Update fmtlib.

7 files changed, 190 insertions, 142 deletions

diff --git a/vendor/README.md b/vendor/README.md
index 3363135a5..d21d0a4c4 100644
--- a/vendor/README.md
+++ b/vendor/README.md
@@ -18,7 +18,7 @@ This directory contains vendored dependencies that are shipped with InspIRCd to
 
 **License** — MIT License
 
-**Version** — 11.1.4
+**Version** — 11.2.0
 
 **Website** — [https://github.com/fmtlib/fmt/](https://github.com/fmtlib/fmt/)
 
diff --git a/vendor/fmt/base.h b/vendor/fmt/base.h
index b886317d6..87b3fd7cb 100644
--- a/vendor/fmt/base.h
+++ b/vendor/fmt/base.h
@@ -21,7 +21,7 @@
 #endif
 
 // The fmt library version in the form major * 10000 + minor * 100 + patch.
-#define FMT_VERSION 110104
+#define FMT_VERSION 110200
 
 // Detect compiler versions.
 #if defined(__clang__) && !defined(__ibmxl__)
@@ -209,20 +209,6 @@
 #  define FMT_DEPRECATED /* deprecated */
 #endif
 
-#ifdef FMT_ALWAYS_INLINE
-// Use the provided definition.
-#elif FMT_GCC_VERSION || FMT_CLANG_VERSION
-#  define FMT_ALWAYS_INLINE inline __attribute__((always_inline))
-#else
-#  define FMT_ALWAYS_INLINE inline
-#endif
-// A version of FMT_ALWAYS_INLINE to prevent code bloat in debug mode.
-#ifdef NDEBUG
-#  define FMT_INLINE FMT_ALWAYS_INLINE
-#else
-#  define FMT_INLINE inline
-#endif
-
 #if FMT_GCC_VERSION || FMT_CLANG_VERSION
 #  define FMT_VISIBILITY(value) __attribute__((visibility(value)))
 #else
@@ -249,6 +235,28 @@
 #  define FMT_MSC_WARNING(...)
 #endif
 
+// Enable minimal optimizations for more compact code in debug mode.
+FMT_PRAGMA_GCC(push_options)
+#if !defined(__OPTIMIZE__) && !defined(__CUDACC__) && !defined(FMT_MODULE)
+FMT_PRAGMA_GCC(optimize("Og"))
+#  define FMT_GCC_OPTIMIZED
+#endif
+FMT_PRAGMA_CLANG(diagnostic push)
+
+#ifdef FMT_ALWAYS_INLINE
+// Use the provided definition.
+#elif FMT_GCC_VERSION || FMT_CLANG_VERSION
+#  define FMT_ALWAYS_INLINE inline __attribute__((always_inline))
+#else
+#  define FMT_ALWAYS_INLINE inline
+#endif
+// A version of FMT_ALWAYS_INLINE to prevent code bloat in debug mode.
+#if defined(NDEBUG) || defined(FMT_GCC_OPTIMIZED)
+#  define FMT_INLINE FMT_ALWAYS_INLINE
+#else
+#  define FMT_INLINE inline
+#endif
+
 #ifndef FMT_BEGIN_NAMESPACE
 #  define FMT_BEGIN_NAMESPACE \
     namespace fmt {           \
@@ -297,13 +305,6 @@
   using unused = int[];          \
   (void)unused { 0, (expr, 0)... }
 
-// Enable minimal optimizations for more compact code in debug mode.
-FMT_PRAGMA_GCC(push_options)
-#if !defined(__OPTIMIZE__) && !defined(__CUDACC__) && !defined(FMT_MODULE)
-FMT_PRAGMA_GCC(optimize("Og"))
-#endif
-FMT_PRAGMA_CLANG(diagnostic push)
-
 FMT_BEGIN_NAMESPACE
 
 // Implementations of enable_if_t and other metafunctions for older systems.
@@ -325,8 +326,8 @@ using underlying_t = typename std::underlying_type<T>::type;
 template <typename T> using decay_t = typename std::decay<T>::type;
 using nullptr_t = decltype(nullptr);
 
-#if FMT_GCC_VERSION && FMT_GCC_VERSION < 500
-// A workaround for gcc 4.9 to make void_t work in a SFINAE context.
+#if (FMT_GCC_VERSION && FMT_GCC_VERSION < 500) || FMT_MSC_VERSION
+// A workaround for gcc 4.9 & MSVC v141 to make void_t work in a SFINAE context.
 template <typename...> struct void_t_impl {
   using type = void;
 };
@@ -526,20 +527,20 @@ template <typename Char> class basic_string_view {
 
   constexpr basic_string_view() noexcept : data_(nullptr), size_(0) {}
 
-  /// Constructs a string reference object from a C string and a size.
+  /// Constructs a string view object from a C string and a size.
   constexpr basic_string_view(const Char* s, size_t count) noexcept
       : data_(s), size_(count) {}
 
   constexpr basic_string_view(nullptr_t) = delete;
 
-  /// Constructs a string reference object from a C string.
+  /// Constructs a string view object from a C string.
 #if FMT_GCC_VERSION
   FMT_ALWAYS_INLINE
 #endif
   FMT_CONSTEXPR20 basic_string_view(const Char* s) : data_(s) {
 #if FMT_HAS_BUILTIN(__builtin_strlen) || FMT_GCC_VERSION || FMT_CLANG_VERSION
-    if (std::is_same<Char, char>::value) {
-      size_ = __builtin_strlen(detail::narrow(s));
+    if (std::is_same<Char, char>::value && !detail::is_constant_evaluated()) {
+      size_ = __builtin_strlen(detail::narrow(s));  // strlen is not costexpr.
       return;
     }
 #endif
@@ -548,7 +549,7 @@ template <typename Char> class basic_string_view {
     size_ = len;
   }
 
-  /// Constructs a string reference from a `std::basic_string` or a
+  /// Constructs a string view from a `std::basic_string` or a
   /// `std::basic_string_view` object.
   template <typename S,
             FMT_ENABLE_IF(detail::is_std_string_like<S>::value&& std::is_same<
@@ -585,7 +586,6 @@ template <typename Char> class basic_string_view {
     return starts_with(basic_string_view<Char>(s));
   }
 
-  // Lexicographically compare this string reference to other.
   FMT_CONSTEXPR auto compare(basic_string_view other) const -> int {
     int result =
         detail::compare(data_, other.data_, min_of(size_, other.size_));
@@ -616,7 +616,7 @@ template <typename Char> class basic_string_view {
 
 using string_view = basic_string_view<char>;
 
-/// Specifies if `T` is an extended character type. Can be specialized by users.
+// DEPRECATED! Will be merged with is_char and moved to detail.
 template <typename T> struct is_xchar : std::false_type {};
 template <> struct is_xchar<wchar_t> : std::true_type {};
 template <> struct is_xchar<char16_t> : std::true_type {};
@@ -625,7 +625,7 @@ template <> struct is_xchar<char32_t> : std::true_type {};
 template <> struct is_xchar<char8_t> : std::true_type {};
 #endif
 
-// DEPRECATED! Will be replaced with an alias to prevent specializations.
+// Specifies if `T` is a character (code unit) type.
 template <typename T> struct is_char : is_xchar<T> {};
 template <> struct is_char<char> : std::true_type {};
 
@@ -1032,6 +1032,11 @@ enum {
 
 struct view {};
 
+template <typename T, typename Enable = std::true_type>
+struct is_view : std::false_type {};
+template <typename T>
+struct is_view<T, bool_constant<sizeof(T) != 0>> : std::is_base_of<view, T> {};
+
 template <typename Char, typename T> struct named_arg;
 template <typename T> struct is_named_arg : std::false_type {};
 template <typename T> struct is_static_named_arg : std::false_type {};
@@ -1064,6 +1069,16 @@ template <typename Char> struct named_arg_info {
   int id;
 };
 
+// named_args is non-const to suppress a bogus -Wmaybe-uninitalized in gcc 13.
+template <typename Char>
+FMT_CONSTEXPR void check_for_duplicate(named_arg_info<Char>* named_args,
+                                       int named_arg_index,
+                                       basic_string_view<Char> arg_name) {
+  for (int i = 0; i < named_arg_index; ++i) {
+    if (named_args[i].name == arg_name) report_error("duplicate named arg");
+  }
+}
+
 template <typename Char, typename T, FMT_ENABLE_IF(!is_named_arg<T>::value)>
 void init_named_arg(named_arg_info<Char>*, int& arg_index, int&, const T&) {
   ++arg_index;
@@ -1071,6 +1086,7 @@ void init_named_arg(named_arg_info<Char>*, int& arg_index, int&, const T&) {
 template <typename Char, typename T, FMT_ENABLE_IF(is_named_arg<T>::value)>
 void init_named_arg(named_arg_info<Char>* named_args, int& arg_index,
                     int& named_arg_index, const T& arg) {
+  check_for_duplicate<Char>(named_args, named_arg_index, arg.name);
   named_args[named_arg_index++] = {arg.name, arg_index++};
 }
 
@@ -1084,12 +1100,13 @@ template <typename T, typename Char,
           FMT_ENABLE_IF(is_static_named_arg<T>::value)>
 FMT_CONSTEXPR void init_static_named_arg(named_arg_info<Char>* named_args,
                                          int& arg_index, int& named_arg_index) {
+  check_for_duplicate<Char>(named_args, named_arg_index, T::name);
   named_args[named_arg_index++] = {T::name, arg_index++};
 }
 
 // To minimize the number of types we need to deal with, long is translated
 // either to int or to long long depending on its size.
-enum { long_short = sizeof(long) == sizeof(int) };
+enum { long_short = sizeof(long) == sizeof(int) && FMT_BUILTIN_TYPES };
 using long_type = conditional_t<long_short, int, long long>;
 using ulong_type = conditional_t<long_short, unsigned, unsigned long long>;
 
@@ -1706,7 +1723,17 @@ class format_string_checker {
       -> const Char* {
     context_.advance_to(begin);
     if (id >= 0 && id < NUM_ARGS) return parse_funcs_[id](context_);
-    while (begin != end && *begin != '}') ++begin;
+
+    // If id is out of range, it means we do not know the type and cannot parse
+    // the format at compile time. Instead, skip over content until we finish
+    // the format spec, accounting for any nested replacements.
+    for (int bracket_count = 0;
+         begin != end && (bracket_count > 0 || *begin != '}'); ++begin) {
+      if (*begin == '{')
+        ++bracket_count;
+      else if (*begin == '}')
+        --bracket_count;
+    }
     return begin;
   }
 
@@ -2703,7 +2730,7 @@ template <typename... T> struct fstring {
   template <size_t N>
   FMT_CONSTEVAL FMT_ALWAYS_INLINE fstring(const char (&s)[N]) : str(s, N - 1) {
     using namespace detail;
-    static_assert(count<(std::is_base_of<view, remove_reference_t<T>>::value &&
+    static_assert(count<(is_view<remove_cvref_t<T>>::value &&
                          std::is_reference<T>::value)...>() == 0,
                   "passing views as lvalues is disallowed");
     if (FMT_USE_CONSTEVAL) parse_format_string<char>(s, checker(s, arg_pack()));
diff --git a/vendor/fmt/color.h b/vendor/fmt/color.h
index 2faaf3a06..638f15b43 100644
--- a/vendor/fmt/color.h
+++ b/vendor/fmt/color.h
@@ -190,11 +190,11 @@ enum class emphasis : uint8_t {
 // rgb is a struct for red, green and blue colors.
 // Using the name "rgb" makes some editors show the color in a tooltip.
 struct rgb {
-  FMT_CONSTEXPR rgb() : r(0), g(0), b(0) {}
-  FMT_CONSTEXPR rgb(uint8_t r_, uint8_t g_, uint8_t b_) : r(r_), g(g_), b(b_) {}
-  FMT_CONSTEXPR rgb(uint32_t hex)
+  constexpr rgb() : r(0), g(0), b(0) {}
+  constexpr rgb(uint8_t r_, uint8_t g_, uint8_t b_) : r(r_), g(g_), b(b_) {}
+  constexpr rgb(uint32_t hex)
       : r((hex >> 16) & 0xFF), g((hex >> 8) & 0xFF), b(hex & 0xFF) {}
-  FMT_CONSTEXPR rgb(color hex)
+  constexpr rgb(color hex)
       : r((uint32_t(hex) >> 16) & 0xFF),
         g((uint32_t(hex) >> 8) & 0xFF),
         b(uint32_t(hex) & 0xFF) {}
@@ -205,97 +205,135 @@ struct rgb {
 
 namespace detail {
 
-// color is a struct of either a rgb color or a terminal color.
+// A bit-packed variant of an RGB color, a terminal color, or unset color.
+// see text_style for the bit-packing scheme.
 struct color_type {
-  FMT_CONSTEXPR color_type() noexcept : is_rgb(), value{} {}
-  FMT_CONSTEXPR color_type(color rgb_color) noexcept : is_rgb(true), value{} {
-    value.rgb_color = static_cast<uint32_t>(rgb_color);
-  }
-  FMT_CONSTEXPR color_type(rgb rgb_color) noexcept : is_rgb(true), value{} {
-    value.rgb_color = (static_cast<uint32_t>(rgb_color.r) << 16) |
-                      (static_cast<uint32_t>(rgb_color.g) << 8) | rgb_color.b;
+  constexpr color_type() noexcept = default;
+  constexpr color_type(color rgb_color) noexcept
+      : value_(static_cast<uint32_t>(rgb_color) | (1 << 24)) {}
+  constexpr color_type(rgb rgb_color) noexcept
+      : color_type(static_cast<color>(
+            (static_cast<uint32_t>(rgb_color.r) << 16) |
+            (static_cast<uint32_t>(rgb_color.g) << 8) | rgb_color.b)) {}
+  constexpr color_type(terminal_color term_color) noexcept
+      : value_(static_cast<uint32_t>(term_color) | (3 << 24)) {}
+
+  constexpr auto is_terminal_color() const noexcept -> bool {
+    return (value_ & (1 << 25)) != 0;
   }
-  FMT_CONSTEXPR color_type(terminal_color term_color) noexcept
-      : is_rgb(), value{} {
-    value.term_color = static_cast<uint8_t>(term_color);
+
+  constexpr auto value() const noexcept -> uint32_t {
+    return value_ & 0xFFFFFF;
   }
-  bool is_rgb;
-  union color_union {
-    uint8_t term_color;
-    uint32_t rgb_color;
-  } value;
+
+  constexpr color_type(uint32_t value) noexcept : value_(value) {}
+
+  uint32_t value_ = 0;
 };
 }  // namespace detail
 
 /// A text style consisting of foreground and background colors and emphasis.
 class text_style {
+  // The information is packed as follows:
+  // ┌──┐
+  // │ 0│─┐
+  // │..│ ├── foreground color value
+  // │23│─┘
+  // ├──┤
+  // │24│─┬── discriminator for the above value. 00 if unset, 01 if it's
+  // │25│─┘   an RGB color, or 11 if it's a terminal color (10 is unused)
+  // ├──┤
+  // │26│──── overflow bit, always zero (see below)
+  // ├──┤
+  // │27│─┐
+  // │..│ │
+  // │50│ │
+  // ├──┤ │
+  // │51│ ├── background color (same format as the foreground color)
+  // │52│ │
+  // ├──┤ │
+  // │53│─┘
+  // ├──┤
+  // │54│─┐
+  // │..│ ├── emphases
+  // │61│─┘
+  // ├──┤
+  // │62│─┬── unused
+  // │63│─┘
+  // └──┘
+  // The overflow bits are there to make operator|= efficient.
+  // When ORing, we must throw if, for either the foreground or background,
+  // one style specifies a terminal color and the other specifies any color
+  // (terminal or RGB); in other words, if one discriminator is 11 and the
+  // other is 11 or 01.
+  //
+  // We do that check by adding the styles. Consider what adding does to each
+  // possible pair of discriminators:
+  //    00 + 00 = 000
+  //    01 + 00 = 001
+  //    11 + 00 = 011
+  //    01 + 01 = 010
+  //    11 + 01 = 100 (!!)
+  //    11 + 11 = 110 (!!)
+  // In the last two cases, the ones we want to catch, the third bit——the
+  // overflow bit——is set. Bingo.
+  //
+  // We must take into account the possible carry bit from the bits
+  // before the discriminator. The only potentially problematic case is
+  // 11 + 00 = 011 (a carry bit would make it 100, not good!), but a carry
+  // bit is impossible in that case, because 00 (unset color) means the
+  // 24 bits that precede the discriminator are all zero.
+  //
+  // This test can be applied to both colors simultaneously.
+
  public:
   FMT_CONSTEXPR text_style(emphasis em = emphasis()) noexcept
-      : set_foreground_color(), set_background_color(), ems(em) {}
-
-  FMT_CONSTEXPR auto operator|=(const text_style& rhs) -> text_style& {
-    if (!set_foreground_color) {
-      set_foreground_color = rhs.set_foreground_color;
-      foreground_color = rhs.foreground_color;
-    } else if (rhs.set_foreground_color) {
-      if (!foreground_color.is_rgb || !rhs.foreground_color.is_rgb)
-        report_error("can't OR a terminal color");
-      foreground_color.value.rgb_color |= rhs.foreground_color.value.rgb_color;
-    }
+      : style_(static_cast<uint64_t>(em) << 54) {}
 
-    if (!set_background_color) {
-      set_background_color = rhs.set_background_color;
-      background_color = rhs.background_color;
-    } else if (rhs.set_background_color) {
-      if (!background_color.is_rgb || !rhs.background_color.is_rgb)
-        report_error("can't OR a terminal color");
-      background_color.value.rgb_color |= rhs.background_color.value.rgb_color;
-    }
-
-    ems = static_cast<emphasis>(static_cast<uint8_t>(ems) |
-                                static_cast<uint8_t>(rhs.ems));
+  FMT_CONSTEXPR auto operator|=(text_style rhs) -> text_style& {
+    if (((style_ + rhs.style_) & ((1ULL << 26) | (1ULL << 53))) != 0)
+      report_error("can't OR a terminal color");
+    style_ |= rhs.style_;
     return *this;
   }
 
-  friend FMT_CONSTEXPR auto operator|(text_style lhs, const text_style& rhs)
+  friend FMT_CONSTEXPR auto operator|(text_style lhs, text_style rhs)
       -> text_style {
     return lhs |= rhs;
   }
 
+  FMT_CONSTEXPR auto operator==(text_style rhs) const noexcept -> bool {
+    return style_ == rhs.style_;
+  }
+
+  FMT_CONSTEXPR auto operator!=(text_style rhs) const noexcept -> bool {
+    return !(*this == rhs);
+  }
+
   FMT_CONSTEXPR auto has_foreground() const noexcept -> bool {
-    return set_foreground_color;
+    return (style_ & (1 << 24)) != 0;
   }
   FMT_CONSTEXPR auto has_background() const noexcept -> bool {
-    return set_background_color;
+    return (style_ & (1ULL << 51)) != 0;
   }
   FMT_CONSTEXPR auto has_emphasis() const noexcept -> bool {
-    return static_cast<uint8_t>(ems) != 0;
+    return (style_ >> 54) != 0;
   }
   FMT_CONSTEXPR auto get_foreground() const noexcept -> detail::color_type {
     FMT_ASSERT(has_foreground(), "no foreground specified for this style");
-    return foreground_color;
+    return style_ & 0x3FFFFFF;
   }
   FMT_CONSTEXPR auto get_background() const noexcept -> detail::color_type {
     FMT_ASSERT(has_background(), "no background specified for this style");
-    return background_color;
+    return (style_ >> 27) & 0x3FFFFFF;
   }
   FMT_CONSTEXPR auto get_emphasis() const noexcept -> emphasis {
     FMT_ASSERT(has_emphasis(), "no emphasis specified for this style");
-    return ems;
+    return static_cast<emphasis>(style_ >> 54);
   }
 
  private:
-  FMT_CONSTEXPR text_style(bool is_foreground,
-                           detail::color_type text_color) noexcept
-      : set_foreground_color(), set_background_color(), ems() {
-    if (is_foreground) {
-      foreground_color = text_color;
-      set_foreground_color = true;
-    } else {
-      background_color = text_color;
-      set_background_color = true;
-    }
-  }
+  FMT_CONSTEXPR text_style(uint64_t style) noexcept : style_(style) {}
 
   friend FMT_CONSTEXPR auto fg(detail::color_type foreground) noexcept
       -> text_style;
@@ -303,23 +341,19 @@ class text_style {
   friend FMT_CONSTEXPR auto bg(detail::color_type background) noexcept
       -> text_style;
 
-  detail::color_type foreground_color;
-  detail::color_type background_color;
-  bool set_foreground_color;
-  bool set_background_color;
-  emphasis ems;
+  uint64_t style_ = 0;
 };
 
 /// 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);
+  return foreground.value_;
 }
 
 /// 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);
+  return static_cast<uint64_t>(background.value_) << 27;
 }
 
 FMT_CONSTEXPR inline auto operator|(emphasis lhs, emphasis rhs) noexcept
@@ -334,9 +368,9 @@ template <typename Char> struct ansi_color_escape {
                                   const char* esc) noexcept {
     // If we have a terminal color, we need to output another escape code
     // sequence.
-    if (!text_color.is_rgb) {
+    if (text_color.is_terminal_color()) {
       bool is_background = esc == string_view("\x1b[48;2;");
-      uint32_t value = text_color.value.term_color;
+      uint32_t value = text_color.value();
       // Background ASCII codes are the same as the foreground ones but with
       // 10 more.
       if (is_background) value += 10u;
@@ -360,7 +394,7 @@ template <typename Char> struct ansi_color_escape {
     for (int i = 0; i < 7; i++) {
       buffer[i] = static_cast<Char>(esc[i]);
     }
-    rgb color(text_color.value.rgb_color);
+    rgb color(text_color.value());
     to_esc(color.r, buffer + 7, ';');
     to_esc(color.g, buffer + 11, ';');
     to_esc(color.b, buffer + 15, 'm');
@@ -441,32 +475,26 @@ template <typename T> struct styled_arg : view {
 };
 
 template <typename Char>
-void vformat_to(buffer<Char>& buf, const text_style& ts,
-                basic_string_view<Char> fmt,
+void vformat_to(buffer<Char>& buf, text_style ts, basic_string_view<Char> fmt,
                 basic_format_args<buffered_context<Char>> args) {
-  bool has_style = false;
   if (ts.has_emphasis()) {
-    has_style = true;
     auto emphasis = make_emphasis<Char>(ts.get_emphasis());
     buf.append(emphasis.begin(), emphasis.end());
   }
   if (ts.has_foreground()) {
-    has_style = true;
     auto foreground = make_foreground_color<Char>(ts.get_foreground());
     buf.append(foreground.begin(), foreground.end());
   }
   if (ts.has_background()) {
-    has_style = true;
     auto background = make_background_color<Char>(ts.get_background());
     buf.append(background.begin(), background.end());
   }
   vformat_to(buf, fmt, args);
-  if (has_style) reset_color<Char>(buf);
+  if (ts != text_style()) reset_color<Char>(buf);
 }
 }  // namespace detail
 
-inline void vprint(FILE* f, const text_style& ts, string_view fmt,
-                   format_args args) {
+inline void vprint(FILE* f, text_style ts, string_view fmt, format_args args) {
   auto buf = memory_buffer();
   detail::vformat_to(buf, ts, fmt, args);
   print(f, FMT_STRING("{}"), string_view(buf.begin(), buf.size()));
@@ -482,8 +510,7 @@ inline void vprint(FILE* f, const text_style& ts, string_view fmt,
  *                "Elapsed time: {0:.2f} seconds", 1.23);
  */
 template <typename... T>
-void print(FILE* f, const text_style& ts, format_string<T...> fmt,
-           T&&... args) {
+void print(FILE* f, text_style ts, format_string<T...> fmt, T&&... args) {
   vprint(f, ts, fmt.str, vargs<T...>{{args...}});
 }
 
@@ -497,11 +524,11 @@ void print(FILE* f, const text_style& ts, format_string<T...> fmt,
  *                "Elapsed time: {0:.2f} seconds", 1.23);
  */
 template <typename... T>
-void print(const text_style& ts, format_string<T...> fmt, T&&... args) {
+void print(text_style ts, format_string<T...> fmt, T&&... args) {
   return print(stdout, ts, fmt, std::forward<T>(args)...);
 }
 
-inline auto vformat(const text_style& ts, string_view fmt, format_args args)
+inline auto vformat(text_style ts, string_view fmt, format_args args)
     -> std::string {
   auto buf = memory_buffer();
   detail::vformat_to(buf, ts, fmt, args);
@@ -521,7 +548,7 @@ inline auto vformat(const text_style& ts, string_view fmt, format_args args)
  * ```
  */
 template <typename... T>
-inline auto format(const text_style& ts, format_string<T...> fmt, T&&... args)
+inline auto format(text_style ts, format_string<T...> fmt, T&&... args)
     -> std::string {
   return fmt::vformat(ts, fmt.str, vargs<T...>{{args...}});
 }
@@ -529,8 +556,8 @@ inline auto format(const text_style& ts, format_string<T...> fmt, T&&... args)
 /// 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)>
-auto vformat_to(OutputIt out, const text_style& ts, string_view fmt,
-                format_args args) -> OutputIt {
+auto vformat_to(OutputIt out, text_style ts, string_view fmt, format_args args)
+    -> OutputIt {
   auto&& buf = detail::get_buffer<char>(out);
   detail::vformat_to(buf, ts, fmt, args);
   return detail::get_iterator(buf, out);
@@ -548,8 +575,8 @@ auto vformat_to(OutputIt out, const text_style& ts, string_view fmt,
  */
 template <typename OutputIt, typename... T,
           FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, char>::value)>
-inline auto format_to(OutputIt out, const text_style& ts,
-                      format_string<T...> fmt, T&&... args) -> OutputIt {
+inline auto format_to(OutputIt out, text_style ts, format_string<T...> fmt,
+                      T&&... args) -> OutputIt {
   return vformat_to(out, ts, fmt.str, vargs<T...>{{args...}});
 }
 
diff --git a/vendor/fmt/core.h b/vendor/fmt/core.h
deleted file mode 100644
index 8ca735f0c..000000000
--- a/vendor/fmt/core.h
+++ /dev/null
@@ -1,5 +0,0 @@
-// This file is only provided for compatibility and may be removed in future
-// versions. Use fmt/base.h if you don't need fmt::format and fmt/format.h
-// otherwise.
-
-#include "format.h"
diff --git a/vendor/fmt/format-inl.h b/vendor/fmt/format-inl.h
index a5b79dbe4..a1e016611 100644
--- a/vendor/fmt/format-inl.h
+++ b/vendor/fmt/format-inl.h
@@ -212,7 +212,7 @@ inline auto floor_log10_pow2_minus_log10_4_over_3(int e) noexcept -> int {
   return (e * 631305 - 261663) >> 21;
 }
 
-FMT_INLINE_VARIABLE constexpr struct {
+FMT_INLINE_VARIABLE constexpr struct div_small_pow10_infos_struct {
   uint32_t divisor;
   int shift_amount;
 } div_small_pow10_infos[] = {{10, 16}, {100, 16}};
@@ -1097,7 +1097,7 @@ template <> struct cache_accessor<double> {
     return {r.high(), r.low() == 0};
   }
 
-  static auto compute_delta(cache_entry_type const& cache, int beta) noexcept
+  static auto compute_delta(const cache_entry_type& cache, int beta) noexcept
       -> uint32_t {
     return static_cast<uint32_t>(cache.high() >> (64 - 1 - beta));
   }
@@ -1526,9 +1526,8 @@ template <typename F> class glibc_file : public file_base<F> {
   }
 
   void init_buffer() {
-    if (this->file_->_IO_write_ptr) return;
+    if (this->file_->_IO_write_ptr < this->file_->_IO_write_end) return;
     // Force buffer initialization by placing and removing a char in a buffer.
-    assume(this->file_->_IO_write_ptr >= this->file_->_IO_write_end);
     putc_unlocked(0, this->file_);
     --this->file_->_IO_write_ptr;
   }
diff --git a/vendor/fmt/format.h b/vendor/fmt/format.h
index 287e71631..50e571442 100644
--- a/vendor/fmt/format.h
+++ b/vendor/fmt/format.h
@@ -117,6 +117,7 @@
 #  define FMT_NOINLINE
 #endif
 
+// GCC 4.9 doesn't support qualified names in specializations.
 namespace std {
 template <typename T> struct iterator_traits<fmt::basic_appender<T>> {
   using iterator_category = output_iterator_tag;
@@ -705,7 +706,7 @@ using is_integer =
 
 #if defined(FMT_USE_FLOAT128)
 // Use the provided definition.
-#elif FMT_CLANG_VERSION && FMT_HAS_INCLUDE(<quadmath.h>)
+#elif FMT_CLANG_VERSION >= 309 && FMT_HAS_INCLUDE(<quadmath.h>)
 #  define FMT_USE_FLOAT128 1
 #elif FMT_GCC_VERSION && defined(_GLIBCXX_USE_FLOAT128) && \
     !defined(__STRICT_ANSI__)
@@ -721,11 +722,10 @@ struct float128 {};
 
 template <typename T> using is_float128 = std::is_same<T, float128>;
 
-template <typename T>
-using is_floating_point =
-    bool_constant<std::is_floating_point<T>::value || is_float128<T>::value>;
+template <typename T> struct is_floating_point : std::is_floating_point<T> {};
+template <> struct is_floating_point<float128> : std::true_type {};
 
-template <typename T, bool = std::is_floating_point<T>::value>
+template <typename T, bool = is_floating_point<T>::value>
 struct is_fast_float : bool_constant<std::numeric_limits<T>::is_iec559 &&
                                      sizeof(T) <= sizeof(double)> {};
 template <typename T> struct is_fast_float<T, false> : std::false_type {};
@@ -1613,7 +1613,7 @@ constexpr auto convert_float(T value) -> convert_float_result<T> {
 }
 
 template <typename Char, typename OutputIt>
-FMT_NOINLINE FMT_CONSTEXPR auto fill(OutputIt it, size_t n,
+FMT_CONSTEXPR FMT_NOINLINE auto fill(OutputIt it, size_t n,
                                      const basic_specs& specs) -> OutputIt {
   auto fill_size = specs.fill_size();
   if (fill_size == 1) return detail::fill_n(it, n, specs.fill_unit<Char>());
@@ -2472,8 +2472,8 @@ template <typename T>
 struct has_isfinite<T, enable_if_t<sizeof(std::isfinite(T())) != 0>>
     : std::true_type {};
 
-template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value&&
-                                        has_isfinite<T>::value)>
+template <typename T,
+          FMT_ENABLE_IF(is_floating_point<T>::value&& has_isfinite<T>::value)>
 FMT_CONSTEXPR20 auto isfinite(T value) -> bool {
   constexpr T inf = T(std::numeric_limits<double>::infinity());
   if (is_constant_evaluated())
diff --git a/vendor/update.toml b/vendor/update.toml
index d3d8583ef..fe8e8247a 100644
--- a/vendor/update.toml
+++ b/vendor/update.toml
@@ -10,7 +10,7 @@ website = "https://www.openwall.com/crypt/"
 [fmt]
 author  = "Victor Zverovich and fmt contributors"
 depth   = 2
-files   = "{include/fmt/{base,color,compile,core,format,format-inl}.h,LICENSE,src/format.cc}"
+files   = "{include/fmt/{base,color,compile,format,format-inl}.h,LICENSE,src/format.cc}"
 git     = "https://github.com/fmtlib/fmt/"
 license = "MIT License"