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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/first.hpp>
#include <boost/hana/pair.hpp>
#include <boost/hana/second.hpp>
#include <type_traits>
#include <utility>
namespace hana = boost::hana;
struct MoveOnly {
int data_;
MoveOnly(MoveOnly const&) = delete;
MoveOnly& operator=(MoveOnly const&) = delete;
MoveOnly(int data) : data_(data) { }
MoveOnly(MoveOnly&& x) : data_(x.data_) { x.data_ = 0; }
MoveOnly& operator=(MoveOnly&& x)
{ data_ = x.data_; x.data_ = 0; return *this; }
bool operator==(const MoveOnly& x) const { return data_ == x.data_; }
};
struct MoveOnlyDerived : MoveOnly {
MoveOnlyDerived(MoveOnlyDerived&&) = default;
MoveOnlyDerived(int data = 1) : MoveOnly(data) { }
};
template <typename Target>
struct implicit_to {
constexpr operator Target() const { return Target{}; }
};
struct NoMove {
NoMove() = default;
NoMove(NoMove const&) = delete;
NoMove(NoMove&&) = delete;
};
// Note: It is also useful to check with a non-empty class, because that
// triggers different instantiations due to EBO.
struct NoMove_nonempty {
NoMove_nonempty() = default;
NoMove_nonempty(NoMove_nonempty const&) = delete;
NoMove_nonempty(NoMove_nonempty&&) = delete;
int i;
};
int main() {
{
hana::pair<MoveOnly, short> p1(MoveOnly{3}, 4);
hana::pair<MoveOnly, short> p2(std::move(p1));
BOOST_HANA_RUNTIME_CHECK(hana::first(p2) == MoveOnly{3});
BOOST_HANA_RUNTIME_CHECK(hana::second(p2) == 4);
}
// Make sure it works across pair types
{
hana::pair<MoveOnlyDerived, short> p1(MoveOnlyDerived{3}, 4);
hana::pair<MoveOnly, long> p2 = std::move(p1);
BOOST_HANA_RUNTIME_CHECK(hana::first(p2) == MoveOnly{3});
BOOST_HANA_RUNTIME_CHECK(hana::second(p2) == 4);
}
{
struct target1 {
target1() = default;
target1(target1 const&) = delete;
target1(target1&&) = default;
};
struct target2 {
target2() = default;
target2(target2 const&) = delete;
target2(target2&&) = default;
};
using Target = hana::pair<target1, target2>;
Target p1(hana::make_pair(target1{}, target2{})); (void)p1;
Target p2(hana::make_pair(implicit_to<target1>{}, target2{})); (void)p2;
Target p3(hana::make_pair(target1{}, implicit_to<target2>{})); (void)p3;
Target p4(hana::make_pair(implicit_to<target1>{}, implicit_to<target2>{})); (void)p4;
}
// Make sure we don't define the move constructor when it shouldn't be defined.
{
using Pair1 = hana::pair<NoMove, NoMove>;
Pair1 pair1; (void)pair1;
static_assert(!std::is_move_constructible<Pair1>::value, "");
using Pair2 = hana::pair<NoMove_nonempty, NoMove_nonempty>;
Pair2 pair2; (void)pair2;
static_assert(!std::is_move_constructible<Pair2>::value, "");
}
}
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