1 files changed, 38 insertions, 7 deletions

diff --git a/src/google/protobuf/stubs/callback.h b/src/google/protobuf/stubs/callback.h
index bbd507a8..6888f136 100644
--- a/src/google/protobuf/stubs/callback.h
+++ b/src/google/protobuf/stubs/callback.h
@@ -1,8 +1,9 @@
 #ifndef GOOGLE_PROTOBUF_STUBS_CALLBACK_H_
 #define GOOGLE_PROTOBUF_STUBS_CALLBACK_H_
 
+#include <type_traits>
+
 #include <google/protobuf/stubs/macros.h>
-#include <google/protobuf/stubs/type_traits.h>
 
 // ===================================================================
 // emulates google3/base/callback.h
@@ -342,10 +343,33 @@ class FunctionResultCallback_1_1 : public ResultCallback1<R, A1> {
 
 template <typename T>
 struct InternalConstRef {
-  typedef typename remove_reference<T>::type base_type;
+  typedef typename std::remove_reference<T>::type base_type;
   typedef const base_type& type;
 };
 
+template<typename R, typename T>
+class MethodResultCallback_0_0 : public ResultCallback<R> {
+ public:
+  typedef R (T::*MethodType)();
+  MethodResultCallback_0_0(T* object, MethodType method, bool self_deleting)
+      : object_(object),
+        method_(method),
+        self_deleting_(self_deleting) {}
+  ~MethodResultCallback_0_0() {}
+
+  R Run() {
+    bool needs_delete = self_deleting_;
+    R result = (object_->*method_)();
+    if (needs_delete) delete this;
+    return result;
+  }
+
+ private:
+  T* object_;
+  MethodType method_;
+  bool self_deleting_;
+};
+
 template <typename R, typename T, typename P1, typename P2, typename P3,
           typename P4, typename P5, typename A1, typename A2>
 class MethodResultCallback_5_2 : public ResultCallback2<R, A1, A2> {
@@ -374,11 +398,11 @@ class MethodResultCallback_5_2 : public ResultCallback2<R, A1, A2> {
   T* object_;
   MethodType method_;
   bool self_deleting_;
-  typename remove_reference<P1>::type p1_;
-  typename remove_reference<P2>::type p2_;
-  typename remove_reference<P3>::type p3_;
-  typename remove_reference<P4>::type p4_;
-  typename remove_reference<P5>::type p5_;
+  typename std::remove_reference<P1>::type p1_;
+  typename std::remove_reference<P2>::type p2_;
+  typename std::remove_reference<P3>::type p3_;
+  typename std::remove_reference<P4>::type p4_;
+  typename std::remove_reference<P5>::type p5_;
 };
 
 }  // namespace internal
@@ -520,6 +544,13 @@ inline ResultCallback1<R, A1>* NewPermanentCallback(
       function, false, p1);
 }
 
+// See MethodResultCallback_0_0
+template <typename R, typename T1, typename T2>
+inline ResultCallback<R>* NewPermanentCallback(
+    T1* object, R (T2::*function)()) {
+  return new internal::MethodResultCallback_0_0<R, T1>(object, function, false);
+}
+
 // See MethodResultCallback_5_2
 template <typename R, typename T, typename P1, typename P2, typename P3,
           typename P4, typename P5, typename A1, typename A2>