diff --git a/source/ecs/manager.d b/source/ecs/manager.d
index 133b964..20aff6b 100644
--- a/source/ecs/manager.d
+++ b/source/ecs/manager.d
@@ -325,6 +325,7 @@ class EntityManager
             CompInfo[] optional;
             CompInfo[] mutable;
             CompInfo[] req;
+            string entites_array;
         }
 
         static void allocateSystemComponents(ComponentsIndices components_info)(ref System system)
@@ -363,8 +364,10 @@ class EntityManager
                 alias MemberType = typeof(__traits(getMember, Sys.EntitiesData, member));
                 if (member == "length" || is(MemberType == Entity[]) || is(MemberType == const(Entity)[]))
                 {
+                    if(is(MemberType == Entity[]) || is(MemberType == const(Entity)[]))components_info.entites_array = member;
                     continue;
                 }
+
                 string name;
                 static if (isArray!MemberType)
                 { // Workaround. This code is never called with: not an array type, but compiler prints an error
@@ -451,6 +454,8 @@ class EntityManager
             return components_info;
         }
 
+        enum ComponentsIndices components_info = getComponentsInfo();
+
         static void genCompList()(ref System system, ref HashMap!(const(char)[], ushort) components_map)
         {
 
@@ -469,7 +474,7 @@ class EntityManager
                     static assert(0, "EntitiesData members should be arrays of elements!");
             }
 
-            enum ComponentsIndices components_info = getComponentsInfo();
+            //enum ComponentsIndices components_info = getComponentsInfo();
             allocateSystemComponents!(components_info)(system);
 
             foreach (iii, comp_info; components_info.req)
@@ -508,23 +513,16 @@ class EntityManager
         static void fillInputData(ref Sys.EntitiesData input_data, EntityInfo* info,
                 EntitiesBlock* block, uint offset, uint entities_count, System* system)
         {
-            enum ComponentsIndices components_info = getComponentsInfo();
-            static foreach (member; __traits(allMembers, Sys.EntitiesData))
+            //enum ComponentsIndices components_info = getComponentsInfo();
+
+            static if(components_info.entites_array)
             {
-                static if (is(typeof(__traits(getMember, Sys.EntitiesData,
-                        member)) == Entity[]) || is(typeof(__traits(getMember,
-                        Sys.EntitiesData, member)) == const(Entity)[]))
-                {
-                    __traits(getMember, input_data, member) = (cast(Entity*) block.dataBegin())[offset .. entities_count];
-                }
-                else static if (member == "length")
-                {
-                    __traits(getMember, input_data, member) = cast(typeof(input_data.length))(entities_count - offset);
-                }
-                else 
-                {
-                    
-                }
+                __traits(getMember, input_data, components_info.entites_array) = (cast(Entity*) block.dataBegin())[offset .. entities_count];
+            }
+
+            static if(hasMember!(Sys.EntitiesData,"length"))
+            {
+                input_data.length = cast(typeof(input_data.length))(entities_count - offset);
             }
 
             static foreach (iii, comp_info; components_info.req)