New function invocation mechanism. This is the major groundwork for handling virtual functions with default implementations properly

[SVN r16388]

test/m1.cpp

@@ -199,6 +199,9 @@ D take_d_shared_ptr(boost::shared_ptr<D> d) { return *d; }
 
 boost::shared_ptr<A> d_factory() { return boost::shared_ptr<B>(new D); }
 
+struct Unregistered {};
+Unregistered make_unregistered(int) { return Unregistered(); }
+
 BOOST_PYTHON_MODULE(m1)
 {
     using namespace boost::python;
@@ -222,6 +225,8 @@ BOOST_PYTHON_MODULE(m1)
     def("new_noddy", new_noddy);
     def("new_simple", new_simple);
 
+    def("make_unregistered", make_unregistered);
+
       // Expose f() in all its variations
     def("f", f);
     def("f_mutable_ref", f_mutable_ref);

test/newtest.py

@@ -3,6 +3,17 @@
 
 >>> from m2 import *
 
+   Prove that we get an appropriate error from trying to return a type
+   for which we have no registered to_python converter
+
+>>> try:
+...     make_unregistered(1)
+... except TypeError, x:
+...     if not str(x).startswith('No to_python (by-value) converter found for C++ type'):
+...         print str(x)
+... else:
+...     print 'expected a TypeError'
+
 >>> n = new_noddy()
 >>> s = new_simple()
 >>> unwrap_int(n)