Stack data structure using Templates

I swear lately, i'm not getting anything right..and it is p*s**ng me off...this is what happens when I leave C++ to do something else...argh

Code:

---

template<typename T>
class MyOwnStack
{
    public:
        void push(T x);
        T pop() ;
        MyOwnStack(int x) ;
    private:
              T *a ;
              int index;
                       
};
template<typename T> MyOwnStack<T>::MyOwnStack(int x)
{
  a = new T[x];
}
template<typename T> MyOwnStack::push(T x)
{
  a[index++] = x ;               
}

template<typename T> T MyOwnStack<T>::pop()
{
    int a = a[index--];

    return a;
}

int main()
{
 return 0;
}

---

Dev C++ doesn't compile this code, Vis Studio doesn't as well..i really don't know wtf is going wrong..can anyone enlighten me? Thanks

aargh..fixed the code, will upload incorrect code in a mo

Code:

---

template<typename T> void MyOwnStack<T>::push(T x)
template<typename T> T MyOwnStack<T>::pop()
{
        int b = a[index--];
        return b;
}

---

Now, I will give some advice.
Visual C++ only parses template functions for syntax errors unless instantiated. So always do that. You will catch more errors then.
Don't use the same variable names locally as you have on class level. If possible, prefix class level members with something, such as m_.
Don't forget to delete your memory! Or you can use std::vector to dynamically grow it.
Probably should have a default constructor and push should take arguments by const T&.

Also, in the future, put the compile errors in your post.

okie, i have this exact code..in Vis Studio

Code:

---


#include <iostreaM>
using namespace std;
template<typename Z>
struct Node
{
    Z data ;
    Node *next ;
    Node(Z data, Node *next)
    {
          this->data = data ;
          this->next = next ;
    }           
};
template<typename T>
class MyOwnStack
{
    public:
        void push(T x);
        T pop() ;
        MyOwnStack<T>();
    private:
              Node<T> *stackPtr ;
              int index;
                       
};
template<typename T> MyOwnStack<T>::MyOwnStack<T>()
{
                stackPtr = NULL ;
                                }
template<typename T> void MyOwnStack<T>::push(T x)
{
        Node<T> *t = stackPtr;

        stackPtr = new Node<T>(x, t) ;
}

template<typename T> T MyOwnStack<T>::pop()
{
          T t = stackPtr->data ;
        Node<T> *d = stackPtr ;
        stackPtr = stackPtr->next;
        delete d;
        return t;
}

int main()
{
    MyOwnStack<int> myStack ;
   
    myStack.push(10) ;
    return 0;
}

---

but the problem is when i want to use .push(T x) it gives me ridiculous message

Code:

---

Error        1        error LNK2019: unresolved external symbol "public: void __thiscall MyStack<int>::push(int)" (?push@?$MyStack@H@@QAEXH@Z) referenced in function _main        c:\Users\Eman\documents\visual studio 2010\Projects\TemplatedDataStructures\TemplatedDataStructures\main.obj        TemplatedDataStructures

---

what on earth is happening?

Quote:

---

Originally Posted by Elysia

Code:

---

template<typename T> void MyOwnStack<T>::push(T x)
template<typename T> T MyOwnStack<T>::pop()
{
        int b = a[index--];
        return b;
}

---

Now, I will give some advice.
Visual C++ only parses template functions for syntax errors unless instantiated. So always do that. You will catch more errors then.
Don't use the same variable names locally as you have on class level. If possible, prefix class level members with something, such as m_.
Don't forget to delete your memory! Or you can use std::vector to dynamically grow it.
Probably should have a default constructor and push should take arguments by const T&.

Also, in the future, put the compile errors in your post.

---

yo, yeah I saw the error right after I posted...but the freaking error is still happening anyways

You didn't split these into their own files, did you? Ie, one header and one .cpp file for the stack?

I did..but in dev c++ they're in one file..Vis Studio has been giving me link errors lately..but it works most of the time. I doubt that's it though

You cannot split a template declaration and its implementation. Put them both in the same file (header).

you can't be FREAKING serious! lol i lost potential hours of study on this crap..dang!
so where ever I use type T...it must be in the same header...one like coming up :D

EDIT:
bloody hell...copy and paste to header file..0 errors..wow thanks dude.

All your stack needs to be in the header. The code that uses the stack does not need to.
Templates are tricky beings.

Quote:

---

Originally Posted by Elysia

All your stack needs to be in the header. The code that uses the stack does not need to.
Templates are tricky beings.

---

yep, i just copied the cpp of MyStack into it and it works fine..wasted too much time on this lol