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

25 lines
720 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/bool.hpp>
#include <boost/hana/config.hpp>
#include <boost/hana/eval.hpp>
#include <boost/hana/if.hpp>
#include <boost/hana/lazy.hpp>
namespace hana = boost::hana;
int main() {
BOOST_HANA_CONSTEXPR_LAMBDA auto f = hana::make<hana::lazy_tag>([](auto x) {
return 1 / x;
});
BOOST_HANA_CONSTEXPR_LAMBDA auto g = hana::make_lazy([](auto x) {
return x + 1;
});
BOOST_HANA_CONSTEXPR_CHECK(hana::eval(hana::if_(hana::false_c, f(0), g(0))) == 0 + 1);
}