I would caution against using this pattern. In particular, this does not scale to: class A {}; class B : public A {}; class C : public B {}; Usin

I would caution against using this pattern. In particular, this does not scale to: class A {}; class B : public A {}; class C : public B {}; Using the convention of defining `base_type` in the base class means that C will expect B to define `base_type`, which means that B will be cut off from A's `base_type`. This then forces you to use different identifiers, which brings you back to square one (you might as well just explicitly write out the class in that case).