Golang Troublesome problem

SilceManipulationWithInvoking.go

// https://play.golang.org/p/bxTn8L2gf3d
package main

import (
	"fmt"
)

func Remove(arr []int, idx int) (rv []int) {
	rv = arr[:idx]
	rv = append(rv, arr[idx+1:]...)
	return rv
}

func main() {
	arr := [...]int{0, 1, 2, 3, 4, 5, 6}
	fmt.Println(arr, Remove(arr[:], 1))
	// [0 1 2 3 4 5 6] [0 2 3 4 5 6]
	slic := []int{0, 1, 2, 3, 4, 5, 6}
	fmt.Println(slic, Remove(slic, 1))
	// [0 2 3 4 5 6 6] [0 2 3 4 5 6]
}