private void RemoveLast()
{
Debug.Assert(!IsEmpty);
_count--;
_head[--_headCount] = default(T);
// To maintain invariants, we need to make sure the head block isn't empty unless
// the entire block list is empty.
if (_headCount == 0)
{
if (_tail.IsEmpty)
{
// The entire block list is empty, so revert to the initial state.
Reset();
}
else
{
// Throw away the current head block and pretend we've just finished filling the last block.
_capacity -= HeadCapacity;
_head = _tail.RemoveLast();
_headCount = _head.Length;
}
Debug.Assert(IsFull);
}
}