Add ecs::container::detach_finally/destroy_finally helpers

libs/ecs/include/psemek/ecs/container.hpp

@@ -79,6 +79,9 @@ namespace psemek::ecs
 		 */
 		void destroy(handle entity);
 
+		/** Same as destroy(), but via finally() */
+		void destroy_finally(handle entity);
+
 		/** Get an accessor for an entity, which provides access to the entity's components.
 		 *  It is designed to be a single-use object; it cannot be stored as a reference to
 		 *    the entity. Use handle for that instead.
@@ -169,6 +172,10 @@ namespace psemek::ecs
 		template <typename ... Components>
 		void detach(handle entity);
 
+		/** Same as detach(), but via finally() */
+		template <typename ... Components>
+		void detach_finally(handle entity);
+
 		/** Create a query cache that can be used to speed up `apply()` calls.
 		 *
 		 *  The constness of the component types is ignored.
@@ -611,6 +618,15 @@ namespace psemek::ecs
 		--method_recursion_depth_;
 	}
 
+	template <typename ... Components>
+	void container::detach_finally(handle entity)
+	{
+		finally([entity](container & world){
+			if (world.alive(entity))
+				world.detach<Components...>(entity);
+		});
+	}
+
 	template <typename ... Components>
 	query_cache container::cache()
 	{

libs/ecs/source/container.cpp

@@ -36,6 +36,13 @@ namespace psemek::ecs
 
 		--method_recursion_depth_;
 	}
+
+	void container::destroy_finally(handle entity)
+	{
+		finally([entity](container & world){
+			if (world.alive(entity))
+				world.destroy(entity);
+		});
 	}
 
 	accessor container::get(handle entity)