How do I do indexOfObject or a proper containsObject

Question

With an array: How do I do indexOfObject or a proper containsObject?

I mean I know I could just bridge the Array to NSArray an

Answer 1

Apple provide an example of exactly this in the The Swift Programming Language book. Specifically, see the section on Type Constraints in Action (p621 in the iBook).

func findIndex(array: [T], valueToFind: T) -> Int? {
    for (index, value) in enumerate(array) {
        if value == valueToFind {
            return index
        }
    }
    return nil
}

Everything depends upon your type implementing Equatable.

The Swift Programming Language covers that and explains how to implement that protocol:

“The Swift standard library defines a protocol called Equatable, which requires any conforming type to implement the equal to operator (==) and the not equal to operator (!=) to compare any two values of that type. ”

NSHipster has a couple of relevant posts on this subject:

Swift Default Protocol Implementations Swift Comparison Protocols

I also found this answer very useful in implementing Equatable:

How do I implement Swift's Comparable protocol?

Alhough it mentions Comparable, Equatable is a subset and the explanation is good.

Excerpts above from: Apple Inc. “The Swift Programming Language.” iBooks. https://itun.es/gb/jEUH0.l