I meant to add: I implemented it based on the declaration of popLast().
> On Sep 15, 2017, at 13:05 , Roderick Mann via swift-users
> <swift-users@swift.org> wrote:
>
>
>> On Sep 13, 2017, at 18:59 , Jon Shier <j...@jonshier.com> wrote:
>>
>> I think there’s something strange with popFirst. It doesn’t show up in
>> the autocomplete in Xcode, but it compiles, and popLast doesn’t throw the
>> same error. removeFirst doesn’t either, though it’s unsafe. Weird.
>
> extension
> Array
> {
> public
> mutating
> func
> popFirst()
> -> Array.Element?
> {
> if self.count > 0
> {
> return self.removeFirst()
> }
>
> return nil
> }
> }
>
>>
>
>>
>>
>> Jon
>>
>>
>>> On Sep 13, 2017, at 9:47 PM, Zhao Xin via swift-users
>>> <swift-users@swift.org> wrote:
>>>
>>> I begin to think it is related to how you `popFirst()` implemented. Check
>>> it or post it here.
>>>
>>> Zhao Xin
>>>
>>> On Thu, Sep 14, 2017 at 9:36 AM, Roderick Mann <rm...@latencyzero.com>
>>> wrote:
>>> Yeah, that's not it. I made the change you suggested, I get the same error.
>>>
>>>> On Sep 13, 2017, at 18:11 , Zhao Xin <owe...@gmail.com> wrote:
>>>>
>>>> Change `self` to `ModelFetcher`. You are calling a class static property,
>>>> not a class instance property.
>>>>
>>>> Zhao Xin
>>>>
>>>> On Thu, Sep 14, 2017 at 8:37 AM, Rick Mann via swift-users
>>>> <swift-users@swift.org> wrote:
>>>> Moving to Swift 4, I'm running into an issue for which I can't seem to
>>>> find an answer in google:
>>>>
>>>> "Cannot use mutating member on immutable value: 'self' is immutable"
>>>>
>>>> The code looks like:
>>>>
>>>> class
>>>> ModelFetcher : NSObject, URLSessionDelegate
>>>> {
>>>> ...
>>>> static let managerDispatchQueue =
>>>> DispatchQueue(label: "Model Download Manager Queue")
>>>> static var pendingFetchers =
>>>> [ModelFetcher]()
>>>> static var currentFetcher: ModelFetcher?
>>>>
>>>> class
>>>> func
>>>> startNextFetcher()
>>>> {
>>>> self.managerDispatchQueue.async
>>>> {
>>>> guard
>>>> self.currentFetcher == nil,
>>>> let mf = self.pendingFetchers.popFirst()
>>>> ~~~~ ^ error: cannot
>>>> use mutating member on immutable value: 'self' is immutable
>>>> else
>>>> {
>>>> return
>>>> }
>>>>
>>>> self.currentFetcher = mf
>>>> mf.start()
>>>> }
>>>> }
>>>> ...
>>>> }
>>>>
>>>> This code compiled fine in Xcode 8, or in Xcode 9/Swift 3.2 as a
>>>> monolithic app (the error shows up when this code is factored into a
>>>> framework). Other mutating references to self seem to compile okay (e.g.
>>>> "self.currentFetcher = nil" or "self.pendingFetchers.remove(at: idx)").
>>>> Not sure what's special about this one.
>>>>
>>>>
>>>> --
>>>> Rick Mann
>>>> rm...@latencyzero.com
>>>>
>>>>
>>>> _______________________________________________
>>>> swift-users mailing list
>>>> swift-users@swift.org
>>>> https://lists.swift.org/mailman/listinfo/swift-users
>>>>
>>>
>>>
>>> --
>>> Rick Mann
>>> rm...@latencyzero.com
>>>
>>>
>>>
>>> _______________________________________________
>>> swift-users mailing list
>>> swift-users@swift.org
>>> https://lists.swift.org/mailman/listinfo/swift-users
>>
>
>
> --
> Rick Mann
> rm...@latencyzero.com
>
>
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> swift-users@swift.org
> https://lists.swift.org/mailman/listinfo/swift-users
--
Rick Mann
rm...@latencyzero.com
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