Creates an integer from the given floating-point value, if it can be represented exactly.
init?<T>(exactly source: T) where T : BinaryFloatingPoint
A floating-point value to convert to an integer.
If the value passed as
source is not representable exactly, the result is
nil. In the following example, the constant
x is successfully created from a value of
21.0, while the attempt to initialize the constant
let x = Int(exactly: 21.0) // x == Optional(21) let y = Int(exactly: 21.5) // y == nil