number of digits in a hex escape code in C/C++

Question

I\'m having a dispute with a colleague of mine. She says that the following:

char* a = \"\\x000aaxz\";

will/can be seen by the compiler as

Answer 1

§2.13.2/4:

The escape \xhhh consists of the backslash followed by x followed by one or more hexadecimal digits that are taken to specify the value of the desired character. There is no limit to the number of digits in a hexadecimal sequence. A sequence of octal or hexadecimal digits is terminated by the first character that is not an octal digit or a hexadecimal digit, respectively.

She is right.

However, you can terminate it early by eager catenation: the sequence of literals "\x000a" "axz" specifies a single four-character string literal. (2.13.4/3)

Also note that Unicode uses 21-bit code points; it doesn't stop at 16 bits.