Add new nrw_array helper class.

include/osmium/index/id_set.hpp

@@ -408,6 +408,7 @@ namespace osmium {
 
         }; // class IdSetSmall
 
+        /// @deprecated Use nrw_array helper class instead.
         template <template<typename> class IdSetType>
         class NWRIdSet {
 

include/osmium/index/nwr_array.hpp

@@ -0,0 +1,59 @@
+#ifndef OSMIUM_INDEX_NWR_ARRAY_HPP
+#define OSMIUM_INDEX_NWR_ARRAY_HPP
+
+/*
+
+This file is part of Osmium (http://osmcode.org/libosmium).
+
+Copyright 2013-2017 Jochen Topf <jochen@topf.org> and others (see README).
+
+Boost Software License - Version 1.0 - August 17th, 2003
+
+Permission is hereby granted, free of charge, to any person or organization
+obtaining a copy of the software and accompanying documentation covered by
+this license (the "Software") to use, reproduce, display, distribute,
+execute, and transmit the Software, and to prepare derivative works of the
+Software, and to permit third-parties to whom the Software is furnished to
+do so, all subject to the following:
+
+The copyright notices in the Software and this entire statement, including
+the above license grant, this restriction and the following disclaimer,
+must be included in all copies of the Software, in whole or in part, and
+all derivative works of the Software, unless such copies or derivative
+works are solely in the form of machine-executable object code generated by
+a source language processor.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
+
+*/
+
+#include <osmium/osm/item_type.hpp>
+
+namespace osmium {
+
+    template <typename T>
+    class nwr_array {
+
+        T m_sets[3];
+
+    public:
+
+        T& operator()(osmium::item_type type) noexcept {
+            return m_sets[osmium::item_type_to_nwr_index(type)];
+        }
+
+        const T& operator()(osmium::item_type type) const noexcept {
+            return m_sets[osmium::item_type_to_nwr_index(type)];
+        }
+
+    }; // class nwr_array
+
+} // namespace osmium
+
+#endif // OSMIUM_INDEX_NWR_ARRAY_HPP