*** was not declared in this scope

[kayo]

A little old fashion error, maybe.
But I've googled it and found nothing.
I really hope someone could help me.
Thanks.

***.h: In member function ‘virtual void orderedlist<T>::Insert(T)’:
***.h:*: error: ‘front’ was not declared in this scope
***.h: In member function ‘void orderedlist<T>::InsertAfter(GiSTlistnode<T>*, T)’:
***.h:*: error: ‘rear’ was not declared in this scope
***.h: In member function ‘void orderedlist<T>::InsertBefore(GiSTlistnode<T>*, T)’:
***.h:*: error: ‘front’ was not declared in this scope

Below is the code(error lines are bold typed):
#ifndef LIST_H
#define LIST_H

#include <ostream.h>
#include <assert.h>

template<class T> struct GiSTlistnode;

template <class T>
class list{
public:
list(): count(0), front(NULL), rear(NULL) {}
int IsEmpty() const { return front==NULL; }
virtual void Insert(T entry) const{ Append(entry); }
unsigned int Count() const { return count; }
//
//cut
//
#ifdef PRINTING_OBJECTS
void Print(ostream& os) const {
GiSTlistnode<T> *temp=front;

os << "List entries:\n";
while(temp) {
os << "\t" << temp->entry;
temp=temp->next;
}
os << endl;
}
#endif
protected:
//
//cut
//
unsigned int count;
GiSTlistnode<T> *front, *rear;
};

template <class T>
class orderedlist: public list<T>{
public:
orderedlist(int func(T, T)): compare(func), list<T>() { }

virtual void Insert(T entry) {
GiSTlistnode<T> *temp=front;
//
//cut
//
}

private:
void InsertAfter(GiSTlistnode<T> *node, T entry) {
GiSTlistnode<T> *temp=new GiSTlistnode<T>;

temp->entry=entry;
temp->prev=node;
temp->next=node->next;
node->next=temp;
if(rear==node) rear=temp;
else temp->next->prev=temp;
}

void InsertBefore(GiSTlistnode<T> *node, T entry) {
GiSTlistnode<T> *temp=new GiSTlistnode<T>;

temp->entry=entry;
temp->prev=node->prev;
temp->next=node;
node->prev=temp;
if(front==node) front=temp;
else temp->prev->next=temp;
}
//
//cut
//

};

#endif

[kayo]

I wrote the code again:

#ifndef LIST_H
#define LIST_H

#include <ostream.h>
#include <assert.h>

template<class T> struct GiSTlistnode;

template <class T>
class list{
public:
list(): count(0), front(NULL), rear(NULL) {}
int IsEmpty() const { return front==NULL; }
virtual void Insert(T entry) const{ Append(entry); }
unsigned int Count() const { return count; }
//
//cut
//
#ifdef PRINTING_OBJECTS
void Print(ostream& os) const {
GiSTlistnode<T> *temp=front;

os << "List entries:\n";
while(temp) {
os << "\t" << temp->entry;
temp=temp->next;
}
os << endl;
}
#endif
protected:
//
//cut
//
unsigned int count;
GiSTlistnode<T> *front, *rear;
};

template <class T>
class orderedlist: public list<T>{
public:
orderedlist(int func(T, T)): compare(func), list<T>() { }

virtual void Insert(T entry) {
GiSTlistnode<T> *temp=front;
//
//cut
//
}

private:
void InsertAfter(GiSTlistnode<T> *node, T entry) {
GiSTlistnode<T> *temp=new GiSTlistnode<T>;

temp->entry=entry;
temp->prev=node;
temp->next=node->next;
node->next=temp;
if(rear==node) rear=temp;
else temp->next->prev=temp;
}

void InsertBefore(GiSTlistnode<T> *node, T entry) {
GiSTlistnode<T> *temp=new GiSTlistnode<T>;

temp->entry=entry;
temp->prev=node->prev;
temp->next=node;
node->prev=temp;
if(front==node) front=temp;
else temp->prev->next=temp;
}
//
//cut
//

};

#endif

[kbw]

front is not a member of class orderedlist. Neither is rear.

[kayo]

@kbw, thanks for your reply.
but orderlist is a child class of class list (front and rear are member of list)

[guestgulkan]

Although front and rear are members of the base class list template class and you would
expect them to be accessible by the derived template class in the normal way - here is the reason (from the GNU website,) why your program gives errors:

In a template definition, unqualified names will no longer find members of a dependent base (as specified by [temp.dep]/3 in the C++ standard).
 For example, 
	template <typename T> struct B {
	  int m;
	  int n;
	  int f ();
	  int g ();
	};
	int n;
	int g ();
	template <typename T> struct C : B<T> {
	  void h ()
	  {
	    m = 0; // error
	    f ();  // error
	    n = 0; // ::n is modified
	    g ();  // ::g is called
	  }
	};
You must make the names dependent, e.g. by prefixing them with this->. Here is the corrected definition of C<T>::h,

	template <typename T> void C<T>::h ()
	{
	  this->m = 0;
	  this->f ();
	  this->n = 0
	  this->g ();
	}

The full page is here
http://gcc.gnu.org/gcc-3.4/changes.html

[kayo]

@guesgulkan thanks!!! the errors are gone. really thanks.

[kbw]

I read all the temp.dep references in the standard, but couldn't see how the descriptions there override the rules in 3.4.1 with example

namespace A {
  namespace N {
    void f();
  }
}
void A::N::f() {
  i = 5;
  // The following scopes are searched for a declaration of i:
  // 1) outermost block scope of A::N::f, before the use of i
  // 2) scope of namespace N
  // 3) scope of namespace A
  // 4) global scope, before the definition of A::N::f
}

I'll take is as given gcc is correct, but it's not obvious to me why.