In C++, does adding a friend to a class change its memory layout?

Also, does it matter where in the class you declare the friend ? Does it matter if you add a friend class or a friend function ?开发者_运维技巧

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No it doesn't. It's a purely compile-time thing: similar to access modifiers themselves.

Despite the fact that you write the declaration inside the class, you don't really add a friend to a class. You'd basically declare something else as a friend of the class and simply allow it to access the class's private members, as if they were public.

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As mentioned already, it is purely a compile-time mechanism.