Example of the Returning Option Policy

The following is an example of the returning Option policy. In this example, an overflow occurs in an attempt to calculate the square of Int64.Max, and None is returned.

import std.overflow.*
import std.math.*

main() {
    let a: Int64 = Int64.Max
    println(a.checkedPow(UInt64(2)))
}

The running result is as follows:

None