[boost] Re: Re: Re: Adding Loki to Boost (reprise)

From: Aleksey Gurtovoy (agurtovoy_at_[hidden])
Date: 2002-04-12 18:47:35

David A. Greene wrote:
> I agree with this.  The MPL count_if example is really confusing.  I
> have yet to see a convincing example of why such convolutions are
> necessary.  Some have alluded to complex metaprogramming problems
> more easily solved with MPL/"iteration" that recursion/pattern
> matching but I haven't seen them.

When it seems that you don't have enough experience with the domain to
appreciate what the library is has to offer. Nobody forces you to use the
library for whatever tasks you might have. Some people don't use STL and are
happy this way. Your reply implies that we are trying to sell you something
that does not hold its promises. Well, we are not. The last thing I am
interested in is to spend my time trying to convince somebody who has
already made his mind.

> There have been several calls for implementations of Loki facilities
> in MPL and to my knowledge, not one has been posted.

It has been said (and shown) a long time ago that typelist part of Loki is a
subset of MPL. In particular, that means that re-write of every other Loki
facility that depends on typelists is trivial. If you are interested in
porting Loki to MPL - go ahead. I am not, because we don't use Loki
anywhere.

>
> MPL may be nice, I don't know.  It's tough for me to begin using
> it without documentation.

It has the documentation, the docs base is growing, and personally I am
always glad to answer whatever usage question one might have. If it's not
enough of the service for you, sorry.

> Such information has been promised for
> quite some time now and it seems it's still not up-to-date.

I should be missing something. Are you paying us to write the docs?

> I hope MPL makes it into Boost.  A metaprogramming library would
> be extremely useful.  Can MPL support algorithms written using
> recursion?  If it can handle recursion as well as iteration, I'd
> be happier.

You've asked this question before, and it has been already answered.

"You can always write your own recursive algorithms with MPL type lists. The
termination are detected slightly differently to allow for different
sequences, but that's about it."

Aleksey