compiling a templated class

what is the correct way to compile a class that uses templates. i keep getting an error msg on the linking step. can some one help?

"Stack.h"

Code:

---


#pragmaonce
 
template <class xtype>
struct node
{
        xtype info;
        node * next;
};
 
template<class xtype>
class Stack
{
private:
        node<xtype> * top;
public:
        Stack(void);
        ~Stack(void);
        void Push(xtype);
        void Pop(xtype&);
        bool Isfull(void);
        bool Isempty(void);
};
 


---

"Stack.cpp"

Code:

---


#include"Stack.h"
 
template <class xtype>
Stack<xtype>::Stack(void)
{
        top = NULL;
}
 
template <class xtype>
Stack<xtype>::~Stack(void)
{
        node<xtype>* q;
        while(top != NULL)
        {
                  q = top;
                  top = top->next;
                  delete q;
        }
}
 
template <class xtype>
void Stack<xtype>::Push(xtype item)
{
        node<xtype>* p;
        p = new node<xtype>;
        p->next = top;
        p->info = item;
        top = p;
}
 
template <class xtype>
void Stack<xtype>::Pop(xtype& item)
{
        if( !Isempty() )
        {
                  item = top->info;
                  node<xtype>* p;
                  p = top;
                  top = top->next;
                  delete p;
        }
 
}
 
template <class xtype>
bool Stack<xtype>::Isfull()
{
        node<xtype>* freestore;
        freestore = new node<xtype>;
 
        if(freestore == NULL)
                  return true;
        else
        {
                  delete freestore;
                  return false;
        }
 
}
 
template <class xtype>
bool Stack<xtype>::Isempty()
{
        return (top == NULL);
}
 


---

"main.cpp"

Code:

---

#include"Stack.h"
using namespace std;
int main()
{
        Stack<int> q;
return 0;
 
}
 


---

EROR

Code:

---


------ Build started: Project: LinkedStack, Configuration: Debug Win32 ------
 
Compiling...
 
main.cpp
 
Stack.cpp
 
Generating Code...
 
Linking...
 
main.obj : error LNK2019: unresolved external symbol "public: __thiscall Stack<int>::~Stack<int>(void)" (??1?$Stack@H@@QAE@XZ) referenced in function _main
 
main.obj : error LNK2019: unresolved external symbol "public: __thiscall Stack<int>::Stack<int>(void)" (??0?$Stack@H@@QAE@XZ) referenced in function _main
 
C:\CPLUSPLUS\LinkedStack\Debug\LinkedStack.exe : fatal error LNK1120: 2 unresolved externals
 
Build log was saved at "file://c:\CPLUSPLUS\LinkedStack\Debug\BuildLog.htm"
 
LinkedStack - 3 error(s), 0 warning(s)
 
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
 


---

remove "#include "stack.h"" from stack.cpp, and instead put "#include "stack.cpp"" at the bottom of stack.h.

thanks googler for the help but I've tried that did it work for you. I get the infamous error:
.\Stack.cpp(3) : error C2143: syntax error : missing ';' before '<'
which I think means that my template is illegal somehow. these are all the errors i get
"ERRORS"

Code:

---

 
------ Build started: Project: LinkedStack, Configuration: Debug Win32 ------

Compiling...

Stack.cpp

.\Stack.cpp(3) : error C2143: syntax error : missing ';' before '<'

.\Stack.cpp(3) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int

.\Stack.cpp(3) : error C2988: unrecognizable template declaration/definition

.\Stack.cpp(3) : error C2059: syntax error : '<'

.\Stack.cpp(8) : error C2588: '::~Stack' : illegal global destructor

.\Stack.cpp(8) : fatal error C1903: unable to recover from previous error(s); stopping compilation

main.cpp

Generating Code...

Build log was saved at "file://c:\CPLUSPLUS\LinkedStack\Debug\BuildLog.htm"

LinkedStack - 6 error(s), 0 warning(s)

========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========



---

For most compilers you have to keep template-code ( declaration and implementation ) in one file. Looks like you are using an MS-compiler. This one cannot handle the extern - keyword.
The problem is that the compiler cannot know where you have put the implementation of your template-functions if you #include the declaration-part only.
BTW you cannot compile templates. Code is generated when you instantiate a template.
K

Quote:

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Originally Posted by sublyme

thanks googler for the help but I've tried that did it work for you.

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Oops, sorry, I forgot. You shouldn't compile Stack.cpp directly as a source file in your project. Use the project settings to mark it as "exclude from build". You should only compile main.cpp in your example.

thanks for the help guys i really appreciate it. everything works fine now i did what you said googler.

Have a look at this FAQ.