Overriding static variables when subclassing

Question

I have a class, lets call it A, and within that class definition I have the following:

static QPainterPath *path;

Which is to say, I\'m dec

Answer 1

I know this question has been answered, but there is an other way to set the value of a similar static variable for multiple classes through a helper class and some template specialization.

It doesn't exactly answer the question since it is not connected with subclassing in any way, but I've encountered the same issue and I found a different solution I wanted to share.

Example :

template 
struct Helper {
  static QPainterPath* path;
  static void routine();
}

// Define default values
template  QPainterPath* Helper::path = some_default_value;
template  void Helper::routine { do_somehing(); }

class Derived {};

// Define specialized values for Derived
QPainterPath* Helper::path = some_other_value;
void Helper::routine { do_somehing_else(); }

int main(int argc, char** argv) {
  QPainterPath* path = Helper::path;
  Helper::routine();
  return 0;
}

Pros:

• clean, compile time initialization
• static access (no instantiation)
• you can declare specialized static functions too

Cons:

• no virtualization, you need the exact type to retrieve the information