Compiler Warning (level 1) C4486

'function' : a private virtual method of a ref class or value class should be marked 'sealed'

Since a private virtual member function of a managed class or struct cannot be accessed or overridden, it should be marked sealed.

The following sample generates C4486.

// C4486.cpp
// compile with: /clr /c /W1
ref class B {
   virtual void f() {}   // C4486
   virtual void f1() sealed {}   // OK

The following sample shows one possible use of a private sealed, virtual function.

// C4486_b.cpp
// compile with: /clr /c
ref class B {};

ref class D : B {};

interface class I {
   B^ mf();

ref class E : I {
   virtual B^ g() sealed = I::mf {
      return gcnew B;

   virtual D^ mf() {
      return gcnew D;