```
$ ~/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)

{
    
    auto settings = context->getSettingsRef();
    if (templates[column_idx]->parseExpression(buf, format_settings, settings))
    {
        ++rows_parsed_using_template[column_idx];
        return true;
    }
    
    
    if (column->empty())
        column = IColumn::mutate(templates[column_idx]->evaluateAll(block_missing_values, column_idx));
    else
    {
        ColumnPtr evaluated = templates[column_idx]->evaluateAll(block_missing_values, column_idx, column->size());
        column->insertRangeFrom(*evaluated, 0, evaluated->size());
    }
    
    templates[column_idx].reset();
    buf.rollbackToCheckpoint();
    
    return parseExpression(*column, column_idx);
}
bool ValuesBlockInputFormat::tryReadValue(IColumn & column, size_t column_idx)