check if a object is ina array

gistfile1.go

func Contains(obj interface{}, target interface{}) (bool, error) {
    targetValue := reflect.ValueOf(target)
    switch reflect.TypeOf(target).Kind() {
    case reflect.Slice, reflect.Array:
        for i := 0; i < targetValue.Len(); i++ {
            if targetValue.Index(i).Interface() == obj {
                return true, nil
            }
        }
    case reflect.Map:
        if targetValue.MapIndex(reflect.ValueOf(obj)).IsValid() {
            return true, nil
        }
    }
    return false, errors.New("not in")
}