Hi Xiaoshan,
>I'am doing some work that equires me to use the stl's hash_map and hash_set
There is no STL hash_map and hash_set.
I recommend using BOOST <www.boost.org>, which is a group working to expand STL and other general purpose tools for C++2008 (or thereabouts). Without looking, I'm guessing they have a hash_map and hash_set you could use.
Quite a few of the BOOST contributors are also C++ committee members.
HTH, --Eljay
