| // -*- 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 |