package main

import (
    "fmt"
)

func main() {
    arr := [...]int{0, 1, 2}
    for i := range arr {
        fmt.Println(i, ":", arr, arr[:i], arr[i+1:], "::", append(arr[:i], arr[i+1:]...))

    }
    fmt.Println("arr :", arr)
}

0 : [0 1 2] [] [2 2] :: [1 2]
1 : [1 2 2] [1] [2] :: [1 2]
2 : [1 2 2] [1 2] [] :: [1 2]
arr : [1 2 2]