```
$ echo '20210101,A' | clickhouse-local --input-format CSV --structure 'd Date, s String' --query "SELECT * FROM table"
Code: 27. DB::Exception: Cannot parse input: expected ',' before: '20210101,A\n': 
Row 1:
Column 0,   name: d, type: Date,   ERROR: text "20210101,A" is not like Date

: While executing ParallelParsingBlockInputFormat: While executing File. (CANNOT_PARSE_INPUT_ASSERTION_FAILED)
```

**How to solve**

Disambiguate while parsing by absense of separators between YYYY-MM-DD.
{
    ReadBufferFromMemory in(pos, end - pos);
    tryReadIntText<check_overflow>(x, in);
    return pos + in.count();
}
template <typename T>
inline T parse(const char * data, size_t size)
{
    T res;
    ReadBufferFromMemory buf(data, size);
    readText(res, buf);
    return res;
}
template <typename T>
inline bool tryParse(T & res, const char * data, size_t size)
{
    ReadBufferFromMemory buf(data, size);
    return tryReadText(res, buf);
}
template <typename T>
inline void readTextWithSizeSuffix(T & x, ReadBuffer & buf) { readText(x, buf); }