CODEWITHSUNDEEP
c++templatesdata-structures
Ruchi
Ruchi

Reputation: 693

using struct template in template class implementation

I am trying to learn templates usage in c++. I have created a struct node which I am using in queue class implementation but I am getting compiler error: Error" expected type specifier before qnode in member function bool MyQueue::add(T data)

#include <iostream>

using namespace std;

template <typename T>
struct qnode {
   qnode* Node;
   T data;
};

template <class T>
class MyQueue {
    qnode<T>* front;
    qnode<T>* end;
    public:
    MyQueue() {
        front=NULL;
        end=NULL;
    }
    bool add (T n);
    T get(void);
    bool empty(void)
    {
        if ( front == NULL)
            return true;
        else
            return false;
    }

    size_t size(void)
    {

    }
 };

 template <typename T>
    bool MyQueue<T>::add ( T n)
    {
        qnode<T>* temp = new qnode;
        temp->data = n;
        temp->Node = NULL;
        if ( front == NULL )
        {
            cout << "Adding front qnode " << endl;
            front = end= temp;
           // front->Node = end;
            return true;
        }
            cout << "Adding  qnode " << endl;
        end->Node = temp;
        end=temp;
   //delete temp;

        return true;
    }

I am looking forward for a nice explanation for how template parameters get resolved in such nested implementation.

Upvotes: 0

Views: 261

Answers (1)

Sam Cristall
Sam Cristall

Reputation: 4387

Your new has a syntax error. 

qnode<T>* temp = new qnode;

should be 

qnode<T>* temp = new qnode<T>();

Remember, a template class without template parameters is meaningless to the compiler. Whenever you type qnode (after the initial declaration), you need to type its template parameters as well!

Upvotes: 2

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