[boost] Any, variant and more, and Sobol sequences

From: Geoff Leyland (geoff.leyland_at_[hidden])
Date: 2002-07-25 07:02:31

Hi,

I'm new to Boost, so please excuse me if I bring up any stuff that's 
been dealt with ages ago:  I've been reading the list for a while, but 
not forever, and it's a *lot* of volume.  There's a few questions I'd 
like to ask, and things to propose.  I've only got the released Boost 
1.28, so if things have changed a lot since then, please excuse me again.

1) I've got some very crude classes for something I call "run-time 
structures" (naming things isn't my strong point).  These are for 
handling, well, structures that get created at run time - like one has 
in MATLAB or Python or so on.  If x is one I can go:

x("a.b") = 2.0;
x("a.c.d") = "hello";

if (x("a.c.d").isa<string>())
   std::cout << x("a.c.d").be<string>();

and so on.  It throws semi-informative exceptions for wrong types and 
has a nasty little type-promotion mechanism so that, for example, char 
*'s are stored as strings.  It's *very* rudimentary, and it only does 
what I need it to do.  However, what I need it to do is slowly getting 
more complex.  In the long run I can dream of it reading these in from 
text files, which shouldn't be too hard, or changing the underlying 
representation to match MATLAB's or Python's (if that's what you're 
trying to talk to).

I looked quite hard on the web for some existing code to do this before 
I started, but didn't find any. Surely it must have been done a million 
times before (for all those scripting languages.).  Did I not look hard 
enough?

Anyway, it uses a class (called "object" - told you I sucked at names) 
for storing its members in.  On seeing "any" in Boost, I thought I would 
be much better off using that (using nice libraries is better than my 
cruft any day), but looking at any.hpp, I can see that the approaches 
are a bit different.  My object is the equivalent of the holder in any, 
I think.  I also see on the list that any and variant (though I've not 
got variant in boost 1.28) are being redefined.

So, two questions :
Would anyone working on any and variant be interested in what I've got 
(it's really not much) or even just my opinion on what would be nice for 
their any/variant to do?  I'd certainly be interested in getting recent 
copies of any and variant.
Would anyone else be interested in "run-time structures" as described 
above?  If so, what's a better name?  An even better question is: does 
this exist anywhere else?

2) I noticed at the end of random library documentation that Jens Maurer 
asks for Quasi-random sequence generators.  I've got a Sobol sequence 
generator (not a big deal, they're very short), but I also found (from a 
source far more reputable than me) starting data for up to 1111 
dimensions.  Would anyone be interested in this being added to the 
random library?

If you reply, please reply to me as well as the list : I'm only getting 
the digest.

Cheers,
goof