Compiler Error C3388

'type' : not allowed as a constraint, assuming 'ref class' to continue parsing

A constraint was specified on a generic type, but the constraint was not specified correctly. See Constraints on Generic Type Parameters (C++/CLI) for more information.

Example

The following sample generates C3388.

// C3388.cpp  
// compile with: /clr /c  
interface class AA {};  

generic <class T>  
where T : interface class   // C3388  
ref class C {};  

// OK  
generic <class T>  
where T : AA  
ref class D {};