Re: [boost] [log] Comments

Subject: Re: [boost] [log] Comments
From: Rutger ter Borg (rutger_at_[hidden])
Date: 2010-03-16 04:46:21

Vladimir Prus wrote:

> I have now measured the compile time performance. An file that outputs a
> string to std::cout and does nothing else takes 0.27 seconds to compile on
> my system. Compiling the main.cpp from 'log/example/trivial' takes 2.47.
> For avoidance of doubt, I've repeated timing several times, with no
> significant deviation, and it's naturally hot cache case.
> 
> So, including Boost.Log headears appear to add 2.2 seconds to compilation
> time. This might sounds not much, but it adds up. For example, one part of
> KDE, named kdevplatform, has 562 files. So, if every one of them starts to
> use Boost.Log, that would add 1236 seconds, or 20 minutes, to the
> compilation time. The problem is that complete build of that project
> (which already uses KDE's logging mechanisms), takes 16 minutes.

Sorry for jumping in. At the risk of asking a silly question: shouldn't the 
include guards kick in and keep this overhead in the realms of constant time 
instead of linear time?

Regards,

Rutger