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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;
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