include/__format/formatter_output.h - llvm-project/libcxx - Git at Google

 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//

 #ifndef _LIBCPP___FORMAT_FORMATTER_OUTPUT_H
 #define _LIBCPP___FORMAT_FORMATTER_OUTPUT_H

 #include <__algorithm/ranges_copy.h>
 #include <__algorithm/ranges_fill_n.h>
 #include <__algorithm/ranges_transform.h>
 #include <__bit/countl.h>
 #include <__concepts/same_as.h>
 #include <__config>
 #include <__format/buffer.h>
 #include <__format/concepts.h>
 #include <__format/formatter.h>
 #include <__format/parser_std_format_spec.h>
 #include <__format/unicode.h>
 #include <__iterator/back_insert_iterator.h>
 #include <__iterator/concepts.h>
 #include <__iterator/iterator_traits.h>
 #include <__memory/addressof.h>
 #include <__memory/pointer_traits.h>
 #include <__utility/move.h>
 #include <__utility/unreachable.h>
 #include <cstddef>
 #include <string_view>

 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif

 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>

 _LIBCPP_BEGIN_NAMESPACE_STD

 #if _LIBCPP_STD_VER >= 20

 namespace __formatter {

 _LIBCPP_HIDE_FROM_ABI constexpr char __hex_to_upper(char __c) {
   switch (__c) {
   case 'a':
     return 'A';
   case 'b':
     return 'B';
   case 'c':
     return 'C';
   case 'd':
     return 'D';
   case 'e':
     return 'E';
   case 'f':
     return 'F';
   }
   return __c;
 }

 struct _LIBCPP_EXPORTED_FROM_ABI __padding_size_result {
   size_t __before_;
   size_t __after_;
 };

 _LIBCPP_HIDE_FROM_ABI constexpr __padding_size_result
 __padding_size(size_t __size, size_t __width, __format_spec::__alignment __align) {
   _LIBCPP_ASSERT_INTERNAL(__width > __size, "don't call this function when no padding is required");
   _LIBCPP_ASSERT_INTERNAL(
       __align != __format_spec::__alignment::__zero_padding, "the caller should have handled the zero-padding");

   size_t __fill = __width - __size;
   switch (__align) {
   case __format_spec::__alignment::__zero_padding:
     __libcpp_unreachable();

   case __format_spec::__alignment::__left:
     return {0, __fill};

   case __format_spec::__alignment::__center: {
     // The extra padding is divided per [format.string.std]/3
     // __before = floor(__fill, 2);
     // __after = ceil(__fill, 2);
     size_t __before = __fill / 2;
     size_t __after  = __fill - __before;
     return {__before, __after};
   }
   case __format_spec::__alignment::__default:
   case __format_spec::__alignment::__right:
     return {__fill, 0};
   }
   __libcpp_unreachable();
 }

 /// Copy wrapper.
 ///
 /// This uses a "mass output function" of __format::__output_buffer when possible.
 template <__fmt_char_type _CharT, __fmt_char_type _OutCharT = _CharT>
 _LIBCPP_HIDE_FROM_ABI auto __copy(basic_string_view<_CharT> __str, output_iterator<const _OutCharT&> auto __out_it)
     -> decltype(__out_it) {
   if constexpr (std::same_as<decltype(__out_it), std::back_insert_iterator<__format::__output_buffer<_OutCharT>>>) {
     __out_it.__get_container()->__copy(__str);
     return __out_it;
   } else if constexpr (std::same_as<decltype(__out_it), typename __format::__retarget_buffer<_OutCharT>::__iterator>) {
     __out_it.__buffer_->__copy(__str);
     return __out_it;
   } else {
     return std::ranges::copy(__str, std::move(__out_it)).out;
   }
 }

 template <contiguous_iterator _Iterator,
           __fmt_char_type _CharT    = typename iterator_traits<_Iterator>::value_type,
           __fmt_char_type _OutCharT = _CharT>
 _LIBCPP_HIDE_FROM_ABI auto __copy(_Iterator __first, _Iterator __last, output_iterator<const _OutCharT&> auto __out_it)
     -> decltype(__out_it) {
   return __formatter::__copy(basic_string_view{__first, __last}, std::move(__out_it));
 }

 template <contiguous_iterator _Iterator,
           __fmt_char_type _CharT    = typename iterator_traits<_Iterator>::value_type,
           __fmt_char_type _OutCharT = _CharT>
 _LIBCPP_HIDE_FROM_ABI auto __copy(_Iterator __first, size_t __n, output_iterator<const _OutCharT&> auto __out_it)
     -> decltype(__out_it) {
   return __formatter::__copy(basic_string_view{std::to_address(__first), __n}, std::move(__out_it));
 }

 /// Transform wrapper.
 ///
 /// This uses a "mass output function" of __format::__output_buffer when possible.
 template <contiguous_iterator _Iterator,
           __fmt_char_type _CharT    = typename iterator_traits<_Iterator>::value_type,
           __fmt_char_type _OutCharT = _CharT,
           class _UnaryOperation>
 _LIBCPP_HIDE_FROM_ABI auto __transform(
     _Iterator __first, _Iterator __last, output_iterator<const _OutCharT&> auto __out_it, _UnaryOperation __operation)
     -> decltype(__out_it) {
   if constexpr (std::same_as<decltype(__out_it), std::back_insert_iterator<__format::__output_buffer<_OutCharT>>>) {
     __out_it.__get_container()->__transform(__first, __last, std::move(__operation));
     return __out_it;
   } else if constexpr (std::same_as<decltype(__out_it), typename __format::__retarget_buffer<_OutCharT>::__iterator>) {
     __out_it.__buffer_->__transform(__first, __last, std::move(__operation));
     return __out_it;
   } else {
     return std::ranges::transform(__first, __last, std::move(__out_it), __operation).out;
   }
 }

 /// Fill wrapper.
 ///
 /// This uses a "mass output function" of __format::__output_buffer when possible.
 template <__fmt_char_type _CharT, output_iterator<const _CharT&> _OutIt>
 _LIBCPP_HIDE_FROM_ABI _OutIt __fill(_OutIt __out_it, size_t __n, _CharT __value) {
   if constexpr (std::same_as<decltype(__out_it), std::back_insert_iterator<__format::__output_buffer<_CharT>>>) {
     __out_it.__get_container()->__fill(__n, __value);
     return __out_it;
   } else if constexpr (std::same_as<decltype(__out_it), typename __format::__retarget_buffer<_CharT>::__iterator>) {
     __out_it.__buffer_->__fill(__n, __value);
     return __out_it;
   } else {
     return std::ranges::fill_n(std::move(__out_it), __n, __value);
   }
 }

 #  ifndef _LIBCPP_HAS_NO_UNICODE
 template <__fmt_char_type _CharT, output_iterator<const _CharT&> _OutIt>
   requires(same_as<_CharT, char>)
 _LIBCPP_HIDE_FROM_ABI _OutIt __fill(_OutIt __out_it, size_t __n, __format_spec::__code_point<_CharT> __value) {
   std::size_t __bytes = std::countl_one(static_cast<unsigned char>(__value.__data[0]));
   if (__bytes == 0)
     return __formatter::__fill(std::move(__out_it), __n, __value.__data[0]);

   for (size_t __i = 0; __i < __n; ++__i)
     __out_it = __formatter::__copy(
         std::addressof(__value.__data[0]), std::addressof(__value.__data[0]) + __bytes, std::move(__out_it));
   return __out_it;
 }

 #    ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 template <__fmt_char_type _CharT, output_iterator<const _CharT&> _OutIt>
   requires(same_as<_CharT, wchar_t> && sizeof(wchar_t) == 2)
 _LIBCPP_HIDE_FROM_ABI _OutIt __fill(_OutIt __out_it, size_t __n, __format_spec::__code_point<_CharT> __value) {
   if (!__unicode::__is_high_surrogate(__value.__data[0]))
     return __formatter::__fill(std::move(__out_it), __n, __value.__data[0]);

   for (size_t __i = 0; __i < __n; ++__i)
     __out_it = __formatter::__copy(
         std::addressof(__value.__data[0]), std::addressof(__value.__data[0]) + 2, std::move(__out_it));
   return __out_it;
 }

 template <__fmt_char_type _CharT, output_iterator<const _CharT&> _OutIt>
   requires(same_as<_CharT, wchar_t> && sizeof(wchar_t) == 4)
 _LIBCPP_HIDE_FROM_ABI _OutIt __fill(_OutIt __out_it, size_t __n, __format_spec::__code_point<_CharT> __value) {
   return __formatter::__fill(std::move(__out_it), __n, __value.__data[0]);
 }
 #    endif // _LIBCPP_HAS_NO_WIDE_CHARACTERS
 #  else    // _LIBCPP_HAS_NO_UNICODE
 template <__fmt_char_type _CharT, output_iterator<const _CharT&> _OutIt>
 _LIBCPP_HIDE_FROM_ABI _OutIt __fill(_OutIt __out_it, size_t __n, __format_spec::__code_point<_CharT> __value) {
   return __formatter::__fill(std::move(__out_it), __n, __value.__data[0]);
 }
 #  endif   // _LIBCPP_HAS_NO_UNICODE

 /// Writes the input to the output with the required padding.
 ///
 /// Since the output column width is specified the function can be used for
 /// ASCII and Unicode output.
 ///
 /// \pre \a __size <= \a __width. Using this function when this pre-condition
 ///      doesn't hold incurs an unwanted overhead.
 ///
 /// \param __str       The string to write.
 /// \param __out_it    The output iterator to write to.
 /// \param __specs     The parsed formatting specifications.
 /// \param __size      The (estimated) output column width. When the elements
 ///                    to be written are ASCII the following condition holds
 ///                    \a __size == \a __last - \a __first.
 ///
 /// \returns           An iterator pointing beyond the last element written.
 ///
 /// \note The type of the elements in range [\a __first, \a __last) can differ
 /// from the type of \a __specs. Integer output uses \c std::to_chars for its
 /// conversion, which means the [\a __first, \a __last) always contains elements
 /// of the type \c char.
 template <class _CharT, class _ParserCharT>
 _LIBCPP_HIDE_FROM_ABI auto
 __write(basic_string_view<_CharT> __str,
         output_iterator<const _CharT&> auto __out_it,
         __format_spec::__parsed_specifications<_ParserCharT> __specs,
         ptrdiff_t __size) -> decltype(__out_it) {
   if (__size >= __specs.__width_)
     return __formatter::__copy(__str, std::move(__out_it));

   __padding_size_result __padding = __formatter::__padding_size(__size, __specs.__width_, __specs.__std_.__alignment_);
   __out_it                        = __formatter::__fill(std::move(__out_it), __padding.__before_, __specs.__fill_);
   __out_it                        = __formatter::__copy(__str, std::move(__out_it));
   return __formatter::__fill(std::move(__out_it), __padding.__after_, __specs.__fill_);
 }

 template <contiguous_iterator _Iterator, class _ParserCharT>
 _LIBCPP_HIDE_FROM_ABI auto
 __write(_Iterator __first,
         _Iterator __last,
         output_iterator<const iter_value_t<_Iterator>&> auto __out_it,
         __format_spec::__parsed_specifications<_ParserCharT> __specs,
         ptrdiff_t __size) -> decltype(__out_it) {
   _LIBCPP_ASSERT_VALID_INPUT_RANGE(__first <= __last, "Not a valid range");
   return __formatter::__write(basic_string_view{__first, __last}, std::move(__out_it), __specs, __size);
 }

 /// \overload
 ///
 /// Calls the function above where \a __size = \a __last - \a __first.
 template <contiguous_iterator _Iterator, class _ParserCharT>
 _LIBCPP_HIDE_FROM_ABI auto
 __write(_Iterator __first,
         _Iterator __last,
         output_iterator<const iter_value_t<_Iterator>&> auto __out_it,
         __format_spec::__parsed_specifications<_ParserCharT> __specs) -> decltype(__out_it) {
   _LIBCPP_ASSERT_VALID_INPUT_RANGE(__first <= __last, "Not a valid range");
   return __formatter::__write(__first, __last, std::move(__out_it), __specs, __last - __first);
 }

 template <contiguous_iterator _Iterator,
           class _CharT = typename iterator_traits<_Iterator>::value_type,
           class _ParserCharT,
           class _UnaryOperation>
 _LIBCPP_HIDE_FROM_ABI auto __write_transformed(
     _Iterator __first,
     _Iterator __last,
     output_iterator<const _CharT&> auto __out_it,
     __format_spec::__parsed_specifications<_ParserCharT> __specs,
     _UnaryOperation __op) -> decltype(__out_it) {
   _LIBCPP_ASSERT_VALID_INPUT_RANGE(__first <= __last, "Not a valid range");

   ptrdiff_t __size = __last - __first;
   if (__size >= __specs.__width_)
     return __formatter::__transform(__first, __last, std::move(__out_it), __op);

   __padding_size_result __padding = __formatter::__padding_size(__size, __specs.__width_, __specs.__alignment_);
   __out_it                        = __formatter::__fill(std::move(__out_it), __padding.__before_, __specs.__fill_);
   __out_it                        = __formatter::__transform(__first, __last, std::move(__out_it), __op);
   return __formatter::__fill(std::move(__out_it), __padding.__after_, __specs.__fill_);
 }

 /// Writes a string using format's width estimation algorithm.
 ///
 /// \pre !__specs.__has_precision()
 ///
 /// \note When \c _LIBCPP_HAS_NO_UNICODE is defined the function assumes the
 /// input is ASCII.
 template <class _CharT>
 _LIBCPP_HIDE_FROM_ABI auto __write_string_no_precision(
     basic_string_view<_CharT> __str,
     output_iterator<const _CharT&> auto __out_it,
     __format_spec::__parsed_specifications<_CharT> __specs) -> decltype(__out_it) {
   _LIBCPP_ASSERT_INTERNAL(!__specs.__has_precision(), "use __write_string");

   // No padding -> copy the string
   if (!__specs.__has_width())
     return __formatter::__copy(__str, std::move(__out_it));

   // Note when the estimated width is larger than size there's no padding. So
   // there's no reason to get the real size when the estimate is larger than or
   // equal to the minimum field width.
   size_t __size =
       __format_spec::__estimate_column_width(__str, __specs.__width_, __format_spec::__column_width_rounding::__up)
           .__width_;
   return __formatter::__write(__str, std::move(__out_it), __specs, __size);
 }

 template <class _CharT>
 _LIBCPP_HIDE_FROM_ABI int __truncate(basic_string_view<_CharT>& __str, int __precision) {
   __format_spec::__column_width_result __result =
       __format_spec::__estimate_column_width(__str, __precision, __format_spec::__column_width_rounding::__down);
   __str = basic_string_view<_CharT>{__str.begin(), __result.__last_};
   return __result.__width_;
 }

 } // namespace __formatter

 #endif //_LIBCPP_STD_VER >= 20

 _LIBCPP_END_NAMESPACE_STD

 _LIBCPP_POP_MACROS

 #endif // _LIBCPP___FORMAT_FORMATTER_OUTPUT_H
	// -- C++ --
	//===----------------------------------------------------------------------===//
	//
	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
	// See https://llvm.org/LICENSE.txt for license information.
	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
	//
	//===----------------------------------------------------------------------===//

	#ifndef _LIBCPP___FORMAT_FORMATTER_OUTPUT_H
	#define _LIBCPP___FORMAT_FORMATTER_OUTPUT_H

	#include <__algorithm/ranges_copy.h>
	#include <__algorithm/ranges_fill_n.h>
	#include <__algorithm/ranges_transform.h>
	#include <__bit/countl.h>
	#include <__concepts/same_as.h>
	#include <__config>
	#include <__format/buffer.h>
	#include <__format/concepts.h>
	#include <__format/formatter.h>
	#include <__format/parser_std_format_spec.h>
	#include <__format/unicode.h>
	#include <__iterator/back_insert_iterator.h>
	#include <__iterator/concepts.h>
	#include <__iterator/iterator_traits.h>
	#include <__memory/addressof.h>
	#include <__memory/pointer_traits.h>
	#include <__utility/move.h>
	#include <__utility/unreachable.h>
	#include <cstddef>
	#include <string_view>

	#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
	# pragma GCC system_header
	#endif

	_LIBCPP_PUSH_MACROS
	#include <__undef_macros>

	_LIBCPP_BEGIN_NAMESPACE_STD

	#if _LIBCPP_STD_VER >= 20

	namespace __formatter {

	_LIBCPP_HIDE_FROM_ABI constexpr char __hex_to_upper(char __c) {
	switch (__c) {
	case 'a':
	return 'A';
	case 'b':
	return 'B';
	case 'c':
	return 'C';
	case 'd':
	return 'D';
	case 'e':
	return 'E';
	case 'f':
	return 'F';
	}
	return __c;
	}

	struct _LIBCPP_EXPORTED_FROM_ABI __padding_size_result {
	size_t __before_;
	size_t __after_;
	};

	_LIBCPP_HIDE_FROM_ABI constexpr __padding_size_result
	__padding_size(size_t __size, size_t __width, __format_spec::__alignment __align) {
	_LIBCPP_ASSERT_INTERNAL(__width > __size, "don't call this function when no padding is required");
	_LIBCPP_ASSERT_INTERNAL(
	__align != __format_spec::__alignment::__zero_padding, "the caller should have handled the zero-padding");

	size_t __fill = __width - __size;
	switch (__align) {
	case __format_spec::__alignment::__zero_padding:
	__libcpp_unreachable();

	case __format_spec::__alignment::__left:
	return {0, __fill};

	case __format_spec::__alignment::__center: {
	// The extra padding is divided per [format.string.std]/3
	// __before = floor(__fill, 2);
	// __after = ceil(__fill, 2);
	size_t __before = __fill / 2;
	size_t __after = __fill - __before;
	return {__before, __after};
	}
	case __format_spec::__alignment::__default:
	case __format_spec::__alignment::__right:
	return {__fill, 0};
	}
	__libcpp_unreachable();
	}

	/// Copy wrapper.
	///
	/// This uses a "mass output function" of __format::__output_buffer when possible.
	template <__fmt_char_type _CharT, __fmt_char_type _OutCharT = _CharT>
	_LIBCPP_HIDE_FROM_ABI auto __copy(basic_string_view<_CharT> __str, output_iterator<const _OutCharT&> auto __out_it)
	-> decltype(__out_it) {
	if constexpr (std::same_as<decltype(__out_it), std::back_insert_iterator<__format::__output_buffer<_OutCharT>>>) {
	__out_it.__get_container()->__copy(__str);
	return __out_it;
	} else if constexpr (std::same_as<decltype(__out_it), typename __format::__retarget_buffer<_OutCharT>::__iterator>) {
	__out_it.__buffer_->__copy(__str);
	return __out_it;
	} else {
	return std::ranges::copy(__str, std::move(__out_it)).out;
	}
	}

	template <contiguous_iterator _Iterator,
	__fmt_char_type _CharT = typename iterator_traits<_Iterator>::value_type,
	__fmt_char_type _OutCharT = _CharT>
	_LIBCPP_HIDE_FROM_ABI auto __copy(_Iterator __first, _Iterator __last, output_iterator<const _OutCharT&> auto __out_it)
	-> decltype(__out_it) {
	return __formatter::__copy(basic_string_view{__first, __last}, std::move(__out_it));
	}

	template <contiguous_iterator _Iterator,
	__fmt_char_type _CharT = typename iterator_traits<_Iterator>::value_type,
	__fmt_char_type _OutCharT = _CharT>
	_LIBCPP_HIDE_FROM_ABI auto __copy(_Iterator __first, size_t __n, output_iterator<const _OutCharT&> auto __out_it)
	-> decltype(__out_it) {
	return __formatter::__copy(basic_string_view{std::to_address(__first), __n}, std::move(__out_it));
	}

	/// Transform wrapper.
	///
	/// This uses a "mass output function" of __format::__output_buffer when possible.
	template <contiguous_iterator _Iterator,
	__fmt_char_type _CharT = typename iterator_traits<_Iterator>::value_type,
	__fmt_char_type _OutCharT = _CharT,
	class _UnaryOperation>
	_LIBCPP_HIDE_FROM_ABI auto __transform(
	_Iterator __first, _Iterator __last, output_iterator<const _OutCharT&> auto __out_it, _UnaryOperation __operation)
	-> decltype(__out_it) {
	if constexpr (std::same_as<decltype(__out_it), std::back_insert_iterator<__format::__output_buffer<_OutCharT>>>) {
	__out_it.__get_container()->__transform(__first, __last, std::move(__operation));
	return __out_it;
	} else if constexpr (std::same_as<decltype(__out_it), typename __format::__retarget_buffer<_OutCharT>::__iterator>) {
	__out_it.__buffer_->__transform(__first, __last, std::move(__operation));
	return __out_it;
	} else {
	return std::ranges::transform(__first, __last, std::move(__out_it), __operation).out;
	}
	}

	/// Fill wrapper.
	///
	/// This uses a "mass output function" of __format::__output_buffer when possible.
	template <__fmt_char_type _CharT, output_iterator<const _CharT&> _OutIt>
	_LIBCPP_HIDE_FROM_ABI _OutIt __fill(_OutIt __out_it, size_t __n, _CharT __value) {
	if constexpr (std::same_as<decltype(__out_it), std::back_insert_iterator<__format::__output_buffer<_CharT>>>) {
	__out_it.__get_container()->__fill(__n, __value);
	return __out_it;
	} else if constexpr (std::same_as<decltype(__out_it), typename __format::__retarget_buffer<_CharT>::__iterator>) {
	__out_it.__buffer_->__fill(__n, __value);
	return __out_it;
	} else {
	return std::ranges::fill_n(std::move(__out_it), __n, __value);
	}
	}

	# ifndef _LIBCPP_HAS_NO_UNICODE
	template <__fmt_char_type _CharT, output_iterator<const _CharT&> _OutIt>
	requires(same_as<_CharT, char>)
	_LIBCPP_HIDE_FROM_ABI _OutIt __fill(_OutIt __out_it, size_t __n, __format_spec::__code_point<_CharT> __value) {
	std::size_t __bytes = std::countl_one(static_cast<unsigned char>(__value.__data[0]));
	if (__bytes == 0)
	return __formatter::__fill(std::move(__out_it), __n, __value.__data[0]);

	for (size_t __i = 0; __i < __n; ++__i)
	__out_it = __formatter::__copy(
	std::addressof(__value.__data[0]), std::addressof(__value.__data[0]) + __bytes, std::move(__out_it));
	return __out_it;
	}

	# ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
	template <__fmt_char_type _CharT, output_iterator<const _CharT&> _OutIt>
	requires(same_as<_CharT, wchar_t> && sizeof(wchar_t) == 2)
	_LIBCPP_HIDE_FROM_ABI _OutIt __fill(_OutIt __out_it, size_t __n, __format_spec::__code_point<_CharT> __value) {
	if (!__unicode::__is_high_surrogate(__value.__data[0]))
	return __formatter::__fill(std::move(__out_it), __n, __value.__data[0]);

	for (size_t __i = 0; __i < __n; ++__i)
	__out_it = __formatter::__copy(
	std::addressof(__value.__data[0]), std::addressof(__value.__data[0]) + 2, std::move(__out_it));
	return __out_it;
	}

	template <__fmt_char_type _CharT, output_iterator<const _CharT&> _OutIt>
	requires(same_as<_CharT, wchar_t> && sizeof(wchar_t) == 4)
	_LIBCPP_HIDE_FROM_ABI _OutIt __fill(_OutIt __out_it, size_t __n, __format_spec::__code_point<_CharT> __value) {
	return __formatter::__fill(std::move(__out_it), __n, __value.__data[0]);
	}
	# endif // _LIBCPP_HAS_NO_WIDE_CHARACTERS
	# else // _LIBCPP_HAS_NO_UNICODE
	template <__fmt_char_type _CharT, output_iterator<const _CharT&> _OutIt>
	_LIBCPP_HIDE_FROM_ABI _OutIt __fill(_OutIt __out_it, size_t __n, __format_spec::__code_point<_CharT> __value) {
	return __formatter::__fill(std::move(__out_it), __n, __value.__data[0]);
	}
	# endif // _LIBCPP_HAS_NO_UNICODE

	/// Writes the input to the output with the required padding.
	///
	/// Since the output column width is specified the function can be used for
	/// ASCII and Unicode output.
	///
	/// \pre \a __size <= \a __width. Using this function when this pre-condition
	/// doesn't hold incurs an unwanted overhead.
	///
	/// \param __str The string to write.
	/// \param __out_it The output iterator to write to.
	/// \param __specs The parsed formatting specifications.
	/// \param __size The (estimated) output column width. When the elements
	/// to be written are ASCII the following condition holds
	/// \a __size == \a __last - \a __first.
	///
	/// \returns An iterator pointing beyond the last element written.
	///
	/// \note The type of the elements in range [\a __first, \a __last) can differ
	/// from the type of \a __specs. Integer output uses \c std::to_chars for its
	/// conversion, which means the [\a __first, \a __last) always contains elements
	/// of the type \c char.
	template <class _CharT, class _ParserCharT>
	_LIBCPP_HIDE_FROM_ABI auto
	__write(basic_string_view<_CharT> __str,
	output_iterator<const _CharT&> auto __out_it,
	__format_spec::__parsed_specifications<_ParserCharT> __specs,
	ptrdiff_t __size) -> decltype(__out_it) {
	if (__size >= __specs.__width_)
	return __formatter::__copy(__str, std::move(__out_it));

	__padding_size_result __padding = __formatter::__padding_size(__size, __specs.__width_, __specs.__std_.__alignment_);
	__out_it = __formatter::__fill(std::move(__out_it), __padding.__before_, __specs.__fill_);
	__out_it = __formatter::__copy(__str, std::move(__out_it));
	return __formatter::__fill(std::move(__out_it), __padding.__after_, __specs.__fill_);
	}

	template <contiguous_iterator _Iterator, class _ParserCharT>
	_LIBCPP_HIDE_FROM_ABI auto
	__write(_Iterator __first,
	_Iterator __last,
	output_iterator<const iter_value_t<_Iterator>&> auto __out_it,
	__format_spec::__parsed_specifications<_ParserCharT> __specs,
	ptrdiff_t __size) -> decltype(__out_it) {
	_LIBCPP_ASSERT_VALID_INPUT_RANGE(__first <= __last, "Not a valid range");
	return __formatter::__write(basic_string_view{__first, __last}, std::move(__out_it), __specs, __size);
	}

	/// \overload
	///
	/// Calls the function above where \a __size = \a __last - \a __first.
	template <contiguous_iterator _Iterator, class _ParserCharT>
	_LIBCPP_HIDE_FROM_ABI auto
	__write(_Iterator __first,
	_Iterator __last,
	output_iterator<const iter_value_t<_Iterator>&> auto __out_it,
	__format_spec::__parsed_specifications<_ParserCharT> __specs) -> decltype(__out_it) {
	_LIBCPP_ASSERT_VALID_INPUT_RANGE(__first <= __last, "Not a valid range");
	return __formatter::__write(__first, __last, std::move(__out_it), __specs, __last - __first);
	}

	template <contiguous_iterator _Iterator,
	class _CharT = typename iterator_traits<_Iterator>::value_type,
	class _ParserCharT,
	class _UnaryOperation>
	_LIBCPP_HIDE_FROM_ABI auto __write_transformed(
	_Iterator __first,
	_Iterator __last,
	output_iterator<const _CharT&> auto __out_it,
	__format_spec::__parsed_specifications<_ParserCharT> __specs,
	_UnaryOperation __op) -> decltype(__out_it) {
	_LIBCPP_ASSERT_VALID_INPUT_RANGE(__first <= __last, "Not a valid range");

	ptrdiff_t __size = __last - __first;
	if (__size >= __specs.__width_)
	return __formatter::__transform(__first, __last, std::move(__out_it), __op);

	__padding_size_result __padding = __formatter::__padding_size(__size, __specs.__width_, __specs.__alignment_);
	__out_it = __formatter::__fill(std::move(__out_it), __padding.__before_, __specs.__fill_);
	__out_it = __formatter::__transform(__first, __last, std::move(__out_it), __op);
	return __formatter::__fill(std::move(__out_it), __padding.__after_, __specs.__fill_);
	}

	/// Writes a string using format's width estimation algorithm.
	///
	/// \pre !__specs.__has_precision()
	///
	/// \note When \c _LIBCPP_HAS_NO_UNICODE is defined the function assumes the
	/// input is ASCII.
	template <class _CharT>
	_LIBCPP_HIDE_FROM_ABI auto __write_string_no_precision(
	basic_string_view<_CharT> __str,
	output_iterator<const _CharT&> auto __out_it,
	__format_spec::__parsed_specifications<_CharT> __specs) -> decltype(__out_it) {
	_LIBCPP_ASSERT_INTERNAL(!__specs.__has_precision(), "use __write_string");

	// No padding -> copy the string
	if (!__specs.__has_width())
	return __formatter::__copy(__str, std::move(__out_it));

	// Note when the estimated width is larger than size there's no padding. So
	// there's no reason to get the real size when the estimate is larger than or
	// equal to the minimum field width.
	size_t __size =
	__format_spec::__estimate_column_width(__str, __specs.__width_, __format_spec::__column_width_rounding::__up)
	.__width_;
	return __formatter::__write(__str, std::move(__out_it), __specs, __size);
	}

	template <class _CharT>
	_LIBCPP_HIDE_FROM_ABI int __truncate(basic_string_view<_CharT>& __str, int __precision) {
	__format_spec::__column_width_result __result =
	__format_spec::__estimate_column_width(__str, __precision, __format_spec::__column_width_rounding::__down);
	__str = basic_string_view<_CharT>{__str.begin(), __result.__last_};
	return __result.__width_;
	}

	} // namespace __formatter

	#endif //_LIBCPP_STD_VER >= 20

	_LIBCPP_END_NAMESPACE_STD

	_LIBCPP_POP_MACROS

	#endif // _LIBCPP___FORMAT_FORMATTER_OUTPUT_H