| // { dg-do compile { target c++17 } } | |
| #include <optional> | |
| #include <utility> | |
| using pair_t = std::pair<int, int>; | |
| using opt_t = std::optional<pair_t>; | |
| static_assert(std::is_copy_constructible_v<opt_t::value_type>); | |
| static_assert(std::is_copy_assignable_v<opt_t::value_type>); | |
| static_assert(std::is_copy_assignable_v<opt_t>); // assertion fails. | |
| class A | |
| { | |
| void f(const opt_t& opt) | |
| { | |
| _opt = opt; | |
| } | |
| opt_t _opt; | |
| }; |