#rust-lang

why doesn’t ! simply implement every single trait out there?

we would have less trouble and there wouldn’t be any problem with people forgetting to consider ! for their trait

nagisa: it's not possible

there was debate about this on the original RFC,

and it spawned a separate RFC

aturon: not possible as in it doesn’t work out somehow in the typechecking world or “our compiler is flawed”?

i believe the former

one sec

s/typechecking/type theory/

nagisa: bah, sorry, i don't have time to dig into it right this second

IIRC there was a fundamental soundness issue

aturon: no problem

I’ll look for it myself

i remember that it would conflict with mutually exclusive traits

I see there’s a `<! as Trait>::method : A` problem

oh yes, I’m remembering stuff ahah

but sure, the thing above would singlehandedly prevent rust from automatically implementing all the traits for !

and oh wow never type was so long ago. 2015

https://github.com/rust-lang/rfcs/pull/1892 is somewhat in a floating state: should probably just punt on it given the fact that we’ve decided in compiler sprint to just replace uninitialized with an union

you'd also have trouble with traits that have static methods

that's what I said

> I see there’s a `<! as Trait>::method : A` problem

nagisa: IIRC there was a proposal to implement all traits that only had non-static methods, and default associated types to ! where possible

cramertj: that makes the rules complex, among the other things