Queries also provide entity_id

system_scheduler.hpp

@@ -1,6 +1,6 @@
 #pragma once
 #include <functional>
-#include <vector> 
+#include <vector>
 
 namespace zecsy
 {

tests/zecsy.cpp

@@ -2,8 +2,8 @@
 #define CATCH_CONFIG_MAIN
 #include <catch2/catch_all.hpp>
 
-#include "../zecsy.hpp"
 #include "../system_scheduler.hpp"
+#include "../zecsy.hpp"
 
 using namespace zecsy;
 
@@ -193,7 +193,7 @@ TEST_CASE("Create a simple system that processes entities with a specific "
      * Really wanna deduce it to w.query([](Component&){}),
      * but I have some troubles with it
      */
-    w.query<Component>([](Component& c) { c.value++; });
+    w.query<Component>([](entity_id e, Component& c) { c.value++; });
 
     REQUIRE(w.get<Component>(e0).value == 1);
     REQUIRE(w.get<Component>(e1).value == 21);
@@ -223,20 +223,16 @@ TEST_CASE("Test a systems ability to query and process only entities with a "
     auto e2 = w.make_entity();
     w.set(e2, C1{});
 
-    int count = 0;
-
     REQUIRE(w.get<C0>(e0).value == 0);
     REQUIRE(w.get<C1>(e0).value == 10);
 
-    w.query<C0, C1>([&count](C0& c0, C1& c1)
+    w.query<C0, C1>([e0](entity_id e, C0& c0, C1& c1)
     {
+        REQUIRE(e == e0);
         c0.value++;
         c1.value++;
-        count++;
     });
 
-    REQUIRE(count == 1);
-
     REQUIRE(w.get<C0>(e0).value == 1);
     REQUIRE(w.get<C1>(e0).value == 11);
 

zecsy.hpp

@@ -63,7 +63,7 @@ namespace zecsy
         void remove(entity_id e);
 
         template<Component... T>
-        void query(std::invocable<T&...> auto&& system);
+        void query(std::invocable<entity_id, T&...> auto&& system);
 
     private:
         using comp_id = size_t;
@@ -228,13 +228,13 @@ namespace zecsy
     }
 
     template<Component... T>
-    inline void world::query(std::invocable<T&...> auto&& system)
+    inline void world::query(std::invocable<entity_id, T&...> auto&& system)
     {
         for(auto e: alive_entities)
         {
             if((has<T...>(e)))
             {
-                system(get<T>(e)...);
+                system(e, get<T>(e)...);
             }
         }
     }