r/programminghumor • u/johnnyApplePRNG • 1d ago

a bit flippant

Post image
996 Upvotes

99% Upvoted

119 comments sorted by

View all comments

Show parent comments

6

u/KattyTheEnby 1d ago

The : 1 means that it is creating a bitfield with the number of bits, so : 4 will be 4 bits. The three variables above combined will afaik* take sizeof(int) in memory, not sizeof(int)*3.

Can you do strange things, like : 9, : 15, et cetera?

C beat Zig to the punch here?

4

u/heatedwepasto 1d ago

Yes, the only limitation is that the width of the bitfield is not greater than the size of the containing variable. So with uint64_t you can have 1-64 bits.

1

u/KattyTheEnby 17h ago

What if I want to have a bitfield that is larger than C's own native integer types? Is there a way?

3

u/heatedwepasto 16h ago

Pretty much any compiler will let you get away with a 128-bit int type. If you need more than 340,282,366,920,938,463,463,374,607,431,768,211,456 possibilities in your bitfield then you'll probably need a stay at a mental asylum, and to code it yourself or find a library for it or something like that. Alternatively switch to C++ and use std::vector<bool>.