Re: [Boost-users] [netlib] throwing exceptions with http_client.cpp

Subject: Re: [Boost-users] [netlib] throwing exceptions with http_client.cpp
From: Christian Henning (chhenning_at_[hidden])
Date: 2010-11-18 14:22:23

Hi Dean,

>
> Well, to explain a few reasons why, I'd have to point you to the paper
> I wrote for BoostCon 2010 which I also gave a talk about. [0] In a
> nutshell:
>
> 1. I use Boost.Spirit internally for parsing -- that already exercises
> the compiler alone.
>
> 2. The tag dispatch mechanism used to determine the behavior of the
> implementation at compile time relies on template metaprogramming.
> Traits, factories, and selections are done using tag dispatch which
> relies heavily on Boost.MPL.
>
> 3. The amount of code that's already in the library lends itself to
> using a lot of memory, and especially since everything is a template,
> that's more time the compiler spends in processing the templates.
>
> The code generated then is as efficient as the compiler can make it --
> I hide nothing from the optimizer, and all the opportunities for
> optimization are there. Functions are inlined, loops unrolled, and in
> some cases operations are vectorized by the compiler's optimizer.
>
> I'm trying (hard) to get the compile times down but adding new
> features to the HTTP server part and later on supporting more
> overloads to member and free (template) functions will only make the
> compile time pretty heavy (or heavier, depending on how you look at
> it). ;)
>

Thanks for your insight. It's very interesting!

I'm sure this idea already came up but why not let the user have the
option of making parts of netlib compile into a lib?

Thanks,
Christian