I used boost::signals in number of projects and found one thing inconvenient. I could easily connect anything to signal but sometimes it became hard to disconnect form it. It's ok if a connection time is bounded by a lifetime of trackable or connection objects. I used to use Group id for disconnection, but sometimes I needed it for call priority. ( In that case I would write a special GroupCompare function but it looked ugly. ) For experimental purposes, I constructed an alternative approach. For connection/disconnection management I used the following syntax: struct Test { void test( bool, int ); }; void f( bool ); signal<void (bool)> s; s.connect( &Test::test, t, _1, 5 ); s.disconnect( &Test::test, t, _1, 5 ); s.connect( &f, _1 ); s.disconnect( &f, _1 ); I just form a hash code from the arguments. It certainly makes the process longer, but in most cases I don't need something extremely fast there. In my projects, the performance is important in invocation process. It's only a variant, there might be a lot of other ways. So actually my suggestion is why not to have both approaches of connection/disconnection management? One for fast connection/disconnection and the other for extra control over it. -- Best regards, Nick mailto:kolach56@yandex.ru