Can I overload an operator in Objective-C?

Question

Is it possible to override operator use in Objective-C?

For example

myClassInstance + myClassInstance

calls a custom function to add the two.

Answer 1

No, you can't do this in Objective-C.

Answer 2

Operator overloading is not a feature of Objective-C. If two instances of your classes can be added together, provide a method and allow them to be added using that method:

Thing *result = [thingOne thingByAddingThing:thingTwo];

Or, if your class is mutable:

[thingOne addThing:thingTwo];

Answer 3

First, operator overloading is evil. Second, C doesn't have operator overloading, and Objective-C is a proper superset of C, which only adds a handful of keywords and a messaging syntax.

That being said, if you're using Apple's development environment, you can use Objective-C++ instead of Objective-C, which gives you access to all of C++'s mistakes and misfeatures, including operator overloading. The simplest way to use Objective-C++ is just to change the extension on your implementation files from ".m" to ".mm"