This is a dummy class that allows you to end a Fl_Group in a constructor list of a class:
class MyClass {
Fl_Group group;
Fl_Button button_in_group;
Fl_End end;
Fl_Button button_outside_group;
MyClass();
};
MyClass::MyClass() :
group(10,10,100,100),
button_in_group(20,20,60,30),
end(),
button_outside_group(10,120,60,30)
{}