Perhaps relatedly, it no longer seems possible to mark typealiased closures as @escaping. That was quite handy when you know that closures will always be used asynchronously.
Jon > On Sep 7, 2016, at 6:15 PM, Shawn Erickson via swift-users > <[email protected]> wrote: > > I should note that this issue also appeared in an earlier variant of Swift > after the addition of @escaping but I was on vacation so didn't get a chance > to report it then. It isn't new with the Xcode 8 GM. > > On Wed, Sep 7, 2016 at 3:08 PM Shawn Erickson <[email protected] > <mailto:[email protected]>> wrote: > I like and fully supported the change to @escaping away from @noescape > however in a body of code that I am porting to the latest Swift 3 variant (as > found in Xcode 8 GM) I am hitting an issue for methods that take an optional > completion closure. If optional is involved I can't find a way to apply > @escape to the escaping closure. See the following for an basic example... > > Is their a way to do what I need and/or is this an edge case in the > implementation of @escaping? > > typealias MyCallback = (String)->() > > // Happy > func foo1(bar: String, completion: ((String)->())) { > completion(bar) > } > > // Happy > func foo2(bar: String, completion: MyCallback) { > completion(bar) > } > > // Happy > func foo3(bar: String, completion: ((String)->())? = nil) { > completion?(bar) > } > > // Happy > func foo4(bar: String, completion: MyCallback? = nil) { > completion?(bar) > } > > // Happy > func foo5(bar: String, completion: Optional<MyCallback> = nil) { > completion?(bar) > } > > // Happy > func foo6(bar: String, completion: @escaping (String)->()) { > completion(bar) > } > > // Happy > func foo7(bar: String, completion: @escaping MyCallback) { > completion(bar) > } > > // Unhappy... > // "@escaping attribute only applies to function types" > func foo8(bar: String, completion: @escaping ((String)->())? = nil) { > completion?(bar) > } > > // Unhappy... > // "@escaping attribute only applies to function types" > func foo9(bar: String, completion: @escaping MyCallback? = nil) { > completion?(bar) > } > > // Unhappy... > // "@escaping attribute only applies to function types" > func foo10(bar: String, completion: (@escaping ((String)->()))? = nil) { > completion?(bar) > } > > // Unhappy... > // "@escaping attribute only applies to function types" > func foo11(bar: String, completion: (@escaping MyCallback)? = nil) { > completion?(bar) > } > > // Unhappy... > // "@escaping attribute only applies to function types" > func foo12(bar: String, completion: Optional<@escaping MyCallback> = nil) { > completion?(bar) > } > _______________________________________________ > swift-users mailing list > [email protected] > https://lists.swift.org/mailman/listinfo/swift-users
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