Re: [Boost-users] [fusion] sequence conversion

From: Zeljko Vrba (zvrba_at_[hidden])
Date: 2008-07-22 02:21:35

On Tue, Jul 22, 2008 at 06:57:59AM +0800, Joel de Guzman wrote:
> 
> Really? Seems that you know very little of STL. It's been sold by
> countless people, in books, in mags, as "something abstract and generic".
> It's the very essence of generic programming in C++.
> 
Yes, I'm aware that it's been sold as "something abstract and generic".
Despite this, it boils down to a small set of easy to understand and manually
implemented (to me, at this level -- this is an advantage because I understand
what's going on, and compiler errors are still understandable to a human!)
conventions that enable writing of reusable algorithms for general and special
cases.  And I don't need a big imagination to see what std::map is good for or
when to use std::find.

And now, the last sentence brings us back to square one: me trying to
understand what MPL and fusion are / could be good for and with you jumping
right into the middle of my discussion with Istvan, and you becoming (seemingly
at least) frustrated with trying to help me when I never even explicitly asked 
for help -- it was a question about real-world usage!

==

Anyway, Dave has already recommended Stepanov's slides.  Can you please (yes,
*now* I'm asking for help :-)) recommend something else that explains generic
programming in C++ [*] and which is not so verbose that it uses several pages
and examples to explain why does an adaptable unary function need the
"result_type" typedef.  (This was just an example, and *not* a reference to
Stepanov's slides.. just to give you an idea about what kind of text I'm
after.)  There's a bunch of papers at Stepanov's site, but what to read and
in which order to read it?

[*] My basic mistake is, I guess, drawing parallels with ML.  Generic
programming in C++ is (obviously?) sufficiently different / harder that
analogies do not work well.