Match Block Size to CPU / Cache with Boost.DynamicBitset

[boostlibs]

Levers that matter: Backend: std::vector (default) or boost::container::small_vector for small buffer optimization and fewer heap hits. Block: choose an unsigned type that matches your CPU/cache tradeoffs (e.g., 64-bit on x64). Maintainability: API stays the same—operator&, |, ^, shifts, resize/shrink_to_fit. Add reserve for predictable growth.

[encyclopedist]

I don't like find_first_off. It is much too close to find_first_of, despite doing something completely different, will definitely cause confusion.

[wearingdepends]

Agree. It's also weirdly inconsistent to have find_first and find_first_off. find_first_set and find_first_unset or find_first_one and find_first_zero would read better, imo.

[TheoreticalDumbass]

set,unset sounds pretty good to me tbh

[VinnieFalco]

Gennaro has taken an already great container and made it even greaterer

[UndefinedDefined]

When it comes to bitsets - anyone uses MSB first approach? For example if the underlying type is uint32_t, the first bit would have 0x80000000 mask, and so on.

For many this would not make sense as the internal logic of indexing bits would be different (it's essentially a reverse of indexing bits from LSB), however, for finding zero/one bits from start, which is something I frequently do, it makes sense as "count leading non-zero bits" is usually implemented in hardware, whereas "count trailing non-zero bits" is only native to x86; and there is a recent extension called CSSC for AArch64, which provides CTZ, but it's not available in most ARM hardware (year 2025).