Make functions in this crate const?

[JSorngard]

Now that const_float_arithmetic has been stabilized, will the functions in this crate be made const where possible? Or is this not in scope due to MSRV policy?

[tgross35]

The stabilization definitely would make it possible for some of these functions to work in const contexts. However, I don't think that is an API guarantee we want to make because it would be a pretty significant limit on flexibility (anything that uses SIMD, assembly, or generic algorithms would no longer usable).

I think the better solution is to just move the math functions from std to core, and then make those const using the host machine's implementation. This is already planned but we do need to improve some things in this crate before it is possible (e.g. fix rounding errors, make sure our implementation is performant enough to ship).

[tgross35]

I am going to close this since I don't think we will make any changes in this crate's public API. I brought the topic of const float math up on Zulip since I don't think it has been discussed too much before https://rust-lang.zulipchat.com/#narrow/channel/146212-t-compiler.2Fconst-eval/topic/Const.20float.20math (feel free to drop by there if you have any interest working on it)

[JSorngard]

Makes sense. I might drop by there later to help work on this, could be fun!

[burrbull]

I'd wait for 1.83 (beta now): rust-lang/rust#129195