Std iterator as private member variable

I have the following header file:

Code:

---

#include <list>
using namespace std;
 
template <class T>
class QuickList {
	public:
		// Some public things
 
	private:
		list<T> _theList;
		mutable list<T>::iterator _currentPointer;
};

---

When I try to compile, I get the following errors (line numbers changed to correspond with the code above:

Quote:

---

In file included from quicklist.cpp:1:
quicklist.h:11: error: type `std::list<T, std::allocator<_CharT> >' is not derived from type `QuickList<T>'
quicklist.h:11: error: ISO C++ forbids declaration of `iterator' with no type
quicklist.h:11: error: expected `;' before "_currentPointer"

---

I need the mutable keyword if I want to keep my consts intact. However, if I remove it, I still get this single error:

Quote:

---

In file included from quicklist.cpp:1:
quicklist.h:11: error: expected `;' before "_currentPointer"

---

I don't understand these errors. What am I doing wrong?

Could someone help me with this?

Thanks!

What is in the quicklist.cpp file? One common problem with templates is that definition AND declaration need to be in de .h file. I think you must move your implementation from the .cpp file to the .h file

I am not sure about mutable but you need to use typename:
mutable typename list<T>::iterator _currentPointer;
will compile

typename, huh? I've never seen that one before. But it works! With mutable and everything. Thanks!

When exactly does one use typename?

And edb, I am aware of that problem. But apparently g++ has solved it. Because it now compiles perfectly. (And if, later, it seems not to work, I'll just move everything to the headerfile again.)

The compiler needs to know without any ambiguity that list<T>::iterator is the name of a type and not something else. Inside std::list, iterator could be something else than a type. You can find litterature on that topic in most C++ books; Stroustrup in C++ Programing Language Section C.13.5 for instance.

Ah, because T has not yet been determined. I suppose someone could create a totally seperate std::list<int> class in which iterator is not a type.

Thanks.