Return a newly allocated block of memory of the specified size bytes.
Return a newly allocated block of memory of (at least) the specified positive size (in bytes). If size is 0, a null pointer is returned with no other effect. If this allocator cannot return the requested number of bytes, then it will throw a std::bad_alloc exception in an exception-enabled build, or else will abort the program in a non-exception build. The behavior is undefined unless 0 <= size. Note that the alignment of the address returned conforms to the platform requirement for any object of the specified size. Note that this virtual function hides a two-parameter non-virtual allocate method inherited from bsl::memory_resource; to access the inherited function, upcast the object to bsl::memory_resource& before calling the base-class function.