From: Shue-Cheng CHEN <scchen AT ohriki DOT t DOT u-tokyo DOT ac DOT jp>
Newsgroups: comp.os.msdos.djgpp
Subject: A Problem with Template Class
Date: 25 Sep 1998 07:09:18 GMT
Organization: Graduate School of Engineering, The Univ. of Tokyo, Japan.
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To: djgpp AT delorie DOT com
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Hi!

	I made a main program "test.cc" as follows,

#include <iostream.h>
#include "simarra.h"    // Header for SimpleArray<class T>

int main()
{
     SimpleArray<float> a;
     for (int i=1; i<=6; i++) {
          a[i] = i * 1.1;
          cout << a[i] << "  ";
     }
     cout << endl;
     return 0;
}

It's strange that this main program only works when I placed all 
implementations of the class SimpleArray<T> in the same test.cc.

When the implementations of the main program and the class were 
separated in two different files, e.g., test.cc and SimArra.cc,
in the linking stage, I always got the messages

1.o: In function `main':
1.cc:1: undefined reference to `SimpleArray<float>::SimpleArray(void)'
1.cc:2: undefined reference to `SimpleArray<float>::SimpleArray(void)'
1.cc:6: undefined reference to `SimpleArray<float>::operator[](int)'
1.cc:7: undefined reference to `SimpleArray<float>::operator[](int)'
1.cc:11: undefined reference to `SimpleArray<float>::~SimpleArray(void)'
1.cc(.text+0xc9): undefined reference to
`SimpleArray<float>::~SimpleArray(void)'
1.cc(.text+0xf3): undefined reference to
`SimpleArray<float>::~SimpleArray(void)'
1.cc(.text+0x113): undefined reference to
`SimpleArray<float>::~SimpleArray(void)'

Why did it become undefined?

Thank you in advance.

Shue-Cheng Chen