Swift 4: Cannot subscript a value of type 'String' with an index of type 'CountablePartialRangeFrom<Int>'

Question

So I have this swift code:

func didReceiveResponse(response:String) {
  ...
  let substr = response[11...]

By my interpretation, substr should be a Substring referencing all characters after index 11 in the response string.

What actually happens is this compiler error:

Cannot subscript a value of type 'String' with an index of type 'CountablePartialRangeFrom<Int>'

This seems like it should be obvious, can anyone help please?

Answer 1

Whoops. Seems I needed to just do this:

let idx = response.index(response.startIndex, offsetBy: 11)
let substr = response[idx...]