Prepare for v0.4.3 release

[nicoburns]

Objective

Ensure Taffy compiles on recent nightly versions of rustc

Context

• The trait bound f32: From<f64> is not satisfied #642
• evenly_sized_tracks - fix simple compile error #643
• f32::from(<untyped float>) inference with f16 and f128 rust-lang/rust#123831

[tgross35]

Just FYI we fixed the last item already at ToT, it should work again on the new nightly in about 6ish hours. That being said, I guess it's not the worst thing to try to avoid this pattern in case something winds up changing here in the future.

[nicoburns]

@tgross35 What is "ToT"?

it should work again on the new nightly in about 6ish hours. That being said, I guess it's not the worst thing to try to avoid this pattern in case something winds up changing here in the future.

Excellent, I figured this might get fixed on the rustc side. This particular change (typing the float literal) seems to have no downside, so I figured we might as well merge it.

There is a larger issue for Taffy's API exposed by the rustc issue though, which is that 3rd-party (non-Taffy) callers of the API may still be broken, which would be particularly if those callers were also libraries. That's a little trickier to fix as I think it would require changing the function parameter from impl Into<f32> + Copy to either f32 or impl Into<f64> + Copy which would semver-breaking. I'm not currently planning to fix that issue on the Taffy side.

[tgross35]

@tgross35 What is "ToT"?

Top of tree, think I picked that up from somebody's test suite that tries every commit.

I agree that this is a quite tricky thing to dance around and really don't know what is best either. Thanks for being on top of this, having the little fixes in the ecosystem early is great in case the compiler does change some behavior 👍