memory-pool-allocator | C memory allocator based on pools , thread safe | GPU library

How to code my program to has flexibility to receive custom allocator in advance?

I coded some allocators, but not sure whether I will really need it.
However, I know for sure that if my custom allocator will be plugged-in, I want to use it in some certain parts.

For example, int* B::db should use custom allocator (myNew/myDelete),
while all std::vector should use standard allocator.

While I still don't plug my custom allocator, I wish my program will use standard new/delete as default.