Comparison to empty set returns false for set with no bits set.

[John-Nagle]

"Eq" is true only if the number of bits in the underlying representation is the same. Comparing a bitset against
FixedBitSet::new() is not necessarily true for the empty set.

[John-Nagle]

Maybe define "is_empty()"

[jrraymond]

I see how this could be unintuitive. is_empty already exists.
This is the second time someone has raised this issue ( #44 ) so I'll update the docs to make this behavior clear.

[John-Nagle]

Thanks.
I'll use .is_empty().
As for equality, I think it should be either logical set equality, or not defined at all. Equality of the underlying representation is not what one expects.

[jrraymond]

clarification: is_empty already exists but doesn't do what you want. To compare the number of 1s are equal you can use xs.ones().eq(ys.ones())

The number of 0s isn't part of the underlying implementation. Its already exposed via other methods. There is more discussion on this in #44.

[John-Nagle]

clarification: is_empty already exists but doesn't do what you want.

No, it sure doesn't.

pub fn is_empty(&self) -> bool {
        self.len() == 0
}

That's "is any storage allocated", not "are there any entries".

The documentation does not say that. It needs to be made much, much clearer that "bitset" doesn't work like set theory, so that people are warned away from using it.

[jrraymond]

FixedBitSet is a simple fixed size set of bits that each can be enabled (1 / true) or disabled (0 / false) is clear imo. Bitsets in general are not synonymous with sets of non-negative integers.

Suggestions welcome, snark not appreciated 🤷