update fmt to 8.1.1

deps/fmt/include/fmt/args.h

@@ -0,0 +1,234 @@
+// Formatting library for C++ - dynamic format arguments
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_ARGS_H_
+#define FMT_ARGS_H_
+
+#include <functional>  // std::reference_wrapper
+#include <memory>      // std::unique_ptr
+#include <vector>
+
+#include "core.h"
+
+FMT_BEGIN_NAMESPACE
+
+namespace detail {
+
+template <typename T> struct is_reference_wrapper : std::false_type {};
+template <typename T>
+struct is_reference_wrapper<std::reference_wrapper<T>> : std::true_type {};
+
+template <typename T> const T& unwrap(const T& v) { return v; }
+template <typename T> const T& unwrap(const std::reference_wrapper<T>& v) {
+  return static_cast<const T&>(v);
+}
+
+class dynamic_arg_list {
+  // Workaround for clang's -Wweak-vtables. Unlike for regular classes, for
+  // templates it doesn't complain about inability to deduce single translation
+  // unit for placing vtable. So storage_node_base is made a fake template.
+  template <typename = void> struct node {
+    virtual ~node() = default;
+    std::unique_ptr<node<>> next;
+  };
+
+  template <typename T> struct typed_node : node<> {
+    T value;
+
+    template <typename Arg>
+    FMT_CONSTEXPR typed_node(const Arg& arg) : value(arg) {}
+
+    template <typename Char>
+    FMT_CONSTEXPR typed_node(const basic_string_view<Char>& arg)
+        : value(arg.data(), arg.size()) {}
+  };
+
+  std::unique_ptr<node<>> head_;
+
+ public:
+  template <typename T, typename Arg> const T& push(const Arg& arg) {
+    auto new_node = std::unique_ptr<typed_node<T>>(new typed_node<T>(arg));
+    auto& value = new_node->value;
+    new_node->next = std::move(head_);
+    head_ = std::move(new_node);
+    return value;
+  }
+};
+}  // namespace detail
+
+/**
+  \rst
+  A dynamic version of `fmt::format_arg_store`.
+  It's equipped with a storage to potentially temporary objects which lifetimes
+  could be shorter than the format arguments object.
+
+  It can be implicitly converted into `~fmt::basic_format_args` for passing
+  into type-erased formatting functions such as `~fmt::vformat`.
+  \endrst
+ */
+template <typename Context>
+class dynamic_format_arg_store
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+    // Workaround a GCC template argument substitution bug.
+    : public basic_format_args<Context>
+#endif
+{
+ private:
+  using char_type = typename Context::char_type;
+
+  template <typename T> struct need_copy {
+    static constexpr detail::type mapped_type =
+        detail::mapped_type_constant<T, Context>::value;
+
+    enum {
+      value = !(detail::is_reference_wrapper<T>::value ||
+                std::is_same<T, basic_string_view<char_type>>::value ||
+                std::is_same<T, detail::std_string_view<char_type>>::value ||
+                (mapped_type != detail::type::cstring_type &&
+                 mapped_type != detail::type::string_type &&
+                 mapped_type != detail::type::custom_type))
+    };
+  };
+
+  template <typename T>
+  using stored_type = conditional_t<detail::is_string<T>::value &&
+                                        !has_formatter<T, Context>::value &&
+                                        !detail::is_reference_wrapper<T>::value,
+                                    std::basic_string<char_type>, T>;
+
+  // Storage of basic_format_arg must be contiguous.
+  std::vector<basic_format_arg<Context>> data_;
+  std::vector<detail::named_arg_info<char_type>> named_info_;
+
+  // Storage of arguments not fitting into basic_format_arg must grow
+  // without relocation because items in data_ refer to it.
+  detail::dynamic_arg_list dynamic_args_;
+
+  friend class basic_format_args<Context>;
+
+  unsigned long long get_types() const {
+    return detail::is_unpacked_bit | data_.size() |
+           (named_info_.empty()
+                ? 0ULL
+                : static_cast<unsigned long long>(detail::has_named_args_bit));
+  }
+
+  const basic_format_arg<Context>* data() const {
+    return named_info_.empty() ? data_.data() : data_.data() + 1;
+  }
+
+  template <typename T> void emplace_arg(const T& arg) {
+    data_.emplace_back(detail::make_arg<Context>(arg));
+  }
+
+  template <typename T>
+  void emplace_arg(const detail::named_arg<char_type, T>& arg) {
+    if (named_info_.empty()) {
+      constexpr const detail::named_arg_info<char_type>* zero_ptr{nullptr};
+      data_.insert(data_.begin(), {zero_ptr, 0});
+    }
+    data_.emplace_back(detail::make_arg<Context>(detail::unwrap(arg.value)));
+    auto pop_one = [](std::vector<basic_format_arg<Context>>* data) {
+      data->pop_back();
+    };
+    std::unique_ptr<std::vector<basic_format_arg<Context>>, decltype(pop_one)>
+        guard{&data_, pop_one};
+    named_info_.push_back({arg.name, static_cast<int>(data_.size() - 2u)});
+    data_[0].value_.named_args = {named_info_.data(), named_info_.size()};
+    guard.release();
+  }
+
+ public:
+  constexpr dynamic_format_arg_store() = default;
+
+  /**
+    \rst
+    Adds an argument into the dynamic store for later passing to a formatting
+    function.
+
+    Note that custom types and string types (but not string views) are copied
+    into the store dynamically allocating memory if necessary.
+
+    **Example**::
+
+      fmt::dynamic_format_arg_store<fmt::format_context> store;
+      store.push_back(42);
+      store.push_back("abc");
+      store.push_back(1.5f);
+      std::string result = fmt::vformat("{} and {} and {}", store);
+    \endrst
+  */
+  template <typename T> void push_back(const T& arg) {
+    if (detail::const_check(need_copy<T>::value))
+      emplace_arg(dynamic_args_.push<stored_type<T>>(arg));
+    else
+      emplace_arg(detail::unwrap(arg));
+  }
+
+  /**
+    \rst
+    Adds a reference to the argument into the dynamic store for later passing to
+    a formatting function.
+
+    **Example**::
+
+      fmt::dynamic_format_arg_store<fmt::format_context> store;
+      char band[] = "Rolling Stones";
+      store.push_back(std::cref(band));
+      band[9] = 'c'; // Changing str affects the output.
+      std::string result = fmt::vformat("{}", store);
+      // result == "Rolling Scones"
+    \endrst
+  */
+  template <typename T> void push_back(std::reference_wrapper<T> arg) {
+    static_assert(
+        need_copy<T>::value,
+        "objects of built-in types and string views are always copied");
+    emplace_arg(arg.get());
+  }
+
+  /**
+    Adds named argument into the dynamic store for later passing to a formatting
+    function. ``std::reference_wrapper`` is supported to avoid copying of the
+    argument. The name is always copied into the store.
+  */
+  template <typename T>
+  void push_back(const detail::named_arg<char_type, T>& arg) {
+    const char_type* arg_name =
+        dynamic_args_.push<std::basic_string<char_type>>(arg.name).c_str();
+    if (detail::const_check(need_copy<T>::value)) {
+      emplace_arg(
+          fmt::arg(arg_name, dynamic_args_.push<stored_type<T>>(arg.value)));
+    } else {
+      emplace_arg(fmt::arg(arg_name, arg.value));
+    }
+  }
+
+  /** Erase all elements from the store */
+  void clear() {
+    data_.clear();
+    named_info_.clear();
+    dynamic_args_ = detail::dynamic_arg_list();
+  }
+
+  /**
+    \rst
+    Reserves space to store at least *new_cap* arguments including
+    *new_cap_named* named arguments.
+    \endrst
+  */
+  void reserve(size_t new_cap, size_t new_cap_named) {
+    FMT_ASSERT(new_cap >= new_cap_named,
+               "Set of arguments includes set of named arguments");
+    data_.reserve(new_cap);
+    named_info_.reserve(new_cap_named);
+  }
+};
+
+FMT_END_NAMESPACE
+
+#endif  // FMT_ARGS_H_

deps/fmt/include/fmt/color.h

@@ -10,7 +10,15 @@
 
 #include "format.h"
 
+// __declspec(deprecated) is broken in some MSVC versions.
+#if FMT_MSC_VER
+#  define FMT_DEPRECATED_NONMSVC
+#else
+#  define FMT_DEPRECATED_NONMSVC FMT_DEPRECATED
+#endif
+
 FMT_BEGIN_NAMESPACE
+FMT_MODULE_EXPORT_BEGIN
 
 enum class color : uint32_t {
   alice_blue = 0xF0F8FF,               // rgb(240,248,255)
@@ -177,9 +185,13 @@ enum class terminal_color : uint8_t {
 
 enum class emphasis : uint8_t {
   bold = 1,
-  italic = 1 << 1,
+  faint = 1 << 1,
-  underline = 1 << 2,
+  italic = 1 << 2,
-  strikethrough = 1 << 3
+  underline = 1 << 3,
+  blink = 1 << 4,
+  reverse = 1 << 5,
+  conceal = 1 << 6,
+  strikethrough = 1 << 7,
 };
 
 // rgb is a struct for red, green and blue colors.
@@ -198,7 +210,7 @@ struct rgb {
   uint8_t b;
 };
 
-namespace detail {
+FMT_BEGIN_DETAIL_NAMESPACE
 
 // color is a struct of either a rgb color or a terminal color.
 struct color_type {
@@ -221,9 +233,10 @@ struct color_type {
     uint32_t rgb_color;
   } value;
 };
-}  // namespace detail
 
-// Experimental text formatting support.
+FMT_END_DETAIL_NAMESPACE
+
+/** A text style consisting of foreground and background colors and emphasis. */
 class text_style {
  public:
   FMT_CONSTEXPR text_style(emphasis em = emphasis()) FMT_NOEXCEPT
@@ -260,33 +273,14 @@ class text_style {
     return lhs |= rhs;
   }
 
-  FMT_CONSTEXPR text_style& operator&=(const text_style& rhs) {
+  FMT_DEPRECATED_NONMSVC FMT_CONSTEXPR text_style& operator&=(
-    if (!set_foreground_color) {
-      set_foreground_color = rhs.set_foreground_color;
-      foreground_color = rhs.foreground_color;
-    } else if (rhs.set_foreground_color) {
-      if (!foreground_color.is_rgb || !rhs.foreground_color.is_rgb)
-        FMT_THROW(format_error("can't AND a terminal color"));
-      foreground_color.value.rgb_color &= rhs.foreground_color.value.rgb_color;
-    }
-
-    if (!set_background_color) {
-      set_background_color = rhs.set_background_color;
-      background_color = rhs.background_color;
-    } else if (rhs.set_background_color) {
-      if (!background_color.is_rgb || !rhs.background_color.is_rgb)
-        FMT_THROW(format_error("can't AND a terminal color"));
-      background_color.value.rgb_color &= rhs.background_color.value.rgb_color;
-    }
-
-    ems = static_cast<emphasis>(static_cast<uint8_t>(ems) &
-                                static_cast<uint8_t>(rhs.ems));
-    return *this;
-  }
-
-  friend FMT_CONSTEXPR text_style operator&(text_style lhs,
       const text_style& rhs) {
-    return lhs &= rhs;
+    return and_assign(rhs);
+  }
+
+  FMT_DEPRECATED_NONMSVC friend FMT_CONSTEXPR text_style
+  operator&(text_style lhs, const text_style& rhs) {
+    return lhs.and_assign(rhs);
   }
 
   FMT_CONSTEXPR bool has_foreground() const FMT_NOEXCEPT {
@@ -326,8 +320,34 @@ class text_style {
     }
   }
 
+  // DEPRECATED!
+  FMT_CONSTEXPR text_style& and_assign(const text_style& rhs) {
+    if (!set_foreground_color) {
+      set_foreground_color = rhs.set_foreground_color;
+      foreground_color = rhs.foreground_color;
+    } else if (rhs.set_foreground_color) {
+      if (!foreground_color.is_rgb || !rhs.foreground_color.is_rgb)
+        FMT_THROW(format_error("can't AND a terminal color"));
+      foreground_color.value.rgb_color &= rhs.foreground_color.value.rgb_color;
+    }
+
+    if (!set_background_color) {
+      set_background_color = rhs.set_background_color;
+      background_color = rhs.background_color;
+    } else if (rhs.set_background_color) {
+      if (!background_color.is_rgb || !rhs.background_color.is_rgb)
+        FMT_THROW(format_error("can't AND a terminal color"));
+      background_color.value.rgb_color &= rhs.background_color.value.rgb_color;
+    }
+
+    ems = static_cast<emphasis>(static_cast<uint8_t>(ems) &
+                                static_cast<uint8_t>(rhs.ems));
+    return *this;
+  }
+
   friend FMT_CONSTEXPR_DECL text_style fg(detail::color_type foreground)
       FMT_NOEXCEPT;
+
   friend FMT_CONSTEXPR_DECL text_style bg(detail::color_type background)
       FMT_NOEXCEPT;
 
@@ -338,19 +358,22 @@ class text_style {
   emphasis ems;
 };
 
-FMT_CONSTEXPR text_style fg(detail::color_type foreground) FMT_NOEXCEPT {
+/** Creates a text style from the foreground (text) color. */
-  return text_style(/*is_foreground=*/true, foreground);
+FMT_CONSTEXPR inline text_style fg(detail::color_type foreground) FMT_NOEXCEPT {
+  return text_style(true, foreground);
 }
 
-FMT_CONSTEXPR text_style bg(detail::color_type background) FMT_NOEXCEPT {
+/** Creates a text style from the background color. */
-  return text_style(/*is_foreground=*/false, background);
+FMT_CONSTEXPR inline text_style bg(detail::color_type background) FMT_NOEXCEPT {
+  return text_style(false, background);
 }
 
-FMT_CONSTEXPR text_style operator|(emphasis lhs, emphasis rhs) FMT_NOEXCEPT {
+FMT_CONSTEXPR inline text_style operator|(emphasis lhs,
+                                          emphasis rhs) FMT_NOEXCEPT {
   return text_style(lhs) | rhs;
 }
 
-namespace detail {
+FMT_BEGIN_DETAIL_NAMESPACE
 
 template <typename Char> struct ansi_color_escape {
   FMT_CONSTEXPR ansi_color_escape(detail::color_type text_color,
@@ -358,7 +381,7 @@ template <typename Char> struct ansi_color_escape {
     // If we have a terminal color, we need to output another escape code
     // sequence.
     if (!text_color.is_rgb) {
-      bool is_background = esc == detail::data::background_color;
+      bool is_background = esc == string_view("\x1b[48;2;");
       uint32_t value = text_color.value.term_color;
       // Background ASCII codes are the same as the foreground ones but with
       // 10 more.
@@ -390,16 +413,18 @@ template <typename Char> struct ansi_color_escape {
     buffer[19] = static_cast<Char>(0);
   }
   FMT_CONSTEXPR ansi_color_escape(emphasis em) FMT_NOEXCEPT {
-    uint8_t em_codes[4] = {};
+    uint8_t em_codes[num_emphases] = {};
-    uint8_t em_bits = static_cast<uint8_t>(em);
+    if (has_emphasis(em, emphasis::bold)) em_codes[0] = 1;
-    if (em_bits & static_cast<uint8_t>(emphasis::bold)) em_codes[0] = 1;
+    if (has_emphasis(em, emphasis::faint)) em_codes[1] = 2;
-    if (em_bits & static_cast<uint8_t>(emphasis::italic)) em_codes[1] = 3;
+    if (has_emphasis(em, emphasis::italic)) em_codes[2] = 3;
-    if (em_bits & static_cast<uint8_t>(emphasis::underline)) em_codes[2] = 4;
+    if (has_emphasis(em, emphasis::underline)) em_codes[3] = 4;
-    if (em_bits & static_cast<uint8_t>(emphasis::strikethrough))
+    if (has_emphasis(em, emphasis::blink)) em_codes[4] = 5;
-      em_codes[3] = 9;
+    if (has_emphasis(em, emphasis::reverse)) em_codes[5] = 7;
+    if (has_emphasis(em, emphasis::conceal)) em_codes[6] = 8;
+    if (has_emphasis(em, emphasis::strikethrough)) em_codes[7] = 9;
 
     size_t index = 0;
-    for (int i = 0; i < 4; ++i) {
+    for (size_t i = 0; i < num_emphases; ++i) {
       if (!em_codes[i]) continue;
       buffer[index++] = static_cast<Char>('\x1b');
       buffer[index++] = static_cast<Char>('[');
@@ -411,12 +436,13 @@ template <typename Char> struct ansi_color_escape {
   FMT_CONSTEXPR operator const Char*() const FMT_NOEXCEPT { return buffer; }
 
   FMT_CONSTEXPR const Char* begin() const FMT_NOEXCEPT { return buffer; }
-  FMT_CONSTEXPR const Char* end() const FMT_NOEXCEPT {
+  FMT_CONSTEXPR_CHAR_TRAITS const Char* end() const FMT_NOEXCEPT {
     return buffer + std::char_traits<Char>::length(buffer);
   }
 
  private:
-  Char buffer[7u + 3u * 4u + 1u];
+  static constexpr size_t num_emphases = 8;
+  Char buffer[7u + 3u * num_emphases + 1u];
 
   static FMT_CONSTEXPR void to_esc(uint8_t c, Char* out,
                                    char delimiter) FMT_NOEXCEPT {
@@ -425,18 +451,22 @@ template <typename Char> struct ansi_color_escape {
     out[2] = static_cast<Char>('0' + c % 10);
     out[3] = static_cast<Char>(delimiter);
   }
+  static FMT_CONSTEXPR bool has_emphasis(emphasis em,
+                                         emphasis mask) FMT_NOEXCEPT {
+    return static_cast<uint8_t>(em) & static_cast<uint8_t>(mask);
+  }
 };
 
 template <typename Char>
 FMT_CONSTEXPR ansi_color_escape<Char> make_foreground_color(
     detail::color_type foreground) FMT_NOEXCEPT {
-  return ansi_color_escape<Char>(foreground, detail::data::foreground_color);
+  return ansi_color_escape<Char>(foreground, "\x1b[38;2;");
 }
 
 template <typename Char>
 FMT_CONSTEXPR ansi_color_escape<Char> make_background_color(
     detail::color_type background) FMT_NOEXCEPT {
-  return ansi_color_escape<Char>(background, detail::data::background_color);
+  return ansi_color_escape<Char>(background, "\x1b[48;2;");
 }
 
 template <typename Char>
@@ -455,18 +485,17 @@ inline void fputs<wchar_t>(const wchar_t* chars, FILE* stream) FMT_NOEXCEPT {
 }
 
 template <typename Char> inline void reset_color(FILE* stream) FMT_NOEXCEPT {
-  fputs(detail::data::reset_color, stream);
+  fputs("\x1b[0m", stream);
 }
 
 template <> inline void reset_color<wchar_t>(FILE* stream) FMT_NOEXCEPT {
-  fputs(detail::data::wreset_color, stream);
+  fputs(L"\x1b[0m", stream);
 }
 
 template <typename Char>
 inline void reset_color(buffer<Char>& buffer) FMT_NOEXCEPT {
-  const char* begin = data::reset_color;
+  auto reset_color = string_view("\x1b[0m");
-  const char* end = begin + sizeof(data::reset_color) - 1;
+  buffer.append(reset_color.begin(), reset_color.end());
-  buffer.append(begin, end);
 }
 
 template <typename Char>
@@ -489,10 +518,11 @@ void vformat_to(buffer<Char>& buf, const text_style& ts,
     auto background = detail::make_background_color<Char>(ts.get_background());
     buf.append(background.begin(), background.end());
   }
-  detail::vformat_to(buf, format_str, args);
+  detail::vformat_to(buf, format_str, args, {});
   if (has_style) detail::reset_color<Char>(buf);
 }
-}  // namespace detail
+
+FMT_END_DETAIL_NAMESPACE
 
 template <typename S, typename Char = char_t<S>>
 void vprint(std::FILE* f, const text_style& ts, const S& format,
@@ -523,11 +553,15 @@ void print(std::FILE* f, const text_style& ts, const S& format_str,
 }
 
 /**
+  \rst
   Formats a string and prints it to stdout using ANSI escape sequences to
   specify text formatting.
-  Example:
+
+  **Example**::
+
     fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
                "Elapsed time: {0:.2f} seconds", 1.23);
+  \endrst
  */
 template <typename S, typename... Args,
           FMT_ENABLE_IF(detail::is_string<S>::value)>
@@ -559,7 +593,7 @@ inline std::basic_string<Char> vformat(
 template <typename S, typename... Args, typename Char = char_t<S>>
 inline std::basic_string<Char> format(const text_style& ts, const S& format_str,
                                       const Args&... args) {
-  return vformat(ts, to_string_view(format_str),
+  return fmt::vformat(ts, to_string_view(format_str),
                       fmt::make_args_checked<Args...>(format_str, args...));
 }
 
@@ -571,7 +605,7 @@ template <typename OutputIt, typename Char,
 OutputIt vformat_to(
     OutputIt out, const text_style& ts, basic_string_view<Char> format_str,
     basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-  decltype(detail::get_buffer<Char>(out)) buf(detail::get_buffer_init(out));
+  auto&& buf = detail::get_buffer<Char>(out);
   detail::vformat_to(buf, ts, format_str, args);
   return detail::get_iterator(buf);
 }
@@ -598,6 +632,7 @@ inline auto format_to(OutputIt out, const text_style& ts, const S& format_str,
                     fmt::make_args_checked<Args...>(format_str, args...));
 }
 
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_COLOR_H_

deps/fmt/include/fmt/compile.h

@@ -8,13 +8,135 @@
 #ifndef FMT_COMPILE_H_
 #define FMT_COMPILE_H_
 
-#include <vector>
-
 #include "format.h"
 
 FMT_BEGIN_NAMESPACE
 namespace detail {
 
+// An output iterator that counts the number of objects written to it and
+// discards them.
+class counting_iterator {
+ private:
+  size_t count_;
+
+ public:
+  using iterator_category = std::output_iterator_tag;
+  using difference_type = std::ptrdiff_t;
+  using pointer = void;
+  using reference = void;
+  using _Unchecked_type = counting_iterator;  // Mark iterator as checked.
+
+  struct value_type {
+    template <typename T> void operator=(const T&) {}
+  };
+
+  counting_iterator() : count_(0) {}
+
+  size_t count() const { return count_; }
+
+  counting_iterator& operator++() {
+    ++count_;
+    return *this;
+  }
+  counting_iterator operator++(int) {
+    auto it = *this;
+    ++*this;
+    return it;
+  }
+
+  friend counting_iterator operator+(counting_iterator it, difference_type n) {
+    it.count_ += static_cast<size_t>(n);
+    return it;
+  }
+
+  value_type operator*() const { return {}; }
+};
+
+template <typename Char, typename InputIt>
+inline counting_iterator copy_str(InputIt begin, InputIt end,
+                                  counting_iterator it) {
+  return it + (end - begin);
+}
+
+template <typename OutputIt> class truncating_iterator_base {
+ protected:
+  OutputIt out_;
+  size_t limit_;
+  size_t count_ = 0;
+
+  truncating_iterator_base() : out_(), limit_(0) {}
+
+  truncating_iterator_base(OutputIt out, size_t limit)
+      : out_(out), limit_(limit) {}
+
+ public:
+  using iterator_category = std::output_iterator_tag;
+  using value_type = typename std::iterator_traits<OutputIt>::value_type;
+  using difference_type = std::ptrdiff_t;
+  using pointer = void;
+  using reference = void;
+  using _Unchecked_type =
+      truncating_iterator_base;  // Mark iterator as checked.
+
+  OutputIt base() const { return out_; }
+  size_t count() const { return count_; }
+};
+
+// An output iterator that truncates the output and counts the number of objects
+// written to it.
+template <typename OutputIt,
+          typename Enable = typename std::is_void<
+              typename std::iterator_traits<OutputIt>::value_type>::type>
+class truncating_iterator;
+
+template <typename OutputIt>
+class truncating_iterator<OutputIt, std::false_type>
+    : public truncating_iterator_base<OutputIt> {
+  mutable typename truncating_iterator_base<OutputIt>::value_type blackhole_;
+
+ public:
+  using value_type = typename truncating_iterator_base<OutputIt>::value_type;
+
+  truncating_iterator() = default;
+
+  truncating_iterator(OutputIt out, size_t limit)
+      : truncating_iterator_base<OutputIt>(out, limit) {}
+
+  truncating_iterator& operator++() {
+    if (this->count_++ < this->limit_) ++this->out_;
+    return *this;
+  }
+
+  truncating_iterator operator++(int) {
+    auto it = *this;
+    ++*this;
+    return it;
+  }
+
+  value_type& operator*() const {
+    return this->count_ < this->limit_ ? *this->out_ : blackhole_;
+  }
+};
+
+template <typename OutputIt>
+class truncating_iterator<OutputIt, std::true_type>
+    : public truncating_iterator_base<OutputIt> {
+ public:
+  truncating_iterator() = default;
+
+  truncating_iterator(OutputIt out, size_t limit)
+      : truncating_iterator_base<OutputIt>(out, limit) {}
+
+  template <typename T> truncating_iterator& operator=(T val) {
+    if (this->count_++ < this->limit_) *this->out_++ = val;
+    return *this;
+  }
+
+  truncating_iterator& operator++() { return *this; }
+  truncating_iterator& operator++(int) { return *this; }
+  truncating_iterator& operator*() { return *this; }
+};
+
 // A compile-time string which is compiled into fast formatting code.
 class compiled_string {};
 
@@ -34,336 +156,30 @@ struct is_compiled_string : std::is_base_of<compiled_string, S> {};
     std::string s = fmt::format(FMT_COMPILE("{}"), 42);
   \endrst
  */
-#define FMT_COMPILE(s) FMT_STRING_IMPL(s, fmt::detail::compiled_string)
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+#  define FMT_COMPILE(s) \
+    FMT_STRING_IMPL(s, fmt::detail::compiled_string, explicit)
+#else
+#  define FMT_COMPILE(s) FMT_STRING(s)
+#endif
+
+#if FMT_USE_NONTYPE_TEMPLATE_PARAMETERS
+template <typename Char, size_t N,
+          fmt::detail_exported::fixed_string<Char, N> Str>
+struct udl_compiled_string : compiled_string {
+  using char_type = Char;
+  constexpr operator basic_string_view<char_type>() const {
+    return {Str.data, N - 1};
+  }
+};
+#endif
 
 template <typename T, typename... Tail>
 const T& first(const T& value, const Tail&...) {
   return value;
 }
 
-// Part of a compiled format string. It can be either literal text or a
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
-// replacement field.
-template <typename Char> struct format_part {
-  enum class kind { arg_index, arg_name, text, replacement };
-
-  struct replacement {
-    arg_ref<Char> arg_id;
-    dynamic_format_specs<Char> specs;
-  };
-
-  kind part_kind;
-  union value {
-    int arg_index;
-    basic_string_view<Char> str;
-    replacement repl;
-
-    FMT_CONSTEXPR value(int index = 0) : arg_index(index) {}
-    FMT_CONSTEXPR value(basic_string_view<Char> s) : str(s) {}
-    FMT_CONSTEXPR value(replacement r) : repl(r) {}
-  } val;
-  // Position past the end of the argument id.
-  const Char* arg_id_end = nullptr;
-
-  FMT_CONSTEXPR format_part(kind k = kind::arg_index, value v = {})
-      : part_kind(k), val(v) {}
-
-  static FMT_CONSTEXPR format_part make_arg_index(int index) {
-    return format_part(kind::arg_index, index);
-  }
-  static FMT_CONSTEXPR format_part make_arg_name(basic_string_view<Char> name) {
-    return format_part(kind::arg_name, name);
-  }
-  static FMT_CONSTEXPR format_part make_text(basic_string_view<Char> text) {
-    return format_part(kind::text, text);
-  }
-  static FMT_CONSTEXPR format_part make_replacement(replacement repl) {
-    return format_part(kind::replacement, repl);
-  }
-};
-
-template <typename Char> struct part_counter {
-  unsigned num_parts = 0;
-
-  FMT_CONSTEXPR void on_text(const Char* begin, const Char* end) {
-    if (begin != end) ++num_parts;
-  }
-
-  FMT_CONSTEXPR int on_arg_id() { return ++num_parts, 0; }
-  FMT_CONSTEXPR int on_arg_id(int) { return ++num_parts, 0; }
-  FMT_CONSTEXPR int on_arg_id(basic_string_view<Char>) {
-    return ++num_parts, 0;
-  }
-
-  FMT_CONSTEXPR void on_replacement_field(int, const Char*) {}
-
-  FMT_CONSTEXPR const Char* on_format_specs(int, const Char* begin,
-                                            const Char* end) {
-    // Find the matching brace.
-    unsigned brace_counter = 0;
-    for (; begin != end; ++begin) {
-      if (*begin == '{') {
-        ++brace_counter;
-      } else if (*begin == '}') {
-        if (brace_counter == 0u) break;
-        --brace_counter;
-      }
-    }
-    return begin;
-  }
-
-  FMT_CONSTEXPR void on_error(const char*) {}
-};
-
-// Counts the number of parts in a format string.
-template <typename Char>
-FMT_CONSTEXPR unsigned count_parts(basic_string_view<Char> format_str) {
-  part_counter<Char> counter;
-  parse_format_string<true>(format_str, counter);
-  return counter.num_parts;
-}
-
-template <typename Char, typename PartHandler>
-class format_string_compiler : public error_handler {
- private:
-  using part = format_part<Char>;
-
-  PartHandler handler_;
-  part part_;
-  basic_string_view<Char> format_str_;
-  basic_format_parse_context<Char> parse_context_;
-
- public:
-  FMT_CONSTEXPR format_string_compiler(basic_string_view<Char> format_str,
-                                       PartHandler handler)
-      : handler_(handler),
-        format_str_(format_str),
-        parse_context_(format_str) {}
-
-  FMT_CONSTEXPR void on_text(const Char* begin, const Char* end) {
-    if (begin != end)
-      handler_(part::make_text({begin, to_unsigned(end - begin)}));
-  }
-
-  FMT_CONSTEXPR int on_arg_id() {
-    part_ = part::make_arg_index(parse_context_.next_arg_id());
-    return 0;
-  }
-
-  FMT_CONSTEXPR int on_arg_id(int id) {
-    parse_context_.check_arg_id(id);
-    part_ = part::make_arg_index(id);
-    return 0;
-  }
-
-  FMT_CONSTEXPR int on_arg_id(basic_string_view<Char> id) {
-    part_ = part::make_arg_name(id);
-    return 0;
-  }
-
-  FMT_CONSTEXPR void on_replacement_field(int, const Char* ptr) {
-    part_.arg_id_end = ptr;
-    handler_(part_);
-  }
-
-  FMT_CONSTEXPR const Char* on_format_specs(int, const Char* begin,
-                                            const Char* end) {
-    auto repl = typename part::replacement();
-    dynamic_specs_handler<basic_format_parse_context<Char>> handler(
-        repl.specs, parse_context_);
-    auto it = parse_format_specs(begin, end, handler);
-    if (*it != '}') on_error("missing '}' in format string");
-    repl.arg_id = part_.part_kind == part::kind::arg_index
-                      ? arg_ref<Char>(part_.val.arg_index)
-                      : arg_ref<Char>(part_.val.str);
-    auto part = part::make_replacement(repl);
-    part.arg_id_end = begin;
-    handler_(part);
-    return it;
-  }
-};
-
-// Compiles a format string and invokes handler(part) for each parsed part.
-template <bool IS_CONSTEXPR, typename Char, typename PartHandler>
-FMT_CONSTEXPR void compile_format_string(basic_string_view<Char> format_str,
-                                         PartHandler handler) {
-  parse_format_string<IS_CONSTEXPR>(
-      format_str,
-      format_string_compiler<Char, PartHandler>(format_str, handler));
-}
-
-template <typename OutputIt, typename Context, typename Id>
-void format_arg(
-    basic_format_parse_context<typename Context::char_type>& parse_ctx,
-    Context& ctx, Id arg_id) {
-  ctx.advance_to(visit_format_arg(
-      arg_formatter<OutputIt, typename Context::char_type>(ctx, &parse_ctx),
-      ctx.arg(arg_id)));
-}
-
-// vformat_to is defined in a subnamespace to prevent ADL.
-namespace cf {
-template <typename Context, typename OutputIt, typename CompiledFormat>
-auto vformat_to(OutputIt out, CompiledFormat& cf,
-                basic_format_args<Context> args) -> typename Context::iterator {
-  using char_type = typename Context::char_type;
-  basic_format_parse_context<char_type> parse_ctx(
-      to_string_view(cf.format_str_));
-  Context ctx(out, args);
-
-  const auto& parts = cf.parts();
-  for (auto part_it = std::begin(parts); part_it != std::end(parts);
-       ++part_it) {
-    const auto& part = *part_it;
-    const auto& value = part.val;
-
-    using format_part_t = format_part<char_type>;
-    switch (part.part_kind) {
-    case format_part_t::kind::text: {
-      const auto text = value.str;
-      auto output = ctx.out();
-      auto&& it = reserve(output, text.size());
-      it = std::copy_n(text.begin(), text.size(), it);
-      ctx.advance_to(output);
-      break;
-    }
-
-    case format_part_t::kind::arg_index:
-      advance_to(parse_ctx, part.arg_id_end);
-      detail::format_arg<OutputIt>(parse_ctx, ctx, value.arg_index);
-      break;
-
-    case format_part_t::kind::arg_name:
-      advance_to(parse_ctx, part.arg_id_end);
-      detail::format_arg<OutputIt>(parse_ctx, ctx, value.str);
-      break;
-
-    case format_part_t::kind::replacement: {
-      const auto& arg_id_value = value.repl.arg_id.val;
-      const auto arg = value.repl.arg_id.kind == arg_id_kind::index
-                           ? ctx.arg(arg_id_value.index)
-                           : ctx.arg(arg_id_value.name);
-
-      auto specs = value.repl.specs;
-
-      handle_dynamic_spec<width_checker>(specs.width, specs.width_ref, ctx);
-      handle_dynamic_spec<precision_checker>(specs.precision,
-                                             specs.precision_ref, ctx);
-
-      error_handler h;
-      numeric_specs_checker<error_handler> checker(h, arg.type());
-      if (specs.align == align::numeric) checker.require_numeric_argument();
-      if (specs.sign != sign::none) checker.check_sign();
-      if (specs.alt) checker.require_numeric_argument();
-      if (specs.precision >= 0) checker.check_precision();
-
-      advance_to(parse_ctx, part.arg_id_end);
-      ctx.advance_to(
-          visit_format_arg(arg_formatter<OutputIt, typename Context::char_type>(
-                               ctx, nullptr, &specs),
-                           arg));
-      break;
-    }
-    }
-  }
-  return ctx.out();
-}
-}  // namespace cf
-
-struct basic_compiled_format {};
-
-template <typename S, typename = void>
-struct compiled_format_base : basic_compiled_format {
-  using char_type = char_t<S>;
-  using parts_container = std::vector<detail::format_part<char_type>>;
-
-  parts_container compiled_parts;
-
-  explicit compiled_format_base(basic_string_view<char_type> format_str) {
-    compile_format_string<false>(format_str,
-                                 [this](const format_part<char_type>& part) {
-                                   compiled_parts.push_back(part);
-                                 });
-  }
-
-  const parts_container& parts() const { return compiled_parts; }
-};
-
-template <typename Char, unsigned N> struct format_part_array {
-  format_part<Char> data[N] = {};
-  FMT_CONSTEXPR format_part_array() = default;
-};
-
-template <typename Char, unsigned N>
-FMT_CONSTEXPR format_part_array<Char, N> compile_to_parts(
-    basic_string_view<Char> format_str) {
-  format_part_array<Char, N> parts;
-  unsigned counter = 0;
-  // This is not a lambda for compatibility with older compilers.
-  struct {
-    format_part<Char>* parts;
-    unsigned* counter;
-    FMT_CONSTEXPR void operator()(const format_part<Char>& part) {
-      parts[(*counter)++] = part;
-    }
-  } collector{parts.data, &counter};
-  compile_format_string<true>(format_str, collector);
-  if (counter < N) {
-    parts.data[counter] =
-        format_part<Char>::make_text(basic_string_view<Char>());
-  }
-  return parts;
-}
-
-template <typename T> constexpr const T& constexpr_max(const T& a, const T& b) {
-  return (a < b) ? b : a;
-}
-
-template <typename S>
-struct compiled_format_base<S, enable_if_t<is_compile_string<S>::value>>
-    : basic_compiled_format {
-  using char_type = char_t<S>;
-
-  FMT_CONSTEXPR explicit compiled_format_base(basic_string_view<char_type>) {}
-
-// Workaround for old compilers. Format string compilation will not be
-// performed there anyway.
-#if FMT_USE_CONSTEXPR
-  static FMT_CONSTEXPR_DECL const unsigned num_format_parts =
-      constexpr_max(count_parts(to_string_view(S())), 1u);
-#else
-  static const unsigned num_format_parts = 1;
-#endif
-
-  using parts_container = format_part<char_type>[num_format_parts];
-
-  const parts_container& parts() const {
-    static FMT_CONSTEXPR_DECL const auto compiled_parts =
-        compile_to_parts<char_type, num_format_parts>(
-            detail::to_string_view(S()));
-    return compiled_parts.data;
-  }
-};
-
-template <typename S, typename... Args>
-class compiled_format : private compiled_format_base<S> {
- public:
-  using typename compiled_format_base<S>::char_type;
-
- private:
-  basic_string_view<char_type> format_str_;
-
-  template <typename Context, typename OutputIt, typename CompiledFormat>
-  friend auto cf::vformat_to(OutputIt out, CompiledFormat& cf,
-                             basic_format_args<Context> args) ->
-      typename Context::iterator;
-
- public:
-  compiled_format() = delete;
-  explicit constexpr compiled_format(basic_string_view<char_type> format_str)
-      : compiled_format_base<S>(format_str), format_str_(format_str) {}
-};
-
-#ifdef __cpp_if_constexpr
 template <typename... Args> struct type_list {};
 
 // Returns a reference to the argument at index N from [first, rest...].
@@ -374,13 +190,20 @@ constexpr const auto& get([[maybe_unused]] const T& first,
   if constexpr (N == 0)
     return first;
   else
-    return get<N - 1>(rest...);
+    return detail::get<N - 1>(rest...);
+}
+
+template <typename Char, typename... Args>
+constexpr int get_arg_index_by_name(basic_string_view<Char> name,
+                                    type_list<Args...>) {
+  return get_arg_index_by_name<Args...>(name);
 }
 
 template <int N, typename> struct get_type_impl;
 
 template <int N, typename... Args> struct get_type_impl<N, type_list<Args...>> {
-  using type = remove_cvref_t<decltype(get<N>(std::declval<Args>()...))>;
+  using type =
+      remove_cvref_t<decltype(detail::get<N>(std::declval<Args>()...))>;
 };
 
 template <int N, typename T>
@@ -393,7 +216,7 @@ template <typename Char> struct text {
   using char_type = Char;
 
   template <typename OutputIt, typename... Args>
-  OutputIt format(OutputIt out, const Args&...) const {
+  constexpr OutputIt format(OutputIt out, const Args&...) const {
     return write<Char>(out, data);
   }
 };
@@ -412,11 +235,22 @@ template <typename Char> struct code_unit {
   using char_type = Char;
 
   template <typename OutputIt, typename... Args>
-  OutputIt format(OutputIt out, const Args&...) const {
+  constexpr OutputIt format(OutputIt out, const Args&...) const {
     return write<Char>(out, value);
   }
 };
 
+// This ensures that the argument type is convertible to `const T&`.
+template <typename T, int N, typename... Args>
+constexpr const T& get_arg_checked(const Args&... args) {
+  const auto& arg = detail::get<N>(args...);
+  if constexpr (detail::is_named_arg<remove_cvref_t<decltype(arg)>>()) {
+    return arg.value;
+  } else {
+    return arg;
+  }
+}
+
 template <typename Char>
 struct is_compiled_format<code_unit<Char>> : std::true_type {};
 
@@ -425,29 +259,58 @@ template <typename Char, typename T, int N> struct field {
   using char_type = Char;
 
   template <typename OutputIt, typename... Args>
-  OutputIt format(OutputIt out, const Args&... args) const {
+  constexpr OutputIt format(OutputIt out, const Args&... args) const {
-    // This ensures that the argument type is convertile to `const T&`.
+    return write<Char>(out, get_arg_checked<T, N>(args...));
-    const T& arg = get<N>(args...);
-    return write<Char>(out, arg);
   }
 };
 
 template <typename Char, typename T, int N>
 struct is_compiled_format<field<Char, T, N>> : std::true_type {};
 
+// A replacement field that refers to argument with name.
+template <typename Char> struct runtime_named_field {
+  using char_type = Char;
+  basic_string_view<Char> name;
+
+  template <typename OutputIt, typename T>
+  constexpr static bool try_format_argument(
+      OutputIt& out,
+      // [[maybe_unused]] due to unused-but-set-parameter warning in GCC 7,8,9
+      [[maybe_unused]] basic_string_view<Char> arg_name, const T& arg) {
+    if constexpr (is_named_arg<typename std::remove_cv<T>::type>::value) {
+      if (arg_name == arg.name) {
+        out = write<Char>(out, arg.value);
+        return true;
+      }
+    }
+    return false;
+  }
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&... args) const {
+    bool found = (try_format_argument(out, name, args) || ...);
+    if (!found) {
+      FMT_THROW(format_error("argument with specified name is not found"));
+    }
+    return out;
+  }
+};
+
+template <typename Char>
+struct is_compiled_format<runtime_named_field<Char>> : std::true_type {};
+
 // A replacement field that refers to argument N and has format specifiers.
 template <typename Char, typename T, int N> struct spec_field {
   using char_type = Char;
-  mutable formatter<T, Char> fmt;
+  formatter<T, Char> fmt;
 
   template <typename OutputIt, typename... Args>
-  OutputIt format(OutputIt out, const Args&... args) const {
+  constexpr FMT_INLINE OutputIt format(OutputIt out,
-    // This ensures that the argument type is convertile to `const T&`.
+                                       const Args&... args) const {
-    const T& arg = get<N>(args...);
     const auto& vargs =
-        make_format_args<basic_format_context<OutputIt, Char>>(args...);
+        fmt::make_format_args<basic_format_context<OutputIt, Char>>(args...);
     basic_format_context<OutputIt, Char> ctx(out, vargs);
-    return fmt.format(arg, ctx);
+    return fmt.format(get_arg_checked<T, N>(args...), ctx);
   }
 };
 
@@ -460,7 +323,7 @@ template <typename L, typename R> struct concat {
   using char_type = typename L::char_type;
 
   template <typename OutputIt, typename... Args>
-  OutputIt format(OutputIt out, const Args&... args) const {
+  constexpr OutputIt format(OutputIt out, const Args&... args) const {
     out = lhs.format(out, args...);
     return rhs.format(out, args...);
   }
@@ -508,14 +371,79 @@ template <typename T, typename Char> struct parse_specs_result {
   int next_arg_id;
 };
 
+constexpr int manual_indexing_id = -1;
+
 template <typename T, typename Char>
 constexpr parse_specs_result<T, Char> parse_specs(basic_string_view<Char> str,
-                                                  size_t pos, int arg_id) {
+                                                  size_t pos, int next_arg_id) {
   str.remove_prefix(pos);
-  auto ctx = basic_format_parse_context<Char>(str, {}, arg_id + 1);
+  auto ctx = basic_format_parse_context<Char>(str, {}, next_arg_id);
   auto f = formatter<T, Char>();
   auto end = f.parse(ctx);
-  return {f, pos + (end - str.data()) + 1, ctx.next_arg_id()};
+  return {f, pos + fmt::detail::to_unsigned(end - str.data()) + 1,
+          next_arg_id == 0 ? manual_indexing_id : ctx.next_arg_id()};
+}
+
+template <typename Char> struct arg_id_handler {
+  arg_ref<Char> arg_id;
+
+  constexpr int operator()() {
+    FMT_ASSERT(false, "handler cannot be used with automatic indexing");
+    return 0;
+  }
+  constexpr int operator()(int id) {
+    arg_id = arg_ref<Char>(id);
+    return 0;
+  }
+  constexpr int operator()(basic_string_view<Char> id) {
+    arg_id = arg_ref<Char>(id);
+    return 0;
+  }
+
+  constexpr void on_error(const char* message) {
+    FMT_THROW(format_error(message));
+  }
+};
+
+template <typename Char> struct parse_arg_id_result {
+  arg_ref<Char> arg_id;
+  const Char* arg_id_end;
+};
+
+template <int ID, typename Char>
+constexpr auto parse_arg_id(const Char* begin, const Char* end) {
+  auto handler = arg_id_handler<Char>{arg_ref<Char>{}};
+  auto arg_id_end = parse_arg_id(begin, end, handler);
+  return parse_arg_id_result<Char>{handler.arg_id, arg_id_end};
+}
+
+template <typename T, typename Enable = void> struct field_type {
+  using type = remove_cvref_t<T>;
+};
+
+template <typename T>
+struct field_type<T, enable_if_t<detail::is_named_arg<T>::value>> {
+  using type = remove_cvref_t<decltype(T::value)>;
+};
+
+template <typename T, typename Args, size_t END_POS, int ARG_INDEX, int NEXT_ID,
+          typename S>
+constexpr auto parse_replacement_field_then_tail(S format_str) {
+  using char_type = typename S::char_type;
+  constexpr auto str = basic_string_view<char_type>(format_str);
+  constexpr char_type c = END_POS != str.size() ? str[END_POS] : char_type();
+  if constexpr (c == '}') {
+    return parse_tail<Args, END_POS + 1, NEXT_ID>(
+        field<char_type, typename field_type<T>::type, ARG_INDEX>(),
+        format_str);
+  } else if constexpr (c == ':') {
+    constexpr auto result = parse_specs<typename field_type<T>::type>(
+        str, END_POS + 1, NEXT_ID == manual_indexing_id ? 0 : NEXT_ID);
+    return parse_tail<Args, result.end, result.next_arg_id>(
+        spec_field<char_type, typename field_type<T>::type, ARG_INDEX>{
+            result.fmt},
+        format_str);
+  }
 }
 
 // Compiles a non-empty format string and returns the compiled representation
@@ -523,27 +451,59 @@ constexpr parse_specs_result<T, Char> parse_specs(basic_string_view<Char> str,
 template <typename Args, size_t POS, int ID, typename S>
 constexpr auto compile_format_string(S format_str) {
   using char_type = typename S::char_type;
-  constexpr basic_string_view<char_type> str = format_str;
+  constexpr auto str = basic_string_view<char_type>(format_str);
   if constexpr (str[POS] == '{') {
-    if (POS + 1 == str.size())
+    if constexpr (POS + 1 == str.size())
-      throw format_error("unmatched '{' in format string");
+      FMT_THROW(format_error("unmatched '{' in format string"));
     if constexpr (str[POS + 1] == '{') {
       return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
-    } else if constexpr (str[POS + 1] == '}') {
+    } else if constexpr (str[POS + 1] == '}' || str[POS + 1] == ':') {
-      using type = get_type<ID, Args>;
+      static_assert(ID != manual_indexing_id,
-      return parse_tail<Args, POS + 2, ID + 1>(field<char_type, type, ID>(),
+                    "cannot switch from manual to automatic argument indexing");
+      constexpr auto next_id =
+          ID != manual_indexing_id ? ID + 1 : manual_indexing_id;
+      return parse_replacement_field_then_tail<get_type<ID, Args>, Args,
+                                               POS + 1, ID, next_id>(
           format_str);
-    } else if constexpr (str[POS + 1] == ':') {
-      using type = get_type<ID, Args>;
-      constexpr auto result = parse_specs<type>(str, POS + 2, ID);
-      return parse_tail<Args, result.end, result.next_arg_id>(
-          spec_field<char_type, type, ID>{result.fmt}, format_str);
     } else {
-      return unknown_format();
+      constexpr auto arg_id_result =
+          parse_arg_id<ID>(str.data() + POS + 1, str.data() + str.size());
+      constexpr auto arg_id_end_pos = arg_id_result.arg_id_end - str.data();
+      constexpr char_type c =
+          arg_id_end_pos != str.size() ? str[arg_id_end_pos] : char_type();
+      static_assert(c == '}' || c == ':', "missing '}' in format string");
+      if constexpr (arg_id_result.arg_id.kind == arg_id_kind::index) {
+        static_assert(
+            ID == manual_indexing_id || ID == 0,
+            "cannot switch from automatic to manual argument indexing");
+        constexpr auto arg_index = arg_id_result.arg_id.val.index;
+        return parse_replacement_field_then_tail<get_type<arg_index, Args>,
+                                                 Args, arg_id_end_pos,
+                                                 arg_index, manual_indexing_id>(
+            format_str);
+      } else if constexpr (arg_id_result.arg_id.kind == arg_id_kind::name) {
+        constexpr auto arg_index =
+            get_arg_index_by_name(arg_id_result.arg_id.val.name, Args{});
+        if constexpr (arg_index != invalid_arg_index) {
+          constexpr auto next_id =
+              ID != manual_indexing_id ? ID + 1 : manual_indexing_id;
+          return parse_replacement_field_then_tail<
+              decltype(get_type<arg_index, Args>::value), Args, arg_id_end_pos,
+              arg_index, next_id>(format_str);
+        } else {
+          if constexpr (c == '}') {
+            return parse_tail<Args, arg_id_end_pos + 1, ID>(
+                runtime_named_field<char_type>{arg_id_result.arg_id.val.name},
+                format_str);
+          } else if constexpr (c == ':') {
+            return unknown_format();  // no type info for specs parsing
+          }
+        }
+      }
     }
   } else if constexpr (str[POS] == '}') {
-    if (POS + 1 == str.size())
+    if constexpr (POS + 1 == str.size())
-      throw format_error("unmatched '}' in format string");
+      FMT_THROW(format_error("unmatched '}' in format string"));
     return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
   } else {
     constexpr auto end = parse_text(str, POS + 1);
@@ -558,144 +518,125 @@ constexpr auto compile_format_string(S format_str) {
 }
 
 template <typename... Args, typename S,
-          FMT_ENABLE_IF(is_compile_string<S>::value ||
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
-                        detail::is_compiled_string<S>::value)>
 constexpr auto compile(S format_str) {
-  constexpr basic_string_view<typename S::char_type> str = format_str;
+  constexpr auto str = basic_string_view<typename S::char_type>(format_str);
   if constexpr (str.size() == 0) {
     return detail::make_text(str, 0, 0);
   } else {
     constexpr auto result =
         detail::compile_format_string<detail::type_list<Args...>, 0, 0>(
             format_str);
-    if constexpr (std::is_same<remove_cvref_t<decltype(result)>,
-                               detail::unknown_format>()) {
-      return detail::compiled_format<S, Args...>(to_string_view(format_str));
-    } else {
     return result;
   }
-  }
-}
-#else
-template <typename... Args, typename S,
-          FMT_ENABLE_IF(is_compile_string<S>::value)>
-constexpr auto compile(S format_str) -> detail::compiled_format<S, Args...> {
-  return detail::compiled_format<S, Args...>(to_string_view(format_str));
-}
-#endif  // __cpp_if_constexpr
-
-// Compiles the format string which must be a string literal.
-template <typename... Args, typename Char, size_t N>
-auto compile(const Char (&format_str)[N])
-    -> detail::compiled_format<const Char*, Args...> {
-  return detail::compiled_format<const Char*, Args...>(
-      basic_string_view<Char>(format_str, N - 1));
 }
+#endif  // defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
 }  // namespace detail
 
-// DEPRECATED! use FMT_COMPILE instead.
+FMT_MODULE_EXPORT_BEGIN
-template <typename... Args>
-FMT_DEPRECATED auto compile(const Args&... args)
-    -> decltype(detail::compile(args...)) {
-  return detail::compile(args...);
-}
 
-#if FMT_USE_CONSTEXPR
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
-#  ifdef __cpp_if_constexpr
 
 template <typename CompiledFormat, typename... Args,
           typename Char = typename CompiledFormat::char_type,
           FMT_ENABLE_IF(detail::is_compiled_format<CompiledFormat>::value)>
 FMT_INLINE std::basic_string<Char> format(const CompiledFormat& cf,
                                           const Args&... args) {
-  basic_memory_buffer<Char> buffer;
+  auto s = std::basic_string<Char>();
-  cf.format(detail::buffer_appender<Char>(buffer), args...);
+  cf.format(std::back_inserter(s), args...);
-  return to_string(buffer);
+  return s;
 }
 
 template <typename OutputIt, typename CompiledFormat, typename... Args,
           FMT_ENABLE_IF(detail::is_compiled_format<CompiledFormat>::value)>
-OutputIt format_to(OutputIt out, const CompiledFormat& cf,
+constexpr FMT_INLINE OutputIt format_to(OutputIt out, const CompiledFormat& cf,
                                         const Args&... args) {
   return cf.format(out, args...);
 }
-#  endif  // __cpp_if_constexpr
-#endif    // FMT_USE_CONSTEXPR
-
-template <typename CompiledFormat, typename... Args,
-          typename Char = typename CompiledFormat::char_type,
-          FMT_ENABLE_IF(std::is_base_of<detail::basic_compiled_format,
-                                        CompiledFormat>::value)>
-std::basic_string<Char> format(const CompiledFormat& cf, const Args&... args) {
-  basic_memory_buffer<Char> buffer;
-  using context = buffer_context<Char>;
-  detail::cf::vformat_to<context>(detail::buffer_appender<Char>(buffer), cf,
-                                  make_format_args<context>(args...));
-  return to_string(buffer);
-}
 
 template <typename S, typename... Args,
           FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
 FMT_INLINE std::basic_string<typename S::char_type> format(const S&,
                                                            Args&&... args) {
-#ifdef __cpp_if_constexpr
   if constexpr (std::is_same<typename S::char_type, char>::value) {
-    constexpr basic_string_view<typename S::char_type> str = S();
+    constexpr auto str = basic_string_view<typename S::char_type>(S());
-    if (str.size() == 2 && str[0] == '{' && str[1] == '}')
+    if constexpr (str.size() == 2 && str[0] == '{' && str[1] == '}') {
-      return fmt::to_string(detail::first(args...));
+      const auto& first = detail::first(args...);
+      if constexpr (detail::is_named_arg<
+                        remove_cvref_t<decltype(first)>>::value) {
+        return fmt::to_string(first.value);
+      } else {
+        return fmt::to_string(first);
+      }
+    }
   }
-#endif
   constexpr auto compiled = detail::compile<Args...>(S());
+  if constexpr (std::is_same<remove_cvref_t<decltype(compiled)>,
+                             detail::unknown_format>()) {
+    return format(static_cast<basic_string_view<typename S::char_type>>(S()),
+                  std::forward<Args>(args)...);
+  } else {
     return format(compiled, std::forward<Args>(args)...);
-}
+  }
-
-template <typename OutputIt, typename CompiledFormat, typename... Args,
-          FMT_ENABLE_IF(std::is_base_of<detail::basic_compiled_format,
-                                        CompiledFormat>::value)>
-OutputIt format_to(OutputIt out, const CompiledFormat& cf,
-                   const Args&... args) {
-  using char_type = typename CompiledFormat::char_type;
-  using context = format_context_t<OutputIt, char_type>;
-  return detail::cf::vformat_to<context>(out, cf,
-                                         make_format_args<context>(args...));
 }
 
 template <typename OutputIt, typename S, typename... Args,
           FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
-OutputIt format_to(OutputIt out, const S&, const Args&... args) {
+FMT_CONSTEXPR OutputIt format_to(OutputIt out, const S&, Args&&... args) {
   constexpr auto compiled = detail::compile<Args...>(S());
-  return format_to(out, compiled, args...);
+  if constexpr (std::is_same<remove_cvref_t<decltype(compiled)>,
-}
+                             detail::unknown_format>()) {
-
+    return format_to(out,
-template <typename OutputIt, typename CompiledFormat, typename... Args>
+                     static_cast<basic_string_view<typename S::char_type>>(S()),
-auto format_to_n(OutputIt out, size_t n, const CompiledFormat& cf,
+                     std::forward<Args>(args)...);
-                 const Args&... args) ->
+  } else {
-    typename std::enable_if<
+    return format_to(out, compiled, std::forward<Args>(args)...);
-        detail::is_output_iterator<OutputIt,
+  }
-                                   typename CompiledFormat::char_type>::value &&
-            std::is_base_of<detail::basic_compiled_format,
-                            CompiledFormat>::value,
-        format_to_n_result<OutputIt>>::type {
-  auto it =
-      format_to(detail::truncating_iterator<OutputIt>(out, n), cf, args...);
-  return {it.base(), it.count()};
 }
+#endif
 
 template <typename OutputIt, typename S, typename... Args,
           FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
-format_to_n_result<OutputIt> format_to_n(OutputIt out, size_t n, const S&,
+format_to_n_result<OutputIt> format_to_n(OutputIt out, size_t n,
-                                         const Args&... args) {
+                                         const S& format_str, Args&&... args) {
-  constexpr auto compiled = detail::compile<Args...>(S());
+  auto it = format_to(detail::truncating_iterator<OutputIt>(out, n), format_str,
-  auto it = format_to(detail::truncating_iterator<OutputIt>(out, n), compiled,
+                      std::forward<Args>(args)...);
-                      args...);
   return {it.base(), it.count()};
 }
 
-template <typename CompiledFormat, typename... Args>
+template <typename S, typename... Args,
-size_t formatted_size(const CompiledFormat& cf, const Args&... args) {
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
-  return format_to(detail::counting_iterator(), cf, args...).count();
+size_t formatted_size(const S& format_str, const Args&... args) {
+  return format_to(detail::counting_iterator(), format_str, args...).count();
 }
 
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+void print(std::FILE* f, const S& format_str, const Args&... args) {
+  memory_buffer buffer;
+  format_to(std::back_inserter(buffer), format_str, args...);
+  detail::print(f, {buffer.data(), buffer.size()});
+}
+
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+void print(const S& format_str, const Args&... args) {
+  print(stdout, format_str, args...);
+}
+
+#if FMT_USE_NONTYPE_TEMPLATE_PARAMETERS
+inline namespace literals {
+template <detail_exported::fixed_string Str>
+constexpr detail::udl_compiled_string<
+    remove_cvref_t<decltype(Str.data[0])>,
+    sizeof(Str.data) / sizeof(decltype(Str.data[0])), Str>
+operator""_cf() {
+  return {};
+}
+}  // namespace literals
+#endif
+
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_COMPILE_H_

deps/fmt/include/fmt/locale.h

@@ -1,64 +1,2 @@
-// Formatting library for C++ - std::locale support
+#include "xchar.h"
-//
+#warning fmt/locale.h is deprecated, include fmt/format.h or fmt/xchar.h instead
-// Copyright (c) 2012 - present, Victor Zverovich
-// All rights reserved.
-//
-// For the license information refer to format.h.
-
-#ifndef FMT_LOCALE_H_
-#define FMT_LOCALE_H_
-
-#include <locale>
-
-#include "format.h"
-
-FMT_BEGIN_NAMESPACE
-
-namespace detail {
-template <typename Char>
-std::basic_string<Char> vformat(
-    const std::locale& loc, basic_string_view<Char> format_str,
-    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-  basic_memory_buffer<Char> buffer;
-  detail::vformat_to(buffer, format_str, args, detail::locale_ref(loc));
-  return fmt::to_string(buffer);
-}
-}  // namespace detail
-
-template <typename S, typename Char = char_t<S>>
-inline std::basic_string<Char> vformat(
-    const std::locale& loc, const S& format_str,
-    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-  return detail::vformat(loc, to_string_view(format_str), args);
-}
-
-template <typename S, typename... Args, typename Char = char_t<S>>
-inline std::basic_string<Char> format(const std::locale& loc,
-                                      const S& format_str, Args&&... args) {
-  return detail::vformat(loc, to_string_view(format_str),
-                         fmt::make_args_checked<Args...>(format_str, args...));
-}
-
-template <typename S, typename OutputIt, typename... Args,
-          typename Char = char_t<S>,
-          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value)>
-inline OutputIt vformat_to(
-    OutputIt out, const std::locale& loc, const S& format_str,
-    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-  decltype(detail::get_buffer<Char>(out)) buf(detail::get_buffer_init(out));
-  vformat_to(buf, to_string_view(format_str), args, detail::locale_ref(loc));
-  return detail::get_iterator(buf);
-}
-
-template <typename OutputIt, typename S, typename... Args,
-          bool enable = detail::is_output_iterator<OutputIt, char_t<S>>::value>
-inline auto format_to(OutputIt out, const std::locale& loc,
-                      const S& format_str, Args&&... args) ->
-    typename std::enable_if<enable, OutputIt>::type {
-  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
-  return vformat_to(out, loc, to_string_view(format_str), vargs);
-}
-
-FMT_END_NAMESPACE
-
-#endif  // FMT_LOCALE_H_

deps/fmt/include/fmt/os.h

@@ -8,16 +8,12 @@
 #ifndef FMT_OS_H_
 #define FMT_OS_H_
 
-#if defined(__MINGW32__) || defined(__CYGWIN__)
-// Workaround MinGW bug https://sourceforge.net/p/mingw/bugs/2024/.
-#  undef __STRICT_ANSI__
-#endif
-
 #include <cerrno>
-#include <clocale>  // for locale_t
+#include <clocale>  // locale_t
 #include <cstddef>
 #include <cstdio>
-#include <cstdlib>  // for strtod_l
+#include <cstdlib>       // strtod_l
+#include <system_error>  // std::system_error
 
 #if defined __APPLE__ || defined(__FreeBSD__)
 #  include <xlocale.h>  // for LC_NUMERIC_MASK on OS X
@@ -25,17 +21,20 @@
 
 #include "format.h"
 
+#ifndef FMT_USE_FCNTL
 // UWP doesn't provide _pipe.
-#if FMT_HAS_INCLUDE("winapifamily.h")
+#  if FMT_HAS_INCLUDE("winapifamily.h")
 #    include <winapifamily.h>
-#endif
+#  endif
-#if (FMT_HAS_INCLUDE(<fcntl.h>) || defined(__APPLE__) || \
+#  if (FMT_HAS_INCLUDE(<fcntl.h>) || defined(__APPLE__) || \
        defined(__linux__)) &&                              \
-    (!defined(WINAPI_FAMILY) || (WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP))
+      (!defined(WINAPI_FAMILY) ||                          \
+       (WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP))
 #    include <fcntl.h>  // for O_RDONLY
 #    define FMT_USE_FCNTL 1
-#else
+#  else
 #    define FMT_USE_FCNTL 0
+#  endif
 #endif
 
 #ifndef FMT_POSIX
@@ -74,6 +73,7 @@
 #define FMT_RETRY(result, expression) FMT_RETRY_VAL(result, expression, -1)
 
 FMT_BEGIN_NAMESPACE
+FMT_MODULE_EXPORT_BEGIN
 
 /**
   \rst
@@ -122,19 +122,28 @@ template <typename Char> class basic_cstring_view {
 using cstring_view = basic_cstring_view<char>;
 using wcstring_view = basic_cstring_view<wchar_t>;
 
-// An error code.
+template <typename Char> struct formatter<std::error_code, Char> {
-class error_code {
+  template <typename ParseContext>
- private:
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
-  int value_;
+    return ctx.begin();
+  }
 
- public:
+  template <typename FormatContext>
-  explicit error_code(int value = 0) FMT_NOEXCEPT : value_(value) {}
+  FMT_CONSTEXPR auto format(const std::error_code& ec, FormatContext& ctx) const
-
+      -> decltype(ctx.out()) {
-  int get() const FMT_NOEXCEPT { return value_; }
+    auto out = ctx.out();
+    out = detail::write_bytes(out, ec.category().name(),
+                              basic_format_specs<Char>());
+    out = detail::write<Char>(out, Char(':'));
+    out = detail::write<Char>(out, ec.value());
+    return out;
+  }
 };
 
 #ifdef _WIN32
-namespace detail {
+FMT_API const std::error_category& system_category() FMT_NOEXCEPT;
+
+FMT_BEGIN_DETAIL_NAMESPACE
 // A converter from UTF-16 to UTF-8.
 // It is only provided for Windows since other systems support UTF-8 natively.
 class utf16_to_utf8 {
@@ -143,7 +152,7 @@ class utf16_to_utf8 {
 
  public:
   utf16_to_utf8() {}
-  FMT_API explicit utf16_to_utf8(wstring_view s);
+  FMT_API explicit utf16_to_utf8(basic_string_view<wchar_t> s);
   operator string_view() const { return string_view(&buffer_[0], size()); }
   size_t size() const { return buffer_.size() - 1; }
   const char* c_str() const { return &buffer_[0]; }
@@ -152,22 +161,19 @@ class utf16_to_utf8 {
   // Performs conversion returning a system error code instead of
   // throwing exception on conversion error. This method may still throw
   // in case of memory allocation error.
-  FMT_API int convert(wstring_view s);
+  FMT_API int convert(basic_string_view<wchar_t> s);
 };
 
 FMT_API void format_windows_error(buffer<char>& out, int error_code,
-                                  string_view message) FMT_NOEXCEPT;
+                                  const char* message) FMT_NOEXCEPT;
-}  // namespace detail
+FMT_END_DETAIL_NAMESPACE
 
-/** A Windows error. */
+FMT_API std::system_error vwindows_error(int error_code, string_view format_str,
-class windows_error : public system_error {
+                                         format_args args);
- private:
-  FMT_API void init(int error_code, string_view format_str, format_args args);
 
- public:
+/**
-  /**
  \rst
-   Constructs a :class:`fmt::windows_error` object with the description
+ Constructs a :class:`std::system_error` object with the description
  of the form
 
  .. parsed-literal::
@@ -181,7 +187,7 @@ class windows_error : public system_error {
 
  **Example**::
 
-     // This throws a windows_error with the description
+   // This throws a system_error with the description
    //   cannot open file 'madeup': The system cannot find the file specified.
    // or similar (system message may vary).
    const char *filename = "madeup";
@@ -192,19 +198,31 @@ class windows_error : public system_error {
                               "cannot open file '{}'", filename);
    }
  \endrst
-  */
+*/
-  template <typename... Args>
+template <typename... Args>
-  windows_error(int error_code, string_view message, const Args&... args) {
+std::system_error windows_error(int error_code, string_view message,
-    init(error_code, message, make_format_args(args...));
+                                const Args&... args) {
-  }
+  return vwindows_error(error_code, message, fmt::make_format_args(args...));
-};
+}
 
 // Reports a Windows error without throwing an exception.
 // Can be used to report errors from destructors.
 FMT_API void report_windows_error(int error_code,
-                                  string_view message) FMT_NOEXCEPT;
+                                  const char* message) FMT_NOEXCEPT;
+#else
+inline const std::error_category& system_category() FMT_NOEXCEPT {
+  return std::system_category();
+}
 #endif  // _WIN32
 
+// std::system is not available on some platforms such as iOS (#2248).
+#ifdef __OSX__
+template <typename S, typename... Args, typename Char = char_t<S>>
+void say(const S& format_str, Args&&... args) {
+  std::system(format("say \"{}\"", format(format_str, args...)).c_str());
+}
+#endif
+
 // A buffered file.
 class buffered_file {
  private:
@@ -255,7 +273,7 @@ class buffered_file {
 
   template <typename... Args>
   inline void print(string_view format_str, const Args&... args) {
-    vprint(format_str, make_format_args(args...));
+    vprint(format_str, fmt::make_format_args(args...));
   }
 };
 
@@ -280,7 +298,8 @@ class file {
     WRONLY = FMT_POSIX(O_WRONLY),  // Open for writing only.
     RDWR = FMT_POSIX(O_RDWR),      // Open for reading and writing.
     CREATE = FMT_POSIX(O_CREAT),   // Create if the file doesn't exist.
-    APPEND = FMT_POSIX(O_APPEND)   // Open in append mode.
+    APPEND = FMT_POSIX(O_APPEND),  // Open in append mode.
+    TRUNC = FMT_POSIX(O_TRUNC)     // Truncate the content of the file.
   };
 
   // Constructs a file object which doesn't represent any file.
@@ -295,7 +314,8 @@ class file {
 
   file(file&& other) FMT_NOEXCEPT : fd_(other.fd_) { other.fd_ = -1; }
 
-  file& operator=(file&& other) FMT_NOEXCEPT {
+  // Move assignment is not noexcept because close may throw.
+  file& operator=(file&& other) {
     close();
     fd_ = other.fd_;
     other.fd_ = -1;
@@ -331,7 +351,7 @@ class file {
 
   // Makes fd be the copy of this file descriptor, closing fd first if
   // necessary.
-  FMT_API void dup2(int fd, error_code& ec) FMT_NOEXCEPT;
+  FMT_API void dup2(int fd, std::error_code& ec) FMT_NOEXCEPT;
 
   // Creates a pipe setting up read_end and write_end file objects for reading
   // and writing respectively.
@@ -345,9 +365,10 @@ class file {
 // Returns the memory page size.
 long getpagesize();
 
-namespace detail {
+FMT_BEGIN_DETAIL_NAMESPACE
 
 struct buffer_size {
+  buffer_size() = default;
   size_t value = 0;
   buffer_size operator=(size_t val) const {
     auto bs = buffer_size();
@@ -357,14 +378,14 @@ struct buffer_size {
 };
 
 struct ostream_params {
-  int oflag = file::WRONLY | file::CREATE;
+  int oflag = file::WRONLY | file::CREATE | file::TRUNC;
   size_t buffer_size = BUFSIZ > 32768 ? BUFSIZ : 32768;
 
   ostream_params() {}
 
   template <typename... T>
-  ostream_params(T... params, int oflag) : ostream_params(params...) {
+  ostream_params(T... params, int new_oflag) : ostream_params(params...) {
-    this->oflag = oflag;
+    oflag = new_oflag;
   }
 
   template <typename... T>
@@ -372,23 +393,27 @@ struct ostream_params {
       : ostream_params(params...) {
     this->buffer_size = bs.value;
   }
+
+// Intel has a bug that results in failure to deduce a constructor
+// for empty parameter packs.
+#  if defined(__INTEL_COMPILER) && __INTEL_COMPILER < 2000
+  ostream_params(int new_oflag) : oflag(new_oflag) {}
+  ostream_params(detail::buffer_size bs) : buffer_size(bs.value) {}
+#  endif
 };
-}  // namespace detail
 
-static constexpr detail::buffer_size buffer_size;
+FMT_END_DETAIL_NAMESPACE
 
-// A fast output stream which is not thread-safe.
+// Added {} below to work around default constructor error known to
-class ostream final : private detail::buffer<char> {
+// occur in Xcode versions 7.2.1 and 8.2.1.
+constexpr detail::buffer_size buffer_size{};
+
+/** A fast output stream which is not thread-safe. */
+class FMT_API ostream final : private detail::buffer<char> {
  private:
   file file_;
 
-  void flush() {
+  void grow(size_t) override;
-    if (size() == 0) return;
-    file_.write(data(), size());
-    clear();
-  }
-
-  FMT_API void grow(size_t) override final;
 
   ostream(cstring_view path, const detail::ostream_params& params)
       : file_(path, params.oflag) {
@@ -399,6 +424,7 @@ class ostream final : private detail::buffer<char> {
   ostream(ostream&& other)
       : detail::buffer<char>(other.data(), other.size(), other.capacity()),
         file_(std::move(other.file_)) {
+    other.clear();
     other.set(nullptr, 0);
   }
   ~ostream() {
@@ -406,6 +432,12 @@ class ostream final : private detail::buffer<char> {
     delete[] data();
   }
 
+  void flush() {
+    if (size() == 0) return;
+    file_.write(data(), size());
+    clear();
+  }
+
   template <typename... T>
   friend ostream output_file(cstring_view path, T... params);
 
@@ -414,16 +446,30 @@ class ostream final : private detail::buffer<char> {
     file_.close();
   }
 
-  template <typename S, typename... Args>
+  /**
-  void print(const S& format_str, const Args&... args) {
+    Formats ``args`` according to specifications in ``fmt`` and writes the
-    format_to(detail::buffer_appender<char>(*this), format_str, args...);
+    output to the file.
+   */
+  template <typename... T> void print(format_string<T...> fmt, T&&... args) {
+    vformat_to(detail::buffer_appender<char>(*this), fmt,
+               fmt::make_format_args(args...));
   }
 };
 
 /**
-  Opens a file for writing. Supported parameters passed in `params`:
+  \rst
-  * ``<integer>``: Output flags (``file::WRONLY | file::CREATE`` by default)
+  Opens a file for writing. Supported parameters passed in *params*:
+
+  * ``<integer>``: Flags passed to `open
+    <https://pubs.opengroup.org/onlinepubs/007904875/functions/open.html>`_
+    (``file::WRONLY | file::CREATE`` by default)
   * ``buffer_size=<integer>``: Output buffer size
+
+  **Example**::
+
+    auto out = fmt::output_file("guide.txt");
+    out.print("Don't {}", "Panic");
+  \endrst
  */
 template <typename... T>
 inline ostream output_file(cstring_view path, T... params) {
@@ -466,7 +512,7 @@ class locale {
 
   // Converts string to floating-point number and advances str past the end
   // of the parsed input.
-  double strtod(const char*& str) const {
+  FMT_DEPRECATED double strtod(const char*& str) const {
     char* end = nullptr;
     double result = strtod_l(str, &end, locale_);
     str = end;
@@ -475,6 +521,7 @@ class locale {
 };
 using Locale FMT_DEPRECATED_ALIAS = locale;
 #endif  // FMT_LOCALE
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_OS_H_

deps/fmt/include/fmt/ostream.h

@@ -14,81 +14,44 @@
 
 FMT_BEGIN_NAMESPACE
 
-template <typename Char> class basic_printf_parse_context;
 template <typename OutputIt, typename Char> class basic_printf_context;
 
 namespace detail {
 
-template <class Char> class formatbuf : public std::basic_streambuf<Char> {
+// Checks if T has a user-defined operator<<.
- private:
+template <typename T, typename Char, typename Enable = void>
-  using int_type = typename std::basic_streambuf<Char>::int_type;
+class is_streamable {
-  using traits_type = typename std::basic_streambuf<Char>::traits_type;
-
-  buffer<Char>& buffer_;
-
- public:
-  formatbuf(buffer<Char>& buf) : buffer_(buf) {}
-
- protected:
-  // The put-area is actually 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. The obvious
-  // 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.
-
-  int_type overflow(int_type ch = traits_type::eof()) FMT_OVERRIDE {
-    if (!traits_type::eq_int_type(ch, traits_type::eof()))
-      buffer_.push_back(static_cast<Char>(ch));
-    return ch;
-  }
-
-  std::streamsize xsputn(const Char* s, std::streamsize count) FMT_OVERRIDE {
-    buffer_.append(s, s + count);
-    return count;
-  }
-};
-
-struct converter {
-  template <typename T, FMT_ENABLE_IF(is_integral<T>::value)> converter(T);
-};
-
-template <typename Char> struct test_stream : std::basic_ostream<Char> {
- private:
-  void_t<> operator<<(converter);
-};
-
-// Hide insertion operators for built-in types.
-template <typename Char, typename Traits>
-void_t<> operator<<(std::basic_ostream<Char, Traits>&, Char);
-template <typename Char, typename Traits>
-void_t<> operator<<(std::basic_ostream<Char, Traits>&, char);
-template <typename Traits>
-void_t<> operator<<(std::basic_ostream<char, Traits>&, char);
-template <typename Traits>
-void_t<> operator<<(std::basic_ostream<char, Traits>&, signed char);
-template <typename Traits>
-void_t<> operator<<(std::basic_ostream<char, Traits>&, unsigned char);
-
-// Checks if T has a user-defined operator<< (e.g. not a member of
-// std::ostream).
-template <typename T, typename Char> class is_streamable {
  private:
   template <typename U>
-  static bool_constant<!std::is_same<decltype(std::declval<test_stream<Char>&>()
+  static auto test(int)
-                                              << std::declval<U>()),
+      -> bool_constant<sizeof(std::declval<std::basic_ostream<Char>&>()
-                                     void_t<>>::value>
+                              << std::declval<U>()) != 0>;
-  test(int);
 
-  template <typename> static std::false_type test(...);
+  template <typename> static auto test(...) -> std::false_type;
 
   using result = decltype(test<T>(0));
 
  public:
+  is_streamable() = default;
+
   static const bool value = result::value;
 };
 
+// Formatting of built-in types and arrays is intentionally disabled because
+// it's handled by standard (non-ostream) formatters.
+template <typename T, typename Char>
+struct is_streamable<
+    T, Char,
+    enable_if_t<
+        std::is_arithmetic<T>::value || std::is_array<T>::value ||
+        std::is_pointer<T>::value || std::is_same<T, char8_type>::value ||
+        std::is_same<T, std::basic_string<Char>>::value ||
+        std::is_same<T, std_string_view<Char>>::value ||
+        (std::is_convertible<T, int>::value && !std::is_enum<T>::value)>>
+    : std::false_type {};
+
 // Write the content of buf to os.
+// It is a separate function rather than a part of vprint to simplify testing.
 template <typename Char>
 void write_buffer(std::basic_ostream<Char>& os, buffer<Char>& buf) {
   const Char* buf_data = buf.data();
@@ -106,8 +69,8 @@ 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()) {
-  formatbuf<Char> format_buf(buf);
+  auto&& format_buf = formatbuf<std::basic_streambuf<Char>>(buf);
-  std::basic_ostream<Char> output(&format_buf);
+  auto&& output = std::basic_ostream<Char>(&format_buf);
 #if !defined(FMT_STATIC_THOUSANDS_SEPARATOR)
   if (loc) output.imbue(loc.get<std::locale>());
 #endif
@@ -120,39 +83,33 @@ void format_value(buffer<Char>& buf, const T& value,
 template <typename T, typename Char>
 struct fallback_formatter<T, Char, enable_if_t<is_streamable<T, Char>::value>>
     : private formatter<basic_string_view<Char>, Char> {
-  FMT_CONSTEXPR auto parse(basic_format_parse_context<Char>& ctx)
+  using formatter<basic_string_view<Char>, Char>::parse;
-      -> decltype(ctx.begin()) {
-    return formatter<basic_string_view<Char>, Char>::parse(ctx);
-  }
-  template <typename ParseCtx,
-            FMT_ENABLE_IF(std::is_same<
-                          ParseCtx, basic_printf_parse_context<Char>>::value)>
-  auto parse(ParseCtx& ctx) -> decltype(ctx.begin()) {
-    return ctx.begin();
-  }
 
   template <typename OutputIt>
   auto format(const T& value, basic_format_context<OutputIt, Char>& ctx)
       -> OutputIt {
-    basic_memory_buffer<Char> buffer;
+    auto buffer = basic_memory_buffer<Char>();
     format_value(buffer, value, ctx.locale());
-    basic_string_view<Char> str(buffer.data(), buffer.size());
+    return formatter<basic_string_view<Char>, Char>::format(
-    return formatter<basic_string_view<Char>, Char>::format(str, ctx);
+        {buffer.data(), buffer.size()}, ctx);
   }
+
+  // DEPRECATED!
   template <typename OutputIt>
   auto format(const T& value, basic_printf_context<OutputIt, Char>& ctx)
       -> OutputIt {
-    basic_memory_buffer<Char> buffer;
+    auto buffer = basic_memory_buffer<Char>();
     format_value(buffer, value, ctx.locale());
     return std::copy(buffer.begin(), buffer.end(), ctx.out());
   }
 };
 }  // namespace detail
 
+FMT_MODULE_EXPORT
 template <typename Char>
 void vprint(std::basic_ostream<Char>& os, basic_string_view<Char> format_str,
             basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-  basic_memory_buffer<Char> buffer;
+  auto buffer = basic_memory_buffer<Char>();
   detail::vformat_to(buffer, format_str, args);
   detail::write_buffer(os, buffer);
 }
@@ -166,6 +123,7 @@ void vprint(std::basic_ostream<Char>& os, basic_string_view<Char> format_str,
     fmt::print(cerr, "Don't {}!", "panic");
   \endrst
  */
+FMT_MODULE_EXPORT
 template <typename S, typename... Args,
           typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
 void print(std::basic_ostream<Char>& os, const S& format_str, Args&&... args) {

deps/fmt/include/fmt/posix.h

@@ -1,2 +0,0 @@
-#include "os.h"
-#warning "fmt/posix.h is deprecated; use fmt/os.h instead"

deps/fmt/include/fmt/printf.h

@@ -10,11 +10,54 @@
 
 #include <algorithm>  // std::max
 #include <limits>     // std::numeric_limits
+#include <ostream>
 
-#include "ostream.h"
+#include "format.h"
 
 FMT_BEGIN_NAMESPACE
-namespace detail {
+FMT_MODULE_EXPORT_BEGIN
+
+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 OutputIt, typename Char> class basic_printf_context {
+ private:
+  OutputIt out_;
+  basic_format_args<basic_printf_context> args_;
+
+ public:
+  using char_type = Char;
+  using format_arg = basic_format_arg<basic_printf_context>;
+  using parse_context_type = basic_printf_parse_context<Char>;
+  template <typename T> using formatter_type = printf_formatter<T>;
+
+  /**
+    \rst
+    Constructs a ``printf_context`` object. References to the arguments are
+    stored in the context object so make sure they have appropriate lifetimes.
+    \endrst
+   */
+  basic_printf_context(OutputIt out,
+                       basic_format_args<basic_printf_context> args)
+      : out_(out), args_(args) {}
+
+  OutputIt out() { return out_; }
+  void advance_to(OutputIt it) { out_ = it; }
+
+  detail::locale_ref locale() { return {}; }
+
+  format_arg arg(int id) const { return args_.get(id); }
+
+  FMT_CONSTEXPR void on_error(const char* message) {
+    detail::error_handler().on_error(message);
+  }
+};
+
+FMT_BEGIN_DETAIL_NAMESPACE
 
 // Checks if a value fits in int - used to avoid warnings about comparing
 // signed and unsigned integers.
@@ -178,81 +221,38 @@ template <typename Char> class printf_width_handler {
   }
 };
 
-template <typename Char, typename Context>
+// The ``printf`` argument formatter.
-void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
-             basic_format_args<Context> args) {
-  Context(buffer_appender<Char>(buf), format, args).format();
-}
-}  // namespace detail
-
-// For printing into memory_buffer.
-template <typename Char, typename Context>
-FMT_DEPRECATED void printf(detail::buffer<Char>& buf,
-                           basic_string_view<Char> format,
-                           basic_format_args<Context> args) {
-  return detail::vprintf(buf, format, args);
-}
-using detail::vprintf;
-
-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 OutputIt, typename Char> class basic_printf_context;
-
-/**
-  \rst
-  The ``printf`` argument formatter.
-  \endrst
- */
 template <typename OutputIt, typename Char>
-class printf_arg_formatter : public detail::arg_formatter_base<OutputIt, Char> {
+class printf_arg_formatter : public arg_formatter<Char> {
- public:
-  using iterator = OutputIt;
-
  private:
-  using char_type = Char;
+  using base = arg_formatter<Char>;
-  using base = detail::arg_formatter_base<OutputIt, Char>;
   using context_type = basic_printf_context<OutputIt, Char>;
+  using format_specs = basic_format_specs<Char>;
 
   context_type& context_;
 
-  void write_null_pointer(char) {
+  OutputIt write_null_pointer(bool is_string = false) {
-    this->specs()->type = 0;
+    auto s = this->specs;
-    this->write("(nil)");
+    s.type = presentation_type::none;
-  }
+    return write_bytes(this->out, is_string ? "(null)" : "(nil)", s);
-
-  void write_null_pointer(wchar_t) {
-    this->specs()->type = 0;
-    this->write(L"(nil)");
   }
 
  public:
-  using format_specs = typename base::format_specs;
+  printf_arg_formatter(OutputIt iter, format_specs& s, context_type& ctx)
+      : base{iter, s, locale_ref()}, context_(ctx) {}
 
-  /**
+  OutputIt operator()(monostate value) { return base::operator()(value); }
-    \rst
-    Constructs an argument formatter object.
-    *buffer* is a reference to the output buffer and *specs* contains format
-    specifier information for standard argument types.
-    \endrst
-   */
-  printf_arg_formatter(iterator iter, format_specs& specs, context_type& ctx)
-      : base(iter, &specs, detail::locale_ref()), context_(ctx) {}
 
-  template <typename T, FMT_ENABLE_IF(fmt::detail::is_integral<T>::value)>
+  template <typename T, FMT_ENABLE_IF(detail::is_integral<T>::value)>
-  iterator operator()(T value) {
+  OutputIt operator()(T value) {
-    // MSVC2013 fails to compile separate overloads for bool and char_type so
+    // MSVC2013 fails to compile separate overloads for bool and Char so use
-    // use std::is_same instead.
+    // std::is_same instead.
-    if (std::is_same<T, bool>::value) {
+    if (std::is_same<T, Char>::value) {
-      format_specs& fmt_specs = *this->specs();
+      format_specs fmt_specs = this->specs;
-      if (fmt_specs.type != 's') return base::operator()(value ? 1 : 0);
+      if (fmt_specs.type != presentation_type::none &&
-      fmt_specs.type = 0;
+          fmt_specs.type != presentation_type::chr) {
-      this->write(value != 0);
-    } else if (std::is_same<T, char_type>::value) {
-      format_specs& fmt_specs = *this->specs();
-      if (fmt_specs.type && fmt_specs.type != 'c')
         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.
@@ -260,137 +260,48 @@ class printf_arg_formatter : public detail::arg_formatter_base<OutputIt, Char> {
       // ignored for non-numeric types
       if (fmt_specs.align == align::none || fmt_specs.align == align::numeric)
         fmt_specs.align = align::right;
-      return base::operator()(value);
+      return write<Char>(this->out, static_cast<Char>(value), fmt_specs);
-    } else {
-      return base::operator()(value);
     }
-    return this->out();
+    return base::operator()(value);
   }
 
   template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value)>
-  iterator operator()(T value) {
+  OutputIt operator()(T value) {
     return base::operator()(value);
   }
 
   /** Formats a null-terminated C string. */
-  iterator operator()(const char* value) {
+  OutputIt operator()(const char* value) {
-    if (value)
+    if (value) return base::operator()(value);
-      base::operator()(value);
+    return write_null_pointer(this->specs.type != presentation_type::pointer);
-    else if (this->specs()->type == 'p')
-      write_null_pointer(char_type());
-    else
-      this->write("(null)");
-    return this->out();
   }
 
   /** Formats a null-terminated wide C string. */
-  iterator operator()(const wchar_t* value) {
+  OutputIt operator()(const wchar_t* value) {
-    if (value)
+    if (value) return base::operator()(value);
-      base::operator()(value);
+    return write_null_pointer(this->specs.type != presentation_type::pointer);
-    else if (this->specs()->type == 'p')
-      write_null_pointer(char_type());
-    else
-      this->write(L"(null)");
-    return this->out();
   }
 
-  iterator operator()(basic_string_view<char_type> value) {
+  OutputIt operator()(basic_string_view<Char> value) {
     return base::operator()(value);
   }
 
-  iterator operator()(monostate value) { return base::operator()(value); }
-
   /** Formats a pointer. */
-  iterator operator()(const void* value) {
+  OutputIt operator()(const void* value) {
-    if (value) return base::operator()(value);
+    return value ? base::operator()(value) : write_null_pointer();
-    this->specs()->type = 0;
-    write_null_pointer(char_type());
-    return this->out();
   }
 
   /** Formats an argument of a custom (user-defined) type. */
-  iterator operator()(typename basic_format_arg<context_type>::handle handle) {
+  OutputIt operator()(typename basic_format_arg<context_type>::handle handle) {
-    handle.format(context_.parse_context(), context_);
+    auto parse_ctx =
-    return this->out();
+        basic_printf_parse_context<Char>(basic_string_view<Char>());
+    handle.format(parse_ctx, context_);
+    return this->out;
   }
 };
 
-template <typename T> struct printf_formatter {
+template <typename Char>
-  printf_formatter() = delete;
+void parse_flags(basic_format_specs<Char>& specs, const Char*& it,
-
-  template <typename ParseContext>
-  auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
-    return ctx.begin();
-  }
-
-  template <typename FormatContext>
-  auto format(const T& value, FormatContext& ctx) -> decltype(ctx.out()) {
-    detail::format_value(detail::get_container(ctx.out()), value);
-    return ctx.out();
-  }
-};
-
-/**
- This template formats data and writes the output through an output iterator.
- */
-template <typename OutputIt, typename Char> class basic_printf_context {
- public:
-  /** The character type for the output. */
-  using char_type = Char;
-  using iterator = OutputIt;
-  using format_arg = basic_format_arg<basic_printf_context>;
-  using parse_context_type = basic_printf_parse_context<Char>;
-  template <typename T> using formatter_type = printf_formatter<T>;
-
- private:
-  using format_specs = basic_format_specs<char_type>;
-
-  OutputIt out_;
-  basic_format_args<basic_printf_context> args_;
-  parse_context_type parse_ctx_;
-
-  static void parse_flags(format_specs& specs, const Char*& it,
-                          const Char* end);
-
-  // Returns the argument with specified index or, if arg_index is -1, the next
-  // argument.
-  format_arg get_arg(int arg_index = -1);
-
-  // Parses argument index, flags and width and returns the argument index.
-  int parse_header(const Char*& it, const Char* end, format_specs& specs);
-
- public:
-  /**
-   \rst
-   Constructs a ``printf_context`` object. References to the arguments are
-   stored in the context object so make sure they have appropriate lifetimes.
-   \endrst
-   */
-  basic_printf_context(OutputIt out, basic_string_view<char_type> format_str,
-                       basic_format_args<basic_printf_context> args)
-      : out_(out), args_(args), parse_ctx_(format_str) {}
-
-  OutputIt out() { return out_; }
-  void advance_to(OutputIt it) { out_ = it; }
-
-  detail::locale_ref locale() { return {}; }
-
-  format_arg arg(int id) const { return args_.get(id); }
-
-  parse_context_type& parse_context() { return parse_ctx_; }
-
-  FMT_CONSTEXPR void on_error(const char* message) {
-    parse_ctx_.on_error(message);
-  }
-
-  /** Formats stored arguments and writes the output to the range. */
-  template <typename ArgFormatter = printf_arg_formatter<OutputIt, Char>>
-  OutputIt format();
-};
-
-template <typename OutputIt, typename Char>
-void basic_printf_context<OutputIt, Char>::parse_flags(format_specs& specs,
-                                                       const Char*& it,
                  const Char* end) {
   for (; it != end; ++it) {
     switch (*it) {
@@ -417,35 +328,24 @@ void basic_printf_context<OutputIt, Char>::parse_flags(format_specs& specs,
   }
 }
 
-template <typename OutputIt, typename Char>
+template <typename Char, typename GetArg>
-typename basic_printf_context<OutputIt, Char>::format_arg
+int parse_header(const Char*& it, const Char* end,
-basic_printf_context<OutputIt, Char>::get_arg(int arg_index) {
+                 basic_format_specs<Char>& specs, GetArg get_arg) {
-  if (arg_index < 0)
-    arg_index = parse_ctx_.next_arg_id();
-  else
-    parse_ctx_.check_arg_id(--arg_index);
-  return detail::get_arg(*this, arg_index);
-}
-
-template <typename OutputIt, typename Char>
-int basic_printf_context<OutputIt, Char>::parse_header(const Char*& it,
-                                                       const Char* end,
-                                                       format_specs& specs) {
   int arg_index = -1;
-  char_type c = *it;
+  Char c = *it;
   if (c >= '0' && c <= '9') {
     // Parse an argument index (if followed by '$') or a width possibly
     // preceded with '0' flag(s).
-    detail::error_handler eh;
+    int value = parse_nonnegative_int(it, end, -1);
-    int value = parse_nonnegative_int(it, end, eh);
     if (it != end && *it == '$') {  // value is an argument index
       ++it;
-      arg_index = value;
+      arg_index = value != -1 ? value : max_value<int>();
     } else {
       if (c == '0') specs.fill[0] = '0';
       if (value != 0) {
         // Nonzero value means that we parsed width and don't need to
         // parse it or flags again, so return now.
+        if (value == -1) FMT_THROW(format_error("number is too big"));
         specs.width = value;
         return arg_index;
       }
@@ -455,58 +355,76 @@ int basic_printf_context<OutputIt, Char>::parse_header(const Char*& it,
   // Parse width.
   if (it != end) {
     if (*it >= '0' && *it <= '9') {
-      detail::error_handler eh;
+      specs.width = parse_nonnegative_int(it, end, -1);
-      specs.width = parse_nonnegative_int(it, end, eh);
+      if (specs.width == -1) FMT_THROW(format_error("number is too big"));
     } else if (*it == '*') {
       ++it;
       specs.width = static_cast<int>(visit_format_arg(
-          detail::printf_width_handler<char_type>(specs), get_arg()));
+          detail::printf_width_handler<Char>(specs), get_arg(-1)));
     }
   }
   return arg_index;
 }
 
-template <typename OutputIt, typename Char>
+template <typename Char, typename Context>
-template <typename ArgFormatter>
+void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
-OutputIt basic_printf_context<OutputIt, Char>::format() {
+             basic_format_args<Context> args) {
-  auto out = this->out();
+  using OutputIt = buffer_appender<Char>;
-  const Char* start = parse_ctx_.begin();
+  auto out = OutputIt(buf);
-  const Char* end = parse_ctx_.end();
+  auto context = basic_printf_context<OutputIt, Char>(out, args);
+  auto parse_ctx = basic_printf_parse_context<Char>(format);
+
+  // Returns the argument with specified index or, if arg_index is -1, the next
+  // argument.
+  auto get_arg = [&](int arg_index) {
+    if (arg_index < 0)
+      arg_index = parse_ctx.next_arg_id();
+    else
+      parse_ctx.check_arg_id(--arg_index);
+    return detail::get_arg(context, arg_index);
+  };
+
+  const Char* start = parse_ctx.begin();
+  const Char* end = parse_ctx.end();
   auto it = start;
   while (it != end) {
-    char_type c = *it++;
+    if (!detail::find<false, Char>(it, end, '%', it)) {
-    if (c != '%') continue;
+      it = end;  // detail::find leaves it == nullptr if it doesn't find '%'
+      break;
+    }
+    Char c = *it++;
     if (it != end && *it == c) {
-      out = std::copy(start, it, out);
+      out = detail::write(
+          out, basic_string_view<Char>(start, detail::to_unsigned(it - start)));
       start = ++it;
       continue;
     }
-    out = std::copy(start, it - 1, out);
+    out = detail::write(out, basic_string_view<Char>(
+                                 start, detail::to_unsigned(it - 1 - start)));
 
-    format_specs specs;
+    basic_format_specs<Char> specs;
     specs.align = align::right;
 
     // Parse argument index, flags and width.
-    int arg_index = parse_header(it, end, specs);
+    int arg_index = parse_header(it, end, specs, get_arg);
-    if (arg_index == 0) on_error("argument not found");
+    if (arg_index == 0) parse_ctx.on_error("argument not found");
 
     // Parse precision.
     if (it != end && *it == '.') {
       ++it;
       c = it != end ? *it : 0;
       if ('0' <= c && c <= '9') {
-        detail::error_handler eh;
+        specs.precision = parse_nonnegative_int(it, end, 0);
-        specs.precision = parse_nonnegative_int(it, end, eh);
       } else if (c == '*') {
         ++it;
         specs.precision = static_cast<int>(
-            visit_format_arg(detail::printf_precision_handler(), get_arg()));
+            visit_format_arg(detail::printf_precision_handler(), get_arg(-1)));
       } else {
         specs.precision = 0;
       }
     }
 
-    format_arg arg = get_arg(arg_index);
+    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())
@@ -516,9 +434,10 @@ OutputIt basic_printf_context<OutputIt, Char>::format() {
       auto str = visit_format_arg(detail::get_cstring<Char>(), arg);
       auto str_end = str + specs.precision;
       auto nul = std::find(str, str_end, Char());
-      arg = detail::make_arg<basic_printf_context>(basic_string_view<Char>(
+      arg = detail::make_arg<basic_printf_context<OutputIt, Char>>(
-          str,
+          basic_string_view<Char>(
-          detail::to_unsigned(nul != str_end ? nul - str : specs.precision)));
+              str, detail::to_unsigned(nul != str_end ? nul - str
+                                                      : specs.precision)));
     }
     if (specs.alt && visit_format_arg(detail::is_zero_int(), arg))
       specs.alt = false;
@@ -532,7 +451,7 @@ OutputIt basic_printf_context<OutputIt, Char>::format() {
 
     // Parse length and convert the argument to the required type.
     c = it != end ? *it++ : 0;
-    char_type t = it != end ? *it : 0;
+    Char t = it != end ? *it : 0;
     using detail::convert_arg;
     switch (c) {
     case 'h':
@@ -573,28 +492,34 @@ OutputIt basic_printf_context<OutputIt, Char>::format() {
 
     // Parse type.
     if (it == end) FMT_THROW(format_error("invalid format string"));
-    specs.type = static_cast<char>(*it++);
+    char type = static_cast<char>(*it++);
     if (arg.is_integral()) {
       // Normalize type.
-      switch (specs.type) {
+      switch (type) {
       case 'i':
       case 'u':
-        specs.type = 'd';
+        type = 'd';
         break;
       case 'c':
-        visit_format_arg(detail::char_converter<basic_printf_context>(arg),
+        visit_format_arg(
+            detail::char_converter<basic_printf_context<OutputIt, Char>>(arg),
             arg);
         break;
       }
     }
+    specs.type = parse_presentation_type(type);
+    if (specs.type == presentation_type::none)
+      parse_ctx.on_error("invalid type specifier");
 
     start = it;
 
     // Format argument.
-    out = visit_format_arg(ArgFormatter(out, specs, *this), arg);
+    out = visit_format_arg(
+        detail::printf_arg_formatter<OutputIt, Char>(out, specs, context), arg);
   }
-  return std::copy(start, it, out);
+  detail::write(out, basic_string_view<Char>(start, to_unsigned(it - start)));
 }
+FMT_END_DETAIL_NAMESPACE
 
 template <typename Char>
 using basic_printf_context_t =
@@ -612,9 +537,9 @@ using wprintf_args = basic_format_args<wprintf_context>;
   arguments and can be implicitly converted to `~fmt::printf_args`.
   \endrst
  */
-template <typename... Args>
+template <typename... T>
-inline format_arg_store<printf_context, Args...> make_printf_args(
+inline auto make_printf_args(const T&... args)
-    const Args&... args) {
+    -> format_arg_store<printf_context, T...> {
   return {args...};
 }
 
@@ -624,18 +549,19 @@ inline format_arg_store<printf_context, Args...> make_printf_args(
   arguments and can be implicitly converted to `~fmt::wprintf_args`.
   \endrst
  */
-template <typename... Args>
+template <typename... T>
-inline format_arg_store<wprintf_context, Args...> make_wprintf_args(
+inline auto make_wprintf_args(const T&... args)
-    const Args&... args) {
+    -> format_arg_store<wprintf_context, T...> {
   return {args...};
 }
 
 template <typename S, typename Char = char_t<S>>
-inline std::basic_string<Char> vsprintf(
+inline auto vsprintf(
-    const S& format,
+    const S& fmt,
-    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args) {
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
   basic_memory_buffer<Char> buffer;
-  vprintf(buffer, to_string_view(format), args);
+  vprintf(buffer, to_string_view(fmt), args);
   return to_string(buffer);
 }
 
@@ -648,19 +574,20 @@ inline std::basic_string<Char> vsprintf(
     std::string message = fmt::sprintf("The answer is %d", 42);
   \endrst
 */
-template <typename S, typename... Args,
+template <typename S, typename... T,
           typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
-inline std::basic_string<Char> sprintf(const S& format, const Args&... args) {
+inline auto sprintf(const S& fmt, const T&... args) -> std::basic_string<Char> {
   using context = basic_printf_context_t<Char>;
-  return vsprintf(to_string_view(format), make_format_args<context>(args...));
+  return vsprintf(to_string_view(fmt), fmt::make_format_args<context>(args...));
 }
 
 template <typename S, typename Char = char_t<S>>
-inline int vfprintf(
+inline auto vfprintf(
-    std::FILE* f, const S& format,
+    std::FILE* f, const S& fmt,
-    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args) {
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> int {
   basic_memory_buffer<Char> buffer;
-  vprintf(buffer, to_string_view(format), args);
+  vprintf(buffer, to_string_view(fmt), args);
   size_t size = buffer.size();
   return std::fwrite(buffer.data(), sizeof(Char), size, f) < size
              ? -1
@@ -676,19 +603,19 @@ inline int vfprintf(
     fmt::fprintf(stderr, "Don't %s!", "panic");
   \endrst
  */
-template <typename S, typename... Args,
+template <typename S, typename... T, typename Char = char_t<S>>
-          typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
+inline auto fprintf(std::FILE* f, const S& fmt, const T&... args) -> int {
-inline int fprintf(std::FILE* f, const S& format, const Args&... args) {
   using context = basic_printf_context_t<Char>;
-  return vfprintf(f, to_string_view(format),
+  return vfprintf(f, to_string_view(fmt),
-                  make_format_args<context>(args...));
+                  fmt::make_format_args<context>(args...));
 }
 
 template <typename S, typename Char = char_t<S>>
-inline int vprintf(
+inline auto vprintf(
-    const S& format,
+    const S& fmt,
-    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args) {
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
-  return vfprintf(stdout, to_string_view(format), args);
+    -> int {
+  return vfprintf(stdout, to_string_view(fmt), args);
 }
 
 /**
@@ -700,52 +627,31 @@ inline int vprintf(
     fmt::printf("Elapsed time: %.2f seconds", 1.23);
   \endrst
  */
-template <typename S, typename... Args,
+template <typename S, typename... T, FMT_ENABLE_IF(detail::is_string<S>::value)>
-          FMT_ENABLE_IF(detail::is_string<S>::value)>
+inline auto printf(const S& fmt, const T&... args) -> int {
-inline int printf(const S& format_str, const Args&... args) {
+  return vprintf(
-  using context = basic_printf_context_t<char_t<S>>;
+      to_string_view(fmt),
-  return vprintf(to_string_view(format_str),
+      fmt::make_format_args<basic_printf_context_t<char_t<S>>>(args...));
-                 make_format_args<context>(args...));
 }
 
 template <typename S, typename Char = char_t<S>>
-inline int vfprintf(
+FMT_DEPRECATED auto vfprintf(
-    std::basic_ostream<Char>& os, const S& format,
+    std::basic_ostream<Char>& os, const S& fmt,
-    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args) {
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> int {
   basic_memory_buffer<Char> buffer;
-  vprintf(buffer, to_string_view(format), args);
+  vprintf(buffer, to_string_view(fmt), args);
-  detail::write_buffer(os, buffer);
+  os.write(buffer.data(), static_cast<std::streamsize>(buffer.size()));
   return static_cast<int>(buffer.size());
 }
-
+template <typename S, typename... T, typename Char = char_t<S>>
-/** Formats arguments and writes the output to the range. */
+FMT_DEPRECATED auto fprintf(std::basic_ostream<Char>& os, const S& fmt,
-template <typename ArgFormatter, typename Char,
+                            const T&... args) -> int {
-          typename Context =
+  return vfprintf(os, to_string_view(fmt),
-              basic_printf_context<typename ArgFormatter::iterator, Char>>
+                  fmt::make_format_args<basic_printf_context_t<Char>>(args...));
-typename ArgFormatter::iterator vprintf(
-    detail::buffer<Char>& out, basic_string_view<Char> format_str,
-    basic_format_args<type_identity_t<Context>> args) {
-  typename ArgFormatter::iterator iter(out);
-  Context(iter, format_str, args).template format<ArgFormatter>();
-  return iter;
 }
 
-/**
+FMT_MODULE_EXPORT_END
-  \rst
-  Prints formatted data to the stream *os*.
-
-  **Example**::
-
-    fmt::fprintf(cerr, "Don't %s!", "panic");
-  \endrst
- */
-template <typename S, typename... Args, typename Char = char_t<S>>
-inline int fprintf(std::basic_ostream<Char>& os, const S& format_str,
-                   const Args&... args) {
-  using context = basic_printf_context_t<Char>;
-  return vfprintf(os, to_string_view(format_str),
-                  make_format_args<context>(args...));
-}
 FMT_END_NAMESPACE
 
 #endif  // FMT_PRINTF_H_

deps/fmt/include/fmt/ranges.h

@@ -13,47 +13,13 @@
 #define FMT_RANGES_H_
 
 #include <initializer_list>
+#include <tuple>
 #include <type_traits>
 
 #include "format.h"
 
-// output only up to N items from the range.
-#ifndef FMT_RANGE_OUTPUT_LENGTH_LIMIT
-#  define FMT_RANGE_OUTPUT_LENGTH_LIMIT 256
-#endif
-
 FMT_BEGIN_NAMESPACE
 
-template <typename Char> struct formatting_base {
-  template <typename ParseContext>
-  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
-    return ctx.begin();
-  }
-};
-
-template <typename Char, typename Enable = void>
-struct formatting_range : formatting_base<Char> {
-  static FMT_CONSTEXPR_DECL const size_t range_length_limit =
-      FMT_RANGE_OUTPUT_LENGTH_LIMIT;  // output only up to N items from the
-                                      // range.
-  Char prefix;
-  Char delimiter;
-  Char postfix;
-  formatting_range() : prefix('{'), delimiter(','), postfix('}') {}
-  static FMT_CONSTEXPR_DECL const bool add_delimiter_spaces = true;
-  static FMT_CONSTEXPR_DECL const bool add_prepostfix_space = false;
-};
-
-template <typename Char, typename Enable = void>
-struct formatting_tuple : formatting_base<Char> {
-  Char prefix;
-  Char delimiter;
-  Char postfix;
-  formatting_tuple() : prefix('('), delimiter(','), postfix(')') {}
-  static FMT_CONSTEXPR_DECL const bool add_delimiter_spaces = true;
-  static FMT_CONSTEXPR_DECL const bool add_prepostfix_space = false;
-};
-
 namespace detail {
 
 template <typename RangeT, typename OutputIterator>
@@ -75,8 +41,14 @@ OutputIterator copy(char ch, OutputIterator out) {
   return out;
 }
 
-/// Return true value if T has std::string interface, like std::string_view.
+template <typename OutputIterator>
-template <typename T> class is_like_std_string {
+OutputIterator copy(wchar_t ch, OutputIterator out) {
+  *out++ = ch;
+  return out;
+}
+
+// Returns true if T has a std::string-like interface, like std::string_view.
+template <typename T> class is_std_string_like {
   template <typename U>
   static auto check(U* p)
       -> decltype((void)p->find('a'), p->length(), (void)p->data(), int());
@@ -84,26 +56,118 @@ template <typename T> class is_like_std_string {
 
  public:
   static FMT_CONSTEXPR_DECL const bool value =
-      is_string<T>::value || !std::is_void<decltype(check<T>(nullptr))>::value;
+      is_string<T>::value ||
+      std::is_convertible<T, std_string_view<char>>::value ||
+      !std::is_void<decltype(check<T>(nullptr))>::value;
 };
 
 template <typename Char>
-struct is_like_std_string<fmt::basic_string_view<Char>> : std::true_type {};
+struct is_std_string_like<fmt::basic_string_view<Char>> : std::true_type {};
+
+template <typename T> class is_map {
+  template <typename U> static auto check(U*) -> typename U::mapped_type;
+  template <typename> static void check(...);
+
+ public:
+#ifdef FMT_FORMAT_MAP_AS_LIST
+  static FMT_CONSTEXPR_DECL const bool value = false;
+#else
+  static FMT_CONSTEXPR_DECL const bool value =
+      !std::is_void<decltype(check<T>(nullptr))>::value;
+#endif
+};
+
+template <typename T> class is_set {
+  template <typename U> static auto check(U*) -> typename U::key_type;
+  template <typename> static void check(...);
+
+ public:
+#ifdef FMT_FORMAT_SET_AS_LIST
+  static FMT_CONSTEXPR_DECL const bool value = false;
+#else
+  static FMT_CONSTEXPR_DECL const bool value =
+      !std::is_void<decltype(check<T>(nullptr))>::value && !is_map<T>::value;
+#endif
+};
 
 template <typename... Ts> struct conditional_helper {};
 
 template <typename T, typename _ = void> struct is_range_ : std::false_type {};
 
 #if !FMT_MSC_VER || FMT_MSC_VER > 1800
+
+#  define FMT_DECLTYPE_RETURN(val)  \
+    ->decltype(val) { return val; } \
+    static_assert(                  \
+        true, "")  // This makes it so that a semicolon is required after the
+                   // macro, which helps clang-format handle the formatting.
+
+// C array overload
+template <typename T, std::size_t N>
+auto range_begin(const T (&arr)[N]) -> const T* {
+  return arr;
+}
+template <typename T, std::size_t N>
+auto range_end(const T (&arr)[N]) -> const T* {
+  return arr + N;
+}
+
+template <typename T, typename Enable = void>
+struct has_member_fn_begin_end_t : std::false_type {};
+
 template <typename T>
-struct is_range_<
+struct has_member_fn_begin_end_t<T, void_t<decltype(std::declval<T>().begin()),
-    T, conditional_t<false,
+                                           decltype(std::declval<T>().end())>>
-                     conditional_helper<decltype(std::declval<T>().begin()),
+    : std::true_type {};
-                                        decltype(std::declval<T>().end())>,
+
-                     void>> : std::true_type {};
+// Member function overload
+template <typename T>
+auto range_begin(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).begin());
+template <typename T>
+auto range_end(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).end());
+
+// ADL overload. Only participates in overload resolution if member functions
+// are not found.
+template <typename T>
+auto range_begin(T&& rng)
+    -> enable_if_t<!has_member_fn_begin_end_t<T&&>::value,
+                   decltype(begin(static_cast<T&&>(rng)))> {
+  return begin(static_cast<T&&>(rng));
+}
+template <typename T>
+auto range_end(T&& rng) -> enable_if_t<!has_member_fn_begin_end_t<T&&>::value,
+                                       decltype(end(static_cast<T&&>(rng)))> {
+  return end(static_cast<T&&>(rng));
+}
+
+template <typename T, typename Enable = void>
+struct has_const_begin_end : std::false_type {};
+template <typename T, typename Enable = void>
+struct has_mutable_begin_end : std::false_type {};
+
+template <typename T>
+struct has_const_begin_end<
+    T,
+    void_t<
+        decltype(detail::range_begin(std::declval<const remove_cvref_t<T>&>())),
+        decltype(detail::range_end(std::declval<const remove_cvref_t<T>&>()))>>
+    : std::true_type {};
+
+template <typename T>
+struct has_mutable_begin_end<
+    T, void_t<decltype(detail::range_begin(std::declval<T>())),
+              decltype(detail::range_end(std::declval<T>())),
+              enable_if_t<std::is_copy_constructible<T>::value>>>
+    : std::true_type {};
+
+template <typename T>
+struct is_range_<T, void>
+    : std::integral_constant<bool, (has_const_begin_end<T>::value ||
+                                    has_mutable_begin_end<T>::value)> {};
+#  undef FMT_DECLTYPE_RETURN
 #endif
 
-/// tuple_size and tuple_element check.
+// tuple_size and tuple_element check.
 template <typename T> class is_tuple_like_ {
   template <typename U>
   static auto check(U* p) -> decltype(std::tuple_size<U>::value, int());
@@ -158,33 +222,321 @@ template <class Tuple, class F> void for_each(Tuple&& tup, F&& f) {
 }
 
 template <typename Range>
-using value_type = remove_cvref_t<decltype(*std::declval<Range>().begin())>;
+using value_type =
+    remove_cvref_t<decltype(*detail::range_begin(std::declval<Range>()))>;
 
-template <typename Arg, FMT_ENABLE_IF(!is_like_std_string<
+template <typename OutputIt> OutputIt write_delimiter(OutputIt out) {
-                                      typename std::decay<Arg>::type>::value)>
+  *out++ = ',';
-FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const Arg&) {
+  *out++ = ' ';
-  return add_space ? " {}" : "{}";
+  return out;
 }
 
-template <typename Arg, FMT_ENABLE_IF(is_like_std_string<
+struct singleton {
-                                      typename std::decay<Arg>::type>::value)>
+  unsigned char upper;
-FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const Arg&) {
+  unsigned char lower_count;
-  return add_space ? " \"{}\"" : "\"{}\"";
+};
+
+inline auto is_printable(uint16_t x, const singleton* singletons,
+                         size_t singletons_size,
+                         const unsigned char* singleton_lowers,
+                         const unsigned char* normal, size_t normal_size)
+    -> bool {
+  auto upper = x >> 8;
+  auto lower_start = 0;
+  for (size_t i = 0; i < singletons_size; ++i) {
+    auto s = singletons[i];
+    auto lower_end = lower_start + s.lower_count;
+    if (upper < s.upper) break;
+    if (upper == s.upper) {
+      for (auto j = lower_start; j < lower_end; ++j) {
+        if (singleton_lowers[j] == (x & 0xff)) return false;
+      }
+    }
+    lower_start = lower_end;
+  }
+
+  auto xsigned = static_cast<int>(x);
+  auto current = true;
+  for (size_t i = 0; i < normal_size; ++i) {
+    auto v = static_cast<int>(normal[i]);
+    auto len = (v & 0x80) != 0 ? (v & 0x7f) << 8 | normal[++i] : v;
+    xsigned -= len;
+    if (xsigned < 0) break;
+    current = !current;
+  }
+  return current;
 }
 
-FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const char*) {
+// Returns true iff the code point cp is printable.
-  return add_space ? " \"{}\"" : "\"{}\"";
+// This code is generated by support/printable.py.
-}
+inline auto is_printable(uint32_t cp) -> bool {
-FMT_CONSTEXPR const wchar_t* format_str_quoted(bool add_space, const wchar_t*) {
+  static constexpr singleton singletons0[] = {
-  return add_space ? L" \"{}\"" : L"\"{}\"";
+      {0x00, 1},  {0x03, 5},  {0x05, 6},  {0x06, 3},  {0x07, 6},  {0x08, 8},
+      {0x09, 17}, {0x0a, 28}, {0x0b, 25}, {0x0c, 20}, {0x0d, 16}, {0x0e, 13},
+      {0x0f, 4},  {0x10, 3},  {0x12, 18}, {0x13, 9},  {0x16, 1},  {0x17, 5},
+      {0x18, 2},  {0x19, 3},  {0x1a, 7},  {0x1c, 2},  {0x1d, 1},  {0x1f, 22},
+      {0x20, 3},  {0x2b, 3},  {0x2c, 2},  {0x2d, 11}, {0x2e, 1},  {0x30, 3},
+      {0x31, 2},  {0x32, 1},  {0xa7, 2},  {0xa9, 2},  {0xaa, 4},  {0xab, 8},
+      {0xfa, 2},  {0xfb, 5},  {0xfd, 4},  {0xfe, 3},  {0xff, 9},
+  };
+  static constexpr unsigned char singletons0_lower[] = {
+      0xad, 0x78, 0x79, 0x8b, 0x8d, 0xa2, 0x30, 0x57, 0x58, 0x8b, 0x8c, 0x90,
+      0x1c, 0x1d, 0xdd, 0x0e, 0x0f, 0x4b, 0x4c, 0xfb, 0xfc, 0x2e, 0x2f, 0x3f,
+      0x5c, 0x5d, 0x5f, 0xb5, 0xe2, 0x84, 0x8d, 0x8e, 0x91, 0x92, 0xa9, 0xb1,
+      0xba, 0xbb, 0xc5, 0xc6, 0xc9, 0xca, 0xde, 0xe4, 0xe5, 0xff, 0x00, 0x04,
+      0x11, 0x12, 0x29, 0x31, 0x34, 0x37, 0x3a, 0x3b, 0x3d, 0x49, 0x4a, 0x5d,
+      0x84, 0x8e, 0x92, 0xa9, 0xb1, 0xb4, 0xba, 0xbb, 0xc6, 0xca, 0xce, 0xcf,
+      0xe4, 0xe5, 0x00, 0x04, 0x0d, 0x0e, 0x11, 0x12, 0x29, 0x31, 0x34, 0x3a,
+      0x3b, 0x45, 0x46, 0x49, 0x4a, 0x5e, 0x64, 0x65, 0x84, 0x91, 0x9b, 0x9d,
+      0xc9, 0xce, 0xcf, 0x0d, 0x11, 0x29, 0x45, 0x49, 0x57, 0x64, 0x65, 0x8d,
+      0x91, 0xa9, 0xb4, 0xba, 0xbb, 0xc5, 0xc9, 0xdf, 0xe4, 0xe5, 0xf0, 0x0d,
+      0x11, 0x45, 0x49, 0x64, 0x65, 0x80, 0x84, 0xb2, 0xbc, 0xbe, 0xbf, 0xd5,
+      0xd7, 0xf0, 0xf1, 0x83, 0x85, 0x8b, 0xa4, 0xa6, 0xbe, 0xbf, 0xc5, 0xc7,
+      0xce, 0xcf, 0xda, 0xdb, 0x48, 0x98, 0xbd, 0xcd, 0xc6, 0xce, 0xcf, 0x49,
+      0x4e, 0x4f, 0x57, 0x59, 0x5e, 0x5f, 0x89, 0x8e, 0x8f, 0xb1, 0xb6, 0xb7,
+      0xbf, 0xc1, 0xc6, 0xc7, 0xd7, 0x11, 0x16, 0x17, 0x5b, 0x5c, 0xf6, 0xf7,
+      0xfe, 0xff, 0x80, 0x0d, 0x6d, 0x71, 0xde, 0xdf, 0x0e, 0x0f, 0x1f, 0x6e,
+      0x6f, 0x1c, 0x1d, 0x5f, 0x7d, 0x7e, 0xae, 0xaf, 0xbb, 0xbc, 0xfa, 0x16,
+      0x17, 0x1e, 0x1f, 0x46, 0x47, 0x4e, 0x4f, 0x58, 0x5a, 0x5c, 0x5e, 0x7e,
+      0x7f, 0xb5, 0xc5, 0xd4, 0xd5, 0xdc, 0xf0, 0xf1, 0xf5, 0x72, 0x73, 0x8f,
+      0x74, 0x75, 0x96, 0x2f, 0x5f, 0x26, 0x2e, 0x2f, 0xa7, 0xaf, 0xb7, 0xbf,
+      0xc7, 0xcf, 0xd7, 0xdf, 0x9a, 0x40, 0x97, 0x98, 0x30, 0x8f, 0x1f, 0xc0,
+      0xc1, 0xce, 0xff, 0x4e, 0x4f, 0x5a, 0x5b, 0x07, 0x08, 0x0f, 0x10, 0x27,
+      0x2f, 0xee, 0xef, 0x6e, 0x6f, 0x37, 0x3d, 0x3f, 0x42, 0x45, 0x90, 0x91,
+      0xfe, 0xff, 0x53, 0x67, 0x75, 0xc8, 0xc9, 0xd0, 0xd1, 0xd8, 0xd9, 0xe7,
+      0xfe, 0xff,
+  };
+  static constexpr singleton singletons1[] = {
+      {0x00, 6},  {0x01, 1}, {0x03, 1},  {0x04, 2}, {0x08, 8},  {0x09, 2},
+      {0x0a, 5},  {0x0b, 2}, {0x0e, 4},  {0x10, 1}, {0x11, 2},  {0x12, 5},
+      {0x13, 17}, {0x14, 1}, {0x15, 2},  {0x17, 2}, {0x19, 13}, {0x1c, 5},
+      {0x1d, 8},  {0x24, 1}, {0x6a, 3},  {0x6b, 2}, {0xbc, 2},  {0xd1, 2},
+      {0xd4, 12}, {0xd5, 9}, {0xd6, 2},  {0xd7, 2}, {0xda, 1},  {0xe0, 5},
+      {0xe1, 2},  {0xe8, 2}, {0xee, 32}, {0xf0, 4}, {0xf8, 2},  {0xf9, 2},
+      {0xfa, 2},  {0xfb, 1},
+  };
+  static constexpr unsigned char singletons1_lower[] = {
+      0x0c, 0x27, 0x3b, 0x3e, 0x4e, 0x4f, 0x8f, 0x9e, 0x9e, 0x9f, 0x06, 0x07,
+      0x09, 0x36, 0x3d, 0x3e, 0x56, 0xf3, 0xd0, 0xd1, 0x04, 0x14, 0x18, 0x36,
+      0x37, 0x56, 0x57, 0x7f, 0xaa, 0xae, 0xaf, 0xbd, 0x35, 0xe0, 0x12, 0x87,
+      0x89, 0x8e, 0x9e, 0x04, 0x0d, 0x0e, 0x11, 0x12, 0x29, 0x31, 0x34, 0x3a,
+      0x45, 0x46, 0x49, 0x4a, 0x4e, 0x4f, 0x64, 0x65, 0x5c, 0xb6, 0xb7, 0x1b,
+      0x1c, 0x07, 0x08, 0x0a, 0x0b, 0x14, 0x17, 0x36, 0x39, 0x3a, 0xa8, 0xa9,
+      0xd8, 0xd9, 0x09, 0x37, 0x90, 0x91, 0xa8, 0x07, 0x0a, 0x3b, 0x3e, 0x66,
+      0x69, 0x8f, 0x92, 0x6f, 0x5f, 0xee, 0xef, 0x5a, 0x62, 0x9a, 0x9b, 0x27,
+      0x28, 0x55, 0x9d, 0xa0, 0xa1, 0xa3, 0xa4, 0xa7, 0xa8, 0xad, 0xba, 0xbc,
+      0xc4, 0x06, 0x0b, 0x0c, 0x15, 0x1d, 0x3a, 0x3f, 0x45, 0x51, 0xa6, 0xa7,
+      0xcc, 0xcd, 0xa0, 0x07, 0x19, 0x1a, 0x22, 0x25, 0x3e, 0x3f, 0xc5, 0xc6,
+      0x04, 0x20, 0x23, 0x25, 0x26, 0x28, 0x33, 0x38, 0x3a, 0x48, 0x4a, 0x4c,
+      0x50, 0x53, 0x55, 0x56, 0x58, 0x5a, 0x5c, 0x5e, 0x60, 0x63, 0x65, 0x66,
+      0x6b, 0x73, 0x78, 0x7d, 0x7f, 0x8a, 0xa4, 0xaa, 0xaf, 0xb0, 0xc0, 0xd0,
+      0xae, 0xaf, 0x79, 0xcc, 0x6e, 0x6f, 0x93,
+  };
+  static constexpr unsigned char normal0[] = {
+      0x00, 0x20, 0x5f, 0x22, 0x82, 0xdf, 0x04, 0x82, 0x44, 0x08, 0x1b, 0x04,
+      0x06, 0x11, 0x81, 0xac, 0x0e, 0x80, 0xab, 0x35, 0x28, 0x0b, 0x80, 0xe0,
+      0x03, 0x19, 0x08, 0x01, 0x04, 0x2f, 0x04, 0x34, 0x04, 0x07, 0x03, 0x01,
+      0x07, 0x06, 0x07, 0x11, 0x0a, 0x50, 0x0f, 0x12, 0x07, 0x55, 0x07, 0x03,
+      0x04, 0x1c, 0x0a, 0x09, 0x03, 0x08, 0x03, 0x07, 0x03, 0x02, 0x03, 0x03,
+      0x03, 0x0c, 0x04, 0x05, 0x03, 0x0b, 0x06, 0x01, 0x0e, 0x15, 0x05, 0x3a,
+      0x03, 0x11, 0x07, 0x06, 0x05, 0x10, 0x07, 0x57, 0x07, 0x02, 0x07, 0x15,
+      0x0d, 0x50, 0x04, 0x43, 0x03, 0x2d, 0x03, 0x01, 0x04, 0x11, 0x06, 0x0f,
+      0x0c, 0x3a, 0x04, 0x1d, 0x25, 0x5f, 0x20, 0x6d, 0x04, 0x6a, 0x25, 0x80,
+      0xc8, 0x05, 0x82, 0xb0, 0x03, 0x1a, 0x06, 0x82, 0xfd, 0x03, 0x59, 0x07,
+      0x15, 0x0b, 0x17, 0x09, 0x14, 0x0c, 0x14, 0x0c, 0x6a, 0x06, 0x0a, 0x06,
+      0x1a, 0x06, 0x59, 0x07, 0x2b, 0x05, 0x46, 0x0a, 0x2c, 0x04, 0x0c, 0x04,
+      0x01, 0x03, 0x31, 0x0b, 0x2c, 0x04, 0x1a, 0x06, 0x0b, 0x03, 0x80, 0xac,
+      0x06, 0x0a, 0x06, 0x21, 0x3f, 0x4c, 0x04, 0x2d, 0x03, 0x74, 0x08, 0x3c,
+      0x03, 0x0f, 0x03, 0x3c, 0x07, 0x38, 0x08, 0x2b, 0x05, 0x82, 0xff, 0x11,
+      0x18, 0x08, 0x2f, 0x11, 0x2d, 0x03, 0x20, 0x10, 0x21, 0x0f, 0x80, 0x8c,
+      0x04, 0x82, 0x97, 0x19, 0x0b, 0x15, 0x88, 0x94, 0x05, 0x2f, 0x05, 0x3b,
+      0x07, 0x02, 0x0e, 0x18, 0x09, 0x80, 0xb3, 0x2d, 0x74, 0x0c, 0x80, 0xd6,
+      0x1a, 0x0c, 0x05, 0x80, 0xff, 0x05, 0x80, 0xdf, 0x0c, 0xee, 0x0d, 0x03,
+      0x84, 0x8d, 0x03, 0x37, 0x09, 0x81, 0x5c, 0x14, 0x80, 0xb8, 0x08, 0x80,
+      0xcb, 0x2a, 0x38, 0x03, 0x0a, 0x06, 0x38, 0x08, 0x46, 0x08, 0x0c, 0x06,
+      0x74, 0x0b, 0x1e, 0x03, 0x5a, 0x04, 0x59, 0x09, 0x80, 0x83, 0x18, 0x1c,
+      0x0a, 0x16, 0x09, 0x4c, 0x04, 0x80, 0x8a, 0x06, 0xab, 0xa4, 0x0c, 0x17,
+      0x04, 0x31, 0xa1, 0x04, 0x81, 0xda, 0x26, 0x07, 0x0c, 0x05, 0x05, 0x80,
+      0xa5, 0x11, 0x81, 0x6d, 0x10, 0x78, 0x28, 0x2a, 0x06, 0x4c, 0x04, 0x80,
+      0x8d, 0x04, 0x80, 0xbe, 0x03, 0x1b, 0x03, 0x0f, 0x0d,
+  };
+  static constexpr unsigned char normal1[] = {
+      0x5e, 0x22, 0x7b, 0x05, 0x03, 0x04, 0x2d, 0x03, 0x66, 0x03, 0x01, 0x2f,
+      0x2e, 0x80, 0x82, 0x1d, 0x03, 0x31, 0x0f, 0x1c, 0x04, 0x24, 0x09, 0x1e,
+      0x05, 0x2b, 0x05, 0x44, 0x04, 0x0e, 0x2a, 0x80, 0xaa, 0x06, 0x24, 0x04,
+      0x24, 0x04, 0x28, 0x08, 0x34, 0x0b, 0x01, 0x80, 0x90, 0x81, 0x37, 0x09,
+      0x16, 0x0a, 0x08, 0x80, 0x98, 0x39, 0x03, 0x63, 0x08, 0x09, 0x30, 0x16,
+      0x05, 0x21, 0x03, 0x1b, 0x05, 0x01, 0x40, 0x38, 0x04, 0x4b, 0x05, 0x2f,
+      0x04, 0x0a, 0x07, 0x09, 0x07, 0x40, 0x20, 0x27, 0x04, 0x0c, 0x09, 0x36,
+      0x03, 0x3a, 0x05, 0x1a, 0x07, 0x04, 0x0c, 0x07, 0x50, 0x49, 0x37, 0x33,
+      0x0d, 0x33, 0x07, 0x2e, 0x08, 0x0a, 0x81, 0x26, 0x52, 0x4e, 0x28, 0x08,
+      0x2a, 0x56, 0x1c, 0x14, 0x17, 0x09, 0x4e, 0x04, 0x1e, 0x0f, 0x43, 0x0e,
+      0x19, 0x07, 0x0a, 0x06, 0x48, 0x08, 0x27, 0x09, 0x75, 0x0b, 0x3f, 0x41,
+      0x2a, 0x06, 0x3b, 0x05, 0x0a, 0x06, 0x51, 0x06, 0x01, 0x05, 0x10, 0x03,
+      0x05, 0x80, 0x8b, 0x62, 0x1e, 0x48, 0x08, 0x0a, 0x80, 0xa6, 0x5e, 0x22,
+      0x45, 0x0b, 0x0a, 0x06, 0x0d, 0x13, 0x39, 0x07, 0x0a, 0x36, 0x2c, 0x04,
+      0x10, 0x80, 0xc0, 0x3c, 0x64, 0x53, 0x0c, 0x48, 0x09, 0x0a, 0x46, 0x45,
+      0x1b, 0x48, 0x08, 0x53, 0x1d, 0x39, 0x81, 0x07, 0x46, 0x0a, 0x1d, 0x03,
+      0x47, 0x49, 0x37, 0x03, 0x0e, 0x08, 0x0a, 0x06, 0x39, 0x07, 0x0a, 0x81,
+      0x36, 0x19, 0x80, 0xb7, 0x01, 0x0f, 0x32, 0x0d, 0x83, 0x9b, 0x66, 0x75,
+      0x0b, 0x80, 0xc4, 0x8a, 0xbc, 0x84, 0x2f, 0x8f, 0xd1, 0x82, 0x47, 0xa1,
+      0xb9, 0x82, 0x39, 0x07, 0x2a, 0x04, 0x02, 0x60, 0x26, 0x0a, 0x46, 0x0a,
+      0x28, 0x05, 0x13, 0x82, 0xb0, 0x5b, 0x65, 0x4b, 0x04, 0x39, 0x07, 0x11,
+      0x40, 0x05, 0x0b, 0x02, 0x0e, 0x97, 0xf8, 0x08, 0x84, 0xd6, 0x2a, 0x09,
+      0xa2, 0xf7, 0x81, 0x1f, 0x31, 0x03, 0x11, 0x04, 0x08, 0x81, 0x8c, 0x89,
+      0x04, 0x6b, 0x05, 0x0d, 0x03, 0x09, 0x07, 0x10, 0x93, 0x60, 0x80, 0xf6,
+      0x0a, 0x73, 0x08, 0x6e, 0x17, 0x46, 0x80, 0x9a, 0x14, 0x0c, 0x57, 0x09,
+      0x19, 0x80, 0x87, 0x81, 0x47, 0x03, 0x85, 0x42, 0x0f, 0x15, 0x85, 0x50,
+      0x2b, 0x80, 0xd5, 0x2d, 0x03, 0x1a, 0x04, 0x02, 0x81, 0x70, 0x3a, 0x05,
+      0x01, 0x85, 0x00, 0x80, 0xd7, 0x29, 0x4c, 0x04, 0x0a, 0x04, 0x02, 0x83,
+      0x11, 0x44, 0x4c, 0x3d, 0x80, 0xc2, 0x3c, 0x06, 0x01, 0x04, 0x55, 0x05,
+      0x1b, 0x34, 0x02, 0x81, 0x0e, 0x2c, 0x04, 0x64, 0x0c, 0x56, 0x0a, 0x80,
+      0xae, 0x38, 0x1d, 0x0d, 0x2c, 0x04, 0x09, 0x07, 0x02, 0x0e, 0x06, 0x80,
+      0x9a, 0x83, 0xd8, 0x08, 0x0d, 0x03, 0x0d, 0x03, 0x74, 0x0c, 0x59, 0x07,
+      0x0c, 0x14, 0x0c, 0x04, 0x38, 0x08, 0x0a, 0x06, 0x28, 0x08, 0x22, 0x4e,
+      0x81, 0x54, 0x0c, 0x15, 0x03, 0x03, 0x05, 0x07, 0x09, 0x19, 0x07, 0x07,
+      0x09, 0x03, 0x0d, 0x07, 0x29, 0x80, 0xcb, 0x25, 0x0a, 0x84, 0x06,
+  };
+  auto lower = static_cast<uint16_t>(cp);
+  if (cp < 0x10000) {
+    return is_printable(lower, singletons0,
+                        sizeof(singletons0) / sizeof(*singletons0),
+                        singletons0_lower, normal0, sizeof(normal0));
+  }
+  if (cp < 0x20000) {
+    return is_printable(lower, singletons1,
+                        sizeof(singletons1) / sizeof(*singletons1),
+                        singletons1_lower, normal1, sizeof(normal1));
+  }
+  if (0x2a6de <= cp && cp < 0x2a700) return false;
+  if (0x2b735 <= cp && cp < 0x2b740) return false;
+  if (0x2b81e <= cp && cp < 0x2b820) return false;
+  if (0x2cea2 <= cp && cp < 0x2ceb0) return false;
+  if (0x2ebe1 <= cp && cp < 0x2f800) return false;
+  if (0x2fa1e <= cp && cp < 0x30000) return false;
+  if (0x3134b <= cp && cp < 0xe0100) return false;
+  if (0xe01f0 <= cp && cp < 0x110000) return false;
+  return cp < 0x110000;
 }
 
-FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const char) {
+inline auto needs_escape(uint32_t cp) -> bool {
-  return add_space ? " '{}'" : "'{}'";
+  return cp < 0x20 || cp == 0x7f || cp == '"' || cp == '\\' ||
+         !is_printable(cp);
 }
-FMT_CONSTEXPR const wchar_t* format_str_quoted(bool add_space, const wchar_t) {
+
-  return add_space ? L" '{}'" : L"'{}'";
+template <typename Char> struct find_escape_result {
+  const Char* begin;
+  const Char* end;
+  uint32_t cp;
+};
+
+template <typename Char>
+auto find_escape(const Char* begin, const Char* end)
+    -> find_escape_result<Char> {
+  for (; begin != end; ++begin) {
+    auto cp = static_cast<typename std::make_unsigned<Char>::type>(*begin);
+    if (sizeof(Char) == 1 && cp >= 0x80) continue;
+    if (needs_escape(cp)) return {begin, begin + 1, cp};
+  }
+  return {begin, nullptr, 0};
 }
+
+inline auto find_escape(const char* begin, const char* end)
+    -> find_escape_result<char> {
+  if (!is_utf8()) return find_escape<char>(begin, end);
+  auto result = find_escape_result<char>{end, nullptr, 0};
+  for_each_codepoint(string_view(begin, to_unsigned(end - begin)),
+                     [&](uint32_t cp, string_view sv) {
+                       if (needs_escape(cp)) {
+                         result = {sv.begin(), sv.end(), cp};
+                         return false;
+                       }
+                       return true;
+                     });
+  return result;
+}
+
+template <typename Char, typename OutputIt>
+auto write_range_entry(OutputIt out, basic_string_view<Char> str) -> OutputIt {
+  *out++ = '"';
+  auto begin = str.begin(), end = str.end();
+  do {
+    auto escape = find_escape(begin, end);
+    out = copy_str<Char>(begin, escape.begin, out);
+    begin = escape.end;
+    if (!begin) break;
+    auto c = static_cast<Char>(escape.cp);
+    switch (escape.cp) {
+    case '\n':
+      *out++ = '\\';
+      c = 'n';
+      break;
+    case '\r':
+      *out++ = '\\';
+      c = 'r';
+      break;
+    case '\t':
+      *out++ = '\\';
+      c = 't';
+      break;
+    case '"':
+      FMT_FALLTHROUGH;
+    case '\\':
+      *out++ = '\\';
+      break;
+    default:
+      if (is_utf8()) {
+        if (escape.cp < 0x100) {
+          out = format_to(out, "\\x{:02x}", escape.cp);
+          continue;
+        }
+        if (escape.cp < 0x10000) {
+          out = format_to(out, "\\u{:04x}", escape.cp);
+          continue;
+        }
+        if (escape.cp < 0x110000) {
+          out = format_to(out, "\\U{:08x}", escape.cp);
+          continue;
+        }
+      }
+      for (Char escape_char : basic_string_view<Char>(
+               escape.begin, to_unsigned(escape.end - escape.begin))) {
+        out = format_to(
+            out, "\\x{:02x}",
+            static_cast<typename std::make_unsigned<Char>::type>(escape_char));
+      }
+      continue;
+    }
+    *out++ = c;
+  } while (begin != end);
+  *out++ = '"';
+  return out;
+}
+
+template <typename Char, typename OutputIt, typename T,
+          FMT_ENABLE_IF(std::is_convertible<T, std_string_view<char>>::value)>
+inline auto write_range_entry(OutputIt out, const T& str) -> OutputIt {
+  auto sv = std_string_view<Char>(str);
+  return write_range_entry<Char>(out, basic_string_view<Char>(sv));
+}
+
+template <typename Char, typename OutputIt, typename Arg,
+          FMT_ENABLE_IF(std::is_same<Arg, Char>::value)>
+OutputIt write_range_entry(OutputIt out, const Arg v) {
+  *out++ = '\'';
+  *out++ = v;
+  *out++ = '\'';
+  return out;
+}
+
+template <
+    typename Char, typename OutputIt, typename Arg,
+    FMT_ENABLE_IF(!is_std_string_like<typename std::decay<Arg>::type>::value &&
+                  !std::is_same<Arg, Char>::value)>
+OutputIt write_range_entry(OutputIt out, const Arg& v) {
+  return write<Char>(out, v);
+}
+
 }  // namespace detail
 
 template <typename T> struct is_tuple_like {
@@ -195,55 +547,37 @@ template <typename T> struct is_tuple_like {
 template <typename TupleT, typename Char>
 struct formatter<TupleT, Char, enable_if_t<fmt::is_tuple_like<TupleT>::value>> {
  private:
-  // C++11 generic lambda for format()
+  // C++11 generic lambda for format().
   template <typename FormatContext> struct format_each {
     template <typename T> void operator()(const T& v) {
-      if (i > 0) {
+      if (i > 0) out = detail::write_delimiter(out);
-        if (formatting.add_prepostfix_space) {
+      out = detail::write_range_entry<Char>(out, v);
-          *out++ = ' ';
-        }
-        out = detail::copy(formatting.delimiter, out);
-      }
-      out = format_to(out,
-                      detail::format_str_quoted(
-                          (formatting.add_delimiter_spaces && i > 0), v),
-                      v);
       ++i;
     }
-
+    int i;
-    formatting_tuple<Char>& formatting;
+    typename FormatContext::iterator& out;
-    size_t& i;
-    typename std::add_lvalue_reference<decltype(
-        std::declval<FormatContext>().out())>::type out;
   };
 
  public:
-  formatting_tuple<Char> formatting;
-
   template <typename ParseContext>
   FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
-    return formatting.parse(ctx);
+    return ctx.begin();
   }
 
   template <typename FormatContext = format_context>
   auto format(const TupleT& values, FormatContext& ctx) -> decltype(ctx.out()) {
     auto out = ctx.out();
-    size_t i = 0;
+    *out++ = '(';
-    detail::copy(formatting.prefix, out);
+    detail::for_each(values, format_each<FormatContext>{0, out});
-
+    *out++ = ')';
-    detail::for_each(values, format_each<FormatContext>{formatting, i, out});
+    return out;
-    if (formatting.add_prepostfix_space) {
-      *out++ = ' ';
-    }
-    detail::copy(formatting.postfix, out);
-
-    return ctx.out();
   }
 };
 
 template <typename T, typename Char> struct is_range {
   static FMT_CONSTEXPR_DECL const bool value =
-      detail::is_range_<T>::value && !detail::is_like_std_string<T>::value &&
+      detail::is_range_<T>::value && !detail::is_std_string_like<T>::value &&
+      !detail::is_map<T>::value &&
       !std::is_convertible<T, std::basic_string<Char>>::value &&
       !std::is_constructible<detail::std_string_view<Char>, T>::value;
 };
@@ -251,100 +585,167 @@ template <typename T, typename Char> struct is_range {
 template <typename T, typename Char>
 struct formatter<
     T, Char,
-    enable_if_t<fmt::is_range<T, Char>::value
+    enable_if_t<
-// Workaround a bug in MSVC 2017 and earlier.
+        fmt::is_range<T, Char>::value
-#if !FMT_MSC_VER || FMT_MSC_VER >= 1927
+// Workaround a bug in MSVC 2019 and earlier.
-                &&
+#if !FMT_MSC_VER
-                (has_formatter<detail::value_type<T>, format_context>::value ||
+        && (is_formattable<detail::value_type<T>, Char>::value ||
-                 detail::has_fallback_formatter<detail::value_type<T>,
+            detail::has_fallback_formatter<detail::value_type<T>, Char>::value)
-                                                format_context>::value)
 #endif
         >> {
-  formatting_range<Char> formatting;
-
-  template <typename ParseContext>
-  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
-    return formatting.parse(ctx);
-  }
-
-  template <typename FormatContext>
-  typename FormatContext::iterator format(const T& values, FormatContext& ctx) {
-    auto out = detail::copy(formatting.prefix, ctx.out());
-    size_t i = 0;
-    auto it = values.begin();
-    auto end = values.end();
-    for (; it != end; ++it) {
-      if (i > 0) {
-        if (formatting.add_prepostfix_space) *out++ = ' ';
-        out = detail::copy(formatting.delimiter, out);
-      }
-      out = format_to(out,
-                      detail::format_str_quoted(
-                          (formatting.add_delimiter_spaces && i > 0), *it),
-                      *it);
-      if (++i > formatting.range_length_limit) {
-        out = format_to(out, " ... <other elements>");
-        break;
-      }
-    }
-    if (formatting.add_prepostfix_space) *out++ = ' ';
-    return detail::copy(formatting.postfix, out);
-  }
-};
-
-template <typename Char, typename... T> struct tuple_arg_join : detail::view {
-  const std::tuple<T...>& tuple;
-  basic_string_view<Char> sep;
-
-  tuple_arg_join(const std::tuple<T...>& t, basic_string_view<Char> s)
-      : tuple{t}, sep{s} {}
-};
-
-template <typename Char, typename... T>
-struct formatter<tuple_arg_join<Char, T...>, Char> {
   template <typename ParseContext>
   FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
     return ctx.begin();
   }
 
+  template <
+      typename FormatContext, typename U,
+      FMT_ENABLE_IF(
+          std::is_same<U, conditional_t<detail::has_const_begin_end<T>::value,
+                                        const T, T>>::value)>
+  auto format(U& range, FormatContext& ctx) -> decltype(ctx.out()) {
+#ifdef FMT_DEPRECATED_BRACED_RANGES
+    Char prefix = '{';
+    Char postfix = '}';
+#else
+    Char prefix = detail::is_set<T>::value ? '{' : '[';
+    Char postfix = detail::is_set<T>::value ? '}' : ']';
+#endif
+    auto out = ctx.out();
+    *out++ = prefix;
+    int i = 0;
+    auto it = std::begin(range);
+    auto end = std::end(range);
+    for (; it != end; ++it) {
+      if (i > 0) out = detail::write_delimiter(out);
+      out = detail::write_range_entry<Char>(out, *it);
+      ++i;
+    }
+    *out++ = postfix;
+    return out;
+  }
+};
+
+template <typename T, typename Char>
+struct formatter<
+    T, Char,
+    enable_if_t<
+        detail::is_map<T>::value
+// Workaround a bug in MSVC 2019 and earlier.
+#if !FMT_MSC_VER
+        && (is_formattable<detail::value_type<T>, Char>::value ||
+            detail::has_fallback_formatter<detail::value_type<T>, Char>::value)
+#endif
+        >> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <
+      typename FormatContext, typename U,
+      FMT_ENABLE_IF(
+          std::is_same<U, conditional_t<detail::has_const_begin_end<T>::value,
+                                        const T, T>>::value)>
+  auto format(U& map, FormatContext& ctx) -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    *out++ = '{';
+    int i = 0;
+    for (const auto& item : map) {
+      if (i > 0) out = detail::write_delimiter(out);
+      out = detail::write_range_entry<Char>(out, item.first);
+      *out++ = ':';
+      *out++ = ' ';
+      out = detail::write_range_entry<Char>(out, item.second);
+      ++i;
+    }
+    *out++ = '}';
+    return out;
+  }
+};
+
+template <typename Char, typename... T> struct tuple_join_view : detail::view {
+  const std::tuple<T...>& tuple;
+  basic_string_view<Char> sep;
+
+  tuple_join_view(const std::tuple<T...>& t, basic_string_view<Char> s)
+      : tuple(t), sep{s} {}
+};
+
+template <typename Char, typename... T>
+using tuple_arg_join = tuple_join_view<Char, T...>;
+
+// Define FMT_TUPLE_JOIN_SPECIFIERS to enable experimental format specifiers
+// support in tuple_join. It is disabled by default because of issues with
+// the dynamic width and precision.
+#ifndef FMT_TUPLE_JOIN_SPECIFIERS
+#  define FMT_TUPLE_JOIN_SPECIFIERS 0
+#endif
+
+template <typename Char, typename... T>
+struct formatter<tuple_join_view<Char, T...>, Char> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return do_parse(ctx, std::integral_constant<size_t, sizeof...(T)>());
+  }
+
   template <typename FormatContext>
-  typename FormatContext::iterator format(
+  auto format(const tuple_join_view<Char, T...>& value,
-      const tuple_arg_join<Char, T...>& value, FormatContext& ctx) {
+              FormatContext& ctx) const -> typename FormatContext::iterator {
-    return format(value, ctx, detail::make_index_sequence<sizeof...(T)>{});
+    return do_format(value, ctx,
+                     std::integral_constant<size_t, sizeof...(T)>());
   }
 
  private:
-  template <typename FormatContext, size_t... N>
+  std::tuple<formatter<typename std::decay<T>::type, Char>...> formatters_;
-  typename FormatContext::iterator format(
+
-      const tuple_arg_join<Char, T...>& value, FormatContext& ctx,
+  template <typename ParseContext>
-      detail::index_sequence<N...>) {
+  FMT_CONSTEXPR auto do_parse(ParseContext& ctx,
-    return format_args(value, ctx, std::get<N>(value.tuple)...);
+                              std::integral_constant<size_t, 0>)
+      -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename ParseContext, size_t N>
+  FMT_CONSTEXPR auto do_parse(ParseContext& ctx,
+                              std::integral_constant<size_t, N>)
+      -> decltype(ctx.begin()) {
+    auto end = ctx.begin();
+#if FMT_TUPLE_JOIN_SPECIFIERS
+    end = std::get<sizeof...(T) - N>(formatters_).parse(ctx);
+    if (N > 1) {
+      auto end1 = do_parse(ctx, std::integral_constant<size_t, N - 1>());
+      if (end != end1)
+        FMT_THROW(format_error("incompatible format specs for tuple elements"));
+    }
+#endif
+    return end;
   }
 
   template <typename FormatContext>
-  typename FormatContext::iterator format_args(
+  auto do_format(const tuple_join_view<Char, T...>&, FormatContext& ctx,
-      const tuple_arg_join<Char, T...>&, FormatContext& ctx) {
+                 std::integral_constant<size_t, 0>) const ->
-    // NOTE: for compilers that support C++17, this empty function instantiation
+      typename FormatContext::iterator {
-    // can be replaced with a constexpr branch in the variadic overload.
     return ctx.out();
   }
 
-  template <typename FormatContext, typename Arg, typename... Args>
+  template <typename FormatContext, size_t N>
-  typename FormatContext::iterator format_args(
+  auto do_format(const tuple_join_view<Char, T...>& value, FormatContext& ctx,
-      const tuple_arg_join<Char, T...>& value, FormatContext& ctx,
+                 std::integral_constant<size_t, N>) const ->
-      const Arg& arg, const Args&... args) {
+      typename FormatContext::iterator {
-    using base = formatter<typename std::decay<Arg>::type, Char>;
+    auto out = std::get<sizeof...(T) - N>(formatters_)
-    auto out = ctx.out();
+                   .format(std::get<sizeof...(T) - N>(value.tuple), ctx);
-    out = base{}.format(arg, ctx);
+    if (N > 1) {
-    if (sizeof...(Args) > 0) {
       out = std::copy(value.sep.begin(), value.sep.end(), out);
       ctx.advance_to(out);
-      return format_args(value, ctx, args...);
+      return do_format(value, ctx, std::integral_constant<size_t, N - 1>());
     }
     return out;
   }
 };
 
+FMT_MODULE_EXPORT_BEGIN
+
 /**
   \rst
   Returns an object that formats `tuple` with elements separated by `sep`.
@@ -357,14 +758,15 @@ struct formatter<tuple_arg_join<Char, T...>, Char> {
   \endrst
  */
 template <typename... T>
-FMT_CONSTEXPR tuple_arg_join<char, T...> join(const std::tuple<T...>& tuple,
+FMT_CONSTEXPR auto join(const std::tuple<T...>& tuple, string_view sep)
-                                              string_view sep) {
+    -> tuple_join_view<char, T...> {
   return {tuple, sep};
 }
 
 template <typename... T>
-FMT_CONSTEXPR tuple_arg_join<wchar_t, T...> join(const std::tuple<T...>& tuple,
+FMT_CONSTEXPR auto join(const std::tuple<T...>& tuple,
-                                                 wstring_view sep) {
+                        basic_string_view<wchar_t> sep)
+    -> tuple_join_view<wchar_t, T...> {
   return {tuple, sep};
 }
 
@@ -380,17 +782,12 @@ FMT_CONSTEXPR tuple_arg_join<wchar_t, T...> join(const std::tuple<T...>& tuple,
   \endrst
  */
 template <typename T>
-arg_join<const T*, const T*, char> join(std::initializer_list<T> list,
+auto join(std::initializer_list<T> list, string_view sep)
-                                        string_view sep) {
+    -> join_view<const T*, const T*> {
-  return join(std::begin(list), std::end(list), sep);
-}
-
-template <typename T>
-arg_join<const T*, const T*, wchar_t> join(std::initializer_list<T> list,
-                                           wstring_view sep) {
   return join(std::begin(list), std::end(list), sep);
 }
 
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_RANGES_H_

deps/fmt/include/fmt/xchar.h

@@ -0,0 +1,236 @@
+// Formatting library for C++ - optional wchar_t and exotic character support
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_XCHAR_H_
+#define FMT_XCHAR_H_
+
+#include <cwchar>
+#include <tuple>
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+namespace detail {
+template <typename T>
+using is_exotic_char = bool_constant<!std::is_same<T, char>::value>;
+}
+
+FMT_MODULE_EXPORT_BEGIN
+
+using wstring_view = basic_string_view<wchar_t>;
+using wformat_parse_context = basic_format_parse_context<wchar_t>;
+using wformat_context = buffer_context<wchar_t>;
+using wformat_args = basic_format_args<wformat_context>;
+using wmemory_buffer = basic_memory_buffer<wchar_t>;
+
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+// Workaround broken conversion on older gcc.
+template <typename... Args> using wformat_string = wstring_view;
+#else
+template <typename... Args>
+using wformat_string = basic_format_string<wchar_t, type_identity_t<Args>...>;
+#endif
+
+template <> struct is_char<wchar_t> : std::true_type {};
+template <> struct is_char<detail::char8_type> : std::true_type {};
+template <> struct is_char<char16_t> : std::true_type {};
+template <> struct is_char<char32_t> : std::true_type {};
+
+template <typename... Args>
+constexpr format_arg_store<wformat_context, Args...> make_wformat_args(
+    const Args&... args) {
+  return {args...};
+}
+
+inline namespace literals {
+constexpr auto operator"" _format(const wchar_t* s, size_t n)
+    -> detail::udl_formatter<wchar_t> {
+  return {{s, n}};
+}
+
+#if FMT_USE_USER_DEFINED_LITERALS && !FMT_USE_NONTYPE_TEMPLATE_PARAMETERS
+constexpr detail::udl_arg<wchar_t> operator"" _a(const wchar_t* s, size_t) {
+  return {s};
+}
+#endif
+}  // namespace literals
+
+template <typename It, typename Sentinel>
+auto join(It begin, Sentinel end, wstring_view sep)
+    -> join_view<It, Sentinel, wchar_t> {
+  return {begin, end, sep};
+}
+
+template <typename Range>
+auto join(Range&& range, wstring_view sep)
+    -> join_view<detail::iterator_t<Range>, detail::sentinel_t<Range>,
+                 wchar_t> {
+  return join(std::begin(range), std::end(range), sep);
+}
+
+template <typename T>
+auto join(std::initializer_list<T> list, wstring_view sep)
+    -> join_view<const T*, const T*, wchar_t> {
+  return join(std::begin(list), std::end(list), sep);
+}
+
+template <typename Char, FMT_ENABLE_IF(!std::is_same<Char, char>::value)>
+auto vformat(basic_string_view<Char> format_str,
+             basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
+  basic_memory_buffer<Char> buffer;
+  detail::vformat_to(buffer, format_str, args);
+  return to_string(buffer);
+}
+
+// Pass char_t as a default template parameter instead of using
+// std::basic_string<char_t<S>> to reduce the symbol size.
+template <typename S, typename... Args, typename Char = char_t<S>,
+          FMT_ENABLE_IF(!std::is_same<Char, char>::value)>
+auto format(const S& format_str, Args&&... args) -> std::basic_string<Char> {
+  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
+  return vformat(to_string_view(format_str), vargs);
+}
+
+template <typename Locale, typename S, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_locale<Locale>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto vformat(
+    const Locale& loc, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
+  return detail::vformat(loc, to_string_view(format_str), args);
+}
+
+template <typename Locale, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_locale<Locale>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto format(const Locale& loc, const S& format_str, Args&&... args)
+    -> std::basic_string<Char> {
+  return detail::vformat(loc, to_string_view(format_str),
+                         fmt::make_args_checked<Args...>(format_str, args...));
+}
+
+template <typename OutputIt, typename S, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+auto vformat_to(OutputIt out, const S& format_str,
+                basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> OutputIt {
+  auto&& buf = detail::get_buffer<Char>(out);
+  detail::vformat_to(buf, to_string_view(format_str), args);
+  return detail::get_iterator(buf);
+}
+
+template <typename OutputIt, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto format_to(OutputIt out, const S& fmt, Args&&... args) -> OutputIt {
+  const auto& vargs = fmt::make_args_checked<Args...>(fmt, args...);
+  return vformat_to(out, to_string_view(fmt), vargs);
+}
+
+template <typename S, typename... Args, typename Char, size_t SIZE,
+          typename Allocator, FMT_ENABLE_IF(detail::is_string<S>::value)>
+FMT_DEPRECATED auto format_to(basic_memory_buffer<Char, SIZE, Allocator>& buf,
+                              const S& format_str, Args&&... args) ->
+    typename buffer_context<Char>::iterator {
+  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
+  detail::vformat_to(buf, to_string_view(format_str), vargs, {});
+  return detail::buffer_appender<Char>(buf);
+}
+
+template <typename Locale, typename S, typename OutputIt, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_locale<Locale>::value&&
+                                detail::is_exotic_char<Char>::value)>
+inline auto vformat_to(
+    OutputIt out, const Locale& loc, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) -> OutputIt {
+  auto&& buf = detail::get_buffer<Char>(out);
+  vformat_to(buf, to_string_view(format_str), args, detail::locale_ref(loc));
+  return detail::get_iterator(buf);
+}
+
+template <
+    typename OutputIt, typename Locale, typename S, typename... Args,
+    typename Char = char_t<S>,
+    bool enable = detail::is_output_iterator<OutputIt, Char>::value&&
+        detail::is_locale<Locale>::value&& detail::is_exotic_char<Char>::value>
+inline auto format_to(OutputIt out, const Locale& loc, const S& format_str,
+                      Args&&... args) ->
+    typename std::enable_if<enable, OutputIt>::type {
+  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
+  return vformat_to(out, loc, to_string_view(format_str), vargs);
+}
+
+template <typename OutputIt, typename Char, typename... Args,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto vformat_to_n(
+    OutputIt out, size_t n, basic_string_view<Char> format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> format_to_n_result<OutputIt> {
+  detail::iterator_buffer<OutputIt, Char, detail::fixed_buffer_traits> buf(out,
+                                                                           n);
+  detail::vformat_to(buf, format_str, args);
+  return {buf.out(), buf.count()};
+}
+
+template <typename OutputIt, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto format_to_n(OutputIt out, size_t n, const S& fmt,
+                        const Args&... args) -> format_to_n_result<OutputIt> {
+  const auto& vargs = fmt::make_args_checked<Args...>(fmt, args...);
+  return vformat_to_n(out, n, to_string_view(fmt), vargs);
+}
+
+template <typename S, typename... Args, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_exotic_char<Char>::value)>
+inline auto formatted_size(const S& fmt, Args&&... args) -> size_t {
+  detail::counting_buffer<Char> buf;
+  const auto& vargs = fmt::make_args_checked<Args...>(fmt, args...);
+  detail::vformat_to(buf, to_string_view(fmt), vargs);
+  return buf.count();
+}
+
+inline void vprint(std::FILE* f, wstring_view fmt, wformat_args args) {
+  wmemory_buffer buffer;
+  detail::vformat_to(buffer, fmt, args);
+  buffer.push_back(L'\0');
+  if (std::fputws(buffer.data(), f) == -1)
+    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
+}
+
+inline void vprint(wstring_view fmt, wformat_args args) {
+  vprint(stdout, fmt, args);
+}
+
+template <typename... T>
+void print(std::FILE* f, wformat_string<T...> fmt, T&&... args) {
+  return vprint(f, wstring_view(fmt), fmt::make_wformat_args(args...));
+}
+
+template <typename... T> void print(wformat_string<T...> fmt, T&&... args) {
+  return vprint(wstring_view(fmt), fmt::make_wformat_args(args...));
+}
+
+/**
+  Converts *value* to ``std::wstring`` using the default format for type *T*.
+ */
+template <typename T> inline auto to_wstring(const T& value) -> std::wstring {
+  return format(FMT_STRING(L"{}"), value);
+}
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_XCHAR_H_

deps/fmt/lib/cmake/fmt/fmt-config-version.cmake

@@ -7,15 +7,26 @@
 # PACKAGE_VERSION_COMPATIBLE if the current version is >= requested version.
 # The variable CVF_VERSION must be set before calling configure_file().
 
-set(PACKAGE_VERSION "7.1.3")
+set(PACKAGE_VERSION "8.1.1")
 
-if(PACKAGE_VERSION VERSION_LESS PACKAGE_FIND_VERSION)
+if (PACKAGE_FIND_VERSION_RANGE)
+  # Package version must be in the requested version range
+  if ((PACKAGE_FIND_VERSION_RANGE_MIN STREQUAL "INCLUDE" AND PACKAGE_VERSION VERSION_LESS PACKAGE_FIND_VERSION_MIN)
+      OR ((PACKAGE_FIND_VERSION_RANGE_MAX STREQUAL "INCLUDE" AND PACKAGE_VERSION VERSION_GREATER PACKAGE_FIND_VERSION_MAX)
+        OR (PACKAGE_FIND_VERSION_RANGE_MAX STREQUAL "EXCLUDE" AND PACKAGE_VERSION VERSION_GREATER_EQUAL PACKAGE_FIND_VERSION_MAX)))
     set(PACKAGE_VERSION_COMPATIBLE FALSE)
+  else()
+    set(PACKAGE_VERSION_COMPATIBLE TRUE)
+  endif()
 else()
+  if(PACKAGE_VERSION VERSION_LESS PACKAGE_FIND_VERSION)
+    set(PACKAGE_VERSION_COMPATIBLE FALSE)
+  else()
     set(PACKAGE_VERSION_COMPATIBLE TRUE)
     if(PACKAGE_FIND_VERSION STREQUAL PACKAGE_VERSION)
       set(PACKAGE_VERSION_EXACT TRUE)
     endif()
+  endif()
 endif()
 
 

deps/fmt/lib/cmake/fmt/fmt-targets.cmake

@@ -4,7 +4,7 @@ if("${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION}" LESS 2.5)
    message(FATAL_ERROR "CMake >= 2.6.0 required")
 endif()
 cmake_policy(PUSH)
-cmake_policy(VERSION 2.6...3.17)
+cmake_policy(VERSION 2.6...3.19)
 #----------------------------------------------------------------
 # Generated CMake target import file.
 #----------------------------------------------------------------

deps/fmt/lib/pkgconfig/fmt.pc

@@ -5,7 +5,7 @@ includedir=${prefix}/include
 
 Name: fmt
 Description: A modern formatting library
-Version: 7.1.3
+Version: 8.1.1
 Libs: -L${libdir} -lfmt
 Cflags: -I${includedir}