Creates an immutable copy of an attributed string.
- iOS 2.0+
- macOS 10.4+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
- Core Foundation
The allocator to use to allocate memory for the new attributed string. Pass
kto use the current default allocator.
The attributed string to copy.
An immutable attributed string with characters and attributes identical to those of
NULL if there was a problem copying the object. Ownership follows the The Create Rule.