A missing vtable usually means the first non-inline virtual member function has no definition

Question

I am pretty sure this question is duplicate, but my code is different here, the following is my code. It fails with a \"Undefined symbols\" error, not sure whats missing.

Answer 1

To help anyone else that comes this way looking for help with "NOTE: a missing vtable usually means the first non-inline virtual member function has no definition."

In my case the error was caused by a missing = 0; at the end of the virtual definition. Make sure all the virtual definitions have = 0; at the end.

virtual HRESULT function(int testInput) = 0;

Hopefully this saves someone some time.

Answer 2

Parent::~Parent() is not defined.

You can put the definition directly into the class definition:

class Parent {
   public :
     virtual int func () = 0;
     virtual ~Parent() {};
 };

Or define it separately. Or, since C++11, write virtual ~Parent() = default;.

In any case, a destructor needs a definition.