hana/test/tuple/at.const.cpp
2017-01-07 14:14:18 -08:00

51 lines
1.5 KiB
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/tuple.hpp>
#include <string>
namespace hana = boost::hana;
struct Empty { };
int main() {
{
using T = hana::tuple<int>;
const T t(3);
BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 3);
}
{
using T = hana::tuple<std::string, int>;
const T t("high", 5);
BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == "high");
BOOST_HANA_RUNTIME_CHECK(hana::at_c<1>(t) == 5);
}
{
using T = hana::tuple<double, int>;
constexpr T t(2.718, 5);
static_assert(hana::at_c<0>(t) == 2.718, "");
static_assert(hana::at_c<1>(t) == 5, "");
}
{
using T = hana::tuple<Empty>;
constexpr T t{Empty()};
constexpr Empty e = hana::at_c<0>(t); (void)e;
}
{
using T = hana::tuple<double&, std::string, int>;
double d = 1.5;
const T t(d, "high", 5);
BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 1.5);
BOOST_HANA_RUNTIME_CHECK(hana::at_c<1>(t) == "high");
BOOST_HANA_RUNTIME_CHECK(hana::at_c<2>(t) == 5);
hana::at_c<0>(t) = 2.5;
BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 2.5);
BOOST_HANA_RUNTIME_CHECK(hana::at_c<1>(t) == "high");
BOOST_HANA_RUNTIME_CHECK(hana::at_c<2>(t) == 5);
BOOST_HANA_RUNTIME_CHECK(d == 2.5);
}
}