1// Boost.Geometry Index
2//
3// Copyright (c) 2011-2014 Adam Wulkiewicz, Lodz, Poland.
4//
5// Use, modification and distribution is subject to the Boost Software License,
6// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
7// http://www.boost.org/LICENSE_1_0.txt)
8
9#ifndef BOOST_GEOMETRY_INDEX_EQUAL_TO_HPP
10#define BOOST_GEOMETRY_INDEX_EQUAL_TO_HPP
11
12#include <boost/geometry/algorithms/equals.hpp>
13#include <boost/geometry/index/indexable.hpp>
14
15namespace boost { namespace geometry { namespace index { namespace detail {
16
17template <typename Geometry,
18 typename Tag = typename geometry::tag<Geometry>::type>
19struct equals
20{
21 inline static bool apply(Geometry const& g1, Geometry const& g2)
22 {
23 return geometry::equals(g1, g2);
24 }
25};
26
27template <typename Geometry, typename Tag>
28struct equals<Geometry *, Tag>
29{
30 inline static bool apply(const Geometry * g1, const Geometry * g2)
31 {
32 return g1 == g2;
33 }
34};
35
36template <typename T>
37struct equals<T, void>
38{
39 inline static bool apply(T const& v1, T const& v2)
40 {
41 return v1 == v2;
42 }
43};
44
45template <typename Tuple, size_t I, size_t N>
46struct tuple_equals
47{
48 inline static bool apply(Tuple const& t1, Tuple const& t2)
49 {
50 typedef typename boost::tuples::element<I, Tuple>::type T;
51
52 return equals<T>::apply(boost::get<I>(t1), boost::get<I>(t2))
53 && tuple_equals<Tuple, I+1, N>::apply(t1, t2);
54 }
55};
56
57template <typename Tuple, size_t I>
58struct tuple_equals<Tuple, I, I>
59{
60 inline static bool apply(Tuple const&, Tuple const&)
61 {
62 return true;
63 }
64};
65
66// TODO: Consider this: Since equal_to<> is using geometry::equals() it's possible that
67// two compared Indexables are not exactly the same! They will be spatially equal
68// but not strictly equal. Consider 2 Segments with reversed order of points.
69// Therefore it's possible that during the Value removal different value will be
70// removed than the one that was passed.
71
72/*!
73\brief The function object comparing Values.
74
75It compares Geometries using geometry::equals() function. Other types are compared using operator==.
76The default version handles Values which are Indexables.
77This template is also specialized for std::pair<T1, T2> and boost::tuple<...>.
78
79\tparam Value The type of objects which are compared by this function object.
80\tparam IsIndexable If true, Values are compared using boost::geometry::equals() functions.
81*/
82template <typename Value,
83 bool IsIndexable = is_indexable<Value>::value>
84struct equal_to
85{
86 /*! \brief The type of result returned by function object. */
87 typedef bool result_type;
88
89 /*!
90 \brief Compare values. If Value is a Geometry geometry::equals() function is used.
91
92 \param l First value.
93 \param r Second value.
94 \return true if values are equal.
95 */
96 inline bool operator()(Value const& l, Value const& r) const
97 {
98 return detail::equals<Value>::apply(l ,r);
99 }
100};
101
102/*!
103\brief The function object comparing Values.
104
105This specialization compares values of type std::pair<T1, T2>.
106It compares pairs' first values, then second values.
107
108\tparam T1 The first type.
109\tparam T2 The second type.
110*/
111template <typename T1, typename T2>
112struct equal_to<std::pair<T1, T2>, false>
113{
114 /*! \brief The type of result returned by function object. */
115 typedef bool result_type;
116
117 /*!
118 \brief Compare values. If pair<> Value member is a Geometry geometry::equals() function is used.
119
120 \param l First value.
121 \param r Second value.
122 \return true if values are equal.
123 */
124 inline bool operator()(std::pair<T1, T2> const& l, std::pair<T1, T2> const& r) const
125 {
126 return detail::equals<T1>::apply(l.first, r.first)
127 && detail::equals<T2>::apply(l.second, r.second);
128 }
129};
130
131/*!
132\brief The function object comparing Values.
133
134This specialization compares values of type boost::tuple<...>.
135It compares all members of the tuple from the first one to the last one.
136*/
137template <typename T0, typename T1, typename T2, typename T3, typename T4,
138 typename T5, typename T6, typename T7, typename T8, typename T9>
139struct equal_to<boost::tuple<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>, false>
140{
141 typedef boost::tuple<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9> value_type;
142
143 /*! \brief The type of result returned by function object. */
144 typedef bool result_type;
145
146 /*!
147 \brief Compare values. If tuple<> Value member is a Geometry geometry::equals() function is used.
148
149 \param l First value.
150 \param r Second value.
151 \return true if values are equal.
152 */
153 inline bool operator()(value_type const& l, value_type const& r) const
154 {
155 return detail::tuple_equals<
156 value_type, 0, boost::tuples::length<value_type>::value
157 >::apply(l ,r);
158 }
159};
160
161}}}} // namespace boost::geometry::index::detail
162
163#if !defined(BOOST_NO_CXX11_HDR_TUPLE) && !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
164
165#include <tuple>
166
167namespace boost { namespace geometry { namespace index { namespace detail {
168
169template <typename Tuple, size_t I, size_t N>
170struct std_tuple_equals
171{
172 inline static bool apply(Tuple const& t1, Tuple const& t2)
173 {
174 typedef typename std::tuple_element<I, Tuple>::type T;
175
176 return equals<T>::apply(std::get<I>(t1), std::get<I>(t2))
177 && std_tuple_equals<Tuple, I+1, N>::apply(t1, t2);
178 }
179};
180
181template <typename Tuple, size_t I>
182struct std_tuple_equals<Tuple, I, I>
183{
184 inline static bool apply(Tuple const&, Tuple const&)
185 {
186 return true;
187 }
188};
189
190/*!
191\brief The function object comparing Values.
192
193This specialization compares values of type std::tuple<Args...>.
194It's defined if the compiler supports tuples and variadic templates.
195It compares all members of the tuple from the first one to the last one.
196*/
197template <typename ...Args>
198struct equal_to<std::tuple<Args...>, false>
199{
200 typedef std::tuple<Args...> value_type;
201
202 /*! \brief The type of result returned by function object. */
203 typedef bool result_type;
204
205 /*!
206 \brief Compare values. If tuple<> Value member is a Geometry geometry::equals() function is used.
207
208 \param l First value.
209 \param r Second value.
210 \return true if values are equal.
211 */
212 bool operator()(value_type const& l, value_type const& r) const
213 {
214 return detail::std_tuple_equals<
215 value_type, 0, std::tuple_size<value_type>::value
216 >::apply(l ,r);
217 }
218};
219
220}}}} // namespace boost::geometry::index::detail
221
222#endif // !defined(BOOST_NO_CXX11_HDR_TUPLE) && !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
223
224namespace boost { namespace geometry { namespace index {
225
226/*!
227\brief The function object comparing Values.
228
229The default version handles Values which are Indexables, std::pair<T1, T2>, boost::tuple<...>
230and std::tuple<...> if STD tuples and variadic templates are supported.
231All members are compared from left to right, Geometries using boost::geometry::equals() function,
232other types using operator==.
233
234\tparam Value The type of objects which are compared by this function object.
235*/
236template <typename Value>
237struct equal_to
238 : detail::equal_to<Value>
239{
240 /*! \brief The type of result returned by function object. */
241 typedef typename detail::equal_to<Value>::result_type result_type;
242
243 /*!
244 \brief Compare Values.
245
246 \param l First value.
247 \param r Second value.
248 \return true if Values are equal.
249 */
250 inline bool operator()(Value const& l, Value const& r) const
251 {
252 return detail::equal_to<Value>::operator()(l ,r);
253 }
254};
255
256}}} // namespace boost::geometry::index
257
258#endif // BOOST_GEOMETRY_INDEX_EQUAL_TO_HPP
259

source code of boost/boost/geometry/index/equal_to.hpp