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// Raw memory manipulators -*- C++ -*-
// Copyright (C) 2001-2025 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/*
*
* Copyright (c) 1994
* Hewlett-Packard Company
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Hewlett-Packard Company makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
*
* Copyright (c) 1996,1997
* Silicon Graphics Computer Systems, Inc.
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Silicon Graphics makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*/
/** @file bits/stl_uninitialized.h
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{memory}
*/
#ifndef _STL_UNINITIALIZED_H
#define _STL_UNINITIALIZED_H 1
#if __cplusplus >= 201103L
# include <type_traits>
# include <bits/ptr_traits.h> // to_address
# include <bits/stl_pair.h> // pair
# include <bits/stl_algobase.h> // fill, fill_n
#endif
#include <bits/cpp_type_traits.h> // __is_pointer
#include <bits/stl_iterator_base_funcs.h> // distance, advance
#include <bits/stl_iterator.h> // __niter_base
#include <ext/alloc_traits.h> // __alloc_traits
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/** @addtogroup memory
* @{
*/
/// @cond undocumented
template<typename _ForwardIterator, typename _Alloc = void>
struct _UninitDestroyGuard
{
_GLIBCXX20_CONSTEXPR
explicit
_UninitDestroyGuard(_ForwardIterator& __first, _Alloc& __a)
: _M_first(__first), _M_cur(__builtin_addressof(__first)), _M_alloc(__a)
{ }
_GLIBCXX20_CONSTEXPR
~_UninitDestroyGuard()
{
if (__builtin_expect(_M_cur != 0, 0))
std::_Destroy(_M_first, *_M_cur, _M_alloc);
}
_GLIBCXX20_CONSTEXPR
void release() { _M_cur = 0; }
private:
_ForwardIterator const _M_first;
_ForwardIterator* _M_cur;
_Alloc& _M_alloc;
_UninitDestroyGuard(const _UninitDestroyGuard&);
};
template<typename _ForwardIterator>
struct _UninitDestroyGuard<_ForwardIterator, void>
{
_GLIBCXX20_CONSTEXPR
explicit
_UninitDestroyGuard(_ForwardIterator& __first)
: _M_first(__first), _M_cur(__builtin_addressof(__first))
{ }
_GLIBCXX20_CONSTEXPR
~_UninitDestroyGuard()
{
if (__builtin_expect(_M_cur != 0, 0))
std::_Destroy(_M_first, *_M_cur);
}
_GLIBCXX20_CONSTEXPR
void release() { _M_cur = 0; }
_ForwardIterator const _M_first;
_ForwardIterator* _M_cur;
private:
_UninitDestroyGuard(const _UninitDestroyGuard&);
};
// This is the default implementation of std::uninitialized_copy.
// This can be used with C++20 iterators and non-common ranges.
template<typename _InputIterator, typename _Sentinel,
typename _ForwardIterator>
_GLIBCXX20_CONSTEXPR
_ForwardIterator
__do_uninit_copy(_InputIterator __first, _Sentinel __last,
_ForwardIterator __result)
{
_UninitDestroyGuard<_ForwardIterator> __guard(__result);
for (; __first != __last; ++__first, (void)++__result)
std::_Construct(std::__addressof(*__result), *__first);
__guard.release();
return __result;
}
#if __cplusplus < 201103L
// True if we can unwrap _Iter to get a pointer by using std::__niter_base.
template<typename _Iter,
typename _Base = __decltype(std::__niter_base(*(_Iter*)0))>
struct __unwrappable_niter
{ enum { __value = false }; };
template<typename _Iter, typename _Tp>
struct __unwrappable_niter<_Iter, _Tp*>
{ enum { __value = true }; };
// Use template specialization for C++98 when 'if constexpr' can't be used.
template<bool _CanMemcpy>
struct __uninitialized_copy
{
template<typename _InputIterator, typename _ForwardIterator>
static _ForwardIterator
__uninit_copy(_InputIterator __first, _InputIterator __last,
_ForwardIterator __result)
{ return std::__do_uninit_copy(__first, __last, __result); }
};
template<>
struct __uninitialized_copy<true>
{
// Overload for generic iterators.
template<typename _InputIterator, typename _ForwardIterator>
static _ForwardIterator
__uninit_copy(_InputIterator __first, _InputIterator __last,
_ForwardIterator __result)
{
if (__unwrappable_niter<_InputIterator>::__value
&& __unwrappable_niter<_ForwardIterator>::__value)
{
__uninit_copy(std::__niter_base(__first),
std::__niter_base(__last),
std::__niter_base(__result));
std::advance(__result, std::distance(__first, __last));
return __result;
}
else
return std::__do_uninit_copy(__first, __last, __result);
}
// Overload for pointers.
template<typename _Tp, typename _Up>
static _Up*
__uninit_copy(_Tp* __first, _Tp* __last, _Up* __result)
{
// Ensure that we don't successfully memcpy in cases that should be
// ill-formed because is_constructible<_Up, _Tp&> is false.
typedef __typeof__(static_cast<_Up>(*__first)) __check
__attribute__((__unused__));
const ptrdiff_t __n = __last - __first;
if (__builtin_expect(__n > 0, true))
{
__builtin_memcpy(__result, __first, __n * sizeof(_Tp));
__result += __n;
}
return __result;
}
};
#endif
/// @endcond
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wc++17-extensions"
/**
* @brief Copies the range [first,last) into result.
* @param __first An input iterator.
* @param __last An input iterator.
* @param __result A forward iterator.
* @return __result + (__last - __first)
*
* Like std::copy, but does not require an initialized output range.
*/
template<typename _InputIterator, typename _ForwardIterator>
_GLIBCXX26_CONSTEXPR
inline _ForwardIterator
uninitialized_copy(_InputIterator __first, _InputIterator __last,
_ForwardIterator __result)
{
// We can use memcpy to copy the ranges under these conditions:
//
// _ForwardIterator and _InputIterator are both contiguous iterators,
// so that we can turn them into pointers to pass to memcpy.
// Before C++20 we can't detect all contiguous iterators, so we only
// handle built-in pointers and __normal_iterator<T*, C> types.
//
// The value types of both iterators are trivially-copyable types,
// so that memcpy is not undefined and can begin the lifetime of
// new objects in the output range.
//
// Finally, memcpy from the source type, S, to the destination type, D,
// must give the same value as initialization of D from S would give.
// We require is_trivially_constructible<D, S> to be true, but that is
// not sufficient. Some cases of trivial initialization are not just a
// bitwise copy, even when sizeof(D) == sizeof(S),
// e.g. bit_cast<unsigned>(1.0f) != 1u because the corresponding bits
// of the value representations do not have the same meaning.
// We cannot tell when this condition is true in general,
// so we rely on the __memcpyable trait.
#if __cplusplus >= 201103L
using _Dest = decltype(std::__niter_base(__result));
using _Src = decltype(std::__niter_base(__first));
using _ValT = typename iterator_traits<_ForwardIterator>::value_type;
#if __glibcxx_raw_memory_algorithms >= 202411L // >= C++26
if consteval {
return std::__do_uninit_copy(__first, __last, __result);
}
#endif
if constexpr (!__is_trivially_constructible(_ValT, decltype(*__first)))
return std::__do_uninit_copy(__first, __last, __result);
else if constexpr (__memcpyable<_Dest, _Src>::__value)
{
ptrdiff_t __n = __last - __first;
if (__n > 0) [[__likely__]]
{
using _ValT = typename remove_pointer<_Src>::type;
__builtin_memcpy(std::__niter_base(__result),
std::__niter_base(__first),
__n * sizeof(_ValT));
__result += __n;
}
return __result;
}
#if __cpp_lib_concepts
else if constexpr (contiguous_iterator<_ForwardIterator>
&& contiguous_iterator<_InputIterator>)
{
using _DestPtr = decltype(std::to_address(__result));
using _SrcPtr = decltype(std::to_address(__first));
if constexpr (__memcpyable<_DestPtr, _SrcPtr>::__value)
{
if (auto __n = __last - __first; __n > 0) [[likely]]
{
void* __dest = std::to_address(__result);
const void* __src = std::to_address(__first);
size_t __nbytes = __n * sizeof(remove_pointer_t<_DestPtr>);
__builtin_memcpy(__dest, __src, __nbytes);
__result += __n;
}
return __result;
}
else
return std::__do_uninit_copy(__first, __last, __result);
}
#endif
else
return std::__do_uninit_copy(__first, __last, __result);
#else // C++98
typedef typename iterator_traits<_InputIterator>::value_type
_ValueType1;
typedef typename iterator_traits<_ForwardIterator>::value_type
_ValueType2;
const bool __can_memcpy
= __memcpyable<_ValueType1*, _ValueType2*>::__value
&& __is_trivially_constructible(_ValueType2, __decltype(*__first));
return __uninitialized_copy<__can_memcpy>::
__uninit_copy(__first, __last, __result);
#endif
}
#pragma GCC diagnostic pop
/// @cond undocumented
// This is the default implementation of std::uninitialized_fill.
template<typename _ForwardIterator, typename _Tp>
_GLIBCXX20_CONSTEXPR void
__do_uninit_fill(_ForwardIterator __first, _ForwardIterator __last,
const _Tp& __x)
{
_UninitDestroyGuard<_ForwardIterator> __guard(__first);
for (; __first != __last; ++__first)
std::_Construct(std::__addressof(*__first), __x);
__guard.release();
}
#if __cplusplus < 201103L
// Use template specialization for C++98 when 'if constexpr' can't be used.
template<bool _CanMemset>
struct __uninitialized_fill
{
template<typename _ForwardIterator, typename _Tp>
static void
__uninit_fill(_ForwardIterator __first, _ForwardIterator __last,
const _Tp& __x)
{ std::__do_uninit_fill(__first, __last, __x); }
};
template<>
struct __uninitialized_fill<true>
{
// Overload for generic iterators.
template<typename _ForwardIterator, typename _Tp>
static void
__uninit_fill(_ForwardIterator __first, _ForwardIterator __last,
const _Tp& __x)
{
if (__unwrappable_niter<_ForwardIterator>::__value)
__uninit_fill(std::__niter_base(__first),
std::__niter_base(__last),
__x);
else
std::__do_uninit_copy(__first, __last, __x);
}
// Overload for pointers.
template<typename _Up, typename _Tp>
static void
__uninit_fill(_Up* __first, _Up* __last, const _Tp& __x)
{
// Ensure that we don't successfully memset in cases that should be
// ill-formed because is_constructible<_Up, const _Tp&> is false.
typedef __typeof__(static_cast<_Up>(__x)) __check
__attribute__((__unused__));
if (__first != __last)
__builtin_memset(__first, (unsigned char)__x, __last - __first);
}
};
#endif
/// @endcond
/**
* @brief Copies the value x into the range [first,last).
* @param __first A forward iterator.
* @param __last A forward iterator.
* @param __x The source value.
* @return Nothing.
*
* Like std::fill, but does not require an initialized output range.
*/
template<typename _ForwardIterator, typename _Tp>
_GLIBCXX26_CONSTEXPR
inline void
uninitialized_fill(_ForwardIterator __first, _ForwardIterator __last,
const _Tp& __x)
{
// We would like to use memset to optimize this loop when possible.
// As for std::uninitialized_copy, the optimization requires
// contiguous iterators and trivially copyable value types,
// with the additional requirement that sizeof(_Tp) == 1 because
// memset only writes single bytes.
// FIXME: We could additionally enable this for 1-byte enums.
// Maybe any 1-byte Val if is_trivially_constructible<Val, const T&>?
typedef typename iterator_traits<_ForwardIterator>::value_type
_ValueType;
#if __cplusplus >= 201103L
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wc++17-extensions"
#if __glibcxx_raw_memory_algorithms >= 202411L // >= C++26
if consteval {
return std::__do_uninit_fill(__first, __last, __x);
}
#endif
if constexpr (__is_byte<_ValueType>::__value)
if constexpr (is_same<_ValueType, _Tp>::value
|| is_integral<_Tp>::value)
{
using _BasePtr = decltype(std::__niter_base(__first));
if constexpr (is_pointer<_BasePtr>::value)
{
void* __dest = std::__niter_base(__first);
ptrdiff_t __n = __last - __first;
if (__n > 0) [[__likely__]]
__builtin_memset(__dest, (unsigned char)__x, __n);
return;
}
#if __cpp_lib_concepts
else if constexpr (contiguous_iterator<_ForwardIterator>)
{
auto __dest = std::to_address(__first);
auto __n = __last - __first;
if (__n > 0) [[__likely__]]
__builtin_memset(__dest, (unsigned char)__x, __n);
return;
}
#endif
}
std::__do_uninit_fill(__first, __last, __x);
#pragma GCC diagnostic pop
#else // C++98
const bool __can_memset = __is_byte<_ValueType>::__value
&& __is_integer<_Tp>::__value;
__uninitialized_fill<__can_memset>::__uninit_fill(__first, __last, __x);
#endif
}
/// @cond undocumented
// This is the default implementation of std::uninitialized_fill_n.
template<typename _ForwardIterator, typename _Size, typename _Tp>
_GLIBCXX20_CONSTEXPR
_ForwardIterator
__do_uninit_fill_n(_ForwardIterator __first, _Size __n, const _Tp& __x)
{
_UninitDestroyGuard<_ForwardIterator> __guard(__first);
#if __cplusplus >= 201103L
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wc++17-extensions"
if constexpr (is_integral<_Size>::value)
// Loop will never terminate if __n is negative.
__glibcxx_assert(__n >= 0);
else if constexpr (is_floating_point<_Size>::value)
// Loop will never terminate if __n is not an integer.
__glibcxx_assert(__n >= 0 && static_cast<size_t>(__n) == __n);
#pragma GCC diagnostic pop
#endif
for (; __n--; ++__first)
std::_Construct(std::__addressof(*__first), __x);
__guard.release();
return __first;
}
#if __cplusplus < 201103L
// Use template specialization for C++98 when 'if constexpr' can't be used.
template<bool _CanMemset>
struct __uninitialized_fill_n
{
template<typename _ForwardIterator, typename _Size, typename _Tp>
static _ForwardIterator
__uninit_fill_n(_ForwardIterator __first, _Size __n,
const _Tp& __x)
{ return std::__do_uninit_fill_n(__first, __n, __x); }
};
template<>
struct __uninitialized_fill_n<true>
{
// Overload for generic iterators.
template<typename _ForwardIterator, typename _Size, typename _Tp>
static _ForwardIterator
__uninit_fill_n(_ForwardIterator __first, _Size __n,
const _Tp& __x)
{
if (__unwrappable_niter<_ForwardIterator>::__value)
{
_ForwardIterator __last = __first;
std::advance(__last, __n);
__uninitialized_fill<true>::__uninit_fill(__first, __last, __x);
return __last;
}
else
return std::__do_uninit_fill_n(__first, __n, __x);
}
};
#endif
/// @endcond
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wc++17-extensions"
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// DR 1339. uninitialized_fill_n should return the end of its range
/**
* @brief Copies the value x into the range [first,first+n).
* @param __first A forward iterator.
* @param __n The number of copies to make.
* @param __x The source value.
* @return __first + __n.
*
* Like std::fill_n, but does not require an initialized output range.
*/
template<typename _ForwardIterator, typename _Size, typename _Tp>
_GLIBCXX26_CONSTEXPR
inline _ForwardIterator
uninitialized_fill_n(_ForwardIterator __first, _Size __n, const _Tp& __x)
{
// See uninitialized_fill conditions. We also require _Size to be
// an integer. The standard only requires _Size to be decrementable
// and contextually convertible to bool, so don't assume first+n works.
// FIXME: We could additionally enable this for 1-byte enums.
typedef typename iterator_traits<_ForwardIterator>::value_type
_ValueType;
#if __cplusplus >= 201103L
#if __glibcxx_raw_memory_algorithms >= 202411L // >= C++26
if consteval {
return std::__do_uninit_fill_n(__first, __n, __x);
}
#endif
if constexpr (__is_byte<_ValueType>::__value)
if constexpr (is_integral<_Tp>::value)
if constexpr (is_integral<_Size>::value)
{
using _BasePtr = decltype(std::__niter_base(__first));
if constexpr (is_pointer<_BasePtr>::value)
{
void* __dest = std::__niter_base(__first);
if (__n > 0) [[__likely__]]
{
__builtin_memset(__dest, (unsigned char)__x, __n);
__first += __n;
}
return __first;
}
#if __cpp_lib_concepts
else if constexpr (contiguous_iterator<_ForwardIterator>)
{
auto __dest = std::to_address(__first);
if (__n > 0) [[__likely__]]
{
__builtin_memset(__dest, (unsigned char)__x, __n);
__first += __n;
}
return __first;
}
#endif
}
return std::__do_uninit_fill_n(__first, __n, __x);
#else // C++98
const bool __can_memset = __is_byte<_ValueType>::__value
&& __is_integer<_Tp>::__value
&& __is_integer<_Size>::__value;
return __uninitialized_fill_n<__can_memset>::
__uninit_fill_n(__first, __n, __x);
#endif
}
#pragma GCC diagnostic pop
/// @cond undocumented
// Extensions: versions of uninitialized_copy, uninitialized_fill,
// and uninitialized_fill_n that take an allocator parameter.
// We dispatch back to the standard versions when we're given the
// default allocator. For nondefault allocators we do not use
// any of the POD optimizations.
template<typename _InputIterator, typename _Sentinel,
typename _ForwardIterator, typename _Allocator>
_GLIBCXX20_CONSTEXPR
_ForwardIterator
__uninitialized_copy_a(_InputIterator __first, _Sentinel __last,
_ForwardIterator __result, _Allocator& __alloc)
{
_UninitDestroyGuard<_ForwardIterator, _Allocator>
__guard(__result, __alloc);
typedef __gnu_cxx::__alloc_traits<_Allocator> __traits;
for (; __first != __last; ++__first, (void)++__result)
__traits::construct(__alloc, std::__addressof(*__result), *__first);
__guard.release();
return __result;
}
#if _GLIBCXX_HOSTED
template<typename _InputIterator, typename _Sentinel,
typename _ForwardIterator, typename _Tp>
_GLIBCXX20_CONSTEXPR
inline _ForwardIterator
__uninitialized_copy_a(_InputIterator __first, _Sentinel __last,
_ForwardIterator __result, allocator<_Tp>&)
{
#ifdef __cpp_lib_is_constant_evaluated
if (std::is_constant_evaluated())
return std::__do_uninit_copy(std::move(__first), __last, __result);
#endif
#ifdef __glibcxx_ranges
if constexpr (!is_same_v<_InputIterator, _Sentinel>)
{
// Convert to a common range if possible, to benefit from memcpy
// optimizations that std::uninitialized_copy might use.
if constexpr (sized_sentinel_for<_Sentinel, _InputIterator>
&& random_access_iterator<_InputIterator>)
return std::uninitialized_copy(__first,
__first + (__last - __first),
__result);
else // Just use default implementation.
return std::__do_uninit_copy(std::move(__first), __last, __result);
}
else
return std::uninitialized_copy(std::move(__first), __last, __result);
#else
return std::uninitialized_copy(__first, __last, __result);
#endif
}
#endif
template<typename _InputIterator, typename _ForwardIterator,
typename _Allocator>
_GLIBCXX20_CONSTEXPR
inline _ForwardIterator
__uninitialized_move_a(_InputIterator __first, _InputIterator __last,
_ForwardIterator __result, _Allocator& __alloc)
{
return std::__uninitialized_copy_a(_GLIBCXX_MAKE_MOVE_ITERATOR(__first),
_GLIBCXX_MAKE_MOVE_ITERATOR(__last),
__result, __alloc);
}
template<typename _InputIterator, typename _ForwardIterator,
typename _Allocator>
_GLIBCXX20_CONSTEXPR
inline _ForwardIterator
__uninitialized_move_if_noexcept_a(_InputIterator __first,
_InputIterator __last,
_ForwardIterator __result,
_Allocator& __alloc)
{
return std::__uninitialized_copy_a
(_GLIBCXX_MAKE_MOVE_IF_NOEXCEPT_ITERATOR(__first),
_GLIBCXX_MAKE_MOVE_IF_NOEXCEPT_ITERATOR(__last), __result, __alloc);
}
template<typename _ForwardIterator, typename _Tp, typename _Allocator>
_GLIBCXX20_CONSTEXPR
void
__uninitialized_fill_a(_ForwardIterator __first, _ForwardIterator __last,
const _Tp& __x, _Allocator& __alloc)
{
_UninitDestroyGuard<_ForwardIterator, _Allocator>
__guard(__first, __alloc);
typedef __gnu_cxx::__alloc_traits<_Allocator> __traits;
for (; __first != __last; ++__first)
__traits::construct(__alloc, std::__addressof(*__first), __x);
__guard.release();
}
#if _GLIBCXX_HOSTED
template<typename _ForwardIterator, typename _Tp, typename _Tp2>
_GLIBCXX20_CONSTEXPR
inline void
__uninitialized_fill_a(_ForwardIterator __first, _ForwardIterator __last,
const _Tp& __x, allocator<_Tp2>&)
{
#ifdef __cpp_lib_is_constant_evaluated
if (std::is_constant_evaluated())
return std::__do_uninit_fill(__first, __last, __x);
#endif
std::uninitialized_fill(__first, __last, __x);
}
#endif
template<typename _ForwardIterator, typename _Size, typename _Tp,
typename _Allocator>
_GLIBCXX20_CONSTEXPR
_ForwardIterator
__uninitialized_fill_n_a(_ForwardIterator __first, _Size __n,
const _Tp& __x, _Allocator& __alloc)
{
_UninitDestroyGuard<_ForwardIterator, _Allocator>
__guard(__first, __alloc);
typedef __gnu_cxx::__alloc_traits<_Allocator> __traits;
for (; __n > 0; --__n, (void) ++__first)
__traits::construct(__alloc, std::__addressof(*__first), __x);
__guard.release();
return __first;
}
#if _GLIBCXX_HOSTED
template<typename _ForwardIterator, typename _Size, typename _Tp,
typename _Tp2>
_GLIBCXX20_CONSTEXPR
inline _ForwardIterator
__uninitialized_fill_n_a(_ForwardIterator __first, _Size __n,
const _Tp& __x, allocator<_Tp2>&)
{
#ifdef __cpp_lib_is_constant_evaluated
if (std::is_constant_evaluated())
return std::__do_uninit_fill_n(__first, __n, __x);
#endif
return std::uninitialized_fill_n(__first, __n, __x);
}
#endif
// Extensions: __uninitialized_copy_move, __uninitialized_move_copy,
// __uninitialized_fill_move, __uninitialized_move_fill.
// All of these algorithms take a user-supplied allocator, which is used
// for construction and destruction.
// __uninitialized_copy_move
// Copies [first1, last1) into [result, result + (last1 - first1)), and
// move [first2, last2) into
// [result, result + (last1 - first1) + (last2 - first2)).
template<typename _InputIterator1, typename _InputIterator2,
typename _ForwardIterator, typename _Allocator>
inline _ForwardIterator
__uninitialized_copy_move(_InputIterator1 __first1,
_InputIterator1 __last1,
_InputIterator2 __first2,
_InputIterator2 __last2,
_ForwardIterator __result,
_Allocator& __alloc)
{
_ForwardIterator __mid = std::__uninitialized_copy_a(__first1, __last1,
__result, __alloc);
_UninitDestroyGuard<_ForwardIterator, _Allocator> __guard(__result,
__alloc);
__result = __mid; // Everything up to __mid is now guarded.
__result = std::__uninitialized_move_a(__first2, __last2, __mid, __alloc);
__guard.release();
return __result;
}
// __uninitialized_move_copy
// Moves [first1, last1) into [result, result + (last1 - first1)), and
// copies [first2, last2) into
// [result, result + (last1 - first1) + (last2 - first2)).
template<typename _InputIterator1, typename _InputIterator2,
typename _ForwardIterator, typename _Allocator>
inline _ForwardIterator
__uninitialized_move_copy(_InputIterator1 __first1,
_InputIterator1 __last1,
_InputIterator2 __first2,
_InputIterator2 __last2,
_ForwardIterator __result,
_Allocator& __alloc)
{
_ForwardIterator __mid = std::__uninitialized_move_a(__first1, __last1,
__result, __alloc);
_UninitDestroyGuard<_ForwardIterator, _Allocator> __guard(__result,
__alloc);
__result = __mid; // Everything up to __mid is now guarded.
__result = std::__uninitialized_copy_a(__first2, __last2, __mid, __alloc);
__guard.release();
return __result;
}
// __uninitialized_fill_move
// Fills [result, mid) with x, and moves [first, last) into
// [mid, mid + (last - first)).
template<typename _ForwardIterator, typename _Tp, typename _InputIterator,
typename _Allocator>
inline _ForwardIterator
__uninitialized_fill_move(_ForwardIterator __result, _ForwardIterator __mid,
const _Tp& __x, _InputIterator __first,
_InputIterator __last, _Allocator& __alloc)
{
std::__uninitialized_fill_a(__result, __mid, __x, __alloc);
_UninitDestroyGuard<_ForwardIterator, _Allocator> __guard(__result,
__alloc);
__result = __mid; // Everything up to __mid is now guarded.
__result = std::__uninitialized_move_a(__first, __last, __mid, __alloc);
__guard.release();
return __result;
}
// __uninitialized_move_fill
// Moves [first1, last1) into [first2, first2 + (last1 - first1)), and
// fills [first2 + (last1 - first1), last2) with x.
template<typename _InputIterator, typename _ForwardIterator, typename _Tp,
typename _Allocator>
inline void
__uninitialized_move_fill(_InputIterator __first1, _InputIterator __last1,
_ForwardIterator __first2,
_ForwardIterator __last2, const _Tp& __x,
_Allocator& __alloc)
{
_ForwardIterator __mid2 = std::__uninitialized_move_a(__first1, __last1,
__first2,
__alloc);
_UninitDestroyGuard<_ForwardIterator, _Allocator> __guard(__first2,
__alloc);
__first2 = __mid2; // Everything up to __mid2 is now guarded.
std::__uninitialized_fill_a(__mid2, __last2, __x, __alloc);
__guard.release();
}
/// @endcond
#if __cplusplus >= 201103L
/// @cond undocumented
// Extensions: __uninitialized_default, __uninitialized_default_n,
// __uninitialized_default_a, __uninitialized_default_n_a.
template<bool _TrivialValueType>
struct __uninitialized_default_1
{
template<typename _ForwardIterator>
_GLIBCXX26_CONSTEXPR
static void
__uninit_default(_ForwardIterator __first, _ForwardIterator __last)
{
_UninitDestroyGuard<_ForwardIterator> __guard(__first);
for (; __first != __last; ++__first)
std::_Construct(std::__addressof(*__first));
__guard.release();
}
};
template<>
struct __uninitialized_default_1<true>
{
template<typename _ForwardIterator>
_GLIBCXX26_CONSTEXPR
static void
__uninit_default(_ForwardIterator __first, _ForwardIterator __last)
{
if (__first == __last)
return;
typename iterator_traits<_ForwardIterator>::value_type* __val
= std::__addressof(*__first);
std::_Construct(__val);
if (++__first != __last)
std::fill(__first, __last, *__val);
}
};
template<bool _TrivialValueType>
struct __uninitialized_default_n_1
{
template<typename _ForwardIterator, typename _Size>
_GLIBCXX20_CONSTEXPR
static _ForwardIterator
__uninit_default_n(_ForwardIterator __first, _Size __n)
{
_UninitDestroyGuard<_ForwardIterator> __guard(__first);
for (; __n > 0; --__n, (void) ++__first)
std::_Construct(std::__addressof(*__first));
__guard.release();
return __first;
}
};
template<>
struct __uninitialized_default_n_1<true>
{
template<typename _ForwardIterator, typename _Size>
_GLIBCXX20_CONSTEXPR
static _ForwardIterator
__uninit_default_n(_ForwardIterator __first, _Size __n)
{
if (__n > 0)
{
typename iterator_traits<_ForwardIterator>::value_type* __val
= std::__addressof(*__first);
std::_Construct(__val);
++__first;
__first = std::fill_n(__first, __n - 1, *__val);
}
return __first;
}
};
// __uninitialized_default
// Fills [first, last) with value-initialized value_types.
template<typename _ForwardIterator>
_GLIBCXX26_CONSTEXPR
inline void
__uninitialized_default(_ForwardIterator __first,
_ForwardIterator __last)
{
typedef typename iterator_traits<_ForwardIterator>::value_type
_ValueType;
// trivial types can have deleted assignment
const bool __assignable = is_copy_assignable<_ValueType>::value;
std::__uninitialized_default_1<__is_trivial(_ValueType)
&& __assignable>::
__uninit_default(__first, __last);
}
// __uninitialized_default_n
// Fills [first, first + n) with value-initialized value_types.
template<typename _ForwardIterator, typename _Size>
_GLIBCXX20_CONSTEXPR
inline _ForwardIterator
__uninitialized_default_n(_ForwardIterator __first, _Size __n)
{
#ifdef __cpp_lib_is_constant_evaluated
if (std::is_constant_evaluated())
return __uninitialized_default_n_1<false>::
__uninit_default_n(__first, __n);
#endif
typedef typename iterator_traits<_ForwardIterator>::value_type
_ValueType;
// See uninitialized_fill_n for the conditions for using std::fill_n.
constexpr bool __can_fill
= __and_<is_integral<_Size>, is_copy_assignable<_ValueType>>::value;
return __uninitialized_default_n_1<__is_trivial(_ValueType)
&& __can_fill>::
__uninit_default_n(__first, __n);
}
// __uninitialized_default_a
// Fills [first, last) with value_types constructed by the allocator
// alloc, with no arguments passed to the construct call.
template<typename _ForwardIterator, typename _Allocator>
void
__uninitialized_default_a(_ForwardIterator __first,
_ForwardIterator __last,
_Allocator& __alloc)
{
_UninitDestroyGuard<_ForwardIterator, _Allocator> __guard(__first,
__alloc);
typedef __gnu_cxx::__alloc_traits<_Allocator> __traits;
for (; __first != __last; ++__first)
__traits::construct(__alloc, std::__addressof(*__first));
__guard.release();
}
#if _GLIBCXX_HOSTED
template<typename _ForwardIterator, typename _Tp>
inline void
__uninitialized_default_a(_ForwardIterator __first,
_ForwardIterator __last,
allocator<_Tp>&)
{ std::__uninitialized_default(__first, __last); }
#endif
// __uninitialized_default_n_a
// Fills [first, first + n) with value_types constructed by the allocator
// alloc, with no arguments passed to the construct call.
template<typename _ForwardIterator, typename _Size, typename _Allocator>
_GLIBCXX20_CONSTEXPR _ForwardIterator
__uninitialized_default_n_a(_ForwardIterator __first, _Size __n,
_Allocator& __alloc)
{
_UninitDestroyGuard<_ForwardIterator, _Allocator> __guard(__first,
__alloc);
typedef __gnu_cxx::__alloc_traits<_Allocator> __traits;
for (; __n > 0; --__n, (void) ++__first)
__traits::construct(__alloc, std::__addressof(*__first));
__guard.release();
return __first;
}
#if _GLIBCXX_HOSTED
// __uninitialized_default_n_a specialization for std::allocator,
// which ignores the allocator and value-initializes the elements.
template<typename _ForwardIterator, typename _Size, typename _Tp>
_GLIBCXX20_CONSTEXPR
inline _ForwardIterator
__uninitialized_default_n_a(_ForwardIterator __first, _Size __n,
allocator<_Tp>&)
{ return std::__uninitialized_default_n(__first, __n); }
#endif
template<bool _TrivialValueType>
struct __uninitialized_default_novalue_1
{
template<typename _ForwardIterator>
_GLIBCXX26_CONSTEXPR
static void
__uninit_default_novalue(_ForwardIterator __first,
_ForwardIterator __last)
{
_UninitDestroyGuard<_ForwardIterator> __guard(__first);
for (; __first != __last; ++__first)
std::_Construct_novalue(std::__addressof(*__first));
__guard.release();
}
};
template<>
struct __uninitialized_default_novalue_1<true>
{
template<typename _ForwardIterator>
_GLIBCXX26_CONSTEXPR
static void
__uninit_default_novalue(_ForwardIterator, _ForwardIterator)
{
}
};
template<bool _TrivialValueType>
struct __uninitialized_default_novalue_n_1
{
template<typename _ForwardIterator, typename _Size>
_GLIBCXX26_CONSTEXPR
static _ForwardIterator
__uninit_default_novalue_n(_ForwardIterator __first, _Size __n)
{
_UninitDestroyGuard<_ForwardIterator> __guard(__first);
for (; __n > 0; --__n, (void) ++__first)
std::_Construct_novalue(std::__addressof(*__first));
__guard.release();
return __first;
}
};
template<>
struct __uninitialized_default_novalue_n_1<true>
{
template<typename _ForwardIterator, typename _Size>
_GLIBCXX26_CONSTEXPR
static _ForwardIterator
__uninit_default_novalue_n(_ForwardIterator __first, _Size __n)
{ return std::next(__first, __n); }
};
// __uninitialized_default_novalue
// Fills [first, last) with default-initialized value_types.
template<typename _ForwardIterator>
_GLIBCXX26_CONSTEXPR
inline void
__uninitialized_default_novalue(_ForwardIterator __first,
_ForwardIterator __last)
{
typedef typename iterator_traits<_ForwardIterator>::value_type
_ValueType;
std::__uninitialized_default_novalue_1<
is_trivially_default_constructible<_ValueType>::value>::
__uninit_default_novalue(__first, __last);
}
// __uninitialized_default_novalue_n
// Fills [first, first + n) with default-initialized value_types.
template<typename _ForwardIterator, typename _Size>
_GLIBCXX26_CONSTEXPR
inline _ForwardIterator
__uninitialized_default_novalue_n(_ForwardIterator __first, _Size __n)
{
typedef typename iterator_traits<_ForwardIterator>::value_type
_ValueType;
return __uninitialized_default_novalue_n_1<
is_trivially_default_constructible<_ValueType>::value>::
__uninit_default_novalue_n(__first, __n);
}
template<typename _InputIterator, typename _Size,
typename _ForwardIterator>
_GLIBCXX26_CONSTEXPR
_ForwardIterator
__uninitialized_copy_n(_InputIterator __first, _Size __n,
_ForwardIterator __result, input_iterator_tag)
{
_UninitDestroyGuard<_ForwardIterator> __guard(__result);
for (; __n > 0; --__n, (void) ++__first, ++__result)
std::_Construct(std::__addressof(*__result), *__first);
__guard.release();
return __result;
}
template<typename _RandomAccessIterator, typename _Size,
typename _ForwardIterator>
_GLIBCXX26_CONSTEXPR
inline _ForwardIterator
__uninitialized_copy_n(_RandomAccessIterator __first, _Size __n,
_ForwardIterator __result,
random_access_iterator_tag)
{ return std::uninitialized_copy(__first, __first + __n, __result); }
template<typename _InputIterator, typename _Size,
typename _ForwardIterator>
_GLIBCXX26_CONSTEXPR
pair<_InputIterator, _ForwardIterator>
__uninitialized_copy_n_pair(_InputIterator __first, _Size __n,
_ForwardIterator __result, input_iterator_tag)
{
_UninitDestroyGuard<_ForwardIterator> __guard(__result);
for (; __n > 0; --__n, (void) ++__first, ++__result)
std::_Construct(std::__addressof(*__result), *__first);
__guard.release();
return {__first, __result};
}
template<typename _RandomAccessIterator, typename _Size,
typename _ForwardIterator>
_GLIBCXX26_CONSTEXPR
inline pair<_RandomAccessIterator, _ForwardIterator>
__uninitialized_copy_n_pair(_RandomAccessIterator __first, _Size __n,
_ForwardIterator __result,
random_access_iterator_tag)
{
auto __second_res = uninitialized_copy(__first, __first + __n, __result);
auto __first_res = std::next(__first, __n);
return {__first_res, __second_res};
}
/// @endcond
/**
* @brief Copies the range [first,first+n) into result.
* @param __first An input iterator.
* @param __n The number of elements to copy.
* @param __result An output iterator.
* @return __result + __n
* @since C++11
*
* Like copy_n(), but does not require an initialized output range.
*/
template<typename _InputIterator, typename _Size, typename _ForwardIterator>
_GLIBCXX26_CONSTEXPR
inline _ForwardIterator
uninitialized_copy_n(_InputIterator __first, _Size __n,
_ForwardIterator __result)
{ return std::__uninitialized_copy_n(__first, __n, __result,
std::__iterator_category(__first)); }
/// @cond undocumented
template<typename _InputIterator, typename _Size, typename _ForwardIterator>
_GLIBCXX26_CONSTEXPR
inline pair<_InputIterator, _ForwardIterator>
__uninitialized_copy_n_pair(_InputIterator __first, _Size __n,
_ForwardIterator __result)
{
return
std::__uninitialized_copy_n_pair(__first, __n, __result,
std::__iterator_category(__first));
}
/// @endcond
#endif
#ifdef __glibcxx_raw_memory_algorithms // C++ >= 17
/**
* @brief Default-initializes objects in the range [first,last).
* @param __first A forward iterator.
* @param __last A forward iterator.
* @since C++17
*/
template <typename _ForwardIterator>
_GLIBCXX26_CONSTEXPR
inline void
uninitialized_default_construct(_ForwardIterator __first,
_ForwardIterator __last)
{
std::__uninitialized_default_novalue(__first, __last);
}
/**
* @brief Default-initializes objects in the range [first,first+count).
* @param __first A forward iterator.
* @param __count The number of objects to construct.
* @return __first + __count
* @since C++17
*/
template <typename _ForwardIterator, typename _Size>
_GLIBCXX26_CONSTEXPR
inline _ForwardIterator
uninitialized_default_construct_n(_ForwardIterator __first, _Size __count)
{
return std::__uninitialized_default_novalue_n(__first, __count);
}
/**
* @brief Value-initializes objects in the range [first,last).
* @param __first A forward iterator.
* @param __last A forward iterator.
* @since C++17
*/
template <typename _ForwardIterator>
_GLIBCXX26_CONSTEXPR
inline void
uninitialized_value_construct(_ForwardIterator __first,
_ForwardIterator __last)
{
return std::__uninitialized_default(__first, __last);
}
/**
* @brief Value-initializes objects in the range [first,first+count).
* @param __first A forward iterator.
* @param __count The number of objects to construct.
* @return __result + __count
* @since C++17
*/
template <typename _ForwardIterator, typename _Size>
_GLIBCXX26_CONSTEXPR
inline _ForwardIterator
uninitialized_value_construct_n(_ForwardIterator __first, _Size __count)
{
return std::__uninitialized_default_n(__first, __count);
}
/**
* @brief Move-construct from the range [first,last) into result.
* @param __first An input iterator.
* @param __last An input iterator.
* @param __result An output iterator.
* @return __result + (__first - __last)
* @since C++17
*/
template <typename _InputIterator, typename _ForwardIterator>
_GLIBCXX26_CONSTEXPR
inline _ForwardIterator
uninitialized_move(_InputIterator __first, _InputIterator __last,
_ForwardIterator __result)
{
return std::uninitialized_copy
(_GLIBCXX_MAKE_MOVE_ITERATOR(__first),
_GLIBCXX_MAKE_MOVE_ITERATOR(__last), __result);
}
/**
* @brief Move-construct from the range [first,first+count) into result.
* @param __first An input iterator.
* @param __count The number of objects to initialize.
* @param __result An output iterator.
* @return __result + __count
* @since C++17
*/
template <typename _InputIterator, typename _Size, typename _ForwardIterator>
_GLIBCXX26_CONSTEXPR
inline pair<_InputIterator, _ForwardIterator>
uninitialized_move_n(_InputIterator __first, _Size __count,
_ForwardIterator __result)
{
auto __res = std::__uninitialized_copy_n_pair
(_GLIBCXX_MAKE_MOVE_ITERATOR(__first),
__count, __result);
return {__res.first.base(), __res.second};
}
#endif // __glibcxx_raw_memory_algorithms
#if __cplusplus >= 201103L
/// @cond undocumented
template<typename _Tp, typename _Up, typename _Allocator>
_GLIBCXX20_CONSTEXPR
inline void
__relocate_object_a(_Tp* __restrict __dest, _Up* __restrict __orig,
_Allocator& __alloc)
noexcept(noexcept(std::allocator_traits<_Allocator>::construct(__alloc,
__dest, std::move(*__orig)))
&& noexcept(std::allocator_traits<_Allocator>::destroy(
__alloc, std::__addressof(*__orig))))
{
typedef std::allocator_traits<_Allocator> __traits;
__traits::construct(__alloc, __dest, std::move(*__orig));
__traits::destroy(__alloc, std::__addressof(*__orig));
}
// This class may be specialized for specific types.
// Also known as is_trivially_relocatable.
template<typename _Tp, typename = void>
struct __is_bitwise_relocatable
: __bool_constant<__is_trivial(_Tp)>
{ };
template <typename _InputIterator, typename _ForwardIterator,
typename _Allocator>
_GLIBCXX20_CONSTEXPR
inline _ForwardIterator
__relocate_a_1(_InputIterator __first, _InputIterator __last,
_ForwardIterator __result, _Allocator& __alloc)
noexcept(noexcept(std::__relocate_object_a(std::addressof(*__result),
std::addressof(*__first),
__alloc)))
{
typedef typename iterator_traits<_InputIterator>::value_type
_ValueType;
typedef typename iterator_traits<_ForwardIterator>::value_type
_ValueType2;
static_assert(std::is_same<_ValueType, _ValueType2>::value,
"relocation is only possible for values of the same type");
_ForwardIterator __cur = __result;
for (; __first != __last; ++__first, (void)++__cur)
std::__relocate_object_a(std::__addressof(*__cur),
std::__addressof(*__first), __alloc);
return __cur;
}
#if _GLIBCXX_HOSTED
template <typename _Tp, typename _Up>
_GLIBCXX20_CONSTEXPR
inline __enable_if_t<std::__is_bitwise_relocatable<_Tp>::value, _Tp*>
__relocate_a_1(_Tp* __first, _Tp* __last,
_Tp* __result,
[[__maybe_unused__]] allocator<_Up>& __alloc) noexcept
{
ptrdiff_t __count = __last - __first;
if (__count > 0)
{
#ifdef __cpp_lib_is_constant_evaluated
if (std::is_constant_evaluated())
{
// Can't use memcpy. Wrap the pointer so that __relocate_a_1
// resolves to the non-trivial overload above.
__gnu_cxx::__normal_iterator<_Tp*, void> __out(__result);
__out = std::__relocate_a_1(__first, __last, __out, __alloc);
return __out.base();
}
#endif
__builtin_memcpy(__result, __first, __count * sizeof(_Tp));
}
return __result + __count;
}
#endif
template <typename _InputIterator, typename _ForwardIterator,
typename _Allocator>
_GLIBCXX20_CONSTEXPR
inline _ForwardIterator
__relocate_a(_InputIterator __first, _InputIterator __last,
_ForwardIterator __result, _Allocator& __alloc)
noexcept(noexcept(__relocate_a_1(std::__niter_base(__first),
std::__niter_base(__last),
std::__niter_base(__result), __alloc)))
{
return std::__relocate_a_1(std::__niter_base(__first),
std::__niter_base(__last),
std::__niter_base(__result), __alloc);
}
/// @endcond
#endif // C++11
/// @} group memory
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif /* _STL_UNINITIALIZED_H */