v1/__algorithm/ranges_find_if.h

0001 //===----------------------------------------------------------------------===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008
0009 #ifndef _LIBCPP___ALGORITHM_RANGES_FIND_IF_H
0010 #define _LIBCPP___ALGORITHM_RANGES_FIND_IF_H
0011
0012 #include <__config>
0013 #include <__functional/identity.h>
0014 #include <__functional/invoke.h>
0015 #include <__functional/ranges_operations.h>
0016 #include <__iterator/concepts.h>
0017 #include <__iterator/projected.h>
0018 #include <__ranges/access.h>
0019 #include <__ranges/concepts.h>
0020 #include <__ranges/dangling.h>
0021 #include <__utility/move.h>
0022
0023 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0024 #  pragma GCC system_header
0025 #endif
0026
0027 _LIBCPP_PUSH_MACROS
0028 #include <__undef_macros>
0029
0030 #if _LIBCPP_STD_VER >= 20
0031
0032 _LIBCPP_BEGIN_NAMESPACE_STD
0033
0034 namespace ranges {
0035
0036 template <class _Ip, class _Sp, class _Pred, class _Proj>
0037 _LIBCPP_HIDE_FROM_ABI constexpr _Ip __find_if_impl(_Ip __first, _Sp __last, _Pred& __pred, _Proj& __proj) {
0038   for (; __first != __last; ++__first) {
0039     if (std::invoke(__pred, std::invoke(__proj, *__first)))
0040       break;
0041   }
0042   return __first;
0043 }
0044
0045 struct __find_if {
0046   template <input_iterator _Ip,
0047             sentinel_for<_Ip> _Sp,
0048             class _Proj = identity,
0049             indirect_unary_predicate<projected<_Ip, _Proj>> _Pred>
0050   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Ip
0051   operator()(_Ip __first, _Sp __last, _Pred __pred, _Proj __proj = {}) const {
0052     return ranges::__find_if_impl(std::move(__first), std::move(__last), __pred, __proj);
0053   }
0054
0055   template <input_range _Rp, class _Proj = identity, indirect_unary_predicate<projected<iterator_t<_Rp>, _Proj>> _Pred>
0056   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_Rp>
0057   operator()(_Rp&& __r, _Pred __pred, _Proj __proj = {}) const {
0058     return ranges::__find_if_impl(ranges::begin(__r), ranges::end(__r), __pred, __proj);
0059   }
0060 };
0061
0062 inline namespace __cpo {
0063 inline constexpr auto find_if = __find_if{};
0064 } // namespace __cpo
0065 } // namespace ranges
0066
0067 _LIBCPP_END_NAMESPACE_STD
0068
0069 #endif // _LIBCPP_STD_VER >= 20
0070
0071 _LIBCPP_POP_MACROS
0072
0073 #endif // _LIBCPP___ALGORITHM_RANGES_FIND_IF_H