Recently one of my friends had a strange problem - he wanted to initialize a few variables with a different type in a single for loop. What was even more strange was that he wanted to declare just one of them and both of them have different type. A declaration of variables is forbidden in the loop for C standard which are older than C99, so let’s assume we are using exactly that standard. One of the questions could be “why is your friend so crazy that he would want to do that” - basically he wanted to create a macro which would declare for him a head of the loop very similar to what STAILQ_FOREACH.