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_COUNT_IF_H 10 #define _LIBCPP___ALGORITHM_RANGES_COUNT_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/incrementable_traits.h> 18 #include <__iterator/projected.h> 19 #include <__ranges/access.h> 20 #include <__ranges/concepts.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 #if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES) 28 29 _LIBCPP_BEGIN_NAMESPACE_STD 30 31 namespace ranges { 32 template <class _Iter, class _Sent, class _Proj, class _Pred> 33 _LIBCPP_HIDE_FROM_ABI constexpr 34 iter_difference_t<_Iter> __count_if_impl(_Iter __first, _Sent __last, 35 _Pred& __pred, _Proj& __proj) { 36 iter_difference_t<_Iter> __counter(0); 37 for (; __first != __last; ++__first) { 38 if (std::invoke(__pred, std::invoke(__proj, *__first))) 39 ++__counter; 40 } 41 return __counter; 42 } 43 44 namespace __count_if { 45 struct __fn { 46 template <input_iterator _Iter, sentinel_for<_Iter> _Sent, class _Proj = identity, 47 indirect_unary_predicate<projected<_Iter, _Proj>> _Predicate> 48 _LIBCPP_HIDE_FROM_ABI constexpr 49 iter_difference_t<_Iter> operator()(_Iter __first, _Sent __last, _Predicate __pred, _Proj __proj = {}) const { 50 return ranges::__count_if_impl(std::move(__first), std::move(__last), __pred, __proj); 51 } 52 53 template <input_range _Range, class _Proj = identity, 54 indirect_unary_predicate<projected<iterator_t<_Range>, _Proj>> _Predicate> 55 _LIBCPP_HIDE_FROM_ABI constexpr 56 range_difference_t<_Range> operator()(_Range&& __r, _Predicate __pred, _Proj __proj = {}) const { 57 return ranges::__count_if_impl(ranges::begin(__r), ranges::end(__r), __pred, __proj); 58 } 59 }; 60 } // namespace __count_if 61 62 inline namespace __cpo { 63 inline constexpr auto count_if = __count_if::__fn{}; 64 } // namespace __cpo 65 } // namespace ranges 66 67 _LIBCPP_END_NAMESPACE_STD 68 69 #endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES) 70 71 #endif // _LIBCPP___ALGORITHM_RANGES_COUNT_IF_H 72