How to detect cycles when using shared_ptr

shared_ptr is a reference counting smart pointer in the Boost library.

The problem with reference counting is that it cannot dispose of cycles. I am wondering how one would go about solving this in C++.

Please no suggestions like: "don't make cycles", or "use weak_ptr".

Edit

I don't like suggestions that say to just use a weak_ptr because obviously if you know you will create a cycle, then you wouldn't have a problem. You also cannot know you will have a cycle at compile time if you generate shared_ptrs at runtime.

So please, self delete answers that use weak_ptr in them because I specifically asked not to have those kind of answers...

I haven't found a much better method than drawing large UML graphs and looking out for cycles.

To debug, I use an instance counter going to the registry, like this:

template <DWORD id>
class CDbgInstCount
{
public:
#ifdef _DEBUG
   CDbgInstCount()   { reghelper.Add(id, 1); }
   CDbgInstCount(CDbgInstCount const &) {  reghelper.Add(id, 1); }
   ~CDbgInstCount()  { reghelper.Add(id, -1); }
#else
#endif
};

I just ned to add that to the classes in question, and have a look at the registry.

(The ID, if given as e.g. 'XYZ!' will be converted to a string. Unfortunately, you can't specify a string constant as template parameter)