Compiler Error C3640

 

The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.

The latest version of this topic can be found at Compiler Error C3640.

member' : a referenced or virtual member function of a local class must be defined

The compiler requires certain functions to be defined.

The following sample generates C3640:

// C3640.cpp  
void f()   
{  
   struct S  
   {  
      virtual void f1();   // C3640  
      // Try the following line instead:  
      // virtual void f1(){}  
   };  
}  

Show: