xref: /openbsd-src/gnu/llvm/libcxx/include/__algorithm/ranges_adjacent_find.h (revision 4bdff4bed0e3d54e55670334c7d0077db4170f86)
1*4bdff4beSrobert //===----------------------------------------------------------------------===//
2*4bdff4beSrobert //
3*4bdff4beSrobert // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*4bdff4beSrobert // See https://llvm.org/LICENSE.txt for license information.
5*4bdff4beSrobert // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*4bdff4beSrobert //
7*4bdff4beSrobert //===----------------------------------------------------------------------===//
8*4bdff4beSrobert 
9*4bdff4beSrobert #ifndef _LIBCPP___ALGORITHM_RANGES_ADJACENT_FIND_H
10*4bdff4beSrobert #define _LIBCPP___ALGORITHM_RANGES_ADJACENT_FIND_H
11*4bdff4beSrobert 
12*4bdff4beSrobert #include <__config>
13*4bdff4beSrobert #include <__functional/identity.h>
14*4bdff4beSrobert #include <__functional/invoke.h>
15*4bdff4beSrobert #include <__functional/ranges_operations.h>
16*4bdff4beSrobert #include <__iterator/concepts.h>
17*4bdff4beSrobert #include <__iterator/projected.h>
18*4bdff4beSrobert #include <__ranges/access.h>
19*4bdff4beSrobert #include <__ranges/concepts.h>
20*4bdff4beSrobert #include <__ranges/dangling.h>
21*4bdff4beSrobert #include <__utility/move.h>
22*4bdff4beSrobert 
23*4bdff4beSrobert #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
24*4bdff4beSrobert #  pragma GCC system_header
25*4bdff4beSrobert #endif
26*4bdff4beSrobert 
27*4bdff4beSrobert #if _LIBCPP_STD_VER > 17
28*4bdff4beSrobert 
29*4bdff4beSrobert _LIBCPP_BEGIN_NAMESPACE_STD
30*4bdff4beSrobert 
31*4bdff4beSrobert namespace ranges {
32*4bdff4beSrobert namespace __adjacent_find {
33*4bdff4beSrobert struct __fn {
34*4bdff4beSrobert 
35*4bdff4beSrobert   template <class _Iter, class _Sent, class _Proj, class _Pred>
36*4bdff4beSrobert   _LIBCPP_HIDE_FROM_ABI constexpr static
__adjacent_find_impl__fn37*4bdff4beSrobert   _Iter __adjacent_find_impl(_Iter __first, _Sent __last, _Pred& __pred, _Proj& __proj) {
38*4bdff4beSrobert     if (__first == __last)
39*4bdff4beSrobert       return __first;
40*4bdff4beSrobert 
41*4bdff4beSrobert     auto __i = __first;
42*4bdff4beSrobert     while (++__i != __last) {
43*4bdff4beSrobert       if (std::invoke(__pred, std::invoke(__proj, *__first), std::invoke(__proj, *__i)))
44*4bdff4beSrobert         return __first;
45*4bdff4beSrobert       __first = __i;
46*4bdff4beSrobert     }
47*4bdff4beSrobert     return __i;
48*4bdff4beSrobert   }
49*4bdff4beSrobert 
50*4bdff4beSrobert   template <forward_iterator _Iter, sentinel_for<_Iter> _Sent,
51*4bdff4beSrobert             class _Proj = identity,
52*4bdff4beSrobert             indirect_binary_predicate<projected<_Iter, _Proj>, projected<_Iter, _Proj>> _Pred = ranges::equal_to>
53*4bdff4beSrobert   _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr
operator__fn54*4bdff4beSrobert   _Iter operator()(_Iter __first, _Sent __last, _Pred __pred = {}, _Proj __proj = {}) const {
55*4bdff4beSrobert     return __adjacent_find_impl(std::move(__first), std::move(__last), __pred, __proj);
56*4bdff4beSrobert   }
57*4bdff4beSrobert 
58*4bdff4beSrobert   template <forward_range _Range,
59*4bdff4beSrobert             class _Proj = identity,
60*4bdff4beSrobert             indirect_binary_predicate<projected<iterator_t<_Range>, _Proj>,
61*4bdff4beSrobert                                       projected<iterator_t<_Range>, _Proj>> _Pred = ranges::equal_to>
62*4bdff4beSrobert   _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr
operator__fn63*4bdff4beSrobert   borrowed_iterator_t<_Range> operator()(_Range&& __range, _Pred __pred = {}, _Proj __proj = {}) const {
64*4bdff4beSrobert     return __adjacent_find_impl(ranges::begin(__range), ranges::end(__range), __pred, __proj);
65*4bdff4beSrobert   }
66*4bdff4beSrobert };
67*4bdff4beSrobert } // namespace __adjacent_find
68*4bdff4beSrobert 
69*4bdff4beSrobert inline namespace __cpo {
70*4bdff4beSrobert   inline constexpr auto adjacent_find = __adjacent_find::__fn{};
71*4bdff4beSrobert } // namespace __cpo
72*4bdff4beSrobert } // namespace ranges
73*4bdff4beSrobert 
74*4bdff4beSrobert _LIBCPP_END_NAMESPACE_STD
75*4bdff4beSrobert 
76*4bdff4beSrobert #endif // _LIBCPP_STD_VER > 17
77*4bdff4beSrobert 
78*4bdff4beSrobert #endif // _LIBCPP___ALGORITHM_RANGES_ADJACENT_FIND_H
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