAGE_RELEASE)
+    set(CPACK_DEBIAN_FILE_NAME "${CPACK_DEBIAN_FILE_NAME}-${CPACK_DEBIAN_PACKAGE_RELEASE}")
+endif()
 
 if(CPACK_RPM_PACKAGE_ARCHITECTURE)
     set(CPACK_RPM_FILE_NAME "${CPACK_RPM_FILE_NAME}.${CPACK_RPM_PACKAGE_ARCHITECTURE}")
 endif()
+if(CPACK_DEBIAN_PACKAGE_ARCHITECTURE)
+    set(CPACK_DEBIAN_FILE_NAME "${CPACK_DEBIAN_FILE_NAME}.${CPACK_DEBIAN_PACKAGE_ARCHITECTURE}")
+endif()
 set(CPACK_RPM_FILE_NAME "${CPACK_RPM_FILE_NAME}.rpm")
+set(CPACK_DEBIAN_FILE_NAME "${CPACK_DEBIAN_FILE_NAME}.deb")
 
 if(NOT CPACK_PACKAGE_RELOCATABLE)
     # Depend on pkgconfig rpm to create the system pkgconfig folder

cmake/spdlogConfig.cmake.in

@@ -1,15 +1,20 @@
 # Copyright(c) 2019 spdlog authors
 # Distributed under the MIT License (http://opensource.org/licenses/MIT)
 
+@PACKAGE_INIT@
+
 find_package(Threads REQUIRED)
 
 set(SPDLOG_FMT_EXTERNAL @SPDLOG_FMT_EXTERNAL@)
+set(SPDLOG_FMT_EXTERNAL_HO @SPDLOG_FMT_EXTERNAL_HO@)
 set(config_targets_file @config_targets_file@)
 
-if(SPDLOG_FMT_EXTERNAL)
+if(SPDLOG_FMT_EXTERNAL OR SPDLOG_FMT_EXTERNAL_HO)
     include(CMakeFindDependencyMacro)
     find_dependency(fmt CONFIG)
 endif()
 
 
 include("${CMAKE_CURRENT_LIST_DIR}/${config_targets_file}")
+
+check_required_components(spdlog)

cmake/utils.cmake

@@ -42,6 +42,7 @@ function(spdlog_enable_warnings target_name)
                     -Wextra
                     -Wconversion
                     -pedantic
+                    -Werror
                     -Wfatal-errors>
                     $<$<CXX_COMPILER_ID:MSVC>:${MSVC_OPTIONS}>)
     endif()

cmake/version.rc.in

@@ -1,5 +1,5 @@
 #define APSTUDIO_READONLY_SYMBOLS
-#include "winres.h"
+#include <windows.h>
 #undef APSTUDIO_READONLY_SYMBOLS
 
 LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US

example/CMakeLists.txt

@@ -1,6 +1,6 @@
 # Copyright(c) 2019 spdlog authors Distributed under the MIT License (http://opensource.org/licenses/MIT)
 
-cmake_minimum_required(VERSION 3.2)
+cmake_minimum_required(VERSION 3.10)
 project(spdlog_examples CXX)
 
 if(NOT TARGET spdlog)

example/example.cpp

@@ -5,6 +5,7 @@
 // spdlog usage example
 
 #include <cstdio>
+#include <chrono>
 
 void load_levels_example();
 void stdout_logger_example();
@@ -13,15 +14,21 @@ void rotating_example();
 void daily_example();
 void async_example();
 void binary_example();
+void vector_example();
+void stopwatch_example();
 void trace_example();
 void multi_sink_example();
 void user_defined_example();
 void err_handler_example();
 void syslog_example();
+void udp_example();
 void custom_flags_example();
+void file_events_example();
+void replace_default_logger_example();
 
 #include "spdlog/spdlog.h"
-#include "spdlog/cfg/env.h" // for loading levels from the environment variable
+#include "spdlog/cfg/env.h"  // support for loading levels from the environment variable
+#include "spdlog/fmt/ostr.h" // support for user defined types
 
 int main(int, char *[])
 {
@@ -67,11 +74,16 @@ int main(int, char *[])
         daily_example();
         async_example();
         binary_example();
+        vector_example();
         multi_sink_example();
         user_defined_example();
         err_handler_example();
         trace_example();
+        stopwatch_example();
+        udp_example();
         custom_flags_example();
+        file_events_example();
+        replace_default_logger_example();
 
         // Flush all *registered* loggers using a worker thread every 3 seconds.
         // note: registered loggers *must* be thread safe for this to work correctly!
@@ -107,7 +119,7 @@ void stdout_logger_example()
 void basic_example()
 {
     // Create basic file logger (not rotated).
-    auto my_logger = spdlog::basic_logger_mt("file_logger", "logs/basic-log.txt");
+    auto my_logger = spdlog::basic_logger_mt("file_logger", "logs/basic-log.txt", true);
 }
 
 #include "spdlog/sinks/rotating_file_sink.h"
@@ -127,7 +139,7 @@ void daily_example()
 #include "spdlog/cfg/env.h"
 void load_levels_example()
 {
-    // Set the log level to "info" and mylogger to to "trace":
+    // Set the log level to "info" and mylogger to "trace":
     // SPDLOG_LEVEL=info,mylogger=trace && ./example
     spdlog::cfg::load_env_levels();
     // or from command line:
@@ -178,6 +190,21 @@ void binary_example()
     // logger->info("hexdump style, 20 chars per line {:a}", spdlog::to_hex(buf, 20));
 }
 
+// Log a vector of numbers
+#ifndef SPDLOG_USE_STD_FORMAT
+#    include "spdlog/fmt/ranges.h"
+void vector_example()
+{
+    std::vector<int> vec = {1, 2, 3};
+    spdlog::info("Vector example: {}", vec);
+}
+
+#else
+void vector_example() {}
+#endif
+
+// ! DSPDLOG_USE_STD_FORMAT
+
 // Compile time log levels.
 // define SPDLOG_ACTIVE_LEVEL to required level (e.g. SPDLOG_LEVEL_TRACE)
 void trace_example()
@@ -192,6 +219,25 @@ void trace_example()
     SPDLOG_LOGGER_TRACE(logger, "another trace message");
 }
 
+// stopwatch example
+#include "spdlog/stopwatch.h"
+#include <thread>
+void stopwatch_example()
+{
+    spdlog::stopwatch sw;
+    std::this_thread::sleep_for(std::chrono::milliseconds(123));
+    spdlog::info("Stopwatch: {} seconds", sw);
+}
+
+#include "spdlog/sinks/udp_sink.h"
+void udp_example()
+{
+    spdlog::sinks::udp_sink_config cfg("127.0.0.1", 11091);
+    auto my_logger = spdlog::udp_logger_mt("udplog", cfg);
+    my_logger->set_level(spdlog::level::debug);
+    my_logger->info("hello world");
+}
+
 // A logger with multiple sinks (stdout and file) - each with a different format and log level.
 void multi_sink_example()
 {
@@ -208,21 +254,27 @@ void multi_sink_example()
     logger.info("this message should not appear in the console, only in the file");
 }
 
-// User defined types logging by implementing operator<<
-#include "spdlog/fmt/ostr.h" // must be included
+// User defined types logging
 struct my_type
 {
-    int i;
-    template<typename OStream>
-    friend OStream &operator<<(OStream &os, const my_type &c)
+    int i = 0;
+    explicit my_type(int i)
+        : i(i){};
+};
+
+namespace fmt_lib = spdlog::fmt_lib;
+template<>
+struct fmt_lib::formatter<my_type> : fmt_lib::formatter<std::string>
+{
+    auto format(my_type my, format_context &ctx) -> decltype(ctx.out())
     {
-        return os << "[my_type i=" << c.i << "]";
+        return fmt_lib::format_to(ctx.out(), "[my_type i={}]", my.i);
     }
 };
 
 void user_defined_example()
 {
-    spdlog::info("user defined type: {}", my_type{14});
+    spdlog::info("user defined type: {}", my_type(14));
 }
 
 // Custom error handler. Will be triggered on log failure.
@@ -234,7 +286,7 @@ void err_handler_example()
 
 // syslog example (linux/osx/freebsd)
 #ifndef _WIN32
-#include "spdlog/sinks/syslog_sink.h"
+#    include "spdlog/sinks/syslog_sink.h"
 void syslog_example()
 {
     std::string ident = "spdlog-example";
@@ -245,7 +297,7 @@ void syslog_example()
 
 // Android example.
 #if defined(__ANDROID__)
-#include "spdlog/sinks/android_sink.h"
+#    include "spdlog/sinks/android_sink.h"
 void android_example()
 {
     std::string tag = "spdlog-android";
@@ -278,5 +330,40 @@ void custom_flags_example()
     using spdlog::details::make_unique; // for pre c++14
     auto formatter = make_unique<spdlog::pattern_formatter>();
     formatter->add_flag<my_formatter_flag>('*').set_pattern("[%n] [%*] [%^%l%$] %v");
-    spdlog::set_formatter(std::move(formatter));
+    // set the new formatter using spdlog::set_formatter(formatter) or logger->set_formatter(formatter)
+    // spdlog::set_formatter(std::move(formatter));
+}
+
+void file_events_example()
+{
+    // pass the spdlog::file_event_handlers to file sinks for open/close log file notifications
+    spdlog::file_event_handlers handlers;
+    handlers.before_open = [](spdlog::filename_t filename) { spdlog::info("Before opening {}", filename); };
+    handlers.after_open = [](spdlog::filename_t filename, std::FILE *fstream) {
+        spdlog::info("After opening {}", filename);
+        fputs("After opening\n", fstream);
+    };
+    handlers.before_close = [](spdlog::filename_t filename, std::FILE *fstream) {
+        spdlog::info("Before closing {}", filename);
+        fputs("Before closing\n", fstream);
+    };
+    handlers.after_close = [](spdlog::filename_t filename) { spdlog::info("After closing {}", filename); };
+    auto file_sink = std::make_shared<spdlog::sinks::basic_file_sink_mt>("logs/events-sample.txt", true, handlers);
+    spdlog::logger my_logger("some_logger", file_sink);
+    my_logger.info("Some log line");
+}
+
+void replace_default_logger_example()
+{
+    // store the old logger so we don't break other examples.
+    auto old_logger = spdlog::default_logger();
+
+    auto new_logger = spdlog::basic_logger_mt("new_default_logger", "logs/new-default-log.txt", true);
+    spdlog::set_default_logger(new_logger);
+    spdlog::set_level(spdlog::level::info);
+    spdlog::debug("This message should not be displayed!");
+    spdlog::set_level(spdlog::level::trace);
+    spdlog::debug("This message should be displayed..");
+
+    spdlog::set_default_logger(old_logger);
 }

include/spdlog/async.h

@@ -46,7 +46,7 @@ struct async_factory_impl
         auto tp = registry_inst.get_tp();
         if (tp == nullptr)
         {
-            tp = std::make_shared<details::thread_pool>(details::default_async_q_size, 1);
+            tp = std::make_shared<details::thread_pool>(details::default_async_q_size, 1U);
             registry_inst.set_tp(tp);
         }
 
@@ -73,16 +73,22 @@ inline std::shared_ptr<spdlog::logger> create_async_nb(std::string logger_name,
 }
 
 // set global thread pool.
-inline void init_thread_pool(size_t q_size, size_t thread_count, std::function<void()> on_thread_start)
+inline void init_thread_pool(
+    size_t q_size, size_t thread_count, std::function<void()> on_thread_start, std::function<void()> on_thread_stop)
 {
-    auto tp = std::make_shared<details::thread_pool>(q_size, thread_count, on_thread_start);
+    auto tp = std::make_shared<details::thread_pool>(q_size, thread_count, on_thread_start, on_thread_stop);
     details::registry::instance().set_tp(std::move(tp));
 }
 
-// set global thread pool.
+inline void init_thread_pool(size_t q_size, size_t thread_count, std::function<void()> on_thread_start)
+{
+    init_thread_pool(q_size, thread_count, on_thread_start, [] {});
+}
+
 inline void init_thread_pool(size_t q_size, size_t thread_count)
 {
-    init_thread_pool(q_size, thread_count, [] {});
+    init_thread_pool(
+        q_size, thread_count, [] {}, [] {});
 }
 
 // get the global thread pool.

include/spdlog/async_logger-inl.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/async_logger.h>
+#    include <spdlog/async_logger.h>
 #endif
 
 #include <spdlog/sinks/sink.h>
@@ -62,7 +62,7 @@ SPDLOG_INLINE void spdlog::async_logger::backend_sink_it_(const details::log_msg
             {
                 sink->log(msg);
             }
-            SPDLOG_LOGGER_CATCH()
+            SPDLOG_LOGGER_CATCH(msg.source)
         }
     }
 
@@ -80,7 +80,7 @@ SPDLOG_INLINE void spdlog::async_logger::backend_flush_()
         {
             sink->flush();
         }
-        SPDLOG_LOGGER_CATCH()
+        SPDLOG_LOGGER_CATCH(source_loc())
     }
 }
 

include/spdlog/async_logger.h

@@ -64,5 +64,5 @@ private:
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "async_logger-inl.h"
+#    include "async_logger-inl.h"
 #endif

include/spdlog/cfg/argv.h

@@ -21,7 +21,7 @@ namespace spdlog {
 namespace cfg {
 
 // search for SPDLOG_LEVEL= in the args and use it to init the levels
-void load_argv_levels(int argc, const char **argv)
+inline void load_argv_levels(int argc, const char **argv)
 {
     const std::string spdlog_level_prefix = "SPDLOG_LEVEL=";
     for (int i = 1; i < argc; i++)
@@ -30,13 +30,12 @@ void load_argv_levels(int argc, const char **argv)
         if (arg.find(spdlog_level_prefix) == 0)
         {
             auto levels_string = arg.substr(spdlog_level_prefix.size());
-            auto levels = helpers::extract_levels(levels_string);
-            details::registry::instance().update_levels(std::move(levels));
+            helpers::load_levels(levels_string);
         }
     }
 }
 
-void load_argv_levels(int argc, char **argv)
+inline void load_argv_levels(int argc, char **argv)
 {
     load_argv_levels(argc, const_cast<const char **>(argv));
 }

include/spdlog/cfg/env.h

@@ -17,7 +17,7 @@
 // export SPDLOG_LEVEL=debug
 //
 // turn off all logging except for logger1:
-// export SPDLOG_LEVEL="off,logger1=debug"
+// export SPDLOG_LEVEL="*=off,logger1=debug"
 //
 
 // turn off all logging except for logger1 and logger2:
@@ -25,11 +25,13 @@
 
 namespace spdlog {
 namespace cfg {
-void load_env_levels()
+inline void load_env_levels()
 {
     auto env_val = details::os::getenv("SPDLOG_LEVEL");
-    auto levels = helpers::extract_levels(env_val);
-    details::registry::instance().update_levels(std::move(levels));
+    if (!env_val.empty())
+    {
+        helpers::load_levels(env_val);
+    }
 }
 
 } // namespace cfg

include/spdlog/cfg/helpers-inl.h

@@ -4,13 +4,14 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/cfg/helpers.h>
+#    include <spdlog/cfg/helpers.h>
 #endif
 
 #include <spdlog/spdlog.h>
 #include <spdlog/details/os.h>
 #include <spdlog/details/registry.h>
 
+#include <algorithm>
 #include <string>
 #include <utility>
 #include <sstream>
@@ -78,24 +79,40 @@ inline std::unordered_map<std::string, std::string> extract_key_vals_(const std:
     return rv;
 }
 
-SPDLOG_INLINE log_levels extract_levels(const std::string &input)
+SPDLOG_INLINE void load_levels(const std::string &input)
 {
+    if (input.empty() || input.size() > 512)
+    {
+        return;
+    }
+
     auto key_vals = extract_key_vals_(input);
-    log_levels rv;
+    std::unordered_map<std::string, level::level_enum> levels;
+    level::level_enum global_level = level::info;
+    bool global_level_found = false;
 
     for (auto &name_level : key_vals)
     {
         auto &logger_name = name_level.first;
         auto level_name = to_lower_(name_level.second);
         auto level = level::from_str(level_name);
-        // fallback to "info" if unrecognized level name
+        // ignore unrecognized level names
         if (level == level::off && level_name != "off")
         {
-            level = level::info;
+            continue;
+        }
+        if (logger_name.empty()) // no logger name indicate global level
+        {
+            global_level_found = true;
+            global_level = level;
+        }
+        else
+        {
+            levels[logger_name] = level;
         }
-        rv.set(logger_name, level);
     }
-    return rv;
+
+    details::registry::instance().set_levels(std::move(levels), global_level_found ? &global_level : nullptr);
 }
 
 } // namespace helpers

include/spdlog/cfg/helpers.h

@@ -3,7 +3,8 @@
 
 #pragma once
 
-#include <spdlog/cfg/log_levels.h>
+#include <spdlog/common.h>
+#include <unordered_map>
 
 namespace spdlog {
 namespace cfg {
@@ -17,12 +18,12 @@ namespace helpers {
 // turn off all logging except for logger1: "off,logger1=debug"
 // turn off all logging except for logger1 and logger2: "off,logger1=debug,logger2=info"
 //
-SPDLOG_API log_levels extract_levels(const std::string &txt);
+SPDLOG_API void load_levels(const std::string &txt);
 } // namespace helpers
 
 } // namespace cfg
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "helpers-inl.h"
+#    include "helpers-inl.h"
 #endif // SPDLOG_HEADER_ONLY

include/spdlog/cfg/log_levels.h

@@ -1,47 +0,0 @@
-// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
-// Distributed under the MIT License (http://opensource.org/licenses/MIT)
-
-#pragma once
-
-#include <spdlog/common.h>
-#include <string>
-#include <unordered_map>
-
-namespace spdlog {
-namespace cfg {
-class log_levels
-{
-    std::unordered_map<std::string, spdlog::level::level_enum> levels_;
-    spdlog::level::level_enum default_level_ = level::info;
-
-public:
-    void set(const std::string &logger_name, level::level_enum lvl)
-    {
-        if (logger_name.empty())
-        {
-            default_level_ = lvl;
-        }
-        else
-        {
-            levels_[logger_name] = lvl;
-        }
-    }
-
-    void set_default(level::level_enum lvl)
-    {
-        default_level_ = lvl;
-    }
-
-    level::level_enum get(const std::string &logger_name)
-    {
-        auto it = levels_.find(logger_name);
-        return it != levels_.end() ? it->second : default_level_;
-    }
-
-    level::level_enum default_level()
-    {
-        return default_level_;
-    }
-};
-} // namespace cfg
-} // namespace spdlog

include/spdlog/common-inl.h

@@ -4,16 +4,23 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/common.h>
+#    include <spdlog/common.h>
 #endif
 
+#include <algorithm>
+#include <iterator>
+
 namespace spdlog {
 namespace level {
-static string_view_t level_string_views[] SPDLOG_LEVEL_NAMES;
+
+#if __cplusplus >= 201703L
+constexpr
+#endif
+    static string_view_t level_string_views[] SPDLOG_LEVEL_NAMES;
 
 static const char *short_level_names[] SPDLOG_SHORT_LEVEL_NAMES;
 
-SPDLOG_INLINE string_view_t &to_string_view(spdlog::level::level_enum l) SPDLOG_NOEXCEPT
+SPDLOG_INLINE const string_view_t &to_string_view(spdlog::level::level_enum l) SPDLOG_NOEXCEPT
 {
     return level_string_views[l];
 }
@@ -25,15 +32,10 @@ SPDLOG_INLINE const char *to_short_c_str(spdlog::level::level_enum l) SPDLOG_NOE
 
 SPDLOG_INLINE spdlog::level::level_enum from_str(const std::string &name) SPDLOG_NOEXCEPT
 {
-    int level = 0;
-    for (const auto &level_str : level_string_views)
-    {
-        if (level_str == name)
-        {
-            return static_cast<level::level_enum>(level);
-        }
-        level++;
-    }
+    auto it = std::find(std::begin(level_string_views), std::end(level_string_views), name);
+    if (it != std::end(level_string_views))
+        return static_cast<level::level_enum>(it - std::begin(level_string_views));
+
     // check also for "warn" and "err" before giving up..
     if (name == "warn")
     {
@@ -53,9 +55,13 @@ SPDLOG_INLINE spdlog_ex::spdlog_ex(std::string msg)
 
 SPDLOG_INLINE spdlog_ex::spdlog_ex(const std::string &msg, int last_errno)
 {
+#ifdef SPDLOG_USE_STD_FORMAT
+    msg_ = std::system_error(std::error_code(last_errno, std::generic_category()), msg).what();
+#else
     memory_buf_t outbuf;
-    fmt::format_system_error(outbuf, last_errno, msg);
+    fmt::format_system_error(outbuf, last_errno, msg.c_str());
     msg_ = fmt::to_string(outbuf);
+#endif
 }
 
 SPDLOG_INLINE const char *spdlog_ex::what() const SPDLOG_NOEXCEPT

include/spdlog/common.h

@@ -14,68 +14,95 @@
 #include <string>
 #include <type_traits>
 #include <functional>
+#include <cstdio>
+
+#ifdef SPDLOG_USE_STD_FORMAT
+#    include <string_view>
+#endif
 
 #ifdef SPDLOG_COMPILED_LIB
-#undef SPDLOG_HEADER_ONLY
-#if defined(_WIN32) && defined(SPDLOG_SHARED_LIB)
-#ifdef spdlog_EXPORTS
-#define SPDLOG_API __declspec(dllexport)
-#else
-#define SPDLOG_API __declspec(dllimport)
-#endif
-#else // !defined(_WIN32) || !defined(SPDLOG_SHARED_LIB)
-#define SPDLOG_API
-#endif
-#define SPDLOG_INLINE
+#    undef SPDLOG_HEADER_ONLY
+#    if defined(SPDLOG_SHARED_LIB)
+#        if defined(_WIN32)
+#            ifdef spdlog_EXPORTS
+#                define SPDLOG_API __declspec(dllexport)
+#            else // !spdlog_EXPORTS
+#                define SPDLOG_API __declspec(dllimport)
+#            endif
+#        else // !defined(_WIN32)
+#            define SPDLOG_API __attribute__((visibility("default")))
+#        endif
+#    else // !defined(SPDLOG_SHARED_LIB)
+#        define SPDLOG_API
+#    endif
+#    define SPDLOG_INLINE
 #else // !defined(SPDLOG_COMPILED_LIB)
-#define SPDLOG_API
-#define SPDLOG_HEADER_ONLY
-#define SPDLOG_INLINE inline
+#    define SPDLOG_API
+#    define SPDLOG_HEADER_ONLY
+#    define SPDLOG_INLINE inline
 #endif // #ifdef SPDLOG_COMPILED_LIB
 
 #include <spdlog/fmt/fmt.h>
 
-// visual studio upto 2013 does not support noexcept nor constexpr
+#ifndef SPDLOG_USE_STD_FORMAT
+#    if FMT_VERSION >= 80000 // backward compatibility with fmt versions older than 8
+#        define SPDLOG_FMT_RUNTIME(format_string) fmt::runtime(format_string)
+#        if defined(SPDLOG_WCHAR_FILENAMES) || defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT)
+#            include <spdlog/fmt/xchar.h>
+#        endif
+#    else
+#        define SPDLOG_FMT_RUNTIME(format_string) format_string
+#    endif
+#endif
+
+// visual studio up to 2013 does not support noexcept nor constexpr
 #if defined(_MSC_VER) && (_MSC_VER < 1900)
-#define SPDLOG_NOEXCEPT _NOEXCEPT
-#define SPDLOG_CONSTEXPR
+#    define SPDLOG_NOEXCEPT _NOEXCEPT
+#    define SPDLOG_CONSTEXPR
+#    define SPDLOG_CONSTEXPR_FUNC
 #else
-#define SPDLOG_NOEXCEPT noexcept
-#define SPDLOG_CONSTEXPR constexpr
+#    define SPDLOG_NOEXCEPT noexcept
+#    define SPDLOG_CONSTEXPR constexpr
+#    if __cplusplus >= 201402L
+#        define SPDLOG_CONSTEXPR_FUNC constexpr
+#    else
+#        define SPDLOG_CONSTEXPR_FUNC
+#    endif
 #endif
 
 #if defined(__GNUC__) || defined(__clang__)
-#define SPDLOG_DEPRECATED __attribute__((deprecated))
+#    define SPDLOG_DEPRECATED __attribute__((deprecated))
 #elif defined(_MSC_VER)
-#define SPDLOG_DEPRECATED __declspec(deprecated)
+#    define SPDLOG_DEPRECATED __declspec(deprecated)
 #else
-#define SPDLOG_DEPRECATED
+#    define SPDLOG_DEPRECATED
 #endif
 
 // disable thread local on msvc 2013
 #ifndef SPDLOG_NO_TLS
-#if (defined(_MSC_VER) && (_MSC_VER < 1900)) || defined(__cplusplus_winrt)
-#define SPDLOG_NO_TLS 1
-#endif
+#    if (defined(_MSC_VER) && (_MSC_VER < 1900)) || defined(__cplusplus_winrt)
+#        define SPDLOG_NO_TLS 1
+#    endif
 #endif
 
 #ifndef SPDLOG_FUNCTION
-#define SPDLOG_FUNCTION static_cast<const char *>(__FUNCTION__)
+#    define SPDLOG_FUNCTION static_cast<const char *>(__FUNCTION__)
 #endif
 
 #ifdef SPDLOG_NO_EXCEPTIONS
-#define SPDLOG_TRY
-#define SPDLOG_THROW(ex)                                                                                                                   \
-    do                                                                                                                                     \
-    {                                                                                                                                      \
-        printf("spdlog fatal error: %s\n", ex.what());                                                                                     \
-        std::abort();                                                                                                                      \
-    } while (0)
-#define SPDLOG_CATCH_ALL()
+#    define SPDLOG_TRY
+#    define SPDLOG_THROW(ex)                                                                                                               \
+        do                                                                                                                                 \
+        {                                                                                                                                  \
+            printf("spdlog fatal error: %s\n", ex.what());                                                                                 \
+            std::abort();                                                                                                                  \
+        } while (0)
+#    define SPDLOG_CATCH_STD
 #else
-#define SPDLOG_TRY try
-#define SPDLOG_THROW(ex) throw(ex)
-#define SPDLOG_CATCH_ALL() catch (...)
+#    define SPDLOG_TRY try
+#    define SPDLOG_THROW(ex) throw(ex)
+#    define SPDLOG_CATCH_STD                                                                                                               \
+        catch (const std::exception &) {}
 #endif
 
 namespace spdlog {
@@ -88,33 +115,78 @@ class sink;
 
 #if defined(_WIN32) && defined(SPDLOG_WCHAR_FILENAMES)
 using filename_t = std::wstring;
-#define SPDLOG_FILENAME_T(s) L##s
+// allow macro expansion to occur in SPDLOG_FILENAME_T
+#    define SPDLOG_FILENAME_T_INNER(s) L##s
+#    define SPDLOG_FILENAME_T(s) SPDLOG_FILENAME_T_INNER(s)
 #else
 using filename_t = std::string;
-#define SPDLOG_FILENAME_T(s) s
+#    define SPDLOG_FILENAME_T(s) s
 #endif
 
 using log_clock = std::chrono::system_clock;
 using sink_ptr = std::shared_ptr<sinks::sink>;
 using sinks_init_list = std::initializer_list<sink_ptr>;
 using err_handler = std::function<void(const std::string &err_msg)>;
+#ifdef SPDLOG_USE_STD_FORMAT
+namespace fmt_lib = std;
+
+using string_view_t = std::string_view;
+using memory_buf_t = std::string;
+
+template<typename... Args>
+using format_string_t = std::string_view;
+
+template<class T, class Char = char>
+struct is_convertible_to_basic_format_string : std::integral_constant<bool, std::is_convertible<T, std::basic_string_view<Char>>::value>
+{};
+
+#    if defined(SPDLOG_WCHAR_FILENAMES) || defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT)
+using wstring_view_t = std::wstring_view;
+using wmemory_buf_t = std::wstring;
+
+template<typename... Args>
+using wformat_string_t = std::wstring_view;
+#    endif
+
+#else // use fmt lib instead of std::format
+namespace fmt_lib = fmt;
+
 using string_view_t = fmt::basic_string_view<char>;
-using wstring_view_t = fmt::basic_string_view<wchar_t>;
 using memory_buf_t = fmt::basic_memory_buffer<char, 250>;
 
+template<typename... Args>
+using format_string_t = fmt::format_string<Args...>;
+
+template<class T>
+using remove_cvref_t = typename std::remove_cv<typename std::remove_reference<T>::type>::type;
+
+// clang doesn't like SFINAE disabled constructor in std::is_convertible<> so have to repeat the condition from basic_format_string here,
+// in addition, fmt::basic_runtime<Char> is only convertible to basic_format_string<Char> but not basic_string_view<Char>
+template<class T, class Char = char>
+struct is_convertible_to_basic_format_string
+    : std::integral_constant<bool,
+          std::is_convertible<T, fmt::basic_string_view<Char>>::value || std::is_same<remove_cvref_t<T>, fmt::basic_runtime<Char>>::value>
+{};
+
+#    if defined(SPDLOG_WCHAR_FILENAMES) || defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT)
+using wstring_view_t = fmt::basic_string_view<wchar_t>;
+using wmemory_buf_t = fmt::basic_memory_buffer<wchar_t, 250>;
+
+template<typename... Args>
+using wformat_string_t = fmt::wformat_string<Args...>;
+#    endif
+#endif
+
 #ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
-#ifndef _WIN32
-#error SPDLOG_WCHAR_TO_UTF8_SUPPORT only supported on windows
-#else
-template<typename T>
-struct is_convertible_to_wstring_view : std::is_convertible<T, wstring_view_t>
+#    ifndef _WIN32
+#        error SPDLOG_WCHAR_TO_UTF8_SUPPORT only supported on windows
+#    endif // _WIN32
+#endif     // SPDLOG_WCHAR_TO_UTF8_SUPPORT
+
+template<class T>
+struct is_convertible_to_any_format_string : std::integral_constant<bool, is_convertible_to_basic_format_string<T, char>::value ||
+                                                                              is_convertible_to_basic_format_string<T, wchar_t>::value>
 {};
-#endif // _WIN32
-#else
-template<typename>
-struct is_convertible_to_wstring_view : std::false_type
-{};
-#endif // SPDLOG_WCHAR_TO_UTF8_SUPPORT
 
 #if defined(SPDLOG_NO_ATOMIC_LEVELS)
 using level_t = details::null_atomic_int;
@@ -131,12 +203,12 @@ using level_t = std::atomic<int>;
 #define SPDLOG_LEVEL_OFF 6
 
 #if !defined(SPDLOG_ACTIVE_LEVEL)
-#define SPDLOG_ACTIVE_LEVEL SPDLOG_LEVEL_INFO
+#    define SPDLOG_ACTIVE_LEVEL SPDLOG_LEVEL_INFO
 #endif
 
 // Log level enum
 namespace level {
-enum level_enum
+enum level_enum : int
 {
     trace = SPDLOG_LEVEL_TRACE,
     debug = SPDLOG_LEVEL_DEBUG,
@@ -148,26 +220,34 @@ enum level_enum
     n_levels
 };
 
+#define SPDLOG_LEVEL_NAME_TRACE spdlog::string_view_t("trace", 5)
+#define SPDLOG_LEVEL_NAME_DEBUG spdlog::string_view_t("debug", 5)
+#define SPDLOG_LEVEL_NAME_INFO spdlog::string_view_t("info", 4)
+#define SPDLOG_LEVEL_NAME_WARNING spdlog::string_view_t("warning", 7)
+#define SPDLOG_LEVEL_NAME_ERROR spdlog::string_view_t("error", 5)
+#define SPDLOG_LEVEL_NAME_CRITICAL spdlog::string_view_t("critical", 8)
+#define SPDLOG_LEVEL_NAME_OFF spdlog::string_view_t("off", 3)
+
 #if !defined(SPDLOG_LEVEL_NAMES)
-#define SPDLOG_LEVEL_NAMES                                                                                                                 \
-    {                                                                                                                                      \
-        "trace", "debug", "info", "warning", "error", "critical", "off"                                                                    \
-    }
+#    define SPDLOG_LEVEL_NAMES                                                                                                             \
+        {                                                                                                                                  \
+            SPDLOG_LEVEL_NAME_TRACE, SPDLOG_LEVEL_NAME_DEBUG, SPDLOG_LEVEL_NAME_INFO, SPDLOG_LEVEL_NAME_WARNING, SPDLOG_LEVEL_NAME_ERROR,  \
+                SPDLOG_LEVEL_NAME_CRITICAL, SPDLOG_LEVEL_NAME_OFF                                                                          \
+        }
 #endif
 
 #if !defined(SPDLOG_SHORT_LEVEL_NAMES)
 
-#define SPDLOG_SHORT_LEVEL_NAMES                                                                                                           \
-    {                                                                                                                                      \
-        "T", "D", "I", "W", "E", "C", "O"                                                                                                  \
-    }
+#    define SPDLOG_SHORT_LEVEL_NAMES                                                                                                       \
+        {                                                                                                                                  \
+            "T", "D", "I", "W", "E", "C", "O"                                                                                              \
+        }
 #endif
 
-SPDLOG_API string_view_t &to_string_view(spdlog::level::level_enum l) SPDLOG_NOEXCEPT;
+SPDLOG_API const string_view_t &to_string_view(spdlog::level::level_enum l) SPDLOG_NOEXCEPT;
 SPDLOG_API const char *to_short_c_str(spdlog::level::level_enum l) SPDLOG_NOEXCEPT;
 SPDLOG_API spdlog::level::level_enum from_str(const std::string &name) SPDLOG_NOEXCEPT;
 
-using level_hasher = std::hash<int>;
 } // namespace level
 
 //
@@ -204,8 +284,8 @@ private:
     std::string msg_;
 };
 
-SPDLOG_API void throw_spdlog_ex(const std::string &msg, int last_errno);
-SPDLOG_API void throw_spdlog_ex(std::string msg);
+[[noreturn]] SPDLOG_API void throw_spdlog_ex(const std::string &msg, int last_errno);
+[[noreturn]] SPDLOG_API void throw_spdlog_ex(std::string msg);
 
 struct source_loc
 {
@@ -225,12 +305,31 @@ struct source_loc
     const char *funcname{nullptr};
 };
 
+struct file_event_handlers
+{
+    std::function<void(const filename_t &filename)> before_open;
+    std::function<void(const filename_t &filename, std::FILE *file_stream)> after_open;
+    std::function<void(const filename_t &filename, std::FILE *file_stream)> before_close;
+    std::function<void(const filename_t &filename)> after_close;
+    file_event_handlers()
+        : before_open{nullptr}
+        , after_open{nullptr}
+        , before_close{nullptr}
+        , after_close{nullptr}
+    {}
+};
+
 namespace details {
+
 // make_unique support for pre c++14
 
 #if __cplusplus >= 201402L // C++14 and beyond
+using std::enable_if_t;
 using std::make_unique;
 #else
+template<bool B, class T = void>
+using enable_if_t = typename std::enable_if<B, T>::type;
+
 template<typename T, typename... Args>
 std::unique_ptr<T> make_unique(Args &&... args)
 {
@@ -238,9 +337,23 @@ std::unique_ptr<T> make_unique(Args &&... args)
     return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
 }
 #endif
+
+// to avoid useless casts (see https://github.com/nlohmann/json/issues/2893#issuecomment-889152324)
+template<typename T, typename U, enable_if_t<!std::is_same<T, U>::value, int> = 0>
+constexpr T conditional_static_cast(U value)
+{
+    return static_cast<T>(value);
+}
+
+template<typename T, typename U, enable_if_t<std::is_same<T, U>::value, int> = 0>
+constexpr T conditional_static_cast(U value)
+{
+    return value;
+}
+
 } // namespace details
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "common-inl.h"
+#    include "common-inl.h"
 #endif

include/spdlog/details/backtracer-inl.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/details/backtracer.h>
+#    include <spdlog/details/backtracer.h>
 #endif
 namespace spdlog {
 namespace details {

include/spdlog/details/backtracer.h

@@ -41,5 +41,5 @@ public:
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "backtracer-inl.h"
-#endif
+#    include "backtracer-inl.h"
+#endif

include/spdlog/details/file_helper-inl.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/details/file_helper.h>
+#    include <spdlog/details/file_helper.h>
 #endif
 
 #include <spdlog/details/os.h>
@@ -20,6 +20,10 @@
 namespace spdlog {
 namespace details {
 
+SPDLOG_INLINE file_helper::file_helper(const file_event_handlers &event_handlers)
+    : event_handlers_(event_handlers)
+{}
+
 SPDLOG_INLINE file_helper::~file_helper()
 {
     close();
@@ -29,14 +33,37 @@ SPDLOG_INLINE void file_helper::open(const filename_t &fname, bool truncate)
 {
     close();
     filename_ = fname;
-    auto *mode = truncate ? SPDLOG_FILENAME_T("wb") : SPDLOG_FILENAME_T("ab");
 
+    auto *mode = SPDLOG_FILENAME_T("ab");
+    auto *trunc_mode = SPDLOG_FILENAME_T("wb");
+
+    if (event_handlers_.before_open)
+    {
+        event_handlers_.before_open(filename_);
+    }
     for (int tries = 0; tries < open_tries_; ++tries)
     {
         // create containing folder if not exists already.
         os::create_dir(os::dir_name(fname));
+        if (truncate)
+        {
+            // Truncate by opening-and-closing a tmp file in "wb" mode, always
+            // opening the actual log-we-write-to in "ab" mode, since that
+            // interacts more politely with eternal processes that might
+            // rotate/truncate the file underneath us.
+            std::FILE *tmp;
+            if (os::fopen_s(&tmp, fname, trunc_mode))
+            {
+                continue;
+            }
+            std::fclose(tmp);
+        }
         if (!os::fopen_s(&fd_, fname, mode))
         {
+            if (event_handlers_.after_open)
+            {
+                event_handlers_.after_open(filename_, fd_);
+            }
             return;
         }
 
@@ -57,15 +84,28 @@ SPDLOG_INLINE void file_helper::reopen(bool truncate)
 
 SPDLOG_INLINE void file_helper::flush()
 {
-    std::fflush(fd_);
+    if (std::fflush(fd_) != 0)
+    {
+        throw_spdlog_ex("Failed flush to file " + os::filename_to_str(filename_), errno);
+    }
 }
 
 SPDLOG_INLINE void file_helper::close()
 {
     if (fd_ != nullptr)
     {
+        if (event_handlers_.before_close)
+        {
+            event_handlers_.before_close(filename_, fd_);
+        }
+
         std::fclose(fd_);
         fd_ = nullptr;
+
+        if (event_handlers_.after_close)
+        {
+            event_handlers_.after_close(filename_);
+        }
     }
 }
 
@@ -118,7 +158,7 @@ SPDLOG_INLINE std::tuple<filename_t, filename_t> file_helper::split_by_extension
     }
 
     // treat cases like "/etc/rc.d/somelogfile or "/abc/.hiddenfile"
-    auto folder_index = fname.rfind(details::os::folder_sep);
+    auto folder_index = fname.find_last_of(details::os::folder_seps_filename);
     if (folder_index != filename_t::npos && folder_index >= ext_index - 1)
     {
         return std::make_tuple(fname, filename_t());

include/spdlog/details/file_helper.h

@@ -16,7 +16,8 @@ namespace details {
 class SPDLOG_API file_helper
 {
 public:
-    explicit file_helper() = default;
+    file_helper() = default;
+    explicit file_helper(const file_event_handlers &event_handlers);
 
     file_helper(const file_helper &) = delete;
     file_helper &operator=(const file_helper &) = delete;
@@ -47,13 +48,14 @@ public:
 
 private:
     const int open_tries_ = 5;
-    const int open_interval_ = 10;
+    const unsigned int open_interval_ = 10;
     std::FILE *fd_{nullptr};
     filename_t filename_;
+    file_event_handlers event_handlers_;
 };
 } // namespace details
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "file_helper-inl.h"
+#    include "file_helper-inl.h"
 #endif

include/spdlog/details/fmt_helper.h

@@ -4,9 +4,15 @@
 
 #include <chrono>
 #include <type_traits>
+#include <iterator>
 #include <spdlog/fmt/fmt.h>
 #include <spdlog/common.h>
 
+#ifdef SPDLOG_USE_STD_FORMAT
+#    include <charconv>
+#    include <limits>
+#endif
+
 // Some fmt helpers to efficiently format and pad ints and strings
 namespace spdlog {
 namespace details {
@@ -23,18 +29,73 @@ inline void append_string_view(spdlog::string_view_t view, memory_buf_t &dest)
     dest.append(buf_ptr, buf_ptr + view.size());
 }
 
+#ifdef SPDLOG_USE_STD_FORMAT
+template<typename T>
+inline void append_int(T n, memory_buf_t &dest)
+{
+    // Buffer should be large enough to hold all digits (digits10 + 1) and a sign
+    SPDLOG_CONSTEXPR const auto BUF_SIZE = std::numeric_limits<T>::digits10 + 2;
+    char buf[BUF_SIZE];
+
+    auto [ptr, ec] = std::to_chars(buf, buf + BUF_SIZE, n, 10);
+    if (ec == std::errc())
+    {
+        dest.append(buf, ptr);
+    }
+    else
+    {
+        throw_spdlog_ex("Failed to format int", static_cast<int>(ec));
+    }
+}
+#else
 template<typename T>
 inline void append_int(T n, memory_buf_t &dest)
 {
     fmt::format_int i(n);
     dest.append(i.data(), i.data() + i.size());
 }
+#endif
+
+template<typename T>
+SPDLOG_CONSTEXPR_FUNC unsigned int count_digits_fallback(T n)
+{
+    // taken from fmt: https://github.com/fmtlib/fmt/blob/8.0.1/include/fmt/format.h#L899-L912
+    unsigned int count = 1;
+    for (;;)
+    {
+        // Integer division is slow so do it for a group of four digits instead
+        // of for every digit. The idea comes from the talk by Alexandrescu
+        // "Three Optimization Tips for C++". See speed-test for a comparison.
+        if (n < 10)
+            return count;
+        if (n < 100)
+            return count + 1;
+        if (n < 1000)
+            return count + 2;
+        if (n < 10000)
+            return count + 3;
+        n /= 10000u;
+        count += 4;
+    }
+}
 
 template<typename T>
 inline unsigned int count_digits(T n)
 {
     using count_type = typename std::conditional<(sizeof(T) > sizeof(uint32_t)), uint64_t, uint32_t>::type;
-    return static_cast<unsigned int>(fmt::internal::count_digits(static_cast<count_type>(n)));
+#ifdef SPDLOG_USE_STD_FORMAT
+    return count_digits_fallback(static_cast<count_type>(n));
+#else
+    return static_cast<unsigned int>(fmt::
+// fmt 7.0.0 renamed the internal namespace to detail.
+// See: https://github.com/fmtlib/fmt/issues/1538
+#    if FMT_VERSION < 70000
+            internal
+#    else
+            detail
+#    endif
+        ::count_digits(static_cast<count_type>(n)));
+#endif
 }
 
 inline void pad2(int n, memory_buf_t &dest)
@@ -46,7 +107,7 @@ inline void pad2(int n, memory_buf_t &dest)
     }
     else // unlikely, but just in case, let fmt deal with it
     {
-        fmt::format_to(dest, "{:02}", n);
+        fmt_lib::format_to(std::back_inserter(dest), "{:02}", n);
     }
 }
 

include/spdlog/details/log_msg-inl.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/details/log_msg.h>
+#    include <spdlog/details/log_msg.h>
 #endif
 
 #include <spdlog/details/os.h>

include/spdlog/details/log_msg.h

@@ -15,6 +15,7 @@ struct SPDLOG_API log_msg
     log_msg(source_loc loc, string_view_t logger_name, level::level_enum lvl, string_view_t msg);
     log_msg(string_view_t logger_name, level::level_enum lvl, string_view_t msg);
     log_msg(const log_msg &other) = default;
+    log_msg &operator=(const log_msg &other) = default;
 
     string_view_t logger_name;
     level::level_enum level{level::off};
@@ -32,5 +33,5 @@ struct SPDLOG_API log_msg
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "log_msg-inl.h"
+#    include "log_msg-inl.h"
 #endif

include/spdlog/details/log_msg_buffer-inl.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/details/log_msg_buffer.h>
+#    include <spdlog/details/log_msg_buffer.h>
 #endif
 
 namespace spdlog {

include/spdlog/details/log_msg_buffer.h

@@ -29,5 +29,5 @@ public:
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "log_msg_buffer-inl.h"
+#    include "log_msg_buffer-inl.h"
 #endif

include/spdlog/details/mpmc_blocking_q.h

@@ -49,7 +49,7 @@ public:
         push_cv_.notify_one();
     }
 
-    // try to dequeue item. if no item found. wait upto timeout and try again
+    // try to dequeue item. if no item found. wait up to timeout and try again
     // Return true, if succeeded dequeue item, false otherwise
     bool dequeue_for(T &popped_item, std::chrono::milliseconds wait_duration)
     {
@@ -87,7 +87,7 @@ public:
         push_cv_.notify_one();
     }
 
-    // try to dequeue item. if no item found. wait upto timeout and try again
+    // try to dequeue item. if no item found. wait up to timeout and try again
     // Return true, if succeeded dequeue item, false otherwise
     bool dequeue_for(T &popped_item, std::chrono::milliseconds wait_duration)
     {
@@ -110,6 +110,12 @@ public:
         return q_.overrun_counter();
     }
 
+    size_t size()
+    {
+        std::unique_lock<std::mutex> lock(queue_mutex_);
+        return q_.size();
+    }
+
 private:
     std::mutex queue_mutex_;
     std::condition_variable push_cv_;

include/spdlog/details/os-inl.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/details/os.h>
+#    include <spdlog/details/os.h>
 #endif
 
 #include <spdlog/common.h>
@@ -23,45 +23,45 @@
 
 #ifdef _WIN32
 
-#include <io.h>      // _get_osfhandle and _isatty support
-#include <process.h> //  _get_pid support
-#include <spdlog/details/windows_include.h>
+#    include <io.h>      // _get_osfhandle and _isatty support
+#    include <process.h> //  _get_pid support
+#    include <spdlog/details/windows_include.h>
 
-#ifdef __MINGW32__
-#include <share.h>
-#endif
+#    ifdef __MINGW32__
+#        include <share.h>
+#    endif
 
-#if defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)
-#include <limits>
-#endif
+#    if defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)
+#        include <limits>
+#    endif
 
-#include <direct.h> // for _mkdir/_wmkdir
+#    include <direct.h> // for _mkdir/_wmkdir
 
 #else // unix
 
-#include <fcntl.h>
-#include <unistd.h>
+#    include <fcntl.h>
+#    include <unistd.h>
 
-#ifdef __linux__
-#include <sys/syscall.h> //Use gettid() syscall under linux to get thread id
+#    ifdef __linux__
+#        include <sys/syscall.h> //Use gettid() syscall under linux to get thread id
 
-#elif defined(_AIX)
-#include <pthread.h> // for pthread_getthreadid_np
+#    elif defined(_AIX)
+#        include <pthread.h> // for pthread_getthrds_np
 
-#elif defined(__DragonFly__) || defined(__FreeBSD__)
-#include <pthread_np.h> // for pthread_getthreadid_np
+#    elif defined(__DragonFly__) || defined(__FreeBSD__)
+#        include <pthread_np.h> // for pthread_getthreadid_np
 
-#elif defined(__NetBSD__)
-#include <lwp.h> // for _lwp_self
+#    elif defined(__NetBSD__)
+#        include <lwp.h> // for _lwp_self
 
-#elif defined(__sun)
-#include <thread.h> // for thr_self
-#endif
+#    elif defined(__sun)
+#        include <thread.h> // for thr_self
+#    endif
 
 #endif // unix
 
-#ifndef __has_feature      // Clang - feature checking macros.
-#define __has_feature(x) 0 // Compatibility with non-clang compilers.
+#ifndef __has_feature          // Clang - feature checking macros.
+#    define __has_feature(x) 0 // Compatibility with non-clang compilers.
 #endif
 
 namespace spdlog {
@@ -123,12 +123,12 @@ SPDLOG_INLINE std::tm gmtime() SPDLOG_NOEXCEPT
 SPDLOG_INLINE bool fopen_s(FILE **fp, const filename_t &filename, const filename_t &mode)
 {
 #ifdef _WIN32
-#ifdef SPDLOG_WCHAR_FILENAMES
+#    ifdef SPDLOG_WCHAR_FILENAMES
     *fp = ::_wfsopen((filename.c_str()), mode.c_str(), _SH_DENYNO);
-#else
+#    else
     *fp = ::_fsopen((filename.c_str()), mode.c_str(), _SH_DENYNO);
-#endif
-#if defined(SPDLOG_PREVENT_CHILD_FD)
+#    endif
+#    if defined(SPDLOG_PREVENT_CHILD_FD)
     if (*fp != nullptr)
     {
         auto file_handle = reinterpret_cast<HANDLE>(_get_osfhandle(::_fileno(*fp)));
@@ -138,23 +138,23 @@ SPDLOG_INLINE bool fopen_s(FILE **fp, const filename_t &filename, const filename
             *fp = nullptr;
         }
     }
-#endif
+#    endif
 #else // unix
-#if defined(SPDLOG_PREVENT_CHILD_FD)
+#    if defined(SPDLOG_PREVENT_CHILD_FD)
     const int mode_flag = mode == SPDLOG_FILENAME_T("ab") ? O_APPEND : O_TRUNC;
     const int fd = ::open((filename.c_str()), O_CREAT | O_WRONLY | O_CLOEXEC | mode_flag, mode_t(0644));
     if (fd == -1)
     {
-        return false;
+        return true;
     }
     *fp = ::fdopen(fd, mode.c_str());
     if (*fp == nullptr)
     {
         ::close(fd);
     }
-#else
+#    else
     *fp = ::fopen((filename.c_str()), mode.c_str());
-#endif
+#    endif
 #endif
 
     return *fp == nullptr;
@@ -187,11 +187,11 @@ SPDLOG_INLINE int rename(const filename_t &filename1, const filename_t &filename
 SPDLOG_INLINE bool path_exists(const filename_t &filename) SPDLOG_NOEXCEPT
 {
 #ifdef _WIN32
-#ifdef SPDLOG_WCHAR_FILENAMES
+#    ifdef SPDLOG_WCHAR_FILENAMES
     auto attribs = ::GetFileAttributesW(filename.c_str());
-#else
+#    else
     auto attribs = ::GetFileAttributesA(filename.c_str());
-#endif
+#    endif
     return attribs != INVALID_FILE_ATTRIBUTES;
 #else // common linux/unix all have the stat system call
     struct stat buffer;
@@ -199,6 +199,12 @@ SPDLOG_INLINE bool path_exists(const filename_t &filename) SPDLOG_NOEXCEPT
 #endif
 }
 
+#ifdef _MSC_VER
+// avoid warning about unreachable statement at the end of filesize()
+#    pragma warning(push)
+#    pragma warning(disable : 4702)
+#endif
+
 // Return file size according to open FILE* object
 SPDLOG_INLINE size_t filesize(FILE *f)
 {
@@ -208,59 +214,63 @@ SPDLOG_INLINE size_t filesize(FILE *f)
     }
 #if defined(_WIN32) && !defined(__CYGWIN__)
     int fd = ::_fileno(f);
-#if _WIN64 // 64 bits
+#    if defined(_WIN64) // 64 bits
     __int64 ret = ::_filelengthi64(fd);
     if (ret >= 0)
     {
         return static_cast<size_t>(ret);
     }
 
-#else // windows 32 bits
+#    else // windows 32 bits
     long ret = ::_filelength(fd);
     if (ret >= 0)
     {
         return static_cast<size_t>(ret);
     }
-#endif
+#    endif
 
 #else // unix
-// OpenBSD doesn't compile with :: before the fileno(..)
-#if defined(__OpenBSD__)
+// OpenBSD and AIX doesn't compile with :: before the fileno(..)
+#    if defined(__OpenBSD__) || defined(_AIX)
     int fd = fileno(f);
-#else
+#    else
     int fd = ::fileno(f);
-#endif
+#    endif
 // 64 bits(but not in osx or cygwin, where fstat64 is deprecated)
-#if (defined(__linux__) || defined(__sun) || defined(_AIX)) && (defined(__LP64__) || defined(_LP64))
+#    if (defined(__linux__) || defined(__sun) || defined(_AIX)) && (defined(__LP64__) || defined(_LP64))
     struct stat64 st;
     if (::fstat64(fd, &st) == 0)
     {
         return static_cast<size_t>(st.st_size);
     }
-#else // other unix or linux 32 bits or cygwin
+#    else // other unix or linux 32 bits or cygwin
     struct stat st;
     if (::fstat(fd, &st) == 0)
     {
         return static_cast<size_t>(st.st_size);
     }
-#endif
+#    endif
 #endif
     throw_spdlog_ex("Failed getting file size from fd", errno);
     return 0; // will not be reached.
 }
 
+#ifdef _MSC_VER
+#    pragma warning(pop)
+#endif
+
 // Return utc offset in minutes or throw spdlog_ex on failure
 SPDLOG_INLINE int utc_minutes_offset(const std::tm &tm)
 {
 
 #ifdef _WIN32
-#if _WIN32_WINNT < _WIN32_WINNT_WS08
+#    if _WIN32_WINNT < _WIN32_WINNT_WS08
     TIME_ZONE_INFORMATION tzinfo;
     auto rv = ::GetTimeZoneInformation(&tzinfo);
-#else
+#    else
     DYNAMIC_TIME_ZONE_INFORMATION tzinfo;
     auto rv = ::GetDynamicTimeZoneInformation(&tzinfo);
-#endif
+#    endif
     if (rv == TIME_ZONE_ID_INVALID)
         throw_spdlog_ex("Failed getting timezone info. ", errno);
 
@@ -276,7 +286,7 @@ SPDLOG_INLINE int utc_minutes_offset(const std::tm &tm)
     return offset;
 #else
 
-#if defined(sun) || defined(__sun) || defined(_AIX) || (!defined(_BSD_SOURCE) && !defined(_GNU_SOURCE))
+#    if defined(sun) || defined(__sun) || defined(_AIX) || (!defined(_BSD_SOURCE) && !defined(_GNU_SOURCE))
     // 'tm_gmtoff' field is BSD extension and it's missing on SunOS/Solaris
     struct helper
     {
@@ -295,7 +305,7 @@ SPDLOG_INLINE int utc_minutes_offset(const std::tm &tm)
                 ((local_year / 100 >> 2) - (gmt_year / 100 >> 2))
 
                 // + difference in years * 365 */
-                + (long int)(local_year - gmt_year) * 365);
+                + static_cast<long int>(local_year - gmt_year) * 365);
 
             long int hours = (24 * days) + (localtm.tm_hour - gmtm.tm_hour);
             long int mins = (60 * hours) + (localtm.tm_min - gmtm.tm_min);
@@ -306,9 +316,9 @@ SPDLOG_INLINE int utc_minutes_offset(const std::tm &tm)
     };
 
     auto offset_seconds = helper::calculate_gmt_offset(tm);
-#else
+#    else
     auto offset_seconds = tm.tm_gmtoff;
-#endif
+#    endif
 
     return static_cast<int>(offset_seconds / 60);
 #endif
@@ -322,11 +332,18 @@ SPDLOG_INLINE size_t _thread_id() SPDLOG_NOEXCEPT
 #ifdef _WIN32
     return static_cast<size_t>(::GetCurrentThreadId());
 #elif defined(__linux__)
-#if defined(__ANDROID__) && defined(__ANDROID_API__) && (__ANDROID_API__ < 21)
-#define SYS_gettid __NR_gettid
-#endif
+#    if defined(__ANDROID__) && defined(__ANDROID_API__) && (__ANDROID_API__ < 21)
+#        define SYS_gettid __NR_gettid
+#    endif
     return static_cast<size_t>(::syscall(SYS_gettid));
-#elif defined(_AIX) || defined(__DragonFly__) || defined(__FreeBSD__)
+#elif defined(_AIX)
+    struct __pthrdsinfo buf;
+    int reg_size = 0;
+    pthread_t pt = pthread_self();
+    int retval = pthread_getthrds_np(&pt, PTHRDSINFO_QUERY_TID, &buf, sizeof(buf), NULL, &reg_size);
+    int tid = (!retval) ? buf.__pi_tid : 0;
+    return static_cast<size_t>(tid);
+#elif defined(__DragonFly__) || defined(__FreeBSD__)
     return static_cast<size_t>(::pthread_getthreadid_np());
 #elif defined(__NetBSD__)
     return static_cast<size_t>(::_lwp_self());
@@ -356,7 +373,7 @@ SPDLOG_INLINE size_t thread_id() SPDLOG_NOEXCEPT
 
 // This is avoid msvc issue in sleep_for that happens if the clock changes.
 // See https://github.com/gabime/spdlog/issues/609
-SPDLOG_INLINE void sleep_for_millis(int milliseconds) SPDLOG_NOEXCEPT
+SPDLOG_INLINE void sleep_for_millis(unsigned int milliseconds) SPDLOG_NOEXCEPT
 {
 #if defined(_WIN32)
     ::Sleep(milliseconds);
@@ -371,7 +388,11 @@ SPDLOG_INLINE std::string filename_to_str(const filename_t &filename)
 {
     memory_buf_t buf;
     wstr_to_utf8buf(filename, buf);
+#    ifdef SPDLOG_USE_STD_FORMAT
+    return buf;
+#    else
     return fmt::to_string(buf);
+#    endif
 }
 #else
 SPDLOG_INLINE std::string filename_to_str(const filename_t &filename)
@@ -384,9 +405,9 @@ SPDLOG_INLINE int pid() SPDLOG_NOEXCEPT
 {
 
 #ifdef _WIN32
-    return static_cast<int>(::GetCurrentProcessId());
+    return conditional_static_cast<int>(::GetCurrentProcessId());
 #else
-    return static_cast<int>(::getpid());
+    return conditional_static_cast<int>(::getpid());
 #endif
 }
 
@@ -397,17 +418,26 @@ SPDLOG_INLINE bool is_color_terminal() SPDLOG_NOEXCEPT
 #ifdef _WIN32
     return true;
 #else
-    static constexpr std::array<const char *, 14> terms = {
-        {"ansi", "color", "console", "cygwin", "gnome", "konsole", "kterm", "linux", "msys", "putty", "rxvt", "screen", "vt100", "xterm"}};
 
-    const char *env_p = std::getenv("TERM");
-    if (env_p == nullptr)
-    {
-        return false;
-    }
+    static const bool result = []() {
+        const char *env_colorterm_p = std::getenv("COLORTERM");
+        if (env_colorterm_p != nullptr)
+        {
+            return true;
+        }
+
+        static constexpr std::array<const char *, 16> terms = {{"ansi", "color", "console", "cygwin", "gnome", "konsole", "kterm", "linux",
+            "msys", "putty", "rxvt", "screen", "vt100", "xterm", "alacritty", "vt102"}};
+
+        const char *env_term_p = std::getenv("TERM");
+        if (env_term_p == nullptr)
+        {
+            return false;
+        }
+
+        return std::any_of(terms.begin(), terms.end(), [&](const char *term) { return std::strstr(env_term_p, term) != nullptr; });
+    }();
 
-    static const bool result =
-        std::any_of(terms.begin(), terms.end(), [&](const char *term) { return std::strstr(env_p, term) != nullptr; });
     return result;
 #endif
 }
@@ -427,7 +457,7 @@ SPDLOG_INLINE bool in_terminal(FILE *file) SPDLOG_NOEXCEPT
 #if (defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)) && defined(_WIN32)
 SPDLOG_INLINE void wstr_to_utf8buf(wstring_view_t wstr, memory_buf_t &target)
 {
-    if (wstr.size() > static_cast<size_t>((std::numeric_limits<int>::max)()))
+    if (wstr.size() > static_cast<size_t>((std::numeric_limits<int>::max)()) / 2 - 1)
     {
         throw_spdlog_ex("UTF-16 string is too big to be converted to UTF-8");
     }
@@ -457,7 +487,42 @@ SPDLOG_INLINE void wstr_to_utf8buf(wstring_view_t wstr, memory_buf_t &target)
         }
     }
 
-    throw_spdlog_ex(fmt::format("WideCharToMultiByte failed. Last error: {}", ::GetLastError()));
+    throw_spdlog_ex(fmt_lib::format("WideCharToMultiByte failed. Last error: {}", ::GetLastError()));
+}
+
+SPDLOG_INLINE void utf8_to_wstrbuf(string_view_t str, wmemory_buf_t &target)
+{
+    if (str.size() > static_cast<size_t>((std::numeric_limits<int>::max)()) - 1)
+    {
+        throw_spdlog_ex("UTF-8 string is too big to be converted to UTF-16");
+    }
+
+    int str_size = static_cast<int>(str.size());
+    if (str_size == 0)
+    {
+        target.resize(0);
+        return;
+    }
+
+    int result_size = static_cast<int>(target.capacity());
+    if (str_size + 1 > result_size)
+    {
+        result_size = ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, str.data(), str_size, NULL, 0);
+    }
+
+    if (result_size > 0)
+    {
+        target.resize(result_size);
+        result_size = ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, str.data(), str_size, target.data(), result_size);
+
+        if (result_size > 0)
+        {
+            target.resize(result_size);
+            return;
+        }
+    }
+
+    throw_spdlog_ex(fmt_lib::format("MultiByteToWideChar failed. Last error: {}", ::GetLastError()));
 }
 #endif // (defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)) && defined(_WIN32)
 
@@ -465,11 +530,11 @@ SPDLOG_INLINE void wstr_to_utf8buf(wstring_view_t wstr, memory_buf_t &target)
 static SPDLOG_INLINE bool mkdir_(const filename_t &path)
 {
 #ifdef _WIN32
-#ifdef SPDLOG_WCHAR_FILENAMES
+#    ifdef SPDLOG_WCHAR_FILENAMES
     return ::_wmkdir(path.c_str()) == 0;
-#else
+#    else
     return ::_mkdir(path.c_str()) == 0;
-#endif
+#    endif
 #else
     return ::mkdir(path.c_str(), mode_t(0755)) == 0;
 #endif
@@ -477,7 +542,7 @@ static SPDLOG_INLINE bool mkdir_(const filename_t &path)
 
 // create the given directory - and all directories leading to it
 // return true on success or if the directory already exists
-SPDLOG_INLINE bool create_dir(filename_t path)
+SPDLOG_INLINE bool create_dir(const filename_t &path)
 {
     if (path_exists(path))
     {
@@ -489,15 +554,10 @@ SPDLOG_INLINE bool create_dir(filename_t path)
         return false;
     }
 
-#ifdef _WIN32
-    // support forward slash in windows
-    std::replace(path.begin(), path.end(), '/', folder_sep);
-#endif
-
     size_t search_offset = 0;
     do
     {
-        auto token_pos = path.find(folder_sep, search_offset);
+        auto token_pos = path.find_first_of(folder_seps_filename, search_offset);
         // treat the entire path as a folder if no folder separator not found
         if (token_pos == filename_t::npos)
         {
@@ -521,13 +581,9 @@ SPDLOG_INLINE bool create_dir(filename_t path)
 // "abc/" => "abc"
 // "abc" => ""
 // "abc///" => "abc//"
-SPDLOG_INLINE filename_t dir_name(filename_t path)
+SPDLOG_INLINE filename_t dir_name(const filename_t &path)
 {
-#ifdef _WIN32
-    // support forward slash in windows
-    std::replace(path.begin(), path.end(), '/', folder_sep);
-#endif
-    auto pos = path.find_last_of(folder_sep);
+    auto pos = path.find_last_of(folder_seps_filename);
     return pos != filename_t::npos ? path.substr(0, pos) : filename_t{};
 }
 
@@ -535,14 +591,14 @@ std::string SPDLOG_INLINE getenv(const char *field)
 {
 
 #if defined(_MSC_VER)
-#if defined(__cplusplus_winrt)
+#    if defined(__cplusplus_winrt)
     return std::string{}; // not supported under uwp
-#else
+#    else
     size_t len = 0;
     char buf[128];
     bool ok = ::getenv_s(&len, buf, sizeof(buf), field) == 0;
     return ok ? buf : std::string{};
-#endif
+#    endif
 #else // revert to getenv
     char *buf = ::getenv(field);
     return buf ? buf : std::string{};

include/spdlog/details/os.h

@@ -22,22 +22,27 @@ SPDLOG_API std::tm gmtime() SPDLOG_NOEXCEPT;
 
 // eol definition
 #if !defined(SPDLOG_EOL)
-#ifdef _WIN32
-#define SPDLOG_EOL "\r\n"
-#else
-#define SPDLOG_EOL "\n"
-#endif
+#    ifdef _WIN32
+#        define SPDLOG_EOL "\r\n"
+#    else
+#        define SPDLOG_EOL "\n"
+#    endif
 #endif
 
 SPDLOG_CONSTEXPR static const char *default_eol = SPDLOG_EOL;
 
 // folder separator
-#ifdef _WIN32
-static const char folder_sep = '\\';
-#else
-SPDLOG_CONSTEXPR static const char folder_sep = '/';
+#if !defined(SPDLOG_FOLDER_SEPS)
+#    ifdef _WIN32
+#        define SPDLOG_FOLDER_SEPS "\\/"
+#    else
+#        define SPDLOG_FOLDER_SEPS "/"
+#    endif
 #endif
 
+SPDLOG_CONSTEXPR static const char folder_seps[] = SPDLOG_FOLDER_SEPS;
+SPDLOG_CONSTEXPR static const filename_t::value_type folder_seps_filename[] = SPDLOG_FILENAME_T(SPDLOG_FOLDER_SEPS);
+
 // fopen_s on non windows for writing
 SPDLOG_API bool fopen_s(FILE **fp, const filename_t &filename, const filename_t &mode);
 
@@ -69,7 +74,7 @@ SPDLOG_API size_t thread_id() SPDLOG_NOEXCEPT;
 
 // This is avoid msvc issue in sleep_for that happens if the clock changes.
 // See https://github.com/gabime/spdlog/issues/609
-SPDLOG_API void sleep_for_millis(int milliseconds) SPDLOG_NOEXCEPT;
+SPDLOG_API void sleep_for_millis(unsigned int milliseconds) SPDLOG_NOEXCEPT;
 
 SPDLOG_API std::string filename_to_str(const filename_t &filename);
 
@@ -85,6 +90,8 @@ SPDLOG_API bool in_terminal(FILE *file) SPDLOG_NOEXCEPT;
 
 #if (defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)) && defined(_WIN32)
 SPDLOG_API void wstr_to_utf8buf(wstring_view_t wstr, memory_buf_t &target);
+
+SPDLOG_API void utf8_to_wstrbuf(string_view_t str, wmemory_buf_t &target);
 #endif
 
 // Return directory name from given path or empty string
@@ -92,11 +99,11 @@ SPDLOG_API void wstr_to_utf8buf(wstring_view_t wstr, memory_buf_t &target);
 // "abc/" => "abc"
 // "abc" => ""
 // "abc///" => "abc//"
-SPDLOG_API filename_t dir_name(filename_t path);
+SPDLOG_API filename_t dir_name(const filename_t &path);
 
 // Create a dir from the given path.
 // Return true if succeeded or if this dir already exists.
-SPDLOG_API bool create_dir(filename_t path);
+SPDLOG_API bool create_dir(const filename_t &path);
 
 // non thread safe, cross platform getenv/getenv_s
 // return empty string if field not found
@@ -107,5 +114,5 @@ SPDLOG_API std::string getenv(const char *field);
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "os-inl.h"
+#    include "os-inl.h"
 #endif

include/spdlog/details/periodic_worker-inl.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/details/periodic_worker.h>
+#    include <spdlog/details/periodic_worker.h>
 #endif
 
 namespace spdlog {

include/spdlog/details/periodic_worker.h

@@ -36,5 +36,5 @@ private:
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "periodic_worker-inl.h"
+#    include "periodic_worker-inl.h"
 #endif

include/spdlog/details/registry-inl.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/details/registry.h>
+#    include <spdlog/details/registry.h>
 #endif
 
 #include <spdlog/common.h>
@@ -14,11 +14,11 @@
 
 #ifndef SPDLOG_DISABLE_DEFAULT_LOGGER
 // support for the default stdout color logger
-#ifdef _WIN32
-#include <spdlog/sinks/wincolor_sink.h>
-#else
-#include <spdlog/sinks/ansicolor_sink.h>
-#endif
+#    ifdef _WIN32
+#        include <spdlog/sinks/wincolor_sink.h>
+#    else
+#        include <spdlog/sinks/ansicolor_sink.h>
+#    endif
 #endif // SPDLOG_DISABLE_DEFAULT_LOGGER
 
 #include <chrono>
@@ -36,11 +36,11 @@ SPDLOG_INLINE registry::registry()
 
 #ifndef SPDLOG_DISABLE_DEFAULT_LOGGER
     // create default logger (ansicolor_stdout_sink_mt or wincolor_stdout_sink_mt in windows).
-#ifdef _WIN32
+#    ifdef _WIN32
     auto color_sink = std::make_shared<sinks::wincolor_stdout_sink_mt>();
-#else
+#    else
     auto color_sink = std::make_shared<sinks::ansicolor_stdout_sink_mt>();
-#endif
+#    endif
 
     const char *default_logger_name = "";
     default_logger_ = std::make_shared<spdlog::logger>(default_logger_name, std::move(color_sink));
@@ -67,7 +67,11 @@ SPDLOG_INLINE void registry::initialize_logger(std::shared_ptr<logger> new_logge
         new_logger->set_error_handler(err_handler_);
     }
 
-    new_logger->set_level(levels_.get(new_logger->name()));
+    // set new level according to previously configured level or default level
+    auto it = log_levels_.find(new_logger->name());
+    auto new_level = it != log_levels_.end() ? it->second : global_log_level_;
+    new_logger->set_level(new_level);
+
     new_logger->flush_on(flush_level_);
 
     if (backtrace_n_messages_ > 0)
@@ -171,7 +175,7 @@ SPDLOG_INLINE void registry::set_level(level::level_enum log_level)
     {
         l.second->set_level(log_level);
     }
-    levels_.set_default(log_level);
+    global_log_level_ = log_level;
 }
 
 SPDLOG_INLINE void registry::flush_on(level::level_enum log_level)
@@ -191,14 +195,14 @@ SPDLOG_INLINE void registry::flush_every(std::chrono::seconds interval)
     periodic_flusher_ = details::make_unique<periodic_worker>(clbk, interval);
 }
 
-SPDLOG_INLINE void registry::set_error_handler(void (*handler)(const std::string &msg))
+SPDLOG_INLINE void registry::set_error_handler(err_handler handler)
 {
     std::lock_guard<std::mutex> lock(logger_map_mutex_);
     for (auto &l : loggers_)
     {
         l.second->set_error_handler(handler);
     }
-    err_handler_ = handler;
+    err_handler_ = std::move(handler);
 }
 
 SPDLOG_INLINE void registry::apply_all(const std::function<void(const std::shared_ptr<logger>)> &fun)
@@ -263,14 +267,24 @@ SPDLOG_INLINE void registry::set_automatic_registration(bool automatic_registrat
     automatic_registration_ = automatic_registration;
 }
 
-SPDLOG_INLINE void registry::update_levels(cfg::log_levels levels)
+SPDLOG_INLINE void registry::set_levels(log_levels levels, level::level_enum *global_level)
 {
     std::lock_guard<std::mutex> lock(logger_map_mutex_);
-    levels_ = std::move(levels);
-    for (auto &l : loggers_)
+    log_levels_ = std::move(levels);
+    auto global_level_requested = global_level != nullptr;
+    global_log_level_ = global_level_requested ? *global_level : global_log_level_;
+
+    for (auto &logger : loggers_)
     {
-        auto &logger = l.second;
-        logger->set_level(levels_.get(logger->name()));
+        auto logger_entry = log_levels_.find(logger.first);
+        if (logger_entry != log_levels_.end())
+        {
+            logger.second->set_level(logger_entry->second);
+        }
+        else if (global_level_requested)
+        {
+            logger.second->set_level(*global_level);
+        }
     }
 }
 

include/spdlog/details/registry.h

@@ -9,7 +9,6 @@
 // This class is thread safe
 
 #include <spdlog/common.h>
-#include <spdlog/cfg/log_levels.h>
 
 #include <chrono>
 #include <functional>
@@ -28,6 +27,7 @@ class periodic_worker;
 class SPDLOG_API registry
 {
 public:
+    using log_levels = std::unordered_map<std::string, level::level_enum>;
     registry(const registry &) = delete;
     registry &operator=(const registry &) = delete;
 
@@ -63,7 +63,7 @@ public:
 
     void flush_every(std::chrono::seconds interval);
 
-    void set_error_handler(void (*handler)(const std::string &msg));
+    void set_error_handler(err_handler handler);
 
     void apply_all(const std::function<void(const std::shared_ptr<logger>)> &fun);
 
@@ -80,7 +80,8 @@ public:
 
     void set_automatic_registration(bool automatic_registration);
 
-    void update_levels(cfg::log_levels levels);
+    // set levels for all existing/future loggers. global_level can be null if should not set.
+    void set_levels(log_levels levels, level::level_enum *global_level);
 
     static registry &instance();
 
@@ -90,13 +91,15 @@ private:
 
     void throw_if_exists_(const std::string &logger_name);
     void register_logger_(std::shared_ptr<logger> new_logger);
+    bool set_level_from_cfg_(logger *logger);
     std::mutex logger_map_mutex_, flusher_mutex_;
     std::recursive_mutex tp_mutex_;
     std::unordered_map<std::string, std::shared_ptr<logger>> loggers_;
-    cfg::log_levels levels_;
+    log_levels log_levels_;
     std::unique_ptr<formatter> formatter_;
+    spdlog::level::level_enum global_log_level_ = level::info;
     level::level_enum flush_level_ = level::off;
-    void (*err_handler_)(const std::string &msg);
+    err_handler err_handler_;
     std::shared_ptr<thread_pool> tp_;
     std::unique_ptr<periodic_worker> periodic_flusher_;
     std::shared_ptr<logger> default_logger_;
@@ -108,5 +111,5 @@ private:
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "registry-inl.h"
+#    include "registry-inl.h"
 #endif

include/spdlog/details/synchronous_factory.h

@@ -21,4 +21,4 @@ struct synchronous_factory
         return new_logger;
     }
 };
-} // namespace spdlog
+} // namespace spdlog

include/spdlog/details/tcp_client-windows.h

@@ -8,8 +8,8 @@
 #include <spdlog/common.h>
 #include <spdlog/details/os.h>
 
-#include <windows.h>
 #include <winsock2.h>
+#include <windows.h>
 #include <ws2tcpip.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -25,20 +25,6 @@ class tcp_client
 {
     SOCKET socket_ = INVALID_SOCKET;
 
-    static bool winsock_initialized_()
-    {
-        SOCKET s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
-        if (s == INVALID_SOCKET)
-        {
-            return false;
-        }
-        else
-        {
-            closesocket(s);
-            return true;
-        }
-    }
-
     static void init_winsock_()
     {
         WSADATA wsaData;
@@ -52,13 +38,24 @@ class tcp_client
     static void throw_winsock_error_(const std::string &msg, int last_error)
     {
         char buf[512];
-        ::FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, last_error,
+        ::FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, last_error,
             MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), buf, (sizeof(buf) / sizeof(char)), NULL);
 
-        throw_spdlog_ex(fmt::format("tcp_sink - {}: {}", msg, buf));
+        throw_spdlog_ex(fmt_lib::format("tcp_sink - {}: {}", msg, buf));
     }
 
 public:
+    tcp_client()
+    {
+        init_winsock_();
+    }
+
+    ~tcp_client()
+    {
+        close();
+        ::WSACleanup();
+    }
+
     bool is_connected() const
     {
         return socket_ != INVALID_SOCKET;
@@ -68,7 +65,6 @@ public:
     {
         ::closesocket(socket_);
         socket_ = INVALID_SOCKET;
-        WSACleanup();
     }
 
     SOCKET fd() const
@@ -76,20 +72,9 @@ public:
         return socket_;
     }
 
-    ~tcp_client()
-    {
-        close();
-    }
-
     // try to connect or throw on failure
     void connect(const std::string &host, int port)
     {
-        // initialize winsock if needed
-        if (!winsock_initialized_())
-        {
-            init_winsock_();
-        }
-
         if (is_connected())
         {
             close();
@@ -144,7 +129,7 @@ public:
 
         // set TCP_NODELAY
         int enable_flag = 1;
-        ::setsockopt(socket_, IPPROTO_TCP, TCP_NODELAY, (char *)&enable_flag, sizeof(enable_flag));
+        ::setsockopt(socket_, IPPROTO_TCP, TCP_NODELAY, reinterpret_cast<char *>(&enable_flag), sizeof(enable_flag));
     }
 
     // Send exactly n_bytes of the given data.

include/spdlog/details/tcp_client.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifdef _WIN32
-#error include tcp_client-windows.h instead
+#    error include tcp_client-windows.h instead
 #endif
 
 // tcp client helper
@@ -67,15 +67,18 @@ public:
         auto rv = ::getaddrinfo(host.c_str(), port_str.c_str(), &hints, &addrinfo_result);
         if (rv != 0)
         {
-            auto msg = fmt::format("::getaddrinfo failed: {}", gai_strerror(rv));
-            throw_spdlog_ex(msg);
+            throw_spdlog_ex(fmt_lib::format("::getaddrinfo failed: {}", gai_strerror(rv)));
         }
 
         // Try each address until we successfully connect(2).
         int last_errno = 0;
         for (auto *rp = addrinfo_result; rp != nullptr; rp = rp->ai_next)
         {
-            int const flags = SOCK_CLOEXEC;
+#if defined(SOCK_CLOEXEC)
+            const int flags = SOCK_CLOEXEC;
+#else
+            const int flags = 0;
+#endif
             socket_ = ::socket(rp->ai_family, rp->ai_socktype | flags, rp->ai_protocol);
             if (socket_ == -1)
             {
@@ -87,12 +90,9 @@ public:
             {
                 break;
             }
-            else
-            {
-                last_errno = errno;
-                ::close(socket_);
-                socket_ = -1;
-            }
+            last_errno = errno;
+            ::close(socket_);
+            socket_ = -1;
         }
         ::freeaddrinfo(addrinfo_result);
         if (socket_ == -1)
@@ -102,15 +102,15 @@ public:
 
         // set TCP_NODELAY
         int enable_flag = 1;
-        ::setsockopt(socket_, IPPROTO_TCP, TCP_NODELAY, (char *)&enable_flag, sizeof(enable_flag));
+        ::setsockopt(socket_, IPPROTO_TCP, TCP_NODELAY, reinterpret_cast<char *>(&enable_flag), sizeof(enable_flag));
 
         // prevent sigpipe on systems where MSG_NOSIGNAL is not available
 #if defined(SO_NOSIGPIPE) && !defined(MSG_NOSIGNAL)
-        ::setsockopt(socket_, SOL_SOCKET, SO_NOSIGPIPE, (char *)&enable_flag, sizeof(enable_flag));
+        ::setsockopt(socket_, SOL_SOCKET, SO_NOSIGPIPE, reinterpret_cast<char *>(&enable_flag), sizeof(enable_flag));
 #endif
 
 #if !defined(SO_NOSIGPIPE) && !defined(MSG_NOSIGNAL)
-#error "tcp_sink would raise SIGPIPE since niether SO_NOSIGPIPE nor MSG_NOSIGNAL are available"
+#    error "tcp_sink would raise SIGPIPE since niether SO_NOSIGPIPE nor MSG_NOSIGNAL are available"
 #endif
     }
 

include/spdlog/details/thread_pool-inl.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/details/thread_pool.h>
+#    include <spdlog/details/thread_pool.h>
 #endif
 
 #include <spdlog/common.h>
@@ -13,7 +13,8 @@
 namespace spdlog {
 namespace details {
 
-SPDLOG_INLINE thread_pool::thread_pool(size_t q_max_items, size_t threads_n, std::function<void()> on_thread_start)
+SPDLOG_INLINE thread_pool::thread_pool(
+    size_t q_max_items, size_t threads_n, std::function<void()> on_thread_start, std::function<void()> on_thread_stop)
     : q_(q_max_items)
 {
     if (threads_n == 0 || threads_n > 1000)
@@ -23,15 +24,21 @@ SPDLOG_INLINE thread_pool::thread_pool(size_t q_max_items, size_t threads_n, std
     }
     for (size_t i = 0; i < threads_n; i++)
     {
-        threads_.emplace_back([this, on_thread_start] {
+        threads_.emplace_back([this, on_thread_start, on_thread_stop] {
             on_thread_start();
             this->thread_pool::worker_loop_();
+            on_thread_stop();
         });
     }
 }
 
+SPDLOG_INLINE thread_pool::thread_pool(size_t q_max_items, size_t threads_n, std::function<void()> on_thread_start)
+    : thread_pool(q_max_items, threads_n, on_thread_start, [] {})
+{}
+
 SPDLOG_INLINE thread_pool::thread_pool(size_t q_max_items, size_t threads_n)
-    : thread_pool(q_max_items, threads_n, [] {})
+    : thread_pool(
+          q_max_items, threads_n, [] {}, [] {})
 {}
 
 // message all threads to terminate gracefully join them
@@ -49,7 +56,7 @@ SPDLOG_INLINE thread_pool::~thread_pool()
             t.join();
         }
     }
-    SPDLOG_CATCH_ALL() {}
+    SPDLOG_CATCH_STD
 }
 
 void SPDLOG_INLINE thread_pool::post_log(async_logger_ptr &&worker_ptr, const details::log_msg &msg, async_overflow_policy overflow_policy)
@@ -68,6 +75,11 @@ size_t SPDLOG_INLINE thread_pool::overrun_counter()
     return q_.overrun_counter();
 }
 
+size_t SPDLOG_INLINE thread_pool::queue_size()
+{
+    return q_.size();
+}
+
 void SPDLOG_INLINE thread_pool::post_async_msg_(async_msg &&new_msg, async_overflow_policy overflow_policy)
 {
     if (overflow_policy == async_overflow_policy::block)

include/spdlog/details/thread_pool.h

@@ -27,7 +27,6 @@ enum class async_msg_type
     terminate
 };
 
-#include <spdlog/details/log_msg_buffer.h>
 // Async msg to move to/from the queue
 // Movable only. should never be copied
 struct async_msg : log_msg_buffer
@@ -85,10 +84,11 @@ public:
     using item_type = async_msg;
     using q_type = details::mpmc_blocking_queue<item_type>;
 
+    thread_pool(size_t q_max_items, size_t threads_n, std::function<void()> on_thread_start, std::function<void()> on_thread_stop);
     thread_pool(size_t q_max_items, size_t threads_n, std::function<void()> on_thread_start);
     thread_pool(size_t q_max_items, size_t threads_n);
 
-    // message all threads to terminate gracefully join them
+    // message all threads to terminate gracefully and join them
     ~thread_pool();
 
     thread_pool(const thread_pool &) = delete;
@@ -97,6 +97,7 @@ public:
     void post_log(async_logger_ptr &&worker_ptr, const details::log_msg &msg, async_overflow_policy overflow_policy);
     void post_flush(async_logger_ptr &&worker_ptr, async_overflow_policy overflow_policy);
     size_t overrun_counter();
+    size_t queue_size();
 
 private:
     q_type q_;
@@ -116,5 +117,5 @@ private:
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "thread_pool-inl.h"
+#    include "thread_pool-inl.h"
 #endif

include/spdlog/details/udp_client-windows.h

@@ -0,0 +1,111 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+// Helper RAII over winsock udp client socket.
+// Will throw on construction if socket creation failed.
+
+#include <spdlog/common.h>
+#include <spdlog/details/os.h>
+#include <spdlog/details/windows_include.h>
+#include <winsock2.h>
+#include <ws2tcpip.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string>
+
+#pragma comment(lib, "Ws2_32.lib")
+#pragma comment(lib, "Mswsock.lib")
+#pragma comment(lib, "AdvApi32.lib")
+
+namespace spdlog {
+namespace details {
+class udp_client
+{
+    static constexpr int TX_BUFFER_SIZE = 1024 * 10;
+    SOCKET socket_ = INVALID_SOCKET;
+    sockaddr_in addr_ = {0};
+
+    static void init_winsock_()
+    {
+        WSADATA wsaData;
+        auto rv = ::WSAStartup(MAKEWORD(2, 2), &wsaData);
+        if (rv != 0)
+        {
+            throw_winsock_error_("WSAStartup failed", ::WSAGetLastError());
+        }
+    }
+
+    static void throw_winsock_error_(const std::string &msg, int last_error)
+    {
+        char buf[512];
+        ::FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, last_error,
+            MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), buf, (sizeof(buf) / sizeof(char)), NULL);
+
+        throw_spdlog_ex(fmt_lib::format("udp_sink - {}: {}", msg, buf));
+    }
+
+    void cleanup_()
+    {
+        if (socket_ != INVALID_SOCKET)
+        {
+            ::closesocket(socket_);
+        }
+        socket_ = INVALID_SOCKET;
+        ::WSACleanup();
+    }
+
+public:
+    udp_client(const std::string &host, uint16_t port)
+    {
+        init_winsock_();
+
+        addr_.sin_family = PF_INET;
+        addr_.sin_port = htons(port);
+        addr_.sin_addr.s_addr = INADDR_ANY;
+        if (InetPtonA(PF_INET, host.c_str(), &addr_.sin_addr.s_addr) != 1)
+        {
+            int last_error = ::WSAGetLastError();
+            ::WSACleanup();
+            throw_winsock_error_("error: Invalid address!", last_error);
+        }
+
+        socket_ = ::socket(PF_INET, SOCK_DGRAM, 0);
+        if (socket_ == INVALID_SOCKET)
+        {
+            int last_error = ::WSAGetLastError();
+            ::WSACleanup();
+            throw_winsock_error_("error: Create Socket failed", last_error);
+        }
+
+        int option_value = TX_BUFFER_SIZE;
+        if (::setsockopt(socket_, SOL_SOCKET, SO_SNDBUF, reinterpret_cast<const char *>(&option_value), sizeof(option_value)) < 0)
+        {
+            int last_error = ::WSAGetLastError();
+            cleanup_();
+            throw_winsock_error_("error: setsockopt(SO_SNDBUF) Failed!", last_error);
+        }
+    }
+
+    ~udp_client()
+    {
+        cleanup_();
+    }
+
+    SOCKET fd() const
+    {
+        return socket_;
+    }
+
+    void send(const char *data, size_t n_bytes)
+    {
+        socklen_t tolen = sizeof(struct sockaddr);
+        if (::sendto(socket_, data, static_cast<int>(n_bytes), 0, (struct sockaddr *)&addr_, tolen) == -1)
+        {
+            throw_spdlog_ex("sendto(2) failed", errno);
+        }
+    }
+};
+} // namespace details
+} // namespace spdlog

include/spdlog/details/udp_client.h

@@ -0,0 +1,94 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+// Helper RAII over unix udp client socket.
+// Will throw on construction if the socket creation failed.
+
+#ifdef _WIN32
+#    error "include udp_client-windows.h instead"
+#endif
+
+#include <spdlog/common.h>
+#include <spdlog/details/os.h>
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <netdb.h>
+#include <netinet/udp.h>
+
+#include <string>
+
+namespace spdlog {
+namespace details {
+
+class udp_client
+{
+    static constexpr int TX_BUFFER_SIZE = 1024 * 10;
+    int socket_ = -1;
+    struct sockaddr_in sockAddr_;
+
+    void cleanup_()
+    {
+        if (socket_ != -1)
+        {
+            ::close(socket_);
+            socket_ = -1;
+        }
+    }
+
+public:
+    udp_client(const std::string &host, uint16_t port)
+    {
+        socket_ = ::socket(PF_INET, SOCK_DGRAM, 0);
+        if (socket_ < 0)
+        {
+            throw_spdlog_ex("error: Create Socket Failed!");
+        }
+
+        int option_value = TX_BUFFER_SIZE;
+        if (::setsockopt(socket_, SOL_SOCKET, SO_SNDBUF, reinterpret_cast<const char *>(&option_value), sizeof(option_value)) < 0)
+        {
+            cleanup_();
+            throw_spdlog_ex("error: setsockopt(SO_SNDBUF) Failed!");
+        }
+
+        sockAddr_.sin_family = AF_INET;
+        sockAddr_.sin_port = htons(port);
+
+        if (::inet_aton(host.c_str(), &sockAddr_.sin_addr) == 0)
+        {
+            cleanup_();
+            throw_spdlog_ex("error: Invalid address!");
+        }
+
+        ::memset(sockAddr_.sin_zero, 0x00, sizeof(sockAddr_.sin_zero));
+    }
+
+    ~udp_client()
+    {
+        cleanup_();
+    }
+
+    int fd() const
+    {
+        return socket_;
+    }
+
+    // Send exactly n_bytes of the given data.
+    // On error close the connection and throw.
+    void send(const char *data, size_t n_bytes)
+    {
+        ssize_t toslen = 0;
+        socklen_t tolen = sizeof(struct sockaddr);
+        if ((toslen = ::sendto(socket_, data, n_bytes, 0, (struct sockaddr *)&sockAddr_, tolen)) == -1)
+        {
+            throw_spdlog_ex("sendto(2) failed", errno);
+        }
+    }
+};
+} // namespace details
+} // namespace spdlog

include/spdlog/details/windows_include.h

@@ -1,11 +1,11 @@
 #pragma once
 
 #ifndef NOMINMAX
-#define NOMINMAX // prevent windows redefining min/max
+#    define NOMINMAX // prevent windows redefining min/max
 #endif
 
 #ifndef WIN32_LEAN_AND_MEAN
-#define WIN32_LEAN_AND_MEAN
+#    define WIN32_LEAN_AND_MEAN
 #endif
 
 #include <windows.h>

include/spdlog/fmt/bin_to_hex.h

@@ -6,10 +6,19 @@
 #pragma once
 
 #include <cctype>
+#include <spdlog/common.h>
+
+#if defined(__has_include) && __has_include(<version>)
+#    include <version>
+#endif
+
+#if __cpp_lib_span >= 202002L
+#    include <span>
+#endif
 
 //
 // Support for logging binary data as hex
-// format flags:
+// format flags, any combination of the following:
 // {:X} - print in uppercase.
 // {:s} - don't separate each byte with space.
 // {:p} - don't print the position on each line start.
@@ -38,11 +47,12 @@ public:
         , size_per_line_(size_per_line)
     {}
 
-    It begin() const
+    // do not use begin() and end() to avoid collision with fmt/ranges
+    It get_begin() const
     {
         return begin_;
     }
-    It end() const
+    It get_end() const
     {
         return end_;
     }
@@ -66,6 +76,20 @@ inline details::dump_info<typename Container::const_iterator> to_hex(const Conta
     return details::dump_info<Iter>(std::begin(container), std::end(container), size_per_line);
 }
 
+#if __cpp_lib_span >= 202002L
+
+template<typename Value, size_t Extent>
+inline details::dump_info<typename std::span<Value, Extent>::iterator> to_hex(
+    const std::span<Value, Extent> &container, size_t size_per_line = 32)
+{
+    using Container = std::span<Value, Extent>;
+    static_assert(sizeof(typename Container::value_type) == 1, "sizeof(Container::value_type) != 1");
+    using Iter = typename Container::iterator;
+    return details::dump_info<Iter>(std::begin(container), std::end(container), size_per_line);
+}
+
+#endif
+
 // create dump_info from ranges
 template<typename It>
 inline details::dump_info<It> to_hex(const It range_begin, const It range_end, size_t size_per_line = 32)
@@ -75,10 +99,16 @@ inline details::dump_info<It> to_hex(const It range_begin, const It range_end, s
 
 } // namespace spdlog
 
-namespace fmt {
+namespace
+#ifdef SPDLOG_USE_STD_FORMAT
+    std
+#else
+    fmt
+#endif
+{
 
 template<typename T>
-struct formatter<spdlog::details::dump_info<T>>
+struct formatter<spdlog::details::dump_info<T>, char>
 {
     const char delimiter = ' ';
     bool put_newlines = true;
@@ -89,10 +119,10 @@ struct formatter<spdlog::details::dump_info<T>>
 
     // parse the format string flags
     template<typename ParseContext>
-    auto parse(ParseContext &ctx) -> decltype(ctx.begin())
+    SPDLOG_CONSTEXPR_FUNC auto parse(ParseContext &ctx) -> decltype(ctx.begin())
     {
         auto it = ctx.begin();
-        while (*it && *it != '}')
+        while (it != ctx.end() && *it != '}')
         {
             switch (*it)
             {
@@ -130,21 +160,21 @@ struct formatter<spdlog::details::dump_info<T>>
         SPDLOG_CONSTEXPR const char *hex_lower = "0123456789abcdef";
         const char *hex_chars = use_uppercase ? hex_upper : hex_lower;
 
-#if FMT_VERSION < 60000
+#if !defined(SPDLOG_USE_STD_FORMAT) && FMT_VERSION < 60000
         auto inserter = ctx.begin();
 #else
         auto inserter = ctx.out();
 #endif
 
         int size_per_line = static_cast<int>(the_range.size_per_line());
-        auto start_of_line = the_range.begin();
-        for (auto i = the_range.begin(); i != the_range.end(); i++)
+        auto start_of_line = the_range.get_begin();
+        for (auto i = the_range.get_begin(); i != the_range.get_end(); i++)
         {
             auto ch = static_cast<unsigned char>(*i);
 
-            if (put_newlines && (i == the_range.begin() || i - start_of_line >= size_per_line))
+            if (put_newlines && (i == the_range.get_begin() || i - start_of_line >= size_per_line))
             {
-                if (show_ascii && i != the_range.begin())
+                if (show_ascii && i != the_range.get_begin())
                 {
                     *inserter++ = delimiter;
                     *inserter++ = delimiter;
@@ -155,7 +185,7 @@ struct formatter<spdlog::details::dump_info<T>>
                     }
                 }
 
-                put_newline(inserter, static_cast<size_t>(i - the_range.begin()));
+                put_newline(inserter, static_cast<size_t>(i - the_range.get_begin()));
 
                 // put first byte without delimiter in front of it
                 *inserter++ = hex_chars[(ch >> 4) & 0x0f];
@@ -174,9 +204,9 @@ struct formatter<spdlog::details::dump_info<T>>
         }
         if (show_ascii) // add ascii to last line
         {
-            if (the_range.end() - the_range.begin() > size_per_line)
+            if (the_range.get_end() - the_range.get_begin() > size_per_line)
             {
-                auto blank_num = size_per_line - (the_range.end() - start_of_line);
+                auto blank_num = size_per_line - (the_range.get_end() - start_of_line);
                 while (blank_num-- > 0)
                 {
                     *inserter++ = delimiter;
@@ -189,7 +219,7 @@ struct formatter<spdlog::details::dump_info<T>>
             }
             *inserter++ = delimiter;
             *inserter++ = delimiter;
-            for (auto j = start_of_line; j != the_range.end(); j++)
+            for (auto j = start_of_line; j != the_range.get_end(); j++)
             {
                 auto pc = static_cast<unsigned char>(*j);
                 *inserter++ = std::isprint(pc) ? static_cast<char>(*j) : '.';
@@ -209,8 +239,8 @@ struct formatter<spdlog::details::dump_info<T>>
 
         if (put_positions)
         {
-            fmt::format_to(inserter, "{:<04X}: ", pos);
+            spdlog::fmt_lib::format_to(inserter, "{:04X}: ", pos);
         }
     }
 };
-} // namespace fmt
+} // namespace std

include/spdlog/fmt/bundled/args.h

@@ -0,0 +1,234 @@
+// Formatting library for C++ - dynamic format arguments
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_ARGS_H_
+#define FMT_ARGS_H_
+
+#include <functional>  // std::reference_wrapper
+#include <memory>      // std::unique_ptr
+#include <vector>
+
+#include "core.h"
+
+FMT_BEGIN_NAMESPACE
+
+namespace detail {
+
+template <typename T> struct is_reference_wrapper : std::false_type {};
+template <typename T>
+struct is_reference_wrapper<std::reference_wrapper<T>> : std::true_type {};
+
+template <typename T> const T& unwrap(const T& v) { return v; }
+template <typename T> const T& unwrap(const std::reference_wrapper<T>& v) {
+  return static_cast<const T&>(v);
+}
+
+class dynamic_arg_list {
+  // Workaround for clang's -Wweak-vtables. Unlike for regular classes, for
+  // templates it doesn't complain about inability to deduce single translation
+  // unit for placing vtable. So storage_node_base is made a fake template.
+  template <typename = void> struct node {
+    virtual ~node() = default;
+    std::unique_ptr<node<>> next;
+  };
+
+  template <typename T> struct typed_node : node<> {
+    T value;
+
+    template <typename Arg>
+    FMT_CONSTEXPR typed_node(const Arg& arg) : value(arg) {}
+
+    template <typename Char>
+    FMT_CONSTEXPR typed_node(const basic_string_view<Char>& arg)
+        : value(arg.data(), arg.size()) {}
+  };
+
+  std::unique_ptr<node<>> head_;
+
+ public:
+  template <typename T, typename Arg> const T& push(const Arg& arg) {
+    auto new_node = std::unique_ptr<typed_node<T>>(new typed_node<T>(arg));
+    auto& value = new_node->value;
+    new_node->next = std::move(head_);
+    head_ = std::move(new_node);
+    return value;
+  }
+};
+}  // namespace detail
+
+/**
+  \rst
+  A dynamic version of `fmt::format_arg_store`.
+  It's equipped with a storage to potentially temporary objects which lifetimes
+  could be shorter than the format arguments object.
+
+  It can be implicitly converted into `~fmt::basic_format_args` for passing
+  into type-erased formatting functions such as `~fmt::vformat`.
+  \endrst
+ */
+template <typename Context>
+class dynamic_format_arg_store
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+    // Workaround a GCC template argument substitution bug.
+    : public basic_format_args<Context>
+#endif
+{
+ private:
+  using char_type = typename Context::char_type;
+
+  template <typename T> struct need_copy {
+    static constexpr detail::type mapped_type =
+        detail::mapped_type_constant<T, Context>::value;
+
+    enum {
+      value = !(detail::is_reference_wrapper<T>::value ||
+                std::is_same<T, basic_string_view<char_type>>::value ||
+                std::is_same<T, detail::std_string_view<char_type>>::value ||
+                (mapped_type != detail::type::cstring_type &&
+                 mapped_type != detail::type::string_type &&
+                 mapped_type != detail::type::custom_type))
+    };
+  };
+
+  template <typename T>
+  using stored_type = conditional_t<detail::is_string<T>::value &&
+                                        !has_formatter<T, Context>::value &&
+                                        !detail::is_reference_wrapper<T>::value,
+                                    std::basic_string<char_type>, T>;
+
+  // Storage of basic_format_arg must be contiguous.
+  std::vector<basic_format_arg<Context>> data_;
+  std::vector<detail::named_arg_info<char_type>> named_info_;
+
+  // Storage of arguments not fitting into basic_format_arg must grow
+  // without relocation because items in data_ refer to it.
+  detail::dynamic_arg_list dynamic_args_;
+
+  friend class basic_format_args<Context>;
+
+  unsigned long long get_types() const {
+    return detail::is_unpacked_bit | data_.size() |
+           (named_info_.empty()
+                ? 0ULL
+                : static_cast<unsigned long long>(detail::has_named_args_bit));
+  }
+
+  const basic_format_arg<Context>* data() const {
+    return named_info_.empty() ? data_.data() : data_.data() + 1;
+  }
+
+  template <typename T> void emplace_arg(const T& arg) {
+    data_.emplace_back(detail::make_arg<Context>(arg));
+  }
+
+  template <typename T>
+  void emplace_arg(const detail::named_arg<char_type, T>& arg) {
+    if (named_info_.empty()) {
+      constexpr const detail::named_arg_info<char_type>* zero_ptr{nullptr};
+      data_.insert(data_.begin(), {zero_ptr, 0});
+    }
+    data_.emplace_back(detail::make_arg<Context>(detail::unwrap(arg.value)));
+    auto pop_one = [](std::vector<basic_format_arg<Context>>* data) {
+      data->pop_back();
+    };
+    std::unique_ptr<std::vector<basic_format_arg<Context>>, decltype(pop_one)>
+        guard{&data_, pop_one};
+    named_info_.push_back({arg.name, static_cast<int>(data_.size() - 2u)});
+    data_[0].value_.named_args = {named_info_.data(), named_info_.size()};
+    guard.release();
+  }
+
+ public:
+  constexpr dynamic_format_arg_store() = default;
+
+  /**
+    \rst
+    Adds an argument into the dynamic store for later passing to a formatting
+    function.
+
+    Note that custom types and string types (but not string views) are copied
+    into the store dynamically allocating memory if necessary.
+
+    **Example**::
+
+      fmt::dynamic_format_arg_store<fmt::format_context> store;
+      store.push_back(42);
+      store.push_back("abc");
+      store.push_back(1.5f);
+      std::string result = fmt::vformat("{} and {} and {}", store);
+    \endrst
+  */
+  template <typename T> void push_back(const T& arg) {
+    if (detail::const_check(need_copy<T>::value))
+      emplace_arg(dynamic_args_.push<stored_type<T>>(arg));
+    else
+      emplace_arg(detail::unwrap(arg));
+  }
+
+  /**
+    \rst
+    Adds a reference to the argument into the dynamic store for later passing to
+    a formatting function.
+
+    **Example**::
+
+      fmt::dynamic_format_arg_store<fmt::format_context> store;
+      char band[] = "Rolling Stones";
+      store.push_back(std::cref(band));
+      band[9] = 'c'; // Changing str affects the output.
+      std::string result = fmt::vformat("{}", store);
+      // result == "Rolling Scones"
+    \endrst
+  */
+  template <typename T> void push_back(std::reference_wrapper<T> arg) {
+    static_assert(
+        need_copy<T>::value,
+        "objects of built-in types and string views are always copied");
+    emplace_arg(arg.get());
+  }
+
+  /**
+    Adds named argument into the dynamic store for later passing to a formatting
+    function. ``std::reference_wrapper`` is supported to avoid copying of the
+    argument. The name is always copied into the store.
+  */
+  template <typename T>
+  void push_back(const detail::named_arg<char_type, T>& arg) {
+    const char_type* arg_name =
+        dynamic_args_.push<std::basic_string<char_type>>(arg.name).c_str();
+    if (detail::const_check(need_copy<T>::value)) {
+      emplace_arg(
+          fmt::arg(arg_name, dynamic_args_.push<stored_type<T>>(arg.value)));
+    } else {
+      emplace_arg(fmt::arg(arg_name, arg.value));
+    }
+  }
+
+  /** Erase all elements from the store */
+  void clear() {
+    data_.clear();
+    named_info_.clear();
+    dynamic_args_ = detail::dynamic_arg_list();
+  }
+
+  /**
+    \rst
+    Reserves space to store at least *new_cap* arguments including
+    *new_cap_named* named arguments.
+    \endrst
+  */
+  void reserve(size_t new_cap, size_t new_cap_named) {
+    FMT_ASSERT(new_cap >= new_cap_named,
+               "Set of arguments includes set of named arguments");
+    data_.reserve(new_cap);
+    named_info_.reserve(new_cap_named);
+  }
+};
+
+FMT_END_NAMESPACE
+
+#endif  // FMT_ARGS_H_

include/spdlog/fmt/bundled/color.h

@@ -10,7 +10,15 @@
 
 #include "format.h"
 
+// __declspec(deprecated) is broken in some MSVC versions.
+#if FMT_MSC_VER
+#  define FMT_DEPRECATED_NONMSVC
+#else
+#  define FMT_DEPRECATED_NONMSVC FMT_DEPRECATED
+#endif
+
 FMT_BEGIN_NAMESPACE
+FMT_MODULE_EXPORT_BEGIN
 
 enum class color : uint32_t {
   alice_blue = 0xF0F8FF,               // rgb(240,248,255)
@@ -177,9 +185,13 @@ enum class terminal_color : uint8_t {
 
 enum class emphasis : uint8_t {
   bold = 1,
-  italic = 1 << 1,
-  underline = 1 << 2,
-  strikethrough = 1 << 3
+  faint = 1 << 1,
+  italic = 1 << 2,
+  underline = 1 << 3,
+  blink = 1 << 4,
+  reverse = 1 << 5,
+  conceal = 1 << 6,
+  strikethrough = 1 << 7,
 };
 
 // rgb is a struct for red, green and blue colors.
@@ -198,7 +210,7 @@ struct rgb {
   uint8_t b;
 };
 
-namespace internal {
+FMT_BEGIN_DETAIL_NAMESPACE
 
 // color is a struct of either a rgb color or a terminal color.
 struct color_type {
@@ -221,9 +233,10 @@ struct color_type {
     uint32_t rgb_color;
   } value;
 };
-}  // namespace internal
 
-// Experimental text formatting support.
+FMT_END_DETAIL_NAMESPACE
+
+/** A text style consisting of foreground and background colors and emphasis. */
 class text_style {
  public:
   FMT_CONSTEXPR text_style(emphasis em = emphasis()) FMT_NOEXCEPT
@@ -260,7 +273,55 @@ class text_style {
     return lhs |= rhs;
   }
 
-  FMT_CONSTEXPR text_style& operator&=(const text_style& rhs) {
+  FMT_DEPRECATED_NONMSVC FMT_CONSTEXPR text_style& operator&=(
+      const text_style& rhs) {
+    return and_assign(rhs);
+  }
+
+  FMT_DEPRECATED_NONMSVC friend FMT_CONSTEXPR text_style
+  operator&(text_style lhs, const text_style& rhs) {
+    return lhs.and_assign(rhs);
+  }
+
+  FMT_CONSTEXPR bool has_foreground() const FMT_NOEXCEPT {
+    return set_foreground_color;
+  }
+  FMT_CONSTEXPR bool has_background() const FMT_NOEXCEPT {
+    return set_background_color;
+  }
+  FMT_CONSTEXPR bool has_emphasis() const FMT_NOEXCEPT {
+    return static_cast<uint8_t>(ems) != 0;
+  }
+  FMT_CONSTEXPR detail::color_type get_foreground() const FMT_NOEXCEPT {
+    FMT_ASSERT(has_foreground(), "no foreground specified for this style");
+    return foreground_color;
+  }
+  FMT_CONSTEXPR detail::color_type get_background() const FMT_NOEXCEPT {
+    FMT_ASSERT(has_background(), "no background specified for this style");
+    return background_color;
+  }
+  FMT_CONSTEXPR emphasis get_emphasis() const FMT_NOEXCEPT {
+    FMT_ASSERT(has_emphasis(), "no emphasis specified for this style");
+    return ems;
+  }
+
+ private:
+  FMT_CONSTEXPR text_style(bool is_foreground,
+                           detail::color_type text_color) FMT_NOEXCEPT
+      : set_foreground_color(),
+        set_background_color(),
+        ems() {
+    if (is_foreground) {
+      foreground_color = text_color;
+      set_foreground_color = true;
+    } else {
+      background_color = text_color;
+      set_background_color = true;
+    }
+  }
+
+  // DEPRECATED!
+  FMT_CONSTEXPR text_style& and_assign(const text_style& rhs) {
     if (!set_foreground_color) {
       set_foreground_color = rhs.set_foreground_color;
       foreground_color = rhs.foreground_color;
@@ -284,87 +345,49 @@ class text_style {
     return *this;
   }
 
-  friend FMT_CONSTEXPR text_style operator&(text_style lhs,
-                                            const text_style& rhs) {
-    return lhs &= rhs;
-  }
-
-  FMT_CONSTEXPR bool has_foreground() const FMT_NOEXCEPT {
-    return set_foreground_color;
-  }
-  FMT_CONSTEXPR bool has_background() const FMT_NOEXCEPT {
-    return set_background_color;
-  }
-  FMT_CONSTEXPR bool has_emphasis() const FMT_NOEXCEPT {
-    return static_cast<uint8_t>(ems) != 0;
-  }
-  FMT_CONSTEXPR internal::color_type get_foreground() const FMT_NOEXCEPT {
-    FMT_ASSERT(has_foreground(), "no foreground specified for this style");
-    return foreground_color;
-  }
-  FMT_CONSTEXPR internal::color_type get_background() const FMT_NOEXCEPT {
-    FMT_ASSERT(has_background(), "no background specified for this style");
-    return background_color;
-  }
-  FMT_CONSTEXPR emphasis get_emphasis() const FMT_NOEXCEPT {
-    FMT_ASSERT(has_emphasis(), "no emphasis specified for this style");
-    return ems;
-  }
-
- private:
-  FMT_CONSTEXPR text_style(bool is_foreground,
-                           internal::color_type text_color) FMT_NOEXCEPT
-      : set_foreground_color(),
-        set_background_color(),
-        ems() {
-    if (is_foreground) {
-      foreground_color = text_color;
-      set_foreground_color = true;
-    } else {
-      background_color = text_color;
-      set_background_color = true;
-    }
-  }
-
-  friend FMT_CONSTEXPR_DECL text_style fg(internal::color_type foreground)
-      FMT_NOEXCEPT;
-  friend FMT_CONSTEXPR_DECL text_style bg(internal::color_type background)
+  friend FMT_CONSTEXPR_DECL text_style fg(detail::color_type foreground)
       FMT_NOEXCEPT;
 
-  internal::color_type foreground_color;
-  internal::color_type background_color;
+  friend FMT_CONSTEXPR_DECL text_style bg(detail::color_type background)
+      FMT_NOEXCEPT;
+
+  detail::color_type foreground_color;
+  detail::color_type background_color;
   bool set_foreground_color;
   bool set_background_color;
   emphasis ems;
 };
 
-FMT_CONSTEXPR text_style fg(internal::color_type foreground) FMT_NOEXCEPT {
-  return text_style(/*is_foreground=*/true, foreground);
+/** Creates a text style from the foreground (text) color. */
+FMT_CONSTEXPR inline text_style fg(detail::color_type foreground) FMT_NOEXCEPT {
+  return text_style(true, foreground);
 }
 
-FMT_CONSTEXPR text_style bg(internal::color_type background) FMT_NOEXCEPT {
-  return text_style(/*is_foreground=*/false, background);
+/** Creates a text style from the background color. */
+FMT_CONSTEXPR inline text_style bg(detail::color_type background) FMT_NOEXCEPT {
+  return text_style(false, background);
 }
 
-FMT_CONSTEXPR text_style operator|(emphasis lhs, emphasis rhs) FMT_NOEXCEPT {
+FMT_CONSTEXPR inline text_style operator|(emphasis lhs,
+                                          emphasis rhs) FMT_NOEXCEPT {
   return text_style(lhs) | rhs;
 }
 
-namespace internal {
+FMT_BEGIN_DETAIL_NAMESPACE
 
 template <typename Char> struct ansi_color_escape {
-  FMT_CONSTEXPR ansi_color_escape(internal::color_type text_color,
+  FMT_CONSTEXPR ansi_color_escape(detail::color_type text_color,
                                   const char* esc) FMT_NOEXCEPT {
     // If we have a terminal color, we need to output another escape code
     // sequence.
     if (!text_color.is_rgb) {
-      bool is_background = esc == internal::data::background_color;
+      bool is_background = esc == string_view("\x1b[48;2;");
       uint32_t value = text_color.value.term_color;
       // Background ASCII codes are the same as the foreground ones but with
       // 10 more.
       if (is_background) value += 10u;
 
-      std::size_t index = 0;
+      size_t index = 0;
       buffer[index++] = static_cast<Char>('\x1b');
       buffer[index++] = static_cast<Char>('[');
 
@@ -390,16 +413,18 @@ template <typename Char> struct ansi_color_escape {
     buffer[19] = static_cast<Char>(0);
   }
   FMT_CONSTEXPR ansi_color_escape(emphasis em) FMT_NOEXCEPT {
-    uint8_t em_codes[4] = {};
-    uint8_t em_bits = static_cast<uint8_t>(em);
-    if (em_bits & static_cast<uint8_t>(emphasis::bold)) em_codes[0] = 1;
-    if (em_bits & static_cast<uint8_t>(emphasis::italic)) em_codes[1] = 3;
-    if (em_bits & static_cast<uint8_t>(emphasis::underline)) em_codes[2] = 4;
-    if (em_bits & static_cast<uint8_t>(emphasis::strikethrough))
-      em_codes[3] = 9;
+    uint8_t em_codes[num_emphases] = {};
+    if (has_emphasis(em, emphasis::bold)) em_codes[0] = 1;
+    if (has_emphasis(em, emphasis::faint)) em_codes[1] = 2;
+    if (has_emphasis(em, emphasis::italic)) em_codes[2] = 3;
+    if (has_emphasis(em, emphasis::underline)) em_codes[3] = 4;
+    if (has_emphasis(em, emphasis::blink)) em_codes[4] = 5;
+    if (has_emphasis(em, emphasis::reverse)) em_codes[5] = 7;
+    if (has_emphasis(em, emphasis::conceal)) em_codes[6] = 8;
+    if (has_emphasis(em, emphasis::strikethrough)) em_codes[7] = 9;
 
-    std::size_t index = 0;
-    for (int i = 0; i < 4; ++i) {
+    size_t index = 0;
+    for (size_t i = 0; i < num_emphases; ++i) {
       if (!em_codes[i]) continue;
       buffer[index++] = static_cast<Char>('\x1b');
       buffer[index++] = static_cast<Char>('[');
@@ -411,12 +436,13 @@ template <typename Char> struct ansi_color_escape {
   FMT_CONSTEXPR operator const Char*() const FMT_NOEXCEPT { return buffer; }
 
   FMT_CONSTEXPR const Char* begin() const FMT_NOEXCEPT { return buffer; }
-  FMT_CONSTEXPR const Char* end() const FMT_NOEXCEPT {
+  FMT_CONSTEXPR_CHAR_TRAITS const Char* end() const FMT_NOEXCEPT {
     return buffer + std::char_traits<Char>::length(buffer);
   }
 
  private:
-  Char buffer[7u + 3u * 4u + 1u];
+  static constexpr size_t num_emphases = 8;
+  Char buffer[7u + 3u * num_emphases + 1u];
 
   static FMT_CONSTEXPR void to_esc(uint8_t c, Char* out,
                                    char delimiter) FMT_NOEXCEPT {
@@ -425,18 +451,22 @@ template <typename Char> struct ansi_color_escape {
     out[2] = static_cast<Char>('0' + c % 10);
     out[3] = static_cast<Char>(delimiter);
   }
+  static FMT_CONSTEXPR bool has_emphasis(emphasis em,
+                                         emphasis mask) FMT_NOEXCEPT {
+    return static_cast<uint8_t>(em) & static_cast<uint8_t>(mask);
+  }
 };
 
 template <typename Char>
 FMT_CONSTEXPR ansi_color_escape<Char> make_foreground_color(
-    internal::color_type foreground) FMT_NOEXCEPT {
-  return ansi_color_escape<Char>(foreground, internal::data::foreground_color);
+    detail::color_type foreground) FMT_NOEXCEPT {
+  return ansi_color_escape<Char>(foreground, "\x1b[38;2;");
 }
 
 template <typename Char>
 FMT_CONSTEXPR ansi_color_escape<Char> make_background_color(
-    internal::color_type background) FMT_NOEXCEPT {
-  return ansi_color_escape<Char>(background, internal::data::background_color);
+    detail::color_type background) FMT_NOEXCEPT {
+  return ansi_color_escape<Char>(background, "\x1b[48;2;");
 }
 
 template <typename Char>
@@ -455,82 +485,86 @@ inline void fputs<wchar_t>(const wchar_t* chars, FILE* stream) FMT_NOEXCEPT {
 }
 
 template <typename Char> inline void reset_color(FILE* stream) FMT_NOEXCEPT {
-  fputs(internal::data::reset_color, stream);
+  fputs("\x1b[0m", stream);
 }
 
 template <> inline void reset_color<wchar_t>(FILE* stream) FMT_NOEXCEPT {
-  fputs(internal::data::wreset_color, stream);
+  fputs(L"\x1b[0m", stream);
 }
 
 template <typename Char>
-inline void reset_color(basic_memory_buffer<Char>& buffer) FMT_NOEXCEPT {
-  const char* begin = data::reset_color;
-  const char* end = begin + sizeof(data::reset_color) - 1;
-  buffer.append(begin, end);
+inline void reset_color(buffer<Char>& buffer) FMT_NOEXCEPT {
+  auto reset_color = string_view("\x1b[0m");
+  buffer.append(reset_color.begin(), reset_color.end());
 }
 
 template <typename Char>
-void vformat_to(basic_memory_buffer<Char>& buf, const text_style& ts,
+void vformat_to(buffer<Char>& buf, const text_style& ts,
                 basic_string_view<Char> format_str,
-                basic_format_args<buffer_context<Char>> args) {
+                basic_format_args<buffer_context<type_identity_t<Char>>> args) {
   bool has_style = false;
   if (ts.has_emphasis()) {
     has_style = true;
-    auto emphasis = internal::make_emphasis<Char>(ts.get_emphasis());
+    auto emphasis = detail::make_emphasis<Char>(ts.get_emphasis());
     buf.append(emphasis.begin(), emphasis.end());
   }
   if (ts.has_foreground()) {
     has_style = true;
-    auto foreground =
-        internal::make_foreground_color<Char>(ts.get_foreground());
+    auto foreground = detail::make_foreground_color<Char>(ts.get_foreground());
     buf.append(foreground.begin(), foreground.end());
   }
   if (ts.has_background()) {
     has_style = true;
-    auto background =
-        internal::make_background_color<Char>(ts.get_background());
+    auto background = detail::make_background_color<Char>(ts.get_background());
     buf.append(background.begin(), background.end());
   }
-  internal::vformat_to(buf, format_str, args);
-  if (has_style) internal::reset_color<Char>(buf);
+  detail::vformat_to(buf, format_str, args, {});
+  if (has_style) detail::reset_color<Char>(buf);
 }
-}  // namespace internal
+
+FMT_END_DETAIL_NAMESPACE
 
 template <typename S, typename Char = char_t<S>>
 void vprint(std::FILE* f, const text_style& ts, const S& format,
-            basic_format_args<buffer_context<Char>> args) {
+            basic_format_args<buffer_context<type_identity_t<Char>>> args) {
   basic_memory_buffer<Char> buf;
-  internal::vformat_to(buf, ts, to_string_view(format), args);
+  detail::vformat_to(buf, ts, to_string_view(format), args);
   buf.push_back(Char(0));
-  internal::fputs(buf.data(), f);
+  detail::fputs(buf.data(), f);
 }
 
 /**
+  \rst
   Formats a string and prints it to the specified file stream using ANSI
   escape sequences to specify text formatting.
-  Example:
+
+  **Example**::
+
     fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
                "Elapsed time: {0:.2f} seconds", 1.23);
+  \endrst
  */
 template <typename S, typename... Args,
-          FMT_ENABLE_IF(internal::is_string<S>::value)>
+          FMT_ENABLE_IF(detail::is_string<S>::value)>
 void print(std::FILE* f, const text_style& ts, const S& format_str,
            const Args&... args) {
-  internal::check_format_string<Args...>(format_str);
-  using context = buffer_context<char_t<S>>;
-  format_arg_store<context, Args...> as{args...};
-  vprint(f, ts, format_str, basic_format_args<context>(as));
+  vprint(f, ts, format_str,
+         fmt::make_args_checked<Args...>(format_str, args...));
 }
 
 /**
+  \rst
   Formats a string and prints it to stdout using ANSI escape sequences to
   specify text formatting.
-  Example:
+
+  **Example**::
+
     fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
                "Elapsed time: {0:.2f} seconds", 1.23);
+  \endrst
  */
 template <typename S, typename... Args,
-          FMT_ENABLE_IF(internal::is_string<S>::value)>
+          FMT_ENABLE_IF(detail::is_string<S>::value)>
 void print(const text_style& ts, const S& format_str, const Args&... args) {
   return print(stdout, ts, format_str, args...);
 }
@@ -540,7 +574,7 @@ inline std::basic_string<Char> vformat(
     const text_style& ts, const S& format_str,
     basic_format_args<buffer_context<type_identity_t<Char>>> args) {
   basic_memory_buffer<Char> buf;
-  internal::vformat_to(buf, ts, to_string_view(format_str), args);
+  detail::vformat_to(buf, ts, to_string_view(format_str), args);
   return fmt::to_string(buf);
 }
 
@@ -559,10 +593,46 @@ inline std::basic_string<Char> vformat(
 template <typename S, typename... Args, typename Char = char_t<S>>
 inline std::basic_string<Char> format(const text_style& ts, const S& format_str,
                                       const Args&... args) {
-  return vformat(ts, to_string_view(format_str),
-                 internal::make_args_checked<Args...>(format_str, args...));
+  return fmt::vformat(ts, to_string_view(format_str),
+                      fmt::make_args_checked<Args...>(format_str, args...));
 }
 
+/**
+  Formats a string with the given text_style and writes the output to ``out``.
+ */
+template <typename OutputIt, typename Char,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value)>
+OutputIt vformat_to(
+    OutputIt out, const text_style& ts, basic_string_view<Char> format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  auto&& buf = detail::get_buffer<Char>(out);
+  detail::vformat_to(buf, ts, format_str, args);
+  return detail::get_iterator(buf);
+}
+
+/**
+  \rst
+  Formats arguments with the given text_style, writes the result to the output
+  iterator ``out`` and returns the iterator past the end of the output range.
+
+  **Example**::
+
+    std::vector<char> out;
+    fmt::format_to(std::back_inserter(out),
+                   fmt::emphasis::bold | fg(fmt::color::red), "{}", 42);
+  \endrst
+*/
+template <typename OutputIt, typename S, typename... Args,
+          bool enable = detail::is_output_iterator<OutputIt, char_t<S>>::value&&
+              detail::is_string<S>::value>
+inline auto format_to(OutputIt out, const text_style& ts, const S& format_str,
+                      Args&&... args) ->
+    typename std::enable_if<enable, OutputIt>::type {
+  return vformat_to(out, ts, to_string_view(format_str),
+                    fmt::make_args_checked<Args...>(format_str, args...));
+}
+
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_COLOR_H_

include/spdlog/fmt/bundled/locale.h

@@ -1,78 +1,2 @@
-// Formatting library for C++ - std::locale support
-//
-// Copyright (c) 2012 - present, Victor Zverovich
-// All rights reserved.
-//
-// For the license information refer to format.h.
-
-#ifndef FMT_LOCALE_H_
-#define FMT_LOCALE_H_
-
-#include <locale>
-
-#include "format.h"
-
-FMT_BEGIN_NAMESPACE
-
-namespace internal {
-template <typename Char>
-typename buffer_context<Char>::iterator vformat_to(
-    const std::locale& loc, buffer<Char>& buf,
-    basic_string_view<Char> format_str,
-    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-  using range = buffer_range<Char>;
-  return vformat_to<arg_formatter<range>>(buf, to_string_view(format_str), args,
-                                          internal::locale_ref(loc));
-}
-
-template <typename Char>
-std::basic_string<Char> vformat(
-    const std::locale& loc, basic_string_view<Char> format_str,
-    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-  basic_memory_buffer<Char> buffer;
-  internal::vformat_to(loc, buffer, format_str, args);
-  return fmt::to_string(buffer);
-}
-}  // namespace internal
-
-template <typename S, typename Char = char_t<S>>
-inline std::basic_string<Char> vformat(
-    const std::locale& loc, const S& format_str,
-    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-  return internal::vformat(loc, to_string_view(format_str), args);
-}
-
-template <typename S, typename... Args, typename Char = char_t<S>>
-inline std::basic_string<Char> format(const std::locale& loc,
-                                      const S& format_str, Args&&... args) {
-  return internal::vformat(
-      loc, to_string_view(format_str),
-      internal::make_args_checked<Args...>(format_str, args...));
-}
-
-template <typename S, typename OutputIt, typename... Args,
-          typename Char = enable_if_t<
-              internal::is_output_iterator<OutputIt>::value, char_t<S>>>
-inline OutputIt vformat_to(
-    OutputIt out, const std::locale& loc, const S& format_str,
-    format_args_t<type_identity_t<OutputIt>, Char> args) {
-  using range = internal::output_range<OutputIt, Char>;
-  return vformat_to<arg_formatter<range>>(
-      range(out), to_string_view(format_str), args, internal::locale_ref(loc));
-}
-
-template <typename OutputIt, typename S, typename... Args,
-          FMT_ENABLE_IF(internal::is_output_iterator<OutputIt>::value&&
-                            internal::is_string<S>::value)>
-inline OutputIt format_to(OutputIt out, const std::locale& loc,
-                          const S& format_str, Args&&... args) {
-  internal::check_format_string<Args...>(format_str);
-  using context = format_context_t<OutputIt, char_t<S>>;
-  format_arg_store<context, Args...> as{args...};
-  return vformat_to(out, loc, to_string_view(format_str),
-                    basic_format_args<context>(as));
-}
-
-FMT_END_NAMESPACE
-
-#endif  // FMT_LOCALE_H_
+#include "xchar.h"
+#warning fmt/locale.h is deprecated, include fmt/format.h or fmt/xchar.h instead

include/spdlog/fmt/bundled/os.h

@@ -0,0 +1,527 @@
+// Formatting library for C++ - optional OS-specific functionality
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_OS_H_
+#define FMT_OS_H_
+
+#include <cerrno>
+#include <clocale>  // locale_t
+#include <cstddef>
+#include <cstdio>
+#include <cstdlib>       // strtod_l
+#include <system_error>  // std::system_error
+
+#if defined __APPLE__ || defined(__FreeBSD__)
+#  include <xlocale.h>  // for LC_NUMERIC_MASK on OS X
+#endif
+
+#include "format.h"
+
+#ifndef FMT_USE_FCNTL
+// UWP doesn't provide _pipe.
+#  if FMT_HAS_INCLUDE("winapifamily.h")
+#    include <winapifamily.h>
+#  endif
+#  if (FMT_HAS_INCLUDE(<fcntl.h>) || defined(__APPLE__) || \
+       defined(__linux__)) &&                              \
+      (!defined(WINAPI_FAMILY) ||                          \
+       (WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP))
+#    include <fcntl.h>  // for O_RDONLY
+#    define FMT_USE_FCNTL 1
+#  else
+#    define FMT_USE_FCNTL 0
+#  endif
+#endif
+
+#ifndef FMT_POSIX
+#  if defined(_WIN32) && !defined(__MINGW32__)
+// Fix warnings about deprecated symbols.
+#    define FMT_POSIX(call) _##call
+#  else
+#    define FMT_POSIX(call) call
+#  endif
+#endif
+
+// Calls to system functions are wrapped in FMT_SYSTEM for testability.
+#ifdef FMT_SYSTEM
+#  define FMT_POSIX_CALL(call) FMT_SYSTEM(call)
+#else
+#  define FMT_SYSTEM(call) ::call
+#  ifdef _WIN32
+// Fix warnings about deprecated symbols.
+#    define FMT_POSIX_CALL(call) ::_##call
+#  else
+#    define FMT_POSIX_CALL(call) ::call
+#  endif
+#endif
+
+// Retries the expression while it evaluates to error_result and errno
+// equals to EINTR.
+#ifndef _WIN32
+#  define FMT_RETRY_VAL(result, expression, error_result) \
+    do {                                                  \
+      (result) = (expression);                            \
+    } while ((result) == (error_result) && errno == EINTR)
+#else
+#  define FMT_RETRY_VAL(result, expression, error_result) result = (expression)
+#endif
+
+#define FMT_RETRY(result, expression) FMT_RETRY_VAL(result, expression, -1)
+
+FMT_BEGIN_NAMESPACE
+FMT_MODULE_EXPORT_BEGIN
+
+/**
+  \rst
+  A reference to a null-terminated string. It can be constructed from a C
+  string or ``std::string``.
+
+  You can use one of the following type aliases for common character types:
+
+  +---------------+-----------------------------+
+  | Type          | Definition                  |
+  +===============+=============================+
+  | cstring_view  | basic_cstring_view<char>    |
+  +---------------+-----------------------------+
+  | wcstring_view | basic_cstring_view<wchar_t> |
+  +---------------+-----------------------------+
+
+  This class is most useful as a parameter type to allow passing
+  different types of strings to a function, for example::
+
+    template <typename... Args>
+    std::string format(cstring_view format_str, const Args & ... args);
+
+    format("{}", 42);
+    format(std::string("{}"), 42);
+  \endrst
+ */
+template <typename Char> class basic_cstring_view {
+ private:
+  const Char* data_;
+
+ public:
+  /** Constructs a string reference object from a C string. */
+  basic_cstring_view(const Char* s) : data_(s) {}
+
+  /**
+    \rst
+    Constructs a string reference from an ``std::string`` object.
+    \endrst
+   */
+  basic_cstring_view(const std::basic_string<Char>& s) : data_(s.c_str()) {}
+
+  /** Returns the pointer to a C string. */
+  const Char* c_str() const { return data_; }
+};
+
+using cstring_view = basic_cstring_view<char>;
+using wcstring_view = basic_cstring_view<wchar_t>;
+
+template <typename Char> struct formatter<std::error_code, Char> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  FMT_CONSTEXPR auto format(const std::error_code& ec, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    out = detail::write_bytes(out, ec.category().name(),
+                              basic_format_specs<Char>());
+    out = detail::write<Char>(out, Char(':'));
+    out = detail::write<Char>(out, ec.value());
+    return out;
+  }
+};
+
+#ifdef _WIN32
+FMT_API const std::error_category& system_category() FMT_NOEXCEPT;
+
+FMT_BEGIN_DETAIL_NAMESPACE
+// A converter from UTF-16 to UTF-8.
+// It is only provided for Windows since other systems support UTF-8 natively.
+class utf16_to_utf8 {
+ private:
+  memory_buffer buffer_;
+
+ public:
+  utf16_to_utf8() {}
+  FMT_API explicit utf16_to_utf8(basic_string_view<wchar_t> s);
+  operator string_view() const { return string_view(&buffer_[0], size()); }
+  size_t size() const { return buffer_.size() - 1; }
+  const char* c_str() const { return &buffer_[0]; }
+  std::string str() const { return std::string(&buffer_[0], size()); }
+
+  // Performs conversion returning a system error code instead of
+  // throwing exception on conversion error. This method may still throw
+  // in case of memory allocation error.
+  FMT_API int convert(basic_string_view<wchar_t> s);
+};
+
+FMT_API void format_windows_error(buffer<char>& out, int error_code,
+                                  const char* message) FMT_NOEXCEPT;
+FMT_END_DETAIL_NAMESPACE
+
+FMT_API std::system_error vwindows_error(int error_code, string_view format_str,
+                                         format_args args);
+
+/**
+ \rst
+ Constructs a :class:`std::system_error` object with the description
+ of the form
+
+ .. parsed-literal::
+   *<message>*: *<system-message>*
+
+ where *<message>* is the formatted message and *<system-message>* is the
+ system message corresponding to the error code.
+ *error_code* is a Windows error code as given by ``GetLastError``.
+ If *error_code* is not a valid error code such as -1, the system message
+ will look like "error -1".
+
+ **Example**::
+
+   // This throws a system_error with the description
+   //   cannot open file 'madeup': The system cannot find the file specified.
+   // or similar (system message may vary).
+   const char *filename = "madeup";
+   LPOFSTRUCT of = LPOFSTRUCT();
+   HFILE file = OpenFile(filename, &of, OF_READ);
+   if (file == HFILE_ERROR) {
+     throw fmt::windows_error(GetLastError(),
+                              "cannot open file '{}'", filename);
+   }
+ \endrst
+*/
+template <typename... Args>
+std::system_error windows_error(int error_code, string_view message,
+                                const Args&... args) {
+  return vwindows_error(error_code, message, fmt::make_format_args(args...));
+}
+
+// Reports a Windows error without throwing an exception.
+// Can be used to report errors from destructors.
+FMT_API void report_windows_error(int error_code,
+                                  const char* message) FMT_NOEXCEPT;
+#else
+inline const std::error_category& system_category() FMT_NOEXCEPT {
+  return std::system_category();
+}
+#endif  // _WIN32
+
+// std::system is not available on some platforms such as iOS (#2248).
+#ifdef __OSX__
+template <typename S, typename... Args, typename Char = char_t<S>>
+void say(const S& format_str, Args&&... args) {
+  std::system(format("say \"{}\"", format(format_str, args...)).c_str());
+}
+#endif
+
+// A buffered file.
+class buffered_file {
+ private:
+  FILE* file_;
+
+  friend class file;
+
+  explicit buffered_file(FILE* f) : file_(f) {}
+
+ public:
+  buffered_file(const buffered_file&) = delete;
+  void operator=(const buffered_file&) = delete;
+
+  // Constructs a buffered_file object which doesn't represent any file.
+  buffered_file() FMT_NOEXCEPT : file_(nullptr) {}
+
+  // Destroys the object closing the file it represents if any.
+  FMT_API ~buffered_file() FMT_NOEXCEPT;
+
+ public:
+  buffered_file(buffered_file&& other) FMT_NOEXCEPT : file_(other.file_) {
+    other.file_ = nullptr;
+  }
+
+  buffered_file& operator=(buffered_file&& other) {
+    close();
+    file_ = other.file_;
+    other.file_ = nullptr;
+    return *this;
+  }
+
+  // Opens a file.
+  FMT_API buffered_file(cstring_view filename, cstring_view mode);
+
+  // Closes the file.
+  FMT_API void close();
+
+  // Returns the pointer to a FILE object representing this file.
+  FILE* get() const FMT_NOEXCEPT { return file_; }
+
+  // We place parentheses around fileno to workaround a bug in some versions
+  // of MinGW that define fileno as a macro.
+  FMT_API int(fileno)() const;
+
+  void vprint(string_view format_str, format_args args) {
+    fmt::vprint(file_, format_str, args);
+  }
+
+  template <typename... Args>
+  inline void print(string_view format_str, const Args&... args) {
+    vprint(format_str, fmt::make_format_args(args...));
+  }
+};
+
+#if FMT_USE_FCNTL
+// A file. Closed file is represented by a file object with descriptor -1.
+// Methods that are not declared with FMT_NOEXCEPT may throw
+// fmt::system_error in case of failure. Note that some errors such as
+// closing the file multiple times will cause a crash on Windows rather
+// than an exception. You can get standard behavior by overriding the
+// invalid parameter handler with _set_invalid_parameter_handler.
+class file {
+ private:
+  int fd_;  // File descriptor.
+
+  // Constructs a file object with a given descriptor.
+  explicit file(int fd) : fd_(fd) {}
+
+ public:
+  // Possible values for the oflag argument to the constructor.
+  enum {
+    RDONLY = FMT_POSIX(O_RDONLY),  // Open for reading only.
+    WRONLY = FMT_POSIX(O_WRONLY),  // Open for writing only.
+    RDWR = FMT_POSIX(O_RDWR),      // Open for reading and writing.
+    CREATE = FMT_POSIX(O_CREAT),   // Create if the file doesn't exist.
+    APPEND = FMT_POSIX(O_APPEND),  // Open in append mode.
+    TRUNC = FMT_POSIX(O_TRUNC)     // Truncate the content of the file.
+  };
+
+  // Constructs a file object which doesn't represent any file.
+  file() FMT_NOEXCEPT : fd_(-1) {}
+
+  // Opens a file and constructs a file object representing this file.
+  FMT_API file(cstring_view path, int oflag);
+
+ public:
+  file(const file&) = delete;
+  void operator=(const file&) = delete;
+
+  file(file&& other) FMT_NOEXCEPT : fd_(other.fd_) { other.fd_ = -1; }
+
+  // Move assignment is not noexcept because close may throw.
+  file& operator=(file&& other) {
+    close();
+    fd_ = other.fd_;
+    other.fd_ = -1;
+    return *this;
+  }
+
+  // Destroys the object closing the file it represents if any.
+  FMT_API ~file() FMT_NOEXCEPT;
+
+  // Returns the file descriptor.
+  int descriptor() const FMT_NOEXCEPT { return fd_; }
+
+  // Closes the file.
+  FMT_API void close();
+
+  // Returns the file size. The size has signed type for consistency with
+  // stat::st_size.
+  FMT_API long long size() const;
+
+  // Attempts to read count bytes from the file into the specified buffer.
+  FMT_API size_t read(void* buffer, size_t count);
+
+  // Attempts to write count bytes from the specified buffer to the file.
+  FMT_API size_t write(const void* buffer, size_t count);
+
+  // Duplicates a file descriptor with the dup function and returns
+  // the duplicate as a file object.
+  FMT_API static file dup(int fd);
+
+  // Makes fd be the copy of this file descriptor, closing fd first if
+  // necessary.
+  FMT_API void dup2(int fd);
+
+  // Makes fd be the copy of this file descriptor, closing fd first if
+  // necessary.
+  FMT_API void dup2(int fd, std::error_code& ec) FMT_NOEXCEPT;
+
+  // Creates a pipe setting up read_end and write_end file objects for reading
+  // and writing respectively.
+  FMT_API static void pipe(file& read_end, file& write_end);
+
+  // Creates a buffered_file object associated with this file and detaches
+  // this file object from the file.
+  FMT_API buffered_file fdopen(const char* mode);
+};
+
+// Returns the memory page size.
+long getpagesize();
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+struct buffer_size {
+  buffer_size() = default;
+  size_t value = 0;
+  buffer_size operator=(size_t val) const {
+    auto bs = buffer_size();
+    bs.value = val;
+    return bs;
+  }
+};
+
+struct ostream_params {
+  int oflag = file::WRONLY | file::CREATE | file::TRUNC;
+  size_t buffer_size = BUFSIZ > 32768 ? BUFSIZ : 32768;
+
+  ostream_params() {}
+
+  template <typename... T>
+  ostream_params(T... params, int new_oflag) : ostream_params(params...) {
+    oflag = new_oflag;
+  }
+
+  template <typename... T>
+  ostream_params(T... params, detail::buffer_size bs)
+      : ostream_params(params...) {
+    this->buffer_size = bs.value;
+  }
+
+// Intel has a bug that results in failure to deduce a constructor
+// for empty parameter packs.
+#  if defined(__INTEL_COMPILER) && __INTEL_COMPILER < 2000
+  ostream_params(int new_oflag) : oflag(new_oflag) {}
+  ostream_params(detail::buffer_size bs) : buffer_size(bs.value) {}
+#  endif
+};
+
+FMT_END_DETAIL_NAMESPACE
+
+// Added {} below to work around default constructor error known to
+// occur in Xcode versions 7.2.1 and 8.2.1.
+constexpr detail::buffer_size buffer_size{};
+
+/** A fast output stream which is not thread-safe. */
+class FMT_API ostream final : private detail::buffer<char> {
+ private:
+  file file_;
+
+  void grow(size_t) override;
+
+  ostream(cstring_view path, const detail::ostream_params& params)
+      : file_(path, params.oflag) {
+    set(new char[params.buffer_size], params.buffer_size);
+  }
+
+ public:
+  ostream(ostream&& other)
+      : detail::buffer<char>(other.data(), other.size(), other.capacity()),
+        file_(std::move(other.file_)) {
+    other.clear();
+    other.set(nullptr, 0);
+  }
+  ~ostream() {
+    flush();
+    delete[] data();
+  }
+
+  void flush() {
+    if (size() == 0) return;
+    file_.write(data(), size());
+    clear();
+  }
+
+  template <typename... T>
+  friend ostream output_file(cstring_view path, T... params);
+
+  void close() {
+    flush();
+    file_.close();
+  }
+
+  /**
+    Formats ``args`` according to specifications in ``fmt`` and writes the
+    output to the file.
+   */
+  template <typename... T> void print(format_string<T...> fmt, T&&... args) {
+    vformat_to(detail::buffer_appender<char>(*this), fmt,
+               fmt::make_format_args(args...));
+  }
+};
+
+/**
+  \rst
+  Opens a file for writing. Supported parameters passed in *params*:
+
+  * ``<integer>``: Flags passed to `open
+    <https://pubs.opengroup.org/onlinepubs/007904875/functions/open.html>`_
+    (``file::WRONLY | file::CREATE`` by default)
+  * ``buffer_size=<integer>``: Output buffer size
+
+  **Example**::
+
+    auto out = fmt::output_file("guide.txt");
+    out.print("Don't {}", "Panic");
+  \endrst
+ */
+template <typename... T>
+inline ostream output_file(cstring_view path, T... params) {
+  return {path, detail::ostream_params(params...)};
+}
+#endif  // FMT_USE_FCNTL
+
+#ifdef FMT_LOCALE
+// A "C" numeric locale.
+class locale {
+ private:
+#  ifdef _WIN32
+  using locale_t = _locale_t;
+
+  static void freelocale(locale_t loc) { _free_locale(loc); }
+
+  static double strtod_l(const char* nptr, char** endptr, _locale_t loc) {
+    return _strtod_l(nptr, endptr, loc);
+  }
+#  endif
+
+  locale_t locale_;
+
+ public:
+  using type = locale_t;
+  locale(const locale&) = delete;
+  void operator=(const locale&) = delete;
+
+  locale() {
+#  ifndef _WIN32
+    locale_ = FMT_SYSTEM(newlocale(LC_NUMERIC_MASK, "C", nullptr));
+#  else
+    locale_ = _create_locale(LC_NUMERIC, "C");
+#  endif
+    if (!locale_) FMT_THROW(system_error(errno, "cannot create locale"));
+  }
+  ~locale() { freelocale(locale_); }
+
+  type get() const { return locale_; }
+
+  // Converts string to floating-point number and advances str past the end
+  // of the parsed input.
+  FMT_DEPRECATED double strtod(const char*& str) const {
+    char* end = nullptr;
+    double result = strtod_l(str, &end, locale_);
+    str = end;
+    return result;
+  }
+};
+using Locale FMT_DEPRECATED_ALIAS = locale;
+#endif  // FMT_LOCALE
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_OS_H_

include/spdlog/fmt/bundled/ostream.h

@@ -14,73 +14,46 @@
 
 FMT_BEGIN_NAMESPACE
 
-template <typename CHar> class basic_printf_parse_context;
 template <typename OutputIt, typename Char> class basic_printf_context;
 
-namespace internal {
+namespace detail {
 
-template <class Char> class formatbuf : public std::basic_streambuf<Char> {
- private:
-  using int_type = typename std::basic_streambuf<Char>::int_type;
-  using traits_type = typename std::basic_streambuf<Char>::traits_type;
-
-  buffer<Char>& buffer_;
-
- public:
-  formatbuf(buffer<Char>& buf) : buffer_(buf) {}
-
- protected:
-  // The put-area is actually always empty. This makes the implementation
-  // simpler and has the advantage that the streambuf and the buffer are always
-  // in sync and sputc never writes into uninitialized memory. The obvious
-  // disadvantage is that each call to sputc always results in a (virtual) call
-  // to overflow. There is no disadvantage here for sputn since this always
-  // results in a call to xsputn.
-
-  int_type overflow(int_type ch = traits_type::eof()) FMT_OVERRIDE {
-    if (!traits_type::eq_int_type(ch, traits_type::eof()))
-      buffer_.push_back(static_cast<Char>(ch));
-    return ch;
-  }
-
-  std::streamsize xsputn(const Char* s, std::streamsize count) FMT_OVERRIDE {
-    buffer_.append(s, s + count);
-    return count;
-  }
-};
-
-template <typename Char> struct test_stream : std::basic_ostream<Char> {
- private:
-  // Hide all operator<< from std::basic_ostream<Char>.
-  void_t<> operator<<(null<>);
-  void_t<> operator<<(const Char*);
-
-  template <typename T, FMT_ENABLE_IF(std::is_convertible<T, int>::value &&
-                                      !std::is_enum<T>::value)>
-  void_t<> operator<<(T);
-};
-
-// Checks if T has a user-defined operator<< (e.g. not a member of
-// std::ostream).
-template <typename T, typename Char> class is_streamable {
+// Checks if T has a user-defined operator<<.
+template <typename T, typename Char, typename Enable = void>
+class is_streamable {
  private:
   template <typename U>
-  static bool_constant<!std::is_same<decltype(std::declval<test_stream<Char>&>()
-                                              << std::declval<U>()),
-                                     void_t<>>::value>
-  test(int);
+  static auto test(int)
+      -> bool_constant<sizeof(std::declval<std::basic_ostream<Char>&>()
+                              << std::declval<U>()) != 0>;
 
-  template <typename> static std::false_type test(...);
+  template <typename> static auto test(...) -> std::false_type;
 
   using result = decltype(test<T>(0));
 
  public:
+  is_streamable() = default;
+
   static const bool value = result::value;
 };
 
+// Formatting of built-in types and arrays is intentionally disabled because
+// it's handled by standard (non-ostream) formatters.
+template <typename T, typename Char>
+struct is_streamable<
+    T, Char,
+    enable_if_t<
+        std::is_arithmetic<T>::value || std::is_array<T>::value ||
+        std::is_pointer<T>::value || std::is_same<T, char8_type>::value ||
+        std::is_same<T, std::basic_string<Char>>::value ||
+        std::is_same<T, std_string_view<Char>>::value ||
+        (std::is_convertible<T, int>::value && !std::is_enum<T>::value)>>
+    : std::false_type {};
+
 // Write the content of buf to os.
+// It is a separate function rather than a part of vprint to simplify testing.
 template <typename Char>
-void write(std::basic_ostream<Char>& os, buffer<Char>& buf) {
+void write_buffer(std::basic_ostream<Char>& os, buffer<Char>& buf) {
   const Char* buf_data = buf.data();
   using unsigned_streamsize = std::make_unsigned<std::streamsize>::type;
   unsigned_streamsize size = buf.size();
@@ -96,54 +69,49 @@ void write(std::basic_ostream<Char>& os, buffer<Char>& buf) {
 template <typename Char, typename T>
 void format_value(buffer<Char>& buf, const T& value,
                   locale_ref loc = locale_ref()) {
-  formatbuf<Char> format_buf(buf);
-  std::basic_ostream<Char> output(&format_buf);
+  auto&& format_buf = formatbuf<std::basic_streambuf<Char>>(buf);
+  auto&& output = std::basic_ostream<Char>(&format_buf);
 #if !defined(FMT_STATIC_THOUSANDS_SEPARATOR)
   if (loc) output.imbue(loc.get<std::locale>());
 #endif
-  output.exceptions(std::ios_base::failbit | std::ios_base::badbit);
   output << value;
-  buf.resize(buf.size());
+  output.exceptions(std::ios_base::failbit | std::ios_base::badbit);
+  buf.try_resize(buf.size());
 }
 
 // Formats an object of type T that has an overloaded ostream operator<<.
 template <typename T, typename Char>
 struct fallback_formatter<T, Char, enable_if_t<is_streamable<T, Char>::value>>
     : private formatter<basic_string_view<Char>, Char> {
-  auto parse(basic_format_parse_context<Char>& ctx) -> decltype(ctx.begin()) {
-    return formatter<basic_string_view<Char>, Char>::parse(ctx);
-  }
-  template <typename ParseCtx,
-            FMT_ENABLE_IF(std::is_same<
-                          ParseCtx, basic_printf_parse_context<Char>>::value)>
-  auto parse(ParseCtx& ctx) -> decltype(ctx.begin()) {
-    return ctx.begin();
-  }
+  using formatter<basic_string_view<Char>, Char>::parse;
 
   template <typename OutputIt>
   auto format(const T& value, basic_format_context<OutputIt, Char>& ctx)
       -> OutputIt {
-    basic_memory_buffer<Char> buffer;
+    auto buffer = basic_memory_buffer<Char>();
     format_value(buffer, value, ctx.locale());
-    basic_string_view<Char> str(buffer.data(), buffer.size());
-    return formatter<basic_string_view<Char>, Char>::format(str, ctx);
+    return formatter<basic_string_view<Char>, Char>::format(
+        {buffer.data(), buffer.size()}, ctx);
   }
+
+  // DEPRECATED!
   template <typename OutputIt>
   auto format(const T& value, basic_printf_context<OutputIt, Char>& ctx)
       -> OutputIt {
-    basic_memory_buffer<Char> buffer;
+    auto buffer = basic_memory_buffer<Char>();
     format_value(buffer, value, ctx.locale());
     return std::copy(buffer.begin(), buffer.end(), ctx.out());
   }
 };
-}  // namespace internal
+}  // namespace detail
 
+FMT_MODULE_EXPORT
 template <typename Char>
 void vprint(std::basic_ostream<Char>& os, basic_string_view<Char> format_str,
             basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-  basic_memory_buffer<Char> buffer;
-  internal::vformat_to(buffer, format_str, args);
-  internal::write(os, buffer);
+  auto buffer = basic_memory_buffer<Char>();
+  detail::vformat_to(buffer, format_str, args);
+  detail::write_buffer(os, buffer);
 }
 
 /**
@@ -155,11 +123,12 @@ void vprint(std::basic_ostream<Char>& os, basic_string_view<Char> format_str,
     fmt::print(cerr, "Don't {}!", "panic");
   \endrst
  */
+FMT_MODULE_EXPORT
 template <typename S, typename... Args,
-          typename Char = enable_if_t<internal::is_string<S>::value, char_t<S>>>
+          typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
 void print(std::basic_ostream<Char>& os, const S& format_str, Args&&... args) {
   vprint(os, to_string_view(format_str),
-         internal::make_args_checked<Args...>(format_str, args...));
+         fmt::make_args_checked<Args...>(format_str, args...));
 }
 FMT_END_NAMESPACE
 

include/spdlog/fmt/bundled/posix.h

@@ -1,2 +0,0 @@
-#include "os.h"
-#warning "fmt/posix.h is deprecated; use fmt/os.h instead"

include/spdlog/fmt/bundled/printf.h

@@ -10,11 +10,54 @@
 
 #include <algorithm>  // std::max
 #include <limits>     // std::numeric_limits
+#include <ostream>
 
-#include "ostream.h"
+#include "format.h"
 
 FMT_BEGIN_NAMESPACE
-namespace internal {
+FMT_MODULE_EXPORT_BEGIN
+
+template <typename T> struct printf_formatter { printf_formatter() = delete; };
+
+template <typename Char>
+class basic_printf_parse_context : public basic_format_parse_context<Char> {
+  using basic_format_parse_context<Char>::basic_format_parse_context;
+};
+
+template <typename OutputIt, typename Char> class basic_printf_context {
+ private:
+  OutputIt out_;
+  basic_format_args<basic_printf_context> args_;
+
+ public:
+  using char_type = Char;
+  using format_arg = basic_format_arg<basic_printf_context>;
+  using parse_context_type = basic_printf_parse_context<Char>;
+  template <typename T> using formatter_type = printf_formatter<T>;
+
+  /**
+    \rst
+    Constructs a ``printf_context`` object. References to the arguments are
+    stored in the context object so make sure they have appropriate lifetimes.
+    \endrst
+   */
+  basic_printf_context(OutputIt out,
+                       basic_format_args<basic_printf_context> args)
+      : out_(out), args_(args) {}
+
+  OutputIt out() { return out_; }
+  void advance_to(OutputIt it) { out_ = it; }
+
+  detail::locale_ref locale() { return {}; }
+
+  format_arg arg(int id) const { return args_.get(id); }
+
+  FMT_CONSTEXPR void on_error(const char* message) {
+    detail::error_handler().on_error(message);
+  }
+};
+
+FMT_BEGIN_DETAIL_NAMESPACE
 
 // Checks if a value fits in int - used to avoid warnings about comparing
 // signed and unsigned integers.
@@ -90,11 +133,11 @@ template <typename T, typename Context> class arg_converter {
     if (const_check(sizeof(target_type) <= sizeof(int))) {
       // Extra casts are used to silence warnings.
       if (is_signed) {
-        arg_ = internal::make_arg<Context>(
+        arg_ = detail::make_arg<Context>(
             static_cast<int>(static_cast<target_type>(value)));
       } else {
         using unsigned_type = typename make_unsigned_or_bool<target_type>::type;
-        arg_ = internal::make_arg<Context>(
+        arg_ = detail::make_arg<Context>(
             static_cast<unsigned>(static_cast<unsigned_type>(value)));
       }
     } else {
@@ -102,9 +145,9 @@ template <typename T, typename Context> class arg_converter {
         // glibc's printf doesn't sign extend arguments of smaller types:
         //   std::printf("%lld", -42);  // prints "4294967254"
         // but we don't have to do the same because it's a UB.
-        arg_ = internal::make_arg<Context>(static_cast<long long>(value));
+        arg_ = detail::make_arg<Context>(static_cast<long long>(value));
       } else {
-        arg_ = internal::make_arg<Context>(
+        arg_ = detail::make_arg<Context>(
             static_cast<typename make_unsigned_or_bool<U>::type>(value));
       }
     }
@@ -133,7 +176,7 @@ template <typename Context> class char_converter {
 
   template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
   void operator()(T value) {
-    arg_ = internal::make_arg<Context>(
+    arg_ = detail::make_arg<Context>(
         static_cast<typename Context::char_type>(value));
   }
 
@@ -141,6 +184,13 @@ template <typename Context> class char_converter {
   void operator()(T) {}  // No conversion needed for non-integral types.
 };
 
+// An argument visitor that return a pointer to a C string if argument is a
+// string or null otherwise.
+template <typename Char> struct get_cstring {
+  template <typename T> const Char* operator()(T) { return nullptr; }
+  const Char* operator()(const Char* s) { return s; }
+};
+
 // Checks if an argument is a valid printf width specifier and sets
 // left alignment if it is negative.
 template <typename Char> class printf_width_handler {
@@ -155,7 +205,7 @@ template <typename Char> class printf_width_handler {
   template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
   unsigned operator()(T value) {
     auto width = static_cast<uint32_or_64_or_128_t<T>>(value);
-    if (internal::is_negative(value)) {
+    if (detail::is_negative(value)) {
       specs_.align = align::left;
       width = 0 - width;
     }
@@ -171,217 +221,88 @@ template <typename Char> class printf_width_handler {
   }
 };
 
-template <typename Char, typename Context>
-void printf(buffer<Char>& buf, basic_string_view<Char> format,
-            basic_format_args<Context> args) {
-  Context(std::back_inserter(buf), format, args).format();
-}
-
-template <typename OutputIt, typename Char, typename Context>
-internal::truncating_iterator<OutputIt> printf(
-    internal::truncating_iterator<OutputIt> it, basic_string_view<Char> format,
-    basic_format_args<Context> args) {
-  return Context(it, format, args).format();
-}
-}  // namespace internal
-
-using internal::printf;  // For printing into memory_buffer.
-
-template <typename Range> class printf_arg_formatter;
-
-template <typename Char>
-class basic_printf_parse_context : public basic_format_parse_context<Char> {
-  using basic_format_parse_context<Char>::basic_format_parse_context;
-};
-template <typename OutputIt, typename Char> class basic_printf_context;
-
-/**
-  \rst
-  The ``printf`` argument formatter.
-  \endrst
- */
-template <typename Range>
-class printf_arg_formatter : public internal::arg_formatter_base<Range> {
- public:
-  using iterator = typename Range::iterator;
-
+// The ``printf`` argument formatter.
+template <typename OutputIt, typename Char>
+class printf_arg_formatter : public arg_formatter<Char> {
  private:
-  using char_type = typename Range::value_type;
-  using base = internal::arg_formatter_base<Range>;
-  using context_type = basic_printf_context<iterator, char_type>;
+  using base = arg_formatter<Char>;
+  using context_type = basic_printf_context<OutputIt, Char>;
+  using format_specs = basic_format_specs<Char>;
 
   context_type& context_;
 
-  void write_null_pointer(char) {
-    this->specs()->type = 0;
-    this->write("(nil)");
-  }
-
-  void write_null_pointer(wchar_t) {
-    this->specs()->type = 0;
-    this->write(L"(nil)");
+  OutputIt write_null_pointer(bool is_string = false) {
+    auto s = this->specs;
+    s.type = presentation_type::none;
+    return write_bytes(this->out, is_string ? "(null)" : "(nil)", s);
   }
 
  public:
-  using format_specs = typename base::format_specs;
+  printf_arg_formatter(OutputIt iter, format_specs& s, context_type& ctx)
+      : base{iter, s, locale_ref()}, context_(ctx) {}
 
-  /**
-    \rst
-    Constructs an argument formatter object.
-    *buffer* is a reference to the output buffer and *specs* contains format
-    specifier information for standard argument types.
-    \endrst
-   */
-  printf_arg_formatter(iterator iter, format_specs& specs, context_type& ctx)
-      : base(Range(iter), &specs, internal::locale_ref()), context_(ctx) {}
+  OutputIt operator()(monostate value) { return base::operator()(value); }
 
-  template <typename T, FMT_ENABLE_IF(fmt::internal::is_integral<T>::value)>
-  iterator operator()(T value) {
-    // MSVC2013 fails to compile separate overloads for bool and char_type so
-    // use std::is_same instead.
-    if (std::is_same<T, bool>::value) {
-      format_specs& fmt_specs = *this->specs();
-      if (fmt_specs.type != 's') return base::operator()(value ? 1 : 0);
-      fmt_specs.type = 0;
-      this->write(value != 0);
-    } else if (std::is_same<T, char_type>::value) {
-      format_specs& fmt_specs = *this->specs();
-      if (fmt_specs.type && fmt_specs.type != 'c')
+  template <typename T, FMT_ENABLE_IF(detail::is_integral<T>::value)>
+  OutputIt operator()(T value) {
+    // MSVC2013 fails to compile separate overloads for bool and Char so use
+    // std::is_same instead.
+    if (std::is_same<T, Char>::value) {
+      format_specs fmt_specs = this->specs;
+      if (fmt_specs.type != presentation_type::none &&
+          fmt_specs.type != presentation_type::chr) {
         return (*this)(static_cast<int>(value));
+      }
       fmt_specs.sign = sign::none;
       fmt_specs.alt = false;
-      fmt_specs.align = align::right;
-      return base::operator()(value);
-    } else {
-      return base::operator()(value);
+      fmt_specs.fill[0] = ' ';  // Ignore '0' flag for char types.
+      // align::numeric needs to be overwritten here since the '0' flag is
+      // ignored for non-numeric types
+      if (fmt_specs.align == align::none || fmt_specs.align == align::numeric)
+        fmt_specs.align = align::right;
+      return write<Char>(this->out, static_cast<Char>(value), fmt_specs);
     }
-    return this->out();
+    return base::operator()(value);
   }
 
   template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value)>
-  iterator operator()(T value) {
+  OutputIt operator()(T value) {
     return base::operator()(value);
   }
 
   /** Formats a null-terminated C string. */
-  iterator operator()(const char* value) {
-    if (value)
-      base::operator()(value);
-    else if (this->specs()->type == 'p')
-      write_null_pointer(char_type());
-    else
-      this->write("(null)");
-    return this->out();
+  OutputIt operator()(const char* value) {
+    if (value) return base::operator()(value);
+    return write_null_pointer(this->specs.type != presentation_type::pointer);
   }
 
   /** Formats a null-terminated wide C string. */
-  iterator operator()(const wchar_t* value) {
-    if (value)
-      base::operator()(value);
-    else if (this->specs()->type == 'p')
-      write_null_pointer(char_type());
-    else
-      this->write(L"(null)");
-    return this->out();
+  OutputIt operator()(const wchar_t* value) {
+    if (value) return base::operator()(value);
+    return write_null_pointer(this->specs.type != presentation_type::pointer);
   }
 
-  iterator operator()(basic_string_view<char_type> value) {
+  OutputIt operator()(basic_string_view<Char> value) {
     return base::operator()(value);
   }
 
-  iterator operator()(monostate value) { return base::operator()(value); }
-
   /** Formats a pointer. */
-  iterator operator()(const void* value) {
-    if (value) return base::operator()(value);
-    this->specs()->type = 0;
-    write_null_pointer(char_type());
-    return this->out();
+  OutputIt operator()(const void* value) {
+    return value ? base::operator()(value) : write_null_pointer();
   }
 
   /** Formats an argument of a custom (user-defined) type. */
-  iterator operator()(typename basic_format_arg<context_type>::handle handle) {
-    handle.format(context_.parse_context(), context_);
-    return this->out();
+  OutputIt operator()(typename basic_format_arg<context_type>::handle handle) {
+    auto parse_ctx =
+        basic_printf_parse_context<Char>(basic_string_view<Char>());
+    handle.format(parse_ctx, context_);
+    return this->out;
   }
 };
 
-template <typename T> struct printf_formatter {
-  printf_formatter() = delete;
-
-  template <typename ParseContext>
-  auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
-    return ctx.begin();
-  }
-
-  template <typename FormatContext>
-  auto format(const T& value, FormatContext& ctx) -> decltype(ctx.out()) {
-    internal::format_value(internal::get_container(ctx.out()), value);
-    return ctx.out();
-  }
-};
-
-/** This template formats data and writes the output to a writer. */
-template <typename OutputIt, typename Char> class basic_printf_context {
- public:
-  /** The character type for the output. */
-  using char_type = Char;
-  using iterator = OutputIt;
-  using format_arg = basic_format_arg<basic_printf_context>;
-  using parse_context_type = basic_printf_parse_context<Char>;
-  template <typename T> using formatter_type = printf_formatter<T>;
-
- private:
-  using format_specs = basic_format_specs<char_type>;
-
-  OutputIt out_;
-  basic_format_args<basic_printf_context> args_;
-  parse_context_type parse_ctx_;
-
-  static void parse_flags(format_specs& specs, const Char*& it,
-                          const Char* end);
-
-  // Returns the argument with specified index or, if arg_index is -1, the next
-  // argument.
-  format_arg get_arg(int arg_index = -1);
-
-  // Parses argument index, flags and width and returns the argument index.
-  int parse_header(const Char*& it, const Char* end, format_specs& specs);
-
- public:
-  /**
-   \rst
-   Constructs a ``printf_context`` object. References to the arguments and
-   the writer are stored in the context object so make sure they have
-   appropriate lifetimes.
-   \endrst
-   */
-  basic_printf_context(OutputIt out, basic_string_view<char_type> format_str,
-                       basic_format_args<basic_printf_context> args)
-      : out_(out), args_(args), parse_ctx_(format_str) {}
-
-  OutputIt out() { return out_; }
-  void advance_to(OutputIt it) { out_ = it; }
-
-  internal::locale_ref locale() { return {}; }
-
-  format_arg arg(int id) const { return args_.get(id); }
-
-  parse_context_type& parse_context() { return parse_ctx_; }
-
-  FMT_CONSTEXPR void on_error(const char* message) {
-    parse_ctx_.on_error(message);
-  }
-
-  /** Formats stored arguments and writes the output to the range. */
-  template <typename ArgFormatter = printf_arg_formatter<buffer_range<Char>>>
-  OutputIt format();
-};
-
-template <typename OutputIt, typename Char>
-void basic_printf_context<OutputIt, Char>::parse_flags(format_specs& specs,
-                                                       const Char*& it,
-                                                       const Char* end) {
+template <typename Char>
+void parse_flags(basic_format_specs<Char>& specs, const Char*& it,
+                 const Char* end) {
   for (; it != end; ++it) {
     switch (*it) {
     case '-':
@@ -394,7 +315,9 @@ void basic_printf_context<OutputIt, Char>::parse_flags(format_specs& specs,
       specs.fill[0] = '0';
       break;
     case ' ':
-      specs.sign = sign::space;
+      if (specs.sign != sign::plus) {
+        specs.sign = sign::space;
+      }
       break;
     case '#':
       specs.alt = true;
@@ -405,35 +328,24 @@ void basic_printf_context<OutputIt, Char>::parse_flags(format_specs& specs,
   }
 }
 
-template <typename OutputIt, typename Char>
-typename basic_printf_context<OutputIt, Char>::format_arg
-basic_printf_context<OutputIt, Char>::get_arg(int arg_index) {
-  if (arg_index < 0)
-    arg_index = parse_ctx_.next_arg_id();
-  else
-    parse_ctx_.check_arg_id(--arg_index);
-  return internal::get_arg(*this, arg_index);
-}
-
-template <typename OutputIt, typename Char>
-int basic_printf_context<OutputIt, Char>::parse_header(const Char*& it,
-                                                       const Char* end,
-                                                       format_specs& specs) {
+template <typename Char, typename GetArg>
+int parse_header(const Char*& it, const Char* end,
+                 basic_format_specs<Char>& specs, GetArg get_arg) {
   int arg_index = -1;
-  char_type c = *it;
+  Char c = *it;
   if (c >= '0' && c <= '9') {
     // Parse an argument index (if followed by '$') or a width possibly
     // preceded with '0' flag(s).
-    internal::error_handler eh;
-    int value = parse_nonnegative_int(it, end, eh);
+    int value = parse_nonnegative_int(it, end, -1);
     if (it != end && *it == '$') {  // value is an argument index
       ++it;
-      arg_index = value;
+      arg_index = value != -1 ? value : max_value<int>();
     } else {
       if (c == '0') specs.fill[0] = '0';
       if (value != 0) {
         // Nonzero value means that we parsed width and don't need to
         // parse it or flags again, so return now.
+        if (value == -1) FMT_THROW(format_error("number is too big"));
         specs.width = value;
         return arg_index;
       }
@@ -443,71 +355,104 @@ int basic_printf_context<OutputIt, Char>::parse_header(const Char*& it,
   // Parse width.
   if (it != end) {
     if (*it >= '0' && *it <= '9') {
-      internal::error_handler eh;
-      specs.width = parse_nonnegative_int(it, end, eh);
+      specs.width = parse_nonnegative_int(it, end, -1);
+      if (specs.width == -1) FMT_THROW(format_error("number is too big"));
     } else if (*it == '*') {
       ++it;
       specs.width = static_cast<int>(visit_format_arg(
-          internal::printf_width_handler<char_type>(specs), get_arg()));
+          detail::printf_width_handler<Char>(specs), get_arg(-1)));
     }
   }
   return arg_index;
 }
 
-template <typename OutputIt, typename Char>
-template <typename ArgFormatter>
-OutputIt basic_printf_context<OutputIt, Char>::format() {
-  auto out = this->out();
-  const Char* start = parse_ctx_.begin();
-  const Char* end = parse_ctx_.end();
+template <typename Char, typename Context>
+void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
+             basic_format_args<Context> args) {
+  using OutputIt = buffer_appender<Char>;
+  auto out = OutputIt(buf);
+  auto context = basic_printf_context<OutputIt, Char>(out, args);
+  auto parse_ctx = basic_printf_parse_context<Char>(format);
+
+  // Returns the argument with specified index or, if arg_index is -1, the next
+  // argument.
+  auto get_arg = [&](int arg_index) {
+    if (arg_index < 0)
+      arg_index = parse_ctx.next_arg_id();
+    else
+      parse_ctx.check_arg_id(--arg_index);
+    return detail::get_arg(context, arg_index);
+  };
+
+  const Char* start = parse_ctx.begin();
+  const Char* end = parse_ctx.end();
   auto it = start;
   while (it != end) {
-    char_type c = *it++;
-    if (c != '%') continue;
+    if (!detail::find<false, Char>(it, end, '%', it)) {
+      it = end;  // detail::find leaves it == nullptr if it doesn't find '%'
+      break;
+    }
+    Char c = *it++;
     if (it != end && *it == c) {
-      out = std::copy(start, it, out);
+      out = detail::write(
+          out, basic_string_view<Char>(start, detail::to_unsigned(it - start)));
       start = ++it;
       continue;
     }
-    out = std::copy(start, it - 1, out);
+    out = detail::write(out, basic_string_view<Char>(
+                                 start, detail::to_unsigned(it - 1 - start)));
 
-    format_specs specs;
+    basic_format_specs<Char> specs;
     specs.align = align::right;
 
     // Parse argument index, flags and width.
-    int arg_index = parse_header(it, end, specs);
-    if (arg_index == 0) on_error("argument index out of range");
+    int arg_index = parse_header(it, end, specs, get_arg);
+    if (arg_index == 0) parse_ctx.on_error("argument not found");
 
     // Parse precision.
     if (it != end && *it == '.') {
       ++it;
       c = it != end ? *it : 0;
       if ('0' <= c && c <= '9') {
-        internal::error_handler eh;
-        specs.precision = parse_nonnegative_int(it, end, eh);
+        specs.precision = parse_nonnegative_int(it, end, 0);
       } else if (c == '*') {
         ++it;
         specs.precision = static_cast<int>(
-            visit_format_arg(internal::printf_precision_handler(), get_arg()));
+            visit_format_arg(detail::printf_precision_handler(), get_arg(-1)));
       } else {
         specs.precision = 0;
       }
     }
 
-    format_arg arg = get_arg(arg_index);
-    if (specs.alt && visit_format_arg(internal::is_zero_int(), arg))
+    auto arg = get_arg(arg_index);
+    // For d, i, o, u, x, and X conversion specifiers, if a precision is
+    // specified, the '0' flag is ignored
+    if (specs.precision >= 0 && arg.is_integral())
+      specs.fill[0] =
+          ' ';  // Ignore '0' flag for non-numeric types or if '-' present.
+    if (specs.precision >= 0 && arg.type() == detail::type::cstring_type) {
+      auto str = visit_format_arg(detail::get_cstring<Char>(), arg);
+      auto str_end = str + specs.precision;
+      auto nul = std::find(str, str_end, Char());
+      arg = detail::make_arg<basic_printf_context<OutputIt, Char>>(
+          basic_string_view<Char>(
+              str, detail::to_unsigned(nul != str_end ? nul - str
+                                                      : specs.precision)));
+    }
+    if (specs.alt && visit_format_arg(detail::is_zero_int(), arg))
       specs.alt = false;
     if (specs.fill[0] == '0') {
-      if (arg.is_arithmetic())
+      if (arg.is_arithmetic() && specs.align != align::left)
         specs.align = align::numeric;
       else
-        specs.fill[0] = ' ';  // Ignore '0' flag for non-numeric types.
+        specs.fill[0] = ' ';  // Ignore '0' flag for non-numeric types or if '-'
+                              // flag is also present.
     }
 
     // Parse length and convert the argument to the required type.
     c = it != end ? *it++ : 0;
-    char_type t = it != end ? *it : 0;
-    using internal::convert_arg;
+    Char t = it != end ? *it : 0;
+    using detail::convert_arg;
     switch (c) {
     case 'h':
       if (t == 'h') {
@@ -531,7 +476,7 @@ OutputIt basic_printf_context<OutputIt, Char>::format() {
       convert_arg<intmax_t>(arg, t);
       break;
     case 'z':
-      convert_arg<std::size_t>(arg, t);
+      convert_arg<size_t>(arg, t);
       break;
     case 't':
       convert_arg<std::ptrdiff_t>(arg, t);
@@ -547,33 +492,38 @@ OutputIt basic_printf_context<OutputIt, Char>::format() {
 
     // Parse type.
     if (it == end) FMT_THROW(format_error("invalid format string"));
-    specs.type = static_cast<char>(*it++);
+    char type = static_cast<char>(*it++);
     if (arg.is_integral()) {
       // Normalize type.
-      switch (specs.type) {
+      switch (type) {
       case 'i':
       case 'u':
-        specs.type = 'd';
+        type = 'd';
         break;
       case 'c':
-        visit_format_arg(internal::char_converter<basic_printf_context>(arg),
-                         arg);
+        visit_format_arg(
+            detail::char_converter<basic_printf_context<OutputIt, Char>>(arg),
+            arg);
         break;
       }
     }
+    specs.type = parse_presentation_type(type);
+    if (specs.type == presentation_type::none)
+      parse_ctx.on_error("invalid type specifier");
 
     start = it;
 
     // Format argument.
-    visit_format_arg(ArgFormatter(out, specs, *this), arg);
+    out = visit_format_arg(
+        detail::printf_arg_formatter<OutputIt, Char>(out, specs, context), arg);
   }
-  return std::copy(start, it, out);
+  detail::write(out, basic_string_view<Char>(start, to_unsigned(it - start)));
 }
+FMT_END_DETAIL_NAMESPACE
 
 template <typename Char>
 using basic_printf_context_t =
-    basic_printf_context<std::back_insert_iterator<internal::buffer<Char>>,
-                         Char>;
+    basic_printf_context<detail::buffer_appender<Char>, Char>;
 
 using printf_context = basic_printf_context_t<char>;
 using wprintf_context = basic_printf_context_t<wchar_t>;
@@ -587,9 +537,9 @@ using wprintf_args = basic_format_args<wprintf_context>;
   arguments and can be implicitly converted to `~fmt::printf_args`.
   \endrst
  */
-template <typename... Args>
-inline format_arg_store<printf_context, Args...> make_printf_args(
-    const Args&... args) {
+template <typename... T>
+inline auto make_printf_args(const T&... args)
+    -> format_arg_store<printf_context, T...> {
   return {args...};
 }
 
@@ -599,18 +549,19 @@ inline format_arg_store<printf_context, Args...> make_printf_args(
   arguments and can be implicitly converted to `~fmt::wprintf_args`.
   \endrst
  */
-template <typename... Args>
-inline format_arg_store<wprintf_context, Args...> make_wprintf_args(
-    const Args&... args) {
+template <typename... T>
+inline auto make_wprintf_args(const T&... args)
+    -> format_arg_store<wprintf_context, T...> {
   return {args...};
 }
 
 template <typename S, typename Char = char_t<S>>
-inline std::basic_string<Char> vsprintf(
-    const S& format,
-    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args) {
+inline auto vsprintf(
+    const S& fmt,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
   basic_memory_buffer<Char> buffer;
-  printf(buffer, to_string_view(format), args);
+  vprintf(buffer, to_string_view(fmt), args);
   return to_string(buffer);
 }
 
@@ -623,20 +574,21 @@ inline std::basic_string<Char> vsprintf(
     std::string message = fmt::sprintf("The answer is %d", 42);
   \endrst
 */
-template <typename S, typename... Args,
-          typename Char = enable_if_t<internal::is_string<S>::value, char_t<S>>>
-inline std::basic_string<Char> sprintf(const S& format, const Args&... args) {
+template <typename S, typename... T,
+          typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
+inline auto sprintf(const S& fmt, const T&... args) -> std::basic_string<Char> {
   using context = basic_printf_context_t<Char>;
-  return vsprintf(to_string_view(format), make_format_args<context>(args...));
+  return vsprintf(to_string_view(fmt), fmt::make_format_args<context>(args...));
 }
 
 template <typename S, typename Char = char_t<S>>
-inline int vfprintf(
-    std::FILE* f, const S& format,
-    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args) {
+inline auto vfprintf(
+    std::FILE* f, const S& fmt,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> int {
   basic_memory_buffer<Char> buffer;
-  printf(buffer, to_string_view(format), args);
-  std::size_t size = buffer.size();
+  vprintf(buffer, to_string_view(fmt), args);
+  size_t size = buffer.size();
   return std::fwrite(buffer.data(), sizeof(Char), size, f) < size
              ? -1
              : static_cast<int>(size);
@@ -651,19 +603,19 @@ inline int vfprintf(
     fmt::fprintf(stderr, "Don't %s!", "panic");
   \endrst
  */
-template <typename S, typename... Args,
-          typename Char = enable_if_t<internal::is_string<S>::value, char_t<S>>>
-inline int fprintf(std::FILE* f, const S& format, const Args&... args) {
+template <typename S, typename... T, typename Char = char_t<S>>
+inline auto fprintf(std::FILE* f, const S& fmt, const T&... args) -> int {
   using context = basic_printf_context_t<Char>;
-  return vfprintf(f, to_string_view(format),
-                  make_format_args<context>(args...));
+  return vfprintf(f, to_string_view(fmt),
+                  fmt::make_format_args<context>(args...));
 }
 
 template <typename S, typename Char = char_t<S>>
-inline int vprintf(
-    const S& format,
-    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args) {
-  return vfprintf(stdout, to_string_view(format), args);
+inline auto vprintf(
+    const S& fmt,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> int {
+  return vfprintf(stdout, to_string_view(fmt), args);
 }
 
 /**
@@ -675,52 +627,31 @@ inline int vprintf(
     fmt::printf("Elapsed time: %.2f seconds", 1.23);
   \endrst
  */
-template <typename S, typename... Args,
-          FMT_ENABLE_IF(internal::is_string<S>::value)>
-inline int printf(const S& format_str, const Args&... args) {
-  using context = basic_printf_context_t<char_t<S>>;
-  return vprintf(to_string_view(format_str),
-                 make_format_args<context>(args...));
+template <typename S, typename... T, FMT_ENABLE_IF(detail::is_string<S>::value)>
+inline auto printf(const S& fmt, const T&... args) -> int {
+  return vprintf(
+      to_string_view(fmt),
+      fmt::make_format_args<basic_printf_context_t<char_t<S>>>(args...));
 }
 
 template <typename S, typename Char = char_t<S>>
-inline int vfprintf(
-    std::basic_ostream<Char>& os, const S& format,
-    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args) {
+FMT_DEPRECATED auto vfprintf(
+    std::basic_ostream<Char>& os, const S& fmt,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> int {
   basic_memory_buffer<Char> buffer;
-  printf(buffer, to_string_view(format), args);
-  internal::write(os, buffer);
+  vprintf(buffer, to_string_view(fmt), args);
+  os.write(buffer.data(), static_cast<std::streamsize>(buffer.size()));
   return static_cast<int>(buffer.size());
 }
-
-/** Formats arguments and writes the output to the range. */
-template <typename ArgFormatter, typename Char,
-          typename Context =
-              basic_printf_context<typename ArgFormatter::iterator, Char>>
-typename ArgFormatter::iterator vprintf(
-    internal::buffer<Char>& out, basic_string_view<Char> format_str,
-    basic_format_args<type_identity_t<Context>> args) {
-  typename ArgFormatter::iterator iter(out);
-  Context(iter, format_str, args).template format<ArgFormatter>();
-  return iter;
+template <typename S, typename... T, typename Char = char_t<S>>
+FMT_DEPRECATED auto fprintf(std::basic_ostream<Char>& os, const S& fmt,
+                            const T&... args) -> int {
+  return vfprintf(os, to_string_view(fmt),
+                  fmt::make_format_args<basic_printf_context_t<Char>>(args...));
 }
 
-/**
-  \rst
-  Prints formatted data to the stream *os*.
-
-  **Example**::
-
-    fmt::fprintf(cerr, "Don't %s!", "panic");
-  \endrst
- */
-template <typename S, typename... Args, typename Char = char_t<S>>
-inline int fprintf(std::basic_ostream<Char>& os, const S& format_str,
-                   const Args&... args) {
-  using context = basic_printf_context_t<Char>;
-  return vfprintf(os, to_string_view(format_str),
-                  make_format_args<context>(args...));
-}
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_PRINTF_H_

include/spdlog/fmt/bundled/ranges.h

@@ -13,48 +13,14 @@
 #define FMT_RANGES_H_
 
 #include <initializer_list>
+#include <tuple>
 #include <type_traits>
 
 #include "format.h"
 
-// output only up to N items from the range.
-#ifndef FMT_RANGE_OUTPUT_LENGTH_LIMIT
-#  define FMT_RANGE_OUTPUT_LENGTH_LIMIT 256
-#endif
-
 FMT_BEGIN_NAMESPACE
 
-template <typename Char> struct formatting_base {
-  template <typename ParseContext>
-  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
-    return ctx.begin();
-  }
-};
-
-template <typename Char, typename Enable = void>
-struct formatting_range : formatting_base<Char> {
-  static FMT_CONSTEXPR_DECL const std::size_t range_length_limit =
-      FMT_RANGE_OUTPUT_LENGTH_LIMIT;  // output only up to N items from the
-                                      // range.
-  Char prefix;
-  Char delimiter;
-  Char postfix;
-  formatting_range() : prefix('{'), delimiter(','), postfix('}') {}
-  static FMT_CONSTEXPR_DECL const bool add_delimiter_spaces = true;
-  static FMT_CONSTEXPR_DECL const bool add_prepostfix_space = false;
-};
-
-template <typename Char, typename Enable = void>
-struct formatting_tuple : formatting_base<Char> {
-  Char prefix;
-  Char delimiter;
-  Char postfix;
-  formatting_tuple() : prefix('('), delimiter(','), postfix(')') {}
-  static FMT_CONSTEXPR_DECL const bool add_delimiter_spaces = true;
-  static FMT_CONSTEXPR_DECL const bool add_prepostfix_space = false;
-};
-
-namespace internal {
+namespace detail {
 
 template <typename RangeT, typename OutputIterator>
 OutputIterator copy(const RangeT& range, OutputIterator out) {
@@ -75,8 +41,14 @@ OutputIterator copy(char ch, OutputIterator out) {
   return out;
 }
 
-/// Return true value if T has std::string interface, like std::string_view.
-template <typename T> class is_like_std_string {
+template <typename OutputIterator>
+OutputIterator copy(wchar_t ch, OutputIterator out) {
+  *out++ = ch;
+  return out;
+}
+
+// Returns true if T has a std::string-like interface, like std::string_view.
+template <typename T> class is_std_string_like {
   template <typename U>
   static auto check(U* p)
       -> decltype((void)p->find('a'), p->length(), (void)p->data(), int());
@@ -84,26 +56,118 @@ template <typename T> class is_like_std_string {
 
  public:
   static FMT_CONSTEXPR_DECL const bool value =
-      is_string<T>::value || !std::is_void<decltype(check<T>(nullptr))>::value;
+      is_string<T>::value ||
+      std::is_convertible<T, std_string_view<char>>::value ||
+      !std::is_void<decltype(check<T>(nullptr))>::value;
 };
 
 template <typename Char>
-struct is_like_std_string<fmt::basic_string_view<Char>> : std::true_type {};
+struct is_std_string_like<fmt::basic_string_view<Char>> : std::true_type {};
+
+template <typename T> class is_map {
+  template <typename U> static auto check(U*) -> typename U::mapped_type;
+  template <typename> static void check(...);
+
+ public:
+#ifdef FMT_FORMAT_MAP_AS_LIST
+  static FMT_CONSTEXPR_DECL const bool value = false;
+#else
+  static FMT_CONSTEXPR_DECL const bool value =
+      !std::is_void<decltype(check<T>(nullptr))>::value;
+#endif
+};
+
+template <typename T> class is_set {
+  template <typename U> static auto check(U*) -> typename U::key_type;
+  template <typename> static void check(...);
+
+ public:
+#ifdef FMT_FORMAT_SET_AS_LIST
+  static FMT_CONSTEXPR_DECL const bool value = false;
+#else
+  static FMT_CONSTEXPR_DECL const bool value =
+      !std::is_void<decltype(check<T>(nullptr))>::value && !is_map<T>::value;
+#endif
+};
 
 template <typename... Ts> struct conditional_helper {};
 
 template <typename T, typename _ = void> struct is_range_ : std::false_type {};
 
 #if !FMT_MSC_VER || FMT_MSC_VER > 1800
+
+#  define FMT_DECLTYPE_RETURN(val)  \
+    ->decltype(val) { return val; } \
+    static_assert(                  \
+        true, "")  // This makes it so that a semicolon is required after the
+                   // macro, which helps clang-format handle the formatting.
+
+// C array overload
+template <typename T, std::size_t N>
+auto range_begin(const T (&arr)[N]) -> const T* {
+  return arr;
+}
+template <typename T, std::size_t N>
+auto range_end(const T (&arr)[N]) -> const T* {
+  return arr + N;
+}
+
+template <typename T, typename Enable = void>
+struct has_member_fn_begin_end_t : std::false_type {};
+
 template <typename T>
-struct is_range_<
-    T, conditional_t<false,
-                     conditional_helper<decltype(std::declval<T>().begin()),
-                                        decltype(std::declval<T>().end())>,
-                     void>> : std::true_type {};
+struct has_member_fn_begin_end_t<T, void_t<decltype(std::declval<T>().begin()),
+                                           decltype(std::declval<T>().end())>>
+    : std::true_type {};
+
+// Member function overload
+template <typename T>
+auto range_begin(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).begin());
+template <typename T>
+auto range_end(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).end());
+
+// ADL overload. Only participates in overload resolution if member functions
+// are not found.
+template <typename T>
+auto range_begin(T&& rng)
+    -> enable_if_t<!has_member_fn_begin_end_t<T&&>::value,
+                   decltype(begin(static_cast<T&&>(rng)))> {
+  return begin(static_cast<T&&>(rng));
+}
+template <typename T>
+auto range_end(T&& rng) -> enable_if_t<!has_member_fn_begin_end_t<T&&>::value,
+                                       decltype(end(static_cast<T&&>(rng)))> {
+  return end(static_cast<T&&>(rng));
+}
+
+template <typename T, typename Enable = void>
+struct has_const_begin_end : std::false_type {};
+template <typename T, typename Enable = void>
+struct has_mutable_begin_end : std::false_type {};
+
+template <typename T>
+struct has_const_begin_end<
+    T,
+    void_t<
+        decltype(detail::range_begin(std::declval<const remove_cvref_t<T>&>())),
+        decltype(detail::range_end(std::declval<const remove_cvref_t<T>&>()))>>
+    : std::true_type {};
+
+template <typename T>
+struct has_mutable_begin_end<
+    T, void_t<decltype(detail::range_begin(std::declval<T>())),
+              decltype(detail::range_end(std::declval<T>())),
+              enable_if_t<std::is_copy_constructible<T>::value>>>
+    : std::true_type {};
+
+template <typename T>
+struct is_range_<T, void>
+    : std::integral_constant<bool, (has_const_begin_end<T>::value ||
+                                    has_mutable_begin_end<T>::value)> {};
+#  undef FMT_DECLTYPE_RETURN
 #endif
 
-/// tuple_size and tuple_element check.
+// tuple_size and tuple_element check.
 template <typename T> class is_tuple_like_ {
   template <typename U>
   static auto check(U* p) -> decltype(std::tuple_size<U>::value, int());
@@ -118,26 +182,24 @@ template <typename T> class is_tuple_like_ {
 #if defined(__cpp_lib_integer_sequence) || FMT_MSC_VER >= 1900
 template <typename T, T... N>
 using integer_sequence = std::integer_sequence<T, N...>;
-template <std::size_t... N> using index_sequence = std::index_sequence<N...>;
-template <std::size_t N>
-using make_index_sequence = std::make_index_sequence<N>;
+template <size_t... N> using index_sequence = std::index_sequence<N...>;
+template <size_t N> using make_index_sequence = std::make_index_sequence<N>;
 #else
 template <typename T, T... N> struct integer_sequence {
   using value_type = T;
 
-  static FMT_CONSTEXPR std::size_t size() { return sizeof...(N); }
+  static FMT_CONSTEXPR size_t size() { return sizeof...(N); }
 };
 
-template <std::size_t... N>
-using index_sequence = integer_sequence<std::size_t, N...>;
+template <size_t... N> using index_sequence = integer_sequence<size_t, N...>;
 
-template <typename T, std::size_t N, T... Ns>
+template <typename T, size_t N, T... Ns>
 struct make_integer_sequence : make_integer_sequence<T, N - 1, N - 1, Ns...> {};
 template <typename T, T... Ns>
 struct make_integer_sequence<T, 0, Ns...> : integer_sequence<T, Ns...> {};
 
-template <std::size_t N>
-using make_index_sequence = make_integer_sequence<std::size_t, N>;
+template <size_t N>
+using make_index_sequence = make_integer_sequence<size_t, N>;
 #endif
 
 template <class Tuple, class F, size_t... Is>
@@ -159,183 +221,531 @@ template <class Tuple, class F> void for_each(Tuple&& tup, F&& f) {
   for_each(indexes, std::forward<Tuple>(tup), std::forward<F>(f));
 }
 
-template <typename Arg, FMT_ENABLE_IF(!is_like_std_string<
-                                      typename std::decay<Arg>::type>::value)>
-FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const Arg&) {
-  return add_space ? " {}" : "{}";
+template <typename Range>
+using value_type =
+    remove_cvref_t<decltype(*detail::range_begin(std::declval<Range>()))>;
+
+template <typename OutputIt> OutputIt write_delimiter(OutputIt out) {
+  *out++ = ',';
+  *out++ = ' ';
+  return out;
 }
 
-template <typename Arg, FMT_ENABLE_IF(is_like_std_string<
-                                      typename std::decay<Arg>::type>::value)>
-FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const Arg&) {
-  return add_space ? " \"{}\"" : "\"{}\"";
+struct singleton {
+  unsigned char upper;
+  unsigned char lower_count;
+};
+
+inline auto is_printable(uint16_t x, const singleton* singletons,
+                         size_t singletons_size,
+                         const unsigned char* singleton_lowers,
+                         const unsigned char* normal, size_t normal_size)
+    -> bool {
+  auto upper = x >> 8;
+  auto lower_start = 0;
+  for (size_t i = 0; i < singletons_size; ++i) {
+    auto s = singletons[i];
+    auto lower_end = lower_start + s.lower_count;
+    if (upper < s.upper) break;
+    if (upper == s.upper) {
+      for (auto j = lower_start; j < lower_end; ++j) {
+        if (singleton_lowers[j] == (x & 0xff)) return false;
+      }
+    }
+    lower_start = lower_end;
+  }
+
+  auto xsigned = static_cast<int>(x);
+  auto current = true;
+  for (size_t i = 0; i < normal_size; ++i) {
+    auto v = static_cast<int>(normal[i]);
+    auto len = (v & 0x80) != 0 ? (v & 0x7f) << 8 | normal[++i] : v;
+    xsigned -= len;
+    if (xsigned < 0) break;
+    current = !current;
+  }
+  return current;
 }
 
-FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const char*) {
-  return add_space ? " \"{}\"" : "\"{}\"";
-}
-FMT_CONSTEXPR const wchar_t* format_str_quoted(bool add_space, const wchar_t*) {
-  return add_space ? L" \"{}\"" : L"\"{}\"";
+// Returns true iff the code point cp is printable.
+// This code is generated by support/printable.py.
+inline auto is_printable(uint32_t cp) -> bool {
+  static constexpr singleton singletons0[] = {
+      {0x00, 1},  {0x03, 5},  {0x05, 6},  {0x06, 3},  {0x07, 6},  {0x08, 8},
+      {0x09, 17}, {0x0a, 28}, {0x0b, 25}, {0x0c, 20}, {0x0d, 16}, {0x0e, 13},
+      {0x0f, 4},  {0x10, 3},  {0x12, 18}, {0x13, 9},  {0x16, 1},  {0x17, 5},
+      {0x18, 2},  {0x19, 3},  {0x1a, 7},  {0x1c, 2},  {0x1d, 1},  {0x1f, 22},
+      {0x20, 3},  {0x2b, 3},  {0x2c, 2},  {0x2d, 11}, {0x2e, 1},  {0x30, 3},
+      {0x31, 2},  {0x32, 1},  {0xa7, 2},  {0xa9, 2},  {0xaa, 4},  {0xab, 8},
+      {0xfa, 2},  {0xfb, 5},  {0xfd, 4},  {0xfe, 3},  {0xff, 9},
+  };
+  static constexpr unsigned char singletons0_lower[] = {
+      0xad, 0x78, 0x79, 0x8b, 0x8d, 0xa2, 0x30, 0x57, 0x58, 0x8b, 0x8c, 0x90,
+      0x1c, 0x1d, 0xdd, 0x0e, 0x0f, 0x4b, 0x4c, 0xfb, 0xfc, 0x2e, 0x2f, 0x3f,
+      0x5c, 0x5d, 0x5f, 0xb5, 0xe2, 0x84, 0x8d, 0x8e, 0x91, 0x92, 0xa9, 0xb1,
+      0xba, 0xbb, 0xc5, 0xc6, 0xc9, 0xca, 0xde, 0xe4, 0xe5, 0xff, 0x00, 0x04,
+      0x11, 0x12, 0x29, 0x31, 0x34, 0x37, 0x3a, 0x3b, 0x3d, 0x49, 0x4a, 0x5d,
+      0x84, 0x8e, 0x92, 0xa9, 0xb1, 0xb4, 0xba, 0xbb, 0xc6, 0xca, 0xce, 0xcf,
+      0xe4, 0xe5, 0x00, 0x04, 0x0d, 0x0e, 0x11, 0x12, 0x29, 0x31, 0x34, 0x3a,
+      0x3b, 0x45, 0x46, 0x49, 0x4a, 0x5e, 0x64, 0x65, 0x84, 0x91, 0x9b, 0x9d,
+      0xc9, 0xce, 0xcf, 0x0d, 0x11, 0x29, 0x45, 0x49, 0x57, 0x64, 0x65, 0x8d,
+      0x91, 0xa9, 0xb4, 0xba, 0xbb, 0xc5, 0xc9, 0xdf, 0xe4, 0xe5, 0xf0, 0x0d,
+      0x11, 0x45, 0x49, 0x64, 0x65, 0x80, 0x84, 0xb2, 0xbc, 0xbe, 0xbf, 0xd5,
+      0xd7, 0xf0, 0xf1, 0x83, 0x85, 0x8b, 0xa4, 0xa6, 0xbe, 0xbf, 0xc5, 0xc7,
+      0xce, 0xcf, 0xda, 0xdb, 0x48, 0x98, 0xbd, 0xcd, 0xc6, 0xce, 0xcf, 0x49,
+      0x4e, 0x4f, 0x57, 0x59, 0x5e, 0x5f, 0x89, 0x8e, 0x8f, 0xb1, 0xb6, 0xb7,
+      0xbf, 0xc1, 0xc6, 0xc7, 0xd7, 0x11, 0x16, 0x17, 0x5b, 0x5c, 0xf6, 0xf7,
+      0xfe, 0xff, 0x80, 0x0d, 0x6d, 0x71, 0xde, 0xdf, 0x0e, 0x0f, 0x1f, 0x6e,
+      0x6f, 0x1c, 0x1d, 0x5f, 0x7d, 0x7e, 0xae, 0xaf, 0xbb, 0xbc, 0xfa, 0x16,
+      0x17, 0x1e, 0x1f, 0x46, 0x47, 0x4e, 0x4f, 0x58, 0x5a, 0x5c, 0x5e, 0x7e,
+      0x7f, 0xb5, 0xc5, 0xd4, 0xd5, 0xdc, 0xf0, 0xf1, 0xf5, 0x72, 0x73, 0x8f,
+      0x74, 0x75, 0x96, 0x2f, 0x5f, 0x26, 0x2e, 0x2f, 0xa7, 0xaf, 0xb7, 0xbf,
+      0xc7, 0xcf, 0xd7, 0xdf, 0x9a, 0x40, 0x97, 0x98, 0x30, 0x8f, 0x1f, 0xc0,
+      0xc1, 0xce, 0xff, 0x4e, 0x4f, 0x5a, 0x5b, 0x07, 0x08, 0x0f, 0x10, 0x27,
+      0x2f, 0xee, 0xef, 0x6e, 0x6f, 0x37, 0x3d, 0x3f, 0x42, 0x45, 0x90, 0x91,
+      0xfe, 0xff, 0x53, 0x67, 0x75, 0xc8, 0xc9, 0xd0, 0xd1, 0xd8, 0xd9, 0xe7,
+      0xfe, 0xff,
+  };
+  static constexpr singleton singletons1[] = {
+      {0x00, 6},  {0x01, 1}, {0x03, 1},  {0x04, 2}, {0x08, 8},  {0x09, 2},
+      {0x0a, 5},  {0x0b, 2}, {0x0e, 4},  {0x10, 1}, {0x11, 2},  {0x12, 5},
+      {0x13, 17}, {0x14, 1}, {0x15, 2},  {0x17, 2}, {0x19, 13}, {0x1c, 5},
+      {0x1d, 8},  {0x24, 1}, {0x6a, 3},  {0x6b, 2}, {0xbc, 2},  {0xd1, 2},
+      {0xd4, 12}, {0xd5, 9}, {0xd6, 2},  {0xd7, 2}, {0xda, 1},  {0xe0, 5},
+      {0xe1, 2},  {0xe8, 2}, {0xee, 32}, {0xf0, 4}, {0xf8, 2},  {0xf9, 2},
+      {0xfa, 2},  {0xfb, 1},
+  };
+  static constexpr unsigned char singletons1_lower[] = {
+      0x0c, 0x27, 0x3b, 0x3e, 0x4e, 0x4f, 0x8f, 0x9e, 0x9e, 0x9f, 0x06, 0x07,
+      0x09, 0x36, 0x3d, 0x3e, 0x56, 0xf3, 0xd0, 0xd1, 0x04, 0x14, 0x18, 0x36,
+      0x37, 0x56, 0x57, 0x7f, 0xaa, 0xae, 0xaf, 0xbd, 0x35, 0xe0, 0x12, 0x87,
+      0x89, 0x8e, 0x9e, 0x04, 0x0d, 0x0e, 0x11, 0x12, 0x29, 0x31, 0x34, 0x3a,
+      0x45, 0x46, 0x49, 0x4a, 0x4e, 0x4f, 0x64, 0x65, 0x5c, 0xb6, 0xb7, 0x1b,
+      0x1c, 0x07, 0x08, 0x0a, 0x0b, 0x14, 0x17, 0x36, 0x39, 0x3a, 0xa8, 0xa9,
+      0xd8, 0xd9, 0x09, 0x37, 0x90, 0x91, 0xa8, 0x07, 0x0a, 0x3b, 0x3e, 0x66,
+      0x69, 0x8f, 0x92, 0x6f, 0x5f, 0xee, 0xef, 0x5a, 0x62, 0x9a, 0x9b, 0x27,
+      0x28, 0x55, 0x9d, 0xa0, 0xa1, 0xa3, 0xa4, 0xa7, 0xa8, 0xad, 0xba, 0xbc,
+      0xc4, 0x06, 0x0b, 0x0c, 0x15, 0x1d, 0x3a, 0x3f, 0x45, 0x51, 0xa6, 0xa7,
+      0xcc, 0xcd, 0xa0, 0x07, 0x19, 0x1a, 0x22, 0x25, 0x3e, 0x3f, 0xc5, 0xc6,
+      0x04, 0x20, 0x23, 0x25, 0x26, 0x28, 0x33, 0x38, 0x3a, 0x48, 0x4a, 0x4c,
+      0x50, 0x53, 0x55, 0x56, 0x58, 0x5a, 0x5c, 0x5e, 0x60, 0x63, 0x65, 0x66,
+      0x6b, 0x73, 0x78, 0x7d, 0x7f, 0x8a, 0xa4, 0xaa, 0xaf, 0xb0, 0xc0, 0xd0,
+      0xae, 0xaf, 0x79, 0xcc, 0x6e, 0x6f, 0x93,
+  };
+  static constexpr unsigned char normal0[] = {
+      0x00, 0x20, 0x5f, 0x22, 0x82, 0xdf, 0x04, 0x82, 0x44, 0x08, 0x1b, 0x04,
+      0x06, 0x11, 0x81, 0xac, 0x0e, 0x80, 0xab, 0x35, 0x28, 0x0b, 0x80, 0xe0,
+      0x03, 0x19, 0x08, 0x01, 0x04, 0x2f, 0x04, 0x34, 0x04, 0x07, 0x03, 0x01,
+      0x07, 0x06, 0x07, 0x11, 0x0a, 0x50, 0x0f, 0x12, 0x07, 0x55, 0x07, 0x03,
+      0x04, 0x1c, 0x0a, 0x09, 0x03, 0x08, 0x03, 0x07, 0x03, 0x02, 0x03, 0x03,
+      0x03, 0x0c, 0x04, 0x05, 0x03, 0x0b, 0x06, 0x01, 0x0e, 0x15, 0x05, 0x3a,
+      0x03, 0x11, 0x07, 0x06, 0x05, 0x10, 0x07, 0x57, 0x07, 0x02, 0x07, 0x15,
+      0x0d, 0x50, 0x04, 0x43, 0x03, 0x2d, 0x03, 0x01, 0x04, 0x11, 0x06, 0x0f,
+      0x0c, 0x3a, 0x04, 0x1d, 0x25, 0x5f, 0x20, 0x6d, 0x04, 0x6a, 0x25, 0x80,
+      0xc8, 0x05, 0x82, 0xb0, 0x03, 0x1a, 0x06, 0x82, 0xfd, 0x03, 0x59, 0x07,
+      0x15, 0x0b, 0x17, 0x09, 0x14, 0x0c, 0x14, 0x0c, 0x6a, 0x06, 0x0a, 0x06,
+      0x1a, 0x06, 0x59, 0x07, 0x2b, 0x05, 0x46, 0x0a, 0x2c, 0x04, 0x0c, 0x04,
+      0x01, 0x03, 0x31, 0x0b, 0x2c, 0x04, 0x1a, 0x06, 0x0b, 0x03, 0x80, 0xac,
+      0x06, 0x0a, 0x06, 0x21, 0x3f, 0x4c, 0x04, 0x2d, 0x03, 0x74, 0x08, 0x3c,
+      0x03, 0x0f, 0x03, 0x3c, 0x07, 0x38, 0x08, 0x2b, 0x05, 0x82, 0xff, 0x11,
+      0x18, 0x08, 0x2f, 0x11, 0x2d, 0x03, 0x20, 0x10, 0x21, 0x0f, 0x80, 0x8c,
+      0x04, 0x82, 0x97, 0x19, 0x0b, 0x15, 0x88, 0x94, 0x05, 0x2f, 0x05, 0x3b,
+      0x07, 0x02, 0x0e, 0x18, 0x09, 0x80, 0xb3, 0x2d, 0x74, 0x0c, 0x80, 0xd6,
+      0x1a, 0x0c, 0x05, 0x80, 0xff, 0x05, 0x80, 0xdf, 0x0c, 0xee, 0x0d, 0x03,
+      0x84, 0x8d, 0x03, 0x37, 0x09, 0x81, 0x5c, 0x14, 0x80, 0xb8, 0x08, 0x80,
+      0xcb, 0x2a, 0x38, 0x03, 0x0a, 0x06, 0x38, 0x08, 0x46, 0x08, 0x0c, 0x06,
+      0x74, 0x0b, 0x1e, 0x03, 0x5a, 0x04, 0x59, 0x09, 0x80, 0x83, 0x18, 0x1c,
+      0x0a, 0x16, 0x09, 0x4c, 0x04, 0x80, 0x8a, 0x06, 0xab, 0xa4, 0x0c, 0x17,
+      0x04, 0x31, 0xa1, 0x04, 0x81, 0xda, 0x26, 0x07, 0x0c, 0x05, 0x05, 0x80,
+      0xa5, 0x11, 0x81, 0x6d, 0x10, 0x78, 0x28, 0x2a, 0x06, 0x4c, 0x04, 0x80,
+      0x8d, 0x04, 0x80, 0xbe, 0x03, 0x1b, 0x03, 0x0f, 0x0d,
+  };
+  static constexpr unsigned char normal1[] = {
+      0x5e, 0x22, 0x7b, 0x05, 0x03, 0x04, 0x2d, 0x03, 0x66, 0x03, 0x01, 0x2f,
+      0x2e, 0x80, 0x82, 0x1d, 0x03, 0x31, 0x0f, 0x1c, 0x04, 0x24, 0x09, 0x1e,
+      0x05, 0x2b, 0x05, 0x44, 0x04, 0x0e, 0x2a, 0x80, 0xaa, 0x06, 0x24, 0x04,
+      0x24, 0x04, 0x28, 0x08, 0x34, 0x0b, 0x01, 0x80, 0x90, 0x81, 0x37, 0x09,
+      0x16, 0x0a, 0x08, 0x80, 0x98, 0x39, 0x03, 0x63, 0x08, 0x09, 0x30, 0x16,
+      0x05, 0x21, 0x03, 0x1b, 0x05, 0x01, 0x40, 0x38, 0x04, 0x4b, 0x05, 0x2f,
+      0x04, 0x0a, 0x07, 0x09, 0x07, 0x40, 0x20, 0x27, 0x04, 0x0c, 0x09, 0x36,
+      0x03, 0x3a, 0x05, 0x1a, 0x07, 0x04, 0x0c, 0x07, 0x50, 0x49, 0x37, 0x33,
+      0x0d, 0x33, 0x07, 0x2e, 0x08, 0x0a, 0x81, 0x26, 0x52, 0x4e, 0x28, 0x08,
+      0x2a, 0x56, 0x1c, 0x14, 0x17, 0x09, 0x4e, 0x04, 0x1e, 0x0f, 0x43, 0x0e,
+      0x19, 0x07, 0x0a, 0x06, 0x48, 0x08, 0x27, 0x09, 0x75, 0x0b, 0x3f, 0x41,
+      0x2a, 0x06, 0x3b, 0x05, 0x0a, 0x06, 0x51, 0x06, 0x01, 0x05, 0x10, 0x03,
+      0x05, 0x80, 0x8b, 0x62, 0x1e, 0x48, 0x08, 0x0a, 0x80, 0xa6, 0x5e, 0x22,
+      0x45, 0x0b, 0x0a, 0x06, 0x0d, 0x13, 0x39, 0x07, 0x0a, 0x36, 0x2c, 0x04,
+      0x10, 0x80, 0xc0, 0x3c, 0x64, 0x53, 0x0c, 0x48, 0x09, 0x0a, 0x46, 0x45,
+      0x1b, 0x48, 0x08, 0x53, 0x1d, 0x39, 0x81, 0x07, 0x46, 0x0a, 0x1d, 0x03,
+      0x47, 0x49, 0x37, 0x03, 0x0e, 0x08, 0x0a, 0x06, 0x39, 0x07, 0x0a, 0x81,
+      0x36, 0x19, 0x80, 0xb7, 0x01, 0x0f, 0x32, 0x0d, 0x83, 0x9b, 0x66, 0x75,
+      0x0b, 0x80, 0xc4, 0x8a, 0xbc, 0x84, 0x2f, 0x8f, 0xd1, 0x82, 0x47, 0xa1,
+      0xb9, 0x82, 0x39, 0x07, 0x2a, 0x04, 0x02, 0x60, 0x26, 0x0a, 0x46, 0x0a,
+      0x28, 0x05, 0x13, 0x82, 0xb0, 0x5b, 0x65, 0x4b, 0x04, 0x39, 0x07, 0x11,
+      0x40, 0x05, 0x0b, 0x02, 0x0e, 0x97, 0xf8, 0x08, 0x84, 0xd6, 0x2a, 0x09,
+      0xa2, 0xf7, 0x81, 0x1f, 0x31, 0x03, 0x11, 0x04, 0x08, 0x81, 0x8c, 0x89,
+      0x04, 0x6b, 0x05, 0x0d, 0x03, 0x09, 0x07, 0x10, 0x93, 0x60, 0x80, 0xf6,
+      0x0a, 0x73, 0x08, 0x6e, 0x17, 0x46, 0x80, 0x9a, 0x14, 0x0c, 0x57, 0x09,
+      0x19, 0x80, 0x87, 0x81, 0x47, 0x03, 0x85, 0x42, 0x0f, 0x15, 0x85, 0x50,
+      0x2b, 0x80, 0xd5, 0x2d, 0x03, 0x1a, 0x04, 0x02, 0x81, 0x70, 0x3a, 0x05,
+      0x01, 0x85, 0x00, 0x80, 0xd7, 0x29, 0x4c, 0x04, 0x0a, 0x04, 0x02, 0x83,
+      0x11, 0x44, 0x4c, 0x3d, 0x80, 0xc2, 0x3c, 0x06, 0x01, 0x04, 0x55, 0x05,
+      0x1b, 0x34, 0x02, 0x81, 0x0e, 0x2c, 0x04, 0x64, 0x0c, 0x56, 0x0a, 0x80,
+      0xae, 0x38, 0x1d, 0x0d, 0x2c, 0x04, 0x09, 0x07, 0x02, 0x0e, 0x06, 0x80,
+      0x9a, 0x83, 0xd8, 0x08, 0x0d, 0x03, 0x0d, 0x03, 0x74, 0x0c, 0x59, 0x07,
+      0x0c, 0x14, 0x0c, 0x04, 0x38, 0x08, 0x0a, 0x06, 0x28, 0x08, 0x22, 0x4e,
+      0x81, 0x54, 0x0c, 0x15, 0x03, 0x03, 0x05, 0x07, 0x09, 0x19, 0x07, 0x07,
+      0x09, 0x03, 0x0d, 0x07, 0x29, 0x80, 0xcb, 0x25, 0x0a, 0x84, 0x06,
+  };
+  auto lower = static_cast<uint16_t>(cp);
+  if (cp < 0x10000) {
+    return is_printable(lower, singletons0,
+                        sizeof(singletons0) / sizeof(*singletons0),
+                        singletons0_lower, normal0, sizeof(normal0));
+  }
+  if (cp < 0x20000) {
+    return is_printable(lower, singletons1,
+                        sizeof(singletons1) / sizeof(*singletons1),
+                        singletons1_lower, normal1, sizeof(normal1));
+  }
+  if (0x2a6de <= cp && cp < 0x2a700) return false;
+  if (0x2b735 <= cp && cp < 0x2b740) return false;
+  if (0x2b81e <= cp && cp < 0x2b820) return false;
+  if (0x2cea2 <= cp && cp < 0x2ceb0) return false;
+  if (0x2ebe1 <= cp && cp < 0x2f800) return false;
+  if (0x2fa1e <= cp && cp < 0x30000) return false;
+  if (0x3134b <= cp && cp < 0xe0100) return false;
+  if (0xe01f0 <= cp && cp < 0x110000) return false;
+  return cp < 0x110000;
 }
 
-FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const char) {
-  return add_space ? " '{}'" : "'{}'";
-}
-FMT_CONSTEXPR const wchar_t* format_str_quoted(bool add_space, const wchar_t) {
-  return add_space ? L" '{}'" : L"'{}'";
+inline auto needs_escape(uint32_t cp) -> bool {
+  return cp < 0x20 || cp == 0x7f || cp == '"' || cp == '\\' ||
+         !is_printable(cp);
 }
 
-}  // namespace internal
+template <typename Char> struct find_escape_result {
+  const Char* begin;
+  const Char* end;
+  uint32_t cp;
+};
+
+template <typename Char>
+auto find_escape(const Char* begin, const Char* end)
+    -> find_escape_result<Char> {
+  for (; begin != end; ++begin) {
+    auto cp = static_cast<typename std::make_unsigned<Char>::type>(*begin);
+    if (sizeof(Char) == 1 && cp >= 0x80) continue;
+    if (needs_escape(cp)) return {begin, begin + 1, cp};
+  }
+  return {begin, nullptr, 0};
+}
+
+inline auto find_escape(const char* begin, const char* end)
+    -> find_escape_result<char> {
+  if (!is_utf8()) return find_escape<char>(begin, end);
+  auto result = find_escape_result<char>{end, nullptr, 0};
+  for_each_codepoint(string_view(begin, to_unsigned(end - begin)),
+                     [&](uint32_t cp, string_view sv) {
+                       if (needs_escape(cp)) {
+                         result = {sv.begin(), sv.end(), cp};
+                         return false;
+                       }
+                       return true;
+                     });
+  return result;
+}
+
+template <typename Char, typename OutputIt>
+auto write_range_entry(OutputIt out, basic_string_view<Char> str) -> OutputIt {
+  *out++ = '"';
+  auto begin = str.begin(), end = str.end();
+  do {
+    auto escape = find_escape(begin, end);
+    out = copy_str<Char>(begin, escape.begin, out);
+    begin = escape.end;
+    if (!begin) break;
+    auto c = static_cast<Char>(escape.cp);
+    switch (escape.cp) {
+    case '\n':
+      *out++ = '\\';
+      c = 'n';
+      break;
+    case '\r':
+      *out++ = '\\';
+      c = 'r';
+      break;
+    case '\t':
+      *out++ = '\\';
+      c = 't';
+      break;
+    case '"':
+      FMT_FALLTHROUGH;
+    case '\\':
+      *out++ = '\\';
+      break;
+    default:
+      if (is_utf8()) {
+        if (escape.cp < 0x100) {
+          out = format_to(out, "\\x{:02x}", escape.cp);
+          continue;
+        }
+        if (escape.cp < 0x10000) {
+          out = format_to(out, "\\u{:04x}", escape.cp);
+          continue;
+        }
+        if (escape.cp < 0x110000) {
+          out = format_to(out, "\\U{:08x}", escape.cp);
+          continue;
+        }
+      }
+      for (Char escape_char : basic_string_view<Char>(
+               escape.begin, to_unsigned(escape.end - escape.begin))) {
+        out = format_to(
+            out, "\\x{:02x}",
+            static_cast<typename std::make_unsigned<Char>::type>(escape_char));
+      }
+      continue;
+    }
+    *out++ = c;
+  } while (begin != end);
+  *out++ = '"';
+  return out;
+}
+
+template <typename Char, typename OutputIt, typename T,
+          FMT_ENABLE_IF(std::is_convertible<T, std_string_view<char>>::value)>
+inline auto write_range_entry(OutputIt out, const T& str) -> OutputIt {
+  auto sv = std_string_view<Char>(str);
+  return write_range_entry<Char>(out, basic_string_view<Char>(sv));
+}
+
+template <typename Char, typename OutputIt, typename Arg,
+          FMT_ENABLE_IF(std::is_same<Arg, Char>::value)>
+OutputIt write_range_entry(OutputIt out, const Arg v) {
+  *out++ = '\'';
+  *out++ = v;
+  *out++ = '\'';
+  return out;
+}
+
+template <
+    typename Char, typename OutputIt, typename Arg,
+    FMT_ENABLE_IF(!is_std_string_like<typename std::decay<Arg>::type>::value &&
+                  !std::is_same<Arg, Char>::value)>
+OutputIt write_range_entry(OutputIt out, const Arg& v) {
+  return write<Char>(out, v);
+}
+
+}  // namespace detail
 
 template <typename T> struct is_tuple_like {
   static FMT_CONSTEXPR_DECL const bool value =
-      internal::is_tuple_like_<T>::value && !internal::is_range_<T>::value;
+      detail::is_tuple_like_<T>::value && !detail::is_range_<T>::value;
 };
 
 template <typename TupleT, typename Char>
 struct formatter<TupleT, Char, enable_if_t<fmt::is_tuple_like<TupleT>::value>> {
  private:
-  // C++11 generic lambda for format()
+  // C++11 generic lambda for format().
   template <typename FormatContext> struct format_each {
     template <typename T> void operator()(const T& v) {
-      if (i > 0) {
-        if (formatting.add_prepostfix_space) {
-          *out++ = ' ';
-        }
-        out = internal::copy(formatting.delimiter, out);
-      }
-      out = format_to(out,
-                      internal::format_str_quoted(
-                          (formatting.add_delimiter_spaces && i > 0), v),
-                      v);
+      if (i > 0) out = detail::write_delimiter(out);
+      out = detail::write_range_entry<Char>(out, v);
       ++i;
     }
-
-    formatting_tuple<Char>& formatting;
-    std::size_t& i;
-    typename std::add_lvalue_reference<decltype(
-        std::declval<FormatContext>().out())>::type out;
+    int i;
+    typename FormatContext::iterator& out;
   };
 
  public:
-  formatting_tuple<Char> formatting;
-
-  template <typename ParseContext>
-  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
-    return formatting.parse(ctx);
-  }
-
-  template <typename FormatContext = format_context>
-  auto format(const TupleT& values, FormatContext& ctx) -> decltype(ctx.out()) {
-    auto out = ctx.out();
-    std::size_t i = 0;
-    internal::copy(formatting.prefix, out);
-
-    internal::for_each(values, format_each<FormatContext>{formatting, i, out});
-    if (formatting.add_prepostfix_space) {
-      *out++ = ' ';
-    }
-    internal::copy(formatting.postfix, out);
-
-    return ctx.out();
-  }
-};
-
-template <typename T, typename Char> struct is_range {
-  static FMT_CONSTEXPR_DECL const bool value =
-      internal::is_range_<T>::value &&
-      !internal::is_like_std_string<T>::value &&
-      !std::is_convertible<T, std::basic_string<Char>>::value &&
-      !std::is_constructible<internal::std_string_view<Char>, T>::value;
-};
-
-template <typename RangeT, typename Char>
-struct formatter<RangeT, Char,
-                 enable_if_t<fmt::is_range<RangeT, Char>::value>> {
-  formatting_range<Char> formatting;
-
-  template <typename ParseContext>
-  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
-    return formatting.parse(ctx);
-  }
-
-  template <typename FormatContext>
-  typename FormatContext::iterator format(const RangeT& values,
-                                          FormatContext& ctx) {
-    auto out = internal::copy(formatting.prefix, ctx.out());
-    std::size_t i = 0;
-    for (auto it = values.begin(), end = values.end(); it != end; ++it) {
-      if (i > 0) {
-        if (formatting.add_prepostfix_space) *out++ = ' ';
-        out = internal::copy(formatting.delimiter, out);
-      }
-      out = format_to(out,
-                      internal::format_str_quoted(
-                          (formatting.add_delimiter_spaces && i > 0), *it),
-                      *it);
-      if (++i > formatting.range_length_limit) {
-        out = format_to(out, " ... <other elements>");
-        break;
-      }
-    }
-    if (formatting.add_prepostfix_space) *out++ = ' ';
-    return internal::copy(formatting.postfix, out);
-  }
-};
-
-template <typename Char, typename... T> struct tuple_arg_join : internal::view {
-  const std::tuple<T...>& tuple;
-  basic_string_view<Char> sep;
-
-  tuple_arg_join(const std::tuple<T...>& t, basic_string_view<Char> s)
-      : tuple{t}, sep{s} {}
-};
-
-template <typename Char, typename... T>
-struct formatter<tuple_arg_join<Char, T...>, Char> {
   template <typename ParseContext>
   FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
     return ctx.begin();
   }
 
+  template <typename FormatContext = format_context>
+  auto format(const TupleT& values, FormatContext& ctx) -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    *out++ = '(';
+    detail::for_each(values, format_each<FormatContext>{0, out});
+    *out++ = ')';
+    return out;
+  }
+};
+
+template <typename T, typename Char> struct is_range {
+  static FMT_CONSTEXPR_DECL const bool value =
+      detail::is_range_<T>::value && !detail::is_std_string_like<T>::value &&
+      !detail::is_map<T>::value &&
+      !std::is_convertible<T, std::basic_string<Char>>::value &&
+      !std::is_constructible<detail::std_string_view<Char>, T>::value;
+};
+
+template <typename T, typename Char>
+struct formatter<
+    T, Char,
+    enable_if_t<
+        fmt::is_range<T, Char>::value
+// Workaround a bug in MSVC 2019 and earlier.
+#if !FMT_MSC_VER
+        && (is_formattable<detail::value_type<T>, Char>::value ||
+            detail::has_fallback_formatter<detail::value_type<T>, Char>::value)
+#endif
+        >> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <
+      typename FormatContext, typename U,
+      FMT_ENABLE_IF(
+          std::is_same<U, conditional_t<detail::has_const_begin_end<T>::value,
+                                        const T, T>>::value)>
+  auto format(U& range, FormatContext& ctx) -> decltype(ctx.out()) {
+#ifdef FMT_DEPRECATED_BRACED_RANGES
+    Char prefix = '{';
+    Char postfix = '}';
+#else
+    Char prefix = detail::is_set<T>::value ? '{' : '[';
+    Char postfix = detail::is_set<T>::value ? '}' : ']';
+#endif
+    auto out = ctx.out();
+    *out++ = prefix;
+    int i = 0;
+    auto it = std::begin(range);
+    auto end = std::end(range);
+    for (; it != end; ++it) {
+      if (i > 0) out = detail::write_delimiter(out);
+      out = detail::write_range_entry<Char>(out, *it);
+      ++i;
+    }
+    *out++ = postfix;
+    return out;
+  }
+};
+
+template <typename T, typename Char>
+struct formatter<
+    T, Char,
+    enable_if_t<
+        detail::is_map<T>::value
+// Workaround a bug in MSVC 2019 and earlier.
+#if !FMT_MSC_VER
+        && (is_formattable<detail::value_type<T>, Char>::value ||
+            detail::has_fallback_formatter<detail::value_type<T>, Char>::value)
+#endif
+        >> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <
+      typename FormatContext, typename U,
+      FMT_ENABLE_IF(
+          std::is_same<U, conditional_t<detail::has_const_begin_end<T>::value,
+                                        const T, T>>::value)>
+  auto format(U& map, FormatContext& ctx) -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    *out++ = '{';
+    int i = 0;
+    for (const auto& item : map) {
+      if (i > 0) out = detail::write_delimiter(out);
+      out = detail::write_range_entry<Char>(out, item.first);
+      *out++ = ':';
+      *out++ = ' ';
+      out = detail::write_range_entry<Char>(out, item.second);
+      ++i;
+    }
+    *out++ = '}';
+    return out;
+  }
+};
+
+template <typename Char, typename... T> struct tuple_join_view : detail::view {
+  const std::tuple<T...>& tuple;
+  basic_string_view<Char> sep;
+
+  tuple_join_view(const std::tuple<T...>& t, basic_string_view<Char> s)
+      : tuple(t), sep{s} {}
+};
+
+template <typename Char, typename... T>
+using tuple_arg_join = tuple_join_view<Char, T...>;
+
+// Define FMT_TUPLE_JOIN_SPECIFIERS to enable experimental format specifiers
+// support in tuple_join. It is disabled by default because of issues with
+// the dynamic width and precision.
+#ifndef FMT_TUPLE_JOIN_SPECIFIERS
+#  define FMT_TUPLE_JOIN_SPECIFIERS 0
+#endif
+
+template <typename Char, typename... T>
+struct formatter<tuple_join_view<Char, T...>, Char> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return do_parse(ctx, std::integral_constant<size_t, sizeof...(T)>());
+  }
+
   template <typename FormatContext>
-  typename FormatContext::iterator format(
-      const tuple_arg_join<Char, T...>& value, FormatContext& ctx) {
-    return format(value, ctx, internal::make_index_sequence<sizeof...(T)>{});
+  auto format(const tuple_join_view<Char, T...>& value,
+              FormatContext& ctx) const -> typename FormatContext::iterator {
+    return do_format(value, ctx,
+                     std::integral_constant<size_t, sizeof...(T)>());
   }
 
  private:
-  template <typename FormatContext, size_t... N>
-  typename FormatContext::iterator format(
-      const tuple_arg_join<Char, T...>& value, FormatContext& ctx,
-      internal::index_sequence<N...>) {
-    return format_args(value, ctx, std::get<N>(value.tuple)...);
+  std::tuple<formatter<typename std::decay<T>::type, Char>...> formatters_;
+
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto do_parse(ParseContext& ctx,
+                              std::integral_constant<size_t, 0>)
+      -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename ParseContext, size_t N>
+  FMT_CONSTEXPR auto do_parse(ParseContext& ctx,
+                              std::integral_constant<size_t, N>)
+      -> decltype(ctx.begin()) {
+    auto end = ctx.begin();
+#if FMT_TUPLE_JOIN_SPECIFIERS
+    end = std::get<sizeof...(T) - N>(formatters_).parse(ctx);
+    if (N > 1) {
+      auto end1 = do_parse(ctx, std::integral_constant<size_t, N - 1>());
+      if (end != end1)
+        FMT_THROW(format_error("incompatible format specs for tuple elements"));
+    }
+#endif
+    return end;
   }
 
   template <typename FormatContext>
-  typename FormatContext::iterator format_args(
-      const tuple_arg_join<Char, T...>&, FormatContext& ctx) {
-    // NOTE: for compilers that support C++17, this empty function instantiation
-    // can be replaced with a constexpr branch in the variadic overload.
+  auto do_format(const tuple_join_view<Char, T...>&, FormatContext& ctx,
+                 std::integral_constant<size_t, 0>) const ->
+      typename FormatContext::iterator {
     return ctx.out();
   }
 
-  template <typename FormatContext, typename Arg, typename... Args>
-  typename FormatContext::iterator format_args(
-      const tuple_arg_join<Char, T...>& value, FormatContext& ctx,
-      const Arg& arg, const Args&... args) {
-    using base = formatter<typename std::decay<Arg>::type, Char>;
-    auto out = ctx.out();
-    out = base{}.format(arg, ctx);
-    if (sizeof...(Args) > 0) {
+  template <typename FormatContext, size_t N>
+  auto do_format(const tuple_join_view<Char, T...>& value, FormatContext& ctx,
+                 std::integral_constant<size_t, N>) const ->
+      typename FormatContext::iterator {
+    auto out = std::get<sizeof...(T) - N>(formatters_)
+                   .format(std::get<sizeof...(T) - N>(value.tuple), ctx);
+    if (N > 1) {
       out = std::copy(value.sep.begin(), value.sep.end(), out);
       ctx.advance_to(out);
-      return format_args(value, ctx, args...);
+      return do_format(value, ctx, std::integral_constant<size_t, N - 1>());
     }
     return out;
   }
 };
 
+FMT_MODULE_EXPORT_BEGIN
+
 /**
   \rst
   Returns an object that formats `tuple` with elements separated by `sep`.
@@ -348,14 +758,15 @@ struct formatter<tuple_arg_join<Char, T...>, Char> {
   \endrst
  */
 template <typename... T>
-FMT_CONSTEXPR tuple_arg_join<char, T...> join(const std::tuple<T...>& tuple,
-                                              string_view sep) {
+FMT_CONSTEXPR auto join(const std::tuple<T...>& tuple, string_view sep)
+    -> tuple_join_view<char, T...> {
   return {tuple, sep};
 }
 
 template <typename... T>
-FMT_CONSTEXPR tuple_arg_join<wchar_t, T...> join(const std::tuple<T...>& tuple,
-                                                 wstring_view sep) {
+FMT_CONSTEXPR auto join(const std::tuple<T...>& tuple,
+                        basic_string_view<wchar_t> sep)
+    -> tuple_join_view<wchar_t, T...> {
   return {tuple, sep};
 }
 
@@ -371,17 +782,12 @@ FMT_CONSTEXPR tuple_arg_join<wchar_t, T...> join(const std::tuple<T...>& tuple,
   \endrst
  */
 template <typename T>
-arg_join<internal::iterator_t<const std::initializer_list<T>>, char> join(
-    std::initializer_list<T> list, string_view sep) {
-  return join(std::begin(list), std::end(list), sep);
-}
-
-template <typename T>
-arg_join<internal::iterator_t<const std::initializer_list<T>>, wchar_t> join(
-    std::initializer_list<T> list, wstring_view sep) {
+auto join(std::initializer_list<T> list, string_view sep)
+    -> join_view<const T*, const T*> {
   return join(std::begin(list), std::end(list), sep);
 }
 
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_RANGES_H_

include/spdlog/fmt/bundled/xchar.h

@@ -0,0 +1,236 @@
+// Formatting library for C++ - optional wchar_t and exotic character support
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_XCHAR_H_
+#define FMT_XCHAR_H_
+
+#include <cwchar>
+#include <tuple>
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+namespace detail {
+template <typename T>
+using is_exotic_char = bool_constant<!std::is_same<T, char>::value>;
+}
+
+FMT_MODULE_EXPORT_BEGIN
+
+using wstring_view = basic_string_view<wchar_t>;
+using wformat_parse_context = basic_format_parse_context<wchar_t>;
+using wformat_context = buffer_context<wchar_t>;
+using wformat_args = basic_format_args<wformat_context>;
+using wmemory_buffer = basic_memory_buffer<wchar_t>;
+
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+// Workaround broken conversion on older gcc.
+template <typename... Args> using wformat_string = wstring_view;
+#else
+template <typename... Args>
+using wformat_string = basic_format_string<wchar_t, type_identity_t<Args>...>;
+#endif
+
+template <> struct is_char<wchar_t> : std::true_type {};
+template <> struct is_char<detail::char8_type> : std::true_type {};
+template <> struct is_char<char16_t> : std::true_type {};
+template <> struct is_char<char32_t> : std::true_type {};
+
+template <typename... Args>
+constexpr format_arg_store<wformat_context, Args...> make_wformat_args(
+    const Args&... args) {
+  return {args...};
+}
+
+inline namespace literals {
+constexpr auto operator"" _format(const wchar_t* s, size_t n)
+    -> detail::udl_formatter<wchar_t> {
+  return {{s, n}};
+}
+
+#if FMT_USE_USER_DEFINED_LITERALS && !FMT_USE_NONTYPE_TEMPLATE_PARAMETERS
+constexpr detail::udl_arg<wchar_t> operator"" _a(const wchar_t* s, size_t) {
+  return {s};
+}
+#endif
+}  // namespace literals
+
+template <typename It, typename Sentinel>
+auto join(It begin, Sentinel end, wstring_view sep)
+    -> join_view<It, Sentinel, wchar_t> {
+  return {begin, end, sep};
+}
+
+template <typename Range>
+auto join(Range&& range, wstring_view sep)
+    -> join_view<detail::iterator_t<Range>, detail::sentinel_t<Range>,
+                 wchar_t> {
+  return join(std::begin(range), std::end(range), sep);
+}
+
+template <typename T>
+auto join(std::initializer_list<T> list, wstring_view sep)
+    -> join_view<const T*, const T*, wchar_t> {
+  return join(std::begin(list), std::end(list), sep);
+}
+
+template <typename Char, FMT_ENABLE_IF(!std::is_same<Char, char>::value)>
+auto vformat(basic_string_view<Char> format_str,
+             basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
+  basic_memory_buffer<Char> buffer;
+  detail::vformat_to(buffer, format_str, args);
+  return to_string(buffer);
+}
+
+// Pass char_t as a default template parameter instead of using
+// std::basic_string<char_t<S>> to reduce the symbol size.
+template <typename S, typename... Args, typename Char = char_t<S>,
+          FMT_ENABLE_IF(!std::is_same<Char, char>::value)>
+auto format(const S& format_str, Args&&... args) -> std::basic_string<Char> {
+  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
+  return vformat(to_string_view(format_str), vargs);
+}
+
+template <typename Locale, typename S, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_locale<Locale>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto vformat(
+    const Locale& loc, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
+  return detail::vformat(loc, to_string_view(format_str), args);
+}
+
+template <typename Locale, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_locale<Locale>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto format(const Locale& loc, const S& format_str, Args&&... args)
+    -> std::basic_string<Char> {
+  return detail::vformat(loc, to_string_view(format_str),
+                         fmt::make_args_checked<Args...>(format_str, args...));
+}
+
+template <typename OutputIt, typename S, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+auto vformat_to(OutputIt out, const S& format_str,
+                basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> OutputIt {
+  auto&& buf = detail::get_buffer<Char>(out);
+  detail::vformat_to(buf, to_string_view(format_str), args);
+  return detail::get_iterator(buf);
+}
+
+template <typename OutputIt, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto format_to(OutputIt out, const S& fmt, Args&&... args) -> OutputIt {
+  const auto& vargs = fmt::make_args_checked<Args...>(fmt, args...);
+  return vformat_to(out, to_string_view(fmt), vargs);
+}
+
+template <typename S, typename... Args, typename Char, size_t SIZE,
+          typename Allocator, FMT_ENABLE_IF(detail::is_string<S>::value)>
+FMT_DEPRECATED auto format_to(basic_memory_buffer<Char, SIZE, Allocator>& buf,
+                              const S& format_str, Args&&... args) ->
+    typename buffer_context<Char>::iterator {
+  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
+  detail::vformat_to(buf, to_string_view(format_str), vargs, {});
+  return detail::buffer_appender<Char>(buf);
+}
+
+template <typename Locale, typename S, typename OutputIt, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_locale<Locale>::value&&
+                                detail::is_exotic_char<Char>::value)>
+inline auto vformat_to(
+    OutputIt out, const Locale& loc, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) -> OutputIt {
+  auto&& buf = detail::get_buffer<Char>(out);
+  vformat_to(buf, to_string_view(format_str), args, detail::locale_ref(loc));
+  return detail::get_iterator(buf);
+}
+
+template <
+    typename OutputIt, typename Locale, typename S, typename... Args,
+    typename Char = char_t<S>,
+    bool enable = detail::is_output_iterator<OutputIt, Char>::value&&
+        detail::is_locale<Locale>::value&& detail::is_exotic_char<Char>::value>
+inline auto format_to(OutputIt out, const Locale& loc, const S& format_str,
+                      Args&&... args) ->
+    typename std::enable_if<enable, OutputIt>::type {
+  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
+  return vformat_to(out, loc, to_string_view(format_str), vargs);
+}
+
+template <typename OutputIt, typename Char, typename... Args,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto vformat_to_n(
+    OutputIt out, size_t n, basic_string_view<Char> format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> format_to_n_result<OutputIt> {
+  detail::iterator_buffer<OutputIt, Char, detail::fixed_buffer_traits> buf(out,
+                                                                           n);
+  detail::vformat_to(buf, format_str, args);
+  return {buf.out(), buf.count()};
+}
+
+template <typename OutputIt, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto format_to_n(OutputIt out, size_t n, const S& fmt,
+                        const Args&... args) -> format_to_n_result<OutputIt> {
+  const auto& vargs = fmt::make_args_checked<Args...>(fmt, args...);
+  return vformat_to_n(out, n, to_string_view(fmt), vargs);
+}
+
+template <typename S, typename... Args, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_exotic_char<Char>::value)>
+inline auto formatted_size(const S& fmt, Args&&... args) -> size_t {
+  detail::counting_buffer<Char> buf;
+  const auto& vargs = fmt::make_args_checked<Args...>(fmt, args...);
+  detail::vformat_to(buf, to_string_view(fmt), vargs);
+  return buf.count();
+}
+
+inline void vprint(std::FILE* f, wstring_view fmt, wformat_args args) {
+  wmemory_buffer buffer;
+  detail::vformat_to(buffer, fmt, args);
+  buffer.push_back(L'\0');
+  if (std::fputws(buffer.data(), f) == -1)
+    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
+}
+
+inline void vprint(wstring_view fmt, wformat_args args) {
+  vprint(stdout, fmt, args);
+}
+
+template <typename... T>
+void print(std::FILE* f, wformat_string<T...> fmt, T&&... args) {
+  return vprint(f, wstring_view(fmt), fmt::make_wformat_args(args...));
+}
+
+template <typename... T> void print(wformat_string<T...> fmt, T&&... args) {
+  return vprint(wstring_view(fmt), fmt::make_wformat_args(args...));
+}
+
+/**
+  Converts *value* to ``std::wstring`` using the default format for type *T*.
+ */
+template <typename T> inline auto to_wstring(const T& value) -> std::wstring {
+  return format(FMT_STRING(L"{}"), value);
+}
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_XCHAR_H_

include/spdlog/fmt/chrono.h

@@ -0,0 +1,22 @@
+//
+// Copyright(c) 2016 Gabi Melman.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+//
+
+#pragma once
+//
+// include bundled or external copy of fmtlib's chrono support
+//
+
+#if !defined(SPDLOG_USE_STD_FORMAT)
+#    if !defined(SPDLOG_FMT_EXTERNAL)
+#        ifdef SPDLOG_HEADER_ONLY
+#            ifndef FMT_HEADER_ONLY
+#                define FMT_HEADER_ONLY
+#            endif
+#        endif
+#        include <spdlog/fmt/bundled/chrono.h>
+#    else
+#        include <fmt/chrono.h>
+#    endif
+#endif

include/spdlog/fmt/compile.h

@@ -0,0 +1,22 @@
+//
+// Copyright(c) 2016 Gabi Melman.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+//
+
+#pragma once
+//
+// include bundled or external copy of fmtlib's compile-time support
+//
+
+#if !defined(SPDLOG_USE_STD_FORMAT)
+#    if !defined(SPDLOG_FMT_EXTERNAL)
+#        ifdef SPDLOG_HEADER_ONLY
+#            ifndef FMT_HEADER_ONLY
+#                define FMT_HEADER_ONLY
+#            endif
+#        endif
+#        include <spdlog/fmt/bundled/compile.h>
+#    else
+#        include <fmt/compile.h>
+#    endif
+#endif

include/spdlog/fmt/fmt.h

@@ -10,16 +10,20 @@
 // By default spdlog include its own copy.
 //
 
-#if !defined(SPDLOG_FMT_EXTERNAL)
-#if !defined(SPDLOG_COMPILED_LIB) && !defined(FMT_HEADER_ONLY)
-#define FMT_HEADER_ONLY
-#endif
-#ifndef FMT_USE_WINDOWS_H
-#define FMT_USE_WINDOWS_H 0
-#endif
-#include <spdlog/fmt/bundled/core.h>
-#include <spdlog/fmt/bundled/format.h>
+#if defined(SPDLOG_USE_STD_FORMAT) // SPDLOG_USE_STD_FORMAT is defined - use std::format
+#    include <format>
+#elif !defined(SPDLOG_FMT_EXTERNAL)
+#    if !defined(SPDLOG_COMPILED_LIB) && !defined(FMT_HEADER_ONLY)
+#        define FMT_HEADER_ONLY
+#    endif
+#    ifndef FMT_USE_WINDOWS_H
+#        define FMT_USE_WINDOWS_H 0
+#    endif
+// enable the 'n' flag in for backward compatibility with fmt 6.x
+#    define FMT_DEPRECATED_N_SPECIFIER
+#    include <spdlog/fmt/bundled/core.h>
+#    include <spdlog/fmt/bundled/format.h>
 #else // SPDLOG_FMT_EXTERNAL is defined - use external fmtlib
-#include <fmt/core.h>
-#include <fmt/format.h>
-#endif
+#    include <fmt/core.h>
+#    include <fmt/format.h>
+#endif

include/spdlog/fmt/ostr.h

@@ -8,13 +8,15 @@
 // include bundled or external copy of fmtlib's ostream support
 //
 
-#if !defined(SPDLOG_FMT_EXTERNAL)
-#ifdef SPDLOG_HEADER_ONLY
-#ifndef FMT_HEADER_ONLY
-#define FMT_HEADER_ONLY
-#endif
-#endif
-#include <spdlog/fmt/bundled/ostream.h>
-#else
-#include <fmt/ostream.h>
+#if !defined(SPDLOG_USE_STD_FORMAT)
+#    if !defined(SPDLOG_FMT_EXTERNAL)
+#        ifdef SPDLOG_HEADER_ONLY
+#            ifndef FMT_HEADER_ONLY
+#                define FMT_HEADER_ONLY
+#            endif
+#        endif
+#        include <spdlog/fmt/bundled/ostream.h>
+#    else
+#        include <fmt/ostream.h>
+#    endif
 #endif

include/spdlog/fmt/ranges.h

@@ -0,0 +1,22 @@
+//
+// Copyright(c) 2016 Gabi Melman.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+//
+
+#pragma once
+//
+// include bundled or external copy of fmtlib's ranges support
+//
+
+#if !defined(SPDLOG_USE_STD_FORMAT)
+#    if !defined(SPDLOG_FMT_EXTERNAL)
+#        ifdef SPDLOG_HEADER_ONLY
+#            ifndef FMT_HEADER_ONLY
+#                define FMT_HEADER_ONLY
+#            endif
+#        endif
+#        include <spdlog/fmt/bundled/ranges.h>
+#    else
+#        include <fmt/ranges.h>
+#    endif
+#endif

include/spdlog/fmt/xchar.h

@@ -0,0 +1,22 @@
+//
+// Copyright(c) 2016 Gabi Melman.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+//
+
+#pragma once
+//
+// include bundled or external copy of fmtlib's xchar support
+//
+
+#if !defined(SPDLOG_USE_STD_FORMAT)
+#    if !defined(SPDLOG_FMT_EXTERNAL)
+#        ifdef SPDLOG_HEADER_ONLY
+#            ifndef FMT_HEADER_ONLY
+#                define FMT_HEADER_ONLY
+#            endif
+#        endif
+#        include <spdlog/fmt/bundled/xchar.h>
+#    else
+#        include <fmt/xchar.h>
+#    endif
+#endif

include/spdlog/fwd.h

@@ -11,4 +11,8 @@ namespace sinks {
 class sink;
 }
 
+namespace level {
+enum level_enum : int;
+}
+
 } // namespace spdlog

include/spdlog/logger-inl.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/logger.h>
+#    include <spdlog/logger.h>
 #endif
 
 #include <spdlog/sinks/sink.h>
@@ -185,7 +185,7 @@ SPDLOG_INLINE void logger::sink_it_(const details::log_msg &msg)
             {
                 sink->log(msg);
             }
-            SPDLOG_LOGGER_CATCH()
+            SPDLOG_LOGGER_CATCH(msg.source)
         }
     }
 
@@ -203,7 +203,7 @@ SPDLOG_INLINE void logger::flush_()
         {
             sink->flush();
         }
-        SPDLOG_LOGGER_CATCH()
+        SPDLOG_LOGGER_CATCH(source_loc())
     }
 }
 
@@ -247,7 +247,11 @@ SPDLOG_INLINE void logger::err_handler_(const std::string &msg)
         auto tm_time = details::os::localtime(system_clock::to_time_t(now));
         char date_buf[64];
         std::strftime(date_buf, sizeof(date_buf), "%Y-%m-%d %H:%M:%S", &tm_time);
-        fprintf(stderr, "[*** LOG ERROR #%04zu ***] [%s] [%s] {%s}\n", err_counter, date_buf, name().c_str(), msg.c_str());
+#if defined(USING_R) && defined(R_R_H) // if in R environment
+        REprintf("[*** LOG ERROR #%04zu ***] [%s] [%s] {%s}\n", err_counter, date_buf, name().c_str(), msg.c_str());
+#else
+        std::fprintf(stderr, "[*** LOG ERROR #%04zu ***] [%s] [%s] {%s}\n", err_counter, date_buf, name().c_str(), msg.c_str());
+#endif
     }
 }
 } // namespace spdlog

include/spdlog/logger.h

@@ -19,22 +19,34 @@
 #include <spdlog/details/backtracer.h>
 
 #ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
-#include <spdlog/details/os.h>
+#    ifndef _WIN32
+#        error SPDLOG_WCHAR_TO_UTF8_SUPPORT only supported on windows
+#    endif
+#    include <spdlog/details/os.h>
 #endif
 
 #include <vector>
+
 #ifndef SPDLOG_NO_EXCEPTIONS
-#define SPDLOG_LOGGER_CATCH()                                                                                                              \
-    catch (const std::exception &ex)                                                                                                       \
-    {                                                                                                                                      \
-        err_handler_(ex.what());                                                                                                           \
-    }                                                                                                                                      \
-    catch (...)                                                                                                                            \
-    {                                                                                                                                      \
-        err_handler_("Unknown exception in logger");                                                                                       \
-    }
+#    define SPDLOG_LOGGER_CATCH(location)                                                                                                  \
+        catch (const std::exception &ex)                                                                                                   \
+        {                                                                                                                                  \
+            if (location.filename)                                                                                                         \
+            {                                                                                                                              \
+                err_handler_(fmt_lib::format("{} [{}({})]", ex.what(), location.filename, location.line));                                 \
+            }                                                                                                                              \
+            else                                                                                                                           \
+            {                                                                                                                              \
+                err_handler_(ex.what());                                                                                                   \
+            }                                                                                                                              \
+        }                                                                                                                                  \
+        catch (...)                                                                                                                        \
+        {                                                                                                                                  \
+            err_handler_("Rethrowing unknown exception in logger");                                                                        \
+            throw;                                                                                                                         \
+        }
 #else
-#define SPDLOG_LOGGER_CATCH()
+#    define SPDLOG_LOGGER_CATCH(location)
 #endif
 
 namespace spdlog {
@@ -70,68 +82,18 @@ public:
     logger(const logger &other);
     logger(logger &&other) SPDLOG_NOEXCEPT;
     logger &operator=(logger other) SPDLOG_NOEXCEPT;
-
     void swap(spdlog::logger &other) SPDLOG_NOEXCEPT;
 
     template<typename... Args>
-    void log(source_loc loc, level::level_enum lvl, string_view_t fmt, const Args &... args)
+    void log(source_loc loc, level::level_enum lvl, format_string_t<Args...> fmt, Args &&... args)
     {
-        bool log_enabled = should_log(lvl);
-        bool traceback_enabled = tracer_.enabled();
-        if (!log_enabled && !traceback_enabled)
-        {
-            return;
-        }
-        SPDLOG_TRY
-        {
-            memory_buf_t buf;
-            fmt::format_to(buf, fmt, args...);
-            details::log_msg log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size()));
-            log_it_(log_msg, log_enabled, traceback_enabled);
-        }
-        SPDLOG_LOGGER_CATCH()
+        log_(loc, lvl, fmt, std::forward<Args>(args)...);
     }
 
     template<typename... Args>
-    void log(level::level_enum lvl, string_view_t fmt, const Args &... args)
+    void log(level::level_enum lvl, format_string_t<Args...> fmt, Args &&... args)
     {
-        log(source_loc{}, lvl, fmt, args...);
-    }
-
-    template<typename... Args>
-    void trace(string_view_t fmt, const Args &... args)
-    {
-        log(level::trace, fmt, args...);
-    }
-
-    template<typename... Args>
-    void debug(string_view_t fmt, const Args &... args)
-    {
-        log(level::debug, fmt, args...);
-    }
-
-    template<typename... Args>
-    void info(string_view_t fmt, const Args &... args)
-    {
-        log(level::info, fmt, args...);
-    }
-
-    template<typename... Args>
-    void warn(string_view_t fmt, const Args &... args)
-    {
-        log(level::warn, fmt, args...);
-    }
-
-    template<typename... Args>
-    void error(string_view_t fmt, const Args &... args)
-    {
-        log(level::err, fmt, args...);
-    }
-
-    template<typename... Args>
-    void critical(string_view_t fmt, const Args &... args)
-    {
-        log(level::critical, fmt, args...);
+        log(source_loc{}, lvl, fmt, std::forward<Args>(args)...);
     }
 
     template<typename T>
@@ -140,11 +102,11 @@ public:
         log(source_loc{}, lvl, msg);
     }
 
-    // T can be statically converted to string_view
-    template<class T, typename std::enable_if<std::is_convertible<const T &, spdlog::string_view_t>::value, T>::type * = nullptr>
+    // T cannot be statically converted to format string (including string_view/wstring_view)
+    template<class T, typename std::enable_if<!is_convertible_to_any_format_string<const T &>::value, int>::type = 0>
     void log(source_loc loc, level::level_enum lvl, const T &msg)
     {
-        log(loc, lvl, string_view_t{msg});
+        log(loc, lvl, "{}", msg);
     }
 
     void log(log_clock::time_point log_time, source_loc loc, level::level_enum lvl, string_view_t msg)
@@ -178,15 +140,127 @@ public:
         log(source_loc{}, lvl, msg);
     }
 
-    // T cannot be statically converted to string_view or wstring_view
-    template<class T, typename std::enable_if<!std::is_convertible<const T &, spdlog::string_view_t>::value &&
-                                                  !is_convertible_to_wstring_view<const T &>::value,
-                          T>::type * = nullptr>
-    void log(source_loc loc, level::level_enum lvl, const T &msg)
+    template<typename... Args>
+    void trace(format_string_t<Args...> fmt, Args &&... args)
     {
-        log(loc, lvl, "{}", msg);
+        log(level::trace, fmt, std::forward<Args>(args)...);
     }
 
+    template<typename... Args>
+    void debug(format_string_t<Args...> fmt, Args &&... args)
+    {
+        log(level::debug, fmt, std::forward<Args>(args)...);
+    }
+
+    template<typename... Args>
+    void info(format_string_t<Args...> fmt, Args &&... args)
+    {
+        log(level::info, fmt, std::forward<Args>(args)...);
+    }
+
+    template<typename... Args>
+    void warn(format_string_t<Args...> fmt, Args &&... args)
+    {
+        log(level::warn, fmt, std::forward<Args>(args)...);
+    }
+
+    template<typename... Args>
+    void error(format_string_t<Args...> fmt, Args &&... args)
+    {
+        log(level::err, fmt, std::forward<Args>(args)...);
+    }
+
+    template<typename... Args>
+    void critical(format_string_t<Args...> fmt, Args &&... args)
+    {
+        log(level::critical, fmt, std::forward<Args>(args)...);
+    }
+
+#ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
+    template<typename... Args>
+    void log(source_loc loc, level::level_enum lvl, wformat_string_t<Args...> fmt, Args &&... args)
+    {
+        log_(loc, lvl, fmt, std::forward<Args>(args)...);
+    }
+
+    template<typename... Args>
+    void log(level::level_enum lvl, wformat_string_t<Args...> fmt, Args &&... args)
+    {
+        log(source_loc{}, lvl, fmt, std::forward<Args>(args)...);
+    }
+
+    void log(log_clock::time_point log_time, source_loc loc, level::level_enum lvl, wstring_view_t msg)
+    {
+        bool log_enabled = should_log(lvl);
+        bool traceback_enabled = tracer_.enabled();
+        if (!log_enabled && !traceback_enabled)
+        {
+            return;
+        }
+
+        memory_buf_t buf;
+        details::os::wstr_to_utf8buf(wstring_view_t(msg.data(), msg.size()), buf);
+        details::log_msg log_msg(log_time, loc, name_, lvl, string_view_t(buf.data(), buf.size()));
+        log_it_(log_msg, log_enabled, traceback_enabled);
+    }
+
+    void log(source_loc loc, level::level_enum lvl, wstring_view_t msg)
+    {
+        bool log_enabled = should_log(lvl);
+        bool traceback_enabled = tracer_.enabled();
+        if (!log_enabled && !traceback_enabled)
+        {
+            return;
+        }
+
+        memory_buf_t buf;
+        details::os::wstr_to_utf8buf(wstring_view_t(msg.data(), msg.size()), buf);
+        details::log_msg log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size()));
+        log_it_(log_msg, log_enabled, traceback_enabled);
+    }
+
+    void log(level::level_enum lvl, wstring_view_t msg)
+    {
+        log(source_loc{}, lvl, msg);
+    }
+
+    template<typename... Args>
+    void trace(wformat_string_t<Args...> fmt, Args &&... args)
+    {
+        log(level::trace, fmt, std::forward<Args>(args)...);
+    }
+
+    template<typename... Args>
+    void debug(wformat_string_t<Args...> fmt, Args &&... args)
+    {
+        log(level::debug, fmt, std::forward<Args>(args)...);
+    }
+
+    template<typename... Args>
+    void info(wformat_string_t<Args...> fmt, Args &&... args)
+    {
+        log(level::info, fmt, std::forward<Args>(args)...);
+    }
+
+    template<typename... Args>
+    void warn(wformat_string_t<Args...> fmt, Args &&... args)
+    {
+        log(level::warn, fmt, std::forward<Args>(args)...);
+    }
+
+    template<typename... Args>
+    void error(wformat_string_t<Args...> fmt, Args &&... args)
+    {
+        log(level::err, fmt, std::forward<Args>(args)...);
+    }
+
+    template<typename... Args>
+    void critical(wformat_string_t<Args...> fmt, Args &&... args)
+    {
+        log(level::critical, fmt, std::forward<Args>(args)...);
+    }
+#endif
+
     template<typename T>
     void trace(const T &msg)
     {
@@ -223,99 +297,6 @@ public:
         log(level::critical, msg);
     }
 
-#ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
-#ifndef _WIN32
-#error SPDLOG_WCHAR_TO_UTF8_SUPPORT only supported on windows
-#else
-
-    template<typename... Args>
-    void log(source_loc loc, level::level_enum lvl, wstring_view_t fmt, const Args &... args)
-    {
-        bool log_enabled = should_log(lvl);
-        bool traceback_enabled = tracer_.enabled();
-        if (!log_enabled && !traceback_enabled)
-        {
-            return;
-        }
-        SPDLOG_TRY
-        {
-            // format to wmemory_buffer and convert to utf8
-            fmt::wmemory_buffer wbuf;
-            fmt::format_to(wbuf, fmt, args...);
-
-            memory_buf_t buf;
-            details::os::wstr_to_utf8buf(wstring_view_t(wbuf.data(), wbuf.size()), buf);
-            details::log_msg log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size()));
-            log_it_(log_msg, log_enabled, traceback_enabled);
-        }
-        SPDLOG_LOGGER_CATCH()
-    }
-
-    template<typename... Args>
-    void log(level::level_enum lvl, wstring_view_t fmt, const Args &... args)
-    {
-        log(source_loc{}, lvl, fmt, args...);
-    }
-
-    template<typename... Args>
-    void trace(wstring_view_t fmt, const Args &... args)
-    {
-        log(level::trace, fmt, args...);
-    }
-
-    template<typename... Args>
-    void debug(wstring_view_t fmt, const Args &... args)
-    {
-        log(level::debug, fmt, args...);
-    }
-
-    template<typename... Args>
-    void info(wstring_view_t fmt, const Args &... args)
-    {
-        log(level::info, fmt, args...);
-    }
-
-    template<typename... Args>
-    void warn(wstring_view_t fmt, const Args &... args)
-    {
-        log(level::warn, fmt, args...);
-    }
-
-    template<typename... Args>
-    void error(wstring_view_t fmt, const Args &... args)
-    {
-        log(level::err, fmt, args...);
-    }
-
-    template<typename... Args>
-    void critical(wstring_view_t fmt, const Args &... args)
-    {
-        log(level::critical, fmt, args...);
-    }
-
-    // T can be statically converted to wstring_view
-    template<class T, typename std::enable_if<is_convertible_to_wstring_view<const T &>::value, T>::type * = nullptr>
-    void log(source_loc loc, level::level_enum lvl, const T &msg)
-    {
-        bool log_enabled = should_log(lvl);
-        bool traceback_enabled = tracer_.enabled();
-        if (!log_enabled && !traceback_enabled)
-        {
-            return;
-        }
-
-        SPDLOG_TRY
-        {
-            memory_buf_t buf;
-            details::os::wstr_to_utf8buf(msg, buf);
-            details::log_msg log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size()));
-            log_it_(log_msg, log_enabled, traceback_enabled);
-        }
-        SPDLOG_LOGGER_CATCH()
-    }
-#endif // _WIN32
-#endif // SPDLOG_WCHAR_TO_UTF8_SUPPORT
-
     // return true logging is enabled for the given level.
     bool should_log(level::level_enum msg_level) const
     {
@@ -370,6 +351,80 @@ protected:
     err_handler custom_err_handler_{nullptr};
     details::backtracer tracer_;
 
+    // common implementation for after templated public api has been resolved
+    template<typename... Args>
+    void log_(source_loc loc, level::level_enum lvl, string_view_t fmt, Args &&... args)
+    {
+        bool log_enabled = should_log(lvl);
+        bool traceback_enabled = tracer_.enabled();
+        if (!log_enabled && !traceback_enabled)
+        {
+            return;
+        }
+        SPDLOG_TRY
+        {
+#ifdef SPDLOG_USE_STD_FORMAT
+            memory_buf_t buf = std::vformat(fmt, std::make_format_args(std::forward<Args>(args)...));
+#else
+            memory_buf_t buf;
+            fmt::detail::vformat_to(buf, fmt, fmt::make_format_args(std::forward<Args>(args)...));
+#endif
+            details::log_msg log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size()));
+            log_it_(log_msg, log_enabled, traceback_enabled);
+        }
+        SPDLOG_LOGGER_CATCH(loc)
+    }
+
+#ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
+    template<typename... Args>
+    void log_(source_loc loc, level::level_enum lvl, wstring_view_t fmt, Args &&... args)
+    {
+        bool log_enabled = should_log(lvl);
+        bool traceback_enabled = tracer_.enabled();
+        if (!log_enabled && !traceback_enabled)
+        {
+            return;
+        }
+        SPDLOG_TRY
+        {
+            // format to wmemory_buffer and convert to utf8
+            ;
+#    ifdef SPDLOG_USE_STD_FORMAT
+            wmemory_buf_t wbuf = std::vformat(fmt, std::make_wformat_args(std::forward<Args>(args)...));
+#    else
+            wmemory_buf_t wbuf;
+            fmt::detail::vformat_to(wbuf, fmt, fmt::make_format_args<fmt::wformat_context>(std::forward<Args>(args)...));
+#    endif
+            memory_buf_t buf;
+            details::os::wstr_to_utf8buf(wstring_view_t(wbuf.data(), wbuf.size()), buf);
+            details::log_msg log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size()));
+            log_it_(log_msg, log_enabled, traceback_enabled);
+        }
+        SPDLOG_LOGGER_CATCH(loc)
+    }
+
+    // T can be statically converted to wstring_view, and no formatting needed.
+    template<class T, typename std::enable_if<std::is_convertible<const T &, spdlog::wstring_view_t>::value, int>::type = 0>
+    void log_(source_loc loc, level::level_enum lvl, const T &msg)
+    {
+        bool log_enabled = should_log(lvl);
+        bool traceback_enabled = tracer_.enabled();
+        if (!log_enabled && !traceback_enabled)
+        {
+            return;
+        }
+        SPDLOG_TRY
+        {
+            memory_buf_t buf;
+            details::os::wstr_to_utf8buf(msg, buf);
+            details::log_msg log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size()));
+            log_it_(log_msg, log_enabled, traceback_enabled);
+        }
+        SPDLOG_LOGGER_CATCH(loc)
+    }
+
+#endif // SPDLOG_WCHAR_TO_UTF8_SUPPORT
+
     // log the given message (if the given log level is high enough),
     // and save backtrace (if backtrace is enabled).
     void log_it_(const details::log_msg &log_msg, bool log_enabled, bool traceback_enabled);
@@ -388,5 +443,5 @@ void swap(logger &a, logger &b);
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "logger-inl.h"
+#    include "logger-inl.h"
 #endif

include/spdlog/pattern_formatter-inl.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/pattern_formatter.h>
+#    include <spdlog/pattern_formatter.h>
 #endif
 
 #include <spdlog/details/fmt_helper.h>
@@ -13,11 +13,13 @@
 #include <spdlog/fmt/fmt.h>
 #include <spdlog/formatter.h>
 
+#include <algorithm>
 #include <array>
 #include <chrono>
 #include <ctime>
 #include <cctype>
 #include <cstring>
+#include <iterator>
 #include <memory>
 #include <mutex>
 #include <string>
@@ -45,12 +47,12 @@ public:
             return;
         }
 
-        if (padinfo_.side_ == padding_info::left)
+        if (padinfo_.side_ == padding_info::pad_side::left)
         {
             pad_it(remaining_pad_);
             remaining_pad_ = 0;
         }
-        else if (padinfo_.side_ == padding_info::center)
+        else if (padinfo_.side_ == padding_info::pad_side::center)
         {
             auto half_pad = remaining_pad_ / 2;
             auto reminder = remaining_pad_ & 1;
@@ -127,7 +129,7 @@ public:
 
     void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {
-        string_view_t &level_name = level::to_string_view(msg.level);
+        const string_view_t &level_name = level::to_string_view(msg.level);
         ScopedPadder p(level_name.size(), padinfo_, dest);
         fmt_helper::append_string_view(level_name, dest);
     }
@@ -764,6 +766,7 @@ public:
     {
         if (msg.source.empty())
         {
+            ScopedPadder p(0, padinfo_, dest);
             return;
         }
 
@@ -798,6 +801,7 @@ public:
     {
         if (msg.source.empty())
         {
+            ScopedPadder p(0, padinfo_, dest);
             return;
         }
         size_t text_size = padinfo_.enabled() ? std::char_traits<char>::length(msg.source.filename) : 0;
@@ -814,16 +818,37 @@ public:
         : flag_formatter(padinfo)
     {}
 
+#ifdef _MSC_VER
+#    pragma warning(push)
+#    pragma warning(disable : 4127) // consider using 'if constexpr' instead
+#endif                              // _MSC_VER
     static const char *basename(const char *filename)
     {
-        const char *rv = std::strrchr(filename, os::folder_sep);
-        return rv != nullptr ? rv + 1 : filename;
+        // if the size is 2 (1 character + null terminator) we can use the more efficient strrchr
+        // the branch will be elided by optimizations
+        if (sizeof(os::folder_seps) == 2)
+        {
+            const char *rv = std::strrchr(filename, os::folder_seps[0]);
+            return rv != nullptr ? rv + 1 : filename;
+        }
+        else
+        {
+            const std::reverse_iterator<const char *> begin(filename + std::strlen(filename));
+            const std::reverse_iterator<const char *> end(filename);
+
+            const auto it = std::find_first_of(begin, end, std::begin(os::folder_seps), std::end(os::folder_seps) - 1);
+            return it != end ? it.base() : filename;
+        }
     }
+#ifdef _MSC_VER
+#    pragma warning(pop)
+#endif // _MSC_VER
 
     void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {
         if (msg.source.empty())
         {
+            ScopedPadder p(0, padinfo_, dest);
             return;
         }
         auto filename = basename(msg.source.filename);
@@ -845,6 +870,7 @@ public:
     {
         if (msg.source.empty())
         {
+            ScopedPadder p(0, padinfo_, dest);
             return;
         }
 
@@ -867,6 +893,7 @@ public:
     {
         if (msg.source.empty())
         {
+            ScopedPadder p(0, padinfo_, dest);
             return;
         }
         size_t text_size = padinfo_.enabled() ? std::char_traits<char>::length(msg.source.funcname) : 0;
@@ -903,7 +930,7 @@ private:
 };
 
 // Full info formatter
-// pattern: [%Y-%m-%d %H:%M:%S.%e] [%n] [%l] %v
+// pattern: [%Y-%m-%d %H:%M:%S.%e] [%n] [%l] [%s:%#] %v
 class full_formatter final : public flag_formatter
 {
 public:
@@ -997,6 +1024,7 @@ SPDLOG_INLINE pattern_formatter::pattern_formatter(
     : pattern_(std::move(pattern))
     , eol_(std::move(eol))
     , pattern_time_type_(time_type)
+    , need_localtime_(false)
     , last_log_secs_(0)
     , custom_handlers_(std::move(custom_user_flags))
 {
@@ -1009,6 +1037,7 @@ SPDLOG_INLINE pattern_formatter::pattern_formatter(pattern_time_type time_type,
     : pattern_("%+")
     , eol_(std::move(eol))
     , pattern_time_type_(time_type)
+    , need_localtime_(true)
     , last_log_secs_(0)
 {
     std::memset(&cached_tm_, 0, sizeof(cached_tm_));
@@ -1027,11 +1056,14 @@ SPDLOG_INLINE std::unique_ptr<formatter> pattern_formatter::clone() const
 
 SPDLOG_INLINE void pattern_formatter::format(const details::log_msg &msg, memory_buf_t &dest)
 {
-    auto secs = std::chrono::duration_cast<std::chrono::seconds>(msg.time.time_since_epoch());
-    if (secs != last_log_secs_)
+    if (need_localtime_)
     {
-        cached_tm_ = get_time_(msg);
-        last_log_secs_ = secs;
+        const auto secs = std::chrono::duration_cast<std::chrono::seconds>(msg.time.time_since_epoch());
+        if (secs != last_log_secs_)
+        {
+            cached_tm_ = get_time_(msg);
+            last_log_secs_ = secs;
+        }
     }
 
     for (auto &f : formatters_)
@@ -1045,6 +1077,7 @@ SPDLOG_INLINE void pattern_formatter::format(const details::log_msg &msg, memory
 SPDLOG_INLINE void pattern_formatter::set_pattern(std::string pattern)
 {
     pattern_ = std::move(pattern);
+    need_localtime_ = false;
     compile_pattern_(pattern_);
 }
 
@@ -1075,6 +1108,7 @@ SPDLOG_INLINE void pattern_formatter::handle_flag_(char flag, details::padding_i
     {
     case ('+'): // default formatter
         formatters_.push_back(details::make_unique<details::full_formatter>(padding));
+        need_localtime_ = true;
         break;
 
     case 'n': // logger name
@@ -1099,60 +1133,74 @@ SPDLOG_INLINE void pattern_formatter::handle_flag_(char flag, details::padding_i
 
     case ('a'): // weekday
         formatters_.push_back(details::make_unique<details::a_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('A'): // short weekday
         formatters_.push_back(details::make_unique<details::A_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('b'):
     case ('h'): // month
         formatters_.push_back(details::make_unique<details::b_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('B'): // short month
         formatters_.push_back(details::make_unique<details::B_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('c'): // datetime
         formatters_.push_back(details::make_unique<details::c_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('C'): // year 2 digits
         formatters_.push_back(details::make_unique<details::C_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('Y'): // year 4 digits
         formatters_.push_back(details::make_unique<details::Y_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('D'):
     case ('x'): // datetime MM/DD/YY
         formatters_.push_back(details::make_unique<details::D_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('m'): // month 1-12
         formatters_.push_back(details::make_unique<details::m_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('d'): // day of month 1-31
         formatters_.push_back(details::make_unique<details::d_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('H'): // hours 24
         formatters_.push_back(details::make_unique<details::H_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('I'): // hours 12
         formatters_.push_back(details::make_unique<details::I_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('M'): // minutes
         formatters_.push_back(details::make_unique<details::M_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('S'): // seconds
         formatters_.push_back(details::make_unique<details::S_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('e'): // milliseconds
@@ -1173,23 +1221,28 @@ SPDLOG_INLINE void pattern_formatter::handle_flag_(char flag, details::padding_i
 
     case ('p'): // am/pm
         formatters_.push_back(details::make_unique<details::p_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('r'): // 12 hour clock 02:55:02 pm
         formatters_.push_back(details::make_unique<details::r_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('R'): // 24-hour HH:MM time
         formatters_.push_back(details::make_unique<details::R_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('T'):
     case ('X'): // ISO 8601 time format (HH:MM:SS)
         formatters_.push_back(details::make_unique<details::T_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('z'): // timezone
         formatters_.push_back(details::make_unique<details::z_formatter<Padder>>(padding));
+        need_localtime_ = true;
         break;
 
     case ('P'): // pid
@@ -1246,9 +1299,24 @@ SPDLOG_INLINE void pattern_formatter::handle_flag_(char flag, details::padding_i
 
     default: // Unknown flag appears as is
         auto unknown_flag = details::make_unique<details::aggregate_formatter>();
-        unknown_flag->add_ch('%');
-        unknown_flag->add_ch(flag);
-        formatters_.push_back((std::move(unknown_flag)));
+
+        if (!padding.truncate_)
+        {
+            unknown_flag->add_ch('%');
+            unknown_flag->add_ch(flag);
+            formatters_.push_back((std::move(unknown_flag)));
+        }
+        // fix issue #1617 (prev char was '!' and should have been treated as funcname flag instead of truncating flag)
+        // spdlog::set_pattern("[%10!] %v") => "[      main] some message"
+        // spdlog::set_pattern("[%3!!] %v") => "[mai] some message"
+        else
+        {
+            padding.truncate_ = false;
+            formatters_.push_back(details::make_unique<details::source_funcname_formatter<Padder>>(padding));
+            unknown_flag->add_ch(flag);
+            formatters_.push_back((std::move(unknown_flag)));
+        }
+
         break;
     }
 }
@@ -1270,15 +1338,15 @@ SPDLOG_INLINE details::padding_info pattern_formatter::handle_padspec_(std::stri
     switch (*it)
     {
     case '-':
-        side = padding_info::right;
+        side = padding_info::pad_side::right;
         ++it;
         break;
     case '=':
-        side = padding_info::center;
+        side = padding_info::pad_side::center;
         ++it;
         break;
     default:
-        side = details::padding_info::left;
+        side = details::padding_info::pad_side::left;
         break;
     }
 
@@ -1305,7 +1373,6 @@ SPDLOG_INLINE details::padding_info pattern_formatter::handle_padspec_(std::stri
     {
         truncate = false;
     }
-
     return details::padding_info{std::min<size_t>(width, max_width), side, truncate};
 }
 

include/spdlog/pattern_formatter.h

@@ -22,7 +22,7 @@ namespace details {
 // padding information.
 struct padding_info
 {
-    enum pad_side
+    enum class pad_side
     {
         left,
         right,
@@ -42,7 +42,7 @@ struct padding_info
         return enabled_;
     }
     size_t width_ = 0;
-    pad_side side_ = left;
+    pad_side side_ = pad_side::left;
     bool truncate_ = false;
     bool enabled_ = false;
 };
@@ -68,7 +68,7 @@ class SPDLOG_API custom_flag_formatter : public details::flag_formatter
 public:
     virtual std::unique_ptr<custom_flag_formatter> clone() const = 0;
 
-    void set_padding_info(details::padding_info padding)
+    void set_padding_info(const details::padding_info &padding)
     {
         flag_formatter::padinfo_ = padding;
     }
@@ -92,9 +92,9 @@ public:
     void format(const details::log_msg &msg, memory_buf_t &dest) override;
 
     template<typename T, typename... Args>
-    pattern_formatter &add_flag(char flag, const Args &... args)
+    pattern_formatter &add_flag(char flag, Args &&... args)
     {
-        custom_handlers_[flag] = details::make_unique<T>(args...);
+        custom_handlers_[flag] = details::make_unique<T>(std::forward<Args>(args)...);
         return *this;
     }
     void set_pattern(std::string pattern);
@@ -103,6 +103,7 @@ private:
     std::string pattern_;
     std::string eol_;
     pattern_time_type pattern_time_type_;
+    bool need_localtime_;
     std::tm cached_tm_;
     std::chrono::seconds last_log_secs_;
     std::vector<std::unique_ptr<details::flag_formatter>> formatters_;
@@ -122,5 +123,5 @@ private:
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "pattern_formatter-inl.h"
+#    include "pattern_formatter-inl.h"
 #endif

include/spdlog/sinks/android_sink.h

@@ -5,21 +5,21 @@
 
 #ifdef __ANDROID__
 
-#include <spdlog/details/fmt_helper.h>
-#include <spdlog/details/null_mutex.h>
-#include <spdlog/details/os.h>
-#include <spdlog/sinks/base_sink.h>
-#include <spdlog/details/synchronous_factory.h>
+#    include <spdlog/details/fmt_helper.h>
+#    include <spdlog/details/null_mutex.h>
+#    include <spdlog/details/os.h>
+#    include <spdlog/sinks/base_sink.h>
+#    include <spdlog/details/synchronous_factory.h>
 
-#include <android/log.h>
-#include <chrono>
-#include <mutex>
-#include <string>
-#include <thread>
+#    include <android/log.h>
+#    include <chrono>
+#    include <mutex>
+#    include <string>
+#    include <thread>
 
-#if !defined(SPDLOG_ANDROID_RETRIES)
-#define SPDLOG_ANDROID_RETRIES 2
-#endif
+#    if !defined(SPDLOG_ANDROID_RETRIES)
+#        define SPDLOG_ANDROID_RETRIES 2
+#    endif
 
 namespace spdlog {
 namespace sinks {

include/spdlog/sinks/ansicolor_sink-inl.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/sinks/ansicolor_sink.h>
+#    include <spdlog/sinks/ansicolor_sink.h>
 #endif
 
 #include <spdlog/pattern_formatter.h>
@@ -34,7 +34,7 @@ template<typename ConsoleMutex>
 SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::set_color(level::level_enum color_level, string_view_t color)
 {
     std::lock_guard<mutex_t> lock(mutex_);
-    colors_[color_level] = to_string_(color);
+    colors_[static_cast<size_t>(color_level)] = to_string_(color);
 }
 
 template<typename ConsoleMutex>
@@ -52,7 +52,7 @@ SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::log(const details::log_msg &msg
         // before color range
         print_range_(formatted, 0, msg.color_range_start);
         // in color range
-        print_ccode_(colors_[msg.level]);
+        print_ccode_(colors_[static_cast<size_t>(msg.level)]);
         print_range_(formatted, msg.color_range_start, msg.color_range_end);
         print_ccode_(reset);
         // after color range
@@ -106,6 +106,8 @@ SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::set_color_mode(color_mode mode)
     case color_mode::never:
         should_do_colors_ = false;
         return;
+    default:
+        should_do_colors_ = false;
     }
 }
 

include/spdlog/sinks/ansicolor_sink.h

@@ -114,5 +114,5 @@ using ansicolor_stderr_sink_st = ansicolor_stderr_sink<details::console_nullmute
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "ansicolor_sink-inl.h"
+#    include "ansicolor_sink-inl.h"
 #endif

include/spdlog/sinks/base_sink-inl.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/sinks/base_sink.h>
+#    include <spdlog/sinks/base_sink.h>
 #endif
 
 #include <spdlog/common.h>

include/spdlog/sinks/base_sink.h

@@ -16,7 +16,7 @@
 namespace spdlog {
 namespace sinks {
 template<typename Mutex>
-class base_sink : public sink
+class SPDLOG_API base_sink : public sink
 {
 public:
     base_sink();
@@ -48,5 +48,5 @@ protected:
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "base_sink-inl.h"
+#    include "base_sink-inl.h"
 #endif

include/spdlog/sinks/basic_file_sink-inl.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/sinks/basic_file_sink.h>
+#    include <spdlog/sinks/basic_file_sink.h>
 #endif
 
 #include <spdlog/common.h>
@@ -14,7 +14,8 @@ namespace spdlog {
 namespace sinks {
 
 template<typename Mutex>
-SPDLOG_INLINE basic_file_sink<Mutex>::basic_file_sink(const filename_t &filename, bool truncate)
+SPDLOG_INLINE basic_file_sink<Mutex>::basic_file_sink(const filename_t &filename, bool truncate, const file_event_handlers &event_handlers)
+    : file_helper_{event_handlers}
 {
     file_helper_.open(filename, truncate);
 }

include/spdlog/sinks/basic_file_sink.h

@@ -20,7 +20,7 @@ template<typename Mutex>
 class basic_file_sink final : public base_sink<Mutex>
 {
 public:
-    explicit basic_file_sink(const filename_t &filename, bool truncate = false);
+    explicit basic_file_sink(const filename_t &filename, bool truncate = false, const file_event_handlers &event_handlers = {});
     const filename_t &filename() const;
 
 protected:
@@ -40,19 +40,21 @@ using basic_file_sink_st = basic_file_sink<details::null_mutex>;
 // factory functions
 //
 template<typename Factory = spdlog::synchronous_factory>
-inline std::shared_ptr<logger> basic_logger_mt(const std::string &logger_name, const filename_t &filename, bool truncate = false)
+inline std::shared_ptr<logger> basic_logger_mt(
+    const std::string &logger_name, const filename_t &filename, bool truncate = false, const file_event_handlers &event_handlers = {})
 {
-    return Factory::template create<sinks::basic_file_sink_mt>(logger_name, filename, truncate);
+    return Factory::template create<sinks::basic_file_sink_mt>(logger_name, filename, truncate, event_handlers);
 }
 
 template<typename Factory = spdlog::synchronous_factory>
-inline std::shared_ptr<logger> basic_logger_st(const std::string &logger_name, const filename_t &filename, bool truncate = false)
+inline std::shared_ptr<logger> basic_logger_st(
+    const std::string &logger_name, const filename_t &filename, bool truncate = false, const file_event_handlers &event_handlers = {})
 {
-    return Factory::template create<sinks::basic_file_sink_st>(logger_name, filename, truncate);
+    return Factory::template create<sinks::basic_file_sink_st>(logger_name, filename, truncate, event_handlers);
 }
 
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "basic_file_sink-inl.h"
-#endif
+#    include "basic_file_sink-inl.h"
+#endif

include/spdlog/sinks/daily_file_sink.h

@@ -7,6 +7,7 @@
 #include <spdlog/details/file_helper.h>
 #include <spdlog/details/null_mutex.h>
 #include <spdlog/fmt/fmt.h>
+#include <spdlog/fmt/chrono.h>
 #include <spdlog/sinks/base_sink.h>
 #include <spdlog/details/os.h>
 #include <spdlog/details/circular_q.h>
@@ -31,11 +32,80 @@ struct daily_filename_calculator
     {
         filename_t basename, ext;
         std::tie(basename, ext) = details::file_helper::split_by_extension(filename);
-        return fmt::format(
+        return fmt_lib::format(
             SPDLOG_FILENAME_T("{}_{:04d}-{:02d}-{:02d}{}"), basename, now_tm.tm_year + 1900, now_tm.tm_mon + 1, now_tm.tm_mday, ext);
     }
 };
 
+/*
+ * Generator of daily log file names with strftime format.
+ * Usages:
+ *    auto sink =  std::make_shared<spdlog::sinks::daily_file_format_sink_mt>("myapp-%Y-%m-%d:%H:%M:%S.log", hour, minute);"
+ *    auto logger = spdlog::daily_logger_format_mt("loggername, "myapp-%Y-%m-%d:%X.log", hour,  minute)"
+ *
+ */
+struct daily_filename_format_calculator
+{
+    static filename_t calc_filename(const filename_t &filename, const tm &now_tm)
+    {
+#ifdef SPDLOG_USE_STD_FORMAT
+        // adapted from fmtlib: https://github.com/fmtlib/fmt/blob/8.0.1/include/fmt/chrono.h#L522-L546
+
+        filename_t tm_format;
+        tm_format.append(filename);
+        // By appending an extra space we can distinguish an empty result that
+        // indicates insufficient buffer size from a guaranteed non-empty result
+        // https://github.com/fmtlib/fmt/issues/2238
+        tm_format.push_back(' ');
+
+        const size_t MIN_SIZE = 10;
+        filename_t buf;
+        buf.resize(MIN_SIZE);
+        for (;;)
+        {
+            size_t count = strftime(buf.data(), buf.size(), tm_format.c_str(), &now_tm);
+            if (count != 0)
+            {
+                // Remove the extra space.
+                buf.resize(count - 1);
+                break;
+            }
+            buf.resize(buf.size() * 2);
+        }
+
+        return buf;
+#else
+        // generate fmt datetime format string, e.g. {:%Y-%m-%d}.
+        filename_t fmt_filename = fmt::format(SPDLOG_FILENAME_T("{{:{}}}"), filename);
+#    if defined(_MSC_VER) && defined(SPDLOG_WCHAR_FILENAMES) // for some reason msvc doesn't allow fmt::runtime(..) with wchar here
+        return fmt::format(fmt_filename, now_tm);
+#    else
+        return fmt::format(SPDLOG_FMT_RUNTIME(fmt_filename), now_tm);
+#    endif
+#endif
+    }
+
+private:
+#if defined __GNUC__
+#    pragma GCC diagnostic push
+#    pragma GCC diagnostic ignored "-Wformat-nonliteral"
+#endif
+
+    static size_t strftime(char *str, size_t count, const char *format, const std::tm *time)
+    {
+        return std::strftime(str, count, format, time);
+    }
+
+    static size_t strftime(wchar_t *str, size_t count, const wchar_t *format, const std::tm *time)
+    {
+        return std::wcsftime(str, count, format, time);
+    }
+
+#if defined(__GNUC__)
+#    pragma GCC diagnostic pop
+#endif
+};
+
 /*
  * Rotating file sink based on date.
  * If truncate != false , the created file will be truncated.
@@ -46,10 +116,12 @@ class daily_file_sink final : public base_sink<Mutex>
 {
 public:
     // create daily file sink which rotates on given time
-    daily_file_sink(filename_t base_filename, int rotation_hour, int rotation_minute, bool truncate = false, uint16_t max_files = 0)
+    daily_file_sink(filename_t base_filename, int rotation_hour, int rotation_minute, bool truncate = false, uint16_t max_files = 0,
+        const file_event_handlers &event_handlers = {})
         : base_filename_(std::move(base_filename))
         , rotation_h_(rotation_hour)
         , rotation_m_(rotation_minute)
+        , file_helper_{event_handlers}
         , truncate_(truncate)
         , max_files_(max_files)
         , filenames_q_()
@@ -182,6 +254,8 @@ private:
 
 using daily_file_sink_mt = daily_file_sink<std::mutex>;
 using daily_file_sink_st = daily_file_sink<details::null_mutex>;
+using daily_file_format_sink_mt = daily_file_sink<std::mutex, daily_filename_format_calculator>;
+using daily_file_format_sink_st = daily_file_sink<details::null_mutex, daily_filename_format_calculator>;
 
 } // namespace sinks
 
@@ -189,16 +263,32 @@ using daily_file_sink_st = daily_file_sink<details::null_mutex>;
 // factory functions
 //
 template<typename Factory = spdlog::synchronous_factory>
-inline std::shared_ptr<logger> daily_logger_mt(
-    const std::string &logger_name, const filename_t &filename, int hour = 0, int minute = 0, bool truncate = false, uint16_t max_files = 0)
+inline std::shared_ptr<logger> daily_logger_mt(const std::string &logger_name, const filename_t &filename, int hour = 0, int minute = 0,
+    bool truncate = false, uint16_t max_files = 0, const file_event_handlers &event_handlers = {})
 {
-    return Factory::template create<sinks::daily_file_sink_mt>(logger_name, filename, hour, minute, truncate, max_files);
+    return Factory::template create<sinks::daily_file_sink_mt>(logger_name, filename, hour, minute, truncate, max_files, event_handlers);
 }
 
 template<typename Factory = spdlog::synchronous_factory>
-inline std::shared_ptr<logger> daily_logger_st(
-    const std::string &logger_name, const filename_t &filename, int hour = 0, int minute = 0, bool truncate = false, uint16_t max_files = 0)
+inline std::shared_ptr<logger> daily_logger_format_mt(const std::string &logger_name, const filename_t &filename, int hour = 0,
+    int minute = 0, bool truncate = false, uint16_t max_files = 0, const file_event_handlers &event_handlers = {})
 {
-    return Factory::template create<sinks::daily_file_sink_st>(logger_name, filename, hour, minute, truncate, max_files);
+    return Factory::template create<sinks::daily_file_format_sink_mt>(
+        logger_name, filename, hour, minute, truncate, max_files, event_handlers);
+}
+
+template<typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> daily_logger_st(const std::string &logger_name, const filename_t &filename, int hour = 0, int minute = 0,
+    bool truncate = false, uint16_t max_files = 0, const file_event_handlers &event_handlers = {})
+{
+    return Factory::template create<sinks::daily_file_sink_st>(logger_name, filename, hour, minute, truncate, max_files, event_handlers);
+}
+
+template<typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> daily_logger_format_st(const std::string &logger_name, const filename_t &filename, int hour = 0,
+    int minute = 0, bool truncate = false, uint16_t max_files = 0, const file_event_handlers &event_handlers = {})
+{
+    return Factory::template create<sinks::daily_file_format_sink_st>(
+        logger_name, filename, hour, minute, truncate, max_files, event_handlers);
 }
 } // namespace spdlog

include/spdlog/sinks/dup_filter_sink.h

@@ -7,6 +7,7 @@
 #include <spdlog/details/null_mutex.h>
 #include <spdlog/details/log_msg.h>
 
+#include <cstdio>
 #include <mutex>
 #include <string>
 #include <chrono>
@@ -62,10 +63,13 @@ protected:
         // log the "skipped.." message
         if (skip_counter_ > 0)
         {
-            memory_buf_t buf;
-            fmt::format_to(buf, "Skipped {} duplicate messages..", skip_counter_);
-            details::log_msg skipped_msg{msg.logger_name, msg.level, string_view_t{buf.data(), buf.size()}};
-            dist_sink<Mutex>::sink_it_(skipped_msg);
+            char buf[64];
+            auto msg_size = ::snprintf(buf, sizeof(buf), "Skipped %u duplicate messages..", static_cast<unsigned>(skip_counter_));
+            if (msg_size > 0 && static_cast<size_t>(msg_size) < sizeof(buf))
+            {
+                details::log_msg skipped_msg{msg.logger_name, level::info, string_view_t{buf, static_cast<size_t>(msg_size)}};
+                dist_sink<Mutex>::sink_it_(skipped_msg);
+            }
         }
 
         // log current message

include/spdlog/sinks/hourly_file_sink.h

@@ -0,0 +1,196 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include <spdlog/common.h>
+#include <spdlog/details/file_helper.h>
+#include <spdlog/details/null_mutex.h>
+#include <spdlog/fmt/fmt.h>
+#include <spdlog/sinks/base_sink.h>
+#include <spdlog/details/os.h>
+#include <spdlog/details/circular_q.h>
+#include <spdlog/details/synchronous_factory.h>
+
+#include <chrono>
+#include <cstdio>
+#include <ctime>
+#include <mutex>
+#include <string>
+
+namespace spdlog {
+namespace sinks {
+
+/*
+ * Generator of Hourly log file names in format basename.YYYY-MM-DD-HH.ext
+ */
+struct hourly_filename_calculator
+{
+    // Create filename for the form basename.YYYY-MM-DD-H
+    static filename_t calc_filename(const filename_t &filename, const tm &now_tm)
+    {
+        filename_t basename, ext;
+        std::tie(basename, ext) = details::file_helper::split_by_extension(filename);
+        return fmt_lib::format(SPDLOG_FILENAME_T("{}_{:04d}-{:02d}-{:02d}_{:02d}{}"), basename, now_tm.tm_year + 1900, now_tm.tm_mon + 1,
+            now_tm.tm_mday, now_tm.tm_hour, ext);
+    }
+};
+
+/*
+ * Rotating file sink based on time.
+ * If truncate != false , the created file will be truncated.
+ * If max_files > 0, retain only the last max_files and delete previous.
+ */
+template<typename Mutex, typename FileNameCalc = hourly_filename_calculator>
+class hourly_file_sink final : public base_sink<Mutex>
+{
+public:
+    // create hourly file sink which rotates on given time
+    hourly_file_sink(
+        filename_t base_filename, bool truncate = false, uint16_t max_files = 0, const file_event_handlers &event_handlers = {})
+        : base_filename_(std::move(base_filename))
+        , file_helper_{event_handlers}
+        , truncate_(truncate)
+        , max_files_(max_files)
+        , filenames_q_()
+    {
+        auto now = log_clock::now();
+        auto filename = FileNameCalc::calc_filename(base_filename_, now_tm(now));
+        file_helper_.open(filename, truncate_);
+        rotation_tp_ = next_rotation_tp_();
+
+        if (max_files_ > 0)
+        {
+            init_filenames_q_();
+        }
+    }
+
+    filename_t filename()
+    {
+        std::lock_guard<Mutex> lock(base_sink<Mutex>::mutex_);
+        return file_helper_.filename();
+    }
+
+protected:
+    void sink_it_(const details::log_msg &msg) override
+    {
+        auto time = msg.time;
+        bool should_rotate = time >= rotation_tp_;
+        if (should_rotate)
+        {
+            auto filename = FileNameCalc::calc_filename(base_filename_, now_tm(time));
+            file_helper_.open(filename, truncate_);
+            rotation_tp_ = next_rotation_tp_();
+        }
+        memory_buf_t formatted;
+        base_sink<Mutex>::formatter_->format(msg, formatted);
+        file_helper_.write(formatted);
+
+        // Do the cleaning only at the end because it might throw on failure.
+        if (should_rotate && max_files_ > 0)
+        {
+            delete_old_();
+        }
+    }
+
+    void flush_() override
+    {
+        file_helper_.flush();
+    }
+
+private:
+    void init_filenames_q_()
+    {
+        using details::os::path_exists;
+
+        filenames_q_ = details::circular_q<filename_t>(static_cast<size_t>(max_files_));
+        std::vector<filename_t> filenames;
+        auto now = log_clock::now();
+        while (filenames.size() < max_files_)
+        {
+            auto filename = FileNameCalc::calc_filename(base_filename_, now_tm(now));
+            if (!path_exists(filename))
+            {
+                break;
+            }
+            filenames.emplace_back(filename);
+            now -= std::chrono::hours(1);
+        }
+        for (auto iter = filenames.rbegin(); iter != filenames.rend(); ++iter)
+        {
+            filenames_q_.push_back(std::move(*iter));
+        }
+    }
+
+    tm now_tm(log_clock::time_point tp)
+    {
+        time_t tnow = log_clock::to_time_t(tp);
+        return spdlog::details::os::localtime(tnow);
+    }
+
+    log_clock::time_point next_rotation_tp_()
+    {
+        auto now = log_clock::now();
+        tm date = now_tm(now);
+        date.tm_min = 0;
+        date.tm_sec = 0;
+        auto rotation_time = log_clock::from_time_t(std::mktime(&date));
+        if (rotation_time > now)
+        {
+            return rotation_time;
+        }
+        return {rotation_time + std::chrono::hours(1)};
+    }
+
+    // Delete the file N rotations ago.
+    // Throw spdlog_ex on failure to delete the old file.
+    void delete_old_()
+    {
+        using details::os::filename_to_str;
+        using details::os::remove_if_exists;
+
+        filename_t current_file = file_helper_.filename();
+        if (filenames_q_.full())
+        {
+            auto old_filename = std::move(filenames_q_.front());
+            filenames_q_.pop_front();
+            bool ok = remove_if_exists(old_filename) == 0;
+            if (!ok)
+            {
+                filenames_q_.push_back(std::move(current_file));
+                SPDLOG_THROW(spdlog_ex("Failed removing hourly file " + filename_to_str(old_filename), errno));
+            }
+        }
+        filenames_q_.push_back(std::move(current_file));
+    }
+
+    filename_t base_filename_;
+    log_clock::time_point rotation_tp_;
+    details::file_helper file_helper_;
+    bool truncate_;
+    uint16_t max_files_;
+    details::circular_q<filename_t> filenames_q_;
+};
+
+using hourly_file_sink_mt = hourly_file_sink<std::mutex>;
+using hourly_file_sink_st = hourly_file_sink<details::null_mutex>;
+
+} // namespace sinks
+
+//
+// factory functions
+//
+template<typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> hourly_logger_mt(const std::string &logger_name, const filename_t &filename, bool truncate = false,
+    uint16_t max_files = 0, const file_event_handlers &event_handlers = {})
+{
+    return Factory::template create<sinks::hourly_file_sink_mt>(logger_name, filename, truncate, max_files, event_handlers);
+}
+
+template<typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> hourly_logger_st(const std::string &logger_name, const filename_t &filename, bool truncate = false,
+    uint16_t max_files = 0, const file_event_handlers &event_handlers = {})
+{
+    return Factory::template create<sinks::hourly_file_sink_st>(logger_name, filename, truncate, max_files, event_handlers);
+}
+} // namespace spdlog

include/spdlog/sinks/mongo_sink.h

@@ -0,0 +1,99 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+//
+// Custom sink for mongodb
+// Building and using requires mongocxx library.
+// For building mongocxx library check the url below
+// http://mongocxx.org/mongocxx-v3/installation/
+//
+
+#include "spdlog/common.h"
+#include "spdlog/details/log_msg.h"
+#include "spdlog/sinks/base_sink.h"
+#include <spdlog/details/synchronous_factory.h>
+
+#include <bsoncxx/builder/stream/document.hpp>
+#include <bsoncxx/types.hpp>
+#include <bsoncxx/view_or_value.hpp>
+
+#include <mongocxx/client.hpp>
+#include <mongocxx/instance.hpp>
+#include <mongocxx/uri.hpp>
+
+namespace spdlog {
+namespace sinks {
+template<typename Mutex>
+class mongo_sink : public base_sink<Mutex>
+{
+public:
+    mongo_sink(const std::string &db_name, const std::string &collection_name, const std::string &uri = "mongodb://localhost:27017")
+    {
+        try
+        {
+            client_ = spdlog::details::make_unique<mongocxx::client>(mongocxx::uri{uri});
+            db_name_ = db_name;
+            coll_name_ = collection_name;
+        }
+        catch (const std::exception)
+        {
+            throw spdlog_ex("Error opening database");
+        }
+    }
+
+    ~mongo_sink()
+    {
+        flush_();
+    }
+
+protected:
+    void sink_it_(const details::log_msg &msg) override
+    {
+        using bsoncxx::builder::stream::document;
+        using bsoncxx::builder::stream::finalize;
+
+        if (client_ != nullptr)
+        {
+            auto doc = document{} << "timestamp" << bsoncxx::types::b_date(msg.time) << "level" << level::to_string_view(msg.level).data()
+                                  << "message" << std::string(msg.payload.begin(), msg.payload.end()) << "logger_name"
+                                  << std::string(msg.logger_name.begin(), msg.logger_name.end()) << "thread_id"
+                                  << static_cast<int>(msg.thread_id) << finalize;
+            client_->database(db_name_).collection(coll_name_).insert_one(doc.view());
+        }
+    }
+
+    void flush_() override {}
+
+private:
+    static mongocxx::instance instance_;
+    std::string db_name_;
+    std::string coll_name_;
+    std::unique_ptr<mongocxx::client> client_ = nullptr;
+};
+template<>
+mongocxx::instance mongo_sink<std::mutex>::instance_{};
+
+#include "spdlog/details/null_mutex.h"
+#include <mutex>
+using mongo_sink_mt = mongo_sink<std::mutex>;
+using mongo_sink_st = mongo_sink<spdlog::details::null_mutex>;
+
+} // namespace sinks
+
+template<typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> mongo_logger_mt(const std::string &logger_name, const std::string &db_name,
+    const std::string &collection_name, const std::string &uri = "mongodb://localhost:27017")
+{
+    return Factory::template create<sinks::mongo_sink_mt>(logger_name, db_name, collection_name, uri);
+}
+
+template<typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> mongo_logger_st(const std::string &logger_name, const std::string &db_name,
+    const std::string &collection_name, const std::string &uri = "mongodb://localhost:27017")
+{
+    return Factory::template create<sinks::mongo_sink_st>(logger_name, db_name, collection_name, uri);
+}
+
+} // namespace spdlog

include/spdlog/sinks/msvc_sink.h

@@ -5,14 +5,14 @@
 
 #if defined(_WIN32)
 
-#include <spdlog/details/null_mutex.h>
-#include <spdlog/sinks/base_sink.h>
+#    include <spdlog/details/null_mutex.h>
+#    include <spdlog/sinks/base_sink.h>
 
-#include <spdlog/details/windows_include.h>
-#include <winbase.h>
+#    include <mutex>
+#    include <string>
 
-#include <mutex>
-#include <string>
+// Avoid including windows.h (https://stackoverflow.com/a/30741042)
+extern "C" __declspec(dllimport) void __stdcall OutputDebugStringA(const char *lpOutputString);
 
 namespace spdlog {
 namespace sinks {
@@ -23,15 +23,18 @@ template<typename Mutex>
 class msvc_sink : public base_sink<Mutex>
 {
 public:
-    explicit msvc_sink() {}
+    msvc_sink() = default;
 
 protected:
     void sink_it_(const details::log_msg &msg) override
     {
-
         memory_buf_t formatted;
         base_sink<Mutex>::formatter_->format(msg, formatted);
+#    ifdef SPDLOG_USE_STD_FORMAT
+        OutputDebugStringA(formatted.c_str());
+#    else
         OutputDebugStringA(fmt::to_string(formatted).c_str());
+#    endif
     }
 
     void flush_() override {}

include/spdlog/sinks/qt_sinks.h

@@ -0,0 +1,102 @@
+// Copyright(c) 2015-present, Gabi Melman, mguludag and spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+//
+// Custom sink for QPlainTextEdit or QTextEdit and its childs(QTextBrowser...
+// etc) Building and using requires Qt library.
+//
+
+#include "spdlog/common.h"
+#include "spdlog/details/log_msg.h"
+#include "spdlog/details/synchronous_factory.h"
+#include "spdlog/sinks/base_sink.h"
+
+#include <QTextEdit>
+#include <QPlainTextEdit>
+
+//
+// qt_sink class
+//
+namespace spdlog {
+namespace sinks {
+template<typename Mutex>
+class qt_sink : public base_sink<Mutex>
+{
+public:
+    qt_sink(QObject *qt_object, const std::string &meta_method)
+    {
+        qt_object_ = qt_object;
+        meta_method_ = meta_method;
+    }
+
+    ~qt_sink()
+    {
+        flush_();
+    }
+
+protected:
+    void sink_it_(const details::log_msg &msg) override
+    {
+        memory_buf_t formatted;
+        base_sink<Mutex>::formatter_->format(msg, formatted);
+        string_view_t str = string_view_t(formatted.data(), formatted.size());
+        QMetaObject::invokeMethod(qt_object_, meta_method_.c_str(), Qt::AutoConnection,
+            Q_ARG(QString, QString::fromUtf8(str.data(), static_cast<int>(str.size())).trimmed()));
+    }
+
+    void flush_() override {}
+
+private:
+    QObject *qt_object_ = nullptr;
+    std::string meta_method_;
+};
+
+#include "spdlog/details/null_mutex.h"
+#include <mutex>
+using qt_sink_mt = qt_sink<std::mutex>;
+using qt_sink_st = qt_sink<spdlog::details::null_mutex>;
+} // namespace sinks
+
+//
+// Factory functions
+//
+template<typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> qt_logger_mt(const std::string &logger_name, QTextEdit *qt_object, const std::string &meta_method = "append")
+{
+    return Factory::template create<sinks::qt_sink_mt>(logger_name, qt_object, meta_method);
+}
+
+template<typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> qt_logger_st(const std::string &logger_name, QTextEdit *qt_object, const std::string &meta_method = "append")
+{
+    return Factory::template create<sinks::qt_sink_st>(logger_name, qt_object, meta_method);
+}
+
+template<typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> qt_logger_mt(
+    const std::string &logger_name, QPlainTextEdit *qt_object, const std::string &meta_method = "appendPlainText")
+{
+    return Factory::template create<sinks::qt_sink_mt>(logger_name, qt_object, meta_method);
+}
+
+template<typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> qt_logger_st(
+    const std::string &logger_name, QPlainTextEdit *qt_object, const std::string &meta_method = "appendPlainText")
+{
+    return Factory::template create<sinks::qt_sink_st>(logger_name, qt_object, meta_method);
+}
+
+template<typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> qt_logger_mt(const std::string &logger_name, QObject *qt_object, const std::string &meta_method)
+{
+    return Factory::template create<sinks::qt_sink_mt>(logger_name, qt_object, meta_method);
+}
+
+template<typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> qt_logger_st(const std::string &logger_name, QObject *qt_object, const std::string &meta_method)
+{
+    return Factory::template create<sinks::qt_sink_st>(logger_name, qt_object, meta_method);
+}
+} // namespace spdlog

include/spdlog/sinks/ringbuffer_sink.h

@@ -50,7 +50,11 @@ public:
         {
             memory_buf_t formatted;
             base_sink<Mutex>::formatter_->format(q_.at(i), formatted);
+#ifdef SPDLOG_USE_STD_FORMAT
+            ret.push_back(std::move(formatted));
+#else
             ret.push_back(fmt::to_string(formatted));
+#endif
         }
         return ret;
     }

include/spdlog/sinks/rotating_file_sink-inl.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/sinks/rotating_file_sink.h>
+#    include <spdlog/sinks/rotating_file_sink.h>
 #endif
 
 #include <spdlog/common.h>
@@ -25,16 +25,27 @@ namespace sinks {
 
 template<typename Mutex>
 SPDLOG_INLINE rotating_file_sink<Mutex>::rotating_file_sink(
-    filename_t base_filename, std::size_t max_size, std::size_t max_files, bool rotate_on_open)
+    filename_t base_filename, std::size_t max_size, std::size_t max_files, bool rotate_on_open, const file_event_handlers &event_handlers)
     : base_filename_(std::move(base_filename))
     , max_size_(max_size)
     , max_files_(max_files)
+    , file_helper_{event_handlers}
 {
+    if (max_size == 0)
+    {
+        throw_spdlog_ex("rotating sink constructor: max_size arg cannot be zero");
+    }
+
+    if (max_files > 200000)
+    {
+        throw_spdlog_ex("rotating sink constructor: max_files arg cannot exceed 200000");
+    }
     file_helper_.open(calc_filename(base_filename_, 0));
     current_size_ = file_helper_.size(); // expensive. called only once
     if (rotate_on_open && current_size_ > 0)
     {
         rotate_();
+        current_size_ = 0;
     }
 }
 
@@ -50,7 +61,7 @@ SPDLOG_INLINE filename_t rotating_file_sink<Mutex>::calc_filename(const filename
 
     filename_t basename, ext;
     std::tie(basename, ext) = details::file_helper::split_by_extension(filename);
-    return fmt::format(SPDLOG_FILENAME_T("{}.{}{}"), basename, index, ext);
+    return fmt_lib::format(SPDLOG_FILENAME_T("{}.{}{}"), basename, index, ext);
 }
 
 template<typename Mutex>
@@ -65,13 +76,22 @@ SPDLOG_INLINE void rotating_file_sink<Mutex>::sink_it_(const details::log_msg &m
 {
     memory_buf_t formatted;
     base_sink<Mutex>::formatter_->format(msg, formatted);
-    current_size_ += formatted.size();
-    if (current_size_ > max_size_)
+    auto new_size = current_size_ + formatted.size();
+
+    // rotate if the new estimated file size exceeds max size.
+    // rotate only if the real size > 0 to better deal with full disk (see issue #2261).
+    // we only check the real size when new_size > max_size_ because it is relatively expensive.
+    if (new_size > max_size_)
     {
-        rotate_();
-        current_size_ = formatted.size();
+        file_helper_.flush();
+        if (file_helper_.size() > 0)
+        {
+            rotate_();
+            new_size = formatted.size();
+        }
     }
     file_helper_.write(formatted);
+    current_size_ = new_size;
 }
 
 template<typename Mutex>
@@ -90,6 +110,7 @@ SPDLOG_INLINE void rotating_file_sink<Mutex>::rotate_()
 {
     using details::os::filename_to_str;
     using details::os::path_exists;
+
     file_helper_.close();
     for (auto i = max_files_; i > 0; --i)
     {

include/spdlog/sinks/rotating_file_sink.h

@@ -22,7 +22,8 @@ template<typename Mutex>
 class rotating_file_sink final : public base_sink<Mutex>
 {
 public:
-    rotating_file_sink(filename_t base_filename, std::size_t max_size, std::size_t max_files, bool rotate_on_open = false);
+    rotating_file_sink(filename_t base_filename, std::size_t max_size, std::size_t max_files, bool rotate_on_open = false,
+        const file_event_handlers &event_handlers = {});
     static filename_t calc_filename(const filename_t &filename, std::size_t index);
     filename_t filename();
 
@@ -59,20 +60,22 @@ using rotating_file_sink_st = rotating_file_sink<details::null_mutex>;
 //
 
 template<typename Factory = spdlog::synchronous_factory>
-inline std::shared_ptr<logger> rotating_logger_mt(
-    const std::string &logger_name, const filename_t &filename, size_t max_file_size, size_t max_files, bool rotate_on_open = false)
+inline std::shared_ptr<logger> rotating_logger_mt(const std::string &logger_name, const filename_t &filename, size_t max_file_size,
+    size_t max_files, bool rotate_on_open = false, const file_event_handlers &event_handlers = {})
 {
-    return Factory::template create<sinks::rotating_file_sink_mt>(logger_name, filename, max_file_size, max_files, rotate_on_open);
+    return Factory::template create<sinks::rotating_file_sink_mt>(
+        logger_name, filename, max_file_size, max_files, rotate_on_open, event_handlers);
 }
 
 template<typename Factory = spdlog::synchronous_factory>
-inline std::shared_ptr<logger> rotating_logger_st(
-    const std::string &logger_name, const filename_t &filename, size_t max_file_size, size_t max_files, bool rotate_on_open = false)
+inline std::shared_ptr<logger> rotating_logger_st(const std::string &logger_name, const filename_t &filename, size_t max_file_size,
+    size_t max_files, bool rotate_on_open = false, const file_event_handlers &event_handlers = {})
 {
-    return Factory::template create<sinks::rotating_file_sink_st>(logger_name, filename, max_file_size, max_files, rotate_on_open);
+    return Factory::template create<sinks::rotating_file_sink_st>(
+        logger_name, filename, max_file_size, max_files, rotate_on_open, event_handlers);
 }
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "rotating_file_sink-inl.h"
+#    include "rotating_file_sink-inl.h"
 #endif

include/spdlog/sinks/sink-inl.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/sinks/sink.h>
+#    include <spdlog/sinks/sink.h>
 #endif
 
 #include <spdlog/common.h>

include/spdlog/sinks/sink.h

@@ -31,5 +31,5 @@ protected:
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "sink-inl.h"
+#    include "sink-inl.h"
 #endif

include/spdlog/sinks/stdout_color_sinks-inl.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/sinks/stdout_color_sinks.h>
+#    include <spdlog/sinks/stdout_color_sinks.h>
 #endif
 
 #include <spdlog/logger.h>
@@ -35,4 +35,4 @@ SPDLOG_INLINE std::shared_ptr<logger> stderr_color_st(const std::string &logger_
 {
     return Factory::template create<sinks::stderr_color_sink_st>(logger_name, mode);
 }
-} // namespace spdlog
+} // namespace spdlog

include/spdlog/sinks/stdout_color_sinks.h

@@ -4,9 +4,9 @@
 #pragma once
 
 #ifdef _WIN32
-#include <spdlog/sinks/wincolor_sink.h>
+#    include <spdlog/sinks/wincolor_sink.h>
 #else
-#include <spdlog/sinks/ansicolor_sink.h>
+#    include <spdlog/sinks/ansicolor_sink.h>
 #endif
 
 #include <spdlog/details/synchronous_factory.h>
@@ -41,5 +41,5 @@ std::shared_ptr<logger> stderr_color_st(const std::string &logger_name, color_mo
 } // namespace spdlog
 
 #ifdef SPDLOG_HEADER_ONLY
-#include "stdout_color_sinks-inl.h"
+#    include "stdout_color_sinks-inl.h"
 #endif

include/spdlog/sinks/stdout_sinks-inl.h

@@ -4,13 +4,26 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/sinks/stdout_sinks.h>
+#    include <spdlog/sinks/stdout_sinks.h>
 #endif
 
 #include <spdlog/details/console_globals.h>
 #include <spdlog/pattern_formatter.h>
 #include <memory>
 
+#ifdef _WIN32
+// under windows using fwrite to non-binary stream results in \r\r\n (see issue #1675)
+// so instead we use ::FileWrite
+#    include <spdlog/details/windows_include.h>
+
+#    ifndef _USING_V110_SDK71_ // fileapi.h doesn't exist in winxp
+#        include <fileapi.h>   // WriteFile (..)
+#    endif
+
+#    include <io.h>    // _get_osfhandle(..)
+#    include <stdio.h> // _fileno(..)
+#endif                 // WIN32
+
 namespace spdlog {
 
 namespace sinks {
@@ -20,16 +33,48 @@ SPDLOG_INLINE stdout_sink_base<ConsoleMutex>::stdout_sink_base(FILE *file)
     : mutex_(ConsoleMutex::mutex())
     , file_(file)
     , formatter_(details::make_unique<spdlog::pattern_formatter>())
-{}
+{
+#ifdef _WIN32
+    // get windows handle from the FILE* object
+
+    handle_ = reinterpret_cast<HANDLE>(::_get_osfhandle(::_fileno(file_)));
+
+    // don't throw to support cases where no console is attached,
+    // and let the log method to do nothing if (handle_ == INVALID_HANDLE_VALUE).
+    // throw only if non stdout/stderr target is requested (probably regular file and not console).
+    if (handle_ == INVALID_HANDLE_VALUE && file != stdout && file != stderr)
+    {
+        throw_spdlog_ex("spdlog::stdout_sink_base: _get_osfhandle() failed", errno);
+    }
+#endif // WIN32
+}
 
 template<typename ConsoleMutex>
 SPDLOG_INLINE void stdout_sink_base<ConsoleMutex>::log(const details::log_msg &msg)
 {
+#ifdef _WIN32
+    if (handle_ == INVALID_HANDLE_VALUE)
+    {
+        return;
+    }
     std::lock_guard<mutex_t> lock(mutex_);
     memory_buf_t formatted;
     formatter_->format(msg, formatted);
-    fwrite(formatted.data(), sizeof(char), formatted.size(), file_);
-    fflush(file_); // flush every line to terminal
+    ::fflush(file_); // flush in case there is something in this file_ already
+    auto size = static_cast<DWORD>(formatted.size());
+    DWORD bytes_written = 0;
+    bool ok = ::WriteFile(handle_, formatted.data(), size, &bytes_written, nullptr) != 0;
+    if (!ok)
+    {
+        throw_spdlog_ex("stdout_sink_base: WriteFile() failed. GetLastError(): " + std::to_string(::GetLastError()));
+    }
+#else
+    std::lock_guard<mutex_t> lock(mutex_);
+    memory_buf_t formatted;
+    formatter_->format(msg, formatted);
+    ::fwrite(formatted.data(), sizeof(char), formatted.size(), file_);
+    ::fflush(file_); // flush every line to terminal
+#endif // WIN32
 }
 
 template<typename ConsoleMutex>