Hello Swift community, before Swift 3 drops I’d like to discuss if it is
reasonable to consider to create a standalone type to drop/seal the T.Type
magic?
However this change does not play well with the proposal of dropping the .self
compiler magic.
Some bikeshedding:
public struct Type<T> : Hashable {
// Seal the `.Type` magic into this standalone type.
// Disallow `.Type` usage elsewhere
public let sealed: T.Type
public var hashValue: Int { /* implement somehow */ }
public init() {
// Or do it somehow different for the sake of dropping `.self` magic
self.sealed = T.self
}
}
public func ==<T>(lhs: Type<T>, rhs: Type<T>) -> Bool {
return lhs.hashValue == rhs.hashValue
}
Downside of this approach is the accessibility of the .Type instance:
protocol Initializable {
init()
}
func foo<T : Initializable>(type: Type<T>) -> T {
// It would be nice if we could use `type.init()` instead, but than we
// would need more compiler magic :/
return type.sealed.init()
}
I couldn’t come up with a better name than sealed, if anyone has a better idea
feel free to share your thoughts.
Remember this is a discussion and not (yet) a detailed proposal, where everyone
can provide feedback and bikeshedding for a better design.
--
Adrian Zubarev
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