https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91405
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|WAITING |NEW
--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Something like:
template<typename T>
constexpr bool is_void_v = false;
template<>
constexpr bool is_void_v<void> = true;
template<typename T>
concept Void = is_void_v<T>;
template<typename T>
concept DatabaseTransaction = requires(T a) {
{ a.commit() } -> Void;
};
template<typename T>
concept UserRepository = requires(T a, DatabaseTransaction auto transaction) {
{ a.insert_user_if_not_exists(transaction) } -> Void;
};
which correctly says:
91405.cc:15:60: error: placeholder type not allowed in this context
15 | concept UserRepository = requires(T a, DatabaseTransaction auto
transaction) {
| ^~~~
