_        _   
     / \   ___| |_ 
    / _ \ / __| __|
   / ___ \ (__| |_ 
  /_/   \_\___|\__|
                 
  Act -- Abstract Container Types

  A lower level data structure library for abstract container types.
  Copyright (c) 1999-2001 Ralf S. Engelschall, All Rights Reserved. 

           "`Reuse an expert's code' is the right advice for most people. 
            But it's a useless advice for the experts writing the code 
            in the first place.               -- Dan J. Bernstein

  Design Goals:
  o allows low-level adjustments of data structures
  o uses a general contexts concept (shared memory support, user attachments)
  o is thread-safe + reentrant ?
  o allows the use of arbitrary user key/values
  o allows key/values to be loans or gifts