Yet another bug reported by Peter Bienstman is now fixed.

[SVN r13370]

include/boost/python/object/forward.hpp

@@ -10,28 +10,99 @@
 # include <boost/type_traits/object_traits.hpp>
 # include <boost/type_traits/composite_traits.hpp>
 # include <boost/type_traits/transform_traits.hpp>
+# include <boost/ref.hpp>
 
 namespace boost { namespace python { namespace objects { 
 
+template <class T>
+struct reference_to_value
+{
+    typedef typename add_reference<typename add_const<T>::type>::type reference;
+    
+    reference_to_value(reference x) : m_value(x) {}
+    operator reference() const { return m_value; }
+ private:
+    reference m_value;
+};
+
 // A little metaprogram which selects the type to pass through an
 // intermediate forwarding function when the destination argument type
 // is T.
 template <class T>
 struct forward
-{
-    BOOST_STATIC_CONSTANT(
-        bool, by_value = (is_scalar<T>::value | is_reference<T>::value)
-        );
-
-    typedef typename mpl::select_type<
-        by_value
+    : mpl::select_type<
+        is_scalar<T>::value
         , T
-        , reference_wrapper<
-                typename add_const<T>::type
-          >
-    >::type type;
+        , reference_to_value<T> >
+{
 };
 
+# ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
+template<typename T>
+class unforward
+{
+ public:
+    typedef typename unwrap_reference<T>::type& type;
+};
+
+template<typename T>
+class unforward<reference_to_value<T> >
+{
+ public:
+    typedef T type;
+};
+# else // no partial specialization
+
+namespace detail
+{
+  typedef char (&yes_reference_to_value_t)[1];
+  typedef char (&no_reference_to_value_t)[2];
+      
+  no_reference_to_value_t is_reference_to_value_test(...);
+
+  template<typename T>
+  yes_reference_to_value_t is_reference_to_value_test(type< reference_to_value<T> >);
+
+  template<bool wrapped>
+  struct unforwarder
+  {
+      template <class T>
+      struct apply
+      {
+          typedef typename unwrap_reference<T>::type& type;
+      };
+  };
+
+  template<>
+  struct unforwarder<true>
+  {
+      template <class T>
+      struct apply
+      {
+          typedef typename T::reference type;
+      };
+  };
+
+  template<typename T>
+  class is_reference_to_value
+  {
+   public:
+      BOOST_STATIC_CONSTANT(
+          bool, value = (
+              sizeof(is_reference_to_value_test(type<T>()))
+              == sizeof(yes_reference_to_value_t)));
+  };
+}
+
+template <typename T>
+class unforward
+    : public detail::unforwarder<
+        detail::is_reference_to_value<T>::value
+      >::template apply<T>
+{};
+
+# endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
+
 }}} // namespace boost::python::objects
 
 #endif // FORWARD_DWA20011215_HPP

include/boost/python/object/pointer_holder.hpp

@@ -10,7 +10,7 @@
 # include <boost/python/converter/type_id.hpp>
 # include <boost/python/object/inheritance.hpp>
 # include <boost/python/object/find_instance.hpp>
-# include <boost/ref.hpp>
+# include <boost/python/object/forward.hpp>
 # include <boost/type.hpp>
 # include <boost/mpl/select_type.hpp>
 # include <boost/mpl/apply.hpp>
@@ -31,113 +31,113 @@ struct pointer_holder : instance_holder
     template <class A1>
     pointer_holder(PyObject*, A1 a1)
         : m_p(new Value(
-            (typename unwrap_reference<A1>::type&)(a1)
+            (typename unforward<A1>::type)(a1)
                   ))
     {}
     
     template <class A1, class A2>
     pointer_holder(PyObject*, A1 a1, A2 a2)
         : m_p(new Value(
-            (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
+            (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
             ))
     {}
     
     template <class A1, class A2, class A3>
     pointer_holder(PyObject*, A1 a1, A2 a2, A3 a3)
         : m_p(new Value(
-            (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
+            (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
             ))
     {}
     
     template <class A1, class A2, class A3, class A4>
     pointer_holder(PyObject*, A1 a1, A2 a2, A3 a3, A4 a4)
         : m_p(new Value(
-            (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
+            (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
             ))
     {}
     
     template <class A1, class A2, class A3, class A4, class A5>
     pointer_holder(PyObject*, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5)
         : m_p(new Value(
-            (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
+            (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
             )) {}
     
     template <class A1, class A2, class A3, class A4, class A5, class A6>
     pointer_holder(PyObject*, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6)
         : m_p(new Value(
-            (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
+            (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
             )) {}
     
     template <class A1, class A2, class A3, class A4, class A5, class A6, class A7>
     pointer_holder(PyObject*, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6, A7 a7)
         : m_p(new Value(
-            (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
-            , (typename unwrap_reference<A7>::type&)(a7)
+            (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
+            , (typename unforward<A7>::type)(a7)
             ))
     {}
     
     template <class A1, class A2, class A3, class A4, class A5, class A6, class A7, class A8>
     pointer_holder(PyObject*, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6, A7 a7, A8 a8)
         : m_p(new Value(
-            (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
-            , (typename unwrap_reference<A7>::type&)(a7)
-            , (typename unwrap_reference<A8>::type&)(a8)
+            (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
+            , (typename unforward<A7>::type)(a7)
+            , (typename unforward<A8>::type)(a8)
             ))
     {}
     
     template <class A1, class A2, class A3, class A4, class A5, class A6, class A7, class A8, class A9>
     pointer_holder(PyObject*, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6, A7 a7, A8 a8, A9 a9)
         : m_p(new Value(
-            (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
-            , (typename unwrap_reference<A7>::type&)(a7)
-            , (typename unwrap_reference<A8>::type&)(a8)
-            , (typename unwrap_reference<A9>::type&)(a9)
+            (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
+            , (typename unforward<A7>::type)(a7)
+            , (typename unforward<A8>::type)(a8)
+            , (typename unforward<A9>::type)(a9)
             ))
     {}
     
     template <class A1, class A2, class A3, class A4, class A5, class A6, class A7, class A8, class A9, class A10>
     pointer_holder(PyObject*, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6, A7 a7, A8 a8, A9 a9, A10 a10)
         : m_p(new Value(
-            (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
-            , (typename unwrap_reference<A7>::type&)(a7)
-            , (typename unwrap_reference<A8>::type&)(a8)
-            , (typename unwrap_reference<A9>::type&)(a9)
-            , (typename unwrap_reference<A10>::type&)(a10)
+            (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
+            , (typename unforward<A7>::type)(a7)
+            , (typename unforward<A8>::type)(a8)
+            , (typename unforward<A9>::type)(a9)
+            , (typename unforward<A10>::type)(a10)
             ))
     {}
 
@@ -166,7 +166,7 @@ struct pointer_holder_back_reference : instance_holder
     template <class A1>
     pointer_holder_back_reference(PyObject* p, A1 a1)
         : m_p(new held_type(p
-            , (typename unwrap_reference<A1>::type&)(a1)
+            , (typename unforward<A1>::type)(a1)
                   ))
     {
         void const* x = &instance_finder<held_type>::registration; (void)x;
@@ -176,8 +176,8 @@ struct pointer_holder_back_reference : instance_holder
     template <class A1, class A2>
     pointer_holder_back_reference(PyObject* p, A1 a1, A2 a2)
         : m_p(new held_type(p
-            , (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
+            , (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
             ))
     {
         void const* x = &instance_finder<held_type>::registration; (void)x;
@@ -187,9 +187,9 @@ struct pointer_holder_back_reference : instance_holder
     template <class A1, class A2, class A3>
     pointer_holder_back_reference(PyObject* p, A1 a1, A2 a2, A3 a3)
         : m_p(new held_type(p
-            , (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
+            , (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
             ))
     {
         void const* x = &instance_finder<held_type>::registration; (void)x;
@@ -199,10 +199,10 @@ struct pointer_holder_back_reference : instance_holder
     template <class A1, class A2, class A3, class A4>
     pointer_holder_back_reference(PyObject* p, A1 a1, A2 a2, A3 a3, A4 a4)
         : m_p(new held_type(p
-            , (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
+            , (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
             ))
     {
         void const* x = &instance_finder<held_type>::registration; (void)x;
@@ -212,11 +212,11 @@ struct pointer_holder_back_reference : instance_holder
     template <class A1, class A2, class A3, class A4, class A5>
     pointer_holder_back_reference(PyObject* p, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5)
         : m_p(new held_type(p
-            , (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
+            , (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
             )) {
         void const* x = &instance_finder<held_type>::registration; (void)x;
     }
@@ -225,12 +225,12 @@ struct pointer_holder_back_reference : instance_holder
     template <class A1, class A2, class A3, class A4, class A5, class A6>
     pointer_holder_back_reference(PyObject* p, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6)
         : m_p(new held_type(p
-            , (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
+            , (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
             )) {
         void const* x = &instance_finder<held_type>::registration; (void)x;
     }
@@ -239,13 +239,13 @@ struct pointer_holder_back_reference : instance_holder
     template <class A1, class A2, class A3, class A4, class A5, class A6, class A7>
     pointer_holder_back_reference(PyObject* p, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6, A7 a7)
         : m_p(new held_type(p
-            , (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
-            , (typename unwrap_reference<A7>::type&)(a7)
+            , (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
+            , (typename unforward<A7>::type)(a7)
             ))
     {
         void const* x = &instance_finder<held_type>::registration; (void)x;
@@ -255,14 +255,14 @@ struct pointer_holder_back_reference : instance_holder
     template <class A1, class A2, class A3, class A4, class A5, class A6, class A7, class A8>
     pointer_holder_back_reference(PyObject* p, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6, A7 a7, A8 a8)
         : m_p(new held_type(p
-            , (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
-            , (typename unwrap_reference<A7>::type&)(a7)
-            , (typename unwrap_reference<A8>::type&)(a8)
+            , (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
+            , (typename unforward<A7>::type)(a7)
+            , (typename unforward<A8>::type)(a8)
             ))
     {
         void const* x = &instance_finder<held_type>::registration; (void)x;
@@ -272,15 +272,15 @@ struct pointer_holder_back_reference : instance_holder
     template <class A1, class A2, class A3, class A4, class A5, class A6, class A7, class A8, class A9>
     pointer_holder_back_reference(PyObject* p, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6, A7 a7, A8 a8, A9 a9)
         : m_p(new held_type(p
-            , (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
-            , (typename unwrap_reference<A7>::type&)(a7)
-            , (typename unwrap_reference<A8>::type&)(a8)
-            , (typename unwrap_reference<A9>::type&)(a9)
+            , (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
+            , (typename unforward<A7>::type)(a7)
+            , (typename unforward<A8>::type)(a8)
+            , (typename unforward<A9>::type)(a9)
             ))
     {
         void const* x = &instance_finder<held_type>::registration; (void)x;
@@ -290,16 +290,16 @@ struct pointer_holder_back_reference : instance_holder
     template <class A1, class A2, class A3, class A4, class A5, class A6, class A7, class A8, class A9, class A10>
     pointer_holder_back_reference(PyObject* p, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6, A7 a7, A8 a8, A9 a9, A10 a10)
         : m_p(new held_type(p
-            , (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
-            , (typename unwrap_reference<A7>::type&)(a7)
-            , (typename unwrap_reference<A8>::type&)(a8)
-            , (typename unwrap_reference<A9>::type&)(a9)
-            , (typename unwrap_reference<A10>::type&)(a10)
+            , (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
+            , (typename unforward<A7>::type)(a7)
+            , (typename unforward<A8>::type)(a8)
+            , (typename unforward<A9>::type)(a9)
+            , (typename unforward<A10>::type)(a10)
             ))
     {
         void const* x = &instance_finder<held_type>::registration; (void)x;

include/boost/python/object/value_holder.hpp

@@ -11,7 +11,7 @@
 # include <boost/python/converter/type_id.hpp>
 # include <boost/python/object/inheritance.hpp>
 # include <boost/python/object/find_instance.hpp>
-# include <boost/ref.hpp>
+# include <boost/python/object/forward.hpp>
 
 namespace boost { namespace python { namespace objects { 
 
@@ -25,113 +25,113 @@ struct value_holder : instance_holder
     template <class A1>
     value_holder(PyObject*, A1 a1)
         : m_held(
-            (typename unwrap_reference<A1>::type&)(a1)
+            (typename unforward<A1>::type)(a1)
             )
     {}
     
     template <class A1, class A2>
     value_holder(PyObject*, A1 a1, A2 a2)
         : m_held(
-            (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
+            (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
             )
     {}
     
     template <class A1, class A2, class A3>
     value_holder(PyObject*, A1 a1, A2 a2, A3 a3)
         : m_held(
-            (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
+            (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
             )
     {}
     
     template <class A1, class A2, class A3, class A4>
     value_holder(PyObject*, A1 a1, A2 a2, A3 a3, A4 a4)
         : m_held(
-            (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
+            (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
             )
     {}
     
     template <class A1, class A2, class A3, class A4, class A5>
     value_holder(PyObject*, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5)
         : m_held(
-            (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
+            (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
             ) {}
     
     template <class A1, class A2, class A3, class A4, class A5, class A6>
     value_holder(PyObject*, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6)
         : m_held(
-            (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
+            (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
             ) {}
     
     template <class A1, class A2, class A3, class A4, class A5, class A6, class A7>
     value_holder(PyObject*, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6, A7 a7)
         : m_held(
-            (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
-            , (typename unwrap_reference<A7>::type&)(a7)
+            (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
+            , (typename unforward<A7>::type)(a7)
             )
     {}
     
     template <class A1, class A2, class A3, class A4, class A5, class A6, class A7, class A8>
     value_holder(PyObject*, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6, A7 a7, A8 a8)
         : m_held(
-            (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
-            , (typename unwrap_reference<A7>::type&)(a7)
-            , (typename unwrap_reference<A8>::type&)(a8)
+            (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
+            , (typename unforward<A7>::type)(a7)
+            , (typename unforward<A8>::type)(a8)
             )
     {}
     
     template <class A1, class A2, class A3, class A4, class A5, class A6, class A7, class A8, class A9>
     value_holder(PyObject*, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6, A7 a7, A8 a8, A9 a9)
         : m_held(
-            (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
-            , (typename unwrap_reference<A7>::type&)(a7)
-            , (typename unwrap_reference<A8>::type&)(a8)
-            , (typename unwrap_reference<A9>::type&)(a9)
+            (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
+            , (typename unforward<A7>::type)(a7)
+            , (typename unforward<A8>::type)(a8)
+            , (typename unforward<A9>::type)(a9)
             )
     {}
     
     template <class A1, class A2, class A3, class A4, class A5, class A6, class A7, class A8, class A9, class A10>
     value_holder(PyObject*, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6, A7 a7, A8 a8, A9 a9, A10 a10)
         : m_held(
-            (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
-            , (typename unwrap_reference<A7>::type&)(a7)
-            , (typename unwrap_reference<A8>::type&)(a8)
-            , (typename unwrap_reference<A9>::type&)(a9)
-            , (typename unwrap_reference<A10>::type&)(a10)
+            (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
+            , (typename unforward<A7>::type)(a7)
+            , (typename unforward<A8>::type)(a8)
+            , (typename unforward<A9>::type)(a9)
+            , (typename unforward<A10>::type)(a10)
             )
     {}
 
@@ -155,7 +155,7 @@ struct value_holder_back_reference : instance_holder
     template <class A1>
     value_holder_back_reference(PyObject* p, A1 a1)
         : m_held(p
-            , (typename unwrap_reference<A1>::type&)(a1)
+            , (typename unforward<A1>::type)(a1)
             )
     {
         void const* x = &instance_finder<BackReferenceType>::registration; (void)x;
@@ -165,8 +165,8 @@ struct value_holder_back_reference : instance_holder
     template <class A1, class A2>
     value_holder_back_reference(PyObject* p, A1 a1, A2 a2)
         : m_held(p
-            , (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
+            , (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
             )
     {
         void const* x = &instance_finder<BackReferenceType>::registration; (void)x;
@@ -176,9 +176,9 @@ struct value_holder_back_reference : instance_holder
     template <class A1, class A2, class A3>
     value_holder_back_reference(PyObject* p, A1 a1, A2 a2, A3 a3)
         : m_held(p
-            , (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
+            , (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
             )
     {
         void const* x = &instance_finder<BackReferenceType>::registration; (void)x;
@@ -188,10 +188,10 @@ struct value_holder_back_reference : instance_holder
     template <class A1, class A2, class A3, class A4>
     value_holder_back_reference(PyObject* p, A1 a1, A2 a2, A3 a3, A4 a4)
         : m_held(p
-            , (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
+            , (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
             )
     {
         void const* x = &instance_finder<BackReferenceType>::registration; (void)x;
@@ -201,11 +201,11 @@ struct value_holder_back_reference : instance_holder
     template <class A1, class A2, class A3, class A4, class A5>
     value_holder_back_reference(PyObject* p, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5)
         : m_held(p
-            , (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
+            , (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
             ) {
         void const* x = &instance_finder<BackReferenceType>::registration; (void)x;
     }
@@ -214,12 +214,12 @@ struct value_holder_back_reference : instance_holder
     template <class A1, class A2, class A3, class A4, class A5, class A6>
     value_holder_back_reference(PyObject* p, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6)
         : m_held(p
-            , (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
+            , (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
             ) {
         void const* x = &instance_finder<BackReferenceType>::registration; (void)x;
     }
@@ -228,13 +228,13 @@ struct value_holder_back_reference : instance_holder
     template <class A1, class A2, class A3, class A4, class A5, class A6, class A7>
     value_holder_back_reference(PyObject* p, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6, A7 a7)
         : m_held(p
-            , (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
-            , (typename unwrap_reference<A7>::type&)(a7)
+            , (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
+            , (typename unforward<A7>::type)(a7)
             )
     {
         void const* x = &instance_finder<BackReferenceType>::registration; (void)x;
@@ -244,14 +244,14 @@ struct value_holder_back_reference : instance_holder
     template <class A1, class A2, class A3, class A4, class A5, class A6, class A7, class A8>
     value_holder_back_reference(PyObject* p, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6, A7 a7, A8 a8)
         : m_held(p
-            , (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
-            , (typename unwrap_reference<A7>::type&)(a7)
-            , (typename unwrap_reference<A8>::type&)(a8)
+            , (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
+            , (typename unforward<A7>::type)(a7)
+            , (typename unforward<A8>::type)(a8)
             )
     {
         void const* x = &instance_finder<BackReferenceType>::registration; (void)x;
@@ -261,15 +261,15 @@ struct value_holder_back_reference : instance_holder
     template <class A1, class A2, class A3, class A4, class A5, class A6, class A7, class A8, class A9>
     value_holder_back_reference(PyObject* p, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6, A7 a7, A8 a8, A9 a9)
         : m_held(p
-            , (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
-            , (typename unwrap_reference<A7>::type&)(a7)
-            , (typename unwrap_reference<A8>::type&)(a8)
-            , (typename unwrap_reference<A9>::type&)(a9)
+            , (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
+            , (typename unforward<A7>::type)(a7)
+            , (typename unforward<A8>::type)(a8)
+            , (typename unforward<A9>::type)(a9)
             )
     {
         void const* x = &instance_finder<BackReferenceType>::registration; (void)x;
@@ -279,16 +279,16 @@ struct value_holder_back_reference : instance_holder
     template <class A1, class A2, class A3, class A4, class A5, class A6, class A7, class A8, class A9, class A10>
     value_holder_back_reference(PyObject* p, A1 a1, A2 a2, A3 a3, A4 a4, A5 a5, A6 a6, A7 a7, A8 a8, A9 a9, A10 a10)
         : m_held(p
-            , (typename unwrap_reference<A1>::type&)(a1)
-            , (typename unwrap_reference<A2>::type&)(a2)
-            , (typename unwrap_reference<A3>::type&)(a3)
-            , (typename unwrap_reference<A4>::type&)(a4)
-            , (typename unwrap_reference<A5>::type&)(a5)
-            , (typename unwrap_reference<A6>::type&)(a6)
-            , (typename unwrap_reference<A7>::type&)(a7)
-            , (typename unwrap_reference<A8>::type&)(a8)
-            , (typename unwrap_reference<A9>::type&)(a9)
-            , (typename unwrap_reference<A10>::type&)(a10)
+            , (typename unforward<A1>::type)(a1)
+            , (typename unforward<A2>::type)(a2)
+            , (typename unforward<A3>::type)(a3)
+            , (typename unforward<A4>::type)(a4)
+            , (typename unforward<A5>::type)(a5)
+            , (typename unforward<A6>::type)(a6)
+            , (typename unforward<A7>::type)(a7)
+            , (typename unforward<A8>::type)(a8)
+            , (typename unforward<A9>::type)(a9)
+            , (typename unforward<A10>::type)(a10)
             )
     {
         void const* x = &instance_finder<BackReferenceType>::registration; (void)x;

test/Jamfile

@@ -53,6 +53,7 @@ rule bpl-test ( name ? : files * )
 
 bpl-test bienstman1 ;
 bpl-test bienstman2 ;
+bpl-test bienstman3 ;
 bpl-test try : newtest.py m1.cpp m2.cpp ;
 bpl-test builtin_converters : test_builtin_converters.py test_builtin_converters.cpp ;
 bpl-test test_pointer_adoption ;

test/bienstman1.py

@@ -1,5 +1,6 @@
 '''
->>> import bienstman1_ext
+>>> from bienstman1_ext import *
+>>> # from Numeric import *
 '''
 def run(args = None):
     import sys

test/bienstman2.py

@@ -1,5 +1,5 @@
 '''
->>> import bienstman1_ext.py
+>>> import bienstman2_ext
 '''
 def run(args = None):
     import sys

test/bienstman3.cpp

@@ -0,0 +1,33 @@
+#include <boost/python/module.hpp>
+#include <boost/python/class.hpp>
+#include <boost/mpl/type_list.hpp>
+
+struct V 
+{
+ virtual void f() = 0;
+};
+
+struct B 
+{
+    B(const V&) {}    
+};
+
+BOOST_PYTHON_MODULE_INIT(bienstman3_ext)
+{
+  using namespace boost::python;
+  using boost::mpl::type_list;
+
+  module m("bienstman3_ext");
+  
+  m
+
+    .add(
+      class_<V, boost::noncopyable>("V")
+      )
+
+    .add(
+      class_<B>("B")
+      .def_init(type_list<const V&>())
+      )
+    ;
+}

test/bienstman3.py

@@ -0,0 +1,15 @@
+'''
+>>> from bienstman3_ext import *
+'''
+def run(args = None):
+    import sys
+    import doctest
+
+    if args is not None:
+        sys.argv = args
+    return doctest.testmod(sys.modules.get(__name__))
+    
+if __name__ == '__main__':
+    print "running..."
+    import sys
+    sys.exit(run()[0])