// CS0151: A switch expression of type `X?' cannot be converted to an integral type, bool, char, string, enum or nullable type
// Line: 19

struct X 
{
	public static implicit operator int? (X x)
	{
		return 1;
	}

	static void Main ()
	{
		X? x = null;
		switch (x) {
		default:
			break;
		}
	}
}