[Boost-users] Problem with weak_ptr exception

28 Oct 2009

      I'm having some problems with bad_weak_ptr exceptions. I have reduced my 
code into this test case:

#include <boost/shared_ptr.hpp>
#include <boost/weak_ptr.hpp>

using boost::shared_ptr;
using boost::weak_ptr;

class A
{
		weak_ptr<A> weakThis;

	public:
		virtual ~A(){}

		shared_ptr<A> a;

	shared_ptr<A> getThis ()
	{
		shared_ptr<A> x(weakThis);
		return x;
	}

	void init ()
	{
		a = getThis();
	}

	static shared_ptr<A> create ()
	{
		shared_ptr<A> x(new A);

		x->weakThis = x;
		x->init();

		return x;
	}
};

class B : public A
{
		weak_ptr<B> weakThis;
	public:
		virtual ~B(){}

	shared_ptr<B> getThis ()
	{
		shared_ptr<B> b(weakThis);
		return b;
	}

	static shared_ptr<B> create ()
	{
		shared_ptr<B> x(new B);
		x->weakThis = x;
		x->init();

		return x;
	}
};

int main (char** argv, int argc)
{
	shared_ptr<B> b = B::create();

	return 0;
}

If I create an instance of A instead of B or doesn't call x->init() in 
the B's create function I don't get an exception. The problem is 
creating a shared_ptr from the weak_ptr in getThis.

[Boost-users] Problem with weak_ptr exception

Jacob Carlborg