From c59a28433a9e9f1e642bff2382db5b3e40889312 Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Tue, 22 Aug 2023 23:15:56 +0300
Subject: [PATCH] Better ecs::entity_accessor interface

---
 .../ecs/include/psemek/ecs/entity_accessor.hpp | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/libs/ecs/include/psemek/ecs/entity_accessor.hpp b/libs/ecs/include/psemek/ecs/entity_accessor.hpp
index 10adf552..075ee83e 100644
--- a/libs/ecs/include/psemek/ecs/entity_accessor.hpp
+++ b/libs/ecs/include/psemek/ecs/entity_accessor.hpp
@@ -14,7 +14,7 @@ namespace psemek::ecs
 		{}
 
 		template <typename Component>
-		Component & get()
+		Component * get_if()
 		{
 			util::uuid const uuid = Component::uuid();
 
@@ -22,12 +22,26 @@ namespace psemek::ecs
 
 			for (std::size_t i = 0; i < component_uuids.size(); ++i)
 				if (uuid == component_uuids[i])
-					return *reinterpret_cast<Component *>(table_->get_component_pointers()[i].data + detail::stride<Component>() * row_);
+					return reinterpret_cast<Component *>(table_->get_component_pointers()[i].data + detail::stride<Component>() * row_);
 
+			return nullptr;
+		}
+
+		template <typename Component>
+		Component & get()
+		{
+			if (auto ptr = get_if<Component>())
+				return *ptr;
 			assert(false);
 			__builtin_unreachable();
 		}
 
+		template <typename Component>
+		bool contains() const
+		{
+			return get_if<Component>() != nullptr;
+		}
+
 	private:
 		detail::table * table_;
 		std::uint32_t row_;