> I have been a C coder (I'm not so much any more) for about 12 years of my career, and never came across bitfields in all that time, even when doing embedded w

> I have been a C coder (I'm not so much any more) for about 12 years of my career, and never came across bitfields in all that time, even when doing embedded work These days it shows up in databases stuff, either because you have e.g. one of these flags per row in your database (or imagine keeping track of used/unused fields in an in-memory block of data), which might add up to millions of booleans, and packing them by a ratio of 64 is a big improvement in space and also time it takes to process that data because the denser the data is, the more of it you can read per second and the more of it can fit in CPU caches. Also you can then use SIMD instructions to process it quicker too, etc etc.