// Helper: ImPool<>. Basic keyed storage for contiguous instances, slow/amortized insertion, O(1) indexable, O(Log N) queries by ID over a dense/hot buffer,
// Helper: ImPool<>. Basic keyed storage for contiguous instances, slow/amortized insertion, O(1) indexable, O(Log N) queries by ID over a dense/hot buffer,
// Honor constructor/destructor. Add/remove invalidate all pointers. Indexes have the same lifetime as the associated object.
// Honor constructor/destructor. Add/remove invalidate all pointers. Indexes have the same lifetime as the associated object.