func abs<T where T : SignedNumber>(_: T) Returns the absolute value of x. Concrete instances of SignedNumber can specialize this function by conforming to AbsoluteValuable. Declaration func abs<T where T : SignedNumber>(_ x: T) -> T func abs<T where T : FloatingPoint, T.Magnitude == T>(_: T) Returns the absolute value of x. Declaration func abs<T where T : FloatingPoint, T.Magnitude == T>(_ x: T) -> T