shylie/llvm-project
1
0
Fork 0
Code Issues Pull Requests Actions 6 Packages Projects Releases Wiki Activity
llvm-project/libcxx/include/__memory/uninitialized_algorithms.h
Nikolas Klauser 7458908f12 [libc++] Improve binary size when using __transaction 
__exception_guard is a no-op in -fno-exceptions mode to produce better code-gen. This means that we don't provide the strong exception guarantees. However, Clang doesn't generate cleanup code with exceptions disabled, so even if we wanted to provide the strong exception guarantees we couldn't. This is also only relevant for constructs with a stack of -fexceptions > -fno-exceptions > -fexceptions code, since the exception can't be caught where exceptions are disabled. While -fexceptions > -fno-exceptions is quite common (e.g. libc++.dylib > -fno-exceptions), having another layer with exceptions enabled seems a lot less common, especially one that tries to catch an exception through -fno-exceptions code.

Fixes https://github.com/llvm/llvm-project/issues/56783

Reviewed By: ldionne, Mordante, huixie90, #libc

Spies: EricWF, alexfh, hans, joanahalili, libcxx-commits

Differential Revision: https://reviews.llvm.org/D133661
2023-01-23 04:57:32 +01:00

647 lines
25 KiB
C++
Raw Blame History

// -*- 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 <__algorithm/copy.h>
#include <__algorithm/move.h>
#include <__config>
#include <__iterator/iterator_traits.h>
#include <__iterator/reverse_iterator.h>
#include <__memory/addressof.h>
#include <__memory/allocator_traits.h>
#include <__memory/construct_at.h>
#include <__memory/pointer_traits.h>
#include <__memory/voidify.h>
#include <__type_traits/extent.h>
#include <__type_traits/is_array.h>
#include <__type_traits/is_constant_evaluated.h>
#include <__type_traits/is_trivially_copy_assignable.h>
#include <__type_traits/is_trivially_copy_constructible.h>
#include <__type_traits/is_trivially_move_assignable.h>
#include <__type_traits/is_trivially_move_constructible.h>
#include <__type_traits/is_unbounded_array.h>
#include <__type_traits/negation.h>
#include <__type_traits/remove_const.h>
#include <__type_traits/remove_extent.h>
#include <__utility/exception_guard.h>
#include <__utility/move.h>
#include <__utility/pair.h>
#include <new>
#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>
_LIBCPP_HIDE_FROM_ABI
_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 std::__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);
}
// TODO: Rewrite this to iterate left to right and use reverse_iterators when calling
// 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(!__libcpp_is_unbounded_array<_ValueType>::value,
"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.
__exception_guard __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.
__exception_guard __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.
__exception_guard __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.
__exception_guard __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 > 14
// Destroy all elements in [__first, __last) from left to right using allocator destruction.
template <class _Alloc, class _Iter, class _Sent>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
__allocator_destroy(_Alloc& __alloc, _Iter __first, _Sent __last) {
for (; __first != __last; ++__first)
allocator_traits<_Alloc>::destroy(__alloc, std::__to_address(__first));
}
template <class _Alloc, class _Iter>
class _AllocatorDestroyRangeReverse {
public:
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14
_AllocatorDestroyRangeReverse(_Alloc& __alloc, _Iter& __first, _Iter& __last)
: __alloc_(__alloc), __first_(__first), __last_(__last) {}
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void operator()() const {
std::__allocator_destroy(__alloc_, std::reverse_iterator<_Iter>(__last_), std::reverse_iterator<_Iter>(__first_));
}
private:
_Alloc& __alloc_;
_Iter& __first_;
_Iter& __last_;
};
// Copy-construct [__first1, __last1) in [__first2, __first2 + N), where N is distance(__first1, __last1).
//
// The caller has to ensure that __first2 can hold at least N uninitialized elements. If an exception is thrown the
// already copied elements are destroyed in reverse order of their construction.
template <class _Alloc, class _Iter1, class _Sent1, class _Iter2>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Iter2
__uninitialized_allocator_copy(_Alloc& __alloc, _Iter1 __first1, _Sent1 __last1, _Iter2 __first2) {
auto __destruct_first = __first2;
auto __guard =
std::__make_exception_guard(_AllocatorDestroyRangeReverse<_Alloc, _Iter2>(__alloc, __destruct_first, __first2));
while (__first1 != __last1) {
allocator_traits<_Alloc>::construct(__alloc, std::__to_address(__first2), *__first1);
++__first1;
++__first2;
}
__guard.__complete();
return __first2;
}
template <class _Alloc, class _Type>
struct __allocator_has_trivial_copy_construct : _Not<__has_construct<_Alloc, _Type*, const _Type&> > {};
template <class _Type>
struct __allocator_has_trivial_copy_construct<allocator<_Type>, _Type> : true_type {};
template <class _Alloc,
class _Type,
class _RawType = __remove_const_t<_Type>,
__enable_if_t<
// using _RawType because of the allocator<T const> extension
is_trivially_copy_constructible<_RawType>::value && is_trivially_copy_assignable<_RawType>::value &&
__allocator_has_trivial_copy_construct<_Alloc, _RawType>::value>* = nullptr>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Type*
__uninitialized_allocator_copy(_Alloc&, const _Type* __first1, const _Type* __last1, _Type* __first2) {
// TODO: Remove the const_cast once we drop support for std::allocator<T const>
if (__libcpp_is_constant_evaluated()) {
while (__first1 != __last1) {
std::__construct_at(std::__to_address(__first2), *__first1);
++__first1;
++__first2;
}
return __first2;
} else {
return std::copy(__first1, __last1, const_cast<_RawType*>(__first2));
}
}
// Move-construct the elements [__first1, __last1) into [__first2, __first2 + N)
// if the move constructor is noexcept, where N is distance(__first1, __last1).
//
// Otherwise try to copy all elements. If an exception is thrown the already copied
// elements are destroyed in reverse order of their construction.
template <class _Alloc, class _Iter1, class _Sent1, class _Iter2>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Iter2 __uninitialized_allocator_move_if_noexcept(
_Alloc& __alloc, _Iter1 __first1, _Sent1 __last1, _Iter2 __first2) {
static_assert(__is_cpp17_move_insertable<_Alloc>::value,
"The specified type does not meet the requirements of Cpp17MoveInsertable");
auto __destruct_first = __first2;
auto __guard =
std::__make_exception_guard(_AllocatorDestroyRangeReverse<_Alloc, _Iter2>(__alloc, __destruct_first, __first2));
while (__first1 != __last1) {
#ifndef _LIBCPP_NO_EXCEPTIONS
allocator_traits<_Alloc>::construct(__alloc, std::__to_address(__first2), std::move_if_noexcept(*__first1));
#else
allocator_traits<_Alloc>::construct(__alloc, std::__to_address(__first2), std::move(*__first1));
#endif
++__first1;
++__first2;
}
__guard.__complete();
return __first2;
}
template <class _Alloc, class _Type>
struct __allocator_has_trivial_move_construct : _Not<__has_construct<_Alloc, _Type*, _Type&&> > {};
template <class _Type>
struct __allocator_has_trivial_move_construct<allocator<_Type>, _Type> : true_type {};
#ifndef _LIBCPP_COMPILER_GCC
template <
class _Alloc,
class _Iter1,
class _Iter2,
class _Type = typename iterator_traits<_Iter1>::value_type,
class = __enable_if_t<is_trivially_move_constructible<_Type>::value && is_trivially_move_assignable<_Type>::value &&
__allocator_has_trivial_move_construct<_Alloc, _Type>::value> >
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Iter2
__uninitialized_allocator_move_if_noexcept(_Alloc&, _Iter1 __first1, _Iter1 __last1, _Iter2 __first2) {
if (__libcpp_is_constant_evaluated()) {
while (__first1 != __last1) {
std::__construct_at(std::__to_address(__first2), std::move(*__first1));
++__first1;
++__first2;
}
return __first2;
} else {
return std::move(__first1, __last1, __first2);
}
}
#endif // _LIBCPP_COMPILER_GCC
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___MEMORY_UNINITIALIZED_ALGORITHMS_H
Reference in New Issue View Git Blame Copy Permalink