Reference examples

    void swap( int& left_, int& right_ )
    {
        int temp = left_;
        left_ = right_;
        right_ = temp;
    }

    void f()
    {
        int x = 8;
        int i = 4;
        int& ri = i;
        ri++;          // now i == 5
        ri = x;        // now i == 8
        int& ref2 = 2; // error, RHS must be an lvalue
    }