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llvm-project/libcxx/include/__memory/uninitialized_algorithms.h

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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___MEMORY_UNINITIALIZED_ALGORITHMS_H
#define _LIBCPP___MEMORY_UNINITIALIZED_ALGORITHMS_H
#include <__config>
#include <__iterator/iterator_traits.h>
#include <__memory/addressof.h>
#include <__memory/allocator_traits.h>
#include <__memory/construct_at.h>
#include <__memory/voidify.h>
#include <__utility/move.h>
#include <__utility/pair.h>
#include <__utility/transaction.h>
#include <type_traits>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
// This is a simplified version of C++20 `unreachable_sentinel` that doesn't use concepts and thus can be used in any
// language mode.
struct __unreachable_sentinel {
template <class _Iter>
_LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR bool operator!=(const _Iter&, __unreachable_sentinel) _NOEXCEPT {
return true;
}
};
// uninitialized_copy
template <class _ValueType, class _InputIterator, class _Sentinel1, class _ForwardIterator, class _Sentinel2>
inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator>
__uninitialized_copy(_InputIterator __ifirst, _Sentinel1 __ilast,
_ForwardIterator __ofirst, _Sentinel2 __olast) {
_ForwardIterator __idx = __ofirst;
#ifndef _LIBCPP_NO_EXCEPTIONS
try {
#endif
for (; __ifirst != __ilast && __idx != __olast; ++__ifirst, (void)++__idx)
::new (_VSTD::__voidify(*__idx)) _ValueType(*__ifirst);
#ifndef _LIBCPP_NO_EXCEPTIONS
} catch (...) {
_VSTD::__destroy(__ofirst, __idx);
throw;
}
#endif
return pair<_InputIterator, _ForwardIterator>(_VSTD::move(__ifirst), _VSTD::move(__idx));
}
template <class _InputIterator, class _ForwardIterator>
_ForwardIterator uninitialized_copy(_InputIterator __ifirst, _InputIterator __ilast,
_ForwardIterator __ofirst) {
typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType;
auto __result = _VSTD::__uninitialized_copy<_ValueType>(_VSTD::move(__ifirst), _VSTD::move(__ilast),
_VSTD::move(__ofirst), __unreachable_sentinel());
return _VSTD::move(__result.second);
}
// uninitialized_copy_n
template <class _ValueType, class _InputIterator, class _Size, class _ForwardIterator, class _Sentinel>
inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator>
__uninitialized_copy_n(_InputIterator __ifirst, _Size __n,
_ForwardIterator __ofirst, _Sentinel __olast) {
_ForwardIterator __idx = __ofirst;
#ifndef _LIBCPP_NO_EXCEPTIONS
try {
#endif
for (; __n > 0 && __idx != __olast; ++__ifirst, (void)++__idx, (void)--__n)
::new (_VSTD::__voidify(*__idx)) _ValueType(*__ifirst);
#ifndef _LIBCPP_NO_EXCEPTIONS
} catch (...) {
_VSTD::__destroy(__ofirst, __idx);
throw;
}
#endif
return pair<_InputIterator, _ForwardIterator>(_VSTD::move(__ifirst), _VSTD::move(__idx));
}
template <class _InputIterator, class _Size, class _ForwardIterator>
inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator uninitialized_copy_n(_InputIterator __ifirst, _Size __n,
_ForwardIterator __ofirst) {
typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType;
auto __result = _VSTD::__uninitialized_copy_n<_ValueType>(_VSTD::move(__ifirst), __n, _VSTD::move(__ofirst),
__unreachable_sentinel());
return _VSTD::move(__result.second);
}
// uninitialized_fill
template <class _ValueType, class _ForwardIterator, class _Sentinel, class _Tp>
inline _LIBCPP_HIDE_FROM_ABI
_ForwardIterator __uninitialized_fill(_ForwardIterator __first, _Sentinel __last, const _Tp& __x)
{
_ForwardIterator __idx = __first;
#ifndef _LIBCPP_NO_EXCEPTIONS
try
{
#endif
for (; __idx != __last; ++__idx)
::new (_VSTD::__voidify(*__idx)) _ValueType(__x);
#ifndef _LIBCPP_NO_EXCEPTIONS
}
catch (...)
{
_VSTD::__destroy(__first, __idx);
throw;
}
#endif
return __idx;
}
template <class _ForwardIterator, class _Tp>
inline _LIBCPP_HIDE_FROM_ABI
void uninitialized_fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __x)
{
typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType;
(void)_VSTD::__uninitialized_fill<_ValueType>(__first, __last, __x);
}
// uninitialized_fill_n
template <class _ValueType, class _ForwardIterator, class _Size, class _Tp>
inline _LIBCPP_HIDE_FROM_ABI
_ForwardIterator __uninitialized_fill_n(_ForwardIterator __first, _Size __n, const _Tp& __x)
{
_ForwardIterator __idx = __first;
#ifndef _LIBCPP_NO_EXCEPTIONS
try
{
#endif
for (; __n > 0; ++__idx, (void) --__n)
::new (_VSTD::__voidify(*__idx)) _ValueType(__x);
#ifndef _LIBCPP_NO_EXCEPTIONS
}
catch (...)
{
_VSTD::__destroy(__first, __idx);
throw;
}
#endif
return __idx;
}
template <class _ForwardIterator, class _Size, class _Tp>
inline _LIBCPP_HIDE_FROM_ABI
_ForwardIterator uninitialized_fill_n(_ForwardIterator __first, _Size __n, const _Tp& __x)
{
typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType;
return _VSTD::__uninitialized_fill_n<_ValueType>(__first, __n, __x);
}
#if _LIBCPP_STD_VER > 14
// uninitialized_default_construct
template <class _ValueType, class _ForwardIterator, class _Sentinel>
inline _LIBCPP_HIDE_FROM_ABI
_ForwardIterator __uninitialized_default_construct(_ForwardIterator __first, _Sentinel __last) {
auto __idx = __first;
#ifndef _LIBCPP_NO_EXCEPTIONS
try {
#endif
for (; __idx != __last; ++__idx)
::new (_VSTD::__voidify(*__idx)) _ValueType;
#ifndef _LIBCPP_NO_EXCEPTIONS
} catch (...) {
_VSTD::__destroy(__first, __idx);
throw;
}
#endif
return __idx;
}
template <class _ForwardIterator>
inline _LIBCPP_HIDE_FROM_ABI
void uninitialized_default_construct(_ForwardIterator __first, _ForwardIterator __last) {
using _ValueType = typename iterator_traits<_ForwardIterator>::value_type;
(void)_VSTD::__uninitialized_default_construct<_ValueType>(
_VSTD::move(__first), _VSTD::move(__last));
}
// uninitialized_default_construct_n
template <class _ValueType, class _ForwardIterator, class _Size>
inline _LIBCPP_HIDE_FROM_ABI
_ForwardIterator __uninitialized_default_construct_n(_ForwardIterator __first, _Size __n) {
auto __idx = __first;
#ifndef _LIBCPP_NO_EXCEPTIONS
try {
#endif
for (; __n > 0; ++__idx, (void) --__n)
::new (_VSTD::__voidify(*__idx)) _ValueType;
#ifndef _LIBCPP_NO_EXCEPTIONS
} catch (...) {
_VSTD::__destroy(__first, __idx);
throw;
}
#endif
return __idx;
}
template <class _ForwardIterator, class _Size>
inline _LIBCPP_HIDE_FROM_ABI
_ForwardIterator uninitialized_default_construct_n(_ForwardIterator __first, _Size __n) {
using _ValueType = typename iterator_traits<_ForwardIterator>::value_type;
return _VSTD::__uninitialized_default_construct_n<_ValueType>(_VSTD::move(__first), __n);
}
// uninitialized_value_construct
template <class _ValueType, class _ForwardIterator, class _Sentinel>
inline _LIBCPP_HIDE_FROM_ABI
_ForwardIterator __uninitialized_value_construct(_ForwardIterator __first, _Sentinel __last) {
auto __idx = __first;
#ifndef _LIBCPP_NO_EXCEPTIONS
try {
#endif
for (; __idx != __last; ++__idx)
::new (_VSTD::__voidify(*__idx)) _ValueType();
#ifndef _LIBCPP_NO_EXCEPTIONS
} catch (...) {
_VSTD::__destroy(__first, __idx);
throw;
}
#endif
return __idx;
}
template <class _ForwardIterator>
inline _LIBCPP_HIDE_FROM_ABI
void uninitialized_value_construct(_ForwardIterator __first, _ForwardIterator __last) {
using _ValueType = typename iterator_traits<_ForwardIterator>::value_type;
(void)_VSTD::__uninitialized_value_construct<_ValueType>(
_VSTD::move(__first), _VSTD::move(__last));
}
// uninitialized_value_construct_n
template <class _ValueType, class _ForwardIterator, class _Size>
inline _LIBCPP_HIDE_FROM_ABI
_ForwardIterator __uninitialized_value_construct_n(_ForwardIterator __first, _Size __n) {
auto __idx = __first;
#ifndef _LIBCPP_NO_EXCEPTIONS
try {
#endif
for (; __n > 0; ++__idx, (void) --__n)
::new (_VSTD::__voidify(*__idx)) _ValueType();
#ifndef _LIBCPP_NO_EXCEPTIONS
} catch (...) {
_VSTD::__destroy(__first, __idx);
throw;
}
#endif
return __idx;
}
template <class _ForwardIterator, class _Size>
inline _LIBCPP_HIDE_FROM_ABI
_ForwardIterator uninitialized_value_construct_n(_ForwardIterator __first, _Size __n) {
using _ValueType = typename iterator_traits<_ForwardIterator>::value_type;
return __uninitialized_value_construct_n<_ValueType>(_VSTD::move(__first), __n);
}
// uninitialized_move
template <class _ValueType, class _InputIterator, class _Sentinel1, class _ForwardIterator, class _Sentinel2,
class _IterMove>
inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator>
__uninitialized_move(_InputIterator __ifirst, _Sentinel1 __ilast,
_ForwardIterator __ofirst, _Sentinel2 __olast, _IterMove __iter_move) {
auto __idx = __ofirst;
#ifndef _LIBCPP_NO_EXCEPTIONS
try {
#endif
for (; __ifirst != __ilast && __idx != __olast; ++__idx, (void)++__ifirst) {
::new (_VSTD::__voidify(*__idx)) _ValueType(__iter_move(__ifirst));
}
#ifndef _LIBCPP_NO_EXCEPTIONS
} catch (...) {
_VSTD::__destroy(__ofirst, __idx);
throw;
}
#endif
return {_VSTD::move(__ifirst), _VSTD::move(__idx)};
}
template <class _InputIterator, class _ForwardIterator>
inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator uninitialized_move(_InputIterator __ifirst, _InputIterator __ilast,
_ForwardIterator __ofirst) {
using _ValueType = typename iterator_traits<_ForwardIterator>::value_type;
auto __iter_move = [](auto&& __iter) -> decltype(auto) { return _VSTD::move(*__iter); };
auto __result = _VSTD::__uninitialized_move<_ValueType>(_VSTD::move(__ifirst), _VSTD::move(__ilast),
_VSTD::move(__ofirst), __unreachable_sentinel(), __iter_move);
return _VSTD::move(__result.second);
}
// uninitialized_move_n
template <class _ValueType, class _InputIterator, class _Size, class _ForwardIterator, class _Sentinel, class _IterMove>
inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator>
__uninitialized_move_n(_InputIterator __ifirst, _Size __n,
_ForwardIterator __ofirst, _Sentinel __olast, _IterMove __iter_move) {
auto __idx = __ofirst;
#ifndef _LIBCPP_NO_EXCEPTIONS
try {
#endif
for (; __n > 0 && __idx != __olast; ++__idx, (void)++__ifirst, --__n)
::new (_VSTD::__voidify(*__idx)) _ValueType(__iter_move(__ifirst));
#ifndef _LIBCPP_NO_EXCEPTIONS
} catch (...) {
_VSTD::__destroy(__ofirst, __idx);
throw;
}
#endif
return {_VSTD::move(__ifirst), _VSTD::move(__idx)};
}
template <class _InputIterator, class _Size, class _ForwardIterator>
inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator>
uninitialized_move_n(_InputIterator __ifirst, _Size __n, _ForwardIterator __ofirst) {
using _ValueType = typename iterator_traits<_ForwardIterator>::value_type;
auto __iter_move = [](auto&& __iter) -> decltype(auto) { return _VSTD::move(*__iter); };
return _VSTD::__uninitialized_move_n<_ValueType>(_VSTD::move(__ifirst), __n, _VSTD::move(__ofirst),
__unreachable_sentinel(), __iter_move);
}
#endif // _LIBCPP_STD_VER > 14
#if _LIBCPP_STD_VER > 17
// Destroys every element in the range [first, last) FROM RIGHT TO LEFT using allocator
// destruction. If elements are themselves C-style arrays, they are recursively destroyed
// in the same manner.
//
// This function assumes that destructors do not throw, and that the allocator is bound to
// the correct type.
template<class _Alloc, class _BidirIter, class = __enable_if_t<
__is_cpp17_bidirectional_iterator<_BidirIter>::value
>>
_LIBCPP_HIDE_FROM_ABI
constexpr void __allocator_destroy_multidimensional(_Alloc& __alloc, _BidirIter __first, _BidirIter __last) noexcept {
using _ValueType = typename iterator_traits<_BidirIter>::value_type;
static_assert(is_same_v<typename allocator_traits<_Alloc>::value_type, _ValueType>,
"The allocator should already be rebound to the correct type");
if (__first == __last)
return;
if constexpr (is_array_v<_ValueType>) {
static_assert(!is_unbounded_array_v<_ValueType>,
"arrays of unbounded arrays don't exist, but if they did we would mess up here");
using _Element = remove_extent_t<_ValueType>;
__allocator_traits_rebind_t<_Alloc, _Element> __elem_alloc(__alloc);
do {
--__last;
decltype(auto) __array = *__last;
std::__allocator_destroy_multidimensional(__elem_alloc, __array, __array + extent_v<_ValueType>);
} while (__last != __first);
} else {
do {
--__last;
allocator_traits<_Alloc>::destroy(__alloc, std::addressof(*__last));
} while (__last != __first);
}
}
// Constructs the object at the given location using the allocator's construct method.
//
// If the object being constructed is an array, each element of the array is allocator-constructed,
// recursively. If an exception is thrown during the construction of an array, the initialized
// elements are destroyed in reverse order of initialization using allocator destruction.
//
// This function assumes that the allocator is bound to the correct type.
template<class _Alloc, class _Tp>
_LIBCPP_HIDE_FROM_ABI
constexpr void __allocator_construct_at(_Alloc& __alloc, _Tp* __loc) {
static_assert(is_same_v<typename allocator_traits<_Alloc>::value_type, _Tp>,
"The allocator should already be rebound to the correct type");
if constexpr (is_array_v<_Tp>) {
using _Element = remove_extent_t<_Tp>;
__allocator_traits_rebind_t<_Alloc, _Element> __elem_alloc(__alloc);
size_t __i = 0;
_Tp& __array = *__loc;
// If an exception is thrown, destroy what we have constructed so far in reverse order.
__transaction __guard([&]() { std::__allocator_destroy_multidimensional(__elem_alloc, __array, __array + __i); });
for (; __i != extent_v<_Tp>; ++__i) {
std::__allocator_construct_at(__elem_alloc, std::addressof(__array[__i]));
}
__guard.__complete();
} else {
allocator_traits<_Alloc>::construct(__alloc, __loc);
}
}
// Constructs the object at the given location using the allocator's construct method, passing along
// the provided argument.
//
// If the object being constructed is an array, the argument is also assumed to be an array. Each
// each element of the array being constructed is allocator-constructed from the corresponding
// element of the argument array. If an exception is thrown during the construction of an array,
// the initialized elements are destroyed in reverse order of initialization using allocator
// destruction.
//
// This function assumes that the allocator is bound to the correct type.
template<class _Alloc, class _Tp, class _Arg>
_LIBCPP_HIDE_FROM_ABI
constexpr void __allocator_construct_at(_Alloc& __alloc, _Tp* __loc, _Arg const& __arg) {
static_assert(is_same_v<typename allocator_traits<_Alloc>::value_type, _Tp>,
"The allocator should already be rebound to the correct type");
if constexpr (is_array_v<_Tp>) {
static_assert(is_array_v<_Arg>,
"Provided non-array initialization argument to __allocator_construct_at when "
"trying to construct an array.");
using _Element = remove_extent_t<_Tp>;
__allocator_traits_rebind_t<_Alloc, _Element> __elem_alloc(__alloc);
size_t __i = 0;
_Tp& __array = *__loc;
// If an exception is thrown, destroy what we have constructed so far in reverse order.
__transaction __guard([&]() { std::__allocator_destroy_multidimensional(__elem_alloc, __array, __array + __i); });
for (; __i != extent_v<_Tp>; ++__i) {
std::__allocator_construct_at(__elem_alloc, std::addressof(__array[__i]), __arg[__i]);
}
__guard.__complete();
} else {
allocator_traits<_Alloc>::construct(__alloc, __loc, __arg);
}
}
// Given a range starting at it and containing n elements, initializes each element in the
// range from left to right using the construct method of the allocator (rebound to the
// correct type).
//
// If an exception is thrown, the initialized elements are destroyed in reverse order of
// initialization using allocator_traits destruction. If the elements in the range are C-style
// arrays, they are initialized element-wise using allocator construction, and recursively so.
template<class _Alloc, class _BidirIter, class _Tp, class _Size = typename iterator_traits<_BidirIter>::difference_type>
_LIBCPP_HIDE_FROM_ABI
constexpr void __uninitialized_allocator_fill_n(_Alloc& __alloc, _BidirIter __it, _Size __n, _Tp const& __value) {
using _ValueType = typename iterator_traits<_BidirIter>::value_type;
__allocator_traits_rebind_t<_Alloc, _ValueType> __value_alloc(__alloc);
_BidirIter __begin = __it;
// If an exception is thrown, destroy what we have constructed so far in reverse order.
__transaction __guard([&]() { std::__allocator_destroy_multidimensional(__value_alloc, __begin, __it); });
for (; __n != 0; --__n, ++__it) {
std::__allocator_construct_at(__value_alloc, std::addressof(*__it), __value);
}
__guard.__complete();
}
// Same as __uninitialized_allocator_fill_n, but doesn't pass any initialization argument
// to the allocator's construct method, which results in value initialization.
template<class _Alloc, class _BidirIter, class _Size = typename iterator_traits<_BidirIter>::difference_type>
_LIBCPP_HIDE_FROM_ABI
constexpr void __uninitialized_allocator_value_construct_n(_Alloc& __alloc, _BidirIter __it, _Size __n) {
using _ValueType = typename iterator_traits<_BidirIter>::value_type;
__allocator_traits_rebind_t<_Alloc, _ValueType> __value_alloc(__alloc);
_BidirIter __begin = __it;
// If an exception is thrown, destroy what we have constructed so far in reverse order.
__transaction __guard([&]() { std::__allocator_destroy_multidimensional(__value_alloc, __begin, __it); });
for (; __n != 0; --__n, ++__it) {
std::__allocator_construct_at(__value_alloc, std::addressof(*__it));
}
__guard.__complete();
}
#endif // _LIBCPP_STD_VER > 17
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___MEMORY_UNINITIALIZED_ALGORITHMS_H
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