When you have a pointer to a pointer to a data structure and you dereference it twice and then get the address of a field of the data structure and cast it to a void pointer and pass it to a function returning a void pointer because POSIX threads 
@applejack I mean it doesn't bother me. I've never used OpenMP.
@miria It's extremely based. So is the intel guide on it. Simple and easy
https://www.youtube.com/playlist?list=PLLbPZJxtMs4ZHSamRRYCtvowRS0qIwC-I
This is how you parallelise a for loop, but it has very fine grained control too, including reduction, exclusive zones, tasks, queues, atomics, and more.
