[boost] Re: Formal Review: Command Line & Config library

From: Vladimir Prus (ghost_at_[hidden])
Date: 2003-05-27 07:12:23

Chuck Messenger wrote:

> Vladimir Prus wrote:
> 
>> Yep. This question was raised already. I think that making templates out
>> of all classes is *a* solution, but I'm not sure it's *the* solution. The
>> problem is that extensive template usage would prevent making library ---
>> either shared or static. I think that would be a big downside.
> 
> Why does that matter?  The great majority of other Boost libraries are
> header-file-only.  I think of .cpp components of Boost libraries as a
> sometimes-necessary evil, not as a desired feature.

Becase header-file-only libraries have two problems --- they increase
compilation times and they increase binary size. And you can't share the
code between different applications.

I think that's important practical aspect. In past, I was burned by
overgeneralization --- almost all core classes in a program had template
parameter. It had only one possible value, but I though different ones were
possible. As the result, compilation time was terrible, and no new possible
values for the template parameter became needed.

And these days, I'm rather unhappy with compilation times of BGL...

- Volodya