libstdc++: types_traits.hpp Source File

libstdc++

types_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 detail/types_traits.hpp
38 * Contains a traits class of types used by containers.
39 */
40
41#ifndef PB_DS_TYPES_TRAITS_HPP
42#define PB_DS_TYPES_TRAITS_HPP
43
44#include <algorithm>
45#include <utility>
46#include <ext/pb_ds/tag_and_trait.hpp>
47#include <ext/pb_ds/detail/type_utils.hpp>
48#include <memory>
49
50namespace __gnu_pbds
51{
52 namespace detail
53 {
54 /**
55 * @addtogroup traits Traits
56 * @{
57 */
58
59 /// Primary template.
60 template<typename Key, typename Mapped>
61 struct no_throw_copies
62 {
63 static const bool __simple = is_simple<Key>::value
64 && is_simple<Mapped>::value;
65 typedef integral_constant<int, __simple> indicator;
66 };
67
68 /// Specialization.
69 template<typename Key>
70 struct no_throw_copies<Key, null_type>
71 {
72 typedef integral_constant<int, is_simple<Key>::value> indicator;
73 };
74
75
76 /// Stored value.
77 template<typename _Tv>
78 struct stored_value
79 {
80 typedef _Tv value_type;
81 value_type m_value;
82 };
83
84 /// Stored hash.
85 template<typename _Th>
86 struct stored_hash
87 {
88 typedef _Th hash_type;
89 hash_type m_hash;
90 };
91
92 /// Primary template for representation of stored data.
93 /// Two types of data can be stored: value and hash.
94 template<typename _Tv, typename _Th, bool Store_Hash>
95 struct stored_data
96 : public stored_value<_Tv>, public stored_hash<_Th>
97 { };
98
99 /// Specialization for representation of stored data of just value type.
100 template<typename _Tv, typename _Th>
101 struct stored_data<_Tv, _Th, false>
102 : public stored_value<_Tv>
103 { };
104
105 /// Choose value_type to be a key/value pair or just a key.
106 template<typename Key, typename Mapped>
107 struct select_value_type
108 {
109 typedef std::pair<const Key, Mapped> type;
110 };
111
112 /// Specialization for sets where the key is the value_type.
113 template<typename Key>
114 struct select_value_type<Key, null_type>
115 {
116 typedef Key type;
117 };
118
119 /// Base class for conditionally defining a static data member.
120 template<typename Key, typename Mapped, typename _Alloc, bool Store_Hash>
121 struct maybe_null_type
122 { };
123
124 /// Specialization that defines a static data member of type null_type.
125 template<typename Key,typename _Alloc, bool Store_Hash>
126 struct maybe_null_type<Key, null_type, _Alloc, Store_Hash>
127 {
128 static null_type s_null_type;
129 };
130
131 template<typename Key,typename _Alloc, bool Store_Hash>
132 null_type
133 maybe_null_type<Key, null_type, _Alloc, Store_Hash>::s_null_type;
134
135 /// Consistent API for accessing allocator-related types.
136 template<typename _Alloc, typename T>
137 struct rebind_traits
138#if __cplusplus >= 201103L
139 : std::allocator_traits<_Alloc>::template rebind_traits<T>
140 {
141 using reference = T&;
142 using const_reference = const T&;
143 };
144#else
145 : _Alloc::template rebind<T>::other
146 {
147 typedef typename _Alloc::template rebind<T>::other allocator_type;
148 };
149#endif
150
151
152 /// Traits for abstract types.
153 template<typename Key, typename Mapped, typename _Alloc, bool Store_Hash>
154 struct types_traits
155 : public maybe_null_type<Key, Mapped, _Alloc, Store_Hash>
156 {
157 public:
158 typedef typename _Alloc::size_type size_type;
159 typedef typename select_value_type<Key, Mapped>::type value_type;
160 typedef Key key_type;
161 typedef Mapped mapped_type;
162
163 private:
164 typedef rebind_traits<_Alloc, value_type> __rebind_va;
165 typedef rebind_traits<_Alloc, key_type> __rebind_ka;
166 typedef rebind_traits<_Alloc, mapped_type> __rebind_ma;
167
168 typedef no_throw_copies<Key, Mapped> __nothrowcopy;
169
170 public:
171 typedef typename __rebind_ma::pointer mapped_pointer;
172 typedef typename __rebind_ma::const_pointer mapped_const_pointer;
173 typedef typename __rebind_ma::reference mapped_reference;
174 typedef typename __rebind_ma::const_reference mapped_const_reference;
175
176 typedef typename __rebind_va::pointer pointer;
177 typedef typename __rebind_va::const_pointer const_pointer;
178 typedef typename __rebind_va::reference reference;
179 typedef typename __rebind_va::const_reference const_reference;
180
181 typedef stored_data<value_type, size_type, Store_Hash> stored_data_type;
182
183 typedef typename __rebind_ka::pointer key_pointer;
184 typedef typename __rebind_ka::const_pointer key_const_pointer;
185 typedef typename __rebind_ka::reference key_reference;
186 typedef typename __rebind_ka::const_reference key_const_reference;
187 typedef std::pair<size_type, size_type> comp_hash;
188 typedef integral_constant<int, Store_Hash> store_extra;
189 typedef typename __nothrowcopy::indicator no_throw_indicator;
190
191 store_extra m_store_extra_indicator;
192 no_throw_indicator m_no_throw_copies_indicator;
193 };
194 ///@}
195 } // namespace detail
196} // namespace __gnu_pbds
197
198#endif
algorithm
memory
utility
tag_and_trait.hpp
type_utils.hpp
__gnu_pbds
GNU extensions for policy-based data structures for public use.
Definition assoc_container.hpp:52
std::allocator_traits
Uniform interface to all allocator types.
Definition bits/alloc_traits.h:250
std::pair
Struct holding two objects (or references) of arbitrary type.
Definition stl_pair.h:307
__gnu_pbds::null_type
Represents no type, or absence of type, for template tricks.
Definition tag_and_trait.hpp:210
__gnu_pbds::detail::no_throw_copies
Primary template.
Definition types_traits.hpp:62
__gnu_pbds::detail::stored_value
Stored value.
Definition types_traits.hpp:79
__gnu_pbds::detail::stored_hash
Stored hash.
Definition types_traits.hpp:87
__gnu_pbds::detail::stored_data
Primary template for representation of stored data. Two types of data can be stored: value and hash.
Definition types_traits.hpp:97
__gnu_pbds::detail::select_value_type
Choose value_type to be a key/value pair or just a key.
Definition types_traits.hpp:108
__gnu_pbds::detail::maybe_null_type
Base class for conditionally defining a static data member.
Definition types_traits.hpp:122
__gnu_pbds::detail::rebind_traits
Consistent API for accessing allocator-related types.
Definition types_traits.hpp:140
__gnu_pbds::detail::types_traits
Traits for abstract types.
Definition types_traits.hpp:156