1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071 |
- // 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/first.hpp>
- #include <boost/hana/pair.hpp>
- #include <boost/hana/second.hpp>
- #include <type_traits>
- namespace hana = boost::hana;
- struct NoDefault {
- NoDefault() = delete;
- explicit constexpr NoDefault(int) { }
- };
- struct NoDefault_nonempty {
- NoDefault_nonempty() = delete;
- explicit constexpr NoDefault_nonempty(int k) : i(k) { }
- int i;
- };
- struct DefaultOnly {
- DefaultOnly() = default;
- DefaultOnly(DefaultOnly const&) = delete;
- DefaultOnly(DefaultOnly&&) = delete;
- };
- struct NonConstexprDefault {
- NonConstexprDefault() { }
- };
- int main() {
- {
- hana::pair<float, short*> p;
- BOOST_HANA_RUNTIME_CHECK(hana::first(p) == 0.0f);
- BOOST_HANA_RUNTIME_CHECK(hana::second(p) == nullptr);
- }
- // make sure it also works constexpr
- {
- constexpr hana::pair<float, short*> p;
- static_assert(hana::first(p) == 0.0f, "");
- static_assert(hana::second(p) == nullptr, "");
- }
- // make sure the default constructor is not instantiated when the
- // members of the pair are not default-constructible
- {
- using Pair1 = hana::pair<NoDefault, NoDefault>;
- Pair1 p1{NoDefault{1}, NoDefault{2}}; (void)p1;
- static_assert(!std::is_default_constructible<Pair1>{}, "");
- using Pair2 = hana::pair<NoDefault_nonempty, NoDefault_nonempty>;
- Pair2 p2{NoDefault_nonempty{1}, NoDefault_nonempty{2}}; (void)p2;
- static_assert(!std::is_default_constructible<Pair2>{}, "");
- }
- // make sure it works when only the default constructor is defined
- {
- hana::pair<DefaultOnly, DefaultOnly> p;
- (void)p;
- }
- {
- hana::pair<NonConstexprDefault, NonConstexprDefault> p;
- (void)p;
- }
- }
|