On 03/10/2013 07:00 AM, Henri Verbeet wrote:
On 10 March 2013 08:20, larmbr zhan <nasa4...@gmail.com> wrote:But It behaves different when it is signed or not. According to C Standard,
>>
- For the signed case, once it overflows, resulting in representing a negative value .Actually, signed overflow behavior is undefined according to the standard.
Specifically, some hardware throws an exception on signed arithmetic overflow and C is specifically designed to be hardware independent, so it has to be 'undefined behavior'.
- For the unsigned case, once it overflows, resulting in representing a value reduced modulo the largest value that object could hold.
Nit: modulo the largest value the object can hold _plus one_, but it should be treated as another 'undefined behavior'.
To further complicate the issue, while size_t is always unsigned, size_t can be 16, 18, 32, 36 or 64 bits and still be compliant. So use
'size_t' when you are talking about the size of something, and 'unsigned' for flag sets and counts.
