The storage model of List<T> and its boundary with T[] and [T; N] is not specified
Gap
The three-way split between T[], [T; N] and List<T> reflects the current design. The exact boundary between them, in particular how a growable list's storage is allocated and grown, is not specified and may change in a future release.
Impact
Programs must not depend on capacity, reallocation or aliasing behaviour beyond what the rules state; a later design may move the boundary.
Affects
Resolution
No RFC or issue tracks it yet.