libstdc++-v3/include/ext/pb_ds/detail/branch_policy/branch_policy.hpp

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005, 2006, 2009, 2011 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 branch_policy/branch_policy.hpp
  38  * Contains a base class for branch policies.
  39  */
  40
  41 #ifndef PB_DS_BRANCH_POLICY_BASE_HPP
  42 #define PB_DS_BRANCH_POLICY_BASE_HPP
  43
  44 #include <ext/pb_ds/tag_and_trait.hpp>
  45
  46 namespace __gnu_pbds
  47 {
  48   /// A null node updator, indicating that no node updates are required.
  49   template<typename _Tp1, typename _Tp2, typename _Tp3, typename _Tp4>
  50     struct null_node_update : public null_type
  51     { };
  52
  53   namespace detail
  54   {
  55     /// Primary template, base class for branch structure policies.
  56     template<typename Node_CItr, typename Node_Itr, typename _Alloc>
  57       struct branch_policy
  58       {
  59       protected:
  60         typedef typename Node_Itr::value_type           it_type;
  61         typedef typename std::iterator_traits<it_type>::value_type value_type;
  62         typedef typename value_type::first_type         key_type;
  63
  64         typedef typename remove_const<value_type>::type rcvalue_type;
  65         typedef typename remove_const<key_type>::type   rckey_type;
  66
  67         typedef typename _Alloc::template rebind<rcvalue_type>::other rebind_v;
  68         typedef typename _Alloc::template rebind<rckey_type>::other   rebind_k;
  69
  70         typedef typename rebind_v::reference            reference;
  71         typedef typename rebind_v::const_reference      const_reference;
  72         typedef typename rebind_v::const_pointer        const_pointer;
  73
  74         typedef typename rebind_k::const_reference      key_const_reference;
  75
  76         static inline key_const_reference
  77         extract_key(const_reference r_val)
  78         { return r_val.first; }
  79
  80         virtual it_type
  81         end() = 0;
  82
  83         it_type
  84         end_iterator() const
  85         { return const_cast<branch_policy*>(this)->end(); }
  86
  87         virtual
  88         ~branch_policy() { }
  89       };
  90
  91     /// Specialization for const iterators.
  92     template<typename Node_CItr, typename _Alloc>
  93       struct branch_policy<Node_CItr, Node_CItr, _Alloc>
  94       {
  95       protected:
  96         typedef typename Node_CItr::value_type             it_type;
  97         typedef typename std::iterator_traits<it_type>::value_type value_type;
  98         typedef typename remove_const<value_type>::type            rcvalue_type;
  99         typedef typename _Alloc::template rebind<rcvalue_type>::other rebind_v;
 100         typedef typename rebind_v::reference            reference;
 101         typedef typename rebind_v::const_reference      const_reference;
 102         typedef typename rebind_v::const_pointer        const_pointer;
 103
 104         typedef value_type                              key_type;
 105         typedef typename rebind_v::const_reference      key_const_reference;
 106
 107         static inline key_const_reference
 108         extract_key(const_reference r_val)
 109         { return r_val; }
 110
 111         virtual it_type
 112         end() const = 0;
 113
 114         it_type
 115         end_iterator() const
 116         { return end(); }
 117
 118         virtual
 119         ~branch_policy() { }
 120       };
 121   } // namespace detail
 122 } // namespace __gnu_pbds
 123
 124 #endif // #ifndef PB_DS_BRANCH_POLICY_BASE_HPP