Actually, it tells the compiler that every time it comes across a class called string that isn't fully qualified, it should use std::string. And since he's put it in the global namespace, it will apply everywhere this header is visible.
He really shouldn't do that in a header, but if he at least moved it down a couple of lines so it's inside his private namespace, it at least wouldn't affect anyone else. There is no good reason to do it globally.
He really shouldn't do that in a header, but if he at least moved it down a couple of lines so it's inside his private namespace, it at least wouldn't affect anyone else. There is no good reason to do it globally.