The main issue is that a list of pointers is inefficient but also overkill; a small list is probably fine as an array even if you're mutating it. But intrusive

The main issue is that a list of pointers is inefficient but also overkill; a small list is probably fine as an array even if you're mutating it. But intrusive lists also have clearer ownership, since the object knows all the lists it can be in, and that's handy sometimes.