Yeah, I'm not saying it's difficult, I'm just saying that it's weird that there isn't a standard ManyToMany<T1, T2> class in most programming languages, even th

Yeah, I'm not saying it's difficult, I'm just saying that it's weird that there isn't a standard ManyToMany<T1, T2> class in most programming languages, even though a functional (if perhaps not performance-optimal) implementation is straightforward and should be very useful at least for DB mappings.