private Dictionary<int, List<Component>> entityDictionary = new Dictionary<int, List<Component>>(2000);
private Dictionary<Type, List<Component>> componentDictionary = new Dictionary<Type, List<Component>>(10);

public IEnumerable<T> GetComponents<T>(int entityID) where T : Component
{ ... }

public T GetComponent<T>(int entityID) where T : Component
{ ... }

public T GetNullableComponent<T>(int entityID) where T : Component
{ ... }

public IEnumerable<T> GetComponents<T>() where T: Component
{ ... }

foreach (var hitPoints in world.GetComponents<HitPoints>())
{
	if (authoratative && hitPoints.Armour <= 0.0f)
	{
		// We have just died
		hitPoints.OnDeath();
		world.DeleteComponents(hitPoints.EntityID);
	}
}