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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_FIND_H
#define _LIBCPP___ALGORITHM_FIND_H
#include <__algorithm/find_segment_if.h>
#include <__algorithm/min.h>
#include <__algorithm/unwrap_iter.h>
#include <__bit/countr.h>
#include <__bit/invert_if.h>
#include <__config>
#include <__functional/identity.h>
#include <__functional/invoke.h>
#include <__fwd/bit_reference.h>
#include <__iterator/segmented_iterator.h>
#include <__string/constexpr_c_functions.h>
#include <__type_traits/is_integral.h>
#include <__type_traits/is_same.h>
#include <__type_traits/is_signed.h>
#include <__utility/move.h>
#include <limits>
#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
# include <cwchar>
#endif
#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 _Iter, class _Sent, class _Tp, class _Proj>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _Iter
__find(_Iter __first, _Sent __last, const _Tp& __value, _Proj& __proj) {
for (; __first != __last; ++__first)
if (std::__invoke(__proj, *__first) == __value)
break;
return __first;
}
// trivially equality comparable implementations
template <class _Tp,
class _Up,
class _Proj,
__enable_if_t<__is_identity<_Proj>::value && __libcpp_is_trivially_equality_comparable<_Tp, _Up>::value &&
sizeof(_Tp) == 1,
int> = 0>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _Tp* __find(_Tp* __first, _Tp* __last, const _Up& __value, _Proj&) {
if (auto __ret = std::__constexpr_memchr(__first, __value, __last - __first))
return __ret;
return __last;
}
#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
template <class _Tp,
class _Up,
class _Proj,
__enable_if_t<__is_identity<_Proj>::value && __libcpp_is_trivially_equality_comparable<_Tp, _Up>::value &&
sizeof(_Tp) == sizeof(wchar_t) && _LIBCPP_ALIGNOF(_Tp) >= _LIBCPP_ALIGNOF(wchar_t),
int> = 0>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _Tp* __find(_Tp* __first, _Tp* __last, const _Up& __value, _Proj&) {
if (auto __ret = std::__constexpr_wmemchr(__first, __value, __last - __first))
return __ret;
return __last;
}
#endif // _LIBCPP_HAS_NO_WIDE_CHARACTERS
// TODO: This should also be possible to get right with different signedness
// cast integral types to allow vectorization
template <class _Tp,
class _Up,
class _Proj,
__enable_if_t<__is_identity<_Proj>::value && !__libcpp_is_trivially_equality_comparable<_Tp, _Up>::value &&
is_integral<_Tp>::value && is_integral<_Up>::value &&
is_signed<_Tp>::value == is_signed<_Up>::value,
int> = 0>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _Tp*
__find(_Tp* __first, _Tp* __last, const _Up& __value, _Proj& __proj) {
if (__value < numeric_limits<_Tp>::min() || __value > numeric_limits<_Tp>::max())
return __last;
return std::__find(__first, __last, _Tp(__value), __proj);
}
// __bit_iterator implementation
template <bool _ToFind, class _Cp, bool _IsConst>
_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __bit_iterator<_Cp, _IsConst>
__find_bool(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type __n) {
using _It = __bit_iterator<_Cp, _IsConst>;
using __storage_type = typename _It::__storage_type;
const int __bits_per_word = _It::__bits_per_word;
// 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));
__storage_type __b = std::__invert_if<!_ToFind>(*__first.__seg_) & __m;
if (__b)
return _It(__first.__seg_, static_cast<unsigned>(std::__libcpp_ctz(__b)));
if (__n == __dn)
return __first + __n;
__n -= __dn;
++__first.__seg_;
}
// do middle whole words
for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word) {
__storage_type __b = std::__invert_if<!_ToFind>(*__first.__seg_);
if (__b)
return _It(__first.__seg_, static_cast<unsigned>(std::__libcpp_ctz(__b)));
}
// do last partial word
if (__n > 0) {
__storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
__storage_type __b = std::__invert_if<!_ToFind>(*__first.__seg_) & __m;
if (__b)
return _It(__first.__seg_, static_cast<unsigned>(std::__libcpp_ctz(__b)));
}
return _It(__first.__seg_, static_cast<unsigned>(__n));
}
template <class _Cp, bool _IsConst, class _Tp, class _Proj, __enable_if_t<__is_identity<_Proj>::value, int> = 0>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_iterator<_Cp, _IsConst>
__find(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last, const _Tp& __value, _Proj&) {
if (static_cast<bool>(__value))
return std::__find_bool<true>(__first, static_cast<typename _Cp::size_type>(__last - __first));
return std::__find_bool<false>(__first, static_cast<typename _Cp::size_type>(__last - __first));
}
// segmented iterator implementation
template <class>
struct __find_segment;
template <class _SegmentedIterator,
class _Tp,
class _Proj,
__enable_if_t<__is_segmented_iterator<_SegmentedIterator>::value, int> = 0>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _SegmentedIterator
__find(_SegmentedIterator __first, _SegmentedIterator __last, const _Tp& __value, _Proj& __proj) {
return std::__find_segment_if(std::move(__first), std::move(__last), __find_segment<_Tp>(__value), __proj);
}
template <class _Tp>
struct __find_segment {
const _Tp& __value_;
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR __find_segment(const _Tp& __value) : __value_(__value) {}
template <class _InputIterator, class _Proj>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR _InputIterator
operator()(_InputIterator __first, _InputIterator __last, _Proj& __proj) const {
return std::__find(__first, __last, __value_, __proj);
}
};
// public API
template <class _InputIterator, class _Tp>
_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _InputIterator
find(_InputIterator __first, _InputIterator __last, const _Tp& __value) {
__identity __proj;
return std::__rewrap_iter(
__first, std::__find(std::__unwrap_iter(__first), std::__unwrap_iter(__last), __value, __proj));
}
_LIBCPP_END_NAMESPACE_STD
_LIBCPP_POP_MACROS
#endif // _LIBCPP___ALGORITHM_FIND_H
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