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Stack data structure using Templates

This is a discussion on Stack data structure using Templates within the C++ Programming forums, part of the General Programming Boards category; 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++ ...

  1. #1
    The Dragon Reborn
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    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
    Last edited by Eman; 05-09-2011 at 11:26 AM.
    You ended that sentence with a preposition...Bastard!

  2. #2
    The Dragon Reborn
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    aargh..fixed the code, will upload incorrect code in a mo
    You ended that sentence with a preposition...Bastard!

  3. #3
    C++まいる!Cをこわせ!
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    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.
    Last edited by Elysia; 05-09-2011 at 11:35 AM.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  4. #4
    The Dragon Reborn
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    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?
    Last edited by Eman; 05-09-2011 at 11:50 AM. Reason: It works in Dev C :(
    You ended that sentence with a preposition...Bastard!

  5. #5
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    Quote Originally Posted by Elysia View Post
    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 ended that sentence with a preposition...Bastard!

  6. #6
    C++まいる!Cをこわせ!
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    You didn't split these into their own files, did you? Ie, one header and one .cpp file for the stack?
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  7. #7
    The Dragon Reborn
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    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 ended that sentence with a preposition...Bastard!

  8. #8
    C++まいる!Cをこわせ!
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    You cannot split a template declaration and its implementation. Put them both in the same file (header).
    Eman likes this.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  9. #9
    The Dragon Reborn
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    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

    EDIT:
    bloody hell...copy and paste to header file..0 errors..wow thanks dude.
    You ended that sentence with a preposition...Bastard!

  10. #10
    C++まいる!Cをこわせ!
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    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 Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  11. #11
    The Dragon Reborn
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    Quote Originally Posted by Elysia View Post
    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
    You ended that sentence with a preposition...Bastard!

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