Question

very quick question, let’s say I have a template:

template <class T>
class foo {

 private:
   T SubFoo;
  ...

};

And then I have things like:

 foo < foo < int > > myFoo;

which works fine. In this case, myFoo would have a member called myFoo.SubFoo which would have the type foo < int >.

I would like to have a pointer in myFoo.SubFoo that points to myFoo. I don’t know how to properly call this, a class-member pointer of SubFoo that points to the whole mother class, myFoo. Is this possible? I tried to include the declaration:

template <class T>
class foo {

 private:
  ...
   T SubFoo;
   foo< foo < T > >* p2mother; 
  ...

};

But this does not seem to work.

In general, what I am doing is setting up a recursive structure. It’s quite easy to pass communication down the recursion but I am finding trouble going “upwards”. Maybe I am designing this wrongly in the first place.

Thanks a lot!

Answer 1

The more general case (this works in g++):

template <class T>
struct foo {

 //...
 T SubFoo;
 foo* p2mother; 
 //...
};

foo< int > simple;
foo< foo< int > > complex;

int main() {

  simple.p2mother = &simple;
  complex.p2mother = &complex;
}