Switch to vformat_to

Drive-by: reduce the amount of occurences of #ifdef SPDLOG_USE_STD_FORMAT

include/spdlog/common.h

@@ -44,15 +44,13 @@
 
 #include <spdlog/fmt/fmt.h>
 
-#ifndef SPDLOG_USE_STD_FORMAT
+#if !defined(SPDLOG_USE_STD_FORMAT) && FMT_VERSION >= 80000 // backward compatibility with fmt versions older than 8
-#    if FMT_VERSION >= 80000 // backward compatibility with fmt versions older than 8
+#    define SPDLOG_FMT_RUNTIME(format_string) fmt::runtime(format_string)
-#        define SPDLOG_FMT_RUNTIME(format_string) fmt::runtime(format_string)
+#    if defined(SPDLOG_WCHAR_FILENAMES) || defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT)
-#        if defined(SPDLOG_WCHAR_FILENAMES) || defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT)
+#        include <spdlog/fmt/xchar.h>
-#            include <spdlog/fmt/xchar.h>
-#        endif
-#    else
-#        define SPDLOG_FMT_RUNTIME(format_string) format_string
 #    endif
+#else
+#    define SPDLOG_FMT_RUNTIME(format_string) format_string
 #endif
 
 // visual studio up to 2013 does not support noexcept nor constexpr

include/spdlog/details/fmt_helper.h

@@ -23,6 +23,20 @@ inline spdlog::string_view_t to_string_view(const memory_buf_t &buf) SPDLOG_NOEX
     return spdlog::string_view_t{buf.data(), buf.size()};
 }
 
+#ifdef SPDLOG_USE_STD_FORMAT
+template<typename T>
+std::basic_string<T> to_string(const std::basic_string<T> &buf)
+{
+    return buf;
+}
+#else
+template<typename T, size_t Size>
+std::basic_string<T> to_string(const fmt::basic_memory_buffer<T, Size> &buf)
+{
+    return fmt::to_string(buf);
+}
+#endif
+
 inline void append_string_view(spdlog::string_view_t view, memory_buf_t &dest)
 {
     auto *buf_ptr = view.data();

include/spdlog/details/os-inl.h

@@ -388,11 +388,7 @@ 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 fmt_helper::to_string(buf);
-    return buf;
-#    else
-    return fmt::to_string(buf);
-#    endif
 }
 #else
 SPDLOG_INLINE std::string filename_to_str(const filename_t &filename)

include/spdlog/logger.h

@@ -363,13 +363,10 @@ protected:
         }
         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)...));
+            fmt_lib::vformat_to(std::back_inserter(buf), fmt, fmt_lib::make_format_args(std::forward<Args>(args)...));
-#endif
+
-            details::log_msg log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size()));
+            details::log_msg log_msg(loc, name_, lvl, details::fmt_helper::to_string_view(buf));
             log_it_(log_msg, log_enabled, traceback_enabled);
         }
         SPDLOG_LOGGER_CATCH(loc)
@@ -388,13 +385,9 @@ protected:
         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)...));
+            fmt_lib::vformat_to(std::back_inserter(wbuf), fmt, fmt_lib::make_format_args<fmt_lib::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()));

include/spdlog/sinks/msvc_sink.h

@@ -30,11 +30,8 @@ protected:
     {
         memory_buf_t formatted;
         base_sink<Mutex>::formatter_->format(msg, formatted);
-#    ifdef SPDLOG_USE_STD_FORMAT
+        formatted.push_back('\0'); // add a null terminator for OutputDebugStringA
-        OutputDebugStringA(formatted.c_str());
+        OutputDebugStringA(formatted.data());
-#    else
-        OutputDebugStringA(fmt::to_string(formatted).c_str());
-#    endif
     }
 
     void flush_() override {}

include/spdlog/sinks/ringbuffer_sink.h

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

tests/test_daily_logger.cpp

@@ -5,8 +5,20 @@
 
 #ifdef SPDLOG_USE_STD_FORMAT
 using filename_memory_buf_t = std::basic_string<spdlog::filename_t::value_type>;
+
+std::string filename_buf_to_utf8string(const filename_memory_buf_t &w)
+{
+    spdlog::memory_buf_t buf;
+    spdlog::details::os::wstr_to_utf8buf(w, buf);
+    return spdlog::details::fmt_helper::to_string(buf);
+}
 #else
 using filename_memory_buf_t = fmt::basic_memory_buffer<spdlog::filename_t::value_type, 250>;
+
+std::string filename_buf_to_utf8string(const filename_memory_buf_t &w)
+{
+    return spdlog::details::fmt_helper::to_string(w);
+}
 #endif
 
 TEST_CASE("daily_logger with dateonly calculator", "[daily_logger]")
@@ -30,23 +42,7 @@ TEST_CASE("daily_logger with dateonly calculator", "[daily_logger]")
     }
     logger->flush();
 
-#ifdef SPDLOG_WCHAR_FILENAMES
+    require_message_count(filename_buf_to_utf8string(w), 10);
-    spdlog::memory_buf_t buf;
-#    ifdef SPDLOG_USE_STD_FORMAT
-    spdlog::details::os::wstr_to_utf8buf(w, buf);
-    auto &filename = buf;
-#    else
-    spdlog::details::os::wstr_to_utf8buf(fmt::to_string(w), buf);
-    auto filename = fmt::to_string(buf);
-#    endif
-#else
-#    ifdef SPDLOG_USE_STD_FORMAT
-    auto &filename = w;
-#    else
-    auto filename = fmt::to_string(w);
-#    endif
-#endif
-    require_message_count(filename, 10);
 }
 
 struct custom_daily_file_name_calculator
@@ -56,11 +52,8 @@ struct custom_daily_file_name_calculator
         filename_memory_buf_t w;
         spdlog::fmt_lib::format_to(std::back_inserter(w), SPDLOG_FILENAME_T("{}{:04d}{:02d}{:02d}"), basename, now_tm.tm_year + 1900,
             now_tm.tm_mon + 1, now_tm.tm_mday);
-#ifdef SPDLOG_USE_STD_FORMAT
+
-        return w;
+        return spdlog::details::fmt_helper::to_string(w);
-#else
-        return fmt::to_string(w);
-#endif
     }
 };
 
@@ -85,23 +78,7 @@ TEST_CASE("daily_logger with custom calculator", "[daily_logger]")
 
     logger->flush();
 
-#ifdef SPDLOG_WCHAR_FILENAMES
+    require_message_count(filename_buf_to_utf8string(w), 10);
-    spdlog::memory_buf_t buf;
-#    ifdef SPDLOG_USE_STD_FORMAT
-    spdlog::details::os::wstr_to_utf8buf(w, buf);
-    auto &filename = buf;
-#    else
-    spdlog::details::os::wstr_to_utf8buf(fmt::to_string(w), buf);
-    auto filename = fmt::to_string(buf);
-#    endif
-#else
-#    ifdef SPDLOG_USE_STD_FORMAT
-    auto &filename = w;
-#    else
-    auto filename = fmt::to_string(w);
-#    endif
-#endif
-    require_message_count(filename, 10);
 }
 
 /*

tests/test_errors.cpp

@@ -29,11 +29,7 @@ TEST_CASE("default_error_handler", "[errors]]")
 
     auto logger = spdlog::create<spdlog::sinks::basic_file_sink_mt>("test-error", filename, true);
     logger->set_pattern("%v");
-#ifdef SPDLOG_USE_STD_FORMAT
+    logger->info(SPDLOG_FMT_RUNTIME("Test message {} {}"), 1);
-    logger->info("Test message {} {}", 1);
-#else
-    logger->info(fmt::runtime("Test message {} {}"), 1);
-#endif
     logger->info("Test message {}", 2);
     logger->flush();
 
@@ -53,11 +49,7 @@ TEST_CASE("custom_error_handler", "[errors]]")
     logger->set_error_handler([=](const std::string &) { throw custom_ex(); });
     logger->info("Good message #1");
 
-#ifdef SPDLOG_USE_STD_FORMAT
+    REQUIRE_THROWS_AS(logger->info(SPDLOG_FMT_RUNTIME("Bad format msg {} {}"), "xxx"), custom_ex);
-    REQUIRE_THROWS_AS(logger->info("Bad format msg {} {}", "xxx"), custom_ex);
-#else
-    REQUIRE_THROWS_AS(logger->info(fmt::runtime("Bad format msg {} {}"), "xxx"), custom_ex);
-#endif
     logger->info("Good message #2");
     require_message_count(SIMPLE_LOG, 2);
 }
@@ -96,11 +88,7 @@ TEST_CASE("async_error_handler", "[errors]]")
             ofs << err_msg;
         });
         logger->info("Good message #1");
-#ifdef SPDLOG_USE_STD_FORMAT
+        logger->info(SPDLOG_FMT_RUNTIME("Bad format msg {} {}"), "xxx");
-        logger->info("Bad format msg {} {}", "xxx");
-#else
-        logger->info(fmt::runtime("Bad format msg {} {}"), "xxx");
-#endif
         logger->info("Good message #2");
         spdlog::drop("logger"); // force logger to drain the queue and shutdown
     }

tests/test_fmt_helper.cpp

@@ -3,17 +3,14 @@
 #include "spdlog/details/fmt_helper.h"
 
 using spdlog::memory_buf_t;
+using spdlog::details::fmt_helper::to_string_view;
 
 void test_pad2(int n, const char *expected)
 {
     memory_buf_t buf;
     spdlog::details::fmt_helper::pad2(n, buf);
 
-#ifdef SPDLOG_USE_STD_FORMAT
+    REQUIRE(to_string_view(buf) == expected);
-    REQUIRE(buf == expected);
-#else
-    REQUIRE(fmt::to_string(buf) == expected);
-#endif
 }
 
 void test_pad3(uint32_t n, const char *expected)
@@ -21,11 +18,7 @@ void test_pad3(uint32_t n, const char *expected)
     memory_buf_t buf;
     spdlog::details::fmt_helper::pad3(n, buf);
 
-#ifdef SPDLOG_USE_STD_FORMAT
+    REQUIRE(to_string_view(buf) == expected);
-    REQUIRE(buf == expected);
-#else
-    REQUIRE(fmt::to_string(buf) == expected);
-#endif
 }
 
 void test_pad6(std::size_t n, const char *expected)
@@ -33,11 +26,7 @@ void test_pad6(std::size_t n, const char *expected)
     memory_buf_t buf;
     spdlog::details::fmt_helper::pad6(n, buf);
 
-#ifdef SPDLOG_USE_STD_FORMAT
+    REQUIRE(to_string_view(buf) == expected);
-    REQUIRE(buf == expected);
-#else
-    REQUIRE(fmt::to_string(buf) == expected);
-#endif
 }
 
 void test_pad9(std::size_t n, const char *expected)
@@ -45,11 +34,7 @@ void test_pad9(std::size_t n, const char *expected)
     memory_buf_t buf;
     spdlog::details::fmt_helper::pad9(n, buf);
 
-#ifdef SPDLOG_USE_STD_FORMAT
+    REQUIRE(to_string_view(buf) == expected);
-    REQUIRE(buf == expected);
-#else
-    REQUIRE(fmt::to_string(buf) == expected);
-#endif
 }
 
 TEST_CASE("pad2", "[fmt_helper]")

tests/test_pattern_formatter.cpp

@@ -2,6 +2,7 @@
 #include "test_sink.h"
 
 using spdlog::memory_buf_t;
+using spdlog::details::fmt_helper::to_string_view;
 
 // log to str and return it
 template<typename... Args>
@@ -273,11 +274,7 @@ TEST_CASE("clone-default-formatter", "[pattern_formatter]")
     formatter_1->format(msg, formatted_1);
     formatter_2->format(msg, formatted_2);
 
-#ifdef SPDLOG_USE_STD_FORMAT
+    REQUIRE(to_string_view(formatted_1) == to_string_view(formatted_2));
-    REQUIRE(formatted_1 == formatted_2);
-#else
-    REQUIRE(fmt::to_string(formatted_1) == fmt::to_string(formatted_2));
-#endif
 }
 
 TEST_CASE("clone-default-formatter2", "[pattern_formatter]")
@@ -292,11 +289,7 @@ TEST_CASE("clone-default-formatter2", "[pattern_formatter]")
     formatter_1->format(msg, formatted_1);
     formatter_2->format(msg, formatted_2);
 
-#ifdef SPDLOG_USE_STD_FORMAT
+    REQUIRE(to_string_view(formatted_1) == to_string_view(formatted_2));
-    REQUIRE(formatted_1 == formatted_2);
-#else
-    REQUIRE(fmt::to_string(formatted_1) == fmt::to_string(formatted_2));
-#endif
 }
 
 TEST_CASE("clone-formatter", "[pattern_formatter]")
@@ -311,11 +304,7 @@ TEST_CASE("clone-formatter", "[pattern_formatter]")
     formatter_1->format(msg, formatted_1);
     formatter_2->format(msg, formatted_2);
 
-#ifdef SPDLOG_USE_STD_FORMAT
+    REQUIRE(to_string_view(formatted_1) == to_string_view(formatted_2));
-    REQUIRE(formatted_1 == formatted_2);
-#else
-    REQUIRE(fmt::to_string(formatted_1) == fmt::to_string(formatted_2));
-#endif
 }
 
 TEST_CASE("clone-formatter-2", "[pattern_formatter]")
@@ -331,11 +320,7 @@ TEST_CASE("clone-formatter-2", "[pattern_formatter]")
     formatter_1->format(msg, formatted_1);
     formatter_2->format(msg, formatted_2);
 
-#ifdef SPDLOG_USE_STD_FORMAT
+    REQUIRE(to_string_view(formatted_1) == to_string_view(formatted_2));
-    REQUIRE(formatted_1 == formatted_2);
-#else
-    REQUIRE(fmt::to_string(formatted_1) == fmt::to_string(formatted_2));
-#endif
 }
 
 class custom_test_flag : public spdlog::custom_flag_formatter
@@ -382,13 +367,8 @@ TEST_CASE("clone-custom_formatter", "[pattern_formatter]")
 
     auto expected = spdlog::fmt_lib::format("[logger-name] [custom_output] some message{}", spdlog::details::os::default_eol);
 
-#ifdef SPDLOG_USE_STD_FORMAT
+    REQUIRE(to_string_view(formatted_1) == expected);
-    REQUIRE(formatted_1 == expected);
+    REQUIRE(to_string_view(formatted_2) == expected);
-    REQUIRE(formatted_2 == expected);
-#else
-    REQUIRE(fmt::to_string(formatted_1) == expected);
-    REQUIRE(fmt::to_string(formatted_2) == expected);
-#endif
 }
 
 //
@@ -410,11 +390,7 @@ TEST_CASE("short filename formatter-1", "[pattern_formatter]")
     spdlog::details::log_msg msg(source_loc, "logger-name", spdlog::level::info, "Hello");
     formatter.format(msg, formatted);
 
-#ifdef SPDLOG_USE_STD_FORMAT
+    REQUIRE(to_string_view(formatted) == "myfile.cpp");
-    REQUIRE(formatted == "myfile.cpp");
-#else
-    REQUIRE(fmt::to_string(formatted) == "myfile.cpp");
-#endif
 }
 
 TEST_CASE("short filename formatter-2", "[pattern_formatter]")
@@ -426,11 +402,7 @@ TEST_CASE("short filename formatter-2", "[pattern_formatter]")
     spdlog::details::log_msg msg(source_loc, "logger-name", spdlog::level::info, "Hello");
     formatter.format(msg, formatted);
 
-#ifdef SPDLOG_USE_STD_FORMAT
+    REQUIRE(to_string_view(formatted) == "myfile.cpp:123");
-    REQUIRE(formatted == "myfile.cpp:123");
-#else
-    REQUIRE(fmt::to_string(formatted) == "myfile.cpp:123");
-#endif
 }
 
 TEST_CASE("short filename formatter-3", "[pattern_formatter]")
@@ -442,11 +414,7 @@ TEST_CASE("short filename formatter-3", "[pattern_formatter]")
     spdlog::details::log_msg msg(source_loc, "logger-name", spdlog::level::info, "Hello");
     formatter.format(msg, formatted);
 
-#ifdef SPDLOG_USE_STD_FORMAT
+    REQUIRE(to_string_view(formatted) == " Hello");
-    REQUIRE(formatted == " Hello");
-#else
-    REQUIRE(fmt::to_string(formatted) == " Hello");
-#endif
 }
 
 TEST_CASE("full filename formatter", "[pattern_formatter]")
@@ -458,11 +426,7 @@ TEST_CASE("full filename formatter", "[pattern_formatter]")
     spdlog::details::log_msg msg(source_loc, "logger-name", spdlog::level::info, "Hello");
     formatter.format(msg, formatted);
 
-#ifdef SPDLOG_USE_STD_FORMAT
+    REQUIRE(to_string_view(formatted) == test_path);
-    REQUIRE(formatted == test_path);
-#else
-    REQUIRE(fmt::to_string(formatted) == test_path);
-#endif
 }
 
 TEST_CASE("custom flags", "[pattern_formatter]")
@@ -476,11 +440,7 @@ TEST_CASE("custom flags", "[pattern_formatter]")
     formatter->format(msg, formatted);
     auto expected = spdlog::fmt_lib::format("[logger-name] [custom1] [custom2] some message{}", spdlog::details::os::default_eol);
 
-#ifdef SPDLOG_USE_STD_FORMAT
+    REQUIRE(to_string_view(formatted) == expected);
-    REQUIRE(formatted == expected);
-#else
-    REQUIRE(fmt::to_string(formatted) == expected);
-#endif
 }
 
 TEST_CASE("custom flags-padding", "[pattern_formatter]")
@@ -494,11 +454,7 @@ TEST_CASE("custom flags-padding", "[pattern_formatter]")
     formatter->format(msg, formatted);
     auto expected = spdlog::fmt_lib::format("[logger-name] [custom1] [     custom2] some message{}", spdlog::details::os::default_eol);
 
-#ifdef SPDLOG_USE_STD_FORMAT
+    REQUIRE(to_string_view(formatted) == expected);
-    REQUIRE(formatted == expected);
-#else
-    REQUIRE(fmt::to_string(formatted) == expected);
-#endif
 }
 
 TEST_CASE("custom flags-exception", "[pattern_formatter]")