mojo: Allow circular dependencies between 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 {
 
 template <class T, T v>
 struct IntegralConstant {
   static const T value = v;
 };
 
 template <class T, T v>
 const T IntegralConstant<T, v>::value;
 
 typedef IntegralConstant<bool, true> TrueType;
 typedef IntegralConstant<bool, false> FalseType;
 
 template <class T>
 struct IsConst : FalseType {};
 template <class T>
 struct IsConst<const T> : TrueType {};
 
+template <class T>
+struct IsPointer : FalseType {};
+template <class T>
+struct IsPointer<T*> : TrueType {};
+
 template <bool B, typename T = void>
 struct EnableIf {};
 
 template <typename T>
 struct EnableIf<true, T> {
   typedef T type;
 };
 
 // Types YesType and NoType are guaranteed such that sizeof(YesType) <
 // sizeof(NoType).
@@ skipping 48 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 {};
+template <class T>
+struct RemovePointer<T*> {
+  typedef T type;
+};
+
 }  // namespace internal
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_TEMPLATE_UTIL_H_