> But some callbacks have additional parameters! And in C example code for the
> library they just cast the different callback signatures with (Icallback).
In this case you have no other choice then to use cast to call the C functions
and it's completly justified. I don't know much about iup, though you could try
something like that to make it safer:
proc setCallbackClick(ih: PtrIHandle, handler: proc (arg: PtrIhandle,
mousebutton: cint): cint {.cdecl.}) =
ih.setCallback("CLICK", cast[Icallback](handler))
Run
