Earlier this month I mentioned a tutorial on using compiler directives to create useful warnings and error messages that mentions the unused attribute which can be used to generate warnings when a variable is unused.
There are many other attribute directives available in Objective-C and the engineering team has put together a nice guide to using the attribute directive in Objective-C.
The post goes in-depth with error directives providing:
– an explanation of the attribute directive and why you’d use it
– a listing of many useful attribute directives and how and when to use them
– Some of the dangers that can arise when using the attribute directive and how to avoid them
You can find the tutorial over on the Twitter Engineering Blog.
A very nice guide to attribute directives that provides a nice alternative that provides a nice read when compared to the highly technical compiler documentation available on the attribute directive.