Add and use notifiable base class instead of void*.

Use notifiable as the  base class for trackable, connection, signal_impl,
self_and_iter and destroy_notify_struct.

Use this notifiable* instead of void* for the destroy/notify callback data.
This is a little more type-safe and self-documenting.
Bug #302152

1 files changed, 1 insertions, 2 deletions

diff --git a/sigc++/connection.cc b/sigc++/connection.cc
index 0d1d52e..79d1202 100644
--- a/sigc++/connection.cc
+++ b/sigc++/connection.cc
@@ -99,11 +99,10 @@ void connection::set_slot(slot_base* sl)
     slot_->add_destroy_notify_callback(this, &notify);
 }
 
-void* connection::notify(void* data)
+void connection::notify(notifiable* data)
 {
   auto self = reinterpret_cast<connection*>(data);
   self->slot_ = nullptr;
-  return nullptr;
 }
 
 } /* namespace sigc */