A version of dropFirst() that works on any SequenceType or GeneratorType

WithoutFirst.swift

#!xcrun swift

func withoutFirst<T, G: GeneratorType where G.Element == T>(genGiver: () -> G) -> SequenceOf<T> {
    return SequenceOf {
        _ -> G in
        var g = genGiver()
        g.next()
        return g
    }
}

func withoutFirst<T, S: SequenceType where S.Generator.Element == T>(seq: S) -> SequenceOf<T> {
    // I wish I could just pass seq.generate here, but Swift says "partial application of generic method is not allowed"
    return withoutFirst({ seq.generate() })
}




let someSeq = SequenceOf {
    _ -> GeneratorOf<Int> in
    var x = 10
    return GeneratorOf {
        return x > 0 ? x-- : nil
    }
}

for x in withoutFirst(someSeq) {
    println("\(x)")
}