Ananth Durbha wrote:

I am trying to modify a set of file parser callback functions (for a custom file format) to populate a Boost graph. The callbacks provide a (void*) pointer style parameter passing. But Boost graph method add_vertex(graph) will return a vertex descriptor. How do I obtain the pointer information for this newly added vertex so that the pointer can be cast as (void*) and passed to the appropriate call back?

If you're writing the code that calls the callback, what about something like this (untested): struct CallbackData { /* vertex descriptor type */ vertex_desc; }; ... CallbackData cdata; cdata.vertex_desc = add_vertex(...); (*callback)(reinterpret_cast(&cdata)); Then, inside your callback: void my_callback(void* data) { CallbackData* pdata = reinterpret_cast(data); /* ... use pdata->vertex_desc ... */ } ? If that's not the scenario you have in mind, then please explain more clearly.