1 #ifndef OSMIUM_HANDLER_CHAIN_HPP 2 #define OSMIUM_HANDLER_CHAIN_HPP 3 4 /* 5 6 This file is part of Osmium (https://osmcode.org/libosmium). 7 8 Copyright 2013-2021 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 <tuple> 39 40 #define OSMIUM_CHAIN_HANDLER_CALL(_func_, _type_) \ 41 template <int N, int SIZE, typename THandlers> \ 42 struct call_ ## _func_ { \ 43 void operator()(THandlers& handlers, osmium::_type_& object) { \ 44 std::get<N>(handlers)._func_(object); \ 45 call_ ## _func_<N+1, SIZE, THandlers>()(handlers, object); \ 46 } \ 47 }; \ 48 template <int SIZE, typename THandlers> \ 49 struct call_ ## _func_<SIZE, SIZE, THandlers> { \ 50 void operator()(THandlers&, osmium::_type_&) {} \ 51 }; 52 53 namespace osmium { 54 55 class Node; 56 class Way; 57 class Relation; 58 class Area; 59 class Changeset; 60 61 namespace handler { 62 63 /** 64 * This handler allows chaining of any number of handlers into a single 65 * handler. 66 */ 67 template <typename... THandler> 68 class ChainHandler : public osmium::handler::Handler { 69 70 using handlers_type = std::tuple<THandler&...>; 71 handlers_type m_handlers; 72 73 template <int N, int SIZE, typename THandlers> 74 struct call_flush { operator ()osmium::handler::ChainHandler::call_flush75 void operator()(THandlers& handlers) { 76 std::get<N>(handlers).flush(); 77 call_flush<N + 1, SIZE, THandlers>()(handlers); 78 } 79 }; // struct call_flush 80 81 template <int SIZE, typename THandlers> 82 struct call_flush<SIZE, SIZE, THandlers> { operator ()osmium::handler::ChainHandler::call_flush83 void operator()(THandlers& /*handlers*/) {} 84 }; // struct call_flush 85 86 OSMIUM_CHAIN_HANDLER_CALL(node, Node) 87 OSMIUM_CHAIN_HANDLER_CALL(way, Way) 88 OSMIUM_CHAIN_HANDLER_CALL(relation, Relation) 89 OSMIUM_CHAIN_HANDLER_CALL(changeset, Changeset) 90 OSMIUM_CHAIN_HANDLER_CALL(area, Area) 91 92 public: 93 ChainHandler(THandler &...handlers)94 explicit ChainHandler(THandler&... handlers) : 95 m_handlers(handlers...) { 96 } 97 node(osmium::Node & node)98 void node(osmium::Node& node) { 99 call_node<0, sizeof...(THandler), handlers_type>()(m_handlers, node); 100 } 101 way(osmium::Way & way)102 void way(osmium::Way& way) { 103 call_way<0, sizeof...(THandler), handlers_type>()(m_handlers, way); 104 } 105 relation(osmium::Relation & relation)106 void relation(osmium::Relation& relation) { 107 call_relation<0, sizeof...(THandler), handlers_type>()(m_handlers, relation); 108 } 109 changeset(osmium::Changeset & changeset)110 void changeset(osmium::Changeset& changeset) { 111 call_changeset<0, sizeof...(THandler), handlers_type>()(m_handlers, changeset); 112 } 113 area(osmium::Area & area)114 void area(osmium::Area& area) { 115 call_area<0, sizeof...(THandler), handlers_type>()(m_handlers, area); 116 } 117 flush()118 void flush() { 119 call_flush<0, sizeof...(THandler), handlers_type>()(m_handlers); 120 } 121 122 }; // class ChainHandler 123 124 } // namespace handler 125 126 } // namespace osmium 127 128 #endif // OSMIUM_HANDLER_CHAIN_HPP 129