random.swift

    public var byteRange: [Range<UInt64>]? {
        // Guaranteed to be in pairs. Example:
        // - 0 : 0
        // - 1 : 71826
        // - 2 : 83948
        // - 3 : 34223
        guard let boxedRange = __byteRange else { return nil }
        let range = boxedRange.map { $0.uint64Value }

        var ranges: [Range<UInt64>] = []
        for rangeIndex in stride(from: 0, to: range.count, by: 2) {
            let lower = range[rangeIndex]
            let count = range[rangeIndex + 1]
            ranges.append(Range(uncheckedBounds: (lower: lower, upper: lower + count)))
        }
        return ranges
    }

Not sure if this meets the bar of readability and maintainability but personally I think it improves readability to define fluent extensions:

extension Swift.ClosedRange where Bound: Strideable {
    func by(_ strideAmount: Bound.Stride) -> StrideThrough<Bound> {
        return stride(from: lowerBound, through: upperBound, by: strideAmount)
    }
}

extension Swift.Range where Bound: Strideable {
    func by(_ strideAmount: Bound.Stride) -> StrideTo<Bound> {
        return stride(from: lowerBound, to: upperBound, by: strideAmount)
    }
}

for rangeIndex in (0...7).by(2) {
     // reads as 0 through 7 by 2
}

for rangeIndex in (0..<7).by(2) {
    // reads as 0 to 7 by 2
}

I think it's mildly easier to parse visually than the stride initializer