std::allocator_traits< _Alloc >(3cxx) std::allocator_traits< _Alloc >(3cxx)
NAME
std::allocator_traits< _Alloc > - Uniform interface to all allocator
types.
SYNOPSIS
Inherits __allocator_traits_base.
Inherited by __gnu_cxx::__alloc_traits< _Alloc, typename >.
Public Types
typedef _Alloc allocator_type
The allocator type.
using const_pointer = typename _Ptr< __c_pointer, const value_type
>::type
The allocator's const pointer type.
using const_void_pointer = typename _Ptr< __cv_pointer, const void
>::type
The allocator's const void pointer type.
using difference_type = typename _Diff< _Alloc, pointer >::type
The allocator's difference type.
using is_always_equal = __detected_or_t< typename is_empty< _Alloc
>::type, __equal, _Alloc >
Whether all instances of the allocator type compare equal.
using pointer = __detected_or_t< value_type *, __pointer, _Alloc >
The allocator's pointer type.
using propagate_on_container_copy_assignment = __detected_or_t<
false_type, __pocca, _Alloc >
How the allocator is propagated on copy assignment.
using propagate_on_container_move_assignment = __detected_or_t<
false_type, __pocma, _Alloc >
How the allocator is propagated on move assignment.
using propagate_on_container_swap = __detected_or_t< false_type,
__pocs, _Alloc >
How the allocator is propagated on swap.
template<typename _Tp > using rebind_alloc = __alloc_rebind< _Alloc,
_Tp >
template<typename _Tp > using rebind_traits = allocator_traits<
rebind_alloc< _Tp > >
using size_type = typename _Size< _Alloc, difference_type >::type
The allocator's size type.
typedef _Alloc::value_type value_type
The allocated type.
using void_pointer = typename _Ptr< __v_pointer, void >::type
The allocator's void pointer type.
Static Public Member Functions
static constexpr pointer allocate (_Alloc &__a, size_type __n)
Allocate memory.
static constexpr pointer allocate (_Alloc &__a, size_type __n,
const_void_pointer __hint)
Allocate memory.
template<typename _Tp , typename... _Args> static constexpr auto
construct (_Alloc &__a, _Tp *__p, _Args &&... __args)
noexcept(noexcept(_S_construct(__a, __p, std::forward< _Args
>(__args)...))) -> decltype(_S_construct(__a, __p, std::forward<
_Args >(__args)...))
Construct an object of type _Tp
static constexpr void deallocate (_Alloc &__a, pointer __p, size_type
__n)
Deallocate memory.
template<typename _Tp > static constexpr void destroy (_Alloc &__a, _Tp
*__p) noexcept(noexcept(_S_destroy(__a, __p, 0)))
Destroy an object of type _Tp.
static constexpr size_type max_size (const _Alloc &__a) noexcept
The maximum supported allocation size.
static constexpr _Alloc select_on_container_copy_construction (const
_Alloc &__rhs)
Obtain an allocator to use when copying a container.
Detailed Description
template<typename _Alloc>
struct std::allocator_traits< _Alloc >" Uniform interface to all
allocator types.
Since
C++11
Member Typedef Documentation
template<typename _Alloc > typedef _Alloc std::allocator_traits< _Alloc
>::allocator_type
The allocator type.
template<typename _Alloc > using std::allocator_traits< _Alloc
>::const_pointer = typename _Ptr<__c_pointer, const value_type>::type
The allocator's const pointer type. Alloc::const_pointer if that type
exists, otherwise pointer_traits<pointer>::rebind<const value_type>
template<typename _Alloc > using std::allocator_traits< _Alloc
>::const_void_pointer = typename _Ptr<__cv_pointer, const void>::type
The allocator's const void pointer type. Alloc::const_void_pointer if
that type exists, otherwise pointer_traits<pointer>::rebind<const
void>
template<typename _Alloc > using std::allocator_traits< _Alloc
>::difference_type = typename _Diff<_Alloc, pointer>::type
The allocator's difference type. Alloc::difference_type if that type
exists, otherwise pointer_traits<pointer>::difference_type
template<typename _Alloc > using std::allocator_traits< _Alloc
>::is_always_equal = __detected_or_t<typename is_empty<_Alloc>::type,
__equal, _Alloc>
Whether all instances of the allocator type compare equal.
Alloc::is_always_equal if that type exists, otherwise
is_empty<Alloc>::type
template<typename _Alloc > using std::allocator_traits< _Alloc >::pointer =
__detected_or_t<value_type*, __pointer, _Alloc>
The allocator's pointer type. Alloc::pointer if that type exists,
otherwise value_type*
template<typename _Alloc > using std::allocator_traits< _Alloc
>::propagate_on_container_copy_assignment =
__detected_or_t<false_type, __pocca, _Alloc>
How the allocator is propagated on copy assignment.
Alloc::propagate_on_container_copy_assignment if that type exists,
otherwise false_type
template<typename _Alloc > using std::allocator_traits< _Alloc
>::propagate_on_container_move_assignment =
__detected_or_t<false_type, __pocma, _Alloc>
How the allocator is propagated on move assignment.
Alloc::propagate_on_container_move_assignment if that type exists,
otherwise false_type
template<typename _Alloc > using std::allocator_traits< _Alloc
>::propagate_on_container_swap = __detected_or_t<false_type, __pocs,
_Alloc>
How the allocator is propagated on swap.
Alloc::propagate_on_container_swap if that type exists, otherwise
false_type
template<typename _Alloc > using std::allocator_traits< _Alloc >::size_type
= typename _Size<_Alloc, difference_type>::type
The allocator's size type. Alloc::size_type if that type exists,
otherwise make_unsigned<difference_type>::type
template<typename _Alloc > typedef _Alloc::value_type
std::allocator_traits< _Alloc >::value_type
The allocated type.
template<typename _Alloc > using std::allocator_traits< _Alloc
>::void_pointer = typename _Ptr<__v_pointer, void>::type
The allocator's void pointer type. Alloc::void_pointer if that type
exists, otherwise pointer_traits<pointer>::rebind<void>
Member Function Documentation
template<typename _Alloc > static constexpr pointer std::allocator_traits<
_Alloc >::allocate (_Alloc & __a, size_type __n) [inline], [static],
[constexpr]
Allocate memory.
Parameters
__a An allocator.
__n The number of objects to allocate space for.
Calls a.allocate(n)
template<typename _Alloc > static constexpr pointer std::allocator_traits<
_Alloc >::allocate (_Alloc & __a, size_type __n, const_void_pointer
__hint) [inline], [static], [constexpr]
Allocate memory.
Parameters
__a An allocator.
__n The number of objects to allocate space for.
__hint Aid to locality.
Returns
Memory of suitable size and alignment for n objects of type
value_type
Returns a.allocate(n, hint) if that expression is well-formed,
otherwise returns a.allocate(n)
template<typename _Alloc > template<typename _Tp , typename... _Args>
static constexpr auto std::allocator_traits< _Alloc >::construct
(_Alloc & __a, _Tp * __p, _Args &&... __args) ->
decltype(_S_construct(__a, __p, std::forward<_Args>(__args)...))
[inline], [static], [constexpr], [noexcept]"
Construct an object of type _Tp
Parameters
__a An allocator.
__p Pointer to memory of suitable size and alignment for Tp
__args Constructor arguments.
Calls __a.construct(__p, std::forward<Args>(__args)...) if that
expression is well-formed, otherwise uses placement-new to construct an
object of type _Tp at location __p from the arguments __args...
template<typename _Alloc > static constexpr void std::allocator_traits<
_Alloc >::deallocate (_Alloc & __a, pointer __p, size_type __n)
[inline], [static], [constexpr]
Deallocate memory.
Parameters
__a An allocator.
__p Pointer to the memory to deallocate.
__n The number of objects space was allocated for.
Calls a.deallocate(p, n)
template<typename _Alloc > template<typename _Tp > static constexpr void
std::allocator_traits< _Alloc >::destroy (_Alloc & __a, _Tp * __p)
[inline], [static], [constexpr], [noexcept]
Destroy an object of type _Tp.
Parameters
__a An allocator.
__p Pointer to the object to destroy
Calls __a.destroy(__p) if that expression is well-formed, otherwise
calls __p->~_Tp()
Referenced by std::_Destroy().
template<typename _Alloc > static constexpr size_type
std::allocator_traits< _Alloc >::max_size (const _Alloc & __a)
[inline], [static], [constexpr], [noexcept]
The maximum supported allocation size.
Parameters
__a An allocator.
Returns
__a.max_size() or numeric_limits<size_type>::max()
Returns __a.max_size() if that expression is well-formed, otherwise
returns numeric_limits<size_type>::max()
template<typename _Alloc > static constexpr _Alloc std::allocator_traits<
_Alloc >::select_on_container_copy_construction (const _Alloc & __rhs)
[inline], [static], [constexpr]
Obtain an allocator to use when copying a container.
Parameters
__rhs An allocator.
Returns
__rhs.select_on_container_copy_construction() or __rhs
Returns __rhs.select_on_container_copy_construction() if that
expression is well-formed, otherwise returns __rhs
Author
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