inherited static members

I have a class, WIDGET.

Code:

class WIDGET{
    public:
        WIDGET();//constructor
        ~WIDGET();//destructor
        
        int uid();//returns UID
        
    protected:
        WIDGET* parent;//parent widget pointer
        WIDGETINFO info;//widget data info stuff, yeah...
        std::queue<EVENT> events;//Event queue
        
        CRONOS* cronosInstance;//cronos instance
        EVENTMANAGER* eventManInstance;//event manager instance
        WIDGETMANAGER* widgetManInstance;//widget manager instance

        static char* typeName;//widget type name
        
};

Code:

char* WIDGETMANAGER::typeName = "WIDGET";

And my derived BUTTON class.

Code:

class BUTTON:public WIDGET{
    public:
        BUTTON();
        ~BUTTON();
    private:
        
    protected:
};

Code:

char* BUTTON::typeName = "BUTTON";

However, as I'm sure you've already concluded this throws an error.

ISO C++ does not permit `WIDGET::typeName' to be defined as `BUTTON::typeName'

I guess I could stick this->typeName in the constructor for each derived class but I just thought keeping a static member would be easier and probably more efficient.

>However, as I'm sure you've already concluded this throws an error.
As it should. You seem to be confused about how static members work. typeName exists for all instances of the class in which the member is declared, including children. You don't need to redeclare and certainly not reinitialize typeName:

Code:

#include <iostream>

class base {
protected:
  static char *p;
};

char *base::p = "Base class static member";

class derived: public base {
public:
  derived()
  {
    std::cout<< p <<'\n';
  }
};

int main()
{
  derived b;
}

On the other hand, if you need a static member for each child class, you need to make a new one and qualify to find the base member:

Code:

#include <iostream>

class base {
protected:
  static char *p;
};

char *base::p = "Base class static member";

class derived: public base {
public:
  derived()
  {
    std::cout<< base::p <<'\n';
    std::cout<< p <<'\n';
  }
protected:
  static char *p;
};

char *derived::p = "Derived class static member";

int main()
{
  derived b;
}

But then I would question whether you really need the base class member to be protected when it could probably be private without any loss of functionality.