[boost] Formal Review: dyn_bitset

From: Beman Dawes (bdawes_at_[hidden])
Date: 2002-06-17 15:36:18

I think that dyn_bitset should be accepted.

Issues:

*  As others have mentioned, the name is too cryptic, and should be changed 
to "dynamic_bitset" or similar.  (I don't like "bit_vector" because the 
name leads me to expect an interface like vector<bool>.)

*  Why is there an append(Block) and an append(Block iterator range) but no 
append( dyn_bitset )? Seems like that would be useful, and is tricky to get 
right when size() isn't a multiple of sizeof(Block). It might have to be a 
member template to handle type conversion issues.

*  In the resize() specification, it isn't clear to me what "discarded" 
means in "If num_bits < size() then the bits in the range [0,num_bits) stay 
the same (and the remaining bits are discarded)."  Is there a 
"shrink-to-fit" reallocation, or does the memory remain allocated and the 
discarded bits simply ignored?

*  Shouldn't the dyn_bitset(size_type num_bits, unsigned long value = 0, 
const Allocator& alloc = Allocator()) constructor be made explicit?

*  The documentation should begin with a little table of contents.  See 
www.boost.org/libs/rational/rational.html or 
www.boost.org/libs/utility/operators.htm for examples.

Caveat: I've only looked at the documentation, and have not tried to 
actually use the code.

--Beman