I read at multiple places that Boost.Signals is not threadsafe but I haven't found much more details about it. This simple quote doesn't say really that much. Most applications nowadays have threads - even if they try to be single threaded, some of their libraries may use threads (for example libsdl).
I guess the implementation doesn't have problems with other threads not accessing the slot. So it is at least threadsafe in this sense.
But what exactly works and what would not work? Would it work to use it from multiple threads as long as I don't ever access it at the same time? I.e. if I build my own mutexes around the slot?
Or am I forced to use the slot only in that thread where I created it? Or where I used it for the first time?