text:
#ifndef FMT_FORMAT_H_
#define FMT_FORMAT_H_

#include <cmath>         // std::signbit
#include <cstdint>       // uint32_t
#include <cstring>       // std::memcpy
#include <limits>        // std::numeric_limits
#include <memory>        // std::uninitialized_copy
#include <stdexcept>     // std::runtime_error
#include <system_error>  // std::system_error

#ifdef __cpp_lib_bit_cast
#  include <bit>  // std::bitcast
#endif

#include "core.h"

#if FMT_GCC_VERSION
#  define FMT_GCC_VISIBILITY_HIDDEN __attribute__((visibility("hidden")))
#else
#  define FMT_GCC_VISIBILITY_HIDDEN
#endif

#ifdef __NVCC__
#  define FMT_CUDA_VERSION (__CUDACC_VER_MAJOR__ * 100 + __CUDACC_VER_MINOR__)
#else
#  define FMT_CUDA_VERSION 0
#endif

#ifdef __has_builtin
#  define FMT_HAS_BUILTIN(x) __has_builtin(x)
#else
#  define FMT_HAS_BUILTIN(x) 0
#endif

#if FMT_GCC_VERSION || FMT_CLANG_VERSION
#  define FMT_NOINLINE __attribute__((noinline))
#else
#  define FMT_NOINLINE
#endif

#if FMT_MSC_VERSION
#  define FMT_MSC_DEFAULT = default
#else
#  define FMT_MSC_DEFAULT
#endif

#ifndef FMT_THROW
#  if FMT_EXCEPTIONS
#    if FMT_MSC_VERSION || defined(__NVCC__)
FMT_BEGIN_NAMESPACE
namespace detail {
template <typename Exception> inline void do_throw(const Exception& x) {
  // Silence unreachable code warnings in MSVC and NVCC because these
  // are nearly impossible to fix in a generic code.
  volatile bool b = true;
  if (b) throw x;
}
}  // namespace detail
FMT_END_NAMESPACE
#      define FMT_THROW(x) detail::do_throw(x)
#    else
#      define FMT_THROW(x) throw x
#    endif
#  else
#    define FMT_THROW(x)               \
      do {                             \
        FMT_ASSERT(false, (x).what()); \
      } while (false)
#  endif
#endif

#if FMT_EXCEPTIONS
#  define FMT_TRY try
#  define FMT_CATCH(x) catch (x)
#else
#  define FMT_TRY if (true)
#  define FMT_CATCH(x) if (false)
#endif

#ifndef FMT_MAYBE_UNUSED
#  if FMT_HAS_CPP17_ATTRIBUTE(maybe_unused)
#    define FMT_MAYBE_UNUSED [[maybe_unused]]
#  else
#    define FMT_MAYBE_UNUSED
#  endif
#endif

#ifndef FMT_USE_USER_DEFINED_LITERALS
// EDG based compilers (Intel, NVIDIA, Elbrus, etc), GCC and MSVC support UDLs.
#  if (FMT_HAS_FEATURE(cxx_user_literals) || FMT_GCC_VERSION >= 407 || \
       FMT_MSC_VERSION >= 1900) &&                                     \
      (!defined(__EDG_VERSION__) || __EDG_VERSION__ >= /* UDL feature */ 480)
#    define FMT_USE_USER_DEFINED_LITERALS 1
#  else
#    define FMT_USE_USER_DEFINED_LITERALS 0
#  endif
#endif

// Defining FMT_REDUCE_INT_INSTANTIATIONS to 1, will reduce the number of
// integer formatter template instantiations to just one by only using the
// largest integer type. This results in a reduction in binary size but will
// cause a decrease in integer formatting performance.
#if !defined(FMT_REDUCE_INT_INSTANTIATIONS)
#  define FMT_REDUCE_INT_INSTANTIATIONS 0
#endif

// __builtin_clz is broken in clang with Microsoft CodeGen:
// https://github.com/fmtlib/fmt/issues/519.
#if !FMT_MSC_VERSION
#  if FMT_HAS_BUILTIN(__builtin_clz) || FMT_GCC_VERSION || FMT_ICC_VERSION
#    define FMT_BUILTIN_CLZ(n) __builtin_clz(n)
#  endif
#  if FMT_HAS_BUILTIN(__builtin_clzll) || FMT_GCC_VERSION || FMT_ICC_VERSION
#    define FMT_BUILTIN_CLZLL(n) __builtin_clzll(n)
#  endif
#endif

// __builtin_ctz is broken in Intel Compiler Classic on Windows:
// https://github.com/fmtlib/fmt/issues/2510.
#ifndef __ICL
#  if FMT_HAS_BUILTIN(__builtin_ctz) || FMT_GCC_VERSION || FMT_ICC_VERSION || \
      defined(__NVCOMPILER)
#    define FMT_BUILTIN_CTZ(n) __builtin_ctz(n)
#  endif
#  if FMT_HAS_BUILTIN(__builtin_ctzll) || FMT_GCC_VERSION || \
      FMT_ICC_VERSION || defined(__NVCOMPILER)
#    define FMT_BUILTIN_CTZLL(n) __builtin_ctzll(n)
#  endif
#endif

#if FMT_MSC_VERSION
#  include <intrin.h>  // _BitScanReverse[64], _BitScanForward[64], _umul128
#endif

// Some compilers masquerade as both MSVC and GCC-likes or otherwise support
// __builtin_clz and __builtin_clzll, so only define FMT_BUILTIN_CLZ using the
// MSVC intrinsics if the clz and clzll builtins are not available.
#if FMT_MSC_VERSION && !defined(FMT_BUILTIN_CLZLL) && \
    !defined(FMT_BUILTIN_CTZLL)
FMT_BEGIN_NAMESPACE
namespace detail {
// Avoid Clang with Microsoft CodeGen's -Wunknown-pragmas warning.
#  if !defined(__clang__)
#    pragma intrinsic(_BitScanForward)
#    pragma intrinsic(_BitScanReverse)
#    if defined(_WIN64)
#      pragma intrinsic(_BitScanForward64)
#      pragma intrinsic(_BitScanReverse64)
#    endif
#  endif

inline auto clz(uint32_t x) -> int {
  unsigned long r = 0;
  _BitScanReverse(&r, x);
  FMT_ASSERT(x != 0, "");
  // Static analysis complains about using uninitialized data
  // "r", but the only way that can happen is if "x" is 0,
  // which the callers guarantee to not happen.
  FMT_MSC_WARNING(suppress : 6102)
  return 31 ^ static_cast<int>(r);
}
#  define FMT_BUILTIN_CLZ(n) detail::clz(n)

inline auto clzll(uint64_t x) -> int {
  unsigned long r = 0;
#  ifdef _WIN64
  _BitScanReverse64(&r, x);
#  else
  // Scan the high 32 bits.
  if (_BitScanReverse(&r, static_cast<uint32_t>(x >> 32))) return 63 ^ (r + 32);
  // Scan the low 32 bits.
  _BitScanReverse(&r, static_cast<uint32_t>(x));
#  endif
  FMT_ASSERT(x != 0, "");
  FMT_MSC_WARNING(suppress : 6102)  // Suppress a bogus static analysis warning.
  return 63 ^ static_cast<int>(r);
}
#  define FMT_BUILTIN_CLZLL(n) detail::clzll(n)

inline auto ctz(uint32_t x) -> int {
  unsigned long r = 0;
  _BitScanForward(&r, x);
  FMT_ASSERT(x != 0, "");
  FMT_MSC_WARNING(suppress : 6102)  // Suppress a bogus static analysis warning.
  return static_cast<int>(r);
}
#  define FMT_BUILTIN_CTZ(n) detail::ctz(n)

inline auto ctzll(uint64_t x) -> int {
  unsigned long r = 0;
  FMT_ASSERT(x != 0, "");
  FMT_MSC_WARNING(suppress : 6102)  // Suppress a bogus static analysis warning.
#  ifdef _WIN64
  _BitScanForward64(&r, x);
#  else
  // Scan the low 32 bits.
  if (_BitScanForward(&r, static_cast<uint32_t>(x))) return static_cast<int>(r);
  // Scan the high 32 bits.
  _BitScanForward(&r, static_cast<uint32_t>(x >> 32));
  r += 32;
#  endif
  return static_cast<int>(r);
}
#  define FMT_BUILTIN_CTZLL(n) detail::ctzll(n)
}  // namespace detail
FMT_END_NAMESPACE
#endif

FMT_BEGIN_NAMESPACE
namespace detail {

FMT_CONSTEXPR inline void abort_fuzzing_if(bool condition) {
  ignore_unused(condition);
#ifdef FMT_FUZZ
  if (condition) throw std::runtime_error("fuzzing limit reached");
#endif
}

template <typename CharT, CharT... C> struct string_literal {
  static constexpr CharT value[sizeof...(C)] = {C...};
  constexpr operator basic_string_view<CharT>() const {
    return {value, sizeof...(C)};
  }
};

#if FMT_CPLUSPLUS < 201703L
template <typename CharT, CharT... C>
constexpr CharT string_literal<CharT, C...>::value[sizeof...(C)];
#endif

template <typename Streambuf> class formatbuf : public Streambuf {
 private:
  using char_type = typename Streambuf::char_type;
  using streamsize = decltype(std::declval<Streambuf>().sputn(nullptr, 0));
  using int_type = typename Streambuf::int_type;
  using traits_type = typename Streambuf::traits_type;

  buffer<char_type>& buffer_;

 public:
  explicit formatbuf(buffer<char_type>& buf) : buffer_(buf) {}

 protected:
  // The put area is always empty. This makes the implementation simpler and has
  // the advantage that the streambuf and the buffer are always in sync and
  // sputc never writes into uninitialized memory. A disadvantage is that each
  // call to sputc always results in a (virtual) call to overflow. There is no
  // disadvantage here for sputn since this always results in a call to xsputn.

  auto overflow(int_type ch) -> int_type override {
    if (!traits_type::eq_int_type(ch, traits_type::eof()))
      buffer_.push_back(static_cast<char_type>(ch));
    return ch;
  }

  auto xsputn(const char_type* s, streamsize count) -> streamsize override {
    buffer_.append(s, s + count);
    return count;
  }
};

// Implementation of std::bit_cast for pre-C++20.
template <typename To, typename From, FMT_ENABLE_IF(sizeof(To) == sizeof(From))>
FMT_CONSTEXPR20 auto bit_cast(const From& from) -> To {
#ifdef __cpp_lib_bit_cast
  if (is_constant_evaluated()) return std::bit_cast<To>(from);
#endif
  auto to = To();
  // The cast suppresses a bogus -Wclass-memaccess on GCC.
  std::memcpy(static_cast<void*>(&to), &from, sizeof(to));
  return to;
}

inline auto is_big_endian() -> bool {
#ifdef _WIN32
  return false;
#elif defined(__BIG_ENDIAN__)
  return true;
#elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__)
  return __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__;
#else
  struct bytes {
    char data[sizeof(int)];
  };
  return bit_cast<bytes>(1).data[0] == 0;
#endif
}

class uint128_fallback {
 private:
  uint64_t lo_, hi_;

  friend uint128_fallback umul128(uint64_t x, uint64_t y) noexcept;

 public:
  constexpr uint128_fallback(uint64_t hi, uint64_t lo) : lo_(lo), hi_(hi) {}
  constexpr uint128_fallback(uint64_t value = 0) : lo_(value), hi_(0) {}

  constexpr uint64_t high() const noexcept { return hi_; }
  constexpr uint64_t low() const noexcept { return lo_; }

  template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
  constexpr explicit operator T() const {
    return static_cast<T>(lo_);
  }

  friend constexpr auto operator==(const uint128_fallback& lhs,
                                   const uint128_fallback& rhs) -> bool {
    return lhs.hi_ == rhs.hi_ && lhs.lo_ == rhs.lo_;
  }
  friend constexpr auto operator!=(const uint128_fallback& lhs,
                                   const uint128_fallback& rhs) -> bool {
    return !(lhs == rhs);
  }
  friend constexpr auto operator>(const uint128_fallback& lhs,
                                  const uint128_fallback& rhs) -> bool {
    return lhs.hi_ != rhs.hi_ ? lhs.hi_ > rhs.hi_ : lhs.lo_ > rhs.lo_;
  }
  friend constexpr auto operator|(const uint128_fallback& lhs,
                                  const uint128_fallback& rhs)
      -> uint128_fallback {
    return {lhs.hi_ | rhs.hi_, lhs.lo_ | rhs.lo_};
  }
  friend constexpr auto operator&(const uint128_fallback& lhs,
                                  const uint128_fallback& rhs)
      -> uint128_fallback {
    return {lhs.hi_ & rhs.hi_, lhs.lo_ & rhs.lo_};
  }
  friend auto operator+(const uint128_fallback& lhs,
                        const uint128_fallback& rhs) -> uint128_fallback {
    auto result = uint128_fallback(lhs);
    result += rhs;
    return result;
  }
  friend auto operator*(const uint128_fallback& lhs, uint32_t rhs)
      -> uint128_fallback {
    FMT_ASSERT(lhs.hi_ == 0, "");
    uint64_t hi = (lhs.lo_ >> 32) * rhs;
    uint64_t lo = (lhs.lo_ & ~uint32_t()) * rhs;
    uint64_t new_lo = (hi << 32) + lo;
    return {(hi >> 32) + (new_lo < lo ? 1 : 0), new_lo};
  }
  friend auto operator-(const uint128_fallback& lhs, uint64_t rhs)
      -> uint128_fallback {
    return {lhs.hi_ - (lhs.lo_ < rhs ? 1 : 0), lhs.lo_ - rhs};
  }
  FMT_CONSTEXPR auto operator>>(int shift) const -> uint128_fallback {
    if (shift == 64) return {0, hi_};
    if (shift > 64) return uint128_fallback(0, hi_) >> (shift - 64);
    return {hi_ >> shift, (hi_ << (64 - shift)) | (lo_ >> shift)};
  }
  FMT_CONSTEXPR auto operator<<(int shift) const -> uint128_fallback {
    if (shift == 64) return {lo_, 0};
    if (shift > 64) return uint128_fallback(lo_, 0) << (shift - 64);
    return {hi_ << shift | (lo_ >> (64 - shift)), (lo_ << shift)};
  }
  FMT_CONSTEXPR auto operator>>=(int shift) -> uint128_fallback& {
    return *this = *this >> shift;
  }
  FMT_CONSTEXPR void operator+=(uint128_fallback n) {
    uint64_t new_lo = lo_ + n.lo_;
    uint64_t new_hi = hi_ + n.hi_ + (new_lo < lo_ ? 1 : 0);
    FMT_ASSERT(new_hi >= hi_, "");
    lo_ = new_lo;
    hi_ = new_hi;
  }

  FMT_CONSTEXPR20 uint128_fallback& operator+=(uint64_t n) noexcept {
    if (is_constant_evaluated()) {
      lo_ += n;
      hi_ += (lo_ < n ? 1 : 0);
      return *this;
    }
#if FMT_HAS_BUILTIN(__builtin_addcll) && !defined(__ibmxl__)
    unsigned long long carry;
    lo_ = __builtin_addcll(lo_, n, 0, &carry);
    hi_ += carry;
#elif FMT_HAS_BUILTIN(__builtin_ia32_addcarryx_u64) && !defined(__ibmxl__)
    unsigned long long result;
    auto carry = __builtin_ia32_addcarryx_u64(0, lo_, n, &result);
    lo_ = result;
    hi_ += carry;
#elif defined(_MSC_VER) && defined(_M_X64)
    auto carry = _addcarry_u64(0, lo_, n, &lo_);
    _addcarry_u64(carry, hi_, 0, &hi_);
#else
    lo_ += n;
    hi_ += (lo_ < n ? 1 : 0);
#endif
    return *this;
  }
};

using uint128_t = conditional_t<FMT_USE_INT128, uint128_opt, uint128_fallback>;

#ifdef UINTPTR_MAX
using uintptr_t = ::uintptr_t;
#else
using uintptr_t = uint128_t;
#endif

// Returns the largest possible value for type T. Same as
// std::numeric_limits<T>::max() but shorter and not affected by the max macro.
template <typename T> constexpr auto max_value() -> T {
  return (std::numeric_limits<T>::max)();
}
template <typename T> constexpr auto num_bits() -> int {
  return std::numeric_limits<T>::digits;
}
// std::numeric_limits<T>::digits may return 0 for 128-bit ints.
template <> constexpr auto num_bits<int128_opt>() -> int { return 128; }
template <> constexpr auto num_bits<uint128_t>() -> int { return 128; }

// A heterogeneous bit_cast used for converting 96-bit long double to uint128_t
// and 128-bit pointers to uint128_fallback.
template <typename To, typename From, FMT_ENABLE_IF(sizeof(To) > sizeof(From))>
inline auto bit_cast(const From& from) -> To {
  constexpr auto size = static_cast<int>(sizeof(From) / sizeof(unsigned));
  struct data_t {
    unsigned value[static_cast<unsigned>(size)];
  } data = bit_cast<data_t>(from);
  auto result = To();
  if (const_check(is_big_endian())) {
    for (int i = 0; i < size; ++i)
      result = (result << num_bits<unsigned>()) | data.value[i];
  } else {
    for (int i = size - 1; i >= 0; --i)
      result = (result << num_bits<unsigned>()) | data.value[i];
  }
  return result;
}

FMT_INLINE void assume(bool condition) {
  (void)condition;
#if FMT_HAS_BUILTIN(__builtin_assume) && !FMT_ICC_VERSION
  __builtin_assume(condition);
#endif
}

// An approximation of iterator_t for pre-C++20 systems.
template <typename T>
using iterator_t = decltype(std::begin(std::declval<T&>()));
template <typename T> using sentinel_t = decltype(std::end(std::declval<T&>()));

// A workaround for std::string not having mutable data() until C++17.
template <typename Char>
inline auto get_data(std::basic_string<Char>& s) -> Char* {
  return &s[0];
}
template <typename Container>
inline auto get_data(Container& c) -> typename Container::value_type* {
  return c.data();
}

#if defined(_SECURE_SCL) && _SECURE_SCL
// Make a checked iterator to avoid MSVC warnings.
template <typename T> using checked_ptr = stdext::checked_array_iterator<T*>;
template <typename T>
constexpr auto make_checked(T* p, size_t size) -> checked_ptr<T> {
  return {p, size};
}
#else
template <typename T> using checked_ptr = T*;
template <typename T> constexpr auto make_checked(T* p, size_t) -> T* {
  return p;
}
#endif

// Attempts to reserve space for n extra characters in the output range.
// Returns a pointer to the reserved range or a reference to it.
template <typename Container, FMT_ENABLE_IF(is_contiguous<Container>::value)>
#if FMT_CLANG_VERSION >= 307 && !FMT_ICC_VERSION
__attribute__((no_sanitize("undefined")))
#endif
inline auto
reserve(std::back_insert_iterator<Container> it, size_t n)
    -> checked_ptr<typename Container::value_type> {
  Container& c = get_container(it);
  size_t size = c.size();
  c.resize(size + n);
  return make_checked(get_data(c) + size, n);
}

template <typename T>
inline auto reserve(buffer_appender<T> it, size_t n) -> buffer_appender<T> {
  buffer<T>& buf = get_container(it);
  buf.try_reserve(buf.size() + n);
  return it;
}

template <typename Iterator>
constexpr auto reserve(Iterator& it, size_t) -> Iterator& {
  return it;
}

template <typename OutputIt>
using reserve_iterator =
    remove_reference_t<decltype(reserve(std::declval<OutputIt&>(), 0))>;

template <typename T, typename OutputIt>
constexpr auto to_pointer(OutputIt, size_t) -> T* {
  return nullptr;
}
template <typename T> auto to_pointer(buffer_appender<T> it, size_t n) -> T* {
  buffer<T>& buf = get_container(it);
  auto size = buf.size();
  if (buf.capacity() < size + n) return nullptr;
  buf.try_resize(size + n);
  return buf.data() + size;
}

template <typename Container, FMT_ENABLE_IF(is_contiguous<Container>::value)>
inline auto base_iterator(std::back_insert_iterator<Container>& it,
                          checked_ptr<typename Container::value_type>)
    -> std::back_insert_iterator<Container> {
  return it;
}

template <typename Iterator>
constexpr auto base_iterator(Iterator, Iterator it) -> Iterator {
  return it;
}

// <algorithm> is spectacularly slow to compile in C++20 so use a simple fill_n
// instead (#1998).
template <typename OutputIt, typename Size, typename T>
FMT_CONSTEXPR auto fill_n(OutputIt out, Size count, const T& value)
    -> OutputIt {
  for (Size i = 0; i < count; ++i) *out++ = value;
  return out;
}
template <typename T, typename Size>
FMT_CONSTEXPR20 auto fill_n(T* out, Size count, char value) -> T* {
  if (is_constant_evaluated()) {
    return fill_n<T*, Size, T>(out, count, value);
  }
  std::memset(out, value, to_unsigned(count));
  return out + count;
}

#ifdef __cpp_char8_t
using char8_type = char8_t;
#else
enum char8_type : unsigned char {};
#endif

template <typename OutChar, typename InputIt, typename OutputIt>
FMT_CONSTEXPR FMT_NOINLINE auto copy_str_noinline(InputIt begin, InputIt end,
                                                  OutputIt out) -> OutputIt {
  return copy_str<OutChar>(begin, end, out);
}

// A public domain branchless UTF-8 decoder by Christopher Wellons:
// https://github.com/skeeto/branchless-utf8
/* Decode the next character, c, from s, reporting errors in e.
 *
 * Since this is a branchless decoder, four bytes will be read from the
 * buffer regardless of the actual length of the next character. This
 * means the buffer _must_ have at least three bytes of zero padding
 * following the end of the data stream.
 *
 * Errors are reported in e, which will be non-zero if the parsed
 * character was somehow invalid: invalid byte sequence, non-canonical
 * encoding, or a surrogate half.
 *
 * The function returns a pointer to the next character. When an error
 * occurs, this pointer will be a guess that depends on the particular
 * error, but it will always advance at least one byte.
 */
FMT_CONSTEXPR inline auto utf8_decode(const char* s, uint32_t* c, int* e)
    -> const char* {
  constexpr const int masks[] = {0x00, 0x7f, 0x1f, 0x0f, 0x07};
  constexpr const uint32_t mins[] = {4194304, 0, 128, 2048, 65536};
  constexpr const int shiftc[] = {0, 18, 12, 6, 0};
  constexpr const int shifte[] = {0, 6, 4, 2, 0};

  int len = code_point_length_impl(*s);
  // Compute the pointer to the next character early so that the next
  // iteration can start working on the next character. Neither Clang
  // nor GCC figure out this reordering on their own.
  const char* next = s + len + !len;

  using uchar = unsigned char;

  // Assume a four-byte character and load four bytes. Unused bits are
  // shifted out.
  *c = uint32_t(uchar(s[0]) & masks[len]) << 18;
  *c |= uint32_t(uchar(s[1]) & 0x3f) << 12;
  *c |= uint32_t(uchar(s[2]) & 0x3f) << 6;
  *c |= uint32_t(uchar(s[3]) & 0x3f) << 0;
  *c >>= shiftc[len];

  // Accumulate the various error conditions.
  *e = (*c < mins[len]) << 6;       // non-canonical encoding
  *e |= ((*c >> 11) == 0x1b) << 7;  // surrogate half?
  *e |= (*c > 0x10FFFF) << 8;       // out of range?
  *e |= (uchar(s[1]) & 0xc0) >> 2;
  *e |= (uchar(s[2]) & 0xc0) >> 4;
  *e |= uchar(s[3]) >> 6;
  *e ^= 0x2a;  // top two bits of each tail byte correct?
  *e >>= shifte[len];

  return next;
}

constexpr uint32_t invalid_code_point = ~uint32_t();

// Invokes f(cp, sv) for every code point cp in s with sv being the string view
// corresponding to the code point. cp is invalid_code_point on error.
template <typename F>
FMT_CONSTEXPR void for_each_codepoint(string_view s, F f) {
  auto decode = [f](const char* buf_ptr, const char* ptr) {
    auto cp = uint32_t();
    auto error = 0;
    auto end = utf8_decode(buf_ptr, &cp, &error);
    bool result = f(error ? invalid_code_point : cp,
                    string_view(ptr, error ? 1 : to_unsigned(end - buf_ptr)));
    return result ? (error ? buf_ptr + 1 : end) : nullptr;
  };
  auto p = s.data();
  const size_t block_size = 4;  // utf8_decode always reads blocks of 4 chars.
  if (s.size() >= block_size) {
    for (auto end = p + s.size() - block_size + 1; p < end;) {
      p = decode(p, p);
      if (!p) return;
    }
  }
  if (auto num_chars_left = s.data() + s.size() - p) {
    char buf[2 * block_size - 1] = {};
    copy_str<char>(p, p + num_chars_left, buf);
    const char* buf_ptr = buf;
    do {
      auto end = decode(buf_ptr, p);
      if (!end) return;
      p += end - buf_ptr;
      buf_ptr = end;
    } while (buf_ptr - buf < num_chars_left);
  }
}

template <typename Char>
inline auto compute_width(basic_string_view<Char> s) -> size_t {
  return s.size();
}

// Computes approximate display width of a UTF-8 string.
FMT_CONSTEXPR inline size_t compute_width(string_view s) {
  size_t num_code_points = 0;
  // It is not a lambda for compatibility with C++14.
  struct count_code_points {
    size_t* count;
    FMT_CONSTEXPR auto operator()(uint32_t cp, string_view) const -> bool {
      *count += detail::to_unsigned(
          1 +
          (cp >= 0x1100 &&
           (cp <= 0x115f ||  // Hangul Jamo init. consonants
            cp == 0x2329 ||  // LEFT-POINTING ANGLE BRACKET
            cp == 0x232a ||  // RIGHT-POINTING ANGLE BRACKET
            // CJK ... Yi except IDEOGRAPHIC HALF FILL SPACE:
            (cp >= 0x2e80 && cp <= 0xa4cf && cp != 0x303f) ||
            (cp >= 0xac00 && cp <= 0xd7a3) ||    // Hangul Syllables
            (cp >= 0xf900 && cp <= 0xfaff) ||    // CJK Compatibility Ideographs
            (cp >= 0xfe10 && cp <= 0xfe19) ||    // Vertical Forms
            (cp >= 0xfe30 && cp <= 0xfe6f) ||    // CJK Compatibility Forms
            (cp >= 0xff00 && cp <= 0xff60) ||    // Fullwidth Forms
            (cp >= 0xffe0 && cp <= 0xffe6) ||    // Fullwidth Forms
            (cp >= 0x20000 && cp <= 0x2fffd) ||  // CJK
            (cp >= 0x30000 && cp <= 0x3fffd) ||
            // Miscellaneous Symbols and Pictographs + Emoticons:
            (cp >= 0x1f300 && cp <= 0x1f64f) ||
            // Supplemental Symbols and Pictographs:
            (cp >= 0x1f900 && cp <= 0x1f9ff))));
      return true;
    }
  };
  for_each_codepoint(s, count_code_points{&num_code_points});
  return num_code_points;
}

inline auto compute_width(basic_string_view<char8_type> s) -> size_t {
  return compute_width(
      string_view(reinterpret_cast<const char*>(s.data()), s.size()));
}

template <typename Char>
inline auto code_point_index(basic_string_view<Char> s, size_t n) -> size_t {
  size_t size = s.size();
  return n < size ? n : size;
}

// Calculates the index of the nth code point in a UTF-8 string.
inline auto code_point_index(string_view s, size_t n) -> size_t {
  const char* data = s.data();
  size_t num_code_points = 0;
  for (size_t i = 0, size = s.size(); i != size; ++i) {
    if ((data[i] & 0xc0) != 0x80 && ++num_code_points > n) return i;
  }
  return s.size();
}

inline auto code_point_index(basic_string_view<char8_type> s, size_t n)
    -> size_t {
  return code_point_index(
      string_view(reinterpret_cast<const char*>(s.data()), s.size()), n);
}

#ifndef FMT_USE_FLOAT128
#  ifdef __SIZEOF_FLOAT128__
#    define FMT_USE_FLOAT128 1
#  else
#    define FMT_USE_FLOAT128 0
#  endif
#endif
#if FMT_USE_FLOAT128
using float128 = __float128;
#else
using float128 = void;
#endif
template <typename T> using is_float128 = std::is_same<T, float128>;

template <typename T>
using is_floating_point =
    bool_constant<std::is_floating_point<T>::value || is_float128<T>::value>;

template <typename T, bool = std::is_floating_point<T>::value>
struct is_fast_float : bool_constant<std::numeric_limits<T>::is_iec559 &&
                                     sizeof(T) <= sizeof(double)> {};
template <typename T> struct is_fast_float<T, false> : std::false_type {};

template <typename T>
using is_double_double = bool_constant<std::numeric_limits<T>::digits == 106>;

#ifndef FMT_USE_FULL_CACHE_DRAGONBOX
#  define FMT_USE_FULL_CACHE_DRAGONBOX 0
#endif

template <typename T>
template <typename U>
void buffer<T>::append(const U* begin, const U* end) {
  while (begin != end) {
    auto count = to_unsigned(end - begin);
    try_reserve(size_ + count);
    auto free_cap = capacity_ - size_;
    if (free_cap < count) count = free_cap;
    std::uninitialized_copy_n(begin, count, make_checked(ptr_ + size_, count));
    size_ += count;
    begin += count;
  }
}

template <typename T, typename Enable = void>
struct is_locale : std::false_type {};
template <typename T>
struct is_locale<T, void_t<decltype(T::classic())>> : std::true_type {};
}  // namespace detail

FMT_MODULE_EXPORT_BEGIN

// The number of characters to store in the basic_memory_buffer object itself
// to avoid dynamic memory allocation.
enum { inline_buffer_size = 500 };

/**
  \rst
  A dynamically growing memory buffer for trivially copyable/constructible types
  with the first ``SIZE`` elements stored in the object itself.

  You can use the ``memory_buffer`` type alias for ``char`` instead.

  **Example**::

     auto out = fmt::memory_buffer();
     format_to(std::back_inserter(out), "The answer is {}.", 42);

  This will append the following output to the ``out`` object:

  .. code-block:: none

     The answer is 42.

  The output can be converted to an ``std::string`` with ``to_string(out)``.
  \endrst
 */
template <typename T, size_t SIZE = inline_buffer_size,
          typename Allocator = std::allocator<T>>
class basic_memory_buffer final : public detail::buffer<T> {
 private:
  T store_[SIZE];

  // Don't inherit from Allocator avoid generating type_info for it.
  Allocator alloc_;

  // Deallocate memory allocated by the buffer.
  FMT_CONSTEXPR20 void deallocate() {
    T* data = this->data();
    if (data != store_) alloc_.deallocate(data, this->capacity());
  }

 protected:
  FMT_CONSTEXPR20 void grow(size_t size) override;

 public:
  using value_type = T;
  using const_reference = const T&;

  FMT_CONSTEXPR20 explicit basic_memory_buffer(
      const Allocator& alloc = Allocator())
      : alloc_(alloc) {
    this->set(store_, SIZE);
    if (detail::is_constant_evaluated()) detail::fill_n(store_, SIZE, T());
  }
  FMT_CONSTEXPR20 ~basic_memory_buffer() { deallocate(); }

 private:
  // Move data from other to this buffer.
  FMT_CONSTEXPR20 void move(basic_memory_buffer& other) {
    alloc_ = std::move(other.alloc_);
    T* data = other.data();
    size_t size = other.size(), capacity = other.capacity();
    if (data == other.store_) {
      this->set(store_, capacity);
      detail::copy_str<T>(other.store_, other.store_ + size,
                          detail::make_checked(store_, capacity));
    } else {
      this->set(data, capacity);
      // Set pointer to the inline array so that delete is not called
      // when deallocating.
      other.set(other.store_, 0);
      other.clear();
    }
    this->resize(size);
  }

 public:
  /**
    \rst
    Constructs a :class:`fmt::basic_memory_buffer` object moving the content
    of the other object to it.
    \endrst
   */
  FMT_CONSTEXPR20 basic_memory_buffer(basic_memory_buffer&& other) noexcept {
    move(other);
  }

  /**
    \rst
    Moves the content of the other ``basic_memory_buffer`` object to this one.
    \endrst
   */
  auto operator=(basic_memory_buffer&& other) noexcept -> basic_memory_buffer& {
    FMT_ASSERT(this != &other, "");
    deallocate();
    move(other);
    return *this;
  }

  // Returns a copy of the allocator associated with this buffer.
  auto get_allocator() const -> Allocator { return alloc_; }

  /**
    Resizes the buffer to contain *count* elements. If T is a POD type new
    elements may not be initialized.
   */
  FMT_CONSTEXPR20 void resize(size_t count) { this->try_resize(count); }

  /** Increases the buffer capacity to *new_capacity*. */
  void reserve(size_t new_capacity) { this->try_reserve(new_capacity); }

  // Directly append data into the buffer
  using detail::buffer<T>::append;
  template <typename ContiguousRange>
  void append(const ContiguousRange& range) {
    append(range.data(), range.data() + range.size());
  }
};

template <typename T, size_t SIZE, typename Allocator>
FMT_CONSTEXPR20 void basic_memory_buffer<T, SIZE, Allocator>::grow(
    size_t size) {
  detail::abort_fuzzing_if(size > 5000);
  const size_t max_size = std::allocator_traits<Allocator>::max_size(alloc_);
  size_t old_capacity = this->capacity();
  size_t new_capacity = old_capacity + old_capacity / 2;
  if (size > new_capacity)
    new_capacity = size;
  else if (new_capacity > max_size)
    new_capacity = size > max_size ? size : max_size;
  T* old_data = this->data();
  T* new_data =
      std::allocator_traits<Allocator>::allocate(alloc_, new_capacity);
  // The following code doesn't throw, so the raw pointer above doesn't leak.
  std::uninitialized_copy(old_data, old_data + this->size(),
                          detail::make_checked(new_data, new_capacity));
  this->set(new_data, new_capacity);
  // deallocate must not throw according to the standard, but even if it does,
  // the buffer already uses the new storage and will deallocate it in
  // destructor.
  if (old_data != store_) alloc_.deallocate(old_data, old_capacity);
}

using memory_buffer = basic_memory_buffer<char>;

template <typename T, size_t SIZE, typename Allocator>
struct is_contiguous<basic_memory_buffer<T, SIZE, Allocator>> : std::true_type {
};

namespace detail {
#ifdef _WIN32
FMT_API bool write_console(std::FILE* f, string_view text);
#endif
FMT_API void print(std::FILE*, string_view);
}  // namespace detail

/** A formatting error such as invalid format string. */
FMT_CLASS_API
class FMT_API format_error : public std::runtime_error {
 public:
  explicit format_error(const char* message) : std::runtime_error(message) {}
  explicit format_error(const std::string& message)
      : std::runtime_error(message) {}
  format_error(const format_error&) = default;
  format_error& operator=(const format_error&) = default;
  format_error(format_error&&) = default;
  format_error& operator=(format_error&&) = default;
  ~format_error() noexcept override FMT_MSC_DEFAULT;
};

namespace detail_exported {
#if FMT_USE_NONTYPE_TEMPLATE_ARGS
template <typename Char, size_t N> struct fixed_string {
  constexpr fixed_string(const Char (&str)[N]) {
    detail::copy_str<Char, const Char*, Char*>(static_cast<const Char*>(str),
                                               str + N, data);
  }
  Char data[N] = {};
};
#endif

// Converts a compile-time string to basic_string_view.
template <typename Char, size_t N>
constexpr auto compile_string_to_view(const Char (&s)[N])
    -> basic_string_view<Char> {
  // Remove trailing NUL character if needed. Won't be present if this is used
  // with a raw character array (i.e. not defined as a string).
  return {s, N - (std::char_traits<Char>::to_int_type(s[N - 1]) == 0 ? 1 : 0)};
}
template <typename Char>
constexpr auto compile_string_to_view(detail::std_string_view<Char> s)
    -> basic_string_view<Char> {
  return {s.data(), s.size()};
}
}  // namespace detail_exported

FMT_BEGIN_DETAIL_NAMESPACE

template <typename T> struct is_integral : std::is_integral<T> {};
template <> struct is_integral<int128_opt> : std::true_type {};
template <> struct is_integral<uint128_t> : std::true_type {};

template <typename T>
using is_signed =
    std::integral_constant<bool, std::numeric_limits<T>::is_signed ||
                                     std::is_same<T, int128_opt>::value>;

// Returns true if value is negative, false otherwise.
// Same as `value < 0` but doesn't produce warnings if T is an unsigned type.
template <typename T, FMT_ENABLE_IF(is_signed<T>::value)>
constexpr auto is_negative(T value) -> bool {
  return value < 0;
}
template <typename T, FMT_ENABLE_IF(!is_signed<T>::value)>
constexpr auto is_negative(T) -> bool {
  return false;
}

template <typename T>
FMT_CONSTEXPR auto is_supported_floating_point(T) -> bool {
  if (std::is_same<T, float>()) return FMT_USE_FLOAT;
  if (std::is_same<T, double>()) return FMT_USE_DOUBLE;
  if (std::is_same<T, long double>()) return FMT_USE_LONG_DOUBLE;
  return true;
}

// Smallest of uint32_t, uint64_t, uint128_t that is large enough to
// represent all values of an integral type T.
template <typename T>
using uint32_or_64_or_128_t =
    conditional_t<num_bits<T>() <= 32 && !FMT_REDUCE_INT_INSTANTIATIONS,
                  uint32_t,
                  conditional_t<num_bits<T>() <= 64, uint64_t, uint128_t>>;
template <typename T>
using uint64_or_128_t = conditional_t<num_bits<T>() <= 64, uint64_t, uint128_t>;

#define FMT_POWERS_OF_10(factor)                                             \
  factor * 10, (factor)*100, (factor)*1000, (factor)*10000, (factor)*100000, \
      (factor)*1000000, (factor)*10000000, (factor)*100000000,               \
      (factor)*1000000000

// Converts value in the range [0, 100) to a string.
constexpr const char* digits2(size_t value) {
  // GCC generates slightly better code when value is pointer-size.
  return &"0001020304050607080910111213141516171819"
         "2021222324252627282930313233343536373839"
         "4041424344454647484950515253545556575859"
         "6061626364656667686970717273747576777879"
         "8081828384858687888990919293949596979899"[value * 2];
}

// Sign is a template parameter to workaround a bug in gcc 4.8.
template <typename Char, typename Sign> constexpr Char sign(Sign s) {
#if !FMT_GCC_VERSION || FMT_GCC_VERSION >= 604
  static_assert(std::is_same<Sign, sign_t>::value, "");
#endif
  return static_cast<Char>("\0-+ "[s]);
}

template <typename T> FMT_CONSTEXPR auto count_digits_fallback(T n) -> int {
  int count = 1;
  for (;;) {
    // Integer division is slow so do it for a group of four digits instead
    // of for every digit. The idea comes from the talk by Alexandrescu
    // "Three Optimization Tips for C++". See speed-test for a comparison.
    if (n < 10) return count;
    if (n < 100) return count + 1;
    if (n < 1000) return count + 2;
    if (n < 10000) return count + 3;
    n /= 10000u;
    count += 4;
  }
}
#if FMT_USE_INT128
FMT_CONSTEXPR inline auto count_digits(uint128_opt n) -> int {
  return count_digits_fallback(n);
}
#endif

#ifdef FMT_BUILTIN_CLZLL
// It is a separate function rather than a part of count_digits to workaround
// the lack of static constexpr in constexpr functions.
inline auto do_count_digits(uint64_t n) -> int {
  // This has comparable performance to the version by Kendall Willets
  // (https://github.com/fmtlib/format-benchmark/blob/master/digits10)
  // but uses smaller tables.
  // Maps bsr(n) to ceil(log10(pow(2, bsr(n) + 1) - 1)).
  static constexpr uint8_t bsr2log10[] = {
      1,  1,  1,  2,  2,  2,  3,  3,  3,  4,  4,  4,  4,  5,  5,  5,
      6,  6,  6,  7,  7,  7,  7,  8,  8,  8,  9,  9,  9,  10, 10, 10,
      10, 11, 11, 11, 12, 12, 12, 13, 13, 13, 13, 14, 14, 14, 15, 15,
      15, 16, 16, 16, 16, 17, 17, 17, 18, 18, 18, 19, 19, 19, 19, 20};
  auto t = bsr2log10[FMT_BUILTIN_CLZLL(n | 1) ^ 63];
  static constexpr const uint64_t zero_or_powers_of_10[] = {
      0, 0, FMT_POWERS_OF_10(1U), FMT_POWERS_OF_10(1000000000ULL),
      10000000000000000000ULL};
  return t - (n < zero_or_powers_of_10[t]);
}
#endif

// Returns the number of decimal digits in n. Leading zeros are not counted
// except for n == 0 in which case count_digits returns 1.
FMT_CONSTEXPR20 inline auto count_digits(uint64_t n) -> int {
#ifdef FMT_BUILTIN_CLZLL
  if (!is_constant_evaluated()) {
    return do_count_digits(n);
  }
#endif
  return count_digits_fallback(n);
}

// Counts the number of digits in n. BITS = log2(radix).
template <int BITS, typename UInt>
FMT_CONSTEXPR auto count_digits(UInt n) -> int {
#ifdef FMT_BUILTIN_CLZ
  if (!is_constant_evaluated() && num_bits<UInt>() == 32)
    return (FMT_BUILTIN_CLZ(static_cast<uint32_t>(n) | 1) ^ 31) / BITS + 1;
#endif
  // Lambda avoids unreachable code warnings from NVHPC.
  return [](UInt m) {
    int num_digits = 0;
    do {
      ++num_digits;
    } while ((m >>= BITS) != 0);
    return num_digits;
  }(n);
}

#ifdef FMT_BUILTIN_CLZ
// It is a separate function rather than a part of count_digits to workaround
// the lack of static constexpr in constexpr functions.
FMT_INLINE auto do_count_digits(uint32_t n) -> int {
// An optimization by Kendall Willets from https://bit.ly/3uOIQrB.
// This increments the upper 32 bits (log10(T) - 1) when >= T is added.
#  define FMT_INC(T) (((sizeof(#  T) - 1ull) << 32) - T)
  static constexpr uint64_t table[] = {
      FMT_INC(0),          FMT_INC(0),          FMT_INC(0),           // 8
      FMT_INC(10),         FMT_INC(10),         FMT_INC(10),          // 64
      FMT_INC(100),        FMT_INC(100),        FMT_INC(100),         // 512
      FMT_INC(1000),       FMT_INC(1000),       FMT_INC(1000),        // 4096
      FMT_INC(10000),      FMT_INC(10000),      FMT_INC(10000),       // 32k
      FMT_INC(100000),     FMT_INC(100000),     FMT_INC(100000),      // 256k
      FMT_INC(1000000),    FMT_INC(1000000),    FMT_INC(1000000),     // 2048k
      FMT_INC(10000000),   FMT_INC(10000000),   FMT_INC(10000000),    // 16M
      FMT_INC(100000000),  FMT_INC(100000000),  FMT_INC(100000000),   // 128M
      FMT_INC(1000000000), FMT_INC(1000000000), FMT_INC(1000000000),  // 1024M
      FMT_INC(1000000000), FMT_INC(1000000000)                        // 4B
  };
  auto inc = table[FMT_BUILTIN_CLZ(n | 1) ^ 31];
  return static_cast<int>((n + inc) >> 32);
}
#endif

// Optional version of count_digits for better performance on 32-bit platforms.
FMT_CONSTEXPR20 inline auto count_digits(uint32_t n) -> int {
#ifdef FMT_BUILTIN_CLZ
  if (!is_constant_evaluated()) {
    return do_count_digits(n);
  }
#endif
  return count_digits_fallback(n);
}

template <typename Int> constexpr auto digits10() noexcept -> int {
  return std::numeric_limits<Int>::digits10;
}
template <> constexpr auto digits10<int128_opt>() noexcept -> int { return 38; }
template <> constexpr auto digits10<uint128_t>() noexcept -> int { return 38; }

template <typename Char> struct thousands_sep_result {
  std::string grouping;
  Char thousands_sep;
};

template <typename Char>
FMT_API auto thousands_sep_impl(locale_ref loc) -> thousands_sep_result<Char>;
template <typename Char>
inline auto thousands_sep(locale_ref loc) -> thousands_sep_result<Char> {
  auto result = thousands_sep_impl<char>(loc);
  return {result.grouping, Char(result.thousands_sep)};
}
template <>
inline auto thousands_sep(locale_ref loc) -> thousands_sep_result<wchar_t> {
  return thousands_sep_impl<wchar_t>(loc);
}

template <typename Char>
FMT_API auto decimal_point_impl(locale_ref loc) -> Char;
template <typename Char> inline auto decimal_point(locale_ref loc) -> Char {
  return Char(decimal_point_impl<char>(loc));
}
template <> inline auto decimal_point(locale_ref loc) -> wchar_t {
  return decimal_point_impl<wchar_t>(loc);
}

// Compares two characters for equality.
template <typename Char> auto equal2(const Char* lhs, const char* rhs) -> bool {
  return lhs[0] == Char(rhs[0]) && lhs[1] == Char(rhs[1]);
}
inline auto equal2(const char* lhs, const char* rhs) -> bool {
  return memcmp(lhs, rhs, 2) == 0;
}

// Copies two characters from src to dst.
template <typename Char>
FMT_CONSTEXPR20 FMT_INLINE void copy2(Char* dst, const char* src) {
  if (!is_constant_evaluated() && sizeof(Char) == sizeof(char)) {
    memcpy(dst, src, 2);
    return;
  }
  *dst++ = static_cast<Char>(*src++);
  *dst = static_cast<Char>(*src);
}

template <typename Iterator> struct format_decimal_result {
  Iterator begin;
  Iterator end;
};

// Formats a decimal unsigned integer value writing into out pointing to a
// buffer of specified size. The caller must ensure that the buffer is large
// enough.
template <typename Char, typename UInt>
FMT_CONSTEXPR20 auto format_decimal(Char* out, UInt value, int size)
    -> format_decimal_result<Char*> {
  FMT_ASSERT(size >= count_digits(value), "invalid digit count");
  out += size;
  Char* end = out;
  while (value >= 100) {
    // Integer division is slow so do it for a group of two digits instead
    // of for every digit. The idea comes from the talk by Alexandrescu
    // "Three Optimization Tips for C++". See speed-test for a comparison.
    out -= 2;
    copy2(out, digits2(static_cast<size_t>(value % 100)));
    value /= 100;
  }
  if (value < 10) {
    *--out = static_cast<Char>('0' + value);
    return {out, end};
  }
  out -= 2;
  copy2(out, digits2(static_cast<size_t>(value)));
  return {out, end};
}

template <typename Char, typename UInt, typename Iterator,
          FMT_ENABLE_IF(!std::is_pointer<remove_cvref_t<Iterator>>::value)>
FMT_CONSTEXPR inline auto format_decimal(Iterator out, UInt value, int size)
    -> format_decimal_result<Iterator> {
  // Buffer is large enough to hold all digits (digits10 + 1).
  Char buffer[digits10<UInt>() + 1];
  auto end = format_decimal(buffer, value, size).end;
  return {out, detail::copy_str_noinline<Char>(buffer, end, out)};
}

template <unsigned BASE_BITS, typename Char, typename UInt>
FMT_CONSTEXPR auto format_uint(Char* buffer, UInt value, int num_digits,
                               bool upper = false) -> Char* {
  buffer += num_digits;
  Char* end = buffer;
  do {
    const char* digits = upper ? "0123456789ABCDEF" : "0123456789abcdef";
    unsigned digit = static_cast<unsigned>(value & ((1 << BASE_BITS) - 1));
    *--buffer = static_cast<Char>(BASE_BITS < 4 ? static_cast<char>('0' + digit)
                                                : digits[digit]);
  } while ((value >>= BASE_BITS) != 0);
  return end;
}

template <unsigned BASE_BITS, typename Char, typename It, typename UInt>
inline auto format_uint(It out, UInt value, int num_digits, bool upper = false)
    -> It {
  if (auto ptr = to_pointer<Char>(out, to_unsigned(num_digits))) {
    format_uint<BASE_BITS>(ptr, value, num_digits, upper);
    return out;
  }
  // Buffer should be large enough to hold all digits (digits / BASE_BITS + 1).
  char buffer[num_bits<UInt>() / BASE_BITS + 1];
  format_uint<BASE_BITS>(buffer, value, num_digits, upper);
  return detail::copy_str_noinline<Char>(buffer, buffer + num_digits, out);
}

// A converter from UTF-8 to UTF-16.
class utf8_to_utf16 {
 private:
  basic_memory_buffer<wchar_t> buffer_;

 public:
  FMT_API explicit utf8_to_utf16(string_view s);
  operator basic_string_view<wchar_t>() const { return {&buffer_[0], size()}; }
  auto size() const -> size_t { return buffer_.size() - 1; }
  auto c_str() const -> const wchar_t* { return &buffer_[0]; }
  auto str() const -> std::wstring { return {&buffer_[0], size()}; }
};

namespace dragonbox {

// Type-specific information that Dragonbox uses.
template <typename T, typename Enable = void> struct float_info;

template <> struct float_info<float> {
  using carrier_uint = uint32_t;
  static const int exponent_bits = 8;
  static const int kappa = 1;
  static const int big_divisor = 100;
  static const int small_divisor = 10;
  static const int min_k = -31;
  static const int max_k = 46;
  static const int shorter_interval_tie_lower_threshold = -35;
  static const int shorter_interval_tie_upper_threshold = -35;
};

template <> struct float_info<double> {
  using carrier_uint = uint64_t;
  static const int exponent_bits = 11;
  static const int kappa = 2;
  static const int big_divisor = 1000;
  static const int small_divisor = 100;
  static const int min_k = -292;
  static const int max_k = 326;
  static const int shorter_interval_tie_lower_threshold = -77;
  static const int shorter_interval_tie_upper_threshold = -77;
};

// An 80- or 128-bit floating point number.
template <typename T>
struct float_info<T, enable_if_t<std::numeric_limits<T>::digits == 64 ||
                                 std::numeric_limits<T>::digits == 113 ||
                                 is_float128<T>::value>> {
  using carrier_uint = detail::uint128_t;
  static const int exponent_bits = 15;
};

// A double-double floating point number.
template <typename T>
struct float_info<T, enable_if_t<is_double_double<T>::value>> {
  using carrier_uint = detail::uint128_t;
};

template <typename T> struct decimal_fp {
  using significand_type = typename float_info<T>::carrier_uint;
  significand_type significand;
  int exponent;
};

template <typename T> FMT_API auto to_decimal(T x) noexcept -> decimal_fp<T>;
}  // namespace dragonbox

// Returns true iff Float has the implicit bit which is not stored.
template <typename Float> constexpr bool has_implicit_bit() {
  // An 80-bit FP number has a 64-bit significand an no implicit bit.
  return std::numeric_limits<Float>::digits != 64;
}

// Returns the number of significand bits stored in Float. The implicit bit is
// not counted since it is not stored.
template <typename Float> constexpr int num_significand_bits() {
  // std::numeric_limits may not support __float128.
  return is_float128<Float>() ? 112
                              : (std::numeric_limits<Float>::digits -
                                 (has_implicit_bit<Float>() ? 1 : 0));
}

template <typename Float>
constexpr auto exponent_mask() ->
    typename dragonbox::float_info<Float>::carrier_uint {
  using uint = typename dragonbox::float_info<Float>::carrier_uint;
  return ((uint(1) << dragonbox::float_info<Float>::exponent_bits) - 1)
         << num_significand_bits<Float>();
}
template <typename Float> constexpr auto exponent_bias() -> int {
  // std::numeric_limits may not support __float128.
  return is_float128<Float>() ? 16383
                              : std::numeric_limits<Float>::max_exponent - 1;
}

// Writes the exponent exp in the form "[+-]d{2,3}" to buffer.
template <typename Char, typename It>
FMT_CONSTEXPR auto write_exponent(int exp, It it) -> It {
  FMT_ASSERT(-10000 < exp && exp < 10000, "exponent out of range");
  if (exp < 0) {
    *it++ = static_cast<Char>('-');
    exp = -exp;
  } else {
    *it++ = static_cast<Char>('+');
  }
  if (exp >= 100) {
    const char* top = digits2(to_unsigned(exp / 100));
    if (exp >= 1000) *it++ = static_cast<Char>(top[0]);
    *it++ = static_cast<Char>(top[1]);
    exp %= 100;
  }
  const char* d = digits2(to_unsigned(exp));
  *it++ = static_cast<Char>(d[0]);
  *it++ = static_cast<Char>(d[1]);
  return it;
}

// A floating-point number f * pow(2, e) where F is an unsigned type.
template <typename F> struct basic_fp {
  F f;
  int e;

  static constexpr const int num_significand_bits =
      static_cast<int>(sizeof(F) * num_bits<unsigned char>());

  constexpr basic_fp() : f(0), e(0) {}
  constexpr basic_fp(uint64_t f_val, int e_val) : f(f_val), e(e_val) {}

  // Constructs fp from an IEEE754 floating-point number.
  template <typename Float> FMT_CONSTEXPR basic_fp(Float n) { assign(n); }

  // Assigns n to this and return true iff predecessor is closer than successor.
  template <typename Float, FMT_ENABLE_IF(!is_double_double<Float>::value)>
  FMT_CONSTEXPR auto assign(Float n) -> bool {
    static_assert(std::numeric_limits<Float>::digits <= 113, "unsupported FP");
    // Assume Float is in the format [sign][exponent][significand].
    using carrier_uint = typename dragonbox::float_info<Float>::carrier_uint;
    const auto num_float_significand_bits =
        detail::num_significand_bits<Float>();
    const auto implicit_bit = carrier_uint(1) << num_float_significand_bits;
    const auto significand_mask = implicit_bit - 1;
    auto u = bit_cast<carrier_uint>(n);
    f = static_cast<F>(u & significand_mask);
    auto biased_e = static_cast<int>((u & exponent_mask<Float>()) >>
                                     num_float_significand_bits);
    // The predecessor is closer if n is a normalized power of 2 (f == 0)
    // other than the smallest normalized number (biased_e > 1).
    auto is_predecessor_closer = f == 0 && biased_e > 1;
    if (biased_e == 0)
      biased_e = 1;  // Subnormals use biased exponent 1 (min exponent).
    else if (has_implicit_bit<Float>())
      f += static_cast<F>(implicit_bit);
    e = biased_e - exponent_bias<Float>() - num_float_significand_bits;
    if (!has_implicit_bit<Float>()) ++e;
    return is_predecessor_closer;
  }

  template <typename Float, FMT_ENABLE_IF(is_double_double<Float>::value)>
  FMT_CONSTEXPR auto assign(Float n) -> bool {
    static_assert(std::numeric_limits<double>::is_iec559, "unsupported FP");
    return assign(static_cast<double>(n));
  }
};

using fp = basic_fp<unsigned long long>;

// Normalizes the value converted from double and multiplied by (1 << SHIFT).
template <int SHIFT = 0, typename F>
FMT_CONSTEXPR basic_fp<F> normalize(basic_fp<F> value) {
  // Handle subnormals.
  const auto implicit_bit = F(1) << num_significand_bits<double>();
  const auto shifted_implicit_bit = implicit_bit << SHIFT;
  while ((value.f & shifted_implicit_bit) == 0) {
    value.f <<= 1;
    --value.e;
  }
  // Subtract 1 to account for hidden bit.
  const auto offset = basic_fp<F>::num_significand_bits -
                      num_significand_bits<double>() - SHIFT - 1;
  value.f <<= offset;
  value.e -= offset;
  return value;
}

// Computes lhs * rhs / pow(2, 64) rounded to nearest with half-up tie breaking.
FMT_CONSTEXPR inline uint64_t multiply(uint64_t lhs, uint64_t rhs) {
#if FMT_USE_INT128
  auto product = static_cast<__uint128_t>(lhs) * rhs;
  auto f = static_cast<uint64_t>(product >> 64);
  return (static_cast<uint64_t>(product) & (1ULL << 63)) != 0 ? f + 1 : f;
#else
  // Multiply 32-bit parts of significands.
  uint64_t mask = (1ULL << 32) - 1;
  uint64_t a = lhs >> 32, b = lhs & mask;
  uint64_t c = rhs >> 32, d = rhs & mask;
  uint64_t ac = a * c, bc = b * c, ad = a * d, bd = b * d;
  // Compute mid 64-bit of result and round.
  uint64_t mid = (bd >> 32) + (ad & mask) + (bc & mask) + (1U << 31);
  return ac + (ad >> 32) + (bc >> 32) + (mid >> 32);
#endif
}

FMT_CONSTEXPR inline fp operator*(fp x, fp y) {
  return {multiply(x.f, y.f), x.e + y.e + 64};
}

template <typename T = void> struct basic_data {
  // Normalized 64-bit significands of pow(10, k), for k = -348, -340, ..., 340.
  // These are generated by support/compute-powers.py.
  static constexpr uint64_t pow10_significands[87] = {
      0xfa8fd5a0081c0288, 0xbaaee17fa23ebf76, 0x8b16fb203055ac76,
      0xcf42894a5dce35ea, 0x9a6bb0aa55653b2d, 0xe61acf033d1a45df,
      0xab70fe17c79ac6ca, 0xff77b1fcbebcdc4f, 0xbe5691ef416bd60c,
      0x8dd01fad907ffc3c, 0xd3515c2831559a83, 0x9d71ac8fada6c9b5,
      0xea9c227723ee8bcb, 0xaecc49914078536d, 0x823c12795db6ce57,
      0xc21094364dfb5637, 0x9096ea6f3848984f, 0xd77485cb25823ac7,
      0xa086cfcd97bf97f4, 0xef340a98172aace5, 0xb23867fb2a35b28e,
      0x84c8d4dfd2c63f3b, 0xc5dd44271ad3cdba, 0x936b9fcebb25c996,
      0xdbac6c247d62a584, 0xa3ab66580d5fdaf6, 0xf3e2f893dec3f126,
      0xb5b5ada8aaff80b8, 0x87625f056c7c4a8b, 0xc9bcff6034c13053,
      0x964e858c91ba2655, 0xdff9772470297ebd, 0xa6dfbd9fb8e5b88f,
      0xf8a95fcf88747d94, 0xb94470938fa89bcf, 0x8a08f0f8bf0f156b,
      0xcdb02555653131b6, 0x993fe2c6d07b7fac, 0xe45c10c42a2b3b06,
      0xaa242499697392d3, 0xfd87b5f28300ca0e, 0xbce5086492111aeb,
      0x8cbccc096f5088cc, 0xd1b71758e219652c, 0x9c40000000000000,
      0xe8d4a51000000000, 0xad78ebc5ac620000, 0x813f3978f8940984,
      0xc097ce7bc90715b3, 0x8f7e32ce7bea5c70, 0xd5d238a4abe98068,
      0x9f4f2726179a2245, 0xed63a231d4c4fb27, 0xb0de65388cc8ada8,
      0x83c7088e1aab65db, 0xc45d1df942711d9a, 0x924d692ca61be758,
      0xda01ee641a708dea, 0xa26da3999aef774a, 0xf209787bb47d6b85,
      0xb454e4a179dd1877, 0x865b86925b9bc5c2, 0xc83553c5c8965d3d,
      0x952ab45cfa97a0b3, 0xde469fbd99a05fe3, 0xa59bc234db398c25,
      0xf6c69a72a3989f5c, 0xb7dcbf5354e9bece, 0x88fcf317f22241e2,
      0xcc20ce9bd35c78a5, 0x98165af37b2153df, 0xe2a0b5dc971f303a,
      0xa8d9d1535ce3b396, 0xfb9b7cd9a4a7443c, 0xbb764c4ca7a44410,
      0x8bab8eefb6409c1a, 0xd01fef10a657842c, 0x9b10a4e5e9913129,
      0xe7109bfba19c0c9d, 0xac2820d9623bf429, 0x80444b5e7aa7cf85,
      0xbf21e44003acdd2d, 0x8e679c2f5e44ff8f, 0xd433179d9c8cb841,
      0x9e19db92b4e31ba9, 0xeb96bf6ebadf77d9, 0xaf87023b9bf0ee6b,
  };

#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
#  pragma GCC diagnostic push
#  pragma GCC diagnostic ignored "-Wnarrowing"
#endif
  // Binary exponents of pow(10, k), for k = -348, -340, ..., 340, corresponding
  // to significands above.
  static constexpr int16_t pow10_exponents[87] = {
      -1220, -1193, -1166, -1140, -1113, -1087, -1060, -1034, -1007, -980, -954,
      -927,  -901,  -874,  -847,  -821,  -794,  -768,  -741,  -715,  -688, -661,
      -635,  -608,  -582,  -555,  -529,  -502,  -475,  -449,  -422,  -396, -369,
      -343,  -316,  -289,  -263,  -236,  -210,  -183,  -157,  -130,  -103, -77,
      -50,   -24,   3,     30,    56,    83,    109,   136,   162,   189,  216,
      242,   269,   295,   322,   348,   375,   402,   428,   455,   481,  508,
      534,   561,   588,   614,   641,   667,   694,   720,   747,   774,  800,
      827,   853,   880,   907,   933,   960,   986,   1013,  1039,  1066};
#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
#  pragma GCC diagnostic pop
#endif

  static constexpr uint64_t power_of_10_64[20] = {
      1, FMT_POWERS_OF_10(1ULL), FMT_POWERS_OF_10(1000000000ULL),
      10000000000000000000ULL};
};

#if FMT_CPLUSPLUS < 201703L
template <typename T> constexpr uint64_t basic_data<T>::pow10_significands[];
template <typename T> constexpr int16_t basic_data<T>::pow10_exponents[];
template <typename T> constexpr uint64_t basic_data<T>::power_of_10_64[];
#endif

// This is a struct rather than an alias to avoid shadowing warnings in gcc.
struct data : basic_data<> {};

// Returns a cached power of 10 `c_k = c_k.f * pow(2, c_k.e)` such that its
// (binary) exponent satisfies `min_exponent <= c_k.e <= min_exponent + 28`.
FMT_CONSTEXPR inline fp get_cached_power(int min_exponent,
                                         int& pow10_exponent) {
  const int shift = 32;
  // log10(2) = 0x0.4d104d427de7fbcc...
  const int64_t significand = 0x4d104d427de7fbcc;
  int index = static_cast<int>(
      ((min_exponent + fp::num_significand_bits - 1) * (significand >> shift) +
       ((int64_t(1) << shift) - 1))  // ceil
      >> 32                          // arithmetic shift
  );
  // Decimal exponent of the first (smallest) cached power of 10.
  const int first_dec_exp = -348;
  // Difference between 2 consecutive decimal exponents in cached powers of 10.
  const int dec_exp_step = 8;
  index = (index - first_dec_exp - 1) / dec_exp_step + 1;
  pow10_exponent = first_dec_exp + index * dec_exp_step;
  // Using *(x + index) instead of x[index] avoids an issue with some compilers
  // using the EDG frontend (e.g. nvhpc/22.3 in C++17 mode).
  return {*(data::pow10_significands + index),
          *(data::pow10_exponents + index)};
}

#ifndef _MSC_VER
#  define FMT_SNPRINTF snprintf
#else
FMT_API auto fmt_snprintf(char* buf, size_t size, const char* fmt, ...) -> int;
#  define FMT_SNPRINTF fmt_snprintf
#endif  // _MSC_VER

// Formats a floating-point number with snprintf using the hexfloat format.
template <typename T>
auto snprintf_float(T value, int precision, float_specs specs,
                    buffer<char>& buf) -> int {
  // Buffer capacity must be non-zero, otherwise MSVC's vsnprintf_s will fail.
  FMT_ASSERT(buf.capacity() > buf.size(), "empty buffer");
  FMT_ASSERT(specs.format == float_format::hex, "");
  static_assert(!std::is_same<T, float>::value, "");

  // Build the format string.
  char format[7];  // The longest format is "%#.*Le".
  char* format_ptr = format;
  *format_ptr++ = '%';
  if (specs.showpoint) *format_ptr++ = '#';
  if (precision >= 0) {
    *format_ptr++ = '.';
    *format_ptr++ = '*';
  }
  if (std::is_same<T, long double>()) *format_ptr++ = 'L';
  *format_ptr++ = specs.upper ? 'A' : 'a';
  *format_ptr = '\0';

  // Format using snprintf.
  auto offset = buf.size();
  for (;;) {
    auto begin = buf.data() + offset;
    auto capacity = buf.capacity() - offset;
    abort_fuzzing_if(precision > 100000);
    // Suppress the warning about a nonliteral format string.
    // Cannot use auto because of a bug in MinGW (#1532).
    int (*snprintf_ptr)(char*, size_t, const char*, ...) = FMT_SNPRINTF;
    int result = precision >= 0
                     ? snprintf_ptr(begin, capacity, format, precision, value)
                     : snprintf_ptr(begin, capacity, format, value);
    if (result < 0) {
      // The buffer will grow exponentially.
      buf.try_reserve(buf.capacity() + 1);
      continue;
    }
    auto size = to_unsigned(result);
    // Size equal to capacity means that the last character was truncated.
    if (size < capacity) {
      buf.try_resize(size + offset);
      return 0;
    }
    buf.try_reserve(size + offset + 1);  // Add 1 for the terminating '\0'.
  }
}

template <typename T>
using convert_float_result =
    conditional_t<std::is_same<T, float>::value || sizeof(T) == sizeof(double),
                  double, T>;

template <typename T>
constexpr auto convert_float(T value) -> convert_float_result<T> {
  return static_cast<convert_float_result<T>>(value);
}

template <typename OutputIt, typename Char>
FMT_NOINLINE FMT_CONSTEXPR auto fill(OutputIt it, size_t n,
                                     const fill_t<Char>& fill) -> OutputIt {
  auto fill_size = fill.size();
  if (fill_size == 1) return detail::fill_n(it, n, fill[0]);
  auto data = fill.data();
  for (size_t i = 0; i < n; ++i)
    it = copy_str<Char>(data, data + fill_size, it);
  return it;
}

// Writes the output of f, padded according to format specifications in specs.
// size: output size in code units.
// width: output display width in (terminal) column positions.
template <align::type align = align::left, typename OutputIt, typename Char,
          typename F>
FMT_CONSTEXPR auto write_padded(OutputIt out,
                                const basic_format_specs<Char>& specs,
                                size_t size, size_t width, F&& f) -> OutputIt {
  static_assert(align == align::left || align == align::right, "");
  unsigned spec_width = to_unsigned(specs.width);
  size_t padding = spec_width > width ? spec_width - width : 0;
  // Shifts are encoded as string literals because static constexpr is not
  // supported in constexpr functions.
  auto* shifts = align == align::left ? "\x1f\x1f\x00\x01" : "\x00\x1f\x00\x01";
  size_t left_padding = padding >> shifts[specs.align];
  size_t right_padding = padding - left_padding;
  auto it = reserve(out, size + padding * specs.fill.size());
  if (left_padding != 0) it = fill(it, left_padding, specs.fill);
  it = f(it);
  if (right_padding != 0) it = fill(it, right_padding, specs.fill);
  return base_iterator(out, it);
}

template <align::type align = align::left, typename OutputIt, typename Char,
          typename F>
constexpr auto write_padded(OutputIt out, const basic_format_specs<Char>& specs,
                            size_t size, F&& f) -> OutputIt {
  return write_padded<align>(out, specs, size, size, f);
}

template <align::type align = align::left, typename Char, typename OutputIt>
FMT_CONSTEXPR auto write_bytes(OutputIt out, string_view bytes,
                               const basic_format_specs<Char>& specs)
    -> OutputIt {
  return write_padded<align>(
      out, specs, bytes.size(), [bytes](reserve_iterator<OutputIt> it) {
        const char* data = bytes.data();
        return copy_str<Char>(data, data + bytes.size(), it);
      });
}

template <typename Char, typename OutputIt, typename UIntPtr>
auto write_ptr(OutputIt out, UIntPtr value,
               const basic_format_specs<Char>* specs) -> OutputIt {
  int num_digits = count_digits<4>(value);
  auto size = to_unsigned(num_digits) + size_t(2);
  auto write = [=](reserve_iterator<OutputIt> it) {
    *it++ = static_cast<Char>('0');
    *it++ = static_cast<Char>('x');
    return format_uint<4, Char>(it, value, num_digits);
  };
  return specs ? write_padded<align::right>(out, *specs, size, write)
               : base_iterator(out, write(reserve(out, size)));
}

// Returns true iff the code point cp is printable.
FMT_API auto is_printable(uint32_t cp) -> bool;

inline auto needs_escape(uint32_t cp) -> bool {
  return cp < 0x20 || cp == 0x7f || cp == '"' || cp == '\\' ||
         !is_printable(cp);
}

template <typename Char> struct find_escape_result {
  const Char* begin;
  const Char* end;
  uint32_t cp;
};

template <typename Char>
using make_unsigned_char =
    typename conditional_t<std::is_integral<Char>::value,
                           std::make_unsigned<Char>,
                           type_identity<uint32_t>>::type;

template <typename Char>
auto find_escape(const Char* begin, const Char* end)
    -> find_escape_result<Char> {
  for (; begin != end; ++begin) {
    uint32_t cp = static_cast<make_unsigned_char<Char>>(*begin);
    if (const_check(sizeof(Char) == 1) && cp >= 0x80) continue;
    if (needs_escape(cp)) return {begin, begin + 1, cp};
  }
  return {begin, nullptr, 0};
}

inline auto find_escape(const char* begin, const char* end)
    -> find_escape_result<char> {
  if (!is_utf8()) return find_escape<char>(begin, end);
  auto result = find_escape_result<char>{end, nullptr, 0};
  for_each_codepoint(string_view(begin, to_unsigned(end - begin)),
                     [&](uint32_t cp, string_view sv) {
                       if (needs_escape(cp)) {
                         result = {sv.begin(), sv.end(), cp};
                         return false;
                       }
                       return true;
                     });
  return result;
}

#define FMT_STRING_IMPL(s, base, explicit)                                    \
  [] {                                                                        \
    /* Use the hidden visibility as a workaround for a GCC bug (#1973). */    \
    /* Use a macro-like name to avoid shadowing warnings. */                  \
    struct FMT_GCC_VISIBILITY_HIDDEN FMT_COMPILE_STRING : base {              \
      using char_type FMT_MAYBE_UNUSED = fmt::remove_cvref_t<decltype(s[0])>; \
      FMT_MAYBE_UNUSED FMT_CONSTEXPR explicit                                 \
      operator fmt::basic_string_view<char_type>() const {                    \
        return fmt::detail_exported::compile_string_to_view<char_type>(s);    \
      }                                                                       \
    };                                                                        \
    return FMT_COMPILE_STRING();                                              \
  }()

/**
  \rst
  Constructs a compile-time format string from a string literal *s*.

  **Example**::

    // A compile-time error because 'd' is an invalid specifier for strings.
    std::string s = fmt::format(FMT_STRING("{:d}"), "foo");
  \endrst
 */
#define FMT_STRING(s) FMT_STRING_IMPL(s, fmt::detail::compile_string, )

template <size_t width, typename Char, typename OutputIt>
auto write_codepoint(OutputIt out, char prefix, uint32_t cp) -> OutputIt {
  *out++ = static_cast<Char>('\\');
  *out++ = static_cast<Char>(prefix);
  Char buf[width];
  fill_n(buf, width, static_cast<Char>('0'));
  format_uint<4>(buf, cp, width);
  return copy_str<Char>(buf, buf + width, out);
}

template <typename OutputIt, typename Char>
auto write_escaped_cp(OutputIt out, const find_escape_result<Char>& escape)
    -> OutputIt {
  auto c = static_cast<Char>(escape.cp);
  switch (escape.cp) {
  case '\n':
    *out++ = static_cast<Char>('\\');
    c = static_cast<Char>('n');
    break;
  case '\r':
    *out++ = static_cast<Char>('\\');
    c = static_cast<Char>('r');
    break;
  case '\t':
    *out++ = static_cast<Char>('\\');
    c = static_cast<Char>('t');
    break;
  case '"':
    FMT_FALLTHROUGH;
  case '\'':
    FMT_FALLTHROUGH;
  case '\\':
    *out++ = static_cast<Char>('\\');
    break;
  default:
    if (is_utf8()) {
      if (escape.cp < 0x100) {
        return write_codepoint<2, Char>(out, 'x', escape.cp);
      }
      if (escape.cp < 0x10000) {
        return write_codepoint<4, Char>(out, 'u', escape.cp);
      }
      if (escape.cp < 0x110000) {
        return write_codepoint<8, Char>(out, 'U', escape.cp);
      }
    }
    for (Char escape_char : basic_string_view<Char>(
             escape.begin, to_unsigned(escape.end - escape.begin))) {
      out = write_codepoint<2, Char>(out, 'x',
                                     static_cast<uint32_t>(escape_char) & 0xFF);
    }
    return out;
  }
  *out++ = c;
  return out;
}

template <typename Char, typename OutputIt>
auto write_escaped_string(OutputIt out, basic_string_view<Char> str)
    -> OutputIt {
  *out++ = static_cast<Char>('"');
  auto begin = str.begin(), end = str.end();
  do {
    auto escape = find_escape(begin, end);
    out = copy_str<Char>(begin, escape.begin, out);
    begin = escape.end;
    if (!begin) break;
    out = write_escaped_cp<OutputIt, Char>(out, escape);
  } while (begin != end);
  *out++ = static_cast<Char>('"');
  return out;
}

template <typename Char, typename OutputIt>
auto write_escaped_char(OutputIt out, Char v) -> OutputIt {
  *out++ = static_cast<Char>('\'');
  if ((needs_escape(static_cast<uint32_t>(v)) && v != static_cast<Char>('"')) ||
      v == static_cast<Char>('\'')) {
    out = write_escaped_cp(
        out, find_escape_result<Char>{&v, &v + 1, static_cast<uint32_t>(v)});
  } else {
    *out++ = v;
  }
  *out++ = static_cast<Char>('\'');
  return out;
}

template <typename Char, typename OutputIt>
FMT_CONSTEXPR auto write_char(OutputIt out, Char value,
                              const basic_format_specs<Char>& specs)
    -> OutputIt {
  bool is_debug = specs.type == presentation_type::debug;
  return write_padded(out, specs, 1, [=](reserve_iterator<OutputIt> it) {
    if (is_debug) return write_escaped_char(it, value);
    *it++ = value;
    return it;
  });
}
template <typename Char, typename OutputIt>
FMT_CONSTEXPR auto write(OutputIt out, Char value,
                         const basic_format_specs<Char>& specs,
                         locale_ref loc = {}) -> OutputIt {
  return check_char_specs(specs)
             ? write_char(out, value, specs)
             : write(out, static_cast<int>(value), specs, loc);
}

// Data for write_int that doesn't depend on output iterator type. It is used to
// avoid template code bloat.
template <typename Char> struct write_int_data {
  size_t size;
  size_t padding;

  FMT_CONSTEXPR write_int_data(int num_digits, unsigned prefix,
                               const basic_format_specs<Char>& specs)
      : size((prefix >> 24) + to_unsigned(num_digits)), padding(0) {
    if (specs.align == align::numeric) {
      auto width = to_unsigned(specs.width);
      if (width > size) {
        padding = width - size;
        size = width;
      }
    } else if (specs.precision > num_digits) {
      size = (prefix >> 24) + to_unsigned(specs.precision);
      padding = to_unsigned(specs.precision - num_digits);
    }
  }
};

// Writes an integer in the format
//   <left-padding><prefix><numeric-padding><digits><right-padding>
// where <digits> are written by write_digits(it).
// prefix contains chars in three lower bytes and the size in the fourth byte.
template <typename OutputIt, typename Char, typename W>
FMT_CONSTEXPR FMT_INLINE auto write_int(OutputIt out, int num_digits,
                                        unsigned prefix,
                                        const basic_format_specs<Char>& specs,
                                        W write_digits) -> OutputIt {
  // Slightly faster check for specs.width == 0 && specs.precision == -1.
  if ((specs.width | (specs.precision + 1)) == 0) {
    auto it = reserve(out, to_unsigned(num_digits) + (prefix >> 24));
    if (prefix != 0) {
      for (unsigned p = prefix & 0xffffff; p != 0; p >>= 8)
        *it++ = static_cast<Char>(p & 0xff);
    }
    return base_iterator(out, write_digits(it));
  }
  auto data = write_int_data<Char>(num_digits, prefix, specs);
  return write_padded<align::right>(
      out, specs, data.size, [=](reserve_iterator<OutputIt> it) {
        for (unsigned p = prefix & 0xffffff; p != 0; p >>= 8)
          *it++ = static_cast<Char>(p & 0xff);
        it = detail::fill_n(it, data.padding, static_cast<Char>('0'));
        return write_digits(it);
      });
}

template <typename Char> class digit_grouping {
 private:
  thousands_sep_result<Char> sep_;

  struct next_state {
    std::string::const_iterator group;
    int pos;
  };
  next_state initial_state() const { return {sep_.grouping.begin(), 0}; }

  // Returns the next digit group separator position.
  int next(next_state& state) const {
    if (!sep_.thousands_sep) return max_value<int>();
    if (state.group == sep_.grouping.end())
      return state.pos += sep_.grouping.back();
    if (*state.group <= 0 || *state.group == max_value<char>())
      return max_value<int>();
    state.pos += *state.group++;
    return state.pos;
  }

 public:
  explicit digit_grouping(locale_ref loc, bool localized = true) {
    if (localized)
      sep_ = thousands_sep<Char>(loc);
    else
      sep_.thousands_sep = Char();
  }
  explicit digit_grouping(thousands_sep_result<Char> sep) : sep_(sep) {}

  Char separator() const { return sep_.thousands_sep; }

  int count_separators(int num_digits) const {
    int count = 0;
    auto state = initial_state();
    while (num_digits > next(state)) ++count;
    return count;
  }

  // Applies grouping to digits and write the output to out.
  template <typename Out, typename C>
  Out apply(Out out, basic_string_view<C> digits) const {
    auto num_digits = static_cast<int>(digits.size());
    auto separators = basic_memory_buffer<int>();
    separators.push_back(0);
    auto state = initial_state();
    while (int i = next(state)) {
      if (i >= num_digits) break;
      separators.push_back(i);
    }
    for (int i = 0, sep_index = static_cast<int>(separators.size() - 1);
         i < num_digits; ++i) {
      if (num_digits - i == separators[sep_index]) {
        *out++ = separator();
        --sep_index;
      }
      *out++ = static_cast<Char>(digits[to_unsigned(i)]);
    }
    return out;
  }
};

template <typename OutputIt, typename UInt, typename Char>
auto write_int_localized(OutputIt out, UInt value, unsigned prefix,
                         const basic_format_specs<Char>& specs,
                         const digit_grouping<Char>& grouping) -> OutputIt {
  static_assert(std::is_same<uint64_or_128_t<UInt>, UInt>::value, "");
  int num_digits = count_digits(value);
  char digits[40];
  format_decimal(digits, value, num_digits);
  unsigned size = to_unsigned((prefix != 0 ? 1 : 0) + num_digits +
                              grouping.count_separators(num_digits));
  return write_padded<align::right>(
      out, specs, size, size, [&](reserve_iterator<OutputIt> it) {
        if (prefix != 0) {
          char sign = static_cast<char>(prefix);
          *it++ = static_cast<Char>(sign);
        }
        return grouping.apply(it, string_view(digits, to_unsigned(num_digits)));
      });
}

template <typename OutputIt, typename UInt, typename Char>
auto write_int_localized(OutputIt& out, UInt value, unsigned prefix,
                         const basic_format_specs<Char>& specs, locale_ref loc)
    -> bool {
  auto grouping = digit_grouping<Char>(loc);
  out = write_int_localized(out, value, prefix, specs, grouping);
  return true;
}

FMT_CONSTEXPR inline void prefix_append(unsigned& prefix, unsigned value) {
  prefix |= prefix != 0 ? value << 8 : value;
  prefix += (1u + (value > 0xff ? 1 : 0)) << 24;
}

template <typename UInt> struct write_int_arg {
  UInt abs_value;
  unsigned prefix;
};

template <typename T>
FMT_CONSTEXPR auto make_write_int_arg(T value, sign_t sign)
    -> write_int_arg<uint32_or_64_or_128_t<T>> {
  auto prefix = 0u;
  auto abs_value = static_cast<uint32_or_64_or_128_t<T>>(value);
  if (is_negative(value)) {
    prefix = 0x01000000 | '-';
    abs_value = 0 - abs_value;
  } else {
    constexpr const unsigned prefixes[4] = {0, 0, 0x1000000u | '+',
                                            0x1000000u | ' '};
    prefix = prefixes[sign];
  }
  return {abs_value, prefix};
}

template <typename Char, typename OutputIt, typename T>
FMT_CONSTEXPR FMT_INLINE auto write_int(OutputIt out, write_int_arg<T> arg,
                                        const basic_format_specs<Char>& specs,
                                        locale_ref loc) -> OutputIt {
  static_assert(std::is_same<T, uint32_or_64_or_128_t<T>>::value, "");
  auto abs_value = arg.abs_value;
  auto prefix = arg.prefix;
  switch (specs.type) {
  case presentation_type::none:
  case presentation_type::dec: {
    if (specs.localized &&
        write_int_localized(out, static_cast<uint64_or_128_t<T>>(abs_value),
                            prefix, specs, loc)) {
      return out;
    }
    auto num_digits = count_digits(abs_value);
    return write_int(
        out, num_digits, prefix, specs, [=](reserve_iterator<OutputIt> it) {
          return format_decimal<Char>(it, abs_value, num_digits).end;
        });
  }
  case presentation_type::hex_lower:
  case presentation_type::hex_upper: {
    bool upper = specs.type == presentation_type::hex_upper;
    if (specs.alt)
      prefix_append(prefix, unsigned(upper ? 'X' : 'x') << 8 | '0');
    int num_digits = count_digits<4>(abs_value);
    return write_int(
        out, num_digits, prefix, specs, [=](reserve_iterator<OutputIt> it) {
          return format_uint<4, Char>(it, abs_value, num_digits, upper);
        });
  }
  case presentation_type::bin_lower:
  case presentation_type::bin_upper: {
    bool upper = specs.type == presentation_type::bin_upper;
    if (specs.alt)
      prefix_append(prefix, unsigned(upper ? 'B' : 'b') << 8 | '0');
    int num_digits = count_digits<1>(abs_value);
    return write_int(out, num_digits, prefix, specs,
                     [=](reserve_iterator<OutputIt> it) {
                       return format_uint<1, Char>(it, abs_value, num_digits);
                     });
  }
  case presentation_type::oct: {
    int num_digits = count_digits<3>(abs_value);
    // Octal prefix '0' is counted as a digit, so only add it if precision
    // is not greater than the number of digits.
    if (specs.alt && specs.precision <= num_digits && abs_value != 0)
      prefix_append(prefix, '0');
    return write_int(out, num_digits, prefix, specs,
                     [=](reserve_iterator<OutputIt> it) {
                       return format_uint<3, Char>(it, abs_value, num_digits);
                     });
  }
  case presentation_type::chr:
    return write_char(out, static_cast<Char>(abs_value), specs);
  default:
    throw_format_error("invalid type specifier");
  }
  return out;
}
template <typename Char, typename OutputIt, typename T>
FMT_CONSTEXPR FMT_NOINLINE auto write_int_noinline(
    OutputIt out, write_int_arg<T> arg, const basic_format_specs<Char>& specs,
    locale_ref loc) -> OutputIt {
  return write_int(out, arg, specs, loc);
}
template <typename Char, typename OutputIt, typename T,
          FMT_ENABLE_IF(is_integral<T>::value &&
                        !std::is_same<T, bool>::value &&
                        std::is_same<OutputIt, buffer_appender<Char>>::value)>
FMT_CONSTEXPR FMT_INLINE auto write(OutputIt out, T value,
                                    const basic_format_specs<Char>& specs,
                                    locale_ref loc) -> OutputIt {
  return write_int_noinline(out, make_write_int_arg(value, specs.sign), specs,
                            loc);
}
// An inlined version of write used in format string compilation.
template <typename Char, typename OutputIt, typename T,
          FMT_ENABLE_IF(is_integral<T>::value &&
                        !std::is_same<T, bool>::value &&
                        !std::is_same<OutputIt, buffer_appender<Char>>::value)>
FMT_CONSTEXPR FMT_INLINE auto write(OutputIt out, T value,
                                    const basic_format_specs<Char>& specs,
                                    locale_ref loc) -> OutputIt {
  return write_int(out, make_write_int_arg(value, specs.sign), specs, loc);
}

// An output iterator that counts the number of objects written to it and
// discards them.
class counting_iterator {
 private:
  size_t count_;

 public:
  using iterator_category = std::output_iterator_tag;
  using difference_type = std::ptrdiff_t;
  using pointer = void;
  using reference = void;
  FMT_UNCHECKED_ITERATOR(counting_iterator);

  struct value_type {
    template <typename T> FMT_CONSTEXPR void operator=(const T&) {}
  };

  FMT_CONSTEXPR counting_iterator() : count_(0) {}

  FMT_CONSTEXPR size_t count() const { return count_; }

  FMT_CONSTEXPR counting_iterator& operator++() {
    ++count_;
    return *this;
  }
  FMT_CONSTEXPR counting_iterator operator++(int) {
    auto it = *this;
    ++*this;
    return it;
  }

  FMT_CONSTEXPR friend counting_iterator operator+(counting_iterator it,
                                                   difference_type n) {
    it.count_ += static_cast<size_t>(n);
    return it;
  }

  FMT_CONSTEXPR value_type operator*() const { return {}; }
};

template <typename Char, typename OutputIt>
FMT_CONSTEXPR auto write(OutputIt out, basic_string_view<Char> s,
                         const basic_format_specs<Char>& specs) -> OutputIt {
  auto data = s.data();
  auto size = s.size();
  if (specs.precision >= 0 && to_unsigned(specs.precision) < size)
    size = code_point_index(s, to_unsigned(specs.precision));
  bool is_debug = specs.type == presentation_type::debug;
  size_t width = 0;
  if (specs.width != 0) {
    if (is_debug)
      width = write_escaped_string(counting_iterator{}, s).count();
    else
      width = compute_width(basic_string_view<Char>(data, size));
  }
  return write_padded(out, specs, size, width,
                      [=](reserve_iterator<OutputIt> it) {
                        if (is_debug) return write_escaped_string(it, s);
                        return copy_str<Char>(data, data + size, it);
                      });
}
template <typename Char, typename OutputIt>
FMT_CONSTEXPR auto write(OutputIt out,
                         basic_string_view<type_identity_t<Char>> s,
                         const basic_format_specs<Char>& specs, locale_ref)
    -> OutputIt {
  check_string_type_spec(specs.type);
  return write(out, s, specs);
}
template <typename Char, typename OutputIt>
FMT_CONSTEXPR auto write(OutputIt out, const Char* s,
                         const basic_format_specs<Char>& specs, locale_ref)
    -> OutputIt {
  return check_cstring_type_spec(specs.type)
             ? write(out, basic_string_view<Char>(s), specs, {})
             : write_ptr<Char>(out, bit_cast<uintptr_t>(s), &specs);
}

template <typename Char, typename OutputIt, typename T,
          FMT_ENABLE_IF(is_integral<T>::value &&
                        !std::is_same<T, bool>::value &&
                        !std::is_same<T, Char>::value)>
FMT_CONSTEXPR auto write(OutputIt out, T value) -> OutputIt {
  auto abs_value = static_cast<uint32_or_64_or_128_t<T>>(value);
  bool negative = is_negative(value);
  // Don't do -abs_value since it trips unsigned-integer-overflow sanitizer.
  if (negative) abs_value = ~abs_value + 1;
  int num_digits = count_digits(abs_value);
  auto size = (negative ? 1 : 0) + static_cast<size_t>(num_digits);
  auto it = reserve(out, size);
  if (auto ptr = to_pointer<Char>(it, size)) {
    if (negative) *ptr++ = static_cast<Char>('-');
    format_decimal<Char>(ptr, abs_value, num_digits);
    return out;
  }
  if (negative) *it++ = static_cast<Char>('-');
  it = format_decimal<Char>(it, abs_value, num_digits).end;
  return base_iterator(out, it);
}

template <typename Char, typename OutputIt>
FMT_CONSTEXPR20 auto write_nonfinite(OutputIt out, bool isnan,
                                     basic_format_specs<Char> specs,
                                     const float_specs& fspecs) -> OutputIt {
  auto str =
      isnan ? (fspecs.upper ? "NAN" : "nan") : (fspecs.upper ? "INF" : "inf");
  constexpr size_t str_size = 3;
  auto sign = fspecs.sign;
  auto size = str_size + (sign ? 1 : 0);
  // Replace '0'-padding with space for non-finite values.
  const bool is_zero_fill =
      specs.fill.size() == 1 && *specs.fill.data() == static_cast<Char>('0');
  if (is_zero_fill) specs.fill[0] = static_cast<Char>(' ');
  return write_padded(out, specs, size, [=](reserve_iterator<OutputIt> it) {
    if (sign) *it++ = detail::sign<Char>(sign);
    return copy_str<Char>(str, str + str_size, it);
  });
}

// A decimal floating-point number significand * pow(10, exp).
struct big_decimal_fp {
  const char* significand;
  int significand_size;
  int exponent;
};

constexpr auto get_significand_size(const big_decimal_fp& f) -> int {
  return f.significand_size;
}
template <typename T>
inline auto get_significand_size(const dragonbox::decimal_fp<T>& f) -> int {
  return count_digits(f.significand);
}

template <typename Char, typename OutputIt>
constexpr auto write_significand(OutputIt out, const char* significand,
                                 int significand_size) -> OutputIt {
  return copy_str<Char>(significand, significand + significand_size, out);
}
template <typename Char, typename OutputIt, typename UInt>
inline auto write_significand(OutputIt out, UInt significand,
                              int significand_size) -> OutputIt {
  return format_decimal<Char>(out, significand, significand_size).end;
}
template <typename Char, typename OutputIt, typename T, typename Grouping>
FMT_CONSTEXPR20 auto write_significand(OutputIt out, T significand,
                                       int significand_size, int exponent,
                                       const Grouping& grouping) -> OutputIt {
  if (!grouping.separator()) {
    out = write_significand<Char>(out, significand, significand_size);
    return detail::fill_n(out, exponent, static_cast<Char>('0'));
  }
  auto buffer = memory_buffer();
  write_significand<char>(appender(buffer), significand, significand_size);
  detail::fill_n(appender(buffer), exponent, '0');
  return grouping.apply(out, string_view(buffer.data(), buffer.size()));
}

template <typename Char, typename UInt,
          FMT_ENABLE_IF(std::is_integral<UInt>::value)>
inline auto write_significand(Char* out, UInt significand, int significand_size,
                              int integral_size, Char decimal_point) -> Char* {
  if (!decimal_point)
    return format_decimal(out, significand, significand_size).end;
  out += significand_size + 1;
  Char* end = out;
  int floating_size = significand_size - integral_size;
  for (int i = floating_size / 2; i > 0; --i) {
    out -= 2;
    copy2(out, digits2(static_cast<std::size_t>(significand % 100)));
    significand /= 100;
  }
  if (floating_size % 2 != 0) {
    *--out = static_cast<Char>('0' + significand % 10);
    significand /= 10;
  }
  *--out = decimal_point;
  format_decimal(out - integral_size, significand, integral_size);
  return end;
}

template <typename OutputIt, typename UInt, typename Char,
          FMT_ENABLE_IF(!std::is_pointer<remove_cvref_t<OutputIt>>::value)>
inline auto write_significand(OutputIt out, UInt significand,
                              int significand_size, int integral_size,
                              Char decimal_point) -> OutputIt {
  // Buffer is large enough to hold digits (digits10 + 1) and a decimal point.
  Char buffer[digits10<UInt>() + 2];
  auto end = write_significand(buffer, significand, significand_size,
                               integral_size, decimal_point);
  return detail::copy_str_noinline<Char>(buffer, end, out);
}

template <typename OutputIt, typename Char>
FMT_CONSTEXPR auto write_significand(OutputIt out, const char* significand,
                                     int significand_size, int integral_size,
                                     Char decimal_point) -> OutputIt {
  out = detail::copy_str_noinline<Char>(significand,
                                        significand + integral_size, out);
  if (!decimal_point) return out;
  *out++ = decimal_point;
  return detail::copy_str_noinline<Char>(significand + integral_size,
                                         significand + significand_size, out);
}

template <typename OutputIt, typename Char, typename T, typename Grouping>
FMT_CONSTEXPR20 auto write_significand(OutputIt out, T significand,
                                       int significand_size, int integral_size,
                                       Char decimal_point,
                                       const Grouping& grouping) -> OutputIt {
  if (!grouping.separator()) {
    return write_significand(out, significand, significand_size, integral_size,
                             decimal_point);
  }
  auto buffer = basic_memory_buffer<Char>();
  write_significand(buffer_appender<Char>(buffer), significand,
                    significand_size, integral_size, decimal_point);
  grouping.apply(
      out, basic_string_view<Char>(buffer.data(), to_unsigned(integral_size)));
  return detail::copy_str_noinline<Char>(buffer.data() + integral_size,
                                         buffer.end(), out);
}

template <typename OutputIt, typename DecimalFP, typename Char,
          typename Grouping = digit_grouping<Char>>
FMT_CONSTEXPR20 auto do_write_float(OutputIt out, const DecimalFP& f,
                                    const basic_format_specs<Char>& specs,
                                    float_specs fspecs, locale_ref loc)
    -> OutputIt {
  auto significand = f.significand;
  int significand_size = get_significand_size(f);
  const Char zero = static_cast<Char>('0');
  auto sign = fspecs.sign;
  size_t size = to_unsigned(significand_size) + (sign ? 1 : 0);
  using iterator = reserve_iterator<OutputIt>;

  Char decimal_point =
      fspecs.locale ? detail::decimal_point<Char>(loc) : static_cast<Char>('.');

  int output_exp = f.exponent + significand_size - 1;
  auto use_exp_format = [=]() {
    if (fspecs.format == float_format::exp) return true;
    if (fspecs.format != float_format::general) return false;
    // Use the fixed notation if the exponent is in [exp_lower, exp_upper),
    // e.g. 0.0001 instead of 1e-04. Otherwise use the exponent notation.
    const int exp_lower = -4, exp_upper = 16;
    return output_exp < exp_lower ||
           output_exp >= (fspecs.precision > 0 ? fspecs.precision : exp_upper);
  };
  if (use_exp_format()) {
    int num_zeros = 0;
    if (fspecs.showpoint) {
      num_zeros = fspecs.precision - significand_size;
      if (num_zeros < 0) num_zeros = 0;
      size += to_unsigned(num_zeros);
    } else if (significand_size == 1) {
      decimal_point = Char();
    }
    auto abs_output_exp = output_exp >= 0 ? output_exp : -output_exp;
    int exp_digits = 2;
    if (abs_output_exp >= 100) exp_digits = abs_output_exp >= 1000 ? 4 : 3;

    size += to_unsigned((decimal_point ? 1 : 0) + 2 + exp_digits);
    char exp_char = fspecs.upper ? 'E' : 'e';
    auto write = [=](iterator it) {
      if (sign) *it++ = detail::sign<Char>(sign);
      // Insert a decimal point after the first digit and add an exponent.
      it = write_significand(it, significand, significand_size, 1,
                             decimal_point);
      if (num_zeros > 0) it = detail::fill_n(it, num_zeros, zero);
      *it++ = static_cast<Char>(exp_char);
      return write_exponent<Char>(output_exp, it);
    };
    return specs.width > 0 ? write_padded<align::right>(out, specs, size, write)
                           : base_iterator(out, write(reserve(out, size)));
  }

  int exp = f.exponent + significand_size;
  if (f.exponent >= 0) {
    // 1234e5 -> 123400000[.0+]
    size += to_unsigned(f.exponent);
    int num_zeros = fspecs.precision - exp;
    abort_fuzzing_if(num_zeros > 5000);
    if (fspecs.showpoint) {
      ++size;
      if (num_zeros <= 0 && fspecs.format != float_format::fixed) num_zeros = 1;
      if (num_zeros > 0) size += to_unsigned(num_zeros);
    }
    auto grouping = Grouping(loc, fspecs.locale);
    size += to_unsigned(grouping.count_separators(exp));
    return write_padded<align::right>(out, specs, size, [&](iterator it) {
      if (sign) *it++ = detail::sign<Char>(sign);
      it = write_significand<Char>(it, significand, significand_size,
                                   f.exponent, grouping);
      if (!fspecs.showpoint) return it;
      *it++ = decimal_point;
      return num_zeros > 0 ? detail::fill_n(it, num_zeros, zero) : it;
    });
  } else if (exp > 0) {
    // 1234e-2 -> 12.34[0+]
    int num_zeros = fspecs.showpoint ? fspecs.precision - significand_size : 0;
    size += 1 + to_unsigned(num_zeros > 0 ? num_zeros : 0);
    auto grouping = Grouping(loc, fspecs.locale);
    size += to_unsigned(grouping.count_separators(significand_size));
    return write_padded<align::right>(out, specs, size, [&](iterator it) {
      if (sign) *it++ = detail::sign<Char>(sign);
      it = write_significand(it, significand, significand_size, exp,
                             decimal_point, grouping);
      return num_zeros > 0 ? detail::fill_n(it, num_zeros, zero) : it;
    });
  }
  // 1234e-6 -> 0.001234
  int num_zeros = -exp;
  if (significand_size == 0 && fspecs.precision >= 0 &&
      fspecs.precision < num_zeros) {
    num_zeros = fspecs.precision;
  }
  bool pointy = num_zeros != 0 || significand_size != 0 || fspecs.showpoint;
  size += 1 + (pointy ? 1 : 0) + to_unsigned(num_zeros);
  return write_padded<align::right>(out, specs, size, [&](iterator it) {
    if (sign) *it++ = detail::sign<Char>(sign);
    *it++ = zero;
    if (!pointy) return it;
    *it++ = decimal_point;
    it = detail::fill_n(it, num_zeros, zero);
    return write_significand<Char>(it, significand, significand_size);
  });
}

template <typename Char> class fallback_digit_grouping {
 public:
  constexpr fallback_digit_grouping(locale_ref, bool) {}

  constexpr Char separator() const { return Char(); }

  constexpr int count_separators(int) const { return 0; }

  template <typename Out, typename C>
  constexpr Out apply(Out out, basic_string_view<C>) const {
    return out;
  }
};

template <typename OutputIt, typename DecimalFP, typename Char>
FMT_CONSTEXPR20 auto write_float(OutputIt out, const DecimalFP& f,
                                 const basic_format_specs<Char>& specs,
                                 float_specs fspecs, locale_ref loc)
    -> OutputIt {
  if (is_constant_evaluated()) {
    return do_write_float<OutputIt, DecimalFP, Char,
                          fallback_digit_grouping<Char>>(out, f, specs, fspecs,
                                                         loc);
  } else {
    return do_write_float(out, f, specs, fspecs, loc);
  }
}

template <typename T> constexpr bool isnan(T value) {
  return !(value >= value);  // std::isnan doesn't support __float128.
}

template <typename T, typename Enable = void>
struct has_isfinite : std::false_type {};

template <typename T>
struct has_isfinite<T, enable_if_t<sizeof(std::isfinite(T())) != 0>>
    : std::true_type {};

template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value&&
                                        has_isfinite<T>::value)>
FMT_CONSTEXPR20 bool isfinite(T value) {
  constexpr T inf = T(std::numeric_limits<double>::infinity());
  if (is_constant_evaluated())
    return !detail::isnan(value) && value != inf && value != -inf;
  return std::isfinite(value);
}
template <typename T, FMT_ENABLE_IF(!has_isfinite<T>::value)>
FMT_CONSTEXPR bool isfinite(T value) {
  T inf = T(std::numeric_limits<double>::infinity());
  // std::isfinite doesn't support __float128.
  return !detail::isnan(value) && value != inf && value != -inf;
}

template <typename T, FMT_ENABLE_IF(is_floating_point<T>::value)>
FMT_INLINE FMT_CONSTEXPR bool signbit(T value) {
  if (is_constant_evaluated()) {
#ifdef __cpp_if_constexpr
    if constexpr (std::numeric_limits<double>::is_iec559) {
      auto bits = detail::bit_cast<uint64_t>(static_cast<double>(value));
      return (bits >> (num_bits<uint64_t>() - 1)) != 0;
    }
#endif
  }
  return std::signbit(static_cast<double>(value));
}

enum class round_direction { unknown, up, down };

// Given the divisor (normally a power of 10), the remainder = v % divisor for
// some number v and the error, returns whether v should be rounded up, down, or
// whether the rounding direction can't be determined due to error.
// error should be less than divisor / 2.
FMT_CONSTEXPR inline round_direction get_round_direction(uint64_t divisor,
                                                         uint64_t remainder,
                                                         uint64_t error) {
  FMT_ASSERT(remainder < divisor, "");  // divisor - remainder won't overflow.
  FMT_ASSERT(error < divisor, "");      // divisor - error won't overflow.
  FMT_ASSERT(error < divisor - error, "");  // error * 2 won't overflow.
  // Round down if (remainder + error) * 2 <= divisor.
  if (remainder <= divisor - remainder && error * 2 <= divisor - remainder * 2)
    return round_direction::down;
  // Round up if (remainder - error) * 2 >= divisor.
  if (remainder >= error &&
      remainder - error >= divisor - (remainder - error)) {
    return round_direction::up;
  }
  return round_direction::unknown;
}

namespace digits {
enum result {
  more,  // Generate more digits.
  done,  // Done generating digits.
  error  // Digit generation cancelled due to an error.
};
}

struct gen_digits_handler {
  char* buf;
  int size;
  int precision;
  int exp10;
  bool fixed;

  FMT_CONSTEXPR digits::result on_digit(char digit, uint64_t divisor,
                                        uint64_t remainder, uint64_t error,
                                        bool integral) {
    FMT_ASSERT(remainder < divisor, "");
    buf[size++] = digit;
    if (!integral && error >= remainder) return digits::error;
    if (size < precision) return digits::more;
    if (!integral) {
      // Check if error * 2 < divisor with overflow prevention.
      // The check is not needed for the integral part because error = 1
      // and divisor > (1 << 32) there.
      if (error >= divisor || error >= divisor - error) return digits::error;
    } else {
      FMT_ASSERT(error == 1 && divisor > 2, "");
    }
    auto dir = get_round_direction(divisor, remainder, error);
    if (dir != round_direction::up)
      return dir == round_direction::down ? digits::done : digits::error;
    ++buf[size - 1];
    for (int i = size - 1; i > 0 && buf[i] > '9'; --i) {
      buf[i] = '0';
      ++buf[i - 1];
    }
    if (buf[0] > '9') {
      buf[0] = '1';
      if (fixed)
        buf[size++] = '0';
      else
        ++exp10;
    }
    return digits::done;
  }
};

inline FMT_CONSTEXPR20 void adjust_precision(int& precision, int exp10) {
  // Adjust fixed precision by exponent because it is relative to decimal
  // point.
  if (exp10 > 0 && precision > max_value<int>() - exp10)
    FMT_THROW(format_error("number is too big"));
  precision += exp10;
}

// Generates output using the Grisu digit-gen algorithm.
// error: the size of the region (lower, upper) outside of which numbers
// definitely do not round to value (Delta in Grisu3).
FMT_INLINE FMT_CONSTEXPR20 auto grisu_gen_digits(fp value, uint64_t error,
                                                 int& exp,
                                                 gen_digits_handler& handler)
    -> digits::result {
  const fp one(1ULL << -value.e, value.e);
  // The integral part of scaled value (p1 in Grisu) = value / one. It cannot be
  // zero because it contains a product of two 64-bit numbers with MSB set (due
  // to normalization) - 1, shifted right by at most 60 bits.
  auto integral = static_cast<uint32_t>(value.f >> -one.e);
  FMT_ASSERT(integral != 0, "");
  FMT_ASSERT(integral == value.f >> -one.e, "");
  // The fractional part of scaled value (p2 in Grisu) c = value % one.
  uint64_t fractional = value.f & (one.f - 1);
  exp = count_digits(integral);  // kappa in Grisu.
  // Non-fixed formats require at least one digit and no precision adjustment.
  if (handler.fixed) {
    adjust_precision(handler.precision, exp + handler.exp10);
    // Check if precision is satisfied just by leading zeros, e.g.
    // format("{:.2f}", 0.001) gives "0.00" without generating any digits.
    if (handler.precision <= 0) {
      if (handler.precision < 0) return digits::done;
      // Divide by 10 to prevent overflow.
      uint64_t divisor = data::power_of_10_64[exp - 1] << -one.e;
      auto dir = get_round_direction(divisor, value.f / 10, error * 10);
      if (dir == round_direction::unknown) return digits::error;
      handler.buf[handler.size++] = dir == round_direction::up ? '1' : '0';
      return digits::done;
    }
  }
  // Generate digits for the integral part. This can produce up to 10 digits.
  do {
    uint32_t digit = 0;
    auto divmod_integral = [&](uint32_t divisor) {
      digit = integral / divisor;
      integral %= divisor;
    };
    // This optimization by Milo Yip reduces the number of integer divisions by
    // one per iteration.
    switch (exp) {
    case 10:
      divmod_integral(1000000000);
      break;
    case 9:
      divmod_integral(100000000);
      break;
    case 8:
      divmod_integral(10000000);
      break;
    case 7:
      divmod_integral(1000000);
      break;
    case 6:
      divmod_integral(100000);
      break;
    case 5:
      divmod_integral(10000);
      break;
    case 4:
      divmod_integral(1000);
      break;
    case 3:
      divmod_integral(100);
      break;
    case 2:
      divmod_integral(10);
      break;
    case 1:
      digit = integral;
      integral = 0;
      break;
    default:
      FMT_ASSERT(false, "invalid number of digits");
    }
    --exp;
    auto remainder = (static_cast<uint64_t>(integral) << -one.e) + fractional;
    auto result = handler.on_digit(static_cast<char>('0' + digit),
                                   data::power_of_10_64[exp] << -one.e,
                                   remainder, error, true);
    if (result != digits::more) return result;
  } while (exp > 0);
  // Generate digits for the fractional part.
  for (;;) {
    fractional *= 10;
    error *= 10;
    char digit = static_cast<char>('0' + (fractional >> -one.e));
    fractional &= one.f - 1;
    --exp;
    auto result = handler.on_digit(digit, one.f, fractional, error, false);
    if (result != digits::more) return result;
  }
}

class bigint {
 private:
  // A bigint is stored as an array of bigits (big digits), with bigit at index
  // 0 being the least significant one.
  using bigit = uint32_t;
  using double_bigit = uint64_t;
  enum { bigits_capacity = 32 };
  basic_memory_buffer<bigit, bigits_capacity> bigits_;
  int exp_;

  FMT_CONSTEXPR20 bigit operator[](int index) const {
    return bigits_[to_unsigned(index)];
  }
  FMT_CONSTEXPR20 bigit& operator[](int index) {
    return bigits_[to_unsigned(index)];
  }

  static constexpr const int bigit_bits = num_bits<bigit>();

  friend struct formatter<bigint>;

  FMT_CONSTEXPR20 void subtract_bigits(int index, bigit other, bigit& borrow) {
    auto result = static_cast<double_bigit>((*this)[index]) - other - borrow;
    (*this)[index] = static_cast<bigit>(result);
    borrow = static_cast<bigit>(result >> (bigit_bits * 2 - 1));
  }

  FMT_CONSTEXPR20 void remove_leading_zeros() {
    int num_bigits = static_cast<int>(bigits_.size()) - 1;
    while (num_bigits > 0 && (*this)[num_bigits] == 0) --num_bigits;
    bigits_.resize(to_unsigned(num_bigits + 1));
  }

  // Computes *this -= other assuming aligned bigints and *this >= other.
  FMT_CONSTEXPR20 void subtract_aligned(const bigint& other) {
    FMT_ASSERT(other.exp_ >= exp_, "unaligned bigints");
    FMT_ASSERT(compare(*this, other) >= 0, "");
    bigit borrow = 0;
    int i = other.exp_ - exp_;
    for (size_t j = 0, n = other.bigits_.size(); j != n; ++i, ++j)
      subtract_bigits(i, other.bigits_[j], borrow);
    while (borrow > 0) subtract_bigits(i, 0, borrow);
    remove_leading_zeros();
  }

  FMT_CONSTEXPR20 void multiply(uint32_t value) {
    const double_bigit wide_value = value;
    bigit carry = 0;
    for (size_t i = 0, n = bigits_.size(); i < n; ++i) {
      double_bigit result = bigits_[i] * wide_value + carry;
      bigits_[i] = static_cast<bigit>(result);
      carry = static_cast<bigit>(result >> bigit_bits);
    }
    if (carry != 0) bigits_.push_back(carry);
  }

  template <typename UInt, FMT_ENABLE_IF(std::is_same<UInt, uint64_t>::value ||
                                         std::is_same<UInt, uint128_t>::value)>
  FMT_CONSTEXPR20 void multiply(UInt value) {
    using half_uint =
        conditional_t<std::is_same<UInt, uint128_t>::value, uint64_t, uint32_t>;
    const int shift = num_bits<half_uint>() - bigit_bits;
    const UInt lower = static_cast<half_uint>(value);
    const UInt upper = value >> num_bits<half_uint>();
    UInt carry = 0;
    for (size_t i = 0, n = bigits_.size(); i < n; ++i) {
      UInt result = lower * bigits_[i] + static_cast<bigit>(carry);
      carry = (upper * bigits_[i] << shift) + (result >> bigit_bits) +
              (carry >> bigit_bits);
      bigits_[i] = static_cast<bigit>(result);
    }
    while (carry != 0) {
      bigits_.push_back(static_cast<bigit>(carry));
      carry >>= bigit_bits;
    }
  }

  template <typename UInt, FMT_ENABLE_IF(std::is_same<UInt, uint64_t>::value ||
                                         std::is_same<UInt, uint128_t>::value)>
  FMT_CONSTEXPR20 void assign(UInt n) {
    size_t num_bigits = 0;
    do {
      bigits_[num_bigits++] = static_cast<bigit>(n);
      n >>= bigit_bits;
    } while (n != 0);
    bigits_.resize(num_bigits);
    exp_ = 0;
  }

 public:
  FMT_CONSTEXPR20 bigint() : exp_(0) {}
  explicit bigint(uint64_t n) { assign(n); }

  bigint(const bigint&) = delete;
  void operator=(const bigint&) = delete;

  FMT_CONSTEXPR20 void assign(const bigint& other) {
    auto size = other.bigits_.size();
    bigits_.resize(size);
    auto data = other.bigits_.data();
    std::copy(data, data + size, make_checked(bigits_.data(), size));
    exp_ = other.exp_;
  }

  template <typename Int> FMT_CONSTEXPR20 void operator=(Int n) {
    FMT_ASSERT(n > 0, "");
    assign(uint64_or_128_t<Int>(n));
  }

  FMT_CONSTEXPR20 int num_bigits() const {
    return static_cast<int>(bigits_.size()) + exp_;
  }

  FMT_NOINLINE FMT_CONSTEXPR20 bigint& operator<<=(int shift) {
    FMT_ASSERT(shift >= 0, "");
    exp_ += shift / bigit_bits;
    shift %= bigit_bits;
    if (shift == 0) return *this;
    bigit carry = 0;
    for (size_t i = 0, n = bigits_.size(); i < n; ++i) {
      bigit c = bigits_[i] >> (bigit_bits - shift);
      bigits_[i] = (bigits_[i] << shift) + carry;
      carry = c;
    }
    if (carry != 0) bigits_.push_back(carry);
    return *this;
  }

  template <typename Int> FMT_CONSTEXPR20 bigint& operator*=(Int value) {
    FMT_ASSERT(value > 0, "");
    multiply(uint32_or_64_or_128_t<Int>(value));
    return *this;
  }

  friend FMT_CONSTEXPR20 int compare(const bigint& lhs, const bigint& rhs) {
    int num_lhs_bigits = lhs.num_bigits(), num_rhs_bigits = rhs.num_bigits();
    if (num_lhs_bigits != num_rhs_bigits)
      return num_lhs_bigits > num_rhs_bigits ? 1 : -1;
    int i = static_cast<int>(lhs.bigits_.size()) - 1;
    int j = static_cast<int>(rhs.bigits_.size()) - 1;
    int end = i - j;
    if (end < 0) end = 0;
    for (; i >= end; --i, --j) {
      bigit lhs_bigit = lhs[i], rhs_bigit = rhs[j];
      if (lhs_bigit != rhs_bigit) return lhs_bigit > rhs_bigit ? 1 : -1;
    }
    if (i != j) return i > j ? 1 : -1;
    return 0;
  }

  // Returns compare(lhs1 + lhs2, rhs).
  friend FMT_CONSTEXPR20 int add_compare(const bigint& lhs1, const bigint& lhs2,
                                         const bigint& rhs) {
    auto minimum = [](int a, int b) { return a < b ? a : b; };
    auto maximum = [](int a, int b) { return a > b ? a : b; };
    int max_lhs_bigits = maximum(lhs1.num_bigits(), lhs2.num_bigits());
    int num_rhs_bigits = rhs.num_bigits();
    if (max_lhs_bigits + 1 < num_rhs_bigits) return -1;
    if (max_lhs_bigits > num_rhs_bigits) return 1;
    auto get_bigit = [](const bigint& n, int i) -> bigit {
      return i >= n.exp_ && i < n.num_bigits() ? n[i - n.exp_] : 0;
    };
    double_bigit borrow = 0;
    int min_exp = minimum(minimum(lhs1.exp_, lhs2.exp_), rhs.exp_);
    for (int i = num_rhs_bigits - 1; i >= min_exp; --i) {
      double_bigit sum =
          static_cast<double_bigit>(get_bigit(lhs1, i)) + get_bigit(lhs2, i);
      bigit rhs_bigit = get_bigit(rhs, i);
      if (sum > rhs_bigit + borrow) return 1;
      borrow = rhs_bigit + borrow - sum;
      if (borrow > 1) return -1;
      borrow <<= bigit_bits;
    }
    return borrow != 0 ? -1 : 0;
  }

  // Assigns pow(10, exp) to this bigint.
  FMT_CONSTEXPR20 void assign_pow10(int exp) {
    FMT_ASSERT(exp >= 0, "");
    if (exp == 0) return *this = 1;
    // Find the top bit.
    int bitmask = 1;
    while (exp >= bitmask) bitmask <<= 1;
    bitmask >>= 1;
    // pow(10, exp) = pow(5, exp) * pow(2, exp). First compute pow(5, exp) by
    // repeated squaring and multiplication.
    *this = 5;
    bitmask >>= 1;
    while (bitmask != 0) {
      square();
      if ((exp & bitmask) != 0) *this *= 5;
      bitmask >>= 1;
    }
    *this <<= exp;  // Multiply by pow(2, exp) by shifting.
  }

  FMT_CONSTEXPR20 void square() {
    int num_bigits = static_cast<int>(bigits_.size());
    int num_result_bigits = 2 * num_bigits;
    basic_memory_buffer<bigit, bigits_capacity> n(std::move(bigits_));
    bigits_.resize(to_unsigned(num_result_bigits));
    auto sum = uint128_t();
    for (int bigit_index = 0; bigit_index < num_bigits; ++bigit_index) {
      // Compute bigit at position bigit_index of the result by adding
      // cross-product terms n[i] * n[j] such that i + j == bigit_index.
      for (int i = 0, j = bigit_index; j >= 0; ++i, --j) {
        // Most terms are multiplied twice which can be optimized in the future.
        sum += static_cast<double_bigit>(n[i]) * n[j];
      }
      (*this)[bigit_index] = static_cast<bigit>(sum);
      sum >>= num_bits<bigit>();  // Compute the carry.
    }
    // Do the same for the top half.
    for (int bigit_index = num_bigits; bigit_index < num_result_bigits;
         ++bigit_index) {
      for (int j = num_bigits - 1, i = bigit_index - j; i < num_bigits;)
        sum += static_cast<double_bigit>(n[i++]) * n[j--];
      (*this)[bigit_index] = static_cast<bigit>(sum);
      sum >>= num_bits<bigit>();
    }
    remove_leading_zeros();
    exp_ *= 2;
  }

  // If this bigint has a bigger exponent than other, adds trailing zero to make
  // exponents equal. This simplifies some operations such as subtraction.
  FMT_CONSTEXPR20 void align(const bigint& other) {
    int exp_difference = exp_ - other.exp_;
    if (exp_difference <= 0) return;
    int num_bigits = static_cast<int>(bigits_.size());
    bigits_.resize(to_unsigned(num_bigits + exp_difference));
    for (int i = num_bigits - 1, j = i + exp_difference; i >= 0; --i, --j)
      bigits_[j] = bigits_[i];
    std::uninitialized_fill_n(bigits_.data(), exp_difference, 0);
    exp_ -= exp_difference;
  }

  // Divides this bignum by divisor, assigning the remainder to this and
  // returning the quotient.
  FMT_CONSTEXPR20 int divmod_assign(const bigint& divisor) {
    FMT_ASSERT(this != &divisor, "");
    if (compare(*this, divisor) < 0) return 0;
    FMT_ASSERT(divisor.bigits_[divisor.bigits_.size() - 1u] != 0, "");
    align(divisor);
    int quotient = 0;
    do {
      subtract_aligned(divisor);
      ++quotient;
    } while (compare(*this, divisor) >= 0);
    return quotient;
  }
};

// format_dragon flags.
enum dragon {
  predecessor_closer = 1,
  fixup = 2,  // Run fixup to correct exp10 which can be off by one.
  fixed = 4,
};

// Formats a floating-point number using a variation of the Fixed-Precision
// Positive Floating-Point Printout ((FPP)^2) algorithm by Steele & White:
// https://fmt.dev/papers/p372-steele.pdf.
FMT_CONSTEXPR20 inline void format_dragon(basic_fp<uint128_t> value,
                                          unsigned flags, int num_digits,
                                          buffer<char>& buf, int& exp10) {
  bigint numerator;    // 2 * R in (FPP)^2.
  bigint denominator;  // 2 * S in (FPP)^2.
  // lower and upper are differences between value and corresponding boundaries.
  bigint lower;             // (M^- in (FPP)^2).
  bigint upper_store;       // upper's value if different from lower.
  bigint* upper = nullptr;  // (M^+ in (FPP)^2).
  // Shift numerator and denominator by an extra bit or two (if lower boundary
  // is closer) to make lower and upper integers. This eliminates multiplication
  // by 2 during later computations.
  bool is_predecessor_closer = (flags & dragon::predecessor_closer) != 0;
  int shift = is_predecessor_closer ? 2 : 1;
  if (value.e >= 0) {
    numerator = value.f;
    numerator <<= value.e + shift;
    lower = 1;
    lower <<= value.e;
    if (is_predecessor_closer) {
      upper_store = 1;
      upper_store <<= value.e + 1;
      upper = &upper_store;
    }
    denominator.assign_pow10(exp10);
    denominator <<= shift;
  } else if (exp10 < 0) {
    numerator.assign_pow10(-exp10);
    lower.assign(numerator);
    if (is_predecessor_closer) {
      upper_store.assign(numerator);
      upper_store <<= 1;
      upper = &upper_store;
    }
    numerator *= value.f;
    numerator <<= shift;
    denominator = 1;
    denominator <<= shift - value.e;
  } else {
    numerator = value.f;
    numerator <<= shift;
    denominator.assign_pow10(exp10);
    denominator <<= shift - value.e;
    lower = 1;
    if (is_predecessor_closer) {
      upper_store = 1ULL << 1;
      upper = &upper_store;
    }
  }
  int even = static_cast<int>((value.f & 1) == 0);
  if (!upper) upper = &lower;
  if ((flags & dragon::fixup) != 0) {
    if (add_compare(numerator, *upper, denominator) + even <= 0) {
      --exp10;
      numerator *= 10;
      if (num_digits < 0) {
        lower *= 10;
        if (upper != &lower) *upper *= 10;
      }
    }
    if ((flags & dragon::fixed) != 0) adjust_precision(num_digits, exp10 + 1);
  }
  // Invariant: value == (numerator / denominator) * pow(10, exp10).
  if (num_digits < 0) {
    // Generate the shortest representation.
    num_digits = 0;
    char* data = buf.data();
    for (;;) {
      int digit = numerator.divmod_assign(denominator);
      bool low = compare(numerator, lower) - even < 0;  // numerator <[=] lower.
      // numerator + upper >[=] pow10:
      bool high = add_compare(numerator, *upper, denominator) + even > 0;
      data[num_digits++] = static_cast<char>('0' + digit);
      if (low || high) {
        if (!low) {
          ++data[num_digits - 1];
        } else if (high) {
          int result = add_compare(numerator, numerator, denominator);
          // Round half to even.
          if (result > 0 || (result == 0 && (digit % 2) != 0))
            ++data[num_digits - 1];
        }
        buf.try_resize(to_unsigned(num_digits));
        exp10 -= num_digits - 1;
        return;
      }
      numerator *= 10;
      lower *= 10;
      if (upper != &lower) *upper *= 10;
    }
  }
  // Generate the given number of digits.
  exp10 -= num_digits - 1;
  if (num_digits == 0) {
    denominator *= 10;
    auto digit = add_compare(numerator, numerator, denominator) > 0 ? '1' : '0';
    buf.push_back(digit);
    return;
  }
  buf.try_resize(to_unsigned(num_digits));
  for (int i = 0; i < num_digits - 1; ++i) {
    int digit = numerator.divmod_assign(denominator);
    buf[i] = static_cast<char>('0' + digit);
    numerator *= 10;
  }
  int digit = numerator.divmod_assign(denominator);
  auto result = add_compare(numerator, numerator, denominator);
  if (result > 0 || (result == 0 && (digit % 2) != 0)) {
    if (digit == 9) {
      const auto overflow = '0' + 10;
      buf[num_digits - 1] = overflow;
      // Propagate the carry.
      for (int i = num_digits - 1; i > 0 && buf[i] == overflow; --i) {
        buf[i] = '0';
        ++buf[i - 1];
      }
      if (buf[0] == overflow) {
        buf[0] = '1';
        ++exp10;
      }
      return;
    }
    ++digit;
  }
  buf[num_digits - 1] = static_cast<char>('0' + digit);
}

template <typename Float>
FMT_CONSTEXPR20 auto format_float(Float value, int precision, float_specs specs,
                                  buffer<char>& buf) -> int {
  // float is passed as double to reduce the number of instantiations.
  static_assert(!std::is_same<Float, float>::value, "");
  FMT_ASSERT(value >= 0, "value is negative");
  auto converted_value = convert_float(value);

  const bool fixed = specs.format == float_format::fixed;
  if (value <= 0) {  // <= instead of == to silence a warning.
    if (precision <= 0 || !fixed) {
      buf.push_back('0');
      return 0;
    }
    buf.try_resize(to_unsigned(precision));
    fill_n(buf.data(), precision, '0');
    return -precision;
  }

  int exp = 0;
  bool use_dragon = true;
  unsigned dragon_flags = 0;
  if (!is_fast_float<Float>()) {
    const auto inv_log2_10 = 0.3010299956639812;  // 1 / log2(10)
    using info = dragonbox::float_info<decltype(converted_value)>;
    const auto f = basic_fp<typename info::carrier_uint>(converted_value);
    // Compute exp, an approximate power of 10, such that
    //   10^(exp - 1) <= value < 10^exp or 10^exp <= value < 10^(exp + 1).
    // This is based on log10(value) == log2(value) / log2(10) and approximation
    // of log2(value) by e + num_fraction_bits idea from double-conversion.
    exp = static_cast<int>(
        std::ceil((f.e + count_digits<1>(f.f) - 1) * inv_log2_10 - 1e-10));
    dragon_flags = dragon::fixup;
  } else if (!is_constant_evaluated() && precision < 0) {
    // Use Dragonbox for the shortest format.
    if (specs.binary32) {
      auto dec = dragonbox::to_decimal(static_cast<float>(value));
      write<char>(buffer_appender<char>(buf), dec.significand);
      return dec.exponent;
    }
    auto dec = dragonbox::to_decimal(static_cast<double>(value));
    write<char>(buffer_appender<char>(buf), dec.significand);
    return dec.exponent;
  } else {
    // Use Grisu + Dragon4 for the given precision:
    // https://www.cs.tufts.edu/~nr/cs257/archive/florian-loitsch/printf.pdf.
    const int min_exp = -60;  // alpha in Grisu.
    int cached_exp10 = 0;     // K in Grisu.
    fp normalized = normalize(fp(converted_value));
    const auto cached_pow = get_cached_power(
        min_exp - (normalized.e + fp::num_significand_bits), cached_exp10);
    normalized = normalized * cached_pow;
    gen_digits_handler handler{buf.data(), 0, precision, -cached_exp10, fixed};
    if (grisu_gen_digits(normalized, 1, exp, handler) != digits::error &&
        !is_constant_evaluated()) {
      exp += handler.exp10;
      buf.try_resize(to_unsigned(handler.size));
      use_dragon = false;
    } else {
      exp += handler.size - cached_exp10 - 1;
      precision = handler.precision;
    }
  }
  if (use_dragon) {
    auto f = basic_fp<uint128_t>();
    bool is_predecessor_closer = specs.binary32
                                     ? f.assign(static_cast<float>(value))
                                     : f.assign(converted_value);
    if (is_predecessor_closer) dragon_flags |= dragon::predecessor_closer;
    if (fixed) dragon_flags |= dragon::fixed;
    // Limit precision to the maximum possible number of significant digits in
    // an IEEE754 double because we don't need to generate zeros.
    const int max_double_digits = 767;
    if (precision > max_double_digits) precision = max_double_digits;
    format_dragon(f, dragon_flags, precision, buf, exp);
  }
  if (!fixed && !specs.showpoint) {
    // Remove trailing zeros.
    auto num_digits = buf.size();
    while (num_digits > 0 && buf[num_digits - 1] == '0') {
      --num_digits;
      ++exp;
    }
    buf.try_resize(num_digits);
  }
  return exp;
}

template <typename Char, typename OutputIt, typename T,
          FMT_ENABLE_IF(is_floating_point<T>::value)>
FMT_CONSTEXPR20 auto write(OutputIt out, T value,
                           basic_format_specs<Char> specs, locale_ref loc = {})
    -> OutputIt {
  if (const_check(!is_supported_floating_point(value))) return out;
  float_specs fspecs = parse_float_type_spec(specs);
  fspecs.sign = specs.sign;
  if (detail::signbit(value)) {  // value < 0 is false for NaN so use signbit.
    fspecs.sign = sign::minus;
    value = -value;
  } else if (fspecs.sign == sign::minus) {
    fspecs.sign = sign::none;
  }

  if (!detail::isfinite(value))
    return write_nonfinite(out, detail::isnan(value), specs, fspecs);

  if (specs.align == align::numeric && fspecs.sign) {
    auto it = reserve(out, 1);
    *it++ = detail::sign<Char>(fspecs.sign);
    out = base_iterator(out, it);
    fspecs.sign = sign::none;
    if (specs.width != 0) --specs.width;
  }

  memory_buffer buffer;
  if (fspecs.format == float_format::hex) {
    if (fspecs.sign) buffer.push_back(detail::sign<char>(fspecs.sign));
    snprintf_float(convert_float(value), specs.precision, fspecs, buffer);
    return write_bytes<align::right>(out, {buffer.data(), buffer.size()},
                                     specs);
  }
  int precision = specs.precision >= 0 || specs.type == presentation_type::none
                      ? specs.precision
                      : 6;
  if (fspecs.format == float_format::exp) {
    if (precision == max_value<int>())
      throw_format_error("number is too big");
    else
      ++precision;
  } else if (fspecs.format != float_format::fixed && precision == 0) {
    precision = 1;
  }
  if (const_check(std::is_same<T, float>())) fspecs.binary32 = true;
  int exp = format_float(convert_float(value), precision, fspecs, buffer);
  fspecs.precision = precision;
  auto f = big_decimal_fp{buffer.data(), static_cast<int>(buffer.size()), exp};
  return write_float(out, f, specs, fspecs, loc);
}

template <typename Char, typename OutputIt, typename T,
          FMT_ENABLE_IF(is_fast_float<T>::value)>
FMT_CONSTEXPR20 auto write(OutputIt out, T value) -> OutputIt {
  if (is_constant_evaluated())
    return write(out, value, basic_format_specs<Char>());
  if (const_check(!is_supported_floating_point(value))) return out;

  auto fspecs = float_specs();
  if (detail::signbit(value)) {
    fspecs.sign = sign::minus;
    value = -value;
  }

  constexpr auto specs = basic_format_specs<Char>();
  using floaty = conditional_t<std::is_same<T, long double>::value, double, T>;
  using uint = typename dragonbox::float_info<floaty>::carrier_uint;
  uint mask = exponent_mask<floaty>();
  if ((bit_cast<uint>(value) & mask) == mask)
    return write_nonfinite(out, std::isnan(value), specs, fspecs);

  auto dec = dragonbox::to_decimal(static_cast<floaty>(value));
  return write_float(out, dec, specs, fspecs, {});
}

template <typename Char, typename OutputIt, typename T,
          FMT_ENABLE_IF(is_floating_point<T>::value &&
                        !is_fast_float<T>::value)>
inline auto write(OutputIt out, T value) -> OutputIt {
  return write(out, value, basic_format_specs<Char>());
}

template <typename Char, typename OutputIt>
auto write(OutputIt out, monostate, basic_format_specs<Char> = {},
           locale_ref = {}) -> OutputIt {
  FMT_ASSERT(false, "");
  return out;
}

template <typename Char, typename OutputIt>
FMT_CONSTEXPR auto write(OutputIt out, basic_string_view<Char> value)
    -> OutputIt {
  auto it = reserve(out, value.size());
  it = copy_str_noinline<Char>(value.begin(), value.end(), it);
  return base_iterator(out, it);
}

template <typename Char, typename OutputIt, typename T,
          FMT_ENABLE_IF(is_string<T>::value)>
constexpr auto write(OutputIt out, const T& value) -> OutputIt {
  return write<Char>(out, to_string_view(value));
}

// FMT_ENABLE_IF() condition separated to workaround an MSVC bug.
template <
    typename Char, typename OutputIt, typename T,
    bool check =
        std::is_enum<T>::value && !std::is_same<T, Char>::value &&
        mapped_type_constant<T, basic_format_context<OutputIt, Char>>::value !=
            type::custom_type,
    FMT_ENABLE_IF(check)>
FMT_CONSTEXPR auto write(OutputIt out, T value) -> OutputIt {
  return write<Char>(out, static_cast<underlying_t<T>>(value));
}

template <typename Char, typename OutputIt, typename T,
          FMT_ENABLE_IF(std::is_same<T, bool>::value)>
FMT_CONSTEXPR auto write(OutputIt out, T value,
                         const basic_format_specs<Char>& specs = {},
                         locale_ref = {}) -> OutputIt {
  return specs.type != presentation_type::none &&
                 specs.type != presentation_type::string
             ? write(out, value ? 1 : 0, specs, {})
             : write_bytes(out, value ? "true" : "false", specs);
}

template <typename Char, typename OutputIt>
FMT_CONSTEXPR auto write(OutputIt out, Char value) -> OutputIt {
  auto it = reserve(out, 1);
  *it++ = value;
  return base_iterator(out, it);
}

template <typename Char, typename OutputIt>
FMT_CONSTEXPR_CHAR_TRAITS auto write(OutputIt out, const Char* value)
    -> OutputIt {
  if (!value) {
    throw_format_error("string pointer is null");
  } else {
    out = write(out, basic_string_view<Char>(value));
  }
  return out;
}

template <typename Char, typename OutputIt, typename T,
          FMT_ENABLE_IF(std::is_same<T, void>::value)>
auto write(OutputIt out, const T* value,
           const basic_format_specs<Char>& specs = {}, locale_ref = {})
    -> OutputIt {
  check_pointer_type_spec(specs.type, error_handler());
  return write_ptr<Char>(out, bit_cast<uintptr_t>(value), &specs);
}

// A write overload that handles implicit conversions.
template <typename Char, typename OutputIt, typename T,
          typename Context = basic_format_context<OutputIt, Char>>
FMT_CONSTEXPR auto write(OutputIt out, const T& value) -> enable_if_t<
    std::is_class<T>::value && !is_string<T>::value &&
        !is_floating_point<T>::value && !std::is_same<T, Char>::value &&
        !std::is_same<const T&,
                      decltype(arg_mapper<Context>().map(value))>::value,
    OutputIt> {
  return write<Char>(out, arg_mapper<Context>().map(value));
}

template <typename Char, typename OutputIt, typename T,
          typename Context = basic_format_context<OutputIt, Char>>
FMT_CONSTEXPR auto write(OutputIt out, const T& value)
    -> enable_if_t<mapped_type_constant<T, Context>::value == type::custom_type,
                   OutputIt> {
  using formatter_type =
      conditional_t<has_formatter<T, Context>::value,
                    typename Context::template formatter_type<T>,
                    fallback_formatter<T, Char>>;
  auto ctx = Context(out, {}, {});
  return formatter_type().format(value, ctx);
}

// An argument visitor that formats the argument and writes it via the output
// iterator. It's a class and not a generic lambda for compatibility with C++11.
template <typename Char> struct default_arg_formatter {
  using iterator = buffer_appender<Char>;
  using context = buffer_context<Char>;

  iterator out;
  basic_format_args<context> args;
  locale_ref loc;

  template <typename T> auto operator()(T value) -> iterator {
    return write<Char>(out, value);
  }
  auto operator()(typename basic_format_arg<context>::handle h) -> iterator {
    basic_format_parse_context<Char> parse_ctx({});
    context format_ctx(out, args, loc);
    h.format(parse_ctx, format_ctx);
    return format_ctx.out();
  }
};

template <typename Char> struct arg_formatter {
  using iterator = buffer_appender<Char>;
  using context = buffer_context<Char>;

  iterator out;
  const basic_format_specs<Char>& specs;
  locale_ref locale;

  template <typename T>
  FMT_CONSTEXPR FMT_INLINE auto operator()(T value) -> iterator {
    return detail::write(out, value, specs, locale);
  }
  auto operator()(typename basic_format_arg<context>::handle) -> iterator {
    // User-defined types are handled separately because they require access
    // to the parse context.
    return out;
  }
};

template <typename Char> struct custom_formatter {
  basic_format_parse_context<Char>& parse_ctx;
  buffer_context<Char>& ctx;

  void operator()(
      typename basic_format_arg<buffer_context<Char>>::handle h) const {
    h.format(parse_ctx, ctx);
  }
  template <typename T> void operator()(T) const {}
};

template <typename T>
using is_integer =
    bool_constant<is_integral<T>::value && !std::is_same<T, bool>::value &&
                  !std::is_same<T, char>::value &&
                  !std::is_same<T, wchar_t>::value>;

template <typename ErrorHandler> class width_checker {
 public:
  explicit FMT_CONSTEXPR width_checker(ErrorHandler& eh) : handler_(eh) {}

  template <typename T, FMT_ENABLE_IF(is_integer<T>::value)>
  FMT_CONSTEXPR auto operator()(T value) -> unsigned long long {
    if (is_negative(value)) handler_.on_error("negative width");
    return static_cast<unsigned long long>(value);
  }

  template <typename T, FMT_ENABLE_IF(!is_integer<T>::value)>
  FMT_CONSTEXPR auto operator()(T) -> unsigned long long {
    handler_.on_error("width is not integer");
    return 0;
  }

 private:
  ErrorHandler& handler_;
};

template <typename ErrorHandler> class precision_checker {
 public:
  explicit FMT_CONSTEXPR precision_checker(ErrorHandler& eh) : handler_(eh) {}

  template <typename T, FMT_ENABLE_IF(is_integer<T>::value)>
  FMT_CONSTEXPR auto operator()(T value) -> unsigned long long {
    if (is_negative(value)) handler_.on_error("negative precision");
    return static_cast<unsigned long long>(value);
  }

  template <typename T, FMT_ENABLE_IF(!is_integer<T>::value)>
  FMT_CONSTEXPR auto operator()(T) -> unsigned long long {
    handler_.on_error("precision is not integer");
    return 0;
  }

 private:
  ErrorHandler& handler_;
};

template <template <typename> class Handler, typename FormatArg,
          typename ErrorHandler>
FMT_CONSTEXPR auto get_dynamic_spec(FormatArg arg, ErrorHandler eh) -> int {
  unsigned long long value = visit_format_arg(Handler<ErrorHandler>(eh), arg);
  if (value > to_unsigned(max_value<int>())) eh.on_error("number is too big");
  return static_cast<int>(value);
}

template <typename Context, typename ID>
FMT_CONSTEXPR auto get_arg(Context& ctx, ID id) ->
    typename Context::format_arg {
  auto arg = ctx.arg(id);
  if (!arg) ctx.on_error("argument not found");
  return arg;
}

// The standard format specifier handler with checking.
template <typename Char> class specs_handler : public specs_setter<Char> {
 private:
  basic_format_parse_context<Char>& parse_context_;
  buffer_context<Char>& context_;

  // This is only needed for compatibility with gcc 4.4.
  using format_arg = basic_format_arg<buffer_context<Char>>;

  FMT_CONSTEXPR auto get_arg(auto_id) -> format_arg {
    return detail::get_arg(context_, parse_context_.next_arg_id());
  }

  FMT_CONSTEXPR auto get_arg(int arg_id) -> format_arg {
    parse_context_.check_arg_id(arg_id);
    return detail::get_arg(context_, arg_id);
  }

  FMT_CONSTEXPR auto get_arg(basic_string_view<Char> arg_id) -> format_arg {
    parse_context_.check_arg_id(arg_id);
    return detail::get_arg(context_, arg_id);
  }

 public:
  FMT_CONSTEXPR specs_handler(basic_format_specs<Char>& specs,
                              basic_format_parse_context<Char>& parse_ctx,
                              buffer_context<Char>& ctx)
      : specs_setter<Char>(specs), parse_context_(parse_ctx), context_(ctx) {}

  template <typename Id> FMT_CONSTEXPR void on_dynamic_width(Id arg_id) {
    this->specs_.width = get_dynamic_spec<width_checker>(
        get_arg(arg_id), context_.error_handler());
  }

  template <typename Id> FMT_CONSTEXPR void on_dynamic_precision(Id arg_id) {
    this->specs_.precision = get_dynamic_spec<precision_checker>(
        get_arg(arg_id), context_.error_handler());
  }

  void on_error(const char* message) { context_.on_error(message); }
};

template <template <typename> class Handler, typename Context>
FMT_CONSTEXPR void handle_dynamic_spec(int& value,
                                       arg_ref<typename Context::char_type> ref,
                                       Context& ctx) {
  switch (ref.kind) {
  case arg_id_kind::none:
    break;
  case arg_id_kind::index:
    value = detail::get_dynamic_spec<Handler>(ctx.arg(ref.val.index),
                                              ctx.error_handler());
    break;
  case arg_id_kind::name:
    value = detail::get_dynamic_spec<Handler>(ctx.arg(ref.val.name),
                                              ctx.error_handler());
    break;
  }
}

#if FMT_USE_USER_DEFINED_LITERALS
template <typename Char> struct udl_formatter {
  basic_string_view<Char> str;

  template <typename... T>
  auto operator()(T&&... args) const -> std::basic_string<Char> {
    return vformat(str, fmt::make_format_args<buffer_context<Char>>(args...));
  }
};

#  if FMT_USE_NONTYPE_TEMPLATE_ARGS
template <typename T, typename Char, size_t N,
          fmt::detail_exported::fixed_string<Char, N> Str>
struct statically_named_arg : view {
  static constexpr auto name = Str.data;

  const T& value;
  statically_named_arg(const T& v) : value(v) {}
};

template <typename T, typename Char, size_t N,
          fmt::detail_exported::fixed_string<Char, N> Str>
struct is_named_arg<statically_named_arg<T, Char, N, Str>> : std::true_type {};

template <typename T, typename Char, size_t N,
          fmt::detail_exported::fixed_string<Char, N> Str>
struct is_statically_named_arg<statically_named_arg<T, Char, N, Str>>
    : std::true_type {};

template <typename Char, size_t N,
          fmt::detail_exported::fixed_string<Char, N> Str>
struct udl_arg {
  template <typename T> auto operator=(T&& value) const {
    return statically_named_arg<T, Char, N, Str>(std::forward<T>(value));
  }
};
#  else
template <typename Char> struct udl_arg {
  const Char* str;

  template <typename T> auto operator=(T&& value) const -> named_arg<Char, T> {
    return {str, std::forward<T>(value)};
  }
};
#  endif
#endif  // FMT_USE_USER_DEFINED_LITERALS

template <typename Locale, typename Char>
auto vformat(const Locale& loc, basic_string_view<Char> format_str,
             basic_format_args<buffer_context<type_identity_t<Char>>> args)
    -> std::basic_string<Char> {
  basic_memory_buffer<Char> buffer;
  detail::vformat_to(buffer, format_str, args, detail::locale_ref(loc));
  return {buffer.data(), buffer.size()};
}

using format_func = void (*)(detail::buffer<char>&, int, const char*);

FMT_API void format_error_code(buffer<char>& out, int error_code,
                               string_view message) noexcept;

FMT_API void report_error(format_func func, int error_code,
                          const char* message) noexcept;
FMT_END_DETAIL_NAMESPACE

FMT_API auto vsystem_error(int error_code, string_view format_str,
                           format_args args) -> std::system_error;

/**
 \rst
 Constructs :class:`std::system_error` with a message formatted with
 ``fmt::format(fmt, args...)``.
  *error_code* is a system error code as given by ``errno``.

 **Example**::

   // This throws std::system_error with the description
   //   cannot open file 'madeup': No such file or directory
   // or similar (system message may vary).
   const char* filename = "madeup";
   std::FILE* file = std::fopen(filename, "r");
   if (!file)
     throw fmt::system_error(errno, "cannot open file '{}'", filename);
 \endrst
*/
template <typename... T>
auto system_error(int error_code, format_string<T...> fmt, T&&... args)
    -> std::system_error {
  return vsystem_error(error_code, fmt, fmt::make_format_args(args...));
}

/**
  \rst
  Formats an error message for an error returned by an operating system or a
  language runtime, for example a file opening error, and writes it to *out*.
  The format is the same as the one used by ``std::system_error(ec, message)``
  where ``ec`` is ``std::error_code(error_code, std::generic_category()})``.
  It is implementation-defined but normally looks like:

  .. parsed-literal::
     *<message>*: *<system-message>*

  where *<message>* is the passed message and *<system-message>* is the system
  message corresponding to the error code.
  *error_code* is a system error code as given by ``errno``.
  \endrst
 */
FMT_API void format_system_error(detail::buffer<char>& out, int error_code,
                                 const char* message) noexcept;

// Reports a system error without throwing an exception.
// Can be used to report errors from destructors.
FMT_API void report_system_error(int error_code, const char* message) noexcept;

/** Fast integer formatter. */
class format_int {
 private:
  // Buffer should be large enough to hold all digits (digits10 + 1),
  // a sign and a null character.
  enum { buffer_size = std::numeric_limits<unsigned long long>::digits10 + 3 };
  mutable char buffer_[buffer_size];
  char* str_;

  template <typename UInt> auto format_unsigned(UInt value) -> char* {
    auto n = static_cast<detail::uint32_or_64_or_128_t<UInt>>(value);
    return detail::format_decimal(buffer_, n, buffer_size - 1).begin;
  }

  template <typename Int> auto format_signed(Int value) -> char* {
    auto abs_value = static_cast<detail::uint32_or_64_or_128_t<Int>>(value);
    bool negative = value < 0;
    if (negative) abs_value = 0 - abs_value;
    auto begin = format_unsigned(abs_value);
    if (negative) *--begin = '-';
    return begin;
  }

 public:
  explicit format_int(int value) : str_(format_signed(value)) {}
  explicit format_int(long value) : str_(format_signed(value)) {}
  explicit format_int(long long value) : str_(format_signed(value)) {}
  explicit format_int(unsigned value) : str_(format_unsigned(value)) {}
  explicit format_int(unsigned long value) : str_(format_unsigned(value)) {}
  explicit format_int(unsigned long long value)
      : str_(format_unsigned(value)) {}

  /** Returns the number of characters written to the output buffer. */
  auto size() const -> size_t {
    return detail::to_unsigned(buffer_ - str_ + buffer_size - 1);
  }

  /**
    Returns a pointer to the output buffer content. No terminating null
    character is appended.
   */
  auto data() const -> const char* { return str_; }

  /**
    Returns a pointer to the output buffer content with terminating null
    character appended.
   */
  auto c_str() const -> const char* {
    buffer_[buffer_size - 1] = '\0';
    return str_;
  }

  /**
    \rst
    Returns the content of the output buffer as an ``std::string``.
    \endrst
   */
  auto str() const -> std::string { return std::string(str_, size()); }
};

template <typename T, typename Char>
template <typename FormatContext>
FMT_CONSTEXPR FMT_INLINE auto
formatter<T, Char,
          enable_if_t<detail::type_constant<T, Char>::value !=
                      detail::type::custom_type>>::format(const T& val,
                                                          FormatContext& ctx)
    const -> decltype(ctx.out()) {
  if (specs_.width_ref.kind != detail::arg_id_kind::none ||
      specs_.precision_ref.kind != detail::arg_id_kind::none) {
    auto specs = specs_;
    detail::handle_dynamic_spec<detail::width_checker>(specs.width,
                                                       specs.width_ref, ctx);
    detail::handle_dynamic_spec<detail::precision_checker>(
        specs.precision, specs.precision_ref, ctx);
    return detail::write<Char>(ctx.out(), val, specs, ctx.locale());
  }
  return detail::write<Char>(ctx.out(), val, specs_, ctx.locale());
}

template <typename Char>
struct formatter<void*, Char> : formatter<const void*, Char> {
  template <typename FormatContext>
  auto format(void* val, FormatContext& ctx) const -> decltype(ctx.out()) {
    return formatter<const void*, Char>::format(val, ctx);
  }
};

template <typename Char, size_t N>
struct formatter<Char[N], Char> : formatter<basic_string_view<Char>, Char> {
  template <typename FormatContext>
  FMT_CONSTEXPR auto format(const Char* val, FormatContext& ctx) const
      -> decltype(ctx.out()) {
    return formatter<basic_string_view<Char>, Char>::format(val, ctx);
  }
};

// A formatter for types known only at run time such as variant alternatives.
//
// Usage:
//   using variant = std::variant<int, std::string>;
//   template <>
//   struct formatter<variant>: dynamic_formatter<> {
//     auto format(const variant& v, format_context& ctx) {
//       return visit([&](const auto& val) {
//           return dynamic_formatter<>::format(val, ctx);
//       }, v);
//     }
//   };
template <typename Char = char> class dynamic_formatter {
 private:
  detail::dynamic_format_specs<Char> specs_;
  const Char* format_str_;

  struct null_handler : detail::error_handler {
    void on_align(align_t) {}
    void on_sign(sign_t) {}
    void on_hash() {}
  };

  template <typename Context> void handle_specs(Context& ctx) {
    detail::handle_dynamic_spec<detail::width_checker>(specs_.width,
                                                       specs_.width_ref, ctx);
    detail::handle_dynamic_spec<detail::precision_checker>(
        specs_.precision, specs_.precision_ref, ctx);
  }

 public:
  template <typename ParseContext>
  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
    format_str_ = ctx.begin();
    // Checks are deferred to formatting time when the argument type is known.
    detail::dynamic_specs_handler<ParseContext> handler(specs_, ctx);
    return detail::parse_format_specs(ctx.begin(), ctx.end(), handler);
  }

  template <typename T, typename FormatContext>
  auto format(const T& val, FormatContext& ctx) -> decltype(ctx.out()) {
    handle_specs(ctx);
    detail::specs_checker<null_handler> checker(
        null_handler(), detail::mapped_type_constant<T, FormatContext>::value);
    checker.on_align(specs_.align);
    if (specs_.sign != sign::none) checker.on_sign(specs_.sign);
    if (specs_.alt) checker.on_hash();
    if (specs_.precision >= 0) checker.end_precision();
    return detail::write<Char>(ctx.out(), val, specs_, ctx.locale());
  }
};

/**
  \rst
  Converts ``p`` to ``const void*`` for pointer formatting.

  **Example**::

    auto s = fmt::format("{}", fmt::ptr(p));
  \endrst
 */
template <typename T> auto ptr(T p) -> const void* {
  static_assert(std::is_pointer<T>::value, "");
  return detail::bit_cast<const void*>(p);
}
template <typename T> auto ptr(const std::unique_ptr<T>& p) -> const void* {
  return p.get();
}
template <typename T> auto ptr(const std::shared_ptr<T>& p) -> const void* {
  return p.get();
}

/**
  \rst
  Converts ``e`` to the underlying type.

  **Example**::

    enum class color { red, green, blue };
    auto s = fmt::format("{}", fmt::underlying(color::red));
  \endrst
 */
template <typename Enum>
constexpr auto underlying(Enum e) noexcept -> underlying_t<Enum> {
  return static_cast<underlying_t<Enum>>(e);
}

namespace enums {
template <typename Enum, FMT_ENABLE_IF(std::is_enum<Enum>::value)>
constexpr auto format_as(Enum e) noexcept -> underlying_t<Enum> {
  return static_cast<underlying_t<Enum>>(e);
}
}  // namespace enums

class bytes {
 private:
  string_view data_;
  friend struct formatter<bytes>;

 public:
  explicit bytes(string_view data) : data_(data) {}
};

template <> struct formatter<bytes> {
 private:
  detail::dynamic_format_specs<char> specs_;

 public:
  template <typename ParseContext>
  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
    using handler_type = detail::dynamic_specs_handler<ParseContext>;
    detail::specs_checker<handler_type> handler(handler_type(specs_, ctx),
                                                detail::type::string_type);
    auto it = parse_format_specs(ctx.begin(), ctx.end(), handler);
    detail::check_string_type_spec(specs_.type, ctx.error_handler());
    return it;
  }

  template <typename FormatContext>
  auto format(bytes b, FormatContext& ctx) -> decltype(ctx.out()) {
    detail::handle_dynamic_spec<detail::width_checker>(specs_.width,
                                                       specs_.width_ref, ctx);
    detail::handle_dynamic_spec<detail::precision_checker>(
        specs_.precision, specs_.precision_ref, ctx);
    return detail::write_bytes(ctx.out(), b.data_, specs_);
  }
};

// group_digits_view is not derived from view because it copies the argument.
template <typename T> struct group_digits_view { T value; };

/**
  \rst
  Returns a view that formats an integer value using ',' as a locale-independent
  thousands separator.

  **Example**::

    fmt::print("{}", fmt::group_digits(12345));
    // Output: "12,345"
  \endrst
 */
template <typename T> auto group_digits(T value) -> group_digits_view<T> {
  return {value};
}

template <typename T> struct formatter<group_digits_view<T>> : formatter<T> {
 private:
  detail::dynamic_format_specs<char> specs_;

 public:
  template <typename ParseContext>
  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
    using handler_type = detail::dynamic_specs_handler<ParseContext>;
    detail::specs_checker<handler_type> handler(handler_type(specs_, ctx),
                                                detail::type::int_type);
    auto it = parse_format_specs(ctx.begin(), ctx.end(), handler);
    detail::check_string_type_spec(specs_.type, ctx.error_handler());
    return it;
  }

  template <typename FormatContext>
  auto format(group_digits_view<T> t, FormatContext& ctx)
      -> decltype(ctx.out()) {
    detail::handle_dynamic_spec<detail::width_checker>(specs_.width,
                                                       specs_.width_ref, ctx);
    detail::handle_dynamic_spec<detail::precision_checker>(
        specs_.precision, specs_.precision_ref, ctx);
    return detail::write_int_localized(
        ctx.out(), static_cast<detail::uint64_or_128_t<T>>(t.value), 0, specs_,
        detail::digit_grouping<char>({"\3", ','}));
  }
};

template <typename It, typename Sentinel, typename Char = char>
struct join_view : detail::view {
  It begin;
  Sentinel end;
  basic_string_view<Char> sep;

  join_view(It b, Sentinel e, basic_string_view<Char> s)
      : begin(b), end(e), sep(s) {}
};

template <typename It, typename Sentinel, typename Char>
struct formatter<join_view<It, Sentinel, Char>, Char> {
 private:
  using value_type =
#ifdef __cpp_lib_ranges
      std::iter_value_t<It>;
#else
      typename std::iterator_traits<It>::value_type;
#endif
  using context = buffer_context<Char>;
  using mapper = detail::arg_mapper<context>;

  template <typename T, FMT_ENABLE_IF(has_formatter<T, context>::value)>
  static auto map(const T& value) -> const T& {
    return value;
  }
  template <typename T, FMT_ENABLE_IF(!has_formatter<T, context>::value)>
  static auto map(const T& value) -> decltype(mapper().map(value)) {
    return mapper().map(value);
  }

  using formatter_type =
      conditional_t<is_formattable<value_type, Char>::value,
                    formatter<remove_cvref_t<decltype(map(
                                  std::declval<const value_type&>()))>,
                              Char>,
                    detail::fallback_formatter<value_type, Char>>;

  formatter_type value_formatter_;

 public:
  template <typename ParseContext>
  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
    return value_formatter_.parse(ctx);
  }

  template <typename FormatContext>
  auto format(const join_view<It, Sentinel, Char>& value,
              FormatContext& ctx) const -> decltype(ctx.out()) {
    auto it = value.begin;
    auto out = ctx.out();
    if (it != value.end) {
      out = value_formatter_.format(map(*it), ctx);
      ++it;
      while (it != value.end) {
        out = detail::copy_str<Char>(value.sep.begin(), value.sep.end(), out);
        ctx.advance_to(out);
        out = value_formatter_.format(map(*it), ctx);
        ++it;
      }
    }
    return out;
  }
};

/**
  Returns a view that formats the iterator range `[begin, end)` with elements
  separated by `sep`.
 */
template <typename It, typename Sentinel>
auto join(It begin, Sentinel end, string_view sep) -> join_view<It, Sentinel> {
  return {begin, end, sep};
}

/**
  \rst
  Returns a view that formats `range` with elements separated by `sep`.

  **Example**::

    std::vector<int> v = {1, 2, 3};
    fmt::print("{}", fmt::join(v, ", "));
    // Output: "1, 2, 3"

  ``fmt::join`` applies passed format specifiers to the range elements::

    fmt::print("{:02}", fmt::join(v, ", "));
    // Output: "01, 02, 03"
  \endrst
 */
template <typename Range>
auto join(Range&& range, string_view sep)
    -> join_view<detail::iterator_t<Range>, detail::sentinel_t<Range>> {
  return join(std::begin(range), std::end(range), sep);
}

/**
  \rst
  Converts *value* to ``std::string`` using the default format for type *T*.

  **Example**::

    #include <fmt/format.h>

    std::string answer = fmt::to_string(42);
  \endrst
 */
template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
inline auto to_string(const T& value) -> std::string {
  auto result = std::string();
  detail::write<char>(std::back_inserter(result), value);
  return result;
}

template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
FMT_NODISCARD inline auto to_string(T value) -> std::string {
  // The buffer should be large enough to store the number including the sign
  // or "false" for bool.
  constexpr int max_size = detail::digits10<T>() + 2;
  char buffer[max_size > 5 ? static_cast<unsigned>(max_size) : 5];
  char* begin = buffer;
  return std::string(begin, detail::write<char>(begin, value));
}

template <typename Char, size_t SIZE>
FMT_NODISCARD auto to_string(const basic_memory_buffer<Char, SIZE>& buf)
    -> std::basic_string<Char> {
  auto size = buf.size();
  detail::assume(size < std::basic_string<Char>().max_size());
  return std::basic_string<Char>(buf.data(), size);
}

FMT_BEGIN_DETAIL_NAMESPACE

template <typename Char>
void vformat_to(
    buffer<Char>& buf, basic_string_view<Char> fmt,
    basic_format_args<FMT_BUFFER_CONTEXT(type_identity_t<Char>)> args,
    locale_ref loc) {
  // workaround for msvc bug regarding name-lookup in module
  // link names into function scope
  using detail::arg_formatter;
  using detail::buffer_appender;
  using detail::custom_formatter;
  using detail::default_arg_formatter;
  using detail::get_arg;
  using detail::locale_ref;
  using detail::parse_format_specs;
  using detail::specs_checker;
  using detail::specs_handler;
  using detail::to_unsigned;
  using detail::type;
  using detail::write;
  auto out = buffer_appender<Char>(buf);
  if (fmt.size() == 2 && equal2(fmt.data(), "{}")) {
    auto arg = args.get(0);
    if (!arg) error_handler().on_error("argument not found");
    visit_format_arg(default_arg_formatter<Char>{out, args, loc}, arg);
    return;
  }

  struct format_handler : error_handler {
    basic_format_parse_context<Char> parse_context;
    buffer_context<Char> context;

    format_handler(buffer_appender<Char> p_out, basic_string_view<Char> str,
                   basic_format_args<buffer_context<Char>> p_args,
                   locale_ref p_loc)
        : parse_context(str), context(p_out, p_args, p_loc) {}

    void on_text(const Char* begin, const Char* end) {
      auto text = basic_string_view<Char>(begin, to_unsigned(end - begin));
      context.advance_to(write<Char>(context.out(), text));
    }

    FMT_CONSTEXPR auto on_arg_id() -> int {
      return parse_context.next_arg_id();
    }
    FMT_CONSTEXPR auto on_arg_id(int id) -> int {
      return parse_context.check_arg_id(id), id;
    }
    FMT_CONSTEXPR auto on_arg_id(basic_string_view<Char> id) -> int {
      int arg_id = context.arg_id(id);
      if (arg_id < 0) on_error("argument not found");
      return arg_id;
    }

    FMT_INLINE void on_replacement_field(int id, const Char*) {
      auto arg = get_arg(context, id);
      context.advance_to(visit_format_arg(
          default_arg_formatter<Char>{context.out(), context.args(),
                                      context.locale()},
          arg));
    }

    auto on_format_specs(int id, const Char* begin, const Char* end)
        -> const Char* {
      auto arg = get_arg(context, id);
      if (arg.type() == type::custom_type) {
        parse_context.advance_to(parse_context.begin() +
                                 (begin - &*parse_context.begin()));
        visit_format_arg(custom_formatter<Char>{parse_context, context}, arg);
        return parse_context.begin();
      }
      auto specs = basic_format_specs<Char>();
      specs_checker<specs_handler<Char>> handler(
          specs_handler<Char>(specs, parse_context, context), arg.type());
      begin = parse_format_specs(begin, end, handler);
      if (begin == end || *begin != '}')
        on_error("missing '}' in format string");
      auto f = arg_formatter<Char>{context.out(), specs, context.locale()};
      context.advance_to(visit_format_arg(f, arg));
      return begin;
    }
  };
  detail::parse_format_string<false>(fmt, format_handler(out, fmt, args, loc));
}

#ifndef FMT_HEADER_ONLY
extern template FMT_API auto thousands_sep_impl<char>(locale_ref)
    -> thousands_sep_result<char>;
extern template FMT_API auto thousands_sep_impl<wchar_t>(locale_ref)
    -> thousands_sep_result<wchar_t>;
extern template FMT_API auto decimal_point_impl(locale_ref) -> char;
extern template FMT_API auto decimal_point_impl(locale_ref) -> wchar_t;
#endif  // FMT_HEADER_ONLY

FMT_END_DETAIL_NAMESPACE

#if FMT_USE_USER_DEFINED_LITERALS
inline namespace literals {
/**
  \rst
  User-defined literal equivalent of :func:`fmt::arg`.

  **Example**::

    using namespace fmt::literals;
    fmt::print("Elapsed time: {s:.2f} seconds", "s"_a=1.23);
  \endrst
 */
#  if FMT_USE_NONTYPE_TEMPLATE_ARGS
template <detail_exported::fixed_string Str> constexpr auto operator""_a() {
  using char_t = remove_cvref_t<decltype(Str.data[0])>;
  return detail::udl_arg<char_t, sizeof(Str.data) / sizeof(char_t), Str>();
}
#  else
constexpr auto operator"" _a(const char* s, size_t) -> detail::udl_arg<char> {
  return {s};
}
#  endif
}  // namespace literals
#endif  // FMT_USE_USER_DEFINED_LITERALS

template <typename Locale, FMT_ENABLE_IF(detail::is_locale<Locale>::value)>
inline auto vformat(const Locale& loc, string_view fmt, format_args args)
    -> std::string {
  return detail::vformat(loc, fmt, args);
}

template <typename Locale, typename... T,
          FMT_ENABLE_IF(detail::is_locale<Locale>::value)>
inline auto format(const Locale& loc, format_string<T...> fmt, T&&... args)
    -> std::string {
  return vformat(loc, string_view(fmt), fmt::make_format_args(args...));
}

template <typename OutputIt, typename Locale,
          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, char>::value&&
                            detail::is_locale<Locale>::value)>
auto vformat_to(OutputIt out, const Locale& loc, string_view fmt,
                format_args args) -> OutputIt {
  using detail::get_buffer;
  auto&& buf = get_buffer<char>(out);
  detail::vformat_to(buf, fmt, args, detail::locale_ref(loc));
  return detail::get_iterator(buf);
}

template <typename OutputIt, typename Locale, typename... T,
          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, char>::value&&
                            detail::is_locale<Locale>::value)>
FMT_INLINE auto format_to(OutputIt out, const Locale& loc,
                          format_string<T...> fmt, T&&... args) -> OutputIt {
  return vformat_to(out, loc, fmt, fmt::make_format_args(args...));
}

FMT_MODULE_EXPORT_END
FMT_END_NAMESPACE

#ifdef FMT_HEADER_ONLY
#  define FMT_FUNC inline
#  include "format-inl.h"
#else
#  define FMT_FUNC
#endif

#endif  // FMT_FORMAT_H_

redpajama_set_name: RedPajamaGithub