Xcode 6.3: Swift String 'characters' property not found -

when copy example apple swift manual code

 character in "dog!🐶".characters {         print(character)     }

i error message

could not find member characters

what has happened 'characters' property in xcode 6.3 ?

string property characters available in xcode 7 (swift 2.0). delete .characters , work xcode 6.3 (swift 1.2).

for character in "dog!🐶" {     println(character) }

Macro