LayerMask check

LayerMaskCheck.txt

LayerMasks are used often in Unity Technologies' 3D Game Kit to ensure a given interaction is only permitted/triggered by allowed objects. 
Here are some code snippets they use often in the kit to achieve that check:

public LayerMask layers;
void OnTriggerEnter(Collider other)
{
	if (0 != (layers.value & 1 << other.gameObject.layer))
	{
		// layerMask check is met. Do stuff now.
	}
}

And a class extension that can be used for LayerMasks is here:
public static class LayerMaskExtensions
{
	public static bool Contains(this LayerMask layers, GameObject gameObject)
	{
		return 0 != (layers.value & 1 << gameObject.layer);
	}
}