Port Dictionary extension from Swift 2.2 to Swift 3.0

swift2.swift

extension Dictionary {
    init<S: SequenceType where S.Generator.Element == Element>(pairs: S) {
        self.init()
        for (key, value) in pairs {
            self[key] = value
        }
    }
}

let foo = ["Lorem", "ipsum"]
let bar = ["dolor", "sit"]
let baz = zip(foo, bar)
let qux = baz.lazy
    .map({ ($0.uppercaseString, $1.uppercaseString) })

Dictionary(pairs: baz)
Dictionary(pairs: qux)

swift3.swift

extension Dictionary {
    init<S: Sequence where S.Iterator.Element == Element>(pairs: S) {
        self.init()
        for (key, value) in pairs {
            self[key] = value
        }
    }
}

let foo = ["Lorem", "ipsum"]
let bar = ["dolor", "sit"]
let baz = zip(foo, bar)
let qux = baz.lazy
    .map({ ($0.uppercased(), $1.uppercased()) })

Dictionary(pairs: baz)
Dictionary(pairs: qux)

// Fails to compile with the following error: Generic parameter 'Key' could not be inferred