Update bundled fmt to 11.0.2 (#3236)

include/spdlog/fmt/bundled/args.h

@@ -8,11 +8,13 @@
 #ifndef FMT_ARGS_H_
 #define FMT_ARGS_H_
 
-#include <functional>  // std::reference_wrapper
+#ifndef FMT_MODULE
-#include <memory>      // std::unique_ptr
+#  include <functional>  // std::reference_wrapper
-#include <vector>
+#  include <memory>      // std::unique_ptr
+#  include <vector>
+#endif
 
-#include "core.h"
+#include "format.h"  // std_string_view
 
 FMT_BEGIN_NAMESPACE
 
@@ -28,15 +30,18 @@ auto unwrap(const std::reference_wrapper<T>& v) -> const T& {
   return static_cast<const T&>(v);
 }
 
-class dynamic_arg_list {
+// node is defined outside dynamic_arg_list to workaround a C2504 bug in MSVC
-  // Workaround for clang's -Wweak-vtables. Unlike for regular classes, for
+// 2022 (v17.10.0).
-  // templates it doesn't complain about inability to deduce single translation
+//
-  // unit for placing vtable. So storage_node_base is made a fake template.
+// Workaround for clang's -Wweak-vtables. Unlike for regular classes, for
-  template <typename = void> struct node {
+// templates it doesn't complain about inability to deduce single translation
+// unit for placing vtable. So node is made a fake template.
+template <typename = void> struct node {
   virtual ~node() = default;
   std::unique_ptr<node<>> next;
-  };
+};
 
+class dynamic_arg_list {
   template <typename T> struct typed_node : node<> {
     T value;
 
@@ -62,14 +67,10 @@ class dynamic_arg_list {
 }  // namespace detail
 
 /**
-  \rst
+ * A dynamic list of formatting arguments with storage.
-  A dynamic version of `fmt::format_arg_store`.
+ *
-  It's equipped with a storage to potentially temporary objects which lifetimes
+ * It can be implicitly converted into `fmt::basic_format_args` for passing
-  could be shorter than the format arguments object.
+ * into type-erased formatting functions such as `fmt::vformat`.
-
-  It can be implicitly converted into `~fmt::basic_format_args` for passing
-  into type-erased formatting functions such as `~fmt::vformat`.
-  \endrst
  */
 template <typename Context>
 class dynamic_format_arg_store
@@ -147,21 +148,19 @@ class dynamic_format_arg_store
   constexpr dynamic_format_arg_store() = default;
 
   /**
-    \rst
+   * Adds an argument into the dynamic store for later passing to a formatting
-    Adds an argument into the dynamic store for later passing to a formatting
+   * function.
-    function.
+   *
-
+   * Note that custom types and string types (but not string views) are copied
-    Note that custom types and string types (but not string views) are copied
+   * into the store dynamically allocating memory if necessary.
-    into the store dynamically allocating memory if necessary.
+   *
-
+   * **Example**:
-    **Example**::
+   *
-
+   *     fmt::dynamic_format_arg_store<fmt::format_context> store;
-      fmt::dynamic_format_arg_store<fmt::format_context> store;
+   *     store.push_back(42);
-      store.push_back(42);
+   *     store.push_back("abc");
-      store.push_back("abc");
+   *     store.push_back(1.5f);
-      store.push_back(1.5f);
+   *     std::string result = fmt::vformat("{} and {} and {}", store);
-      std::string result = fmt::vformat("{} and {} and {}", store);
-    \endrst
    */
   template <typename T> void push_back(const T& arg) {
     if (detail::const_check(need_copy<T>::value))
@@ -171,19 +170,17 @@ class dynamic_format_arg_store
   }
 
   /**
-    \rst
+   * Adds a reference to the argument into the dynamic store for later passing
-    Adds a reference to the argument into the dynamic store for later passing to
+   * to a formatting function.
-    a formatting function.
+   *
-
+   * **Example**:
-    **Example**::
+   *
-
+   *     fmt::dynamic_format_arg_store<fmt::format_context> store;
-      fmt::dynamic_format_arg_store<fmt::format_context> store;
+   *     char band[] = "Rolling Stones";
-      char band[] = "Rolling Stones";
+   *     store.push_back(std::cref(band));
-      store.push_back(std::cref(band));
+   *     band[9] = 'c'; // Changing str affects the output.
-      band[9] = 'c'; // Changing str affects the output.
+   *     std::string result = fmt::vformat("{}", store);
-      std::string result = fmt::vformat("{}", store);
+   *     // result == "Rolling Scones"
-      // result == "Rolling Scones"
-    \endrst
    */
   template <typename T> void push_back(std::reference_wrapper<T> arg) {
     static_assert(
@@ -193,9 +190,9 @@ class dynamic_format_arg_store
   }
 
   /**
-    Adds named argument into the dynamic store for later passing to a formatting
+   * Adds named argument into the dynamic store for later passing to a
-    function. ``std::reference_wrapper`` is supported to avoid copying of the
+   * formatting function. `std::reference_wrapper` is supported to avoid
-    argument. The name is always copied into the store.
+   * copying of the argument. The name is always copied into the store.
    */
   template <typename T>
   void push_back(const detail::named_arg<char_type, T>& arg) {
@@ -209,19 +206,15 @@ class dynamic_format_arg_store
     }
   }
 
-  /** Erase all elements from the store */
+  /// Erase all elements from the store.
   void clear() {
     data_.clear();
     named_info_.clear();
     dynamic_args_ = detail::dynamic_arg_list();
   }
 
-  /**
+  /// Reserves space to store at least `new_cap` arguments including
-    \rst
+  /// `new_cap_named` named arguments.
-    Reserves space to store at least *new_cap* arguments including
-    *new_cap_named* named arguments.
-    \endrst
-  */
   void reserve(size_t new_cap, size_t new_cap_named) {
     FMT_ASSERT(new_cap >= new_cap_named,
                "Set of arguments includes set of named arguments");

include/spdlog/fmt/bundled/chrono.h

@@ -8,17 +8,19 @@
 #ifndef FMT_CHRONO_H_
 #define FMT_CHRONO_H_
 
-#include <algorithm>
+#ifndef FMT_MODULE
-#include <chrono>
+#  include <algorithm>
-#include <cmath>    // std::isfinite
+#  include <chrono>
-#include <cstring>  // std::memcpy
+#  include <cmath>    // std::isfinite
-#include <ctime>
+#  include <cstring>  // std::memcpy
-#include <iterator>
+#  include <ctime>
-#include <locale>
+#  include <iterator>
-#include <ostream>
+#  include <locale>
-#include <type_traits>
+#  include <ostream>
+#  include <type_traits>
+#endif
 
-#include "ostream.h"  // formatbuf
+#include "format.h"
 
 FMT_BEGIN_NAMESPACE
 
@@ -94,10 +96,8 @@ FMT_CONSTEXPR auto lossless_integral_conversion(const From from, int& ec)
   return static_cast<To>(from);
 }
 
-/**
+/// Converts From to To, without loss. If the dynamic value of from
- * converts From to To, without loss. If the dynamic value of from
+/// can't be converted to To without loss, ec is set.
- * can't be converted to To without loss, ec is set.
- */
 template <typename To, typename From,
           FMT_ENABLE_IF(!std::is_same<From, To>::value &&
                         std::numeric_limits<From>::is_signed !=
@@ -185,9 +185,7 @@ FMT_CONSTEXPR auto safe_float_conversion(const From from, int& ec) -> To {
   return from;
 }
 
-/**
+/// Safe duration cast between integral durations
- * safe duration cast between integral durations
- */
 template <typename To, typename FromRep, typename FromPeriod,
           FMT_ENABLE_IF(std::is_integral<FromRep>::value),
           FMT_ENABLE_IF(std::is_integral<typename To::rep>::value)>
@@ -237,9 +235,7 @@ auto safe_duration_cast(std::chrono::duration<FromRep, FromPeriod> from,
   return ec ? To() : To(tocount);
 }
 
-/**
+/// Safe duration_cast between floating point durations
- * safe duration_cast between floating point durations
- */
 template <typename To, typename FromRep, typename FromPeriod,
           FMT_ENABLE_IF(std::is_floating_point<FromRep>::value),
           FMT_ENABLE_IF(std::is_floating_point<typename To::rep>::value)>
@@ -329,6 +325,39 @@ inline auto localtime_s(...) -> null<> { return null<>(); }
 inline auto gmtime_r(...) -> null<> { return null<>(); }
 inline auto gmtime_s(...) -> null<> { return null<>(); }
 
+// It is defined here and not in ostream.h because the latter has expensive
+// includes.
+template <typename Streambuf> class formatbuf : public Streambuf {
+ private:
+  using char_type = typename Streambuf::char_type;
+  using streamsize = decltype(std::declval<Streambuf>().sputn(nullptr, 0));
+  using int_type = typename Streambuf::int_type;
+  using traits_type = typename Streambuf::traits_type;
+
+  buffer<char_type>& buffer_;
+
+ public:
+  explicit formatbuf(buffer<char_type>& buf) : buffer_(buf) {}
+
+ protected:
+  // 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;
+  }
+};
+
 inline auto get_classic_locale() -> const std::locale& {
   static const auto& locale = std::locale::classic();
   return locale;
@@ -362,11 +391,12 @@ void write_codecvt(codecvt_result<CodeUnit>& out, string_view in_buf,
 template <typename OutputIt>
 auto write_encoded_tm_str(OutputIt out, string_view in, const std::locale& loc)
     -> OutputIt {
-  if (detail::is_utf8() && loc != get_classic_locale()) {
+  if (detail::use_utf8() && loc != get_classic_locale()) {
     // char16_t and char32_t codecvts are broken in MSVC (linkage errors) and
     // gcc-4.
 #if FMT_MSC_VERSION != 0 ||  \
-    (defined(__GLIBCXX__) && !defined(_GLIBCXX_USE_DUAL_ABI))
+    (defined(__GLIBCXX__) && \
+     (!defined(_GLIBCXX_USE_DUAL_ABI) || _GLIBCXX_USE_DUAL_ABI == 0))
     // The _GLIBCXX_USE_DUAL_ABI macro is always defined in libstdc++ from gcc-5
     // and newer.
     using code_unit = wchar_t;
@@ -382,9 +412,9 @@ auto write_encoded_tm_str(OutputIt out, string_view in, const std::locale& loc)
         to_utf8<code_unit, basic_memory_buffer<char, unit_t::max_size * 4>>();
     if (!u.convert({unit.buf, to_unsigned(unit.end - unit.buf)}))
       FMT_THROW(format_error("failed to format time"));
-    return copy_str<char>(u.c_str(), u.c_str() + u.size(), out);
+    return copy<char>(u.c_str(), u.c_str() + u.size(), out);
   }
-  return copy_str<char>(in.data(), in.data() + in.size(), out);
+  return copy<char>(in.data(), in.data() + in.size(), out);
 }
 
 template <typename Char, typename OutputIt,
@@ -393,7 +423,7 @@ auto write_tm_str(OutputIt out, string_view sv, const std::locale& loc)
     -> OutputIt {
   codecvt_result<Char> unit;
   write_codecvt(unit, sv, loc);
-  return copy_str<Char>(unit.buf, unit.end, out);
+  return copy<Char>(unit.buf, unit.end, out);
 }
 
 template <typename Char, typename OutputIt,
@@ -482,9 +512,9 @@ auto to_time_t(
 FMT_BEGIN_EXPORT
 
 /**
-  Converts given time since epoch as ``std::time_t`` value into calendar time,
+ * Converts given time since epoch as `std::time_t` value into calendar time,
-  expressed in local time. Unlike ``std::localtime``, this function is
+ * expressed in local time. Unlike `std::localtime`, this function is
-  thread-safe on most platforms.
+ * thread-safe on most platforms.
  */
 inline auto localtime(std::time_t time) -> std::tm {
   struct dispatcher {
@@ -531,9 +561,9 @@ inline auto localtime(std::chrono::local_time<Duration> time) -> std::tm {
 #endif
 
 /**
-  Converts given time since epoch as ``std::time_t`` value into calendar time,
+ * Converts given time since epoch as `std::time_t` value into calendar time,
-  expressed in Coordinated Universal Time (UTC). Unlike ``std::gmtime``, this
+ * expressed in Coordinated Universal Time (UTC). Unlike `std::gmtime`, this
-  function is thread-safe on most platforms.
+ * function is thread-safe on most platforms.
  */
 inline auto gmtime(std::time_t time) -> std::tm {
   struct dispatcher {
@@ -646,12 +676,10 @@ enum class numeric_system {
 
 // Glibc extensions for formatting numeric values.
 enum class pad_type {
-  unspecified,
+  // Pad a numeric result string with zeros (the default).
+  zero,
   // Do not pad a numeric result string.
   none,
-  // Pad a numeric result string with zeros even if the conversion specifier
-  // character uses space-padding by default.
-  zero,
   // Pad a numeric result string with spaces.
   space,
 };
@@ -659,7 +687,7 @@ enum class pad_type {
 template <typename OutputIt>
 auto write_padding(OutputIt out, pad_type pad, int width) -> OutputIt {
   if (pad == pad_type::none) return out;
-  return std::fill_n(out, width, pad == pad_type::space ? ' ' : '0');
+  return detail::fill_n(out, width, pad == pad_type::space ? ' ' : '0');
 }
 
 template <typename OutputIt>
@@ -675,8 +703,8 @@ FMT_CONSTEXPR auto parse_chrono_format(const Char* begin, const Char* end,
   if (begin == end || *begin == '}') return begin;
   if (*begin != '%') FMT_THROW(format_error("invalid format"));
   auto ptr = begin;
-  pad_type pad = pad_type::unspecified;
   while (ptr != end) {
+    pad_type pad = pad_type::zero;
     auto c = *ptr;
     if (c == '}') break;
     if (c != '%') {
@@ -696,10 +724,6 @@ FMT_CONSTEXPR auto parse_chrono_format(const Char* begin, const Char* end,
       pad = pad_type::none;
       ++ptr;
       break;
-    case '0':
-      pad = pad_type::zero;
-      ++ptr;
-      break;
     }
     if (ptr == end) FMT_THROW(format_error("invalid format"));
     c = *ptr++;
@@ -759,22 +783,22 @@ FMT_CONSTEXPR auto parse_chrono_format(const Char* begin, const Char* end,
       break;
     // Day of the year/month:
     case 'U':
-      handler.on_dec0_week_of_year(numeric_system::standard);
+      handler.on_dec0_week_of_year(numeric_system::standard, pad);
       break;
     case 'W':
-      handler.on_dec1_week_of_year(numeric_system::standard);
+      handler.on_dec1_week_of_year(numeric_system::standard, pad);
       break;
     case 'V':
-      handler.on_iso_week_of_year(numeric_system::standard);
+      handler.on_iso_week_of_year(numeric_system::standard, pad);
       break;
     case 'j':
       handler.on_day_of_year();
       break;
     case 'd':
-      handler.on_day_of_month(numeric_system::standard);
+      handler.on_day_of_month(numeric_system::standard, pad);
       break;
     case 'e':
-      handler.on_day_of_month_space(numeric_system::standard);
+      handler.on_day_of_month(numeric_system::standard, pad_type::space);
       break;
     // Hour, minute, second:
     case 'H':
@@ -871,19 +895,19 @@ FMT_CONSTEXPR auto parse_chrono_format(const Char* begin, const Char* end,
         handler.on_dec_month(numeric_system::alternative);
         break;
       case 'U':
-        handler.on_dec0_week_of_year(numeric_system::alternative);
+        handler.on_dec0_week_of_year(numeric_system::alternative, pad);
         break;
       case 'W':
-        handler.on_dec1_week_of_year(numeric_system::alternative);
+        handler.on_dec1_week_of_year(numeric_system::alternative, pad);
         break;
       case 'V':
-        handler.on_iso_week_of_year(numeric_system::alternative);
+        handler.on_iso_week_of_year(numeric_system::alternative, pad);
         break;
       case 'd':
-        handler.on_day_of_month(numeric_system::alternative);
+        handler.on_day_of_month(numeric_system::alternative, pad);
         break;
       case 'e':
-        handler.on_day_of_month_space(numeric_system::alternative);
+        handler.on_day_of_month(numeric_system::alternative, pad_type::space);
         break;
       case 'w':
         handler.on_dec0_weekday(numeric_system::alternative);
@@ -936,12 +960,19 @@ template <typename Derived> struct null_chrono_spec_handler {
   FMT_CONSTEXPR void on_abbr_month() { unsupported(); }
   FMT_CONSTEXPR void on_full_month() { unsupported(); }
   FMT_CONSTEXPR void on_dec_month(numeric_system) { unsupported(); }
-  FMT_CONSTEXPR void on_dec0_week_of_year(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_dec0_week_of_year(numeric_system, pad_type) {
-  FMT_CONSTEXPR void on_dec1_week_of_year(numeric_system) { unsupported(); }
+    unsupported();
-  FMT_CONSTEXPR void on_iso_week_of_year(numeric_system) { unsupported(); }
+  }
+  FMT_CONSTEXPR void on_dec1_week_of_year(numeric_system, pad_type) {
+    unsupported();
+  }
+  FMT_CONSTEXPR void on_iso_week_of_year(numeric_system, pad_type) {
+    unsupported();
+  }
   FMT_CONSTEXPR void on_day_of_year() { unsupported(); }
-  FMT_CONSTEXPR void on_day_of_month(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_day_of_month(numeric_system, pad_type) {
-  FMT_CONSTEXPR void on_day_of_month_space(numeric_system) { unsupported(); }
+    unsupported();
+  }
   FMT_CONSTEXPR void on_24_hour(numeric_system) { unsupported(); }
   FMT_CONSTEXPR void on_12_hour(numeric_system) { unsupported(); }
   FMT_CONSTEXPR void on_minute(numeric_system) { unsupported(); }
@@ -979,12 +1010,11 @@ struct tm_format_checker : null_chrono_spec_handler<tm_format_checker> {
   FMT_CONSTEXPR void on_abbr_month() {}
   FMT_CONSTEXPR void on_full_month() {}
   FMT_CONSTEXPR void on_dec_month(numeric_system) {}
-  FMT_CONSTEXPR void on_dec0_week_of_year(numeric_system) {}
+  FMT_CONSTEXPR void on_dec0_week_of_year(numeric_system, pad_type) {}
-  FMT_CONSTEXPR void on_dec1_week_of_year(numeric_system) {}
+  FMT_CONSTEXPR void on_dec1_week_of_year(numeric_system, pad_type) {}
-  FMT_CONSTEXPR void on_iso_week_of_year(numeric_system) {}
+  FMT_CONSTEXPR void on_iso_week_of_year(numeric_system, pad_type) {}
   FMT_CONSTEXPR void on_day_of_year() {}
-  FMT_CONSTEXPR void on_day_of_month(numeric_system) {}
+  FMT_CONSTEXPR void on_day_of_month(numeric_system, pad_type) {}
-  FMT_CONSTEXPR void on_day_of_month_space(numeric_system) {}
   FMT_CONSTEXPR void on_24_hour(numeric_system, pad_type) {}
   FMT_CONSTEXPR void on_12_hour(numeric_system, pad_type) {}
   FMT_CONSTEXPR void on_minute(numeric_system, pad_type) {}
@@ -1061,9 +1091,10 @@ inline auto to_nonnegative_int(T value, Int upper) -> Int {
 }
 template <typename T, typename Int, FMT_ENABLE_IF(!std::is_integral<T>::value)>
 inline auto to_nonnegative_int(T value, Int upper) -> Int {
-  if (value < 0 || value > static_cast<T>(upper))
+  auto int_value = static_cast<Int>(value);
+  if (int_value < 0 || value > static_cast<T>(upper))
     FMT_THROW(format_error("invalid value"));
-  return static_cast<Int>(value);
+  return int_value;
 }
 
 constexpr auto pow10(std::uint32_t n) -> long long {
@@ -1115,22 +1146,27 @@ void write_fractional_seconds(OutputIt& out, Duration d, int precision = -1) {
     if (std::ratio_less<typename subsecond_precision::period,
                         std::chrono::seconds::period>::value) {
       *out++ = '.';
-      out = std::fill_n(out, leading_zeroes, '0');
+      out = detail::fill_n(out, leading_zeroes, '0');
       out = format_decimal<Char>(out, n, num_digits).end;
     }
-  } else {
+  } else if (precision > 0) {
     *out++ = '.';
     leading_zeroes = (std::min)(leading_zeroes, precision);
-    out = std::fill_n(out, leading_zeroes, '0');
     int remaining = precision - leading_zeroes;
-    if (remaining != 0 && remaining < num_digits) {
+    out = detail::fill_n(out, leading_zeroes, '0');
-      n /= to_unsigned(detail::pow10(to_unsigned(num_digits - remaining)));
+    if (remaining < num_digits) {
+      int num_truncated_digits = num_digits - remaining;
+      n /= to_unsigned(detail::pow10(to_unsigned(num_truncated_digits)));
+      if (n) {
         out = format_decimal<Char>(out, n, remaining).end;
+      }
       return;
     }
+    if (n) {
       out = format_decimal<Char>(out, n, num_digits).end;
       remaining -= num_digits;
-    out = std::fill_n(out, remaining, '0');
+    }
+    out = detail::fill_n(out, remaining, '0');
   }
 }
 
@@ -1281,7 +1317,8 @@ class tm_writer {
     }
     uint32_or_64_or_128_t<long long> n = to_unsigned(year);
     const int num_digits = count_digits(n);
-    if (width > num_digits) out_ = std::fill_n(out_, width - num_digits, '0');
+    if (width > num_digits)
+      out_ = detail::fill_n(out_, width - num_digits, '0');
     out_ = format_decimal<Char>(out_, n, num_digits).end;
   }
   void write_year(long long year) {
@@ -1364,7 +1401,7 @@ class tm_writer {
   auto out() const -> OutputIt { return out_; }
 
   FMT_CONSTEXPR void on_text(const Char* begin, const Char* end) {
-    out_ = copy_str<Char>(begin, end, out_);
+    out_ = copy<Char>(begin, end, out_);
   }
 
   void on_abbr_weekday() {
@@ -1411,7 +1448,7 @@ class tm_writer {
       *out_++ = ' ';
       on_abbr_month();
       *out_++ = ' ';
-      on_day_of_month_space(numeric_system::standard);
+      on_day_of_month(numeric_system::standard, pad_type::space);
       *out_++ = ' ';
       on_iso_time();
       *out_++ = ' ';
@@ -1437,7 +1474,7 @@ class tm_writer {
     write_digit2_separated(buf, to_unsigned(tm_mon() + 1),
                            to_unsigned(tm_mday()),
                            to_unsigned(split_year_lower(tm_year())), '/');
-    out_ = copy_str<Char>(std::begin(buf), std::end(buf), out_);
+    out_ = copy<Char>(std::begin(buf), std::end(buf), out_);
   }
   void on_iso_date() {
     auto year = tm_year();
@@ -1453,7 +1490,7 @@ class tm_writer {
     write_digit2_separated(buf + 2, static_cast<unsigned>(year % 100),
                            to_unsigned(tm_mon() + 1), to_unsigned(tm_mday()),
                            '-');
-    out_ = copy_str<Char>(std::begin(buf) + offset, std::end(buf), out_);
+    out_ = copy<Char>(std::begin(buf) + offset, std::end(buf), out_);
   }
 
   void on_utc_offset(numeric_system ns) { format_utc_offset_impl(tm_, ns); }
@@ -1498,24 +1535,26 @@ class tm_writer {
     format_localized('m', 'O');
   }
 
-  void on_dec0_week_of_year(numeric_system ns) {
+  void on_dec0_week_of_year(numeric_system ns, pad_type pad) {
     if (is_classic_ || ns == numeric_system::standard)
-      return write2((tm_yday() + days_per_week - tm_wday()) / days_per_week);
+      return write2((tm_yday() + days_per_week - tm_wday()) / days_per_week,
+                    pad);
     format_localized('U', 'O');
   }
-  void on_dec1_week_of_year(numeric_system ns) {
+  void on_dec1_week_of_year(numeric_system ns, pad_type pad) {
     if (is_classic_ || ns == numeric_system::standard) {
       auto wday = tm_wday();
       write2((tm_yday() + days_per_week -
               (wday == 0 ? (days_per_week - 1) : (wday - 1))) /
-             days_per_week);
+                 days_per_week,
+             pad);
     } else {
       format_localized('W', 'O');
     }
   }
-  void on_iso_week_of_year(numeric_system ns) {
+  void on_iso_week_of_year(numeric_system ns, pad_type pad) {
     if (is_classic_ || ns == numeric_system::standard)
-      return write2(tm_iso_week_of_year());
+      return write2(tm_iso_week_of_year(), pad);
     format_localized('V', 'O');
   }
 
@@ -1529,20 +1568,11 @@ class tm_writer {
     write1(yday / 100);
     write2(yday % 100);
   }
-  void on_day_of_month(numeric_system ns) {
+  void on_day_of_month(numeric_system ns, pad_type pad) {
-    if (is_classic_ || ns == numeric_system::standard) return write2(tm_mday());
+    if (is_classic_ || ns == numeric_system::standard)
+      return write2(tm_mday(), pad);
     format_localized('d', 'O');
   }
-  void on_day_of_month_space(numeric_system ns) {
-    if (is_classic_ || ns == numeric_system::standard) {
-      auto mday = to_unsigned(tm_mday()) % 100;
-      const char* d2 = digits2(mday);
-      *out_++ = mday < 10 ? ' ' : d2[0];
-      *out_++ = d2[1];
-    } else {
-      format_localized('e', 'O');
-    }
-  }
 
   void on_24_hour(numeric_system ns, pad_type pad) {
     if (is_classic_ || ns == numeric_system::standard)
@@ -1586,7 +1616,7 @@ class tm_writer {
       char buf[8];
       write_digit2_separated(buf, to_unsigned(tm_hour12()),
                              to_unsigned(tm_min()), to_unsigned(tm_sec()), ':');
-      out_ = copy_str<Char>(std::begin(buf), std::end(buf), out_);
+      out_ = copy<Char>(std::begin(buf), std::end(buf), out_);
       *out_++ = ' ';
       on_am_pm();
     } else {
@@ -1601,7 +1631,7 @@ class tm_writer {
   void on_iso_time() {
     on_24_hour_time();
     *out_++ = ':';
-    on_second(numeric_system::standard, pad_type::unspecified);
+    on_second(numeric_system::standard, pad_type::zero);
   }
 
   void on_am_pm() {
@@ -1700,10 +1730,10 @@ auto format_duration_value(OutputIt out, Rep val, int) -> OutputIt {
 template <typename Char, typename Rep, typename OutputIt,
           FMT_ENABLE_IF(std::is_floating_point<Rep>::value)>
 auto format_duration_value(OutputIt out, Rep val, int precision) -> OutputIt {
-  auto specs = format_specs<Char>();
+  auto specs = format_specs();
   specs.precision = precision;
-  specs.type = precision >= 0 ? presentation_type::fixed_lower
+  specs.type =
-                              : presentation_type::general_lower;
+      precision >= 0 ? presentation_type::fixed : presentation_type::general;
   return write<Char>(out, val, specs);
 }
 
@@ -1744,8 +1774,10 @@ class get_locale {
 
  public:
   get_locale(bool localized, locale_ref loc) : has_locale_(localized) {
+#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
     if (localized)
       ::new (&locale_) std::locale(loc.template get<std::locale>());
+#endif
   }
   ~get_locale() {
     if (has_locale_) locale_.~locale();
@@ -1840,7 +1872,7 @@ struct chrono_formatter {
     }
   }
 
-  void write(Rep value, int width, pad_type pad = pad_type::unspecified) {
+  void write(Rep value, int width, pad_type pad = pad_type::zero) {
     write_sign();
     if (isnan(value)) return write_nan();
     uint32_or_64_or_128_t<int> n =
@@ -1890,11 +1922,10 @@ struct chrono_formatter {
   void on_iso_week_based_year() {}
   void on_iso_week_based_short_year() {}
   void on_dec_month(numeric_system) {}
-  void on_dec0_week_of_year(numeric_system) {}
+  void on_dec0_week_of_year(numeric_system, pad_type) {}
-  void on_dec1_week_of_year(numeric_system) {}
+  void on_dec1_week_of_year(numeric_system, pad_type) {}
-  void on_iso_week_of_year(numeric_system) {}
+  void on_iso_week_of_year(numeric_system, pad_type) {}
-  void on_day_of_month(numeric_system) {}
+  void on_day_of_month(numeric_system, pad_type) {}
-  void on_day_of_month_space(numeric_system) {}
 
   void on_day_of_year() {
     if (handle_nan_inf()) return;
@@ -1974,7 +2005,7 @@ struct chrono_formatter {
     on_24_hour_time();
     *out++ = ':';
     if (handle_nan_inf()) return;
-    on_second(numeric_system::standard, pad_type::unspecified);
+    on_second(numeric_system::standard, pad_type::zero);
   }
 
   void on_am_pm() {
@@ -1997,53 +2028,215 @@ struct chrono_formatter {
 
 #if defined(__cpp_lib_chrono) && __cpp_lib_chrono >= 201907
 using weekday = std::chrono::weekday;
+using day = std::chrono::day;
+using month = std::chrono::month;
+using year = std::chrono::year;
+using year_month_day = std::chrono::year_month_day;
 #else
 // A fallback version of weekday.
 class weekday {
  private:
-  unsigned char value;
+  unsigned char value_;
 
  public:
   weekday() = default;
-  explicit constexpr weekday(unsigned wd) noexcept
+  constexpr explicit weekday(unsigned wd) noexcept
-      : value(static_cast<unsigned char>(wd != 7 ? wd : 0)) {}
+      : value_(static_cast<unsigned char>(wd != 7 ? wd : 0)) {}
-  constexpr auto c_encoding() const noexcept -> unsigned { return value; }
+  constexpr auto c_encoding() const noexcept -> unsigned { return value_; }
 };
 
-class year_month_day {};
+class day {
+ private:
+  unsigned char value_;
+
+ public:
+  day() = default;
+  constexpr explicit day(unsigned d) noexcept
+      : value_(static_cast<unsigned char>(d)) {}
+  constexpr explicit operator unsigned() const noexcept { return value_; }
+};
+
+class month {
+ private:
+  unsigned char value_;
+
+ public:
+  month() = default;
+  constexpr explicit month(unsigned m) noexcept
+      : value_(static_cast<unsigned char>(m)) {}
+  constexpr explicit operator unsigned() const noexcept { return value_; }
+};
+
+class year {
+ private:
+  int value_;
+
+ public:
+  year() = default;
+  constexpr explicit year(int y) noexcept : value_(y) {}
+  constexpr explicit operator int() const noexcept { return value_; }
+};
+
+class year_month_day {
+ private:
+  fmt::year year_;
+  fmt::month month_;
+  fmt::day day_;
+
+ public:
+  year_month_day() = default;
+  constexpr year_month_day(const year& y, const month& m, const day& d) noexcept
+      : year_(y), month_(m), day_(d) {}
+  constexpr auto year() const noexcept -> fmt::year { return year_; }
+  constexpr auto month() const noexcept -> fmt::month { return month_; }
+  constexpr auto day() const noexcept -> fmt::day { return day_; }
+};
 #endif
 
-// A rudimentary weekday formatter.
+template <typename Char>
-template <typename Char> struct formatter<weekday, Char> {
+struct formatter<weekday, Char> : private formatter<std::tm, Char> {
  private:
-  bool localized = false;
+  bool localized_ = false;
+  bool use_tm_formatter_ = false;
 
  public:
   FMT_CONSTEXPR auto parse(basic_format_parse_context<Char>& ctx)
       -> decltype(ctx.begin()) {
-    auto begin = ctx.begin(), end = ctx.end();
+    auto it = ctx.begin(), end = ctx.end();
-    if (begin != end && *begin == 'L') {
+    if (it != end && *it == 'L') {
-      ++begin;
+      ++it;
-      localized = true;
+      localized_ = true;
+      return it;
     }
-    return begin;
+    use_tm_formatter_ = it != end && *it != '}';
+    return use_tm_formatter_ ? formatter<std::tm, Char>::parse(ctx) : it;
   }
 
   template <typename FormatContext>
   auto format(weekday wd, FormatContext& ctx) const -> decltype(ctx.out()) {
     auto time = std::tm();
     time.tm_wday = static_cast<int>(wd.c_encoding());
-    detail::get_locale loc(localized, ctx.locale());
+    if (use_tm_formatter_) return formatter<std::tm, Char>::format(time, ctx);
+    detail::get_locale loc(localized_, ctx.locale());
     auto w = detail::tm_writer<decltype(ctx.out()), Char>(loc, ctx.out(), time);
     w.on_abbr_weekday();
     return w.out();
   }
 };
 
+template <typename Char>
+struct formatter<day, Char> : private formatter<std::tm, Char> {
+ private:
+  bool use_tm_formatter_ = false;
+
+ public:
+  FMT_CONSTEXPR auto parse(basic_format_parse_context<Char>& ctx)
+      -> decltype(ctx.begin()) {
+    auto it = ctx.begin(), end = ctx.end();
+    use_tm_formatter_ = it != end && *it != '}';
+    return use_tm_formatter_ ? formatter<std::tm, Char>::parse(ctx) : it;
+  }
+
+  template <typename FormatContext>
+  auto format(day d, FormatContext& ctx) const -> decltype(ctx.out()) {
+    auto time = std::tm();
+    time.tm_mday = static_cast<int>(static_cast<unsigned>(d));
+    if (use_tm_formatter_) return formatter<std::tm, Char>::format(time, ctx);
+    detail::get_locale loc(false, ctx.locale());
+    auto w = detail::tm_writer<decltype(ctx.out()), Char>(loc, ctx.out(), time);
+    w.on_day_of_month(detail::numeric_system::standard, detail::pad_type::zero);
+    return w.out();
+  }
+};
+
+template <typename Char>
+struct formatter<month, Char> : private formatter<std::tm, Char> {
+ private:
+  bool localized_ = false;
+  bool use_tm_formatter_ = false;
+
+ public:
+  FMT_CONSTEXPR auto parse(basic_format_parse_context<Char>& ctx)
+      -> decltype(ctx.begin()) {
+    auto it = ctx.begin(), end = ctx.end();
+    if (it != end && *it == 'L') {
+      ++it;
+      localized_ = true;
+      return it;
+    }
+    use_tm_formatter_ = it != end && *it != '}';
+    return use_tm_formatter_ ? formatter<std::tm, Char>::parse(ctx) : it;
+  }
+
+  template <typename FormatContext>
+  auto format(month m, FormatContext& ctx) const -> decltype(ctx.out()) {
+    auto time = std::tm();
+    time.tm_mon = static_cast<int>(static_cast<unsigned>(m)) - 1;
+    if (use_tm_formatter_) return formatter<std::tm, Char>::format(time, ctx);
+    detail::get_locale loc(localized_, ctx.locale());
+    auto w = detail::tm_writer<decltype(ctx.out()), Char>(loc, ctx.out(), time);
+    w.on_abbr_month();
+    return w.out();
+  }
+};
+
+template <typename Char>
+struct formatter<year, Char> : private formatter<std::tm, Char> {
+ private:
+  bool use_tm_formatter_ = false;
+
+ public:
+  FMT_CONSTEXPR auto parse(basic_format_parse_context<Char>& ctx)
+      -> decltype(ctx.begin()) {
+    auto it = ctx.begin(), end = ctx.end();
+    use_tm_formatter_ = it != end && *it != '}';
+    return use_tm_formatter_ ? formatter<std::tm, Char>::parse(ctx) : it;
+  }
+
+  template <typename FormatContext>
+  auto format(year y, FormatContext& ctx) const -> decltype(ctx.out()) {
+    auto time = std::tm();
+    time.tm_year = static_cast<int>(y) - 1900;
+    if (use_tm_formatter_) return formatter<std::tm, Char>::format(time, ctx);
+    detail::get_locale loc(false, ctx.locale());
+    auto w = detail::tm_writer<decltype(ctx.out()), Char>(loc, ctx.out(), time);
+    w.on_year(detail::numeric_system::standard);
+    return w.out();
+  }
+};
+
+template <typename Char>
+struct formatter<year_month_day, Char> : private formatter<std::tm, Char> {
+ private:
+  bool use_tm_formatter_ = false;
+
+ public:
+  FMT_CONSTEXPR auto parse(basic_format_parse_context<Char>& ctx)
+      -> decltype(ctx.begin()) {
+    auto it = ctx.begin(), end = ctx.end();
+    use_tm_formatter_ = it != end && *it != '}';
+    return use_tm_formatter_ ? formatter<std::tm, Char>::parse(ctx) : it;
+  }
+
+  template <typename FormatContext>
+  auto format(year_month_day val, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto time = std::tm();
+    time.tm_year = static_cast<int>(val.year()) - 1900;
+    time.tm_mon = static_cast<int>(static_cast<unsigned>(val.month())) - 1;
+    time.tm_mday = static_cast<int>(static_cast<unsigned>(val.day()));
+    if (use_tm_formatter_) return formatter<std::tm, Char>::format(time, ctx);
+    detail::get_locale loc(true, ctx.locale());
+    auto w = detail::tm_writer<decltype(ctx.out()), Char>(loc, ctx.out(), time);
+    w.on_iso_date();
+    return w.out();
+  }
+};
+
 template <typename Rep, typename Period, typename Char>
 struct formatter<std::chrono::duration<Rep, Period>, Char> {
  private:
-  format_specs<Char> specs_;
+  format_specs specs_;
   detail::arg_ref<Char> width_ref_;
   detail::arg_ref<Char> precision_ref_;
   bool localized_ = false;
@@ -2117,27 +2310,26 @@ struct formatter<std::chrono::time_point<std::chrono::system_clock, Duration>,
   template <typename FormatContext>
   auto format(std::chrono::time_point<std::chrono::system_clock, Duration> val,
               FormatContext& ctx) const -> decltype(ctx.out()) {
+    std::tm tm = gmtime(val);
     using period = typename Duration::period;
     if (detail::const_check(
-            period::num != 1 || period::den != 1 ||
+            period::num == 1 && period::den == 1 &&
-            std::is_floating_point<typename Duration::rep>::value)) {
+            !std::is_floating_point<typename Duration::rep>::value)) {
-      const auto epoch = val.time_since_epoch();
+      return formatter<std::tm, Char>::format(tm, ctx);
-      auto subsecs = detail::fmt_duration_cast<Duration>(
+    }
+    Duration epoch = val.time_since_epoch();
+    Duration subsecs = detail::fmt_duration_cast<Duration>(
         epoch - detail::fmt_duration_cast<std::chrono::seconds>(epoch));
-
     if (subsecs.count() < 0) {
       auto second =
           detail::fmt_duration_cast<Duration>(std::chrono::seconds(1));
-        if (epoch.count() < ((Duration::min)() + second).count())
+      if (tm.tm_sec != 0)
-          FMT_THROW(format_error("duration is too small"));
+        --tm.tm_sec;
-        subsecs += second;
+      else
-        val -= second;
+        tm = gmtime(val - second);
+      subsecs += detail::fmt_duration_cast<Duration>(std::chrono::seconds(1));
     }
-
+    return formatter<std::tm, Char>::do_format(tm, ctx, &subsecs);
-      return formatter<std::tm, Char>::do_format(gmtime(val), ctx, &subsecs);
-    }
-
-    return formatter<std::tm, Char>::format(gmtime(val), ctx);
   }
 };
 
@@ -2185,7 +2377,7 @@ struct formatter<std::chrono::time_point<std::chrono::utc_clock, Duration>,
 
 template <typename Char> struct formatter<std::tm, Char> {
  private:
-  format_specs<Char> specs_;
+  format_specs specs_;
   detail::arg_ref<Char> width_ref_;
 
  protected:

include/spdlog/fmt/bundled/color.h

@@ -227,7 +227,7 @@ struct color_type {
 };
 }  // namespace detail
 
-/** A text style consisting of foreground and background colors and emphasis. */
+/// A text style consisting of foreground and background colors and emphasis.
 class text_style {
  public:
   FMT_CONSTEXPR text_style(emphasis em = emphasis()) noexcept
@@ -239,7 +239,7 @@ class text_style {
       foreground_color = rhs.foreground_color;
     } else if (rhs.set_foreground_color) {
       if (!foreground_color.is_rgb || !rhs.foreground_color.is_rgb)
-        FMT_THROW(format_error("can't OR a terminal color"));
+        report_error("can't OR a terminal color");
       foreground_color.value.rgb_color |= rhs.foreground_color.value.rgb_color;
     }
 
@@ -248,7 +248,7 @@ class text_style {
       background_color = rhs.background_color;
     } else if (rhs.set_background_color) {
       if (!background_color.is_rgb || !rhs.background_color.is_rgb)
-        FMT_THROW(format_error("can't OR a terminal color"));
+        report_error("can't OR a terminal color");
       background_color.value.rgb_color |= rhs.background_color.value.rgb_color;
     }
 
@@ -310,13 +310,13 @@ class text_style {
   emphasis ems;
 };
 
-/** Creates a text style from the foreground (text) color. */
+/// Creates a text style from the foreground (text) color.
 FMT_CONSTEXPR inline auto fg(detail::color_type foreground) noexcept
     -> text_style {
   return text_style(true, foreground);
 }
 
-/** Creates a text style from the background color. */
+/// Creates a text style from the background color.
 FMT_CONSTEXPR inline auto bg(detail::color_type background) noexcept
     -> text_style {
   return text_style(false, background);
@@ -390,8 +390,8 @@ 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_CHAR_TRAITS auto end() const noexcept -> const Char* {
+  FMT_CONSTEXPR20 auto end() const noexcept -> const Char* {
-    return buffer + std::char_traits<Char>::length(buffer);
+    return buffer + basic_string_view<Char>(buffer).size();
   }
 
  private:
@@ -441,9 +441,9 @@ template <typename T> struct styled_arg : detail::view {
 };
 
 template <typename Char>
-void vformat_to(buffer<Char>& buf, const text_style& ts,
+void vformat_to(
-                basic_string_view<Char> format_str,
+    buffer<Char>& buf, const text_style& ts, basic_string_view<Char> format_str,
-                basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+    basic_format_args<buffered_context<type_identity_t<Char>>> args) {
   bool has_style = false;
   if (ts.has_emphasis()) {
     has_style = true;
@@ -466,121 +466,92 @@ void vformat_to(buffer<Char>& buf, const text_style& ts,
 
 }  // namespace detail
 
-inline void vprint(std::FILE* f, const text_style& ts, string_view fmt,
+inline void vprint(FILE* f, const text_style& ts, string_view fmt,
                    format_args args) {
-  // Legacy wide streams are not supported.
   auto buf = memory_buffer();
   detail::vformat_to(buf, ts, fmt, args);
-  if (detail::is_utf8()) {
+  print(f, FMT_STRING("{}"), string_view(buf.begin(), buf.size()));
-    detail::print(f, string_view(buf.begin(), buf.size()));
-    return;
-  }
-  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")));
 }
 
 /**
-  \rst
+ * Formats a string and prints it to the specified file stream using ANSI
-  Formats a string and prints it to the specified file stream using ANSI
+ * escape sequences to specify text formatting.
-  escape sequences to specify text formatting.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
-    fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
+ *                "Elapsed time: {0:.2f} seconds", 1.23);
-               "Elapsed time: {0:.2f} seconds", 1.23);
-  \endrst
  */
-template <typename S, typename... Args,
+template <typename... T>
-          FMT_ENABLE_IF(detail::is_string<S>::value)>
+void print(FILE* f, const text_style& ts, format_string<T...> fmt,
-void print(std::FILE* f, const text_style& ts, const S& format_str,
+           T&&... args) {
-           const Args&... args) {
+  vprint(f, ts, fmt, fmt::make_format_args(args...));
-  vprint(f, ts, format_str,
-         fmt::make_format_args<buffer_context<char_t<S>>>(args...));
 }
 
 /**
-  \rst
+ * Formats a string and prints it to stdout using ANSI escape sequences to
-  Formats a string and prints it to stdout using ANSI escape sequences to
+ * specify text formatting.
-  specify text formatting.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
-    fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
+ *                "Elapsed time: {0:.2f} seconds", 1.23);
-               "Elapsed time: {0:.2f} seconds", 1.23);
-  \endrst
  */
-template <typename S, typename... Args,
+template <typename... T>
-          FMT_ENABLE_IF(detail::is_string<S>::value)>
+void print(const text_style& ts, format_string<T...> fmt, T&&... args) {
-void print(const text_style& ts, const S& format_str, const Args&... args) {
+  return print(stdout, ts, fmt, std::forward<T>(args)...);
-  return print(stdout, ts, format_str, args...);
 }
 
-template <typename S, typename Char = char_t<S>>
+inline auto vformat(const text_style& ts, string_view fmt, format_args args)
-inline auto vformat(
+    -> std::string {
-    const text_style& ts, const S& format_str,
+  auto buf = memory_buffer();
-    basic_format_args<buffer_context<type_identity_t<Char>>> args)
+  detail::vformat_to(buf, ts, fmt, 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);
 }
 
 /**
-  \rst
+ * Formats arguments and returns the result as a string using ANSI escape
-  Formats arguments and returns the result as a string using ANSI
+ * sequences to specify text formatting.
-  escape sequences to specify text formatting.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ * ```
-    #include <fmt/color.h>
+ * #include <fmt/color.h>
-    std::string message = fmt::format(fmt::emphasis::bold | fg(fmt::color::red),
+ * std::string message = fmt::format(fmt::emphasis::bold | fg(fmt::color::red),
-                                      "The answer is {}", 42);
+ *                                   "The answer is {}", 42);
-  \endrst
+ * ```
-*/
+ */
-template <typename S, typename... Args, typename Char = char_t<S>>
+template <typename... T>
-inline auto format(const text_style& ts, const S& format_str,
+inline auto format(const text_style& ts, format_string<T...> fmt, T&&... args)
-                   const Args&... args) -> std::basic_string<Char> {
+    -> std::string {
-  return fmt::vformat(ts, detail::to_string_view(format_str),
+  return fmt::vformat(ts, fmt, fmt::make_format_args(args...));
-                      fmt::make_format_args<buffer_context<Char>>(args...));
 }
 
-/**
+/// Formats a string with the given text_style and writes the output to `out`.
-  Formats a string with the given text_style and writes the output to ``out``.
+template <typename OutputIt,
- */
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, char>::value)>
-template <typename OutputIt, typename Char,
+auto vformat_to(OutputIt out, const text_style& ts, string_view fmt,
-          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value)>
+                format_args args) -> OutputIt {
-auto vformat_to(OutputIt out, const text_style& ts,
+  auto&& buf = detail::get_buffer<char>(out);
-                basic_string_view<Char> format_str,
+  detail::vformat_to(buf, ts, fmt, 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);
 }
 
 /**
-  \rst
+ * Formats arguments with the given text style, writes the result to the output
-  Formats arguments with the given text_style, writes the result to the output
+ * iterator `out` and returns the iterator past the end of the output range.
-  iterator ``out`` and returns the iterator past the end of the output range.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     std::vector<char> out;
-    std::vector<char> out;
+ *     fmt::format_to(std::back_inserter(out),
-    fmt::format_to(std::back_inserter(out),
+ *                    fmt::emphasis::bold | fg(fmt::color::red), "{}", 42);
-                   fmt::emphasis::bold | fg(fmt::color::red), "{}", 42);
+ */
-  \endrst
+template <typename OutputIt, typename... T,
-*/
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, char>::value)>
-template <
+inline auto format_to(OutputIt out, const text_style& ts,
-    typename OutputIt, typename S, typename... Args,
+                      format_string<T...> fmt, T&&... args) -> OutputIt {
-    bool enable = detail::is_output_iterator<OutputIt, char_t<S>>::value &&
+  return vformat_to(out, ts, fmt, fmt::make_format_args(args...));
-                  detail::is_string<S>::value>
-inline auto format_to(OutputIt out, const text_style& ts, const S& format_str,
-                      Args&&... args) ->
-    typename std::enable_if<enable, OutputIt>::type {
-  return vformat_to(out, ts, detail::to_string_view(format_str),
-                    fmt::make_format_args<buffer_context<char_t<S>>>(args...));
 }
 
 template <typename T, typename Char>
@@ -620,16 +591,14 @@ struct formatter<detail::styled_arg<T>, Char> : formatter<T, Char> {
 };
 
 /**
-  \rst
+ * Returns an argument that will be formatted using ANSI escape sequences,
-  Returns an argument that will be formatted using ANSI escape sequences,
+ * to be used in a formatting function.
-  to be used in a formatting function.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     fmt::print("Elapsed time: {0:.2f} seconds",
-    fmt::print("Elapsed time: {0:.2f} seconds",
+ *                fmt::styled(1.23, fmt::fg(fmt::color::green) |
-               fmt::styled(1.23, fmt::fg(fmt::color::green) |
+ *                                  fmt::bg(fmt::color::blue)));
-                                 fmt::bg(fmt::color::blue)));
-  \endrst
  */
 template <typename T>
 FMT_CONSTEXPR auto styled(const T& value, text_style ts)

include/spdlog/fmt/bundled/compile.h

@@ -8,39 +8,41 @@
 #ifndef FMT_COMPILE_H_
 #define FMT_COMPILE_H_
 
+#ifndef FMT_MODULE
+#  include <iterator>  // std::back_inserter
+#endif
+
 #include "format.h"
 
 FMT_BEGIN_NAMESPACE
-namespace detail {
-
-template <typename Char, typename InputIt>
-FMT_CONSTEXPR inline auto copy_str(InputIt begin, InputIt end,
-                                   counting_iterator it) -> counting_iterator {
-  return it + (end - begin);
-}
 
 // A compile-time string which is compiled into fast formatting code.
-class compiled_string {};
+FMT_EXPORT class compiled_string {};
+
+namespace detail {
+
+template <typename T, typename InputIt>
+FMT_CONSTEXPR inline auto copy(InputIt begin, InputIt end, counting_iterator it)
+    -> counting_iterator {
+  return it + (end - begin);
+}
 
 template <typename S>
 struct is_compiled_string : std::is_base_of<compiled_string, S> {};
 
 /**
-  \rst
+ * Converts a string literal `s` into a format string that will be parsed at
-  Converts a string literal *s* into a format string that will be parsed at
+ * compile time and converted into efficient formatting code. Requires C++17
-  compile time and converted into efficient formatting code. Requires C++17
+ * `constexpr if` compiler support.
-  ``constexpr if`` compiler support.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     // Converts 42 into std::string using the most efficient method and no
-    // Converts 42 into std::string using the most efficient method and no
+ *     // runtime format string processing.
-    // runtime format string processing.
+ *     std::string s = fmt::format(FMT_COMPILE("{}"), 42);
-    std::string s = fmt::format(FMT_COMPILE("{}"), 42);
-  \endrst
  */
 #if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
-#  define FMT_COMPILE(s) \
+#  define FMT_COMPILE(s) FMT_STRING_IMPL(s, fmt::compiled_string, explicit)
-    FMT_STRING_IMPL(s, fmt::detail::compiled_string, explicit)
 #else
 #  define FMT_COMPILE(s) FMT_STRING(s)
 #endif
@@ -144,9 +146,9 @@ 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...);
-    if constexpr (std::is_convertible_v<T, basic_string_view<Char>>) {
+    if constexpr (std::is_convertible<T, basic_string_view<Char>>::value) {
       auto s = basic_string_view<Char>(arg);
-      return copy_str<Char>(s.begin(), s.end(), out);
+      return copy<Char>(s.begin(), s.end(), out);
     }
     return write<Char>(out, arg);
   }
@@ -236,13 +238,12 @@ constexpr size_t parse_text(basic_string_view<Char> str, size_t pos) {
 }
 
 template <typename Args, size_t POS, int ID, typename S>
-constexpr auto compile_format_string(S format_str);
+constexpr auto compile_format_string(S fmt);
 
 template <typename Args, size_t POS, int ID, typename T, typename S>
-constexpr auto parse_tail(T head, S format_str) {
+constexpr auto parse_tail(T head, S fmt) {
-  if constexpr (POS !=
+  if constexpr (POS != basic_string_view<typename S::char_type>(fmt).size()) {
-                basic_string_view<typename S::char_type>(format_str).size()) {
+    constexpr auto tail = compile_format_string<Args, POS, ID>(fmt);
-    constexpr auto tail = compile_format_string<Args, POS, ID>(format_str);
     if constexpr (std::is_same<remove_cvref_t<decltype(tail)>,
                                unknown_format>())
       return tail;
@@ -313,14 +314,13 @@ struct field_type<T, enable_if_t<detail::is_named_arg<T>::value>> {
 
 template <typename T, typename Args, size_t END_POS, int ARG_INDEX, int NEXT_ID,
           typename S>
-constexpr auto parse_replacement_field_then_tail(S format_str) {
+constexpr auto parse_replacement_field_then_tail(S fmt) {
   using char_type = typename S::char_type;
-  constexpr auto str = basic_string_view<char_type>(format_str);
+  constexpr auto str = basic_string_view<char_type>(fmt);
   constexpr char_type c = END_POS != str.size() ? str[END_POS] : char_type();
   if constexpr (c == '}') {
     return parse_tail<Args, END_POS + 1, NEXT_ID>(
-        field<char_type, typename field_type<T>::type, ARG_INDEX>(),
+        field<char_type, typename field_type<T>::type, ARG_INDEX>(), fmt);
-        format_str);
   } else if constexpr (c != ':') {
     FMT_THROW(format_error("expected ':'"));
   } else {
@@ -333,7 +333,7 @@ constexpr auto parse_replacement_field_then_tail(S format_str) {
       return parse_tail<Args, result.end + 1, result.next_arg_id>(
           spec_field<char_type, typename field_type<T>::type, ARG_INDEX>{
               result.fmt},
-          format_str);
+          fmt);
     }
   }
 }
@@ -341,22 +341,21 @@ constexpr auto parse_replacement_field_then_tail(S format_str) {
 // Compiles a non-empty format string and returns the compiled representation
 // or unknown_format() on unrecognized input.
 template <typename Args, size_t POS, int ID, typename S>
-constexpr auto compile_format_string(S format_str) {
+constexpr auto compile_format_string(S fmt) {
   using char_type = typename S::char_type;
-  constexpr auto str = basic_string_view<char_type>(format_str);
+  constexpr auto str = basic_string_view<char_type>(fmt);
   if constexpr (str[POS] == '{') {
     if constexpr (POS + 1 == str.size())
       FMT_THROW(format_error("unmatched '{' in format string"));
     if constexpr (str[POS + 1] == '{') {
-      return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
+      return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), fmt);
     } else if constexpr (str[POS + 1] == '}' || str[POS + 1] == ':') {
       static_assert(ID != manual_indexing_id,
                     "cannot switch from manual to automatic argument indexing");
       constexpr auto next_id =
           ID != manual_indexing_id ? ID + 1 : manual_indexing_id;
       return parse_replacement_field_then_tail<get_type<ID, Args>, Args,
-                                               POS + 1, ID, next_id>(
+                                               POS + 1, ID, next_id>(fmt);
-          format_str);
     } else {
       constexpr auto arg_id_result =
           parse_arg_id<ID>(str.data() + POS + 1, str.data() + str.size());
@@ -372,7 +371,7 @@ constexpr auto compile_format_string(S format_str) {
         return parse_replacement_field_then_tail<get_type<arg_index, Args>,
                                                  Args, arg_id_end_pos,
                                                  arg_index, manual_indexing_id>(
-            format_str);
+            fmt);
       } 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{});
@@ -381,11 +380,11 @@ constexpr auto compile_format_string(S format_str) {
               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);
+              arg_index, next_id>(fmt);
         } 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);
+              fmt);
         } else if constexpr (c == ':') {
           return unknown_format();  // no type info for specs parsing
         }
@@ -394,29 +393,26 @@ 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"));
-    return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
+    return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), fmt);
   } else {
     constexpr auto end = parse_text(str, POS + 1);
     if constexpr (end - POS > 1) {
-      return parse_tail<Args, end, ID>(make_text(str, POS, end - POS),
+      return parse_tail<Args, end, ID>(make_text(str, POS, end - POS), fmt);
-                                       format_str);
     } else {
-      return parse_tail<Args, end, ID>(code_unit<char_type>{str[POS]},
+      return parse_tail<Args, end, ID>(code_unit<char_type>{str[POS]}, fmt);
-                                       format_str);
     }
   }
 }
 
 template <typename... Args, typename S,
           FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
-constexpr auto compile(S format_str) {
+constexpr auto compile(S fmt) {
-  constexpr auto str = basic_string_view<typename S::char_type>(format_str);
+  constexpr auto str = basic_string_view<typename S::char_type>(fmt);
   if constexpr (str.size() == 0) {
     return detail::make_text(str, 0, 0);
   } else {
     constexpr auto result =
-        detail::compile_format_string<detail::type_list<Args...>, 0, 0>(
+        detail::compile_format_string<detail::type_list<Args...>, 0, 0>(fmt);
-            format_str);
     return result;
   }
 }
@@ -488,35 +484,33 @@ 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)
+auto format_to_n(OutputIt out, size_t n, const S& fmt, Args&&... args)
     -> format_to_n_result<OutputIt> {
   using traits = detail::fixed_buffer_traits;
   auto buf = detail::iterator_buffer<OutputIt, char, traits>(out, n);
-  fmt::format_to(std::back_inserter(buf), format_str,
+  fmt::format_to(std::back_inserter(buf), fmt, std::forward<Args>(args)...);
-                 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 auto formatted_size(const S& fmt, const Args&... args)
     -> size_t {
-  return fmt::format_to(detail::counting_iterator(), format_str, args...)
+  return fmt::format_to(detail::counting_iterator(), fmt, args...).count();
-      .count();
 }
 
 template <typename S, typename... Args,
           FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
-void print(std::FILE* f, const S& format_str, const Args&... args) {
+void print(std::FILE* f, const S& fmt, const Args&... args) {
   memory_buffer buffer;
-  fmt::format_to(std::back_inserter(buffer), format_str, args...);
+  fmt::format_to(std::back_inserter(buffer), fmt, args...);
   detail::print(f, {buffer.data(), buffer.size()});
 }
 
 template <typename S, typename... Args,
           FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
-void print(const S& format_str, const Args&... args) {
+void print(const S& fmt, const Args&... args) {
-  print(stdout, format_str, args...);
+  print(stdout, fmt, args...);
 }
 
 #if FMT_USE_NONTYPE_TEMPLATE_ARGS

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

@@ -8,17 +8,19 @@
 #ifndef FMT_FORMAT_INL_H_
 #define FMT_FORMAT_INL_H_
 
-#include <algorithm>
+#ifndef FMT_MODULE
-#include <cerrno>  // errno
+#  include <algorithm>
-#include <climits>
+#  include <cerrno>  // errno
-#include <cmath>
+#  include <climits>
-#include <exception>
+#  include <cmath>
+#  include <exception>
 
-#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
+#  if !defined(FMT_STATIC_THOUSANDS_SEPARATOR)
 #    include <locale>
+#  endif
 #endif
 
-#if defined(_WIN32) && !defined(FMT_WINDOWS_NO_WCHAR)
+#if defined(_WIN32) && !defined(FMT_USE_WRITE_CONSOLE)
 #  include <io.h>  // _isatty
 #endif
 
@@ -36,10 +38,6 @@ FMT_FUNC void assert_fail(const char* file, int line, const char* message) {
   std::terminate();
 }
 
-FMT_FUNC void throw_format_error(const char* message) {
-  FMT_THROW(format_error(message));
-}
-
 FMT_FUNC void format_error_code(detail::buffer<char>& out, int error_code,
                                 string_view message) noexcept {
   // Report error code making sure that the output fits into
@@ -56,7 +54,7 @@ FMT_FUNC void format_error_code(detail::buffer<char>& out, int error_code,
     ++error_code_size;
   }
   error_code_size += detail::to_unsigned(detail::count_digits(abs_value));
-  auto it = buffer_appender<char>(out);
+  auto it = appender(out);
   if (message.size() <= inline_buffer_size - error_code_size)
     fmt::format_to(it, FMT_STRING("{}{}"), message, SEP);
   fmt::format_to(it, FMT_STRING("{}{}"), ERROR_STR, error_code);
@@ -113,8 +111,12 @@ template <typename Char> FMT_FUNC Char decimal_point_impl(locale_ref) {
 #endif
 
 FMT_FUNC auto write_loc(appender out, loc_value value,
-                        const format_specs<>& specs, locale_ref loc) -> bool {
+                        const format_specs& specs, locale_ref loc) -> bool {
-#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
+#ifdef FMT_STATIC_THOUSANDS_SEPARATOR
+  value.visit(loc_writer<>{
+      out, specs, std::string(1, FMT_STATIC_THOUSANDS_SEPARATOR), "\3", "."});
+  return true;
+#else
   auto locale = loc.get<std::locale>();
   // We cannot use the num_put<char> facet because it may produce output in
   // a wrong encoding.
@@ -123,10 +125,13 @@ FMT_FUNC auto write_loc(appender out, loc_value value,
     return std::use_facet<facet>(locale).put(out, value, specs);
   return facet(locale).put(out, value, specs);
 #endif
-  return false;
 }
 }  // namespace detail
 
+FMT_FUNC void report_error(const char* message) {
+  FMT_THROW(format_error(message));
+}
+
 template <typename Locale> typename Locale::id format_facet<Locale>::id;
 
 #ifndef FMT_STATIC_THOUSANDS_SEPARATOR
@@ -138,7 +143,7 @@ template <typename Locale> format_facet<Locale>::format_facet(Locale& loc) {
 
 template <>
 FMT_API FMT_FUNC auto format_facet<std::locale>::do_put(
-    appender out, loc_value val, const format_specs<>& specs) const -> bool {
+    appender out, loc_value val, const format_specs& specs) const -> bool {
   return val.visit(
       detail::loc_writer<>{out, specs, separator_, grouping_, decimal_point_});
 }
@@ -1411,7 +1416,7 @@ FMT_FUNC void format_system_error(detail::buffer<char>& out, int error_code,
                                   const char* message) noexcept {
   FMT_TRY {
     auto ec = std::error_code(error_code, std::generic_category());
-    write(std::back_inserter(out), std::system_error(ec, message).what());
+    detail::write(appender(out), std::system_error(ec, message).what());
     return;
   }
   FMT_CATCH(...) {}
@@ -1432,9 +1437,242 @@ FMT_FUNC auto vformat(string_view fmt, format_args args) -> std::string {
 }
 
 namespace detail {
-#if !defined(_WIN32) || defined(FMT_WINDOWS_NO_WCHAR)
+
+template <typename T> struct span {
+  T* data;
+  size_t size;
+};
+
+template <typename F> auto flockfile(F* f) -> decltype(_lock_file(f)) {
+  _lock_file(f);
+}
+template <typename F> auto funlockfile(F* f) -> decltype(_unlock_file(f)) {
+  _unlock_file(f);
+}
+
+#ifndef getc_unlocked
+template <typename F> auto getc_unlocked(F* f) -> decltype(_fgetc_nolock(f)) {
+  return _fgetc_nolock(f);
+}
+#endif
+
+template <typename F = FILE, typename Enable = void>
+struct has_flockfile : std::false_type {};
+
+template <typename F>
+struct has_flockfile<F, void_t<decltype(flockfile(&std::declval<F&>()))>>
+    : std::true_type {};
+
+// A FILE wrapper. F is FILE defined as a template parameter to make system API
+// detection work.
+template <typename F> class file_base {
+ public:
+  F* file_;
+
+ public:
+  file_base(F* file) : file_(file) {}
+  operator F*() const { return file_; }
+
+  // Reads a code unit from the stream.
+  auto get() -> int {
+    int result = getc_unlocked(file_);
+    if (result == EOF && ferror(file_) != 0)
+      FMT_THROW(system_error(errno, FMT_STRING("getc failed")));
+    return result;
+  }
+
+  // Puts the code unit back into the stream buffer.
+  void unget(char c) {
+    if (ungetc(c, file_) == EOF)
+      FMT_THROW(system_error(errno, FMT_STRING("ungetc failed")));
+  }
+
+  void flush() { fflush(this->file_); }
+};
+
+// A FILE wrapper for glibc.
+template <typename F> class glibc_file : public file_base<F> {
+ private:
+  enum {
+    line_buffered = 0x200,  // _IO_LINE_BUF
+    unbuffered = 2          // _IO_UNBUFFERED
+  };
+
+ public:
+  using file_base<F>::file_base;
+
+  auto is_buffered() const -> bool {
+    return (this->file_->_flags & unbuffered) == 0;
+  }
+
+  void init_buffer() {
+    if (this->file_->_IO_write_ptr) return;
+    // Force buffer initialization by placing and removing a char in a buffer.
+    putc_unlocked(0, this->file_);
+    --this->file_->_IO_write_ptr;
+  }
+
+  // Returns the file's read buffer.
+  auto get_read_buffer() const -> span<const char> {
+    auto ptr = this->file_->_IO_read_ptr;
+    return {ptr, to_unsigned(this->file_->_IO_read_end - ptr)};
+  }
+
+  // Returns the file's write buffer.
+  auto get_write_buffer() const -> span<char> {
+    auto ptr = this->file_->_IO_write_ptr;
+    return {ptr, to_unsigned(this->file_->_IO_buf_end - ptr)};
+  }
+
+  void advance_write_buffer(size_t size) { this->file_->_IO_write_ptr += size; }
+
+  bool needs_flush() const {
+    if ((this->file_->_flags & line_buffered) == 0) return false;
+    char* end = this->file_->_IO_write_end;
+    return memchr(end, '\n', to_unsigned(this->file_->_IO_write_ptr - end));
+  }
+
+  void flush() { fflush_unlocked(this->file_); }
+};
+
+// A FILE wrapper for Apple's libc.
+template <typename F> class apple_file : public file_base<F> {
+ private:
+  enum {
+    line_buffered = 1,  // __SNBF
+    unbuffered = 2      // __SLBF
+  };
+
+ public:
+  using file_base<F>::file_base;
+
+  auto is_buffered() const -> bool {
+    return (this->file_->_flags & unbuffered) == 0;
+  }
+
+  void init_buffer() {
+    if (this->file_->_p) return;
+    // Force buffer initialization by placing and removing a char in a buffer.
+    putc_unlocked(0, this->file_);
+    --this->file_->_p;
+    ++this->file_->_w;
+  }
+
+  auto get_read_buffer() const -> span<const char> {
+    return {reinterpret_cast<char*>(this->file_->_p),
+            to_unsigned(this->file_->_r)};
+  }
+
+  auto get_write_buffer() const -> span<char> {
+    return {reinterpret_cast<char*>(this->file_->_p),
+            to_unsigned(this->file_->_bf._base + this->file_->_bf._size -
+                        this->file_->_p)};
+  }
+
+  void advance_write_buffer(size_t size) {
+    this->file_->_p += size;
+    this->file_->_w -= size;
+  }
+
+  bool needs_flush() const {
+    if ((this->file_->_flags & line_buffered) == 0) return false;
+    return memchr(this->file_->_p + this->file_->_w, '\n',
+                  to_unsigned(-this->file_->_w));
+  }
+};
+
+// A fallback FILE wrapper.
+template <typename F> class fallback_file : public file_base<F> {
+ private:
+  char next_;  // The next unconsumed character in the buffer.
+  bool has_next_ = false;
+
+ public:
+  using file_base<F>::file_base;
+
+  auto is_buffered() const -> bool { return false; }
+  auto needs_flush() const -> bool { return false; }
+  void init_buffer() {}
+
+  auto get_read_buffer() const -> span<const char> {
+    return {&next_, has_next_ ? 1u : 0u};
+  }
+
+  auto get_write_buffer() const -> span<char> { return {nullptr, 0}; }
+
+  void advance_write_buffer(size_t) {}
+
+  auto get() -> int {
+    has_next_ = false;
+    return file_base<F>::get();
+  }
+
+  void unget(char c) {
+    file_base<F>::unget(c);
+    next_ = c;
+    has_next_ = true;
+  }
+};
+
+#ifndef FMT_USE_FALLBACK_FILE
+#  define FMT_USE_FALLBACK_FILE 1
+#endif
+
+template <typename F,
+          FMT_ENABLE_IF(sizeof(F::_p) != 0 && !FMT_USE_FALLBACK_FILE)>
+auto get_file(F* f, int) -> apple_file<F> {
+  return f;
+}
+template <typename F,
+          FMT_ENABLE_IF(sizeof(F::_IO_read_ptr) != 0 && !FMT_USE_FALLBACK_FILE)>
+inline auto get_file(F* f, int) -> glibc_file<F> {
+  return f;
+}
+
+inline auto get_file(FILE* f, ...) -> fallback_file<FILE> { return f; }
+
+using file_ref = decltype(get_file(static_cast<FILE*>(nullptr), 0));
+
+template <typename F = FILE, typename Enable = void>
+class file_print_buffer : public buffer<char> {
+ public:
+  explicit file_print_buffer(F*) : buffer(nullptr, size_t()) {}
+};
+
+template <typename F>
+class file_print_buffer<F, enable_if_t<has_flockfile<F>::value>>
+    : public buffer<char> {
+ private:
+  file_ref file_;
+
+  static void grow(buffer<char>& base, size_t) {
+    auto& self = static_cast<file_print_buffer&>(base);
+    self.file_.advance_write_buffer(self.size());
+    if (self.file_.get_write_buffer().size == 0) self.file_.flush();
+    auto buf = self.file_.get_write_buffer();
+    FMT_ASSERT(buf.size > 0, "");
+    self.set(buf.data, buf.size);
+    self.clear();
+  }
+
+ public:
+  explicit file_print_buffer(F* f) : buffer(grow, size_t()), file_(f) {
+    flockfile(f);
+    file_.init_buffer();
+    auto buf = file_.get_write_buffer();
+    set(buf.data, buf.size);
+  }
+  ~file_print_buffer() {
+    file_.advance_write_buffer(size());
+    bool flush = file_.needs_flush();
+    F* f = file_;    // Make funlockfile depend on the template parameter F
+    funlockfile(f);  // for the system API detection to work.
+    if (flush) fflush(file_);
+  }
+};
+
+#if !defined(_WIN32) || defined(FMT_USE_WRITE_CONSOLE)
 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(  //
@@ -1445,23 +1683,21 @@ FMT_FUNC bool write_console(int fd, string_view text) {
   return WriteConsoleW(reinterpret_cast<void*>(_get_osfhandle(fd)), u16.c_str(),
                        static_cast<dword>(u16.size()), nullptr, nullptr) != 0;
 }
-
-FMT_FUNC auto write_console(std::FILE* f, string_view text) -> bool {
-  return write_console(_fileno(f), text);
-}
 #endif
 
 #ifdef _WIN32
 // Print assuming legacy (non-Unicode) encoding.
-FMT_FUNC void vprint_mojibake(std::FILE* f, string_view fmt, format_args args) {
+FMT_FUNC void vprint_mojibake(std::FILE* f, string_view fmt, format_args args,
+                              bool newline) {
   auto buffer = memory_buffer();
   detail::vformat_to(buffer, fmt, args);
+  if (newline) buffer.push_back('\n');
   fwrite_fully(buffer.data(), buffer.size(), f);
 }
 #endif
 
 FMT_FUNC void print(std::FILE* f, string_view text) {
-#ifdef _WIN32
+#if defined(_WIN32) && !defined(FMT_USE_WRITE_CONSOLE)
   int fd = _fileno(f);
   if (_isatty(fd)) {
     std::fflush(f);
@@ -1472,12 +1708,26 @@ FMT_FUNC void print(std::FILE* f, string_view text) {
 }
 }  // namespace detail
 
-FMT_FUNC void vprint(std::FILE* f, string_view fmt, format_args args) {
+FMT_FUNC void vprint_buffered(std::FILE* f, string_view fmt, format_args args) {
   auto buffer = memory_buffer();
   detail::vformat_to(buffer, fmt, args);
   detail::print(f, {buffer.data(), buffer.size()});
 }
 
+FMT_FUNC void vprint(std::FILE* f, string_view fmt, format_args args) {
+  if (!detail::file_ref(f).is_buffered() || !detail::has_flockfile<>())
+    return vprint_buffered(f, fmt, args);
+  auto&& buffer = detail::file_print_buffer<>(f);
+  return detail::vformat_to(buffer, fmt, args);
+}
+
+FMT_FUNC void vprintln(std::FILE* f, string_view fmt, format_args args) {
+  auto buffer = memory_buffer();
+  detail::vformat_to(buffer, fmt, args);
+  buffer.push_back('\n');
+  detail::print(f, {buffer.data(), buffer.size()});
+}
+
 FMT_FUNC void vprint(string_view fmt, format_args args) {
   vprint(stdout, fmt, args);
 }

include/spdlog/fmt/bundled/os.h

@@ -8,18 +8,18 @@
 #ifndef FMT_OS_H_
 #define FMT_OS_H_
 
-#include <cerrno>
-#include <cstddef>
-#include <cstdio>
-#include <system_error>  // std::system_error
-
 #include "format.h"
 
-#if defined __APPLE__ || defined(__FreeBSD__)
+#ifndef FMT_MODULE
+#  include <cerrno>
+#  include <cstddef>
+#  include <cstdio>
+#  include <system_error>  // std::system_error
+
 #  if FMT_HAS_INCLUDE(<xlocale.h>)
-#    include <xlocale.h>  // for LC_NUMERIC_MASK on OS X
+#    include <xlocale.h>  // LC_NUMERIC_MASK on macOS
 #  endif
-#endif
+#endif  // FMT_MODULE
 
 #ifndef FMT_USE_FCNTL
 // UWP doesn't provide _pipe.
@@ -77,46 +77,33 @@ FMT_BEGIN_NAMESPACE
 FMT_BEGIN_EXPORT
 
 /**
-  \rst
+ * A reference to a null-terminated string. It can be constructed from a C
-  A reference to a null-terminated string. It can be constructed from a C
+ * string or `std::string`.
-  string or ``std::string``.
+ *
-
+ * You can use one of the following type aliases for common character types:
-  You can use one of the following type aliases for common character types:
+ *
-
+ * +---------------+-----------------------------+
-  +---------------+-----------------------------+
+ * | Type          | Definition                  |
-  | Type          | Definition                  |
+ * +===============+=============================+
-  +===============+=============================+
+ * | cstring_view  | basic_cstring_view<char>    |
-  | cstring_view  | basic_cstring_view<char>    |
+ * +---------------+-----------------------------+
-  +---------------+-----------------------------+
+ * | wcstring_view | basic_cstring_view<wchar_t> |
-  | wcstring_view | basic_cstring_view<wchar_t> |
+ * +---------------+-----------------------------+
-  +---------------+-----------------------------+
+ *
-
+ * This class is most useful as a parameter type for functions that wrap C APIs.
-  This class is most useful as a parameter type to allow passing
-  different types of strings to a function, for example::
-
-    template <typename... Args>
-    std::string format(cstring_view format_str, const Args & ... args);
-
-    format("{}", 42);
-    format(std::string("{}"), 42);
-  \endrst
  */
 template <typename Char> class basic_cstring_view {
  private:
   const Char* data_;
 
  public:
-  /** Constructs a string reference object from a C string. */
+  /// Constructs a string reference object from a C string.
   basic_cstring_view(const Char* s) : data_(s) {}
 
-  /**
+  /// Constructs a string reference from an `std::string` object.
-    \rst
-    Constructs a string reference from an ``std::string`` object.
-    \endrst
-   */
   basic_cstring_view(const std::basic_string<Char>& s) : data_(s.c_str()) {}
 
-  /** Returns the pointer to a C string. */
+  /// Returns the pointer to a C string.
   auto c_str() const -> const Char* { return data_; }
 };
 
@@ -135,33 +122,30 @@ FMT_API std::system_error vwindows_error(int error_code, string_view format_str,
                                          format_args args);
 
 /**
- \rst
+ * Constructs a `std::system_error` object with the description of the form
- Constructs a :class:`std::system_error` object with the description
+ *
- of the form
+ *     <message>: <system-message>
-
+ *
- .. parsed-literal::
+ * where `<message>` is the formatted message and `<system-message>` is the
-   *<message>*: *<system-message>*
+ * system message corresponding to the error code.
-
+ * `error_code` is a Windows error code as given by `GetLastError`.
- where *<message>* is the formatted message and *<system-message>* is the
+ * If `error_code` is not a valid error code such as -1, the system message
- system message corresponding to the error code.
+ * will look like "error -1".
- *error_code* is a Windows error code as given by ``GetLastError``.
+ *
- If *error_code* is not a valid error code such as -1, the system message
+ * **Example**:
- will look like "error -1".
+ *
-
+ *     // This throws a system_error with the description
- **Example**::
+ *     //   cannot open file 'madeup': The system cannot find the file
-
+ * specified.
-   // This throws a system_error with the description
+ *     // or similar (system message may vary).
-   //   cannot open file 'madeup': The system cannot find the file specified.
+ *     const char *filename = "madeup";
-   // or similar (system message may vary).
+ *     LPOFSTRUCT of = LPOFSTRUCT();
-   const char *filename = "madeup";
+ *     HFILE file = OpenFile(filename, &of, OF_READ);
-   LPOFSTRUCT of = LPOFSTRUCT();
+ *     if (file == HFILE_ERROR) {
-   HFILE file = OpenFile(filename, &of, OF_READ);
+ *       throw fmt::windows_error(GetLastError(),
-   if (file == HFILE_ERROR) {
+ *                                "cannot open file '{}'", filename);
-     throw fmt::windows_error(GetLastError(),
+ *     }
-                              "cannot open file '{}'", filename);
+ */
-   }
- \endrst
-*/
 template <typename... Args>
 std::system_error windows_error(int error_code, string_view message,
                                 const Args&... args) {
@@ -227,17 +211,16 @@ class buffered_file {
 
   FMT_API auto descriptor() const -> int;
 
-  void vprint(string_view format_str, format_args args) {
+  template <typename... T>
-    fmt::vprint(file_, format_str, args);
+  inline void print(string_view fmt, const T&... args) {
-  }
+    const auto& vargs = fmt::make_format_args(args...);
-
+    detail::is_locking<T...>() ? fmt::vprint_buffered(file_, fmt, vargs)
-  template <typename... Args>
+                               : fmt::vprint(file_, fmt, vargs);
-  inline void print(string_view format_str, const Args&... args) {
-    vprint(format_str, fmt::make_format_args(args...));
   }
 };
 
 #if FMT_USE_FCNTL
+
 // A file. Closed file is represented by a file object with descriptor -1.
 // Methods that are not declared with noexcept may throw
 // fmt::system_error in case of failure. Note that some errors such as
@@ -251,6 +234,8 @@ class FMT_API file {
   // Constructs a file object with a given descriptor.
   explicit file(int fd) : fd_(fd) {}
 
+  friend struct pipe;
+
  public:
   // Possible values for the oflag argument to the constructor.
   enum {
@@ -313,11 +298,6 @@ class FMT_API file {
   // necessary.
   void dup2(int fd, std::error_code& ec) noexcept;
 
-  // 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;
@@ -329,6 +309,15 @@ class FMT_API file {
 #  endif
 };
 
+struct FMT_API pipe {
+  file read_end;
+  file write_end;
+
+  // Creates a pipe setting up read_end and write_end file objects for reading
+  // and writing respectively.
+  pipe();
+};
+
 // Returns the memory page size.
 auto getpagesize() -> long;
 
@@ -370,13 +359,14 @@ struct ostream_params {
 };
 
 class file_buffer final : public buffer<char> {
+ private:
   file file_;
 
-  FMT_API void grow(size_t) override;
+  FMT_API static void grow(buffer<char>& buf, size_t);
 
  public:
   FMT_API file_buffer(cstring_view path, const ostream_params& params);
-  FMT_API file_buffer(file_buffer&& other);
+  FMT_API file_buffer(file_buffer&& other) noexcept;
   FMT_API ~file_buffer();
 
   void flush() {
@@ -393,11 +383,10 @@ class file_buffer final : public buffer<char> {
 
 }  // namespace detail
 
-// Added {} below to work around default constructor error known to
+constexpr auto buffer_size = detail::buffer_size();
-// 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. */
+/// A fast output stream for writing from a single thread. Writing from
+/// multiple threads without external synchronization may result in a data race.
 class FMT_API ostream {
  private:
   FMT_MSC_WARNING(suppress : 4251)
@@ -418,30 +407,25 @@ class FMT_API ostream {
 
   void close() { buffer_.close(); }
 
-  /**
+  /// Formats `args` according to specifications in `fmt` and writes the
-    Formats ``args`` according to specifications in ``fmt`` and writes the
+  /// output to the file.
-    output to the file.
-   */
   template <typename... T> void print(format_string<T...> fmt, T&&... args) {
-    vformat_to(std::back_inserter(buffer_), fmt,
+    vformat_to(appender(buffer_), fmt, fmt::make_format_args(args...));
-               fmt::make_format_args(args...));
   }
 };
 
 /**
-  \rst
+ * Opens a file for writing. Supported parameters passed in `params`:
-  Opens a file for writing. Supported parameters passed in *params*:
+ *
-
+ * - `<integer>`: Flags passed to [open](
-  * ``<integer>``: Flags passed to `open
+ *   https://pubs.opengroup.org/onlinepubs/007904875/functions/open.html)
-    <https://pubs.opengroup.org/onlinepubs/007904875/functions/open.html>`_
+ *   (`file::WRONLY | file::CREATE | file::TRUNC` by default)
-    (``file::WRONLY | file::CREATE | file::TRUNC`` by default)
+ * - `buffer_size=<integer>`: Output buffer size
-  * ``buffer_size=<integer>``: Output buffer size
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     auto out = fmt::output_file("guide.txt");
-    auto out = fmt::output_file("guide.txt");
+ *     out.print("Don't {}", "Panic");
-    out.print("Don't {}", "Panic");
-  \endrst
  */
 template <typename... T>
 inline auto output_file(cstring_view path, T... params) -> ostream {

include/spdlog/fmt/bundled/ostream.h

@@ -8,7 +8,9 @@
 #ifndef FMT_OSTREAM_H_
 #define FMT_OSTREAM_H_
 
-#include <fstream>  // std::filebuf
+#ifndef FMT_MODULE
+#  include <fstream>  // std::filebuf
+#endif
 
 #ifdef _WIN32
 #  ifdef __GLIBCXX__
@@ -18,42 +20,11 @@
 #  include <io.h>
 #endif
 
-#include "format.h"
+#include "chrono.h"  // formatbuf
 
 FMT_BEGIN_NAMESPACE
 namespace detail {
 
-template <typename Streambuf> class formatbuf : public Streambuf {
- private:
-  using char_type = typename Streambuf::char_type;
-  using streamsize = decltype(std::declval<Streambuf>().sputn(nullptr, 0));
-  using int_type = typename Streambuf::int_type;
-  using traits_type = typename Streambuf::traits_type;
-
-  buffer<char_type>& buffer_;
-
- public:
-  explicit formatbuf(buffer<char_type>& buf) : buffer_(buf) {}
-
- protected:
-  // 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;
-  }
-};
-
 // Generate a unique explicit instantion in every translation unit using a tag
 // type in an anonymous namespace.
 namespace {
@@ -73,12 +44,12 @@ auto get_file(std::filebuf&) -> FILE*;
 inline auto write_ostream_unicode(std::ostream& os, fmt::string_view data)
     -> bool {
   FILE* f = nullptr;
-#if FMT_MSC_VERSION
+#if FMT_MSC_VERSION && FMT_USE_RTTI
   if (auto* buf = dynamic_cast<std::filebuf*>(os.rdbuf()))
     f = get_file(*buf);
   else
     return false;
-#elif defined(_WIN32) && defined(__GLIBCXX__)
+#elif defined(_WIN32) && defined(__GLIBCXX__) && FMT_USE_RTTI
   auto* rdbuf = os.rdbuf();
   if (auto* sfbuf = dynamic_cast<__gnu_cxx::stdio_sync_filebuf<char>*>(rdbuf))
     f = sfbuf->file();
@@ -143,9 +114,8 @@ template <typename Char>
 struct basic_ostream_formatter : formatter<basic_string_view<Char>, Char> {
   void set_debug_format() = delete;
 
-  template <typename T, typename OutputIt>
+  template <typename T, typename Context>
-  auto format(const T& value, basic_format_context<OutputIt, Char>& ctx) const
+  auto format(const T& value, Context& ctx) const -> decltype(ctx.out()) {
-      -> OutputIt {
     auto buffer = basic_memory_buffer<Char>();
     detail::format_value(buffer, value);
     return formatter<basic_string_view<Char>, Char>::format(
@@ -158,22 +128,20 @@ using ostream_formatter = basic_ostream_formatter<char>;
 template <typename T, typename Char>
 struct formatter<detail::streamed_view<T>, Char>
     : basic_ostream_formatter<Char> {
-  template <typename OutputIt>
+  template <typename Context>
-  auto format(detail::streamed_view<T> view,
+  auto format(detail::streamed_view<T> view, Context& ctx) const
-              basic_format_context<OutputIt, Char>& ctx) const -> OutputIt {
+      -> decltype(ctx.out()) {
     return basic_ostream_formatter<Char>::format(view.value, ctx);
   }
 };
 
 /**
-  \rst
+ * Returns a view that formats `value` via an ostream `operator<<`.
-  Returns a view that formats `value` via an ostream ``operator<<``.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     fmt::print("Current thread id: {}\n",
-    fmt::print("Current thread id: {}\n",
+ *                fmt::streamed(std::this_thread::get_id()));
-               fmt::streamed(std::this_thread::get_id()));
-  \endrst
  */
 template <typename T>
 constexpr auto streamed(const T& value) -> detail::streamed_view<T> {
@@ -194,7 +162,7 @@ inline void vprint_directly(std::ostream& os, string_view format_str,
 FMT_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) {
+            typename detail::vformat_args<Char>::type args) {
   auto buffer = basic_memory_buffer<Char>();
   detail::vformat_to(buffer, format_str, args);
   if (detail::write_ostream_unicode(os, {buffer.data(), buffer.size()})) return;
@@ -202,18 +170,16 @@ void vprint(std::basic_ostream<Char>& os,
 }
 
 /**
-  \rst
+ * Prints formatted data to the stream `os`.
-  Prints formatted data to the stream *os*.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     fmt::print(cerr, "Don't {}!", "panic");
-    fmt::print(cerr, "Don't {}!", "panic");
-  \endrst
  */
 FMT_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())
+  if (detail::use_utf8())
     vprint(os, fmt, vargs);
   else
     detail::vprint_directly(os, fmt, vargs);
@@ -224,7 +190,7 @@ template <typename... Args>
 void print(std::wostream& os,
            basic_format_string<wchar_t, type_identity_t<Args>...> fmt,
            Args&&... args) {
-  vprint(os, fmt, fmt::make_format_args<buffer_context<wchar_t>>(args...));
+  vprint(os, fmt, fmt::make_format_args<buffered_context<wchar_t>>(args...));
 }
 
 FMT_EXPORT template <typename... T>

include/spdlog/fmt/bundled/printf.h

@@ -8,8 +8,10 @@
 #ifndef FMT_PRINTF_H_
 #define FMT_PRINTF_H_
 
-#include <algorithm>  // std::max
+#ifndef FMT_MODULE
-#include <limits>     // std::numeric_limits
+#  include <algorithm>  // std::max
+#  include <limits>     // std::numeric_limits
+#endif
 
 #include "format.h"
 
@@ -22,7 +24,7 @@ template <typename T> struct printf_formatter {
 
 template <typename Char> class basic_printf_context {
  private:
-  detail::buffer_appender<Char> out_;
+  basic_appender<Char> out_;
   basic_format_args<basic_printf_context> args_;
 
   static_assert(std::is_same<Char, char>::value ||
@@ -34,28 +36,20 @@ template <typename Char> class basic_printf_context {
   using parse_context_type = basic_format_parse_context<Char>;
   template <typename T> using formatter_type = printf_formatter<T>;
 
-  /**
+  /// Constructs a `printf_context` object. References to the arguments are
-    \rst
+  /// stored in the context object so make sure they have appropriate lifetimes.
-    Constructs a ``printf_context`` object. References to the arguments are
+  basic_printf_context(basic_appender<Char> out,
-    stored in the context object so make sure they have appropriate lifetimes.
-    \endrst
-   */
-  basic_printf_context(detail::buffer_appender<Char> out,
                        basic_format_args<basic_printf_context> args)
       : out_(out), args_(args) {}
 
-  auto out() -> detail::buffer_appender<Char> { return out_; }
+  auto out() -> basic_appender<Char> { return out_; }
-  void advance_to(detail::buffer_appender<Char>) {}
+  void advance_to(basic_appender<Char>) {}
 
   auto locale() -> detail::locale_ref { return {}; }
 
   auto arg(int id) const -> basic_format_arg<basic_printf_context> {
     return args_.get(id);
   }
-
-  FMT_CONSTEXPR void on_error(const char* message) {
-    detail::error_handler().on_error(message);
-  }
 };
 
 namespace detail {
@@ -64,7 +58,7 @@ namespace detail {
 // signed and unsigned integers.
 template <bool IsSigned> struct int_checker {
   template <typename T> static auto fits_in_int(T value) -> bool {
-    unsigned max = max_value<int>();
+    unsigned max = to_unsigned(max_value<int>());
     return value <= max;
   }
   static auto fits_in_int(bool) -> bool { return true; }
@@ -82,13 +76,13 @@ struct printf_precision_handler {
   template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
   auto operator()(T value) -> int {
     if (!int_checker<std::numeric_limits<T>::is_signed>::fits_in_int(value))
-      throw_format_error("number is too big");
+      report_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 {
-    throw_format_error("precision is not integer");
+    report_error("precision is not integer");
     return 0;
   }
 };
@@ -165,7 +159,7 @@ template <typename T, typename Context> class arg_converter {
 // unsigned).
 template <typename T, typename Context, typename Char>
 void convert_arg(basic_format_arg<Context>& arg, Char type) {
-  visit_format_arg(arg_converter<T, Context>(arg, type), arg);
+  arg.visit(arg_converter<T, Context>(arg, type));
 }
 
 // Converts an integer argument to char for printf.
@@ -195,12 +189,12 @@ template <typename Char> struct get_cstring {
 
 // 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 {
+class printf_width_handler {
  private:
-  format_specs<Char>& specs_;
+  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 {
@@ -209,14 +203,14 @@ template <typename Char> class printf_width_handler {
       specs_.align = align::left;
       width = 0 - width;
     }
-    unsigned int_max = max_value<int>();
+    unsigned int_max = to_unsigned(max_value<int>());
-    if (width > int_max) throw_format_error("number is too big");
+    if (width > int_max) report_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 {
-    throw_format_error("width is not integer");
+    report_error("width is not integer");
     return 0;
   }
 };
@@ -224,12 +218,12 @@ template <typename Char> class printf_width_handler {
 // 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)
+auto make_arg_formatter(basic_appender<Char> iter, format_specs& s)
     -> arg_formatter<Char> {
   return {iter, s, locale_ref()};
 }
 
-// The ``printf`` argument formatter.
+// The `printf` argument formatter.
 template <typename Char>
 class printf_arg_formatter : public arg_formatter<Char> {
  private:
@@ -241,11 +235,11 @@ class printf_arg_formatter : public arg_formatter<Char> {
   void 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);
+    write_bytes<Char>(this->out, is_string ? "(null)" : "(nil)", s);
   }
 
  public:
-  printf_arg_formatter(buffer_appender<Char> iter, format_specs<Char>& s,
+  printf_arg_formatter(basic_appender<Char> iter, format_specs& s,
                        context_type& ctx)
       : base(make_arg_formatter(iter, s)), context_(ctx) {}
 
@@ -259,19 +253,18 @@ class printf_arg_formatter : public arg_formatter<Char> {
       base::operator()(value);
       return;
     }
-    format_specs<Char> fmt_specs = this->specs;
+    format_specs s = this->specs;
-    if (fmt_specs.type != presentation_type::none &&
+    if (s.type != presentation_type::none && s.type != presentation_type::chr) {
-        fmt_specs.type != presentation_type::chr) {
       return (*this)(static_cast<int>(value));
     }
-    fmt_specs.sign = sign::none;
+    s.sign = sign::none;
-    fmt_specs.alt = false;
+    s.alt = false;
-    fmt_specs.fill[0] = ' ';  // Ignore '0' flag for char types.
+    s.fill = ' ';  // Ignore '0' flag for char types.
     // align::numeric needs to be overwritten here since the '0' flag is
     // ignored for non-numeric types
-    if (fmt_specs.align == align::none || fmt_specs.align == align::numeric)
+    if (s.align == align::none || s.align == align::numeric)
-      fmt_specs.align = align::right;
+      s.align = align::right;
-    write<Char>(this->out, static_cast<Char>(value), fmt_specs);
+    write<Char>(this->out, static_cast<Char>(value), s);
   }
 
   template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value)>
@@ -279,7 +272,6 @@ class printf_arg_formatter : public arg_formatter<Char> {
     base::operator()(value);
   }
 
-  /** Formats a null-terminated C string. */
   void operator()(const char* value) {
     if (value)
       base::operator()(value);
@@ -287,7 +279,6 @@ class printf_arg_formatter : public arg_formatter<Char> {
       write_null_pointer(this->specs.type != presentation_type::pointer);
   }
 
-  /** Formats a null-terminated wide C string. */
   void operator()(const wchar_t* value) {
     if (value)
       base::operator()(value);
@@ -297,7 +288,6 @@ class printf_arg_formatter : public arg_formatter<Char> {
 
   void operator()(basic_string_view<Char> value) { base::operator()(value); }
 
-  /** Formats a pointer. */
   void operator()(const void* value) {
     if (value)
       base::operator()(value);
@@ -305,7 +295,6 @@ class printf_arg_formatter : public arg_formatter<Char> {
       write_null_pointer();
   }
 
-  /** Formats an argument of a custom (user-defined) type. */
   void operator()(typename basic_format_arg<context_type>::handle handle) {
     auto parse_ctx = basic_format_parse_context<Char>({});
     handle.format(parse_ctx, context_);
@@ -313,7 +302,7 @@ class printf_arg_formatter : public arg_formatter<Char> {
 };
 
 template <typename Char>
-void parse_flags(format_specs<Char>& specs, const Char*& it, const Char* end) {
+void parse_flags(format_specs& specs, const Char*& it, const Char* end) {
   for (; it != end; ++it) {
     switch (*it) {
     case '-':
@@ -323,7 +312,7 @@ void parse_flags(format_specs<Char>& specs, const Char*& it, const Char* end) {
       specs.sign = sign::plus;
       break;
     case '0':
-      specs.fill[0] = '0';
+      specs.fill = '0';
       break;
     case ' ':
       if (specs.sign != sign::plus) specs.sign = sign::space;
@@ -338,7 +327,7 @@ 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,
+auto parse_header(const Char*& it, const Char* end, format_specs& specs,
                   GetArg get_arg) -> int {
   int arg_index = -1;
   Char c = *it;
@@ -350,11 +339,11 @@ auto parse_header(const Char*& it, const Char* end, format_specs<Char>& specs,
       ++it;
       arg_index = value != -1 ? value : max_value<int>();
     } else {
-      if (c == '0') specs.fill[0] = '0';
+      if (c == '0') specs.fill = '0';
       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) report_error("number is too big");
         specs.width = value;
         return arg_index;
       }
@@ -365,17 +354,17 @@ 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) report_error("number is too big");
     } else if (*it == '*') {
       ++it;
-      specs.width = static_cast<int>(visit_format_arg(
+      specs.width = static_cast<int>(
-          detail::printf_width_handler<Char>(specs), get_arg(-1)));
+          get_arg(-1).visit(detail::printf_width_handler(specs)));
     }
   }
   return arg_index;
 }
 
-inline auto parse_printf_presentation_type(char c, type t)
+inline auto parse_printf_presentation_type(char c, type t, bool& upper)
     -> presentation_type {
   using pt = presentation_type;
   constexpr auto integral_set = sint_set | uint_set | bool_set | char_set;
@@ -384,26 +373,31 @@ inline auto parse_printf_presentation_type(char c, type t)
     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;
+    upper = true;
-  case 'a':
+    FMT_FALLTHROUGH;
-    return in(t, float_set) ? pt::hexfloat_lower : pt::none;
+  case 'x':
-  case 'A':
+    return in(t, integral_set) ? pt::hex : pt::none;
-    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;
+    upper = true;
-  case 'f':
+    FMT_FALLTHROUGH;
-    return in(t, float_set) ? pt::fixed_lower : pt::none;
+  case 'e':
+    return in(t, float_set) ? pt::exp : pt::none;
   case 'F':
-    return in(t, float_set) ? pt::fixed_upper : pt::none;
+    upper = true;
-  case 'g':
+    FMT_FALLTHROUGH;
-    return in(t, float_set) ? pt::general_lower : pt::none;
+  case 'f':
+    return in(t, float_set) ? pt::fixed : pt::none;
   case 'G':
-    return in(t, float_set) ? pt::general_upper : pt::none;
+    upper = true;
+    FMT_FALLTHROUGH;
+  case 'g':
+    return in(t, float_set) ? pt::general : pt::none;
+  case 'A':
+    upper = true;
+    FMT_FALLTHROUGH;
+  case 'a':
+    return in(t, float_set) ? pt::hexfloat : pt::none;
   case 'c':
     return in(t, integral_set) ? pt::chr : pt::none;
   case 's':
@@ -418,7 +412,7 @@ inline auto parse_printf_presentation_type(char c, type t)
 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 iterator = basic_appender<Char>;
   auto out = iterator(buf);
   auto context = basic_printf_context<Char>(out, args);
   auto parse_ctx = basic_format_parse_context<Char>(format);
@@ -449,12 +443,12 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
     }
     write(out, basic_string_view<Char>(start, to_unsigned(it - 1 - start)));
 
-    auto specs = format_specs<Char>();
+    auto specs = format_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) report_error("argument not found");
 
     // Parse precision.
     if (it != end && *it == '.') {
@@ -464,8 +458,8 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
         specs.precision = parse_nonnegative_int(it, end, 0);
       } else if (c == '*') {
         ++it;
-        specs.precision = static_cast<int>(
+        specs.precision =
-            visit_format_arg(printf_precision_handler(), get_arg(-1)));
+            static_cast<int>(get_arg(-1).visit(printf_precision_handler()));
       } else {
         specs.precision = 0;
       }
@@ -476,22 +470,22 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
     // specified, the '0' flag is ignored
     if (specs.precision >= 0 && arg.is_integral()) {
       // Ignore '0' for non-numeric types or if '-' present.
-      specs.fill[0] = ' ';
+      specs.fill = ' ';
     }
     if (specs.precision >= 0 && arg.type() == type::cstring_type) {
-      auto str = visit_format_arg(get_cstring<Char>(), arg);
+      auto str = arg.visit(get_cstring<Char>());
       auto str_end = str + specs.precision;
       auto nul = std::find(str, str_end, Char());
       auto sv = basic_string_view<Char>(
           str, to_unsigned(nul != str_end ? nul - str : specs.precision));
       arg = make_arg<basic_printf_context<Char>>(sv);
     }
-    if (specs.alt && visit_format_arg(is_zero_int(), arg)) specs.alt = false;
+    if (specs.alt && arg.visit(is_zero_int())) specs.alt = false;
-    if (specs.fill[0] == '0') {
+    if (specs.fill.template get<Char>() == '0') {
       if (arg.is_arithmetic() && specs.align != align::left)
         specs.align = align::numeric;
       else
-        specs.fill[0] = ' ';  // Ignore '0' flag for non-numeric types or if '-'
+        specs.fill = ' ';  // Ignore '0' flag for non-numeric types or if '-'
                            // flag is also present.
     }
 
@@ -536,7 +530,7 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
     }
 
     // Parse type.
-    if (it == end) throw_format_error("invalid format string");
+    if (it == end) report_error("invalid format string");
     char type = static_cast<char>(*it++);
     if (arg.is_integral()) {
       // Normalize type.
@@ -546,18 +540,20 @@ 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);
+        arg.visit(char_converter<basic_printf_context<Char>>(arg));
         break;
       }
     }
-    specs.type = parse_printf_presentation_type(type, arg.type());
+    bool upper = false;
+    specs.type = parse_printf_presentation_type(type, arg.type(), upper);
     if (specs.type == presentation_type::none)
-      throw_format_error("invalid format specifier");
+      report_error("invalid format specifier");
+    specs.upper = upper;
 
     start = it;
 
     // Format argument.
-    visit_format_arg(printf_arg_formatter<Char>(out, specs, context), arg);
+    arg.visit(printf_arg_formatter<Char>(out, specs, context));
   }
   write(out, basic_string_view<Char>(start, to_unsigned(it - start)));
 }
@@ -569,29 +565,21 @@ using wprintf_context = basic_printf_context<wchar_t>;
 using printf_args = basic_format_args<printf_context>;
 using wprintf_args = basic_format_args<wprintf_context>;
 
-/**
+/// Constructs an `format_arg_store` object that contains references to
-  \rst
+/// arguments and can be implicitly converted to `printf_args`.
-  Constructs an `~fmt::format_arg_store` object that contains references to
+template <typename Char = char, typename... T>
-  arguments and can be implicitly converted to `~fmt::printf_args`.
+inline auto make_printf_args(T&... args)
-  \endrst
+    -> decltype(fmt::make_format_args<basic_printf_context<Char>>(args...)) {
- */
+  return fmt::make_format_args<basic_printf_context<Char>>(args...);
-template <typename... T>
-inline auto make_printf_args(const T&... args)
-    -> format_arg_store<printf_context, T...> {
-  return {args...};
 }
 
-// DEPRECATED!
+template <typename Char> struct vprintf_args {
-template <typename... T>
+  using type = basic_format_args<basic_printf_context<Char>>;
-inline auto make_wprintf_args(const T&... args)
+};
-    -> format_arg_store<wprintf_context, T...> {
-  return {args...};
-}
 
 template <typename Char>
-inline auto vsprintf(
+inline auto vsprintf(basic_string_view<Char> fmt,
-    basic_string_view<Char> fmt,
+                     typename vprintf_args<Char>::type args)
-    basic_format_args<basic_printf_context<type_identity_t<Char>>> args)
     -> std::basic_string<Char> {
   auto buf = basic_memory_buffer<Char>();
   detail::vprintf(buf, fmt, args);
@@ -599,26 +587,22 @@ inline auto vsprintf(
 }
 
 /**
-  \rst
+ * Formats `args` according to specifications in `fmt` and returns the result
-  Formats arguments and returns the result as a string.
+ * as as string.
-
+ *
-  **Example**::
+ * **Example**:
-
+ *
-    std::string message = fmt::sprintf("The answer is %d", 42);
+ *     std::string message = fmt::sprintf("The answer is %d", 42);
-  \endrst
+ */
-*/
+template <typename S, typename... T, typename Char = char_t<S>>
-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> {
   return vsprintf(detail::to_string_view(fmt),
                   fmt::make_format_args<basic_printf_context<Char>>(args...));
 }
 
 template <typename Char>
-inline auto vfprintf(
+inline auto vfprintf(std::FILE* f, basic_string_view<Char> fmt,
-    std::FILE* f, basic_string_view<Char> fmt,
+                     typename vprintf_args<Char>::type args) -> int {
-    basic_format_args<basic_printf_context<type_identity_t<Char>>> args)
-    -> int {
   auto buf = basic_memory_buffer<Char>();
   detail::vprintf(buf, fmt, args);
   size_t size = buf.size();
@@ -628,36 +612,33 @@ inline auto vfprintf(
 }
 
 /**
-  \rst
+ * Formats `args` according to specifications in `fmt` and writes the output
-  Prints formatted data to the file *f*.
+ * to `f`.
-
+ *
-  **Example**::
+ * **Example**:
-
+ *
-    fmt::fprintf(stderr, "Don't %s!", "panic");
+ *     fmt::fprintf(stderr, "Don't %s!", "panic");
-  \endrst
  */
 template <typename S, typename... T, typename Char = char_t<S>>
 inline auto fprintf(std::FILE* f, const S& fmt, const T&... args) -> int {
   return vfprintf(f, detail::to_string_view(fmt),
-                  fmt::make_format_args<basic_printf_context<Char>>(args...));
+                  make_printf_args<Char>(args...));
 }
 
 template <typename Char>
-FMT_DEPRECATED inline auto vprintf(
+FMT_DEPRECATED inline auto vprintf(basic_string_view<Char> fmt,
-    basic_string_view<Char> fmt,
+                                   typename vprintf_args<Char>::type args)
-    basic_format_args<basic_printf_context<type_identity_t<Char>>> args)
     -> int {
   return vfprintf(stdout, fmt, args);
 }
 
 /**
-  \rst
+ * Formats `args` according to specifications in `fmt` and writes the output
-  Prints formatted data to ``stdout``.
+ * to `stdout`.
-
+ *
-  **Example**::
+ * **Example**:
-
+ *
-    fmt::printf("Elapsed time: %.2f seconds", 1.23);
+ *   fmt::printf("Elapsed time: %.2f seconds", 1.23);
-  \endrst
  */
 template <typename... T>
 inline auto printf(string_view fmt, const T&... args) -> int {
@@ -666,7 +647,7 @@ inline auto printf(string_view fmt, const T&... args) -> int {
 template <typename... T>
 FMT_DEPRECATED inline auto printf(basic_string_view<wchar_t> fmt,
                                   const T&... args) -> int {
-  return vfprintf(stdout, fmt, make_wprintf_args(args...));
+  return vfprintf(stdout, fmt, make_printf_args<wchar_t>(args...));
 }
 
 FMT_END_EXPORT

include/spdlog/fmt/bundled/ranges.h

@@ -8,67 +8,31 @@
 #ifndef FMT_RANGES_H_
 #define FMT_RANGES_H_
 
-#include <initializer_list>
+#ifndef FMT_MODULE
-#include <tuple>
+#  include <initializer_list>
-#include <type_traits>
+#  include <iterator>
+#  include <string>
+#  include <tuple>
+#  include <type_traits>
+#  include <utility>
+#endif
 
 #include "format.h"
 
 FMT_BEGIN_NAMESPACE
 
+FMT_EXPORT
+enum class range_format { disabled, map, set, sequence, string, debug_string };
+
 namespace detail {
 
-template <typename Range, typename OutputIt>
-auto copy(const Range& range, OutputIt out) -> OutputIt {
-  for (auto it = range.begin(), end = range.end(); it != end; ++it)
-    *out++ = *it;
-  return out;
-}
-
-template <typename OutputIt>
-auto copy(const char* str, OutputIt out) -> OutputIt {
-  while (*str) *out++ = *str++;
-  return out;
-}
-
-template <typename OutputIt> auto copy(char ch, OutputIt out) -> OutputIt {
-  *out++ = ch;
-  return out;
-}
-
-template <typename OutputIt> auto copy(wchar_t ch, OutputIt out) -> OutputIt {
-  *out++ = ch;
-  return out;
-}
-
-// Returns true if T has a std::string-like interface, like std::string_view.
-template <typename T> class is_std_string_like {
-  template <typename U>
-  static auto check(U* p)
-      -> decltype((void)p->find('a'), p->length(), (void)p->data(), int());
-  template <typename> static void check(...);
-
- public:
-  static constexpr const bool value =
-      is_string<T>::value ||
-      std::is_convertible<T, std_string_view<char>>::value ||
-      !std::is_void<decltype(check<T>(nullptr))>::value;
-};
-
-template <typename Char>
-struct is_std_string_like<fmt::basic_string_view<Char>> : std::true_type {};
-
 template <typename T> class is_map {
   template <typename U> static auto check(U*) -> typename U::mapped_type;
   template <typename> static void check(...);
 
  public:
-#ifdef FMT_FORMAT_MAP_AS_LIST  // DEPRECATED!
-  static constexpr const bool value = false;
-#else
   static constexpr const bool value =
       !std::is_void<decltype(check<T>(nullptr))>::value;
-#endif
 };
 
 template <typename T> class is_set {
@@ -76,12 +40,8 @@ template <typename T> class is_set {
   template <typename> static void check(...);
 
  public:
-#ifdef FMT_FORMAT_SET_AS_LIST  // DEPRECATED!
-  static constexpr const bool value = false;
-#else
   static constexpr const bool value =
       !std::is_void<decltype(check<T>(nullptr))>::value && !is_map<T>::value;
-#endif
 };
 
 template <typename... Ts> struct conditional_helper {};
@@ -110,17 +70,17 @@ template <typename T, typename Enable = void>
 struct has_member_fn_begin_end_t : std::false_type {};
 
 template <typename T>
-struct has_member_fn_begin_end_t<T, void_t<decltype(std::declval<T>().begin()),
+struct has_member_fn_begin_end_t<T, void_t<decltype(*std::declval<T>().begin()),
                                            decltype(std::declval<T>().end())>>
     : std::true_type {};
 
-// Member function overload
+// Member function overloads.
 template <typename T>
 auto range_begin(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).begin());
 template <typename T>
 auto range_end(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).end());
 
-// ADL overload. Only participates in overload resolution if member functions
+// ADL overloads. Only participate in overload resolution if member functions
 // are not found.
 template <typename T>
 auto range_begin(T&& rng)
@@ -141,16 +101,16 @@ struct has_mutable_begin_end : std::false_type {};
 
 template <typename T>
 struct has_const_begin_end<
-    T,
+    T, void_t<decltype(*detail::range_begin(
-    void_t<
+                  std::declval<const remove_cvref_t<T>&>())),
-        decltype(detail::range_begin(std::declval<const remove_cvref_t<T>&>())),
+              decltype(detail::range_end(
-        decltype(detail::range_end(std::declval<const remove_cvref_t<T>&>()))>>
+                  std::declval<const remove_cvref_t<T>&>()))>>
     : std::true_type {};
 
 template <typename T>
 struct has_mutable_begin_end<
-    T, void_t<decltype(detail::range_begin(std::declval<T>())),
+    T, void_t<decltype(*detail::range_begin(std::declval<T&>())),
-              decltype(detail::range_end(std::declval<T>())),
+              decltype(detail::range_end(std::declval<T&>())),
               // the extra int here is because older versions of MSVC don't
               // SFINAE properly unless there are distinct types
               int>> : std::true_type {};
@@ -206,12 +166,13 @@ 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 <size_t... Is>
-  static auto check2(index_sequence<Is...>,
+  static auto all_true(index_sequence<Is...>,
-                     integer_sequence<bool, (Is == Is)...>) -> std::true_type;
+                       integer_sequence<bool, (Is >= 0)...>) -> std::true_type;
-  static auto check2(...) -> std::false_type;
+  static auto all_true(...) -> std::false_type;
-  template <std::size_t... Is>
+
-  static auto check(index_sequence<Is...>) -> decltype(check2(
+  template <size_t... Is>
+  static auto check(index_sequence<Is...>) -> decltype(all_true(
       index_sequence<Is...>{},
       integer_sequence<bool,
                        (is_formattable<typename std::tuple_element<Is, T>::type,
@@ -292,6 +253,18 @@ FMT_CONSTEXPR auto maybe_set_debug_format(Formatter& f, bool set)
 template <typename Formatter>
 FMT_CONSTEXPR void maybe_set_debug_format(Formatter&, ...) {}
 
+template <typename T>
+struct range_format_kind_
+    : 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> {};
+
+template <range_format K>
+using range_format_constant = std::integral_constant<range_format, K>;
+
 // These are not generic lambdas for compatibility with C++11.
 template <typename ParseContext> struct parse_empty_specs {
   template <typename Formatter> FMT_CONSTEXPR void operator()(Formatter& f) {
@@ -305,8 +278,7 @@ template <typename FormatContext> struct format_tuple_element {
 
   template <typename T>
   void operator()(const formatter<T, char_type>& f, const T& v) {
-    if (i > 0)
+    if (i > 0) ctx.advance_to(detail::copy<char_type>(separator, ctx.out()));
-      ctx.advance_to(detail::copy_str<char_type>(separator, ctx.out()));
     ctx.advance_to(f.format(v, ctx));
     ++i;
   }
@@ -358,8 +330,7 @@ struct formatter<Tuple, Char,
   template <typename ParseContext>
   FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
     auto it = ctx.begin();
-    if (it != ctx.end() && *it != '}')
+    if (it != ctx.end() && *it != '}') report_error("invalid format specifier");
-      FMT_THROW(format_error("invalid format specifier"));
     detail::for_each(formatters_, detail::parse_empty_specs<ParseContext>{ctx});
     return it;
   }
@@ -367,19 +338,17 @@ struct formatter<Tuple, Char,
   template <typename FormatContext>
   auto format(const Tuple& value, FormatContext& ctx) const
       -> decltype(ctx.out()) {
-    ctx.advance_to(detail::copy_str<Char>(opening_bracket_, ctx.out()));
+    ctx.advance_to(detail::copy<Char>(opening_bracket_, ctx.out()));
     detail::for_each2(
         formatters_, value,
         detail::format_tuple_element<FormatContext>{0, ctx, separator_});
-    return detail::copy_str<Char>(closing_bracket_, ctx.out());
+    return detail::copy<Char>(closing_bracket_, ctx.out());
   }
 };
 
 template <typename T, typename Char> struct is_range {
   static constexpr const bool value =
-      detail::is_range_<T>::value && !detail::is_std_string_like<T>::value &&
+      detail::is_range_<T>::value && !detail::has_to_string_view<T>::value;
-      !std::is_convertible<T, std::basic_string<Char>>::value &&
-      !std::is_convertible<T, detail::std_string_view<Char>>::value;
 };
 
 namespace detail {
@@ -401,8 +370,8 @@ template <typename Context> struct range_mapper {
 
 template <typename Char, typename Element>
 using range_formatter_type =
-    formatter<remove_cvref_t<decltype(range_mapper<buffer_context<Char>>{}.map(
+    formatter<remove_cvref_t<decltype(range_mapper<buffered_context<Char>>{}
-                  std::declval<Element>()))>,
+                                          .map(std::declval<Element>()))>,
               Char>;
 
 template <typename R>
@@ -438,6 +407,24 @@ struct range_formatter<
       detail::string_literal<Char, '['>{};
   basic_string_view<Char> closing_bracket_ =
       detail::string_literal<Char, ']'>{};
+  bool is_debug = false;
+
+  template <typename Output, typename It, typename Sentinel, typename U = T,
+            FMT_ENABLE_IF(std::is_same<U, Char>::value)>
+  auto write_debug_string(Output& out, It it, Sentinel end) const -> Output {
+    auto buf = basic_memory_buffer<Char>();
+    for (; it != end; ++it) buf.push_back(*it);
+    auto specs = format_specs();
+    specs.type = presentation_type::debug;
+    return detail::write<Char>(
+        out, basic_string_view<Char>(buf.data(), buf.size()), specs);
+  }
+
+  template <typename Output, typename It, typename Sentinel, typename U = T,
+            FMT_ENABLE_IF(!std::is_same<U, Char>::value)>
+  auto write_debug_string(Output& out, It, Sentinel) const -> Output {
+    return out;
+  }
 
  public:
   FMT_CONSTEXPR range_formatter() {}
@@ -460,17 +447,37 @@ struct range_formatter<
   FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
     auto it = ctx.begin();
     auto end = ctx.end();
+    detail::maybe_set_debug_format(underlying_, true);
+    if (it == end) return underlying_.parse(ctx);
 
-    if (it != end && *it == 'n') {
+    switch (detail::to_ascii(*it)) {
+    case 'n':
       set_brackets({}, {});
       ++it;
+      break;
+    case '?':
+      is_debug = true;
+      set_brackets({}, {});
+      ++it;
+      if (it == end || *it != 's') report_error("invalid format specifier");
+      FMT_FALLTHROUGH;
+    case 's':
+      if (!std::is_same<T, Char>::value)
+        report_error("invalid format specifier");
+      if (!is_debug) {
+        set_brackets(detail::string_literal<Char, '"'>{},
+                     detail::string_literal<Char, '"'>{});
+        set_separator({});
+        detail::maybe_set_debug_format(underlying_, false);
+      }
+      ++it;
+      return it;
     }
 
     if (it != end && *it != '}') {
-      if (*it != ':') FMT_THROW(format_error("invalid format specifier"));
+      if (*it != ':') report_error("invalid format specifier");
+      detail::maybe_set_debug_format(underlying_, false);
       ++it;
-    } else {
-      detail::maybe_set_debug_format(underlying_, true);
     }
 
     ctx.advance_to(it);
@@ -479,80 +486,27 @@ struct range_formatter<
 
   template <typename R, typename FormatContext>
   auto format(R&& range, FormatContext& ctx) const -> decltype(ctx.out()) {
-    detail::range_mapper<buffer_context<Char>> mapper;
+    auto mapper = detail::range_mapper<buffered_context<Char>>();
     auto out = ctx.out();
-    out = detail::copy_str<Char>(opening_bracket_, out);
-    int i = 0;
     auto it = detail::range_begin(range);
     auto end = detail::range_end(range);
+    if (is_debug) return write_debug_string(out, std::move(it), end);
+
+    out = detail::copy<Char>(opening_bracket_, out);
+    int i = 0;
     for (; it != end; ++it) {
-      if (i > 0) out = detail::copy_str<Char>(separator_, out);
+      if (i > 0) out = detail::copy<Char>(separator_, out);
       ctx.advance_to(out);
-      auto&& item = *it;
+      auto&& item = *it;  // Need an lvalue
       out = underlying_.format(mapper.map(item), ctx);
       ++i;
     }
-    out = detail::copy_str<Char>(closing_bracket_, out);
+    out = detail::copy<Char>(closing_bracket_, out);
     return out;
   }
 };
 
-enum class range_format { disabled, map, set, sequence, string, debug_string };
+FMT_EXPORT
-
-namespace detail {
-template <typename T>
-struct range_format_kind_
-    : 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> {};
-
-template <range_format K, typename R, typename Char, typename Enable = void>
-struct range_default_formatter;
-
-template <range_format K>
-using range_format_constant = std::integral_constant<range_format, K>;
-
-template <range_format K, typename R, typename Char>
-struct range_default_formatter<
-    K, R, Char,
-    enable_if_t<(K == range_format::sequence || K == range_format::map ||
-                 K == range_format::set)>> {
-  using range_type = detail::maybe_const_range<R>;
-  range_formatter<detail::uncvref_type<range_type>, Char> underlying_;
-
-  FMT_CONSTEXPR range_default_formatter() { init(range_format_constant<K>()); }
-
-  FMT_CONSTEXPR void init(range_format_constant<range_format::set>) {
-    underlying_.set_brackets(detail::string_literal<Char, '{'>{},
-                             detail::string_literal<Char, '}'>{});
-  }
-
-  FMT_CONSTEXPR void init(range_format_constant<range_format::map>) {
-    underlying_.set_brackets(detail::string_literal<Char, '{'>{},
-                             detail::string_literal<Char, '}'>{});
-    underlying_.underlying().set_brackets({}, {});
-    underlying_.underlying().set_separator(
-        detail::string_literal<Char, ':', ' '>{});
-  }
-
-  FMT_CONSTEXPR void init(range_format_constant<range_format::sequence>) {}
-
-  template <typename ParseContext>
-  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
-    return underlying_.parse(ctx);
-  }
-
-  template <typename FormatContext>
-  auto format(range_type& range, FormatContext& ctx) const
-      -> decltype(ctx.out()) {
-    return underlying_.format(range, ctx);
-  }
-};
-}  // namespace detail
-
 template <typename T, typename Char, typename Enable = void>
 struct range_format_kind
     : conditional_t<
@@ -562,18 +516,221 @@ struct range_format_kind
 template <typename R, typename Char>
 struct formatter<
     R, Char,
-    enable_if_t<conjunction<bool_constant<range_format_kind<R, Char>::value !=
+    enable_if_t<conjunction<
-                                          range_format::disabled>
+        bool_constant<
+            range_format_kind<R, Char>::value != range_format::disabled &&
+            range_format_kind<R, Char>::value != range_format::map &&
+            range_format_kind<R, Char>::value != range_format::string &&
+            range_format_kind<R, Char>::value != range_format::debug_string>
 // Workaround a bug in MSVC 2015 and earlier.
 #if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1910
         ,
         detail::is_formattable_delayed<R, Char>
 #endif
-                            >::value>>
+        >::value>> {
-    : detail::range_default_formatter<range_format_kind<R, Char>::value, R,
+ private:
-                                      Char> {
+  using range_type = detail::maybe_const_range<R>;
+  range_formatter<detail::uncvref_type<range_type>, Char> range_formatter_;
+
+ public:
+  using nonlocking = void;
+
+  FMT_CONSTEXPR formatter() {
+    if (detail::const_check(range_format_kind<R, Char>::value !=
+                            range_format::set))
+      return;
+    range_formatter_.set_brackets(detail::string_literal<Char, '{'>{},
+                                  detail::string_literal<Char, '}'>{});
+  }
+
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return range_formatter_.parse(ctx);
+  }
+
+  template <typename FormatContext>
+  auto format(range_type& range, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    return range_formatter_.format(range, ctx);
+  }
 };
 
+// A map formatter.
+template <typename R, typename Char>
+struct formatter<
+    R, Char,
+    enable_if_t<range_format_kind<R, Char>::value == range_format::map>> {
+ private:
+  using map_type = detail::maybe_const_range<R>;
+  using element_type = detail::uncvref_type<map_type>;
+
+  decltype(detail::tuple::get_formatters<element_type, Char>(
+      detail::tuple_index_sequence<element_type>())) formatters_;
+  bool no_delimiters_ = false;
+
+ public:
+  FMT_CONSTEXPR formatter() {}
+
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    auto it = ctx.begin();
+    auto end = ctx.end();
+    if (it != end) {
+      if (detail::to_ascii(*it) == 'n') {
+        no_delimiters_ = true;
+        ++it;
+      }
+      if (it != end && *it != '}') {
+        if (*it != ':') report_error("invalid format specifier");
+        ++it;
+      }
+      ctx.advance_to(it);
+    }
+    detail::for_each(formatters_, detail::parse_empty_specs<ParseContext>{ctx});
+    return it;
+  }
+
+  template <typename FormatContext>
+  auto format(map_type& map, FormatContext& ctx) const -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    basic_string_view<Char> open = detail::string_literal<Char, '{'>{};
+    if (!no_delimiters_) out = detail::copy<Char>(open, out);
+    int i = 0;
+    auto mapper = detail::range_mapper<buffered_context<Char>>();
+    basic_string_view<Char> sep = detail::string_literal<Char, ',', ' '>{};
+    for (auto&& value : map) {
+      if (i > 0) out = detail::copy<Char>(sep, out);
+      ctx.advance_to(out);
+      detail::for_each2(formatters_, mapper.map(value),
+                        detail::format_tuple_element<FormatContext>{
+                            0, ctx, detail::string_literal<Char, ':', ' '>{}});
+      ++i;
+    }
+    basic_string_view<Char> close = detail::string_literal<Char, '}'>{};
+    if (!no_delimiters_) out = detail::copy<Char>(close, out);
+    return out;
+  }
+};
+
+// A (debug_)string formatter.
+template <typename R, typename Char>
+struct formatter<
+    R, Char,
+    enable_if_t<range_format_kind<R, Char>::value == range_format::string ||
+                range_format_kind<R, Char>::value ==
+                    range_format::debug_string>> {
+ private:
+  using range_type = detail::maybe_const_range<R>;
+  using string_type =
+      conditional_t<std::is_constructible<
+                        detail::std_string_view<Char>,
+                        decltype(detail::range_begin(std::declval<R>())),
+                        decltype(detail::range_end(std::declval<R>()))>::value,
+                    detail::std_string_view<Char>, std::basic_string<Char>>;
+
+  formatter<string_type, Char> underlying_;
+
+ public:
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return underlying_.parse(ctx);
+  }
+
+  template <typename FormatContext>
+  auto format(range_type& range, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    if (detail::const_check(range_format_kind<R, Char>::value ==
+                            range_format::debug_string))
+      *out++ = '"';
+    out = underlying_.format(
+        string_type{detail::range_begin(range), detail::range_end(range)}, ctx);
+    if (detail::const_check(range_format_kind<R, Char>::value ==
+                            range_format::debug_string))
+      *out++ = '"';
+    return out;
+  }
+};
+
+template <typename It, typename Sentinel, typename Char = char>
+struct join_view : detail::view {
+  It begin;
+  Sentinel end;
+  basic_string_view<Char> sep;
+
+  join_view(It b, Sentinel e, basic_string_view<Char> s)
+      : begin(std::move(b)), end(e), sep(s) {}
+};
+
+template <typename It, typename Sentinel, typename Char>
+struct formatter<join_view<It, Sentinel, Char>, Char> {
+ private:
+  using value_type =
+#ifdef __cpp_lib_ranges
+      std::iter_value_t<It>;
+#else
+      typename std::iterator_traits<It>::value_type;
+#endif
+  formatter<remove_cvref_t<value_type>, Char> value_formatter_;
+
+  using view_ref = conditional_t<std::is_copy_constructible<It>::value,
+                                 const join_view<It, Sentinel, Char>&,
+                                 join_view<It, Sentinel, Char>&&>;
+
+ public:
+  using nonlocking = void;
+
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> const Char* {
+    return value_formatter_.parse(ctx);
+  }
+
+  template <typename FormatContext>
+  auto format(view_ref& value, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto it = std::forward<view_ref>(value).begin;
+    auto out = ctx.out();
+    if (it == value.end) return out;
+    out = value_formatter_.format(*it, ctx);
+    ++it;
+    while (it != value.end) {
+      out = detail::copy<Char>(value.sep.begin(), value.sep.end(), out);
+      ctx.advance_to(out);
+      out = value_formatter_.format(*it, ctx);
+      ++it;
+    }
+    return out;
+  }
+};
+
+/// Returns a view that formats the iterator range `[begin, end)` with elements
+/// separated by `sep`.
+template <typename It, typename Sentinel>
+auto join(It begin, Sentinel end, string_view sep) -> join_view<It, Sentinel> {
+  return {std::move(begin), end, sep};
+}
+
+/**
+ * Returns a view that formats `range` with elements separated by `sep`.
+ *
+ * **Example**:
+ *
+ *     auto v = std::vector<int>{1, 2, 3};
+ *     fmt::print("{}", fmt::join(v, ", "));
+ *     // Output: 1, 2, 3
+ *
+ * `fmt::join` applies passed format specifiers to the range elements:
+ *
+ *     fmt::print("{:02}", fmt::join(v, ", "));
+ *     // Output: 01, 02, 03
+ */
+template <typename Range>
+auto join(Range&& r, string_view sep)
+    -> join_view<decltype(detail::range_begin(r)),
+                 decltype(detail::range_end(r))> {
+  return {detail::range_begin(r), detail::range_end(r), sep};
+}
+
 template <typename Char, typename... T> struct tuple_join_view : detail::view {
   const std::tuple<T...>& tuple;
   basic_string_view<Char> sep;
@@ -623,7 +780,7 @@ struct formatter<tuple_join_view<Char, T...>, Char> {
     if (N > 1) {
       auto end1 = do_parse(ctx, std::integral_constant<size_t, N - 1>());
       if (end != end1)
-        FMT_THROW(format_error("incompatible format specs for tuple elements"));
+        report_error("incompatible format specs for tuple elements");
     }
 #endif
     return end;
@@ -642,13 +799,11 @@ struct formatter<tuple_join_view<Char, T...>, Char> {
       typename FormatContext::iterator {
     auto out = std::get<sizeof...(T) - N>(formatters_)
                    .format(std::get<sizeof...(T) - N>(value.tuple), ctx);
-    if (N > 1) {
+    if (N <= 1) return out;
-      out = std::copy(value.sep.begin(), value.sep.end(), out);
+    out = detail::copy<Char>(value.sep, out);
     ctx.advance_to(out);
     return do_format(value, ctx, std::integral_constant<size_t, N - 1>());
   }
-    return out;
-  }
 };
 
 namespace detail {
@@ -692,15 +847,13 @@ struct formatter<
 FMT_BEGIN_EXPORT
 
 /**
-  \rst
+ * Returns an object that formats `std::tuple` with elements separated by `sep`.
-  Returns an object that formats `tuple` with elements separated by `sep`.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     auto t = std::tuple<int, char>{1, 'a'};
-    std::tuple<int, char> t = {1, 'a'};
+ *     fmt::print("{}", fmt::join(t, ", "));
-    fmt::print("{}", fmt::join(t, ", "));
+ *     // Output: 1, a
-    // Output: "1, a"
-  \endrst
  */
 template <typename... T>
 FMT_CONSTEXPR auto join(const std::tuple<T...>& tuple, string_view sep)
@@ -708,23 +861,14 @@ FMT_CONSTEXPR auto join(const std::tuple<T...>& tuple, string_view sep)
   return {tuple, sep};
 }
 
-template <typename... T>
-FMT_CONSTEXPR auto join(const std::tuple<T...>& tuple,
-                        basic_string_view<wchar_t> sep)
-    -> tuple_join_view<wchar_t, T...> {
-  return {tuple, sep};
-}
-
 /**
-  \rst
+ * Returns an object that formats `std::initializer_list` with elements
-  Returns an object that formats `initializer_list` with elements separated by
+ * separated by `sep`.
-  `sep`.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     fmt::print("{}", fmt::join({1, 2, 3}, ", "));
-    fmt::print("{}", fmt::join({1, 2, 3}, ", "));
+ *     // Output: "1, 2, 3"
-    // Output: "1, 2, 3"
-  \endrst
  */
 template <typename T>
 auto join(std::initializer_list<T> list, string_view sep)

include/spdlog/fmt/bundled/std.h

@@ -8,25 +8,24 @@
 #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>)
+#ifndef FMT_MODULE
-#  include <version>
+#  include <atomic>
-#endif
+#  include <bitset>
-// Checking FMT_CPLUSPLUS for warning suppression in MSVC.
+#  include <complex>
-#if FMT_CPLUSPLUS >= 201703L
+#  include <cstdlib>
+#  include <exception>
+#  include <memory>
+#  include <thread>
+#  include <type_traits>
+#  include <typeinfo>
+#  include <utility>
+#  include <vector>
+
+// Check FMT_CPLUSPLUS to suppress a bogus warning in MSVC.
+#  if FMT_CPLUSPLUS >= 201703L
 #    if FMT_HAS_INCLUDE(<filesystem>)
 #      include <filesystem>
 #    endif
@@ -36,10 +35,19 @@
 #    if FMT_HAS_INCLUDE(<optional>)
 #      include <optional>
 #    endif
-#endif
+#  endif
-
+// Use > instead of >= in the version check because <source_location> may be
-#if FMT_CPLUSPLUS > 201703L && FMT_HAS_INCLUDE(<source_location>)
+// available after C++17 but before C++20 is marked as implemented.
+#  if FMT_CPLUSPLUS > 201703L && FMT_HAS_INCLUDE(<source_location>)
 #    include <source_location>
+#  endif
+#  if FMT_CPLUSPLUS > 202002L && FMT_HAS_INCLUDE(<expected>)
+#    include <expected>
+#  endif
+#endif  // FMT_MODULE
+
+#if FMT_HAS_INCLUDE(<version>)
+#  include <version>
 #endif
 
 // GCC 4 does not support FMT_HAS_INCLUDE.
@@ -52,17 +60,6 @@
 #  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
@@ -117,7 +114,7 @@ void write_escaped_path(basic_memory_buffer<Char>& quoted,
 FMT_EXPORT
 template <typename Char> struct formatter<std::filesystem::path, Char> {
  private:
-  format_specs<Char> specs_;
+  format_specs specs_;
   detail::arg_ref<Char> width_ref_;
   bool debug_ = false;
   char path_type_ = 0;
@@ -137,18 +134,16 @@ template <typename Char> struct formatter<std::filesystem::path, Char> {
       debug_ = true;
       ++it;
     }
-    if (it != end && (*it == 'g')) path_type_ = *it++;
+    if (it != end && (*it == 'g')) path_type_ = detail::to_ascii(*it++);
     return it;
   }
 
   template <typename FormatContext>
   auto format(const std::filesystem::path& p, FormatContext& ctx) const {
     auto specs = specs_;
-#  ifdef _WIN32
+    auto path_string =
-    auto path_string = !path_type_ ? p.native() : p.generic_wstring();
+        !path_type_ ? p.native()
-#  else
+                    : p.generic_string<std::filesystem::path::value_type>();
-    auto path_string = !path_type_ ? p.native() : p.generic_string();
-#  endif
 
     detail::handle_dynamic_spec<detail::width_checker>(specs.width, width_ref_,
                                                        ctx);
@@ -163,6 +158,22 @@ template <typename Char> struct formatter<std::filesystem::path, Char> {
                          specs);
   }
 };
+
+class path : public std::filesystem::path {
+ public:
+  auto display_string() const -> std::string {
+    const std::filesystem::path& base = *this;
+    return fmt::format(FMT_STRING("{}"), base);
+  }
+  auto system_string() const -> std::string { return string(); }
+
+  auto generic_display_string() const -> std::string {
+    const std::filesystem::path& base = *this;
+    return fmt::format(FMT_STRING("{:g}"), base);
+  }
+  auto generic_system_string() const -> std::string { return generic_string(); }
+};
+
 FMT_END_NAMESPACE
 #endif  // FMT_CPP_LIB_FILESYSTEM
 
@@ -242,6 +253,56 @@ struct formatter<std::optional<T>, Char,
 FMT_END_NAMESPACE
 #endif  // __cpp_lib_optional
 
+#if defined(__cpp_lib_expected) || FMT_CPP_LIB_VARIANT
+
+FMT_BEGIN_NAMESPACE
+namespace detail {
+
+template <typename Char, typename OutputIt, typename T>
+auto write_escaped_alternative(OutputIt out, const T& v) -> OutputIt {
+  if constexpr (has_to_string_view<T>::value)
+    return write_escaped_string<Char>(out, detail::to_string_view(v));
+  if constexpr (std::is_same_v<T, Char>) return write_escaped_char(out, v);
+  return write<Char>(out, v);
+}
+
+}  // namespace detail
+
+FMT_END_NAMESPACE
+#endif
+
+#ifdef __cpp_lib_expected
+FMT_BEGIN_NAMESPACE
+
+FMT_EXPORT
+template <typename T, typename E, typename Char>
+struct formatter<std::expected<T, E>, Char,
+                 std::enable_if_t<is_formattable<T, Char>::value &&
+                                  is_formattable<E, Char>::value>> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  auto format(const std::expected<T, E>& value, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+
+    if (value.has_value()) {
+      out = detail::write<Char>(out, "expected(");
+      out = detail::write_escaped_alternative<Char>(out, *value);
+    } else {
+      out = detail::write<Char>(out, "unexpected(");
+      out = detail::write_escaped_alternative<Char>(out, value.error());
+    }
+    *out++ = ')';
+    return out;
+  }
+};
+FMT_END_NAMESPACE
+#endif  // __cpp_lib_expected
+
 #ifdef __cpp_lib_source_location
 FMT_BEGIN_NAMESPACE
 FMT_EXPORT
@@ -291,16 +352,6 @@ template <typename T, typename C> class is_variant_formattable_ {
       decltype(check(variant_index_sequence<T>{}))::value;
 };
 
-template <typename Char, typename OutputIt, typename T>
-auto write_variant_alternative(OutputIt out, const T& v) -> OutputIt {
-  if constexpr (is_string<T>::value)
-    return write_escaped_string<Char>(out, detail::to_string_view(v));
-  else if constexpr (std::is_same_v<T, Char>)
-    return write_escaped_char(out, v);
-  else
-    return write<Char>(out, v);
-}
-
 }  // namespace detail
 
 template <typename T> struct is_variant_like {
@@ -346,7 +397,7 @@ struct formatter<
     FMT_TRY {
       std::visit(
           [&](const auto& v) {
-            out = detail::write_variant_alternative<Char>(out, v);
+            out = detail::write_escaped_alternative<Char>(out, v);
           },
           value);
     }
@@ -372,44 +423,18 @@ template <typename Char> struct formatter<std::error_code, Char> {
   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_bytes<Char>(out, ec.category().name(), format_specs());
     out = detail::write<Char>(out, Char(':'));
     out = detail::write<Char>(out, ec.value());
     return out;
   }
 };
 
-FMT_EXPORT
+#if FMT_USE_RTTI
-template <typename T, typename Char>
+namespace detail {
-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:
+template <typename Char, typename OutputIt>
-  FMT_CONSTEXPR auto parse(basic_format_parse_context<Char>& ctx)
+auto write_demangled_name(OutputIt out, const std::type_info& ti) -> OutputIt {
-      -> 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;
@@ -448,21 +473,85 @@ struct formatter<
   } else {
     demangled_name_view = string_view(ti.name());
   }
-    out = detail::write_bytes(out, demangled_name_view, spec);
+  return detail::write_bytes<Char>(out, demangled_name_view);
 #  elif FMT_MSC_VERSION
-    string_view demangled_name_view(ti.name());
+  const string_view demangled_name(ti.name());
-    if (demangled_name_view.starts_with("class "))
+  for (std::size_t i = 0; i < demangled_name.size(); ++i) {
-      demangled_name_view.remove_prefix(6);
+    auto sub = demangled_name;
-    else if (demangled_name_view.starts_with("struct "))
+    sub.remove_prefix(i);
-      demangled_name_view.remove_prefix(7);
+    if (sub.starts_with("enum ")) {
-    out = detail::write_bytes(out, demangled_name_view, spec);
+      i += 4;
+      continue;
+    }
+    if (sub.starts_with("class ") || sub.starts_with("union ")) {
+      i += 5;
+      continue;
+    }
+    if (sub.starts_with("struct ")) {
+      i += 6;
+      continue;
+    }
+    if (*sub.begin() != ' ') *out++ = *sub.begin();
+  }
+  return out;
 #  else
-    out = detail::write_bytes(out, string_view(ti.name()), spec);
+  return detail::write_bytes<Char>(out, string_view(ti.name()));
 #  endif
+}
+
+}  // namespace detail
+
+FMT_EXPORT
+template <typename Char>
+struct formatter<std::type_info, Char  // DEPRECATED! Mixing code unit types.
+                 > {
+ public:
+  FMT_CONSTEXPR auto parse(basic_format_parse_context<Char>& ctx)
+      -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename Context>
+  auto format(const std::type_info& ti, Context& ctx) const
+      -> decltype(ctx.out()) {
+    return detail::write_demangled_name<Char>(ctx.out(), ti);
+  }
+};
+#endif
+
+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_RTTI != 0;
+    }
+    return it;
+  }
+
+  template <typename Context>
+  auto format(const std::exception& ex, Context& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+#if FMT_USE_RTTI
+    if (with_typename_) {
+      out = detail::write_demangled_name<Char>(out, typeid(ex));
       *out++ = ':';
       *out++ = ' ';
-    return detail::write_bytes(out, string_view(ex.what()), spec);
+    }
 #endif
+    return detail::write_bytes<Char>(out, string_view(ex.what()));
   }
 };
 
@@ -509,6 +598,14 @@ struct formatter<BitRef, Char,
   }
 };
 
+template <typename T, typename Deleter>
+auto ptr(const std::unique_ptr<T, Deleter>& p) -> const void* {
+  return p.get();
+}
+template <typename T> auto ptr(const std::shared_ptr<T>& p) -> const void* {
+  return p.get();
+}
+
 FMT_EXPORT
 template <typename T, typename Char>
 struct formatter<std::atomic<T>, Char,
@@ -533,5 +630,70 @@ struct formatter<std::atomic_flag, Char> : formatter<bool, Char> {
 };
 #endif  // __cpp_lib_atomic_flag_test
 
+FMT_EXPORT
+template <typename T, typename Char> struct formatter<std::complex<T>, Char> {
+ private:
+  detail::dynamic_format_specs<Char> specs_;
+
+  template <typename FormatContext, typename OutputIt>
+  FMT_CONSTEXPR auto do_format(const std::complex<T>& c,
+                               detail::dynamic_format_specs<Char>& specs,
+                               FormatContext& ctx, OutputIt out) const
+      -> OutputIt {
+    if (c.real() != 0) {
+      *out++ = Char('(');
+      out = detail::write<Char>(out, c.real(), specs, ctx.locale());
+      specs.sign = sign::plus;
+      out = detail::write<Char>(out, c.imag(), specs, ctx.locale());
+      if (!detail::isfinite(c.imag())) *out++ = Char(' ');
+      *out++ = Char('i');
+      *out++ = Char(')');
+      return out;
+    }
+    out = detail::write<Char>(out, c.imag(), specs, ctx.locale());
+    if (!detail::isfinite(c.imag())) *out++ = Char(' ');
+    *out++ = Char('i');
+    return out;
+  }
+
+ public:
+  FMT_CONSTEXPR auto parse(basic_format_parse_context<Char>& ctx)
+      -> decltype(ctx.begin()) {
+    if (ctx.begin() == ctx.end() || *ctx.begin() == '}') return ctx.begin();
+    return parse_format_specs(ctx.begin(), ctx.end(), specs_, ctx,
+                              detail::type_constant<T, Char>::value);
+  }
+
+  template <typename FormatContext>
+  auto format(const std::complex<T>& c, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto specs = specs_;
+    if (specs.width_ref.kind != detail::arg_id_kind::none ||
+        specs.precision_ref.kind != detail::arg_id_kind::none) {
+      detail::handle_dynamic_spec<detail::width_checker>(specs.width,
+                                                         specs.width_ref, ctx);
+      detail::handle_dynamic_spec<detail::precision_checker>(
+          specs.precision, specs.precision_ref, ctx);
+    }
+
+    if (specs.width == 0) return do_format(c, specs, ctx, ctx.out());
+    auto buf = basic_memory_buffer<Char>();
+
+    auto outer_specs = format_specs();
+    outer_specs.width = specs.width;
+    outer_specs.fill = specs.fill;
+    outer_specs.align = specs.align;
+
+    specs.width = 0;
+    specs.fill = {};
+    specs.align = align::none;
+
+    do_format(c, specs, ctx, basic_appender<Char>(buf));
+    return detail::write<Char>(ctx.out(),
+                               basic_string_view<Char>(buf.data(), buf.size()),
+                               outer_specs);
+  }
+};
+
 FMT_END_NAMESPACE
 #endif  // FMT_STD_H_

include/spdlog/fmt/bundled/xchar.h

@@ -8,12 +8,15 @@
 #ifndef FMT_XCHAR_H_
 #define FMT_XCHAR_H_
 
-#include <cwchar>
+#include "color.h"
-
 #include "format.h"
+#include "ranges.h"
 
-#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
+#ifndef FMT_MODULE
+#  include <cwchar>
+#  if !defined(FMT_STATIC_THOUSANDS_SEPARATOR)
 #    include <locale>
+#  endif
 #endif
 
 FMT_BEGIN_NAMESPACE
@@ -22,9 +25,24 @@ 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,
+template <typename S, typename = void> struct format_string_char {};
-                      loc_value value, const format_specs<wchar_t>& specs,
+
-                      locale_ref loc) -> bool {
+template <typename S>
+struct format_string_char<
+    S, void_t<decltype(sizeof(detail::to_string_view(std::declval<S>())))>> {
+  using type = char_t<S>;
+};
+
+template <typename S>
+struct format_string_char<S, enable_if_t<is_compile_string<S>::value>> {
+  using type = typename S::char_type;
+};
+
+template <typename S>
+using format_string_char_t = typename format_string_char<S>::type;
+
+inline auto write_loc(basic_appender<wchar_t> out, loc_value value,
+                      const format_specs& specs, locale_ref loc) -> bool {
 #ifndef FMT_STATIC_THOUSANDS_SEPARATOR
   auto& numpunct =
       std::use_facet<std::numpunct<wchar_t>>(loc.get<std::locale>());
@@ -41,7 +59,7 @@ FMT_BEGIN_EXPORT
 
 using wstring_view = basic_string_view<wchar_t>;
 using wformat_parse_context = basic_format_parse_context<wchar_t>;
-using wformat_context = buffer_context<wchar_t>;
+using wformat_context = buffered_context<wchar_t>;
 using wformat_args = basic_format_args<wformat_context>;
 using wmemory_buffer = basic_memory_buffer<wchar_t>;
 
@@ -58,14 +76,18 @@ inline auto runtime(wstring_view s) -> runtime_format_string<wchar_t> {
 #endif
 
 template <> struct is_char<wchar_t> : std::true_type {};
-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 {};
 
+#ifdef __cpp_char8_t
+template <>
+struct is_char<char8_t> : bool_constant<detail::is_utf8_enabled()> {};
+#endif
+
 template <typename... T>
-constexpr auto make_wformat_args(const T&... args)
+constexpr auto make_wformat_args(T&... args)
-    -> format_arg_store<wformat_context, T...> {
+    -> decltype(fmt::make_format_args<wformat_context>(args...)) {
-  return {args...};
+  return fmt::make_format_args<wformat_context>(args...);
 }
 
 inline namespace literals {
@@ -96,9 +118,15 @@ auto join(std::initializer_list<T> list, wstring_view sep)
   return join(std::begin(list), std::end(list), sep);
 }
 
+template <typename... T>
+auto join(const std::tuple<T...>& tuple, basic_string_view<wchar_t> sep)
+    -> tuple_join_view<wchar_t, T...> {
+  return {tuple, sep};
+}
+
 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)
+             typename detail::vformat_args<Char>::type args)
     -> std::basic_string<Char> {
   auto buf = basic_memory_buffer<Char>();
   detail::vformat_to(buf, format_str, args);
@@ -110,63 +138,74 @@ auto format(wformat_string<T...> fmt, T&&... args) -> std::wstring {
   return vformat(fmt::wstring_view(fmt), fmt::make_wformat_args(args...));
 }
 
+template <typename OutputIt, typename... T>
+auto format_to(OutputIt out, wformat_string<T...> fmt, T&&... args)
+    -> OutputIt {
+  return vformat_to(out, fmt::wstring_view(fmt),
+                    fmt::make_wformat_args(args...));
+}
+
 // 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... T,
+          typename Char = detail::format_string_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> {
   return vformat(detail::to_string_view(format_str),
-                 fmt::make_format_args<buffer_context<Char>>(args...));
+                 fmt::make_format_args<buffered_context<Char>>(args...));
 }
 
-template <typename Locale, typename S, typename Char = char_t<S>,
+template <typename Locale, typename S,
+          typename Char = detail::format_string_char_t<S>,
           FMT_ENABLE_IF(detail::is_locale<Locale>::value&&
                             detail::is_exotic_char<Char>::value)>
-inline auto vformat(
+inline auto vformat(const Locale& loc, const S& format_str,
-    const Locale& loc, const S& format_str,
+                    typename detail::vformat_args<Char>::type args)
-    basic_format_args<buffer_context<type_identity_t<Char>>> args)
     -> std::basic_string<Char> {
   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... T,
+          typename Char = detail::format_string_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)
     -> std::basic_string<Char> {
-  return detail::vformat(loc, detail::to_string_view(format_str),
+  return detail::vformat(
-                         fmt::make_format_args<buffer_context<Char>>(args...));
+      loc, detail::to_string_view(format_str),
+      fmt::make_format_args<buffered_context<Char>>(args...));
 }
 
-template <typename OutputIt, typename S, typename Char = char_t<S>,
+template <typename OutputIt, typename S,
+          typename Char = detail::format_string_char_t<S>,
           FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
                             detail::is_exotic_char<Char>::value)>
 auto vformat_to(OutputIt out, const S& format_str,
-                basic_format_args<buffer_context<type_identity_t<Char>>> args)
+                typename detail::vformat_args<Char>::type args) -> OutputIt {
-    -> 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);
 }
 
 template <typename OutputIt, typename S, typename... T,
-          typename Char = char_t<S>,
+          typename Char = detail::format_string_char_t<S>,
-          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value &&
-                            detail::is_exotic_char<Char>::value)>
+                        !std::is_same<Char, char>::value &&
+                        !std::is_same<Char, wchar_t>::value)>
 inline auto format_to(OutputIt out, const S& fmt, T&&... args) -> OutputIt {
   return vformat_to(out, detail::to_string_view(fmt),
-                    fmt::make_format_args<buffer_context<Char>>(args...));
+                    fmt::make_format_args<buffered_context<Char>>(args...));
 }
 
 template <typename Locale, typename S, typename OutputIt, typename... Args,
-          typename Char = char_t<S>,
+          typename Char = detail::format_string_char_t<S>,
           FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
                             detail::is_locale<Locale>::value&&
                                 detail::is_exotic_char<Char>::value)>
-inline auto vformat_to(
+inline auto vformat_to(OutputIt out, const Locale& loc, const S& format_str,
-    OutputIt out, const Locale& loc, const S& format_str,
+                       typename detail::vformat_args<Char>::type args)
-    basic_format_args<buffer_context<type_identity_t<Char>>> args) -> OutputIt {
+    -> OutputIt {
   auto&& buf = detail::get_buffer<Char>(out);
   vformat_to(buf, detail::to_string_view(format_str), args,
              detail::locale_ref(loc));
@@ -174,7 +213,7 @@ inline auto vformat_to(
 }
 
 template <typename OutputIt, typename Locale, typename S, typename... T,
-          typename Char = char_t<S>,
+          typename Char = detail::format_string_char_t<S>,
           bool enable = detail::is_output_iterator<OutputIt, Char>::value &&
                         detail::is_locale<Locale>::value &&
                         detail::is_exotic_char<Char>::value>
@@ -182,15 +221,15 @@ inline auto format_to(OutputIt out, const Locale& loc, const S& format_str,
                       T&&... args) ->
     typename std::enable_if<enable, OutputIt>::type {
   return vformat_to(out, loc, detail::to_string_view(format_str),
-                    fmt::make_format_args<buffer_context<Char>>(args...));
+                    fmt::make_format_args<buffered_context<Char>>(args...));
 }
 
 template <typename OutputIt, typename Char, typename... Args,
           FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
                             detail::is_exotic_char<Char>::value)>
-inline auto vformat_to_n(
+inline auto vformat_to_n(OutputIt out, size_t n,
-    OutputIt out, size_t n, basic_string_view<Char> format_str,
+                         basic_string_view<Char> format_str,
-    basic_format_args<buffer_context<type_identity_t<Char>>> args)
+                         typename detail::vformat_args<Char>::type args)
     -> format_to_n_result<OutputIt> {
   using traits = detail::fixed_buffer_traits;
   auto buf = detail::iterator_buffer<OutputIt, Char, traits>(out, n);
@@ -199,21 +238,22 @@ inline auto vformat_to_n(
 }
 
 template <typename OutputIt, typename S, typename... T,
-          typename Char = char_t<S>,
+          typename Char = detail::format_string_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)
     -> format_to_n_result<OutputIt> {
-  return vformat_to_n(out, n, detail::to_string_view(fmt),
+  return vformat_to_n(out, n, fmt::basic_string_view<Char>(fmt),
-                      fmt::make_format_args<buffer_context<Char>>(args...));
+                      fmt::make_format_args<buffered_context<Char>>(args...));
 }
 
-template <typename S, typename... T, typename Char = char_t<S>,
+template <typename S, typename... T,
+          typename Char = detail::format_string_char_t<S>,
           FMT_ENABLE_IF(detail::is_exotic_char<Char>::value)>
 inline auto formatted_size(const S& fmt, T&&... args) -> size_t {
   auto buf = detail::counting_buffer<Char>();
   detail::vformat_to(buf, detail::to_string_view(fmt),
-                     fmt::make_format_args<buffer_context<Char>>(args...));
+                     fmt::make_format_args<buffered_context<Char>>(args...));
   return buf.count();
 }
 
@@ -247,9 +287,32 @@ template <typename... T> void println(wformat_string<T...> fmt, T&&... args) {
   return print(L"{}\n", fmt::format(fmt, std::forward<T>(args)...));
 }
 
-/**
+inline auto vformat(const text_style& ts, wstring_view fmt, wformat_args args)
-  Converts *value* to ``std::wstring`` using the default format for type *T*.
+    -> std::wstring {
- */
+  auto buf = wmemory_buffer();
+  detail::vformat_to(buf, ts, fmt, args);
+  return fmt::to_string(buf);
+}
+
+template <typename... T>
+inline auto format(const text_style& ts, wformat_string<T...> fmt, T&&... args)
+    -> std::wstring {
+  return fmt::vformat(ts, fmt, fmt::make_wformat_args(args...));
+}
+
+template <typename... T>
+FMT_DEPRECATED void print(std::FILE* f, const text_style& ts,
+                          wformat_string<T...> fmt, const T&... args) {
+  vprint(f, ts, fmt, fmt::make_wformat_args(args...));
+}
+
+template <typename... T>
+FMT_DEPRECATED void print(const text_style& ts, wformat_string<T...> fmt,
+                          const T&... args) {
+  return print(stdout, ts, fmt, 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);
 }

src/bundled_fmtlib_format.cpp

@@ -13,29 +13,31 @@
 FMT_BEGIN_NAMESPACE
 namespace detail {
 
-template FMT_API auto dragonbox::to_decimal(float x) noexcept -> dragonbox::decimal_fp<float>;
+template FMT_API auto dragonbox::to_decimal(float x) noexcept
-template FMT_API auto dragonbox::to_decimal(double x) noexcept -> dragonbox::decimal_fp<double>;
+    -> dragonbox::decimal_fp<float>;
+template FMT_API auto dragonbox::to_decimal(double x) noexcept
+    -> dragonbox::decimal_fp<double>;
 
-    #ifndef FMT_STATIC_THOUSANDS_SEPARATOR
+#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
 template FMT_API locale_ref::locale_ref(const std::locale& loc);
 template FMT_API auto locale_ref::get<std::locale>() const -> std::locale;
-    #endif
+#endif
 
 // Explicit instantiations for char.
 
-template FMT_API auto thousands_sep_impl(locale_ref) -> thousands_sep_result<char>;
+template FMT_API auto thousands_sep_impl(locale_ref)
+    -> thousands_sep_result<char>;
 template FMT_API auto decimal_point_impl(locale_ref) -> char;
 
 template FMT_API void buffer<char>::append(const char*, const char*);
 
-template FMT_API void vformat_to(buffer<char>&,
+template FMT_API void vformat_to(buffer<char>&, string_view,
-                                 string_view,
+                                 typename vformat_args<>::type, locale_ref);
-                                 typename vformat_args<>::type,
-                                 locale_ref);
 
 // Explicit instantiations for wchar_t.
 
-template FMT_API auto thousands_sep_impl(locale_ref) -> thousands_sep_result<wchar_t>;
+template FMT_API auto thousands_sep_impl(locale_ref)
+    -> thousands_sep_result<wchar_t>;
 template FMT_API auto decimal_point_impl(locale_ref) -> wchar_t;
 
 template FMT_API void buffer<wchar_t>::append(const wchar_t*, const wchar_t*);