I actually (and pedantically, I'm afraid) meant that neither in C or C++ is it true that "foofoo" takes up double the size of "foo" - both will have a zero char

I actually (and pedantically, I'm afraid) meant that neither in C or C++ is it true that "foofoo" takes up double the size of "foo" - both will have a zero character at the end. The sizeof operator when applied to each will also return values that indicate that one is not double of the value of the other.