| // -*- C++ -*- |
| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef _LIBCPP___ALGORITHM_COUNT_H |
| #define _LIBCPP___ALGORITHM_COUNT_H |
| |
| #include <__algorithm/iterator_operations.h> |
| #include <__algorithm/min.h> |
| #include <__bit/invert_if.h> |
| #include <__bit/popcount.h> |
| #include <__config> |
| #include <__functional/identity.h> |
| #include <__functional/invoke.h> |
| #include <__fwd/bit_reference.h> |
| #include <__iterator/iterator_traits.h> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| _LIBCPP_PUSH_MACROS |
| #include <__undef_macros> |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| // generic implementation |
| template <class _AlgPolicy, class _Iter, class _Sent, class _Tp, class _Proj> |
| _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 typename _IterOps<_AlgPolicy>::template __difference_type<_Iter> |
| __count(_Iter __first, _Sent __last, const _Tp& __value, _Proj& __proj) { |
| typename _IterOps<_AlgPolicy>::template __difference_type<_Iter> __r(0); |
| for (; __first != __last; ++__first) |
| if (std::__invoke(__proj, *__first) == __value) |
| ++__r; |
| return __r; |
| } |
| |
| // __bit_iterator implementation |
| template <bool _ToCount, class _Cp, bool _IsConst> |
| _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 typename __bit_iterator<_Cp, _IsConst>::difference_type |
| __count_bool(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type __n) { |
| using _It = __bit_iterator<_Cp, _IsConst>; |
| using __storage_type = typename _It::__storage_type; |
| using difference_type = typename _It::difference_type; |
| |
| const int __bits_per_word = _It::__bits_per_word; |
| difference_type __r = 0; |
| // do first partial word |
| if (__first.__ctz_ != 0) { |
| __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_); |
| __storage_type __dn = std::min(__clz_f, __n); |
| __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn)); |
| __r = std::__libcpp_popcount(std::__invert_if<!_ToCount>(*__first.__seg_) & __m); |
| __n -= __dn; |
| ++__first.__seg_; |
| } |
| // do middle whole words |
| for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word) |
| __r += std::__libcpp_popcount(std::__invert_if<!_ToCount>(*__first.__seg_)); |
| // do last partial word |
| if (__n > 0) { |
| __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n); |
| __r += std::__libcpp_popcount(std::__invert_if<!_ToCount>(*__first.__seg_) & __m); |
| } |
| return __r; |
| } |
| |
| template <class, class _Cp, bool _IsConst, class _Tp, class _Proj, __enable_if_t<__is_identity<_Proj>::value, int> = 0> |
| _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __iter_diff_t<__bit_iterator<_Cp, _IsConst> > |
| __count(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last, const _Tp& __value, _Proj&) { |
| if (__value) |
| return std::__count_bool<true>(__first, static_cast<typename _Cp::size_type>(__last - __first)); |
| return std::__count_bool<false>(__first, static_cast<typename _Cp::size_type>(__last - __first)); |
| } |
| |
| template <class _InputIterator, class _Tp> |
| _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __iter_diff_t<_InputIterator> |
| count(_InputIterator __first, _InputIterator __last, const _Tp& __value) { |
| __identity __proj; |
| return std::__count<_ClassicAlgPolicy>(__first, __last, __value, __proj); |
| } |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| _LIBCPP_POP_MACROS |
| |
| #endif // _LIBCPP___ALGORITHM_COUNT_H |