// 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 #include #include #include namespace hana = boost::hana; template struct undefined { }; int main() { auto container = ::seq; { auto storage1 = container(); auto storage2 = container(); auto joined = hana::experimental::joined(storage1, storage2); BOOST_HANA_CONSTANT_CHECK(hana::is_empty(joined)); } { auto storage1 = container(undefined<0>{}); auto storage2 = container(); auto joined = hana::experimental::joined(storage1, storage2); BOOST_HANA_CONSTANT_CHECK(hana::not_(hana::is_empty(joined))); } { auto storage1 = container(undefined<0>{}); auto storage2 = container(undefined<1>{}); auto joined = hana::experimental::joined(storage1, storage2); BOOST_HANA_CONSTANT_CHECK(hana::not_(hana::is_empty(joined))); } { auto storage1 = container(); auto storage2 = container(undefined<0>{}); auto joined = hana::experimental::joined(storage1, storage2); BOOST_HANA_CONSTANT_CHECK(hana::not_(hana::is_empty(joined))); } }