> On Sep 8, 2017, at 5:14 PM, Xiaodi Wu via swift-evolution 
> <swift-evolution@swift.org> wrote:
> 
> Here, people just want an array of all cases. Give them an array of all 
> cases. When it's not possible (i.e., in the case of cases with associated 
> values), don't do it.


I agree it should be Int-indexed; that seems to be what people want from this.

I seem to recall that there is information about the available enum cases in 
the module metadata. If so, and if we're willing to lock that in as part of the 
ABI design, I think we should write—or at least allow for—a custom Int-indexed 
collection, because this may allow us to recurse into associated value types. 
If we aren't going to have suitable metadata, though, I agree we should just 
use an Array. There are pathological cases where instantiating a large Array 
might be burdensome, but sometimes you just have to ignore the pathological 
cases.

(The "infinite recursion" problem with associated values is actually relatively 
easy to solve, by the way: Don't allow, or at least don't generate, 
`ValuesEnumerable` conformance on enums with `indirect` cases.)

-- 
Brent Royal-Gordon
Architechies

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