This is the perfect spot to use a bitfield. You can tell it signed or unsigned, and the compiler will deal with it all and optimize. No bit ops to get wrong or maintain. Very readable and scalable.
> ... this explicitly relies on shifting something into the sign bit, which depending on the exact flavor of language standard you’re using is either not allowed or at best fairly recently ..
An unsigned has no sign bit, so the left shift just needs to be unsigned to make it "technically correct".
(Remember to not use smaller than int types though, due to integer promotion issues)
Of course doing the undefined thing works on almost any platform except DS9k, but that last formulation is quite elegant. It's a bit like byteswapping in that it's fairly simple to do but it's even simpler to not do by just never relying on the machine endianness.
This is the perfect spot to use a bitfield. You can tell it signed or unsigned, and the compiler will deal with it all and optimize. No bit ops to get wrong or maintain. Very readable and scalable.
> ... this explicitly relies on shifting something into the sign bit, which depending on the exact flavor of language standard you’re using is either not allowed or at best fairly recently ..
An unsigned has no sign bit, so the left shift just needs to be unsigned to make it "technically correct".
(Remember to not use smaller than int types though, due to integer promotion issues)
Of course doing the undefined thing works on almost any platform except DS9k, but that last formulation is quite elegant. It's a bit like byteswapping in that it's fairly simple to do but it's even simpler to not do by just never relying on the machine endianness.