Ios 编译器无法对这个表达式 swift 4 进行类型判断

更新Xcode后，我在代码中出现以下错误:

编译器无法合理地对此表达式进行类型判断 时间；请try 将表达式分解为不同的子表达式

代码:

//check popup in window frame

let spaceFromLeftSide = cutOutViewX.constant + cutOutViewWidth.constant/2 - (options.textWidth + padding*2)/2

if spaceFromLeftSide < 0{

    if options.side == .bottom {
        messageRightSpaceFromBottomDot.constant -= spaceFromLeftSide - padding
    }
    else if options.side == .top{
        messageRightSpaceFromTopDot.constant += spaceFromLeftSide - padding
    }
}

let spaceFromRightSide = cutOutViewX.constant + cutOutViewWidth.constant/2 + (options.textWidth + padding*2)/2

if spaceFromRightSide > targetView.frame.size.width{

    if options.side == .bottom {
        messageRightSpaceFromBottomDot.constant -= spaceFromRightSide - ( targetView.frame.size.width )
    }
    else if options.side == .top{
        messageRightSpaceFromTopDot.constant += spaceFromRightSide - ( targetView.frame.size.width )
    }
}

行中有错误:

let spaceFromRightSide = cutOutViewX.constant + cutOutViewWidth.constant/2 + (options.textWidth + padding*2)/2

怎么解决这个问题呢？