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File : s-sopco4.adb


------------------------------------------------------------------------------
--                                                                          --
--                         GNAT RUN-TIME COMPONENTS                         --
--                                                                          --
--           S Y S T E M . S T R I N G _ O P S _ C O N C A T _ 4            --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--                            $Revision: 1.1 $                              --
--                                                                          --
--          Copyright (C) 1992-1998, Free Software Foundation, Inc.         --
--                                                                          --
-- GNAT is free software;  you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 2,  or (at your option) any later ver- --
-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
-- for  more details.  You should have  received  a copy of the GNU General --
-- Public License  distributed with GNAT;  see file COPYING.  If not, write --
-- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
-- MA 02111-1307, USA.                                                      --
--                                                                          --
-- As a special exception,  if other files  instantiate  generics from this --
-- unit, or you link  this unit with other files  to produce an executable, --
-- this  unit  does not  by itself cause  the resulting  executable  to  be --
-- covered  by the  GNU  General  Public  License.  This exception does not --
-- however invalidate  any other reasons why  the executable file  might be --
-- covered by the  GNU Public License.                                      --
--                                                                          --
-- 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). --
--                                                                          --
------------------------------------------------------------------------------

package body System.String_Ops_Concat_4 is

   ------------------
   -- Str_Concat_4 --
   ------------------

   function Str_Concat_4 (S1, S2, S3, S4 : String) return String is
   begin
      if S1'Length <= 0 then
         return S2 & S3 & S4;

      else
         declare
            L12 : constant Natural := S1'Length + S2'Length;
            L13 : constant Natural := L12 + S3'Length;
            L14 : constant Natural := L13 + S4'Length;
            R : String (S1'First .. S1'First + L14 - 1);

         begin
            R (S1'First       .. S1'Last)            := S1;
            R (S1'Last + 1    .. S1'First + L12 - 1) := S2;
            R (S1'First + L12 .. S1'First + L13 - 1) := S3;
            R (S1'First + L13 .. R'Last)             := S4;
            return R;
         end;
      end if;
   end Str_Concat_4;

end System.String_Ops_Concat_4;