C++ sizeof wrapper class

Question

Suppose I have a class A that does not inherit from anything, has no virtual methods, and has exactly one variable of type T. Does C++ guarantee sizeof(A) == sizeof(T)?

EDIT:

Also if T were a composite type, would it make a difference?

Answer 1

No, it might be more than sizeof(T) due to padding.

Answer 2

I don't think it explicitly guarantees it, but I don't think it would ever be different.