[boost] [signals2] trunk - vc++ 10 warning about assignment operator

Subject: [boost] [signals2] trunk - vc++ 10 warning about assignment operator
From: Edward Diener (eldiener_at_[hidden])
Date: 2011-05-11 22:06:57

An attempt to instantiate a signals2 signal of the form:

   template <class T> class notification_boost_signal2
     {

     public:

     boost::signals2::signal<void (const i_some_interface<T> 
&,boost::optional<T>,T)> sig;

      };

for notification_boost_signal2<char>, gives the error message in vc++ of:

"C:\Programming\VersionControl\boost\boost/signals2/detail/signal_template.hpp(367) 
: warning C4512: 
'boost::signals2::detail::signal3_impl<R,T1,T2,T3,Combiner,Group,GroupCompare,SlotFunction,ExtendedSlotFunction,Mutex>::slot_invoker' 
: assignment operator could not be generated"

There is a huge template trace leading up to this final warning, but 
before giving it I wonder if anyone knows what it is about ? Perhaps 
Frank Mori Hess or Douglas Gregor is out there and can tell me what is 
happening.