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// -*- 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_EXT 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
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