add ability for descendent to clone interface

1 files changed, 8 insertions, 3 deletions

diff --git a/system/include/emscripten/bind.h b/system/include/emscripten/bind.h
index 48a0fd58..56a3b62c 100755
--- a/system/include/emscripten/bind.h
+++ b/system/include/emscripten/bind.h
@@ -887,9 +887,7 @@ namespace emscripten {
         wrapper() {}    // to avoid error "call to implicitly deleted construrtor..."
 
         wrapper(InterfaceType* interface) {
-            // why dynamic_cast causes javascript crash?
-            wrapper<InterfaceType>* iw = static_cast<wrapper<InterfaceType>*>(interface);
-            jsobj = iw->jsobj;
+            cloneInterface(interface);
         }
 
         // Not necessary in any example so far, but appeases a compiler warning.
@@ -919,6 +917,13 @@ namespace emscripten {
             return Caller<ReturnType, Args...>::call(*jsobj, name, args...);
         }
 
+    protected:
+        void cloneInterface(InterfaceType* interface) {
+            // why dynamic_cast causes javascript crash?
+            wrapper<InterfaceType>* iw = static_cast<wrapper<InterfaceType>*>(interface);
+            jsobj = iw->jsobj;
+        }
+
     private:
         // this class only exists because you can't partially specialize function templates
         template<typename ReturnType, typename... Args>