[spinlocked]

"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.

[marshray]

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

[shrughes]

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.

[spinlocked]

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

[marshray]

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

[spinlocked]

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