字符数组上的Swift模糊下标错误不一致

Question

我的代码如下。我已经添加了行号以便于参考。

我没有得到的是第32行失败，错误是＆＃34;带有基本类型＆＃39; [字符]＆＃39;的不明确的下标。和索引类型＆＃39; CountableClosedRange＆＃39;＆＃34;，但第12,16和20行工作正常。

 1 import Foundation
 2 
 3 struct PhoneNumber: CustomStringConvertible {
 4     var parsed: [ Character ]
 5     let badNum: [ Character ] = Array( "0000000000" )
 6     
 7     var number: String {
 8         return String( parsed )
 9     }
10    
11     var areaCode: String {
12         return String( parsed[ 0...2 ] ) // fine
13     }
14    
15     var exchange: String {
16         return String( parsed[ 3...5 ] ) // fine
17     }
18    
19     var subscriber: String {
20         return String( parsed[ 6...9 ] ) // fine
21     }
22    
23     var description: String {
24         return "(\( areaCode )) \( exchange )-\( subscriber )"
25     }
26    
27     init( _ startingNumber: String ) {
28         parsed = Array( startingNumber.components( separatedBy:
29             CharacterSet.decimalDigits.inverted ).joined() )
30         
31         if parsed.count == 11 && parsed[ 0 ] == "1" {
32             // parsed = parsed[ 1...9 ] // This Fails with error: ambiguous subscript with base type '[Character]' and index type 'CountableClosedRange<Int>'
33             
34             parsed.remove( at: 0 )   // This Works fine
35         } else if parsed.count != 10 {
36             parsed = badNum
37         }
38     }
39 }
40 
41 print( PhoneNumber( "+1.703.283.7360" ) )