Question

#define MyLog(msg...) MyLogWith(__func__,##msg);

MyLog(@"I do not know...");

What do ... and ## mean in this definition? Is there a special meaning to them being combined with msg: msg.. or ##msg?

Answer 1

msg... means to take any amount of arguments.
,##msg means paste the arguments, and erase the preceding , if the argument count is 0
msg has no special meaning, its just the name for the arguments, e.g.

#define MyLog(args...) MyLogWith(__func__,##args);

will do the same