// +build go1.9 package main import ( "fmt" "math/bits" ) func main() { const n = 100 // START OMIT fmt.Printf("%d (%b) has %d bits set to one\n", n, n, bits.OnesCount(n)) fmt.Printf("%d reversed is %d\n", n, bits.Reverse(n)) fmt.Printf("%d can be encoded in %d bits\n", n, bits.Len(n)) // END OMIT }