W3cubDocs

/C++

std::pmr::polymorphic_allocator<T>::allocate_object

template< class U >
U* allocate_object( std::size_t n = 1 );
(since C++20)

Allocates storage for n objects of type U using the underlying memory resource.

If SIZE_MAX / sizeof(U) < n, throws std::length_error, otherwise equivalent to return static_cast<U*>(allocate_bytes(n * sizeof(U), alignof(U)) );

Parameters

n - the number of objects to allocate storage for

Return value

A pointer to the allocated storage.

Notes

This function was introduced for use with the fully-specialized allocator std::polymorphic_allocator<>, but it may be useful in any specialization as a shortcut to avoid having to rebind from std::polymorphic_allocator<T> to std::polymorphic_allocator<U>.

Since U is not deduced, it must be provided as a template argument when calling this function.

Exceptions

Throws std::length_error if n > SIZE_MAX / sizeof(T); may also any exceptions thrown by the call to resource()->allocate.

See also

(C++20)
Allocate raw aligned memory from the underlying resource
(public member function)
(C++20)
Allocates and constructs an object
(public member function)
Allocate memory
(public member function)
[static]
allocates uninitialized storage using the allocator
(public static member function of std::allocator_traits<Alloc>)
allocates memory
(public member function of std::pmr::memory_resource)

© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
http://en.cppreference.com/w/cpp/memory/polymorphic_allocator/allocate_object