update fmtlib

7 files changed, 1320 insertions, 1278 deletions

diff --git a/source/extern/fmt/core.h b/source/extern/fmt/core.h
index 9062026..b51c140 100644
--- a/source/extern/fmt/core.h
+++ b/source/extern/fmt/core.h
@@ -13,11 +13,12 @@
 #include <cstring>  // std::strlen
 #include <iterator>
 #include <limits>
+#include <memory>  // std::addressof
 #include <string>
 #include <type_traits>
 
 // The fmt library version in the form major * 10000 + minor * 100 + patch.
-#define FMT_VERSION 100000
+#define FMT_VERSION 100201
 
 #if defined(__clang__) && !defined(__ibmxl__)
 #  define FMT_CLANG_VERSION (__clang_major__ * 100 + __clang_minor__)
@@ -92,7 +93,7 @@
 #ifndef FMT_USE_CONSTEXPR
 #  if (FMT_HAS_FEATURE(cxx_relaxed_constexpr) || FMT_MSC_VERSION >= 1912 || \
        (FMT_GCC_VERSION >= 600 && FMT_CPLUSPLUS >= 201402L)) &&             \
-      !FMT_ICC_VERSION && !defined(__NVCC__)
+      !FMT_ICC_VERSION && (!defined(__NVCC__) || FMT_CPLUSPLUS >= 202002L)
 #    define FMT_USE_CONSTEXPR 1
 #  else
 #    define FMT_USE_CONSTEXPR 0
@@ -104,9 +105,12 @@
 #  define FMT_CONSTEXPR
 #endif
 
-#if ((FMT_CPLUSPLUS >= 202002L) &&                            \
-     (!defined(_GLIBCXX_RELEASE) || _GLIBCXX_RELEASE > 9)) || \
-    (FMT_CPLUSPLUS >= 201709L && FMT_GCC_VERSION >= 1002)
+#if (FMT_CPLUSPLUS >= 202002L ||                                \
+     (FMT_CPLUSPLUS >= 201709L && FMT_GCC_VERSION >= 1002)) &&  \
+    ((!defined(_GLIBCXX_RELEASE) || _GLIBCXX_RELEASE >= 10) &&  \
+     (!defined(_LIBCPP_VERSION) || _LIBCPP_VERSION >= 10000) && \
+     (!FMT_MSC_VERSION || FMT_MSC_VERSION >= 1928)) &&          \
+    defined(__cpp_lib_is_constant_evaluated)
 #  define FMT_CONSTEXPR20 constexpr
 #else
 #  define FMT_CONSTEXPR20
@@ -162,9 +166,6 @@
 #  endif
 #endif
 
-// An inline std::forward replacement.
-#define FMT_FORWARD(...) static_cast<decltype(__VA_ARGS__)&&>(__VA_ARGS__)
-
 #ifdef _MSC_VER
 #  define FMT_UNCHECKED_ITERATOR(It) \
     using _Unchecked_type = It  // Mark iterator as checked.
@@ -181,24 +182,26 @@
     }
 #endif
 
-#ifndef FMT_MODULE_EXPORT
-#  define FMT_MODULE_EXPORT
+#ifndef FMT_EXPORT
+#  define FMT_EXPORT
 #  define FMT_BEGIN_EXPORT
 #  define FMT_END_EXPORT
 #endif
 
+#if FMT_GCC_VERSION || FMT_CLANG_VERSION
+#  define FMT_VISIBILITY(value) __attribute__((visibility(value)))
+#else
+#  define FMT_VISIBILITY(value)
+#endif
+
 #if !defined(FMT_HEADER_ONLY) && defined(_WIN32)
-#  ifdef FMT_LIB_EXPORT
+#  if defined(FMT_LIB_EXPORT)
 #    define FMT_API __declspec(dllexport)
 #  elif defined(FMT_SHARED)
 #    define FMT_API __declspec(dllimport)
 #  endif
-#else
-#  if defined(FMT_LIB_EXPORT) || defined(FMT_SHARED)
-#    if defined(__GNUC__) || defined(__clang__)
-#      define FMT_API __attribute__((visibility("default")))
-#    endif
-#  endif
+#elif defined(FMT_LIB_EXPORT) || defined(FMT_SHARED)
+#  define FMT_API FMT_VISIBILITY("default")
 #endif
 #ifndef FMT_API
 #  define FMT_API
@@ -224,8 +227,9 @@
         __apple_build_version__ >= 14000029L) &&                 \
        FMT_CPLUSPLUS >= 202002L) ||                              \
       (defined(__cpp_consteval) &&                               \
-       (!FMT_MSC_VERSION || _MSC_FULL_VER >= 193030704))
-// consteval is broken in MSVC before VS2022 and Apple clang before 14.
+       (!FMT_MSC_VERSION || FMT_MSC_VERSION >= 1929))
+// consteval is broken in MSVC before VS2019 version 16.10 and Apple clang
+// before 14.
 #    define FMT_CONSTEVAL consteval
 #    define FMT_HAS_CONSTEVAL
 #  else
@@ -244,10 +248,13 @@
 #  endif
 #endif
 
-#if defined __cpp_inline_variables && __cpp_inline_variables >= 201606L
-#  define FMT_INLINE_VARIABLE inline
-#else
-#  define FMT_INLINE_VARIABLE
+// GCC < 5 requires this-> in decltype
+#ifndef FMT_DECLTYPE_THIS
+#  if FMT_GCC_VERSION && FMT_GCC_VERSION < 500
+#    define FMT_DECLTYPE_THIS this->
+#  else
+#    define FMT_DECLTYPE_THIS
+#  endif
 #endif
 
 // Enable minimal optimizations for more compact code in debug mode.
@@ -271,11 +278,18 @@ template <typename T>
 using remove_const_t = typename std::remove_const<T>::type;
 template <typename T>
 using remove_cvref_t = typename std::remove_cv<remove_reference_t<T>>::type;
-template <typename T> struct type_identity { using type = T; };
+template <typename T> struct type_identity {
+  using type = T;
+};
 template <typename T> using type_identity_t = typename type_identity<T>::type;
 template <typename T>
 using underlying_t = typename std::underlying_type<T>::type;
 
+// Checks whether T is a container with contiguous storage.
+template <typename T> struct is_contiguous : std::false_type {};
+template <typename Char>
+struct is_contiguous<std::basic_string<Char>> : std::true_type {};
+
 struct monostate {
   constexpr monostate() {}
 };
@@ -289,8 +303,11 @@ struct monostate {
 #  define FMT_ENABLE_IF(...) fmt::enable_if_t<(__VA_ARGS__), int> = 0
 #endif
 
+// This is defined in core.h instead of format.h to avoid injecting in std.
+// It is a template to avoid undesirable implicit conversions to std::byte.
 #ifdef __cpp_lib_byte
-inline auto format_as(std::byte b) -> unsigned char {
+template <typename T, FMT_ENABLE_IF(std::is_same<T, std::byte>::value)>
+inline auto format_as(T b) -> unsigned char {
   return static_cast<unsigned char>(b);
 }
 #endif
@@ -394,7 +411,7 @@ FMT_CONSTEXPR inline auto is_utf8() -> bool {
   compiled with a different ``-std`` option than the client code (which is not
   recommended).
  */
-FMT_MODULE_EXPORT
+FMT_EXPORT
 template <typename Char> class basic_string_view {
  private:
   const Char* data_;
@@ -454,15 +471,15 @@ template <typename Char> class basic_string_view {
     size_ -= n;
   }
 
-  FMT_CONSTEXPR_CHAR_TRAITS bool starts_with(
-      basic_string_view<Char> sv) const noexcept {
+  FMT_CONSTEXPR_CHAR_TRAITS auto starts_with(
+      basic_string_view<Char> sv) const noexcept -> bool {
     return size_ >= sv.size_ &&
            std::char_traits<Char>::compare(data_, sv.data_, sv.size_) == 0;
   }
-  FMT_CONSTEXPR_CHAR_TRAITS bool starts_with(Char c) const noexcept {
+  FMT_CONSTEXPR_CHAR_TRAITS auto starts_with(Char c) const noexcept -> bool {
     return size_ >= 1 && std::char_traits<Char>::eq(*data_, c);
   }
-  FMT_CONSTEXPR_CHAR_TRAITS bool starts_with(const Char* s) const {
+  FMT_CONSTEXPR_CHAR_TRAITS auto starts_with(const Char* s) const -> bool {
     return starts_with(basic_string_view<Char>(s));
   }
 
@@ -497,11 +514,11 @@ template <typename Char> class basic_string_view {
   }
 };
 
-FMT_MODULE_EXPORT
+FMT_EXPORT
 using string_view = basic_string_view<char>;
 
 /** Specifies if ``T`` is a character type. Can be specialized by users. */
-FMT_MODULE_EXPORT
+FMT_EXPORT
 template <typename T> struct is_char : std::false_type {};
 template <> struct is_char<char> : std::true_type {};
 
@@ -600,10 +617,10 @@ FMT_TYPE_CONSTANT(const Char*, cstring_type);
 FMT_TYPE_CONSTANT(basic_string_view<Char>, string_type);
 FMT_TYPE_CONSTANT(const void*, pointer_type);
 
-constexpr bool is_integral_type(type t) {
+constexpr auto is_integral_type(type t) -> bool {
   return t > type::none_type && t <= type::last_integer_type;
 }
-constexpr bool is_arithmetic_type(type t) {
+constexpr auto is_arithmetic_type(type t) -> bool {
   return t > type::none_type && t <= type::last_numeric_type;
 }
 
@@ -627,6 +644,7 @@ enum {
   pointer_set = set(type::pointer_type)
 };
 
+// DEPRECATED!
 FMT_NORETURN FMT_API void throw_format_error(const char* message);
 
 struct error_handler {
@@ -639,6 +657,9 @@ struct error_handler {
 };
 }  // namespace detail
 
+/** Throws ``format_error`` with a given message. */
+using detail::throw_format_error;
+
 /** String's character type. */
 template <typename S> using char_t = typename detail::char_t_impl<S>::type;
 
@@ -649,7 +670,7 @@ template <typename S> using char_t = typename detail::char_t_impl<S>::type;
   You can use the ``format_parse_context`` type alias for ``char`` instead.
   \endrst
  */
-FMT_MODULE_EXPORT
+FMT_EXPORT
 template <typename Char> class basic_format_parse_context {
  private:
   basic_string_view<Char> format_str_;
@@ -715,7 +736,7 @@ template <typename Char> class basic_format_parse_context {
   FMT_CONSTEXPR void check_dynamic_spec(int arg_id);
 };
 
-FMT_MODULE_EXPORT
+FMT_EXPORT
 using format_parse_context = basic_format_parse_context<char>;
 
 namespace detail {
@@ -756,72 +777,6 @@ class compile_parse_context : public basic_format_parse_context<Char> {
 #endif
   }
 };
-}  // namespace detail
-
-template <typename Char>
-FMT_CONSTEXPR void basic_format_parse_context<Char>::do_check_arg_id(int id) {
-  // Argument id is only checked at compile-time during parsing because
-  // formatting has its own validation.
-  if (detail::is_constant_evaluated() &&
-      (!FMT_GCC_VERSION || FMT_GCC_VERSION >= 1200)) {
-    using context = detail::compile_parse_context<Char>;
-    if (id >= static_cast<context*>(this)->num_args())
-      detail::throw_format_error("argument not found");
-  }
-}
-
-template <typename Char>
-FMT_CONSTEXPR void basic_format_parse_context<Char>::check_dynamic_spec(
-    int arg_id) {
-  if (detail::is_constant_evaluated() &&
-      (!FMT_GCC_VERSION || FMT_GCC_VERSION >= 1200)) {
-    using context = detail::compile_parse_context<Char>;
-    static_cast<context*>(this)->check_dynamic_spec(arg_id);
-  }
-}
-
-FMT_MODULE_EXPORT template <typename Context> class basic_format_arg;
-FMT_MODULE_EXPORT template <typename Context> class basic_format_args;
-FMT_MODULE_EXPORT template <typename Context> class dynamic_format_arg_store;
-
-// A formatter for objects of type T.
-FMT_MODULE_EXPORT
-template <typename T, typename Char = char, typename Enable = void>
-struct formatter {
-  // A deleted default constructor indicates a disabled formatter.
-  formatter() = delete;
-};
-
-// Specifies if T has an enabled formatter specialization. A type can be
-// formattable even if it doesn't have a formatter e.g. via a conversion.
-template <typename T, typename Context>
-using has_formatter =
-    std::is_constructible<typename Context::template formatter_type<T>>;
-
-// Checks whether T is a container with contiguous storage.
-template <typename T> struct is_contiguous : std::false_type {};
-template <typename Char>
-struct is_contiguous<std::basic_string<Char>> : std::true_type {};
-
-class appender;
-
-namespace detail {
-
-template <typename Context, typename T>
-constexpr auto has_const_formatter_impl(T*)
-    -> decltype(typename Context::template formatter_type<T>().format(
-                    std::declval<const T&>(), std::declval<Context&>()),
-                true) {
-  return true;
-}
-template <typename Context>
-constexpr auto has_const_formatter_impl(...) -> bool {
-  return false;
-}
-template <typename T, typename Context>
-constexpr auto has_const_formatter() -> bool {
-  return has_const_formatter_impl<Context>(static_cast<T*>(nullptr));
-}
 
 // Extracts a reference to the container from back_insert_iterator.
 template <typename Container>
@@ -867,7 +822,7 @@ template <typename T> class buffer {
  protected:
   // Don't initialize ptr_ since it is not accessed to save a few cycles.
   FMT_MSC_WARNING(suppress : 26495)
-  buffer(size_t sz) noexcept : size_(sz), capacity_(sz) {}
+  FMT_CONSTEXPR buffer(size_t sz) noexcept : size_(sz), capacity_(sz) {}
 
   FMT_CONSTEXPR20 buffer(T* p = nullptr, size_t sz = 0, size_t cap = 0) noexcept
       : ptr_(p), size_(sz), capacity_(cap) {}
@@ -882,6 +837,7 @@ template <typename T> class buffer {
   }
 
   /** Increases the buffer capacity to hold at least *capacity* elements. */
+  // DEPRECATED!
   virtual FMT_CONSTEXPR20 void grow(size_t capacity) = 0;
 
  public:
@@ -903,10 +859,8 @@ template <typename T> class buffer {
   /** Returns the capacity of this buffer. */
   constexpr auto capacity() const noexcept -> size_t { return capacity_; }
 
-  /** Returns a pointer to the buffer data. */
+  /** Returns a pointer to the buffer data (not null-terminated). */
   FMT_CONSTEXPR auto data() noexcept -> T* { return ptr_; }
-
-  /** Returns a pointer to the buffer data. */
   FMT_CONSTEXPR auto data() const noexcept -> const T* { return ptr_; }
 
   /** Clears this buffer. */
@@ -1099,6 +1053,79 @@ template <typename T = char> class counting_buffer final : public buffer<T> {
 
   auto count() -> size_t { return count_ + this->size(); }
 };
+}  // namespace detail
+
+template <typename Char>
+FMT_CONSTEXPR void basic_format_parse_context<Char>::do_check_arg_id(int id) {
+  // Argument id is only checked at compile-time during parsing because
+  // formatting has its own validation.
+  if (detail::is_constant_evaluated() &&
+      (!FMT_GCC_VERSION || FMT_GCC_VERSION >= 1200)) {
+    using context = detail::compile_parse_context<Char>;
+    if (id >= static_cast<context*>(this)->num_args())
+      detail::throw_format_error("argument not found");
+  }
+}
+
+template <typename Char>
+FMT_CONSTEXPR void basic_format_parse_context<Char>::check_dynamic_spec(
+    int arg_id) {
+  if (detail::is_constant_evaluated() &&
+      (!FMT_GCC_VERSION || FMT_GCC_VERSION >= 1200)) {
+    using context = detail::compile_parse_context<Char>;
+    static_cast<context*>(this)->check_dynamic_spec(arg_id);
+  }
+}
+
+FMT_EXPORT template <typename Context> class basic_format_arg;
+FMT_EXPORT template <typename Context> class basic_format_args;
+FMT_EXPORT template <typename Context> class dynamic_format_arg_store;
+
+// A formatter for objects of type T.
+FMT_EXPORT
+template <typename T, typename Char = char, typename Enable = void>
+struct formatter {
+  // A deleted default constructor indicates a disabled formatter.
+  formatter() = delete;
+};
+
+// Specifies if T has an enabled formatter specialization. A type can be
+// formattable even if it doesn't have a formatter e.g. via a conversion.
+template <typename T, typename Context>
+using has_formatter =
+    std::is_constructible<typename Context::template formatter_type<T>>;
+
+// An output iterator that appends to a buffer.
+// It is used to reduce symbol sizes for the common case.
+class appender : public std::back_insert_iterator<detail::buffer<char>> {
+  using base = std::back_insert_iterator<detail::buffer<char>>;
+
+ public:
+  using std::back_insert_iterator<detail::buffer<char>>::back_insert_iterator;
+  appender(base it) noexcept : base(it) {}
+  FMT_UNCHECKED_ITERATOR(appender);
+
+  auto operator++() noexcept -> appender& { return *this; }
+  auto operator++(int) noexcept -> appender { return *this; }
+};
+
+namespace detail {
+
+template <typename Context, typename T>
+constexpr auto has_const_formatter_impl(T*)
+    -> decltype(typename Context::template formatter_type<T>().format(
+                    std::declval<const T&>(), std::declval<Context&>()),
+                true) {
+  return true;
+}
+template <typename Context>
+constexpr auto has_const_formatter_impl(...) -> bool {
+  return false;
+}
+template <typename T, typename Context>
+constexpr auto has_const_formatter() -> bool {
+  return has_const_formatter_impl<Context>(static_cast<T*>(nullptr));
+}
 
 template <typename T>
 using buffer_appender = conditional_t<std::is_same<T, char>::value, appender,
@@ -1274,9 +1301,9 @@ template <typename Context> class value {
   FMT_INLINE value(const named_arg_info<char_type>* args, size_t size)
       : named_args{args, size} {}
 
-  template <typename T> FMT_CONSTEXPR FMT_INLINE value(T& val) {
-    using value_type = remove_cvref_t<T>;
-    custom.value = const_cast<value_type*>(&val);
+  template <typename T> FMT_CONSTEXPR20 FMT_INLINE value(T& val) {
+    using value_type = remove_const_t<T>;
+    custom.value = const_cast<value_type*>(std::addressof(val));
     // Get the formatter type through the context to allow different contexts
     // have different extension points, e.g. `formatter<T>` for `format` and
     // `printf_formatter<T>` for `printf`.
@@ -1297,13 +1324,11 @@ template <typename Context> class value {
     parse_ctx.advance_to(f.parse(parse_ctx));
     using qualified_type =
         conditional_t<has_const_formatter<T, Context>(), const T, T>;
+    // Calling format through a mutable reference is deprecated.
     ctx.advance_to(f.format(*static_cast<qualified_type*>(arg), ctx));
   }
 };
 
-template <typename Context, typename T>
-FMT_CONSTEXPR auto make_arg(T&& value) -> basic_format_arg<Context>;
-
 // 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) };
@@ -1313,7 +1338,7 @@ using ulong_type = conditional_t<long_short, unsigned, unsigned long long>;
 template <typename T> struct format_as_result {
   template <typename U,
             FMT_ENABLE_IF(std::is_enum<U>::value || std::is_class<U>::value)>
-  static auto map(U*) -> decltype(format_as(std::declval<U>()));
+  static auto map(U*) -> remove_cvref_t<decltype(format_as(std::declval<U>()))>;
   static auto map(...) -> void;
 
   using type = decltype(map(static_cast<T*>(nullptr)));
@@ -1415,9 +1440,8 @@ template <typename Context> struct arg_mapper {
       FMT_ENABLE_IF(
           std::is_pointer<T>::value || std::is_member_pointer<T>::value ||
           std::is_function<typename std::remove_pointer<T>::type>::value ||
-          (std::is_convertible<const T&, const void*>::value &&
-           !std::is_convertible<const T&, const char_type*>::value &&
-           !has_formatter<T, Context>::value))>
+          (std::is_array<T>::value &&
+           !std::is_convertible<T, const char_type*>::value))>
   FMT_CONSTEXPR auto map(const T&) -> unformattable_pointer {
     return {};
   }
@@ -1431,39 +1455,39 @@ template <typename Context> struct arg_mapper {
   // Only map owning types because mapping views can be unsafe.
   template <typename T, typename U = format_as_t<T>,
             FMT_ENABLE_IF(std::is_arithmetic<U>::value)>
-  FMT_CONSTEXPR FMT_INLINE auto map(const T& val) -> decltype(this->map(U())) {
+  FMT_CONSTEXPR FMT_INLINE auto map(const T& val)
+      -> decltype(FMT_DECLTYPE_THIS map(U())) {
     return map(format_as(val));
   }
 
-  template <typename T, typename U = remove_cvref_t<T>>
-  struct formattable
-      : bool_constant<has_const_formatter<U, Context>() ||
-                      (has_formatter<U, Context>::value &&
-                       !std::is_const<remove_reference_t<T>>::value)> {};
+  template <typename T, typename U = remove_const_t<T>>
+  struct formattable : bool_constant<has_const_formatter<U, Context>() ||
+                                     (has_formatter<U, Context>::value &&
+                                      !std::is_const<T>::value)> {};
 
   template <typename T, FMT_ENABLE_IF(formattable<T>::value)>
-  FMT_CONSTEXPR FMT_INLINE auto do_map(T&& val) -> T& {
+  FMT_CONSTEXPR FMT_INLINE auto do_map(T& val) -> T& {
     return val;
   }
   template <typename T, FMT_ENABLE_IF(!formattable<T>::value)>
-  FMT_CONSTEXPR FMT_INLINE auto do_map(T&&) -> unformattable {
+  FMT_CONSTEXPR FMT_INLINE auto do_map(T&) -> unformattable {
     return {};
   }
 
-  template <typename T, typename U = remove_cvref_t<T>,
+  template <typename T, typename U = remove_const_t<T>,
             FMT_ENABLE_IF((std::is_class<U>::value || std::is_enum<U>::value ||
                            std::is_union<U>::value) &&
                           !is_string<U>::value && !is_char<U>::value &&
                           !is_named_arg<U>::value &&
                           !std::is_arithmetic<format_as_t<U>>::value)>
-  FMT_CONSTEXPR FMT_INLINE auto map(T&& val)
-      -> decltype(this->do_map(std::forward<T>(val))) {
-    return do_map(std::forward<T>(val));
+  FMT_CONSTEXPR FMT_INLINE auto map(T& val)
+      -> decltype(FMT_DECLTYPE_THIS do_map(val)) {
+    return do_map(val);
   }
 
   template <typename T, FMT_ENABLE_IF(is_named_arg<T>::value)>
   FMT_CONSTEXPR FMT_INLINE auto map(const T& named_arg)
-      -> decltype(this->map(named_arg.value)) {
+      -> decltype(FMT_DECLTYPE_THIS map(named_arg.value)) {
     return map(named_arg.value);
   }
 
@@ -1481,31 +1505,132 @@ enum { packed_arg_bits = 4 };
 enum { max_packed_args = 62 / packed_arg_bits };
 enum : unsigned long long { is_unpacked_bit = 1ULL << 63 };
 enum : unsigned long long { has_named_args_bit = 1ULL << 62 };
-}  // namespace detail
 
-// An output iterator that appends to a buffer.
-// It is used to reduce symbol sizes for the common case.
-class appender : public std::back_insert_iterator<detail::buffer<char>> {
-  using base = std::back_insert_iterator<detail::buffer<char>>;
+template <typename Char, typename InputIt>
+auto copy_str(InputIt begin, InputIt end, appender out) -> appender {
+  get_container(out).append(begin, end);
+  return out;
+}
+template <typename Char, typename InputIt>
+auto copy_str(InputIt begin, InputIt end,
+              std::back_insert_iterator<std::string> out)
+    -> std::back_insert_iterator<std::string> {
+  get_container(out).append(begin, end);
+  return out;
+}
+
+template <typename Char, typename R, typename OutputIt>
+FMT_CONSTEXPR auto copy_str(R&& rng, OutputIt out) -> OutputIt {
+  return detail::copy_str<Char>(rng.begin(), rng.end(), out);
+}
+
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 500
+// A workaround for gcc 4.8 to make void_t work in a SFINAE context.
+template <typename...> struct void_t_impl {
+  using type = void;
+};
+template <typename... T> using void_t = typename void_t_impl<T...>::type;
+#else
+template <typename...> using void_t = void;
+#endif
+
+template <typename It, typename T, typename Enable = void>
+struct is_output_iterator : std::false_type {};
+
+template <typename It, typename T>
+struct is_output_iterator<
+    It, T,
+    void_t<typename std::iterator_traits<It>::iterator_category,
+           decltype(*std::declval<It>() = std::declval<T>())>>
+    : std::true_type {};
+
+template <typename It> struct is_back_insert_iterator : std::false_type {};
+template <typename Container>
+struct is_back_insert_iterator<std::back_insert_iterator<Container>>
+    : std::true_type {};
+
+// A type-erased reference to an std::locale to avoid a heavy <locale> include.
+class locale_ref {
+ private:
+  const void* locale_;  // A type-erased pointer to std::locale.
 
  public:
-  using std::back_insert_iterator<detail::buffer<char>>::back_insert_iterator;
-  appender(base it) noexcept : base(it) {}
-  FMT_UNCHECKED_ITERATOR(appender);
+  constexpr FMT_INLINE locale_ref() : locale_(nullptr) {}
+  template <typename Locale> explicit locale_ref(const Locale& loc);
 
-  auto operator++() noexcept -> appender& { return *this; }
-  auto operator++(int) noexcept -> appender { return *this; }
+  explicit operator bool() const noexcept { return locale_ != nullptr; }
+
+  template <typename Locale> auto get() const -> Locale;
 };
 
-// A formatting argument. It is a trivially copyable/constructible type to
-// allow storage in basic_memory_buffer.
+template <typename> constexpr auto encode_types() -> unsigned long long {
+  return 0;
+}
+
+template <typename Context, typename Arg, typename... Args>
+constexpr auto encode_types() -> unsigned long long {
+  return static_cast<unsigned>(mapped_type_constant<Arg, Context>::value) |
+         (encode_types<Context, Args...>() << packed_arg_bits);
+}
+
+#if defined(__cpp_if_constexpr)
+// This type is intentionally undefined, only used for errors
+template <typename T, typename Char> struct type_is_unformattable_for;
+#endif
+
+template <bool PACKED, typename Context, typename T, FMT_ENABLE_IF(PACKED)>
+FMT_CONSTEXPR FMT_INLINE auto make_arg(T& val) -> value<Context> {
+  using arg_type = remove_cvref_t<decltype(arg_mapper<Context>().map(val))>;
+
+  constexpr bool formattable_char =
+      !std::is_same<arg_type, unformattable_char>::value;
+  static_assert(formattable_char, "Mixing character types is disallowed.");
+
+  // Formatting of arbitrary pointers is disallowed. If you want to format a
+  // pointer cast it to `void*` or `const void*`. In particular, this forbids
+  // formatting of `[const] volatile char*` printed as bool by iostreams.
+  constexpr bool formattable_pointer =
+      !std::is_same<arg_type, unformattable_pointer>::value;
+  static_assert(formattable_pointer,
+                "Formatting of non-void pointers is disallowed.");
+
+  constexpr bool formattable = !std::is_same<arg_type, unformattable>::value;
+#if defined(__cpp_if_constexpr)
+  if constexpr (!formattable) {
+    type_is_unformattable_for<T, typename Context::char_type> _;
+  }
+#endif
+  static_assert(
+      formattable,
+      "Cannot format an argument. To make type T formattable provide a "
+      "formatter<T> specialization: https://fmt.dev/latest/api.html#udt");
+  return {arg_mapper<Context>().map(val)};
+}
+
+template <typename Context, typename T>
+FMT_CONSTEXPR auto make_arg(T& val) -> basic_format_arg<Context> {
+  auto arg = basic_format_arg<Context>();
+  arg.type_ = mapped_type_constant<T, Context>::value;
+  arg.value_ = make_arg<true, Context>(val);
+  return arg;
+}
+
+template <bool PACKED, typename Context, typename T, FMT_ENABLE_IF(!PACKED)>
+FMT_CONSTEXPR inline auto make_arg(T& val) -> basic_format_arg<Context> {
+  return make_arg<Context>(val);
+}
+}  // namespace detail
+FMT_BEGIN_EXPORT
+
+// A formatting argument. Context is a template parameter for the compiled API
+// where output can be unbuffered.
 template <typename Context> class basic_format_arg {
  private:
   detail::value<Context> value_;
   detail::type type_;
 
   template <typename ContextType, typename T>
-  friend FMT_CONSTEXPR auto detail::make_arg(T&& value)
+  friend FMT_CONSTEXPR auto detail::make_arg(T& value)
       -> basic_format_arg<ContextType>;
 
   template <typename Visitor, typename Ctx>
@@ -1550,6 +1675,15 @@ template <typename Context> class basic_format_arg {
   auto is_arithmetic() const -> bool {
     return detail::is_arithmetic_type(type_);
   }
+
+  FMT_INLINE auto format_custom(const char_type* parse_begin,
+                                typename Context::parse_context_type& parse_ctx,
+                                Context& ctx) -> bool {
+    if (type_ != detail::type::custom_type) return false;
+    parse_ctx.advance_to(parse_begin);
+    value_.custom.format(value_.custom.value, parse_ctx, ctx);
+    return true;
+  }
 };
 
 /**
@@ -1559,7 +1693,7 @@ template <typename Context> class basic_format_arg {
   ``vis(value)`` will be called with the value of type ``double``.
   \endrst
  */
-FMT_MODULE_EXPORT
+// DEPRECATED!
 template <typename Visitor, typename Context>
 FMT_CONSTEXPR FMT_INLINE auto visit_format_arg(
     Visitor&& vis, const basic_format_arg<Context>& arg) -> decltype(vis(0)) {
@@ -1601,123 +1735,6 @@ FMT_CONSTEXPR FMT_INLINE auto visit_format_arg(
   return vis(monostate());
 }
 
-namespace detail {
-
-template <typename Char, typename InputIt>
-auto copy_str(InputIt begin, InputIt end, appender out) -> appender {
-  get_container(out).append(begin, end);
-  return out;
-}
-
-template <typename Char, typename R, typename OutputIt>
-FMT_CONSTEXPR auto copy_str(R&& rng, OutputIt out) -> OutputIt {
-  return detail::copy_str<Char>(rng.begin(), rng.end(), out);
-}
-
-#if FMT_GCC_VERSION && FMT_GCC_VERSION < 500
-// A workaround for gcc 4.8 to make void_t work in a SFINAE context.
-template <typename...> struct void_t_impl { using type = void; };
-template <typename... T> using void_t = typename void_t_impl<T...>::type;
-#else
-template <typename...> using void_t = void;
-#endif
-
-template <typename It, typename T, typename Enable = void>
-struct is_output_iterator : std::false_type {};
-
-template <typename It, typename T>
-struct is_output_iterator<
-    It, T,
-    void_t<typename std::iterator_traits<It>::iterator_category,
-           decltype(*std::declval<It>() = std::declval<T>())>>
-    : std::true_type {};
-
-template <typename It> struct is_back_insert_iterator : std::false_type {};
-template <typename Container>
-struct is_back_insert_iterator<std::back_insert_iterator<Container>>
-    : std::true_type {};
-
-template <typename It>
-struct is_contiguous_back_insert_iterator : std::false_type {};
-template <typename Container>
-struct is_contiguous_back_insert_iterator<std::back_insert_iterator<Container>>
-    : is_contiguous<Container> {};
-template <>
-struct is_contiguous_back_insert_iterator<appender> : std::true_type {};
-
-// A type-erased reference to an std::locale to avoid a heavy <locale> include.
-class locale_ref {
- private:
-  const void* locale_;  // A type-erased pointer to std::locale.
-
- public:
-  constexpr FMT_INLINE locale_ref() : locale_(nullptr) {}
-  template <typename Locale> explicit locale_ref(const Locale& loc);
-
-  explicit operator bool() const noexcept { return locale_ != nullptr; }
-
-  template <typename Locale> auto get() const -> Locale;
-};
-
-template <typename> constexpr auto encode_types() -> unsigned long long {
-  return 0;
-}
-
-template <typename Context, typename Arg, typename... Args>
-constexpr auto encode_types() -> unsigned long long {
-  return static_cast<unsigned>(mapped_type_constant<Arg, Context>::value) |
-         (encode_types<Context, Args...>() << packed_arg_bits);
-}
-
-template <typename Context, typename T>
-FMT_CONSTEXPR FMT_INLINE auto make_value(T&& val) -> value<Context> {
-  using arg_type = remove_cvref_t<decltype(arg_mapper<Context>().map(val))>;
-
-  constexpr bool formattable_char =
-      !std::is_same<arg_type, unformattable_char>::value;
-  static_assert(formattable_char, "Mixing character types is disallowed.");
-
-  // Formatting of arbitrary pointers is disallowed. If you want to format a
-  // pointer cast it to `void*` or `const void*`. In particular, this forbids
-  // formatting of `[const] volatile char*` printed as bool by iostreams.
-  constexpr bool formattable_pointer =
-      !std::is_same<arg_type, unformattable_pointer>::value;
-  static_assert(formattable_pointer,
-                "Formatting of non-void pointers is disallowed.");
-
-  constexpr bool formattable = !std::is_same<arg_type, unformattable>::value;
-  static_assert(
-      formattable,
-      "Cannot format an argument. To make type T formattable provide a "
-      "formatter<T> specialization: https://fmt.dev/latest/api.html#udt");
-  return {arg_mapper<Context>().map(val)};
-}
-
-template <typename Context, typename T>
-FMT_CONSTEXPR auto make_arg(T&& value) -> basic_format_arg<Context> {
-  auto arg = basic_format_arg<Context>();
-  arg.type_ = mapped_type_constant<T, Context>::value;
-  arg.value_ = make_value<Context>(value);
-  return arg;
-}
-
-// The DEPRECATED type template parameter is there to avoid an ODR violation
-// when using a fallback formatter in one translation unit and an implicit
-// conversion in another (not recommended).
-template <bool IS_PACKED, typename Context, type, typename T,
-          FMT_ENABLE_IF(IS_PACKED)>
-FMT_CONSTEXPR FMT_INLINE auto make_arg(T&& val) -> value<Context> {
-  return make_value<Context>(val);
-}
-
-template <bool IS_PACKED, typename Context, type, typename T,
-          FMT_ENABLE_IF(!IS_PACKED)>
-FMT_CONSTEXPR inline auto make_arg(T&& value) -> basic_format_arg<Context> {
-  return make_arg<Context>(value);
-}
-}  // namespace detail
-FMT_BEGIN_EXPORT
-
 // Formatting context.
 template <typename OutputIt, typename Char> class basic_format_context {
  private:
@@ -1755,6 +1772,7 @@ template <typename OutputIt, typename Char> class basic_format_context {
   }
   auto args() const -> const format_args& { return args_; }
 
+  // DEPRECATED!
   FMT_CONSTEXPR auto error_handler() -> detail::error_handler { return {}; }
   void on_error(const char* message) { error_handler().on_error(message); }
 
@@ -1777,7 +1795,7 @@ using format_context = buffer_context<char>;
 template <typename T, typename Char = char>
 using is_formattable = bool_constant<!std::is_base_of<
     detail::unformattable, decltype(detail::arg_mapper<buffer_context<Char>>()
-                                        .map(std::declval<T>()))>::value>;
+                                        .map(std::declval<T&>()))>::value>;
 
 /**
   \rst
@@ -1795,7 +1813,7 @@ class format_arg_store
 {
  private:
   static const size_t num_args = sizeof...(Args);
-  static const size_t num_named_args = detail::count_named_args<Args...>();
+  static constexpr size_t num_named_args = detail::count_named_args<Args...>();
   static const bool is_packed = num_args <= detail::max_packed_args;
 
   using value_type = conditional_t<is_packed, detail::value<Context>,
@@ -1816,16 +1834,14 @@ class format_arg_store
 
  public:
   template <typename... T>
-  FMT_CONSTEXPR FMT_INLINE format_arg_store(T&&... args)
+  FMT_CONSTEXPR FMT_INLINE format_arg_store(T&... args)
       :
 #if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
         basic_format_args<Context>(*this),
 #endif
-        data_{detail::make_arg<
-            is_packed, Context,
-            detail::mapped_type_constant<remove_cvref_t<T>, Context>::value>(
-            FMT_FORWARD(args))...} {
-    detail::init_named_args(data_.named_args(), 0, 0, args...);
+        data_{detail::make_arg<is_packed, Context>(args)...} {
+    if (detail::const_check(num_named_args != 0))
+      detail::init_named_args(data_.named_args(), 0, 0, args...);
   }
 };
 
@@ -1833,14 +1849,15 @@ class format_arg_store
   \rst
   Constructs a `~fmt::format_arg_store` object that contains references to
   arguments and can be implicitly converted to `~fmt::format_args`. `Context`
-  can be omitted in which case it defaults to `~fmt::context`.
+  can be omitted in which case it defaults to `~fmt::format_context`.
   See `~fmt::arg` for lifetime considerations.
   \endrst
  */
+// Arguments are taken by lvalue references to avoid some lifetime issues.
 template <typename Context = format_context, typename... T>
-constexpr auto make_format_args(T&&... args)
+constexpr auto make_format_args(T&... args)
     -> format_arg_store<Context, remove_cvref_t<T>...> {
-  return {FMT_FORWARD(args)...};
+  return {args...};
 }
 
 /**
@@ -1868,7 +1885,7 @@ FMT_END_EXPORT
   ``vformat``::
 
     void vlog(string_view format_str, format_args args);  // OK
-    format_args args = make_format_args(42);  // Error: dangling reference
+    format_args args = make_format_args();  // Error: dangling reference
   \endrst
  */
 template <typename Context> class basic_format_args {
@@ -1985,7 +2002,7 @@ template <typename Context> class basic_format_args {
 /** An alias to ``basic_format_args<format_context>``. */
 // A separate type would result in shorter symbols but break ABI compatibility
 // between clang and gcc on ARM (#1919).
-FMT_MODULE_EXPORT using format_args = basic_format_args<format_context>;
+FMT_EXPORT using format_args = basic_format_args<format_context>;
 
 // We cannot use enum classes as bit fields because of a gcc bug, so we put them
 // in namespaces instead (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61414).
@@ -2317,9 +2334,12 @@ FMT_CONSTEXPR FMT_INLINE auto parse_format_specs(
     dynamic_format_specs<Char>& specs;
     type arg_type;
 
-    FMT_CONSTEXPR auto operator()(pres type, int set) -> const Char* {
-      if (!in(arg_type, set)) throw_format_error("invalid format specifier");
-      specs.type = type;
+    FMT_CONSTEXPR auto operator()(pres pres_type, int set) -> const Char* {
+      if (!in(arg_type, set)) {
+        if (arg_type == type::none_type) return begin;
+        throw_format_error("invalid format specifier");
+      }
+      specs.type = pres_type;
       return begin + 1;
     }
   } parse_presentation_type{begin, specs, arg_type};
@@ -2336,6 +2356,7 @@ FMT_CONSTEXPR FMT_INLINE auto parse_format_specs(
     case '+':
     case '-':
     case ' ':
+      if (arg_type == type::none_type) return begin;
       enter_state(state::sign, in(arg_type, sint_set | float_set));
       switch (c) {
       case '+':
@@ -2351,14 +2372,17 @@ FMT_CONSTEXPR FMT_INLINE auto parse_format_specs(
       ++begin;
       break;
     case '#':
+      if (arg_type == type::none_type) return begin;
       enter_state(state::hash, is_arithmetic_type(arg_type));
       specs.alt = true;
       ++begin;
       break;
     case '0':
       enter_state(state::zero);
-      if (!is_arithmetic_type(arg_type))
+      if (!is_arithmetic_type(arg_type)) {
+        if (arg_type == type::none_type) return begin;
         throw_format_error("format specifier requires numeric argument");
+      }
       if (specs.align == align::none) {
         // Ignore 0 if align is specified for compatibility with std::format.
         specs.align = align::numeric;
@@ -2380,12 +2404,14 @@ FMT_CONSTEXPR FMT_INLINE auto parse_format_specs(
       begin = parse_dynamic_spec(begin, end, specs.width, specs.width_ref, ctx);
       break;
     case '.':
+      if (arg_type == type::none_type) return begin;
       enter_state(state::precision,
                   in(arg_type, float_set | string_set | cstring_set));
       begin = parse_precision(begin, end, specs.precision, specs.precision_ref,
                               ctx);
       break;
     case 'L':
+      if (arg_type == type::none_type) return begin;
       enter_state(state::locale, is_arithmetic_type(arg_type));
       specs.localized = true;
       ++begin;
@@ -2419,6 +2445,8 @@ FMT_CONSTEXPR FMT_INLINE auto parse_format_specs(
     case 'G':
       return parse_presentation_type(pres::general_upper, float_set);
     case 'c':
+      if (arg_type == type::bool_type)
+        throw_format_error("invalid format specifier");
       return parse_presentation_type(pres::chr, integral_set);
     case 's':
       return parse_presentation_type(pres::string,
@@ -2557,7 +2585,17 @@ FMT_CONSTEXPR auto parse_format_specs(ParseContext& ctx)
       mapped_type_constant<T, context>::value != type::custom_type,
       decltype(arg_mapper<context>().map(std::declval<const T&>())),
       typename strip_named_arg<T>::type>;
+#if defined(__cpp_if_constexpr)
+  if constexpr (std::is_default_constructible<
+                    formatter<mapped_type, char_type>>::value) {
+    return formatter<mapped_type, char_type>().parse(ctx);
+  } else {
+    type_is_unformattable_for<T, char_type> _;
+    return ctx.begin();
+  }
+#else
   return formatter<mapped_type, char_type>().parse(ctx);
+#endif
 }
 
 // Checks char specs and returns true iff the presentation type is char-like.
@@ -2573,8 +2611,6 @@ FMT_CONSTEXPR auto check_char_specs(const format_specs<Char>& specs) -> bool {
   return true;
 }
 
-constexpr FMT_INLINE_VARIABLE int invalid_arg_index = -1;
-
 #if FMT_USE_NONTYPE_TEMPLATE_ARGS
 template <int N, typename T, typename... Args, typename Char>
 constexpr auto get_arg_index_by_name(basic_string_view<Char> name) -> int {
@@ -2584,7 +2620,7 @@ constexpr auto get_arg_index_by_name(basic_string_view<Char> name) -> int {
   if constexpr (sizeof...(Args) > 0)
     return get_arg_index_by_name<N + 1, Args...>(name);
   (void)name;  // Workaround an MSVC bug about "unused" parameter.
-  return invalid_arg_index;
+  return -1;
 }
 #endif
 
@@ -2595,7 +2631,7 @@ FMT_CONSTEXPR auto get_arg_index_by_name(basic_string_view<Char> name) -> int {
     return get_arg_index_by_name<0, Args...>(name);
 #endif
   (void)name;
-  return invalid_arg_index;
+  return -1;
 }
 
 template <typename Char, typename... Args> class format_string_checker {
@@ -2609,15 +2645,15 @@ template <typename Char, typename... Args> class format_string_checker {
   // needed for compile-time checks: https://godbolt.org/z/GvWzcTjh1.
   using parse_func = const Char* (*)(parse_context_type&);
 
+  type types_[num_args > 0 ? static_cast<size_t>(num_args) : 1];
   parse_context_type context_;
   parse_func parse_funcs_[num_args > 0 ? static_cast<size_t>(num_args) : 1];
-  type types_[num_args > 0 ? static_cast<size_t>(num_args) : 1];
 
  public:
   explicit FMT_CONSTEXPR format_string_checker(basic_string_view<Char> fmt)
-      : context_(fmt, num_args, types_),
-        parse_funcs_{&parse_format_specs<Args, parse_context_type>...},
-        types_{mapped_type_constant<Args, buffer_context<Char>>::value...} {}
+      : types_{mapped_type_constant<Args, buffer_context<Char>>::value...},
+        context_(fmt, num_args, types_),
+        parse_funcs_{&parse_format_specs<Args, parse_context_type>...} {}
 
   FMT_CONSTEXPR void on_text(const Char*, const Char*) {}
 
@@ -2628,7 +2664,7 @@ template <typename Char, typename... Args> class format_string_checker {
   FMT_CONSTEXPR auto on_arg_id(basic_string_view<Char> id) -> int {
 #if FMT_USE_NONTYPE_TEMPLATE_ARGS
     auto index = get_arg_index_by_name<Args...>(id);
-    if (index == invalid_arg_index) on_error("named argument is not found");
+    if (index < 0) on_error("named argument is not found");
     return index;
 #else
     (void)id;
@@ -2637,7 +2673,9 @@ template <typename Char, typename... Args> class format_string_checker {
 #endif
   }
 
-  FMT_CONSTEXPR void on_replacement_field(int, const Char*) {}
+  FMT_CONSTEXPR void on_replacement_field(int id, const Char* begin) {
+    on_format_specs(id, begin, begin);  // Call parse() on empty specs.
+  }
 
   FMT_CONSTEXPR auto on_format_specs(int id, const Char* begin, const Char*)
       -> const Char* {
@@ -2674,7 +2712,9 @@ template <typename Char = char> struct vformat_args {
   using type = basic_format_args<
       basic_format_context<std::back_insert_iterator<buffer<Char>>, Char>>;
 };
-template <> struct vformat_args<char> { using type = format_args; };
+template <> struct vformat_args<char> {
+  using type = format_args;
+};
 
 // Use vformat_args and avoid type_identity to keep symbols short.
 template <typename Char>
@@ -2720,27 +2760,6 @@ struct formatter<T, Char,
       -> decltype(ctx.out());
 };
 
-#define FMT_FORMAT_AS(Type, Base)                                        \
-  template <typename Char>                                               \
-  struct formatter<Type, Char> : formatter<Base, Char> {                 \
-    template <typename FormatContext>                                    \
-    auto format(const Type& val, FormatContext& ctx) const               \
-        -> decltype(ctx.out()) {                                         \
-      return formatter<Base, Char>::format(static_cast<Base>(val), ctx); \
-    }                                                                    \
-  }
-
-FMT_FORMAT_AS(signed char, int);
-FMT_FORMAT_AS(unsigned char, unsigned);
-FMT_FORMAT_AS(short, int);
-FMT_FORMAT_AS(unsigned short, unsigned);
-FMT_FORMAT_AS(long, long long);
-FMT_FORMAT_AS(unsigned long, unsigned long long);
-FMT_FORMAT_AS(Char*, const Char*);
-FMT_FORMAT_AS(std::basic_string<Char>, basic_string_view<Char>);
-FMT_FORMAT_AS(std::nullptr_t, const void*);
-FMT_FORMAT_AS(detail::std_string_view<Char>, basic_string_view<Char>);
-
 template <typename Char = char> struct runtime_format_string {
   basic_string_view<Char> str;
 };
diff --git a/source/extern/fmt/format-inl.h b/source/extern/fmt/format-inl.h
index 5bae3c7..efac5d1 100644
--- a/source/extern/fmt/format-inl.h
+++ b/source/extern/fmt/format-inl.h
@@ -18,7 +18,7 @@
 #  include <locale>
 #endif
 
-#ifdef _WIN32
+#if defined(_WIN32) && !defined(FMT_WINDOWS_NO_WCHAR)
 #  include <io.h>  // _isatty
 #endif
 
@@ -58,8 +58,8 @@ FMT_FUNC void format_error_code(detail::buffer<char>& out, int error_code,
   error_code_size += detail::to_unsigned(detail::count_digits(abs_value));
   auto it = buffer_appender<char>(out);
   if (message.size() <= inline_buffer_size - error_code_size)
-    format_to(it, FMT_STRING("{}{}"), message, SEP);
-  format_to(it, FMT_STRING("{}{}"), ERROR_STR, error_code);
+    fmt::format_to(it, FMT_STRING("{}{}"), message, SEP);
+  fmt::format_to(it, FMT_STRING("{}{}"), ERROR_STR, error_code);
   FMT_ASSERT(out.size() <= inline_buffer_size, "");
 }
 
@@ -73,9 +73,8 @@ FMT_FUNC void report_error(format_func func, int error_code,
 }
 
 // A wrapper around fwrite that throws on error.
-inline void fwrite_fully(const void* ptr, size_t size, size_t count,
-                         FILE* stream) {
-  size_t written = std::fwrite(ptr, size, count, stream);
+inline void fwrite_fully(const void* ptr, size_t count, FILE* stream) {
+  size_t written = std::fwrite(ptr, 1, count, stream);
   if (written < count)
     FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
 }
@@ -86,7 +85,7 @@ locale_ref::locale_ref(const Locale& loc) : locale_(&loc) {
   static_assert(std::is_same<Locale, std::locale>::value, "");
 }
 
-template <typename Locale> Locale locale_ref::get() const {
+template <typename Locale> auto locale_ref::get() const -> Locale {
   static_assert(std::is_same<Locale, std::locale>::value, "");
   return locale_ ? *static_cast<const std::locale*>(locale_) : std::locale();
 }
@@ -98,7 +97,8 @@ FMT_FUNC auto thousands_sep_impl(locale_ref loc) -> thousands_sep_result<Char> {
   auto thousands_sep = grouping.empty() ? Char() : facet.thousands_sep();
   return {std::move(grouping), thousands_sep};
 }
-template <typename Char> FMT_FUNC Char decimal_point_impl(locale_ref loc) {
+template <typename Char>
+FMT_FUNC auto decimal_point_impl(locale_ref loc) -> Char {
   return std::use_facet<std::numpunct<Char>>(loc.get<std::locale>())
       .decimal_point();
 }
@@ -144,24 +144,25 @@ FMT_API FMT_FUNC auto format_facet<std::locale>::do_put(
 }
 #endif
 
-FMT_FUNC std::system_error vsystem_error(int error_code, string_view fmt,
-                                         format_args args) {
+FMT_FUNC auto vsystem_error(int error_code, string_view fmt, format_args args)
+    -> std::system_error {
   auto ec = std::error_code(error_code, std::generic_category());
   return std::system_error(ec, vformat(fmt, args));
 }
 
 namespace detail {
 
-template <typename F> inline bool operator==(basic_fp<F> x, basic_fp<F> y) {
+template <typename F>
+inline auto operator==(basic_fp<F> x, basic_fp<F> y) -> bool {
   return x.f == y.f && x.e == y.e;
 }
 
 // Compilers should be able to optimize this into the ror instruction.
-FMT_CONSTEXPR inline uint32_t rotr(uint32_t n, uint32_t r) noexcept {
+FMT_CONSTEXPR inline auto rotr(uint32_t n, uint32_t r) noexcept -> uint32_t {
   r &= 31;
   return (n >> r) | (n << (32 - r));
 }
-FMT_CONSTEXPR inline uint64_t rotr(uint64_t n, uint32_t r) noexcept {
+FMT_CONSTEXPR inline auto rotr(uint64_t n, uint32_t r) noexcept -> uint64_t {
   r &= 63;
   return (n >> r) | (n << (64 - r));
 }
@@ -170,14 +171,14 @@ FMT_CONSTEXPR inline uint64_t rotr(uint64_t n, uint32_t r) noexcept {
 namespace dragonbox {
 // Computes upper 64 bits of multiplication of a 32-bit unsigned integer and a
 // 64-bit unsigned integer.
-inline uint64_t umul96_upper64(uint32_t x, uint64_t y) noexcept {
+inline auto umul96_upper64(uint32_t x, uint64_t y) noexcept -> uint64_t {
   return umul128_upper64(static_cast<uint64_t>(x) << 32, y);
 }
 
 // Computes lower 128 bits of multiplication of a 64-bit unsigned integer and a
 // 128-bit unsigned integer.
-inline uint128_fallback umul192_lower128(uint64_t x,
-                                         uint128_fallback y) noexcept {
+inline auto umul192_lower128(uint64_t x, uint128_fallback y) noexcept
+    -> uint128_fallback {
   uint64_t high = x * y.high();
   uint128_fallback high_low = umul128(x, y.low());
   return {high + high_low.high(), high_low.low()};
@@ -185,12 +186,12 @@ inline uint128_fallback umul192_lower128(uint64_t x,
 
 // Computes lower 64 bits of multiplication of a 32-bit unsigned integer and a
 // 64-bit unsigned integer.
-inline uint64_t umul96_lower64(uint32_t x, uint64_t y) noexcept {
+inline auto umul96_lower64(uint32_t x, uint64_t y) noexcept -> uint64_t {
   return x * y;
 }
 
 // Various fast log computations.
-inline int floor_log10_pow2_minus_log10_4_over_3(int e) noexcept {
+inline auto floor_log10_pow2_minus_log10_4_over_3(int e) noexcept -> int {
   FMT_ASSERT(e <= 2936 && e >= -2985, "too large exponent");
   return (e * 631305 - 261663) >> 21;
 }
@@ -204,7 +205,7 @@ FMT_INLINE_VARIABLE constexpr struct {
 // divisible by pow(10, N).
 // Precondition: n <= pow(10, N + 1).
 template <int N>
-bool check_divisibility_and_divide_by_pow10(uint32_t& n) noexcept {
+auto check_divisibility_and_divide_by_pow10(uint32_t& n) noexcept -> bool {
   // The numbers below are chosen such that:
   //   1. floor(n/d) = floor(nm / 2^k) where d=10 or d=100,
   //   2. nm mod 2^k < m if and only if n is divisible by d,
@@ -229,7 +230,7 @@ bool check_divisibility_and_divide_by_pow10(uint32_t& n) noexcept {
 
 // Computes floor(n / pow(10, N)) for small n and N.
 // Precondition: n <= pow(10, N + 1).
-template <int N> uint32_t small_division_by_pow10(uint32_t n) noexcept {
+template <int N> auto small_division_by_pow10(uint32_t n) noexcept -> uint32_t {
   constexpr auto info = div_small_pow10_infos[N - 1];
   FMT_ASSERT(n <= info.divisor * 10, "n is too large");
   constexpr uint32_t magic_number =
@@ -238,12 +239,12 @@ template <int N> uint32_t small_division_by_pow10(uint32_t n) noexcept {
 }
 
 // Computes floor(n / 10^(kappa + 1)) (float)
-inline uint32_t divide_by_10_to_kappa_plus_1(uint32_t n) noexcept {
+inline auto divide_by_10_to_kappa_plus_1(uint32_t n) noexcept -> uint32_t {
   // 1374389535 = ceil(2^37/100)
   return static_cast<uint32_t>((static_cast<uint64_t>(n) * 1374389535) >> 37);
 }
 // Computes floor(n / 10^(kappa + 1)) (double)
-inline uint64_t divide_by_10_to_kappa_plus_1(uint64_t n) noexcept {
+inline auto divide_by_10_to_kappa_plus_1(uint64_t n) noexcept -> uint64_t {
   // 2361183241434822607 = ceil(2^(64+7)/1000)
   return umul128_upper64(n, 2361183241434822607ull) >> 7;
 }
@@ -255,7 +256,7 @@ template <> struct cache_accessor<float> {
   using carrier_uint = float_info<float>::carrier_uint;
   using cache_entry_type = uint64_t;
 
-  static uint64_t get_cached_power(int k) noexcept {
+  static auto get_cached_power(int k) noexcept -> uint64_t {
     FMT_ASSERT(k >= float_info<float>::min_k && k <= float_info<float>::max_k,
                "k is out of range");
     static constexpr const uint64_t pow10_significands[] = {
@@ -297,20 +298,23 @@ template <> struct cache_accessor<float> {
     bool is_integer;
   };
 
-  static compute_mul_result compute_mul(
-      carrier_uint u, const cache_entry_type& cache) noexcept {
+  static auto compute_mul(carrier_uint u,
+                          const cache_entry_type& cache) noexcept
+      -> compute_mul_result {
     auto r = umul96_upper64(u, cache);
     return {static_cast<carrier_uint>(r >> 32),
             static_cast<carrier_uint>(r) == 0};
   }
 
-  static uint32_t compute_delta(const cache_entry_type& cache,
-                                int beta) noexcept {
+  static auto compute_delta(const cache_entry_type& cache, int beta) noexcept
+      -> uint32_t {
     return static_cast<uint32_t>(cache >> (64 - 1 - beta));
   }
 
-  static compute_mul_parity_result compute_mul_parity(
-      carrier_uint two_f, const cache_entry_type& cache, int beta) noexcept {
+  static auto compute_mul_parity(carrier_uint two_f,
+                                 const cache_entry_type& cache,
+                                 int beta) noexcept
+      -> compute_mul_parity_result {
     FMT_ASSERT(beta >= 1, "");
     FMT_ASSERT(beta < 64, "");
 
@@ -319,22 +323,22 @@ template <> struct cache_accessor<float> {
             static_cast<uint32_t>(r >> (32 - beta)) == 0};
   }
 
-  static carrier_uint compute_left_endpoint_for_shorter_interval_case(
-      const cache_entry_type& cache, int beta) noexcept {
+  static auto compute_left_endpoint_for_shorter_interval_case(
+      const cache_entry_type& cache, int beta) noexcept -> carrier_uint {
     return static_cast<carrier_uint>(
         (cache - (cache >> (num_significand_bits<float>() + 2))) >>
         (64 - num_significand_bits<float>() - 1 - beta));
   }
 
-  static carrier_uint compute_right_endpoint_for_shorter_interval_case(
-      const cache_entry_type& cache, int beta) noexcept {
+  static auto compute_right_endpoint_for_shorter_interval_case(
+      const cache_entry_type& cache, int beta) noexcept -> carrier_uint {
     return static_cast<carrier_uint>(
         (cache + (cache >> (num_significand_bits<float>() + 1))) >>
         (64 - num_significand_bits<float>() - 1 - beta));
   }
 
-  static carrier_uint compute_round_up_for_shorter_interval_case(
-      const cache_entry_type& cache, int beta) noexcept {
+  static auto compute_round_up_for_shorter_interval_case(
+      const cache_entry_type& cache, int beta) noexcept -> carrier_uint {
     return (static_cast<carrier_uint>(
                 cache >> (64 - num_significand_bits<float>() - 2 - beta)) +
             1) /
@@ -346,7 +350,7 @@ template <> struct cache_accessor<double> {
   using carrier_uint = float_info<double>::carrier_uint;
   using cache_entry_type = uint128_fallback;
 
-  static uint128_fallback get_cached_power(int k) noexcept {
+  static auto get_cached_power(int k) noexcept -> uint128_fallback {
     FMT_ASSERT(k >= float_info<double>::min_k && k <= float_info<double>::max_k,
                "k is out of range");
 
@@ -985,8 +989,7 @@ template <> struct cache_accessor<double> {
       {0xe0accfa875af45a7, 0x93eb1b80a33b8606},
       {0x8c6c01c9498d8b88, 0xbc72f130660533c4},
       {0xaf87023b9bf0ee6a, 0xeb8fad7c7f8680b5},
-      { 0xdb68c2ca82ed2a05,
-        0xa67398db9f6820e2 }
+      {0xdb68c2ca82ed2a05, 0xa67398db9f6820e2},
 #else
       {0xff77b1fcbebcdc4f, 0x25e8e89c13bb0f7b},
       {0xce5d73ff402d98e3, 0xfb0a3d212dc81290},
@@ -1071,19 +1074,22 @@ template <> struct cache_accessor<double> {
     bool is_integer;
   };
 
-  static compute_mul_result compute_mul(
-      carrier_uint u, const cache_entry_type& cache) noexcept {
+  static auto compute_mul(carrier_uint u,
+                          const cache_entry_type& cache) noexcept
+      -> compute_mul_result {
     auto r = umul192_upper128(u, cache);
     return {r.high(), r.low() == 0};
   }
 
-  static uint32_t compute_delta(cache_entry_type const& cache,
-                                int beta) noexcept {
+  static auto compute_delta(cache_entry_type const& cache, int beta) noexcept
+      -> uint32_t {
     return static_cast<uint32_t>(cache.high() >> (64 - 1 - beta));
   }
 
-  static compute_mul_parity_result compute_mul_parity(
-      carrier_uint two_f, const cache_entry_type& cache, int beta) noexcept {
+  static auto compute_mul_parity(carrier_uint two_f,
+                                 const cache_entry_type& cache,
+                                 int beta) noexcept
+      -> compute_mul_parity_result {
     FMT_ASSERT(beta >= 1, "");
     FMT_ASSERT(beta < 64, "");
 
@@ -1092,35 +1098,35 @@ template <> struct cache_accessor<double> {
             ((r.high() << beta) | (r.low() >> (64 - beta))) == 0};
   }
 
-  static carrier_uint compute_left_endpoint_for_shorter_interval_case(
-      const cache_entry_type& cache, int beta) noexcept {
+  static auto compute_left_endpoint_for_shorter_interval_case(
+      const cache_entry_type& cache, int beta) noexcept -> carrier_uint {
     return (cache.high() -
             (cache.high() >> (num_significand_bits<double>() + 2))) >>
            (64 - num_significand_bits<double>() - 1 - beta);
   }
 
-  static carrier_uint compute_right_endpoint_for_shorter_interval_case(
-      const cache_entry_type& cache, int beta) noexcept {
+  static auto compute_right_endpoint_for_shorter_interval_case(
+      const cache_entry_type& cache, int beta) noexcept -> carrier_uint {
     return (cache.high() +
             (cache.high() >> (num_significand_bits<double>() + 1))) >>
            (64 - num_significand_bits<double>() - 1 - beta);
   }
 
-  static carrier_uint compute_round_up_for_shorter_interval_case(
-      const cache_entry_type& cache, int beta) noexcept {
+  static auto compute_round_up_for_shorter_interval_case(
+      const cache_entry_type& cache, int beta) noexcept -> carrier_uint {
     return ((cache.high() >> (64 - num_significand_bits<double>() - 2 - beta)) +
             1) /
            2;
   }
 };
 
-FMT_FUNC uint128_fallback get_cached_power(int k) noexcept {
+FMT_FUNC auto get_cached_power(int k) noexcept -> uint128_fallback {
   return cache_accessor<double>::get_cached_power(k);
 }
 
 // Various integer checks
 template <typename T>
-bool is_left_endpoint_integer_shorter_interval(int exponent) noexcept {
+auto is_left_endpoint_integer_shorter_interval(int exponent) noexcept -> bool {
   const int case_shorter_interval_left_endpoint_lower_threshold = 2;
   const int case_shorter_interval_left_endpoint_upper_threshold = 3;
   return exponent >= case_shorter_interval_left_endpoint_lower_threshold &&
@@ -1128,16 +1134,12 @@ bool is_left_endpoint_integer_shorter_interval(int exponent) noexcept {
 }
 
 // Remove trailing zeros from n and return the number of zeros removed (float)
-FMT_INLINE int remove_trailing_zeros(uint32_t& n) noexcept {
+FMT_INLINE int remove_trailing_zeros(uint32_t& n, int s = 0) noexcept {
   FMT_ASSERT(n != 0, "");
   // Modular inverse of 5 (mod 2^32): (mod_inv_5 * 5) mod 2^32 = 1.
-  // See https://github.com/fmtlib/fmt/issues/3163 for more details.
-  const uint32_t mod_inv_5 = 0xcccccccd;
-  // Casts are needed to workaround a bug in MSVC 19.22 and older.
-  const uint32_t mod_inv_25 =
-      static_cast<uint32_t>(uint64_t(mod_inv_5) * mod_inv_5);
+  constexpr uint32_t mod_inv_5 = 0xcccccccd;
+  constexpr uint32_t mod_inv_25 = 0xc28f5c29;  // = mod_inv_5 * mod_inv_5
 
-  int s = 0;
   while (true) {
     auto q = rotr(n * mod_inv_25, 2);
     if (q > max_value<uint32_t>() / 100) break;
@@ -1162,32 +1164,17 @@ FMT_INLINE int remove_trailing_zeros(uint64_t& n) noexcept {
 
   // Is n is divisible by 10^8?
   if ((nm.high() & ((1ull << (90 - 64)) - 1)) == 0 && nm.low() < magic_number) {
-    // If yes, work with the quotient.
+    // If yes, work with the quotient...
     auto n32 = static_cast<uint32_t>(nm.high() >> (90 - 64));
-
-    const uint32_t mod_inv_5 = 0xcccccccd;
-    const uint32_t mod_inv_25 = mod_inv_5 * mod_inv_5;
-
-    int s = 8;
-    while (true) {
-      auto q = rotr(n32 * mod_inv_25, 2);
-      if (q > max_value<uint32_t>() / 100) break;
-      n32 = q;
-      s += 2;
-    }
-    auto q = rotr(n32 * mod_inv_5, 1);
-    if (q <= max_value<uint32_t>() / 10) {
-      n32 = q;
-      s |= 1;
-    }
-
+    // ... and use the 32 bit variant of the function
+    int s = remove_trailing_zeros(n32, 8);
     n = n32;
     return s;
   }
 
   // If n is not divisible by 10^8, work with n itself.
-  const uint64_t mod_inv_5 = 0xcccccccccccccccd;
-  const uint64_t mod_inv_25 = mod_inv_5 * mod_inv_5;
+  constexpr uint64_t mod_inv_5 = 0xcccccccccccccccd;
+  constexpr uint64_t mod_inv_25 = 0x8f5c28f5c28f5c29;  // mod_inv_5 * mod_inv_5
 
   int s = 0;
   while (true) {
@@ -1253,7 +1240,7 @@ FMT_INLINE decimal_fp<T> shorter_interval_case(int exponent) noexcept {
   return ret_value;
 }
 
-template <typename T> decimal_fp<T> to_decimal(T x) noexcept {
+template <typename T> auto to_decimal(T x) noexcept -> decimal_fp<T> {
   // Step 1: integer promotion & Schubfach multiplier calculation.
 
   using carrier_uint = typename float_info<T>::carrier_uint;
@@ -1392,15 +1379,15 @@ template <> struct formatter<detail::bigint> {
     for (auto i = n.bigits_.size(); i > 0; --i) {
       auto value = n.bigits_[i - 1u];
       if (first) {
-        out = format_to(out, FMT_STRING("{:x}"), value);
+        out = fmt::format_to(out, FMT_STRING("{:x}"), value);
         first = false;
         continue;
       }
-      out = format_to(out, FMT_STRING("{:08x}"), value);
+      out = fmt::format_to(out, FMT_STRING("{:08x}"), value);
     }
     if (n.exp_ > 0)
-      out = format_to(out, FMT_STRING("p{}"),
-                      n.exp_ * detail::bigint::bigit_bits);
+      out = fmt::format_to(out, FMT_STRING("p{}"),
+                           n.exp_ * detail::bigint::bigit_bits);
     return out;
   }
 };
@@ -1436,7 +1423,7 @@ FMT_FUNC void report_system_error(int error_code,
   report_error(format_system_error, error_code, message);
 }
 
-FMT_FUNC std::string vformat(string_view fmt, format_args args) {
+FMT_FUNC auto vformat(string_view fmt, format_args args) -> std::string {
   // Don't optimize the "{}" case to keep the binary size small and because it
   // can be better optimized in fmt::format anyway.
   auto buffer = memory_buffer();
@@ -1445,33 +1432,43 @@ FMT_FUNC std::string vformat(string_view fmt, format_args args) {
 }
 
 namespace detail {
-#ifndef _WIN32
-FMT_FUNC bool write_console(std::FILE*, string_view) { return false; }
+#if !defined(_WIN32) || defined(FMT_WINDOWS_NO_WCHAR)
+FMT_FUNC auto write_console(int, string_view) -> bool { return false; }
+FMT_FUNC auto write_console(std::FILE*, string_view) -> bool { return false; }
 #else
 using dword = conditional_t<sizeof(long) == 4, unsigned long, unsigned>;
 extern "C" __declspec(dllimport) int __stdcall WriteConsoleW(  //
     void*, const void*, dword, dword*, void*);
 
-FMT_FUNC bool write_console(std::FILE* f, string_view text) {
-  auto fd = _fileno(f);
-  if (!_isatty(fd)) return false;
+FMT_FUNC bool write_console(int fd, string_view text) {
   auto u16 = utf8_to_utf16(text);
-  auto written = dword();
   return WriteConsoleW(reinterpret_cast<void*>(_get_osfhandle(fd)), u16.c_str(),
-                       static_cast<uint32_t>(u16.size()), &written, nullptr);
+                       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) {
   auto buffer = memory_buffer();
-  detail::vformat_to(buffer, fmt,
-                     basic_format_args<buffer_context<char>>(args));
-  fwrite_fully(buffer.data(), 1, buffer.size(), f);
+  detail::vformat_to(buffer, fmt, args);
+  fwrite_fully(buffer.data(), buffer.size(), f);
 }
 #endif
 
 FMT_FUNC void print(std::FILE* f, string_view text) {
-  if (!write_console(f, text)) fwrite_fully(text.data(), 1, text.size(), f);
+#ifdef _WIN32
+  int fd = _fileno(f);
+  if (_isatty(fd)) {
+    std::fflush(f);
+    if (write_console(fd, text)) return;
+  }
+#endif
+  fwrite_fully(text.data(), text.size(), f);
 }
 }  // namespace detail
 
diff --git a/source/extern/fmt/format.h b/source/extern/fmt/format.h
index ed8b29e..7637c8a 100644
--- a/source/extern/fmt/format.h
+++ b/source/extern/fmt/format.h
@@ -43,14 +43,15 @@
 #include <system_error>      // std::system_error
 
 #ifdef __cpp_lib_bit_cast
-#  include <bit>  // std::bitcast
+#  include <bit>  // std::bit_cast
 #endif
 
 #include "core.h"
 
-#ifndef FMT_BEGIN_DETAIL_NAMESPACE
-#  define FMT_BEGIN_DETAIL_NAMESPACE namespace detail {
-#  define FMT_END_DETAIL_NAMESPACE }
+#if defined __cpp_inline_variables && __cpp_inline_variables >= 201606L
+#  define FMT_INLINE_VARIABLE inline
+#else
+#  define FMT_INLINE_VARIABLE
 #endif
 
 #if FMT_HAS_CPP17_ATTRIBUTE(fallthrough)
@@ -78,16 +79,25 @@
 #  endif
 #endif
 
-#if FMT_GCC_VERSION
-#  define FMT_GCC_VISIBILITY_HIDDEN __attribute__((visibility("hidden")))
-#else
-#  define FMT_GCC_VISIBILITY_HIDDEN
+#ifndef FMT_NO_UNIQUE_ADDRESS
+#  if FMT_CPLUSPLUS >= 202002L
+#    if FMT_HAS_CPP_ATTRIBUTE(no_unique_address)
+#      define FMT_NO_UNIQUE_ADDRESS [[no_unique_address]]
+// VS2019 v16.10 and later except clang-cl (https://reviews.llvm.org/D110485)
+#    elif (FMT_MSC_VERSION >= 1929) && !FMT_CLANG_VERSION
+#      define FMT_NO_UNIQUE_ADDRESS [[msvc::no_unique_address]]
+#    endif
+#  endif
+#endif
+#ifndef FMT_NO_UNIQUE_ADDRESS
+#  define FMT_NO_UNIQUE_ADDRESS
 #endif
 
-#ifdef __NVCC__
-#  define FMT_CUDA_VERSION (__CUDACC_VER_MAJOR__ * 100 + __CUDACC_VER_MINOR__)
+// Visibility when compiled as a shared library/object.
+#if defined(FMT_LIB_EXPORT) || defined(FMT_SHARED)
+#  define FMT_SO_VISIBILITY(value) FMT_VISIBILITY(value)
 #else
-#  define FMT_CUDA_VERSION 0
+#  define FMT_SO_VISIBILITY(value)
 #endif
 
 #ifdef __has_builtin
@@ -120,10 +130,8 @@ FMT_END_NAMESPACE
 #      define FMT_THROW(x) throw x
 #    endif
 #  else
-#    define FMT_THROW(x)               \
-      do {                             \
-        FMT_ASSERT(false, (x).what()); \
-      } while (false)
+#    define FMT_THROW(x) \
+      ::fmt::detail::assert_fail(__FILE__, __LINE__, (x).what())
 #  endif
 #endif
 
@@ -145,7 +153,10 @@ FMT_END_NAMESPACE
 
 #ifndef FMT_USE_USER_DEFINED_LITERALS
 // EDG based compilers (Intel, NVIDIA, Elbrus, etc), GCC and MSVC support UDLs.
-#  if (FMT_HAS_FEATURE(cxx_user_literals) || FMT_GCC_VERSION >= 407 || \
+//
+// GCC before 4.9 requires a space in `operator"" _a` which is invalid in later
+// compiler versions.
+#  if (FMT_HAS_FEATURE(cxx_user_literals) || FMT_GCC_VERSION >= 409 || \
        FMT_MSC_VERSION >= 1900) &&                                     \
       (!defined(__EDG_VERSION__) || __EDG_VERSION__ >= /* UDL feature */ 480)
 #    define FMT_USE_USER_DEFINED_LITERALS 1
@@ -266,19 +277,6 @@ FMT_END_NAMESPACE
 #endif
 
 FMT_BEGIN_NAMESPACE
-
-template <typename...> struct disjunction : std::false_type {};
-template <typename P> struct disjunction<P> : P {};
-template <typename P1, typename... Pn>
-struct disjunction<P1, Pn...>
-    : conditional_t<bool(P1::value), P1, disjunction<Pn...>> {};
-
-template <typename...> struct conjunction : std::true_type {};
-template <typename P> struct conjunction<P> : P {};
-template <typename P1, typename... Pn>
-struct conjunction<P1, Pn...>
-    : conditional_t<bool(P1::value), conjunction<Pn...>, P1> {};
-
 namespace detail {
 
 FMT_CONSTEXPR inline void abort_fuzzing_if(bool condition) {
@@ -300,37 +298,6 @@ template <typename CharT, CharT... C>
 constexpr CharT string_literal<CharT, C...>::value[sizeof...(C)];
 #endif
 
-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;
-  }
-};
-
 // Implementation of std::bit_cast for pre-C++20.
 template <typename To, typename From, FMT_ENABLE_IF(sizeof(To) == sizeof(From))>
 FMT_CONSTEXPR20 auto bit_cast(const From& from) -> To {
@@ -362,14 +329,12 @@ class uint128_fallback {
  private:
   uint64_t lo_, hi_;
 
-  friend uint128_fallback umul128(uint64_t x, uint64_t y) noexcept;
-
  public:
   constexpr uint128_fallback(uint64_t hi, uint64_t lo) : lo_(lo), hi_(hi) {}
   constexpr uint128_fallback(uint64_t value = 0) : lo_(value), hi_(0) {}
 
-  constexpr uint64_t high() const noexcept { return hi_; }
-  constexpr uint64_t low() const noexcept { return lo_; }
+  constexpr auto high() const noexcept -> uint64_t { return hi_; }
+  constexpr auto low() const noexcept -> uint64_t { return lo_; }
 
   template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
   constexpr explicit operator T() const {
@@ -445,7 +410,7 @@ class uint128_fallback {
     hi_ &= n.hi_;
   }
 
-  FMT_CONSTEXPR20 uint128_fallback& operator+=(uint64_t n) noexcept {
+  FMT_CONSTEXPR20 auto operator+=(uint64_t n) noexcept -> uint128_fallback& {
     if (is_constant_evaluated()) {
       lo_ += n;
       hi_ += (lo_ < n ? 1 : 0);
@@ -536,6 +501,8 @@ FMT_INLINE void assume(bool condition) {
   (void)condition;
 #if FMT_HAS_BUILTIN(__builtin_assume) && !FMT_ICC_VERSION
   __builtin_assume(condition);
+#elif FMT_GCC_VERSION
+  if (!condition) __builtin_unreachable();
 #endif
 }
 
@@ -554,20 +521,6 @@ inline auto get_data(Container& c) -> typename Container::value_type* {
   return c.data();
 }
 
-#if defined(_SECURE_SCL) && _SECURE_SCL
-// Make a checked iterator to avoid MSVC warnings.
-template <typename T> using checked_ptr = stdext::checked_array_iterator<T*>;
-template <typename T>
-constexpr auto make_checked(T* p, size_t size) -> checked_ptr<T> {
-  return {p, size};
-}
-#else
-template <typename T> using checked_ptr = T*;
-template <typename T> constexpr auto make_checked(T* p, size_t) -> T* {
-  return p;
-}
-#endif
-
 // Attempts to reserve space for n extra characters in the output range.
 // Returns a pointer to the reserved range or a reference to it.
 template <typename Container, FMT_ENABLE_IF(is_contiguous<Container>::value)>
@@ -575,12 +528,12 @@ template <typename Container, FMT_ENABLE_IF(is_contiguous<Container>::value)>
 __attribute__((no_sanitize("undefined")))
 #endif
 inline auto
-reserve(std::back_insert_iterator<Container> it, size_t n)
-    -> checked_ptr<typename Container::value_type> {
+reserve(std::back_insert_iterator<Container> it, size_t n) ->
+    typename Container::value_type* {
   Container& c = get_container(it);
   size_t size = c.size();
   c.resize(size + n);
-  return make_checked(get_data(c) + size, n);
+  return get_data(c) + size;
 }
 
 template <typename T>
@@ -612,8 +565,8 @@ template <typename T> auto to_pointer(buffer_appender<T> it, size_t n) -> T* {
 }
 
 template <typename Container, FMT_ENABLE_IF(is_contiguous<Container>::value)>
-inline auto base_iterator(std::back_insert_iterator<Container>& it,
-                          checked_ptr<typename Container::value_type>)
+inline auto base_iterator(std::back_insert_iterator<Container> it,
+                          typename Container::value_type*)
     -> std::back_insert_iterator<Container> {
   return it;
 }
@@ -747,7 +700,7 @@ inline auto compute_width(basic_string_view<Char> s) -> size_t {
 }
 
 // Computes approximate display width of a UTF-8 string.
-FMT_CONSTEXPR inline size_t compute_width(string_view s) {
+FMT_CONSTEXPR inline auto compute_width(string_view s) -> size_t {
   size_t num_code_points = 0;
   // It is not a lambda for compatibility with C++14.
   struct count_code_points {
@@ -794,12 +747,17 @@ inline auto code_point_index(basic_string_view<Char> s, size_t n) -> size_t {
 
 // Calculates the index of the nth code point in a UTF-8 string.
 inline auto code_point_index(string_view s, size_t n) -> size_t {
-  const char* data = s.data();
-  size_t num_code_points = 0;
-  for (size_t i = 0, size = s.size(); i != size; ++i) {
-    if ((data[i] & 0xc0) != 0x80 && ++num_code_points > n) return i;
-  }
-  return s.size();
+  size_t result = s.size();
+  const char* begin = s.begin();
+  for_each_codepoint(s, [begin, &n, &result](uint32_t, string_view sv) {
+    if (n != 0) {
+      --n;
+      return true;
+    }
+    result = to_unsigned(sv.begin() - begin);
+    return false;
+  });
+  return result;
 }
 
 inline auto code_point_index(basic_string_view<char8_type> s, size_t n)
@@ -881,7 +839,7 @@ void buffer<T>::append(const U* begin, const U* end) {
     try_reserve(size_ + count);
     auto free_cap = capacity_ - size_;
     if (free_cap < count) count = free_cap;
-    std::uninitialized_copy_n(begin, count, make_checked(ptr_ + size_, count));
+    std::uninitialized_copy_n(begin, count, ptr_ + size_);
     size_ += count;
     begin += count;
   }
@@ -909,7 +867,7 @@ enum { inline_buffer_size = 500 };
   **Example**::
 
      auto out = fmt::memory_buffer();
-     format_to(std::back_inserter(out), "The answer is {}.", 42);
+     fmt::format_to(std::back_inserter(out), "The answer is {}.", 42);
 
   This will append the following output to the ``out`` object:
 
@@ -926,8 +884,8 @@ class basic_memory_buffer final : public detail::buffer<T> {
  private:
   T store_[SIZE];
 
-  // Don't inherit from Allocator avoid generating type_info for it.
-  Allocator alloc_;
+  // Don't inherit from Allocator to avoid generating type_info for it.
+  FMT_NO_UNIQUE_ADDRESS Allocator alloc_;
 
   // Deallocate memory allocated by the buffer.
   FMT_CONSTEXPR20 void deallocate() {
@@ -948,9 +906,10 @@ class basic_memory_buffer final : public detail::buffer<T> {
     T* old_data = this->data();
     T* new_data =
         std::allocator_traits<Allocator>::allocate(alloc_, new_capacity);
+    // Suppress a bogus -Wstringop-overflow in gcc 13.1 (#3481).
+    detail::assume(this->size() <= new_capacity);
     // The following code doesn't throw, so the raw pointer above doesn't leak.
-    std::uninitialized_copy(old_data, old_data + this->size(),
-                            detail::make_checked(new_data, new_capacity));
+    std::uninitialized_copy_n(old_data, this->size(), new_data);
     this->set(new_data, new_capacity);
     // deallocate must not throw according to the standard, but even if it does,
     // the buffer already uses the new storage and will deallocate it in
@@ -978,8 +937,7 @@ class basic_memory_buffer final : public detail::buffer<T> {
     size_t size = other.size(), capacity = other.capacity();
     if (data == other.store_) {
       this->set(store_, capacity);
-      detail::copy_str<T>(other.store_, other.store_ + size,
-                          detail::make_checked(store_, capacity));
+      detail::copy_str<T>(other.store_, other.store_ + size, store_);
     } else {
       this->set(data, capacity);
       // Set pointer to the inline array so that delete is not called
@@ -1025,7 +983,6 @@ class basic_memory_buffer final : public detail::buffer<T> {
   /** Increases the buffer capacity to *new_capacity*. */
   void reserve(size_t new_capacity) { this->try_reserve(new_capacity); }
 
-  // Directly append data into the buffer
   using detail::buffer<T>::append;
   template <typename ContiguousRange>
   void append(const ContiguousRange& range) {
@@ -1041,9 +998,11 @@ struct is_contiguous<basic_memory_buffer<T, SIZE, Allocator>> : std::true_type {
 
 FMT_END_EXPORT
 namespace detail {
-FMT_API bool write_console(std::FILE* f, string_view text);
+FMT_API auto write_console(int fd, string_view text) -> bool;
+FMT_API auto write_console(std::FILE* f, string_view text) -> bool;
 FMT_API void print(std::FILE*, string_view);
 }  // namespace detail
+
 FMT_BEGIN_EXPORT
 
 // Suppress a misleading warning in older versions of clang.
@@ -1052,7 +1011,7 @@ FMT_BEGIN_EXPORT
 #endif
 
 /** An error reported from a formatting function. */
-class FMT_API format_error : public std::runtime_error {
+class FMT_SO_VISIBILITY("default") format_error : public std::runtime_error {
  public:
   using std::runtime_error::runtime_error;
 };
@@ -1128,7 +1087,7 @@ template <typename Locale> class format_facet : public Locale::facet {
   }
 };
 
-FMT_BEGIN_DETAIL_NAMESPACE
+namespace detail {
 
 // Returns true if value is negative, false otherwise.
 // Same as `value < 0` but doesn't produce warnings if T is an unsigned type.
@@ -1159,13 +1118,13 @@ using uint32_or_64_or_128_t =
 template <typename T>
 using uint64_or_128_t = conditional_t<num_bits<T>() <= 64, uint64_t, uint128_t>;
 
-#define FMT_POWERS_OF_10(factor)                                             \
-  factor * 10, (factor)*100, (factor)*1000, (factor)*10000, (factor)*100000, \
-      (factor)*1000000, (factor)*10000000, (factor)*100000000,               \
-      (factor)*1000000000
+#define FMT_POWERS_OF_10(factor)                                  \
+  factor * 10, (factor) * 100, (factor) * 1000, (factor) * 10000, \
+      (factor) * 100000, (factor) * 1000000, (factor) * 10000000, \
+      (factor) * 100000000, (factor) * 1000000000
 
 // Converts value in the range [0, 100) to a string.
-constexpr const char* digits2(size_t value) {
+constexpr auto digits2(size_t value) -> const char* {
   // GCC generates slightly better code when value is pointer-size.
   return &"0001020304050607080910111213141516171819"
          "2021222324252627282930313233343536373839"
@@ -1175,7 +1134,7 @@ constexpr const char* digits2(size_t value) {
 }
 
 // Sign is a template parameter to workaround a bug in gcc 4.8.
-template <typename Char, typename Sign> constexpr Char sign(Sign s) {
+template <typename Char, typename Sign> constexpr auto sign(Sign s) -> Char {
 #if !FMT_GCC_VERSION || FMT_GCC_VERSION >= 604
   static_assert(std::is_same<Sign, sign_t>::value, "");
 #endif
@@ -1257,7 +1216,7 @@ FMT_CONSTEXPR auto count_digits(UInt n) -> int {
 FMT_INLINE auto do_count_digits(uint32_t n) -> int {
 // An optimization by Kendall Willets from https://bit.ly/3uOIQrB.
 // This increments the upper 32 bits (log10(T) - 1) when >= T is added.
-#  define FMT_INC(T) (((sizeof(#  T) - 1ull) << 32) - T)
+#  define FMT_INC(T) (((sizeof(#T) - 1ull) << 32) - T)
   static constexpr uint64_t table[] = {
       FMT_INC(0),          FMT_INC(0),          FMT_INC(0),           // 8
       FMT_INC(10),         FMT_INC(10),         FMT_INC(10),          // 64
@@ -1393,14 +1352,14 @@ FMT_CONSTEXPR auto format_uint(Char* buffer, UInt value, int num_digits,
 }
 
 template <unsigned BASE_BITS, typename Char, typename It, typename UInt>
-inline auto format_uint(It out, UInt value, int num_digits, bool upper = false)
-    -> It {
+FMT_CONSTEXPR inline auto format_uint(It out, UInt value, int num_digits,
+                                      bool upper = false) -> It {
   if (auto ptr = to_pointer<Char>(out, to_unsigned(num_digits))) {
     format_uint<BASE_BITS>(ptr, value, num_digits, upper);
     return out;
   }
   // Buffer should be large enough to hold all digits (digits / BASE_BITS + 1).
-  char buffer[num_bits<UInt>() / BASE_BITS + 1];
+  char buffer[num_bits<UInt>() / BASE_BITS + 1] = {};
   format_uint<BASE_BITS>(buffer, value, num_digits, upper);
   return detail::copy_str_noinline<Char>(buffer, buffer + num_digits, out);
 }
@@ -1418,47 +1377,54 @@ class utf8_to_utf16 {
   auto str() const -> std::wstring { return {&buffer_[0], size()}; }
 };
 
+enum class to_utf8_error_policy { abort, replace };
+
 // A converter from UTF-16/UTF-32 (host endian) to UTF-8.
-template <typename WChar, typename Buffer = memory_buffer>
-class unicode_to_utf8 {
+template <typename WChar, typename Buffer = memory_buffer> class to_utf8 {
  private:
   Buffer buffer_;
 
  public:
-  unicode_to_utf8() {}
-  explicit unicode_to_utf8(basic_string_view<WChar> s) {
+  to_utf8() {}
+  explicit to_utf8(basic_string_view<WChar> s,
+                   to_utf8_error_policy policy = to_utf8_error_policy::abort) {
     static_assert(sizeof(WChar) == 2 || sizeof(WChar) == 4,
                   "Expect utf16 or utf32");
-
-    if (!convert(s))
+    if (!convert(s, policy))
       FMT_THROW(std::runtime_error(sizeof(WChar) == 2 ? "invalid utf16"
                                                       : "invalid utf32"));
   }
   operator string_view() const { return string_view(&buffer_[0], size()); }
-  size_t size() const { return buffer_.size() - 1; }
-  const char* c_str() const { return &buffer_[0]; }
-  std::string str() const { return std::string(&buffer_[0], size()); }
+  auto size() const -> size_t { return buffer_.size() - 1; }
+  auto c_str() const -> const char* { return &buffer_[0]; }
+  auto str() const -> std::string { return std::string(&buffer_[0], size()); }
 
   // Performs conversion returning a bool instead of throwing exception on
   // conversion error. This method may still throw in case of memory allocation
   // error.
-  bool convert(basic_string_view<WChar> s) {
-    if (!convert(buffer_, s)) return false;
+  auto convert(basic_string_view<WChar> s,
+               to_utf8_error_policy policy = to_utf8_error_policy::abort)
+      -> bool {
+    if (!convert(buffer_, s, policy)) return false;
     buffer_.push_back(0);
     return true;
   }
-  static bool convert(Buffer& buf, basic_string_view<WChar> s) {
+  static auto convert(Buffer& buf, basic_string_view<WChar> s,
+                      to_utf8_error_policy policy = to_utf8_error_policy::abort)
+      -> bool {
     for (auto p = s.begin(); p != s.end(); ++p) {
       uint32_t c = static_cast<uint32_t>(*p);
       if (sizeof(WChar) == 2 && c >= 0xd800 && c <= 0xdfff) {
-        // surrogate pair
+        // Handle a surrogate pair.
         ++p;
         if (p == s.end() || (c & 0xfc00) != 0xd800 || (*p & 0xfc00) != 0xdc00) {
-          return false;
+          if (policy == to_utf8_error_policy::abort) return false;
+          buf.append(string_view("\xEF\xBF\xBD"));
+          --p;
+        } else {
+          c = (c << 10) + static_cast<uint32_t>(*p) - 0x35fdc00;
         }
-        c = (c << 10) + static_cast<uint32_t>(*p) - 0x35fdc00;
-      }
-      if (c < 0x80) {
+      } else if (c < 0x80) {
         buf.push_back(static_cast<char>(c));
       } else if (c < 0x800) {
         buf.push_back(static_cast<char>(0xc0 | (c >> 6)));
@@ -1481,14 +1447,14 @@ class unicode_to_utf8 {
 };
 
 // Computes 128-bit result of multiplication of two 64-bit unsigned integers.
-inline uint128_fallback umul128(uint64_t x, uint64_t y) noexcept {
+inline auto umul128(uint64_t x, uint64_t y) noexcept -> uint128_fallback {
 #if FMT_USE_INT128
   auto p = static_cast<uint128_opt>(x) * static_cast<uint128_opt>(y);
   return {static_cast<uint64_t>(p >> 64), static_cast<uint64_t>(p)};
 #elif defined(_MSC_VER) && defined(_M_X64)
-  auto result = uint128_fallback();
-  result.lo_ = _umul128(x, y, &result.hi_);
-  return result;
+  auto hi = uint64_t();
+  auto lo = _umul128(x, y, &hi);
+  return {hi, lo};
 #else
   const uint64_t mask = static_cast<uint64_t>(max_value<uint32_t>());
 
@@ -1512,19 +1478,19 @@ inline uint128_fallback umul128(uint64_t x, uint64_t y) noexcept {
 namespace dragonbox {
 // Computes floor(log10(pow(2, e))) for e in [-2620, 2620] using the method from
 // https://fmt.dev/papers/Dragonbox.pdf#page=28, section 6.1.
-inline int floor_log10_pow2(int e) noexcept {
+inline auto floor_log10_pow2(int e) noexcept -> int {
   FMT_ASSERT(e <= 2620 && e >= -2620, "too large exponent");
   static_assert((-1 >> 1) == -1, "right shift is not arithmetic");
   return (e * 315653) >> 20;
 }
 
-inline int floor_log2_pow10(int e) noexcept {
+inline auto floor_log2_pow10(int e) noexcept -> int {
   FMT_ASSERT(e <= 1233 && e >= -1233, "too large exponent");
   return (e * 1741647) >> 19;
 }
 
 // Computes upper 64 bits of multiplication of two 64-bit unsigned integers.
-inline uint64_t umul128_upper64(uint64_t x, uint64_t y) noexcept {
+inline auto umul128_upper64(uint64_t x, uint64_t y) noexcept -> uint64_t {
 #if FMT_USE_INT128
   auto p = static_cast<uint128_opt>(x) * static_cast<uint128_opt>(y);
   return static_cast<uint64_t>(p >> 64);
@@ -1537,14 +1503,14 @@ inline uint64_t umul128_upper64(uint64_t x, uint64_t y) noexcept {
 
 // Computes upper 128 bits of multiplication of a 64-bit unsigned integer and a
 // 128-bit unsigned integer.
-inline uint128_fallback umul192_upper128(uint64_t x,
-                                         uint128_fallback y) noexcept {
+inline auto umul192_upper128(uint64_t x, uint128_fallback y) noexcept
+    -> uint128_fallback {
   uint128_fallback r = umul128(x, y.high());
   r += umul128_upper64(x, y.low());
   return r;
 }
 
-FMT_API uint128_fallback get_cached_power(int k) noexcept;
+FMT_API auto get_cached_power(int k) noexcept -> uint128_fallback;
 
 // Type-specific information that Dragonbox uses.
 template <typename T, typename Enable = void> struct float_info;
@@ -1598,14 +1564,14 @@ template <typename T> FMT_API auto to_decimal(T x) noexcept -> decimal_fp<T>;
 }  // namespace dragonbox
 
 // Returns true iff Float has the implicit bit which is not stored.
-template <typename Float> constexpr bool has_implicit_bit() {
+template <typename Float> constexpr auto has_implicit_bit() -> bool {
   // An 80-bit FP number has a 64-bit significand an no implicit bit.
   return std::numeric_limits<Float>::digits != 64;
 }
 
 // Returns the number of significand bits stored in Float. The implicit bit is
 // not counted since it is not stored.
-template <typename Float> constexpr int num_significand_bits() {
+template <typename Float> constexpr auto num_significand_bits() -> int {
   // std::numeric_limits may not support __float128.
   return is_float128<Float>() ? 112
                               : (std::numeric_limits<Float>::digits -
@@ -1698,7 +1664,7 @@ using fp = basic_fp<unsigned long long>;
 
 // Normalizes the value converted from double and multiplied by (1 << SHIFT).
 template <int SHIFT = 0, typename F>
-FMT_CONSTEXPR basic_fp<F> normalize(basic_fp<F> value) {
+FMT_CONSTEXPR auto normalize(basic_fp<F> value) -> basic_fp<F> {
   // Handle subnormals.
   const auto implicit_bit = F(1) << num_significand_bits<double>();
   const auto shifted_implicit_bit = implicit_bit << SHIFT;
@@ -1715,7 +1681,7 @@ FMT_CONSTEXPR basic_fp<F> normalize(basic_fp<F> value) {
 }
 
 // Computes lhs * rhs / pow(2, 64) rounded to nearest with half-up tie breaking.
-FMT_CONSTEXPR inline uint64_t multiply(uint64_t lhs, uint64_t rhs) {
+FMT_CONSTEXPR inline auto multiply(uint64_t lhs, uint64_t rhs) -> uint64_t {
 #if FMT_USE_INT128
   auto product = static_cast<__uint128_t>(lhs) * rhs;
   auto f = static_cast<uint64_t>(product >> 64);
@@ -1732,124 +1698,13 @@ FMT_CONSTEXPR inline uint64_t multiply(uint64_t lhs, uint64_t rhs) {
 #endif
 }
 
-FMT_CONSTEXPR inline fp operator*(fp x, fp y) {
+FMT_CONSTEXPR inline auto operator*(fp x, fp y) -> fp {
   return {multiply(x.f, y.f), x.e + y.e + 64};
 }
 
-template <typename T = void> struct basic_data {
-  // Normalized 64-bit significands of pow(10, k), for k = -348, -340, ..., 340.
-  // These are generated by support/compute-powers.py.
-  static constexpr uint64_t pow10_significands[87] = {
-      0xfa8fd5a0081c0288, 0xbaaee17fa23ebf76, 0x8b16fb203055ac76,
-      0xcf42894a5dce35ea, 0x9a6bb0aa55653b2d, 0xe61acf033d1a45df,
-      0xab70fe17c79ac6ca, 0xff77b1fcbebcdc4f, 0xbe5691ef416bd60c,
-      0x8dd01fad907ffc3c, 0xd3515c2831559a83, 0x9d71ac8fada6c9b5,
-      0xea9c227723ee8bcb, 0xaecc49914078536d, 0x823c12795db6ce57,
-      0xc21094364dfb5637, 0x9096ea6f3848984f, 0xd77485cb25823ac7,
-      0xa086cfcd97bf97f4, 0xef340a98172aace5, 0xb23867fb2a35b28e,
-      0x84c8d4dfd2c63f3b, 0xc5dd44271ad3cdba, 0x936b9fcebb25c996,
-      0xdbac6c247d62a584, 0xa3ab66580d5fdaf6, 0xf3e2f893dec3f126,
-      0xb5b5ada8aaff80b8, 0x87625f056c7c4a8b, 0xc9bcff6034c13053,
-      0x964e858c91ba2655, 0xdff9772470297ebd, 0xa6dfbd9fb8e5b88f,
-      0xf8a95fcf88747d94, 0xb94470938fa89bcf, 0x8a08f0f8bf0f156b,
-      0xcdb02555653131b6, 0x993fe2c6d07b7fac, 0xe45c10c42a2b3b06,
-      0xaa242499697392d3, 0xfd87b5f28300ca0e, 0xbce5086492111aeb,
-      0x8cbccc096f5088cc, 0xd1b71758e219652c, 0x9c40000000000000,
-      0xe8d4a51000000000, 0xad78ebc5ac620000, 0x813f3978f8940984,
-      0xc097ce7bc90715b3, 0x8f7e32ce7bea5c70, 0xd5d238a4abe98068,
-      0x9f4f2726179a2245, 0xed63a231d4c4fb27, 0xb0de65388cc8ada8,
-      0x83c7088e1aab65db, 0xc45d1df942711d9a, 0x924d692ca61be758,
-      0xda01ee641a708dea, 0xa26da3999aef774a, 0xf209787bb47d6b85,
-      0xb454e4a179dd1877, 0x865b86925b9bc5c2, 0xc83553c5c8965d3d,
-      0x952ab45cfa97a0b3, 0xde469fbd99a05fe3, 0xa59bc234db398c25,
-      0xf6c69a72a3989f5c, 0xb7dcbf5354e9bece, 0x88fcf317f22241e2,
-      0xcc20ce9bd35c78a5, 0x98165af37b2153df, 0xe2a0b5dc971f303a,
-      0xa8d9d1535ce3b396, 0xfb9b7cd9a4a7443c, 0xbb764c4ca7a44410,
-      0x8bab8eefb6409c1a, 0xd01fef10a657842c, 0x9b10a4e5e9913129,
-      0xe7109bfba19c0c9d, 0xac2820d9623bf429, 0x80444b5e7aa7cf85,
-      0xbf21e44003acdd2d, 0x8e679c2f5e44ff8f, 0xd433179d9c8cb841,
-      0x9e19db92b4e31ba9, 0xeb96bf6ebadf77d9, 0xaf87023b9bf0ee6b,
-  };
-
-#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
-#  pragma GCC diagnostic push
-#  pragma GCC diagnostic ignored "-Wnarrowing"
-#endif
-  // Binary exponents of pow(10, k), for k = -348, -340, ..., 340, corresponding
-  // to significands above.
-  static constexpr int16_t pow10_exponents[87] = {
-      -1220, -1193, -1166, -1140, -1113, -1087, -1060, -1034, -1007, -980, -954,
-      -927,  -901,  -874,  -847,  -821,  -794,  -768,  -741,  -715,  -688, -661,
-      -635,  -608,  -582,  -555,  -529,  -502,  -475,  -449,  -422,  -396, -369,
-      -343,  -316,  -289,  -263,  -236,  -210,  -183,  -157,  -130,  -103, -77,
-      -50,   -24,   3,     30,    56,    83,    109,   136,   162,   189,  216,
-      242,   269,   295,   322,   348,   375,   402,   428,   455,   481,  508,
-      534,   561,   588,   614,   641,   667,   694,   720,   747,   774,  800,
-      827,   853,   880,   907,   933,   960,   986,   1013,  1039,  1066};
-#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
-#  pragma GCC diagnostic pop
-#endif
-
-  static constexpr uint64_t power_of_10_64[20] = {
-      1, FMT_POWERS_OF_10(1ULL), FMT_POWERS_OF_10(1000000000ULL),
-      10000000000000000000ULL};
-
-  // For checking rounding thresholds.
-  // The kth entry is chosen to be the smallest integer such that the
-  // upper 32-bits of 10^(k+1) times it is strictly bigger than 5 * 10^k.
-  static constexpr uint32_t fractional_part_rounding_thresholds[8] = {
-      2576980378,  // ceil(2^31 + 2^32/10^1)
-      2190433321,  // ceil(2^31 + 2^32/10^2)
-      2151778616,  // ceil(2^31 + 2^32/10^3)
-      2147913145,  // ceil(2^31 + 2^32/10^4)
-      2147526598,  // ceil(2^31 + 2^32/10^5)
-      2147487943,  // ceil(2^31 + 2^32/10^6)
-      2147484078,  // ceil(2^31 + 2^32/10^7)
-      2147483691   // ceil(2^31 + 2^32/10^8)
-  };
-};
-
-#if FMT_CPLUSPLUS < 201703L
-template <typename T> constexpr uint64_t basic_data<T>::pow10_significands[];
-template <typename T> constexpr int16_t basic_data<T>::pow10_exponents[];
-template <typename T> constexpr uint64_t basic_data<T>::power_of_10_64[];
-template <typename T>
-constexpr uint32_t basic_data<T>::fractional_part_rounding_thresholds[];
-#endif
-
-// This is a struct rather than an alias to avoid shadowing warnings in gcc.
-struct data : basic_data<> {};
-
-// Returns a cached power of 10 `c_k = c_k.f * pow(2, c_k.e)` such that its
-// (binary) exponent satisfies `min_exponent <= c_k.e <= min_exponent + 28`.
-FMT_CONSTEXPR inline fp get_cached_power(int min_exponent,
-                                         int& pow10_exponent) {
-  const int shift = 32;
-  // log10(2) = 0x0.4d104d427de7fbcc...
-  const int64_t significand = 0x4d104d427de7fbcc;
-  int index = static_cast<int>(
-      ((min_exponent + fp::num_significand_bits - 1) * (significand >> shift) +
-       ((int64_t(1) << shift) - 1))  // ceil
-      >> 32                          // arithmetic shift
-  );
-  // Decimal exponent of the first (smallest) cached power of 10.
-  const int first_dec_exp = -348;
-  // Difference between 2 consecutive decimal exponents in cached powers of 10.
-  const int dec_exp_step = 8;
-  index = (index - first_dec_exp - 1) / dec_exp_step + 1;
-  pow10_exponent = first_dec_exp + index * dec_exp_step;
-  // Using *(x + index) instead of x[index] avoids an issue with some compilers
-  // using the EDG frontend (e.g. nvhpc/22.3 in C++17 mode).
-  return {*(data::pow10_significands + index),
-          *(data::pow10_exponents + index)};
-}
-
-template <typename T>
+template <typename T, bool doublish = num_bits<T>() == num_bits<double>()>
 using convert_float_result =
-    conditional_t<std::is_same<T, float>::value ||
-                      std::numeric_limits<T>::digits ==
-                          std::numeric_limits<double>::digits,
-                  double, T>;
+    conditional_t<std::is_same<T, float>::value || doublish, double, T>;
 
 template <typename T>
 constexpr auto convert_float(T value) -> convert_float_result<T> {
@@ -1970,7 +1825,7 @@ inline auto find_escape(const char* begin, const char* end)
   [] {                                                                        \
     /* Use the hidden visibility as a workaround for a GCC bug (#1973). */    \
     /* Use a macro-like name to avoid shadowing warnings. */                  \
-    struct FMT_GCC_VISIBILITY_HIDDEN FMT_COMPILE_STRING : base {              \
+    struct FMT_VISIBILITY("hidden") FMT_COMPILE_STRING : base {               \
       using char_type FMT_MAYBE_UNUSED = fmt::remove_cvref_t<decltype(s[0])>; \
       FMT_MAYBE_UNUSED FMT_CONSTEXPR explicit                                 \
       operator fmt::basic_string_view<char_type>() const {                    \
@@ -2065,11 +1920,13 @@ auto write_escaped_string(OutputIt out, basic_string_view<Char> str)
 
 template <typename Char, typename OutputIt>
 auto write_escaped_char(OutputIt out, Char v) -> OutputIt {
+  Char v_array[1] = {v};
   *out++ = static_cast<Char>('\'');
   if ((needs_escape(static_cast<uint32_t>(v)) && v != static_cast<Char>('"')) ||
       v == static_cast<Char>('\'')) {
-    out = write_escaped_cp(
-        out, find_escape_result<Char>{&v, &v + 1, static_cast<uint32_t>(v)});
+    out = write_escaped_cp(out,
+                           find_escape_result<Char>{v_array, v_array + 1,
+                                                    static_cast<uint32_t>(v)});
   } else {
     *out++ = v;
   }
@@ -2158,10 +2015,10 @@ template <typename Char> class digit_grouping {
     std::string::const_iterator group;
     int pos;
   };
-  next_state initial_state() const { return {grouping_.begin(), 0}; }
+  auto initial_state() const -> next_state { return {grouping_.begin(), 0}; }
 
   // Returns the next digit group separator position.
-  int next(next_state& state) const {
+  auto next(next_state& state) const -> int {
     if (thousands_sep_.empty()) return max_value<int>();
     if (state.group == grouping_.end()) return state.pos += grouping_.back();
     if (*state.group <= 0 || *state.group == max_value<char>())
@@ -2180,9 +2037,9 @@ template <typename Char> class digit_grouping {
   digit_grouping(std::string grouping, std::basic_string<Char> sep)
       : grouping_(std::move(grouping)), thousands_sep_(std::move(sep)) {}
 
-  bool has_separator() const { return !thousands_sep_.empty(); }
+  auto has_separator() const -> bool { return !thousands_sep_.empty(); }
 
-  int count_separators(int num_digits) const {
+  auto count_separators(int num_digits) const -> int {
     int count = 0;
     auto state = initial_state();
     while (num_digits > next(state)) ++count;
@@ -2191,7 +2048,7 @@ template <typename Char> class digit_grouping {
 
   // Applies grouping to digits and write the output to out.
   template <typename Out, typename C>
-  Out apply(Out out, basic_string_view<C> digits) const {
+  auto apply(Out out, basic_string_view<C> digits) const -> Out {
     auto num_digits = static_cast<int>(digits.size());
     auto separators = basic_memory_buffer<int>();
     separators.push_back(0);
@@ -2214,24 +2071,66 @@ template <typename Char> class digit_grouping {
   }
 };
 
+FMT_CONSTEXPR inline void prefix_append(unsigned& prefix, unsigned value) {
+  prefix |= prefix != 0 ? value << 8 : value;
+  prefix += (1u + (value > 0xff ? 1 : 0)) << 24;
+}
+
 // Writes a decimal integer with digit grouping.
 template <typename OutputIt, typename UInt, typename Char>
 auto write_int(OutputIt out, UInt value, unsigned prefix,
                const format_specs<Char>& specs,
                const digit_grouping<Char>& grouping) -> OutputIt {
   static_assert(std::is_same<uint64_or_128_t<UInt>, UInt>::value, "");
-  int num_digits = count_digits(value);
-  char digits[40];
-  format_decimal(digits, value, num_digits);
-  unsigned size = to_unsigned((prefix != 0 ? 1 : 0) + num_digits +
-                              grouping.count_separators(num_digits));
+  int num_digits = 0;
+  auto buffer = memory_buffer();
+  switch (specs.type) {
+  case presentation_type::none:
+  case presentation_type::dec: {
+    num_digits = count_digits(value);
+    format_decimal<char>(appender(buffer), value, num_digits);
+    break;
+  }
+  case presentation_type::hex_lower:
+  case presentation_type::hex_upper: {
+    bool upper = specs.type == presentation_type::hex_upper;
+    if (specs.alt)
+      prefix_append(prefix, unsigned(upper ? 'X' : 'x') << 8 | '0');
+    num_digits = count_digits<4>(value);
+    format_uint<4, char>(appender(buffer), value, num_digits, upper);
+    break;
+  }
+  case presentation_type::bin_lower:
+  case presentation_type::bin_upper: {
+    bool upper = specs.type == presentation_type::bin_upper;
+    if (specs.alt)
+      prefix_append(prefix, unsigned(upper ? 'B' : 'b') << 8 | '0');
+    num_digits = count_digits<1>(value);
+    format_uint<1, char>(appender(buffer), value, num_digits);
+    break;
+  }
+  case presentation_type::oct: {
+    num_digits = count_digits<3>(value);
+    // Octal prefix '0' is counted as a digit, so only add it if precision
+    // is not greater than the number of digits.
+    if (specs.alt && specs.precision <= num_digits && value != 0)
+      prefix_append(prefix, '0');
+    format_uint<3, char>(appender(buffer), value, num_digits);
+    break;
+  }
+  case presentation_type::chr:
+    return write_char(out, static_cast<Char>(value), specs);
+  default:
+    throw_format_error("invalid format specifier");
+  }
+
+  unsigned size = (prefix != 0 ? prefix >> 24 : 0) + to_unsigned(num_digits) +
+                  to_unsigned(grouping.count_separators(num_digits));
   return write_padded<align::right>(
       out, specs, size, size, [&](reserve_iterator<OutputIt> it) {
-        if (prefix != 0) {
-          char sign = static_cast<char>(prefix);
-          *it++ = static_cast<Char>(sign);
-        }
-        return grouping.apply(it, string_view(digits, to_unsigned(num_digits)));
+        for (unsigned p = prefix & 0xffffff; p != 0; p >>= 8)
+          *it++ = static_cast<Char>(p & 0xff);
+        return grouping.apply(it, string_view(buffer.data(), buffer.size()));
       });
 }
 
@@ -2244,11 +2143,6 @@ inline auto write_loc(OutputIt, loc_value, const format_specs<Char>&,
   return false;
 }
 
-FMT_CONSTEXPR inline void prefix_append(unsigned& prefix, unsigned value) {
-  prefix |= prefix != 0 ? value << 8 : value;
-  prefix += (1u + (value > 0xff ? 1 : 0)) << 24;
-}
-
 template <typename UInt> struct write_int_arg {
   UInt abs_value;
   unsigned prefix;
@@ -2395,25 +2289,25 @@ class counting_iterator {
 
   FMT_CONSTEXPR counting_iterator() : count_(0) {}
 
-  FMT_CONSTEXPR size_t count() const { return count_; }
+  FMT_CONSTEXPR auto count() const -> size_t { return count_; }
 
-  FMT_CONSTEXPR counting_iterator& operator++() {
+  FMT_CONSTEXPR auto operator++() -> counting_iterator& {
     ++count_;
     return *this;
   }
-  FMT_CONSTEXPR counting_iterator operator++(int) {
+  FMT_CONSTEXPR auto operator++(int) -> counting_iterator {
     auto it = *this;
     ++*this;
     return it;
   }
 
-  FMT_CONSTEXPR friend counting_iterator operator+(counting_iterator it,
-                                                   difference_type n) {
+  FMT_CONSTEXPR friend auto operator+(counting_iterator it, difference_type n)
+      -> counting_iterator {
     it.count_ += static_cast<size_t>(n);
     return it;
   }
 
-  FMT_CONSTEXPR value_type operator*() const { return {}; }
+  FMT_CONSTEXPR auto operator*() const -> value_type { return {}; }
 };
 
 template <typename Char, typename OutputIt>
@@ -2448,9 +2342,10 @@ template <typename Char, typename OutputIt>
 FMT_CONSTEXPR auto write(OutputIt out, const Char* s,
                          const format_specs<Char>& specs, locale_ref)
     -> OutputIt {
-  return specs.type != presentation_type::pointer
-             ? write(out, basic_string_view<Char>(s), specs, {})
-             : write_ptr<Char>(out, bit_cast<uintptr_t>(s), &specs);
+  if (specs.type == presentation_type::pointer)
+    return write_ptr<Char>(out, bit_cast<uintptr_t>(s), &specs);
+  if (!s) throw_format_error("string pointer is null");
+  return write(out, basic_string_view<Char>(s), specs, {});
 }
 
 template <typename Char, typename OutputIt, typename T,
@@ -2475,6 +2370,49 @@ FMT_CONSTEXPR auto write(OutputIt out, T value) -> OutputIt {
   return base_iterator(out, it);
 }
 
+// DEPRECATED!
+template <typename Char>
+FMT_CONSTEXPR auto parse_align(const Char* begin, const Char* end,
+                               format_specs<Char>& specs) -> const Char* {
+  FMT_ASSERT(begin != end, "");
+  auto align = align::none;
+  auto p = begin + code_point_length(begin);
+  if (end - p <= 0) p = begin;
+  for (;;) {
+    switch (to_ascii(*p)) {
+    case '<':
+      align = align::left;
+      break;
+    case '>':
+      align = align::right;
+      break;
+    case '^':
+      align = align::center;
+      break;
+    }
+    if (align != align::none) {
+      if (p != begin) {
+        auto c = *begin;
+        if (c == '}') return begin;
+        if (c == '{') {
+          throw_format_error("invalid fill character '{'");
+          return begin;
+        }
+        specs.fill = {begin, to_unsigned(p - begin)};
+        begin = p + 1;
+      } else {
+        ++begin;
+      }
+      break;
+    } else if (p == begin) {
+      break;
+    }
+    p = begin;
+  }
+  specs.align = align;
+  return begin;
+}
+
 // A floating-point presentation format.
 enum class float_format : unsigned char {
   general,  // General: exponent notation or fixed point based on magnitude.
@@ -2493,9 +2431,8 @@ struct float_specs {
   bool showpoint : 1;
 };
 
-template <typename ErrorHandler = error_handler, typename Char>
-FMT_CONSTEXPR auto parse_float_type_spec(const format_specs<Char>& specs,
-                                         ErrorHandler&& eh = {})
+template <typename Char>
+FMT_CONSTEXPR auto parse_float_type_spec(const format_specs<Char>& specs)
     -> float_specs {
   auto result = float_specs();
   result.showpoint = specs.alt;
@@ -2531,7 +2468,7 @@ FMT_CONSTEXPR auto parse_float_type_spec(const format_specs<Char>& specs,
     result.format = float_format::hex;
     break;
   default:
-    eh.on_error("invalid format specifier");
+    throw_format_error("invalid format specifier");
     break;
   }
   return result;
@@ -2770,12 +2707,12 @@ template <typename Char> class fallback_digit_grouping {
  public:
   constexpr fallback_digit_grouping(locale_ref, bool) {}
 
-  constexpr bool has_separator() const { return false; }
+  constexpr auto has_separator() const -> bool { return false; }
 
-  constexpr int count_separators(int) const { return 0; }
+  constexpr auto count_separators(int) const -> int { return 0; }
 
   template <typename Out, typename C>
-  constexpr Out apply(Out out, basic_string_view<C>) const {
+  constexpr auto apply(Out out, basic_string_view<C>) const -> Out {
     return out;
   }
 };
@@ -2794,7 +2731,7 @@ FMT_CONSTEXPR20 auto write_float(OutputIt out, const DecimalFP& f,
   }
 }
 
-template <typename T> constexpr bool isnan(T value) {
+template <typename T> constexpr auto isnan(T value) -> bool {
   return !(value >= value);  // std::isnan doesn't support __float128.
 }
 
@@ -2807,14 +2744,14 @@ struct has_isfinite<T, enable_if_t<sizeof(std::isfinite(T())) != 0>>
 
 template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value&&
                                         has_isfinite<T>::value)>
-FMT_CONSTEXPR20 bool isfinite(T value) {
+FMT_CONSTEXPR20 auto isfinite(T value) -> bool {
   constexpr T inf = T(std::numeric_limits<double>::infinity());
   if (is_constant_evaluated())
     return !detail::isnan(value) && value < inf && value > -inf;
   return std::isfinite(value);
 }
 template <typename T, FMT_ENABLE_IF(!has_isfinite<T>::value)>
-FMT_CONSTEXPR bool isfinite(T value) {
+FMT_CONSTEXPR auto isfinite(T value) -> bool {
   T inf = T(std::numeric_limits<double>::infinity());
   // std::isfinite doesn't support __float128.
   return !detail::isnan(value) && value < inf && value > -inf;
@@ -2833,78 +2770,6 @@ FMT_INLINE FMT_CONSTEXPR bool signbit(T value) {
   return std::signbit(static_cast<double>(value));
 }
 
-enum class round_direction { unknown, up, down };
-
-// Given the divisor (normally a power of 10), the remainder = v % divisor for
-// some number v and the error, returns whether v should be rounded up, down, or
-// whether the rounding direction can't be determined due to error.
-// error should be less than divisor / 2.
-FMT_CONSTEXPR inline round_direction get_round_direction(uint64_t divisor,
-                                                         uint64_t remainder,
-                                                         uint64_t error) {
-  FMT_ASSERT(remainder < divisor, "");  // divisor - remainder won't overflow.
-  FMT_ASSERT(error < divisor, "");      // divisor - error won't overflow.
-  FMT_ASSERT(error < divisor - error, "");  // error * 2 won't overflow.
-  // Round down if (remainder + error) * 2 <= divisor.
-  if (remainder <= divisor - remainder && error * 2 <= divisor - remainder * 2)
-    return round_direction::down;
-  // Round up if (remainder - error) * 2 >= divisor.
-  if (remainder >= error &&
-      remainder - error >= divisor - (remainder - error)) {
-    return round_direction::up;
-  }
-  return round_direction::unknown;
-}
-
-namespace digits {
-enum result {
-  more,  // Generate more digits.
-  done,  // Done generating digits.
-  error  // Digit generation cancelled due to an error.
-};
-}
-
-struct gen_digits_handler {
-  char* buf;
-  int size;
-  int precision;
-  int exp10;
-  bool fixed;
-
-  FMT_CONSTEXPR digits::result on_digit(char digit, uint64_t divisor,
-                                        uint64_t remainder, uint64_t error,
-                                        bool integral) {
-    FMT_ASSERT(remainder < divisor, "");
-    buf[size++] = digit;
-    if (!integral && error >= remainder) return digits::error;
-    if (size < precision) return digits::more;
-    if (!integral) {
-      // Check if error * 2 < divisor with overflow prevention.
-      // The check is not needed for the integral part because error = 1
-      // and divisor > (1 << 32) there.
-      if (error >= divisor || error >= divisor - error) return digits::error;
-    } else {
-      FMT_ASSERT(error == 1 && divisor > 2, "");
-    }
-    auto dir = get_round_direction(divisor, remainder, error);
-    if (dir != round_direction::up)
-      return dir == round_direction::down ? digits::done : digits::error;
-    ++buf[size - 1];
-    for (int i = size - 1; i > 0 && buf[i] > '9'; --i) {
-      buf[i] = '0';
-      ++buf[i - 1];
-    }
-    if (buf[0] > '9') {
-      buf[0] = '1';
-      if (fixed)
-        buf[size++] = '0';
-      else
-        ++exp10;
-    }
-    return digits::done;
-  }
-};
-
 inline FMT_CONSTEXPR20 void adjust_precision(int& precision, int exp10) {
   // Adjust fixed precision by exponent because it is relative to decimal
   // point.
@@ -2913,101 +2778,6 @@ inline FMT_CONSTEXPR20 void adjust_precision(int& precision, int exp10) {
   precision += exp10;
 }
 
-// Generates output using the Grisu digit-gen algorithm.
-// error: the size of the region (lower, upper) outside of which numbers
-// definitely do not round to value (Delta in Grisu3).
-FMT_INLINE FMT_CONSTEXPR20 auto grisu_gen_digits(fp value, uint64_t error,
-                                                 int& exp,
-                                                 gen_digits_handler& handler)
-    -> digits::result {
-  const fp one(1ULL << -value.e, value.e);
-  // The integral part of scaled value (p1 in Grisu) = value / one. It cannot be
-  // zero because it contains a product of two 64-bit numbers with MSB set (due
-  // to normalization) - 1, shifted right by at most 60 bits.
-  auto integral = static_cast<uint32_t>(value.f >> -one.e);
-  FMT_ASSERT(integral != 0, "");
-  FMT_ASSERT(integral == value.f >> -one.e, "");
-  // The fractional part of scaled value (p2 in Grisu) c = value % one.
-  uint64_t fractional = value.f & (one.f - 1);
-  exp = count_digits(integral);  // kappa in Grisu.
-  // Non-fixed formats require at least one digit and no precision adjustment.
-  if (handler.fixed) {
-    adjust_precision(handler.precision, exp + handler.exp10);
-    // Check if precision is satisfied just by leading zeros, e.g.
-    // format("{:.2f}", 0.001) gives "0.00" without generating any digits.
-    if (handler.precision <= 0) {
-      if (handler.precision < 0) return digits::done;
-      // Divide by 10 to prevent overflow.
-      uint64_t divisor = data::power_of_10_64[exp - 1] << -one.e;
-      auto dir = get_round_direction(divisor, value.f / 10, error * 10);
-      if (dir == round_direction::unknown) return digits::error;
-      handler.buf[handler.size++] = dir == round_direction::up ? '1' : '0';
-      return digits::done;
-    }
-  }
-  // Generate digits for the integral part. This can produce up to 10 digits.
-  do {
-    uint32_t digit = 0;
-    auto divmod_integral = [&](uint32_t divisor) {
-      digit = integral / divisor;
-      integral %= divisor;
-    };
-    // This optimization by Milo Yip reduces the number of integer divisions by
-    // one per iteration.
-    switch (exp) {
-    case 10:
-      divmod_integral(1000000000);
-      break;
-    case 9:
-      divmod_integral(100000000);
-      break;
-    case 8:
-      divmod_integral(10000000);
-      break;
-    case 7:
-      divmod_integral(1000000);
-      break;
-    case 6:
-      divmod_integral(100000);
-      break;
-    case 5:
-      divmod_integral(10000);
-      break;
-    case 4:
-      divmod_integral(1000);
-      break;
-    case 3:
-      divmod_integral(100);
-      break;
-    case 2:
-      divmod_integral(10);
-      break;
-    case 1:
-      digit = integral;
-      integral = 0;
-      break;
-    default:
-      FMT_ASSERT(false, "invalid number of digits");
-    }
-    --exp;
-    auto remainder = (static_cast<uint64_t>(integral) << -one.e) + fractional;
-    auto result = handler.on_digit(static_cast<char>('0' + digit),
-                                   data::power_of_10_64[exp] << -one.e,
-                                   remainder, error, true);
-    if (result != digits::more) return result;
-  } while (exp > 0);
-  // Generate digits for the fractional part.
-  for (;;) {
-    fractional *= 10;
-    error *= 10;
-    char digit = static_cast<char>('0' + (fractional >> -one.e));
-    fractional &= one.f - 1;
-    --exp;
-    auto result = handler.on_digit(digit, one.f, fractional, error, false);
-    if (result != digits::more) return result;
-  }
-}
-
 class bigint {
  private:
   // A bigint is stored as an array of bigits (big digits), with bigit at index
@@ -3018,10 +2788,10 @@ class bigint {
   basic_memory_buffer<bigit, bigits_capacity> bigits_;
   int exp_;
 
-  FMT_CONSTEXPR20 bigit operator[](int index) const {
+  FMT_CONSTEXPR20 auto operator[](int index) const -> bigit {
     return bigits_[to_unsigned(index)];
   }
-  FMT_CONSTEXPR20 bigit& operator[](int index) {
+  FMT_CONSTEXPR20 auto operator[](int index) -> bigit& {
     return bigits_[to_unsigned(index)];
   }
 
@@ -3108,7 +2878,7 @@ class bigint {
     auto size = other.bigits_.size();
     bigits_.resize(size);
     auto data = other.bigits_.data();
-    std::copy(data, data + size, make_checked(bigits_.data(), size));
+    copy_str<bigit>(data, data + size, bigits_.data());
     exp_ = other.exp_;
   }
 
@@ -3117,11 +2887,11 @@ class bigint {
     assign(uint64_or_128_t<Int>(n));
   }
 
-  FMT_CONSTEXPR20 int num_bigits() const {
+  FMT_CONSTEXPR20 auto num_bigits() const -> int {
     return static_cast<int>(bigits_.size()) + exp_;
   }
 
-  FMT_NOINLINE FMT_CONSTEXPR20 bigint& operator<<=(int shift) {
+  FMT_NOINLINE FMT_CONSTEXPR20 auto operator<<=(int shift) -> bigint& {
     FMT_ASSERT(shift >= 0, "");
     exp_ += shift / bigit_bits;
     shift %= bigit_bits;
@@ -3136,13 +2906,15 @@ class bigint {
     return *this;
   }
 
-  template <typename Int> FMT_CONSTEXPR20 bigint& operator*=(Int value) {
+  template <typename Int>
+  FMT_CONSTEXPR20 auto operator*=(Int value) -> bigint& {
     FMT_ASSERT(value > 0, "");
     multiply(uint32_or_64_or_128_t<Int>(value));
     return *this;
   }
 
-  friend FMT_CONSTEXPR20 int compare(const bigint& lhs, const bigint& rhs) {
+  friend FMT_CONSTEXPR20 auto compare(const bigint& lhs, const bigint& rhs)
+      -> int {
     int num_lhs_bigits = lhs.num_bigits(), num_rhs_bigits = rhs.num_bigits();
     if (num_lhs_bigits != num_rhs_bigits)
       return num_lhs_bigits > num_rhs_bigits ? 1 : -1;
@@ -3159,8 +2931,9 @@ class bigint {
   }
 
   // Returns compare(lhs1 + lhs2, rhs).
-  friend FMT_CONSTEXPR20 int add_compare(const bigint& lhs1, const bigint& lhs2,
-                                         const bigint& rhs) {
+  friend FMT_CONSTEXPR20 auto add_compare(const bigint& lhs1,
+                                          const bigint& lhs2, const bigint& rhs)
+      -> int {
     auto minimum = [](int a, int b) { return a < b ? a : b; };
     auto maximum = [](int a, int b) { return a > b ? a : b; };
     int max_lhs_bigits = maximum(lhs1.num_bigits(), lhs2.num_bigits());
@@ -3241,13 +3014,13 @@ class bigint {
     bigits_.resize(to_unsigned(num_bigits + exp_difference));
     for (int i = num_bigits - 1, j = i + exp_difference; i >= 0; --i, --j)
       bigits_[j] = bigits_[i];
-    std::uninitialized_fill_n(bigits_.data(), exp_difference, 0);
+    std::uninitialized_fill_n(bigits_.data(), exp_difference, 0u);
     exp_ -= exp_difference;
   }
 
   // Divides this bignum by divisor, assigning the remainder to this and
   // returning the quotient.
-  FMT_CONSTEXPR20 int divmod_assign(const bigint& divisor) {
+  FMT_CONSTEXPR20 auto divmod_assign(const bigint& divisor) -> int {
     FMT_ASSERT(this != &divisor, "");
     if (compare(*this, divisor) < 0) return 0;
     FMT_ASSERT(divisor.bigits_[divisor.bigits_.size() - 1u] != 0, "");
@@ -3322,6 +3095,7 @@ FMT_CONSTEXPR20 inline void format_dragon(basic_fp<uint128_t> value,
   }
   int even = static_cast<int>((value.f & 1) == 0);
   if (!upper) upper = &lower;
+  bool shortest = num_digits < 0;
   if ((flags & dragon::fixup) != 0) {
     if (add_compare(numerator, *upper, denominator) + even <= 0) {
       --exp10;
@@ -3334,7 +3108,7 @@ FMT_CONSTEXPR20 inline void format_dragon(basic_fp<uint128_t> value,
     if ((flags & dragon::fixed) != 0) adjust_precision(num_digits, exp10 + 1);
   }
   // Invariant: value == (numerator / denominator) * pow(10, exp10).
-  if (num_digits < 0) {
+  if (shortest) {
     // Generate the shortest representation.
     num_digits = 0;
     char* data = buf.data();
@@ -3364,7 +3138,7 @@ FMT_CONSTEXPR20 inline void format_dragon(basic_fp<uint128_t> value,
   }
   // Generate the given number of digits.
   exp10 -= num_digits - 1;
-  if (num_digits == 0) {
+  if (num_digits <= 0) {
     denominator *= 10;
     auto digit = add_compare(numerator, numerator, denominator) > 0 ? '1' : '0';
     buf.push_back(digit);
@@ -3389,7 +3163,10 @@ FMT_CONSTEXPR20 inline void format_dragon(basic_fp<uint128_t> value,
       }
       if (buf[0] == overflow) {
         buf[0] = '1';
-        ++exp10;
+        if ((flags & dragon::fixed) != 0)
+          buf.push_back('0');
+        else
+          ++exp10;
       }
       return;
     }
@@ -3486,6 +3263,17 @@ FMT_CONSTEXPR20 void format_hexfloat(Float value, int precision,
   format_hexfloat(static_cast<double>(value), precision, specs, buf);
 }
 
+constexpr auto fractional_part_rounding_thresholds(int index) -> uint32_t {
+  // For checking rounding thresholds.
+  // The kth entry is chosen to be the smallest integer such that the
+  // upper 32-bits of 10^(k+1) times it is strictly bigger than 5 * 10^k.
+  // It is equal to ceil(2^31 + 2^32/10^(k + 1)).
+  // These are stored in a string literal because we cannot have static arrays
+  // in constexpr functions and non-static ones are poorly optimized.
+  return U"\x9999999a\x828f5c29\x80418938\x80068db9\x8000a7c6\x800010c7"
+         U"\x800001ae\x8000002b"[index];
+}
+
 template <typename Float>
 FMT_CONSTEXPR20 auto format_float(Float value, int precision, float_specs specs,
                                   buffer<char>& buf) -> int {
@@ -3508,7 +3296,7 @@ FMT_CONSTEXPR20 auto format_float(Float value, int precision, float_specs specs,
   int exp = 0;
   bool use_dragon = true;
   unsigned dragon_flags = 0;
-  if (!is_fast_float<Float>()) {
+  if (!is_fast_float<Float>() || is_constant_evaluated()) {
     const auto inv_log2_10 = 0.3010299956639812;  // 1 / log2(10)
     using info = dragonbox::float_info<decltype(converted_value)>;
     const auto f = basic_fp<typename info::carrier_uint>(converted_value);
@@ -3516,10 +3304,11 @@ FMT_CONSTEXPR20 auto format_float(Float value, int precision, float_specs specs,
     //   10^(exp - 1) <= value < 10^exp or 10^exp <= value < 10^(exp + 1).
     // This is based on log10(value) == log2(value) / log2(10) and approximation
     // of log2(value) by e + num_fraction_bits idea from double-conversion.
-    exp = static_cast<int>(
-        std::ceil((f.e + count_digits<1>(f.f) - 1) * inv_log2_10 - 1e-10));
+    auto e = (f.e + count_digits<1>(f.f) - 1) * inv_log2_10 - 1e-10;
+    exp = static_cast<int>(e);
+    if (e > exp) ++exp;  // Compute ceil.
     dragon_flags = dragon::fixup;
-  } else if (!is_constant_evaluated() && precision < 0) {
+  } else if (precision < 0) {
     // Use Dragonbox for the shortest format.
     if (specs.binary32) {
       auto dec = dragonbox::to_decimal(static_cast<float>(value));
@@ -3529,25 +3318,6 @@ FMT_CONSTEXPR20 auto format_float(Float value, int precision, float_specs specs,
     auto dec = dragonbox::to_decimal(static_cast<double>(value));
     write<char>(buffer_appender<char>(buf), dec.significand);
     return dec.exponent;
-  } else if (is_constant_evaluated()) {
-    // Use Grisu + Dragon4 for the given precision:
-    // https://www.cs.tufts.edu/~nr/cs257/archive/florian-loitsch/printf.pdf.
-    const int min_exp = -60;  // alpha in Grisu.
-    int cached_exp10 = 0;     // K in Grisu.
-    fp normalized = normalize(fp(converted_value));
-    const auto cached_pow = get_cached_power(
-        min_exp - (normalized.e + fp::num_significand_bits), cached_exp10);
-    normalized = normalized * cached_pow;
-    gen_digits_handler handler{buf.data(), 0, precision, -cached_exp10, fixed};
-    if (grisu_gen_digits(normalized, 1, exp, handler) != digits::error &&
-        !is_constant_evaluated()) {
-      exp += handler.exp10;
-      buf.try_resize(to_unsigned(handler.size));
-      use_dragon = false;
-    } else {
-      exp += handler.size - cached_exp10 - 1;
-      precision = handler.precision;
-    }
   } else {
     // Extract significand bits and exponent bits.
     using info = dragonbox::float_info<double>;
@@ -3566,7 +3336,7 @@ FMT_CONSTEXPR20 auto format_float(Float value, int precision, float_specs specs,
       significand <<= 1;
     } else {
       // Normalize subnormal inputs.
-      FMT_ASSERT(significand != 0, "zeros should not appear hear");
+      FMT_ASSERT(significand != 0, "zeros should not appear here");
       int shift = countl_zero(significand);
       FMT_ASSERT(shift >= num_bits<uint64_t>() - num_significand_bits<double>(),
                  "");
@@ -3603,9 +3373,7 @@ FMT_CONSTEXPR20 auto format_float(Float value, int precision, float_specs specs,
     }
 
     // Compute the actual number of decimal digits to print.
-    if (fixed) {
-      adjust_precision(precision, exp + digits_in_the_first_segment);
-    }
+    if (fixed) adjust_precision(precision, exp + digits_in_the_first_segment);
 
     // Use Dragon4 only when there might be not enough digits in the first
     // segment.
@@ -3710,12 +3478,12 @@ FMT_CONSTEXPR20 auto format_float(Float value, int precision, float_specs specs,
           //    fractional part is strictly larger than 1/2.
           if (precision < 9) {
             uint32_t fractional_part = static_cast<uint32_t>(prod);
-            should_round_up = fractional_part >=
-                                  data::fractional_part_rounding_thresholds
-                                      [8 - number_of_digits_to_print] ||
-                              ((fractional_part >> 31) &
-                               ((digits & 1) | (second_third_subsegments != 0) |
-                                has_more_segments)) != 0;
+            should_round_up =
+                fractional_part >= fractional_part_rounding_thresholds(
+                                       8 - number_of_digits_to_print) ||
+                ((fractional_part >> 31) &
+                 ((digits & 1) | (second_third_subsegments != 0) |
+                  has_more_segments)) != 0;
           }
           // Rounding at the subsegment boundary.
           // In this case, the fractional part is at least 1/2 if and only if
@@ -3750,12 +3518,12 @@ FMT_CONSTEXPR20 auto format_float(Float value, int precision, float_specs specs,
             // of 19 digits, so in this case the third segment should be
             // consisting of a genuine digit from the input.
             uint32_t fractional_part = static_cast<uint32_t>(prod);
-            should_round_up = fractional_part >=
-                                  data::fractional_part_rounding_thresholds
-                                      [8 - number_of_digits_to_print] ||
-                              ((fractional_part >> 31) &
-                               ((digits & 1) | (third_subsegment != 0) |
-                                has_more_segments)) != 0;
+            should_round_up =
+                fractional_part >= fractional_part_rounding_thresholds(
+                                       8 - number_of_digits_to_print) ||
+                ((fractional_part >> 31) &
+                 ((digits & 1) | (third_subsegment != 0) |
+                  has_more_segments)) != 0;
           }
           // Rounding at the subsegment boundary.
           else {
@@ -3987,8 +3755,11 @@ template <typename Char, typename OutputIt, typename T,
 FMT_CONSTEXPR auto write(OutputIt out, const T& value)
     -> enable_if_t<mapped_type_constant<T, Context>::value == type::custom_type,
                    OutputIt> {
+  auto formatter = typename Context::template formatter_type<T>();
+  auto parse_ctx = typename Context::parse_context_type({});
+  formatter.parse(parse_ctx);
   auto ctx = Context(out, {}, {});
-  return typename Context::template formatter_type<T>().format(value, ctx);
+  return formatter.format(value, ctx);
 }
 
 // An argument visitor that formats the argument and writes it via the output
@@ -4031,74 +3802,50 @@ template <typename Char> struct arg_formatter {
   }
 };
 
-template <typename Char> struct custom_formatter {
-  basic_format_parse_context<Char>& parse_ctx;
-  buffer_context<Char>& ctx;
-
-  void operator()(
-      typename basic_format_arg<buffer_context<Char>>::handle h) const {
-    h.format(parse_ctx, ctx);
-  }
-  template <typename T> void operator()(T) const {}
-};
-
-template <typename ErrorHandler> class width_checker {
- public:
-  explicit FMT_CONSTEXPR width_checker(ErrorHandler& eh) : handler_(eh) {}
-
+struct width_checker {
   template <typename T, FMT_ENABLE_IF(is_integer<T>::value)>
   FMT_CONSTEXPR auto operator()(T value) -> unsigned long long {
-    if (is_negative(value)) handler_.on_error("negative width");
+    if (is_negative(value)) throw_format_error("negative width");
     return static_cast<unsigned long long>(value);
   }
 
   template <typename T, FMT_ENABLE_IF(!is_integer<T>::value)>
   FMT_CONSTEXPR auto operator()(T) -> unsigned long long {
-    handler_.on_error("width is not integer");
+    throw_format_error("width is not integer");
     return 0;
   }
-
- private:
-  ErrorHandler& handler_;
 };
 
-template <typename ErrorHandler> class precision_checker {
- public:
-  explicit FMT_CONSTEXPR precision_checker(ErrorHandler& eh) : handler_(eh) {}
-
+struct precision_checker {
   template <typename T, FMT_ENABLE_IF(is_integer<T>::value)>
   FMT_CONSTEXPR auto operator()(T value) -> unsigned long long {
-    if (is_negative(value)) handler_.on_error("negative precision");
+    if (is_negative(value)) throw_format_error("negative precision");
     return static_cast<unsigned long long>(value);
   }
 
   template <typename T, FMT_ENABLE_IF(!is_integer<T>::value)>
   FMT_CONSTEXPR auto operator()(T) -> unsigned long long {
-    handler_.on_error("precision is not integer");
+    throw_format_error("precision is not integer");
     return 0;
   }
-
- private:
-  ErrorHandler& handler_;
 };
 
-template <template <typename> class Handler, typename FormatArg,
-          typename ErrorHandler>
-FMT_CONSTEXPR auto get_dynamic_spec(FormatArg arg, ErrorHandler eh) -> int {
-  unsigned long long value = visit_format_arg(Handler<ErrorHandler>(eh), arg);
-  if (value > to_unsigned(max_value<int>())) eh.on_error("number is too big");
+template <typename Handler, typename FormatArg>
+FMT_CONSTEXPR auto get_dynamic_spec(FormatArg arg) -> int {
+  unsigned long long value = visit_format_arg(Handler(), arg);
+  if (value > to_unsigned(max_value<int>()))
+    throw_format_error("number is too big");
   return static_cast<int>(value);
 }
 
 template <typename Context, typename ID>
-FMT_CONSTEXPR auto get_arg(Context& ctx, ID id) ->
-    typename Context::format_arg {
+FMT_CONSTEXPR auto get_arg(Context& ctx, ID id) -> decltype(ctx.arg(id)) {
   auto arg = ctx.arg(id);
   if (!arg) ctx.on_error("argument not found");
   return arg;
 }
 
-template <template <typename> class Handler, typename Context>
+template <typename Handler, typename Context>
 FMT_CONSTEXPR void handle_dynamic_spec(int& value,
                                        arg_ref<typename Context::char_type> ref,
                                        Context& ctx) {
@@ -4106,26 +3853,15 @@ FMT_CONSTEXPR void handle_dynamic_spec(int& value,
   case arg_id_kind::none:
     break;
   case arg_id_kind::index:
-    value = detail::get_dynamic_spec<Handler>(get_arg(ctx, ref.val.index),
-                                              ctx.error_handler());
+    value = detail::get_dynamic_spec<Handler>(get_arg(ctx, ref.val.index));
     break;
   case arg_id_kind::name:
-    value = detail::get_dynamic_spec<Handler>(get_arg(ctx, ref.val.name),
-                                              ctx.error_handler());
+    value = detail::get_dynamic_spec<Handler>(get_arg(ctx, ref.val.name));
     break;
   }
 }
 
 #if FMT_USE_USER_DEFINED_LITERALS
-template <typename Char> struct udl_formatter {
-  basic_string_view<Char> str;
-
-  template <typename... T>
-  auto operator()(T&&... args) const -> std::basic_string<Char> {
-    return vformat(str, fmt::make_format_args<buffer_context<Char>>(args...));
-  }
-};
-
 #  if FMT_USE_NONTYPE_TEMPLATE_ARGS
 template <typename T, typename Char, size_t N,
           fmt::detail_exported::fixed_string<Char, N> Str>
@@ -4179,28 +3915,28 @@ FMT_API void format_error_code(buffer<char>& out, int error_code,
 
 FMT_API void report_error(format_func func, int error_code,
                           const char* message) noexcept;
-FMT_END_DETAIL_NAMESPACE
+}  // namespace detail
 
 FMT_API auto vsystem_error(int error_code, string_view format_str,
                            format_args args) -> std::system_error;
 
 /**
- \rst
- Constructs :class:`std::system_error` with a message formatted with
- ``fmt::format(fmt, args...)``.
+  \rst
+  Constructs :class:`std::system_error` with a message formatted with
+  ``fmt::format(fmt, args...)``.
   *error_code* is a system error code as given by ``errno``.
 
- **Example**::
-
-   // This throws std::system_error with the description
-   //   cannot open file 'madeup': No such file or directory
-   // or similar (system message may vary).
-   const char* filename = "madeup";
-   std::FILE* file = std::fopen(filename, "r");
-   if (!file)
-     throw fmt::system_error(errno, "cannot open file '{}'", filename);
- \endrst
-*/
+  **Example**::
+
+    // This throws std::system_error with the description
+    //   cannot open file 'madeup': No such file or directory
+    // or similar (system message may vary).
+    const char* filename = "madeup";
+    std::FILE* file = std::fopen(filename, "r");
+    if (!file)
+      throw fmt::system_error(errno, "cannot open file '{}'", filename);
+  \endrst
+ */
 template <typename... T>
 auto system_error(int error_code, format_string<T...> fmt, T&&... args)
     -> std::system_error {
@@ -4292,32 +4028,32 @@ class format_int {
 
 template <typename T, typename Char>
 struct formatter<T, Char, enable_if_t<detail::has_format_as<T>::value>>
-    : private formatter<detail::format_as_t<T>> {
-  using base = formatter<detail::format_as_t<T>>;
-  using base::parse;
-
+    : formatter<detail::format_as_t<T>, Char> {
   template <typename FormatContext>
   auto format(const T& value, FormatContext& ctx) const -> decltype(ctx.out()) {
+    using base = formatter<detail::format_as_t<T>, Char>;
     return base::format(format_as(value), ctx);
   }
 };
 
-template <typename Char>
-struct formatter<void*, Char> : formatter<const void*, Char> {
-  template <typename FormatContext>
-  auto format(void* val, FormatContext& ctx) const -> decltype(ctx.out()) {
-    return formatter<const void*, Char>::format(val, ctx);
-  }
-};
+#define FMT_FORMAT_AS(Type, Base) \
+  template <typename Char>        \
+  struct formatter<Type, Char> : formatter<Base, Char> {}
+
+FMT_FORMAT_AS(signed char, int);
+FMT_FORMAT_AS(unsigned char, unsigned);
+FMT_FORMAT_AS(short, int);
+FMT_FORMAT_AS(unsigned short, unsigned);
+FMT_FORMAT_AS(long, detail::long_type);
+FMT_FORMAT_AS(unsigned long, detail::ulong_type);
+FMT_FORMAT_AS(Char*, const Char*);
+FMT_FORMAT_AS(std::basic_string<Char>, basic_string_view<Char>);
+FMT_FORMAT_AS(std::nullptr_t, const void*);
+FMT_FORMAT_AS(detail::std_string_view<Char>, basic_string_view<Char>);
+FMT_FORMAT_AS(void*, const void*);
 
 template <typename Char, size_t N>
-struct formatter<Char[N], Char> : formatter<basic_string_view<Char>, Char> {
-  template <typename FormatContext>
-  FMT_CONSTEXPR auto format(const Char* val, FormatContext& ctx) const
-      -> decltype(ctx.out()) {
-    return formatter<basic_string_view<Char>, Char>::format(val, ctx);
-  }
-};
+struct formatter<Char[N], Char> : formatter<basic_string_view<Char>, Char> {};
 
 /**
   \rst
@@ -4393,7 +4129,9 @@ template <> struct formatter<bytes> {
 };
 
 // group_digits_view is not derived from view because it copies the argument.
-template <typename T> struct group_digits_view { T value; };
+template <typename T> struct group_digits_view {
+  T value;
+};
 
 /**
   \rst
@@ -4434,6 +4172,59 @@ template <typename T> struct formatter<group_digits_view<T>> : formatter<T> {
   }
 };
 
+template <typename T> struct nested_view {
+  const formatter<T>* fmt;
+  const T* value;
+};
+
+template <typename T> struct formatter<nested_view<T>> {
+  FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> const char* {
+    return ctx.begin();
+  }
+  auto format(nested_view<T> view, format_context& ctx) const
+      -> decltype(ctx.out()) {
+    return view.fmt->format(*view.value, ctx);
+  }
+};
+
+template <typename T> struct nested_formatter {
+ private:
+  int width_;
+  detail::fill_t<char> fill_;
+  align_t align_ : 4;
+  formatter<T> formatter_;
+
+ public:
+  constexpr nested_formatter() : width_(0), align_(align_t::none) {}
+
+  FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> const char* {
+    auto specs = detail::dynamic_format_specs<char>();
+    auto it = parse_format_specs(ctx.begin(), ctx.end(), specs, ctx,
+                                 detail::type::none_type);
+    width_ = specs.width;
+    fill_ = specs.fill;
+    align_ = specs.align;
+    ctx.advance_to(it);
+    return formatter_.parse(ctx);
+  }
+
+  template <typename F>
+  auto write_padded(format_context& ctx, F write) const -> decltype(ctx.out()) {
+    if (width_ == 0) return write(ctx.out());
+    auto buf = memory_buffer();
+    write(std::back_inserter(buf));
+    auto specs = format_specs<>();
+    specs.width = width_;
+    specs.fill = fill_;
+    specs.align = align_;
+    return detail::write(ctx.out(), string_view(buf.data(), buf.size()), specs);
+  }
+
+  auto nested(const T& value) const -> nested_view<T> {
+    return nested_view<T>{&formatter_, &value};
+  }
+};
+
 // DEPRECATED! join_view will be moved to ranges.h.
 template <typename It, typename Sentinel, typename Char = char>
 struct join_view : detail::view {
@@ -4523,7 +4314,8 @@ auto join(Range&& range, string_view sep)
     std::string answer = fmt::to_string(42);
   \endrst
  */
-template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
+template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value &&
+                                    !detail::has_format_as<T>::value)>
 inline auto to_string(const T& value) -> std::string {
   auto buffer = memory_buffer();
   detail::write<char>(appender(buffer), value);
@@ -4548,7 +4340,15 @@ FMT_NODISCARD auto to_string(const basic_memory_buffer<Char, SIZE>& buf)
   return std::basic_string<Char>(buf.data(), size);
 }
 
-FMT_BEGIN_DETAIL_NAMESPACE
+template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value &&
+                                    detail::has_format_as<T>::value)>
+inline auto to_string(const T& value) -> std::string {
+  return to_string(format_as(value));
+}
+
+FMT_END_EXPORT
+
+namespace detail {
 
 template <typename Char>
 void vformat_to(buffer<Char>& buf, basic_string_view<Char> fmt,
@@ -4556,7 +4356,7 @@ void vformat_to(buffer<Char>& buf, basic_string_view<Char> fmt,
   auto out = buffer_appender<Char>(buf);
   if (fmt.size() == 2 && equal2(fmt.data(), "{}")) {
     auto arg = args.get(0);
-    if (!arg) error_handler().on_error("argument not found");
+    if (!arg) throw_format_error("argument not found");
     visit_format_arg(default_arg_formatter<Char>{out, args, loc}, arg);
     return;
   }
@@ -4583,7 +4383,7 @@ void vformat_to(buffer<Char>& buf, basic_string_view<Char> fmt,
     }
     FMT_CONSTEXPR auto on_arg_id(basic_string_view<Char> id) -> int {
       int arg_id = context.arg_id(id);
-      if (arg_id < 0) on_error("argument not found");
+      if (arg_id < 0) throw_format_error("argument not found");
       return arg_id;
     }
 
@@ -4598,11 +4398,9 @@ void vformat_to(buffer<Char>& buf, basic_string_view<Char> fmt,
     auto on_format_specs(int id, const Char* begin, const Char* end)
         -> const Char* {
       auto arg = get_arg(context, id);
-      if (arg.type() == type::custom_type) {
-        parse_context.advance_to(begin);
-        visit_format_arg(custom_formatter<Char>{parse_context, context}, arg);
+      // Not using a visitor for custom types gives better codegen.
+      if (arg.format_custom(begin, parse_context, context))
         return parse_context.begin();
-      }
       auto specs = detail::dynamic_format_specs<Char>();
       begin = parse_format_specs(begin, end, specs, parse_context, arg.type());
       detail::handle_dynamic_spec<detail::width_checker>(
@@ -4610,7 +4408,7 @@ void vformat_to(buffer<Char>& buf, basic_string_view<Char> fmt,
       detail::handle_dynamic_spec<detail::precision_checker>(
           specs.precision, specs.precision_ref, context);
       if (begin == end || *begin != '}')
-        on_error("missing '}' in format string");
+        throw_format_error("missing '}' in format string");
       auto f = arg_formatter<Char>{context.out(), specs, context.locale()};
       context.advance_to(visit_format_arg(f, arg));
       return begin;
@@ -4619,6 +4417,8 @@ void vformat_to(buffer<Char>& buf, basic_string_view<Char> fmt,
   detail::parse_format_string<false>(fmt, format_handler(out, fmt, args, loc));
 }
 
+FMT_BEGIN_EXPORT
+
 #ifndef FMT_HEADER_ONLY
 extern template FMT_API void vformat_to(buffer<char>&, string_view,
                                         typename vformat_args<>::type,
@@ -4631,7 +4431,7 @@ extern template FMT_API auto decimal_point_impl(locale_ref) -> char;
 extern template FMT_API auto decimal_point_impl(locale_ref) -> wchar_t;
 #endif  // FMT_HEADER_ONLY
 
-FMT_END_DETAIL_NAMESPACE
+}  // namespace detail
 
 #if FMT_USE_USER_DEFINED_LITERALS
 inline namespace literals {
@@ -4651,7 +4451,7 @@ template <detail_exported::fixed_string Str> constexpr auto operator""_a() {
   return detail::udl_arg<char_t, sizeof(Str.data) / sizeof(char_t), Str>();
 }
 #  else
-constexpr auto operator"" _a(const char* s, size_t) -> detail::udl_arg<char> {
+constexpr auto operator""_a(const char* s, size_t) -> detail::udl_arg<char> {
   return {s};
 }
 #  endif
@@ -4711,16 +4511,16 @@ formatter<T, Char,
                       detail::type::custom_type>>::format(const T& val,
                                                           FormatContext& ctx)
     const -> decltype(ctx.out()) {
-  if (specs_.width_ref.kind != detail::arg_id_kind::none ||
-      specs_.precision_ref.kind != detail::arg_id_kind::none) {
-    auto specs = specs_;
-    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);
-    return detail::write<Char>(ctx.out(), val, specs, ctx.locale());
-  }
-  return detail::write<Char>(ctx.out(), val, specs_, ctx.locale());
+  if (specs_.width_ref.kind == detail::arg_id_kind::none &&
+      specs_.precision_ref.kind == detail::arg_id_kind::none) {
+    return detail::write<Char>(ctx.out(), val, specs_, ctx.locale());
+  }
+  auto specs = specs_;
+  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);
+  return detail::write<Char>(ctx.out(), val, specs, ctx.locale());
 }
 
 FMT_END_NAMESPACE
diff --git a/source/extern/fmt/ostream.h b/source/extern/fmt/ostream.h
index ce65909..26fb3b5 100644
--- a/source/extern/fmt/ostream.h
+++ b/source/extern/fmt/ostream.h
@@ -10,19 +10,50 @@
 
 #include <fstream>  // std::filebuf
 
-#if defined(_WIN32) && defined(__GLIBCXX__)
-#  include <ext/stdio_filebuf.h>
-#  include <ext/stdio_sync_filebuf.h>
-#elif defined(_WIN32) && defined(_LIBCPP_VERSION)
-#  include <__std_stream>
+#ifdef _WIN32
+#  ifdef __GLIBCXX__
+#    include <ext/stdio_filebuf.h>
+#    include <ext/stdio_sync_filebuf.h>
+#  endif
+#  include <io.h>
 #endif
 
 #include "format.h"
 
 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 {
@@ -37,36 +68,40 @@ class file_access {
 template class file_access<file_access_tag, std::filebuf,
                            &std::filebuf::_Myfile>;
 auto get_file(std::filebuf&) -> FILE*;
-#elif defined(_WIN32) && defined(_LIBCPP_VERSION)
-template class file_access<file_access_tag, std::__stdoutbuf<char>,
-                           &std::__stdoutbuf<char>::__file_>;
-auto get_file(std::__stdoutbuf<char>&) -> FILE*;
 #endif
 
-inline bool write_ostream_unicode(std::ostream& os, fmt::string_view data) {
+inline auto write_ostream_unicode(std::ostream& os, fmt::string_view data)
+    -> bool {
+  FILE* f = nullptr;
 #if FMT_MSC_VERSION
   if (auto* buf = dynamic_cast<std::filebuf*>(os.rdbuf()))
-    if (FILE* f = get_file(*buf)) return write_console(f, data);
+    f = get_file(*buf);
+  else
+    return false;
 #elif defined(_WIN32) && defined(__GLIBCXX__)
   auto* rdbuf = os.rdbuf();
-  FILE* c_file;
   if (auto* sfbuf = dynamic_cast<__gnu_cxx::stdio_sync_filebuf<char>*>(rdbuf))
-    c_file = sfbuf->file();
+    f = sfbuf->file();
   else if (auto* fbuf = dynamic_cast<__gnu_cxx::stdio_filebuf<char>*>(rdbuf))
-    c_file = fbuf->file();
+    f = fbuf->file();
   else
     return false;
-  if (c_file) return write_console(c_file, data);
-#elif defined(_WIN32) && defined(_LIBCPP_VERSION)
-  if (auto* buf = dynamic_cast<std::__stdoutbuf<char>*>(os.rdbuf()))
-    if (FILE* f = get_file(*buf)) return write_console(f, data);
 #else
-  ignore_unused(os, data);
+  ignore_unused(os, data, f);
+#endif
+#ifdef _WIN32
+  if (f) {
+    int fd = _fileno(f);
+    if (_isatty(fd)) {
+      os.flush();
+      return write_console(fd, data);
+    }
+  }
 #endif
   return false;
 }
-inline bool write_ostream_unicode(std::wostream&,
-                                  fmt::basic_string_view<wchar_t>) {
+inline auto write_ostream_unicode(std::wostream&,
+                                  fmt::basic_string_view<wchar_t>) -> bool {
   return false;
 }
 
@@ -87,18 +122,19 @@ void write_buffer(std::basic_ostream<Char>& os, buffer<Char>& buf) {
 }
 
 template <typename Char, typename T>
-void format_value(buffer<Char>& buf, const T& value,
-                  locale_ref loc = locale_ref()) {
+void format_value(buffer<Char>& buf, const T& value) {
   auto&& format_buf = formatbuf<std::basic_streambuf<Char>>(buf);
   auto&& output = std::basic_ostream<Char>(&format_buf);
 #if !defined(FMT_STATIC_THOUSANDS_SEPARATOR)
-  if (loc) output.imbue(loc.get<std::locale>());
+  output.imbue(std::locale::classic());  // The default is always unlocalized.
 #endif
   output << value;
   output.exceptions(std::ios_base::failbit | std::ios_base::badbit);
 }
 
-template <typename T> struct streamed_view { const T& value; };
+template <typename T> struct streamed_view {
+  const T& value;
+};
 
 }  // namespace detail
 
@@ -111,7 +147,7 @@ struct basic_ostream_formatter : formatter<basic_string_view<Char>, Char> {
   auto format(const T& value, basic_format_context<OutputIt, Char>& ctx) const
       -> OutputIt {
     auto buffer = basic_memory_buffer<Char>();
-    detail::format_value(buffer, value, ctx.locale());
+    detail::format_value(buffer, value);
     return formatter<basic_string_view<Char>, Char>::format(
         {buffer.data(), buffer.size()}, ctx);
   }
@@ -140,7 +176,7 @@ struct formatter<detail::streamed_view<T>, Char>
   \endrst
  */
 template <typename T>
-auto streamed(const T& value) -> detail::streamed_view<T> {
+constexpr auto streamed(const T& value) -> detail::streamed_view<T> {
   return {value};
 }
 
@@ -155,7 +191,7 @@ inline void vprint_directly(std::ostream& os, string_view format_str,
 
 }  // namespace detail
 
-FMT_MODULE_EXPORT template <typename Char>
+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) {
@@ -174,7 +210,7 @@ void vprint(std::basic_ostream<Char>& os,
     fmt::print(cerr, "Don't {}!", "panic");
   \endrst
  */
-FMT_MODULE_EXPORT template <typename... T>
+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())
@@ -183,7 +219,7 @@ void print(std::ostream& os, format_string<T...> fmt, T&&... args) {
     detail::vprint_directly(os, fmt, vargs);
 }
 
-FMT_MODULE_EXPORT
+FMT_EXPORT
 template <typename... Args>
 void print(std::wostream& os,
            basic_format_string<wchar_t, type_identity_t<Args>...> fmt,
@@ -191,12 +227,12 @@ void print(std::wostream& os,
   vprint(os, fmt, fmt::make_format_args<buffer_context<wchar_t>>(args...));
 }
 
-FMT_MODULE_EXPORT template <typename... T>
+FMT_EXPORT template <typename... T>
 void println(std::ostream& os, format_string<T...> fmt, T&&... args) {
   fmt::print(os, "{}\n", fmt::format(fmt, std::forward<T>(args)...));
 }
 
-FMT_MODULE_EXPORT
+FMT_EXPORT
 template <typename... Args>
 void println(std::wostream& os,
              basic_format_string<wchar_t, type_identity_t<Args>...> fmt,
diff --git a/source/extern/fmt/printf.h b/source/extern/fmt/printf.h
index 554715e..07e8157 100644
--- a/source/extern/fmt/printf.h
+++ b/source/extern/fmt/printf.h
@@ -16,22 +16,22 @@
 FMT_BEGIN_NAMESPACE
 FMT_BEGIN_EXPORT
 
-template <typename T> struct printf_formatter { printf_formatter() = delete; };
-
-template <typename Char>
-class basic_printf_parse_context : public basic_format_parse_context<Char> {
-  using basic_format_parse_context<Char>::basic_format_parse_context;
+template <typename T> struct printf_formatter {
+  printf_formatter() = delete;
 };
 
-template <typename OutputIt, typename Char> class basic_printf_context {
+template <typename Char> class basic_printf_context {
  private:
-  OutputIt out_;
+  detail::buffer_appender<Char> out_;
   basic_format_args<basic_printf_context> args_;
 
+  static_assert(std::is_same<Char, char>::value ||
+                    std::is_same<Char, wchar_t>::value,
+                "Unsupported code unit type.");
+
  public:
   using char_type = Char;
-  using format_arg = basic_format_arg<basic_printf_context>;
-  using parse_context_type = basic_printf_parse_context<Char>;
+  using parse_context_type = basic_format_parse_context<Char>;
   template <typename T> using formatter_type = printf_formatter<T>;
 
   /**
@@ -40,75 +40,77 @@ template <typename OutputIt, typename Char> class basic_printf_context {
     stored in the context object so make sure they have appropriate lifetimes.
     \endrst
    */
-  basic_printf_context(OutputIt out,
+  basic_printf_context(detail::buffer_appender<Char> out,
                        basic_format_args<basic_printf_context> args)
       : out_(out), args_(args) {}
 
-  OutputIt out() { return out_; }
-  void advance_to(OutputIt it) { out_ = it; }
+  auto out() -> detail::buffer_appender<Char> { return out_; }
+  void advance_to(detail::buffer_appender<Char>) {}
 
-  detail::locale_ref locale() { return {}; }
+  auto locale() -> detail::locale_ref { return {}; }
 
-  format_arg arg(int id) const { return args_.get(id); }
+  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);
   }
 };
 
-FMT_BEGIN_DETAIL_NAMESPACE
+namespace detail {
 
 // Checks if a value fits in int - used to avoid warnings about comparing
 // signed and unsigned integers.
 template <bool IsSigned> struct int_checker {
-  template <typename T> static bool fits_in_int(T value) {
+  template <typename T> static auto fits_in_int(T value) -> bool {
     unsigned max = max_value<int>();
     return value <= max;
   }
-  static bool fits_in_int(bool) { return true; }
+  static auto fits_in_int(bool) -> bool { return true; }
 };
 
 template <> struct int_checker<true> {
-  template <typename T> static bool fits_in_int(T value) {
+  template <typename T> static auto fits_in_int(T value) -> bool {
     return value >= (std::numeric_limits<int>::min)() &&
            value <= max_value<int>();
   }
-  static bool fits_in_int(int) { return true; }
+  static auto fits_in_int(int) -> bool { return true; }
 };
 
-class printf_precision_handler {
- public:
+struct printf_precision_handler {
   template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
-  int operator()(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");
     return (std::max)(static_cast<int>(value), 0);
   }
 
   template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
-  int operator()(T) {
+  auto operator()(T) -> int {
     throw_format_error("precision is not integer");
     return 0;
   }
 };
 
 // An argument visitor that returns true iff arg is a zero integer.
-class is_zero_int {
- public:
+struct is_zero_int {
   template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
-  bool operator()(T value) {
+  auto operator()(T value) -> bool {
     return value == 0;
   }
 
   template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
-  bool operator()(T) {
+  auto operator()(T) -> bool {
     return false;
   }
 };
 
 template <typename T> struct make_unsigned_or_bool : std::make_unsigned<T> {};
 
-template <> struct make_unsigned_or_bool<bool> { using type = bool; };
+template <> struct make_unsigned_or_bool<bool> {
+  using type = bool;
+};
 
 template <typename T, typename Context> class arg_converter {
  private:
@@ -132,22 +134,23 @@ template <typename T, typename Context> class arg_converter {
     if (const_check(sizeof(target_type) <= sizeof(int))) {
       // Extra casts are used to silence warnings.
       if (is_signed) {
-        arg_ = detail::make_arg<Context>(
-            static_cast<int>(static_cast<target_type>(value)));
+        auto n = static_cast<int>(static_cast<target_type>(value));
+        arg_ = detail::make_arg<Context>(n);
       } else {
         using unsigned_type = typename make_unsigned_or_bool<target_type>::type;
-        arg_ = detail::make_arg<Context>(
-            static_cast<unsigned>(static_cast<unsigned_type>(value)));
+        auto n = static_cast<unsigned>(static_cast<unsigned_type>(value));
+        arg_ = detail::make_arg<Context>(n);
       }
     } else {
       if (is_signed) {
         // glibc's printf doesn't sign extend arguments of smaller types:
         //   std::printf("%lld", -42);  // prints "4294967254"
         // but we don't have to do the same because it's a UB.
-        arg_ = detail::make_arg<Context>(static_cast<long long>(value));
+        auto n = static_cast<long long>(value);
+        arg_ = detail::make_arg<Context>(n);
       } else {
-        arg_ = detail::make_arg<Context>(
-            static_cast<typename make_unsigned_or_bool<U>::type>(value));
+        auto n = static_cast<typename make_unsigned_or_bool<U>::type>(value);
+        arg_ = detail::make_arg<Context>(n);
       }
     }
   }
@@ -175,8 +178,8 @@ template <typename Context> class char_converter {
 
   template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
   void operator()(T value) {
-    arg_ = detail::make_arg<Context>(
-        static_cast<typename Context::char_type>(value));
+    auto c = static_cast<typename Context::char_type>(value);
+    arg_ = detail::make_arg<Context>(c);
   }
 
   template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
@@ -186,8 +189,8 @@ template <typename Context> class char_converter {
 // An argument visitor that return a pointer to a C string if argument is a
 // string or null otherwise.
 template <typename Char> struct get_cstring {
-  template <typename T> const Char* operator()(T) { return nullptr; }
-  const Char* operator()(const Char* s) { return s; }
+  template <typename T> auto operator()(T) -> const Char* { return nullptr; }
+  auto operator()(const Char* s) -> const Char* { return s; }
 };
 
 // Checks if an argument is a valid printf width specifier and sets
@@ -200,7 +203,7 @@ template <typename Char> class printf_width_handler {
   explicit printf_width_handler(format_specs<Char>& specs) : specs_(specs) {}
 
   template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
-  unsigned operator()(T value) {
+  auto operator()(T value) -> unsigned {
     auto width = static_cast<uint32_or_64_or_128_t<T>>(value);
     if (detail::is_negative(value)) {
       specs_.align = align::left;
@@ -212,7 +215,7 @@ template <typename Char> class printf_width_handler {
   }
 
   template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
-  unsigned operator()(T) {
+  auto operator()(T) -> unsigned {
     throw_format_error("width is not integer");
     return 0;
   }
@@ -227,80 +230,85 @@ auto make_arg_formatter(buffer_appender<Char> iter, format_specs<Char>& s)
 }
 
 // The ``printf`` argument formatter.
-template <typename OutputIt, typename Char>
+template <typename Char>
 class printf_arg_formatter : public arg_formatter<Char> {
  private:
   using base = arg_formatter<Char>;
-  using context_type = basic_printf_context<OutputIt, Char>;
+  using context_type = basic_printf_context<Char>;
 
   context_type& context_;
 
-  OutputIt write_null_pointer(bool is_string = false) {
+  void write_null_pointer(bool is_string = false) {
     auto s = this->specs;
     s.type = presentation_type::none;
-    return write_bytes(this->out, is_string ? "(null)" : "(nil)", s);
+    write_bytes(this->out, is_string ? "(null)" : "(nil)", s);
   }
 
  public:
-  printf_arg_formatter(OutputIt iter, format_specs<Char>& s, context_type& ctx)
+  printf_arg_formatter(buffer_appender<Char> iter, format_specs<Char>& s,
+                       context_type& ctx)
       : base(make_arg_formatter(iter, s)), context_(ctx) {}
 
-  OutputIt operator()(monostate value) { return base::operator()(value); }
+  void operator()(monostate value) { base::operator()(value); }
 
   template <typename T, FMT_ENABLE_IF(detail::is_integral<T>::value)>
-  OutputIt operator()(T value) {
+  void operator()(T value) {
     // MSVC2013 fails to compile separate overloads for bool and Char so use
     // std::is_same instead.
-    if (std::is_same<T, Char>::value) {
-      format_specs<Char> fmt_specs = this->specs;
-      if (fmt_specs.type != presentation_type::none &&
-          fmt_specs.type != presentation_type::chr) {
-        return (*this)(static_cast<int>(value));
-      }
-      fmt_specs.sign = sign::none;
-      fmt_specs.alt = false;
-      fmt_specs.fill[0] = ' ';  // 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)
-        fmt_specs.align = align::right;
-      return write<Char>(this->out, static_cast<Char>(value), fmt_specs);
+    if (!std::is_same<T, Char>::value) {
+      base::operator()(value);
+      return;
+    }
+    format_specs<Char> fmt_specs = this->specs;
+    if (fmt_specs.type != presentation_type::none &&
+        fmt_specs.type != presentation_type::chr) {
+      return (*this)(static_cast<int>(value));
     }
-    return base::operator()(value);
+    fmt_specs.sign = sign::none;
+    fmt_specs.alt = false;
+    fmt_specs.fill[0] = ' ';  // 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)
+      fmt_specs.align = align::right;
+    write<Char>(this->out, static_cast<Char>(value), fmt_specs);
   }
 
   template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value)>
-  OutputIt operator()(T value) {
-    return base::operator()(value);
+  void operator()(T value) {
+    base::operator()(value);
   }
 
   /** Formats a null-terminated C string. */
-  OutputIt operator()(const char* value) {
-    if (value) return base::operator()(value);
-    return write_null_pointer(this->specs.type != presentation_type::pointer);
+  void operator()(const char* value) {
+    if (value)
+      base::operator()(value);
+    else
+      write_null_pointer(this->specs.type != presentation_type::pointer);
   }
 
   /** Formats a null-terminated wide C string. */
-  OutputIt operator()(const wchar_t* value) {
-    if (value) return base::operator()(value);
-    return write_null_pointer(this->specs.type != presentation_type::pointer);
+  void operator()(const wchar_t* value) {
+    if (value)
+      base::operator()(value);
+    else
+      write_null_pointer(this->specs.type != presentation_type::pointer);
   }
 
-  OutputIt operator()(basic_string_view<Char> value) {
-    return base::operator()(value);
-  }
+  void operator()(basic_string_view<Char> value) { base::operator()(value); }
 
   /** Formats a pointer. */
-  OutputIt operator()(const void* value) {
-    return value ? base::operator()(value) : write_null_pointer();
+  void operator()(const void* value) {
+    if (value)
+      base::operator()(value);
+    else
+      write_null_pointer();
   }
 
   /** Formats an argument of a custom (user-defined) type. */
-  OutputIt operator()(typename basic_format_arg<context_type>::handle handle) {
-    auto parse_ctx =
-        basic_printf_parse_context<Char>(basic_string_view<Char>());
+  void operator()(typename basic_format_arg<context_type>::handle handle) {
+    auto parse_ctx = basic_format_parse_context<Char>({});
     handle.format(parse_ctx, context_);
-    return this->out;
   }
 };
 
@@ -318,9 +326,7 @@ void parse_flags(format_specs<Char>& specs, const Char*& it, const Char* end) {
       specs.fill[0] = '0';
       break;
     case ' ':
-      if (specs.sign != sign::plus) {
-        specs.sign = sign::space;
-      }
+      if (specs.sign != sign::plus) specs.sign = sign::space;
       break;
     case '#':
       specs.alt = true;
@@ -332,8 +338,8 @@ void parse_flags(format_specs<Char>& specs, const Char*& it, const Char* end) {
 }
 
 template <typename Char, typename GetArg>
-int parse_header(const Char*& it, const Char* end, format_specs<Char>& specs,
-                 GetArg get_arg) {
+auto parse_header(const Char*& it, const Char* end, format_specs<Char>& specs,
+                  GetArg get_arg) -> int {
   int arg_index = -1;
   Char c = *it;
   if (c >= '0' && c <= '9') {
@@ -414,8 +420,8 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
              basic_format_args<Context> args) {
   using iterator = buffer_appender<Char>;
   auto out = iterator(buf);
-  auto context = basic_printf_context<iterator, Char>(out, args);
-  auto parse_ctx = basic_printf_parse_context<Char>(format);
+  auto context = basic_printf_context<Char>(out, args);
+  auto parse_ctx = basic_format_parse_context<Char>(format);
 
   // Returns the argument with specified index or, if arg_index is -1, the next
   // argument.
@@ -437,12 +443,11 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
     }
     Char c = *it++;
     if (it != end && *it == c) {
-      out = write(out, basic_string_view<Char>(start, to_unsigned(it - start)));
+      write(out, basic_string_view<Char>(start, to_unsigned(it - start)));
       start = ++it;
       continue;
     }
-    out =
-        write(out, basic_string_view<Char>(start, to_unsigned(it - 1 - start)));
+    write(out, basic_string_view<Char>(start, to_unsigned(it - 1 - start)));
 
     auto specs = format_specs<Char>();
     specs.align = align::right;
@@ -469,16 +474,17 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
     auto arg = get_arg(arg_index);
     // For d, i, o, u, x, and X conversion specifiers, if a precision is
     // specified, the '0' flag is ignored
-    if (specs.precision >= 0 && arg.is_integral())
-      specs.fill[0] =
-          ' ';  // Ignore '0' flag for non-numeric types or if '-' present.
+    if (specs.precision >= 0 && arg.is_integral()) {
+      // Ignore '0' for non-numeric types or if '-' present.
+      specs.fill[0] = ' ';
+    }
     if (specs.precision >= 0 && arg.type() == type::cstring_type) {
       auto str = visit_format_arg(get_cstring<Char>(), arg);
       auto str_end = str + specs.precision;
       auto nul = std::find(str, str_end, Char());
-      arg = make_arg<basic_printf_context<iterator, Char>>(
-          basic_string_view<Char>(
-              str, to_unsigned(nul != str_end ? nul - str : specs.precision)));
+      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.fill[0] == '0') {
@@ -540,8 +546,7 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
         type = 'd';
         break;
       case 'c':
-        visit_format_arg(
-            char_converter<basic_printf_context<iterator, Char>>(arg), arg);
+        visit_format_arg(char_converter<basic_printf_context<Char>>(arg), arg);
         break;
       }
     }
@@ -552,19 +557,14 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
     start = it;
 
     // Format argument.
-    out = visit_format_arg(
-        printf_arg_formatter<iterator, Char>(out, specs, context), arg);
+    visit_format_arg(printf_arg_formatter<Char>(out, specs, context), arg);
   }
   write(out, basic_string_view<Char>(start, to_unsigned(it - start)));
 }
-FMT_END_DETAIL_NAMESPACE
-
-template <typename Char>
-using basic_printf_context_t =
-    basic_printf_context<detail::buffer_appender<Char>, Char>;
+}  // namespace detail
 
-using printf_context = basic_printf_context_t<char>;
-using wprintf_context = basic_printf_context_t<wchar_t>;
+using printf_context = basic_printf_context<char>;
+using wprintf_context = basic_printf_context<wchar_t>;
 
 using printf_args = basic_format_args<printf_context>;
 using wprintf_args = basic_format_args<wprintf_context>;
@@ -581,25 +581,20 @@ inline auto make_printf_args(const T&... args)
   return {args...};
 }
 
-/**
-  \rst
-  Constructs an `~fmt::format_arg_store` object that contains references to
-  arguments and can be implicitly converted to `~fmt::wprintf_args`.
-  \endrst
- */
+// DEPRECATED!
 template <typename... T>
 inline auto make_wprintf_args(const T&... args)
     -> format_arg_store<wprintf_context, T...> {
   return {args...};
 }
 
-template <typename S, typename Char = char_t<S>>
+template <typename Char>
 inline auto vsprintf(
-    const S& fmt,
-    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    basic_string_view<Char> fmt,
+    basic_format_args<basic_printf_context<type_identity_t<Char>>> args)
     -> std::basic_string<Char> {
   auto buf = basic_memory_buffer<Char>();
-  detail::vprintf(buf, detail::to_string_view(fmt), args);
+  detail::vprintf(buf, fmt, args);
   return to_string(buf);
 }
 
@@ -615,18 +610,17 @@ inline auto vsprintf(
 template <typename S, typename... T,
           typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
 inline auto sprintf(const S& fmt, const T&... args) -> std::basic_string<Char> {
-  using context = basic_printf_context_t<Char>;
   return vsprintf(detail::to_string_view(fmt),
-                  fmt::make_format_args<context>(args...));
+                  fmt::make_format_args<basic_printf_context<Char>>(args...));
 }
 
-template <typename S, typename Char = char_t<S>>
+template <typename Char>
 inline auto vfprintf(
-    std::FILE* f, const S& fmt,
-    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    std::FILE* f, basic_string_view<Char> fmt,
+    basic_format_args<basic_printf_context<type_identity_t<Char>>> args)
     -> int {
   auto buf = basic_memory_buffer<Char>();
-  detail::vprintf(buf, detail::to_string_view(fmt), args);
+  detail::vprintf(buf, fmt, args);
   size_t size = buf.size();
   return std::fwrite(buf.data(), sizeof(Char), size, f) < size
              ? -1
@@ -644,17 +638,16 @@ inline auto vfprintf(
  */
 template <typename S, typename... T, typename Char = char_t<S>>
 inline auto fprintf(std::FILE* f, const S& fmt, const T&... args) -> int {
-  using context = basic_printf_context_t<Char>;
   return vfprintf(f, detail::to_string_view(fmt),
-                  fmt::make_format_args<context>(args...));
+                  fmt::make_format_args<basic_printf_context<Char>>(args...));
 }
 
-template <typename S, typename Char = char_t<S>>
-inline auto vprintf(
-    const S& fmt,
-    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+template <typename Char>
+FMT_DEPRECATED inline auto vprintf(
+    basic_string_view<Char> fmt,
+    basic_format_args<basic_printf_context<type_identity_t<Char>>> args)
     -> int {
-  return vfprintf(stdout, detail::to_string_view(fmt), args);
+  return vfprintf(stdout, fmt, args);
 }
 
 /**
@@ -666,11 +659,14 @@ inline auto vprintf(
     fmt::printf("Elapsed time: %.2f seconds", 1.23);
   \endrst
  */
-template <typename S, typename... T, FMT_ENABLE_IF(detail::is_string<S>::value)>
-inline auto printf(const S& fmt, const T&... args) -> int {
-  return vprintf(
-      detail::to_string_view(fmt),
-      fmt::make_format_args<basic_printf_context_t<char_t<S>>>(args...));
+template <typename... T>
+inline auto printf(string_view fmt, const T&... args) -> int {
+  return vfprintf(stdout, fmt, make_printf_args(args...));
+}
+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...));
 }
 
 FMT_END_EXPORT
diff --git a/source/extern/fmt/ranges.h b/source/extern/fmt/ranges.h
index 266b9e1..3638fff 100644
--- a/source/extern/fmt/ranges.h
+++ b/source/extern/fmt/ranges.h
@@ -1,13 +1,9 @@
-// Formatting library for C++ - experimental range support
+// Formatting library for C++ - range and tuple support
 //
-// Copyright (c) 2012 - present, Victor Zverovich
+// Copyright (c) 2012 - present, Victor Zverovich and {fmt} contributors
 // All rights reserved.
 //
 // For the license information refer to format.h.
-//
-// Copyright (c) 2018 - present, Remotion (Igor Schulz)
-// All Rights Reserved
-// {fmt} support for ranges, containers and types tuple interface.
 
 #ifndef FMT_RANGES_H_
 #define FMT_RANGES_H_
@@ -187,7 +183,7 @@ template <size_t N> using make_index_sequence = std::make_index_sequence<N>;
 template <typename T, T... N> struct integer_sequence {
   using value_type = T;
 
-  static FMT_CONSTEXPR size_t size() { return sizeof...(N); }
+  static FMT_CONSTEXPR auto size() -> size_t { return sizeof...(N); }
 };
 
 template <size_t... N> using index_sequence = integer_sequence<size_t, N...>;
@@ -211,15 +207,15 @@ class is_tuple_formattable_ {
 };
 template <typename T, typename C> class is_tuple_formattable_<T, C, true> {
   template <std::size_t... Is>
-  static std::true_type check2(index_sequence<Is...>,
-                               integer_sequence<bool, (Is == Is)...>);
-  static std::false_type check2(...);
+  static auto check2(index_sequence<Is...>,
+                     integer_sequence<bool, (Is == Is)...>) -> std::true_type;
+  static auto check2(...) -> std::false_type;
   template <std::size_t... Is>
-  static decltype(check2(
+  static auto check(index_sequence<Is...>) -> decltype(check2(
       index_sequence<Is...>{},
-      integer_sequence<
-          bool, (is_formattable<typename std::tuple_element<Is, T>::type,
-                                C>::value)...>{})) check(index_sequence<Is...>);
+      integer_sequence<bool,
+                       (is_formattable<typename std::tuple_element<Is, T>::type,
+                                       C>::value)...>{}));
 
  public:
   static constexpr const bool value =
@@ -421,6 +417,12 @@ struct is_formattable_delayed
 #endif
 }  // namespace detail
 
+template <typename...> struct conjunction : std::true_type {};
+template <typename P> struct conjunction<P> : P {};
+template <typename P1, typename... Pn>
+struct conjunction<P1, Pn...>
+    : conditional_t<bool(P1::value), conjunction<Pn...>, P1> {};
+
 template <typename T, typename Char, typename Enable = void>
 struct range_formatter;
 
@@ -486,7 +488,8 @@ struct range_formatter<
     for (; it != end; ++it) {
       if (i > 0) out = detail::copy_str<Char>(separator_, out);
       ctx.advance_to(out);
-      out = underlying_.format(mapper.map(*it), ctx);
+      auto&& item = *it;
+      out = underlying_.format(mapper.map(item), ctx);
       ++i;
     }
     out = detail::copy_str<Char>(closing_bracket_, out);
@@ -668,8 +671,11 @@ template <typename Container> struct all {
 }  // namespace detail
 
 template <typename T, typename Char>
-struct formatter<T, Char,
-                 enable_if_t<detail::is_container_adaptor_like<T>::value>>
+struct formatter<
+    T, Char,
+    enable_if_t<conjunction<detail::is_container_adaptor_like<T>,
+                            bool_constant<range_format_kind<T, Char>::value ==
+                                          range_format::disabled>>::value>>
     : formatter<detail::all<typename T::container_type>, Char> {
   using all = detail::all<typename T::container_type>;
   template <typename FormatContext>
diff --git a/source/extern/fmt/std.h b/source/extern/fmt/std.h
index 4c2a28c..7cff115 100644
--- a/source/extern/fmt/std.h
+++ b/source/extern/fmt/std.h
@@ -8,6 +8,8 @@
 #ifndef FMT_STD_H_
 #define FMT_STD_H_
 
+#include <atomic>
+#include <bitset>
 #include <cstdlib>
 #include <exception>
 #include <memory>
@@ -15,7 +17,9 @@
 #include <type_traits>
 #include <typeinfo>
 #include <utility>
+#include <vector>
 
+#include "format.h"
 #include "ostream.h"
 
 #if FMT_HAS_INCLUDE(<version>)
@@ -34,6 +38,10 @@
 #  endif
 #endif
 
+#if FMT_CPLUSPLUS > 201703L && FMT_HAS_INCLUDE(<source_location>)
+#  include <source_location>
+#endif
+
 // GCC 4 does not support FMT_HAS_INCLUDE.
 #if FMT_HAS_INCLUDE(<cxxabi.h>) || defined(__GLIBCXX__)
 #  include <cxxabi.h>
@@ -44,67 +52,155 @@
 #  endif
 #endif
 
-#ifdef __cpp_lib_filesystem
+// Check if typeid is available.
+#ifndef FMT_USE_TYPEID
+// __RTTI is for EDG compilers. In MSVC typeid is available without RTTI.
+#  if defined(__GXX_RTTI) || FMT_HAS_FEATURE(cxx_rtti) || FMT_MSC_VERSION || \
+      defined(__INTEL_RTTI__) || defined(__RTTI)
+#    define FMT_USE_TYPEID 1
+#  else
+#    define FMT_USE_TYPEID 0
+#  endif
+#endif
+
+// For older Xcode versions, __cpp_lib_xxx flags are inaccurately defined.
+#ifndef FMT_CPP_LIB_FILESYSTEM
+#  ifdef __cpp_lib_filesystem
+#    define FMT_CPP_LIB_FILESYSTEM __cpp_lib_filesystem
+#  else
+#    define FMT_CPP_LIB_FILESYSTEM 0
+#  endif
+#endif
+
+#ifndef FMT_CPP_LIB_VARIANT
+#  ifdef __cpp_lib_variant
+#    define FMT_CPP_LIB_VARIANT __cpp_lib_variant
+#  else
+#    define FMT_CPP_LIB_VARIANT 0
+#  endif
+#endif
+
+#if FMT_CPP_LIB_FILESYSTEM
 FMT_BEGIN_NAMESPACE
 
 namespace detail {
 
-template <typename Char>
-void write_escaped_path(basic_memory_buffer<Char>& quoted,
-                        const std::filesystem::path& p) {
-  write_escaped_string<Char>(std::back_inserter(quoted), p.string<Char>());
-}
-#  ifdef _WIN32
-template <>
-inline void write_escaped_path<char>(memory_buffer& quoted,
-                                     const std::filesystem::path& p) {
-  auto buf = basic_memory_buffer<wchar_t>();
-  write_escaped_string<wchar_t>(std::back_inserter(buf), p.native());
-  // Convert UTF-16 to UTF-8.
-  if (!unicode_to_utf8<wchar_t>::convert(quoted, {buf.data(), buf.size()}))
-    FMT_THROW(std::runtime_error("invalid utf16"));
+template <typename Char, typename PathChar>
+auto get_path_string(const std::filesystem::path& p,
+                     const std::basic_string<PathChar>& native) {
+  if constexpr (std::is_same_v<Char, char> && std::is_same_v<PathChar, wchar_t>)
+    return to_utf8<wchar_t>(native, to_utf8_error_policy::replace);
+  else
+    return p.string<Char>();
 }
-#  endif
-template <>
-inline void write_escaped_path<std::filesystem::path::value_type>(
-    basic_memory_buffer<std::filesystem::path::value_type>& quoted,
-    const std::filesystem::path& p) {
-  write_escaped_string<std::filesystem::path::value_type>(
-      std::back_inserter(quoted), p.native());
+
+template <typename Char, typename PathChar>
+void write_escaped_path(basic_memory_buffer<Char>& quoted,
+                        const std::filesystem::path& p,
+                        const std::basic_string<PathChar>& native) {
+  if constexpr (std::is_same_v<Char, char> &&
+                std::is_same_v<PathChar, wchar_t>) {
+    auto buf = basic_memory_buffer<wchar_t>();
+    write_escaped_string<wchar_t>(std::back_inserter(buf), native);
+    bool valid = to_utf8<wchar_t>::convert(quoted, {buf.data(), buf.size()});
+    FMT_ASSERT(valid, "invalid utf16");
+  } else if constexpr (std::is_same_v<Char, PathChar>) {
+    write_escaped_string<std::filesystem::path::value_type>(
+        std::back_inserter(quoted), native);
+  } else {
+    write_escaped_string<Char>(std::back_inserter(quoted), p.string<Char>());
+  }
 }
 
 }  // namespace detail
 
-FMT_MODULE_EXPORT
-template <typename Char>
-struct formatter<std::filesystem::path, Char>
-    : formatter<basic_string_view<Char>> {
+FMT_EXPORT
+template <typename Char> struct formatter<std::filesystem::path, Char> {
+ private:
+  format_specs<Char> specs_;
+  detail::arg_ref<Char> width_ref_;
+  bool debug_ = false;
+  char path_type_ = 0;
+
+ public:
+  FMT_CONSTEXPR void set_debug_format(bool set = true) { debug_ = set; }
+
   template <typename ParseContext> FMT_CONSTEXPR auto parse(ParseContext& ctx) {
-    auto out = formatter<basic_string_view<Char>>::parse(ctx);
-    this->set_debug_format(false);
-    return out;
+    auto it = ctx.begin(), end = ctx.end();
+    if (it == end) return it;
+
+    it = detail::parse_align(it, end, specs_);
+    if (it == end) return it;
+
+    it = detail::parse_dynamic_spec(it, end, specs_.width, width_ref_, ctx);
+    if (it != end && *it == '?') {
+      debug_ = true;
+      ++it;
+    }
+    if (it != end && (*it == 'g')) path_type_ = *it++;
+    return it;
   }
+
   template <typename FormatContext>
-  auto format(const std::filesystem::path& p, FormatContext& ctx) const ->
-      typename FormatContext::iterator {
+  auto format(const std::filesystem::path& p, FormatContext& ctx) const {
+    auto specs = specs_;
+#  ifdef _WIN32
+    auto path_string = !path_type_ ? p.native() : p.generic_wstring();
+#  else
+    auto path_string = !path_type_ ? p.native() : p.generic_string();
+#  endif
+
+    detail::handle_dynamic_spec<detail::width_checker>(specs.width, width_ref_,
+                                                       ctx);
+    if (!debug_) {
+      auto s = detail::get_path_string<Char>(p, path_string);
+      return detail::write(ctx.out(), basic_string_view<Char>(s), specs);
+    }
     auto quoted = basic_memory_buffer<Char>();
-    detail::write_escaped_path(quoted, p);
-    return formatter<basic_string_view<Char>>::format(
-        basic_string_view<Char>(quoted.data(), quoted.size()), ctx);
+    detail::write_escaped_path(quoted, p, path_string);
+    return detail::write(ctx.out(),
+                         basic_string_view<Char>(quoted.data(), quoted.size()),
+                         specs);
   }
 };
 FMT_END_NAMESPACE
-#endif
+#endif  // FMT_CPP_LIB_FILESYSTEM
 
 FMT_BEGIN_NAMESPACE
-FMT_MODULE_EXPORT
+FMT_EXPORT
+template <std::size_t N, typename Char>
+struct formatter<std::bitset<N>, Char> : nested_formatter<string_view> {
+ private:
+  // Functor because C++11 doesn't support generic lambdas.
+  struct writer {
+    const std::bitset<N>& bs;
+
+    template <typename OutputIt>
+    FMT_CONSTEXPR auto operator()(OutputIt out) -> OutputIt {
+      for (auto pos = N; pos > 0; --pos) {
+        out = detail::write<Char>(out, bs[pos - 1] ? Char('1') : Char('0'));
+      }
+
+      return out;
+    }
+  };
+
+ public:
+  template <typename FormatContext>
+  auto format(const std::bitset<N>& bs, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    return write_padded(ctx, writer{bs});
+  }
+};
+
+FMT_EXPORT
 template <typename Char>
 struct formatter<std::thread::id, Char> : basic_ostream_formatter<Char> {};
 FMT_END_NAMESPACE
 
 #ifdef __cpp_lib_optional
 FMT_BEGIN_NAMESPACE
-FMT_MODULE_EXPORT
+FMT_EXPORT
 template <typename T, typename Char>
 struct formatter<std::optional<T>, Char,
                  std::enable_if_t<is_formattable<T, Char>::value>> {
@@ -132,7 +228,7 @@ struct formatter<std::optional<T>, Char,
   }
 
   template <typename FormatContext>
-  auto format(std::optional<T> const& opt, FormatContext& ctx) const
+  auto format(const std::optional<T>& opt, FormatContext& ctx) const
       -> decltype(ctx.out()) {
     if (!opt) return detail::write<Char>(ctx.out(), none);
 
@@ -146,24 +242,33 @@ struct formatter<std::optional<T>, Char,
 FMT_END_NAMESPACE
 #endif  // __cpp_lib_optional
 
-#ifdef __cpp_lib_variant
+#ifdef __cpp_lib_source_location
 FMT_BEGIN_NAMESPACE
-FMT_MODULE_EXPORT
-template <typename Char> struct formatter<std::monostate, Char> {
-  template <typename ParseContext>
-  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+FMT_EXPORT
+template <> struct formatter<std::source_location> {
+  template <typename ParseContext> FMT_CONSTEXPR auto parse(ParseContext& ctx) {
     return ctx.begin();
   }
 
   template <typename FormatContext>
-  auto format(const std::monostate&, FormatContext& ctx) const
+  auto format(const std::source_location& loc, FormatContext& ctx) const
       -> decltype(ctx.out()) {
     auto out = ctx.out();
-    out = detail::write<Char>(out, "monostate");
+    out = detail::write(out, loc.file_name());
+    out = detail::write(out, ':');
+    out = detail::write<char>(out, loc.line());
+    out = detail::write(out, ':');
+    out = detail::write<char>(out, loc.column());
+    out = detail::write(out, ": ");
+    out = detail::write(out, loc.function_name());
     return out;
   }
 };
+FMT_END_NAMESPACE
+#endif
 
+#if FMT_CPP_LIB_VARIANT
+FMT_BEGIN_NAMESPACE
 namespace detail {
 
 template <typename T>
@@ -197,6 +302,7 @@ auto write_variant_alternative(OutputIt out, const T& v) -> OutputIt {
 }
 
 }  // namespace detail
+
 template <typename T> struct is_variant_like {
   static constexpr const bool value = detail::is_variant_like_<T>::value;
 };
@@ -206,7 +312,21 @@ template <typename T, typename C> struct is_variant_formattable {
       detail::is_variant_formattable_<T, C>::value;
 };
 
-FMT_MODULE_EXPORT
+FMT_EXPORT
+template <typename Char> struct formatter<std::monostate, Char> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  auto format(const std::monostate&, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    return detail::write<Char>(ctx.out(), "monostate");
+  }
+};
+
+FMT_EXPORT
 template <typename Variant, typename Char>
 struct formatter<
     Variant, Char,
@@ -223,13 +343,14 @@ struct formatter<
     auto out = ctx.out();
 
     out = detail::write<Char>(out, "variant(");
-    try {
+    FMT_TRY {
       std::visit(
           [&](const auto& v) {
             out = detail::write_variant_alternative<Char>(out, v);
           },
           value);
-    } catch (const std::bad_variant_access&) {
+    }
+    FMT_CATCH(const std::bad_variant_access&) {
       detail::write<Char>(out, "valueless by exception");
     }
     *out++ = ')';
@@ -237,10 +358,10 @@ struct formatter<
   }
 };
 FMT_END_NAMESPACE
-#endif  // __cpp_lib_variant
+#endif  // FMT_CPP_LIB_VARIANT
 
 FMT_BEGIN_NAMESPACE
-FMT_MODULE_EXPORT
+FMT_EXPORT
 template <typename Char> struct formatter<std::error_code, Char> {
   template <typename ParseContext>
   FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
@@ -258,10 +379,10 @@ template <typename Char> struct formatter<std::error_code, Char> {
   }
 };
 
-FMT_MODULE_EXPORT
+FMT_EXPORT
 template <typename T, typename Char>
 struct formatter<
-    T, Char,
+    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;
@@ -274,7 +395,7 @@ struct formatter<
     if (it == end || *it == '}') return it;
     if (*it == 't') {
       ++it;
-      with_typename_ = true;
+      with_typename_ = FMT_USE_TYPEID != 0;
     }
     return it;
   }
@@ -287,11 +408,12 @@ struct formatter<
     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
+#  ifdef FMT_HAS_ABI_CXA_DEMANGLE
     int status = 0;
     std::size_t size = 0;
-    std::unique_ptr<char, decltype(&std::free)> demangled_name_ptr(
+    std::unique_ptr<char, void (*)(void*)> demangled_name_ptr(
         abi::__cxa_demangle(ti.name(), nullptr, &size, &status), &std::free);
 
     string_view demangled_name_view;
@@ -327,23 +449,89 @@ struct formatter<
       demangled_name_view = string_view(ti.name());
     }
     out = detail::write_bytes(out, demangled_name_view, spec);
-#elif FMT_MSC_VERSION
+#  elif FMT_MSC_VERSION
     string_view demangled_name_view(ti.name());
     if (demangled_name_view.starts_with("class "))
       demangled_name_view.remove_prefix(6);
     else if (demangled_name_view.starts_with("struct "))
       demangled_name_view.remove_prefix(7);
     out = detail::write_bytes(out, demangled_name_view, spec);
-#else
+#  else
     out = detail::write_bytes(out, string_view(ti.name()), spec);
+#  endif
+    *out++ = ':';
+    *out++ = ' ';
+    return detail::write_bytes(out, string_view(ex.what()), spec);
 #endif
-    out = detail::write<Char>(out, Char(':'));
-    out = detail::write<Char>(out, Char(' '));
-    out = detail::write_bytes(out, string_view(ex.what()), spec);
+  }
+};
 
-    return out;
+namespace detail {
+
+template <typename T, typename Enable = void>
+struct has_flip : std::false_type {};
+
+template <typename T>
+struct has_flip<T, void_t<decltype(std::declval<T>().flip())>>
+    : std::true_type {};
+
+template <typename T> struct is_bit_reference_like {
+  static constexpr const bool value =
+      std::is_convertible<T, bool>::value &&
+      std::is_nothrow_assignable<T, bool>::value && has_flip<T>::value;
+};
+
+#ifdef _LIBCPP_VERSION
+
+// Workaround for libc++ incompatibility with C++ standard.
+// According to the Standard, `bitset::operator[] const` returns bool.
+template <typename C>
+struct is_bit_reference_like<std::__bit_const_reference<C>> {
+  static constexpr const bool value = true;
+};
+
+#endif
+
+}  // namespace detail
+
+// We can't use std::vector<bool, Allocator>::reference and
+// std::bitset<N>::reference because the compiler can't deduce Allocator and N
+// in partial specialization.
+FMT_EXPORT
+template <typename BitRef, typename Char>
+struct formatter<BitRef, Char,
+                 enable_if_t<detail::is_bit_reference_like<BitRef>::value>>
+    : formatter<bool, Char> {
+  template <typename FormatContext>
+  FMT_CONSTEXPR auto format(const BitRef& v, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    return formatter<bool, Char>::format(v, ctx);
   }
 };
-FMT_END_NAMESPACE
 
+FMT_EXPORT
+template <typename T, typename Char>
+struct formatter<std::atomic<T>, Char,
+                 enable_if_t<is_formattable<T, Char>::value>>
+    : formatter<T, Char> {
+  template <typename FormatContext>
+  auto format(const std::atomic<T>& v, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    return formatter<T, Char>::format(v.load(), ctx);
+  }
+};
+
+#ifdef __cpp_lib_atomic_flag_test
+FMT_EXPORT
+template <typename Char>
+struct formatter<std::atomic_flag, Char> : formatter<bool, Char> {
+  template <typename FormatContext>
+  auto format(const std::atomic_flag& v, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    return formatter<bool, Char>::format(v.test(), ctx);
+  }
+};
+#endif  // __cpp_lib_atomic_flag_test
+
+FMT_END_NAMESPACE
 #endif  // FMT_STD_H_