2 //===----------------------------------------------------------------------===//
4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 // See https://llvm.org/LICENSE.txt for license information.
6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
8 //===----------------------------------------------------------------------===//
10 #ifndef _LIBCPP___RANGES_DANGLING_H
11 #define _LIBCPP___RANGES_DANGLING_H
14 #include <__ranges/access.h>
15 #include <__ranges/concepts.h>
16 #include <type_traits>
18 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
19 #pragma GCC system_header
23 #include <__undef_macros>
25 _LIBCPP_BEGIN_NAMESPACE_STD
27 #if !defined(_LIBCPP_HAS_NO_RANGES)
32 _LIBCPP_HIDE_FROM_ABI constexpr dangling(auto&&...) noexcept {}
36 using borrowed_iterator_t = _If<borrowed_range<_Rp>, iterator_t<_Rp>, dangling>;
38 // borrowed_subrange_t defined in <__ranges/subrange.h>
41 #endif // !_LIBCPP_HAS_NO_RANGES
43 _LIBCPP_END_NAMESPACE_STD
47 #endif // _LIBCPP___RANGES_DANGLING_H