std::experimental::pmr::polymorphic_allocator

 

C++

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Freestanding and hosted

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Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

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Strings library

Containers library

Iterators library

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Filesystem library (C++17)

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Technical specifications

Symbols index

External libraries

 

Library fundamentals

experimental::optional

experimental::any

experimental::basic_string_view

experimental::sample

experimental::shared_ptr

experimental::weak_ptr

experimental::apply

experimental::invocation_typeexperimental::raw_invocation_type

experimental::search

experimental::default_searcherexperimental::make_default_searcher

experimental::boyer_moore_searcherexperimental::make_boyer_moore_searcher

experimental::boyer_moore_horspool_searcherexperimental::make_boyer_moore_horspool_searcher

Type-erased and polymorphic allocators

Variable templates for type traits

 

Polymorphic allocator library

polymorphic_allocator

Convenience aliases for containers using polymorphic_allocator

Memory resource classes

memory_resource

synchronized_pool_resource

unsynchronized_pool_resource

monotonic_buffer_resource

resource_adaptor

Global memory resources

new_delete_resource

null_memory_resource

get_default_resource

set_default_resource

Type-erased allocator support for existing classes

function

packaged_task

promise

 

std::experimental::pmr::polymorphic_allocator

Member functions

polymorphic_allocator::polymorphic_allocator

polymorphic_allocator::operator=

polymorphic_allocator::allocate

polymorphic_allocator::deallocate

polymorphic_allocator::construct

polymorphic_allocator::destroy

polymorphic_allocator::select_on_container_copy_construction

polymorphic_allocator::resource

Non-member functions

operator==operator!=

 

Defined in header <experimental/memory_resource>
template< class T > class polymorphic_allocator;		(library fundamentals TS)

The class template std::experimental::pmr::polymorphic_allocator is an Allocator whose allocation behavior depends on the memory resource it is constructed with. Thus, different instances of polymorphic_allocator can exhibit entirely different allocation behavior. This runtime polymorphism allows objects using polymorphic_allocator to behave as if they used different allocator types at run time despite the identical static allocator type.

Member types

Member type	definition
value_type	T

Member functions

(constructor)	constructs a polymorphic_allocator (public member function)
(destructor) (implicitly declared)	implicitly declared destructor (public member function)
operator=	copy assignment operator (public member function)
Public member functions
allocate	allocate memory (public member function)
deallocate	deallocate memory (public member function)
construct	constructs an object in allocated storage (public member function)
destroy	destroys an object in allocated storage (public member function)
select_on_container_copy_construction	create a new polymorphic_allocator for use by a container's copy constructor (public member function)
resource	returns a pointer to the underlying memory resource (public member function)

Non-member functions

operator==operator!=

compare two polymorphic_allocators (function)