Set the address of the default allocator to the specified basicAllocator unless calls to this method have been disabled. Return 0 on success and a non-zero value otherwise. This method will fail if either defaultAllocator, lockDefaultAllocator, or allocator with argument 0 has been called previously in this process. In C++17 and later, a successful call to this method will also set the default std::pmr::memory_resource. The behavior is undefined unless basicAllocator is the address of an allocator with sufficient lifetime to satisfy all allocation requests within this process, and unless there is only one thread started within this process. Note that this method is intended for use only by the owner of main (or for use in testing) where the caller affirmatively takes responsibility for the behavior of all clients of the default allocator, and should not be used for any other purpose.