The iostream library was always up to the standards as defined by ANSI standard in VC++.
The old lib (in pre-VC++ 6) was implemented correctly according the old ANSI standard and the new lib (VC++ 6) according the new ANSI standard.
In both cases, no changes were made to the functionality of "cout" vs strings.
I think mac messed up his libs by accident, and should re-install after completely un-installing

LOL
But there is another aspect. Omg lol.
He might use an incompatible iostream lib. For example, using a VC++ 5 iostream in a VC++ 6 environment!
But then again, it still means that his VC++ environment is messed up

.