73 lines
1.8 KiB
C++
73 lines
1.8 KiB
C++
// Copyright Louis Dionne 2013-2022
|
|
// 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/bool.hpp>
|
|
#include <boost/hana/detail/wrong.hpp>
|
|
#include <boost/hana/fwd/hash.hpp>
|
|
#include <boost/hana/map.hpp>
|
|
#include <boost/hana/pair.hpp>
|
|
#include <boost/hana/type.hpp>
|
|
|
|
#include <utility>
|
|
namespace hana = boost::hana;
|
|
|
|
|
|
// This test makes sure that we do not instantiate rogue constructors when
|
|
// doing copies and moves
|
|
|
|
template <int i>
|
|
struct Trap {
|
|
Trap() = default;
|
|
Trap(Trap const&) = default;
|
|
#ifndef BOOST_HANA_WORKAROUND_MSVC_MULTIPLECTOR_106654
|
|
Trap(Trap&) = default;
|
|
#endif
|
|
Trap(Trap&&) = default;
|
|
|
|
template <typename X>
|
|
Trap(X&&) {
|
|
static_assert(hana::detail::wrong<X>{},
|
|
"this constructor must not be instantiated");
|
|
}
|
|
};
|
|
|
|
template <int i, int j>
|
|
constexpr auto operator==(Trap<i> const&, Trap<j> const&)
|
|
{ return hana::bool_c<i == j>; }
|
|
|
|
template <int i, int j>
|
|
constexpr auto operator!=(Trap<i> const&, Trap<j> const&)
|
|
{ return hana::bool_c<i != j>; }
|
|
|
|
namespace boost { namespace hana {
|
|
template <int i>
|
|
struct hash_impl<Trap<i>> {
|
|
static constexpr auto apply(Trap<i> const&)
|
|
{ return hana::type_c<Trap<i>>; };
|
|
};
|
|
}}
|
|
|
|
int main() {
|
|
{
|
|
auto expr = hana::make_map(
|
|
hana::make_pair(Trap<0>{}, Trap<0>{})
|
|
);
|
|
auto implicit_copy = expr;
|
|
decltype(expr) explicit_copy(expr);
|
|
|
|
(void)implicit_copy;
|
|
(void)explicit_copy;
|
|
}
|
|
{
|
|
auto expr = hana::make_map(
|
|
hana::make_pair(Trap<0>{}, Trap<0>{})
|
|
);
|
|
auto implicit_move = std::move(expr);
|
|
decltype(expr) explicit_move(std::move(implicit_move));
|
|
|
|
(void)implicit_move;
|
|
(void)explicit_move;
|
|
}
|
|
}
|