 
            
            
            
            
                16 Feb
                
                    2007
                
            
            
                16 Feb
                
                '07
                
            
            
            
        
    
                9:36 a.m.
            
        std::cout << ((x + y) * user_selected_unit) << std::endl;
How is this different from/better than std::cout << quantity<your_system::psi>(x+y) << std::endl; or, if you prefer, typedef quantity<your_system::psi> psi; std::cout << psi(x+y) << std::endl; ?? Matthias