Question

I want to do this:

template <enum Type>
class Message {
private:
     Type m_type
};

enum StdInMessages { PrintHello, Echo, ... };
class StdInMsg : Message<StdInMessages>
{ ... }

enum NetworkMessages { DoSomethingElse, Shutdown ... };
class NetworkMsg : Message<NetworkMessages>
{ ... }

Of course, the actual messages are slightly different

Why doesn’t this work?

template <enum T> class ATemplate {};

I get this error

error: use of enum ‘T’ without previous declaration

Answer 1

Because that’s not valid syntax for a template unless what you’re looking for is what Konrad answered.

You need to either use typename or class.

The following should do it:

enum X
{
   a
};

template <typename T> class ATemplate {};

ATemplate<X> A;