Novice question about D: From my brief reading, it looks like appending to a slice in D avoids the "invalidate all references into the old allocation" problem in a similar way to how Go does it, by having the GC keep the old allocations alive as long as there are references into them. Is that right? How does that interact with optional garbage collection? Is there anything like C++'s std::vector or Rust's Vec that D programmers reach for when the GC is off?