------------------------------------------------------------------------------
--                                                                          --
--                         GNAT RUNTIME COMPONENTS                          --
--                                                                          --
--                      S Y S T E M . W I D _ E N U M                       --
--                                                                          --
--                                 S p e c                                  --
--                                                                          --
--                            $Revision: 1.6 $
--                                                                          --
--          Copyright (C) 1992-2000 Free Software Foundation, Inc.          --
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-- GNAT is free software;  you can  redistribute it  and/or modify it under --
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-- covered by the  GNU Public License.                                      --
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-- GNAT was originally developed  by the GNAT team at  New York University. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
--                                                                          --
------------------------------------------------------------------------------

--  This package contains the routine used for Enumeration_Type'Width

package System.Wid_Enum is
pragma Pure (Wid_Enum);

   function Width_Enumeration_8
     (Names   : String;
      Indexes : System.Address;
      Lo, Hi  : Natural)
      return    Natural;
   --  Used to compute Enum'Width where Enum is some enumeration subtype
   --  other than those defined in package Standard. Names is a string with
   --  a lower bound of 1 containing the characters of all the enumeration
   --  literals concatenated together in sequence. Indexes is the address
   --  of an array of type array (0 .. N) of Natural_8, where N is the
   --  number of enumeration literals in the type. The Indexes values are
   --  the starting subscript of each enumeration literal, indexed by Pos
   --  values, with an extra entry at the end containing Names'Length + 1.
   --  The reason that Indexes is passed by address is that the actual type
   --  is created on the fly by the expander.
   --
   --  Lo and Hi are the Pos values of the lower and upper bounds of the
   --  subtype. The result is the value of Width, i.e. the maximum value
   --  of the length of any enumeration literal in the given range.

   function Width_Enumeration_16
     (Names   : String;
      Indexes : System.Address;
      Lo, Hi  : Natural)
      return    Natural;
   --  Identical to Width_Enumeration_8 except that it handles types
   --  using array (0 .. Num) of Natural_16 for the Indexes table.

   function Width_Enumeration_32
     (Names   : String;
      Indexes : System.Address;
      Lo, Hi  : Natural)
      return    Natural;
   --  Identical to Width_Enumeration_8 except that it handles types
   --  using array (0 .. Num) of Natural_32 for the Indexes table.

end System.Wid_Enum;
