1 /////////////////////////////////////////////////////////////////////////////
2 //
3 // (C) Copyright Ion Gaztanaga  2007-2014
4 //
5 // Distributed under the Boost Software License, Version 1.0.
6 //    (See accompanying file LICENSE_1_0.txt or copy at
7 //          http://www.boost.org/LICENSE_1_0.txt)
8 //
9 // See http://www.boost.org/libs/intrusive for documentation.
10 //
11 /////////////////////////////////////////////////////////////////////////////
12 
13 #ifndef BOOST_INTRUSIVE_OPTIONS_HPP
14 #define BOOST_INTRUSIVE_OPTIONS_HPP
15 
16 #include <boost/intrusive/detail/config_begin.hpp>
17 #include <boost/intrusive/intrusive_fwd.hpp>
18 #include <boost/intrusive/link_mode.hpp>
19 #include <boost/intrusive/pack_options.hpp>
20 #include <boost/intrusive/detail/mpl.hpp>
21 
22 #if defined(BOOST_HAS_PRAGMA_ONCE)
23 #  pragma once
24 #endif
25 
26 namespace boost {
27 namespace intrusive {
28 
29 #ifndef BOOST_INTRUSIVE_DOXYGEN_INVOKED
30 
31 struct empty
32 {};
33 
34 template<class Functor>
35 struct fhtraits;
36 
37 template<class T, class Hook, Hook T::* P>
38 struct mhtraits;
39 
40 struct dft_tag;
41 struct member_tag;
42 
43 template<class SupposedValueTraits>
44 struct is_default_hook_tag;
45 
46 #endif   //#ifndef BOOST_INTRUSIVE_DOXYGEN_INVOKED
47 
48 //!This option setter specifies if the intrusive
49 //!container stores its size as a member to
50 //!obtain constant-time size() member.
51 BOOST_INTRUSIVE_OPTION_CONSTANT(constant_time_size, bool, Enabled, constant_time_size)
52 
53 //!This option setter specifies a container header holder type
54 BOOST_INTRUSIVE_OPTION_TYPE(header_holder_type, HeaderHolder, HeaderHolder, header_holder_type)
55 
56 //!This option setter specifies the type that
57 //!the container will use to store its size.
58 BOOST_INTRUSIVE_OPTION_TYPE(size_type, SizeType, SizeType, size_type)
59 
60 //!This option setter specifies the strict weak ordering
61 //!comparison functor for the value type
62 BOOST_INTRUSIVE_OPTION_TYPE(compare, Compare, Compare, compare)
63 
64 //!This option setter specifies the a function object
65 //!that specifies the type of the key of an associative
66 //!container and an operator to obtain it from a value type.
67 //!
68 //!This function object must the define a `key_type` and
69 //!a member with signature `const key_type & operator()(const value_type &) const`
70 //!that will return the key from a value_type of an associative container
71 BOOST_INTRUSIVE_OPTION_TYPE(key_of_value, KeyOfValue, KeyOfValue, key_of_value)
72 
73 //!This option setter for scapegoat containers specifies if
74 //!the intrusive scapegoat container should use a non-variable
75 //!alpha value that does not need floating-point operations.
76 //!
77 //!If activated, the fixed alpha value is 1/sqrt(2). This
78 //!option also saves some space in the container since
79 //!the alpha value and some additional data does not need
80 //!to be stored in the container.
81 //!
82 //!If the user only needs an alpha value near 1/sqrt(2), this
83 //!option also improves performance since avoids logarithm
84 //!and division operations when rebalancing the tree.
85 BOOST_INTRUSIVE_OPTION_CONSTANT(floating_point, bool, Enabled, floating_point)
86 
87 //!This option setter specifies the equality
88 //!functor for the value type
89 BOOST_INTRUSIVE_OPTION_TYPE(equal, Equal, Equal, equal)
90 
91 //!This option setter specifies the equality
92 //!functor for the value type
93 BOOST_INTRUSIVE_OPTION_TYPE(priority, Priority, Priority, priority)
94 
95 //!This option setter specifies the hash
96 //!functor for the value type
97 BOOST_INTRUSIVE_OPTION_TYPE(hash, Hash, Hash, hash)
98 
99 //!This option setter specifies the relationship between the type
100 //!to be managed by the container (the value type) and the node to be
101 //!used in the node algorithms. It also specifies the linking policy.
102 BOOST_INTRUSIVE_OPTION_TYPE(value_traits, ValueTraits, ValueTraits, proto_value_traits)
103 
104 //#define BOOST_INTRUSIVE_COMMA ,
105 //#define BOOST_INTRUSIVE_LESS <
106 //#define BOOST_INTRUSIVE_MORE >
107 //BOOST_INTRUSIVE_OPTION_TYPE (member_hook, Parent BOOST_INTRUSIVE_COMMA class MemberHook BOOST_INTRUSIVE_COMMA MemberHook Parent::* PtrToMember , mhtraits BOOST_INTRUSIVE_LESS Parent BOOST_INTRUSIVE_COMMA MemberHook BOOST_INTRUSIVE_COMMA PtrToMember BOOST_INTRUSIVE_MORE , proto_value_traits)
108 //template< class Parent , class MemberHook , MemberHook Parent::* PtrToMember>
109 //struct member_hook {
110 //   template<class Base> struct pack : Base {
111 //      typedef mhtraits < Parent , MemberHook , PtrToMember > proto_value_traits;
112 //   };
113 //};
114 //
115 //#undef BOOST_INTRUSIVE_COMMA
116 //#undef BOOST_INTRUSIVE_LESS
117 //#undef BOOST_INTRUSIVE_MORE
118 
119 //!This option setter specifies the member hook the
120 //!container must use.
121 template< typename Parent
122         , typename MemberHook
123         , MemberHook Parent::* PtrToMember>
124 struct member_hook
125 {
126 // @cond
127 //   typedef typename MemberHook::hooktags::node_traits node_traits;
128 //   typedef typename node_traits::node node_type;
129 //   typedef node_type Parent::* Ptr2MemNode;
130 //   typedef mhtraits
131 //      < Parent
132 //      , node_traits
133 //      //This cast is really ugly but necessary to reduce template bloat.
134 //      //Since we control the layout between the hook and the node, and there is
135 //      //always single inheritance, the offset of the node is exactly the offset of
136 //      //the hook. Since the node type is shared between all member hooks, this saves
137 //      //quite a lot of symbol stuff.
138 //      , (Ptr2MemNode)PtrToMember
139 //      , MemberHook::hooktags::link_mode> member_value_traits;
140    typedef mhtraits <Parent, MemberHook, PtrToMember> member_value_traits;
141    template<class Base>
142    struct pack : Base
143    {
144       typedef member_value_traits proto_value_traits;
145    };
146 /// @endcond
147 };
148 
149 //!This option setter specifies the function object that will
150 //!be used to convert between values to be inserted in a container
151 //!and the hook to be used for that purpose.
152 BOOST_INTRUSIVE_OPTION_TYPE(function_hook, Functor, fhtraits<Functor>, proto_value_traits)
153 
154 //!This option setter specifies that the container
155 //!must use the specified base hook
156 BOOST_INTRUSIVE_OPTION_TYPE(base_hook, BaseHook, BaseHook, proto_value_traits)
157 
158 //!This option setter specifies the type of
159 //!a void pointer. This will instruct the hook
160 //!to use this type of pointer instead of the
161 //!default one
162 BOOST_INTRUSIVE_OPTION_TYPE(void_pointer, VoidPointer, VoidPointer, void_pointer)
163 
164 //!This option setter specifies the type of
165 //!the tag of a base hook. A type cannot have two
166 //!base hooks of the same type, so a tag can be used
167 //!to differentiate two base hooks with otherwise same type
168 BOOST_INTRUSIVE_OPTION_TYPE(tag, Tag, Tag, tag)
169 
170 //!This option setter specifies the link mode
171 //!(normal_link, safe_link or auto_unlink)
172 BOOST_INTRUSIVE_OPTION_CONSTANT(link_mode, link_mode_type, LinkType, link_mode)
173 
174 //!This option setter specifies if the hook
175 //!should be optimized for size instead of for speed.
176 BOOST_INTRUSIVE_OPTION_CONSTANT(optimize_size, bool, Enabled, optimize_size)
177 
178 //!This option setter specifies if the slist container should
179 //!use a linear implementation instead of a circular one.
180 BOOST_INTRUSIVE_OPTION_CONSTANT(linear, bool, Enabled, linear)
181 
182 //!If true, slist also stores a pointer to the last element of the singly linked list.
183 //!This allows O(1) swap and splice_after(iterator, slist &) for circular slists and makes
184 //!possible new functions like push_back(reference) and back().
185 BOOST_INTRUSIVE_OPTION_CONSTANT(cache_last, bool, Enabled, cache_last)
186 
187 //!This option setter specifies the bucket traits
188 //!class for unordered associative containers. When this option is specified,
189 //!instead of using the default bucket traits, a user defined holder will be defined
190 BOOST_INTRUSIVE_OPTION_TYPE(bucket_traits, BucketTraits, BucketTraits, bucket_traits)
191 
192 //!This option setter specifies if the unordered hook
193 //!should offer room to store the hash value.
194 //!Storing the hash in the hook will speed up rehashing
195 //!processes in applications where rehashing is frequent,
196 //!rehashing might throw or the value is heavy to hash.
197 BOOST_INTRUSIVE_OPTION_CONSTANT(store_hash, bool, Enabled, store_hash)
198 
199 //!This option setter specifies if the unordered hook
200 //!should offer room to store another link to another node
201 //!with the same key.
202 //!Storing this link will speed up lookups and insertions on
203 //!unordered_multiset containers with a great number of elements
204 //!with the same key.
205 BOOST_INTRUSIVE_OPTION_CONSTANT(optimize_multikey, bool, Enabled, optimize_multikey)
206 
207 //!This option setter specifies if the bucket array will be always power of two.
208 //!This allows using masks instead of the default modulo operation to determine
209 //!the bucket number from the hash value, leading to better performance.
210 //!In debug mode, if power of two buckets mode is activated, the bucket length
211 //!will be checked with assertions.
212 BOOST_INTRUSIVE_OPTION_CONSTANT(power_2_buckets, bool, Enabled, power_2_buckets)
213 
214 //!This option setter specifies if the container will cache a pointer to the first
215 //!non-empty bucket so that begin() is always constant-time.
216 //!This is specially helpful when we can have containers with a few elements
217 //!but with big bucket arrays (that is, hashtables with low load factors).
218 BOOST_INTRUSIVE_OPTION_CONSTANT(cache_begin, bool, Enabled, cache_begin)
219 
220 //!This option setter specifies if the container will compare the hash value
221 //!before comparing objects. This option can't be specified if store_hash<>
222 //!is not true.
223 //!This is specially helpful when we have containers with a high load factor.
224 //!and the comparison function is much more expensive that comparing already
225 //!stored hash values.
226 BOOST_INTRUSIVE_OPTION_CONSTANT(compare_hash, bool, Enabled, compare_hash)
227 
228 //!This option setter specifies if the hash container will use incremental
229 //!hashing. With incremental hashing the cost of hash table expansion is spread
230 //!out across each hash table insertion operation, as opposed to be incurred all at once.
231 //!Therefore linear hashing is well suited for interactive applications or real-time
232 //!appplications where the worst-case insertion time of non-incremental hash containers
233 //!(rehashing the whole bucket array) is not admisible.
234 BOOST_INTRUSIVE_OPTION_CONSTANT(incremental, bool, Enabled, incremental)
235 
236 /// @cond
237 
238 struct hook_defaults
239 {
240    typedef void* void_pointer;
241    static const link_mode_type link_mode = safe_link;
242    typedef dft_tag tag;
243    static const bool optimize_size = false;
244    static const bool store_hash = false;
245    static const bool linear = false;
246    static const bool optimize_multikey = false;
247 };
248 
249 /// @endcond
250 
251 }  //namespace intrusive {
252 }  //namespace boost {
253 
254 #include <boost/intrusive/detail/config_end.hpp>
255 
256 #endif   //#ifndef BOOST_INTRUSIVE_OPTIONS_HPP
257