can I use SFINAE to selectively define a member variable in a template class?

Question

So what I want to do is to create a template class which may or may not contain a member variable based on the template argument passed in. like following:

t         


        

Answer 1

I think this is what you are looking for.

The class template does not have any member data by default.

template
class base
{
};

Add a specialization of the class template that has the member data.

template
class base
{
   foov m_var;
};