Bear in mind that this is an intentionally simple and plain string class,
devoid of many features which might be found in a more complete
implementation. 

The reason I say 'intentionally' is purely because it was written for a
specific set of uses than to be the be-all and everything-including-your-
kitchen-sink-string-class.  In particular, the aims I had in mind were:

  1.  Portable,

  2.  Small but efficient - where sizeof(str) == sizeof(char *) in
      almost all C++ implementations,

  3.  Doesn't rely upon, but allows for, NUL terminators, so avoids
      lots of redundant length calculations as is common in C. The
      library attempts to use memory operations rather than C string
      operations where possible,

  4.  As much as possible is implemented in-line for speed. All common
      operations are centralised into a 'core' set of private functions.

  5.  Copy constructors and assignment are cheap operations by use of
      reference counting. This makes passing objects by value very cheap
      (requires no as few as possible memory allocations / copying of
      string data), and is conservative with memory.

  6.  Should be easily exchanged with char*.

  7.  Memory management of strings made possible by use of a single
      memory allocation function for string data (easily replaced or
      enhanced)

  8.  Uses absolutely no third party classes, so is stand-alone, making
      it highly reusable,

  9.  Requires no additional include files from the standard library.

  10. Avoids use of cast operators for char const * and therefore 
      prevents problems caused by creation of temporaries (these can
      also occur with member c_str(), but at least you have to explicitly
      invoke it rather than causing a temporary to be used in a dangerous
      manner without notification).


  cheers,
  David Nugent
  Moderator ('93-'94) of the FidoNet C++ international EchoMail conference