Merge branch 'master' into jgrpp

# Conflicts:
#	CMakeLists.txt
#	src/3rdparty/md5/md5.h
#	src/3rdparty/squirrel/squirrel/squtils.h
#	src/animated_tile.cpp
#	src/console_func.h
#	src/core/CMakeLists.txt
#	src/core/container_func.hpp
#	src/core/smallstack_type.hpp
#	src/crashlog.cpp
#	src/crashlog.h
#	src/debug.h
#	src/economy.cpp
#	src/gamelog.cpp
#	src/industry_gui.cpp
#	src/lang/catalan.txt
#	src/misc_gui.cpp
#	src/network/network_content.h
#	src/newgrf.cpp
#	src/newgrf.h
#	src/newgrf_config.cpp
#	src/newgrf_config.h
#	src/newgrf_gui.cpp
#	src/os/unix/font_unix.cpp
#	src/os/windows/crashlog_win.cpp
#	src/rail_cmd.cpp
#	src/saveload/animated_tile_sl.cpp
#	src/script/api/script_tilelist.cpp
#	src/settings.cpp
#	src/settingsgen/settingsgen.cpp
#	src/sl/oldloader_sl.cpp
#	src/station.cpp
#	src/station_cmd.cpp
#	src/stdafx.h
#	src/strgen/strgen.cpp
#	src/strgen/strgen_base.cpp
#	src/table/settings/gui_settings.ini
#	src/train_gui.cpp
#	src/vehicle.cpp
#	src/vehicle_base.h
#	src/vehicle_cmd.cpp
#	src/vehicle_gui_base.h
#	src/viewport_sprite_sorter.h

src/core/container_func.hpp

@@ -5,7 +5,7 @@
  * 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 Functions related to use of containers. */
+/** @file container_func.hpp Some simple functions to help with accessing containers. */
 
 #ifndef CONTAINER_FUNC_HPP
 #define CONTAINER_FUNC_HPP
@@ -13,6 +13,42 @@
 #include <iterator>
 #include <algorithm>
 
+/**
+ * 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;
+}
+
 template <typename C, typename UP> unsigned int container_unordered_remove_if (C &container, UP predicate) {
 	unsigned int removecount = 0;
 	for (auto it = container.begin(); it != container.end();) {