[swift-evolution] [Pitch] Allow closures/default params to satisfy protocol requirements

[Adrian Zubarev]

Theoretically speaking optional could potentially become some language sugar right?

protocol P {
    // Variable with label
    var foo(a:) : ((Int) -> Void)? { get }
     
    // more sugared version
    var foo: ((a: Int) -> Void)? { get }
}

extension P {
    // (1)
    var foo: ((a: Int) -> Void)? { return nil }
}

// Everything from above with even more sugar
protocol P {
    // default implementation (1) is inferred
    optional func foo(a: Int)
}



-- 
Adrian Zubarev
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