Hi all, I am doing some research to use boost-signals library. I was reading the Tutorial of boost-signals library and have tested the Documents-View example , and understand the basic to use it. In the tutorial , there is a template function named visit_each , I suppose it is a iteration function to iterate all the slots or signals . However, there is not much information about how to use visit_each. I try to look into source code but as a newbie in template programming I really could not understand the source code. I wonder the creator of signal library have done some update on the tutorial and add in example on visit_each or other new interface/function Besides, apart from what mentioned in the tutorial, what are the benefit if a class is derived from trackable ? Sorry if my question are a bit weird.