@ScalarOperator(CAST)
    @LiteralParameters("x")
    @SqlType("varchar(x)")
    public static Slice castToVarchar(@SqlType(StandardTypes.DOUBLE) double value)
    {
        return utf8Slice(String.valueOf(value));
    }
@Test
    public void testCastToVarchar()
    {
        assertFunction("cast(37.7E0 as varchar)", VARCHAR, "37.7");
        assertFunction("cast(17.1E0 as varchar)", VARCHAR, "17.1");
    }