On Tuesday 04 March 2003 10:02 am, Marc Jacobs wrote: > I'm trying to use a member function as a callback to a C-style library. > I've got the bind working by itself, but the resulting function object does > not convert to the type required by the library. Clearly a boost::bind > object is not a simple function pointer and the type is being checked by > the compiler. Is there any way to coerce the types and still use > boost::bind? I have no control over the declaration or definition of the > C-style library. Here's a sample: [snip code]
Unfortunately, this isn't generally possible. boost::bind objects can carry state with them but function pointers cannot. However, if you have some way to associate arbitrary data with each callback (even if its just a void pointer), such as: typedef void (*callback_type)( int i, void* user_data ); Then you can use a combination of bind and function to create a "thunk" routine mapping the void* to a boost::function object. The technique is described here: http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?Generalizing_C-Style_Callbacks Doug _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
