Bump bundled fmt to version 6.1.0

include/spdlog/fmt/bundled/chrono.h

@@ -16,16 +16,291 @@
 #include <locale>
 #include <sstream>
 
-// enable safe chrono durations, unless explicitly disabled
+FMT_BEGIN_NAMESPACE
+
+// Enable safe chrono durations, unless explicitly disabled.
 #ifndef FMT_SAFE_DURATION_CAST
 #  define FMT_SAFE_DURATION_CAST 1
 #endif
-
 #if FMT_SAFE_DURATION_CAST
-#  include "safe-duration-cast.h"
-#endif
 
-FMT_BEGIN_NAMESPACE
+// For conversion between std::chrono::durations without undefined
+// behaviour or erroneous results.
+// This is a stripped down version of duration_cast, for inclusion in fmt.
+// See https://github.com/pauldreik/safe_duration_cast
+//
+// Copyright Paul Dreik 2019
+namespace safe_duration_cast {
+
+template <typename To, typename From,
+          FMT_ENABLE_IF(!std::is_same<From, To>::value &&
+                        std::numeric_limits<From>::is_signed ==
+                            std::numeric_limits<To>::is_signed)>
+FMT_CONSTEXPR To lossless_integral_conversion(const From from, int& ec) {
+  ec = 0;
+  using F = std::numeric_limits<From>;
+  using T = std::numeric_limits<To>;
+  static_assert(F::is_integer, "From must be integral");
+  static_assert(T::is_integer, "To must be integral");
+
+  // A and B are both signed, or both unsigned.
+  if (F::digits <= T::digits) {
+    // From fits in To without any problem.
+  } else {
+    // From does not always fit in To, resort to a dynamic check.
+    if (from < T::min() || from > T::max()) {
+      // outside range.
+      ec = 1;
+      return {};
+    }
+  }
+  return static_cast<To>(from);
+}
+
+/**
+ * converts From to To, without loss. If the dynamic value of from
+ * can't be converted to To without loss, ec is set.
+ */
+template <typename To, typename From,
+          FMT_ENABLE_IF(!std::is_same<From, To>::value &&
+                        std::numeric_limits<From>::is_signed !=
+                            std::numeric_limits<To>::is_signed)>
+FMT_CONSTEXPR To lossless_integral_conversion(const From from, int& ec) {
+  ec = 0;
+  using F = std::numeric_limits<From>;
+  using T = std::numeric_limits<To>;
+  static_assert(F::is_integer, "From must be integral");
+  static_assert(T::is_integer, "To must be integral");
+
+  if (F::is_signed && !T::is_signed) {
+    // From may be negative, not allowed!
+    if (fmt::internal::is_negative(from)) {
+      ec = 1;
+      return {};
+    }
+
+    // From is positive. Can it always fit in To?
+    if (F::digits <= T::digits) {
+      // yes, From always fits in To.
+    } else {
+      // from may not fit in To, we have to do a dynamic check
+      if (from > static_cast<From>(T::max())) {
+        ec = 1;
+        return {};
+      }
+    }
+  }
+
+  if (!F::is_signed && T::is_signed) {
+    // can from be held in To?
+    if (F::digits < T::digits) {
+      // yes, From always fits in To.
+    } else {
+      // from may not fit in To, we have to do a dynamic check
+      if (from > static_cast<From>(T::max())) {
+        // outside range.
+        ec = 1;
+        return {};
+      }
+    }
+  }
+
+  // reaching here means all is ok for lossless conversion.
+  return static_cast<To>(from);
+
+}  // function
+
+template <typename To, typename From,
+          FMT_ENABLE_IF(std::is_same<From, To>::value)>
+FMT_CONSTEXPR To lossless_integral_conversion(const From from, int& ec) {
+  ec = 0;
+  return from;
+}  // function
+
+// clang-format off
+/**
+ * converts From to To if possible, otherwise ec is set.
+ *
+ * input                            |    output
+ * ---------------------------------|---------------
+ * NaN                              | NaN
+ * Inf                              | Inf
+ * normal, fits in output           | converted (possibly lossy)
+ * normal, does not fit in output   | ec is set
+ * subnormal                        | best effort
+ * -Inf                             | -Inf
+ */
+// clang-format on
+template <typename To, typename From,
+          FMT_ENABLE_IF(!std::is_same<From, To>::value)>
+FMT_CONSTEXPR To safe_float_conversion(const From from, int& ec) {
+  ec = 0;
+  using T = std::numeric_limits<To>;
+  static_assert(std::is_floating_point<From>::value, "From must be floating");
+  static_assert(std::is_floating_point<To>::value, "To must be floating");
+
+  // catch the only happy case
+  if (std::isfinite(from)) {
+    if (from >= T::lowest() && from <= T::max()) {
+      return static_cast<To>(from);
+    }
+    // not within range.
+    ec = 1;
+    return {};
+  }
+
+  // nan and inf will be preserved
+  return static_cast<To>(from);
+}  // function
+
+template <typename To, typename From,
+          FMT_ENABLE_IF(std::is_same<From, To>::value)>
+FMT_CONSTEXPR To safe_float_conversion(const From from, int& ec) {
+  ec = 0;
+  static_assert(std::is_floating_point<From>::value, "From must be floating");
+  return from;
+}
+
+/**
+ * safe duration cast between integral durations
+ */
+template <typename To, typename FromRep, typename FromPeriod,
+          FMT_ENABLE_IF(std::is_integral<FromRep>::value),
+          FMT_ENABLE_IF(std::is_integral<typename To::rep>::value)>
+To safe_duration_cast(std::chrono::duration<FromRep, FromPeriod> from,
+                      int& ec) {
+  using From = std::chrono::duration<FromRep, FromPeriod>;
+  ec = 0;
+  // the basic idea is that we need to convert from count() in the from type
+  // to count() in the To type, by multiplying it with this:
+  struct Factor
+      : std::ratio_divide<typename From::period, typename To::period> {};
+
+  static_assert(Factor::num > 0, "num must be positive");
+  static_assert(Factor::den > 0, "den must be positive");
+
+  // the conversion is like this: multiply from.count() with Factor::num
+  // /Factor::den and convert it to To::rep, all this without
+  // overflow/underflow. let's start by finding a suitable type that can hold
+  // both To, From and Factor::num
+  using IntermediateRep =
+      typename std::common_type<typename From::rep, typename To::rep,
+                                decltype(Factor::num)>::type;
+
+  // safe conversion to IntermediateRep
+  IntermediateRep count =
+      lossless_integral_conversion<IntermediateRep>(from.count(), ec);
+  if (ec) {
+    return {};
+  }
+  // multiply with Factor::num without overflow or underflow
+  if (Factor::num != 1) {
+    const auto max1 = internal::max_value<IntermediateRep>() / Factor::num;
+    if (count > max1) {
+      ec = 1;
+      return {};
+    }
+    const auto min1 = std::numeric_limits<IntermediateRep>::min() / Factor::num;
+    if (count < min1) {
+      ec = 1;
+      return {};
+    }
+    count *= Factor::num;
+  }
+
+  // this can't go wrong, right? den>0 is checked earlier.
+  if (Factor::den != 1) {
+    count /= Factor::den;
+  }
+  // convert to the to type, safely
+  using ToRep = typename To::rep;
+  const ToRep tocount = lossless_integral_conversion<ToRep>(count, ec);
+  if (ec) {
+    return {};
+  }
+  return To{tocount};
+}
+
+/**
+ * safe duration_cast between floating point durations
+ */
+template <typename To, typename FromRep, typename FromPeriod,
+          FMT_ENABLE_IF(std::is_floating_point<FromRep>::value),
+          FMT_ENABLE_IF(std::is_floating_point<typename To::rep>::value)>
+To safe_duration_cast(std::chrono::duration<FromRep, FromPeriod> from,
+                      int& ec) {
+  using From = std::chrono::duration<FromRep, FromPeriod>;
+  ec = 0;
+  if (std::isnan(from.count())) {
+    // nan in, gives nan out. easy.
+    return To{std::numeric_limits<typename To::rep>::quiet_NaN()};
+  }
+  // maybe we should also check if from is denormal, and decide what to do about
+  // it.
+
+  // +-inf should be preserved.
+  if (std::isinf(from.count())) {
+    return To{from.count()};
+  }
+
+  // the basic idea is that we need to convert from count() in the from type
+  // to count() in the To type, by multiplying it with this:
+  struct Factor
+      : std::ratio_divide<typename From::period, typename To::period> {};
+
+  static_assert(Factor::num > 0, "num must be positive");
+  static_assert(Factor::den > 0, "den must be positive");
+
+  // the conversion is like this: multiply from.count() with Factor::num
+  // /Factor::den and convert it to To::rep, all this without
+  // overflow/underflow. let's start by finding a suitable type that can hold
+  // both To, From and Factor::num
+  using IntermediateRep =
+      typename std::common_type<typename From::rep, typename To::rep,
+                                decltype(Factor::num)>::type;
+
+  // force conversion of From::rep -> IntermediateRep to be safe,
+  // even if it will never happen be narrowing in this context.
+  IntermediateRep count =
+      safe_float_conversion<IntermediateRep>(from.count(), ec);
+  if (ec) {
+    return {};
+  }
+
+  // multiply with Factor::num without overflow or underflow
+  if (Factor::num != 1) {
+    constexpr auto max1 = internal::max_value<IntermediateRep>() /
+                          static_cast<IntermediateRep>(Factor::num);
+    if (count > max1) {
+      ec = 1;
+      return {};
+    }
+    constexpr auto min1 = std::numeric_limits<IntermediateRep>::lowest() /
+                          static_cast<IntermediateRep>(Factor::num);
+    if (count < min1) {
+      ec = 1;
+      return {};
+    }
+    count *= static_cast<IntermediateRep>(Factor::num);
+  }
+
+  // this can't go wrong, right? den>0 is checked earlier.
+  if (Factor::den != 1) {
+    using common_t = typename std::common_type<IntermediateRep, intmax_t>::type;
+    count /= static_cast<common_t>(Factor::den);
+  }
+
+  // convert to the to type, safely
+  using ToRep = typename To::rep;
+
+  const ToRep tocount = safe_float_conversion<ToRep>(count, ec);
+  if (ec) {
+    return {};
+  }
+  return To{tocount};
+}
+}  // namespace safe_duration_cast
+#endif
 
 // Prevents expansion of a preceding token as a function-style macro.
 // Usage: f FMT_NOMACRO()
@@ -403,7 +678,7 @@ inline bool isfinite(T value) {
   return std::isfinite(value);
 }
 
-// Convers value to int and checks that it's in the range [0, upper).
+// Converts value to int and checks that it's in the range [0, upper).
 template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
 inline int to_nonnegative_int(T value, int upper) {
   FMT_ASSERT(value >= 0 && value <= upper, "invalid value");
@@ -582,8 +857,8 @@ struct chrono_formatter {
   void write(Rep value, int width) {
     write_sign();
     if (isnan(value)) return write_nan();
-    uint32_or_64_t<int> n = to_unsigned(
+    uint32_or_64_or_128_t<int> n =
-        to_nonnegative_int(value, (std::numeric_limits<int>::max)()));
+        to_unsigned(to_nonnegative_int(value, max_value<int>()));
     int num_digits = internal::count_digits(n);
     if (width > num_digits) out = std::fill_n(out, width - num_digits, '0');
     out = format_decimal<char_type>(out, n, num_digits);
@@ -728,7 +1003,7 @@ struct formatter<std::chrono::duration<Rep, Period>, Char> {
 
   struct spec_handler {
     formatter& f;
-    basic_parse_context<Char>& context;
+    basic_format_parse_context<Char>& context;
     basic_string_view<Char> format_str;
 
     template <typename Id> FMT_CONSTEXPR arg_ref_type make_arg_ref(Id arg_id) {
@@ -738,8 +1013,7 @@ struct formatter<std::chrono::duration<Rep, Period>, Char> {
 
     FMT_CONSTEXPR arg_ref_type make_arg_ref(basic_string_view<Char> arg_id) {
       context.check_arg_id(arg_id);
-      const auto str_val = internal::string_view_metadata(format_str, arg_id);
+      return arg_ref_type(arg_id);
-      return arg_ref_type(str_val);
     }
 
     FMT_CONSTEXPR arg_ref_type make_arg_ref(internal::auto_id) {
@@ -750,7 +1024,7 @@ struct formatter<std::chrono::duration<Rep, Period>, Char> {
     void on_fill(Char fill) { f.specs.fill[0] = fill; }
     void on_align(align_t align) { f.specs.align = align; }
     void on_width(unsigned width) { f.specs.width = width; }
-    void on_precision(unsigned precision) { f.precision = precision; }
+    void on_precision(unsigned _precision) { f.precision = _precision; }
     void end_precision() {}
 
     template <typename Id> void on_dynamic_width(Id arg_id) {
@@ -762,13 +1036,13 @@ struct formatter<std::chrono::duration<Rep, Period>, Char> {
     }
   };
 
-  using iterator = typename basic_parse_context<Char>::iterator;
+  using iterator = typename basic_format_parse_context<Char>::iterator;
   struct parse_range {
     iterator begin;
     iterator end;
   };
 
-  FMT_CONSTEXPR parse_range do_parse(basic_parse_context<Char>& ctx) {
+  FMT_CONSTEXPR parse_range do_parse(basic_format_parse_context<Char>& ctx) {
     auto begin = ctx.begin(), end = ctx.end();
     if (begin == end || *begin == '}') return {begin, begin};
     spec_handler handler{*this, ctx, format_str};
@@ -789,7 +1063,7 @@ struct formatter<std::chrono::duration<Rep, Period>, Char> {
  public:
   formatter() : precision(-1) {}
 
-  FMT_CONSTEXPR auto parse(basic_parse_context<Char>& ctx)
+  FMT_CONSTEXPR auto parse(basic_format_parse_context<Char>& ctx)
       -> decltype(ctx.begin()) {
     auto range = do_parse(ctx);
     format_str = basic_string_view<Char>(
@@ -806,10 +1080,10 @@ struct formatter<std::chrono::duration<Rep, Period>, Char> {
     auto out = std::back_inserter(buf);
     using range = internal::output_range<decltype(ctx.out()), Char>;
     internal::basic_writer<range> w(range(ctx.out()));
-    internal::handle_dynamic_spec<internal::width_checker>(
+    internal::handle_dynamic_spec<internal::width_checker>(specs.width,
-        specs.width, width_ref, ctx, format_str.begin());
+                                                           width_ref, ctx);
     internal::handle_dynamic_spec<internal::precision_checker>(
-        precision, precision_ref, ctx, format_str.begin());
+        precision, precision_ref, ctx);
     if (begin == end || *begin == '}') {
       out = internal::format_chrono_duration_value(out, d.count(), precision);
       internal::format_chrono_duration_unit<Period>(out);

include/spdlog/fmt/bundled/color.h

@@ -299,15 +299,15 @@ class text_style {
     return static_cast<uint8_t>(ems) != 0;
   }
   FMT_CONSTEXPR internal::color_type get_foreground() const FMT_NOEXCEPT {
-    assert(has_foreground() && "no foreground specified for this style");
+    FMT_ASSERT(has_foreground(), "no foreground specified for this style");
     return foreground_color;
   }
   FMT_CONSTEXPR internal::color_type get_background() const FMT_NOEXCEPT {
-    assert(has_background() && "no background specified for this style");
+    FMT_ASSERT(has_background(), "no background specified for this style");
     return background_color;
   }
   FMT_CONSTEXPR emphasis get_emphasis() const FMT_NOEXCEPT {
-    assert(has_emphasis() && "no emphasis specified for this style");
+    FMT_ASSERT(has_emphasis(), "no emphasis specified for this style");
     return ems;
   }
 
@@ -470,58 +470,41 @@ inline void reset_color(basic_memory_buffer<Char>& buffer) FMT_NOEXCEPT {
 }
 
 template <typename Char>
-std::basic_string<Char> vformat(const text_style& ts,
+void vformat_to(basic_memory_buffer<Char>& buf, const text_style& ts,
-                                basic_string_view<Char> format_str,
+                basic_string_view<Char> format_str,
-                                basic_format_args<buffer_context<Char> > args) {
+                basic_format_args<buffer_context<Char>> args) {
-  basic_memory_buffer<Char> buffer;
   bool has_style = false;
   if (ts.has_emphasis()) {
     has_style = true;
-    ansi_color_escape<Char> escape = make_emphasis<Char>(ts.get_emphasis());
+    auto emphasis = internal::make_emphasis<Char>(ts.get_emphasis());
-    buffer.append(escape.begin(), escape.end());
+    buf.append(emphasis.begin(), emphasis.end());
   }
   if (ts.has_foreground()) {
     has_style = true;
-    ansi_color_escape<Char> escape =
+    auto foreground =
-        make_foreground_color<Char>(ts.get_foreground());
+        internal::make_foreground_color<Char>(ts.get_foreground());
-    buffer.append(escape.begin(), escape.end());
+    buf.append(foreground.begin(), foreground.end());
   }
   if (ts.has_background()) {
     has_style = true;
-    ansi_color_escape<Char> escape =
+    auto background =
-        make_background_color<Char>(ts.get_background());
+        internal::make_background_color<Char>(ts.get_background());
-    buffer.append(escape.begin(), escape.end());
+    buf.append(background.begin(), background.end());
   }
-  internal::vformat_to(buffer, format_str, args);
+  vformat_to(buf, format_str, args);
   if (has_style) {
-    reset_color<Char>(buffer);
+    internal::reset_color<Char>(buf);
   }
-  return fmt::to_string(buffer);
 }
 }  // namespace internal
 
-template <typename S, typename Char = char_t<S> >
+template <typename S, typename Char = char_t<S>>
 void vprint(std::FILE* f, const text_style& ts, const S& format,
-            basic_format_args<buffer_context<Char> > args) {
+            basic_format_args<buffer_context<Char>> args) {
-  bool has_style = false;
+  basic_memory_buffer<Char> buf;
-  if (ts.has_emphasis()) {
+  internal::vformat_to(buf, ts, to_string_view(format), args);
-    has_style = true;
+  buf.push_back(Char(0));
-    internal::fputs<Char>(internal::make_emphasis<Char>(ts.get_emphasis()), f);
+  internal::fputs(buf.data(), f);
-  }
-  if (ts.has_foreground()) {
-    has_style = true;
-    internal::fputs<Char>(
-        internal::make_foreground_color<Char>(ts.get_foreground()), f);
-  }
-  if (ts.has_background()) {
-    has_style = true;
-    internal::fputs<Char>(
-        internal::make_background_color<Char>(ts.get_background()), f);
-  }
-  vprint(f, format, args);
-  if (has_style) {
-    internal::reset_color<Char>(f);
-  }
 }
 
 /**
@@ -536,7 +519,7 @@ template <typename S, typename... Args,
 void print(std::FILE* f, const text_style& ts, const S& format_str,
            const Args&... args) {
   internal::check_format_string<Args...>(format_str);
-  using context = buffer_context<char_t<S> >;
+  using context = buffer_context<char_t<S>>;
   format_arg_store<context, Args...> as{args...};
   vprint(f, ts, format_str, basic_format_args<context>(as));
 }
@@ -554,11 +537,13 @@ void print(const text_style& ts, const S& format_str, const Args&... args) {
   return print(stdout, ts, format_str, args...);
 }
 
-template <typename S, typename Char = char_t<S> >
+template <typename S, typename Char = char_t<S>>
 inline std::basic_string<Char> vformat(
     const text_style& ts, const S& format_str,
-    basic_format_args<buffer_context<Char> > args) {
+    basic_format_args<buffer_context<Char>> args) {
-  return internal::vformat(ts, to_string_view(format_str), args);
+  basic_memory_buffer<Char> buf;
+  internal::vformat_to(buf, ts, to_string_view(format_str), args);
+  return fmt::to_string(buf);
 }
 
 /**
@@ -573,11 +558,11 @@ inline std::basic_string<Char> vformat(
                                       "The answer is {}", 42);
   \endrst
 */
-template <typename S, typename... Args, typename Char = char_t<S> >
+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 internal::vformat(ts, to_string_view(format_str),
+  return vformat(ts, to_string_view(format_str),
-                           {internal::make_args_checked(format_str, args...)});
+                 {internal::make_args_checked<Args...>(format_str, args...)});
 }
 
 FMT_END_NAMESPACE

include/spdlog/fmt/bundled/compile.h

@@ -14,433 +14,557 @@
 FMT_BEGIN_NAMESPACE
 namespace internal {
 
+// Part of a compiled format string. It can be either literal text or a
+// replacement field.
 template <typename Char> struct format_part {
- public:
+  enum class kind { arg_index, arg_name, text, replacement };
-  struct named_argument_id {
-    FMT_CONSTEXPR named_argument_id(internal::string_view_metadata id)
-        : id(id) {}
-    internal::string_view_metadata id;
-  };
-
-  struct argument_id {
-    FMT_CONSTEXPR argument_id() : argument_id(0u) {}
-
-    FMT_CONSTEXPR argument_id(unsigned id)
-        : which(which_arg_id::index), val(id) {}
-
-    FMT_CONSTEXPR argument_id(internal::string_view_metadata id)
-        : which(which_arg_id::named_index), val(id) {}
 
-    enum class which_arg_id { index, named_index };
+  struct replacement {
-
+    arg_ref<Char> arg_id;
-    which_arg_id which;
+    dynamic_format_specs<Char> specs;
-
-    union value {
-      FMT_CONSTEXPR value() : index(0u) {}
-      FMT_CONSTEXPR value(unsigned id) : index(id) {}
-      FMT_CONSTEXPR value(internal::string_view_metadata id)
-          : named_index(id) {}
-
-      unsigned index;
-      internal::string_view_metadata named_index;
-    } val;
   };
 
-  struct specification {
+  kind part_kind;
-    FMT_CONSTEXPR specification() : arg_id(0u) {}
+  union value {
-    FMT_CONSTEXPR specification(unsigned id) : arg_id(id) {}
+    unsigned arg_index;
+    basic_string_view<Char> str;
+    replacement repl;
 
-    FMT_CONSTEXPR specification(internal::string_view_metadata id)
+    FMT_CONSTEXPR value(unsigned index = 0) : arg_index(index) {}
-        : arg_id(id) {}
+    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;
 
-    argument_id arg_id;
+  FMT_CONSTEXPR format_part(kind k = kind::arg_index, value v = {})
-    internal::dynamic_format_specs<Char> parsed_specs;
+      : part_kind(k), val(v) {}
-  };
 
-  FMT_CONSTEXPR format_part()
+  static FMT_CONSTEXPR format_part make_arg_index(unsigned index) {
-      : which(kind::argument_id), end_of_argument_id(0u), val(0u) {}
+    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);
+  }
+};
 
-  FMT_CONSTEXPR format_part(internal::string_view_metadata text)
+template <typename Char> struct part_counter {
-      : which(kind::text), end_of_argument_id(0u), val(text) {}
+  unsigned num_parts = 0;
 
-  FMT_CONSTEXPR format_part(unsigned id)
+  FMT_CONSTEXPR void on_text(const Char* begin, const Char* end) {
-      : which(kind::argument_id), end_of_argument_id(0u), val(id) {}
+    if (begin != end) ++num_parts;
+  }
 
-  FMT_CONSTEXPR format_part(named_argument_id arg_id)
+  FMT_CONSTEXPR void on_arg_id() { ++num_parts; }
-      : which(kind::named_argument_id), end_of_argument_id(0u), val(arg_id) {}
+  FMT_CONSTEXPR void on_arg_id(unsigned) { ++num_parts; }
+  FMT_CONSTEXPR void on_arg_id(basic_string_view<Char>) { ++num_parts; }
 
-  FMT_CONSTEXPR format_part(specification spec)
+  FMT_CONSTEXPR void on_replacement_field(const Char*) {}
-      : which(kind::specification), end_of_argument_id(0u), val(spec) {}
 
-  enum class kind { argument_id, named_argument_id, text, specification };
+  FMT_CONSTEXPR const Char* on_format_specs(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;
+  }
 
-  kind which;
+  FMT_CONSTEXPR void on_error(const char*) {}
-  std::size_t end_of_argument_id;
-  union value {
-    FMT_CONSTEXPR value() : arg_id(0u) {}
-    FMT_CONSTEXPR value(unsigned id) : arg_id(id) {}
-    FMT_CONSTEXPR value(named_argument_id named_id)
-        : named_arg_id(named_id.id) {}
-    FMT_CONSTEXPR value(internal::string_view_metadata t) : text(t) {}
-    FMT_CONSTEXPR value(specification s) : spec(s) {}
-    unsigned arg_id;
-    internal::string_view_metadata named_arg_id;
-    internal::string_view_metadata text;
-    specification spec;
-  } val;
 };
 
-template <typename Char, typename PartsContainer>
+// Counts the number of parts in a format string.
-class format_preparation_handler : public internal::error_handler {
+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>;
 
- public:
+  PartHandler handler_;
-  using iterator = typename basic_string_view<Char>::iterator;
+  part part_;
+  basic_string_view<Char> format_str_;
+  basic_format_parse_context<Char> parse_context_;
 
-  FMT_CONSTEXPR format_preparation_handler(basic_string_view<Char> format,
+ public:
-                                           PartsContainer& parts)
+  FMT_CONSTEXPR format_string_compiler(basic_string_view<Char> format_str,
-      : parts_(parts), format_(format), parse_context_(format) {}
+                                       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) return;
+    if (begin != end)
-    const auto offset = begin - format_.data();
+      handler_(part::make_text({begin, to_unsigned(end - begin)}));
-    const auto size = end - begin;
-    parts_.push_back(part(string_view_metadata(offset, size)));
   }
 
   FMT_CONSTEXPR void on_arg_id() {
-    parts_.push_back(part(parse_context_.next_arg_id()));
+    part_ = part::make_arg_index(parse_context_.next_arg_id());
   }
 
   FMT_CONSTEXPR void on_arg_id(unsigned id) {
     parse_context_.check_arg_id(id);
-    parts_.push_back(part(id));
+    part_ = part::make_arg_index(id);
   }
 
   FMT_CONSTEXPR void on_arg_id(basic_string_view<Char> id) {
-    const auto view = string_view_metadata(format_, id);
+    part_ = part::make_arg_name(id);
-    const auto arg_id = typename part::named_argument_id(view);
-    parts_.push_back(part(arg_id));
   }
 
   FMT_CONSTEXPR void on_replacement_field(const Char* ptr) {
-    parts_.back().end_of_argument_id = ptr - format_.begin();
+    part_.arg_id_end = ptr;
+    handler_(part_);
   }
 
   FMT_CONSTEXPR const Char* on_format_specs(const Char* begin,
                                             const Char* end) {
-    const auto specs_offset = to_unsigned(begin - format_.begin());
+    auto repl = typename part::replacement();
-
+    dynamic_specs_handler<basic_format_parse_context<Char>> handler(
-    using parse_context = basic_parse_context<Char>;
+        repl.specs, parse_context_);
-    internal::dynamic_format_specs<Char> parsed_specs;
+    auto it = parse_format_specs(begin, end, handler);
-    dynamic_specs_handler<parse_context> handler(parsed_specs, parse_context_);
+    if (*it != '}') on_error("missing '}' in format string");
-    begin = parse_format_specs(begin, end, handler);
+    repl.arg_id = part_.part_kind == part::kind::arg_index
-
+                      ? arg_ref<Char>(part_.val.arg_index)
-    if (*begin != '}') on_error("missing '}' in format string");
+                      : arg_ref<Char>(part_.val.str);
-
+    auto part = part::make_replacement(repl);
-    auto& last_part = parts_.back();
+    part.arg_id_end = begin;
-    auto specs = last_part.which == part::kind::argument_id
+    handler_(part);
-                     ? typename part::specification(last_part.val.arg_id)
+    return it;
-                     : typename part::specification(last_part.val.named_arg_id);
-    specs.parsed_specs = parsed_specs;
-    last_part = part(specs);
-    last_part.end_of_argument_id = specs_offset;
-    return begin;
   }
-
- private:
-  PartsContainer& parts_;
-  basic_string_view<Char> format_;
-  basic_parse_context<Char> parse_context_;
 };
 
-template <typename Format, typename PreparedPartsProvider, typename... Args>
+// Compiles a format string and invokes handler(part) for each parsed part.
-class prepared_format {
+template <bool IS_CONSTEXPR, typename Char, typename PartHandler>
- public:
+FMT_CONSTEXPR void compile_format_string(basic_string_view<Char> format_str,
-  using char_type = char_t<Format>;
+                                         PartHandler handler) {
-  using format_part_t = format_part<char_type>;
+  parse_format_string<IS_CONSTEXPR>(
-
+      format_str,
-  constexpr prepared_format(Format f)
+      format_string_compiler<Char, PartHandler>(format_str, handler));
-      : format_(std::move(f)), parts_provider_(to_string_view(format_)) {}
+}
-
-  prepared_format() = delete;
-
-  using context = buffer_context<char_type>;
-
-  template <typename Range, typename Context>
-  auto vformat_to(Range out, basic_format_args<Context> args) const ->
-      typename Context::iterator {
-    const auto format_view = internal::to_string_view(format_);
-    basic_parse_context<char_type> parse_ctx(format_view);
-    Context ctx(out.begin(), args);
-
-    const auto& parts = parts_provider_.parts();
-    for (auto part_it = parts.begin(); part_it != parts.end(); ++part_it) {
-      const auto& part = *part_it;
-      const auto& value = part.val;
-
-      switch (part.which) {
-      case format_part_t::kind::text: {
-        const auto text = value.text.to_view(format_view.data());
-        auto output = ctx.out();
-        auto&& it = internal::reserve(output, text.size());
-        it = std::copy_n(text.begin(), text.size(), it);
-        ctx.advance_to(output);
-      } break;
-
-      case format_part_t::kind::argument_id: {
-        advance_parse_context_to_specification(parse_ctx, part);
-        format_arg<Range>(parse_ctx, ctx, value.arg_id);
-      } break;
-
-      case format_part_t::kind::named_argument_id: {
-        advance_parse_context_to_specification(parse_ctx, part);
-        const auto named_arg_id =
-            value.named_arg_id.to_view(format_view.data());
-        format_arg<Range>(parse_ctx, ctx, named_arg_id);
-      } break;
-      case format_part_t::kind::specification: {
-        const auto& arg_id_value = value.spec.arg_id.val;
-        const auto arg = value.spec.arg_id.which ==
-                                 format_part_t::argument_id::which_arg_id::index
-                             ? ctx.arg(arg_id_value.index)
-                             : ctx.arg(arg_id_value.named_index.to_view(
-                                   to_string_view(format_).data()));
-
-        auto specs = value.spec.parsed_specs;
-
-        handle_dynamic_spec<internal::width_checker>(
-            specs.width, specs.width_ref, ctx, format_view.begin());
-        handle_dynamic_spec<internal::precision_checker>(
-            specs.precision, specs.precision_ref, ctx, format_view.begin());
-
-        check_prepared_specs(specs, arg.type());
-        advance_parse_context_to_specification(parse_ctx, part);
-        ctx.advance_to(
-            visit_format_arg(arg_formatter<Range>(ctx, nullptr, &specs), arg));
-      } break;
-      }
-    }
 
-    return ctx.out();
+template <typename Range, typename Context, typename Id>
-  }
+void format_arg(
+    basic_format_parse_context<typename Range::value_type>& parse_ctx,
+    Context& ctx, Id arg_id) {
+  ctx.advance_to(
+      visit_format_arg(arg_formatter<Range>(ctx, &parse_ctx), ctx.arg(arg_id)));
+}
 
- private:
+// vformat_to is defined in a subnamespace to prevent ADL.
-  void advance_parse_context_to_specification(
+namespace cf {
-      basic_parse_context<char_type>& parse_ctx,
+template <typename Context, typename Range, typename CompiledFormat>
-      const format_part_t& part) const {
+auto vformat_to(Range out, CompiledFormat& cf, basic_format_args<Context> args)
-    const auto view = to_string_view(format_);
+    -> typename Context::iterator {
-    const auto specification_begin = view.data() + part.end_of_argument_id;
+  using char_type = typename Context::char_type;
-    advance_to(parse_ctx, specification_begin);
+  basic_format_parse_context<char_type> parse_ctx(
-  }
+      to_string_view(cf.format_str_));
+  Context ctx(out.begin(), 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;
+    }
 
-  template <typename Range, typename Context, typename Id>
+    case format_part_t::kind::arg_index:
-  void format_arg(basic_parse_context<char_type>& parse_ctx, Context& ctx,
+      advance_to(parse_ctx, part.arg_id_end);
-                  Id arg_id) const {
+      internal::format_arg<Range>(parse_ctx, ctx, value.arg_index);
-    parse_ctx.check_arg_id(arg_id);
+      break;
-    const auto stopped_at =
+
-        visit_format_arg(arg_formatter<Range>(ctx), ctx.arg(arg_id));
+    case format_part_t::kind::arg_name:
-    ctx.advance_to(stopped_at);
+      advance_to(parse_ctx, part.arg_id_end);
+      internal::format_arg<Range>(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<Range>(ctx, nullptr, &specs), arg));
+      break;
+    }
+    }
   }
+  return ctx.out();
+}
+}  // namespace cf
 
-  template <typename Char>
+struct basic_compiled_format {};
-  void check_prepared_specs(const basic_format_specs<Char>& specs,
-                            internal::type arg_type) const {
-    internal::error_handler h;
-    numeric_specs_checker<internal::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();
-  }
 
- private:
+template <typename S, typename = void>
-  Format format_;
+struct compiled_format_base : basic_compiled_format {
-  PreparedPartsProvider parts_provider_;
+  using char_type = char_t<S>;
-};
+  using parts_container = std::vector<internal::format_part<char_type>>;
 
-template <typename Char> struct part_counter {
+  parts_container compiled_parts;
-  unsigned num_parts = 0;
 
-  FMT_CONSTEXPR void on_text(const Char* begin, const Char* end) {
+  explicit compiled_format_base(basic_string_view<char_type> format_str) {
-    if (begin != end) ++num_parts;
+    compile_format_string<false>(format_str,
+                                 [this](const format_part<char_type>& part) {
+                                   compiled_parts.push_back(part);
+                                 });
   }
 
-  FMT_CONSTEXPR void on_arg_id() { ++num_parts; }
+  const parts_container& parts() const { return compiled_parts; }
-  FMT_CONSTEXPR void on_arg_id(unsigned) { ++num_parts; }
+};
-  FMT_CONSTEXPR void on_arg_id(basic_string_view<Char>) { ++num_parts; }
 
-  FMT_CONSTEXPR void on_replacement_field(const Char*) {}
+template <typename Char, unsigned N> struct format_part_array {
+  format_part<Char> data[N] = {};
+  FMT_CONSTEXPR format_part_array() = default;
+};
 
-  FMT_CONSTEXPR const Char* on_format_specs(const Char* begin,
+template <typename Char, unsigned N>
-                                            const Char* end) {
+FMT_CONSTEXPR format_part_array<Char, N> compile_to_parts(
-    // Find the matching brace.
+    basic_string_view<Char> format_str) {
-    unsigned braces_counter = 0;
+  format_part_array<Char, N> parts;
-    for (; begin != end; ++begin) {
+  unsigned counter = 0;
-      if (*begin == '{') {
+  // This is not a lambda for compatibility with older compilers.
-        ++braces_counter;
+  struct {
-      } else if (*begin == '}') {
+    format_part<Char>* parts;
-        if (braces_counter == 0u) break;
+    unsigned* counter;
-        --braces_counter;
+    FMT_CONSTEXPR void operator()(const format_part<Char>& part) {
-      }
+      parts[(*counter)++] = part;
     }
-    return begin;
+  } 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;
+}
 
-  FMT_CONSTEXPR void on_error(const char*) {}
+template <typename T> constexpr const T& constexpr_max(const T& a, const T& b) {
-};
+  return (a < b) ? b : a;
+}
 
-template <typename Format> class compiletime_prepared_parts_type_provider {
+template <typename S>
- private:
+struct compiled_format_base<S, enable_if_t<is_compile_string<S>::value>>
-  using char_type = char_t<Format>;
+    : basic_compiled_format {
+  using char_type = char_t<S>;
 
-  static FMT_CONSTEXPR unsigned count_parts() {
+  FMT_CONSTEXPR explicit compiled_format_base(basic_string_view<char_type>) {}
-    FMT_CONSTEXPR_DECL const auto text = to_string_view(Format{});
-    part_counter<char_type> counter;
-    internal::parse_format_string</*IS_CONSTEXPR=*/true>(text, counter);
-    return counter.num_parts;
-  }
 
-// Workaround for old compilers. Compiletime parts preparation will not be
+// Workaround for old compilers. Format string compilation will not be
-// performed with them anyway.
+// performed there anyway.
 #if FMT_USE_CONSTEXPR
-  static FMT_CONSTEXPR_DECL const unsigned number_of_format_parts =
+  static FMT_CONSTEXPR_DECL const unsigned num_format_parts =
-      compiletime_prepared_parts_type_provider::count_parts();
+      constexpr_max(count_parts(to_string_view(S())), 1u);
 #else
-  static const unsigned number_of_format_parts = 0u;
+  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>(
+            internal::to_string_view(S()));
+    return compiled_parts.data;
+  }
+};
+
+template <typename S, typename... Args>
+class compiled_format : private compiled_format_base<S> {
  public:
-  template <unsigned N> struct format_parts_array {
+  using typename compiled_format_base<S>::char_type;
-    using value_type = format_part<char_type>;
 
-    FMT_CONSTEXPR format_parts_array() : arr{} {}
+ private:
+  basic_string_view<char_type> format_str_;
 
-    FMT_CONSTEXPR value_type& operator[](unsigned ind) { return arr[ind]; }
+  template <typename Context, typename Range, typename CompiledFormat>
+  friend auto cf::vformat_to(Range out, CompiledFormat& cf,
+                             basic_format_args<Context> args) ->
+      typename Context::iterator;
 
-    FMT_CONSTEXPR const value_type* begin() const { return arr; }
+ public:
-    FMT_CONSTEXPR const value_type* end() const { return begin() + N; }
+  compiled_format() = delete;
+  explicit constexpr compiled_format(basic_string_view<char_type> format_str)
+      : compiled_format_base<S>(format_str), format_str_(format_str) {}
+};
 
-   private:
+#ifdef __cpp_if_constexpr
-    value_type arr[N];
+template <typename... Args> struct type_list {};
-  };
+
+// Returns a reference to the argument at index N from [first, rest...].
+template <int N, typename T, typename... Args>
+constexpr const auto& get(const T& first, const Args&... rest) {
+  static_assert(N < 1 + sizeof...(Args), "index is out of bounds");
+  if constexpr (N == 0)
+    return first;
+  else
+    return get<N - 1>(rest...);
+}
 
-  struct empty {
+template <int N, typename> struct get_type_impl;
-    // Parts preparator will search for it
-    using value_type = format_part<char_type>;
-  };
 
-  using type = conditional_t<number_of_format_parts != 0,
+template <int N, typename... Args> struct get_type_impl<N, type_list<Args...>> {
-                             format_parts_array<number_of_format_parts>, empty>;
+  using type = remove_cvref_t<decltype(get<N>(std::declval<Args>()...))>;
 };
 
-template <typename Parts> class compiletime_prepared_parts_collector {
+template <int N, typename T>
- private:
+using get_type = typename get_type_impl<N, T>::type;
-  using format_part = typename Parts::value_type;
 
- public:
+template <typename Char> struct text {
-  FMT_CONSTEXPR explicit compiletime_prepared_parts_collector(Parts& parts)
+  basic_string_view<Char> data;
-      : parts_{parts}, counter_{0u} {}
+  using char_type = Char;
 
-  FMT_CONSTEXPR void push_back(format_part part) { parts_[counter_++] = part; }
+  template <typename OutputIt, typename... Args>
+  OutputIt format(OutputIt out, const Args&...) const {
+    // TODO: reserve
+    return copy_str<Char>(data.begin(), data.end(), out);
+  }
+};
 
-  FMT_CONSTEXPR format_part& back() { return parts_[counter_ - 1]; }
+template <typename Char>
+constexpr text<Char> make_text(basic_string_view<Char> s, size_t pos,
+                               size_t size) {
+  return {{&s[pos], size}};
+}
 
- private:
+template <typename Char, typename OutputIt, typename T,
-  Parts& parts_;
+          std::enable_if_t<std::is_integral_v<T>, int> = 0>
-  unsigned counter_;
+OutputIt format_default(OutputIt out, T value) {
-};
+  // TODO: reserve
+  format_int fi(value);
+  return std::copy(fi.data(), fi.data() + fi.size(), out);
+}
 
-template <typename PartsContainer, typename Char>
+template <typename Char, typename OutputIt>
-FMT_CONSTEXPR PartsContainer prepare_parts(basic_string_view<Char> format) {
+OutputIt format_default(OutputIt out, double value) {
-  PartsContainer parts;
+  writer w(out);
-  internal::parse_format_string</*IS_CONSTEXPR=*/false>(
+  w.write(value);
-      format, format_preparation_handler<Char, PartsContainer>(format, parts));
+  return w.out();
-  return parts;
 }
 
-template <typename PartsContainer, typename Char>
+template <typename Char, typename OutputIt>
-FMT_CONSTEXPR PartsContainer
+OutputIt format_default(OutputIt out, Char value) {
-prepare_compiletime_parts(basic_string_view<Char> format) {
+  *out++ = value;
-  using collector = compiletime_prepared_parts_collector<PartsContainer>;
+  return out;
+}
 
-  PartsContainer parts;
+template <typename Char, typename OutputIt>
-  collector c(parts);
+OutputIt format_default(OutputIt out, const Char* value) {
-  internal::parse_format_string</*IS_CONSTEXPR=*/true>(
+  auto length = std::char_traits<Char>::length(value);
-      format, format_preparation_handler<Char, collector>(format, c));
+  return copy_str<Char>(value, value + length, out);
-  return parts;
 }
 
-template <typename PartsContainer> class runtime_parts_provider {
+// A replacement field that refers to argument N.
- public:
+template <typename Char, typename T, int N> struct field {
-  runtime_parts_provider() = delete;
+  using char_type = Char;
-  template <typename Char>
-  runtime_parts_provider(basic_string_view<Char> format)
-      : parts_(prepare_parts<PartsContainer>(format)) {}
 
-  const PartsContainer& parts() const { return parts_; }
+  template <typename OutputIt, typename... Args>
+  OutputIt format(OutputIt out, const Args&... args) const {
+    // This ensures that the argument type is convertile to `const T&`.
+    const T& arg = get<N>(args...);
+    return format_default<Char>(out, arg);
+  }
+};
 
- private:
+template <typename L, typename R> struct concat {
-  PartsContainer parts_;
+  L lhs;
+  R rhs;
+  using char_type = typename L::char_type;
+
+  template <typename OutputIt, typename... Args>
+  OutputIt format(OutputIt out, const Args&... args) const {
+    out = lhs.format(out, args...);
+    return rhs.format(out, args...);
+  }
 };
 
-template <typename Format, typename PartsContainer>
+template <typename L, typename R>
-struct compiletime_parts_provider {
+constexpr concat<L, R> make_concat(L lhs, R rhs) {
-  compiletime_parts_provider() = delete;
+  return {lhs, rhs};
-  template <typename Char>
+}
-  FMT_CONSTEXPR compiletime_parts_provider(basic_string_view<Char>) {}
 
-  const PartsContainer& parts() const {
+struct unknown_format {};
-    static FMT_CONSTEXPR_DECL const PartsContainer prepared_parts =
-        prepare_compiletime_parts<PartsContainer>(
-            internal::to_string_view(Format{}));
 
-    return prepared_parts;
+template <typename Char>
+constexpr size_t parse_text(basic_string_view<Char> str, size_t pos) {
+  for (size_t size = str.size(); pos != size; ++pos) {
+    if (str[pos] == '{' || str[pos] == '}') break;
   }
-};
+  return pos;
+}
+
+template <typename Args, size_t POS, int ID, typename S>
+constexpr auto compile_format_string(S format_str);
+
+template <typename Args, size_t POS, int ID, typename T, typename S>
+constexpr auto parse_tail(T head, S format_str) {
+  if constexpr (POS != to_string_view(format_str).size()) {
+    constexpr auto tail = compile_format_string<Args, POS, ID>(format_str);
+    if constexpr (std::is_same<remove_cvref_t<decltype(tail)>,
+                               unknown_format>())
+      return tail;
+    else
+      return make_concat(head, tail);
+  } else {
+    return head;
+  }
+}
+
+// Compiles a non-empty format string and returns the compiled representation
+// or unknown_format() on unrecognized input.
+template <typename Args, size_t POS, int ID, typename S>
+constexpr auto compile_format_string(S format_str) {
+  using char_type = typename S::char_type;
+  constexpr basic_string_view<char_type> str = format_str;
+  if constexpr (str[POS] == '{') {
+    if (POS + 1 == str.size())
+      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] == '}') {
+      using type = get_type<ID, Args>;
+      if constexpr (std::is_same<type, int>::value) {
+        return parse_tail<Args, POS + 2, ID + 1>(field<char_type, type, ID>(),
+                                                 format_str);
+      } else {
+        return unknown_format();
+      }
+    } else {
+      return unknown_format();
+    }
+  } else if constexpr (str[POS] == '}') {
+    if (POS + 1 == str.size())
+      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);
+    return parse_tail<Args, end, ID>(make_text(str, POS, end - POS),
+                                     format_str);
+  }
+}
+#endif  // __cpp_if_constexpr
 }  // namespace internal
 
 #if FMT_USE_CONSTEXPR
+#  ifdef __cpp_if_constexpr
 template <typename... Args, typename S,
           FMT_ENABLE_IF(is_compile_string<S>::value)>
-FMT_CONSTEXPR auto compile(S format_str) -> internal::prepared_format<
+constexpr auto compile(S format_str) {
-    S,
+  constexpr basic_string_view<typename S::char_type> str = format_str;
-    internal::compiletime_parts_provider<
+  if constexpr (str.size() == 0) {
-        S,
+    return internal::make_text(str, 0, 0);
-        typename internal::compiletime_prepared_parts_type_provider<S>::type>,
+  } else {
-    Args...> {
+    constexpr auto result =
-  return format_str;
+        internal::compile_format_string<internal::type_list<Args...>, 0, 0>(
+            format_str);
+    if constexpr (std::is_same<remove_cvref_t<decltype(result)>,
+                               internal::unknown_format>()) {
+      return internal::compiled_format<S, Args...>(to_string_view(format_str));
+    } else {
+      return result;
+    }
+  }
 }
-#endif
 
+template <typename CompiledFormat, typename... Args,
+          typename Char = typename CompiledFormat::char_type,
+          FMT_ENABLE_IF(!std::is_base_of<internal::basic_compiled_format,
+                                         CompiledFormat>::value)>
+std::basic_string<Char> format(const CompiledFormat& cf, const Args&... args) {
+  basic_memory_buffer<Char> buffer;
+  using range = buffer_range<Char>;
+  using context = buffer_context<Char>;
+  cf.format(std::back_inserter(buffer), args...);
+  return to_string(buffer);
+}
+
+template <typename OutputIt, typename CompiledFormat, typename... Args,
+          FMT_ENABLE_IF(!std::is_base_of<internal::basic_compiled_format,
+                                         CompiledFormat>::value)>
+OutputIt format_to(OutputIt out, const CompiledFormat& cf,
+                   const Args&... args) {
+  return cf.format(out, args...);
+}
+#  else
+template <typename... Args, typename S,
+          FMT_ENABLE_IF(is_compile_string<S>::value)>
+constexpr auto compile(S format_str) -> internal::compiled_format<S, Args...> {
+  return internal::compiled_format<S, Args...>(to_string_view(format_str));
+}
+#  endif  // __cpp_if_constexpr
+#endif    // FMT_USE_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]) -> internal::prepared_format<
+auto compile(const Char (&format_str)[N])
-    std::basic_string<Char>,
+    -> internal::compiled_format<const Char*, Args...> {
-    internal::runtime_parts_provider<std::vector<internal::format_part<Char>>>,
+  return internal::compiled_format<const Char*, Args...>(
-    Args...> {
+      basic_string_view<Char>(format_str, N - 1));
-  return std::basic_string<Char>(format_str, N - 1);
 }
 
 template <typename CompiledFormat, typename... Args,
-          typename Char = typename CompiledFormat::char_type>
+          typename Char = typename CompiledFormat::char_type,
+          FMT_ENABLE_IF(std::is_base_of<internal::basic_compiled_format,
+                                        CompiledFormat>::value)>
 std::basic_string<Char> format(const CompiledFormat& cf, const Args&... args) {
   basic_memory_buffer<Char> buffer;
-  using range = internal::buffer_range<Char>;
+  using range = buffer_range<Char>;
   using context = buffer_context<Char>;
-  cf.template vformat_to<range, context>(range(buffer),
+  internal::cf::vformat_to<context>(range(buffer), cf,
-                                         {make_format_args<context>(args...)});
+                                    {make_format_args<context>(args...)});
   return to_string(buffer);
 }
 
-template <typename OutputIt, typename CompiledFormat, typename... Args>
+template <typename OutputIt, typename CompiledFormat, typename... Args,
+          FMT_ENABLE_IF(std::is_base_of<internal::basic_compiled_format,
+                                        CompiledFormat>::value)>
 OutputIt format_to(OutputIt out, const CompiledFormat& cf,
                    const Args&... args) {
   using char_type = typename CompiledFormat::char_type;
   using range = internal::output_range<OutputIt, char_type>;
   using context = format_context_t<OutputIt, char_type>;
-  return cf.template vformat_to<range, context>(
+  return internal::cf::vformat_to<context>(
-      range(out), {make_format_args<context>(args...)});
+      range(out), cf, {make_format_args<context>(args...)});
 }
 
 template <typename OutputIt, typename CompiledFormat, typename... Args,
@@ -455,10 +579,7 @@ format_to_n_result<OutputIt> format_to_n(OutputIt out, size_t n,
 
 template <typename CompiledFormat, typename... Args>
 std::size_t formatted_size(const CompiledFormat& cf, const Args&... args) {
-  return fmt::format_to(
+  return format_to(internal::counting_iterator(), cf, args...).count();
-             internal::counting_iterator<typename CompiledFormat::char_type>(),
-             cf, args...)
-      .count();
 }
 
 FMT_END_NAMESPACE

include/spdlog/fmt/bundled/core.h

@@ -8,7 +8,6 @@
 #ifndef FMT_CORE_H_
 #define FMT_CORE_H_
 
-#include <cassert>
 #include <cstdio>  // std::FILE
 #include <cstring>
 #include <iterator>
@@ -16,7 +15,7 @@
 #include <type_traits>
 
 // The fmt library version in the form major * 10000 + minor * 100 + patch.
-#define FMT_VERSION 60000
+#define FMT_VERSION 60100
 
 #ifdef __has_feature
 #  define FMT_HAS_FEATURE(x) __has_feature(x)
@@ -49,6 +48,12 @@
 #  define FMT_HAS_GXX_CXX11 0
 #endif
 
+#ifdef __NVCC__
+#  define FMT_NVCC __NVCC__
+#else
+#  define FMT_NVCC 0
+#endif
+
 #ifdef _MSC_VER
 #  define FMT_MSC_VER _MSC_VER
 #else
@@ -60,7 +65,8 @@
 #ifndef FMT_USE_CONSTEXPR
 #  define FMT_USE_CONSTEXPR                                           \
     (FMT_HAS_FEATURE(cxx_relaxed_constexpr) || FMT_MSC_VER >= 1910 || \
-     (FMT_GCC_VERSION >= 600 && __cplusplus >= 201402L))
+     (FMT_GCC_VERSION >= 600 && __cplusplus >= 201402L)) &&           \
+        !FMT_NVCC
 #endif
 #if FMT_USE_CONSTEXPR
 #  define FMT_CONSTEXPR constexpr
@@ -133,6 +139,13 @@
 #  endif
 #endif
 
+// Workaround broken [[deprecated]] in the Intel compiler and NVCC.
+#if defined(__INTEL_COMPILER) || FMT_NVCC
+#  define FMT_DEPRECATED_ALIAS
+#else
+#  define FMT_DEPRECATED_ALIAS FMT_DEPRECATED
+#endif
+
 #ifndef FMT_BEGIN_NAMESPACE
 #  if FMT_HAS_FEATURE(cxx_inline_namespaces) || FMT_GCC_VERSION >= 404 || \
       FMT_MSC_VER >= 1900
@@ -154,9 +167,9 @@
 
 #if !defined(FMT_HEADER_ONLY) && defined(_WIN32)
 #  ifdef FMT_EXPORT
-#    define FMT_API __declspec(dllexport)
+#    define FMT_API __pragma(warning(suppress : 4275)) __declspec(dllexport)
 #  elif defined(FMT_SHARED)
-#    define FMT_API __declspec(dllimport)
+#    define FMT_API __pragma(warning(suppress : 4275)) __declspec(dllimport)
 #    define FMT_EXTERN_TEMPLATE_API FMT_API
 #  endif
 #endif
@@ -173,10 +186,6 @@
 #  define FMT_EXTERN
 #endif
 
-#ifndef FMT_ASSERT
-#  define FMT_ASSERT(condition, message) assert((condition) && message)
-#endif
-
 // libc++ supports string_view in pre-c++17.
 #if (FMT_HAS_INCLUDE(<string_view>) &&                       \
      (__cplusplus > 201402L || defined(_LIBCPP_VERSION))) || \
@@ -200,6 +209,8 @@ template <typename T>
 using remove_reference_t = typename std::remove_reference<T>::type;
 template <typename T>
 using remove_const_t = typename std::remove_const<T>::type;
+template <typename T>
+using remove_cvref_t = typename std::remove_cv<remove_reference_t<T>>::type;
 
 struct monostate {};
 
@@ -213,6 +224,19 @@ namespace internal {
 // A workaround for gcc 4.8 to make void_t work in a SFINAE context.
 template <typename... Ts> struct void_t_impl { using type = void; };
 
+void assert_fail(const char* file, int line, const char* message);
+
+#ifndef FMT_ASSERT
+#  ifdef NDEBUG
+#    define FMT_ASSERT(condition, message)
+#  else
+#    define FMT_ASSERT(condition, message) \
+      ((condition)                         \
+           ? void()                        \
+           : fmt::internal::assert_fail(__FILE__, __LINE__, (message)))
+#  endif
+#endif
+
 #if defined(FMT_USE_STRING_VIEW)
 template <typename Char> using std_string_view = std::basic_string_view<Char>;
 #elif defined(FMT_USE_EXPERIMENTAL_STRING_VIEW)
@@ -222,7 +246,21 @@ using std_string_view = std::experimental::basic_string_view<Char>;
 template <typename T> struct std_string_view {};
 #endif
 
-// Casts nonnegative integer to unsigned.
+#ifdef FMT_USE_INT128
+// Do nothing.
+#elif defined(__SIZEOF_INT128__)
+#  define FMT_USE_INT128 1
+using int128_t = __int128_t;
+using uint128_t = __uint128_t;
+#else
+#  define FMT_USE_INT128 0
+#endif
+#if !FMT_USE_INT128
+struct int128_t {};
+struct uint128_t {};
+#endif
+
+// Casts a nonnegative integer to unsigned.
 template <typename Int>
 FMT_CONSTEXPR typename std::make_unsigned<Int>::type to_unsigned(Int value) {
   FMT_ASSERT(value >= 0, "negative value");
@@ -266,10 +304,11 @@ template <typename Char> class basic_string_view {
       : data_(s), size_(std::char_traits<Char>::length(s)) {}
 
   /** Constructs a string reference from a ``std::basic_string`` object. */
-  template <typename Alloc>
+  template <typename Traits, typename Alloc>
-  FMT_CONSTEXPR basic_string_view(const std::basic_string<Char, Alloc>& s)
+  FMT_CONSTEXPR basic_string_view(
-      FMT_NOEXCEPT : data_(s.data()),
+      const std::basic_string<Char, Traits, Alloc>& s) FMT_NOEXCEPT
-                     size_(s.size()) {}
+      : data_(s.data()),
+        size_(s.size()) {}
 
   template <
       typename S,
@@ -286,6 +325,8 @@ template <typename Char> class basic_string_view {
   FMT_CONSTEXPR iterator begin() const { return data_; }
   FMT_CONSTEXPR iterator end() const { return data_ + size_; }
 
+  FMT_CONSTEXPR const Char& operator[](size_t pos) const { return data_[pos]; }
+
   FMT_CONSTEXPR void remove_prefix(size_t n) {
     data_ += n;
     size_ -= n;
@@ -357,10 +398,10 @@ inline basic_string_view<Char> to_string_view(const Char* s) {
   return s;
 }
 
-template <typename Char, typename Traits, typename Allocator>
+template <typename Char, typename Traits, typename Alloc>
 inline basic_string_view<Char> to_string_view(
-    const std::basic_string<Char, Traits, Allocator>& s) {
+    const std::basic_string<Char, Traits, Alloc>& s) {
-  return {s.data(), s.size()};
+  return s;
 }
 
 template <typename Char>
@@ -405,8 +446,8 @@ template <typename S> struct char_t_impl<S, enable_if_t<is_string<S>::value>> {
 };
 
 struct error_handler {
-  FMT_CONSTEXPR error_handler() {}
+  FMT_CONSTEXPR error_handler() = default;
-  FMT_CONSTEXPR error_handler(const error_handler&) {}
+  FMT_CONSTEXPR error_handler(const error_handler&) = default;
 
   // This function is intentionally not constexpr to give a compile-time error.
   FMT_NORETURN FMT_API void on_error(const char* message);
@@ -416,10 +457,24 @@ struct error_handler {
 /** String's character type. */
 template <typename S> using char_t = typename internal::char_t_impl<S>::type;
 
-// Parsing context consisting of a format string range being parsed and an
+/**
-// argument counter for automatic indexing.
+  \rst
+  Parsing context consisting of a format string range being parsed and an
+  argument counter for automatic indexing.
+
+  You can use one of the following type aliases for common character types:
+
+  +-----------------------+-------------------------------------+
+  | Type                  | Definition                          |
+  +=======================+=====================================+
+  | format_parse_context  | basic_format_parse_context<char>    |
+  +-----------------------+-------------------------------------+
+  | wformat_parse_context | basic_format_parse_context<wchar_t> |
+  +-----------------------+-------------------------------------+
+  \endrst
+ */
 template <typename Char, typename ErrorHandler = internal::error_handler>
-class basic_parse_context : private ErrorHandler {
+class basic_format_parse_context : private ErrorHandler {
  private:
   basic_string_view<Char> format_str_;
   int next_arg_id_;
@@ -428,38 +483,47 @@ class basic_parse_context : private ErrorHandler {
   using char_type = Char;
   using iterator = typename basic_string_view<Char>::iterator;
 
-  explicit FMT_CONSTEXPR basic_parse_context(basic_string_view<Char> format_str,
+  explicit FMT_CONSTEXPR basic_format_parse_context(
-                                             ErrorHandler eh = ErrorHandler())
+      basic_string_view<Char> format_str, ErrorHandler eh = ErrorHandler())
       : ErrorHandler(eh), format_str_(format_str), next_arg_id_(0) {}
 
-  // Returns an iterator to the beginning of the format string range being
+  /**
-  // parsed.
+    Returns an iterator to the beginning of the format string range being
+    parsed.
+   */
   FMT_CONSTEXPR iterator begin() const FMT_NOEXCEPT {
     return format_str_.begin();
   }
 
-  // Returns an iterator past the end of the format string range being parsed.
+  /**
+    Returns an iterator past the end of the format string range being parsed.
+   */
   FMT_CONSTEXPR iterator end() const FMT_NOEXCEPT { return format_str_.end(); }
 
-  // Advances the begin iterator to ``it``.
+  /** Advances the begin iterator to ``it``. */
   FMT_CONSTEXPR void advance_to(iterator it) {
     format_str_.remove_prefix(internal::to_unsigned(it - begin()));
   }
 
-  // Returns the next argument index.
+  /**
+    Reports an error if using the manual argument indexing; otherwise returns
+    the next argument index and switches to the automatic indexing.
+   */
   FMT_CONSTEXPR int next_arg_id() {
     if (next_arg_id_ >= 0) return next_arg_id_++;
     on_error("cannot switch from manual to automatic argument indexing");
     return 0;
   }
 
-  FMT_CONSTEXPR bool check_arg_id(int) {
+  /**
-    if (next_arg_id_ > 0) {
+    Reports an error if using the automatic argument indexing; otherwise
+    switches to the manual indexing.
+   */
+  FMT_CONSTEXPR void check_arg_id(int) {
+    if (next_arg_id_ > 0)
       on_error("cannot switch from automatic to manual argument indexing");
-      return false;
+    else
-    }
+      next_arg_id_ = -1;
-    next_arg_id_ = -1;
-    return true;
   }
 
   FMT_CONSTEXPR void check_arg_id(basic_string_view<Char>) {}
@@ -471,11 +535,14 @@ class basic_parse_context : private ErrorHandler {
   FMT_CONSTEXPR ErrorHandler error_handler() const { return *this; }
 };
 
-using format_parse_context = basic_parse_context<char>;
+using format_parse_context = basic_format_parse_context<char>;
-using wformat_parse_context = basic_parse_context<wchar_t>;
+using wformat_parse_context = basic_format_parse_context<wchar_t>;
 
-using parse_context FMT_DEPRECATED = basic_parse_context<char>;
+template <typename Char, typename ErrorHandler = internal::error_handler>
-using wparse_context FMT_DEPRECATED = basic_parse_context<wchar_t>;
+using basic_parse_context FMT_DEPRECATED_ALIAS =
+    basic_format_parse_context<Char, ErrorHandler>;
+using parse_context FMT_DEPRECATED_ALIAS = basic_format_parse_context<char>;
+using wparse_context FMT_DEPRECATED_ALIAS = basic_format_parse_context<wchar_t>;
 
 template <typename Context> class basic_format_arg;
 template <typename Context> class basic_format_args;
@@ -492,20 +559,17 @@ struct FMT_DEPRECATED convert_to_int
     : bool_constant<!std::is_arithmetic<T>::value &&
                     std::is_convertible<T, int>::value> {};
 
-namespace internal {
-
 // Specifies if T has an enabled formatter specialization. A type can be
 // formattable even if it doesn't have a formatter e.g. via a conversion.
 template <typename T, typename Context>
 using has_formatter =
     std::is_constructible<typename Context::template formatter_type<T>>;
 
+namespace internal {
+
 /** A contiguous memory buffer with an optional growing ability. */
 template <typename T> class buffer {
  private:
-  buffer(const buffer&) = delete;
-  void operator=(const buffer&) = delete;
-
   T* ptr_;
   std::size_t size_;
   std::size_t capacity_;
@@ -532,7 +596,9 @@ template <typename T> class buffer {
   using value_type = T;
   using const_reference = const T&;
 
-  virtual ~buffer() {}
+  buffer(const buffer&) = delete;
+  void operator=(const buffer&) = delete;
+  virtual ~buffer() = default;
 
   T* begin() FMT_NOEXCEPT { return ptr_; }
   T* end() FMT_NOEXCEPT { return ptr_ + size_; }
@@ -626,10 +692,13 @@ enum type {
   uint_type,
   long_long_type,
   ulong_long_type,
+  int128_type,
+  uint128_type,
   bool_type,
   char_type,
   last_integer_type = char_type,
   // followed by floating-point types.
+  float_type,
   double_type,
   long_double_type,
   last_numeric_type = long_double_type,
@@ -652,20 +721,23 @@ FMT_TYPE_CONSTANT(int, int_type);
 FMT_TYPE_CONSTANT(unsigned, uint_type);
 FMT_TYPE_CONSTANT(long long, long_long_type);
 FMT_TYPE_CONSTANT(unsigned long long, ulong_long_type);
+FMT_TYPE_CONSTANT(int128_t, int128_type);
+FMT_TYPE_CONSTANT(uint128_t, uint128_type);
 FMT_TYPE_CONSTANT(bool, bool_type);
 FMT_TYPE_CONSTANT(Char, char_type);
+FMT_TYPE_CONSTANT(float, float_type);
 FMT_TYPE_CONSTANT(double, double_type);
 FMT_TYPE_CONSTANT(long double, long_double_type);
 FMT_TYPE_CONSTANT(const Char*, cstring_type);
 FMT_TYPE_CONSTANT(basic_string_view<Char>, string_type);
 FMT_TYPE_CONSTANT(const void*, pointer_type);
 
-FMT_CONSTEXPR bool is_integral(type t) {
+FMT_CONSTEXPR bool is_integral_type(type t) {
   FMT_ASSERT(t != named_arg_type, "invalid argument type");
   return t > none_type && t <= last_integer_type;
 }
 
-FMT_CONSTEXPR bool is_arithmetic(type t) {
+FMT_CONSTEXPR bool is_arithmetic_type(type t) {
   FMT_ASSERT(t != named_arg_type, "invalid argument type");
   return t > none_type && t <= last_numeric_type;
 }
@@ -676,7 +748,7 @@ template <typename Char> struct string_value {
 };
 
 template <typename Context> struct custom_value {
-  using parse_context = basic_parse_context<typename Context::char_type>;
+  using parse_context = basic_format_parse_context<typename Context::char_type>;
   const void* value;
   void (*format)(const void* arg, parse_context& parse_ctx, Context& ctx);
 };
@@ -691,8 +763,11 @@ template <typename Context> class value {
     unsigned uint_value;
     long long long_long_value;
     unsigned long long ulong_long_value;
+    int128_t int128_value;
+    uint128_t uint128_value;
     bool bool_value;
     char_type char_value;
+    float float_value;
     double double_value;
     long double long_double_value;
     const void* pointer;
@@ -705,6 +780,9 @@ template <typename Context> class value {
   FMT_CONSTEXPR value(unsigned val) : uint_value(val) {}
   value(long long val) : long_long_value(val) {}
   value(unsigned long long val) : ulong_long_value(val) {}
+  value(int128_t val) : int128_value(val) {}
+  value(uint128_t val) : uint128_value(val) {}
+  value(float val) : float_value(val) {}
   value(double val) : double_value(val) {}
   value(long double val) : long_double_value(val) {}
   value(bool val) : bool_value(val) {}
@@ -732,9 +810,9 @@ template <typename Context> class value {
  private:
   // Formats an argument of a custom type, such as a user-defined class.
   template <typename T, typename Formatter>
-  static void format_custom_arg(const void* arg,
+  static void format_custom_arg(
-                                basic_parse_context<char_type>& parse_ctx,
+      const void* arg, basic_format_parse_context<char_type>& parse_ctx,
-                                Context& ctx) {
+      Context& ctx) {
     Formatter f;
     parse_ctx.advance_to(f.parse(parse_ctx));
     ctx.advance_to(f.format(*static_cast<const T*>(arg), ctx));
@@ -764,6 +842,8 @@ template <typename Context> struct arg_mapper {
   FMT_CONSTEXPR ulong_type map(unsigned long val) { return val; }
   FMT_CONSTEXPR long long map(long long val) { return val; }
   FMT_CONSTEXPR unsigned long long map(unsigned long long val) { return val; }
+  FMT_CONSTEXPR int128_t map(int128_t val) { return val; }
+  FMT_CONSTEXPR uint128_t map(uint128_t val) { return val; }
   FMT_CONSTEXPR bool map(bool val) { return val; }
 
   template <typename T, FMT_ENABLE_IF(is_char<T>::value)>
@@ -774,7 +854,7 @@ template <typename Context> struct arg_mapper {
     return val;
   }
 
-  FMT_CONSTEXPR double map(float val) { return static_cast<double>(val); }
+  FMT_CONSTEXPR float map(float val) { return val; }
   FMT_CONSTEXPR double map(double val) { return val; }
   FMT_CONSTEXPR long double map(long double val) { return val; }
 
@@ -793,6 +873,15 @@ template <typename Context> struct arg_mapper {
   FMT_CONSTEXPR basic_string_view<char_type> map(const T& val) {
     return basic_string_view<char_type>(val);
   }
+  template <
+      typename T,
+      FMT_ENABLE_IF(
+          std::is_constructible<std_string_view<char_type>, T>::value &&
+          !std::is_constructible<basic_string_view<char_type>, T>::value &&
+          !is_string<T>::value)>
+  FMT_CONSTEXPR basic_string_view<char_type> map(const T& val) {
+    return std_string_view<char_type>(val);
+  }
   FMT_CONSTEXPR const char* map(const signed char* val) {
     static_assert(std::is_same<char_type, char>::value, "invalid string type");
     return reinterpret_cast<const char*>(val);
@@ -818,11 +907,14 @@ template <typename Context> struct arg_mapper {
             FMT_ENABLE_IF(std::is_enum<T>::value &&
                           !has_formatter<T, Context>::value &&
                           !has_fallback_formatter<T, Context>::value)>
-  FMT_CONSTEXPR int map(const T& val) {
+  FMT_CONSTEXPR auto map(const T& val) -> decltype(
-    return static_cast<int>(val);
+      map(static_cast<typename std::underlying_type<T>::type>(val))) {
+    return map(static_cast<typename std::underlying_type<T>::type>(val));
   }
   template <typename T,
             FMT_ENABLE_IF(!is_string<T>::value && !is_char<T>::value &&
+                          !std::is_constructible<basic_string_view<char_type>,
+                                                 T>::value &&
                           (has_formatter<T, Context>::value ||
                            has_fallback_formatter<T, Context>::value))>
   FMT_CONSTEXPR const T& map(const T& val) {
@@ -841,12 +933,13 @@ template <typename Context> struct arg_mapper {
 // A type constant after applying arg_mapper<Context>.
 template <typename T, typename Context>
 using mapped_type_constant =
-    type_constant<decltype(arg_mapper<Context>().map(std::declval<T>())),
+    type_constant<decltype(arg_mapper<Context>().map(std::declval<const T&>())),
                   typename Context::char_type>;
 
+enum { packed_arg_bits = 5 };
 // Maximum number of arguments with packed types.
-enum { max_packed_args = 15 };
+enum { max_packed_args = 63 / packed_arg_bits };
-enum : unsigned long long { is_unpacked_bit = 1ull << 63 };
+enum : unsigned long long { is_unpacked_bit = 1ULL << 63 };
 
 template <typename Context> class arg_map;
 }  // namespace internal
@@ -877,7 +970,8 @@ template <typename Context> class basic_format_arg {
    public:
     explicit handle(internal::custom_value<Context> custom) : custom_(custom) {}
 
-    void format(basic_parse_context<char_type>& parse_ctx, Context& ctx) const {
+    void format(basic_format_parse_context<char_type>& parse_ctx,
+                Context& ctx) const {
       custom_.format(custom_.value, parse_ctx, ctx);
     }
 
@@ -893,8 +987,8 @@ template <typename Context> class basic_format_arg {
 
   internal::type type() const { return type_; }
 
-  bool is_integral() const { return internal::is_integral(type_); }
+  bool is_integral() const { return internal::is_integral_type(type_); }
-  bool is_arithmetic() const { return internal::is_arithmetic(type_); }
+  bool is_arithmetic() const { return internal::is_arithmetic_type(type_); }
 };
 
 /**
@@ -923,10 +1017,22 @@ FMT_CONSTEXPR auto visit_format_arg(Visitor&& vis,
     return vis(arg.value_.long_long_value);
   case internal::ulong_long_type:
     return vis(arg.value_.ulong_long_value);
+#if FMT_USE_INT128
+  case internal::int128_type:
+    return vis(arg.value_.int128_value);
+  case internal::uint128_type:
+    return vis(arg.value_.uint128_value);
+#else
+  case internal::int128_type:
+  case internal::uint128_type:
+    break;
+#endif
   case internal::bool_type:
     return vis(arg.value_.bool_value);
   case internal::char_type:
     return vis(arg.value_.char_value);
+  case internal::float_type:
+    return vis(arg.value_.float_value);
   case internal::double_type:
     return vis(arg.value_.double_value);
   case internal::long_double_type:
@@ -948,9 +1054,6 @@ namespace internal {
 // A map from argument names to their values for named arguments.
 template <typename Context> class arg_map {
  private:
-  arg_map(const arg_map&) = delete;
-  void operator=(const arg_map&) = delete;
-
   using char_type = typename Context::char_type;
 
   struct entry {
@@ -968,6 +1071,8 @@ template <typename Context> class arg_map {
   }
 
  public:
+  arg_map(const arg_map&) = delete;
+  void operator=(const arg_map&) = delete;
   arg_map() : map_(nullptr), size_(0) {}
   void init(const basic_format_args<Context>& args);
   ~arg_map() { delete[] map_; }
@@ -990,6 +1095,8 @@ class locale_ref {
   locale_ref() : locale_(nullptr) {}
   template <typename Locale> explicit locale_ref(const Locale& loc);
 
+  explicit operator bool() const FMT_NOEXCEPT { return locale_ != nullptr; }
+
   template <typename Locale> Locale get() const;
 };
 
@@ -998,7 +1105,7 @@ template <typename> constexpr unsigned long long encode_types() { return 0; }
 template <typename Context, typename Arg, typename... Args>
 constexpr unsigned long long encode_types() {
   return mapped_type_constant<Arg, Context>::value |
-         (encode_types<Context, Args...>() << 4);
+         (encode_types<Context, Args...>() << packed_arg_bits);
 }
 
 template <typename Context, typename T>
@@ -1034,14 +1141,13 @@ template <typename OutputIt, typename Char> class basic_format_context {
   internal::arg_map<basic_format_context> map_;
   internal::locale_ref loc_;
 
-  basic_format_context(const basic_format_context&) = delete;
-  void operator=(const basic_format_context&) = delete;
-
  public:
   using iterator = OutputIt;
   using format_arg = basic_format_arg<basic_format_context>;
   template <typename T> using formatter_type = formatter<T, char_type>;
 
+  basic_format_context(const basic_format_context&) = delete;
+  void operator=(const basic_format_context&) = delete;
   /**
    Constructs a ``basic_format_context`` object. References to the arguments are
    stored in the object so make sure they have appropriate lifetimes.
@@ -1143,8 +1249,9 @@ template <typename Context> class basic_format_args {
   bool is_packed() const { return (types_ & internal::is_unpacked_bit) == 0; }
 
   internal::type type(int index) const {
-    int shift = index * 4;
+    int shift = index * internal::packed_arg_bits;
-    return static_cast<internal::type>((types_ & (0xfull << shift)) >> shift);
+    unsigned int mask = (1 << internal::packed_arg_bits) - 1;
+    return static_cast<internal::type>((types_ >> shift) & mask);
   }
 
   friend class internal::arg_map<Context>;
@@ -1371,7 +1478,7 @@ inline std::basic_string<Char> format(const S& format_str, Args&&... args) {
 }
 
 FMT_API void vprint(std::FILE* f, string_view format_str, format_args args);
-FMT_API void vprint(std::FILE* f, wstring_view format_str, wformat_args args);
+FMT_API void vprint(string_view format_str, format_args args);
 
 /**
   \rst
@@ -1391,9 +1498,6 @@ inline void print(std::FILE* f, const S& format_str, Args&&... args) {
          internal::make_args_checked<Args...>(format_str, args...));
 }
 
-FMT_API void vprint(string_view format_str, format_args args);
-FMT_API void vprint(wstring_view format_str, wformat_args args);
-
 /**
   \rst
   Prints formatted data to ``stdout``.

include/spdlog/fmt/bundled/ostream.h

@@ -46,9 +46,13 @@ template <class Char> class formatbuf : public std::basic_streambuf<Char> {
 
 template <typename Char> struct test_stream : std::basic_ostream<Char> {
  private:
-  struct null;
   // Hide all operator<< from std::basic_ostream<Char>.
-  void operator<<(null);
+  void_t<> operator<<(null<>);
+  void_t<> operator<<(const Char*);
+
+  template <typename T, FMT_ENABLE_IF(std::is_convertible<T, int>::value &&
+                                      !std::is_enum<T>::value)>
+  void_t<> operator<<(T);
 };
 
 // Checks if T has a user-defined operator<< (e.g. not a member of
@@ -56,9 +60,9 @@ template <typename Char> struct test_stream : std::basic_ostream<Char> {
 template <typename T, typename Char> class is_streamable {
  private:
   template <typename U>
-  static decltype((void)(std::declval<test_stream<Char>&>()
+  static bool_constant<!std::is_same<decltype(std::declval<test_stream<Char>&>()
-                         << std::declval<U>()),
+                                              << std::declval<U>()),
-                  std::true_type())
+                                     void_t<>>::value>
   test(int);
 
   template <typename> static std::false_type test(...);
@@ -75,8 +79,7 @@ void write(std::basic_ostream<Char>& os, buffer<Char>& buf) {
   const Char* buf_data = buf.data();
   using unsigned_streamsize = std::make_unsigned<std::streamsize>::type;
   unsigned_streamsize size = buf.size();
-  unsigned_streamsize max_size =
+  unsigned_streamsize max_size = to_unsigned(max_value<std::streamsize>());
-      to_unsigned((std::numeric_limits<std::streamsize>::max)());
   do {
     unsigned_streamsize n = size <= max_size ? size : max_size;
     os.write(buf_data, static_cast<std::streamsize>(n));
@@ -86,9 +89,11 @@ void write(std::basic_ostream<Char>& os, buffer<Char>& buf) {
 }
 
 template <typename Char, typename T>
-void format_value(buffer<Char>& buf, const T& value) {
+void format_value(buffer<Char>& buf, const T& value,
+                  locale_ref loc = locale_ref()) {
   formatbuf<Char> format_buf(buf);
   std::basic_ostream<Char> output(&format_buf);
+  if (loc) output.imbue(loc.get<std::locale>());
   output.exceptions(std::ios_base::failbit | std::ios_base::badbit);
   output << value;
   buf.resize(buf.size());
@@ -101,7 +106,7 @@ struct fallback_formatter<T, Char, enable_if_t<is_streamable<T, Char>::value>>
   template <typename Context>
   auto format(const T& value, Context& ctx) -> decltype(ctx.out()) {
     basic_memory_buffer<Char> buffer;
-    format_value(buffer, value);
+    format_value(buffer, value, ctx.locale());
     basic_string_view<Char> str(buffer.data(), buffer.size());
     return formatter<basic_string_view<Char>, Char>::format(str, ctx);
   }

include/spdlog/fmt/bundled/posix.h

@@ -13,11 +13,10 @@
 #  undef __STRICT_ANSI__
 #endif
 
-#include <errno.h>
+#include <cerrno>
-#include <fcntl.h>   // for O_RDONLY
+#include <clocale>  // for locale_t
-#include <locale.h>  // for locale_t
+#include <cstdio>
-#include <stdio.h>
+#include <cstdlib>  // for strtod_l
-#include <stdlib.h>  // for strtod_l
 
 #include <cstddef>
 
@@ -27,6 +26,18 @@
 
 #include "format.h"
 
+// UWP doesn't provide _pipe.
+#if FMT_HAS_INCLUDE("winapifamily.h")
+#  include <winapifamily.h>
+#endif
+#if FMT_HAS_INCLUDE("fcntl.h") && \
+    (!defined(WINAPI_FAMILY) || (WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP))
+#  include <fcntl.h>  // for O_RDONLY
+#  define FMT_USE_FCNTL 1
+#else
+#  define FMT_USE_FCNTL 0
+#endif
+
 #ifndef FMT_POSIX
 #  if defined(_WIN32) && !defined(__MINGW32__)
 // Fix warnings about deprecated symbols.
@@ -54,8 +65,8 @@
 #ifndef _WIN32
 #  define FMT_RETRY_VAL(result, expression, error_result) \
     do {                                                  \
-      result = (expression);                              \
+      (result) = (expression);                            \
-    } while (result == error_result && errno == EINTR)
+    } while ((result) == (error_result) && errno == EINTR)
 #else
 #  define FMT_RETRY_VAL(result, expression, error_result) result = (expression)
 #endif
@@ -132,16 +143,15 @@ class buffered_file {
   explicit buffered_file(FILE* f) : file_(f) {}
 
  public:
+  buffered_file(const buffered_file&) = delete;
+  void operator=(const buffered_file&) = delete;
+
   // Constructs a buffered_file object which doesn't represent any file.
   buffered_file() FMT_NOEXCEPT : file_(nullptr) {}
 
   // Destroys the object closing the file it represents if any.
   FMT_API ~buffered_file() FMT_NOEXCEPT;
 
- private:
-  buffered_file(const buffered_file&) = delete;
-  void operator=(const buffered_file&) = delete;
-
  public:
   buffered_file(buffered_file&& other) FMT_NOEXCEPT : file_(other.file_) {
     other.file_ = nullptr;
@@ -177,6 +187,7 @@ class buffered_file {
   }
 };
 
+#if FMT_USE_FCNTL
 // A file. Closed file is represented by a file object with descriptor -1.
 // Methods that are not declared with FMT_NOEXCEPT may throw
 // fmt::system_error in case of failure. Note that some errors such as
@@ -204,14 +215,13 @@ class file {
   // Opens a file and constructs a file object representing this file.
   FMT_API file(cstring_view path, int oflag);
 
- private:
+ public:
   file(const file&) = delete;
   void operator=(const file&) = delete;
 
- public:
   file(file&& other) FMT_NOEXCEPT : fd_(other.fd_) { other.fd_ = -1; }
 
-  file& operator=(file&& other) {
+  file& operator=(file&& other) FMT_NOEXCEPT {
     close();
     fd_ = other.fd_;
     other.fd_ = -1;
@@ -260,6 +270,7 @@ class file {
 
 // Returns the memory page size.
 long getpagesize();
+#endif  // FMT_USE_FCNTL
 
 #ifdef FMT_LOCALE
 // A "C" numeric locale.
@@ -283,11 +294,10 @@ class Locale {
 
   locale_t locale_;
 
-  Locale(const Locale&) = delete;
-  void operator=(const Locale&) = delete;
-
  public:
   using type = locale_t;
+  Locale(const Locale&) = delete;
+  void operator=(const Locale&) = delete;
 
   Locale() : locale_(newlocale(LC_NUMERIC_MASK, "C", nullptr)) {
     if (!locale_) FMT_THROW(system_error(errno, "cannot create locale"));

include/spdlog/fmt/bundled/printf.h

@@ -1,4 +1,4 @@
-// Formatting library for C++
+// Formatting library for C++ - legacy printf implementation
 //
 // Copyright (c) 2012 - 2016, Victor Zverovich
 // All rights reserved.
@@ -8,7 +8,7 @@
 #ifndef FMT_PRINTF_H_
 #define FMT_PRINTF_H_
 
-#include <algorithm>  // std::fill_n
+#include <algorithm>  // std::max
 #include <limits>     // std::numeric_limits
 
 #include "ostream.h"
@@ -16,15 +16,11 @@
 FMT_BEGIN_NAMESPACE
 namespace internal {
 
-// A helper function to suppress bogus "conditional expression is constant"
-// warnings.
-template <typename T> inline T const_check(T value) { return value; }
-
 // Checks if a value fits in int - used to avoid warnings about comparing
 // signed and unsigned integers.
 template <bool IsSigned> struct int_checker {
   template <typename T> static bool fits_in_int(T value) {
-    unsigned max = std::numeric_limits<int>::max();
+    unsigned max = max_value<int>();
     return value <= max;
   }
   static bool fits_in_int(bool) { return true; }
@@ -33,7 +29,7 @@ template <bool IsSigned> struct int_checker {
 template <> struct int_checker<true> {
   template <typename T> static bool fits_in_int(T value) {
     return value >= std::numeric_limits<int>::min() &&
-           value <= std::numeric_limits<int>::max();
+           value <= max_value<int>();
   }
   static bool fits_in_int(int) { return true; }
 };
@@ -158,12 +154,12 @@ template <typename Char> class printf_width_handler {
 
   template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
   unsigned operator()(T value) {
-    auto width = static_cast<uint32_or_64_t<T>>(value);
+    auto width = static_cast<uint32_or_64_or_128_t<T>>(value);
     if (internal::is_negative(value)) {
       specs_.align = align::left;
       width = 0 - width;
     }
-    unsigned int_max = std::numeric_limits<int>::max();
+    unsigned int_max = max_value<int>();
     if (width > int_max) FMT_THROW(format_error("number is too big"));
     return static_cast<unsigned>(width);
   }
@@ -235,7 +231,7 @@ class printf_arg_formatter : public internal::arg_formatter_base<Range> {
   printf_arg_formatter(iterator iter, format_specs& specs, context_type& ctx)
       : base(Range(iter), &specs, internal::locale_ref()), context_(ctx) {}
 
-  template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
+  template <typename T, FMT_ENABLE_IF(fmt::internal::is_integral<T>::value)>
   iterator operator()(T value) {
     // MSVC2013 fails to compile separate overloads for bool and char_type so
     // use std::is_same instead.
@@ -332,14 +328,14 @@ template <typename OutputIt, typename Char> class basic_printf_context {
 
   OutputIt out_;
   basic_format_args<basic_printf_context> args_;
-  basic_parse_context<Char> parse_ctx_;
+  basic_format_parse_context<Char> 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 equal
   // to the maximum unsigned value, the next argument.
-  format_arg get_arg(unsigned arg_index = std::numeric_limits<unsigned>::max());
+  format_arg get_arg(unsigned arg_index = internal::max_value<unsigned>());
 
   // Parses argument index, flags and width and returns the argument index.
   unsigned parse_header(const Char*& it, const Char* end, format_specs& specs);
@@ -361,15 +357,14 @@ template <typename OutputIt, typename Char> class basic_printf_context {
 
   format_arg arg(unsigned id) const { return args_.get(id); }
 
-  basic_parse_context<Char>& parse_context() { return parse_ctx_; }
+  basic_format_parse_context<Char>& 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 =
+  template <typename ArgFormatter = printf_arg_formatter<buffer_range<Char>>>
-                printf_arg_formatter<internal::buffer_range<Char>>>
   OutputIt format();
 };
 
@@ -403,7 +398,7 @@ void basic_printf_context<OutputIt, Char>::parse_flags(format_specs& specs,
 template <typename OutputIt, typename Char>
 typename basic_printf_context<OutputIt, Char>::format_arg
 basic_printf_context<OutputIt, Char>::get_arg(unsigned arg_index) {
-  if (arg_index == std::numeric_limits<unsigned>::max())
+  if (arg_index == internal::max_value<unsigned>())
     arg_index = parse_ctx_.next_arg_id();
   else
     parse_ctx_.check_arg_id(--arg_index);
@@ -413,7 +408,7 @@ basic_printf_context<OutputIt, Char>::get_arg(unsigned arg_index) {
 template <typename OutputIt, typename Char>
 unsigned basic_printf_context<OutputIt, Char>::parse_header(
     const Char*& it, const Char* end, format_specs& specs) {
-  unsigned arg_index = std::numeric_limits<unsigned>::max();
+  unsigned arg_index = internal::max_value<unsigned>();
   char_type c = *it;
   if (c >= '0' && c <= '9') {
     // Parse an argument index (if followed by '$') or a width possibly
@@ -470,6 +465,7 @@ OutputIt basic_printf_context<OutputIt, Char>::format() {
 
     // Parse argument index, flags and width.
     unsigned arg_index = parse_header(it, end, specs);
+    if (arg_index == 0) on_error("argument index out of range");
 
     // Parse precision.
     if (it != end && *it == '.') {

include/spdlog/fmt/bundled/ranges.h

@@ -246,7 +246,8 @@ template <typename T, typename Char> struct is_range {
   static FMT_CONSTEXPR_DECL const bool value =
       internal::is_range_<T>::value &&
       !internal::is_like_std_string<T>::value &&
-      !std::is_convertible<T, std::basic_string<Char>>::value;
+      !std::is_convertible<T, std::basic_string<Char>>::value &&
+      !std::is_constructible<internal::std_string_view<Char>, T>::value;
 };
 
 template <typename RangeT, typename Char>
@@ -283,6 +284,82 @@ struct formatter<RangeT, Char,
   }
 };
 
+template <typename Char, typename... T> struct tuple_arg_join : internal::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 FormatContext::iterator format(
+      const tuple_arg_join<Char, T...>& value, FormatContext& ctx) {
+    return format(value, ctx, internal::make_index_sequence<sizeof...(T)>{});
+  }
+
+ private:
+  template <typename FormatContext, size_t... N>
+  typename FormatContext::iterator format(
+      const tuple_arg_join<Char, T...>& value, FormatContext& ctx,
+      internal::index_sequence<N...>) {
+    return format_args(value, ctx, std::get<N>(value.tuple)...);
+  }
+
+  template <typename FormatContext>
+  typename FormatContext::iterator format_args(
+      const tuple_arg_join<Char, T...>&, FormatContext& ctx) {
+    // NOTE: for compilers that support C++17, this empty function instantiation
+    // can be replaced with a constexpr branch in the variadic overload.
+    return ctx.out();
+  }
+
+  template <typename FormatContext, typename Arg, typename... Args>
+  typename FormatContext::iterator format_args(
+      const tuple_arg_join<Char, T...>& value, FormatContext& ctx,
+      const Arg& arg, const Args&... args) {
+    using base = formatter<typename std::decay<Arg>::type, Char>;
+    auto out = ctx.out();
+    out = base{}.format(arg, ctx);
+    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 out;
+  }
+};
+
+/**
+  \rst
+  Returns an object that formats `tuple` with elements separated by `sep`.
+
+  **Example**::
+
+    std::tuple<int, char> t = {1, 'a'};
+    fmt::print("{}", fmt::join(t, ", "));
+    // Output: "1, a"
+  \endrst
+ */
+template <typename... T>
+FMT_CONSTEXPR tuple_arg_join<char, T...> join(const std::tuple<T...>& tuple,
+                                              string_view sep) {
+  return {tuple, sep};
+}
+
+template <typename... T>
+FMT_CONSTEXPR tuple_arg_join<wchar_t, T...> join(const std::tuple<T...>& tuple,
+                                                 wstring_view sep) {
+  return {tuple, sep};
+}
+
 FMT_END_NAMESPACE
 
 #endif  // FMT_RANGES_H_

include/spdlog/fmt/bundled/safe-duration-cast.h

@@ -1,293 +0,0 @@
-/*
- * For conversion between std::chrono::durations without undefined
- * behaviour or erroneous results.
- * This is a stripped down version of duration_cast, for inclusion in fmt.
- * See https://github.com/pauldreik/safe_duration_cast
- *
- * Copyright Paul Dreik 2019
- *
- * This file is licensed under the fmt license, see format.h
- */
-
-#include <chrono>
-#include <cmath>
-#include <limits>
-#include <type_traits>
-
-#include "format.h"
-
-FMT_BEGIN_NAMESPACE
-
-namespace safe_duration_cast {
-
-template <typename To, typename From,
-          FMT_ENABLE_IF(!std::is_same<From, To>::value &&
-                        std::numeric_limits<From>::is_signed ==
-                            std::numeric_limits<To>::is_signed)>
-FMT_CONSTEXPR To lossless_integral_conversion(const From from, int& ec) {
-  ec = 0;
-  using F = std::numeric_limits<From>;
-  using T = std::numeric_limits<To>;
-  static_assert(F::is_integer, "From must be integral");
-  static_assert(T::is_integer, "To must be integral");
-
-  // A and B are both signed, or both unsigned.
-  if (F::digits <= T::digits) {
-    // From fits in To without any problem.
-  } else {
-    // From does not always fit in To, resort to a dynamic check.
-    if (from < T::min() || from > T::max()) {
-      // outside range.
-      ec = 1;
-      return {};
-    }
-  }
-  return static_cast<To>(from);
-}
-
-/**
- * converts From to To, without loss. If the dynamic value of from
- * can't be converted to To without loss, ec is set.
- */
-template <typename To, typename From,
-          FMT_ENABLE_IF(!std::is_same<From, To>::value &&
-                        std::numeric_limits<From>::is_signed !=
-                            std::numeric_limits<To>::is_signed)>
-FMT_CONSTEXPR To lossless_integral_conversion(const From from, int& ec) {
-  ec = 0;
-  using F = std::numeric_limits<From>;
-  using T = std::numeric_limits<To>;
-  static_assert(F::is_integer, "From must be integral");
-  static_assert(T::is_integer, "To must be integral");
-
-  if (F::is_signed && !T::is_signed) {
-    // From may be negative, not allowed!
-    if (from < 0) {
-      ec = 1;
-      return {};
-    }
-
-    // From is positive. Can it always fit in To?
-    if (F::digits <= T::digits) {
-      // yes, From always fits in To.
-    } else {
-      // from may not fit in To, we have to do a dynamic check
-      if (from > static_cast<From>(T::max())) {
-        ec = 1;
-        return {};
-      }
-    }
-  }
-
-  if (!F::is_signed && T::is_signed) {
-    // can from be held in To?
-    if (F::digits < T::digits) {
-      // yes, From always fits in To.
-    } else {
-      // from may not fit in To, we have to do a dynamic check
-      if (from > static_cast<From>(T::max())) {
-        // outside range.
-        ec = 1;
-        return {};
-      }
-    }
-  }
-
-  // reaching here means all is ok for lossless conversion.
-  return static_cast<To>(from);
-
-}  // function
-
-template <typename To, typename From,
-          FMT_ENABLE_IF(std::is_same<From, To>::value)>
-FMT_CONSTEXPR To lossless_integral_conversion(const From from, int& ec) {
-  ec = 0;
-  return from;
-}  // function
-
-// clang-format off
-/**
- * converts From to To if possible, otherwise ec is set.
- *
- * input                            |    output
- * ---------------------------------|---------------
- * NaN                              | NaN
- * Inf                              | Inf
- * normal, fits in output           | converted (possibly lossy)
- * normal, does not fit in output   | ec is set
- * subnormal                        | best effort
- * -Inf                             | -Inf
- */
-// clang-format on
-template <typename To, typename From,
-          FMT_ENABLE_IF(!std::is_same<From, To>::value)>
-FMT_CONSTEXPR To safe_float_conversion(const From from, int& ec) {
-  ec = 0;
-  using T = std::numeric_limits<To>;
-  static_assert(std::is_floating_point<From>::value, "From must be floating");
-  static_assert(std::is_floating_point<To>::value, "To must be floating");
-
-  // catch the only happy case
-  if (std::isfinite(from)) {
-    if (from >= T::lowest() && from <= T::max()) {
-      return static_cast<To>(from);
-    }
-    // not within range.
-    ec = 1;
-    return {};
-  }
-
-  // nan and inf will be preserved
-  return static_cast<To>(from);
-}  // function
-
-template <typename To, typename From,
-          FMT_ENABLE_IF(std::is_same<From, To>::value)>
-FMT_CONSTEXPR To safe_float_conversion(const From from, int& ec) {
-  ec = 0;
-  static_assert(std::is_floating_point<From>::value, "From must be floating");
-  return from;
-}
-
-/**
- * safe duration cast between integral durations
- */
-template <typename To, typename FromRep, typename FromPeriod,
-          FMT_ENABLE_IF(std::is_integral<FromRep>::value),
-          FMT_ENABLE_IF(std::is_integral<typename To::rep>::value)>
-To safe_duration_cast(std::chrono::duration<FromRep, FromPeriod> from,
-                      int& ec) {
-  using From = std::chrono::duration<FromRep, FromPeriod>;
-  ec = 0;
-  // the basic idea is that we need to convert from count() in the from type
-  // to count() in the To type, by multiplying it with this:
-  using Factor = std::ratio_divide<typename From::period, typename To::period>;
-
-  static_assert(Factor::num > 0, "num must be positive");
-  static_assert(Factor::den > 0, "den must be positive");
-
-  // the conversion is like this: multiply from.count() with Factor::num
-  // /Factor::den and convert it to To::rep, all this without
-  // overflow/underflow. let's start by finding a suitable type that can hold
-  // both To, From and Factor::num
-  using IntermediateRep =
-      typename std::common_type<typename From::rep, typename To::rep,
-                                decltype(Factor::num)>::type;
-
-  // safe conversion to IntermediateRep
-  IntermediateRep count =
-      lossless_integral_conversion<IntermediateRep>(from.count(), ec);
-  if (ec) {
-    return {};
-  }
-  // multiply with Factor::num without overflow or underflow
-  if (Factor::num != 1) {
-    constexpr auto max1 =
-        std::numeric_limits<IntermediateRep>::max() / Factor::num;
-    if (count > max1) {
-      ec = 1;
-      return {};
-    }
-    constexpr auto min1 =
-        std::numeric_limits<IntermediateRep>::min() / Factor::num;
-    if (count < min1) {
-      ec = 1;
-      return {};
-    }
-    count *= Factor::num;
-  }
-
-  // this can't go wrong, right? den>0 is checked earlier.
-  if (Factor::den != 1) {
-    count /= Factor::den;
-  }
-  // convert to the to type, safely
-  using ToRep = typename To::rep;
-  const ToRep tocount = lossless_integral_conversion<ToRep>(count, ec);
-  if (ec) {
-    return {};
-  }
-  return To{tocount};
-}
-
-/**
- * safe duration_cast between floating point durations
- */
-template <typename To, typename FromRep, typename FromPeriod,
-          FMT_ENABLE_IF(std::is_floating_point<FromRep>::value),
-          FMT_ENABLE_IF(std::is_floating_point<typename To::rep>::value)>
-To safe_duration_cast(std::chrono::duration<FromRep, FromPeriod> from,
-                      int& ec) {
-  using From = std::chrono::duration<FromRep, FromPeriod>;
-  ec = 0;
-  if (std::isnan(from.count())) {
-    // nan in, gives nan out. easy.
-    return To{std::numeric_limits<typename To::rep>::quiet_NaN()};
-  }
-  // maybe we should also check if from is denormal, and decide what to do about
-  // it.
-
-  // +-inf should be preserved.
-  if (std::isinf(from.count())) {
-    return To{from.count()};
-  }
-
-  // the basic idea is that we need to convert from count() in the from type
-  // to count() in the To type, by multiplying it with this:
-  using Factor = std::ratio_divide<typename From::period, typename To::period>;
-
-  static_assert(Factor::num > 0, "num must be positive");
-  static_assert(Factor::den > 0, "den must be positive");
-
-  // the conversion is like this: multiply from.count() with Factor::num
-  // /Factor::den and convert it to To::rep, all this without
-  // overflow/underflow. let's start by finding a suitable type that can hold
-  // both To, From and Factor::num
-  using IntermediateRep =
-      typename std::common_type<typename From::rep, typename To::rep,
-                                decltype(Factor::num)>::type;
-
-  // force conversion of From::rep -> IntermediateRep to be safe,
-  // even if it will never happen be narrowing in this context.
-  IntermediateRep count =
-      safe_float_conversion<IntermediateRep>(from.count(), ec);
-  if (ec) {
-    return {};
-  }
-
-  // multiply with Factor::num without overflow or underflow
-  if (Factor::num != 1) {
-    constexpr auto max1 = std::numeric_limits<IntermediateRep>::max() /
-                          static_cast<IntermediateRep>(Factor::num);
-    if (count > max1) {
-      ec = 1;
-      return {};
-    }
-    constexpr auto min1 = std::numeric_limits<IntermediateRep>::lowest() /
-                          static_cast<IntermediateRep>(Factor::num);
-    if (count < min1) {
-      ec = 1;
-      return {};
-    }
-    count *= static_cast<IntermediateRep>(Factor::num);
-  }
-
-  // this can't go wrong, right? den>0 is checked earlier.
-  if (Factor::den != 1) {
-    using common_t = typename std::common_type<IntermediateRep, intmax_t>::type;
-    count /= static_cast<common_t>(Factor::den);
-  }
-
-  // convert to the to type, safely
-  using ToRep = typename To::rep;
-
-  const ToRep tocount = safe_float_conversion<ToRep>(count, ec);
-  if (ec) {
-    return {};
-  }
-  return To{tocount};
-}
-
-}  // namespace safe_duration_cast
-
-FMT_END_NAMESPACE

src/fmt.cpp

@@ -9,27 +9,60 @@
 #if !defined(SPDLOG_FMT_EXTERNAL)
 #include "spdlog/fmt/bundled/format-inl.h"
 
+
 FMT_BEGIN_NAMESPACE
-template struct internal::basic_data<void>;
+template struct FMT_API internal::basic_data<void>;
-template FMT_API internal::locale_ref::locale_ref(const std::locale &loc);
+
+// Workaround a bug in MSVC2013 that prevents instantiation of format_float.
+int (*instantiate_format_float)(double, int, internal::float_specs,
+                                internal::buffer<char>&) =
+internal::format_float;
+
+#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
+template FMT_API internal::locale_ref::locale_ref(const std::locale& loc);
 template FMT_API std::locale internal::locale_ref::get<std::locale>() const;
+#endif
 
 // Explicit instantiations for char.
+
+template FMT_API std::string internal::grouping_impl<char>(locale_ref);
 template FMT_API char internal::thousands_sep_impl(locale_ref);
 template FMT_API char internal::decimal_point_impl(locale_ref);
-template FMT_API void internal::buffer<char>::append(const char *, const char *);
+
-template FMT_API void internal::arg_map<format_context>::init(const basic_format_args<format_context> &args);
+template FMT_API void internal::buffer<char>::append(const char*, const char*);
-template FMT_API std::string internal::vformat<char>(string_view, basic_format_args<format_context>);
+
-template FMT_API format_context::iterator internal::vformat_to(internal::buffer<char> &, string_view, basic_format_args<format_context>);
+template FMT_API void internal::arg_map<format_context>::init(
-template FMT_API char *internal::sprintf_format(double, internal::buffer<char> &, sprintf_specs);
+        const basic_format_args<format_context>& args);
-template FMT_API char *internal::sprintf_format(long double, internal::buffer<char> &, sprintf_specs);
+
+template FMT_API std::string internal::vformat<char>(
+        string_view, basic_format_args<format_context>);
+
+template FMT_API format_context::iterator internal::vformat_to(
+        internal::buffer<char>&, string_view, basic_format_args<format_context>);
+
+template FMT_API int internal::snprintf_float(double, int,
+                                              internal::float_specs,
+                                              internal::buffer<char>&);
+template FMT_API int internal::snprintf_float(long double, int,
+                                              internal::float_specs,
+                                              internal::buffer<char>&);
+template FMT_API int internal::format_float(double, int, internal::float_specs,
+                                            internal::buffer<char>&);
+template FMT_API int internal::format_float(long double, int,
+                                            internal::float_specs,
+                                            internal::buffer<char>&);
 
 // Explicit instantiations for wchar_t.
+
+template FMT_API std::string internal::grouping_impl<wchar_t>(locale_ref);
 template FMT_API wchar_t internal::thousands_sep_impl(locale_ref);
 template FMT_API wchar_t internal::decimal_point_impl(locale_ref);
-template FMT_API void internal::buffer<wchar_t>::append(const wchar_t *, const wchar_t *);
+
-template FMT_API void internal::arg_map<wformat_context>::init(const basic_format_args<wformat_context> &);
+template FMT_API void internal::buffer<wchar_t>::append(const wchar_t*,
-template FMT_API std::wstring internal::vformat<wchar_t>(wstring_view, basic_format_args<wformat_context>);
+                                                        const wchar_t*);
+
+template FMT_API std::wstring internal::vformat<wchar_t>(
+        wstring_view, basic_format_args<wformat_context>);
 FMT_END_NAMESPACE
 
 #endif