Use pointers to make generic functions work

atom.go

@@ -16,22 +16,20 @@ type Countable interface {
 	*xml.Attr | *Person | *Category | *Link | *ExtensionElement | *Entry
 }
 
-func addToSlice[C Countable](slice []C, countable C) {
-	if slice == nil {
-		slice = make([]C, 1)
-		slice[0] = countable
-	} else {
-		slice = append(slice, countable)
+func addToSlice[C Countable](slice *[]C, countable C) {
+	if *slice == nil {
+		*slice = make([]C, 0)
 	}
+	*slice = append(*slice, countable)
 }
 
-func deleteFromSlice[C Countable](slice []C, id int) error {
-	length := len(slice)
+func deleteFromSlice[C Countable](slice *[]C, id int) error {
+	length := len(*slice)
 	if id > length {
 		return fmt.Errorf("id %v out of range %v", id, length)
 	}
 
-	slice = append(slice[:id], slice[id+1:]...)
+	*slice = append((*slice)[:id], (*slice)[id+1:]...)
 	return nil
 }