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- // 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 {};
- struct S {
- constexpr S()
- : a{1, Empty{}},
- k(hana::at_c<0>(a)),
- e(hana::at_c<1>(a))
- { }
- hana::tuple<int, Empty> a;
- int k;
- Empty e;
- };
- constexpr hana::tuple<int, int> getP () { return { 3, 4 }; }
- int main() {
- {
- using T = hana::tuple<int>;
- T t(3);
- BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 3);
- hana::at_c<0>(t) = 2;
- BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 2);
- }
- {
- using T = hana::tuple<std::string, int>;
- T t("high", 5);
- BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == "high");
- BOOST_HANA_RUNTIME_CHECK(hana::at_c<1>(t) == 5);
- hana::at_c<0>(t) = "four";
- hana::at_c<1>(t) = 4;
- BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == "four");
- BOOST_HANA_RUNTIME_CHECK(hana::at_c<1>(t) == 4);
- }
- {
- using T = hana::tuple<double&, std::string, int>;
- double d = 1.5;
- 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;
- hana::at_c<1>(t) = "four";
- hana::at_c<2>(t) = 4;
- BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 2.5);
- BOOST_HANA_RUNTIME_CHECK(hana::at_c<1>(t) == "four");
- BOOST_HANA_RUNTIME_CHECK(hana::at_c<2>(t) == 4);
- BOOST_HANA_RUNTIME_CHECK(d == 2.5);
- }
- // get on a rvalue tuple
- {
- static_assert(hana::at_c<0>(hana::tuple<float, int, double, long>{0.0f, 1, 2.0, 3L}) == 0, "" );
- static_assert(hana::at_c<1>(hana::tuple<float, int, double, long>{0.0f, 1, 2.0, 3L}) == 1, "" );
- static_assert(hana::at_c<2>(hana::tuple<float, int, double, long>{0.0f, 1, 2.0, 3L}) == 2, "" );
- static_assert(hana::at_c<3>(hana::tuple<float, int, double, long>{0.0f, 1, 2.0, 3L}) == 3, "" );
- static_assert(S().k == 1, "");
- static_assert(hana::at_c<1>(getP()) == 4, "");
- }
- {
- // make sure get<> returns the right types
- struct T { };
- struct U { };
- struct V { };
- hana::tuple<T, U, V> xs{};
- (void)static_cast<T>(hana::at_c<0>(xs));
- (void)static_cast<U>(hana::at_c<1>(xs));
- (void)static_cast<V>(hana::at_c<2>(xs));
- }
- }
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