2 files changed, 14 insertions, 6 deletions
diff --git a/bindings/cpp/upb/def.hpp b/bindings/cpp/upb/def.hpp
index 6500243..d64625c 100644
--- a/bindings/cpp/upb/def.hpp
+++ b/bindings/cpp/upb/def.hpp
@@ -17,9 +17,14 @@ namespace upb {
 
 class MessageDef : public upb_msgdef {
  public:
+  // Converting from C types to C++ wrapper types.
   static MessageDef* Cast(upb_msgdef *md) { return (MessageDef*)md; }
+  static const MessageDef* Cast(const upb_msgdef *md) {
+    return (const MessageDef*)md;
+  }
 
-  void Unref() { return upb_msgdef_unref(this); }
+  void Ref() const { upb_msgdef_ref(this); }
+  void Unref() const { upb_msgdef_unref(this); }
 
  private:
   MessageDef();
@@ -28,14 +33,20 @@ class MessageDef : public upb_msgdef {
 
 class SymbolTable : public upb_symtab {
  public:
+  // Converting from C types to C++ wrapper types.
   static SymbolTable* Cast(upb_symtab *s) { return (SymbolTable*)s; }
+  static const SymbolTable* Cast(const upb_symtab *s) {
+    return (SymbolTable*)s;
+  }
+
   static SymbolTable* New() { return Cast(upb_symtab_new()); }
 
-  void Unref() { return upb_symtab_unref(this); }
+  void Ref() const { upb_symtab_unref(this); }
+  void Unref() const { upb_symtab_unref(this); }
 
   // If the given name refers to a message in this symbol table, returns a new
   // ref to that MessageDef object, otherwise returns NULL.
-  MessageDef* LookupMessage(const char *name) {
+  const MessageDef* LookupMessage(const char *name) const {
     return MessageDef::Cast(upb_symtab_lookupmsg(this, name));
   }
 
diff --git a/bindings/cpp/upb/handlers.hpp b/bindings/cpp/upb/handlers.hpp
index e72c0a4..07683f6 100644
--- a/bindings/cpp/upb/handlers.hpp
+++ b/bindings/cpp/upb/handlers.hpp
@@ -4,9 +4,6 @@
  * Copyright (c) 2011 Google Inc.  See LICENSE for details.
  * Author: Josh Haberman <jhaberman@gmail.com>
  *
- * Note!  This file is a proof-of-concept for C++ wrappers and does not
- * yet build.
- *
  * upb::Handlers is a generic visitor-like interface for iterating over a
  * stream of protobuf data.  You can register function pointers that will be
  * called for each message and/or field as the data is being parsed or iterated