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___ALGORITHM_RANGES_ITERATOR_CONCEPT_H
10 #define _LIBCPP___ALGORITHM_RANGES_ITERATOR_CONCEPT_H
11 
12 #include <__config>
13 #include <__iterator/concepts.h>
14 #include <__iterator/iterator_traits.h>
15 #include <__type_traits/remove_cvref.h>
16 
17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
18 #  pragma GCC system_header
19 #endif
20 
21 #if _LIBCPP_STD_VER > 17
22 
23 _LIBCPP_BEGIN_NAMESPACE_STD
24 
25 namespace ranges {
26 
27 template <class _IterMaybeQualified>
__get_iterator_concept()28 consteval auto __get_iterator_concept() {
29   using _Iter = __remove_cvref_t<_IterMaybeQualified>;
30 
31   if constexpr (contiguous_iterator<_Iter>)
32     return contiguous_iterator_tag();
33   else if constexpr (random_access_iterator<_Iter>)
34     return random_access_iterator_tag();
35   else if constexpr (bidirectional_iterator<_Iter>)
36     return bidirectional_iterator_tag();
37   else if constexpr (forward_iterator<_Iter>)
38     return forward_iterator_tag();
39   else if constexpr (input_iterator<_Iter>)
40     return input_iterator_tag();
41 }
42 
43 template <class _Iter>
44 using __iterator_concept = decltype(__get_iterator_concept<_Iter>());
45 
46 } // namespace ranges
47 _LIBCPP_END_NAMESPACE_STD
48 
49 #endif // _LIBCPP_STD_VER > 17
50 
51 #endif // _LIBCPP___ALGORITHM_RANGES_ITERATOR_CONCEPT_H
52