String Stream

    #include <cassert>
    #include <string> 
    #include <sstream> 
    int main()
    {
        const double PI = 3.1415926;
        double value;
        std::stringstream  buffer;  // text buffer
        buffer.precision( 8 );      // increase default precision
        buffer << PI;               // formatted output  
        buffer >> value;            // formatted input  
        assert( PI == value );
        std::string text; 
        text = buffer.str( );  // returns std::string  
        buffer.str( "" );      // clear buffer  
        return 0;
    }