Revert "Updated bundled fmt to 10.2.1"

This reverts commit d8e0ad46bf.

include/spdlog/fmt/bundled/args.h

@@ -1,4 +1,4 @@
-// Formatting library for C++ - dynamic argument lists
+// Formatting library for C++ - dynamic format arguments
 //
 // Copyright (c) 2012 - present, Victor Zverovich
 // All rights reserved.
@@ -22,9 +22,8 @@ template <typename T> struct is_reference_wrapper : std::false_type {};
 template <typename T>
 struct is_reference_wrapper<std::reference_wrapper<T>> : std::true_type {};
 
-template <typename T> auto unwrap(const T& v) -> const T& { return v; }
+template <typename T> const T& unwrap(const T& v) { return v; }
-template <typename T>
+template <typename T> const T& unwrap(const std::reference_wrapper<T>& v) {
-auto unwrap(const std::reference_wrapper<T>& v) -> const T& {
   return static_cast<const T&>(v);
 }
 
@@ -51,7 +50,7 @@ class dynamic_arg_list {
   std::unique_ptr<node<>> head_;
 
  public:
-  template <typename T, typename Arg> auto push(const Arg& arg) -> const T& {
+  template <typename T, typename Arg> const T& push(const Arg& arg) {
     auto new_node = std::unique_ptr<typed_node<T>>(new typed_node<T>(arg));
     auto& value = new_node->value;
     new_node->next = std::move(head_);
@@ -111,14 +110,14 @@ class dynamic_format_arg_store
 
   friend class basic_format_args<Context>;
 
-  auto get_types() const -> unsigned long long {
+  unsigned long long get_types() const {
     return detail::is_unpacked_bit | data_.size() |
            (named_info_.empty()
                 ? 0ULL
                 : static_cast<unsigned long long>(detail::has_named_args_bit));
   }
 
-  auto data() const -> const basic_format_arg<Context>* {
+  const basic_format_arg<Context>* data() const {
     return named_info_.empty() ? data_.data() : data_.data() + 1;
   }
 

include/spdlog/fmt/bundled/color.h

@@ -11,7 +11,7 @@
 #include "format.h"
 
 FMT_BEGIN_NAMESPACE
-FMT_BEGIN_EXPORT
+FMT_MODULE_EXPORT_BEGIN
 
 enum class color : uint32_t {
   alice_blue = 0xF0F8FF,               // rgb(240,248,255)
@@ -203,7 +203,7 @@ struct rgb {
   uint8_t b;
 };
 
-namespace detail {
+FMT_BEGIN_DETAIL_NAMESPACE
 
 // color is a struct of either a rgb color or a terminal color.
 struct color_type {
@@ -225,7 +225,8 @@ struct color_type {
     uint32_t rgb_color;
   } value;
 };
-}  // namespace detail
+
+FMT_END_DETAIL_NAMESPACE
 
 /** A text style consisting of foreground and background colors and emphasis. */
 class text_style {
@@ -233,7 +234,7 @@ class text_style {
   FMT_CONSTEXPR text_style(emphasis em = emphasis()) noexcept
       : set_foreground_color(), set_background_color(), ems(em) {}
 
-  FMT_CONSTEXPR auto operator|=(const text_style& rhs) -> text_style& {
+  FMT_CONSTEXPR text_style& operator|=(const text_style& rhs) {
     if (!set_foreground_color) {
       set_foreground_color = rhs.set_foreground_color;
       foreground_color = rhs.foreground_color;
@@ -257,29 +258,29 @@ class text_style {
     return *this;
   }
 
-  friend FMT_CONSTEXPR auto operator|(text_style lhs, const text_style& rhs)
+  friend FMT_CONSTEXPR text_style operator|(text_style lhs,
-      -> text_style {
+                                            const text_style& rhs) {
     return lhs |= rhs;
   }
 
-  FMT_CONSTEXPR auto has_foreground() const noexcept -> bool {
+  FMT_CONSTEXPR bool has_foreground() const noexcept {
     return set_foreground_color;
   }
-  FMT_CONSTEXPR auto has_background() const noexcept -> bool {
+  FMT_CONSTEXPR bool has_background() const noexcept {
     return set_background_color;
   }
-  FMT_CONSTEXPR auto has_emphasis() const noexcept -> bool {
+  FMT_CONSTEXPR bool has_emphasis() const noexcept {
     return static_cast<uint8_t>(ems) != 0;
   }
-  FMT_CONSTEXPR auto get_foreground() const noexcept -> detail::color_type {
+  FMT_CONSTEXPR detail::color_type get_foreground() const noexcept {
     FMT_ASSERT(has_foreground(), "no foreground specified for this style");
     return foreground_color;
   }
-  FMT_CONSTEXPR auto get_background() const noexcept -> detail::color_type {
+  FMT_CONSTEXPR detail::color_type get_background() const noexcept {
     FMT_ASSERT(has_background(), "no background specified for this style");
     return background_color;
   }
-  FMT_CONSTEXPR auto get_emphasis() const noexcept -> emphasis {
+  FMT_CONSTEXPR emphasis get_emphasis() const noexcept {
     FMT_ASSERT(has_emphasis(), "no emphasis specified for this style");
     return ems;
   }
@@ -297,11 +298,9 @@ class text_style {
     }
   }
 
-  friend FMT_CONSTEXPR auto fg(detail::color_type foreground) noexcept
+  friend FMT_CONSTEXPR text_style fg(detail::color_type foreground) noexcept;
-      -> text_style;
 
-  friend FMT_CONSTEXPR auto bg(detail::color_type background) noexcept
+  friend FMT_CONSTEXPR text_style bg(detail::color_type background) noexcept;
-      -> text_style;
 
   detail::color_type foreground_color;
   detail::color_type background_color;
@@ -311,23 +310,20 @@ class text_style {
 };
 
 /** Creates a text style from the foreground (text) color. */
-FMT_CONSTEXPR inline auto fg(detail::color_type foreground) noexcept
+FMT_CONSTEXPR inline text_style fg(detail::color_type foreground) noexcept {
-    -> text_style {
   return text_style(true, foreground);
 }
 
 /** Creates a text style from the background color. */
-FMT_CONSTEXPR inline auto bg(detail::color_type background) noexcept
+FMT_CONSTEXPR inline text_style bg(detail::color_type background) noexcept {
-    -> text_style {
   return text_style(false, background);
 }
 
-FMT_CONSTEXPR inline auto operator|(emphasis lhs, emphasis rhs) noexcept
+FMT_CONSTEXPR inline text_style operator|(emphasis lhs, emphasis rhs) noexcept {
-    -> text_style {
   return text_style(lhs) | rhs;
 }
 
-namespace detail {
+FMT_BEGIN_DETAIL_NAMESPACE
 
 template <typename Char> struct ansi_color_escape {
   FMT_CONSTEXPR ansi_color_escape(detail::color_type text_color,
@@ -389,8 +385,8 @@ template <typename Char> struct ansi_color_escape {
   }
   FMT_CONSTEXPR operator const Char*() const noexcept { return buffer; }
 
-  FMT_CONSTEXPR auto begin() const noexcept -> const Char* { return buffer; }
+  FMT_CONSTEXPR const Char* begin() const noexcept { return buffer; }
-  FMT_CONSTEXPR_CHAR_TRAITS auto end() const noexcept -> const Char* {
+  FMT_CONSTEXPR_CHAR_TRAITS const Char* end() const noexcept {
     return buffer + std::char_traits<Char>::length(buffer);
   }
 
@@ -405,39 +401,56 @@ template <typename Char> struct ansi_color_escape {
     out[2] = static_cast<Char>('0' + c % 10);
     out[3] = static_cast<Char>(delimiter);
   }
-  static FMT_CONSTEXPR auto has_emphasis(emphasis em, emphasis mask) noexcept
+  static FMT_CONSTEXPR bool has_emphasis(emphasis em, emphasis mask) noexcept {
-      -> bool {
     return static_cast<uint8_t>(em) & static_cast<uint8_t>(mask);
   }
 };
 
 template <typename Char>
-FMT_CONSTEXPR auto make_foreground_color(detail::color_type foreground) noexcept
+FMT_CONSTEXPR ansi_color_escape<Char> make_foreground_color(
-    -> ansi_color_escape<Char> {
+    detail::color_type foreground) noexcept {
   return ansi_color_escape<Char>(foreground, "\x1b[38;2;");
 }
 
 template <typename Char>
-FMT_CONSTEXPR auto make_background_color(detail::color_type background) noexcept
+FMT_CONSTEXPR ansi_color_escape<Char> make_background_color(
-    -> ansi_color_escape<Char> {
+    detail::color_type background) noexcept {
   return ansi_color_escape<Char>(background, "\x1b[48;2;");
 }
 
 template <typename Char>
-FMT_CONSTEXPR auto make_emphasis(emphasis em) noexcept
+FMT_CONSTEXPR ansi_color_escape<Char> make_emphasis(emphasis em) noexcept {
-    -> ansi_color_escape<Char> {
   return ansi_color_escape<Char>(em);
 }
 
+template <typename Char> inline void fputs(const Char* chars, FILE* stream) {
+  int result = std::fputs(chars, stream);
+  if (result < 0)
+    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
+}
+
+template <> inline void fputs<wchar_t>(const wchar_t* chars, FILE* stream) {
+  int result = std::fputws(chars, stream);
+  if (result < 0)
+    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
+}
+
+template <typename Char> inline void reset_color(FILE* stream) {
+  fputs("\x1b[0m", stream);
+}
+
+template <> inline void reset_color<wchar_t>(FILE* stream) {
+  fputs(L"\x1b[0m", stream);
+}
+
 template <typename Char> inline void reset_color(buffer<Char>& buffer) {
   auto reset_color = string_view("\x1b[0m");
   buffer.append(reset_color.begin(), reset_color.end());
 }
 
-template <typename T> struct styled_arg : detail::view {
+template <typename T> struct styled_arg {
   const T& value;
   text_style style;
-  styled_arg(const T& v, text_style s) : value(v), style(s) {}
 };
 
 template <typename Char>
@@ -464,21 +477,19 @@ void vformat_to(buffer<Char>& buf, const text_style& ts,
   if (has_style) detail::reset_color<Char>(buf);
 }
 
-}  // namespace detail
+FMT_END_DETAIL_NAMESPACE
 
-inline void vprint(std::FILE* f, const text_style& ts, string_view fmt,
+template <typename S, typename Char = char_t<S>>
-                   format_args args) {
+void vprint(std::FILE* f, const text_style& ts, const S& format,
-  // Legacy wide streams are not supported.
+            basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-  auto buf = memory_buffer();
+  basic_memory_buffer<Char> buf;
-  detail::vformat_to(buf, ts, fmt, args);
+  detail::vformat_to(buf, ts, detail::to_string_view(format), args);
   if (detail::is_utf8()) {
-    detail::print(f, string_view(buf.begin(), buf.size()));
+    detail::print(f, basic_string_view<Char>(buf.begin(), buf.size()));
-    return;
+  } else {
+    buf.push_back(Char(0));
+    detail::fputs(buf.data(), f);
   }
-  buf.push_back('\0');
-  int result = std::fputs(buf.data(), f);
-  if (result < 0)
-    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
 }
 
 /**
@@ -518,10 +529,9 @@ void print(const text_style& ts, const S& format_str, const Args&... args) {
 }
 
 template <typename S, typename Char = char_t<S>>
-inline auto vformat(
+inline std::basic_string<Char> vformat(
     const text_style& ts, const S& format_str,
-    basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-    -> std::basic_string<Char> {
   basic_memory_buffer<Char> buf;
   detail::vformat_to(buf, ts, detail::to_string_view(format_str), args);
   return fmt::to_string(buf);
@@ -540,8 +550,8 @@ inline auto vformat(
   \endrst
 */
 template <typename S, typename... Args, typename Char = char_t<S>>
-inline auto format(const text_style& ts, const S& format_str,
+inline std::basic_string<Char> format(const text_style& ts, const S& format_str,
-                   const Args&... args) -> std::basic_string<Char> {
+                                      const Args&... args) {
   return fmt::vformat(ts, detail::to_string_view(format_str),
                       fmt::make_format_args<buffer_context<Char>>(args...));
 }
@@ -551,13 +561,12 @@ inline auto format(const text_style& ts, const S& format_str,
  */
 template <typename OutputIt, typename Char,
           FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value)>
-auto vformat_to(OutputIt out, const text_style& ts,
+OutputIt vformat_to(
-                basic_string_view<Char> format_str,
+    OutputIt out, const text_style& ts, basic_string_view<Char> format_str,
-                basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-    -> OutputIt {
   auto&& buf = detail::get_buffer<Char>(out);
   detail::vformat_to(buf, ts, format_str, args);
-  return detail::get_iterator(buf, out);
+  return detail::get_iterator(buf);
 }
 
 /**
@@ -572,8 +581,7 @@ auto vformat_to(OutputIt out, const text_style& ts,
                    fmt::emphasis::bold | fg(fmt::color::red), "{}", 42);
   \endrst
 */
-template <
+template <typename OutputIt, typename S, typename... Args,
-    typename OutputIt, typename S, typename... Args,
           bool enable = detail::is_output_iterator<OutputIt, char_t<S>>::value&&
               detail::is_string<S>::value>
 inline auto format_to(OutputIt out, const text_style& ts, const S& format_str,
@@ -637,7 +645,7 @@ FMT_CONSTEXPR auto styled(const T& value, text_style ts)
   return detail::styled_arg<remove_cvref_t<T>>{value, ts};
 }
 
-FMT_END_EXPORT
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_COLOR_H_

include/spdlog/fmt/bundled/compile.h

@@ -14,11 +14,89 @@ FMT_BEGIN_NAMESPACE
 namespace detail {
 
 template <typename Char, typename InputIt>
-FMT_CONSTEXPR inline auto copy_str(InputIt begin, InputIt end,
+FMT_CONSTEXPR inline counting_iterator copy_str(InputIt begin, InputIt end,
-                                   counting_iterator it) -> counting_iterator {
+                                                counting_iterator it) {
   return it + (end - begin);
 }
 
+template <typename OutputIt> class truncating_iterator_base {
+ protected:
+  OutputIt out_;
+  size_t limit_;
+  size_t count_ = 0;
+
+  truncating_iterator_base() : out_(), limit_(0) {}
+
+  truncating_iterator_base(OutputIt out, size_t limit)
+      : out_(out), limit_(limit) {}
+
+ public:
+  using iterator_category = std::output_iterator_tag;
+  using value_type = typename std::iterator_traits<OutputIt>::value_type;
+  using difference_type = std::ptrdiff_t;
+  using pointer = void;
+  using reference = void;
+  FMT_UNCHECKED_ITERATOR(truncating_iterator_base);
+
+  OutputIt base() const { return out_; }
+  size_t count() const { return count_; }
+};
+
+// An output iterator that truncates the output and counts the number of objects
+// written to it.
+template <typename OutputIt,
+          typename Enable = typename std::is_void<
+              typename std::iterator_traits<OutputIt>::value_type>::type>
+class truncating_iterator;
+
+template <typename OutputIt>
+class truncating_iterator<OutputIt, std::false_type>
+    : public truncating_iterator_base<OutputIt> {
+  mutable typename truncating_iterator_base<OutputIt>::value_type blackhole_;
+
+ public:
+  using value_type = typename truncating_iterator_base<OutputIt>::value_type;
+
+  truncating_iterator() = default;
+
+  truncating_iterator(OutputIt out, size_t limit)
+      : truncating_iterator_base<OutputIt>(out, limit) {}
+
+  truncating_iterator& operator++() {
+    if (this->count_++ < this->limit_) ++this->out_;
+    return *this;
+  }
+
+  truncating_iterator operator++(int) {
+    auto it = *this;
+    ++*this;
+    return it;
+  }
+
+  value_type& operator*() const {
+    return this->count_ < this->limit_ ? *this->out_ : blackhole_;
+  }
+};
+
+template <typename OutputIt>
+class truncating_iterator<OutputIt, std::true_type>
+    : public truncating_iterator_base<OutputIt> {
+ public:
+  truncating_iterator() = default;
+
+  truncating_iterator(OutputIt out, size_t limit)
+      : truncating_iterator_base<OutputIt>(out, limit) {}
+
+  template <typename T> truncating_iterator& operator=(T val) {
+    if (this->count_++ < this->limit_) *this->out_++ = val;
+    return *this;
+  }
+
+  truncating_iterator& operator++() { return *this; }
+  truncating_iterator& operator++(int) { return *this; }
+  truncating_iterator& operator*() { return *this; }
+};
+
 // A compile-time string which is compiled into fast formatting code.
 class compiled_string {};
 
@@ -57,7 +135,7 @@ struct udl_compiled_string : compiled_string {
 #endif
 
 template <typename T, typename... Tail>
-auto first(const T& value, const Tail&...) -> const T& {
+const T& first(const T& value, const Tail&...) {
   return value;
 }
 
@@ -118,8 +196,7 @@ template <typename Char> struct code_unit {
 
   template <typename OutputIt, typename... Args>
   constexpr OutputIt format(OutputIt out, const Args&...) const {
-    *out++ = value;
+    return write<Char>(out, value);
-    return out;
   }
 };
 
@@ -143,12 +220,7 @@ template <typename Char, typename T, int N> struct field {
 
   template <typename OutputIt, typename... Args>
   constexpr OutputIt format(OutputIt out, const Args&... args) const {
-    const T& arg = get_arg_checked<T, N>(args...);
+    return write<Char>(out, get_arg_checked<T, N>(args...));
-    if constexpr (std::is_convertible_v<T, basic_string_view<Char>>) {
-      auto s = basic_string_view<Char>(arg);
-      return copy_str<Char>(s.begin(), s.end(), out);
-    }
-    return write<Char>(out, arg);
   }
 };
 
@@ -259,14 +331,14 @@ template <typename T, typename Char> struct parse_specs_result {
   int next_arg_id;
 };
 
-enum { manual_indexing_id = -1 };
+constexpr int manual_indexing_id = -1;
 
 template <typename T, typename Char>
 constexpr parse_specs_result<T, Char> parse_specs(basic_string_view<Char> str,
                                                   size_t pos, int next_arg_id) {
   str.remove_prefix(pos);
-  auto ctx =
+  auto ctx = compile_parse_context<Char>(str, max_value<int>(), nullptr, {},
-      compile_parse_context<Char>(str, max_value<int>(), nullptr, next_arg_id);
+                                         next_arg_id);
   auto f = formatter<T, Char>();
   auto end = f.parse(ctx);
   return {f, pos + fmt::detail::to_unsigned(end - str.data()),
@@ -276,18 +348,22 @@ constexpr parse_specs_result<T, Char> parse_specs(basic_string_view<Char> str,
 template <typename Char> struct arg_id_handler {
   arg_ref<Char> arg_id;
 
-  constexpr int on_auto() {
+  constexpr int operator()() {
     FMT_ASSERT(false, "handler cannot be used with automatic indexing");
     return 0;
   }
-  constexpr int on_index(int id) {
+  constexpr int operator()(int id) {
     arg_id = arg_ref<Char>(id);
     return 0;
   }
-  constexpr int on_name(basic_string_view<Char> id) {
+  constexpr int operator()(basic_string_view<Char> id) {
     arg_id = arg_ref<Char>(id);
     return 0;
   }
+
+  constexpr void on_error(const char* message) {
+    FMT_THROW(format_error(message));
+  }
 };
 
 template <typename Char> struct parse_arg_id_result {
@@ -376,13 +452,14 @@ constexpr auto compile_format_string(S format_str) {
       } else if constexpr (arg_id_result.arg_id.kind == arg_id_kind::name) {
         constexpr auto arg_index =
             get_arg_index_by_name(arg_id_result.arg_id.val.name, Args{});
-        if constexpr (arg_index >= 0) {
+        if constexpr (arg_index != invalid_arg_index) {
           constexpr auto next_id =
               ID != manual_indexing_id ? ID + 1 : manual_indexing_id;
           return parse_replacement_field_then_tail<
               decltype(get_type<arg_index, Args>::value), Args, arg_id_end_pos,
               arg_index, next_id>(format_str);
-        } else if constexpr (c == '}') {
+        } else {
+          if constexpr (c == '}') {
             return parse_tail<Args, arg_id_end_pos + 1, ID>(
                 runtime_named_field<char_type>{arg_id_result.arg_id.val.name},
                 format_str);
@@ -391,6 +468,7 @@ constexpr auto compile_format_string(S format_str) {
           }
         }
       }
+    }
   } else if constexpr (str[POS] == '}') {
     if constexpr (POS + 1 == str.size())
       FMT_THROW(format_error("unmatched '}' in format string"));
@@ -423,7 +501,7 @@ constexpr auto compile(S format_str) {
 #endif  // defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
 }  // namespace detail
 
-FMT_BEGIN_EXPORT
+FMT_MODULE_EXPORT_BEGIN
 
 #if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
 
@@ -488,19 +566,17 @@ FMT_CONSTEXPR OutputIt format_to(OutputIt out, const S&, Args&&... args) {
 
 template <typename OutputIt, typename S, typename... Args,
           FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
-auto format_to_n(OutputIt out, size_t n, const S& format_str, Args&&... args)
+format_to_n_result<OutputIt> format_to_n(OutputIt out, size_t n,
-    -> format_to_n_result<OutputIt> {
+                                         const S& format_str, Args&&... args) {
-  using traits = detail::fixed_buffer_traits;
+  auto it = fmt::format_to(detail::truncating_iterator<OutputIt>(out, n),
-  auto buf = detail::iterator_buffer<OutputIt, char, traits>(out, n);
+                           format_str, std::forward<Args>(args)...);
-  fmt::format_to(std::back_inserter(buf), format_str,
+  return {it.base(), it.count()};
-                 std::forward<Args>(args)...);
-  return {buf.out(), buf.count()};
 }
 
 template <typename S, typename... Args,
           FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
-FMT_CONSTEXPR20 auto formatted_size(const S& format_str, const Args&... args)
+FMT_CONSTEXPR20 size_t formatted_size(const S& format_str,
-    -> size_t {
+                                      const Args&... args) {
   return fmt::format_to(detail::counting_iterator(), format_str, args...)
       .count();
 }
@@ -529,7 +605,7 @@ template <detail_exported::fixed_string Str> constexpr auto operator""_cf() {
 }  // namespace literals
 #endif
 
-FMT_END_EXPORT
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_COMPILE_H_

include/spdlog/fmt/bundled/format-inl.h

@@ -9,16 +9,20 @@
 #define FMT_FORMAT_INL_H_
 
 #include <algorithm>
+#include <cctype>
 #include <cerrno>  // errno
 #include <climits>
 #include <cmath>
+#include <cstdarg>
+#include <cstring>  // std::memmove
+#include <cwchar>
 #include <exception>
 
 #ifndef FMT_STATIC_THOUSANDS_SEPARATOR
 #  include <locale>
 #endif
 
-#if defined(_WIN32) && !defined(FMT_WINDOWS_NO_WCHAR)
+#ifdef _WIN32
 #  include <io.h>  // _isatty
 #endif
 
@@ -58,8 +62,8 @@ FMT_FUNC void format_error_code(detail::buffer<char>& out, int error_code,
   error_code_size += detail::to_unsigned(detail::count_digits(abs_value));
   auto it = buffer_appender<char>(out);
   if (message.size() <= inline_buffer_size - error_code_size)
-    fmt::format_to(it, FMT_STRING("{}{}"), message, SEP);
+    format_to(it, FMT_STRING("{}{}"), message, SEP);
-  fmt::format_to(it, FMT_STRING("{}{}"), ERROR_STR, error_code);
+  format_to(it, FMT_STRING("{}{}"), ERROR_STR, error_code);
   FMT_ASSERT(out.size() <= inline_buffer_size, "");
 }
 
@@ -73,8 +77,9 @@ FMT_FUNC void report_error(format_func func, int error_code,
 }
 
 // A wrapper around fwrite that throws on error.
-inline void fwrite_fully(const void* ptr, size_t count, FILE* stream) {
+inline void fwrite_fully(const void* ptr, size_t size, size_t count,
-  size_t written = std::fwrite(ptr, 1, count, stream);
+                         FILE* stream) {
+  size_t written = std::fwrite(ptr, size, count, stream);
   if (written < count)
     FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
 }
@@ -85,7 +90,7 @@ locale_ref::locale_ref(const Locale& loc) : locale_(&loc) {
   static_assert(std::is_same<Locale, std::locale>::value, "");
 }
 
-template <typename Locale> auto locale_ref::get() const -> Locale {
+template <typename Locale> Locale locale_ref::get() const {
   static_assert(std::is_same<Locale, std::locale>::value, "");
   return locale_ ? *static_cast<const std::locale*>(locale_) : std::locale();
 }
@@ -97,8 +102,7 @@ FMT_FUNC auto thousands_sep_impl(locale_ref loc) -> thousands_sep_result<Char> {
   auto thousands_sep = grouping.empty() ? Char() : facet.thousands_sep();
   return {std::move(grouping), thousands_sep};
 }
-template <typename Char>
+template <typename Char> FMT_FUNC Char decimal_point_impl(locale_ref loc) {
-FMT_FUNC auto decimal_point_impl(locale_ref loc) -> Char {
   return std::use_facet<std::numpunct<Char>>(loc.get<std::locale>())
       .decimal_point();
 }
@@ -111,74 +115,96 @@ template <typename Char> FMT_FUNC Char decimal_point_impl(locale_ref) {
   return '.';
 }
 #endif
-
-FMT_FUNC auto write_loc(appender out, loc_value value,
-                        const format_specs<>& specs, locale_ref loc) -> bool {
-#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
-  auto locale = loc.get<std::locale>();
-  // We cannot use the num_put<char> facet because it may produce output in
-  // a wrong encoding.
-  using facet = format_facet<std::locale>;
-  if (std::has_facet<facet>(locale))
-    return std::use_facet<facet>(locale).put(out, value, specs);
-  return facet(locale).put(out, value, specs);
-#endif
-  return false;
-}
 }  // namespace detail
 
-template <typename Locale> typename Locale::id format_facet<Locale>::id;
+#if !FMT_MSC_VERSION
-
+FMT_API FMT_FUNC format_error::~format_error() noexcept = default;
-#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
-template <typename Locale> format_facet<Locale>::format_facet(Locale& loc) {
-  auto& numpunct = std::use_facet<std::numpunct<char>>(loc);
-  grouping_ = numpunct.grouping();
-  if (!grouping_.empty()) separator_ = std::string(1, numpunct.thousands_sep());
-}
-
-template <>
-FMT_API FMT_FUNC auto format_facet<std::locale>::do_put(
-    appender out, loc_value val, const format_specs<>& specs) const -> bool {
-  return val.visit(
-      detail::loc_writer<>{out, specs, separator_, grouping_, decimal_point_});
-}
 #endif
 
-FMT_FUNC auto vsystem_error(int error_code, string_view fmt, format_args args)
+FMT_FUNC std::system_error vsystem_error(int error_code, string_view format_str,
-    -> std::system_error {
+                                         format_args args) {
   auto ec = std::error_code(error_code, std::generic_category());
-  return std::system_error(ec, vformat(fmt, args));
+  return std::system_error(ec, vformat(format_str, args));
 }
 
 namespace detail {
 
-template <typename F>
+template <typename F> inline bool operator==(basic_fp<F> x, basic_fp<F> y) {
-inline auto operator==(basic_fp<F> x, basic_fp<F> y) -> bool {
   return x.f == y.f && x.e == y.e;
 }
 
 // Compilers should be able to optimize this into the ror instruction.
-FMT_CONSTEXPR inline auto rotr(uint32_t n, uint32_t r) noexcept -> uint32_t {
+FMT_CONSTEXPR inline uint32_t rotr(uint32_t n, uint32_t r) noexcept {
   r &= 31;
   return (n >> r) | (n << (32 - r));
 }
-FMT_CONSTEXPR inline auto rotr(uint64_t n, uint32_t r) noexcept -> uint64_t {
+FMT_CONSTEXPR inline uint64_t rotr(uint64_t n, uint32_t r) noexcept {
   r &= 63;
   return (n >> r) | (n << (64 - r));
 }
 
+// Computes 128-bit result of multiplication of two 64-bit unsigned integers.
+inline uint128_fallback umul128(uint64_t x, uint64_t y) noexcept {
+#if FMT_USE_INT128
+  auto p = static_cast<uint128_opt>(x) * static_cast<uint128_opt>(y);
+  return {static_cast<uint64_t>(p >> 64), static_cast<uint64_t>(p)};
+#elif defined(_MSC_VER) && defined(_M_X64)
+  auto result = uint128_fallback();
+  result.lo_ = _umul128(x, y, &result.hi_);
+  return result;
+#else
+  const uint64_t mask = static_cast<uint64_t>(max_value<uint32_t>());
+
+  uint64_t a = x >> 32;
+  uint64_t b = x & mask;
+  uint64_t c = y >> 32;
+  uint64_t d = y & mask;
+
+  uint64_t ac = a * c;
+  uint64_t bc = b * c;
+  uint64_t ad = a * d;
+  uint64_t bd = b * d;
+
+  uint64_t intermediate = (bd >> 32) + (ad & mask) + (bc & mask);
+
+  return {ac + (intermediate >> 32) + (ad >> 32) + (bc >> 32),
+          (intermediate << 32) + (bd & mask)};
+#endif
+}
+
 // Implementation of Dragonbox algorithm: https://github.com/jk-jeon/dragonbox.
 namespace dragonbox {
+// Computes upper 64 bits of multiplication of two 64-bit unsigned integers.
+inline uint64_t umul128_upper64(uint64_t x, uint64_t y) noexcept {
+#if FMT_USE_INT128
+  auto p = static_cast<uint128_opt>(x) * static_cast<uint128_opt>(y);
+  return static_cast<uint64_t>(p >> 64);
+#elif defined(_MSC_VER) && defined(_M_X64)
+  return __umulh(x, y);
+#else
+  return umul128(x, y).high();
+#endif
+}
+
+// Computes upper 128 bits of multiplication of a 64-bit unsigned integer and a
+// 128-bit unsigned integer.
+inline uint128_fallback umul192_upper128(uint64_t x,
+                                         uint128_fallback y) noexcept {
+  uint128_fallback r = umul128(x, y.high());
+  r += umul128_upper64(x, y.low());
+  return r;
+}
+
 // Computes upper 64 bits of multiplication of a 32-bit unsigned integer and a
 // 64-bit unsigned integer.
-inline auto umul96_upper64(uint32_t x, uint64_t y) noexcept -> uint64_t {
+inline uint64_t umul96_upper64(uint32_t x, uint64_t y) noexcept {
   return umul128_upper64(static_cast<uint64_t>(x) << 32, y);
 }
 
 // Computes lower 128 bits of multiplication of a 64-bit unsigned integer and a
 // 128-bit unsigned integer.
-inline auto umul192_lower128(uint64_t x, uint128_fallback y) noexcept
+inline uint128_fallback umul192_lower128(uint64_t x,
-    -> uint128_fallback {
+                                         uint128_fallback y) noexcept {
   uint64_t high = x * y.high();
   uint128_fallback high_low = umul128(x, y.low());
   return {high + high_low.high(), high_low.low()};
@@ -186,17 +212,29 @@ inline auto umul192_lower128(uint64_t x, uint128_fallback y) noexcept
 
 // Computes lower 64 bits of multiplication of a 32-bit unsigned integer and a
 // 64-bit unsigned integer.
-inline auto umul96_lower64(uint32_t x, uint64_t y) noexcept -> uint64_t {
+inline uint64_t umul96_lower64(uint32_t x, uint64_t y) noexcept {
   return x * y;
 }
 
+// Computes floor(log10(pow(2, e))) for e in [-2620, 2620] using the method from
+// https://fmt.dev/papers/Dragonbox.pdf#page=28, section 6.1.
+inline int floor_log10_pow2(int e) noexcept {
+  FMT_ASSERT(e <= 2620 && e >= -2620, "too large exponent");
+  static_assert((-1 >> 1) == -1, "right shift is not arithmetic");
+  return (e * 315653) >> 20;
+}
+
 // Various fast log computations.
-inline auto floor_log10_pow2_minus_log10_4_over_3(int e) noexcept -> int {
+inline int floor_log2_pow10(int e) noexcept {
+  FMT_ASSERT(e <= 1233 && e >= -1233, "too large exponent");
+  return (e * 1741647) >> 19;
+}
+inline int floor_log10_pow2_minus_log10_4_over_3(int e) noexcept {
   FMT_ASSERT(e <= 2936 && e >= -2985, "too large exponent");
   return (e * 631305 - 261663) >> 21;
 }
 
-FMT_INLINE_VARIABLE constexpr struct {
+static constexpr struct {
   uint32_t divisor;
   int shift_amount;
 } div_small_pow10_infos[] = {{10, 16}, {100, 16}};
@@ -205,7 +243,7 @@ FMT_INLINE_VARIABLE constexpr struct {
 // divisible by pow(10, N).
 // Precondition: n <= pow(10, N + 1).
 template <int N>
-auto check_divisibility_and_divide_by_pow10(uint32_t& n) noexcept -> bool {
+bool check_divisibility_and_divide_by_pow10(uint32_t& n) noexcept {
   // The numbers below are chosen such that:
   //   1. floor(n/d) = floor(nm / 2^k) where d=10 or d=100,
   //   2. nm mod 2^k < m if and only if n is divisible by d,
@@ -230,7 +268,7 @@ auto check_divisibility_and_divide_by_pow10(uint32_t& n) noexcept -> bool {
 
 // Computes floor(n / pow(10, N)) for small n and N.
 // Precondition: n <= pow(10, N + 1).
-template <int N> auto small_division_by_pow10(uint32_t n) noexcept -> uint32_t {
+template <int N> uint32_t small_division_by_pow10(uint32_t n) noexcept {
   constexpr auto info = div_small_pow10_infos[N - 1];
   FMT_ASSERT(n <= info.divisor * 10, "n is too large");
   constexpr uint32_t magic_number =
@@ -239,24 +277,24 @@ template <int N> auto small_division_by_pow10(uint32_t n) noexcept -> uint32_t {
 }
 
 // Computes floor(n / 10^(kappa + 1)) (float)
-inline auto divide_by_10_to_kappa_plus_1(uint32_t n) noexcept -> uint32_t {
+inline uint32_t divide_by_10_to_kappa_plus_1(uint32_t n) noexcept {
   // 1374389535 = ceil(2^37/100)
   return static_cast<uint32_t>((static_cast<uint64_t>(n) * 1374389535) >> 37);
 }
 // Computes floor(n / 10^(kappa + 1)) (double)
-inline auto divide_by_10_to_kappa_plus_1(uint64_t n) noexcept -> uint64_t {
+inline uint64_t divide_by_10_to_kappa_plus_1(uint64_t n) noexcept {
   // 2361183241434822607 = ceil(2^(64+7)/1000)
   return umul128_upper64(n, 2361183241434822607ull) >> 7;
 }
 
 // Various subroutines using pow10 cache
-template <typename T> struct cache_accessor;
+template <class T> struct cache_accessor;
 
 template <> struct cache_accessor<float> {
   using carrier_uint = float_info<float>::carrier_uint;
   using cache_entry_type = uint64_t;
 
-  static auto get_cached_power(int k) noexcept -> uint64_t {
+  static uint64_t get_cached_power(int k) noexcept {
     FMT_ASSERT(k >= float_info<float>::min_k && k <= float_info<float>::max_k,
                "k is out of range");
     static constexpr const uint64_t pow10_significands[] = {
@@ -298,23 +336,20 @@ template <> struct cache_accessor<float> {
     bool is_integer;
   };
 
-  static auto compute_mul(carrier_uint u,
+  static compute_mul_result compute_mul(
-                          const cache_entry_type& cache) noexcept
+      carrier_uint u, const cache_entry_type& cache) noexcept {
-      -> compute_mul_result {
     auto r = umul96_upper64(u, cache);
     return {static_cast<carrier_uint>(r >> 32),
             static_cast<carrier_uint>(r) == 0};
   }
 
-  static auto compute_delta(const cache_entry_type& cache, int beta) noexcept
+  static uint32_t compute_delta(const cache_entry_type& cache,
-      -> uint32_t {
+                                int beta) noexcept {
     return static_cast<uint32_t>(cache >> (64 - 1 - beta));
   }
 
-  static auto compute_mul_parity(carrier_uint two_f,
+  static compute_mul_parity_result compute_mul_parity(
-                                 const cache_entry_type& cache,
+      carrier_uint two_f, const cache_entry_type& cache, int beta) noexcept {
-                                 int beta) noexcept
-      -> compute_mul_parity_result {
     FMT_ASSERT(beta >= 1, "");
     FMT_ASSERT(beta < 64, "");
 
@@ -323,22 +358,22 @@ template <> struct cache_accessor<float> {
             static_cast<uint32_t>(r >> (32 - beta)) == 0};
   }
 
-  static auto compute_left_endpoint_for_shorter_interval_case(
+  static carrier_uint compute_left_endpoint_for_shorter_interval_case(
-      const cache_entry_type& cache, int beta) noexcept -> carrier_uint {
+      const cache_entry_type& cache, int beta) noexcept {
     return static_cast<carrier_uint>(
         (cache - (cache >> (num_significand_bits<float>() + 2))) >>
         (64 - num_significand_bits<float>() - 1 - beta));
   }
 
-  static auto compute_right_endpoint_for_shorter_interval_case(
+  static carrier_uint compute_right_endpoint_for_shorter_interval_case(
-      const cache_entry_type& cache, int beta) noexcept -> carrier_uint {
+      const cache_entry_type& cache, int beta) noexcept {
     return static_cast<carrier_uint>(
         (cache + (cache >> (num_significand_bits<float>() + 1))) >>
         (64 - num_significand_bits<float>() - 1 - beta));
   }
 
-  static auto compute_round_up_for_shorter_interval_case(
+  static carrier_uint compute_round_up_for_shorter_interval_case(
-      const cache_entry_type& cache, int beta) noexcept -> carrier_uint {
+      const cache_entry_type& cache, int beta) noexcept {
     return (static_cast<carrier_uint>(
                 cache >> (64 - num_significand_bits<float>() - 2 - beta)) +
             1) /
@@ -350,7 +385,7 @@ template <> struct cache_accessor<double> {
   using carrier_uint = float_info<double>::carrier_uint;
   using cache_entry_type = uint128_fallback;
 
-  static auto get_cached_power(int k) noexcept -> uint128_fallback {
+  static uint128_fallback get_cached_power(int k) noexcept {
     FMT_ASSERT(k >= float_info<double>::min_k && k <= float_info<double>::max_k,
                "k is out of range");
 
@@ -974,22 +1009,8 @@ template <> struct cache_accessor<double> {
       {0xfcf62c1dee382c42, 0x46729e03dd9ed7b6},
       {0x9e19db92b4e31ba9, 0x6c07a2c26a8346d2},
       {0xc5a05277621be293, 0xc7098b7305241886},
-      {0xf70867153aa2db38, 0xb8cbee4fc66d1ea8},
+      { 0xf70867153aa2db38,
-      {0x9a65406d44a5c903, 0x737f74f1dc043329},
+        0xb8cbee4fc66d1ea8 }
-      {0xc0fe908895cf3b44, 0x505f522e53053ff3},
-      {0xf13e34aabb430a15, 0x647726b9e7c68ff0},
-      {0x96c6e0eab509e64d, 0x5eca783430dc19f6},
-      {0xbc789925624c5fe0, 0xb67d16413d132073},
-      {0xeb96bf6ebadf77d8, 0xe41c5bd18c57e890},
-      {0x933e37a534cbaae7, 0x8e91b962f7b6f15a},
-      {0xb80dc58e81fe95a1, 0x723627bbb5a4adb1},
-      {0xe61136f2227e3b09, 0xcec3b1aaa30dd91d},
-      {0x8fcac257558ee4e6, 0x213a4f0aa5e8a7b2},
-      {0xb3bd72ed2af29e1f, 0xa988e2cd4f62d19e},
-      {0xe0accfa875af45a7, 0x93eb1b80a33b8606},
-      {0x8c6c01c9498d8b88, 0xbc72f130660533c4},
-      {0xaf87023b9bf0ee6a, 0xeb8fad7c7f8680b5},
-      {0xdb68c2ca82ed2a05, 0xa67398db9f6820e2},
 #else
       {0xff77b1fcbebcdc4f, 0x25e8e89c13bb0f7b},
       {0xce5d73ff402d98e3, 0xfb0a3d212dc81290},
@@ -1013,8 +1034,8 @@ template <> struct cache_accessor<double> {
       {0x8da471a9de737e24, 0x5ceaecfed289e5d3},
       {0xe4d5e82392a40515, 0x0fabaf3feaa5334b},
       {0xb8da1662e7b00a17, 0x3d6a751f3b936244},
-      {0x95527a5202df0ccb, 0x0f37801e0c43ebc9},
+      { 0x95527a5202df0ccb,
-      {0xf13e34aabb430a15, 0x647726b9e7c68ff0}
+        0x0f37801e0c43ebc9 }
 #endif
     };
 
@@ -1074,22 +1095,19 @@ template <> struct cache_accessor<double> {
     bool is_integer;
   };
 
-  static auto compute_mul(carrier_uint u,
+  static compute_mul_result compute_mul(
-                          const cache_entry_type& cache) noexcept
+      carrier_uint u, const cache_entry_type& cache) noexcept {
-      -> compute_mul_result {
     auto r = umul192_upper128(u, cache);
     return {r.high(), r.low() == 0};
   }
 
-  static auto compute_delta(cache_entry_type const& cache, int beta) noexcept
+  static uint32_t compute_delta(cache_entry_type const& cache,
-      -> uint32_t {
+                                int beta) noexcept {
     return static_cast<uint32_t>(cache.high() >> (64 - 1 - beta));
   }
 
-  static auto compute_mul_parity(carrier_uint two_f,
+  static compute_mul_parity_result compute_mul_parity(
-                                 const cache_entry_type& cache,
+      carrier_uint two_f, const cache_entry_type& cache, int beta) noexcept {
-                                 int beta) noexcept
-      -> compute_mul_parity_result {
     FMT_ASSERT(beta >= 1, "");
     FMT_ASSERT(beta < 64, "");
 
@@ -1098,35 +1116,31 @@ template <> struct cache_accessor<double> {
             ((r.high() << beta) | (r.low() >> (64 - beta))) == 0};
   }
 
-  static auto compute_left_endpoint_for_shorter_interval_case(
+  static carrier_uint compute_left_endpoint_for_shorter_interval_case(
-      const cache_entry_type& cache, int beta) noexcept -> carrier_uint {
+      const cache_entry_type& cache, int beta) noexcept {
     return (cache.high() -
             (cache.high() >> (num_significand_bits<double>() + 2))) >>
            (64 - num_significand_bits<double>() - 1 - beta);
   }
 
-  static auto compute_right_endpoint_for_shorter_interval_case(
+  static carrier_uint compute_right_endpoint_for_shorter_interval_case(
-      const cache_entry_type& cache, int beta) noexcept -> carrier_uint {
+      const cache_entry_type& cache, int beta) noexcept {
     return (cache.high() +
             (cache.high() >> (num_significand_bits<double>() + 1))) >>
            (64 - num_significand_bits<double>() - 1 - beta);
   }
 
-  static auto compute_round_up_for_shorter_interval_case(
+  static carrier_uint compute_round_up_for_shorter_interval_case(
-      const cache_entry_type& cache, int beta) noexcept -> carrier_uint {
+      const cache_entry_type& cache, int beta) noexcept {
     return ((cache.high() >> (64 - num_significand_bits<double>() - 2 - beta)) +
             1) /
            2;
   }
 };
 
-FMT_FUNC auto get_cached_power(int k) noexcept -> uint128_fallback {
-  return cache_accessor<double>::get_cached_power(k);
-}
-
 // Various integer checks
-template <typename T>
+template <class T>
-auto is_left_endpoint_integer_shorter_interval(int exponent) noexcept -> bool {
+bool is_left_endpoint_integer_shorter_interval(int exponent) noexcept {
   const int case_shorter_interval_left_endpoint_lower_threshold = 2;
   const int case_shorter_interval_left_endpoint_upper_threshold = 3;
   return exponent >= case_shorter_interval_left_endpoint_lower_threshold &&
@@ -1134,12 +1148,12 @@ auto is_left_endpoint_integer_shorter_interval(int exponent) noexcept -> bool {
 }
 
 // Remove trailing zeros from n and return the number of zeros removed (float)
-FMT_INLINE int remove_trailing_zeros(uint32_t& n, int s = 0) noexcept {
+FMT_INLINE int remove_trailing_zeros(uint32_t& n) noexcept {
   FMT_ASSERT(n != 0, "");
-  // Modular inverse of 5 (mod 2^32): (mod_inv_5 * 5) mod 2^32 = 1.
+  const uint32_t mod_inv_5 = 0xcccccccd;
-  constexpr uint32_t mod_inv_5 = 0xcccccccd;
+  const uint32_t mod_inv_25 = mod_inv_5 * mod_inv_5;
-  constexpr uint32_t mod_inv_25 = 0xc28f5c29;  // = mod_inv_5 * mod_inv_5
 
+  int s = 0;
   while (true) {
     auto q = rotr(n * mod_inv_25, 2);
     if (q > max_value<uint32_t>() / 100) break;
@@ -1151,6 +1165,7 @@ FMT_INLINE int remove_trailing_zeros(uint32_t& n, int s = 0) noexcept {
     n = q;
     s |= 1;
   }
+
   return s;
 }
 
@@ -1164,17 +1179,32 @@ FMT_INLINE int remove_trailing_zeros(uint64_t& n) noexcept {
 
   // Is n is divisible by 10^8?
   if ((nm.high() & ((1ull << (90 - 64)) - 1)) == 0 && nm.low() < magic_number) {
-    // If yes, work with the quotient...
+    // If yes, work with the quotient.
     auto n32 = static_cast<uint32_t>(nm.high() >> (90 - 64));
-    // ... and use the 32 bit variant of the function
+
-    int s = remove_trailing_zeros(n32, 8);
+    const uint32_t mod_inv_5 = 0xcccccccd;
+    const uint32_t mod_inv_25 = mod_inv_5 * mod_inv_5;
+
+    int s = 8;
+    while (true) {
+      auto q = rotr(n32 * mod_inv_25, 2);
+      if (q > max_value<uint32_t>() / 100) break;
+      n32 = q;
+      s += 2;
+    }
+    auto q = rotr(n32 * mod_inv_5, 1);
+    if (q <= max_value<uint32_t>() / 10) {
+      n32 = q;
+      s |= 1;
+    }
+
     n = n32;
     return s;
   }
 
   // If n is not divisible by 10^8, work with n itself.
-  constexpr uint64_t mod_inv_5 = 0xcccccccccccccccd;
+  const uint64_t mod_inv_5 = 0xcccccccccccccccd;
-  constexpr uint64_t mod_inv_25 = 0x8f5c28f5c28f5c29;  // mod_inv_5 * mod_inv_5
+  const uint64_t mod_inv_25 = mod_inv_5 * mod_inv_5;
 
   int s = 0;
   while (true) {
@@ -1193,7 +1223,7 @@ FMT_INLINE int remove_trailing_zeros(uint64_t& n) noexcept {
 }
 
 // The main algorithm for shorter interval case
-template <typename T>
+template <class T>
 FMT_INLINE decimal_fp<T> shorter_interval_case(int exponent) noexcept {
   decimal_fp<T> ret_value;
   // Compute k and beta
@@ -1240,7 +1270,7 @@ FMT_INLINE decimal_fp<T> shorter_interval_case(int exponent) noexcept {
   return ret_value;
 }
 
-template <typename T> auto to_decimal(T x) noexcept -> decimal_fp<T> {
+template <typename T> decimal_fp<T> to_decimal(T x) noexcept {
   // Step 1: integer promotion & Schubfach multiplier calculation.
 
   using carrier_uint = typename float_info<T>::carrier_uint;
@@ -1364,6 +1394,17 @@ small_divisor_case_label:
   return ret_value;
 }
 }  // namespace dragonbox
+
+#ifdef _MSC_VER
+FMT_FUNC auto fmt_snprintf(char* buf, size_t size, const char* fmt, ...)
+    -> int {
+  auto args = va_list();
+  va_start(args, fmt);
+  int result = vsnprintf_s(buf, size, _TRUNCATE, fmt, args);
+  va_end(args);
+  return result;
+}
+#endif
 }  // namespace detail
 
 template <> struct formatter<detail::bigint> {
@@ -1372,21 +1413,22 @@ template <> struct formatter<detail::bigint> {
     return ctx.begin();
   }
 
-  auto format(const detail::bigint& n, format_context& ctx) const
+  template <typename FormatContext>
-      -> format_context::iterator {
+  auto format(const detail::bigint& n, FormatContext& ctx) const ->
+      typename FormatContext::iterator {
     auto out = ctx.out();
     bool first = true;
     for (auto i = n.bigits_.size(); i > 0; --i) {
       auto value = n.bigits_[i - 1u];
       if (first) {
-        out = fmt::format_to(out, FMT_STRING("{:x}"), value);
+        out = format_to(out, FMT_STRING("{:x}"), value);
         first = false;
         continue;
       }
-      out = fmt::format_to(out, FMT_STRING("{:08x}"), value);
+      out = format_to(out, FMT_STRING("{:08x}"), value);
     }
     if (n.exp_ > 0)
-      out = fmt::format_to(out, FMT_STRING("p{}"),
+      out = format_to(out, FMT_STRING("p{}"),
                       n.exp_ * detail::bigint::bigit_bits);
     return out;
   }
@@ -1423,7 +1465,7 @@ FMT_FUNC void report_system_error(int error_code,
   report_error(format_system_error, error_code, message);
 }
 
-FMT_FUNC auto vformat(string_view fmt, format_args args) -> std::string {
+FMT_FUNC std::string vformat(string_view fmt, format_args args) {
   // Don't optimize the "{}" case to keep the binary size small and because it
   // can be better optimized in fmt::format anyway.
   auto buffer = memory_buffer();
@@ -1432,54 +1474,57 @@ FMT_FUNC auto vformat(string_view fmt, format_args args) -> std::string {
 }
 
 namespace detail {
-#if !defined(_WIN32) || defined(FMT_WINDOWS_NO_WCHAR)
+#ifdef _WIN32
-FMT_FUNC auto write_console(int, string_view) -> bool { return false; }
-FMT_FUNC auto write_console(std::FILE*, string_view) -> bool { return false; }
-#else
 using dword = conditional_t<sizeof(long) == 4, unsigned long, unsigned>;
 extern "C" __declspec(dllimport) int __stdcall WriteConsoleW(  //
     void*, const void*, dword, dword*, void*);
 
-FMT_FUNC bool write_console(int fd, string_view text) {
+FMT_FUNC bool write_console(std::FILE* f, string_view text) {
-  auto u16 = utf8_to_utf16(text);
+  auto fd = _fileno(f);
-  return WriteConsoleW(reinterpret_cast<void*>(_get_osfhandle(fd)), u16.c_str(),
+  if (_isatty(fd)) {
-                       static_cast<dword>(u16.size()), nullptr, nullptr) != 0;
+    detail::utf8_to_utf16 u16(string_view(text.data(), text.size()));
+    auto written = detail::dword();
+    if (detail::WriteConsoleW(reinterpret_cast<void*>(_get_osfhandle(fd)),
+                              u16.c_str(), static_cast<uint32_t>(u16.size()),
+                              &written, nullptr)) {
+      return true;
     }
-
-FMT_FUNC auto write_console(std::FILE* f, string_view text) -> bool {
-  return write_console(_fileno(f), text);
   }
-#endif
+  // We return false if the file descriptor was not TTY, or it was but
-
+  // SetConsoleW failed which can happen if the output has been redirected to
-#ifdef _WIN32
+  // NUL. In both cases when we return false, we should attempt to do regular
-// Print assuming legacy (non-Unicode) encoding.
+  // write via fwrite or std::ostream::write.
-FMT_FUNC void vprint_mojibake(std::FILE* f, string_view fmt, format_args args) {
+  return false;
-  auto buffer = memory_buffer();
-  detail::vformat_to(buffer, fmt, args);
-  fwrite_fully(buffer.data(), buffer.size(), f);
 }
 #endif
 
 FMT_FUNC void print(std::FILE* f, string_view text) {
 #ifdef _WIN32
-  int fd = _fileno(f);
+  if (write_console(f, text)) return;
-  if (_isatty(fd)) {
-    std::fflush(f);
-    if (write_console(fd, text)) return;
-  }
 #endif
-  fwrite_fully(text.data(), text.size(), f);
+  detail::fwrite_fully(text.data(), 1, text.size(), f);
 }
 }  // namespace detail
 
-FMT_FUNC void vprint(std::FILE* f, string_view fmt, format_args args) {
+FMT_FUNC void vprint(std::FILE* f, string_view format_str, format_args args) {
-  auto buffer = memory_buffer();
+  memory_buffer buffer;
-  detail::vformat_to(buffer, fmt, args);
+  detail::vformat_to(buffer, format_str, args);
   detail::print(f, {buffer.data(), buffer.size()});
 }
 
-FMT_FUNC void vprint(string_view fmt, format_args args) {
+#ifdef _WIN32
-  vprint(stdout, fmt, args);
+// Print assuming legacy (non-Unicode) encoding.
+FMT_FUNC void detail::vprint_mojibake(std::FILE* f, string_view format_str,
+                                      format_args args) {
+  memory_buffer buffer;
+  detail::vformat_to(buffer, format_str,
+                     basic_format_args<buffer_context<char>>(args));
+  fwrite_fully(buffer.data(), 1, buffer.size(), f);
+}
+#endif
+
+FMT_FUNC void vprint(string_view format_str, format_args args) {
+  vprint(stdout, format_str, args);
 }
 
 namespace detail {

include/spdlog/fmt/bundled/os.h

@@ -13,13 +13,11 @@
 #include <cstdio>
 #include <system_error>  // std::system_error
 
-#include "format.h"
-
 #if defined __APPLE__ || defined(__FreeBSD__)
-#  if FMT_HAS_INCLUDE(<xlocale.h>)
 #  include <xlocale.h>  // for LC_NUMERIC_MASK on OS X
 #endif
-#endif
+
+#include "format.h"
 
 #ifndef FMT_USE_FCNTL
 // UWP doesn't provide _pipe.
@@ -48,7 +46,6 @@
 
 // Calls to system functions are wrapped in FMT_SYSTEM for testability.
 #ifdef FMT_SYSTEM
-#  define FMT_HAS_SYSTEM
 #  define FMT_POSIX_CALL(call) FMT_SYSTEM(call)
 #else
 #  define FMT_SYSTEM(call) ::call
@@ -74,7 +71,7 @@
 #define FMT_RETRY(result, expression) FMT_RETRY_VAL(result, expression, -1)
 
 FMT_BEGIN_NAMESPACE
-FMT_BEGIN_EXPORT
+FMT_MODULE_EXPORT_BEGIN
 
 /**
   \rst
@@ -117,19 +114,57 @@ template <typename Char> class basic_cstring_view {
   basic_cstring_view(const std::basic_string<Char>& s) : data_(s.c_str()) {}
 
   /** Returns the pointer to a C string. */
-  auto c_str() const -> const Char* { return data_; }
+  const Char* c_str() const { return data_; }
 };
 
 using cstring_view = basic_cstring_view<char>;
 using wcstring_view = basic_cstring_view<wchar_t>;
 
+template <typename Char> struct formatter<std::error_code, Char> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  FMT_CONSTEXPR auto format(const std::error_code& ec, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    out = detail::write_bytes(out, ec.category().name(),
+                              basic_format_specs<Char>());
+    out = detail::write<Char>(out, Char(':'));
+    out = detail::write<Char>(out, ec.value());
+    return out;
+  }
+};
+
 #ifdef _WIN32
 FMT_API const std::error_category& system_category() noexcept;
 
-namespace detail {
+FMT_BEGIN_DETAIL_NAMESPACE
+// A converter from UTF-16 to UTF-8.
+// It is only provided for Windows since other systems support UTF-8 natively.
+class utf16_to_utf8 {
+ private:
+  memory_buffer buffer_;
+
+ public:
+  utf16_to_utf8() {}
+  FMT_API explicit utf16_to_utf8(basic_string_view<wchar_t> s);
+  operator string_view() const { return string_view(&buffer_[0], size()); }
+  size_t size() const { return buffer_.size() - 1; }
+  const char* c_str() const { return &buffer_[0]; }
+  std::string str() const { return std::string(&buffer_[0], size()); }
+
+  // Performs conversion returning a system error code instead of
+  // throwing exception on conversion error. This method may still throw
+  // in case of memory allocation error.
+  FMT_API int convert(basic_string_view<wchar_t> s);
+};
+
 FMT_API void format_windows_error(buffer<char>& out, int error_code,
                                   const char* message) noexcept;
-}
+FMT_END_DETAIL_NAMESPACE
 
 FMT_API std::system_error vwindows_error(int error_code, string_view format_str,
                                          format_args args);
@@ -172,7 +207,7 @@ std::system_error windows_error(int error_code, string_view message,
 // Can be used to report errors from destructors.
 FMT_API void report_windows_error(int error_code, const char* message) noexcept;
 #else
-inline auto system_category() noexcept -> const std::error_category& {
+inline const std::error_category& system_category() noexcept {
   return std::system_category();
 }
 #endif  // _WIN32
@@ -209,7 +244,7 @@ class buffered_file {
     other.file_ = nullptr;
   }
 
-  auto operator=(buffered_file&& other) -> buffered_file& {
+  buffered_file& operator=(buffered_file&& other) {
     close();
     file_ = other.file_;
     other.file_ = nullptr;
@@ -223,9 +258,9 @@ class buffered_file {
   FMT_API void close();
 
   // Returns the pointer to a FILE object representing this file.
-  auto get() const noexcept -> FILE* { return file_; }
+  FILE* get() const noexcept { return file_; }
 
-  FMT_API auto descriptor() const -> int;
+  FMT_API int descriptor() const;
 
   void vprint(string_view format_str, format_args args) {
     fmt::vprint(file_, format_str, args);
@@ -275,7 +310,7 @@ class FMT_API file {
   file(file&& other) noexcept : fd_(other.fd_) { other.fd_ = -1; }
 
   // Move assignment is not noexcept because close may throw.
-  auto operator=(file&& other) -> file& {
+  file& operator=(file&& other) {
     close();
     fd_ = other.fd_;
     other.fd_ = -1;
@@ -286,24 +321,24 @@ class FMT_API file {
   ~file() noexcept;
 
   // Returns the file descriptor.
-  auto descriptor() const noexcept -> int { return fd_; }
+  int descriptor() const noexcept { return fd_; }
 
   // Closes the file.
   void close();
 
   // Returns the file size. The size has signed type for consistency with
   // stat::st_size.
-  auto size() const -> long long;
+  long long size() const;
 
   // Attempts to read count bytes from the file into the specified buffer.
-  auto read(void* buffer, size_t count) -> size_t;
+  size_t read(void* buffer, size_t count);
 
   // Attempts to write count bytes from the specified buffer to the file.
-  auto write(const void* buffer, size_t count) -> size_t;
+  size_t write(const void* buffer, size_t count);
 
   // Duplicates a file descriptor with the dup function and returns
   // the duplicate as a file object.
-  static auto dup(int fd) -> file;
+  static file dup(int fd);
 
   // Makes fd be the copy of this file descriptor, closing fd first if
   // necessary.
@@ -315,29 +350,22 @@ class FMT_API file {
 
   // Creates a pipe setting up read_end and write_end file objects for reading
   // and writing respectively.
-  // DEPRECATED! Taking files as out parameters is deprecated.
   static void pipe(file& read_end, file& write_end);
 
   // Creates a buffered_file object associated with this file and detaches
   // this file object from the file.
-  auto fdopen(const char* mode) -> buffered_file;
+  buffered_file fdopen(const char* mode);
-
-#  if defined(_WIN32) && !defined(__MINGW32__)
-  // Opens a file and constructs a file object representing this file by
-  // wcstring_view filename. Windows only.
-  static file open_windows_file(wcstring_view path, int oflag);
-#  endif
 };
 
 // Returns the memory page size.
-auto getpagesize() -> long;
+long getpagesize();
 
-namespace detail {
+FMT_BEGIN_DETAIL_NAMESPACE
 
 struct buffer_size {
   buffer_size() = default;
   size_t value = 0;
-  auto operator=(size_t val) const -> buffer_size {
+  buffer_size operator=(size_t val) const {
     auto bs = buffer_size();
     bs.value = val;
     return bs;
@@ -369,61 +397,56 @@ struct ostream_params {
 #  endif
 };
 
-class file_buffer final : public buffer<char> {
+FMT_END_DETAIL_NAMESPACE
-  file file_;
-
-  FMT_API void grow(size_t) override;
-
- public:
-  FMT_API file_buffer(cstring_view path, const ostream_params& params);
-  FMT_API file_buffer(file_buffer&& other);
-  FMT_API ~file_buffer();
-
-  void flush() {
-    if (size() == 0) return;
-    file_.write(data(), size() * sizeof(data()[0]));
-    clear();
-  }
-
-  void close() {
-    flush();
-    file_.close();
-  }
-};
-
-}  // namespace detail
 
 // Added {} below to work around default constructor error known to
 // occur in Xcode versions 7.2.1 and 8.2.1.
 constexpr detail::buffer_size buffer_size{};
 
 /** A fast output stream which is not thread-safe. */
-class FMT_API ostream {
+class FMT_API ostream final : private detail::buffer<char> {
  private:
-  FMT_MSC_WARNING(suppress : 4251)
+  file file_;
-  detail::file_buffer buffer_;
+
+  void grow(size_t) override;
 
   ostream(cstring_view path, const detail::ostream_params& params)
-      : buffer_(path, params) {}
+      : file_(path, params.oflag) {
+    set(new char[params.buffer_size], params.buffer_size);
+  }
 
  public:
-  ostream(ostream&& other) : buffer_(std::move(other.buffer_)) {}
+  ostream(ostream&& other)
+      : detail::buffer<char>(other.data(), other.size(), other.capacity()),
+        file_(std::move(other.file_)) {
+    other.clear();
+    other.set(nullptr, 0);
+  }
+  ~ostream() {
+    flush();
+    delete[] data();
+  }
 
-  ~ostream();
+  void flush() {
-
+    if (size() == 0) return;
-  void flush() { buffer_.flush(); }
+    file_.write(data(), size());
+    clear();
+  }
 
   template <typename... T>
-  friend auto output_file(cstring_view path, T... params) -> ostream;
+  friend ostream output_file(cstring_view path, T... params);
 
-  void close() { buffer_.close(); }
+  void close() {
+    flush();
+    file_.close();
+  }
 
   /**
     Formats ``args`` according to specifications in ``fmt`` and writes the
     output to the file.
    */
   template <typename... T> void print(format_string<T...> fmt, T&&... args) {
-    vformat_to(std::back_inserter(buffer_), fmt,
+    vformat_to(detail::buffer_appender<char>(*this), fmt,
                fmt::make_format_args(args...));
   }
 };
@@ -444,12 +467,12 @@ class FMT_API ostream {
   \endrst
  */
 template <typename... T>
-inline auto output_file(cstring_view path, T... params) -> ostream {
+inline ostream output_file(cstring_view path, T... params) {
   return {path, detail::ostream_params(params...)};
 }
 #endif  // FMT_USE_FCNTL
 
-FMT_END_EXPORT
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_OS_H_

include/spdlog/fmt/bundled/ostream.h

@@ -8,58 +8,61 @@
 #ifndef FMT_OSTREAM_H_
 #define FMT_OSTREAM_H_
 
-#include <fstream>  // std::filebuf
+#include <fstream>
-
+#include <ostream>
-#ifdef _WIN32
+#if defined(_WIN32) && defined(__GLIBCXX__)
-#  ifdef __GLIBCXX__
 #  include <ext/stdio_filebuf.h>
 #  include <ext/stdio_sync_filebuf.h>
-#  endif
+#elif defined(_WIN32) && defined(_LIBCPP_VERSION)
-#  include <io.h>
+#  include <__std_stream>
 #endif
 
 #include "format.h"
 
 FMT_BEGIN_NAMESPACE
+
+template <typename OutputIt, typename Char> class basic_printf_context;
+
 namespace detail {
 
-template <typename Streambuf> class formatbuf : public Streambuf {
+// Checks if T has a user-defined operator<<.
+template <typename T, typename Char, typename Enable = void>
+class is_streamable {
  private:
-  using char_type = typename Streambuf::char_type;
+  template <typename U>
-  using streamsize = decltype(std::declval<Streambuf>().sputn(nullptr, 0));
+  static auto test(int)
-  using int_type = typename Streambuf::int_type;
+      -> bool_constant<sizeof(std::declval<std::basic_ostream<Char>&>()
-  using traits_type = typename Streambuf::traits_type;
+                              << std::declval<U>()) != 0>;
 
-  buffer<char_type>& buffer_;
+  template <typename> static auto test(...) -> std::false_type;
+
+  using result = decltype(test<T>(0));
 
  public:
-  explicit formatbuf(buffer<char_type>& buf) : buffer_(buf) {}
+  is_streamable() = default;
 
- protected:
+  static const bool value = result::value;
-  // The put area is always empty. This makes the implementation simpler and has
-  // the advantage that the streambuf and the buffer are always in sync and
-  // sputc never writes into uninitialized memory. A disadvantage is that each
-  // call to sputc always results in a (virtual) call to overflow. There is no
-  // disadvantage here for sputn since this always results in a call to xsputn.
-
-  auto overflow(int_type ch) -> int_type override {
-    if (!traits_type::eq_int_type(ch, traits_type::eof()))
-      buffer_.push_back(static_cast<char_type>(ch));
-    return ch;
-  }
-
-  auto xsputn(const char_type* s, streamsize count) -> streamsize override {
-    buffer_.append(s, s + count);
-    return count;
-  }
 };
 
+// Formatting of built-in types and arrays is intentionally disabled because
+// it's handled by standard (non-ostream) formatters.
+template <typename T, typename Char>
+struct is_streamable<
+    T, Char,
+    enable_if_t<
+        std::is_arithmetic<T>::value || std::is_array<T>::value ||
+        std::is_pointer<T>::value || std::is_same<T, char8_type>::value ||
+        std::is_convertible<T, fmt::basic_string_view<Char>>::value ||
+        std::is_same<T, std_string_view<Char>>::value ||
+        (std::is_convertible<T, int>::value && !std::is_enum<T>::value)>>
+    : std::false_type {};
+
 // Generate a unique explicit instantion in every translation unit using a tag
 // type in an anonymous namespace.
 namespace {
 struct file_access_tag {};
 }  // namespace
-template <typename Tag, typename BufType, FILE* BufType::*FileMemberPtr>
+template <class Tag, class BufType, FILE* BufType::*FileMemberPtr>
 class file_access {
   friend auto get_file(BufType& obj) -> FILE* { return obj.*FileMemberPtr; }
 };
@@ -68,40 +71,36 @@ class file_access {
 template class file_access<file_access_tag, std::filebuf,
                            &std::filebuf::_Myfile>;
 auto get_file(std::filebuf&) -> FILE*;
+#elif defined(_WIN32) && defined(_LIBCPP_VERSION)
+template class file_access<file_access_tag, std::__stdoutbuf<char>,
+                           &std::__stdoutbuf<char>::__file_>;
+auto get_file(std::__stdoutbuf<char>&) -> FILE*;
 #endif
 
-inline auto write_ostream_unicode(std::ostream& os, fmt::string_view data)
+inline bool write_ostream_unicode(std::ostream& os, fmt::string_view data) {
-    -> bool {
-  FILE* f = nullptr;
 #if FMT_MSC_VERSION
   if (auto* buf = dynamic_cast<std::filebuf*>(os.rdbuf()))
-    f = get_file(*buf);
+    if (FILE* f = get_file(*buf)) return write_console(f, data);
-  else
-    return false;
 #elif defined(_WIN32) && defined(__GLIBCXX__)
   auto* rdbuf = os.rdbuf();
-  if (auto* sfbuf = dynamic_cast<__gnu_cxx::stdio_sync_filebuf<char>*>(rdbuf))
+  FILE* c_file;
-    f = sfbuf->file();
+  if (auto* fbuf = dynamic_cast<__gnu_cxx::stdio_sync_filebuf<char>*>(rdbuf))
+    c_file = fbuf->file();
   else if (auto* fbuf = dynamic_cast<__gnu_cxx::stdio_filebuf<char>*>(rdbuf))
-    f = fbuf->file();
+    c_file = fbuf->file();
   else
     return false;
+  if (c_file) return write_console(c_file, data);
+#elif defined(_WIN32) && defined(_LIBCPP_VERSION)
+  if (auto* buf = dynamic_cast<std::__stdoutbuf<char>*>(os.rdbuf()))
+    if (FILE* f = get_file(*buf)) return write_console(f, data);
 #else
-  ignore_unused(os, data, f);
+  ignore_unused(os, data);
-#endif
-#ifdef _WIN32
-  if (f) {
-    int fd = _fileno(f);
-    if (_isatty(fd)) {
-      os.flush();
-      return write_console(fd, data);
-    }
-  }
 #endif
   return false;
 }
-inline auto write_ostream_unicode(std::wostream&,
+inline bool write_ostream_unicode(std::wostream&,
-                                  fmt::basic_string_view<wchar_t>) -> bool {
+                                  fmt::basic_string_view<wchar_t>) {
   return false;
 }
 
@@ -122,19 +121,18 @@ void write_buffer(std::basic_ostream<Char>& os, buffer<Char>& buf) {
 }
 
 template <typename Char, typename T>
-void format_value(buffer<Char>& buf, const T& value) {
+void format_value(buffer<Char>& buf, const T& value,
+                  locale_ref loc = locale_ref()) {
   auto&& format_buf = formatbuf<std::basic_streambuf<Char>>(buf);
   auto&& output = std::basic_ostream<Char>(&format_buf);
 #if !defined(FMT_STATIC_THOUSANDS_SEPARATOR)
-  output.imbue(std::locale::classic());  // The default is always unlocalized.
+  if (loc) output.imbue(loc.get<std::locale>());
 #endif
   output << value;
   output.exceptions(std::ios_base::failbit | std::ios_base::badbit);
 }
 
-template <typename T> struct streamed_view {
+template <typename T> struct streamed_view { const T& value; };
-  const T& value;
-};
 
 }  // namespace detail
 
@@ -147,7 +145,7 @@ struct basic_ostream_formatter : formatter<basic_string_view<Char>, Char> {
   auto format(const T& value, basic_format_context<OutputIt, Char>& ctx) const
       -> OutputIt {
     auto buffer = basic_memory_buffer<Char>();
-    detail::format_value(buffer, value);
+    format_value(buffer, value, ctx.locale());
     return formatter<basic_string_view<Char>, Char>::format(
         {buffer.data(), buffer.size()}, ctx);
   }
@@ -176,12 +174,19 @@ struct formatter<detail::streamed_view<T>, Char>
   \endrst
  */
 template <typename T>
-constexpr auto streamed(const T& value) -> detail::streamed_view<T> {
+auto streamed(const T& value) -> detail::streamed_view<T> {
   return {value};
 }
 
 namespace detail {
 
+// Formats an object of type T that has an overloaded ostream operator<<.
+template <typename T, typename Char>
+struct fallback_formatter<T, Char, enable_if_t<is_streamable<T, Char>::value>>
+    : basic_ostream_formatter<Char> {
+  using basic_ostream_formatter<Char>::format;
+};
+
 inline void vprint_directly(std::ostream& os, string_view format_str,
                             format_args args) {
   auto buffer = memory_buffer();
@@ -191,7 +196,7 @@ inline void vprint_directly(std::ostream& os, string_view format_str,
 
 }  // namespace detail
 
-FMT_EXPORT template <typename Char>
+FMT_MODULE_EXPORT template <typename Char>
 void vprint(std::basic_ostream<Char>& os,
             basic_string_view<type_identity_t<Char>> format_str,
             basic_format_args<buffer_context<type_identity_t<Char>>> args) {
@@ -210,7 +215,7 @@ void vprint(std::basic_ostream<Char>& os,
     fmt::print(cerr, "Don't {}!", "panic");
   \endrst
  */
-FMT_EXPORT template <typename... T>
+FMT_MODULE_EXPORT template <typename... T>
 void print(std::ostream& os, format_string<T...> fmt, T&&... args) {
   const auto& vargs = fmt::make_format_args(args...);
   if (detail::is_utf8())
@@ -219,7 +224,7 @@ void print(std::ostream& os, format_string<T...> fmt, T&&... args) {
     detail::vprint_directly(os, fmt, vargs);
 }
 
-FMT_EXPORT
+FMT_MODULE_EXPORT
 template <typename... Args>
 void print(std::wostream& os,
            basic_format_string<wchar_t, type_identity_t<Args>...> fmt,
@@ -227,19 +232,6 @@ void print(std::wostream& os,
   vprint(os, fmt, fmt::make_format_args<buffer_context<wchar_t>>(args...));
 }
 
-FMT_EXPORT template <typename... T>
-void println(std::ostream& os, format_string<T...> fmt, T&&... args) {
-  fmt::print(os, "{}\n", fmt::format(fmt, std::forward<T>(args)...));
-}
-
-FMT_EXPORT
-template <typename... Args>
-void println(std::wostream& os,
-             basic_format_string<wchar_t, type_identity_t<Args>...> fmt,
-             Args&&... args) {
-  print(os, L"{}\n", fmt::format(fmt, std::forward<Args>(args)...));
-}
-
 FMT_END_NAMESPACE
 
 #endif  // FMT_OSTREAM_H_

include/spdlog/fmt/bundled/printf.h

@@ -14,24 +14,24 @@
 #include "format.h"
 
 FMT_BEGIN_NAMESPACE
-FMT_BEGIN_EXPORT
+FMT_MODULE_EXPORT_BEGIN
 
-template <typename T> struct printf_formatter {
+template <typename T> struct printf_formatter { printf_formatter() = delete; };
-  printf_formatter() = delete;
+
+template <typename Char>
+class basic_printf_parse_context : public basic_format_parse_context<Char> {
+  using basic_format_parse_context<Char>::basic_format_parse_context;
 };
 
-template <typename Char> class basic_printf_context {
+template <typename OutputIt, typename Char> class basic_printf_context {
  private:
-  detail::buffer_appender<Char> out_;
+  OutputIt out_;
   basic_format_args<basic_printf_context> args_;
 
-  static_assert(std::is_same<Char, char>::value ||
-                    std::is_same<Char, wchar_t>::value,
-                "Unsupported code unit type.");
-
  public:
   using char_type = Char;
-  using parse_context_type = basic_format_parse_context<Char>;
+  using format_arg = basic_format_arg<basic_printf_context>;
+  using parse_context_type = basic_printf_parse_context<Char>;
   template <typename T> using formatter_type = printf_formatter<T>;
 
   /**
@@ -40,77 +40,75 @@ template <typename Char> class basic_printf_context {
     stored in the context object so make sure they have appropriate lifetimes.
     \endrst
    */
-  basic_printf_context(detail::buffer_appender<Char> out,
+  basic_printf_context(OutputIt out,
                        basic_format_args<basic_printf_context> args)
       : out_(out), args_(args) {}
 
-  auto out() -> detail::buffer_appender<Char> { return out_; }
+  OutputIt out() { return out_; }
-  void advance_to(detail::buffer_appender<Char>) {}
+  void advance_to(OutputIt it) { out_ = it; }
 
-  auto locale() -> detail::locale_ref { return {}; }
+  detail::locale_ref locale() { return {}; }
 
-  auto arg(int id) const -> basic_format_arg<basic_printf_context> {
+  format_arg arg(int id) const { return args_.get(id); }
-    return args_.get(id);
-  }
 
   FMT_CONSTEXPR void on_error(const char* message) {
     detail::error_handler().on_error(message);
   }
 };
 
-namespace detail {
+FMT_BEGIN_DETAIL_NAMESPACE
 
 // Checks if a value fits in int - used to avoid warnings about comparing
 // signed and unsigned integers.
 template <bool IsSigned> struct int_checker {
-  template <typename T> static auto fits_in_int(T value) -> bool {
+  template <typename T> static bool fits_in_int(T value) {
     unsigned max = max_value<int>();
     return value <= max;
   }
-  static auto fits_in_int(bool) -> bool { return true; }
+  static bool fits_in_int(bool) { return true; }
 };
 
 template <> struct int_checker<true> {
-  template <typename T> static auto fits_in_int(T value) -> bool {
+  template <typename T> static bool fits_in_int(T value) {
     return value >= (std::numeric_limits<int>::min)() &&
            value <= max_value<int>();
   }
-  static auto fits_in_int(int) -> bool { return true; }
+  static bool fits_in_int(int) { return true; }
 };
 
-struct printf_precision_handler {
+class printf_precision_handler {
+ public:
   template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
-  auto operator()(T value) -> int {
+  int operator()(T value) {
     if (!int_checker<std::numeric_limits<T>::is_signed>::fits_in_int(value))
-      throw_format_error("number is too big");
+      FMT_THROW(format_error("number is too big"));
     return (std::max)(static_cast<int>(value), 0);
   }
 
   template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
-  auto operator()(T) -> int {
+  int operator()(T) {
-    throw_format_error("precision is not integer");
+    FMT_THROW(format_error("precision is not integer"));
     return 0;
   }
 };
 
 // An argument visitor that returns true iff arg is a zero integer.
-struct is_zero_int {
+class is_zero_int {
+ public:
   template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
-  auto operator()(T value) -> bool {
+  bool operator()(T value) {
     return value == 0;
   }
 
   template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
-  auto operator()(T) -> bool {
+  bool operator()(T) {
     return false;
   }
 };
 
 template <typename T> struct make_unsigned_or_bool : std::make_unsigned<T> {};
 
-template <> struct make_unsigned_or_bool<bool> {
+template <> struct make_unsigned_or_bool<bool> { using type = bool; };
-  using type = bool;
-};
 
 template <typename T, typename Context> class arg_converter {
  private:
@@ -134,23 +132,22 @@ template <typename T, typename Context> class arg_converter {
     if (const_check(sizeof(target_type) <= sizeof(int))) {
       // Extra casts are used to silence warnings.
       if (is_signed) {
-        auto n = static_cast<int>(static_cast<target_type>(value));
+        arg_ = detail::make_arg<Context>(
-        arg_ = detail::make_arg<Context>(n);
+            static_cast<int>(static_cast<target_type>(value)));
       } else {
         using unsigned_type = typename make_unsigned_or_bool<target_type>::type;
-        auto n = static_cast<unsigned>(static_cast<unsigned_type>(value));
+        arg_ = detail::make_arg<Context>(
-        arg_ = detail::make_arg<Context>(n);
+            static_cast<unsigned>(static_cast<unsigned_type>(value)));
       }
     } else {
       if (is_signed) {
         // glibc's printf doesn't sign extend arguments of smaller types:
         //   std::printf("%lld", -42);  // prints "4294967254"
         // but we don't have to do the same because it's a UB.
-        auto n = static_cast<long long>(value);
+        arg_ = detail::make_arg<Context>(static_cast<long long>(value));
-        arg_ = detail::make_arg<Context>(n);
       } else {
-        auto n = static_cast<typename make_unsigned_or_bool<U>::type>(value);
+        arg_ = detail::make_arg<Context>(
-        arg_ = detail::make_arg<Context>(n);
+            static_cast<typename make_unsigned_or_bool<U>::type>(value));
       }
     }
   }
@@ -178,8 +175,8 @@ template <typename Context> class char_converter {
 
   template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
   void operator()(T value) {
-    auto c = static_cast<typename Context::char_type>(value);
+    arg_ = detail::make_arg<Context>(
-    arg_ = detail::make_arg<Context>(c);
+        static_cast<typename Context::char_type>(value));
   }
 
   template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
@@ -189,77 +186,68 @@ template <typename Context> class char_converter {
 // An argument visitor that return a pointer to a C string if argument is a
 // string or null otherwise.
 template <typename Char> struct get_cstring {
-  template <typename T> auto operator()(T) -> const Char* { return nullptr; }
+  template <typename T> const Char* operator()(T) { return nullptr; }
-  auto operator()(const Char* s) -> const Char* { return s; }
+  const Char* operator()(const Char* s) { return s; }
 };
 
 // Checks if an argument is a valid printf width specifier and sets
 // left alignment if it is negative.
 template <typename Char> class printf_width_handler {
  private:
-  format_specs<Char>& specs_;
+  using format_specs = basic_format_specs<Char>;
+
+  format_specs& specs_;
 
  public:
-  explicit printf_width_handler(format_specs<Char>& specs) : specs_(specs) {}
+  explicit printf_width_handler(format_specs& specs) : specs_(specs) {}
 
   template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
-  auto operator()(T value) -> unsigned {
+  unsigned operator()(T value) {
     auto width = static_cast<uint32_or_64_or_128_t<T>>(value);
     if (detail::is_negative(value)) {
       specs_.align = align::left;
       width = 0 - width;
     }
     unsigned int_max = max_value<int>();
-    if (width > int_max) throw_format_error("number is too big");
+    if (width > int_max) FMT_THROW(format_error("number is too big"));
     return static_cast<unsigned>(width);
   }
 
   template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
-  auto operator()(T) -> unsigned {
+  unsigned operator()(T) {
-    throw_format_error("width is not integer");
+    FMT_THROW(format_error("width is not integer"));
     return 0;
   }
 };
 
-// Workaround for a bug with the XL compiler when initializing
-// printf_arg_formatter's base class.
-template <typename Char>
-auto make_arg_formatter(buffer_appender<Char> iter, format_specs<Char>& s)
-    -> arg_formatter<Char> {
-  return {iter, s, locale_ref()};
-}
-
 // The ``printf`` argument formatter.
-template <typename Char>
+template <typename OutputIt, typename Char>
 class printf_arg_formatter : public arg_formatter<Char> {
  private:
   using base = arg_formatter<Char>;
-  using context_type = basic_printf_context<Char>;
+  using context_type = basic_printf_context<OutputIt, Char>;
+  using format_specs = basic_format_specs<Char>;
 
   context_type& context_;
 
-  void write_null_pointer(bool is_string = false) {
+  OutputIt write_null_pointer(bool is_string = false) {
     auto s = this->specs;
     s.type = presentation_type::none;
-    write_bytes(this->out, is_string ? "(null)" : "(nil)", s);
+    return write_bytes(this->out, is_string ? "(null)" : "(nil)", s);
   }
 
  public:
-  printf_arg_formatter(buffer_appender<Char> iter, format_specs<Char>& s,
+  printf_arg_formatter(OutputIt iter, format_specs& s, context_type& ctx)
-                       context_type& ctx)
+      : base{iter, s, locale_ref()}, context_(ctx) {}
-      : base(make_arg_formatter(iter, s)), context_(ctx) {}
 
-  void operator()(monostate value) { base::operator()(value); }
+  OutputIt operator()(monostate value) { return base::operator()(value); }
 
   template <typename T, FMT_ENABLE_IF(detail::is_integral<T>::value)>
-  void operator()(T value) {
+  OutputIt operator()(T value) {
     // MSVC2013 fails to compile separate overloads for bool and Char so use
     // std::is_same instead.
-    if (!std::is_same<T, Char>::value) {
+    if (std::is_same<T, Char>::value) {
-      base::operator()(value);
+      format_specs fmt_specs = this->specs;
-      return;
-    }
-    format_specs<Char> fmt_specs = this->specs;
       if (fmt_specs.type != presentation_type::none &&
           fmt_specs.type != presentation_type::chr) {
         return (*this)(static_cast<int>(value));
@@ -271,49 +259,49 @@ class printf_arg_formatter : public arg_formatter<Char> {
       // ignored for non-numeric types
       if (fmt_specs.align == align::none || fmt_specs.align == align::numeric)
         fmt_specs.align = align::right;
-    write<Char>(this->out, static_cast<Char>(value), fmt_specs);
+      return write<Char>(this->out, static_cast<Char>(value), fmt_specs);
+    }
+    return base::operator()(value);
   }
 
   template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value)>
-  void operator()(T value) {
+  OutputIt operator()(T value) {
-    base::operator()(value);
+    return base::operator()(value);
   }
 
   /** Formats a null-terminated C string. */
-  void operator()(const char* value) {
+  OutputIt operator()(const char* value) {
-    if (value)
+    if (value) return base::operator()(value);
-      base::operator()(value);
+    return write_null_pointer(this->specs.type != presentation_type::pointer);
-    else
-      write_null_pointer(this->specs.type != presentation_type::pointer);
   }
 
   /** Formats a null-terminated wide C string. */
-  void operator()(const wchar_t* value) {
+  OutputIt operator()(const wchar_t* value) {
-    if (value)
+    if (value) return base::operator()(value);
-      base::operator()(value);
+    return write_null_pointer(this->specs.type != presentation_type::pointer);
-    else
-      write_null_pointer(this->specs.type != presentation_type::pointer);
   }
 
-  void operator()(basic_string_view<Char> value) { base::operator()(value); }
+  OutputIt operator()(basic_string_view<Char> value) {
+    return base::operator()(value);
+  }
 
   /** Formats a pointer. */
-  void operator()(const void* value) {
+  OutputIt operator()(const void* value) {
-    if (value)
+    return value ? base::operator()(value) : write_null_pointer();
-      base::operator()(value);
-    else
-      write_null_pointer();
   }
 
   /** Formats an argument of a custom (user-defined) type. */
-  void operator()(typename basic_format_arg<context_type>::handle handle) {
+  OutputIt operator()(typename basic_format_arg<context_type>::handle handle) {
-    auto parse_ctx = basic_format_parse_context<Char>({});
+    auto parse_ctx =
+        basic_printf_parse_context<Char>(basic_string_view<Char>());
     handle.format(parse_ctx, context_);
+    return this->out;
   }
 };
 
 template <typename Char>
-void parse_flags(format_specs<Char>& specs, const Char*& it, const Char* end) {
+void parse_flags(basic_format_specs<Char>& specs, const Char*& it,
+                 const Char* end) {
   for (; it != end; ++it) {
     switch (*it) {
     case '-':
@@ -326,7 +314,9 @@ void parse_flags(format_specs<Char>& specs, const Char*& it, const Char* end) {
       specs.fill[0] = '0';
       break;
     case ' ':
-      if (specs.sign != sign::plus) specs.sign = sign::space;
+      if (specs.sign != sign::plus) {
+        specs.sign = sign::space;
+      }
       break;
     case '#':
       specs.alt = true;
@@ -338,8 +328,8 @@ void parse_flags(format_specs<Char>& specs, const Char*& it, const Char* end) {
 }
 
 template <typename Char, typename GetArg>
-auto parse_header(const Char*& it, const Char* end, format_specs<Char>& specs,
+int parse_header(const Char*& it, const Char* end,
-                  GetArg get_arg) -> int {
+                 basic_format_specs<Char>& specs, GetArg get_arg) {
   int arg_index = -1;
   Char c = *it;
   if (c >= '0' && c <= '9') {
@@ -354,7 +344,7 @@ auto parse_header(const Char*& it, const Char* end, format_specs<Char>& specs,
       if (value != 0) {
         // Nonzero value means that we parsed width and don't need to
         // parse it or flags again, so return now.
-        if (value == -1) throw_format_error("number is too big");
+        if (value == -1) FMT_THROW(format_error("number is too big"));
         specs.width = value;
         return arg_index;
       }
@@ -365,7 +355,7 @@ auto parse_header(const Char*& it, const Char* end, format_specs<Char>& specs,
   if (it != end) {
     if (*it >= '0' && *it <= '9') {
       specs.width = parse_nonnegative_int(it, end, -1);
-      if (specs.width == -1) throw_format_error("number is too big");
+      if (specs.width == -1) FMT_THROW(format_error("number is too big"));
     } else if (*it == '*') {
       ++it;
       specs.width = static_cast<int>(visit_format_arg(
@@ -375,53 +365,13 @@ auto parse_header(const Char*& it, const Char* end, format_specs<Char>& specs,
   return arg_index;
 }
 
-inline auto parse_printf_presentation_type(char c, type t)
-    -> presentation_type {
-  using pt = presentation_type;
-  constexpr auto integral_set = sint_set | uint_set | bool_set | char_set;
-  switch (c) {
-  case 'd':
-    return in(t, integral_set) ? pt::dec : pt::none;
-  case 'o':
-    return in(t, integral_set) ? pt::oct : pt::none;
-  case 'x':
-    return in(t, integral_set) ? pt::hex_lower : pt::none;
-  case 'X':
-    return in(t, integral_set) ? pt::hex_upper : pt::none;
-  case 'a':
-    return in(t, float_set) ? pt::hexfloat_lower : pt::none;
-  case 'A':
-    return in(t, float_set) ? pt::hexfloat_upper : pt::none;
-  case 'e':
-    return in(t, float_set) ? pt::exp_lower : pt::none;
-  case 'E':
-    return in(t, float_set) ? pt::exp_upper : pt::none;
-  case 'f':
-    return in(t, float_set) ? pt::fixed_lower : pt::none;
-  case 'F':
-    return in(t, float_set) ? pt::fixed_upper : pt::none;
-  case 'g':
-    return in(t, float_set) ? pt::general_lower : pt::none;
-  case 'G':
-    return in(t, float_set) ? pt::general_upper : pt::none;
-  case 'c':
-    return in(t, integral_set) ? pt::chr : pt::none;
-  case 's':
-    return in(t, string_set | cstring_set) ? pt::string : pt::none;
-  case 'p':
-    return in(t, pointer_set | cstring_set) ? pt::pointer : pt::none;
-  default:
-    return pt::none;
-  }
-}
-
 template <typename Char, typename Context>
 void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
              basic_format_args<Context> args) {
-  using iterator = buffer_appender<Char>;
+  using OutputIt = buffer_appender<Char>;
-  auto out = iterator(buf);
+  auto out = OutputIt(buf);
-  auto context = basic_printf_context<Char>(out, args);
+  auto context = basic_printf_context<OutputIt, Char>(out, args);
-  auto parse_ctx = basic_format_parse_context<Char>(format);
+  auto parse_ctx = basic_printf_parse_context<Char>(format);
 
   // Returns the argument with specified index or, if arg_index is -1, the next
   // argument.
@@ -437,24 +387,26 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
   const Char* end = parse_ctx.end();
   auto it = start;
   while (it != end) {
-    if (!find<false, Char>(it, end, '%', it)) {
+    if (!detail::find<false, Char>(it, end, '%', it)) {
-      it = end;  // find leaves it == nullptr if it doesn't find '%'.
+      it = end;  // detail::find leaves it == nullptr if it doesn't find '%'
       break;
     }
     Char c = *it++;
     if (it != end && *it == c) {
-      write(out, basic_string_view<Char>(start, to_unsigned(it - start)));
+      out = detail::write(
+          out, basic_string_view<Char>(start, detail::to_unsigned(it - start)));
       start = ++it;
       continue;
     }
-    write(out, basic_string_view<Char>(start, to_unsigned(it - 1 - start)));
+    out = detail::write(out, basic_string_view<Char>(
+                                 start, detail::to_unsigned(it - 1 - start)));
 
-    auto specs = format_specs<Char>();
+    basic_format_specs<Char> specs;
     specs.align = align::right;
 
     // Parse argument index, flags and width.
     int arg_index = parse_header(it, end, specs, get_arg);
-    if (arg_index == 0) throw_format_error("argument not found");
+    if (arg_index == 0) parse_ctx.on_error("argument not found");
 
     // Parse precision.
     if (it != end && *it == '.') {
@@ -465,7 +417,7 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
       } else if (c == '*') {
         ++it;
         specs.precision = static_cast<int>(
-            visit_format_arg(printf_precision_handler(), get_arg(-1)));
+            visit_format_arg(detail::printf_precision_handler(), get_arg(-1)));
       } else {
         specs.precision = 0;
       }
@@ -474,19 +426,20 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
     auto arg = get_arg(arg_index);
     // For d, i, o, u, x, and X conversion specifiers, if a precision is
     // specified, the '0' flag is ignored
-    if (specs.precision >= 0 && arg.is_integral()) {
+    if (specs.precision >= 0 && arg.is_integral())
-      // Ignore '0' for non-numeric types or if '-' present.
+      specs.fill[0] =
-      specs.fill[0] = ' ';
+          ' ';  // Ignore '0' flag for non-numeric types or if '-' present.
-    }
+    if (specs.precision >= 0 && arg.type() == detail::type::cstring_type) {
-    if (specs.precision >= 0 && arg.type() == type::cstring_type) {
+      auto str = visit_format_arg(detail::get_cstring<Char>(), arg);
-      auto str = visit_format_arg(get_cstring<Char>(), arg);
       auto str_end = str + specs.precision;
       auto nul = std::find(str, str_end, Char());
-      auto sv = basic_string_view<Char>(
+      arg = detail::make_arg<basic_printf_context<OutputIt, Char>>(
-          str, to_unsigned(nul != str_end ? nul - str : specs.precision));
+          basic_string_view<Char>(
-      arg = make_arg<basic_printf_context<Char>>(sv);
+              str, detail::to_unsigned(nul != str_end ? nul - str
+                                                      : specs.precision)));
     }
-    if (specs.alt && visit_format_arg(is_zero_int(), arg)) specs.alt = false;
+    if (specs.alt && visit_format_arg(detail::is_zero_int(), arg))
+      specs.alt = false;
     if (specs.fill[0] == '0') {
       if (arg.is_arithmetic() && specs.align != align::left)
         specs.align = align::numeric;
@@ -498,6 +451,7 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
     // Parse length and convert the argument to the required type.
     c = it != end ? *it++ : 0;
     Char t = it != end ? *it : 0;
+    using detail::convert_arg;
     switch (c) {
     case 'h':
       if (t == 'h') {
@@ -536,7 +490,7 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
     }
 
     // Parse type.
-    if (it == end) throw_format_error("invalid format string");
+    if (it == end) FMT_THROW(format_error("invalid format string"));
     char type = static_cast<char>(*it++);
     if (arg.is_integral()) {
       // Normalize type.
@@ -546,25 +500,32 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
         type = 'd';
         break;
       case 'c':
-        visit_format_arg(char_converter<basic_printf_context<Char>>(arg), arg);
+        visit_format_arg(
+            detail::char_converter<basic_printf_context<OutputIt, Char>>(arg),
+            arg);
         break;
       }
     }
-    specs.type = parse_printf_presentation_type(type, arg.type());
+    specs.type = parse_presentation_type(type);
     if (specs.type == presentation_type::none)
-      throw_format_error("invalid format specifier");
+      parse_ctx.on_error("invalid type specifier");
 
     start = it;
 
     // Format argument.
-    visit_format_arg(printf_arg_formatter<Char>(out, specs, context), arg);
+    out = visit_format_arg(
+        detail::printf_arg_formatter<OutputIt, Char>(out, specs, context), arg);
   }
-  write(out, basic_string_view<Char>(start, to_unsigned(it - start)));
+  detail::write(out, basic_string_view<Char>(start, to_unsigned(it - start)));
 }
-}  // namespace detail
+FMT_END_DETAIL_NAMESPACE
 
-using printf_context = basic_printf_context<char>;
+template <typename Char>
-using wprintf_context = basic_printf_context<wchar_t>;
+using basic_printf_context_t =
+    basic_printf_context<detail::buffer_appender<Char>, Char>;
+
+using printf_context = basic_printf_context_t<char>;
+using wprintf_context = basic_printf_context_t<wchar_t>;
 
 using printf_args = basic_format_args<printf_context>;
 using wprintf_args = basic_format_args<wprintf_context>;
@@ -581,21 +542,26 @@ inline auto make_printf_args(const T&... args)
   return {args...};
 }
 
-// DEPRECATED!
+/**
+  \rst
+  Constructs an `~fmt::format_arg_store` object that contains references to
+  arguments and can be implicitly converted to `~fmt::wprintf_args`.
+  \endrst
+ */
 template <typename... T>
 inline auto make_wprintf_args(const T&... args)
     -> format_arg_store<wprintf_context, T...> {
   return {args...};
 }
 
-template <typename Char>
+template <typename S, typename Char = char_t<S>>
 inline auto vsprintf(
-    basic_string_view<Char> fmt,
+    const S& fmt,
-    basic_format_args<basic_printf_context<type_identity_t<Char>>> args)
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
     -> std::basic_string<Char> {
-  auto buf = basic_memory_buffer<Char>();
+  basic_memory_buffer<Char> buffer;
-  detail::vprintf(buf, fmt, args);
+  vprintf(buffer, detail::to_string_view(fmt), args);
-  return to_string(buf);
+  return to_string(buffer);
 }
 
 /**
@@ -610,19 +576,20 @@ inline auto vsprintf(
 template <typename S, typename... T,
           typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
 inline auto sprintf(const S& fmt, const T&... args) -> std::basic_string<Char> {
+  using context = basic_printf_context_t<Char>;
   return vsprintf(detail::to_string_view(fmt),
-                  fmt::make_format_args<basic_printf_context<Char>>(args...));
+                  fmt::make_format_args<context>(args...));
 }
 
-template <typename Char>
+template <typename S, typename Char = char_t<S>>
 inline auto vfprintf(
-    std::FILE* f, basic_string_view<Char> fmt,
+    std::FILE* f, const S& fmt,
-    basic_format_args<basic_printf_context<type_identity_t<Char>>> args)
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
     -> int {
-  auto buf = basic_memory_buffer<Char>();
+  basic_memory_buffer<Char> buffer;
-  detail::vprintf(buf, fmt, args);
+  vprintf(buffer, detail::to_string_view(fmt), args);
-  size_t size = buf.size();
+  size_t size = buffer.size();
-  return std::fwrite(buf.data(), sizeof(Char), size, f) < size
+  return std::fwrite(buffer.data(), sizeof(Char), size, f) < size
              ? -1
              : static_cast<int>(size);
 }
@@ -638,16 +605,17 @@ inline auto vfprintf(
  */
 template <typename S, typename... T, typename Char = char_t<S>>
 inline auto fprintf(std::FILE* f, const S& fmt, const T&... args) -> int {
+  using context = basic_printf_context_t<Char>;
   return vfprintf(f, detail::to_string_view(fmt),
-                  fmt::make_format_args<basic_printf_context<Char>>(args...));
+                  fmt::make_format_args<context>(args...));
 }
 
-template <typename Char>
+template <typename S, typename Char = char_t<S>>
-FMT_DEPRECATED inline auto vprintf(
+inline auto vprintf(
-    basic_string_view<Char> fmt,
+    const S& fmt,
-    basic_format_args<basic_printf_context<type_identity_t<Char>>> args)
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
     -> int {
-  return vfprintf(stdout, fmt, args);
+  return vfprintf(stdout, detail::to_string_view(fmt), args);
 }
 
 /**
@@ -659,17 +627,14 @@ FMT_DEPRECATED inline auto vprintf(
     fmt::printf("Elapsed time: %.2f seconds", 1.23);
   \endrst
  */
-template <typename... T>
+template <typename S, typename... T, FMT_ENABLE_IF(detail::is_string<S>::value)>
-inline auto printf(string_view fmt, const T&... args) -> int {
+inline auto printf(const S& fmt, const T&... args) -> int {
-  return vfprintf(stdout, fmt, make_printf_args(args...));
+  return vprintf(
-}
+      detail::to_string_view(fmt),
-template <typename... T>
+      fmt::make_format_args<basic_printf_context_t<char_t<S>>>(args...));
-FMT_DEPRECATED inline auto printf(basic_string_view<wchar_t> fmt,
-                                  const T&... args) -> int {
-  return vfprintf(stdout, fmt, make_wprintf_args(args...));
 }
 
-FMT_END_EXPORT
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_PRINTF_H_

include/spdlog/fmt/bundled/ranges.h

@@ -1,9 +1,13 @@
-// Formatting library for C++ - range and tuple support
+// Formatting library for C++ - experimental range support
 //
-// Copyright (c) 2012 - present, Victor Zverovich and {fmt} contributors
+// Copyright (c) 2012 - present, Victor Zverovich
 // All rights reserved.
 //
 // For the license information refer to format.h.
+//
+// Copyright (c) 2018 - present, Remotion (Igor Schulz)
+// All Rights Reserved
+// {fmt} support for ranges, containers and types tuple interface.
 
 #ifndef FMT_RANGES_H_
 #define FMT_RANGES_H_
@@ -18,25 +22,27 @@ FMT_BEGIN_NAMESPACE
 
 namespace detail {
 
-template <typename Range, typename OutputIt>
+template <typename RangeT, typename OutputIterator>
-auto copy(const Range& range, OutputIt out) -> OutputIt {
+OutputIterator copy(const RangeT& range, OutputIterator out) {
   for (auto it = range.begin(), end = range.end(); it != end; ++it)
     *out++ = *it;
   return out;
 }
 
-template <typename OutputIt>
+template <typename OutputIterator>
-auto copy(const char* str, OutputIt out) -> OutputIt {
+OutputIterator copy(const char* str, OutputIterator out) {
   while (*str) *out++ = *str++;
   return out;
 }
 
-template <typename OutputIt> auto copy(char ch, OutputIt out) -> OutputIt {
+template <typename OutputIterator>
+OutputIterator copy(char ch, OutputIterator out) {
   *out++ = ch;
   return out;
 }
 
-template <typename OutputIt> auto copy(wchar_t ch, OutputIt out) -> OutputIt {
+template <typename OutputIterator>
+OutputIterator copy(wchar_t ch, OutputIterator out) {
   *out++ = ch;
   return out;
 }
@@ -63,7 +69,7 @@ template <typename T> class is_map {
   template <typename> static void check(...);
 
  public:
-#ifdef FMT_FORMAT_MAP_AS_LIST  // DEPRECATED!
+#ifdef FMT_FORMAT_MAP_AS_LIST
   static constexpr const bool value = false;
 #else
   static constexpr const bool value =
@@ -76,7 +82,7 @@ template <typename T> class is_set {
   template <typename> static void check(...);
 
  public:
-#ifdef FMT_FORMAT_SET_AS_LIST  // DEPRECATED!
+#ifdef FMT_FORMAT_SET_AS_LIST
   static constexpr const bool value = false;
 #else
   static constexpr const bool value =
@@ -151,9 +157,8 @@ template <typename T>
 struct has_mutable_begin_end<
     T, void_t<decltype(detail::range_begin(std::declval<T>())),
               decltype(detail::range_end(std::declval<T>())),
-              // the extra int here is because older versions of MSVC don't
+              enable_if_t<std::is_copy_constructible<T>::value>>>
-              // SFINAE properly unless there are distinct types
+    : std::true_type {};
-              int>> : std::true_type {};
 
 template <typename T>
 struct is_range_<T, void>
@@ -183,7 +188,7 @@ template <size_t N> using make_index_sequence = std::make_index_sequence<N>;
 template <typename T, T... N> struct integer_sequence {
   using value_type = T;
 
-  static FMT_CONSTEXPR auto size() -> size_t { return sizeof...(N); }
+  static FMT_CONSTEXPR size_t size() { return sizeof...(N); }
 };
 
 template <size_t... N> using index_sequence = integer_sequence<size_t, N...>;
@@ -206,61 +211,41 @@ class is_tuple_formattable_ {
   static constexpr const bool value = false;
 };
 template <typename T, typename C> class is_tuple_formattable_<T, C, true> {
-  template <std::size_t... Is>
+  template <std::size_t... I>
-  static auto check2(index_sequence<Is...>,
+  static std::true_type check2(index_sequence<I...>,
-                     integer_sequence<bool, (Is == Is)...>) -> std::true_type;
+                               integer_sequence<bool, (I == I)...>);
-  static auto check2(...) -> std::false_type;
+  static std::false_type check2(...);
-  template <std::size_t... Is>
+  template <std::size_t... I>
-  static auto check(index_sequence<Is...>) -> decltype(check2(
+  static decltype(check2(
-      index_sequence<Is...>{},
+      index_sequence<I...>{},
-      integer_sequence<bool,
+      integer_sequence<
-                       (is_formattable<typename std::tuple_element<Is, T>::type,
+          bool, (is_formattable<typename std::tuple_element<I, T>::type,
-                                       C>::value)...>{}));
+                                C>::value)...>{})) check(index_sequence<I...>);
 
  public:
   static constexpr const bool value =
       decltype(check(tuple_index_sequence<T>{}))::value;
 };
 
-template <typename Tuple, typename F, size_t... Is>
+template <class Tuple, class F, size_t... Is>
-FMT_CONSTEXPR void for_each(index_sequence<Is...>, Tuple&& t, F&& f) {
+void for_each(index_sequence<Is...>, Tuple&& tup, F&& f) noexcept {
   using std::get;
-  // Using a free function get<Is>(Tuple) now.
+  // using free function get<I>(T) now.
-  const int unused[] = {0, ((void)f(get<Is>(t)), 0)...};
+  const int _[] = {0, ((void)f(get<Is>(tup)), 0)...};
-  ignore_unused(unused);
+  (void)_;  // blocks warnings
 }
 
-template <typename Tuple, typename F>
+template <class T>
-FMT_CONSTEXPR void for_each(Tuple&& t, F&& f) {
+FMT_CONSTEXPR make_index_sequence<std::tuple_size<T>::value> get_indexes(
-  for_each(tuple_index_sequence<remove_cvref_t<Tuple>>(),
+    T const&) {
-           std::forward<Tuple>(t), std::forward<F>(f));
+  return {};
 }
 
-template <typename Tuple1, typename Tuple2, typename F, size_t... Is>
+template <class Tuple, class F> void for_each(Tuple&& tup, F&& f) {
-void for_each2(index_sequence<Is...>, Tuple1&& t1, Tuple2&& t2, F&& f) {
+  const auto indexes = get_indexes(tup);
-  using std::get;
+  for_each(indexes, std::forward<Tuple>(tup), std::forward<F>(f));
-  const int unused[] = {0, ((void)f(get<Is>(t1), get<Is>(t2)), 0)...};
-  ignore_unused(unused);
 }
 
-template <typename Tuple1, typename Tuple2, typename F>
-void for_each2(Tuple1&& t1, Tuple2&& t2, F&& f) {
-  for_each2(tuple_index_sequence<remove_cvref_t<Tuple1>>(),
-            std::forward<Tuple1>(t1), std::forward<Tuple2>(t2),
-            std::forward<F>(f));
-}
-
-namespace tuple {
-// Workaround a bug in MSVC 2019 (v140).
-template <typename Char, typename... T>
-using result_t = std::tuple<formatter<remove_cvref_t<T>, Char>...>;
-
-using std::get;
-template <typename Tuple, typename Char, std::size_t... Is>
-auto get_formatters(index_sequence<Is...>)
-    -> result_t<Char, decltype(get<Is>(std::declval<Tuple>()))...>;
-}  // namespace tuple
-
 #if FMT_MSC_VERSION && FMT_MSC_VERSION < 1920
 // Older MSVC doesn't get the reference type correctly for arrays.
 template <typename R> struct range_reference_type_impl {
@@ -284,37 +269,45 @@ using range_reference_type =
 template <typename Range>
 using uncvref_type = remove_cvref_t<range_reference_type<Range>>;
 
-template <typename Formatter>
+template <typename Range>
-FMT_CONSTEXPR auto maybe_set_debug_format(Formatter& f, bool set)
+using uncvref_first_type =
-    -> decltype(f.set_debug_format(set)) {
+    remove_cvref_t<decltype(std::declval<range_reference_type<Range>>().first)>;
-  f.set_debug_format(set);
-}
-template <typename Formatter>
-FMT_CONSTEXPR void maybe_set_debug_format(Formatter&, ...) {}
 
-// These are not generic lambdas for compatibility with C++11.
+template <typename Range>
-template <typename ParseContext> struct parse_empty_specs {
+using uncvref_second_type = remove_cvref_t<
-  template <typename Formatter> FMT_CONSTEXPR void operator()(Formatter& f) {
+    decltype(std::declval<range_reference_type<Range>>().second)>;
-    f.parse(ctx);
-    detail::maybe_set_debug_format(f, true);
-  }
-  ParseContext& ctx;
-};
-template <typename FormatContext> struct format_tuple_element {
-  using char_type = typename FormatContext::char_type;
 
-  template <typename T>
+template <typename OutputIt> OutputIt write_delimiter(OutputIt out) {
-  void operator()(const formatter<T, char_type>& f, const T& v) {
+  *out++ = ',';
-    if (i > 0)
+  *out++ = ' ';
-      ctx.advance_to(detail::copy_str<char_type>(separator, ctx.out()));
+  return out;
-    ctx.advance_to(f.format(v, ctx));
-    ++i;
 }
 
-  int i;
+template <typename Char, typename OutputIt>
-  FormatContext& ctx;
+auto write_range_entry(OutputIt out, basic_string_view<Char> str) -> OutputIt {
-  basic_string_view<char_type> separator;
+  return write_escaped_string(out, str);
-};
+}
+
+template <typename Char, typename OutputIt, typename T,
+          FMT_ENABLE_IF(std::is_convertible<T, std_string_view<char>>::value)>
+inline auto write_range_entry(OutputIt out, const T& str) -> OutputIt {
+  auto sv = std_string_view<Char>(str);
+  return write_range_entry<Char>(out, basic_string_view<Char>(sv));
+}
+
+template <typename Char, typename OutputIt, typename Arg,
+          FMT_ENABLE_IF(std::is_same<Arg, Char>::value)>
+OutputIt write_range_entry(OutputIt out, const Arg v) {
+  return write_escaped_char(out, v);
+}
+
+template <
+    typename Char, typename OutputIt, typename Arg,
+    FMT_ENABLE_IF(!is_std_string_like<typename std::decay<Arg>::type>::value &&
+                  !std::is_same<Arg, Char>::value)>
+OutputIt write_range_entry(OutputIt out, const Arg& v) {
+  return write<Char>(out, v);
+}
 
 }  // namespace detail
 
@@ -328,20 +321,29 @@ template <typename T, typename C> struct is_tuple_formattable {
       detail::is_tuple_formattable_<T, C>::value;
 };
 
-template <typename Tuple, typename Char>
+template <typename TupleT, typename Char>
-struct formatter<Tuple, Char,
+struct formatter<TupleT, Char,
-                 enable_if_t<fmt::is_tuple_like<Tuple>::value &&
+                 enable_if_t<fmt::is_tuple_like<TupleT>::value &&
-                             fmt::is_tuple_formattable<Tuple, Char>::value>> {
+                             fmt::is_tuple_formattable<TupleT, Char>::value>> {
  private:
-  decltype(detail::tuple::get_formatters<Tuple, Char>(
-      detail::tuple_index_sequence<Tuple>())) formatters_;
-
   basic_string_view<Char> separator_ = detail::string_literal<Char, ',', ' '>{};
   basic_string_view<Char> opening_bracket_ =
       detail::string_literal<Char, '('>{};
   basic_string_view<Char> closing_bracket_ =
       detail::string_literal<Char, ')'>{};
 
+  // C++11 generic lambda for format().
+  template <typename FormatContext> struct format_each {
+    template <typename T> void operator()(const T& v) {
+      if (i > 0) out = detail::copy_str<Char>(separator, out);
+      out = detail::write_range_entry<Char>(out, v);
+      ++i;
+    }
+    int i;
+    typename FormatContext::iterator& out;
+    basic_string_view<Char> separator;
+  };
+
  public:
   FMT_CONSTEXPR formatter() {}
 
@@ -357,21 +359,17 @@ struct formatter<Tuple, Char,
 
   template <typename ParseContext>
   FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
-    auto it = ctx.begin();
+    return ctx.begin();
-    if (it != ctx.end() && *it != '}')
-      FMT_THROW(format_error("invalid format specifier"));
-    detail::for_each(formatters_, detail::parse_empty_specs<ParseContext>{ctx});
-    return it;
   }
 
-  template <typename FormatContext>
+  template <typename FormatContext = format_context>
-  auto format(const Tuple& value, FormatContext& ctx) const
+  auto format(const TupleT& values, FormatContext& ctx) const
       -> decltype(ctx.out()) {
-    ctx.advance_to(detail::copy_str<Char>(opening_bracket_, ctx.out()));
+    auto out = ctx.out();
-    detail::for_each2(
+    out = detail::copy_str<Char>(opening_bracket_, out);
-        formatters_, value,
+    detail::for_each(values, format_each<FormatContext>{0, out, separator_});
-        detail::format_tuple_element<FormatContext>{0, ctx, separator_});
+    out = detail::copy_str<Char>(closing_bracket_, out);
-    return detail::copy_str<Char>(closing_bracket_, ctx.out());
+    return out;
   }
 };
 
@@ -400,10 +398,12 @@ template <typename Context> struct range_mapper {
 };
 
 template <typename Char, typename Element>
-using range_formatter_type =
+using range_formatter_type = conditional_t<
+    is_formattable<Element, Char>::value,
     formatter<remove_cvref_t<decltype(range_mapper<buffer_context<Char>>{}.map(
                   std::declval<Element>()))>,
-              Char>;
+              Char>,
+    fallback_formatter<Element, Char>>;
 
 template <typename R>
 using maybe_const_range =
@@ -413,15 +413,12 @@ using maybe_const_range =
 #if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1910
 template <typename R, typename Char>
 struct is_formattable_delayed
-    : is_formattable<uncvref_type<maybe_const_range<R>>, Char> {};
+    : disjunction<
+          is_formattable<uncvref_type<maybe_const_range<R>>, Char>,
+          has_fallback_formatter<uncvref_type<maybe_const_range<R>>, Char>> {};
 #endif
-}  // namespace detail
 
-template <typename...> struct conjunction : std::true_type {};
+}  // namespace detail
-template <typename P> struct conjunction<P> : P {};
-template <typename P1, typename... Pn>
-struct conjunction<P1, Pn...>
-    : conditional_t<bool(P1::value), conjunction<Pn...>, P1> {};
 
 template <typename T, typename Char, typename Enable = void>
 struct range_formatter;
@@ -429,16 +426,32 @@ struct range_formatter;
 template <typename T, typename Char>
 struct range_formatter<
     T, Char,
-    enable_if_t<conjunction<std::is_same<T, remove_cvref_t<T>>,
+    enable_if_t<conjunction<
-                            is_formattable<T, Char>>::value>> {
+        std::is_same<T, remove_cvref_t<T>>,
+        disjunction<is_formattable<T, Char>,
+                    detail::has_fallback_formatter<T, Char>>>::value>> {
  private:
   detail::range_formatter_type<Char, T> underlying_;
+  bool custom_specs_ = false;
   basic_string_view<Char> separator_ = detail::string_literal<Char, ',', ' '>{};
   basic_string_view<Char> opening_bracket_ =
       detail::string_literal<Char, '['>{};
   basic_string_view<Char> closing_bracket_ =
       detail::string_literal<Char, ']'>{};
 
+  template <class U>
+  FMT_CONSTEXPR static auto maybe_set_debug_format(U& u, int)
+      -> decltype(u.set_debug_format()) {
+    u.set_debug_format();
+  }
+
+  template <class U>
+  FMT_CONSTEXPR static void maybe_set_debug_format(U&, ...) {}
+
+  FMT_CONSTEXPR void maybe_set_debug_format() {
+    maybe_set_debug_format(underlying_, 0);
+  }
+
  public:
   FMT_CONSTEXPR range_formatter() {}
 
@@ -460,24 +473,31 @@ struct range_formatter<
   FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
     auto it = ctx.begin();
     auto end = ctx.end();
+    if (it == end || *it == '}') {
+      maybe_set_debug_format();
+      return it;
+    }
 
-    if (it != end && *it == 'n') {
+    if (*it == 'n') {
       set_brackets({}, {});
       ++it;
     }
 
-    if (it != end && *it != '}') {
+    if (*it == '}') {
-      if (*it != ':') FMT_THROW(format_error("invalid format specifier"));
+      maybe_set_debug_format();
-      ++it;
+      return it;
-    } else {
-      detail::maybe_set_debug_format(underlying_, true);
     }
 
+    if (*it != ':')
+      FMT_THROW(format_error("no other top-level range formatters supported"));
+
+    custom_specs_ = true;
+    ++it;
     ctx.advance_to(it);
     return underlying_.parse(ctx);
   }
 
-  template <typename R, typename FormatContext>
+  template <typename R, class FormatContext>
   auto format(R&& range, FormatContext& ctx) const -> decltype(ctx.out()) {
     detail::range_mapper<buffer_context<Char>> mapper;
     auto out = ctx.out();
@@ -487,9 +507,9 @@ struct range_formatter<
     auto end = detail::range_end(range);
     for (; it != end; ++it) {
       if (i > 0) out = detail::copy_str<Char>(separator_, out);
+      ;
       ctx.advance_to(out);
-      auto&& item = *it;
+      out = underlying_.format(mapper.map(*it), ctx);
-      out = underlying_.format(mapper.map(item), ctx);
       ++i;
     }
     out = detail::copy_str<Char>(closing_bracket_, out);
@@ -500,14 +520,13 @@ struct range_formatter<
 enum class range_format { disabled, map, set, sequence, string, debug_string };
 
 namespace detail {
-template <typename T>
+template <typename T> struct range_format_kind_ {
-struct range_format_kind_
+  static constexpr auto value = std::is_same<range_reference_type<T>, T>::value
-    : std::integral_constant<range_format,
-                             std::is_same<uncvref_type<T>, T>::value
                                     ? range_format::disabled
                                 : is_map<T>::value ? range_format::map
                                 : is_set<T>::value ? range_format::set
-                                                : range_format::sequence> {};
+                                                   : range_format::sequence;
+};
 
 template <range_format K, typename R, typename Char, typename Enable = void>
 struct range_default_formatter;
@@ -582,6 +601,9 @@ template <typename Char, typename... T> struct tuple_join_view : detail::view {
       : tuple(t), sep{s} {}
 };
 
+template <typename Char, typename... T>
+using tuple_arg_join = tuple_join_view<Char, T...>;
+
 // Define FMT_TUPLE_JOIN_SPECIFIERS to enable experimental format specifiers
 // support in tuple_join. It is disabled by default because of issues with
 // the dynamic width and precision.
@@ -651,45 +673,7 @@ struct formatter<tuple_join_view<Char, T...>, Char> {
   }
 };
 
-namespace detail {
+FMT_MODULE_EXPORT_BEGIN
-// Check if T has an interface like a container adaptor (e.g. std::stack,
-// std::queue, std::priority_queue).
-template <typename T> class is_container_adaptor_like {
-  template <typename U> static auto check(U* p) -> typename U::container_type;
-  template <typename> static void check(...);
-
- public:
-  static constexpr const bool value =
-      !std::is_void<decltype(check<T>(nullptr))>::value;
-};
-
-template <typename Container> struct all {
-  const Container& c;
-  auto begin() const -> typename Container::const_iterator { return c.begin(); }
-  auto end() const -> typename Container::const_iterator { return c.end(); }
-};
-}  // namespace detail
-
-template <typename T, typename Char>
-struct formatter<
-    T, Char,
-    enable_if_t<conjunction<detail::is_container_adaptor_like<T>,
-                            bool_constant<range_format_kind<T, Char>::value ==
-                                          range_format::disabled>>::value>>
-    : formatter<detail::all<typename T::container_type>, Char> {
-  using all = detail::all<typename T::container_type>;
-  template <typename FormatContext>
-  auto format(const T& t, FormatContext& ctx) const -> decltype(ctx.out()) {
-    struct getter : T {
-      static auto get(const T& t) -> all {
-        return {t.*(&getter::c)};  // Access c through the derived class.
-      }
-    };
-    return formatter<all>::format(getter::get(t), ctx);
-  }
-};
-
-FMT_BEGIN_EXPORT
 
 /**
   \rst
@@ -732,7 +716,7 @@ auto join(std::initializer_list<T> list, string_view sep)
   return join(std::begin(list), std::end(list), sep);
 }
 
-FMT_END_EXPORT
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_RANGES_H_

include/spdlog/fmt/bundled/std.h

@@ -8,18 +8,10 @@
 #ifndef FMT_STD_H_
 #define FMT_STD_H_
 
-#include <atomic>
-#include <bitset>
-#include <cstdlib>
-#include <exception>
-#include <memory>
 #include <thread>
 #include <type_traits>
-#include <typeinfo>
 #include <utility>
-#include <vector>
 
-#include "format.h"
 #include "ostream.h"
 
 #if FMT_HAS_INCLUDE(<version>)
@@ -33,258 +25,94 @@
 #  if FMT_HAS_INCLUDE(<variant>)
 #    include <variant>
 #  endif
-#  if FMT_HAS_INCLUDE(<optional>)
-#    include <optional>
-#  endif
 #endif
 
-#if FMT_CPLUSPLUS > 201703L && FMT_HAS_INCLUDE(<source_location>)
-#  include <source_location>
-#endif
-
-// GCC 4 does not support FMT_HAS_INCLUDE.
-#if FMT_HAS_INCLUDE(<cxxabi.h>) || defined(__GLIBCXX__)
-#  include <cxxabi.h>
-// Android NDK with gabi++ library on some architectures does not implement
-// abi::__cxa_demangle().
-#  ifndef __GABIXX_CXXABI_H__
-#    define FMT_HAS_ABI_CXA_DEMANGLE
-#  endif
-#endif
-
-// Check if typeid is available.
-#ifndef FMT_USE_TYPEID
-// __RTTI is for EDG compilers. In MSVC typeid is available without RTTI.
-#  if defined(__GXX_RTTI) || FMT_HAS_FEATURE(cxx_rtti) || FMT_MSC_VERSION || \
-      defined(__INTEL_RTTI__) || defined(__RTTI)
-#    define FMT_USE_TYPEID 1
-#  else
-#    define FMT_USE_TYPEID 0
-#  endif
-#endif
-
-// For older Xcode versions, __cpp_lib_xxx flags are inaccurately defined.
-#ifndef FMT_CPP_LIB_FILESYSTEM
 #ifdef __cpp_lib_filesystem
-#    define FMT_CPP_LIB_FILESYSTEM __cpp_lib_filesystem
-#  else
-#    define FMT_CPP_LIB_FILESYSTEM 0
-#  endif
-#endif
-
-#ifndef FMT_CPP_LIB_VARIANT
-#  ifdef __cpp_lib_variant
-#    define FMT_CPP_LIB_VARIANT __cpp_lib_variant
-#  else
-#    define FMT_CPP_LIB_VARIANT 0
-#  endif
-#endif
-
-#if FMT_CPP_LIB_FILESYSTEM
 FMT_BEGIN_NAMESPACE
 
 namespace detail {
 
-template <typename Char, typename PathChar>
+template <typename Char>
-auto get_path_string(const std::filesystem::path& p,
-                     const std::basic_string<PathChar>& native) {
-  if constexpr (std::is_same_v<Char, char> && std::is_same_v<PathChar, wchar_t>)
-    return to_utf8<wchar_t>(native, to_utf8_error_policy::replace);
-  else
-    return p.string<Char>();
-}
-
-template <typename Char, typename PathChar>
 void write_escaped_path(basic_memory_buffer<Char>& quoted,
-                        const std::filesystem::path& p,
+                        const std::filesystem::path& p) {
-                        const std::basic_string<PathChar>& native) {
-  if constexpr (std::is_same_v<Char, char> &&
-                std::is_same_v<PathChar, wchar_t>) {
-    auto buf = basic_memory_buffer<wchar_t>();
-    write_escaped_string<wchar_t>(std::back_inserter(buf), native);
-    bool valid = to_utf8<wchar_t>::convert(quoted, {buf.data(), buf.size()});
-    FMT_ASSERT(valid, "invalid utf16");
-  } else if constexpr (std::is_same_v<Char, PathChar>) {
-    write_escaped_string<std::filesystem::path::value_type>(
-        std::back_inserter(quoted), native);
-  } else {
   write_escaped_string<Char>(std::back_inserter(quoted), p.string<Char>());
 }
+#  ifdef _WIN32
+template <>
+inline void write_escaped_path<char>(basic_memory_buffer<char>& quoted,
+                                     const std::filesystem::path& p) {
+  auto s = p.u8string();
+  write_escaped_string<char>(
+      std::back_inserter(quoted),
+      string_view(reinterpret_cast<const char*>(s.c_str()), s.size()));
+}
+#  endif
+template <>
+inline void write_escaped_path<std::filesystem::path::value_type>(
+    basic_memory_buffer<std::filesystem::path::value_type>& quoted,
+    const std::filesystem::path& p) {
+  write_escaped_string<std::filesystem::path::value_type>(
+      std::back_inserter(quoted), p.native());
 }
 
 }  // namespace detail
 
-FMT_EXPORT
+template <typename Char>
-template <typename Char> struct formatter<std::filesystem::path, Char> {
+struct formatter<std::filesystem::path, Char>
- private:
+    : formatter<basic_string_view<Char>> {
-  format_specs<Char> specs_;
-  detail::arg_ref<Char> width_ref_;
-  bool debug_ = false;
-  char path_type_ = 0;
-
- public:
-  FMT_CONSTEXPR void set_debug_format(bool set = true) { debug_ = set; }
-
-  template <typename ParseContext> FMT_CONSTEXPR auto parse(ParseContext& ctx) {
-    auto it = ctx.begin(), end = ctx.end();
-    if (it == end) return it;
-
-    it = detail::parse_align(it, end, specs_);
-    if (it == end) return it;
-
-    it = detail::parse_dynamic_spec(it, end, specs_.width, width_ref_, ctx);
-    if (it != end && *it == '?') {
-      debug_ = true;
-      ++it;
-    }
-    if (it != end && (*it == 'g')) path_type_ = *it++;
-    return it;
-  }
-
   template <typename FormatContext>
-  auto format(const std::filesystem::path& p, FormatContext& ctx) const {
+  auto format(const std::filesystem::path& p, FormatContext& ctx) const ->
-    auto specs = specs_;
+      typename FormatContext::iterator {
-#  ifdef _WIN32
+    basic_memory_buffer<Char> quoted;
-    auto path_string = !path_type_ ? p.native() : p.generic_wstring();
+    detail::write_escaped_path(quoted, p);
-#  else
+    return formatter<basic_string_view<Char>>::format(
-    auto path_string = !path_type_ ? p.native() : p.generic_string();
+        basic_string_view<Char>(quoted.data(), quoted.size()), ctx);
-#  endif
-
-    detail::handle_dynamic_spec<detail::width_checker>(specs.width, width_ref_,
-                                                       ctx);
-    if (!debug_) {
-      auto s = detail::get_path_string<Char>(p, path_string);
-      return detail::write(ctx.out(), basic_string_view<Char>(s), specs);
-    }
-    auto quoted = basic_memory_buffer<Char>();
-    detail::write_escaped_path(quoted, p, path_string);
-    return detail::write(ctx.out(),
-                         basic_string_view<Char>(quoted.data(), quoted.size()),
-                         specs);
   }
 };
 FMT_END_NAMESPACE
-#endif  // FMT_CPP_LIB_FILESYSTEM
+#endif
 
 FMT_BEGIN_NAMESPACE
-FMT_EXPORT
-template <std::size_t N, typename Char>
-struct formatter<std::bitset<N>, Char> : nested_formatter<string_view> {
- private:
-  // Functor because C++11 doesn't support generic lambdas.
-  struct writer {
-    const std::bitset<N>& bs;
-
-    template <typename OutputIt>
-    FMT_CONSTEXPR auto operator()(OutputIt out) -> OutputIt {
-      for (auto pos = N; pos > 0; --pos) {
-        out = detail::write<Char>(out, bs[pos - 1] ? Char('1') : Char('0'));
-      }
-
-      return out;
-    }
-  };
-
- public:
-  template <typename FormatContext>
-  auto format(const std::bitset<N>& bs, FormatContext& ctx) const
-      -> decltype(ctx.out()) {
-    return write_padded(ctx, writer{bs});
-  }
-};
-
-FMT_EXPORT
 template <typename Char>
 struct formatter<std::thread::id, Char> : basic_ostream_formatter<Char> {};
 FMT_END_NAMESPACE
 
-#ifdef __cpp_lib_optional
+#ifdef __cpp_lib_variant
 FMT_BEGIN_NAMESPACE
-FMT_EXPORT
+template <typename Char> struct formatter<std::monostate, Char> {
-template <typename T, typename Char>
+  template <typename ParseContext>
-struct formatter<std::optional<T>, Char,
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
-                 std::enable_if_t<is_formattable<T, Char>::value>> {
- private:
-  formatter<T, Char> underlying_;
-  static constexpr basic_string_view<Char> optional =
-      detail::string_literal<Char, 'o', 'p', 't', 'i', 'o', 'n', 'a', 'l',
-                             '('>{};
-  static constexpr basic_string_view<Char> none =
-      detail::string_literal<Char, 'n', 'o', 'n', 'e'>{};
-
-  template <class U>
-  FMT_CONSTEXPR static auto maybe_set_debug_format(U& u, bool set)
-      -> decltype(u.set_debug_format(set)) {
-    u.set_debug_format(set);
-  }
-
-  template <class U>
-  FMT_CONSTEXPR static void maybe_set_debug_format(U&, ...) {}
-
- public:
-  template <typename ParseContext> FMT_CONSTEXPR auto parse(ParseContext& ctx) {
-    maybe_set_debug_format(underlying_, true);
-    return underlying_.parse(ctx);
-  }
-
-  template <typename FormatContext>
-  auto format(const std::optional<T>& opt, FormatContext& ctx) const
-      -> decltype(ctx.out()) {
-    if (!opt) return detail::write<Char>(ctx.out(), none);
-
-    auto out = ctx.out();
-    out = detail::write<Char>(out, optional);
-    ctx.advance_to(out);
-    out = underlying_.format(*opt, ctx);
-    return detail::write(out, ')');
-  }
-};
-FMT_END_NAMESPACE
-#endif  // __cpp_lib_optional
-
-#ifdef __cpp_lib_source_location
-FMT_BEGIN_NAMESPACE
-FMT_EXPORT
-template <> struct formatter<std::source_location> {
-  template <typename ParseContext> FMT_CONSTEXPR auto parse(ParseContext& ctx) {
     return ctx.begin();
   }
 
   template <typename FormatContext>
-  auto format(const std::source_location& loc, FormatContext& ctx) const
+  auto format(const std::monostate&, FormatContext& ctx) const
       -> decltype(ctx.out()) {
     auto out = ctx.out();
-    out = detail::write(out, loc.file_name());
+    out = detail::write<Char>(out, "monostate");
-    out = detail::write(out, ':');
-    out = detail::write<char>(out, loc.line());
-    out = detail::write(out, ':');
-    out = detail::write<char>(out, loc.column());
-    out = detail::write(out, ": ");
-    out = detail::write(out, loc.function_name());
     return out;
   }
 };
-FMT_END_NAMESPACE
-#endif
 
-#if FMT_CPP_LIB_VARIANT
-FMT_BEGIN_NAMESPACE
 namespace detail {
 
 template <typename T>
 using variant_index_sequence =
     std::make_index_sequence<std::variant_size<T>::value>;
 
-template <typename> struct is_variant_like_ : std::false_type {};
+// variant_size and variant_alternative check.
-template <typename... Types>
+template <typename T, typename U = void>
-struct is_variant_like_<std::variant<Types...>> : std::true_type {};
+struct is_variant_like_ : std::false_type {};
+template <typename T>
+struct is_variant_like_<T, std::void_t<decltype(std::variant_size<T>::value)>>
+    : std::true_type {};
 
-// formattable element check.
+// formattable element check
 template <typename T, typename C> class is_variant_formattable_ {
-  template <std::size_t... Is>
+  template <std::size_t... I>
   static std::conjunction<
-      is_formattable<std::variant_alternative_t<Is, T>, C>...>
+      is_formattable<std::variant_alternative_t<I, T>, C>...>
-      check(std::index_sequence<Is...>);
+      check(std::index_sequence<I...>);
 
  public:
   static constexpr const bool value =
@@ -312,21 +140,6 @@ template <typename T, typename C> struct is_variant_formattable {
       detail::is_variant_formattable_<T, C>::value;
 };
 
-FMT_EXPORT
-template <typename Char> struct formatter<std::monostate, Char> {
-  template <typename ParseContext>
-  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
-    return ctx.begin();
-  }
-
-  template <typename FormatContext>
-  auto format(const std::monostate&, FormatContext& ctx) const
-      -> decltype(ctx.out()) {
-    return detail::write<Char>(ctx.out(), "monostate");
-  }
-};
-
-FMT_EXPORT
 template <typename Variant, typename Char>
 struct formatter<
     Variant, Char,
@@ -343,195 +156,16 @@ struct formatter<
     auto out = ctx.out();
 
     out = detail::write<Char>(out, "variant(");
-    FMT_TRY {
     std::visit(
         [&](const auto& v) {
           out = detail::write_variant_alternative<Char>(out, v);
         },
         value);
-    }
-    FMT_CATCH(const std::bad_variant_access&) {
-      detail::write<Char>(out, "valueless by exception");
-    }
     *out++ = ')';
     return out;
   }
 };
 FMT_END_NAMESPACE
-#endif  // FMT_CPP_LIB_VARIANT
-
-FMT_BEGIN_NAMESPACE
-FMT_EXPORT
-template <typename Char> struct formatter<std::error_code, Char> {
-  template <typename ParseContext>
-  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
-    return ctx.begin();
-  }
-
-  template <typename FormatContext>
-  FMT_CONSTEXPR auto format(const std::error_code& ec, FormatContext& ctx) const
-      -> decltype(ctx.out()) {
-    auto out = ctx.out();
-    out = detail::write_bytes(out, ec.category().name(), format_specs<Char>());
-    out = detail::write<Char>(out, Char(':'));
-    out = detail::write<Char>(out, ec.value());
-    return out;
-  }
-};
-
-FMT_EXPORT
-template <typename T, typename Char>
-struct formatter<
-    T, Char,  // DEPRECATED! Mixing code unit types.
-    typename std::enable_if<std::is_base_of<std::exception, T>::value>::type> {
- private:
-  bool with_typename_ = false;
-
- public:
-  FMT_CONSTEXPR auto parse(basic_format_parse_context<Char>& ctx)
-      -> decltype(ctx.begin()) {
-    auto it = ctx.begin();
-    auto end = ctx.end();
-    if (it == end || *it == '}') return it;
-    if (*it == 't') {
-      ++it;
-      with_typename_ = FMT_USE_TYPEID != 0;
-    }
-    return it;
-  }
-
-  template <typename OutputIt>
-  auto format(const std::exception& ex,
-              basic_format_context<OutputIt, Char>& ctx) const -> OutputIt {
-    format_specs<Char> spec;
-    auto out = ctx.out();
-    if (!with_typename_)
-      return detail::write_bytes(out, string_view(ex.what()), spec);
-
-#if FMT_USE_TYPEID
-    const std::type_info& ti = typeid(ex);
-#  ifdef FMT_HAS_ABI_CXA_DEMANGLE
-    int status = 0;
-    std::size_t size = 0;
-    std::unique_ptr<char, void (*)(void*)> demangled_name_ptr(
-        abi::__cxa_demangle(ti.name(), nullptr, &size, &status), &std::free);
-
-    string_view demangled_name_view;
-    if (demangled_name_ptr) {
-      demangled_name_view = demangled_name_ptr.get();
-
-      // Normalization of stdlib inline namespace names.
-      // libc++ inline namespaces.
-      //  std::__1::*       -> std::*
-      //  std::__1::__fs::* -> std::*
-      // libstdc++ inline namespaces.
-      //  std::__cxx11::*             -> std::*
-      //  std::filesystem::__cxx11::* -> std::filesystem::*
-      if (demangled_name_view.starts_with("std::")) {
-        char* begin = demangled_name_ptr.get();
-        char* to = begin + 5;  // std::
-        for (char *from = to, *end = begin + demangled_name_view.size();
-             from < end;) {
-          // This is safe, because demangled_name is NUL-terminated.
-          if (from[0] == '_' && from[1] == '_') {
-            char* next = from + 1;
-            while (next < end && *next != ':') next++;
-            if (next[0] == ':' && next[1] == ':') {
-              from = next + 2;
-              continue;
-            }
-          }
-          *to++ = *from++;
-        }
-        demangled_name_view = {begin, detail::to_unsigned(to - begin)};
-      }
-    } else {
-      demangled_name_view = string_view(ti.name());
-    }
-    out = detail::write_bytes(out, demangled_name_view, spec);
-#  elif FMT_MSC_VERSION
-    string_view demangled_name_view(ti.name());
-    if (demangled_name_view.starts_with("class "))
-      demangled_name_view.remove_prefix(6);
-    else if (demangled_name_view.starts_with("struct "))
-      demangled_name_view.remove_prefix(7);
-    out = detail::write_bytes(out, demangled_name_view, spec);
-#  else
-    out = detail::write_bytes(out, string_view(ti.name()), spec);
-#  endif
-    *out++ = ':';
-    *out++ = ' ';
-    return detail::write_bytes(out, string_view(ex.what()), spec);
-#endif
-  }
-};
-
-namespace detail {
-
-template <typename T, typename Enable = void>
-struct has_flip : std::false_type {};
-
-template <typename T>
-struct has_flip<T, void_t<decltype(std::declval<T>().flip())>>
-    : std::true_type {};
-
-template <typename T> struct is_bit_reference_like {
-  static constexpr const bool value =
-      std::is_convertible<T, bool>::value &&
-      std::is_nothrow_assignable<T, bool>::value && has_flip<T>::value;
-};
-
-#ifdef _LIBCPP_VERSION
-
-// Workaround for libc++ incompatibility with C++ standard.
-// According to the Standard, `bitset::operator[] const` returns bool.
-template <typename C>
-struct is_bit_reference_like<std::__bit_const_reference<C>> {
-  static constexpr const bool value = true;
-};
-
 #endif
 
-}  // namespace detail
-
-// We can't use std::vector<bool, Allocator>::reference and
-// std::bitset<N>::reference because the compiler can't deduce Allocator and N
-// in partial specialization.
-FMT_EXPORT
-template <typename BitRef, typename Char>
-struct formatter<BitRef, Char,
-                 enable_if_t<detail::is_bit_reference_like<BitRef>::value>>
-    : formatter<bool, Char> {
-  template <typename FormatContext>
-  FMT_CONSTEXPR auto format(const BitRef& v, FormatContext& ctx) const
-      -> decltype(ctx.out()) {
-    return formatter<bool, Char>::format(v, ctx);
-  }
-};
-
-FMT_EXPORT
-template <typename T, typename Char>
-struct formatter<std::atomic<T>, Char,
-                 enable_if_t<is_formattable<T, Char>::value>>
-    : formatter<T, Char> {
-  template <typename FormatContext>
-  auto format(const std::atomic<T>& v, FormatContext& ctx) const
-      -> decltype(ctx.out()) {
-    return formatter<T, Char>::format(v.load(), ctx);
-  }
-};
-
-#ifdef __cpp_lib_atomic_flag_test
-FMT_EXPORT
-template <typename Char>
-struct formatter<std::atomic_flag, Char> : formatter<bool, Char> {
-  template <typename FormatContext>
-  auto format(const std::atomic_flag& v, FormatContext& ctx) const
-      -> decltype(ctx.out()) {
-    return formatter<bool, Char>::format(v.test(), ctx);
-  }
-};
-#endif  // __cpp_lib_atomic_flag_test
-
-FMT_END_NAMESPACE
 #endif  // FMT_STD_H_

include/spdlog/fmt/bundled/xchar.h

@@ -12,32 +12,13 @@
 
 #include "format.h"
 
-#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
-#  include <locale>
-#endif
-
 FMT_BEGIN_NAMESPACE
 namespace detail {
-
 template <typename T>
 using is_exotic_char = bool_constant<!std::is_same<T, char>::value>;
-
-inline auto write_loc(std::back_insert_iterator<detail::buffer<wchar_t>> out,
-                      loc_value value, const format_specs<wchar_t>& specs,
-                      locale_ref loc) -> bool {
-#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
-  auto& numpunct =
-      std::use_facet<std::numpunct<wchar_t>>(loc.get<std::locale>());
-  auto separator = std::wstring();
-  auto grouping = numpunct.grouping();
-  if (!grouping.empty()) separator = std::wstring(1, numpunct.thousands_sep());
-  return value.visit(loc_writer<wchar_t>{out, specs, separator, grouping, {}});
-#endif
-  return false;
 }
-}  // namespace detail
 
-FMT_BEGIN_EXPORT
+FMT_MODULE_EXPORT_BEGIN
 
 using wstring_view = basic_string_view<wchar_t>;
 using wformat_parse_context = basic_format_parse_context<wchar_t>;
@@ -52,9 +33,7 @@ inline auto runtime(wstring_view s) -> wstring_view { return s; }
 #else
 template <typename... Args>
 using wformat_string = basic_format_string<wchar_t, type_identity_t<Args>...>;
-inline auto runtime(wstring_view s) -> runtime_format_string<wchar_t> {
+inline auto runtime(wstring_view s) -> basic_runtime<wchar_t> { return {{s}}; }
-  return {{s}};
-}
 #endif
 
 template <> struct is_char<wchar_t> : std::true_type {};
@@ -62,16 +41,15 @@ template <> struct is_char<detail::char8_type> : std::true_type {};
 template <> struct is_char<char16_t> : std::true_type {};
 template <> struct is_char<char32_t> : std::true_type {};
 
-template <typename... T>
+template <typename... Args>
-constexpr auto make_wformat_args(const T&... args)
+constexpr format_arg_store<wformat_context, Args...> make_wformat_args(
-    -> format_arg_store<wformat_context, T...> {
+    const Args&... args) {
   return {args...};
 }
 
 inline namespace literals {
 #if FMT_USE_USER_DEFINED_LITERALS && !FMT_USE_NONTYPE_TEMPLATE_ARGS
-constexpr auto operator""_a(const wchar_t* s, size_t)
+constexpr detail::udl_arg<wchar_t> operator"" _a(const wchar_t* s, size_t) {
-    -> detail::udl_arg<wchar_t> {
   return {s};
 }
 #endif
@@ -100,9 +78,9 @@ template <typename Char, FMT_ENABLE_IF(!std::is_same<Char, char>::value)>
 auto vformat(basic_string_view<Char> format_str,
              basic_format_args<buffer_context<type_identity_t<Char>>> args)
     -> std::basic_string<Char> {
-  auto buf = basic_memory_buffer<Char>();
+  basic_memory_buffer<Char> buffer;
-  detail::vformat_to(buf, format_str, args);
+  detail::vformat_to(buffer, format_str, args);
-  return to_string(buf);
+  return to_string(buffer);
 }
 
 template <typename... T>
@@ -112,10 +90,10 @@ auto format(wformat_string<T...> fmt, T&&... args) -> std::wstring {
 
 // Pass char_t as a default template parameter instead of using
 // std::basic_string<char_t<S>> to reduce the symbol size.
-template <typename S, typename... T, typename Char = char_t<S>,
+template <typename S, typename... Args, typename Char = char_t<S>,
           FMT_ENABLE_IF(!std::is_same<Char, char>::value &&
                         !std::is_same<Char, wchar_t>::value)>
-auto format(const S& format_str, T&&... args) -> std::basic_string<Char> {
+auto format(const S& format_str, Args&&... args) -> std::basic_string<Char> {
   return vformat(detail::to_string_view(format_str),
                  fmt::make_format_args<buffer_context<Char>>(args...));
 }
@@ -130,10 +108,11 @@ inline auto vformat(
   return detail::vformat(loc, detail::to_string_view(format_str), args);
 }
 
-template <typename Locale, typename S, typename... T, typename Char = char_t<S>,
+template <typename Locale, typename S, typename... Args,
+          typename Char = char_t<S>,
           FMT_ENABLE_IF(detail::is_locale<Locale>::value&&
                             detail::is_exotic_char<Char>::value)>
-inline auto format(const Locale& loc, const S& format_str, T&&... args)
+inline auto format(const Locale& loc, const S& format_str, Args&&... args)
     -> std::basic_string<Char> {
   return detail::vformat(loc, detail::to_string_view(format_str),
                          fmt::make_format_args<buffer_context<Char>>(args...));
@@ -147,14 +126,14 @@ auto vformat_to(OutputIt out, const S& format_str,
     -> OutputIt {
   auto&& buf = detail::get_buffer<Char>(out);
   detail::vformat_to(buf, detail::to_string_view(format_str), args);
-  return detail::get_iterator(buf, out);
+  return detail::get_iterator(buf);
 }
 
-template <typename OutputIt, typename S, typename... T,
+template <typename OutputIt, typename S, typename... Args,
           typename Char = char_t<S>,
           FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
                             detail::is_exotic_char<Char>::value)>
-inline auto format_to(OutputIt out, const S& fmt, T&&... args) -> OutputIt {
+inline auto format_to(OutputIt out, const S& fmt, Args&&... args) -> OutputIt {
   return vformat_to(out, detail::to_string_view(fmt),
                     fmt::make_format_args<buffer_context<Char>>(args...));
 }
@@ -170,18 +149,18 @@ inline auto vformat_to(
   auto&& buf = detail::get_buffer<Char>(out);
   vformat_to(buf, detail::to_string_view(format_str), args,
              detail::locale_ref(loc));
-  return detail::get_iterator(buf, out);
+  return detail::get_iterator(buf);
 }
 
-template <typename OutputIt, typename Locale, typename S, typename... T,
+template <
+    typename OutputIt, typename Locale, typename S, typename... Args,
     typename Char = char_t<S>,
     bool enable = detail::is_output_iterator<OutputIt, Char>::value&&
-                        detail::is_locale<Locale>::value &&
+        detail::is_locale<Locale>::value&& detail::is_exotic_char<Char>::value>
-                        detail::is_exotic_char<Char>::value>
 inline auto format_to(OutputIt out, const Locale& loc, const S& format_str,
-                      T&&... args) ->
+                      Args&&... args) ->
     typename std::enable_if<enable, OutputIt>::type {
-  return vformat_to(out, loc, detail::to_string_view(format_str),
+  return vformat_to(out, loc, to_string_view(format_str),
                     fmt::make_format_args<buffer_context<Char>>(args...));
 }
 
@@ -192,36 +171,36 @@ inline auto vformat_to_n(
     OutputIt out, size_t n, basic_string_view<Char> format_str,
     basic_format_args<buffer_context<type_identity_t<Char>>> args)
     -> format_to_n_result<OutputIt> {
-  using traits = detail::fixed_buffer_traits;
+  detail::iterator_buffer<OutputIt, Char, detail::fixed_buffer_traits> buf(out,
-  auto buf = detail::iterator_buffer<OutputIt, Char, traits>(out, n);
+                                                                           n);
   detail::vformat_to(buf, format_str, args);
   return {buf.out(), buf.count()};
 }
 
-template <typename OutputIt, typename S, typename... T,
+template <typename OutputIt, typename S, typename... Args,
           typename Char = char_t<S>,
           FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
                             detail::is_exotic_char<Char>::value)>
-inline auto format_to_n(OutputIt out, size_t n, const S& fmt, T&&... args)
+inline auto format_to_n(OutputIt out, size_t n, const S& fmt,
-    -> format_to_n_result<OutputIt> {
+                        const Args&... args) -> format_to_n_result<OutputIt> {
   return vformat_to_n(out, n, detail::to_string_view(fmt),
                       fmt::make_format_args<buffer_context<Char>>(args...));
 }
 
-template <typename S, typename... T, typename Char = char_t<S>,
+template <typename S, typename... Args, typename Char = char_t<S>,
           FMT_ENABLE_IF(detail::is_exotic_char<Char>::value)>
-inline auto formatted_size(const S& fmt, T&&... args) -> size_t {
+inline auto formatted_size(const S& fmt, Args&&... args) -> size_t {
-  auto buf = detail::counting_buffer<Char>();
+  detail::counting_buffer<Char> buf;
   detail::vformat_to(buf, detail::to_string_view(fmt),
                      fmt::make_format_args<buffer_context<Char>>(args...));
   return buf.count();
 }
 
 inline void vprint(std::FILE* f, wstring_view fmt, wformat_args args) {
-  auto buf = wmemory_buffer();
+  wmemory_buffer buffer;
-  detail::vformat_to(buf, fmt, args);
+  detail::vformat_to(buffer, fmt, args);
-  buf.push_back(L'\0');
+  buffer.push_back(L'\0');
-  if (std::fputws(buf.data(), f) == -1)
+  if (std::fputws(buffer.data(), f) == -1)
     FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
 }
 
@@ -238,22 +217,13 @@ template <typename... T> void print(wformat_string<T...> fmt, T&&... args) {
   return vprint(wstring_view(fmt), fmt::make_wformat_args(args...));
 }
 
-template <typename... T>
-void println(std::FILE* f, wformat_string<T...> fmt, T&&... args) {
-  return print(f, L"{}\n", fmt::format(fmt, std::forward<T>(args)...));
-}
-
-template <typename... T> void println(wformat_string<T...> fmt, T&&... args) {
-  return print(L"{}\n", fmt::format(fmt, std::forward<T>(args)...));
-}
-
 /**
   Converts *value* to ``std::wstring`` using the default format for type *T*.
  */
 template <typename T> inline auto to_wstring(const T& value) -> std::wstring {
   return format(FMT_STRING(L"{}"), value);
 }
-FMT_END_EXPORT
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_XCHAR_H_

src/bundled_fmtlib_format.cpp

@@ -28,9 +28,12 @@ template FMT_API auto decimal_point_impl(locale_ref) -> char;
 
 template FMT_API void buffer<char>::append(const char *, const char *);
 
+// DEPRECATED!
+// There is no correspondent extern template in format.h because of
+// incompatibility between clang and gcc (#2377).
 template FMT_API void vformat_to(buffer<char> &,
                                  string_view,
-                                 typename vformat_args<>::type,
+                                 basic_format_args<FMT_BUFFER_CONTEXT(char)>,
                                  locale_ref);
 
 // Explicit instantiations for wchar_t.