How to convert String to CFMutableString?

Question

The question is very simple. Just how to convert swift String to CFMutableString. I only found How to convert a swift String to CFString. Any help will be appreciated.

Answer 1

as CFMutableString is toll-free bridged from NSMutableString, you can just create NSMutableString from your String then cast it to CFMutableString:

let str: String = "test 123"
let cfmStr = NSMutableString(string: str) as CFMutableString

Answer 2

Most immutable classes in Cocoa has a mutableCopy() method to return a mutable clone of itself. NSString.mutableCopy() returns an NSMutableString. NSData.mutableCopy() returns an NSMutableData, etc.

You can then bridge from Cocoa (NS*) to Foundation (CF*) class:

let str = "Hello world"
let cfString = (str as NSString).mutableCopy() as! CFMutableString

Answer 3

Using the test string let str: String = "test 123"

For CFMutableString do:

(str as! CFMutableString)

For CFString you can do:

let cfStr: CFString = str

or

(str as CFString)

since the cast always succeeds.