Creates a mutable dictionary which is optimized for dealing with a known set of keys.
- iOS 6.0+
- macOS 10.8+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
A new mutable dictionary optimized for a known set of keys.
Keys that are not in the key set can still be set in the dictionary, but that usage is not optimal.
Creating and Initializing a Mutable Dictionary
Initializes a newly allocated mutable dictionary, allocating enough memory to hold
Initializes a newly allocated mutable dictionary.