The application of pyplusplus.function_transformers.modify_type doesn't suppress the W1040 warning for the old type.
If Py++ is exposing a function whose argument does not have a Python binding then it outputs a W1040 warning 'The declaration is unexposed, but there are other declarations, which refer to it. This could cause "no to_python converter found" run time error.'
When pyplusplus.function_transformers.modify_type is subsequently applied to the function such that the unexposed old type is replaced with an exposed new type then the W1040 warning for that function should be suppressed.
This bug was found in SVN revision 1856.