how to realease memory in STL?

[Fenglou Mao]

hi, all,
    I used a data structure in my program like this:

         vector<vector<vector<vector<set<double> > > > > x;

    to store my data, but I have so many data in my program,
it used so much memory, so I want to write the datas into
disk, then release the memory, I use code below to do it,
i,j,k,l is long int for loop. 

         set<double>& data=s[i][j][k][l];
         data.erase(data.begin(),data.end());                           

but when I run my program, it seemed it not release the memory,
who can help me?

   Thank you very much.

Sincerely Yours,

FengLou Mao
*******************************
ADD:Mr. FengLou Mao
    Institute of Physical Chemistry
    Peking University
    BeiJing
    P.R.China
Tel:86-10-62756833
Fax:86-10-62751725