I straight up never got a nice answer from StackOverflow on this. Say you have 5 classes, each requiring access to the data members/functions of the others. What's a nice way to solve this problem? I've thought of only two nice methods:

• Pass pointers/shared-pointers etc to each class, but not through the constructor but a setter function
• Pass lambdas or std::function everywhere. Yuck! Still doesn't put each object in a valid state in the constructor.