And this kind of leak is the same kind that is actually difficult to prevent and debug with manual allocation -- it's present / reachable in some structure, but

And this kind of leak is the same kind that is actually difficult to prevent and debug with manual allocation -- it's present / reachable in some structure, but not intentionally. Say you have a cache of items -- how big should it grow? Can it free space under memory pressure? If you reuse items, do they own collections (e.g., std::vec) that hold on to reserved but unused space (e.g. clear() doesn't free memory)? These are the hard problems and they are approximately the same with or without GC.