DRTVWR-476: Remove special case for listen(boost::bind(weak_ptr)).

LLEventDetail::visit_and_connect() promised special treatment for the
specific case when an LLEventPump::listen() listener was composed of (possibly
nested) boost::bind() objects storing boost::weak_ptr values -- specifically
boost::bind() rather than std::bind or lambdas, specifically boost::weak_ptr
rather than std::weak_ptr.

Outside of self-tests, it does not appear that anyone actually uses that
support.

There is good reason not to: it's a silent side effect of a complicated
compile-time inspection that could be silently derailed by use of std::bind()
or a lambda or a std::weak_ptr. Can you be sure you've engaged that promise?
How?

A more robust guarantee can be achieved by storing an LLTempBoundConnection in
the transient object itself. When the object is destroyed, the listener is
disconnected. Normal C++ rules around object destruction guarantee it. This
idiom is widely used.

There are a couple good reasons to remove the visit_and_connect() machinery:

* boost::bind() and boost::weak_ptr do not constitute the wave of the future.
  Preferring those constructs to lambdas and std::weak_ptr penalizes new code,
  whether by silently failing or by discouraging use of modern idioms.
* The visit_and_connect() machinery was always complicated, and apparently
  never very robust. Most of its promised features have been commented out
  over the years. Making the code base simpler, clearer and more maintainable
  is always a useful effect.

LLEventDetail::visit_and_connect() was also used by the four
LLNotificationChannelBase::connectMumble() methods. Streamline those as well.

Of course, remove related test code.

1 files changed, 8 insertions, 26 deletions

diff --git a/indra/llui/llnotifications.h b/indra/llui/llnotifications.h
index 62cf41256b..cac687f53d 100644
--- a/indra/llui/llnotifications.h
+++ b/indra/llui/llnotifications.h
@@ -746,42 +746,24 @@ public:
 	virtual ~LLNotificationChannelBase() {}
 	// you can also connect to a Channel, so you can be notified of
 	// changes to this channel
-	template <typename LISTENER>
-    LLBoundListener connectChanged(const LISTENER& slot)
+    LLBoundListener connectChanged(const LLEventListener& slot)
     {
-        // Examine slot to see if it binds an LLEventTrackable subclass, or a
-        // boost::shared_ptr to something, or a boost::weak_ptr to something.
         // Call this->connectChangedImpl() to actually connect it.
-        return LLEventDetail::visit_and_connect(slot,
-                                  boost::bind(&LLNotificationChannelBase::connectChangedImpl,
-                                              this,
-                                              _1));
+        return connectChangedImpl(slot);
     }
-	template <typename LISTENER>
-    LLBoundListener connectAtFrontChanged(const LISTENER& slot)
+    LLBoundListener connectAtFrontChanged(const LLEventListener& slot)
     {
-        return LLEventDetail::visit_and_connect(slot,
-                                  boost::bind(&LLNotificationChannelBase::connectAtFrontChangedImpl,
-                                              this,
-                                              _1));
+        return connectAtFrontChangedImpl(slot);
     }
-    template <typename LISTENER>
-	LLBoundListener connectPassedFilter(const LISTENER& slot)
+    LLBoundListener connectPassedFilter(const LLEventListener& slot)
     {
         // see comments in connectChanged()
-        return LLEventDetail::visit_and_connect(slot,
-                                  boost::bind(&LLNotificationChannelBase::connectPassedFilterImpl,
-                                              this,
-                                              _1));
+        return connectPassedFilterImpl(slot);
     }
-    template <typename LISTENER>
-	LLBoundListener connectFailedFilter(const LISTENER& slot)
+    LLBoundListener connectFailedFilter(const LLEventListener& slot)
     {
         // see comments in connectChanged()
-        return LLEventDetail::visit_and_connect(slot,
-                                  boost::bind(&LLNotificationChannelBase::connectFailedFilterImpl,
-                                              this,
-                                              _1));
+        return connectFailedFilterImpl(slot);
     }
 
 	// use this when items change or to add a new one