[Dev-C++] template and prototype

[<h.r...@gm...>]

> > -----Original Message-----
> > Subject: [Dev-C++] template and prototype
> > 
> > 
> > Hello,
> > 
> > Is it forbidden to have a prototype of a template in a header file ? 
> > For example:
> > 
> > a.h
> > template <class T> T sqr(T x);
> > 
> > a.cpp
> > template <class T> T sqr(T x) { return x * x; }
> > 
> > this doesnt link.
> > If I put the definition 
> > template <class T> T sqr(T x) { return x * x; }
> > in the header, it works.
> 
> If you want to place the definition in one file and use declarations to
> the rest, you must place the keyword export in the template definition
> in the style:
> 
> export template <class T>
> T sqr(T x) { return x*x; }
> 
> 
> Then you can use the declaration in the way you used it to access the
> template from other translation units. The export is necessary to make
> it possible someone to make a compiler that knows what is going on. :)
> If you do not like export you must provide the template definition in
> every unit you use it (templates have by default local scope in contrast
> to ordinary functions).
> 
> Ioannis

Hi Ioannis,
many thanks for the quick answer.
I followed your tip but the linker means:

3 hr_math.cpp
 warning: keyword 'export' not implemented and will be ignored

Horst

PS: sorry Ioannis for the PM

-- 
--------------------------
Horst Rößner
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