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

[Niels Andriesse]

And CustomStringConvertible (to String) is basically the inverse of
LosslessStringConvertible (from String).

On Mon, Jul 24, 2017 at 3:23 PM, Niels Andriesse <andriesseniels at gmail.com>
wrote:

> 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 CustomStringConvert
> ible, 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/proto
>> col/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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