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------------------------------------------------------------------------------

--                                                                          --

--                         GNAT LIBRARY COMPONENTS                          --

--                                                                          --

--         A D A . C O N T A I N E R S . P R I M E _ N U M B E R S          --

--                                                                          --

--                                 B o d y                                  --

--                                                                          --

--          Copyright (C) 2004-2009, 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 3,  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.                                     --

--                                                                          --

-- As a special exception under Section 7 of GPL version 3, you are granted --

-- additional permissions described in the GCC Runtime Library Exception,   --

-- version 3.1, as published by the Free Software Foundation.               --

--                                                                          --

-- You should have received a copy of the GNU General Public License and    --

-- a copy of the GCC Runtime Library Exception along with this program;     --

-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --

-- <http://www.gnu.org/licenses/>.                                          --

--                                                                          --

-- This unit was originally developed by Matthew J Heaney.                  --

------------------------------------------------------------------------------

package body Ada.Containers.Prime_Numbers is

   --------------

   -- To_Prime --

   --------------

   function To_Prime (Length : Count_Type) return Hash_Type is

      I, J, K : Integer'Base;

      Index   : Integer'Base;

   begin

      I := Primes'Last - Primes'First;

      Index := Primes'First;

      while I > 0 loop

         J := I / 2;

         K := Index + J;

         if Primes (K) < Hash_Type (Length) then

            Index := K + 1;

            I := I - J - 1;

         else

            I := J;

         end if;

      end loop;

      return Primes (Index);

   end To_Prime;

end Ada.Containers.Prime_Numbers;