CODEWITHSUNDEEP
swift
tripleblep
tripleblep

Reputation: 540

Casting arrays to specific types in Swift

Say I have two arrays:

var exterior: Array<(name: String, value: (code: Code, pass: Bool))> = []
var interior: Array<(name: String, value: (code: Code, type: Type, pass: Bool))> = []

I have a UISegmentedControl that, depending on which segment is selected, will show data from the respective array. To reduce boilerplate, I'd like to use one fuction for setup:

func build(section: Section) {
    var data: Array<Any>

    switch section {
    case .Exterior:
        data = exterior
    case .Interior:
        data = interior
    }

    for i in 0...data.count - 1 where i % 4 == 0 {
        for y in i...i + 4 {
            guard y < data.count - 1 else {
                break
            }
            switch section {
            case .Exterior:
                let v = data as! Array<(String, (Report.Code, Bool))>
                // Do stuff here...
            case .Interior:
                let v = data as! Array<(String, (Report.Code, Report.Type, Bool))>
                // Do stuff here...
            }
        }
    }
}

This won't work since I cannot cast to an array that holds Any. If I change the type of both interior and exterior to Any and try casing them to their respective types, I get an error: can't unsafeBitCast between types of different sizes. What are my options in this situation?

Upvotes: 0

Views: 416

Answers (1)

werediver
werediver

Reputation: 4757

You cannot cast Array<Any> to Array<AnyOther>, because there is no inheritance between Array<Any> and Array<AnyOther>. You should actually convert such arrays like so:

let xs: [Any] = [1, 2, 3, 4, 5]
let ys: [Int] = xs.flatMap { $0 as? Int }
print(ys.dynamicType) // Array<Int>
print(ys) // [1, 2, 3, 4, 5]

Upvotes: 3

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