Codechange: rename smallvec_type to container_func and use only when needed

src/core/container_func.hpp

@@ -0,0 +1,49 @@
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file container_func.hpp Some simple functions to help with accessing containers. */
+
+#ifndef CONTAINER_FUNC_HPP
+#define CONTAINER_FUNC_HPP
+
+/**
+ * Helper function to append an item to a container if it is not already contained.
+ * The container must have a \c emplace_back function.
+ * Consider using std::set, std::unordered_set or std::flat_set in new code.
+ *
+ * @param container A reference to the container to be extended
+ * @param item Reference to the item to be copy-constructed if not found
+ *
+ * @return Whether the item was already present
+ */
+template <typename Container>
+inline bool include(Container &container, typename Container::const_reference &item)
+{
+	const bool is_member = std::find(container.begin(), container.end(), item) != container.end();
+	if (!is_member) container.emplace_back(item);
+	return is_member;
+}
+
+/**
+ * Helper function to get the index of an item
+ * Consider using std::set, std::unordered_set or std::flat_set in new code.
+ *
+ * @param container A reference to the container to be searched.
+ * @param item Reference to the item to be search for
+ *
+ * @return Index of element if found, otherwise -1
+ */
+template <typename Container>
+int find_index(Container const &container, typename Container::const_reference item)
+{
+	auto const it = std::find(container.begin(), container.end(), item);
+	if (it != container.end()) return std::distance(container.begin(), it);
+
+	return -1;
+}
+
+#endif /* CONTAINER_FUNC_HPP */