Challenge: Make a data type for holding one of 8 directions allowing increment and overflow

[H. S. Teoh]

On Thu, Mar 14, 2024 at 11:39:33PM +0000, Liam McGillivray via Digitalmars-d-learn wrote:
[...]
> I tried to rework the functions to use bitwise operations, but it was
> difficult to figure out the correct logic. I decided that it's not
> worth the hassle, so I just changed the value storage from `bool[3]`
> to `ubyte`.
[...]

Just wanted to note that while in theory bool[3] could be optimized by
the compiler for compact storage, what you're most likely to get is 3
bytes, one for each bool, or perhaps even 3 ints (24 bytes). When
dealing with units of data smaller than a byte, you generally need to do
it manually, because memory is not addressable by individual bits,
making it difficult to implement things like slicing an array of bool.
So the compiler is most likely to simplify things by making it an array
of bytes rather than emit complex bit manipulation code to make up for
the lack of bit-addressability in the underlying hardware.

Using bit operators like others have pointed out in this thread is
probably the best way to implement what you want.


T

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