"insertions to the end of a variable-length array are very fast"

really tptacek? its O(1) ammortized over time, and when N grows it becomes really slow because it involves reallocation and a linear copy of all elements.

You have a magic allocator for your list nodes that does better than O(1) amortized?

Being better than O(n) worst case is the target here, not O(1) amortized. For example, O(1) amortized and O(log n) worst case is a thing.

Do you need magic to create an O(1) allocator for a pool of fixed size objects?

Yes, when (as in the general case of std::list) the number of objects is not known in advance.

true. however, libstdc++ implements __pool_alloc for a reason.

Someone wants to know about linked lists, and your comment is to use some other data structure that has a different purpose?

Different purpose?

Linked lists are good for adding and removing elements. Variable length arrays are good for allocating a known amount of space at runtime.

The "variable" in "variable length" describes the fact that you don't know how much space you need, and insertions to the end of a variable-length array are very fast. I can see why you thought my comment was weird, now.