At method

P At(String key, [ int count = 1 ])

Returns the P stored in key, allocating (or reallocating) if necessary.

If the slot already exists and its current capacity is >= count, the existing pointer is reused. If capacity is insufficient the old block is freed and a new one of size count is allocated.

key – slot identifier (must not be null). count – minimum element capacity required (default: 1).

Implementation

P At(String key, [int count = 1]) {
  final existing = slots[key];
  if (existing != null) {
    final (ptr, currentCount) = existing;

    if (count <= currentCount) {
      slots[key] = (ptr, count);
      return ptr;
    }

    freeFunc(pointerToSource(ptr));
  }

  final ptr = pointerFactory(allocatorFunc(count));
  slots[key] = (ptr, count);
  return ptr;
}