> On Jul 22, 2016, at 4:55 PM, Daniel Duan via swift-evolution
> <swift-evolution@swift.org> wrote:
>
>> Well, it's still a very real question whether we ought to have the
>> additional API surface implied by areSame, or wether we should collapse
>> it with ===.
>>
>
> To spell this out (because I had to think about it for a second): === will be
> derived from
> <=>, but also becomes default implementation for ==, which remains open for
> customization.
>
> I like this idea. If we keep === as a separate thing, now users have 3
> “opportunities” to define
> equality. The must be few, if any, use cases for this.
>
> Would love to see if anyone on the list can give us an example. Otherwise we
> should make
> areSame === again™!
If `===` is the new `areSame`, and `Hashable` is based on `===`, wouldn't that
mean that objects could only be hashed (and thus, be looked up in Dictionary
and Set) by identity? So, for instance, code like this:
var set = Set<NSString>()
set.insert("test")
set.insert("test")
print(set.count)
Would print "2"? Or worse, might print "1" or "2" depending on the details of
how Swift generates literals and Foundation implements short strings?
Am I the only one who thinks that's a problem?
--
Brent Royal-Gordon
Architechies
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