std::experimental::pmr:: resource_adaptor, std::pmr::experimental:: resource_adaptor

From cppreference.com
C++
Experimental
Library fundamentals
Polymorphic allocator library
template < class Alloc >

using resource_adaptor = /*resource-adaptor-imp*/ <
typename std:: allocator_traits < Alloc > ::

template rebind_alloc < char >> ;
(library fundamentals TS)
template < class Alloc >
class /*resource-adaptor-imp*/ : public memory_resource ; // for exposition only
(library fundamentals TS)

The alias template resource_adaptor adapts the allocator type Alloc with a memory_resource interface. The allocator is rebound to a char value type before it is actually adapted (using the resource-adaptor-imp class template), so that adapting specializations of the same allocator template always yields the same type, regardless of the value type the allocator template is originally instantiated with.

resource_adaptor is defined in namespace std::experimental::pmr , and the base type memory_resorce in this page is std::experimental::pmr::memory_resource .

(library fundamentals TS)
(until library fundamentals TS v3)

resource_adaptor is defined in namespace std::pmr::experimental , and the base type memory_resorce in this page is std::pmr::memory_resource .

(library fundamentals TS v3)

resource-adaptor-imp is a class template whose members are described below. The name resource-adaptor-imp is for exposition purposes only and not normative.

In addition to meeting the Allocator requirements, Alloc must additionally satisfy the following requirements:

Member types of resource-adaptor-imp

Member type Definition
allocator_type Alloc

Member functions of resource-adaptor-imp

resource-adaptor-imp :: resource-adaptor-imp

/*resource-adaptor-imp*/ ( ) = default ;
(1) (library fundamentals TS)
/*resource-adaptor-imp*/ ( const /*resource-adaptor-imp*/ & other )
= default ;
(2) (library fundamentals TS)
/*resource-adaptor-imp*/ ( /*resource-adaptor-imp*/ && other )
= default ;
(3) (library fundamentals TS)
explicit /*resource-adaptor-imp*/ ( const Alloc & a2 ) ;
(4) (library fundamentals TS)
explicit /*resource-adaptor-imp*/ ( Alloc && a2 ) ;
(5) (library fundamentals TS)
1) Default constructor. Default constructs the wrapped allocator.
2) Copy constructor. Copy constructs the wrapped allocator from the allocator wrapped by other .
3) Move constructor. Move constructs the wrapped allocator from the allocator wrapped by other .
4) Initializes the wrapped allocator with a2 .
5) Initializes the wrapped allocator with std :: move ( a2 ) .

Parameters

other - another resource-adaptor-imp object to copy or move from
a2 - another Alloc object to copy or move from

resource-adaptor-imp :: get_allocator

allocator_type get_allocator ( ) const ;
(library fundamentals TS)

Returns a copy of the wrapped allocator.

resource-adaptor-imp :: operator=

/*resource-adaptor-imp*/ & operator = ( const /*resource-adaptor-imp*/ & other )
= default ;
(library fundamentals TS)

Defaulted copy assignment operator. Copy assigns the wrapped allocator from that of other .

resource-adaptor-imp :: do_allocate

protected :
virtual void * do_allocate ( std:: size_t bytes, std:: size_t alignment ) ;
(library fundamentals TS)

Allocates memory using the allocate member function of the wrapped allocator.

resource-adaptor-imp :: do_deallocate

protected :
virtual void do_deallocate ( void * p, std:: size_t bytes, std:: size_t alignment ) ;
(library fundamentals TS)

Deallocates the storage pointed to by p using the deallocate member function of the wrapped allocator.

p must have been allocated using the allocate member function of an allocator that compares equal to the wrapped allocator, and must not have been subsequently deallocated.

resource-adaptor-imp :: do_is_equal

protected :
virtual bool do_is_equal ( const memory_resource & other ) const noexcept ;
(library fundamentals TS)

Let p be dynamic_cast < const /*resource-adaptor-imp*/ * > ( & other ) . If p is a null pointer value, returns false . Otherwise, return the result of comparing the allocators wrapped by * p and * this using operator == .

Retrieved from " https://en.cppreference.com/mwiki/index.php?title=cpp/experimental/resource_adaptor&oldid=150327 "