Method operator==

test/parse_into.cpp:66–71

    friend
    bool operator==( Z const& z1, Z const& z2 )
    {
        X const& x1 = z1;
        X const& x2 = z2;
        return (x1 == x2) && z1.d == z2.d;
    }

    BOOST_DESCRIBE_CLASS(Z, (X), (), (), (d))
};