From cppreference.com
template<classU>voiddeallocate_object(U*p,std::size_tn=1);(since C++20)Deallocates the storage pointed to by p, which must have been allocated from a
x that compares equal to *resource(), using x.allocate(n*sizeof(U),alignof(U)), typically through a call to allocate_object<U>(n).
Equivalent to deallocate_bytes(p,n*sizeof(U),alignof(U));.
Parameters
p - pointer to memory to deallocate n - number of objects of type U the memory was for Exceptions
Throws nothing.
Notes
This function was introduced for use with the fully-specialized allocator std::pmr::polymorphic_allocator<>, but it may be useful in any specialization.
See also
(C++20)
free raw memory obtained from allocate_bytes
(public member function)
(C++20)
destroys and deallocates an object
(public member function)
[static]
deallocates storage using the allocator
(public static member function of std::allocator_traits<Alloc>)
deallocates memory
(public member function of std::pmr::memory_resource)