I think the key words are "reentrant function" which in the context means atomic, pure functions. He didn't say something about OO, like DI or multiple inherita

I think the key words are "reentrant function" which in the context means atomic, pure functions. He didn't say something about OO, like DI or multiple inheritance in a some clean way, or something about classes or structs. This is more FP than not. By far.