Delete EnumSet and remove its final use in rustc

[jroesch]

This commit adds an implementation of BuiltinBounds that does not depend on external data structures and removes EnumSet in the standard collections library. We should probably have both a person from the compiler team and libs team look this one over.

r? @gankro

[Gankra]

To be clear: EnumSet is already deprecated from libstd, and isn't re-exported there. As such you can just delete it. It's an internal implementation detail that was kept in exclusively for rustc's consumption.

[Gankra]

self.bits |= match ... ?

[Gankra]

You could also just cast the BuiltinBound to an integer. So

pubfninsert(&mutself,bound){self.bits |= (1 << (bound asu8));}pubfncontains(&self,bound){((self.bits >> (bound asu8))&1) == 1}

[jroesch]

Yeah good point some of these are probably just my functional programmer side coming through ;)

[Gankra]

The collection logic seems legit.

[Gankra]

@jroesch What's the status on this; do you need any more review? r=me if this is good to go.

[jroesch]

@gankro I didn't receive any negative feedback the second time so I assume that we are good to go.

[Gankra]

@bors r+

[bors]

📌 Commit 2c8ab28 has been approved by Gankro

[bors]

⌛ Testing commit 2c8ab28 with merge 057a1d7...

[bors]

💔 Test failed - auto-mac-64-nopt-t

[jroesch]

I didn't run the full test suite since this wasn't a huge change, but one test was still mentioning CLike 😢

[alexcrichton]

@bors: r=Gankro f4ff8ef

[bors]

⌛ Testing commit f4ff8ef with merge ef9570c...

[bors]

💔 Test failed - auto-mac-64-nopt-t

[tamird]

isn't this almost exactly the same as bitflags?

[steveklabnik]

@jroesch seems like a straightforward failure here

[tamird]

metaquestion: what is the difference between EnumSet/BitSet and bitflags?

[arielb1]

@tamird

One is a macro which declares a statically-sized set, the other is a dynamically-resizing set.

[Gankra]

@arielb1 EnumSet also has a statically known size (number of variants).

[tamird]

Seems like we can avoid introducing BitSet and just use bitflags!

[Gankra]

This sound plausible, yes. @jroesch what's the status?

[jroesch]

@gankro I had forgot this PR was still hanging around. I fixed the test failure, but we could just use bitflags if you don't foresee any problems.

[bors]

☔ The latest upstream changes (presumably #26870) made this pull request unmergeable. Please resolve the merge conflicts.

[jroesch]

I've decided I'm just going to remove BuiltinBounds as per @eddyb 's suggestion will follow up on this PR.

[Gankra]

I'm just going to close this PR, since it sounds like the new one will just be fresh work.

Good luck!