Problem using a privatly defined struct

I have this code:

Code:

template <class T>
class SortedList
{
private:
	struct Node
	{
		T data;
		Node* next;
	};
	
	Node* m_head;
	Node* m_current;
public:
	friend bool operator==<T>(const SortedList<T>& L1, const SortedList<T>& L2);

and i try to use Node in the friend function:

Code:

template <class T>
bool operator==(const SortedList<T>& L1, const SortedList<T>& L2) 
{
	SortedList<T>::Node* head1 = L1.m_head;
	SortedList<T>::Node* head2 = L2.m_head;
	while (head1 != NULL && head2 != NULL) {
		if (head1->data != head2->data) {
			return false;
		}
		head1 = head1->next;
		head2 = head2->next;
	}
	return (head1 == NULL && head2 == NULL);
}

the compiler (g++) doesn't recognize the type, although i made this function friend... i guess it's template related, but i can't find any info on how to do it with templates...

it just says:

Code:

../sortedlist.h:163: error: ‘head1’ was not declared in this scope
../sortedlist.h:164: error: ‘head2’ was not declared in this scope

anyone?

You may need to indicate that operator== is a template function:

Code:

    template <class T_>
    friend bool operator==(const SortedList<T_>& L1, const SortedList<T_>& L2);

And then you might need the typename keyword, as you normally do for types nested within templated types:

Code:

	typename SortedList<T>::Node* head1 = L1.m_head;
	typename SortedList<T>::Node* head2 = L2.m_head;

thank you!!

"typename" was what i've been looking for.

the first thing you suggested isn't necessary because i predefined operator== as a template.