returning a reference to Object C++

chens_83 · 10-10-2003, 02:17 AM

i have a template stack class that holds structure objects .. The trouble comes when i want to play around with the top element of the stack
I use this code

Code:

T& top(){
return stck[tos];
}

and in main or another function

Code:

stack <entry*> ob;
entry *temp = new entry;
temp->s = 12;
temp->t = "adfadsf";
ob.push(temp);
entry = ob.top(); //this doesnt work : /

this works for the pop() function but not for top !!!

Mohsen · 10-10-2003, 06:37 AM

Please send us the implmentation of your push and pop functions. You may firs --'d the tos and then returned it for the pop. And for the push first store the value and then ++'d the tos : stack[tos]++ = PushVal;

chens_83 · 10-10-2003, 10:37 AM

Code:

		template <class T>const T& stack<T>::top(){
			return stck[size];	
		}

		template <class T> void stack<T>::push(const T& x){
			
			if(size == 100 ){
				cout << "Stack is full" << endl;
			}

			else{
				stck[size] = x;
				size ++;
			}
		}

		template <class T> T stack<T>::pop(){

			if(size == 0 ){
				return 0;
			}

			else{
    		   tos --;
				return stck[size];
			}
		}

mr_segfault · 10-10-2003, 09:16 PM

It looks to me like you would want

Code:

template <class T>const T& stack<T>::top()
{
  return stck[size-1];
}

Since size is always pointing just above the stack top

.

Cheers..