Quote Originally Posted by 17.6.1.1 Library contents
3: Whenever a name x defined in the standard library is mentioned, the name x is assumed to be fully qualified as ::std::x, unless explicitly described otherwise. For example, if the Effects section for library function F is described as calling library function G, the function ::std::G is meant.
I was reading the standard, and came across this. I noticed that the std namespace was fully qualified to reference the "global" std namespace. While I realize it is probably overkill to do it in an everyday program ("::std::string myString"), I asked myself this question: Can it even serve a use to fully qualify std? I know the standard makes it illegal to put anything inside the std namespace (except for full template sepcializations), so is there a point?

Can you think of a case where writing ::std would be mandatory?