Re: [boost] dynamic_bitset request

From: Victor A. Wagner, Jr. (vawjr_at_[hidden])
Date: 2002-08-05 11:25:03

At Tuesday 2002/07/30 20:23, you wrote:
>Ok... my schedule precludes this from happening before the weekend unless 
>some unusual things happen at my client's.
>I'll see where I can get by then.
>At Monday 2002/07/29 11:11, you wrote:
>
>>That's a good start. Why don't you finish fleshing this out in C++.
>>
>>BTW, it would be nice if I could implement this "set" interface for
>>dynamic_bitset without conflicting with current operations. For example,
>>operator<= is already taken to mean lexicographically less or equal.
>>However, if that leads to too much ugliness, we can always go the adaptor
>>route.

my schedule precluded my doing any serious coding on this, but I did 
(finally at 0100 this morning) get a chance to actually look at the 
implementation of dynamic_bitset.

If there are people who see some "lexicographic" ordering to the elements 
of a set, then we've got some differences to address.  From my point of 
view, all the elements in a set are of "equal importance" and the < and > 
operators should return the  same results independent of the underlying 
implementation.

With that in mind, it appears that one could simply have operator <=() 
(and >=() with the args reversed) call is_subset_of() and have operator <() 
(>() ditto above) call is_proper_subset().

The operators |=() and &=() appear to be already implemented.

The only remaining thing to be handled would then be  operator -=() and 
operator -() (possibly both the unary and binary flavors).

NOTE: these changes will ALTER the behavior of the any current code which 
counts on there being some lexicographic meaning in dynamic_bitset.

Should it be determined that lexicographic comparisons have utility, then 
mayhaps we should abandon attempts to map C++ "set" onto the mathematical 
set concept.
Victor A. Wagner Jr.      http://rudbek.com
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