How to define function using type that references type of itself in Swift?

Question

I've read many articles about using Self inside protocol but I am still confused how to achieve some behaviour.

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Code

protocol Bindable {

    @discardableResult
    func bind(_ target: inout Self) -> Self
}

extension Bindable {

    @discardableResult
    func bind(_ target: inout Self) -> Self {
        target = self
        return self
    }
}

---

Attempt

extension NSView: Bindable {}    // ERROR

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Error

Complain I am using Self so it can be any subclass of NSView

Protocol 'Bindable' requirement 'bind' cannot be satisfied by a non-final class ('NSView') because it uses 'Self' in a non-parameter, non-result type position

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Question:

How should I implement protocol Bindable so it uses current variable type?

or

How to apply protocol to any type to make function require type of variable itself?

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Tests

Everything works ... except application to NSView

class MyView: NSView {}

let view: NSView
let myTarget: MyView
    
NSView().bind(&view)               // OK
(MyView() as NSView).bind(&view)   // OK
MyView().bind(&myTarget)           // OK
    
NSView().bind(&myTarget)          // Error = OK (expected)
MyView().bind(&view)              // Error = OK (expected)

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It seems compiler understands and does exactly what I want to achieve. Clearly recognises type of variable and allows only its type as a parameter. It is strange that auto-completion and semantic is correct but it's not compilable.