compiling a templated class

[sublyme]

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"

 
#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"

 
#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"

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

EROR

 
------ 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 ==========
 

[googler]

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

[sublyme]

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"

  
------ 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 ==========

[ZuK]

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

[googler]

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

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.

[sublyme]

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

[Graham]

Have a look at this FAQ.