How to create a template of template

[Harmony60]

I like to abort creating a template class called Tab, which looks like this:

template < typename T >
class Tab{
protected :
  int t ;
  T *v ;
public :
// etc... 
}

Then I created a class called Vec as:

class Vec : public Tab <double>
{
//... 
}

This Vec works without problems.

Now I would like to create a class GroupVec like this:

//in the .hpp 
class GroupVec : public Tab <Vec>
{
...
}
//in the .cpp, the constructor would
  GroupVec::GroupVec(int a, int b)
    :  Table<Vec(a)>(b)
  {
  }

This method does not work. Is it possible to create a template of template?

[Reegan]

Is it possible to create a template of template?

yes, there is no problem

However this line seems to me suspicious:

:  Table<Vec(a)>(b)

Can you post the code that created you the problem and also the error message?

[Harmony60]

Thank you for your reply. Indeed, I find it weird, but I do not know how to express the idea that I would only have an object of my class GroupVec which is a Tab of b object of class Vec which themselves are large of size a.

[Reegan]

Apart from that, you can follow the example of vector (and provide an instance that will be copied to each element) and secondly, you can also ask whether, for a two-dimensional array, your structure is really adapted.

Why, for example, not have been directly Tab <Tab <double>>? You have a special need on the control lines (or columns, it depends)