links for 2009-02-21

Pointers to non-static members are different to ordinary C function pointers since they need the this-pointer of a class object to be passed. Thus ordinary function pointers and non-static member functions have different and incompatible signatures! If you just want to callback to a member of a specific class you just change your code from an ordinary function pointer to a pointer to a member function. But what can you do, if you want to callback to a non-static member of an arbitrary class? It's a little bit difficult. You need to write a static member function as a wrapper. A static member function has the same signature as a C function! Then you cast the pointer to the object on which you want to invoke the member function to void* and pass it to the wrapper as an additional argument or via a global variable. If you use a global variable it is very important, that you make sure that it will always point to the correct object! Of course…