From 57fb1e8f1fa2b9ad8b6de7161954fd3a819ee2ec Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Thu, 22 Jul 2021 10:51:32 +0300
Subject: [PATCH] Add non-throwing util::ecs::get_if

---
 libs/util/include/psemek/util/ecs.hpp | 39 +++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/libs/util/include/psemek/util/ecs.hpp b/libs/util/include/psemek/util/ecs.hpp
index cd351b9d..815396dc 100644
--- a/libs/util/include/psemek/util/ecs.hpp
+++ b/libs/util/include/psemek/util/ecs.hpp
@@ -263,6 +263,18 @@ namespace psemek::util
 		template <typename Component>
 		typename Component::data const & get(handle species, handle entity) const;
 
+		template <typename Component>
+		Component * get_if(handle species);
+
+		template <typename Component>
+		Component const * get_if(handle species) const;
+
+		template <typename Component>
+		typename Component::data * get_if(handle species, handle entity);
+
+		template <typename Component>
+		typename Component::data const * get_if(handle species, handle entity) const;
+
 		template <typename Behavior>
 		void apply(Behavior && behavior) const;
 
@@ -328,6 +340,33 @@ namespace psemek::util
 		return const_cast<typename Component::data const &>(const_cast<ecs *>(this)->get<Component>(species, entity));
 	}
 
+	template <typename Component>
+	Component * ecs::get_if(handle species)
+	{
+		return species_[species]->get_species_component<Component>();
+	}
+
+	template <typename Component>
+	Component const * ecs::get_if(handle species) const
+	{
+		return const_cast<typename Component::data const *>(const_cast<ecs *>(this)->get<Component>(species));
+	}
+
+	template <typename Component>
+	typename Component::data * ecs::get_if(handle species, handle entity)
+	{
+		auto p = species_[species]->get_entity_component<Component>();
+		if (p)
+			return p + entity;
+		return p;
+	}
+
+	template <typename Component>
+	typename Component::data const * ecs::get_if(handle species, handle entity) const
+	{
+		return const_cast<typename Component::data const *>(const_cast<ecs *>(this)->get<Component>(species, entity));
+	}
+
 	template <typename Behavior>
 	void ecs::apply(Behavior && behavior) const
 	{