Message-ID: <397BC997.9C504DD9@puckbell.net>
From: Tasci Synx <nospam AT puckbell DOT net>
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Subject: Enabling Static Data in Templates
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Date: Sun, 23 Jul 2000 21:44:07 -0700
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To: djgpp AT delorie DOT com
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Reply-To: djgpp AT delorie DOT com

This might be a problem with djgpp, so I wanted to ask here.

The Ansi C++ standard gives an example of a static data member in a
templated class:
---------------------------------------------------------
template<class T> class X {
	static T s;
};
template<class T> T X<T>::s = 0;
---------------------------------------------------------
However, upon putting such a thing in a header file, I received a linker
error.

test.o: In function `foo<int>::blech(void)':
test.cpp:15: undefined reference to `foo<int>::bar'
collect2: ld returned 1 exit status

Here is the test code I compiled:

---------------------------------------------------------
// in test.h
#include <iostream>
using std::cout;

template <class Type>
struct foo
{
	static Type bar;
	static void blech(void);
};

template <class Type> Type foo<Type>::bar = 33;

template <class Type> inline void foo<Type>::blech(void)
{
	cout << "Pass the bar:" << bar << endl;
}
---------------------------------------------------------
---------------------------------------------------------
// in test.cpp

#include "test.h"

void main(void)
{
	foo<int> test;
	test.blech();
}
---------------------------------------------------------

Is this a problem specific to djgpp?  Is there a switch I can use to
make sure my static templated data members are created properly?

Thank you.


Tasci

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