$ cat package main
import (
"fmt"
"math"
)
func main() {
x := 1.0 - math.Pow(2.0, -52)
y := math.Cbrt(x)
fmt.Printf("%20.17f %20.17f\n", x, y)
}
$ go version
go version go1.8.3 linux/amd64
$ go run main.go
0.99999999999999978 0.99999999999999989
さすが独自実装