I would be scared of using it for IO... With a struct bit field, I don't know wh... | Hacker News

Hacker Newsnew | past | comments | ask | show | jobs | submit

mort96 on July 31, 2025 | parent | context | favorite | on: Writing memory efficient C structs

I would be scared of using it for IO... With a struct bit field, I don't know what bit offset a field ends up with, I don't know how it gets padded, and I don't know how large the generated load and store becomes. I'd rather do the bit operations and store myself.

gizmo686 on July 31, 2025 [–]

__attribute__((packed)) is pretty much required for this use case.

mort96 on July 31, 2025 | [–]

That gets rid of the padding issue, but still does little to tell me which bit corresponds to which field.

Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact