paul@hackingwithswift. For a small application that I want to implement I’d like to stick with MVVM. Closure captures 'escapingClosure' before it is declared. There are several other possible errors related to closure captures being able to effectively make structs into reference types (thereby destroying any guarentees that come from being a value-type) I was trying to understand why the above code is working with the former, but not with the latter. myThing = "thing" } but that would only change the value of the variable myself , and not affect anything outside of your function. 这个闭包并没有“逃逸 (escape)”到函数体外。. e. 1 (20G224) Additional Detail from JIRA Votes 0 Component/s Compiler Labels Bug Assigne. ContentView. Connect and share knowledge within a single location that is structured and easy to search. " Therefore, the 'self' can not be mutable. wrappedValue. 0. Viewed 5k times. In the main content view of my app, I display a list of these homeTeam. Which mean they cannot be mutated. Sending x and y from gesture to struct (Please help!) Dec '21. {"payload":{"allShortcutsEnabled":false,"fileTree":{"proposals":{"items":[{"name":"0001-keywords-as-argument-labels. Look at the below code:But now I'm getting a "Escaping closure captures mutating 'self' parameter" – Dante. The whole point is the closure captures and can modify state outside itself. Learn more about TeamsIn Swift 1. made from cast-iron?. Otherwise these models get downloaded on the first run of the image/container. async { self. Using Swift. SPONSORED Elevate your skills from design to SwiftUI by joining Design to SwiftUI, where you'll become skilled in weaving in unique design elements that enhance both aesthetics and user experience. 1. implicit/non-escaping references). That's the meaning of a mutating self parameter . Anyway if you like to use your code, then capture the self inside your mutation method like below: mutating func getUserWorkspace (base: String, completed: @escaping () -> ()) { let url = URL (string: "some url")! var request = URLRequest (url: url) var myself = self request. 0. dataTask (with. md","path":"proposals/0001-keywords-as-argument. The mutating keyword allows a function on an enum to mutate itself, but is there a way to extend that ability to escaping closures? I'm looking for a definition of the timer handler in start () below that will move MyTimer back to its . Escaping closure captures mutating 'self' parameter. before you use them in your code, such as self. Escaping closure captures mutating 'self' parameter. Capture self, though… mutating func anotherMethod() { someMethod { [self] in self } }. it just capture the copied value, but before the function returns it is not called. Following code produces Escaping closure captures mutating 'self' parameter error: struct Foo { @State var count = 0 init { Timer. How to run a function inside a body of SWIFT UI? 0. 如果考虑到内存的. game = game } func fetchUser (uid: String) { User. Stack Overflow | The World’s Largest Online Community for DevelopersStack Overflow | The World’s Largest Online Community for DevelopersPrevious ID SR-9743 Radar rdar://problem/56835205 Original Reporter CTMacUser (JIRA User) Type Bug Status Resolved Resolution Cannot Reproduce Attachment: Download Environment macOS Mojave 10. (SE-0103){"payload":{"allShortcutsEnabled":false,"fileTree":{"proposals":{"items":[{"name":"0001-keywords-as-argument-labels. All review feedback should be either on this forum thread or, if you would like to keep your feedback private, directly to the review. This is not generally true. Since the closure can be stored and live outside the scope of the function, the struct/enum inside the closure (self) will be copied (it is a value) as a parameter of the closure. For example, that variable may be a local. for me anyway. In one of the views of my application I need to mutate some data. Difficulty trying to use a struct to replace a cluster of stored properties in a class. The only change SE-0269 results in is that you don't need to explicitly write out self. I use this boolean to show a view on a certain state of the view. Non-Escaping Closures. {"payload":{"allShortcutsEnabled":false,"fileTree":{"proposals":{"items":[{"name":"0001-keywords-as-argument-labels. firstIndex (where: { $0. – Ozgur Vatansever Aug 14 at 15:55 Escaping Closures. By default a closure is nonescaping like your dispatch parameter, but you are calling it inside an escaping closure which probably is the closure that you pass as a parameter in getMovies function. That's straightforward. What you actually seem to have implemented is a struct (or class) containing a timer. image = $0 } // 雖然下面的語法沒有出現錯誤訊息，但依然沒用Escaping closure captures mutating 'self' parameter Hello, I am new to swift programming and I've been having this error "Escaping closure captures mutating. schedule (after: . extension Array where Element: Identifiable { mutating func getBinding (of instance: Element) -> Binding<Element> { if let index = self. {"payload":{"allShortcutsEnabled":false,"fileTree":{"proposals":{"items":[{"name":"0001-keywords-as-argument-labels. in the closure, but when using [unowned self], you can omit self. Modified 3 years ago. Then in your is_new getter, compare the expiry time with the current time. turnON(). If I'm running this code in a struct I get this error: Escaping closure captures mutating 'self' parameter. {"payload":{"allShortcutsEnabled":false,"fileTree":{"proposals":{"items":[{"name":"0001-keywords-as-argument-labels. The other solution would be to have the transition function return the new state, and have receive. The type owning your call to FirebaseRef. Stack Overflow | The World’s Largest Online Community for Developers{"payload":{"allShortcutsEnabled":false,"fileTree":{"proposals":{"items":[{"name":"0001-keywords-as-argument-labels. . If you use a guard let, your closure captures self at the beginning of the closure. init (initialValue. Add a. Protocol '. import Combine class GameViewModel: ObservableObject { @Published var game : Game @Published var user : User? init (game: Game) { self. He also suggest we investigate changing the default language rule for optional parameter closures. init (responseDate)) { moveBack () } } private mutating func. onShow() } 1 file 0 forks 0 comments 0 stars plivesey / Pirates Hint #3. onReceive(_:perform) which can be called on any view. If this were allowed, then there is the possibility that self may not exist by the time the closure executes. In a member func declaration self is always an implicit parameter. But if you make it @escaping, you get error: escaping closure captures mutating 'self' parameter. {"payload":{"allShortcutsEnabled":false,"fileTree":{"proposals":{"items":[{"name":"0001-keywords-as-argument-labels. class , capture-list , closure , escapingclosure , struct. I hope you can help. posts. . Escaping closures// This actually throws an error: Escaping closure captures mutating 'self' parameter: toastManager. Masalah: Saya mendapatkan Escaping closure captures mutating 'self' parameterkesalahan seperti yang ditunjukkan pada kode. You can use onReceive to subscribe to Combine Publisher s in SwiftUI View s. 1 Why is Swift @escaping closure not working? 3. current. Hi Alexander, yes the wilderness. [self] in is implicit, for. From the 'net:-=-A closure keeps a strong reference to every object the closure captures — and that includes self if you access any property or instance method of self inside the closure, because all of these carry an implicit self parameter. Do I need to use a class in this case? Or is there some implementation that I don't know/haven't thought of (maybe with Combine?)? Any advice is much appreciated! P. Escaping closure captures mutating 'self' parameter. Swift ui Escaping closure captures mutating 'self' parameter. init (initialValue. Dan saya menduga parameter escaping closureis the func startTimerdan yang menyinggung 'self' parameteradalah countDownTime, tetapi saya tidak begitu yakin apa yang terjadi atau mengapa itu salah. An escaping closure that refers to self needs special consideration if self refers to an instance of a class. async { throws Cannot convert value of type ' ()' to closure result type ' [Post]' and final 3. Here. append(str) modifies the parent ContentView object out of dataTask closure and that is not good for some reason. swift class GetLocations :ObservableObject { @Published var arrLocations = NSArray () func getLocNames (Action:String, Id: String, completion: @escaping (NSArray) -> Void) { //fetch data from server let session = URLSession. Swift 5 : What's 'Escaping closure captures mutating 'self' parameter' and how to fix it. SwiftUI run method on view when Published view model member value changes. This dissertation is an ethnographic study, accomplished through semi-structured interviews and participant observation, of the cultural world of third party Apple software developers who use Apple’s Cocoa libraries to create apps. When you declare a function that takes a closure as one of its parameters, you can write @escaping before the parameter’s type to indicate that the closure is allowed to escape. center, spacing: 20, content: {Text("d")}) this is a instance of struct VStack, and when creating an instance of it, the third parameter takes closure as a parameter. Closure parameters are non-escaping by default, rather than explicitly being annotated with @noescape. latitude and . I need to fetch data before view loads and display the data in a button text. And the result of the closure is indirectly used by transform, so it doesn't actually escape. Oct 16, 2019. Accessing an actor's isolated state from within a SwiftUI view. In the Core Audio Recorder example the AudioQueueInputCallback function is written as a variable binding outside the class Recorder. I'm trying to create an extension for Int, that increments its value progressively through time. e. In your case you are modifying the value of self. bytes) } } } } In the ReaderInformations. increase() // may work } If you change model to reference type, i. There is only one copy of the Counter instance and that’s. The simple solution is to update your owning type to a reference once (class). md","path":"proposals/0001-keywords-as-argument. This is not allowed. s: The way you're setting self. Swift. View Pirates Hint #3. I am trying to use it inside a struct, but I am not able to access any instance methods. You can fix this by either removing @escaping, or you change the value types to reference types. If we are sending some self value into it, that will risk the closure behave differently upon its execution. But it doesn't seem to be what you are actually doing. (() -> _). Swift protocol error: 'weak' cannot be applied to non-class type. For a small application that I want to implement I’d like to stick with MVVM. Learn more about TeamsresponseDecodable(of: PeopleListM. In Swift 1. Even if you can bypass that, you still have the problem of using self before all of its variables are initialized ( toggleBinding specifically). the closure that is capturing x is escaping kind or nonescaping kind. How to fix "error: escaping closure captures mutating 'self' parameter. it just capture the copied value, but before the function returns it is not called. {"payload":{"allShortcutsEnabled":false,"fileTree":{"proposals":{"items":[{"name":"0001-keywords-as-argument-labels. クロージャのescapingやキャプチャに関し. (Do you have some other reason for wanting to store the timer. Does not solve the problem but breaks the code instead. Learn more about TeamsI have a program that has two main classes, Team and Player. I understand the problem with trying to modify a struct from within a closure, but I don't know what I'd need to change to be able to update the UI, based on the results from the face detection request. Stack Overflow | The World’s Largest Online Community for DevelopersStack Overflow | The World’s Largest Online Community for DevelopersNon-escaping closure can't capture mutating self in Swift 3. Escaping closure captures mutating 'self' parameter You’re now watching this thread. ios; swift; swiftui; Share. There are additional methods that allow you to make requests using Parameters dictionaries and ParameterEncoding. 34. 0. Creating a simple card game (Set) and I have a function in the model that deals X cards onto the deck. This proposal does not yet specify how to control the calling convention of the self parameter for methods. My playground sample code looks like this: class MyFoo: ObservableObject { @Published var bar: String init (bar: String) { self. Stack Overflow | The World’s Largest Online Community for DevelopersStack Overflow | The World’s Largest Online Community for DevelopersStack Overflow Public questions & answers; Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Talent Build your employer brand ; Advertising Reach developers & technologists worldwide; Labs The future of collective knowledge sharing; About the companyBusiness, Economics, and Finance. But if you make it @escaping, you get error: escaping closure captures mutating 'self' parameter. Escaping closure captures mutating 'self' parameter (I really need help!) – SwiftUI – Hacking with Swift forums. repo = repoData, it causes memory-leak because you captured self strongly. i. Hot Network Questions Space-ships and stations. The observeSingleEvent(of:with:) method. In Swift 3, inout parameters are no longer allowed to be captured by @escaping closures, which eliminates the confusion of expecting a pass-by-reference. {"payload":{"allShortcutsEnabled":false,"fileTree":{"proposals":{"items":[{"name":"0000-conversion-protocol-conventions. dataTask. 101. A copy is used to ensure that the closure can use self without having to use self, as the compiler will complain that "Escaping closure captures mutating self parameter" (hence the reason that OverlapContainer. The compiler knows that you are changing the structure by mutating dataAPI parameter. if self. com's AI search assistant which allows users to find summarized answers to questions without needing to browse multiple websites. If you’ve opted in to email or web notifications, you’ll be notified when there’s activity. 1. { // assign function directly instead of via capturing closure viewModel = TimerViewModel(totalTime: 15, finished: timerCallback) } var body: some View { Text("Demo") } private func. In Swift 3, it’s the other way around: closure parameters are non-escaping by default. md","path":"proposals/0001-keywords-as-argument. . Button(action: {self. DispatchQueue. The usual solution to mutating state inside of an escaping closure is to pass that state as an inout parameter to the closure. the first answer i read indicated that structs cannot be mutated. Q&A for work. {"payload":{"allShortcutsEnabled":false,"fileTree":{"proposals":{"items":[{"name":"0001-keywords-as-argument-labels. For example, I have a form that is shown as a model sheet. Swift: How to wait for an asynchronous, @escaping closure (inline) Hot Network Questions Writing songs on piano that are meant for a guitar-led bandfunc exampleFunction() { functionWithEscapingClosure(onSuccess: { result in self. Even the name UILogic , while just a name, hints that you may need to rethink your use of the MVVM architecture. h has been modified since the module file. Since the closure can be stored and live outside the scope of the function, the struct/enum inside the closure (self) will be copied (it is a value) as a parameter of the closure. Connect and share knowledge within a single location that is structured and easy to search. This is not allowed. The function that "animates" your struct change should be outside it, in UILogic , for example. {"payload":{"allShortcutsEnabled":false,"fileTree":{"proposals":{"items":[{"name":"0001-keywords-as-argument-labels. {"payload":{"allShortcutsEnabled":false,"fileTree":{"proposals":{"items":[{"name":"0001-keywords-as-argument-labels. struct MyView: View { @State var current: Int = 0 var body: some View { Text (" (current)") . onChange (of: observable. Actually it sees that if after changing the inout parameter if the function returns or not i. md","path":"proposals/0001-keywords-as-argument. Protocol '. 0. A closure is said to escape a function when the closure is passed as an argument to the function, but is called after the function returns. sync { self. 这个闭包并没有“逃逸 (escape)”到函数体外。. being explicitly added to referenced identifiers. global(). wrappedValue. toggle). February 2, 2022. md","path":"proposals/0001-keywords-as-argument. I have a StateWrapper struct that conforms to DynamicProperty, allowing it to hold state that a SwiftUI view can access and react to. Team has an array built in which holds 23 instances of the Player class, all with their own properties and methods. This is not allowed. getById (id: uid). {"payload":{"allShortcutsEnabled":false,"fileTree":{"proposals":{"items":[{"name":"0001-keywords-as-argument-labels. Hi Alexander, yes the wilderness. ' to make capture semantics explicit". The @escaping attribute indicates that the closure will be called sometime after the function ends. Based on this and the empty set your descriptiveDate and descriptiveInt don't need to be Binding just a get for a String. error: Converting non-escaping parameter 'completionHandler' to generic parameter 'Element' may allow it to escape By Definition: "A non escaping closure goes out of the scope and stops existing in memory as soon as the function body gets executed. Special property wrappers like @State let you mutate values later on, but you're attempting to set the actual value on the struct by using _activity = State(. Create a HomeViewModel - this class will handle the API calls. Escaping closure captures mutating 'self' parameter Error. import SwiftUI import Combine class HomeViewModel: ObservableObject, Identifiable { @Published var companyName: String = "" private var db = Firestore. longitude of the struct without having to use the wilderness part explicitly? Capturing an inout parameter, including self in a mutating method. parameter, result: result) } } As you've probably noticed, this will cause a memory leak, since onSuccess is an escaping closure and it's retaining self. 2. struct ContentView: View { @State var buttonText = "Initial Button Label" var body: some View { VStack { Text (buttonText) Button (action: { self. 0 Error: Escaping closures can only capture inout parameters explicitly by value Escaping closure captures mutating 'self' parameter I understand that the line items. Actually you must capture weak self in each closure if you assume that viewController may be dismissed at some time during load. . Swift ui Escaping closure captures mutating 'self' parameter. CryptoStack Overflow | The World’s Largest Online Community for DevelopersPrevious ID SR-9743 Radar rdar://problem/56835205 Original Reporter CTMacUser (JIRA User) Type Bug Status Resolved Resolution Cannot Reproduce Attachment: Download Environment macOS Mojave 10. firstIndex (where: { $0. Protocol '. (where I use an explicit self. Hi, I’m new to Swift and also to SwiftUI. Stack Overflow Public questions & answers; Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Talent Build your employer brand ; Advertising Reach developers & technologists worldwide; Labs The future of collective knowledge sharing; About the companyStack Overflow | The World’s Largest Online Community for DevelopersStack Overflow Public questions & answers; Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Talent Build your employer brand ; Advertising Reach developers & technologists worldwide; About the companyWhen a closure is escaping (as marked by the @escaping parameter attribute) it means that it will be stored somehow (either as a property, or by being captured by another closure). So just saving a closure in some variable doesn't necessarily mean it's leaked outside the function. You could also move the code to a separate function, but still declare those vars with an initail value in init() – workingdog support Ukraine{"payload":{"allShortcutsEnabled":false,"fileTree":{"proposals":{"items":[{"name":"0001-keywords-as-argument-labels. MyView { MyContent() } but what I want is to pass a parameter in the closure, like. 5 seco. Swift, actor: Actor-isolated property 'scanning' can not be mutated from a non-isolated context. Improve this question. Why can't I mutate a variable initially set to a certain parameter when the func was called? Related. Worse, one attempt flagged a warning that the behavior may be undefined and the use of a mutating function will be removed in a later version of Swift. Stack Overflow | The World’s Largest Online Community for DevelopersA closure is said to escape a function when the closure is passed as an argument to the function, but is called after the function returns. Improve this question. If you’ve opted in to email or web notifications, you’ll be notified when there’s activity. ; class, the reference itself does not change even when you mutate its properties, because reference just points to some memory whose content is modified, but. ⛔️ escaping closure captures mutating 'self' parameter. ' can only be used as a generic constraint because it has Self or associated type⛔️ escaping closure captures mutating 'self' parameter. An alternative when the closure is owned by the class itself is [unowned self]. And it's also the only option Swift allows. As Joakim alluded to, anonymous arguments are the $0, $1, arguments that are just based on the order of the parameters. – ctietze. I've tried using Timer in ContentView to call a function that updates it, but I can't capture self in its init (Escaping closure captures mutating 'self' parameter) or have a @objc function in the view (@objc can only be used with members of classes, @objc protocols, and concrete extensions of classes). A closure is said to escape a function when the closure is passed as an argument to the function, but is called after the function returns. of course) this throws a. md","path":"proposals/0001-keywords-as-argument. When you declare a function that takes a closure as one of its parameters, you can write @escaping before the parameter’s type to indicate that the closure is allowed to escape. numberToDisplay += 1 // you can't mutate a struct without mutating function self. Find centralized, trusted content and collaborate around the technologies you use most. 1 Answer. . off state: private enum MyTimer { case off case on (Date, Timer) // start time, timer mutating func start. An escaping closure is like a function variable that can be performed at a later time. Connect and share knowledge within a single location that is structured and easy to search. Basically, it's about memory management (explicit/escaping vs. Applying borrow and take modifiers to the self parameter of methods. So at here VStack(alignment: . g. was built?{"payload":{"allShortcutsEnabled":false,"fileTree":{"proposals":{"items":[{"name":"0001-keywords-as-argument-labels. x and Swift 2. Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question. Contentview. In Swift the semantics of self reference being captured are not allowed to be explicit, thus referring to any member of an object inside a closure requires you to show your full commitment to capturing with self. Last modified. If you are making an asynchronous network request you do want the closure to retain self for when the request finishes. Don't do that, just store the expiry time. A closure is said to escape a function when the closure is passed as an argument to the function, but is called after the function returns. I've tried using Timer in ContentView to call a function that updates it, but I can't capture self in its init (Escaping closure captures mutating 'self' parameter) or have a @objc function in the view (@objc can only be used with members of classes, @objc protocols, and concrete extensions of classes). I'm not sure how to approach this problem. observeSingleEvent (of:with:) is most likely a value type (a struct ?), in which case a mutating context may not explicitly capture self in an @escaping closure. In case of [weak self] you still need to explicitly write self. firstName = firstName. If I change to a class the error does not occurs. Structures and enumerations don’t allow shared mutability, as discussed in Structures and Enumerations Are Value Types. md","path":"proposals/0001-keywords-as-argument. bytes) } } } } In the ReaderInformations. var body: some View { Text ("Some view here") . I tried to write an "editor" class that could retain a reference to a property on a different object for later mutation. You can capture them strongly, weakly, or unowned. As the error said, in the escaping closure, you're capturing and mutating self (actually self. 8. import Combine class GameViewModel: ObservableObject { @Published var game : Game @Published var user : User? init (game: Game) { self. The block closure is marked with the @escaping parameter attribute, which means it may escape the body of its function, and even the lifetime of self (in your context). Q&A for work. The noescape-by-default rule only applies to these closures at function parameter position, otherwise they are escaping. dismiss () } } This isn't what I want. value!. If you knew your closure wouldn’t escape the function body, you could mark the parameter with the @noescape attribute. Swift 's behavior when closures capture `inout` parameters and escape their enclosing context is a common source of confusion. 1 (13A1030d), MacOS 11. ~~A better way (IMO) would be to create a mutating func to do your firebase call and update the values inside mutating function. S. Teams. Yes. bar }}} var foo = Foo (bar: true) let closure = foo. 1 Answer. Escaping closure captures mutating 'self' parameter. 8,478 6 6 gold badges 39 39 silver badges 53 53 bronze badges. content = content() } To use that I will do. Optional), tuples, structs, etc. – vrwim. just as when using. But async tasks in the model are giving me a headache. Additionally, my issue has to do with the fact that it is not recognizing. This is not allowed. option 1 & 2 produce a compile error: "Escaping closure captures mutating 'self' parameter", this is an architectural issue, do not mutate a view state during view render cycle, rather change the view's data model outside of the render cycle and let the re-render of the view reflect that change, that is why - options 3 & 4 are preferred either. 将闭包传递给函数. This means we can pass Content. If the escaping closure isn’t property released, you’ve created a strong reference cycle between self and the closure. x, closure parameter was @escaping by default, means that closure can be escape during the function body execution. md","path":"proposals/0001-keywords-as-argument. MyView {value in MyContent() } How do I declare the view to have that?👉 StackOverflow： What's 'Escaping closure captures mutating 'self' parameter' and how to fix itところが、イニシャライザで実装しているようにStateの変更をトリガーにUITextViewのプロパティを変更したいと思っても、Escaping closure captures mutating 'self' parameterというエラーが出てコンパイルできません。The introducing of @escaping or @nonEscaping for optional closures should be easily accepted. This has been asked and answered before. DispatchQueue. Hi, I’m new to Swift and also to SwiftUI. So, after a function returns, a variable that is passed as &variable will have the modified value In most cases, Swift manages memory…2. 1 Answer. Your solution throws 3 errors 1. _invitationsList = State< [Appointment]?>. If n were copied into the closure, this couldn't work. longitude are the lines I’m focusing on. Learn when escaping is really useful. if don’t want to escape closure parameters mark it as. You can subscribe to it in order to set the description property, but you'd have to move this whole logic into an ObservableObject view model, since you cannot mutate a View. 函数执行闭包（或不执行）. I'm told that this is because the analysis isn't particularly thorough, and just checks to see if the closure is immediately passed as a nonescaping parameter. import Foundation public struct Trigger { public var value = false public. Previous ID SR-15459 Radar None Original Reporter @okla Type Bug Environment Xcode 13. swift. そしてこれがファイルの写真です. If n were copied into the closure, this couldn't work. The function does not fire neither onNext nor onCompleted event and is being disposed immediately. Heap and stack should all be completely abstracted for the swift programmer. append(path). And it's also the only option Swift allows. 15 . Is there a way to say update the . So my. To solve this problem, Swift provides a few different ways to capture variables and resources in escaping closures. bool1 = true which is changing the value of self. Does anyone know how I can make something like this work? swiftui; Share. The whole point is the closure captures and can modify state outside itself. Escaping closure captures mutating 'self' parameter _ そして私がこのレッスンで何を逃したのかや私が何を逃したのかわからない. I want to pop in response to an event on my observable. dev. SAVE 50% To celebrate Black Friday, all our books and bundles are half price, so you can take your Swift knowledge further without spending big!Get the Swift Power Pack to build your iOS career faster, get the Swift Platform Pack to builds apps for macOS, watchOS, and beyond, or get the Swift Plus Pack to learn advanced design patterns, testing skills, and more. Swift ui Escaping closure captures mutating 'self' parameter. ios. data = data DispatchQueue. Value types are copied (at least effectively) on assignment, so if a closure captures a mutable value type which copy is being mutated? Early Swift had a compromise semantics which did the expected thing most of the time, but produced confusing results at. 函数返回. Swift 5: O que é o 'fechamento de escape captura o parâmetro' self 'mutante' e como corrigi-lo . onResponse!(characteristic. It never occurred to me that I can use this approach to "work around" the "Escaping closure captures mutating self parameter" error! Will certainly try it next time when I need it.