new (new slot in vtable) (C++/CLI and C++/CX)

Article
08/03/2021

The new keyword indicates that a virtual member will get a new slot in the vtable.

All Runtimes

(There are no remarks for this language feature that apply to all runtimes.)

Windows Runtime

Not supported in Windows Runtime.

Common Language Runtime

Remarks

In a /clr compilation, new indicates that a virtual member will get a new slot in the vtable; that the function does not override a base class method.

new causes the newslot modifier to be added to the IL for the function. For more information about newslot, see:

Requirements

Compiler option: /clr

Examples

The following sample shows the effect of new.

// newslot.cpp
// compile with: /clr
ref class C {
public:
   virtual void f() {
      System::Console::WriteLine("C::f() called");
   }

   virtual void g() {
      System::Console::WriteLine("C::g() called");
   }
};

ref class D : public C {
public:
   virtual void f() new {
      System::Console::WriteLine("D::f() called");
   }

   virtual void g() override {
      System::Console::WriteLine("D::g() called");
   }
};

ref class E : public D {
public:
   virtual void f() override {
      System::Console::WriteLine("E::f() called");
   }
};

int main() {
   D^ d = gcnew D;
   C^ c = gcnew D;

   c->f();   // calls C::f
   d->f();   // calls D::f

   c->g();   // calls D::g
   d->g();   // calls D::g

   D ^ e = gcnew E;
   e->f();   // calls E::f
}

C::f() called

D::f() called

D::g() called

D::g() called

E::f() called