[ObjC] Document what there are unions with only one item.

PiperOrigin-RevId: 718977595
protocolbuffers · Jan 23, 2025 · 7f7e5ba · 7f7e5ba
1 parent 5bcbf5c
commit 7f7e5ba
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/objectivec/GPBDescriptor_PackagePrivate.h b/objectivec/GPBDescriptor_PackagePrivate.h
@@ -129,9 +129,13 @@ typedef NS_OPTIONS(uint8_t, GPBExtensionOptions) {
 typedef struct GPBExtensionDescription {
   GPBGenericValue defaultValue;
   const char *singletonName;
+  // Historically this had more than one entry, but the union name is referenced in the generated
+  // code so it can't be removed without breaking compatibility.
   union {
     Class clazz;
   } extendedClass;
+  // Historically this had more than one entry, but the union name is referenced in the generated
+  // code so it can't be removed without breaking compatibility.
   union {
     Class clazz;
   } messageOrGroupClass;