47f705b33f tests: add fuzz tests for BitSet (Pieter Wuille)
59a6df6bd5 util: add BitSet (Pieter Wuille)
Pull request description:
Extracted from #30126.
This introduces the `BitSet` data structure, inspired by `std::bitset`, but with a few features that cannot be implemented on top without efficiency loss:
* Finding the first set bit (`First`)
* Finding the last set bit (`Last`)
* Iterating over all set bits (`begin` and `end`).
And a few other operators/member functions that help readability for #30126:
* `operator-` for set subtraction
* `Overlaps()` for testing whether intersection is non-empty
* `IsSupersetOf()` for testing (non-strict) supersetness
* `IsSubsetOf()` for testing (non-strict) subsetness
* `Fill()` to construct a set with all numbers from 0 to n-1, inclusive
* `Singleton()` to construct a set with one specific element.
Everything is tested through a simulation-based fuzz test that compares the behavior with normal `std::bitset` equivalent operations.
ACKs for top commit:
instagibbs:
ACK 47f705b33f
achow101:
ACK 47f705b33f
cbergqvist:
re-ACK 47f705b33f
theStack:
Code-review ACK 47f705b33f
Tree-SHA512: e451bf4b801f193239ee434b6b614f5a2ac7bb49c70af5aba24c2ac0c54acbef4672556800e4ac799ae835632bdba716209c5ca8c37433a6883dab4eb7cd67c1
91e0beede2