```
$ ~/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 field = from.get<DecimalField<From>>();
    T value = convertDecimals<DataTypeDecimal<From>, DataTypeDecimal<T>>(field.getValue(), field.getScale(), type.getScale());
    return DecimalField<T>(value, type.getScale());
}
template <typename To>
static Field convertDecimalType(const Field & from, const To & type)
{
    if (from.getType() == Field::Types::UInt64)
        return convertIntToDecimalType<UInt64>(from, type);
    if (from.getType() == Field::Types::Int64)
        return convertIntToDecimalType<Int64>(from, type);
    if (from.getType() == Field::Types::String)
        return convertStringToDecimalType(from, type);
    if (from.getType() == Field::Types::Decimal32)
        return convertDecimalToDecimalType<Decimal32>(from, type);
    if (from.getType() == Field::Types::Decimal64)
        return convertDecimalToDecimalType<Decimal64>(from, type);
    if (from.getType() == Field::Types::Decimal128)
        return convertDecimalToDecimalType<Decimal128>(from, type);
    throw Exception("Type mismatch in IN or VALUES section. Expected: " + type.getName() + ". Got: "
        + Field::Types::toString(from.getType()), ErrorCodes::TYPE_MISMATCH);
}
Field convertFieldToTypeImpl(const Field & src, const IDataType & type, const IDataType * from_type_hint)
{