hana/example/optional/make.cpp
2017-01-07 14:14:18 -08:00

21 lines
711 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/core/make.hpp>
#include <boost/hana/equal.hpp>
#include <boost/hana/optional.hpp>
namespace hana = boost::hana;
int main() {
constexpr auto x = hana::make<hana::optional_tag>();
BOOST_HANA_CONSTANT_CHECK(x == hana::make_optional());
BOOST_HANA_CONSTANT_CHECK(hana::is_nothing(x));
constexpr auto just_x = hana::make<hana::optional_tag>('x');
static_assert(just_x == hana::make_optional('x'), "");
BOOST_HANA_CONSTANT_CHECK(hana::is_just(just_x));
}