https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101221
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Ever confirmed|0 |1
Status|UNCONFIRMED |NEW
Last reconfirmed| |2022-01-18
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The code from the attachment is:
namespace One {
typedef enum { A, B } Type;
template <Type type,typename T> class AClass;
template <typename T>
class AClass<A,T> { };
template <typename T>
class AClass<B,T> { };
}
typedef One::Type NewType;
template <NewType type,typename T>
using OtherNew = One::AClass;
class BClass {
typedef One::Type Type;
template <Type type,typename T>
using New = One::AClass;
};
With -std=gnu++17 we print:
101221.C:16:18: error: missing template arguments after 'AClass<...auto...>'
16 | using OtherNew = One::AClass;
| ^~~
101221.C:4:43: note: 'template<One::Type type, class T> class One::AClass'
declared here
4 | template <Type type,typename T> class AClass;
| ^~~~~~
101221.C:23:17: error: missing template arguments after 'AClass<...auto...>'
23 | using New = One::AClass;
| ^~~
101221.C:4:43: note: 'template<One::Type type, class T> class One::AClass'
declared here
4 | template <Type type,typename T> class AClass;
| ^~~~~~
With -std=gnu++20 we print:
101221.C:16:18: error: 'auto' not allowed in alias declaration
16 | using OtherNew = One::AClass;
| ^~~
101221.C:23:17: error: 'auto' not allowed in alias declaration
23 | using New = One::AClass;
| ^~~
Both diagnostics are wrong.
Clang prints the same error for C++17 and C++20.
