Getting the size of member variable

Question

If there is a POD structure, with some member variables, for example like this:

struct foo
{
   short a;
   int b;
   char c[50];
   // ...
};

Answer 1

5.3.3/1:

The sizeof operator yields the number of bytes in the object representation of its operand. The operand is either an expression, which is not evaluated, or a parenthesized type-id.

The above means the following construct is well defined:

sizeof( ((foo *) 0)->a);