dynamictype.swift

protocol P {
    var dynamicTypeAsMember: P.Type { get }
}
struct T: P {}

extension P {
    var dynamicTypeAsMember: P.Type {
        return self.dynamicType
    }
}

func type<T>(of value: T) -> T.Type {
    return value.dynamicType
}

let t = T()
let p: P = T()

let typeofT = type(of: t)  // == T.self
let typeofP = type(of: p)  // == P.self???

t.dynamicTypeAsMember // == T.self
p.dynamicTypeAsMember // == T.self