我正在尝试执行以下操作：
@H_404_18@var i = -(abs(-3))
要么
var i = -abs(-3)
要么
var i = -abs(3)
要么
var i = -(abs(3))
但我得到一个错误,说使用减号是模棱两可的.为什么？
var i = -(abs(-3))
要么
var i = -abs(-3)
要么
var i = -abs(3)
要么
var i = -(abs(3))
但我得到一个错误,说使用减号是模棱两可的.为什么？
error: ambiguous use of operator '-'
var i = -(abs(-3))
^
Swift.-:2:20: note: found this candidate
prefix public func -(x: Float) -> Float
^
Swift.-:2:20: note: found this candidate
prefix public func -(x: Double) -> Double
^
Swift.-:2:20: note: found this candidate
prefix public func -(x: Float80) -> Float80
^
CoreGraphics.-:2:20: note: found this candidate
prefix public func -(x: CGFloat) -> CGFloat
您可以使用显式Int作为参数来解决它：
var i = -(abs(-Int(3)))
或者在结果上使用类型注释：
var i : Int = -(abs(-3))
正如@vacawama所注意到的,还有更多可能的解决方案.
将任何子表达式转换为Int使编译器感到高兴：
var i1 = -(abs(-(3 as Int))) var i2 = -(abs((-3) as Int)) var i3 = -(abs(-3) as Int) var i4 = -(abs(-3)) as Int
