How to find the architecture of the system using pointers?

[VladimirF]

But Vlad since the code is built for a specific target how can the size of the pointer change in runtime?

I meant that you can only determine if the code was built for 32-bit or for 64-bit, NOT if it runs on 64-bit.

Or do you mean to use two separate builds and use them to test the system?

Well, you can use only one (64-bit) build and see if it even runs on your system

But seriously, I have asked OP – what is he looking for?
What is my “architecture” if I run 32-bit Windows on 64-bit CPU? Or emulate 64-bit environment on a 32-bit CPU?