NAME¶

std::experimental::pmr::resource_adaptor - std::experimental::pmr::resource_adaptor

Synopsis¶

Defined in header <experimental/memory_resource>
template< class Alloc >

using resource_adaptor = /*resource-adaptor-imp*/< (library fundamentals
typename std::allocator_traits<Allocator>:: TS)

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

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-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, Allocator must additionally
satisfy the following requirements:

* std::allocator_traits<Alloc>::pointer shall be identical to Alloc::value_type*.
* std::allocator_traits<Alloc>::const_pointer shall be identical to
Alloc::value_type const*.
* std::allocator_traits<Alloc>::void_pointer shall be identical to void*.
* std::allocator_traits<Alloc>::const_const_pointer shall be identical to void
const*.

The type memory_resorce in this page denotes std::experimental::pmr::memory_resource
in LFTS v1 and v2, but denotes std::pmr::memory_resource since LFTS v3.

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*/& (library
other) (2) fundamentals TS)
= default;
/*resource-adaptor-imp*/(/*resource-adaptor-imp*/&& other) (3) (library
= default; 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) (library fundamentals TS)
= default;

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 (library fundamentals TS)
alignment);

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, (library fundamentals TS)
std::size_t alignment);

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) (library fundamentals TS)
const noexcept;

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==.