From: Jason Green <news AT jgreen4 DOT fsnet DOT co DOT uk>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Library with templates - help !!!!!!!!!!!!!
Date: Sat, 20 Jan 2001 14:49:05 +0000
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To: djgpp AT delorie DOT com
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"Rafal Maj" <maj_rafal AT poczta DOT onet DOT pl> wrote:

> Hi,
> I have problem when I compile program using library with templates.
> Project file contains bugmain.cc & bug.cc. In this example, bugmain.cc is my
> mian program, bug.cc is my library & bug.h is library header. I have
> problems to build my program when I'm using templates in my library.
> I get error report :

> Error: bugmain.o: In function `main':
> bugmain.cc(2) Error: undefined reference to `box<int>::move(int)'

> I know, that there are options like -frepo, no-implict-templates, etc... but
> I realy don't know how to set them to make my exaple work.

You don't need to worry about those options for this particular
problem, it's not DJGPP specific.

> If You can help me, please write exacly what should be compiler & linker
> options, and what I have to change inside my source files.

ok, below is rearranged how it should be, note that bug.cc no longer
exists:

> ================== BUGMAIN.CC =================
> #include "bug.h"
int main() {     /* <-- main returns an int */
>   box<int> b;
>   b.move(5);
> }
> ================== BUG.H ===============
> template <class typ>
> class box {
>   public :
>     typ x,y;
>     void move(typ d);
> };

> template <class typ> void box<typ>::move(typ d) {
>   x+=d;  y+=d;
> }
> =========================================================

compile with: gpp -O2 -Wall -W bugmain.cc -o bugmain