Re: [boost] Dynamic sized bitset

From: Beman Dawes (bdawes_at_[hidden])
Date: 2001-11-26 08:22:14

At 12:27 AM 11/26/2001, Matt Austern wrote:

 >My question: why do we need both bitset<> and vector<bool>?  What are
 >the real differences?
 >
 >Except for trivial syntactic issues, here's all I can really come up
 >with:
 > - vector<bool> provides STL iterators and dynamic resizing, and
 >   bitset doesn't.
 > - bitset provides conversion to/from long, simple I/O, and
 >   bitwise operations.  vector<bool> doesn't provide any of
 >   those things.
 >
 >Seems to me that we should really be looking at extending vector<bool>,
 >not extending bitset.  A few trivial addons to vector<bool>, and we've
 >got a class that does everything bitset does and more.  (Yeah, I know:
 >vector<bool> shouldn't be spelled vector<bool>, it should be spelled
 >bit_vector.  Details.)

Exactly!

Unification of bitset, dyn_bitset, and vector<bool> seems within reach, and 
seems like an elegant solution to several issues:

*  A replacement for vector<bool> which does meet container requirements.
*  bitset isn't an STL container.
*  bitset users wish both static and dynamic allocation flavors.

--Beman