V2.x no std format (#3271)

* Removed SPDLOG_USE_STD_FORMAT

* Removed SPDLOG_USE_STD_FORMAT

* clang-format

* Fix windows.yml ci

* Fix ci

.github/workflows/linux.yml

@@ -58,26 +58,4 @@ jobs:
             -DSPDLOG_SANITIZE_ADDRESS=${{ matrix.config.asan || 'OFF' }} \
             -DSPDLOG_SANITIZE_THREAD=${{ matrix.config.tsan || 'OFF' }}
           make -j 4
-          ctest -j 4 --output-on-failure
-
-  # -----------------------------------------------------------------------
-  # OS X build matrix
-  # -----------------------------------------------------------------------
-  build_osx:
-    runs-on: macOS-latest
-    name: "OS X Clang (C++17, Release)"
-    steps:
-      - uses: actions/checkout@v4
-      - name: Build
-        run: |
-          mkdir -p build && cd build
-          cmake .. \
-            -DCMAKE_BUILD_TYPE=Release \
-            -DCMAKE_CXX_STANDARD=17 \
-            -DSPDLOG_BUILD_EXAMPLE=ON \
-            -DSPDLOG_BUILD_WARNINGS=ON \
-            -DSPDLOG_BUILD_BENCH=OFF \
-            -DSPDLOG_BUILD_TESTS=ON \
-            -DSPDLOG_SANITIZE_ADDRESS=OFF
-          make -j 4
-          ctest -j 4 --output-on-failure
+          ctest -j 4 --output-on-failure          

.github/workflows/windows.yml

@@ -57,7 +57,6 @@ jobs:
             -D SPDLOG_BUILD_EXAMPLE=${{ matrix.config.BUILD_EXAMPLE }} `
             -D SPDLOG_BUILD_TESTS=ON `
             -D SPDLOG_BUILD_WARNINGS=${{ matrix.config.FATAL_ERRORS }} `
-            -D SPDLOG_USE_STD_FORMAT=${{ matrix.config.USE_STD_FORMAT }} `
             -D CMAKE_CXX_STANDARD=${{ matrix.config.CXX_STANDARD }} ..
 
       - name: Build
@@ -118,7 +117,6 @@ jobs:
             -D SPDLOG_BUILD_EXAMPLE=${{ matrix.config.BUILD_EXAMPLE }} `
             -D SPDLOG_BUILD_TESTS=ON `
             -D SPDLOG_BUILD_WARNINGS=${{ matrix.config.FATAL_ERRORS }} `
-            -D SPDLOG_USE_STD_FORMAT=${{ matrix.config.USE_STD_FORMAT }} `
             -D CMAKE_CXX_STANDARD=${{ matrix.config.CXX_STANDARD }} ..
 
       - name: Build

CMakeLists.txt

@@ -34,7 +34,6 @@ elseif(CMAKE_CXX_STANDARD LESS 17)
 endif()
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
-
 set(CMAKE_CXX_EXTENSIONS OFF)
 
 if(CMAKE_SYSTEM_NAME MATCHES "CYGWIN" OR CMAKE_SYSTEM_NAME MATCHES "MSYS" OR CMAKE_SYSTEM_NAME MATCHES "MINGW")
@@ -58,7 +57,6 @@ option(SPDLOG_BUILD_ALL "Build all artifacts" OFF)
 # build shared option
 option(SPDLOG_BUILD_SHARED "Build shared library" OFF)
 
-
 # example options
 option(SPDLOG_BUILD_EXAMPLE "Build example" ${SPDLOG_MASTER_PROJECT})
 
@@ -77,19 +75,9 @@ option(SPDLOG_BUILD_WARNINGS "Enable compiler warnings" OFF)
 # install options
 option(SPDLOG_SYSTEM_INCLUDES "Include as system headers (skip for clang-tidy)." OFF)
 option(SPDLOG_INSTALL "Generate the install target" ${SPDLOG_MASTER_PROJECT})
-option(SPDLOG_USE_STD_FORMAT "Use std::format instead of fmt library." OFF)
 option(SPDLOG_FMT_EXTERNAL "Use external fmt library instead of of fetching from gitub." OFF)
-
 option(SPDLOG_NO_EXCEPTIONS "Compile with -fno-exceptions. Call abort() on any spdlog exceptions" OFF)
 
-if(SPDLOG_USE_STD_FORMAT AND CMAKE_CXX_STANDARD LESS 20)
-    message(FATAL_ERROR "SPDLOG_USE_STD_FORMAT must be used with CMAKE_CXX_STANDARD >= 20")
-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_FILENAMES "Support wchar filenames" OFF)
@@ -126,35 +114,31 @@ if(SPDLOG_BUILD_SHARED)
 endif()
 
 if(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
-	# place dlls and libs and executables in the same directory
-	set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin/$<CONFIG>)
-	set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin/$<CONFIG>)
-	set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin/$<CONFIG>)
-	set(CMAKE_PDB_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin/$<CONFIG>)
-
-	# make sure __cplusplus is defined
-	add_compile_options(/Zc:__cplusplus)
-	# enable parallel build for the solution
-	add_compile_options(/MP)
+    # place dlls and libs and executables in the same directory
+    set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin/$<CONFIG>)
+    set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin/$<CONFIG>)
+    set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin/$<CONFIG>)
+    set(CMAKE_PDB_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin/$<CONFIG>)
+
+    # make sure __cplusplus is defined
+    add_compile_options(/Zc:__cplusplus)
+    # enable parallel build for the solution
+    add_compile_options(/MP)
 endif()
 
-
 message(STATUS "spdlog version: ${SPDLOG_VERSION}")
 message(STATUS "spdlog build type: " ${CMAKE_BUILD_TYPE})
 message(STATUS "spdlog build shared: " ${BUILD_SHARED_LIBS})
-message(STATUS "spdlog use std format: " ${SPDLOG_USE_STD_FORMAT})
 message(STATUS "spdlog fmt external: " ${SPDLOG_FMT_EXTERNAL})
 
 # ---------------------------------------------------------------------------------------
-# Find {fmt} library if not using std::format
+# Find {fmt} library
 # ---------------------------------------------------------------------------------------
-if(NOT SPDLOG_USE_STD_FORMAT)
-    if (SPDLOG_FMT_EXTERNAL)
-        find_package(fmt REQUIRED)
-        message(STATUS "Using external fmt lib version: ${fmt_VERSION}")
-    else()
-        include(cmake/fmtlib.cmake)
-    endif()
+if(SPDLOG_FMT_EXTERNAL)
+    find_package(fmt REQUIRED)
+    message(STATUS "Using external fmt lib version: ${fmt_VERSION}")
+else()
+    include(cmake/fmtlib.cmake)
 endif()
 
 # ---------------------------------------------------------------------------------------
@@ -217,8 +201,7 @@ set(SPDLOG_HEADERS
     "include/spdlog/sinks/syslog_sink.h"
     "include/spdlog/sinks/systemd_sink.h"
     "include/spdlog/sinks/tcp_sink.h"
-    "include/spdlog/sinks/udp_sink.h"
-)
+    "include/spdlog/sinks/udp_sink.h")
 
 set(SPDLOG_SRCS
     "src/async_logger.cpp"
@@ -242,20 +225,18 @@ set(SPDLOG_SRCS
     "src/sinks/stdout_sinks.cpp")
 
 if(WIN32)
-    list(APPEND SPDLOG_SRCS
-            "src/details/os_windows.cpp"
-            "src/sinks/wincolor_sink.cpp")
-    list(APPEND SPDLOG_HEADERS
-            "include/spdlog/details/tcp_client_windows.h"
-            "include/spdlog/details/udp_client_windows.h"
-            "include/spdlog/details/windows_include.h"
-            "include/spdlog/sinks/win_eventlog_sink.h"
-            "include/spdlog/sinks/wincolor_sink.h")
+    list(APPEND SPDLOG_SRCS "src/details/os_windows.cpp" "src/sinks/wincolor_sink.cpp")
+    list(
+        APPEND
+        SPDLOG_HEADERS
+        "include/spdlog/details/tcp_client_windows.h"
+        "include/spdlog/details/udp_client_windows.h"
+        "include/spdlog/details/windows_include.h"
+        "include/spdlog/sinks/win_eventlog_sink.h"
+        "include/spdlog/sinks/wincolor_sink.h")
 else()
     list(APPEND SPDLOG_SRCS "src/details/os_unix.cpp")
-    list(APPEND SPDLOG_HEADERS
-            "include/spdlog/details/tcp_client_unix.h"
-            "include/spdlog/details/udp_client_unix.h")
+    list(APPEND SPDLOG_HEADERS "include/spdlog/details/tcp_client_unix.h" "include/spdlog/details/udp_client_unix.h")
 endif()
 
 # Generate spdlog_config.h based on the current configuration
@@ -287,16 +268,14 @@ endif()
 
 set_target_properties(spdlog PROPERTIES PUBLIC_HEADER "${SPDLOG_HEADERS}")
 
-target_include_directories(spdlog ${SPDLOG_INCLUDES_LEVEL} PUBLIC
-        "$<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/include>"
-         "$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>")
+target_include_directories(spdlog ${SPDLOG_INCLUDES_LEVEL} PUBLIC "$<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/include>"
+                                                                  "$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>")
 
 target_link_libraries(spdlog PUBLIC Threads::Threads)
-if(NOT SPDLOG_USE_STD_FORMAT)
-    target_link_libraries(spdlog PUBLIC fmt::fmt)
-endif()
+target_link_libraries(spdlog PUBLIC fmt::fmt)
 spdlog_enable_warnings(spdlog)
-set_target_properties(spdlog PROPERTIES VERSION ${SPDLOG_VERSION} SOVERSION  ${SPDLOG_VERSION_MAJOR}.${SPDLOG_VERSION_MINOR})
+set_target_properties(spdlog PROPERTIES VERSION ${SPDLOG_VERSION} SOVERSION
+                                                                  ${SPDLOG_VERSION_MAJOR}.${SPDLOG_VERSION_MINOR})
 set_target_properties(spdlog PROPERTIES DEBUG_POSTFIX d)
 
 # set source groups for visual studio
@@ -313,7 +292,6 @@ if(ANDROID)
     target_link_libraries(spdlog PUBLIC log)
 endif()
 
-
 # ---------------------------------------------------------------------------------------
 # If exceptions are disabled, disable them in the bundled fmt as well
 # ---------------------------------------------------------------------------------------
@@ -403,8 +381,7 @@ if(SPDLOG_INSTALL)
     # ---------------------------------------------------------------------------------------
     include(cmake/spdlogCPack.cmake)
 
-    # Install spdlog_config.h file
-    # Assume your tweakme.h.in is located in the same directory as CMakeLists.txt
+    # Install spdlog_config.h file Assume your tweakme.h.in is located in the same directory as CMakeLists.txt
     set(TWEAKME_IN "${CMAKE_CURRENT_SOURCE_DIR}/tweakme.h.in")
     set(TWEAKME_OUT "${CMAKE_CURRENT_BINARY_DIR}/include/spdlog/tweakme.h")
 endif()

bench/CMakeLists.txt

@@ -22,7 +22,7 @@ if(NOT benchmark_FOUND)
     # 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)
-	set_target_properties(benchmark PROPERTIES FOLDER "third-party")
+    set_target_properties(benchmark PROPERTIES FOLDER "third-party")
 endif()
 
 add_executable(bench bench.cpp)

bench/bench.cpp

@@ -6,17 +6,7 @@
 //
 // bench.cpp : spdlog benchmarks
 //
-#include "spdlog/sinks/basic_file_sink.h"
-#include "spdlog/sinks/daily_file_sink.h"
-#include "spdlog/sinks/null_sink.h"
-#include "spdlog/sinks/rotating_file_sink.h"
-#include "spdlog/spdlog.h"
-
-#if defined(SPDLOG_USE_STD_FORMAT)
-    #include <format>
-#else
-    #include <fmt/format.h>
-#endif
+#include <fmt/format.h>
 
 #include <atomic>
 #include <cstdlib>  // EXIT_FAILURE
@@ -24,6 +14,11 @@
 #include <string>
 #include <thread>
 
+#include "spdlog/sinks/basic_file_sink.h"
+#include "spdlog/sinks/daily_file_sink.h"
+#include "spdlog/sinks/null_sink.h"
+#include "spdlog/sinks/rotating_file_sink.h"
+#include "spdlog/spdlog.h"
 #include "utils.h"
 
 void bench(int howmany, std::shared_ptr<spdlog::logger> log);

cmake/fmtlib.cmake

@@ -1,15 +1,13 @@
 include(FetchContent)
 
 FetchContent_Declare(
-        fmt
-        DOWNLOAD_EXTRACT_TIMESTAMP FALSE
-        URL https://github.com/fmtlib/fmt/archive/refs/tags/11.0.2.tar.gz
-        URL_HASH SHA256=6cb1e6d37bdcb756dbbe59be438790db409cdb4868c66e888d5df9f13f7c027f)
+    fmt DOWNLOAD_EXTRACT_TIMESTAMP FALSE URL https://github.com/fmtlib/fmt/archive/refs/tags/11.0.2.tar.gz
+    URL_HASH SHA256=6cb1e6d37bdcb756dbbe59be438790db409cdb4868c66e888d5df9f13f7c027f)
 FetchContent_GetProperties(fmt)
 if(NOT fmt_POPULATED)
     FetchContent_Populate(fmt)
     # We do not require os features of fmt
     set(FMT_OS OFF CACHE BOOL "Disable FMT_OS" FORCE)
     add_subdirectory(${fmt_SOURCE_DIR} ${fmt_BINARY_DIR})
-	set_target_properties(fmt PROPERTIES FOLDER "third-party")
-endif ()
+    set_target_properties(fmt PROPERTIES FOLDER "third-party")
+endif()

cmake/spdlogConfig.cmake.in

@@ -7,10 +7,7 @@ include(CMakeFindDependencyMacro)
 
 find_package(Threads REQUIRED)
 
-set(SPDLOG_USE_STD_FORMAT @SPDLOG_USE_STD_FORMAT@)
-if(NOT SPDLOG_USE_STD_FORMAT)
-    find_dependency(fmt CONFIG)
-endif()
+find_dependency(fmt CONFIG)
 
 set(config_targets_file @config_targets_file@)
 include("${CMAKE_CURRENT_LIST_DIR}/${config_targets_file}")

cmake/spdlog_config.h.in

@@ -27,9 +27,5 @@
 // Disable default logger creation
 #cmakedefine SPDLOG_DISABLE_DEFAULT_LOGGER
 
-// Use std::format instead of fmtlib
-#cmakedefine SPDLOG_USE_STD_FORMAT
-
 // Use external fmtlib instead of bundled
 #cmakedefine SPDLOG_FMT_EXTERNAL
-

example/CMakeLists.txt

@@ -9,4 +9,4 @@ if(NOT TARGET spdlog)
 endif()
 
 add_executable(example example.cpp)
-target_link_libraries(example PRIVATE spdlog::spdlog $<$<BOOL:${MINGW}>:ws2_32>)
+target_link_libraries(example PRIVATE spdlog::spdlog $<$<BOOL:${MINGW}>:ws2_32>)

example/example.cpp

@@ -161,8 +161,7 @@ void async_example() {
 // {:p} - don't print the position on each line start.
 // {:n} - don't split the output to lines.
 
-#if !defined SPDLOG_USE_STD_FORMAT || defined(_MSC_VER)
-    #include "spdlog/fmt/bin_to_hex.h"
+#include "spdlog/fmt/bin_to_hex.h"
 void binary_example() {
     std::vector<char> buf;
     for (int i = 0; i < 80; i++) {
@@ -177,26 +176,14 @@ void binary_example() {
     // logger->info("hexdump style: {:a}", spdlog::to_hex(buf));
     // logger->info("hexdump style, 20 chars per line {:a}", spdlog::to_hex(buf, 20));
 }
-#else
-void binary_example() {
-    // not supported with std::format yet
-}
-#endif
 
 // Log a vector of numbers
-#ifndef SPDLOG_USE_STD_FORMAT
-    #include "fmt/ranges.h"
+#include "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() {
@@ -250,7 +237,6 @@ struct my_type {
         : i(i) {}
 };
 
-#ifndef SPDLOG_USE_STD_FORMAT  // when using fmtlib
 template <>
 struct fmt::formatter<my_type> : fmt::formatter<std::string> {
     auto format(my_type my, format_context &ctx) const -> decltype(ctx.out()) {
@@ -258,15 +244,6 @@ struct fmt::formatter<my_type> : fmt::formatter<std::string> {
     }
 };
 
-#else  // when using std::format
-template <>
-struct std::formatter<my_type> : std::formatter<std::string> {
-    auto format(my_type my, format_context &ctx) const -> decltype(ctx.out()) {
-        return format_to(ctx.out(), "[my_type i={}]", my.i);
-    }
-};
-#endif
-
 void user_defined_example() { spdlog::info("user defined type: {}", my_type(14)); }
 
 // Custom error handler. Will be triggered on log failure.

include/spdlog/common.h

@@ -21,10 +21,6 @@
     #include <version>
 #endif
 
-#ifdef SPDLOG_USE_STD_FORMAT
-    #include <format>
-#endif
-
 #if defined(SPDLOG_SHARED_LIB)
     #if defined(_WIN32)
         #ifdef spdlog_EXPORTS
@@ -41,15 +37,10 @@
 
 #include "fmt/fmt.h"
 
-#if !defined(SPDLOG_USE_STD_FORMAT) && FMT_VERSION >= 80000  // backward compatibility with fmt versions older than 8
-    #define SPDLOG_FMT_RUNTIME(format_string) fmt::runtime(format_string)
-    #define SPDLOG_FMT_STRING(format_string) FMT_STRING(format_string)
-    #if defined(SPDLOG_WCHAR_FILENAMES)
-        #include "fmt/xchar.h"
-    #endif
-#else
-    #define SPDLOG_FMT_RUNTIME(format_string) format_string
-    #define SPDLOG_FMT_STRING(format_string) format_string
+#define SPDLOG_FMT_RUNTIME(format_string) fmt::runtime(format_string)
+#define SPDLOG_FMT_STRING(format_string) FMT_STRING(format_string)
+#if defined(SPDLOG_WCHAR_FILENAMES)
+    #include "fmt/xchar.h"
 #endif
 
 #ifndef SPDLOG_FUNCTION
@@ -98,29 +89,14 @@ using err_handler = std::function<void(const std::string &err_msg)>;
 using string_view_t = std::basic_string_view<char>;
 using wstring_view_t = std::basic_string_view<wchar_t>;
 
-#ifdef SPDLOG_USE_STD_FORMAT
-namespace fmt_lib = std;
-using memory_buf_t = std::string;
-using wmemory_buf_t = std::wstring;
-
-template <typename... Args>
-    #if __cpp_lib_format >= 202207L
-        using format_string_t = std::format_string<Args...>;
-    #else
-        using format_string_t = std::string_view;
-    #endif
-
-    #define SPDLOG_BUF_TO_STRING(x) x
-#else  // use fmt lib instead of std::format
 namespace fmt_lib = fmt;
-
 using memory_buf_t = fmt::basic_memory_buffer<char, 250>;
+using wmemory_buf_t = fmt::basic_memory_buffer<wchar_t, 250>;
+
 template <typename... Args>
 using format_string_t = fmt::format_string<Args...>;
-using wmemory_buf_t = fmt::basic_memory_buffer<wchar_t, 250>;
-    #define SPDLOG_BUF_TO_STRING(x) fmt::to_string(x)
-#endif  // SPDLOG_USE_STD_FORMAT
 
+#define SPDLOG_BUF_TO_STRING(x) fmt::to_string(x)
 #define SPDLOG_LEVEL_TRACE 0
 #define SPDLOG_LEVEL_DEBUG 1
 #define SPDLOG_LEVEL_INFO 2
@@ -231,27 +207,10 @@ namespace details {
 [[nodiscard]] constexpr spdlog::wstring_view_t to_string_view(spdlog::wstring_view_t str) noexcept { return str; }
 #endif
 
-// convert format_string<...> to string_view depending on format lib versions
-#if defined(SPDLOG_USE_STD_FORMAT)
-    #if __cpp_lib_format >= 202207L  // std::format and __cpp_lib_format >= 202207L
-template <typename T, typename... Args>
-[[nodiscard]] constexpr std::basic_string_view<T> to_string_view(std::basic_format_string<T, Args...> fmt) noexcept {
-    return fmt.get();
-}
-    #else  // std::format and __cpp_lib_format < 202207L
-template <typename T, typename... Args>
-[[nodiscard]] constexpr std::basic_string_view<T> to_string_view(std::basic_format_string<T, Args...> fmt) noexcept {
-    return fmt;
-}
-    #endif
-#else  // {fmt} version
-
 template <typename T, typename... Args>
 [[nodiscard]] constexpr fmt::basic_string_view<T> to_string_view(fmt::basic_format_string<T, Args...> fmt) noexcept {
     return fmt;
 }
 
-#endif
-
 }  // namespace details
 }  // namespace spdlog

include/spdlog/details/fmt_helper.h

@@ -9,11 +9,6 @@
 #include "../common.h"
 #include "../fmt/fmt.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 {
@@ -24,27 +19,11 @@ 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
-    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>
 constexpr unsigned int count_digits_fallback(T n) {
@@ -66,19 +45,16 @@ constexpr unsigned int count_digits_fallback(T n) {
 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;
-#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
+// fmt 7.0.0 renamed the internal namespace to detail.
+// See: https://github.com/fmtlib/fmt/issues/1538
+#if FMT_VERSION < 70000
                                          internal
-    #else
+#else
                                          detail
-    #endif
-                                     ::count_digits(static_cast<count_type>(n)));
 #endif
+                                     ::count_digits(static_cast<count_type>(n)));
 }
 
 inline void pad2(int n, memory_buf_t &dest) {

include/spdlog/fmt/bin_to_hex.h

@@ -88,13 +88,7 @@ inline details::dump_info<It> to_hex(const It range_begin, const It range_end, s
 
 }  // namespace spdlog
 
-namespace
-#ifdef SPDLOG_USE_STD_FORMAT
-    std
-#else
-    fmt
-#endif
-{
+namespace fmt {
 
 template <typename T>
 struct formatter<spdlog::details::dump_info<T>, char> {
@@ -142,13 +136,7 @@ struct formatter<spdlog::details::dump_info<T>, char> {
         constexpr const char *hex_upper = "0123456789ABCDEF";
         constexpr const char *hex_lower = "0123456789abcdef";
         const char *hex_chars = use_uppercase ? hex_upper : hex_lower;
-
-#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.get_begin();
         for (auto i = the_range.get_begin(); i != the_range.get_end(); i++) {
@@ -215,4 +203,4 @@ struct formatter<spdlog::details::dump_info<T>, char> {
         }
     }
 };
-}  // namespace std
+}  // namespace fmt

include/spdlog/fmt/fmt.h

@@ -5,14 +5,5 @@
 
 #pragma once
 
-//
-// Include a bundled header-only copy of fmtlib or an external one.
-// By default, spdlog include its own copy.
-//
 #include "../spdlog_config.h"
-
-#if defined(SPDLOG_USE_STD_FORMAT)  // use std::format
-    #include <format>
-#else
-    #include "fmt/format.h"
-#endif
+#include "fmt/format.h"

include/spdlog/logger.h

@@ -187,14 +187,9 @@ protected:
     void log_with_format_(source_loc loc, level lvl, const format_string_t<Args...> &fmt, Args &&...args) {
         assert(should_log(lvl));
         SPDLOG_TRY {
-#ifdef SPDLOG_USE_STD_FORMAT
-            auto formatted = std::vformat(fmt, std::make_format_args(args...));
-            sink_it_(details::log_msg(loc, name_, lvl, formatted));
-#else  // use {fmt} lib
             memory_buf_t buf;
             fmt::vformat_to(std::back_inserter(buf), fmt, fmt::make_format_args(args...));
             sink_it_(details::log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size())));
-#endif
         }
         SPDLOG_LOGGER_CATCH(loc)
     }

include/spdlog/stopwatch.h

@@ -51,13 +51,7 @@ public:
 }  // namespace spdlog
 
 // Support for fmt formatting  (e.g. "{:012.9}" or just "{}")
-namespace
-#ifdef SPDLOG_USE_STD_FORMAT
-    std
-#else
-    fmt
-#endif
-{
+namespace fmt {
 
 template <>
 struct formatter<spdlog::stopwatch> : formatter<double> {
@@ -66,4 +60,4 @@ struct formatter<spdlog::stopwatch> : formatter<double> {
         return formatter<double>::format(sw.elapsed().count(), ctx);
     }
 };
-}  // namespace std
+}  // namespace fmt

src/common.cpp

@@ -26,13 +26,9 @@ spdlog_ex::spdlog_ex(std::string msg)
     : msg_(std::move(msg)) {}
 
 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.c_str());
     msg_ = fmt::to_string(outbuf);
-#endif
 }
 
 const char *spdlog_ex::what() const noexcept { return msg_.c_str(); }

tests/CMakeLists.txt

@@ -19,12 +19,12 @@ if(Catch2_FOUND)
 else()
     message(STATUS "Bundled version of Catch will be downloaded and used.")
     include(FetchContent)
-    FetchContent_Declare(Catch2
-            GIT_REPOSITORY https://github.com/catchorg/Catch2.git
-            GIT_TAG 53d0d913a422d356b23dd927547febdf69ee9081 # v3.5.0
+    FetchContent_Declare(
+        Catch2 GIT_REPOSITORY https://github.com/catchorg/Catch2.git
+        GIT_TAG 53d0d913a422d356b23dd927547febdf69ee9081 # v3.5.0
     )
     FetchContent_MakeAvailable(Catch2)
-	set_target_properties(Catch2 Catch2WithMain PROPERTIES FOLDER "third-party")
+    set_target_properties(Catch2 Catch2WithMain PROPERTIES FOLDER "third-party")
 endif()
 
 set(SPDLOG_UTESTS_SOURCES
@@ -52,7 +52,8 @@ set(SPDLOG_UTESTS_SOURCES
     test_source_location.cpp
     test_no_source_location.cpp
     test_log_level.cpp
-    test_include_sinks.cpp)
+    test_include_sinks.cpp
+    test_bin_to_hex.cpp)
 
 if(WIN32)
     list(APPEND SPDLOG_UTESTS_SOURCES test_eventlog.cpp)
@@ -66,10 +67,6 @@ if(systemd_FOUND)
     list(APPEND SPDLOG_UTESTS_SOURCES test_systemd.cpp)
 endif()
 
-if(NOT SPDLOG_USE_STD_FORMAT)
-    list(APPEND SPDLOG_UTESTS_SOURCES test_bin_to_hex.cpp)
-endif()
-
 enable_testing()
 
 function(spdlog_prepare_test test_target spdlog_lib)
@@ -82,9 +79,9 @@ function(spdlog_prepare_test test_target spdlog_lib)
     target_link_libraries(${test_target} PRIVATE Catch2::Catch2WithMain)
     if(SPDLOG_SANITIZE_ADDRESS)
         spdlog_enable_addr_sanitizer(${test_target})
-    elseif (SPDLOG_SANITIZE_THREAD)
+    elseif(SPDLOG_SANITIZE_THREAD)
         spdlog_enable_thread_sanitizer(${test_target})
-    endif ()
+    endif()
     add_test(NAME ${test_target} COMMAND ${test_target})
     set_tests_properties(${test_target} PROPERTIES RUN_SERIAL ON)
 endfunction()

tests/test_create_dir.cpp

@@ -81,8 +81,7 @@ TEST_CASE("dir_name", "[create_dir]") {
     // clang-format off
     #include <windows.h>
     #include <fileapi.h>
-    // clang-format on
-
+// clang-format on
 
 std::string get_full_path(const std::string &relative_folder_path) {
     char full_path[MAX_PATH];

tests/test_daily_and_rotation_loggers.cpp

@@ -6,11 +6,7 @@
 #include "spdlog/sinks/daily_file_sink.h"
 #include "spdlog/sinks/rotating_file_sink.h"
 
-#ifdef SPDLOG_USE_STD_FORMAT
-using filename_memory_buf_t = std::basic_string<spdlog::filename_t::value_type>;
-#else
-using filename_memory_buf_t = fmt::basic_memory_buffer<spdlog::filename_t::value_type, 250>;
-#endif
+using filename_memory_buf_t = spdlog::memory_buf_t;
 
 #ifdef SPDLOG_WCHAR_FILENAMES
 std::string filename_buf_to_utf8string(const filename_memory_buf_t &w) {

tests/test_errors.cpp

@@ -18,7 +18,6 @@ protected:
 };
 struct custom_ex {};
 
-#if !defined(SPDLOG_USE_STD_FORMAT)  // std formt doesn't fully support runtime format strings
 TEST_CASE("default_error_handler", "[errors]") {
     prepare_logdir();
     spdlog::filename_t filename = SPDLOG_FILENAME_T(SIMPLE_LOG);
@@ -45,7 +44,6 @@ TEST_CASE("custom_error_handler", "[errors]") {
     logger->info("Good message #2");
     require_message_count(SIMPLE_LOG, 2);
 }
-#endif
 
 TEST_CASE("default_error_handler2", "[errors]") {
     spdlog::drop_all();
@@ -61,7 +59,6 @@ TEST_CASE("flush_error_handler", "[errors]") {
     REQUIRE_THROWS_AS(logger->flush(), custom_ex);
 }
 
-#if !defined(SPDLOG_USE_STD_FORMAT)  // std formt doesn't fully support runtime format strings
 TEST_CASE("async_error_handler", "[errors]") {
     prepare_logdir();
     std::string err_msg("log failed with some msg");
@@ -86,7 +83,6 @@ TEST_CASE("async_error_handler", "[errors]") {
     require_message_count(SIMPLE_ASYNC_LOG, 2);
     REQUIRE(file_contents("test_logs/custom_err.txt") == err_msg);
 }
-#endif
 
 // Make sure async error handler is executed
 TEST_CASE("async_error_handler2", "[errors]") {