Bill McLean wrote:

Marshall,

Thanks for the reply. You have touched upon an issue that I'm not sure how to solve.

The general problem is how to use boost::function and boost::bind to register a member callback function for a c style library.

A proxy function that has signature of the c callback function and the correct instance of the class containing the member function to call.

Any thoughts or approaches to solve it.

I don't think it's possible to do so in a type-safe manner. The problem is that deep inside the (Mac OS X) file system, there's some code that looks like this: push <param1> push <param2> ... push <param6> jsr (callback fn) And that just won't work with boost::function or boost::bind expressions. You can do it using a "trampoline function", but again, w/o type safety: // psuedo code void FSEventStreamTrampoline ( < params > ) { boost::function< void ( cb = clientCallBackInfo; return cb ( params ); } ..... callBack = boost::bind(&fsmon :: osx::detail::FSEventTriggered, this, _1, _2, _3, _4, _5, _6); streamRef = FSEventStreamCreate(NULL, FSEventStreamTrampoline, &callBack, pathsToWatch, kFSEventStreamEventIdSinceNow, LATENCY, kFSEventStreamCreateFlagNone ); and you have to package up the information that you previously passed as "callbackInfo". This may not work anyway, since I'm mixing boost::function and boost::bind here - but you get the idea. -- -- Marshall Marshall Clow Idio Software mailto:marshall@idio.com It is by caffeine alone I set my mind in motion. It is by the beans of Java that thoughts acquire speed, the hands acquire shaking, the shaking becomes a warning. It is by caffeine alone I set my mind in motion.