1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef _LIBCPP___TUPLE_TUPLE_LIKE_H
10#define _LIBCPP___TUPLE_TUPLE_LIKE_H
11
12#include <__config>
13#include <__fwd/subrange.h>
14#include <__tuple/tuple_like_no_subrange.h>
15#include <__tuple/tuple_size.h>
16#include <__type_traits/remove_cvref.h>
17
18#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
19# pragma GCC system_header
20#endif
21
22_LIBCPP_BEGIN_NAMESPACE_STD
23
24#if _LIBCPP_STD_VER >= 20
25
26template <class _Tp>
27inline constexpr bool __is_ranges_subrange_v = false;
28
29template <class _Iter, class _Sent, ranges::subrange_kind _Kind>
30inline constexpr bool __is_ranges_subrange_v<ranges::subrange<_Iter, _Sent, _Kind>> = true;
31
32template <class _Tp>
33concept __tuple_like = __tuple_like_no_subrange<_Tp> || __is_ranges_subrange_v<remove_cvref_t<_Tp>>;
34
35// As of writing this comment every use of `pair-like` in the standard excludes `ranges::subrange`, so
36// you most likely want to use `__pair_like_no_subrange` if you're looking for `pair-like`.
37
38#endif // _LIBCPP_STD_VER >= 20
39
40_LIBCPP_END_NAMESPACE_STD
41
42#endif // _LIBCPP___TUPLE_TUPLE_LIKE_H
43