From ebeb3707b157ff386d8d78947cc2253858efb9bc Mon Sep 17 00:00:00 2001
From: Charles Milette <charles.milette@gmail.com>
Date: Thu, 21 Apr 2022 21:46:58 -0400
Subject: [PATCH 01/10] Switch to vformat_to

Drive-by: reduce the amount of occurences of #ifdef SPDLOG_USE_STD_FORMAT
---
 include/spdlog/common.h                | 14 +++---
 include/spdlog/details/fmt_helper.h    | 14 ++++++
 include/spdlog/details/os-inl.h        |  6 +--
 include/spdlog/logger.h                | 17 ++-----
 include/spdlog/sinks/msvc_sink.h       |  7 +--
 include/spdlog/sinks/ringbuffer_sink.h |  6 +--
 tests/test_daily_logger.cpp            | 55 ++++++--------------
 tests/test_errors.cpp                  | 18 ++-----
 tests/test_fmt_helper.cpp              | 25 ++-------
 tests/test_pattern_formatter.cpp       | 70 +++++---------------------
 10 files changed, 66 insertions(+), 166 deletions(-)

diff --git a/include/spdlog/common.h b/include/spdlog/common.h
index 8259c733..f0b2a996 100644
--- a/include/spdlog/common.h
+++ b/include/spdlog/common.h
@@ -44,15 +44,13 @@
 
 #include <spdlog/fmt/fmt.h>
 
-#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
+#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)
+#    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
 
 // visual studio up to 2013 does not support noexcept nor constexpr
diff --git a/include/spdlog/details/fmt_helper.h b/include/spdlog/details/fmt_helper.h
index 1a60bc0d..9a1b69d3 100644
--- a/include/spdlog/details/fmt_helper.h
+++ b/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();
diff --git a/include/spdlog/details/os-inl.h b/include/spdlog/details/os-inl.h
index c3bf691c..aa4ff709 100644
--- a/include/spdlog/details/os-inl.h
+++ b/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 buf;
-#    else
-    return fmt::to_string(buf);
-#    endif
+    return fmt_helper::to_string(buf);
 }
 #else
 SPDLOG_INLINE std::string filename_to_str(const filename_t &filename)
diff --git a/include/spdlog/logger.h b/include/spdlog/logger.h
index a8abae41..9f4bc1a6 100644
--- a/include/spdlog/logger.h
+++ b/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)...));
-#endif
-            details::log_msg log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size()));
+            fmt_lib::vformat_to(std::back_inserter(buf), fmt, fmt_lib::make_format_args(std::forward<Args>(args)...));
+
+            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)...));
-#    endif
+            fmt_lib::vformat_to(std::back_inserter(wbuf), fmt, fmt_lib::make_format_args<fmt_lib::wformat_context>(std::forward<Args>(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()));
diff --git a/include/spdlog/sinks/msvc_sink.h b/include/spdlog/sinks/msvc_sink.h
index cf2516d7..b1dfd305 100644
--- a/include/spdlog/sinks/msvc_sink.h
+++ b/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
-        OutputDebugStringA(formatted.c_str());
-#    else
-        OutputDebugStringA(fmt::to_string(formatted).c_str());
-#    endif
+        formatted.push_back('\0'); // add a null terminator for OutputDebugStringA
+        OutputDebugStringA(formatted.data());
     }
 
     void flush_() override {}
diff --git a/include/spdlog/sinks/ringbuffer_sink.h b/include/spdlog/sinks/ringbuffer_sink.h
index 5836d98b..de31c99c 100644
--- a/include/spdlog/sinks/ringbuffer_sink.h
+++ b/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(std::move(formatted));
-#else
-            ret.push_back(fmt::to_string(formatted));
-#endif
+            ret.push_back(fmt_helper::to_string(formatted));
         }
         return ret;
     }
diff --git a/tests/test_daily_logger.cpp b/tests/test_daily_logger.cpp
index cf93c46e..8cd9d206 100644
--- a/tests/test_daily_logger.cpp
+++ b/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
-    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);
+    require_message_count(filename_buf_to_utf8string(w), 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;
-#else
-        return fmt::to_string(w);
-#endif
+
+        return spdlog::details::fmt_helper::to_string(w);
     }
 };
 
@@ -85,23 +78,7 @@ TEST_CASE("daily_logger with custom calculator", "[daily_logger]")
 
     logger->flush();
 
-#ifdef SPDLOG_WCHAR_FILENAMES
-    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);
+    require_message_count(filename_buf_to_utf8string(w), 10);
 }
 
 /*
diff --git a/tests/test_errors.cpp b/tests/test_errors.cpp
index c7aef812..896e5b0a 100644
--- a/tests/test_errors.cpp
+++ b/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("Test message {} {}", 1);
-#else
-    logger->info(fmt::runtime("Test message {} {}"), 1);
-#endif
+    logger->info(SPDLOG_FMT_RUNTIME("Test message {} {}"), 1);
     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("Bad format msg {} {}", "xxx"), custom_ex);
-#else
-    REQUIRE_THROWS_AS(logger->info(fmt::runtime("Bad format msg {} {}"), "xxx"), custom_ex);
-#endif
+    REQUIRE_THROWS_AS(logger->info(SPDLOG_FMT_RUNTIME("Bad format msg {} {}"), "xxx"), custom_ex);
     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("Bad format msg {} {}", "xxx");
-#else
-        logger->info(fmt::runtime("Bad format msg {} {}"), "xxx");
-#endif
+        logger->info(SPDLOG_FMT_RUNTIME("Bad format msg {} {}"), "xxx");
         logger->info("Good message #2");
         spdlog::drop("logger"); // force logger to drain the queue and shutdown
     }
diff --git a/tests/test_fmt_helper.cpp b/tests/test_fmt_helper.cpp
index dde5d482..a7edccf3 100644
--- a/tests/test_fmt_helper.cpp
+++ b/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(buf == expected);
-#else
-    REQUIRE(fmt::to_string(buf) == expected);
-#endif
+    REQUIRE(to_string_view(buf) == expected);
 }
 
 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(buf == expected);
-#else
-    REQUIRE(fmt::to_string(buf) == expected);
-#endif
+    REQUIRE(to_string_view(buf) == expected);
 }
 
 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(buf == expected);
-#else
-    REQUIRE(fmt::to_string(buf) == expected);
-#endif
+    REQUIRE(to_string_view(buf) == expected);
 }
 
 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(buf == expected);
-#else
-    REQUIRE(fmt::to_string(buf) == expected);
-#endif
+    REQUIRE(to_string_view(buf) == expected);
 }
 
 TEST_CASE("pad2", "[fmt_helper]")
diff --git a/tests/test_pattern_formatter.cpp b/tests/test_pattern_formatter.cpp
index 02a1bc2b..e4ea6cc3 100644
--- a/tests/test_pattern_formatter.cpp
+++ b/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(formatted_1 == formatted_2);
-#else
-    REQUIRE(fmt::to_string(formatted_1) == fmt::to_string(formatted_2));
-#endif
+    REQUIRE(to_string_view(formatted_1) == to_string_view(formatted_2));
 }
 
 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(formatted_1 == formatted_2);
-#else
-    REQUIRE(fmt::to_string(formatted_1) == fmt::to_string(formatted_2));
-#endif
+    REQUIRE(to_string_view(formatted_1) == to_string_view(formatted_2));
 }
 
 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(formatted_1 == formatted_2);
-#else
-    REQUIRE(fmt::to_string(formatted_1) == fmt::to_string(formatted_2));
-#endif
+    REQUIRE(to_string_view(formatted_1) == to_string_view(formatted_2));
 }
 
 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(formatted_1 == formatted_2);
-#else
-    REQUIRE(fmt::to_string(formatted_1) == fmt::to_string(formatted_2));
-#endif
+    REQUIRE(to_string_view(formatted_1) == to_string_view(formatted_2));
 }
 
 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(formatted_1 == expected);
-    REQUIRE(formatted_2 == expected);
-#else
-    REQUIRE(fmt::to_string(formatted_1) == expected);
-    REQUIRE(fmt::to_string(formatted_2) == expected);
-#endif
+    REQUIRE(to_string_view(formatted_1) == expected);
+    REQUIRE(to_string_view(formatted_2) == expected);
 }
 
 //
@@ -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(formatted == "myfile.cpp");
-#else
-    REQUIRE(fmt::to_string(formatted) == "myfile.cpp");
-#endif
+    REQUIRE(to_string_view(formatted) == "myfile.cpp");
 }
 
 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(formatted == "myfile.cpp:123");
-#else
-    REQUIRE(fmt::to_string(formatted) == "myfile.cpp:123");
-#endif
+    REQUIRE(to_string_view(formatted) == "myfile.cpp:123");
 }
 
 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(formatted == " Hello");
-#else
-    REQUIRE(fmt::to_string(formatted) == " Hello");
-#endif
+    REQUIRE(to_string_view(formatted) == " Hello");
 }
 
 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(formatted == test_path);
-#else
-    REQUIRE(fmt::to_string(formatted) == test_path);
-#endif
+    REQUIRE(to_string_view(formatted) == test_path);
 }
 
 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(formatted == expected);
-#else
-    REQUIRE(fmt::to_string(formatted) == expected);
-#endif
+    REQUIRE(to_string_view(formatted) == expected);
 }
 
 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(formatted == expected);
-#else
-    REQUIRE(fmt::to_string(formatted) == expected);
-#endif
+    REQUIRE(to_string_view(formatted) == expected);
 }
 
 TEST_CASE("custom flags-exception", "[pattern_formatter]")

From 3cf94968e774ef814af26d53eb77ec3bacd9c194 Mon Sep 17 00:00:00 2001
From: Charles Milette <charles.milette@gmail.com>
Date: Thu, 21 Apr 2022 22:11:16 -0400
Subject: [PATCH 02/10] Add missing include

---
 include/spdlog/logger.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/spdlog/logger.h b/include/spdlog/logger.h
index 9f4bc1a6..fd076052 100644
--- a/include/spdlog/logger.h
+++ b/include/spdlog/logger.h
@@ -17,6 +17,7 @@
 #include <spdlog/common.h>
 #include <spdlog/details/log_msg.h>
 #include <spdlog/details/backtracer.h>
+#include <spdlog/details/fmt_helper.h>
 
 #ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
 #    ifndef _WIN32

From 91019f4f4629b0a35d333c713f1ab87559301210 Mon Sep 17 00:00:00 2001
From: Charles Milette <charles.milette@gmail.com>
Date: Thu, 21 Apr 2022 22:36:04 -0400
Subject: [PATCH 03/10] Fix bad #ifdef

---
 tests/test_daily_logger.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/test_daily_logger.cpp b/tests/test_daily_logger.cpp
index 8cd9d206..85150f00 100644
--- a/tests/test_daily_logger.cpp
+++ b/tests/test_daily_logger.cpp
@@ -3,7 +3,7 @@
  */
 #include "includes.h"
 
-#ifdef SPDLOG_USE_STD_FORMAT
+#ifdef SPDLOG_WCHAR_FILENAMES
 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)

From 56adf64ccf5b25ec2b3e644f2c203cf7dd218e30 Mon Sep 17 00:00:00 2001
From: Charles Milette <charles.milette@gmail.com>
Date: Thu, 21 Apr 2022 22:43:13 -0400
Subject: [PATCH 04/10] Actually fix bad #ifdef

---
 tests/test_daily_logger.cpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/tests/test_daily_logger.cpp b/tests/test_daily_logger.cpp
index 85150f00..5b27336d 100644
--- a/tests/test_daily_logger.cpp
+++ b/tests/test_daily_logger.cpp
@@ -3,9 +3,13 @@
  */
 #include "includes.h"
 
-#ifdef SPDLOG_WCHAR_FILENAMES
+#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
 
+#ifdef SPDLOG_WCHAR_FILENAMES
 std::string filename_buf_to_utf8string(const filename_memory_buf_t &w)
 {
     spdlog::memory_buf_t buf;
@@ -13,8 +17,6 @@ std::string filename_buf_to_utf8string(const filename_memory_buf_t &w)
     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);

From c203b4df8e32111f4260c55121543322d329cda0 Mon Sep 17 00:00:00 2001
From: Charles Milette <charles.milette@gmail.com>
Date: Thu, 21 Apr 2022 23:38:12 -0400
Subject: [PATCH 05/10] Fix conversion from fmt::memory_buffer to
 fmt::string_view

---
 tests/test_daily_logger.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/test_daily_logger.cpp b/tests/test_daily_logger.cpp
index 5b27336d..8bcc6d72 100644
--- a/tests/test_daily_logger.cpp
+++ b/tests/test_daily_logger.cpp
@@ -13,7 +13,7 @@ using filename_memory_buf_t = fmt::basic_memory_buffer<spdlog::filename_t::value
 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);
+    spdlog::details::os::wstr_to_utf8buf(spdlog::wstring_view_t(w.data(), w.size()), buf);
     return spdlog::details::fmt_helper::to_string(buf);
 }
 #else

From ee00f2e07d3bb7424593a6d0965f9cd163d45fa3 Mon Sep 17 00:00:00 2001
From: Charles Milette <charles.milette@gmail.com>
Date: Fri, 22 Apr 2022 22:52:56 -0400
Subject: [PATCH 06/10] Remove fmt_helper.h include from logger.h

---
 include/spdlog/logger.h | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/include/spdlog/logger.h b/include/spdlog/logger.h
index fd076052..05a40a52 100644
--- a/include/spdlog/logger.h
+++ b/include/spdlog/logger.h
@@ -17,7 +17,6 @@
 #include <spdlog/common.h>
 #include <spdlog/details/log_msg.h>
 #include <spdlog/details/backtracer.h>
-#include <spdlog/details/fmt_helper.h>
 
 #ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
 #    ifndef _WIN32
@@ -367,7 +366,7 @@ protected:
             memory_buf_t buf;
             fmt_lib::vformat_to(std::back_inserter(buf), fmt, fmt_lib::make_format_args(std::forward<Args>(args)...));
 
-            details::log_msg log_msg(loc, name_, lvl, details::fmt_helper::to_string_view(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)

From 714cf12822a0356a02caaca4c77d26fd63c6a2bd Mon Sep 17 00:00:00 2001
From: Charles Milette <charles.milette@gmail.com>
Date: Fri, 22 Apr 2022 23:28:28 -0400
Subject: [PATCH 07/10] Add fmt_helper.h include to includes.h and os-inl.h

---
 include/spdlog/details/os-inl.h | 1 +
 tests/includes.h                | 1 +
 tests/test_fmt_helper.cpp       | 1 -
 3 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/spdlog/details/os-inl.h b/include/spdlog/details/os-inl.h
index aa4ff709..4c17804b 100644
--- a/include/spdlog/details/os-inl.h
+++ b/include/spdlog/details/os-inl.h
@@ -33,6 +33,7 @@
 
 #    if defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)
 #        include <limits>
+#        include <spdlog/details/fmt_helper.h>
 #    endif
 
 #    include <direct.h> // for _mkdir/_wmkdir
diff --git a/tests/includes.h b/tests/includes.h
index 7285873a..e6805280 100644
--- a/tests/includes.h
+++ b/tests/includes.h
@@ -17,6 +17,7 @@
 
 #include "spdlog/spdlog.h"
 #include "spdlog/async.h"
+#include "spdlog/details/fmt_helper.h"
 #include "spdlog/sinks/basic_file_sink.h"
 #include "spdlog/sinks/daily_file_sink.h"
 #include "spdlog/sinks/null_sink.h"
diff --git a/tests/test_fmt_helper.cpp b/tests/test_fmt_helper.cpp
index a7edccf3..a9db5d02 100644
--- a/tests/test_fmt_helper.cpp
+++ b/tests/test_fmt_helper.cpp
@@ -1,6 +1,5 @@
 
 #include "includes.h"
-#include "spdlog/details/fmt_helper.h"
 
 using spdlog::memory_buf_t;
 using spdlog::details::fmt_helper::to_string_view;

From 37dd6bb15907f96eb8050bc259ca0660a0d0e7a4 Mon Sep 17 00:00:00 2001
From: Charles Milette <charles.milette@gmail.com>
Date: Mon, 25 Apr 2022 21:59:56 -0400
Subject: [PATCH 08/10] Address PR review comments

---
 include/spdlog/details/fmt_helper.h    |  6 +++---
 include/spdlog/details/os-inl.h        |  2 +-
 include/spdlog/sinks/ringbuffer_sink.h |  3 ++-
 tests/test_daily_logger.cpp            | 14 +++++++-------
 4 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/include/spdlog/details/fmt_helper.h b/include/spdlog/details/fmt_helper.h
index 9a1b69d3..9ed30d0e 100644
--- a/include/spdlog/details/fmt_helper.h
+++ b/include/spdlog/details/fmt_helper.h
@@ -25,13 +25,13 @@ inline spdlog::string_view_t to_string_view(const memory_buf_t &buf) SPDLOG_NOEX
 
 #ifdef SPDLOG_USE_STD_FORMAT
 template<typename T>
-std::basic_string<T> to_string(const std::basic_string<T> &buf)
+std::basic_string<T> to_string(std::basic_string<T> &&buf)
 {
-    return buf;
+    return std::move(buf);
 }
 #else
 template<typename T, size_t Size>
-std::basic_string<T> to_string(const fmt::basic_memory_buffer<T, Size> &buf)
+std::basic_string<T> to_string(fmt::basic_memory_buffer<T, Size> &&buf)
 {
     return fmt::to_string(buf);
 }
diff --git a/include/spdlog/details/os-inl.h b/include/spdlog/details/os-inl.h
index 4c17804b..aaefcf83 100644
--- a/include/spdlog/details/os-inl.h
+++ b/include/spdlog/details/os-inl.h
@@ -389,7 +389,7 @@ SPDLOG_INLINE std::string filename_to_str(const filename_t &filename)
 {
     memory_buf_t buf;
     wstr_to_utf8buf(filename, buf);
-    return fmt_helper::to_string(buf);
+    return fmt_helper::to_string(std::move(buf));
 }
 #else
 SPDLOG_INLINE std::string filename_to_str(const filename_t &filename)
diff --git a/include/spdlog/sinks/ringbuffer_sink.h b/include/spdlog/sinks/ringbuffer_sink.h
index de31c99c..7e0c56d0 100644
--- a/include/spdlog/sinks/ringbuffer_sink.h
+++ b/include/spdlog/sinks/ringbuffer_sink.h
@@ -5,6 +5,7 @@
 
 #include "spdlog/sinks/base_sink.h"
 #include "spdlog/details/circular_q.h"
+#include "spdlog/details/fmt_helper.h"
 #include "spdlog/details/log_msg_buffer.h"
 #include "spdlog/details/null_mutex.h"
 
@@ -50,7 +51,7 @@ public:
         {
             memory_buf_t formatted;
             base_sink<Mutex>::formatter_->format(q_.at(i), formatted);
-            ret.push_back(fmt_helper::to_string(formatted));
+            ret.push_back(details::fmt_helper::to_string(std::move(formatted)));
         }
         return ret;
     }
diff --git a/tests/test_daily_logger.cpp b/tests/test_daily_logger.cpp
index 8bcc6d72..a83c4c48 100644
--- a/tests/test_daily_logger.cpp
+++ b/tests/test_daily_logger.cpp
@@ -10,16 +10,16 @@ using filename_memory_buf_t = fmt::basic_memory_buffer<spdlog::filename_t::value
 #endif
 
 #ifdef SPDLOG_WCHAR_FILENAMES
-std::string filename_buf_to_utf8string(const filename_memory_buf_t &w)
+std::string filename_buf_to_utf8string(filename_memory_buf_t &&w)
 {
     spdlog::memory_buf_t buf;
     spdlog::details::os::wstr_to_utf8buf(spdlog::wstring_view_t(w.data(), w.size()), buf);
-    return spdlog::details::fmt_helper::to_string(buf);
+    return spdlog::details::fmt_helper::to_string(std::move(buf));
 }
 #else
-std::string filename_buf_to_utf8string(const filename_memory_buf_t &w)
+std::string filename_buf_to_utf8string(filename_memory_buf_t &&w)
 {
-    return spdlog::details::fmt_helper::to_string(w);
+    return spdlog::details::fmt_helper::to_string(std::move(w));
 }
 #endif
 
@@ -44,7 +44,7 @@ TEST_CASE("daily_logger with dateonly calculator", "[daily_logger]")
     }
     logger->flush();
 
-    require_message_count(filename_buf_to_utf8string(w), 10);
+    require_message_count(filename_buf_to_utf8string(std::move(w)), 10);
 }
 
 struct custom_daily_file_name_calculator
@@ -55,7 +55,7 @@ struct custom_daily_file_name_calculator
         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);
 
-        return spdlog::details::fmt_helper::to_string(w);
+        return spdlog::details::fmt_helper::to_string(std::move(w));
     }
 };
 
@@ -80,7 +80,7 @@ TEST_CASE("daily_logger with custom calculator", "[daily_logger]")
 
     logger->flush();
 
-    require_message_count(filename_buf_to_utf8string(w), 10);
+    require_message_count(filename_buf_to_utf8string(std::move(w)), 10);
 }
 
 /*

From cd4f6c146629843627e086424a8ad69a03ff9ca9 Mon Sep 17 00:00:00 2001
From: Charles Milette <charles.milette@gmail.com>
Date: Tue, 26 Apr 2022 23:25:35 -0400
Subject: [PATCH 09/10] Replace fmt_helper::to_string by a macro

---
 include/spdlog/common.h                |  5 +++--
 include/spdlog/details/os-inl.h        |  3 +--
 include/spdlog/sinks/ringbuffer_sink.h |  3 +--
 tests/test_daily_logger.cpp            | 14 +++++++-------
 4 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/include/spdlog/common.h b/include/spdlog/common.h
index f0b2a996..443c058a 100644
--- a/include/spdlog/common.h
+++ b/include/spdlog/common.h
@@ -145,7 +145,7 @@ using wmemory_buf_t = std::wstring;
 template<typename... Args>
 using wformat_string_t = std::wstring_view;
 #    endif
-
+#    define SPDLOG_BUF_TO_STRING(x) x
 #else // use fmt lib instead of std::format
 namespace fmt_lib = fmt;
 
@@ -173,6 +173,7 @@ using wmemory_buf_t = fmt::basic_memory_buffer<wchar_t, 250>;
 template<typename... Args>
 using wformat_string_t = fmt::wformat_string<Args...>;
 #    endif
+#    define SPDLOG_BUF_TO_STRING(x) fmt::to_string(x)
 #endif
 
 #ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
@@ -323,7 +324,7 @@ 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)
+std::unique_ptr<T> make_unique(Args &&...args)
 {
     static_assert(!std::is_array<T>::value, "arrays not supported");
     return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
diff --git a/include/spdlog/details/os-inl.h b/include/spdlog/details/os-inl.h
index aaefcf83..b9bab53c 100644
--- a/include/spdlog/details/os-inl.h
+++ b/include/spdlog/details/os-inl.h
@@ -33,7 +33,6 @@
 
 #    if defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)
 #        include <limits>
-#        include <spdlog/details/fmt_helper.h>
 #    endif
 
 #    include <direct.h> // for _mkdir/_wmkdir
@@ -389,7 +388,7 @@ SPDLOG_INLINE std::string filename_to_str(const filename_t &filename)
 {
     memory_buf_t buf;
     wstr_to_utf8buf(filename, buf);
-    return fmt_helper::to_string(std::move(buf));
+    return SPDLOG_BUF_TO_STRING(buf);
 }
 #else
 SPDLOG_INLINE std::string filename_to_str(const filename_t &filename)
diff --git a/include/spdlog/sinks/ringbuffer_sink.h b/include/spdlog/sinks/ringbuffer_sink.h
index 7e0c56d0..d2fc8c49 100644
--- a/include/spdlog/sinks/ringbuffer_sink.h
+++ b/include/spdlog/sinks/ringbuffer_sink.h
@@ -5,7 +5,6 @@
 
 #include "spdlog/sinks/base_sink.h"
 #include "spdlog/details/circular_q.h"
-#include "spdlog/details/fmt_helper.h"
 #include "spdlog/details/log_msg_buffer.h"
 #include "spdlog/details/null_mutex.h"
 
@@ -51,7 +50,7 @@ public:
         {
             memory_buf_t formatted;
             base_sink<Mutex>::formatter_->format(q_.at(i), formatted);
-            ret.push_back(details::fmt_helper::to_string(std::move(formatted)));
+            ret.push_back(SPDLOG_BUF_TO_STRING(std::move(formatted)));
         }
         return ret;
     }
diff --git a/tests/test_daily_logger.cpp b/tests/test_daily_logger.cpp
index a83c4c48..c6e685de 100644
--- a/tests/test_daily_logger.cpp
+++ b/tests/test_daily_logger.cpp
@@ -10,16 +10,16 @@ using filename_memory_buf_t = fmt::basic_memory_buffer<spdlog::filename_t::value
 #endif
 
 #ifdef SPDLOG_WCHAR_FILENAMES
-std::string filename_buf_to_utf8string(filename_memory_buf_t &&w)
+std::string filename_buf_to_utf8string(const filename_memory_buf_t &w)
 {
     spdlog::memory_buf_t buf;
     spdlog::details::os::wstr_to_utf8buf(spdlog::wstring_view_t(w.data(), w.size()), buf);
-    return spdlog::details::fmt_helper::to_string(std::move(buf));
+    return SPDLOG_BUF_TO_STRING(buf);
 }
 #else
-std::string filename_buf_to_utf8string(filename_memory_buf_t &&w)
+std::string filename_buf_to_utf8string(const filename_memory_buf_t &w)
 {
-    return spdlog::details::fmt_helper::to_string(std::move(w));
+    return SPDLOG_BUF_TO_STRING(w);
 }
 #endif
 
@@ -44,7 +44,7 @@ TEST_CASE("daily_logger with dateonly calculator", "[daily_logger]")
     }
     logger->flush();
 
-    require_message_count(filename_buf_to_utf8string(std::move(w)), 10);
+    require_message_count(filename_buf_to_utf8string(w), 10);
 }
 
 struct custom_daily_file_name_calculator
@@ -55,7 +55,7 @@ struct custom_daily_file_name_calculator
         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);
 
-        return spdlog::details::fmt_helper::to_string(std::move(w));
+        return SPDLOG_BUF_TO_STRING(w);
     }
 };
 
@@ -80,7 +80,7 @@ TEST_CASE("daily_logger with custom calculator", "[daily_logger]")
 
     logger->flush();
 
-    require_message_count(filename_buf_to_utf8string(std::move(w)), 10);
+    require_message_count(filename_buf_to_utf8string(w), 10);
 }
 
 /*

From 8338a48c5ba8c70d504bf1cc91f2a512ebc5b8b5 Mon Sep 17 00:00:00 2001
From: Charles Milette <charles.milette@gmail.com>
Date: Tue, 26 Apr 2022 23:27:55 -0400
Subject: [PATCH 10/10] Remove fmt_helper::to_string

---
 include/spdlog/details/fmt_helper.h | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/include/spdlog/details/fmt_helper.h b/include/spdlog/details/fmt_helper.h
index 9ed30d0e..1a60bc0d 100644
--- a/include/spdlog/details/fmt_helper.h
+++ b/include/spdlog/details/fmt_helper.h
@@ -23,20 +23,6 @@ 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(std::basic_string<T> &&buf)
-{
-    return std::move(buf);
-}
-#else
-template<typename T, size_t Size>
-std::basic_string<T> to_string(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();