```
$ ~/arc/build/clickhouse/programs/clickhouse client
ClickHouse client version 21.2.1.1-arcadia.
Connecting to localhost:9000 as user default.
Connected to ClickHouse server version 21.2.1 revision 54447.

max42-dev.sas.yp-c.yandex.net :) create table t(a Tuple(UInt8, UInt8)) engine = Log()

CREATE TABLE t
(
    `a` Tuple(UInt8, UInt8)
)
ENGINE = Log

Query id: b49dbb5d-d2a9-4c99-b90e-00c60edf2103

Ok.

0 rows in set. Elapsed: 0.005 sec. 

max42-dev.sas.yp-c.yandex.net :) insert into t values ((NULL, 42))

INSERT INTO t VALUES

Query id: 318d6f3e-f3bc-467c-85ff-62da908230dd

Logical error: 'Unexpected literal type inside Array: Nothing. It's a bug'.
Aborted (core dumped)
```

This is CH similar to one from Arcadia r7788360 (~fresh master version from GH).

(you don't have to strictly follow this form)

* succeed, because the source and the requested types of the
                 * element are compatible, but the value is not convertible
                 * (e.g. trying to convert -1 from Int8 to UInt8). In these
                 * cases, consider the whole tuple also compatible but not
                 * convertible. According to the specification of this function,
                 * we must return Null in this case.
                 *
                 * The following elements might be not even compatible, so it
                 * makes sense to check them to detect user errors. Remember
                 * that there is an unconvertible element, and try to process
                 * the remaining ones. The convertFieldToType for each element
                 * will throw if it detects incompatibility.
                 */
                have_unconvertible_element = true;
            }
            return have_unconvertible_element ? Field(Null()) : Field(res);
        }
    }
    else if (const DataTypeAggregateFunction * agg_func_type = typeid_cast<const DataTypeAggregateFunction *>(&type))
    {
        if (src.getType() != Field::Types::AggregateFunctionState)
            throw Exception(String("Cannot convert ") + src.getTypeName() + " to " + agg_func_type->getName(),
                    ErrorCodes::TYPE_MISMATCH);
        const auto & name = src.get<AggregateFunctionStateData>().name;
        if (agg_func_type->getName() != name)
            throw Exception("Cannot convert " + name + " to " + agg_func_type->getName(), ErrorCodes::TYPE_MISMATCH);
        return src;
    }
    
    if (src.getType() == Field::Types::String)