// -*- 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_TUPLE_H
#define _LIBCPP___FORMAT_FORMATTER_TUPLE_H
#include <__algorithm/ranges_copy.h>
#include <__chrono/statically_widen.h>
#include <__config>
#include <__format/buffer.h>
#include <__format/concepts.h>
#include <__format/format_context.h>
#include <__format/format_error.h>
#include <__format/format_parse_context.h>
#include <__format/formatter.h>
#include <__format/formatter_output.h>
#include <__format/parser_std_format_spec.h>
#include <__type_traits/remove_cvref.h>
#include <__utility/integer_sequence.h>
#include <__utility/pair.h>
#include <string_view>
#include <tuple>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER >= 23
template <__fmt_char_type _CharT, class _Tuple, formattable<_CharT>... _Args>
struct _LIBCPP_TEMPLATE_VIS __formatter_tuple {
_LIBCPP_HIDE_FROM_ABI constexpr void set_separator(basic_string_view<_CharT> __separator) noexcept {
__separator_ = __separator;
}
_LIBCPP_HIDE_FROM_ABI constexpr void
set_brackets(basic_string_view<_CharT> __opening_bracket, basic_string_view<_CharT> __closing_bracket) noexcept {
__opening_bracket_ = __opening_bracket;
__closing_bracket_ = __closing_bracket;
}
template <class _ParseContext>
_LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
auto __begin = __parser_.__parse(__ctx, __format_spec::__fields_tuple);
auto __end = __ctx.end();
// Note 'n' is part of the type here
if (__parser_.__clear_brackets_)
set_brackets({}, {});
else if (__begin != __end && *__begin == _CharT('m')) {
if constexpr (sizeof...(_Args) == 2) {
set_separator(_LIBCPP_STATICALLY_WIDEN(_CharT, ": "));
set_brackets({}, {});
++__begin;
} else
std::__throw_format_error("Type m requires a pair or a tuple with two elements");
}
if (__begin != __end && *__begin != _CharT('}'))
std::__throw_format_error("The format specifier should consume the input or end with a '}'");
__ctx.advance_to(__begin);
// [format.tuple]/7
// ... For each element e in underlying_, if e.set_debug_format()
// is a valid expression, calls e.set_debug_format().
std::__for_each_index_sequence(make_index_sequence<sizeof...(_Args)>(), [&]<size_t _Index> {
auto& __formatter = std::get<_Index>(__underlying_);
__formatter.parse(__ctx);
// Unlike the range_formatter we don't guard against evil parsers. Since
// this format-spec never has a format-spec for the underlying type
// adding the test would give additional overhead.
std::__set_debug_format(__formatter);
});
return __begin;
}
template <class _FormatContext>
typename _FormatContext::iterator _LIBCPP_HIDE_FROM_ABI
format(conditional_t<(formattable<const _Args, _CharT> && ...), const _Tuple&, _Tuple&> __tuple,
_FormatContext& __ctx) const {
__format_spec::__parsed_specifications<_CharT> __specs = __parser_.__get_parsed_std_specifications(__ctx);
if (!__specs.__has_width())
return __format_tuple(__tuple, __ctx);
// The size of the buffer needed is:
// - open bracket characters
// - close bracket character
// - n elements where every element may have a different size
// - (n -1) separators
// The size of the element is hard to predict, knowing the type helps but
// it depends on the format-spec. As an initial estimate we guess 6
// characters.
// Typically both brackets are 1 character and the separator is 2
// characters. Which means there will be
// (n - 1) * 2 + 1 + 1 = n * 2 character
// So estimate 8 times the range size as buffer.
__format::__retarget_buffer<_CharT> __buffer{8 * tuple_size_v<_Tuple>};
basic_format_context<typename __format::__retarget_buffer<_CharT>::__iterator, _CharT> __c{
__buffer.__make_output_iterator(), __ctx};
__format_tuple(__tuple, __c);
return __formatter::__write_string_no_precision(basic_string_view{__buffer.__view()}, __ctx.out(), __specs);
}
template <class _FormatContext>
_LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator __format_tuple(auto&& __tuple, _FormatContext& __ctx) const {
__ctx.advance_to(std::ranges::copy(__opening_bracket_, __ctx.out()).out);
std::__for_each_index_sequence(make_index_sequence<sizeof...(_Args)>(), [&]<size_t _Index> {
if constexpr (_Index)
__ctx.advance_to(std::ranges::copy(__separator_, __ctx.out()).out);
__ctx.advance_to(std::get<_Index>(__underlying_).format(std::get<_Index>(__tuple), __ctx));
});
return std::ranges::copy(__closing_bracket_, __ctx.out()).out;
}
__format_spec::__parser<_CharT> __parser_{.__alignment_ = __format_spec::__alignment::__left};
private:
tuple<formatter<remove_cvref_t<_Args>, _CharT>...> __underlying_;
basic_string_view<_CharT> __separator_ = _LIBCPP_STATICALLY_WIDEN(_CharT, ", ");
basic_string_view<_CharT> __opening_bracket_ = _LIBCPP_STATICALLY_WIDEN(_CharT, "(");
basic_string_view<_CharT> __closing_bracket_ = _LIBCPP_STATICALLY_WIDEN(_CharT, ")");
};
template <__fmt_char_type _CharT, formattable<_CharT>... _Args>
struct _LIBCPP_TEMPLATE_VIS formatter<pair<_Args...>, _CharT>
: public __formatter_tuple<_CharT, pair<_Args...>, _Args...> {};
template <__fmt_char_type _CharT, formattable<_CharT>... _Args>
struct _LIBCPP_TEMPLATE_VIS formatter<tuple<_Args...>, _CharT>
: public __formatter_tuple<_CharT, tuple<_Args...>, _Args...> {};
#endif // _LIBCPP_STD_VER >= 23
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___FORMAT_FORMATTER_TUPLE_H
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