libstdc++
synth_access_traits.hpp
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25 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
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35 
36 /**
37  * @file pat_trie_/synth_access_traits.hpp
38  * Contains an implementation class for a patricia tree.
39  */
40 
41 #ifndef PB_DS_SYNTH_E_ACCESS_TRAITS_HPP
42 #define PB_DS_SYNTH_E_ACCESS_TRAITS_HPP
43 
45 
46 namespace __gnu_pbds
47 {
48  namespace detail
49  {
50 
51 #define PB_DS_SYNTH_E_ACCESS_TRAITS_T_DEC \
52  template<typename Type_Traits, bool Set, typename _ATraits>
53 
54 #define PB_DS_SYNTH_E_ACCESS_TRAITS_C_DEC \
55  synth_access_traits<Type_Traits, Set, _ATraits>
56 
57  /// Synthetic element access traits.
58  template<typename Type_Traits, bool Set, typename _ATraits>
59  struct synth_access_traits : public _ATraits
60  {
61  typedef _ATraits base_type;
62  typedef typename base_type::const_iterator const_iterator;
63  typedef Type_Traits type_traits;
64  typedef typename type_traits::const_reference const_reference;
65  typedef typename type_traits::key_const_reference key_const_reference;
66 
68 
69  synth_access_traits(const base_type&);
70 
71  inline bool
72  equal_prefixes(const_iterator, const_iterator, const_iterator,
73  const_iterator, bool compare_after = true) const;
74 
75  bool
76  equal_keys(key_const_reference, key_const_reference) const;
77 
78  bool
79  cmp_prefixes(const_iterator, const_iterator, const_iterator,
80  const_iterator, bool compare_after = false) const;
81 
82  bool
83  cmp_keys(key_const_reference, key_const_reference) const;
84 
85  inline static key_const_reference
86  extract_key(const_reference);
87 
88 #ifdef _GLIBCXX_DEBUG
89  bool
90  operator()(key_const_reference, key_const_reference);
91 #endif
92 
93  private:
94  inline static key_const_reference
95  extract_key(const_reference, true_type);
96 
97  inline static key_const_reference
98  extract_key(const_reference, false_type);
99 
100  static integral_constant<int, Set> s_set_ind;
101  };
102 
103  PB_DS_SYNTH_E_ACCESS_TRAITS_T_DEC
104  integral_constant<int,Set>
105  PB_DS_SYNTH_E_ACCESS_TRAITS_C_DEC::s_set_ind;
106 
107  PB_DS_SYNTH_E_ACCESS_TRAITS_T_DEC
108  PB_DS_SYNTH_E_ACCESS_TRAITS_C_DEC::
109  synth_access_traits()
110  { }
111 
112  PB_DS_SYNTH_E_ACCESS_TRAITS_T_DEC
113  PB_DS_SYNTH_E_ACCESS_TRAITS_C_DEC::
114  synth_access_traits(const _ATraits& r_traits)
115  : _ATraits(r_traits)
116  { }
117 
118  PB_DS_SYNTH_E_ACCESS_TRAITS_T_DEC
119  inline bool
120  PB_DS_SYNTH_E_ACCESS_TRAITS_C_DEC::
121  equal_prefixes(const_iterator b_l, const_iterator e_l, const_iterator b_r,
122  const_iterator e_r, bool compare_after /*= false */) const
123  {
124  while (b_l != e_l)
125  {
126  if (b_r == e_r)
127  return false;
128  if (base_type::e_pos(*b_l) != base_type::e_pos(*b_r))
129  return false;
130  ++b_l;
131  ++b_r;
132  }
133  return (!compare_after || b_r == e_r);
134  }
135 
136  PB_DS_SYNTH_E_ACCESS_TRAITS_T_DEC
137  bool
138  PB_DS_SYNTH_E_ACCESS_TRAITS_C_DEC::
139  equal_keys(key_const_reference r_lhs_key,
140  key_const_reference r_rhs_key) const
141  {
142  return equal_prefixes(base_type::begin(r_lhs_key),
143  base_type::end(r_lhs_key),
144  base_type::begin(r_rhs_key),
145  base_type::end(r_rhs_key),
146  true);
147  }
148 
149  PB_DS_SYNTH_E_ACCESS_TRAITS_T_DEC
150  bool
151  PB_DS_SYNTH_E_ACCESS_TRAITS_C_DEC::
152  cmp_prefixes(const_iterator b_l, const_iterator e_l, const_iterator b_r,
153  const_iterator e_r, bool compare_after /* = false*/) const
154  {
155  while (b_l != e_l)
156  {
157  if (b_r == e_r)
158  return false;
159 
160  const typename base_type::size_type l_pos = base_type::e_pos(*b_l);
161  const typename base_type::size_type r_pos = base_type::e_pos(*b_r);
162  if (l_pos != r_pos)
163  return l_pos < r_pos;
164  ++b_l;
165  ++b_r;
166  }
167 
168  if (!compare_after)
169  return false;
170  return b_r != e_r;
171  }
172 
173  PB_DS_SYNTH_E_ACCESS_TRAITS_T_DEC
174  bool
175  PB_DS_SYNTH_E_ACCESS_TRAITS_C_DEC::
176  cmp_keys(key_const_reference r_lhs_key,
177  key_const_reference r_rhs_key) const
178  {
179  return cmp_prefixes(base_type::begin(r_lhs_key),
180  base_type::end(r_lhs_key),
181  base_type::begin(r_rhs_key),
182  base_type::end(r_rhs_key),
183  true);
184  }
185 
186  PB_DS_SYNTH_E_ACCESS_TRAITS_T_DEC
187  inline typename PB_DS_SYNTH_E_ACCESS_TRAITS_C_DEC::key_const_reference
188  PB_DS_SYNTH_E_ACCESS_TRAITS_C_DEC::
189  extract_key(const_reference r_val)
190  { return extract_key(r_val, s_set_ind); }
191 
192  PB_DS_SYNTH_E_ACCESS_TRAITS_T_DEC
193  inline typename PB_DS_SYNTH_E_ACCESS_TRAITS_C_DEC::key_const_reference
194  PB_DS_SYNTH_E_ACCESS_TRAITS_C_DEC::
195  extract_key(const_reference r_val, true_type)
196  { return r_val; }
197 
198  PB_DS_SYNTH_E_ACCESS_TRAITS_T_DEC
199  inline typename PB_DS_SYNTH_E_ACCESS_TRAITS_C_DEC::key_const_reference
200  PB_DS_SYNTH_E_ACCESS_TRAITS_C_DEC::
201  extract_key(const_reference r_val, false_type)
202  { return r_val.first; }
203 
204 #ifdef _GLIBCXX_DEBUG
205  PB_DS_SYNTH_E_ACCESS_TRAITS_T_DEC
206  bool
207  PB_DS_SYNTH_E_ACCESS_TRAITS_C_DEC::
208  operator()(key_const_reference r_lhs, key_const_reference r_rhs)
209  { return cmp_keys(r_lhs, r_rhs); }
210 #endif
211 
212 #undef PB_DS_SYNTH_E_ACCESS_TRAITS_T_DEC
213 #undef PB_DS_SYNTH_E_ACCESS_TRAITS_C_DEC
214 
215  } // namespace detail
216 } // namespace __gnu_pbds
217 
218 #endif
integral_constant< bool, true > true_type
The type used as a compile-time boolean with true value.
Definition: type_traits:75
integral_constant< bool, false > false_type
The type used as a compile-time boolean with false value.
Definition: type_traits:78
_Tp * end(valarray< _Tp > &__va) noexcept
Return an iterator pointing to one past the last element of the valarray.
Definition: valarray:1234
_Tp * begin(valarray< _Tp > &__va) noexcept
Return an iterator pointing to the first element of the valarray.
Definition: valarray:1214
GNU extensions for policy-based data structures for public use.
Synthetic element access traits.