xref: /freebsd-src/contrib/llvm-project/libcxx/include/__iterator/projected.h (revision 81ad626541db97eb356e2c1d4a20eb2a26a766ab)
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 #ifndef _LIBCPP___ITERATOR_PROJECTED_H
10fe6060f1SDimitry Andric #define _LIBCPP___ITERATOR_PROJECTED_H
11fe6060f1SDimitry Andric 
12fe6060f1SDimitry Andric #include <__config>
13fe6060f1SDimitry Andric #include <__iterator/concepts.h>
14fe6060f1SDimitry Andric #include <__iterator/incrementable_traits.h>
15fe6060f1SDimitry Andric #include <type_traits>
16fe6060f1SDimitry Andric 
17fe6060f1SDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
18fe6060f1SDimitry Andric #  pragma GCC system_header
19fe6060f1SDimitry Andric #endif
20fe6060f1SDimitry Andric 
21fe6060f1SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD
22fe6060f1SDimitry Andric 
23*81ad6265SDimitry Andric #if _LIBCPP_STD_VER > 17
24fe6060f1SDimitry Andric 
25fe6060f1SDimitry Andric template<indirectly_readable _It, indirectly_regular_unary_invocable<_It> _Proj>
26fe6060f1SDimitry Andric struct projected {
27fe6060f1SDimitry Andric   using value_type = remove_cvref_t<indirect_result_t<_Proj&, _It>>;
28fe6060f1SDimitry Andric   indirect_result_t<_Proj&, _It> operator*() const; // not defined
29fe6060f1SDimitry Andric };
30fe6060f1SDimitry Andric 
31fe6060f1SDimitry Andric template<weakly_incrementable _It, class _Proj>
32fe6060f1SDimitry Andric struct incrementable_traits<projected<_It, _Proj>> {
33fe6060f1SDimitry Andric   using difference_type = iter_difference_t<_It>;
34fe6060f1SDimitry Andric };
35fe6060f1SDimitry Andric 
36*81ad6265SDimitry Andric #endif // _LIBCPP_STD_VER > 17
37fe6060f1SDimitry Andric 
38fe6060f1SDimitry Andric _LIBCPP_END_NAMESPACE_STD
39fe6060f1SDimitry Andric 
40fe6060f1SDimitry Andric #endif // _LIBCPP___ITERATOR_PROJECTED_H
41