If you use a calling convention that mandates the use of stack, you would see that push, or at least have a byte reserved. AFAICT the C++ standard itself does

If you use a calling convention that mandates the use of stack, you would see that push, or at least have a byte reserved. AFAICT the C++ standard itself does not specify the particulars of calling convention, which is a function of the platform, compiler and flags/attributes.