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_FIND_IF_H
10 #define _LIBCPP___ALGORITHM_RANGES_FIND_IF_H
11 
12 #include <__config>
13 #include <__functional/identity.h>
14 #include <__functional/invoke.h>
15 #include <__functional/ranges_operations.h>
16 #include <__iterator/concepts.h>
17 #include <__iterator/projected.h>
18 #include <__ranges/access.h>
19 #include <__ranges/concepts.h>
20 #include <__ranges/dangling.h>
21 #include <__utility/move.h>
22 
23 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
24 #  pragma GCC system_header
25 #endif
26 
27 _LIBCPP_PUSH_MACROS
28 #include <__undef_macros>
29 
30 #if _LIBCPP_STD_VER >= 20
31 
32 _LIBCPP_BEGIN_NAMESPACE_STD
33 
34 namespace ranges {
35 
36 template <class _Ip, class _Sp, class _Pred, class _Proj>
37 _LIBCPP_HIDE_FROM_ABI constexpr _Ip __find_if_impl(_Ip __first, _Sp __last, _Pred& __pred, _Proj& __proj) {
38   for (; __first != __last; ++__first) {
39     if (std::invoke(__pred, std::invoke(__proj, *__first)))
40       break;
41   }
42   return __first;
43 }
44 
45 namespace __find_if {
46 struct __fn {
47   template <input_iterator _Ip,
48             sentinel_for<_Ip> _Sp,
49             class _Proj = identity,
50             indirect_unary_predicate<projected<_Ip, _Proj>> _Pred>
51   _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr _Ip
52   operator()(_Ip __first, _Sp __last, _Pred __pred, _Proj __proj = {}) const {
53     return ranges::__find_if_impl(std::move(__first), std::move(__last), __pred, __proj);
54   }
55 
56   template <input_range _Rp, class _Proj = identity, indirect_unary_predicate<projected<iterator_t<_Rp>, _Proj>> _Pred>
57   _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_Rp>
58   operator()(_Rp&& __r, _Pred __pred, _Proj __proj = {}) const {
59     return ranges::__find_if_impl(ranges::begin(__r), ranges::end(__r), __pred, __proj);
60   }
61 };
62 } // namespace __find_if
63 
64 inline namespace __cpo {
65 inline constexpr auto find_if = __find_if::__fn{};
66 } // namespace __cpo
67 } // namespace ranges
68 
69 _LIBCPP_END_NAMESPACE_STD
70 
71 #endif // _LIBCPP_STD_VER >= 20
72 
73 _LIBCPP_POP_MACROS
74 
75 #endif // _LIBCPP___ALGORITHM_RANGES_FIND_IF_H
76