Implement unions as members of structs.

mojo/public/cpp/bindings/lib/template_util.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_TEMPLATE_UTIL_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_LIB_TEMPLATE_UTIL_H_
 
 namespace mojo {
 namespace internal {
 
@@ skipping 82 matching lines @@
   static Derived* CreateDerived();
   static char(&Check(Base*))[1];
   static char(&Check(...))[2];
 
  public:
   static bool const value = sizeof Check(CreateDerived()) == 1 &&
                             !IsSame<Base const, void const>::value;
 };
 
 template <class T>
-struct RemovePointer {};
+struct RemovePointer {
+  typedef T type;
+};
 template <class T>
 struct RemovePointer<T*> {
   typedef T type;
 };
 
 template <template <typename...> class Template, typename T>
 struct IsSpecializationOf : FalseType {};
 
 template <template <typename...> class Template, typename... Args>
 struct IsSpecializationOf<Template, Template<Args...>> : TrueType {};
 
 template <bool B, typename T, typename F>
 struct Conditional {
   typedef T type;
 };
 
 template <typename T, typename F>
 struct Conditional<false, T, F> {
   typedef F type;
 };
 
 }  // namespace internal
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_TEMPLATE_UTIL_H_