Compiler Error C2283

'identifier': pure specifier or abstract override specifier not allowed on unnamed struct

A member function of an unnamed class or structure is declared with a pure specifier, which is not permitted.

The following sample generates C2283:

// C2283.cpp
// compile with: /c
struct {
   virtual void func() = 0;   // C2283
};
struct T {
   virtual void func() = 0;   // OK
};