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

29 lines
707 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/fold_left.hpp>
#include <boost/hana/optional.hpp>
#include <laws/base.hpp>
namespace hana = boost::hana;
int main() {
hana::test::ct_eq<2> x{};
hana::test::ct_eq<3> s{};
hana::test::_injection<0> f{};
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::fold_left(hana::just(x), s, f),
f(s, x)
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::fold_left(hana::nothing, s, f),
s
));
}