formIndex(_:offsetBy:limitedBy:)
Declaration
func formIndex(_ i: inout FlattenSequence<Base>.Index, offsetBy n: Int, limitedBy limit: FlattenSequence<Base>.Index) -> Boolfunc formIndex(_ i: inout FlattenSequence<Base>.Index, offsetBy n: Int, limitedBy limit: FlattenSequence<Base>.Index) -> Bool