If I compile the following wih MSVC++ 8.0: #include <list> typedef list<int> foo; the compiler complains, fairly enough, with some syntax error due to the fact that there's no "list" in the global namespace (we missed a prefixing std::). But if I now try this: #include <boost/functional/hash/detail/float_functions.hpp> #include <list> typedef list<int> foo; compilation succeeds! Somehow, <boost/functional/hash/detail/float_functions.hpp> is importing namespace std into the global namespace, presumably with a using directive. I tried to examine the offending header an saw no obvious using directive to blame, so I hope someone more knowledgeable can take a look at this problem. Thank you, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo