From cppreference.com
template<classU>U*allocate_object(std::size_tn=1);(since C++20)Allocates storage for n objects of type U using the underlying memory resource.
If std::numeric_limits<std::size_t>::max()/sizeof(U)<n, throws
, otherwise equivalent to returnstatic_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::pmr::polymorphic_allocator<>, but it may be useful in any specialization as a shortcut to avoid having to rebind from std::pmr::polymorphic_allocator<T> to std::pmr::polymorphic_allocator<U>.
Since U is not deduced, it must be provided as a template argument when calling this function.
Exceptions
Throws
if n>std::numeric_limits<std::size_t>::max()/sizeof(U); may also be 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)