associated types for Brent

gistfile1.swift

protocol Value : Equatable {
}

protocol Smashable {
    typealias TargetValue : Value
    func valueBySmashingOtherValue<SomeOtherValue : Value>(value: SomeOtherValue) -> TargetValue
}

struct Bar : Value {
}
func ==(lhs:Bar, rhs:Bar) -> Bool {
    return false
}

struct Foo : Value, Smashable {
    func valueBySmashingOtherValue<SomeOtherValue : Value>(value: SomeOtherValue) -> Bar {
        return Bar()
    }
}
func ==(lhs:Foo, rhs:Foo) -> Bool {
    return false
}

// or actually, is Smashable supposed to extend Value and always smash other stuff to its own type? If so, maybe this,

protocol Value : Equatable {
}

protocol Smashable {
    func valueBySmashingOtherValue<SomeOtherValue : Value>(val: SomeOtherValue) -> Self
}

struct Bar : Value {
}
func ==(lhs:Bar, rhs:Bar) -> Bool {
    return false
}

struct Foo : Value, Smashable {
    func valueBySmashingOtherValue<SomeOtherValue : Value>(val: SomeOtherValue) -> Foo {
        return Foo()
    }
}
func ==(lhs:Foo, rhs:Foo) -> Bool {
    return false
}