It may be syntactically terse but I'm not sure it's elegant as you would need to do several checks before this line or else you could end up with some pretty ma

It may be syntactically terse but I'm not sure it's elegant as you would need to do several checks before this line or else you could end up with some pretty major bugs. For example, you would need to ensure that sizeof p is >= sizeof q, or else you will end up with a buffer overflow. This then implies that q has a length and therefore a \0. So you will need to iterate through the string once to find the \0 (which may not be there). Failure to do this can lead to execution of arbitrary code, which is why null terminated strings are indefensible frankly.