include boost header file using "" or <>

Question

Why does tuple documentation say to use, for example:

#include "boost/tuple/tuple.hpp"

and not

#include <boost/tuple/tuple.hpp>

I know that it's not probable my code will have a file called "boost/tuple/tuple.hpp", but using include <> states explicitly not to look in the curent directory.

So what is the reason?

Answer 1

Using <> does not mean "don't look in the current directory" - It means look in an implementation defined place and then look somewhere else, also implementation defined. Either, both or neither of these could be the current directory. This is one of the more useless bits of the C++ standard.