class Queue with customers

[ledzepdoors1]

template < class DT >
void Queue<DT>:: enqueue ( const DT &newDataItem )
throw ( logic_error )

// Inserts newElement at the rear of a queue.

{
QueueNode<DT> *p; // Pointer to enqueued data item

//make p a new QueueNode that has newDataItem and link of zero
p = new QueueNode(newDataItem, 0);

//If there are no nodes, set the front to be this new node
if ( p ==0 )
{
front = new;
}

//Otherwise, add the new node to the end
else
{
appendNode(newDataItem);
}

//Reassign the rear to p
rear = p;
}
*/these are the errors i need help with*/
d:\queuelnk.cpp(58) : error C2955: 'QueueNode' : use of class template requires template argument list
d:\queuelnk.h(19) : see declaration of 'QueueNode'
c:\program files\microsoft visual studio\vc98\include\xstring(79) : while compiling class-template member function 'void __thiscall Queue<int>::enqueue(const int &)'
d:\queuelnk.cpp(58) : error C2955: 'QueueNode' : use of class template requires template argument list
d:\queuelnk.h(19) : see declaration of 'QueueNode'
c:\program files\microsoft visual studio\vc98\include\xstring(79) : while compiling class-template member function 'void __thiscall Queue<int>::enqueue(const int &)'
d:\queuelnk.cpp(58) : error C2514: 'QueueNode' : class has no constructors
d:\queuelnk.h(19) : see declaration of 'QueueNode'
c:\program files\microsoft visual studio\vc98\include\xstring(79) : while compiling class-template member function 'void __thiscall Queue<int>::enqueue(const int &)'
d:\queuelnk.cpp(63) : error C2059: syntax error : ';'
c:\program files\microsoft visual studio\vc98\include\xstring(79) : while compiling class-template member function 'void __thiscall Queue<int>::enqueue(const int &)'
d:\queuelnk.cpp(64) : error C2143: syntax error : missing ';' before '}'
c:\program files\microsoft visual studio\vc98\include\xstring(79) : while compiling class-template member function 'void __thiscall Queue<int>::enqueue(const int &)'
d:\queuelnk.cpp(64) : error C2143: syntax error : missing ';' before '}'

[zb0S216C]

ledzepdoors1 wrote:

p = new QueueNode(newDataItem, 0); (sic)

QueueNode needs < DT > immediately after it.

_Wazzak

[ledzepdoors1]

Thank you, now that simply I did not see lol. I'm still having errors with this function tho. I believe it may be the rest of the implementation but I'm not quite sure. I'm new with queues and stacks and still in the basis of learning.

[zb0S216C]

Errors wrote:

'QueueNode' : class has no constructors (sic)

You need to give QueueNode a constructor that accepts a DT object and a pointer/int object. By looking at the error, it's telling me that QueueNode doesn't have a constructor that accepts the arguments you gave to it. The error is misleading since all structures have a constructor and destructor, regardless (the compiler adds them implicitly if no user-defined constructors are made).

_Wazzak

[ledzepdoors1]

[small]
template < class DT >
void Queue<DT>:: enqueue ( const DT &newDataItem )
throw ( logic_error )

// Inserts newElement at the rear of a queue.

{
QueueNode<DT> *p; // Pointer to enqueued data item
//make p a new QueueNode that has newDataItem and link of zero
p = new QueueNode<DT> (newDataItem, 0);
//If there are no nodes, set the front to be this new node
p -> info = newDataItem;
P -> next = NULL;
if(rear == NULL)
{
front = p;
}
//Otherwise, add the new node to the end
else
{
rear -> next = p;
}
//Reassign the rear to p
rear = p;

}

ok now thats what i changed it to. And in the header file it does show that.
|
|
|
V

class Queue;

template < class DT >
class QueueNode // Facilitator class for the Queue class
{
private:

// Constructor
QueueNode ( const DT &nodeData, QueueNode *nextPtr );

// Data members
DT dataItem; // Queue data item
QueueNode *next; // Pointer to the next element

friend class Queue<DT>;
};[/small]

[zb0S216C]

So what's the issue now? It compiles just fine with VC++ (I had to create a dummy Queue class to get it compile).

_Wazzak

[ledzepdoors1]

Ive tried it out and it works. I guess from maybe trying it too many times and the same error just reoccurring. well the problem im having is that info is not part of the class QueueNode. And I have no idea how to dequeue in main.

[ledzepdoors1]

Never mind I keep making simple mistakes don't reply to the class thing I said lol. Anyway, I'm going to be working on my main now. I'm like I said earlier just not sure exactly how, but I will try it. This is a whole class with Queue and QueueNode for customers in a calling center. All I have left to do now is to dequeue the customer in main and allow timeArrived to be the returned value. Calculate the waitTime, totalWait, averageWait and maxWait. Any hints I would surely appreciate it. Thank you.