Hi Reuben, > it gives me confidence a) because the code is from gnulib
Well, what gives me confidence is not the mere fact that it's from gnulib, but that it has a unit test that was verified to pass on all kinds of platforms. > The only inelegance is having > to code up a struct type to pass around the privdata argument even for > something as simple as passing data in and reading it out again. That's life, in C. A callback consists of a function pointer plus a privdata pointer, which is declared as 'void *' but actually some specialized pointer. C's type system does not have co-variant and contra-variant inference logic [1], therefore you have to cast this privdata argument manually. Bruno [1] http://en.wikipedia.org/wiki/Covariance_and_contravariance_(computer_science) -- In memoriam Adam Czerniaków <http://en.wikipedia.org/wiki/Adam_Czerniaków>
