[swift-evolution] [Pre-pitch] Conform Int (and others) to LosslessStringConvertible

[Niels Andriesse]

Just want to point out that conforming Int to LosslessStringConvertible like
this would mean assuming a radix of 10 in the implementation. That said,
this would be consistent with the way Int implements CustomStringConvertible,
which also uses a radix of 10.

On Mon, Jul 24, 2017 at 4:36 AM, David Sweeris via swift-evolution <
swift-evolution at swift.org> wrote:

>
> On Jul 23, 2017, at 09:15, Matheus Martins via swift-evolution <
> swift-evolution at swift.org> wrote:
>
> I came across what i think is an inconsistency in the standard library.
>
> Why are some numeric types like Int not conforming to
> LosslessStringConvertible by default while Float and Double do conform to
> it in the standard library?
>
> I came across this while trying to write some generic code:
>
> func array<T: LosslessStringConvertible>(_ text: String) -> [T?] {
> return text.components(separatedBy: " ").map { T($0) }
> }
>
> It seems rather inconsistent to me that that allows me to do:
>
> let floats: [Float] = array("1.0 2.2 3")
>
> but i can't do:
>
> let ints: [Int] = array("1 2 3 4 5 6")
> "type 'Int' does not conform to protocol 'LosslessStringConvertible'"
>
> To further my point, Int is used as the sole example in the
> LosslessStringConvertible docs: http://swiftdoc.org/v3.0/protocol/
> LosslessStringConvertible/
> Yet it does not actually conform to it.
>
> This seems way too basic for me to feel comfortable pitching it here, but
> i searched and couldn't find any discussion on this on any mailing list or
> website.
>
>
> Sounds like it's a bug to me, either in the docs or stdlib, depending on
> the intended behavior. Although I doubt they would've used Int in the docs
> if they weren't intending Int to conform to it.
>
> - Dave Sweeris
>
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>
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