[LC++]template and gcc

[Chris Vine]

On Monday 25 March 2002 11:04 am, Vincent Penquerc'h wrote:
> > class Dummy: public run<int> {} dummy;
>
> You can also simply instantiate your template in an object file,
> to tell the compiler that you do use it, so it can generate the
> right code:
>
> #include "run.h"
>
> template class Running<int>;
>
> This is as when you do:
>
> void foo(void);
>
> to tell the compiler there is something that's called foo,
> except that the compiler will instanciate the template (generate
> code for it templated for int).

I used to adopt the brute force method of instantiating a template 
by deriving from it because it was the only way I could be sure of getting 
gcc-2.7.2 to generate the required object code (the "template class 
Running<int>;" approach wasn't reliable with that compiler).  I also remember 
when Borland C++/Turbo C++ used to do it by means of dummy typedefs (this was 
the CFront 2.5 or 3.0 days).

I don't bother now to use a separate object file to instantiate required 
templates (and I suspect it is very rare to instantiate templates this way in 
code written nowadays) because it is a hassle to keep things in sync that 
way, particularly with the adoption of the STL.  Presumably linkers have got 
a lot smarter in adopting techniques to avoid duplicate code.

Chris.