hana/test/optional/flatten.cpp
2017-01-07 14:14:18 -08:00

29 lines
788 B
C++

// 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 <boost/hana/assert.hpp>
#include <boost/hana/equal.hpp>
#include <boost/hana/flatten.hpp>
#include <boost/hana/optional.hpp>
#include <laws/base.hpp>
namespace hana = boost::hana;
using hana::test::ct_eq;
int main() {
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::flatten(hana::nothing),
hana::nothing
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::flatten(hana::just(hana::nothing)),
hana::nothing
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::flatten(hana::just(hana::just(ct_eq<4>{}))),
hana::just(ct_eq<4>{})
));
}