libstdc++-v3/testsuite/util/hash_fn/dna_str_limit.hpp

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005-2020 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the terms
   7 // of the GNU General Public License as published by the Free Software
   8 // Foundation; either version 3, or (at your option) any later
   9 // version.
  10
  11 // This library is distributed in the hope that it will be useful, but
  12 // WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 // General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License
  17 // along with this library; see the file COPYING3.  If not see
  18 // <http://www.gnu.org/licenses/>.
  19
  20
  21 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
  22
  23 // Permission to use, copy, modify, sell, and distribute this software
  24 // is hereby granted without fee, provided that the above copyright
  25 // notice appears in all copies, and that both that copyright notice
  26 // and this permission notice appear in supporting documentation. None
  27 // of the above authors, nor IBM Haifa Research Laboratories, make any
  28 // representation about the suitability of this software for any
  29 // purpose. It is provided "as is" without express or implied
  30 // warranty.
  31
  32 /**
  33  * @file dna_str_limit.hpp
  34  * Contains a function for finding the numer of characters
  35  *    to access in a DNA string.
  36  */
  37
  38 #ifndef PB_DS_DNA_STR_LIMIT_HPP
  39 #define PB_DS_DNA_STR_LIMIT_HPP
  40
  41 #include <string>
  42
  43 namespace __gnu_pbds
  44 {
  45   namespace test
  46   {
  47     size_t
  48     dna_str_limit(size_t size)
  49     {
  50       size_t ret = 1;
  51       size_t calc_size = 4;
  52       while (calc_size < size)
  53         {
  54           ++ret;
  55           calc_size = calc_size << 2;
  56         }
  57       return ret;
  58     }
  59   } // namespace test
  60 } // namespace __gnu_pbds
  61
  62 #endif // #ifndef PB_DS_DNA_STR_LIMIT_HPP