// 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; struct undefined { }; int main() { auto container = ::seq; { auto xs = container(); auto tr = hana::experimental::transformed(xs, undefined{}); BOOST_HANA_CONSTANT_CHECK(hana::is_empty(tr)); } { auto xs = container(undefined{}); auto tr = hana::experimental::transformed(xs, undefined{}); BOOST_HANA_CONSTANT_CHECK(hana::not_(hana::is_empty(tr))); } { auto xs = container(undefined{}, undefined{}); auto tr = hana::experimental::transformed(xs, undefined{}); BOOST_HANA_CONSTANT_CHECK(hana::not_(hana::is_empty(tr))); } }