Return the index of the added element

source.go

@@ -28,9 +28,9 @@ func NewSource() *Source {
 	return &Source{CommonAttributes: newCommonAttributes()}
 }
 
-// AddAuthor adds the Person as an author to the Source.
-func (s *Source) AddAuthor(p *Person) {
-	addToSlice(&s.Authors, p)
+// AddAuthor adds the Person as an author to the Source. It returns an int.
+func (s *Source) AddAuthor(p *Person) int {
+	return addToSlice(&s.Authors, p)
 }
 
 // DeleteAuthor deletes the Person at index from the Source. It return an error.
@@ -41,9 +41,9 @@ func (s *Source) DeleteAuthor(index int) error {
 	return nil
 }
 
-// AddCategory adds the Category to the Source.
-func (s *Source) AddCategory(c *Category) {
-	addToSlice(&s.Categories, c)
+// AddCategory adds the Category to the Source. It returns an int.
+func (s *Source) AddCategory(c *Category) int {
+	return addToSlice(&s.Categories, c)
 }
 
 // DeleteCategory deletes the Category at index from the Source. It return an
@@ -55,9 +55,10 @@ func (s *Source) DeleteCategory(index int) error {
 	return nil
 }
 
-// AddContributor adds the Person as a contributor to the Source.
-func (s *Source) AddContributor(c *Person) {
-	addToSlice(&s.Contributors, c)
+// AddContributor adds the Person as a contributor to the Source. It returns an
+// int.
+func (s *Source) AddContributor(c *Person) int {
+	return addToSlice(&s.Contributors, c)
 }
 
 // DeleteContributor deletes the Person at index from the Source. It return an
@@ -69,9 +70,9 @@ func (s *Source) DeleteContributor(index int) error {
 	return nil
 }
 
-// AddLink adds the Link to the Source.
-func (s *Source) AddLink(l *Link) {
-	addToSlice(&s.Links, l)
+// AddLink adds the Link to the Source. It returns an int.
+func (s *Source) AddLink(l *Link) int {
+	return addToSlice(&s.Links, l)
 }
 
 // DeleteLink deletes the Link at index from the Source. It return an error.
@@ -82,9 +83,9 @@ func (s *Source) DeleteLink(index int) error {
 	return nil
 }
 
-// AddExtension adds the ExtensionElement to the Source.
-func (s *Source) AddExtension(e *ExtensionElement) {
-	addToSlice(&s.Extensions, e)
+// AddExtension adds the ExtensionElement to the Source. It returns an int.
+func (s *Source) AddExtension(e *ExtensionElement) int {
+	return addToSlice(&s.Extensions, e)
 }
 
 // DeleteExtension deletes the Extension at index from the Source. It return an