[boost] boost::null

24 Feb 2006

      What about a null_helper class?
This is my approach:

namespace boost {
static class null_helper
{
public:
   template <typename T>
   inline operator shared_ptr<T>() const { return shared_ptr<T>(); }

   template <typename T>
   inline operator T *() const { return 0; }
}null;
}

I find this very useful in samples like this:

class node
{
public:
   node(boost::shared_ptr<node> parent = boost::null,    // instead of 
boost::shared_ptr<node>()
           int *value = boost::null);                                   // 
no difference from ordinary pointers
};

Waiting for your feedback ;)

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Raffaele Romito