C bitfields are problematic and often aren't used in places where you'd think they'd be useful. Zig seems to be doing its best to get bitfields right.
Just one thing that Zig improves: in C if you need the bit offsets of the fields you'll still need lots of defines with the offsets/masks and such. In Zig it can be extracted from the packed struct at comptime
Don’t get me wrong, it’s a cool feature, the only problem I see here is zero readability, what if I’m looking at this code or trying to figure out the value of a register mangled by such a call, “I” find it very hard to read and understand what is happening there. I can read hex offsets and masks to know what’s what is happening to bitfield at any given time… just MHO.
Just one thing that Zig improves: in C if you need the bit offsets of the fields you'll still need lots of defines with the offsets/masks and such. In Zig it can be extracted from the packed struct at comptime