id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
7080	make_constructor Does Not Initialize base_wrapper	team@…	Ralf W. Grosse-Kunstleve	"When binding a shared_ptr to Python, we're using a custom allocator defined using make_constructor:

{{{
class_< Controller, shared_ptr<Controller>, boost::noncopyable >(""Controller"", no_init)
            .def(""__init__"", boost::python::make_constructor(&Controller::make));
}}}

This works as expected except when classes are derived in Python.  In those cases, get_override does not work, since m_self is NULL.  If you use init<>() in the class_ constructor, instead of the make_constructor line, it works as expected.


The bug is that make_constructor does not initialize the base_wrapper.  I've tried a fix as follows, and it's now functional -- though I can't say if this is a good way to solve it.

{{{
+++ make_constructor.hpp
@@ -59,6 +59,7 @@
           void* memory = holder::allocate(this->m_self, offsetof(instance_t, storage), sizeof(holder));
           try {
               (new (memory) holder(x))->install(this->m_self);
+			  python::detail::initialize_wrapper(this->m_self, get_pointer(x));
           }
           catch(...) {
               holder::deallocate(this->m_self, memory);
}}}

It's also possible to fix this by partially specializing ""template <typename T> struct install_holder;"" before boost::python is included."	Bugs	new	To Be Determined	python USE GITHUB	Boost 1.51.0	Problem