v1/__fwd/subrange.h

0001 //===---------------------------------------------------------------------===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===---------------------------------------------------------------------===//
0008
0009 #ifndef _LIBCPP___FWD_SUBRANGE_H
0010 #define _LIBCPP___FWD_SUBRANGE_H
0011
0012 #include <__concepts/copyable.h>
0013 #include <__config>
0014 #include <__cstddef/size_t.h>
0015 #include <__iterator/concepts.h>
0016
0017 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0018 #  pragma GCC system_header
0019 #endif
0020
0021 #if _LIBCPP_STD_VER >= 20
0022
0023 _LIBCPP_BEGIN_NAMESPACE_STD
0024
0025 namespace ranges {
0026
0027 enum class subrange_kind : bool { unsized, sized };
0028
0029 template <input_or_output_iterator _Iter, sentinel_for<_Iter> _Sent, subrange_kind _Kind>
0030   requires(_Kind == subrange_kind::sized || !sized_sentinel_for<_Sent, _Iter>)
0031 class _LIBCPP_TEMPLATE_VIS subrange;
0032
0033 template <size_t _Index, class _Iter, class _Sent, subrange_kind _Kind>
0034   requires((_Index == 0 && copyable<_Iter>) || _Index == 1)
0035 _LIBCPP_HIDE_FROM_ABI constexpr auto get(const subrange<_Iter, _Sent, _Kind>&);
0036
0037 template <size_t _Index, class _Iter, class _Sent, subrange_kind _Kind>
0038   requires(_Index < 2)
0039 _LIBCPP_HIDE_FROM_ABI constexpr auto get(subrange<_Iter, _Sent, _Kind>&&);
0040
0041 } // namespace ranges
0042
0043 using ranges::get;
0044
0045 _LIBCPP_END_NAMESPACE_STD
0046
0047 #endif // _LIBCPP_STD_VER >= 20
0048
0049 #endif // _LIBCPP___FWD_SUBRANGE_H