@objc is redundant when used with implicit Objective-C attribute SW-R1011

The @objc attribute is used to expose Swift declarations to Objective-C code. However, it can be redundant in some cases, where the declaration is already implicitly @objc, or it's not necessary for the declaration to be exposed to Objective-C code.

Having a redundant @objc attribute adds unnecessary overhead to the code, and can make it harder to read and maintain. It's important to avoid using redundant @objc attributes, especially in performance-critical code.

In summary, it's important to avoid using redundant @objc attributes as they add unnecessary overhead to the code and can make it harder to read and maintain.

Here are some examples of redundant @objc attribute usage:

Bad practice

@objc @IBInspectable private var foo: String? {}

@objcMembers
class Foo: NSObject {
    @objc var bar: Any?
    @objc var foo: Any?
    @objc
    class Bar {
        @objc
        var foo: Any?
    }
}

Recommended

@objc private var foo: String? {}

@objcMembers
class Foo {
    var bar: Any?
    @objc
    class Bar: NSObject {
        @objc
        var foo: Any?
    }
}