Unified usage of fmt::memory_buffer across the codebase

25 files changed, 94 insertions, 100 deletions

diff --git a/include/spdlog/common-inl.h b/include/spdlog/common-inl.h
index 95fedcd0..7ba12511 100644
--- a/include/spdlog/common-inl.h
+++ b/include/spdlog/common-inl.h
@@ -44,7 +44,7 @@ SPDLOG_INLINE spdlog_ex::spdlog_ex(std::string msg)
 
 SPDLOG_INLINE spdlog_ex::spdlog_ex(const std::string &msg, int last_errno)
 {
-    fmt::memory_buffer outbuf;
+    memory_buf_t outbuf;
     fmt::format_system_error(outbuf, last_errno, msg);
     msg_ = fmt::to_string(outbuf);
 }
diff --git a/include/spdlog/common.h b/include/spdlog/common.h
index 8058cada..d1fa4776 100644
--- a/include/spdlog/common.h
+++ b/include/spdlog/common.h
@@ -105,6 +105,8 @@ using basic_string_view_t = fmt::basic_string_view<T>;
 
 using string_view_t = basic_string_view_t<char>;
 
+using memory_buf_t = fmt::basic_memory_buffer<char, 250>;
+
 #ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
 #ifndef _WIN32
 #error SPDLOG_WCHAR_TO_UTF8_SUPPORT only supported on windows
diff --git a/include/spdlog/details/file_helper-inl.h b/include/spdlog/details/file_helper-inl.h
index 891107c9..d8c9cab4 100644
--- a/include/spdlog/details/file_helper-inl.h
+++ b/include/spdlog/details/file_helper-inl.h
@@ -66,7 +66,7 @@ SPDLOG_INLINE void file_helper::close()
     }
 }
 
-SPDLOG_INLINE void file_helper::write(const fmt::memory_buffer &buf)
+SPDLOG_INLINE void file_helper::write(const memory_buf_t &buf)
 {
     size_t msg_size = buf.size();
     auto data = buf.data();
diff --git a/include/spdlog/details/file_helper.h b/include/spdlog/details/file_helper.h
index 6fdecd06..990d99e3 100644
--- a/include/spdlog/details/file_helper.h
+++ b/include/spdlog/details/file_helper.h
@@ -26,7 +26,7 @@ public:
     void reopen(bool truncate);
     void flush();
     void close();
-    void write(const fmt::memory_buffer &buf);
+    void write(const memory_buf_t &buf);
     size_t size() const;
     const filename_t &filename() const;
     static bool file_exists(const filename_t &fname);
diff --git a/include/spdlog/details/fmt_helper.h b/include/spdlog/details/fmt_helper.h
index 67494ed5..ebb747c6 100644
--- a/include/spdlog/details/fmt_helper.h
+++ b/include/spdlog/details/fmt_helper.h
@@ -12,21 +12,14 @@ namespace spdlog {
 namespace details {
 namespace fmt_helper {
 
-template<size_t Buffer_Size>
-inline spdlog::string_view_t to_string_view(const fmt::basic_memory_buffer<char, Buffer_Size> &buf) SPDLOG_NOEXCEPT
+inline spdlog::string_view_t to_string_view(const memory_buf_t &buf) SPDLOG_NOEXCEPT
 {
     return spdlog::string_view_t(buf.data(), buf.size());
 }
 
-template<size_t Buffer_Size1, size_t Buffer_Size2>
-inline void append_buf(const fmt::basic_memory_buffer<char, Buffer_Size1> &buf, fmt::basic_memory_buffer<char, Buffer_Size2> &dest)
-{
-    auto *buf_ptr = buf.data();
-    dest.append(buf_ptr, buf_ptr + buf.size());
-}
 
-template<size_t Buffer_Size>
-inline void append_string_view(spdlog::string_view_t view, fmt::basic_memory_buffer<char, Buffer_Size> &dest)
+
+inline void append_string_view(spdlog::string_view_t view, memory_buf_t &dest)
 {
     auto *buf_ptr = view.data();
     if (buf_ptr != nullptr)
@@ -35,8 +28,8 @@ inline void append_string_view(spdlog::string_view_t view, fmt::basic_memory_buf
     }
 }
 
-template<typename T, size_t Buffer_Size>
-inline void append_int(T n, fmt::basic_memory_buffer<char, Buffer_Size> &dest)
+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());
@@ -49,8 +42,7 @@ inline unsigned count_digits(T n)
     return static_cast<unsigned>(fmt::internal::count_digits(static_cast<count_type>(n)));
 }
 
-template<size_t Buffer_Size>
-inline void pad2(int n, fmt::basic_memory_buffer<char, Buffer_Size> &dest)
+inline void pad2(int n, memory_buf_t &dest)
 {
     if (n > 99)
     {
@@ -72,8 +64,8 @@ inline void pad2(int n, fmt::basic_memory_buffer<char, Buffer_Size> &dest)
     }
 }
 
-template<typename T, size_t Buffer_Size>
-inline void pad_uint(T n, unsigned int width, fmt::basic_memory_buffer<char, Buffer_Size> &dest)
+template<typename T>
+inline void pad_uint(T n, unsigned int width, memory_buf_t &dest)
 {
     static_assert(std::is_unsigned<T>::value, "pad_uint must get unsigned T");
     auto digits = count_digits(n);
@@ -85,20 +77,20 @@ inline void pad_uint(T n, unsigned int width, fmt::basic_memory_buffer<char, Buf
     append_int(n, dest);
 }
 
-template<typename T, size_t Buffer_Size>
-inline void pad3(T n, fmt::basic_memory_buffer<char, Buffer_Size> &dest)
+template<typename T>
+inline void pad3(T n, memory_buf_t &dest)
 {
     pad_uint(n, 3, dest);
 }
 
-template<typename T, size_t Buffer_Size>
-inline void pad6(T n, fmt::basic_memory_buffer<char, Buffer_Size> &dest)
+template<typename T>
+inline void pad6(T n, memory_buf_t &dest)
 {
     pad_uint(n, 6, dest);
 }
 
-template<typename T, size_t Buffer_Size>
-inline void pad9(T n, fmt::basic_memory_buffer<char, Buffer_Size> &dest)
+template<typename T>
+inline void pad9(T n, memory_buf_t &dest)
 {
     pad_uint(n, 9, dest);
 }
diff --git a/include/spdlog/details/log_msg_buffer.h b/include/spdlog/details/log_msg_buffer.h
index 0089cce5..2326f81f 100644
--- a/include/spdlog/details/log_msg_buffer.h
+++ b/include/spdlog/details/log_msg_buffer.h
@@ -14,7 +14,7 @@ namespace details {
 
 class log_msg_buffer : public log_msg
 {
-    fmt::basic_memory_buffer<char, 250> buffer;
+    memory_buf_t buffer;
     void update_string_views()
     {
         logger_name = string_view_t{buffer.data(), logger_name.size()};
diff --git a/include/spdlog/details/os-inl.h b/include/spdlog/details/os-inl.h
index 242405da..b40a5391 100644
--- a/include/spdlog/details/os-inl.h
+++ b/include/spdlog/details/os-inl.h
@@ -350,7 +350,7 @@ SPDLOG_INLINE void sleep_for_millis(int milliseconds) SPDLOG_NOEXCEPT
 #if defined(_WIN32) && defined(SPDLOG_WCHAR_FILENAMES)
 SPDLOG_INLINE std::string filename_to_str(const filename_t &filename)
 {
-    fmt::memory_buffer buf;
+    memory_buf_t buf;
     wstr_to_utf8buf(filename, buf);
     return fmt::to_string(buf);
 }
@@ -406,7 +406,7 @@ 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(basic_string_view_t<wchar_t> wstr, fmt::memory_buffer &target)
+SPDLOG_INLINE void wstr_to_utf8buf(basic_string_view_t<wchar_t> wstr, memory_buf_t &target)
 {
     if (wstr.size() > static_cast<size_t>(std::numeric_limits<int>::max()))
     {
diff --git a/include/spdlog/details/os.h b/include/spdlog/details/os.h
index 27694494..46f523f9 100644
--- a/include/spdlog/details/os.h
+++ b/include/spdlog/details/os.h
@@ -81,7 +81,7 @@ bool is_color_terminal() SPDLOG_NOEXCEPT;
 bool in_terminal(FILE *file) SPDLOG_NOEXCEPT;
 
 #if (defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)) && defined(_WIN32)
-void wstr_to_utf8buf(basic_string_view_t<wchar_t> wstr, fmt::memory_buffer &target);
+void wstr_to_utf8buf(basic_string_view_t<wchar_t> wstr, memory_buf_t &target);
 #endif
 
 } // namespace os
diff --git a/include/spdlog/details/pattern_formatter-inl.h b/include/spdlog/details/pattern_formatter-inl.h
index a086dcc5..5f395d59 100644
--- a/include/spdlog/details/pattern_formatter-inl.h
+++ b/include/spdlog/details/pattern_formatter-inl.h
@@ -35,7 +35,7 @@ namespace details {
 class scoped_padder
 {
 public:
-    scoped_padder(size_t wrapped_size, const padding_info &padinfo, fmt::memory_buffer &dest)
+    scoped_padder(size_t wrapped_size, const padding_info &padinfo, memory_buf_t &dest)
         : padinfo_(padinfo)
         , dest_(dest)
     {
@@ -78,14 +78,14 @@ private:
     }
 
     const padding_info &padinfo_;
-    fmt::memory_buffer &dest_;
+    memory_buf_t &dest_;
     size_t total_pad_;
     string_view_t spaces_{"                                                                ", 64};
 };
 
 struct null_scoped_padder
 {
-    null_scoped_padder(size_t /*wrapped_size*/, const padding_info & /*padinfo*/, fmt::memory_buffer & /*dest*/) {}
+    null_scoped_padder(size_t /*wrapped_size*/, const padding_info & /*padinfo*/, memory_buf_t & /*dest*/) {}
 };
 
 template<typename ScopedPadder>
@@ -96,7 +96,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {
         ScopedPadder p(msg.logger_name.size(), padinfo_, dest);
         fmt_helper::append_string_view(msg.logger_name, dest);
@@ -112,7 +112,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
+    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);
         ScopedPadder p(level_name.size(), padinfo_, dest);
@@ -129,7 +129,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {
         string_view_t level_name{level::to_short_c_str(msg.level)};
         ScopedPadder p(level_name.size(), padinfo_, dest);
@@ -162,7 +162,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override
     {
         string_view_t field_value{days[static_cast<size_t>(tm_time.tm_wday)]};
         ScopedPadder p(field_value.size(), padinfo_, dest);
@@ -181,7 +181,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override
     {
         string_view_t field_value{full_days[static_cast<size_t>(tm_time.tm_wday)]};
         ScopedPadder p(field_value.size(), padinfo_, dest);
@@ -200,7 +200,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override
     {
         string_view_t field_value{months[static_cast<size_t>(tm_time.tm_mon)]};
         ScopedPadder p(field_value.size(), padinfo_, dest);
@@ -220,7 +220,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override
     {
         string_view_t field_value{full_months[static_cast<size_t>(tm_time.tm_mon)]};
         ScopedPadder p(field_value.size(), padinfo_, dest);
@@ -237,7 +237,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override
     {
         const size_t field_size = 24;
         ScopedPadder p(field_size, padinfo_, dest);
@@ -269,7 +269,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override
     {
         const size_t field_size = 2;
         ScopedPadder p(field_size, padinfo_, dest);
@@ -286,7 +286,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override
     {
         const size_t field_size = 10;
         ScopedPadder p(field_size, padinfo_, dest);
@@ -308,7 +308,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override
     {
         const size_t field_size = 4;
         ScopedPadder p(field_size, padinfo_, dest);
@@ -325,7 +325,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override
     {
         const size_t field_size = 2;
         ScopedPadder p(field_size, padinfo_, dest);
@@ -342,7 +342,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override
     {
         const size_t field_size = 2;
         ScopedPadder p(field_size, padinfo_, dest);
@@ -359,7 +359,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override
     {
         const size_t field_size = 2;
         ScopedPadder p(field_size, padinfo_, dest);
@@ -376,7 +376,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override
     {
         const size_t field_size = 2;
         ScopedPadder p(field_size, padinfo_, dest);
@@ -393,7 +393,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override
     {
         const size_t field_size = 2;
         ScopedPadder p(field_size, padinfo_, dest);
@@ -410,7 +410,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override
     {
         const size_t field_size = 2;
         ScopedPadder p(field_size, padinfo_, dest);
@@ -427,7 +427,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {
         auto millis = fmt_helper::time_fraction<std::chrono::milliseconds>(msg.time);
         const size_t field_size = 3;
@@ -445,7 +445,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {
         auto micros = fmt_helper::time_fraction<std::chrono::microseconds>(msg.time);
 
@@ -464,7 +464,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {
         auto ns = fmt_helper::time_fraction<std::chrono::nanoseconds>(msg.time);
         const size_t field_size = 9;
@@ -482,7 +482,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {
         const size_t field_size = 10;
         ScopedPadder p(field_size, padinfo_, dest);
@@ -501,7 +501,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override
     {
         const size_t field_size = 2;
         ScopedPadder p(field_size, padinfo_, dest);
@@ -518,7 +518,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override
     {
         const size_t field_size = 11;
         ScopedPadder p(field_size, padinfo_, dest);
@@ -542,7 +542,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override
     {
         const size_t field_size = 5;
         ScopedPadder p(field_size, padinfo_, dest);
@@ -562,7 +562,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override
     {
         const size_t field_size = 8;
         ScopedPadder p(field_size, padinfo_, dest);
@@ -588,7 +588,7 @@ public:
     z_formatter(const z_formatter &) = delete;
     z_formatter &operator=(const z_formatter &) = delete;
 
-    void format(const details::log_msg &msg, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &msg, const std::tm &tm_time, memory_buf_t &dest) override
     {
         const size_t field_size = 6;
         ScopedPadder p(field_size, padinfo_, dest);
@@ -644,7 +644,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {
         const auto field_size = fmt_helper::count_digits(msg.thread_id);
         ScopedPadder p(field_size, padinfo_, dest);
@@ -661,7 +661,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &, memory_buf_t &dest) override
     {
         const auto pid = static_cast<uint32_t>(details::os::pid());
         auto field_size = fmt_helper::count_digits(pid);
@@ -678,7 +678,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {
         ScopedPadder p(msg.payload.size(), padinfo_, dest);
         fmt_helper::append_string_view(msg.payload, dest);
@@ -692,7 +692,7 @@ public:
         : ch_(ch)
     {}
 
-    void format(const details::log_msg &, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &, memory_buf_t &dest) override
     {
         dest.push_back(ch_);
     }
@@ -711,7 +711,7 @@ public:
     {
         str_ += ch;
     }
-    void format(const details::log_msg &, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &, const std::tm &, memory_buf_t &dest) override
     {
         fmt_helper::append_string_view(str_, dest);
     }
@@ -728,7 +728,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {
         msg.color_range_start = dest.size();
     }
@@ -741,7 +741,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {
         msg.color_range_end = dest.size();
     }
@@ -756,7 +756,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {
         if (msg.source.empty())
         {
@@ -782,7 +782,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {
         if (msg.source.empty())
         {
@@ -808,7 +808,7 @@ public:
         return rv != nullptr ? rv + 1 : filename;
     }
 
-    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {
         if (msg.source.empty())
         {
@@ -829,7 +829,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {
         if (msg.source.empty())
         {
@@ -851,7 +851,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {
         if (msg.source.empty())
         {
@@ -876,7 +876,7 @@ public:
         , last_message_time_(log_clock::now())
     {}
 
-    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {
         auto delta = msg.time - last_message_time_;
         auto delta_units = std::chrono::duration_cast<DurationUnits>(delta);
@@ -898,7 +898,7 @@ public:
         : flag_formatter(padinfo)
     {}
 
-    void format(const details::log_msg &msg, const std::tm &tm_time, fmt::memory_buffer &dest) override
+    void format(const details::log_msg &msg, const std::tm &tm_time, memory_buf_t &dest) override
     {
         using std::chrono::duration_cast;
         using std::chrono::milliseconds;
@@ -934,7 +934,7 @@ public:
 
             cache_timestamp_ = secs;
         }
-        fmt_helper::append_buf(cached_datetime_, dest);
+        dest.append(cached_datetime_.data(), cached_datetime_.data()+cached_datetime_.size());
 
         auto millis = fmt_helper::time_fraction<milliseconds>(msg.time);
         fmt_helper::pad3(static_cast<uint32_t>(millis.count()), dest);
@@ -981,7 +981,7 @@ public:
 
 private:
     std::chrono::seconds cache_timestamp_{0};
-    fmt::basic_memory_buffer<char, 128> cached_datetime_;
+    memory_buf_t cached_datetime_;
 };
 
 } // namespace details
@@ -1012,7 +1012,7 @@ SPDLOG_INLINE std::unique_ptr<formatter> pattern_formatter::clone() const
     return details::make_unique<pattern_formatter>(pattern_, pattern_time_type_, eol_);
 }
 
-SPDLOG_INLINE void pattern_formatter::format(const details::log_msg &msg, fmt::memory_buffer &dest)
+SPDLOG_INLINE void pattern_formatter::format(const details::log_msg &msg, memory_buf_t &dest)
 {
 #ifndef SPDLOG_NO_DATETIME
     auto secs = std::chrono::duration_cast<std::chrono::seconds>(msg.time.time_since_epoch());
diff --git a/include/spdlog/details/pattern_formatter.h b/include/spdlog/details/pattern_formatter.h
index 1fcaf394..7191ea9b 100644
--- a/include/spdlog/details/pattern_formatter.h
+++ b/include/spdlog/details/pattern_formatter.h
@@ -50,7 +50,7 @@ public:
     {}
     flag_formatter() = default;
     virtual ~flag_formatter() = default;
-    virtual void format(const details::log_msg &msg, const std::tm &tm_time, fmt::memory_buffer &dest) = 0;
+    virtual void format(const details::log_msg &msg, const std::tm &tm_time, memory_buf_t &dest) = 0;
 
 protected:
     padding_info padinfo_;
@@ -71,7 +71,7 @@ public:
     pattern_formatter &operator=(const pattern_formatter &other) = delete;
 
     std::unique_ptr<formatter> clone() const override;
-    void format(const details::log_msg &msg, fmt::memory_buffer &dest) override;
+    void format(const details::log_msg &msg, memory_buf_t &dest) override;
 
 private:
     std::string pattern_;
diff --git a/include/spdlog/formatter.h b/include/spdlog/formatter.h
index b133f6e9..9a4ed035 100644
--- a/include/spdlog/formatter.h
+++ b/include/spdlog/formatter.h
@@ -12,7 +12,7 @@ class formatter
 {
 public:
     virtual ~formatter() = default;
-    virtual void format(const details::log_msg &msg, fmt::memory_buffer &dest) = 0;
+    virtual void format(const details::log_msg &msg, memory_buf_t &dest) = 0;
     virtual std::unique_ptr<formatter> clone() const = 0;
 };
 } // namespace spdlog
diff --git a/include/spdlog/logger.h b/include/spdlog/logger.h
index 8151603e..767abdbd 100644
--- a/include/spdlog/logger.h
+++ b/include/spdlog/logger.h
@@ -87,7 +87,7 @@ public:
         }
         SPDLOG_TRY
         {
-            fmt::memory_buffer buf;
+            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()));
             if (level_enabled)
@@ -243,7 +243,7 @@ public:
             fmt::wmemory_buffer wbuf;
             fmt::format_to(wbuf, fmt, args...);
 
-            fmt::memory_buffer buf;
+            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()));
 
@@ -312,7 +312,7 @@ public:
 
         try
         {
-            fmt::memory_buffer buf;
+            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()));
diff --git a/include/spdlog/sinks/android_sink.h b/include/spdlog/sinks/android_sink.h
index 14c6ff3b..d1e87f2d 100644
--- a/include/spdlog/sinks/android_sink.h
+++ b/include/spdlog/sinks/android_sink.h
@@ -40,7 +40,7 @@ protected:
     void sink_it_(const details::log_msg &msg) override
     {
         const android_LogPriority priority = convert_to_android_(msg.level);
-        fmt::memory_buffer formatted;
+        memory_buf_t formatted;
         if (use_raw_msg_)
         {
             details::fmt_helper::append_string_view(msg.payload, formatted);
diff --git a/include/spdlog/sinks/ansicolor_sink-inl.h b/include/spdlog/sinks/ansicolor_sink-inl.h
index 13a0691e..280ad7cd 100644
--- a/include/spdlog/sinks/ansicolor_sink-inl.h
+++ b/include/spdlog/sinks/ansicolor_sink-inl.h
@@ -44,7 +44,7 @@ SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::log(const details::log_msg &msg
     // If color is not supported in the terminal, log as is instead.
     std::lock_guard<mutex_t> lock(mutex_);
 
-    fmt::memory_buffer formatted;
+    memory_buf_t formatted;
     formatter_->format(msg, formatted);
     if (should_do_colors_ && msg.color_range_end > msg.color_range_start)
     {
@@ -115,7 +115,7 @@ SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::print_ccode_(const string_view_
 }
 
 template<typename ConsoleMutex>
-SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::print_range_(const fmt::memory_buffer &formatted, size_t start, size_t end)
+SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::print_range_(const memory_buf_t &formatted, size_t start, size_t end)
 {
     fwrite(formatted.data() + start, sizeof(char), end - start, target_file_);
 }
diff --git a/include/spdlog/sinks/ansicolor_sink.h b/include/spdlog/sinks/ansicolor_sink.h
index f383b5a5..6ef10e78 100644
--- a/include/spdlog/sinks/ansicolor_sink.h
+++ b/include/spdlog/sinks/ansicolor_sink.h
@@ -82,7 +82,7 @@ private:
     std::unique_ptr<spdlog::formatter> formatter_;
     std::unordered_map<level::level_enum, string_view_t, level::level_hasher> colors_;
     void print_ccode_(const string_view_t &color_code);
-    void print_range_(const fmt::memory_buffer &formatted, size_t start, size_t end);
+    void print_range_(const memory_buf_t &formatted, size_t start, size_t end);
 };
 
 template<typename ConsoleMutex>
diff --git a/include/spdlog/sinks/basic_file_sink-inl.h b/include/spdlog/sinks/basic_file_sink-inl.h
index 108b8ff7..0e5275a9 100644
--- a/include/spdlog/sinks/basic_file_sink-inl.h
+++ b/include/spdlog/sinks/basic_file_sink-inl.h
@@ -28,7 +28,7 @@ SPDLOG_INLINE const filename_t &basic_file_sink<Mutex>::filename() const
 template<typename Mutex>
 SPDLOG_INLINE void basic_file_sink<Mutex>::sink_it_(const details::log_msg &msg)
 {
-    fmt::memory_buffer formatted;
+    memory_buf_t formatted;
     base_sink<Mutex>::formatter_->format(msg, formatted);
     file_helper_.write(formatted);
 }
diff --git a/include/spdlog/sinks/daily_file_sink.h b/include/spdlog/sinks/daily_file_sink.h
index 341b5c42..7fc0626e 100644
--- a/include/spdlog/sinks/daily_file_sink.h
+++ b/include/spdlog/sinks/daily_file_sink.h
@@ -30,7 +30,7 @@ struct daily_filename_calculator
     {
         filename_t basename, ext;
         std::tie(basename, ext) = details::file_helper::split_by_extension(filename);
-        std::conditional<std::is_same<filename_t::value_type, char>::value, fmt::memory_buffer, fmt::wmemory_buffer>::type w;
+        std::conditional<std::is_same<filename_t::value_type, char>::value, memory_buf_t, fmt::wmemory_buffer>::type w;
         fmt::format_to(
             w, SPDLOG_FILENAME_T("{}_{:04d}-{:02d}-{:02d}{}"), basename, now_tm.tm_year + 1900, now_tm.tm_mon + 1, now_tm.tm_mday, ext);
         return fmt::to_string(w);
@@ -78,7 +78,7 @@ protected:
             file_helper_.open(FileNameCalc::calc_filename(base_filename_, now_tm(time)), truncate_);
             rotation_tp_ = next_rotation_tp_();
         }
-        fmt::memory_buffer formatted;
+        memory_buf_t formatted;
         base_sink<Mutex>::formatter_->format(msg, formatted);
         file_helper_.write(formatted);
     }
diff --git a/include/spdlog/sinks/dup_filter_sink.h b/include/spdlog/sinks/dup_filter_sink.h
index 66c59359..ab116a05 100644
--- a/include/spdlog/sinks/dup_filter_sink.h
+++ b/include/spdlog/sinks/dup_filter_sink.h
@@ -66,7 +66,7 @@ protected:
         // log the "skipped.." message
         if (skip_counter_ > 0)
         {
-            fmt::basic_memory_buffer<char, 64> buf;
+            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);
diff --git a/include/spdlog/sinks/msvc_sink.h b/include/spdlog/sinks/msvc_sink.h
index 08e029a0..39b2ce91 100644
--- a/include/spdlog/sinks/msvc_sink.h
+++ b/include/spdlog/sinks/msvc_sink.h
@@ -28,7 +28,7 @@ protected:
     void sink_it_(const details::log_msg &msg) override
     {
 
-        fmt::memory_buffer formatted;
+        memory_buf_t formatted;
         base_sink<Mutex>::formatter_->format(msg, formatted);
         OutputDebugStringA(fmt::to_string(formatted).c_str());
     }
diff --git a/include/spdlog/sinks/ostream_sink.h b/include/spdlog/sinks/ostream_sink.h
index 6a728a3a..8d47d770 100644
--- a/include/spdlog/sinks/ostream_sink.h
+++ b/include/spdlog/sinks/ostream_sink.h
@@ -25,7 +25,7 @@ public:
 protected:
     void sink_it_(const details::log_msg &msg) override
     {
-        fmt::memory_buffer formatted;
+        memory_buf_t formatted;
         base_sink<Mutex>::formatter_->format(msg, formatted);
         ostream_.write(formatted.data(), static_cast<std::streamsize>(formatted.size()));
         if (force_flush_)
diff --git a/include/spdlog/sinks/rotating_file_sink-inl.h b/include/spdlog/sinks/rotating_file_sink-inl.h
index cb67e337..5e2b1fd9 100644
--- a/include/spdlog/sinks/rotating_file_sink-inl.h
+++ b/include/spdlog/sinks/rotating_file_sink-inl.h
@@ -43,7 +43,7 @@ SPDLOG_INLINE rotating_file_sink<Mutex>::rotating_file_sink(
 template<typename Mutex>
 SPDLOG_INLINE filename_t rotating_file_sink<Mutex>::calc_filename(const filename_t &filename, std::size_t index)
 {
-    typename std::conditional<std::is_same<filename_t::value_type, char>::value, fmt::memory_buffer, fmt::wmemory_buffer>::type w;
+    typename std::conditional<std::is_same<filename_t::value_type, char>::value, memory_buf_t, fmt::wmemory_buffer>::type w;
     if (index != 0u)
     {
         filename_t basename, ext;
@@ -66,7 +66,7 @@ SPDLOG_INLINE const filename_t &rotating_file_sink<Mutex>::filename() const
 template<typename Mutex>
 SPDLOG_INLINE void rotating_file_sink<Mutex>::sink_it_(const details::log_msg &msg)
 {
-    fmt::memory_buffer formatted;
+    memory_buf_t formatted;
     base_sink<Mutex>::formatter_->format(msg, formatted);
     current_size_ += formatted.size();
     if (current_size_ > max_size_)
diff --git a/include/spdlog/sinks/stdout_sinks-inl.h b/include/spdlog/sinks/stdout_sinks-inl.h
index 19ecdaae..e7894987 100644
--- a/include/spdlog/sinks/stdout_sinks-inl.h
+++ b/include/spdlog/sinks/stdout_sinks-inl.h
@@ -26,7 +26,7 @@ template<typename ConsoleMutex>
 SPDLOG_INLINE void stdout_sink_base<ConsoleMutex>::log(const details::log_msg &msg)
 {
     std::lock_guard<mutex_t> lock(mutex_);
-    fmt::memory_buffer formatted;
+    memory_buf_t formatted;
     formatter_->format(msg, formatted);
     fwrite(formatted.data(), sizeof(char), formatted.size(), file_);
     fflush(file_); // flush every line to terminal
diff --git a/include/spdlog/sinks/syslog_sink.h b/include/spdlog/sinks/syslog_sink.h
index fe868c32..aeaa943e 100644
--- a/include/spdlog/sinks/syslog_sink.h
+++ b/include/spdlog/sinks/syslog_sink.h
@@ -50,7 +50,7 @@ protected:
 
         if (enable_formatting_)
         {
-            fmt::memory_buffer formatted;
+            memory_buf_t formatted;
             base_sink<Mutex>::formatter_->format(msg, formatted);
             payload = string_view_t(formatted.data(), formatted.size());
         }
diff --git a/include/spdlog/sinks/wincolor_sink-inl.h b/include/spdlog/sinks/wincolor_sink-inl.h
index e058ce7c..84dbbff2 100644
--- a/include/spdlog/sinks/wincolor_sink-inl.h
+++ b/include/spdlog/sinks/wincolor_sink-inl.h
@@ -52,7 +52,7 @@ template<typename ConsoleMutex>
 void SPDLOG_INLINE wincolor_sink<ConsoleMutex>::log(const details::log_msg &msg)
 {
     std::lock_guard<mutex_t> lock(mutex_);
-    fmt::memory_buffer formatted;
+    memory_buf_t formatted;
     formatter_->format(msg, formatted);
     if (!in_console_)
     {
@@ -131,14 +131,14 @@ WORD SPDLOG_INLINE wincolor_sink<ConsoleMutex>::set_foreground_color_(WORD attri
 
 // print a range of formatted message to console
 template<typename ConsoleMutex>
-void SPDLOG_INLINE wincolor_sink<ConsoleMutex>::print_range_(const fmt::memory_buffer &formatted, size_t start, size_t end)
+void SPDLOG_INLINE wincolor_sink<ConsoleMutex>::print_range_(const memory_buf_t &formatted, size_t start, size_t end)
 {
     auto size = static_cast<DWORD>(end - start);
     ::WriteConsoleA(out_handle_, formatted.data() + start, size, nullptr, nullptr);
 }
 
 template<typename ConsoleMutex>
-void SPDLOG_INLINE wincolor_sink<ConsoleMutex>::write_to_file_(const fmt::memory_buffer &formatted)
+void SPDLOG_INLINE wincolor_sink<ConsoleMutex>::write_to_file_(const memory_buf_t &formatted)
 {
     auto size = static_cast<DWORD>(formatted.size());
     if (size == 0)
diff --git a/include/spdlog/sinks/wincolor_sink.h b/include/spdlog/sinks/wincolor_sink.h
index 0ff43e07..22099e28 100644
--- a/include/spdlog/sinks/wincolor_sink.h
+++ b/include/spdlog/sinks/wincolor_sink.h
@@ -58,10 +58,10 @@ protected:
     WORD set_foreground_color_(WORD attribs);
 
     // print a range of formatted message to console
-    void print_range_(const fmt::memory_buffer &formatted, size_t start, size_t end);
+    void print_range_(const memory_buf_t &formatted, size_t start, size_t end);
 
     // in case we are redirected to file (not in console mode)
-    void write_to_file_(const fmt::memory_buffer &formatted);
+    void write_to_file_(const memory_buf_t &formatted);
 };
 
 template<typename ConsoleMutex>