swift - 扩展双轮放置 Swift 3

Question

我有以下扩展

extension Double {
    func roundToPlaces(places:Int) -> Double {
        let divisor = pow(10.0, Double(places))
        return (self * divisor).rounded / divisor
    }
}

当我将它更新到 Swift 3 时，它不起作用。我尝试了解决方案 here , 但我得到了

二元运算符“/”不能应用于“_”和“Double”类型的操作数错误

Answer 1

你忘记了一对括号:应该是 rounded() 而不是 rounded:

extension Double {
    func roundToPlaces(places:Int) -> Double {
        let divisor = pow(10.0, Double(places))
        return (self * divisor).rounded() / divisor
    }
}