| // { dg-do compile { target c++17 } } |
| |
| #include <optional> |
| |
| // C++ < 26: |
| // T shall be a type other than cv in_place_t or cv nullopt_t |
| // that meets the Cpp17Destructible requirements |
| // C++ >= 26: |
| // A type X is a valid contained type for optional if X is an lvalue reference |
| // type or a complete non-array object type, and remove_cvref_t<X> is a type |
| // other than in_place_t or nullopt_t. If a specialization of optional |
| // is instantiated with a type T that is not a valid contained type for |
| // optional, the program is ill-formed. If T is an object type, |
| // T shall meet the Cpp17Destructible requirements |
| |
| std::optional<std::nullopt_t> o1; // { dg-error "here" } |
| std::optional<const std::nullopt_t> o2; // { dg-error "here" } |
| std::optional<std::in_place_t> o3; // { dg-error "here" } |
| std::optional<const std::in_place_t> o4; // { dg-error "here" } |
| std::optional<int&> o5; // { dg-error "here" "optional<T&> is a C++26 feature" { target c++23_down } } |
| std::optional<int[1]> o6; // { dg-error "here" } |
| std::optional<int[]> o7; // { dg-error "here" } |
| std::optional<int()> o8; // { dg-error "here" } |
| std::optional<const int &> o9; // { dg-error "here" "optional<T&> is a C++26 feature" { target c++23_down } } |
| std::optional<std::in_place_t &> o10; // { dg-error "here" } |
| std::optional<const std::in_place_t &> o11; // { dg-error "here" } |
| std::optional<std::nullopt_t &> o12; // { dg-error "here" } |
| std::optional<const std::nullopt_t &> o13; // { dg-error "here" } |
| std::optional<int &&> o14; // { dg-error "here" } |
| std::optional<const int &&> o15; // { dg-error "here" } |
| |
| // { dg-error "static assertion failed" "" { target *-*-* } 0 } |
| |
| // { dg-prune-output "forming pointer to reference type" } |
| // { dg-prune-output "union may not have reference type" } |
| // { dg-prune-output "function returning an array" } |
| // { dg-prune-output "flexible array member .* in union" } |
| // { dg-prune-output "function returning a function" } |
| // { dg-prune-output "invalidly declared function type" } |
