Libosmium  2.17.3
Fast and flexible C++ library for working with OpenStreetMap data
dynamic_handler.hpp
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1 #ifndef OSMIUM_DYNAMIC_HANDLER_HPP
2 #define OSMIUM_DYNAMIC_HANDLER_HPP
3 
4 /*
5 
6 This file is part of Osmium (https://osmcode.org/libosmium).
7 
8 Copyright 2013-2022 Jochen Topf <jochen@topf.org> and others (see README).
9 
10 Boost Software License - Version 1.0 - August 17th, 2003
11 
12 Permission is hereby granted, free of charge, to any person or organization
13 obtaining a copy of the software and accompanying documentation covered by
14 this license (the "Software") to use, reproduce, display, distribute,
15 execute, and transmit the Software, and to prepare derivative works of the
16 Software, and to permit third-parties to whom the Software is furnished to
17 do so, all subject to the following:
18 
19 The copyright notices in the Software and this entire statement, including
20 the above license grant, this restriction and the following disclaimer,
21 must be included in all copies of the Software, in whole or in part, and
22 all derivative works of the Software, unless such copies or derivative
23 works are solely in the form of machine-executable object code generated by
24 a source language processor.
25 
26 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
29 SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
30 FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
31 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
32 DEALINGS IN THE SOFTWARE.
33 
34 */
35 
36 #include <osmium/handler.hpp>
37 
38 #include <memory>
39 #include <utility>
40 
41 namespace osmium {
42 
43  class Node;
44  class Way;
45  class Relation;
46  class Area;
47  class Changeset;
48 
49  namespace handler {
50 
51  namespace detail {
52 
53  class HandlerWrapperBase {
54 
55  public:
56 
57  HandlerWrapperBase() = default;
58 
59  HandlerWrapperBase(const HandlerWrapperBase&) = default;
60  HandlerWrapperBase& operator=(const HandlerWrapperBase&) = default;
61 
62  HandlerWrapperBase(HandlerWrapperBase&&) noexcept = default;
63  HandlerWrapperBase& operator=(HandlerWrapperBase&&) noexcept = default;
64 
65  virtual ~HandlerWrapperBase() noexcept = default;
66 
67  virtual void node(const osmium::Node& /*node*/) {
68  }
69 
70  virtual void way(const osmium::Way& /*way*/) {
71  }
72 
73  virtual void relation(const osmium::Relation& /*relation*/) {
74  }
75 
76  virtual void area(const osmium::Area& /*area*/) {
77  }
78 
79  virtual void changeset(const osmium::Changeset& /*changeset*/) {
80  }
81 
82  virtual void flush() {
83  }
84 
85  }; // class HandlerWrapperBase
86 
87 
88  // The following uses trick from
89  // https://stackoverflow.com/questions/257288/is-it-possible-to-write-a-c-template-to-check-for-a-functions-existence
90  // to either call handler style functions or visitor style operator().
91 
92 #define OSMIUM_DYNAMIC_HANDLER_DISPATCH(_name_, _type_) \
93 template <typename THandler> \
94 auto _name_##_dispatch(THandler& handler, const osmium::_type_& object, int) -> decltype(handler._name_(object), void()) { \
95  handler._name_(object); \
96 } \
97 template <typename THandler> \
98 auto _name_##_dispatch(THandler& handler, const osmium::_type_& object, long) -> decltype(handler(object), void()) { \
99  handler(object); \
100 }
101 
104  OSMIUM_DYNAMIC_HANDLER_DISPATCH(relation, Relation)
105  OSMIUM_DYNAMIC_HANDLER_DISPATCH(changeset, Changeset)
107 
108  template <typename THandler>
109  auto flush_dispatch(THandler& handler, int /*dispatch*/) -> decltype(handler.flush(), void()) {
110  handler.flush();
111  }
112 
113  template <typename THandler>
114  void flush_dispatch(THandler& /*handler*/, long /*dispatch*/) { // NOLINT(google-runtime-int)
115  }
116 
117  template <typename THandler>
118  class HandlerWrapper : public HandlerWrapperBase {
119 
120  THandler m_handler;
121 
122  public:
123 
124  template <typename... TArgs>
125  explicit HandlerWrapper(TArgs&&... args) :
126  m_handler(std::forward<TArgs>(args)...) {
127  }
128 
129  HandlerWrapper(const HandlerWrapper&) = default;
130  HandlerWrapper& operator=(const HandlerWrapper&) = default;
131 
132  HandlerWrapper(HandlerWrapper&&) noexcept = default;
133  HandlerWrapper& operator=(HandlerWrapper&&) noexcept = default;
134 
135  ~HandlerWrapper() noexcept override = default;
136 
137  void node(const osmium::Node& node) final {
138  node_dispatch(m_handler, node, 0);
139  }
140 
141  void way(const osmium::Way& way) final {
142  way_dispatch(m_handler, way, 0);
143  }
144 
145  void relation(const osmium::Relation& relation) final {
146  relation_dispatch(m_handler, relation, 0);
147  }
148 
149  void area(const osmium::Area& area) final {
150  area_dispatch(m_handler, area, 0);
151  }
152 
153  void changeset(const osmium::Changeset& changeset) final {
154  changeset_dispatch(m_handler, changeset, 0);
155  }
156 
157  void flush() final {
158  flush_dispatch(m_handler, 0);
159  }
160 
161  }; // class HandlerWrapper
162 
163  } // namespace detail
164 
166 
167  using impl_ptr = std::unique_ptr<osmium::handler::detail::HandlerWrapperBase>;
169 
170  public:
171 
173  m_impl(new osmium::handler::detail::HandlerWrapperBase) {
174  }
175 
176  template <typename THandler, typename... TArgs>
177  void set(TArgs&&... args) {
178  m_impl.reset(new osmium::handler::detail::HandlerWrapper<THandler>{std::forward<TArgs>(args)...});
179  }
180 
181  void node(const osmium::Node& node) {
182  m_impl->node(node);
183  }
184 
185  void way(const osmium::Way& way) {
186  m_impl->way(way);
187  }
188 
190  m_impl->relation(relation);
191  }
192 
193  void area(const osmium::Area& area) {
194  m_impl->area(area);
195  }
196 
198  m_impl->changeset(changeset);
199  }
200 
201  void flush() {
202  m_impl->flush();
203  }
204 
205  }; // class DynamicHandler
206 
207  } // namespace handler
208 
209 } // namespace osmium
210 
211 #endif // OSMIUM_DYNAMIC_HANDLER_HPP
Definition: area.hpp:126
An OSM Changeset, a group of changes made by a single user over a short period of time.
Definition: changeset.hpp:148
Definition: node.hpp:48
Definition: relation.hpp:168
Definition: way.hpp:72
Definition: dynamic_handler.hpp:165
impl_ptr m_impl
Definition: dynamic_handler.hpp:168
void node(const osmium::Node &node)
Definition: dynamic_handler.hpp:181
void changeset(const osmium::Changeset &changeset)
Definition: dynamic_handler.hpp:197
void set(TArgs &&... args)
Definition: dynamic_handler.hpp:177
void way(const osmium::Way &way)
Definition: dynamic_handler.hpp:185
void flush()
Definition: dynamic_handler.hpp:201
void area(const osmium::Area &area)
Definition: dynamic_handler.hpp:193
std::unique_ptr< osmium::handler::detail::HandlerWrapperBase > impl_ptr
Definition: dynamic_handler.hpp:167
DynamicHandler()
Definition: dynamic_handler.hpp:172
void relation(const osmium::Relation &relation)
Definition: dynamic_handler.hpp:189
Definition: handler.hpp:71
#define OSMIUM_DYNAMIC_HANDLER_DISPATCH(_name_, _type_)
Definition: dynamic_handler.hpp:92
Definition: attr.hpp:342
@ forward
Linestring has same direction as way.
@ changeset
Definition: entity_bits.hpp:75
@ relation
Definition: entity_bits.hpp:70
@ area
Definition: entity_bits.hpp:72
@ way
Definition: entity_bits.hpp:69
Namespace for everything in the Osmium library.
Definition: assembler.hpp:53
Definition: location.hpp:555