xref: /freebsd-src/contrib/llvm-project/libcxx/include/__algorithm/iterator_operations.h (revision 753f127f3ace09432b2baeffd71a308760641a62)
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_ITERATOR_OPERATIONS_H
10 #define _LIBCPP___ALGORITHM_ITERATOR_OPERATIONS_H
11 
12 #include <__algorithm/iter_swap.h>
13 #include <__config>
14 #include <__iterator/advance.h>
15 #include <__iterator/distance.h>
16 #include <__iterator/iter_move.h>
17 #include <__iterator/iter_swap.h>
18 #include <__iterator/iterator_traits.h>
19 #include <__iterator/next.h>
20 #include <__utility/forward.h>
21 #include <__utility/move.h>
22 #include <type_traits>
23 
24 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
25 #  pragma GCC system_header
26 #endif
27 
28 _LIBCPP_BEGIN_NAMESPACE_STD
29 
30 template <class _AlgPolicy> struct _IterOps;
31 
32 #if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
33 struct _RangeAlgPolicy {};
34 
35 template <>
36 struct _IterOps<_RangeAlgPolicy> {
37   static constexpr auto advance = ranges::advance;
38   static constexpr auto distance = ranges::distance;
39   static constexpr auto __iter_move = ranges::iter_move;
40   static constexpr auto iter_swap = ranges::iter_swap;
41   static constexpr auto next = ranges::next;
42   static constexpr auto __advance_to = ranges::advance;
43 };
44 #endif
45 
46 struct _ClassicAlgPolicy {};
47 
48 template <>
49 struct _IterOps<_ClassicAlgPolicy> {
50 
51   // advance
52   template <class _Iter, class _Distance>
53   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
54   static void advance(_Iter& __iter, _Distance __count) {
55     std::advance(__iter, __count);
56   }
57 
58   // distance
59   template <class _Iter>
60   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
61   static typename iterator_traits<_Iter>::difference_type distance(_Iter __first, _Iter __last) {
62     return std::distance(__first, __last);
63   }
64 
65   // iter_move
66   template <class _Iter>
67   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
68   // Declaring the return type is necessary for the C++03 mode (which doesn't support placeholder return types).
69   static typename iterator_traits<__uncvref_t<_Iter> >::value_type&& __iter_move(_Iter&& __i) {
70     return std::move(*std::forward<_Iter>(__i));
71   }
72 
73   // iter_swap
74   template <class _Iter1, class _Iter2>
75   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
76   static void iter_swap(_Iter1&& __a, _Iter2&& __b) {
77     std::iter_swap(std::forward<_Iter1>(__a), std::forward<_Iter2>(__b));
78   }
79 
80   // next
81   template <class _Iterator>
82   _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_AFTER_CXX11
83   _Iterator next(_Iterator, _Iterator __last) {
84     return __last;
85   }
86 
87   template <class _Iter>
88   _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_AFTER_CXX11 void __advance_to(_Iter& __first, _Iter __last) {
89     __first = __last;
90   }
91 };
92 
93 _LIBCPP_END_NAMESPACE_STD
94 
95 #endif // _LIBCPP___ALGORITHM_ITERATOR_OPERATIONS_H
96