attempt to allow rvalue references of custom types

Author: rhaschke

include/pybind11/cast.h

@@ -880,10 +880,11 @@ template <typename type> class type_caster_base : public type_caster_generic {
             nullptr, nullptr, holder);
     }
 
-    template <typename T> using cast_op_type = detail::cast_op_type<T>;
+    template <typename T> using cast_op_type = detail::movable_cast_op_type<T>;
 
     operator itype*() { return (type *) value; }
     operator itype&() { if (!value) throw reference_cast_error(); return *((itype *) value); }
+    operator itype&&() && { if (!value) throw reference_cast_error(); return std::move(*((itype *) value)); }
 
 protected:
     using Constructor = void *(*)(const void *);

tests/test_move_arg.cpp

@@ -18,7 +18,7 @@ PYBIND11_MODULE(test_move_arg, m) {
 		std::cout << "access " << item << "\n";
 	}, py::call_guard<py::scoped_ostream_redirect>());
 
-#if 0 // rvalue arguments fail during compilation
+#if 1 // works for this example now, but failing for other unit tests
 	m.def("consume", [](Item&& item) {
 		std::cout << "consume " << item << "\n  ";
 		Item sink(std::move(item));

tests/test_move_arg.py

@@ -1,12 +1,12 @@
 import pytest
-from test_move_arg import Item, access
+from test_move_arg import *
 
 
 def test():
     item = Item(42)
     other = item
     access(item)
-    print(item)
+    consume(item)
     del item
     print(other)