contrib/gcc-8.0/libstdc++-v3/include/ext/pb_ds/detail/hash_fn/sample_range_hashing.hpp

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005-2018 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 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
  26
  27 // Permission to use, copy, modify, sell, and distribute this software
  28 // is hereby granted without fee, provided that the above copyright
  29 // notice appears in all copies, and that both that copyright notice
  30 // and this permission notice appear in supporting documentation. None
  31 // of the above authors, nor IBM Haifa Research Laboratories, make any
  32 // representation about the suitability of this software for any
  33 // purpose. It is provided "as is" without express or implied
  34 // warranty.
  35
  36 /**
  37  * @file sample_range_hashing.hpp
  38  * Contains a range hashing policy.
  39  */
  40
  41 #ifndef PB_DS_SAMPLE_RANGE_HASHING_HPP
  42 #define PB_DS_SAMPLE_RANGE_HASHING_HPP
  43
  44 namespace __gnu_pbds
  45 {
  46   /// A sample range-hashing functor.
  47   class sample_range_hashing
  48   {
  49   public:
  50     /// Size type.
  51     typedef std::size_t size_type;
  52
  53     /// Default constructor.
  54     sample_range_hashing();
  55
  56     /// Copy constructor.
  57     sample_range_hashing(const sample_range_hashing& other);
  58
  59     /// Swaps content.
  60     inline void
  61     swap(sample_range_hashing& other);
  62
  63   protected:
  64     /// Notifies the policy object that the container's size has
  65     /// changed to argument's size.
  66     void
  67     notify_resized(size_type);
  68
  69     /// Transforms the __hash value hash into a ranged-hash value.
  70     inline size_type
  71     operator()(size_type ) const;
  72   };
  73 }
  74 #endif // #ifndef PB_DS_SAMPLE_RANGE_HASHING_HPP