I've just uploaded this release to

  http://www.pogner.demon.co.uk/components/bc/

Changes:

  Added the ability to delete the item an Iterator is currently
  indicating (Delete_Item_At (It : Iterator)). Note, this feature
  doesn't yet work for Bags, Maps, Rings or Sets.

  The C++ code offers two variants of accessors such as Queues.Front,
  one of which returns a value while the other returns a
  reference. The second case is now supported by generics such as eg
  Queues.Process_Front.

  The Copy operation of Collections, Queues, Rings and Stacks checks
  for self-assignment before proceeding.

  Synchronized Unbounded Rings now support blocking (balking); eg, an
  attempt to Pop will block until the Ring has something in it to
  pop. For related reasons, the Pop_Value operation is provided.

  AVL Trees had an error (inherited from the C++) which would
  sometimes corrupt the Tree on deletion.

  Containers have new versions of the Visit and Modify generics that
  include a parameter as an argument to Visit and Modify that is
  passed to the Apply routine. Thanks to Steve Doiel.

  Added pragma Elaborate_Body throughout.

  Continued the renaming of Container parameters from Obj to something
  slightly more mnemonic.

Best wishes for 2000!