Add ToSliceE([]any) -> []interface{}

cast_test.go

@@ -682,6 +682,10 @@ func TestToSliceE(t *testing.T) {
 	}{
 		{[]interface{}{1, 3}, []interface{}{1, 3}, false},
 		{[]map[string]interface{}{{"k1": 1}, {"k2": 2}}, []interface{}{map[string]interface{}{"k1": 1}, map[string]interface{}{"k2": 2}}, false},
+		{[]int{1, 2}, []interface{}{1, 2}, false},
+		{[]struct{}{{}, {}}, []interface{}{struct{}{}, struct{}{}}, false},
+		{[]interface{}{nil, nil}, []interface{}{nil, nil}, false},
+		{[]*int{nil, nil}, []interface{}{(*int)(nil), (*int)(nil)}, false},
 		// errors
 		{nil, nil, true},
 		{testing.T{}, nil, true},

caste.go

@@ -1186,18 +1186,26 @@ func ToStringMapInt64E(i interface{}) (map[string]int64, error) {
 
 // ToSliceE casts an interface to a []interface{} type.
 func ToSliceE(i interface{}) ([]interface{}, error) {
-	var s []interface{}
+	if i == nil {
+		return nil, fmt.Errorf("unable to cast %#v of type %T to []interface{}", i, i)
+	}
 
 	switch v := i.(type) {
 	case []interface{}:
-		return append(s, v...), nil
+		return v, nil
-	case []map[string]interface{}:
-		for _, u := range v {
-			s = append(s, u)
 	}
-		return s, nil
+
+	kind := reflect.TypeOf(i).Kind()
+	switch kind {
+	case reflect.Slice, reflect.Array:
+		s := reflect.ValueOf(i)
+		a := make([]interface{}, s.Len())
+		for j := 0; j < s.Len(); j++ {
+			a[j] = s.Index(j).Interface()
+		}
+		return a, nil
 	default:
-		return s, fmt.Errorf("unable to cast %#v of type %T to []interface{}", i, i)
+		return nil, fmt.Errorf("unable to cast %#v of type %T to []interface{}", i, i)
 	}
 }