Have a template parameter that can be pointer type or non-pointer type

Question

Suppose I have something like:

template 
void do_something(T t){
  pass_it_somewhere(t);
  t->do_something();
}

Now it wo

Answer 1

You could create a dereference mechanism as below:

template
std::enable_if_t::value, std::remove_pointer_t&> dereference(T& t) { 
  return *t; 
}

template
std::enable_if_t::value, T&> dereference(T& t) {
  return t;
}

and use it in your function as:

template 
void do_something(T t){
  pass_it_somewhere(dereference(t));
  dereference(t).do_something();
}

Live Demo

This way you'll have to do only with concrete versions of T.