Common update:

-added multiple new function to allocate template and add entity
-updated README.md (complete initial version)
-empty components now don't take memory
-fixedd small bug with TestRunner
-added many new tests (HashMap, Vector, EntityMeta, ...)
-added default hashing function to HashMap
-fixed critical bug with adding entities
-fixed small bug with adding entity with remplacement components
-added asserts into code to better bug detection
-small performance improvement for events
-added ComponentRef structure which contain data pointer and componentID
-remove EntityID from Event structure
-now events are handled before removing entiteis
-fixed GDC compilation
-fixed rendering of rotated sprites
-added weapons as separate entities to space ship and others
-added Tower enemy to SpaceInvaders demo
-added Boss to SpaceInvaders demo (boss has four tower attached to it)
-Boss towers shoot multiple bullets upon death
-fixed critical bug with demos switching
-fixed critical bug related to adding/removing entities form inside onAdd/onRemove entity callback
-added animation support
-added particles sypport and particles for firing and explostions, and more
-multithreaded rendering now has same rendering order as singlethreaded
-application automaticallu detect host CPU threads count
-added upgrades to SPaceInvaders demo
-fixed texture memory freeing
-improved documentation
-improved multithreaded performance
-improve shader code
-fixed registration issue
-some additional performance improvements
-added depth and colors to rendering parameters
-jobs now has names corresponding to their systems
-change execute() -> willExecute()
-added EntityMeta structure to speedup getting fetching components form entity
-improved multithreading rendering
-added possibility tio change number of threads runtime
-added bullets collision detection in SpaceInvaders demo
-some CI changes
-added VBO batch rendering (current default, no render mode switch yet)
-fixed camera positioning calculation
-fixed buffer issue with WebGL
-added viewport scalling (at least 300 pixels height). Pixels are scalled if screen is bigger.
-center demos gameplay area
-added fullpage html template for Emscripten build
-added many new sprites to atlas
-fixed critical bug with CPU usage in multithreaded mode
-snake render tile coresponding to body part
-snake is destroyed after collision and emit some particles
-added some functionality to vectors
-fixed documentation issue in Manager.d
-more minor code changes and cleanup

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;
+}