std::allocator construct/destroy vs. placement new/p->~T()

Question

For a project of mine, I am writing some STL containers from scratch (I have my reasons). Since I am mimicking the functionality and interfaces of the STL so closely I am do

Answer 1

This is just to hide the details of allocation in a method. i.e., we are providing the APIs for construction and destruction, in the future we can change the implementation. Now we are using placement new to allocate the memory, in the future if we want to change the allocation we just have to change these two methods.