Function main

example/functional/flip.cpp:15–21

};

int main() {
    BOOST_HANA_CONSTEXPR_CHECK(minus(3, 0) == 3 - 0);
    BOOST_HANA_CONSTEXPR_CHECK(hana::flip(minus)(3, 0) == 0 - 3);

    BOOST_HANA_CONSTEXPR_CHECK(minus(3, 0, 1) == 3 - 0 - 1);
    BOOST_HANA_CONSTEXPR_CHECK(hana::flip(minus)(3, 0, 1) == 0 - 3 - 1);
}