Function tryConvertTypeToNullable

src/Interpreters/join_common.cpp:107–112

DataTypePtr tryConvertTypeToNullable(const DataTypePtr & type)
{
    if (canBecomeNullable(type))
        return convertTypeToNullable(type);
    return type;
}

DataTypePtr removeTypeNullability(const DataTypePtr & type)
{