[SR-6001] Protocols inheriting from classes #48558
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@DougGregor, @slavapestov, sound familiar? |
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We haven't implemented protocols inheriting from classes yet, however it is a part of SE-0156 and we should do it eventually. I'll take this. |
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Comment by Erich Graham (JIRA) Looks like SE-0156's status is Implemented. Is this bug still slated to be done then? Relevant forum post: https://forums.swift.org/t/defining-protocols-for-certain-class-types-only/8702/11 |
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I think we just forgot to update the status of this, no? Works fine for me with Swift 4.1: class Strawman {
}
protocol Fooable where Self: Strawman {
func foo()
}
extension Strawman: Fooable {
public func foo() { print("Foo!") }
}
let s = Strawman()
s.foo()prints |
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Comment by Erich Graham (JIRA) This code does not work, Swift 4.1: protocol HeaderViewing where Self: UIView {
func set(title: String)
}
class MyView: UIView, HeaderViewing {
override init(frame: CGRect) {
super.init(frame: frame)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func set(title: String) {
}
}
let myView: HeaderViewing = MyView(frame: .zero)
myView.set(title: "Hello")
myView.removeFromSuperview() /** Value of type 'HeaderViewing' has no member 'removeFromSuperview' */ |
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Comment by Erich Graham (JIRA) Any idea if this bug will be resolved in 4.2 or 5.0? This forces the above example to define the variable as `let myView: HeaderViewing & UIView` when it should work as written, `let myView: HeaderViewing` |
AnthonyLatsis
added
the
crash
This issue was closed.
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Environment
Swift 4
Additional Detail from JIRA
md5: e5e571eae12cbeb9d9440144200dc67c
duplicates:
Issue Description:
class Strawman {
}
protocol Fooable where Self: Strawman {
func foo()
}
// This doesn't seem like an especially useful thing to do
// and might reasonably be an error, but I think hard
// crashing the compiler is a bit much.
extension Strawman: Fooable {
public func foo() { print("Foo!") }
}
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