[swift-evolution] stored properties in extensions (was: associated objects)

[Charles Srstka]

Right. The question is whether we *need* to add stored properties out-of-module, and what the use case for that is. To me it seems that adding them in-module is by far the more common use case, for the purposes of implementing protocols.

At any rate, the rewrite option would be a great addition to Swift regardless of what our answer to the first question is.

Charles

> On Oct 9, 2016, at 4:32 PM, Jay Abbott <jay at abbott.me.uk> wrote:
> 
> Charles,
> 
> That would be good. It is a nicer way to write what is already possible to achieve, but it's not a way to 'implement' stored properties in extensions.
> 
> On Sun, 9 Oct 2016 at 21:45 Charles Srstka <cocoadev at charlessoft.com <mailto:cocoadev at charlessoft.com>> wrote:
> *Replace both instances of “class C: P” with just “class C” since the conformance comes in the extension. That’s what I get for writing this quickly.
> 
> Charles
> 
>> On Oct 9, 2016, at 3:43 PM, Charles Srstka <cocoadev at charlessoft.com <mailto:cocoadev at charlessoft.com>> wrote:
>> 
>> protocol P {
>> 	var foo: String { get }
>> 	func bar()
>> }
>> 
>> protocol Q {
>> 	var baz: Int { get }
>> 	func qux()
>> }
>> 
>> class C: P {
>> 	var foo: String // <- what is this doing here?
>> 	var baz: Int // <- ditto
>> }
>> 
>> extension C: P {
>> 	func bar() {}
>> }
>> 
>> extension C: Q {
>> 	func qux() {}
>> }
>> 
>> we could simply:
>> 
>> protocol P {
>> 	var foo: String { get }
>> 	func bar()
>> }
>> 
>> class C: P {}
>> 
>> extension C: P {
>> 	var foo: String
>> 	func bar() {}
>> }
>> 
>> extension C: Q {
>> 	var baz: Int
>> 	func qux() {}
>> }
> 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20161010/e289b5a0/attachment.html>