Function main

example/functional/compose.cpp:11–21

int main() {
    BOOST_HANA_CONSTEXPR_LAMBDA auto to_char = [](int x) {
        return static_cast<char>(x + 48);
    };

    BOOST_HANA_CONSTEXPR_LAMBDA auto increment = [](auto x) {
        return x + 1;
    };

    BOOST_HANA_CONSTEXPR_CHECK(hana::compose(to_char, increment)(3) == '4');
}