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stl_compares.h
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1/**
2 * PANDA 3D SOFTWARE
3 * Copyright (c) Carnegie Mellon University. All rights reserved.
4 *
5 * All use of this software is subject to the terms of the revised BSD
6 * license. You should have received a copy of this license along
7 * with this source code in a file named "LICENSE."
8 *
9 * @file stl_compares.h
10 * @author drose
11 * @date 2004-09-28
12 */
13
14#ifndef STL_COMPARES_H
15#define STL_COMPARES_H
16
17#include "dtoolbase.h"
18#include "cmath.h"
19#include "nearly_zero.h"
20#include "addHash.h"
21
22#include <assert.h>
23
24#ifdef HAVE_STL_HASH
25#include <hash_map> // for hash_compare
26
27 template<class Key, class Compare = std::less<Key> >
28 class stl_hash_compare : public stdext::hash_compare<Key, Compare> {
29 public:
30 INLINE bool is_equal(const Key &a, const Key &b) const {
31 return !operator()(a, b) && !operator()(b, a);
32 }
33};
34
35#else
36
37#include <map> // for less
38
39// This is declared for the cases in which we don't have STL_HASH available.
40 template<class Key, class Compare = std::less<Key> >
41 class stl_hash_compare : public Compare {
42 public:
43 INLINE size_t operator () (const Key &key) const {
44 return (size_t)key;
45 }
46 INLINE bool operator () (const Key &a, const Key &b) const {
47 return Compare::operator ()(a, b);
48 }
49 INLINE bool is_equal(const Key &a, const Key &b) const {
50 return !operator()(a, b) && !operator()(b, a);
51 }
52};
53
54#endif // HAVE_STL_HASH
55
56/**
57 * Compares two floating point numbers, within threshold of equivalence.
58 */
59 template<class Key>
60 class floating_point_threshold {
61 public:
62 INLINE floating_point_threshold(Key threshold = get_nearly_zero_value((Key)0));
63 INLINE bool operator () (const Key &a, const Key &b) const;
64 const Key _threshold;
65};
66
67/**
68 * An STL function object class, this is intended to be used on any ordered
69 * collection of class objects that contain a compare_to() method. It defines
70 * the order of the objects via compare_to().
71 */
72 template<class Key>
73 class compare_to {
74 public:
75 INLINE bool operator () (const Key &a, const Key &b) const;
76 INLINE bool is_equal(const Key &a, const Key &b) const;
77};
78
79/**
80 * An STL function object class, this is intended to be used on any ordered
81 * collection of pointers to classes that contain an operator <() method. It
82 * defines the order of the pointers via operator <().
83 */
84 template<class Key>
85 class indirect_less {
86 public:
87 INLINE bool operator () (const Key &a, const Key &b) const;
88};
89
90/**
91 * An STL function object class, this is intended to be used on any ordered
92 * collection of pointers to classes that contain a compare_to() method. It
93 * defines the order of the pointers via compare_to().
94 */
95 template<class Key>
96 class indirect_compare_to {
97 public:
98 INLINE bool operator () (const Key &a, const Key &b) const;
99 INLINE bool is_equal(const Key &a, const Key &b) const;
100};
101
102/**
103 * An STL function object class, this is intended to be used on any ordered
104 * collection of pointers to classes that define a get_name() method,
105 * particularly for things that derive from Namable. It defines the order of
106 * the pointers by case-sensitive name comparison.
107 */
108 template<class Key>
109 class indirect_compare_names {
110 public:
111 INLINE bool operator () (const Key &a, const Key &b) const;
112 INLINE bool is_equal(const Key &a, const Key &b) const;
113};
114
115/**
116 * This is the default hash_compare class, which assumes the Key is a size_t
117 * value or can be implicitly converted to a size_t value (for instance, via a
118 * size_t typecast operator). It is the same as the system-provided
119 * hash_compare.
120 */
121 template<class Key, class Compare = std::less<Key> >
122 class integer_hash : public stl_hash_compare<Key, Compare> {
123 public:
124 INLINE static size_t add_hash(size_t start, const Key &key);
125};
126
127/**
128 * This is the default hash_compare class, which assumes the Key is a pointer
129 * value. It is the same as the system-provided hash_compare.
130 */
131 class pointer_hash : public stl_hash_compare<const void *, std::less<const void *> > {
132 public:
133 INLINE static size_t add_hash(size_t start, const void *key);
134};
135
136/**
137 * This hash_compare class hashes a float or a double.
138 */
139 template<class Key>
140 class floating_point_hash : public stl_hash_compare<Key> {
141 public:
142 INLINE floating_point_hash(Key threshold = get_nearly_zero_value((Key)0));
143 INLINE size_t operator () (const Key &key) const;
144 INLINE bool operator () (const Key &a, const Key &b) const;
145 INLINE size_t add_hash(size_t start, const Key &key) const;
146 const Key _threshold;
147};
148
149/**
150 * This hash_compare class hashes a string. It assumes the Key is a string or
151 * provides begin() and end() methods that iterate through Key::value_type.
152 */
153 template<class Key, class Compare = std::less<Key> >
154 class sequence_hash : public stl_hash_compare<Key, Compare> {
155 public:
156 INLINE size_t operator () (const Key &key) const;
157 INLINE bool operator () (const Key &a, const Key &b) const {
158 return stl_hash_compare<Key, Compare>::operator () (a, b);
159 }
160 INLINE static size_t add_hash(size_t start, const Key &key);
161};
162
163/**
164 * This hash_compare class hashes a class object. It assumes the Key provides
165 * a method called get_hash() that returns a size_t.
166 */
167 template<class Key, class Compare = std::less<Key> >
168 class method_hash : public stl_hash_compare<Key, Compare> {
169 public:
170 INLINE size_t operator () (const Key &key) const;
171 INLINE bool operator () (const Key &a, const Key &b) const {
172 return stl_hash_compare<Key, Compare>::operator () (a, b);
173 }
174};
175
176/**
177 * This hash_compare class hashes a pointer to a class object. It assumes the
178 * Key is a pointer to a class that provides a method called get_hash() that
179 * returns a size_t.
180 */
181 template<class Key, class Compare>
182 class indirect_method_hash : public stl_hash_compare<Key, Compare> {
183 public:
184 INLINE size_t operator () (const Key &key) const;
185 INLINE bool operator () (const Key &a, const Key &b) const {
186 return stl_hash_compare<Key, Compare>::operator () (a, b);
187 }
188};
189
190/**
191 * An STL function object class, this is intended to be used on any ordered
192 * collection of pointers to classes that contain an operator ==() method. It
193 * defines the equality of the pointers via operator ==().
194 *
195 * Since it doesn't define the ordering of the pointers, it can only be used
196 * with hash containers.
197 */
198 template<class Key>
199 class indirect_equals_hash {
200 public:
201 INLINE size_t operator () (const Key &key) const;
202 INLINE bool is_equal(const Key &a, const Key &b) const;
203};
204
205#include "stl_compares.I"
206
207 typedef floating_point_hash<float> float_hash;
208 typedef floating_point_hash<double> double_hash;
209 typedef integer_hash<int> int_hash;
210 typedef integer_hash<size_t> size_t_hash;
211 typedef sequence_hash<std::string> string_hash;
212 typedef sequence_hash<std::wstring> wstring_hash;
213
214 template<class Key>
215 class indirect_less_hash : public indirect_method_hash<Key, indirect_less<Key> > {
216};
217
218 template<class Key>
219 class indirect_compare_to_hash : public indirect_method_hash<Key, indirect_compare_to<Key> > {
220};
221
222 template<class Key>
223 class indirect_compare_names_hash : public indirect_method_hash<Key, indirect_compare_names<Key> > {
224};
225
226#endif
addHash.h
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
compare_to
An STL function object class, this is intended to be used on any ordered collection of class objects ...
Definition stl_compares.h:73
compare_to::is_equal
bool is_equal(const Key &a, const Key &b) const
Returns true if a is equivalent to b, false otherwise.
Definition stl_compares.I:47
compare_to::operator()
bool operator()(const Key &a, const Key &b) const
Returns true if a sorts before b, false otherwise.
Definition stl_compares.I:38
floating_point_hash
This hash_compare class hashes a float or a double.
Definition stl_compares.h:140
floating_point_hash::operator()
size_t operator()(const Key &key) const
Computes a size_t hash from the float.
Definition stl_compares.I:131
floating_point_hash::add_hash
size_t add_hash(size_t start, const Key &key) const
Adds the indicated key into a running hash.
Definition stl_compares.I:149
floating_point_threshold::operator()
bool operator()(const Key &a, const Key &b) const
Returns true if a sorts before b, false otherwise.
Definition stl_compares.I:29
indirect_compare_names_hash
Definition stl_compares.h:223
indirect_compare_names
An STL function object class, this is intended to be used on any ordered collection of pointers to cl...
Definition stl_compares.h:109
indirect_compare_names::operator()
bool operator()(const Key &a, const Key &b) const
Returns true if a sorts before b, false otherwise.
Definition stl_compares.I:83
indirect_compare_names::is_equal
bool is_equal(const Key &a, const Key &b) const
Returns true if a is equivalent to b, false otherwise.
Definition stl_compares.I:92
indirect_compare_to_hash
Definition stl_compares.h:219
indirect_compare_to
An STL function object class, this is intended to be used on any ordered collection of pointers to cl...
Definition stl_compares.h:96
indirect_compare_to::operator()
bool operator()(const Key &a, const Key &b) const
Returns true if a sorts before b, false otherwise.
Definition stl_compares.I:65
indirect_compare_to::is_equal
bool is_equal(const Key &a, const Key &b) const
Returns true if a is equivalent to b, false otherwise.
Definition stl_compares.I:74
indirect_equals_hash
An STL function object class, this is intended to be used on any ordered collection of pointers to cl...
Definition stl_compares.h:199
indirect_equals_hash::is_equal
bool is_equal(const Key &a, const Key &b) const
Returns true if a is equal to b, false otherwise.
Definition stl_compares.I:211
indirect_equals_hash::operator()
size_t operator()(const Key &key) const
Calls the Key's get_hash() method.
Definition stl_compares.I:202
indirect_less_hash
Definition stl_compares.h:215
indirect_less
An STL function object class, this is intended to be used on any ordered collection of pointers to cl...
Definition stl_compares.h:85
indirect_less::operator()
bool operator()(const Key &a, const Key &b) const
Returns true if a sorts before b, false otherwise.
Definition stl_compares.I:56
indirect_method_hash
This hash_compare class hashes a pointer to a class object.
Definition stl_compares.h:182
indirect_method_hash::operator()
size_t operator()(const Key &key) const
Calls the Key's get_hash() method.
Definition stl_compares.I:193
integer_hash
This is the default hash_compare class, which assumes the Key is a size_t value or can be implicitly ...
Definition stl_compares.h:122
integer_hash::add_hash
static size_t add_hash(size_t start, const Key &key)
Adds the indicated key into a running hash.
Definition stl_compares.I:101
method_hash
This hash_compare class hashes a class object.
Definition stl_compares.h:168
method_hash::operator()
size_t operator()(const Key &key) const
Calls the Key's get_hash() method.
Definition stl_compares.I:184
pointer_hash
This is the default hash_compare class, which assumes the Key is a pointer value.
Definition stl_compares.h:131
pointer_hash::add_hash
static size_t add_hash(size_t start, const void *key)
Adds the indicated key into a running hash.
Definition stl_compares.I:110
sequence_hash
This hash_compare class hashes a string.
Definition stl_compares.h:154
sequence_hash::operator()
size_t operator()(const Key &key) const
Trivially computes a size_t hash from the components of the string.
Definition stl_compares.I:159
sequence_hash::add_hash
static size_t add_hash(size_t start, const Key &key)
Adds the elements of the indicated key into a running hash.
Definition stl_compares.I:168
stl_hash_compare
Definition stl_compares.h:41
cmath.h
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
dtoolbase.h
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
nearly_zero.h
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
stl_compares.I
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.