Rust const generics MVP hits beta
I am extremely excited for this feature, especially now that I live in "absolutely no allocations" embedded land.<p>But also, beyond that, this is pretty much the last major feature that I've wanted in Rust. I've got some long-form writing in my head about this, but previously, I would have cast it as two or 2.5 features:<p>* const generics<p>* GATs<p>* specialization (this is the half)<p>However, when I've started to think about explaining these sorts of things, GATs (and to some degree specialization) feel much more to me like a removal of a restriction on combinations of features, more than "new features" strictly speaking. I think the line between these two perspectives is fascinating. On some level, you can even cast const generics in this way too: what it's really doing is making arrays a first-class feature of the language. I think that's a bigger stretch than GATs though, so I am not fully sure I'd make that argument. (The minimum feature we're stabilizing now basically does only this, but we do plan on going farther, so it feels true on a technicality now but not later.)<p>Regardless, it's been nice to see how much we've slowed down in adding major things. November of 2019 was the last time we had a feature this large hit stable. 18 months between huge things feels much more like the cadence of more mature languages that have been around a lot longer than Rust.<p>There is still a lot of work to do removing restrictions on existing features, especially const fn and const generics. But Rust is really starting to feel "done" to me, personally.