My brain at 5:00 AM

Error correction, motherfucker, do you speak it?

@kamen Depends on implementation. Actual data could be anything.

In C, 255 used to be very common (because bitwise compares); I’m not sure about now.

Yup. Better use a VARCHAR(3) to store YES or No, to make that app more efficient. 🤣

I've actually seen that in a productive app.

@Root I've never seen the numeric representation of `true` be anything other than 1 in either C or C++.

Also, if you're doing a bitwise check against a logical value, you're doing it wrong.

@junon history is history. 🤷🏻‍♀️

@Demolishun That doesn't make any sense. Have an example?

@root sorry didn't mean I thought you were being disingenuous, I should have added a question: which compilers did this, and when? Isn't it standardized to 1 now?

I fail to see how a memory cell being 255 would set a cpu flag. Perhaps if the architecture did so upon a read, or if you did an INC and checked for 8-bit overflow via CF, but then you could also just do a DEC and check for ZF.

Perhaps the MSB lane could be checked and set to the flag - but so could the LSB lane. Actually.... that'd be really useful.

Either way, I see less of a benefit, philosophically speaking, of treating 255 as true.

In fact, in C or C++, non-zero is boolean truthy, so it wouldn't make a lot of difference anyway unless you're doing arithmetic or bitwise operations on the value, which (again, philosophically) is not very smart.

~(0) is 255 hurr durr
Accept it.
255.
No waste.

@melezorus34 Only if your register is 8-bits...

It's possible to use bit size allocations in C++.

When I wrote a chess engine, it was about 3x faster to use a bit vector instead of an array of booleans.

That’s why you should always create flag registers of 8 boolean values you intend to track at once stored in a single integer to make sure you don’t lose the memory space.

Then you can write functions to grab the right binary big from it on demand because you forgot how to retrieve it otherwise!

@hashedram I'm very suspicious about that number. How were the booleans aligned? How large is sizeof(bool)? How large was the array? Did the array cross a cache line boundary? Bitsets are not free, on any platform. Cheap yes, but they are not inherently going to speed up execution unless there's an optimization around memory access.

If you're performing many operations on the same bitset then maybe it was a register promotion but I'd like to see the godbolt of whatever it is you did.

Also your first statement is wrong. You cannot allocate sub-byte memory. You probably meant bitwise operations, which... yes, of course you can.

@junon @Demolishun It’s been so long I simply don’t remember specifics. Also, I’ve seen the same behavior referenced by others here on devRant, so it’s not my brain fabricating memories.

@junon

1) It was years ago
2) I specifically measured it
3) Duh

@hashedram "Duh" is not how computer science works. Shameful approach to a discussion.

@junon meh