Problem with template class on GCC

[Shivanand]

Hello everyone,

Im facing problems with linking C++ templates in GCC on a MAC.

Following is the error GCC throws when I put template declaration in
".h" file and definition in ".cpp" file.
/usr/bin/ld: Undefined symbols:
JQualifier<double, 3>::JQualifier(int, long)
JQualifier<double, 3>::~JQualifier()

I get no errors when I put the class definitions inline (i.e. define
the instance methods inside the class). Can anyone please tell me what
I am doing wrong ?

Thanks in Advance

Following is the code snippet :

//--------------- JQualifier.h ---------------------------
template <typename T, int n>
class JQualifier
{
public :
JQualifier (int type, long uid);
~JQualifier () ;

};

//--------------- JQualifier.h ---------------------------


//--------------- JQualifier.cpp ---------------------------
#include "JQualifier.h"

template <typename T, int n>
JQualifier<T, n>::JQualifier (int type, long uid)
{

}

template <typename T, int n>
JQualifier<T, n>::~JQualifier ()
{

}
//--------------- JQualifier.cpp ---------------------------

//---------------- Main.cpp ----------------------------------

#include <iostream>
#include <JQualifier.h>

int main (int argc, char * const argv[]) {

JQualifier<double, 3> obj (1, 1) ;
return 0;
}

//---------------- Main.cpp ----------------------------------

Regards
Shivanand

 

[kostas]

Hello everyone,

Im facing problems with linking C++ templates in GCC on a MAC.

Following is the error GCC throws when I put template declaration in
".h" file and definition in ".cpp" file.
/usr/bin/ld: Undefined symbols:
JQualifier<double, 3>::JQualifier(int, long)
JQualifier<double, 3>::~JQualifier()

I get no errors when I put the class definitions inline (i.e. define
the instance methods inside the class). Can anyone please tell me what
I am doing wrong ?

it's a faq
http://www.parashift.com/c++-faq-lite/templates.html#faq-35.13

 

[Sumit Rajan]

it's a faq
http://www.parashift.com/c++-faq-lite/templates.html#faq-35.13

See:
http://www.parashift.com/c++-faq-lite/templates.html#faq-35.12

You may like to read all the Q&A's in that section.

 

[Sumit Rajan]

See:
http://www.parashift.com/c++-faq-lite/templates.html#faq-35.12

You may like to read all the Q&A's in that section.

Sorry...I missed out addressing that post to the OPl

Regards,

 

[Shivanand]

Thanks Sumit
Thanks kostas,

Made necessary changes to the code. now it works.

Regards
Shivanand