add lua/C++ dynamic_cast<>

2 files changed, 39 insertions, 0 deletions

diff --git a/libs/lua/LuaBridge/detail/CFunctions.h b/libs/lua/LuaBridge/detail/CFunctions.h
index 15bc7022b3..9f1712995a 100644
--- a/libs/lua/LuaBridge/detail/CFunctions.h
+++ b/libs/lua/LuaBridge/detail/CFunctions.h
@@ -379,6 +379,29 @@ struct CFunc
   };
 
 
+  template <class T, class R>
+  struct CastClass
+  {
+    static int f (lua_State* L)
+    {
+      T * const t = Userdata::get <T> (L, 1, false );
+      Stack <R*>::push (L, dynamic_cast<R*>(t));
+      return 1;
+    }
+  };
+
+  template <class T, class R>
+  struct CastConstClass
+  {
+    static int f (lua_State* L)
+    {
+      T const* const t = Userdata::get <T> (L, 1, true);
+      Stack <R const*>::push (L, dynamic_cast<R const*>(t));
+      return 1;
+    }
+  };
+
+
   template <class T>
   struct PtrNullCheck
   {
diff --git a/libs/lua/LuaBridge/detail/Namespace.h b/libs/lua/LuaBridge/detail/Namespace.h
index 590f25be4a..79a0786d40 100644
--- a/libs/lua/LuaBridge/detail/Namespace.h
+++ b/libs/lua/LuaBridge/detail/Namespace.h
@@ -1048,6 +1048,22 @@ private:
       return *this;
     }
 
+    template <class U>
+    Class <T>& addCast (char const* name)
+    {
+      PRINTDOC("Cast", _name << name,
+          type_name< U >(),
+          type_name< U >() << " (" << type_name< T >() << "::*)()")
+
+      assert (lua_istable (L, -1));
+      lua_pushcclosure (L, &CFunc::CastClass <T, U>::f, 0);
+      rawsetfield (L, -3, name); // class table
+
+      lua_pushcclosure (L, &CFunc::CastConstClass <T, U>::f, 0);
+      rawsetfield (L, -4, name); // const table
+      return *this;
+    }
+
   };
 
   /** C Array to/from table */