ceph/src/boost/libs/hana/test/set/cnstr.trap.cpp

   1 // Copyright Louis Dionne 2013-2016
   2 // Distributed under the Boost Software License, Version 1.0.
   3 // (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
   4
   5 #include <boost/hana/bool.hpp>
   6 #include <boost/hana/detail/wrong.hpp>
   7 #include <boost/hana/fwd/hash.hpp>
   8 #include <boost/hana/set.hpp>
   9 #include <boost/hana/type.hpp>
  10
  11 #include <utility>
  12 namespace hana = boost::hana;
  13
  14
  15 // This test makes sure that we do not instantiate rogue constructors when
  16 // doing copies and moves
  17
  18 template <int i>
  19 struct Trap {
  20     Trap() = default;
  21     Trap(Trap const&) = default;
  22     Trap(Trap&) = default;
  23     Trap(Trap&&) = default;
  24
  25     template <typename X>
  26     Trap(X&&) {
  27         static_assert(hana::detail::wrong<X>{},
  28         "this constructor must not be instantiated");
  29     }
  30 };
  31
  32 template <int i, int j>
  33 constexpr auto operator==(Trap<i> const&, Trap<j> const&)
  34 { return hana::bool_c<i == j>; }
  35
  36 template <int i, int j>
  37 constexpr auto operator!=(Trap<i> const&, Trap<j> const&)
  38 { return hana::bool_c<i != j>; }
  39
  40 namespace boost { namespace hana {
  41     template <int i>
  42     struct hash_impl<Trap<i>> {
  43         static constexpr auto apply(Trap<i> const&)
  44         { return hana::type_c<Trap<i>>; };
  45     };
  46 }}
  47
  48 int main() {
  49     {
  50         auto expr = hana::make_set(Trap<0>{});
  51         auto implicit_copy = expr;
  52         decltype(expr) explicit_copy(expr);
  53
  54         (void)implicit_copy;
  55         (void)explicit_copy;
  56     }
  57     {
  58         auto expr = hana::make_set(Trap<0>{});
  59         auto implicit_move = std::move(expr);
  60         decltype(expr) explicit_move(std::move(implicit_move));
  61
  62         (void)implicit_move;
  63         (void)explicit_move;
  64     }
  65 }