Scoped temporary variable in C++

gistfile1.cpp

// http://stackoverflow.com/a/2553109/227159

/**
 * In its constructor temp_value stores a reference to a variable and a copy of the
 * variable's original value. In its destructor it restores the referenced variable
 * to its original value. So, no matter what you did to the variable between
 * construction and destruction, it will be reset when the temp_value object goes out
 * of scope.
 */

template < class T >
class temp_value {
    public :
        temp_value(T& var) : _var(var), _original(var) {}
        ~temp_value()        { _var = _original; }
    private :
        T&  _var;
        T   _original;
        temp_value(const temp_value&);
        temp_value& operator=(const temp_value&);
};