Move ECS to Bubel module

source/bubel/ecs/traits.d

@@ -0,0 +1,39 @@
+module bubel.ecs.traits;
+
+import std.traits;
+
+bool isForeachDelegateWithTypes(DG, Types...)()
+{
+	return is(DG == delegate) && is(ReturnType!DG == int) && is(Parameters!DG == Types);
+}
+
+unittest
+{
+	assert(isForeachDelegateWithTypes!(int delegate(int, int), int, int));
+	assert(isForeachDelegateWithTypes!(int delegate(ref int, ref int), int, int));
+	assert(!isForeachDelegateWithTypes!(int delegate(double), int, int));
+}
+
+/************************************************************************************************************************
+	Returns index of Component/Entity array in System's EntitiesData struct
+*/
+static long getIndexOfTypeInEntitiesData(EntitiesData, Type)()
+{
+	alias EntitiesDataFields = Fields!(EntitiesData);
+	long index = -1;
+	foreach (fieldNum, FieldType; Fields!(EntitiesData))
+	{
+
+		static if (!isBasicType!(FieldType)) // Not basic type     
+		{
+				// FieldType should be something like: 'const(SomeComponent)[]'
+				enum bool entitiesMatches = is(Type == Unqual!(ForeachType!(FieldType)));
+				static if (entitiesMatches)
+					{
+					index = fieldNum;
+					break;
+				}
+			}
+	}
+	return index;
+}