// Copyright Louis Dionne 2013-2017 // 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 #include namespace hana = boost::hana; struct Foo { }; int main() { auto just = hana::just(Foo{}); static_assert(std::is_same>{}, ""); auto nothing = hana::nothing; static_assert(std::is_same>{}, ""); }