hana/example/at_key.cpp
2017-02-07 21:27:28 -08:00

28 lines
830 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/at_key.hpp>
#include <boost/hana/integral_constant.hpp>
#include <boost/hana/map.hpp>
#include <boost/hana/pair.hpp>
#include <boost/hana/type.hpp>
#include <string>
namespace hana = boost::hana;
int main() {
auto m = hana::make_map(
hana::make_pair(hana::type<int>{}, std::string{"int"}),
hana::make_pair(hana::int_<3>{}, std::string{"3"})
);
BOOST_HANA_RUNTIME_CHECK(hana::at_key(m, hana::type<int>{}) == "int");
// usage as operator[]
BOOST_HANA_RUNTIME_CHECK(m[hana::type<int>{}] == "int");
BOOST_HANA_RUNTIME_CHECK(m[hana::int_<3>{}] == "3");
}