RE: [boost] MPL Experiences

From: Aleksey Gurtovoy (agurtovoy_at_[hidden])
Date: 2002-09-06 06:02:41

Jaap Suter wrote:
> I am using a clean Boost 1.28 distribution downloaded from
> http://boost.sourceforge.net/release/boost_1_28_0.zip over 
> which I installed the full library + all its dependencies that I 
> downloaded from
> http://www.mywikinet.com/mpl/mpl_23_jul_02_full.zip.
> 
> I hope that is the latest 'stable' release. If not, where can 
> I find that one? I'm a little hesitant to dive into CVS myself. 
> I prefer nicely packaged zip files that work right away :).

I am working on the new revision of the library that fixes a couple of bugs
and takes into account most of the review comments, but currently the above
archive is the latest public release.

[...]

> I'd like to make the following remarks:
> 
> 1. The file boost/mpl/contains.hpp contains a bug in my 
> distribution. It includes "boost/mpl/logical_not.hpp" whereas 
> that should be "boost/mpl/logical/not.hpp".

Thanks for the report, fixed in local sources.

> 2. What happened to mpl::for_each and mpl::push_back? Did I 
> overlook them?

'mpl::push_back' is there, it's just that currently there is no container
that implements it ;). It's gonna be fixed in the release version. 

As for 'for_each' - if you mean 'for_each' function template
(http://www.mywikinet.com/mpl/paper/html/codegeneration.html), it's present
as well - see "boost/mpl/for_each.hpp".

> 3. Is there any chance on a mpl::set container? I made my own 
> push_back that checks whether an element already exists, and 
> does nothing in that case. But I am sure more people could use 
> an mpl::set.

You can wait until I get to it, or you are welcome to contribute :).

> 4. In my humble opinion (no offense to any of you) but the 
> documentation can definitely be improved. 

Definitely.

[...] 

>     - Where is the reference documentation for mpl::if_, 
> mpl::apply_if, lambda facilities, etc? There is more in the mpl 
> than the reference describes.

Yep, will be fixed in the release version.

>     - I'd like a better explanation and more examples of both the
> fold/algorithm stuff, and the lambda facilities.

Working on it.

>     - Why does the mini-tutorial only talk about compile-time if's?

The same here :).

[...]

> 5. I highly recommend adding a default unsigned_int_c to the 
> library. I am using integral_c< size_t, n > very often.

Hmm, 'mpl::integral_c<std::size_t,n>' is indeed a little bit too verbose;
I'll consider adding 'mpl::size_t_c<>' (mpl::size_t<>?).

[...]

> All in all, great work! 

Thanks for your feedback!

Aleksey