templated members in non-template classes

Given a class with a templated member:

Code:

---

template<typename T> class tmpl_class {};

class some_class
{
  tmpl_class<T>& tmpl_member;
public:
  template<typename T>
  some_class( tmpl_class<T>& oc )
    : tmpl_member(oc)
  {}
};

---

I can't tell if this is valid code (no compiler atm). I'm sure there has to be a way to have a non-template class have templated members, but I haven't figured it out yet. In fact, I just came up with the idea above right now, even though I've been trying to figure this out for a week. Sorry if it's offensively incorrect. :)

Why are you trying to do this exactly? If you want to have templated members, then you need to declare the class with a template. Unless you're trying to do the following:

Code:

---

template<typename T> class tmpl_class {};

class some_class
{
  tmpl_class<std::string>& tmpl_member;
public:
  some_class( tmpl_class<std::string>& oc )
    : tmpl_member(oc)
  {}
};

---

Which more or less defeats the purpose of tmpl_class.

In code, I'd do something like this:

Code:

---

void f()
{
  tmpl_class<std::string> service; // std::string is just an example
  some_class handle(service);
}

---

I simply want some_class to work with any type of service, and for the code to show that (ie. some_class shouldn't be templated). The thing is, if I were using inheritance from an ABC rather than a templated class, doing this would be simple. I'd essentially be using the bridge pattern. Surely there's a way to transpose that idea over to templates?

A more direct question would be: can a non-template class have a member that is itself a template, whose template parameter depends on what the class is constructed with?

Quote:

---

can a non-template class have a member that is itself a template, whose template parameter depends on what the class is constructed with?

---

No, because the constructor is called at run time but the template argument type needs to be known at compile time to build a template for compilation.