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POUsing Boost Python with Weak Ptrs?
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2009-10-26T13:49:27.167
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2011-08-09T01:57:15.180
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Trying to set up a dependency in C++ with a parent-child relationship. The parent contains the child and the child has a weak pointer to the parent. I would also like to be able to derive from the parent in Python. However, when I do this, I get a weak pointer error connecting up this parent-child relationship. C++ code: <pre><code>#include <boost/python.hpp> #include <boost/shared_ptr.hpp> #include <boost/enable_shared_from_this.hpp> using namespace boost; using namespace boost::python; struct Child; struct Parent : public enable_shared_from_this<Parent> { void initialize(); shared_ptr<Child> m_child; }; struct Child: public enable_shared_from_this<Child> { void setParent(shared_ptr<Parent> ptr); weak_ptr<Parent> m_parent; }; void Parent::initialize() { shared_ptr<Child> ptr(new Child); m_child = ptr; m_child->setParent(shared_from_this()); } void Child::setParent(shared_ptr<Parent> ptr) { m_parent = ptr; } static PyObject* create(PyObject* object) { PyObject* instance = PyObject_CallObject(object, NULL); Parent* parent = extract<Parent*>(instance); parent->initialize(); return instance; } </code></pre> Python binding: <pre><code>BOOST_PYTHON_MODULE(test_module) { class_<Parent>("Parent"); def("create", &create); } </code></pre> Python code: <pre><code>from test_module import * class Test(Parent): def __init__(self): Parent.__init__(self) n = create(Test) </code></pre> Error: <pre><code>Traceback (most recent call last): File "main.py", line 8, in <module> n = create(Test) RuntimeError: tr1::bad_weak_ptr </code></pre> If I try and convert the extracted pointer to Parent into a shared_ptr, I get a free() invalid pointer error in Python. Is there a way of getting round this problem or should I give up using weak pointers with Boost Python?
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<c++><python><boost><weak-references><boost-python>
Title
Using Boost Python with Weak Ptrs?
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