[swift-evolution] [Proposal] Allow enumerating cases in enumerations

[Saagar Jha]

+1 since it makes it easy to get the number of possible enum values, but I
thought I'd tell you: there's no "Wind" type in Pokémon. It's "Flying".
On Sun, Jul 3, 2016 at 18:36 Gabriel Lanata via swift-evolution <
swift-evolution at swift.org> wrote:

> Hello, this has been proposed multiple times before in different ways.
>
> Link to detailed proposal draft:
>
> https://github.com/gabriellanata/swift-evolution/blob/master/proposals/NNNN-allow-enumerating-cases-in-enumerations.md
>
> It is currently not possible to enumerate through all the possible cases
> of an enumeration object without adding a hardcoded value or recurring to
> unsafe workarounds. The proposal is to add a method of obtaining an array
> or set of all the possible cases natively for enumerations without
> associated values.
>
> The proposed solution is to implement a native `.cases` static var for
> all enumerations without associated values. This would provide a strict
> type-safe way of enumerating though the possible cases without risking
> runtime errors. The resulting code is a lot cleaner and less prone to
> errors caused by forgetting to update the hardcoded values when modifying
> cases.
>
> Resulting code:
>
>    enum PokemonType {
>        case Fire, Grass, Water, Wind
>    }
>    for pokemonType in PokemonType.cases {
>        // Do stuff
>    }
>    PokemonType.cases.count // Returns 4
>
>
> -------
> Gabriel
>
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>
-- 
-Saagar Jha
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