Add template parameter to ReturnValue::Set.

E.g., v8-i18n wants to set the return value with a different type of a Persistent.

BUG=NONE
R=dcarney@chromium.org, svenpanne@chromium.org

Review URL: https://codereview.chromium.org/16102002

Patch from Marja Hölttä <marja@chromium.org>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14826 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

include/v8.h

@@ -2779,8 +2779,8 @@ class ReturnValue {
  public:
   V8_INLINE(explicit ReturnValue(internal::Object** slot));
   // Handle setters
-  V8_INLINE(void Set(const Persistent<T>& handle));
-  V8_INLINE(void Set(const Handle<T> handle));
+  template <typename S> V8_INLINE(void Set(const Persistent<S>& handle));
+  template <typename S> V8_INLINE(void Set(const Handle<S> handle));
   // Fast primitive setters
   V8_INLINE(void Set(bool value));
   V8_INLINE(void Set(double i));
@@ -5684,12 +5684,16 @@ template<typename T>
 ReturnValue<T>::ReturnValue(internal::Object** slot) : value_(slot) {}
 
 template<typename T>
-void ReturnValue<T>::Set(const Persistent<T>& handle) {
+template<typename S>
+void ReturnValue<T>::Set(const Persistent<S>& handle) {
+  TYPE_CHECK(T, S);
   *value_ = *reinterpret_cast<internal::Object**>(*handle);
 }
 
 template<typename T>
-void ReturnValue<T>::Set(const Handle<T> handle) {
+template<typename S>
+void ReturnValue<T>::Set(const Handle<S> handle) {
+  TYPE_CHECK(T, S);
   *value_ = *reinterpret_cast<internal::Object**>(*handle);
 }
 

test/cctest/test-api.cc

@@ -1074,6 +1074,12 @@ void FastReturnValueCallback<void>(
   }
 }
 
+template<>
+void FastReturnValueCallback<Object>(
+    const v8::FunctionCallbackInfo<v8::Value>& info) {
+  info.GetReturnValue().Set(Object::New());
+}
+
 template<typename T>
 Handle<Value> TestFastReturnValues() {
   LocalContext env;
@@ -1118,6 +1124,8 @@ THREADED_TEST(FastReturnValues) {
       CHECK(value->IsUndefined());
     }
   }
+  value = TestFastReturnValues<Object>();
+  CHECK(value->IsObject());
 }