Why can't I multi-declare a class

Question

I can do this

extern int i;
extern int i;

But I can\'t do the same with a class

class A {
..
}
class A {
..
}

Answer 1

You can declare a class and an object multiple times, what you can't do is define it more than once.

extern makes this a declaration and not a definition (because there is no initializer):

extern int a;

The body makes your class a definition and not just a declaration. You can define a class once.