// Copyright Louis Dionne 2013-2016 // Distributed under the Boost Software License, Version 1.0. // (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt) #include #include #include #include #include #include #include #include #include namespace hana = boost::hana; // First take the type of an object, and then tell whether it's integral constexpr auto is_integral = hana::compose(hana::trait, hana::typeid_); static_assert(hana::filter(hana::make_tuple(1, 2.0, 3, 4.0), is_integral) == hana::make_tuple(1, 3), ""); static_assert(hana::filter(hana::just(3), is_integral) == hana::just(3), ""); BOOST_HANA_CONSTANT_CHECK(hana::filter(hana::just(3.0), is_integral) == hana::nothing); int main() { }