在Golang类型断言中可以使用反射数组类型吗？

I need to check if interface{} is an array and create corresponding slice if it is. Unfortunately I do not know array length in advance.

For example:

import (
  "reflect"
)
func AnythingToSlice(a interface{}) []interface{} {
  rt := reflect.TypeOf(a)
  switch rt.Kind() {
  case reflect.Slice:
    slice, ok := a.([]interface{})
    if ok {
      return slice
    }
    // it works

  case reflect.Array:
    // return a[:]
    // it doesn't work: cannot slice a (type interface {})   
    //
    array, ok := a.([reflect.ValueOf(a).Len()]interface{})
    // :-((( non-constant array bound reflect.ValueOf(a).Len()
    if ok {
       return array[:]
    }

  }
  return []interface{}(a)
}