RE: [boost] MPL Experiences

From: Iain K.Hanson (iain.hanson_at_[hidden])
Date: 2002-09-05 11:25:57

> -----Original Message-----
> From: boost-bounces_at_[hidden]
> [mailto:boost-bounces_at_[hidden]]On Behalf Of David Abrahams
> Sent: 05 September 2002 15:13
>
> The paper isn't supposed to be a reference manual. What would
> you like to
> see it cover?
>

Unfortunately, it is the closest thing we have to a user guide and I suspect
many thought that it would form the basis of a user guide. I presume that
this was not necessarily the original intent.

I'd be interested to know what your intended target audience was? Going from
the hello world of metaprogramming of factorial through to fold, bind, and
the fsm in approx 39 pages sure covers a lot of ground.

As someone who has read both C&E and MC++D but is by no stretch of the
imagination a fluent meta programmer, I found the first part of the paper
very easy to understand. But some of the techniques used in the more
advanced examples defy me. Primarily, specialising templates with a
different number of parameters than the in definition ( both more and less
parameters ) which I think is what is meant in the paper by polymorphic
behaviour and type template parameters. I appreciate that I am deficient in
my knowledge of C++ but I have not seen a discussion of this technique and
what it means anywhere.

On a more general note, the section on lambda is very short and it would be
nice to know which facilities of boost::lambda have been implemented
 compare and contrast ). A reference to the boost::lambda documentation
 which is very well written IMHO ) would also not go amiss.

Finally, the fsm example is declared as:

class player : state_machine< player >

I like to know what state_machine< player >  brings to the party? I.e. could
the code for this be included.

Irrespective of whether you make any changes to refelect these comments, I
found it a very good paper and I learnt a lot from it. Many thanks to you
both.

/ikh