// Copyright Louis Dionne 2013-2017 // Copyright Jason Rice 2017 // 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 <boost/hana/core/is_a.hpp> #include <boost/hana/equal.hpp> #include <boost/hana/index_if.hpp> #include <boost/hana/integral_constant.hpp> #include <boost/hana/optional.hpp> #include <boost/hana/tuple.hpp> namespace hana = boost::hana; constexpr auto xs = hana::make_tuple(0, '1', 2.0); static_assert(hana::index_if(xs, hana::is_an<int>) == hana::just(hana::size_c<0>), ""); static_assert(hana::index_if(xs, hana::is_a<char>) == hana::just(hana::size_c<1>), ""); static_assert(hana::index_if(xs, hana::is_a<double>) == hana::just(hana::size_c<2>), ""); static_assert(hana::index_if(xs, hana::is_a<hana::tuple_tag>) == hana::nothing, ""); int main() { }