Compiler Warning C4687
'class': a sealed abstract class cannot implement an interface 'interface'
A sealed, abstract type is typically only useful to hold static member functions.
For more information, see abstract (Visual C+)and sealed.
C4687 is issued as an error by default. You can suppress C4687 with the warning pragma. If you are certain that you want to implement an interface in a sealed, abstract type, you can suppress C4687.
Example
The following sample generates C4687.
// C4687.cpp
// compile with: /clr /c
interface class A {};
ref struct B sealed abstract : A {}; // C4687
ref struct C sealed : A {}; // OK
ref struct D abstract : A {}; // OK