| // -*- 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_CONCEPTS_H |
| #define _LIBCPP___FORMAT_CONCEPTS_H |
| |
| #include <__concepts/same_as.h> |
| #include <__concepts/semiregular.h> |
| #include <__config> |
| #include <__format/format_parse_context.h> |
| #include <__fwd/format.h> |
| #include <__fwd/tuple.h> |
| #include <__tuple/tuple_size.h> |
| #include <__type_traits/is_specialization.h> |
| #include <__type_traits/remove_const.h> |
| #include <__type_traits/remove_reference.h> |
| #include <__utility/pair.h> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| #if _LIBCPP_STD_VER >= 20 |
| |
| /// The character type specializations of \ref formatter. |
| template <class _CharT> |
| concept __fmt_char_type = |
| same_as<_CharT, char> |
| # ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS |
| || same_as<_CharT, wchar_t> |
| # endif |
| ; |
| |
| // The output iterator isn't specified. A formatter should accept any |
| // output_iterator. This iterator is a minimal iterator to test the concept. |
| // (Note testing for (w)format_context would be a valid choice, but requires |
| // selecting the proper one depending on the type of _CharT.) |
| template <class _CharT> |
| using __fmt_iter_for = _CharT*; |
| |
| template <class _Tp, class _Context, class _Formatter = typename _Context::template formatter_type<remove_const_t<_Tp>>> |
| concept __formattable_with = |
| semiregular<_Formatter> && |
| requires(_Formatter& __f, |
| const _Formatter& __cf, |
| _Tp&& __t, |
| _Context __fc, |
| basic_format_parse_context<typename _Context::char_type> __pc) { |
| { __f.parse(__pc) } -> same_as<typename decltype(__pc)::iterator>; |
| { __cf.format(__t, __fc) } -> same_as<typename _Context::iterator>; |
| }; |
| |
| template <class _Tp, class _CharT> |
| concept __formattable = |
| __formattable_with<remove_reference_t<_Tp>, basic_format_context<__fmt_iter_for<_CharT>, _CharT>>; |
| |
| # if _LIBCPP_STD_VER >= 23 |
| template <class _Tp, class _CharT> |
| concept formattable = __formattable<_Tp, _CharT>; |
| |
| // [tuple.like] defines a tuple-like exposition only concept. This concept is |
| // not related to that. Therefore it uses a different name for the concept. |
| // |
| // TODO FMT Add a test to validate we fail when using that concept after P2165 |
| // has been implemented. |
| template <class _Tp> |
| concept __fmt_pair_like = |
| __is_specialization_v<_Tp, pair> || (__is_specialization_v<_Tp, tuple> && tuple_size_v<_Tp> == 2); |
| |
| # endif //_LIBCPP_STD_VER >= 23 |
| #endif //_LIBCPP_STD_VER >= 20 |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___FORMAT_CONCEPTS_H |