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___FWD_SUBRANGE_H 10 #define _LIBCPP___FWD_SUBRANGE_H 11 12 #include <__concepts/copyable.h> 13 #include <__config> 14 #include <__iterator/concepts.h> 15 #include <cstddef> 16 17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 18 # pragma GCC system_header 19 #endif 20 21 #if _LIBCPP_STD_VER >= 20 22 23 _LIBCPP_BEGIN_NAMESPACE_STD 24 25 namespace ranges { 26 27 enum class subrange_kind : bool { unsized, sized }; 28 29 template <input_or_output_iterator _Iter, sentinel_for<_Iter> _Sent, subrange_kind _Kind> 30 requires(_Kind == subrange_kind::sized || !sized_sentinel_for<_Sent, _Iter>) 31 class _LIBCPP_TEMPLATE_VIS subrange; 32 33 template <size_t _Index, class _Iter, class _Sent, subrange_kind _Kind> 34 requires((_Index == 0 && copyable<_Iter>) || _Index == 1) 35 _LIBCPP_HIDE_FROM_ABI constexpr auto get(const subrange<_Iter, _Sent, _Kind>&); 36 37 template <size_t _Index, class _Iter, class _Sent, subrange_kind _Kind> 38 requires(_Index < 2) 39 _LIBCPP_HIDE_FROM_ABI constexpr auto get(subrange<_Iter, _Sent, _Kind>&&); 40 41 } // namespace ranges 42 43 using ranges::get; 44 45 _LIBCPP_END_NAMESPACE_STD 46 47 #endif // _LIBCPP_STD_VER >= 20 48 49 #endif // _LIBCPP___FWD_SUBRANGE_H 50