xref: /freebsd-src/contrib/llvm-project/libcxx/include/__ranges/dangling.h (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1fe6060f1SDimitry Andric // -*- C++ -*-
2fe6060f1SDimitry Andric //===----------------------------------------------------------------------===//
3fe6060f1SDimitry Andric //
4fe6060f1SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5fe6060f1SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
6fe6060f1SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7fe6060f1SDimitry Andric //
8fe6060f1SDimitry Andric //===----------------------------------------------------------------------===//
9fe6060f1SDimitry Andric 
10fe6060f1SDimitry Andric #ifndef _LIBCPP___RANGES_DANGLING_H
11fe6060f1SDimitry Andric #define _LIBCPP___RANGES_DANGLING_H
12fe6060f1SDimitry Andric 
13fe6060f1SDimitry Andric #include <__config>
14fe6060f1SDimitry Andric #include <__ranges/access.h>
15fe6060f1SDimitry Andric #include <__ranges/concepts.h>
16bdd1243dSDimitry Andric #include <__type_traits/conditional.h>
17fe6060f1SDimitry Andric 
18fe6060f1SDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
19fe6060f1SDimitry Andric #  pragma GCC system_header
20fe6060f1SDimitry Andric #endif
21fe6060f1SDimitry Andric 
22fe6060f1SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD
23fe6060f1SDimitry Andric 
24*06c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 20
25fe6060f1SDimitry Andric 
26fe6060f1SDimitry Andric namespace ranges {
27fe6060f1SDimitry Andric struct dangling {
28fe6060f1SDimitry Andric   dangling() = default;
danglingdangling29fe6060f1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI constexpr dangling(auto&&...) noexcept {}
30fe6060f1SDimitry Andric };
31fe6060f1SDimitry Andric 
32fe6060f1SDimitry Andric template <range _Rp>
33fe6060f1SDimitry Andric using borrowed_iterator_t = _If<borrowed_range<_Rp>, iterator_t<_Rp>, dangling>;
34fe6060f1SDimitry Andric 
35fe6060f1SDimitry Andric // borrowed_subrange_t defined in <__ranges/subrange.h>
36fe6060f1SDimitry Andric } // namespace ranges
37fe6060f1SDimitry Andric 
38*06c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 20
39fe6060f1SDimitry Andric 
40fe6060f1SDimitry Andric _LIBCPP_END_NAMESPACE_STD
41fe6060f1SDimitry Andric 
42fe6060f1SDimitry Andric #endif // _LIBCPP___RANGES_DANGLING_H
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