At 12:51 PM -0400 6/8/06, Beman Dawes wrote:
Gennaro Prota wrote:
* there is no guarantee that an unsigned char has 8 bits...
The C and C++ standards specify char, signed char, and unsigned char all have exactly 8 bits, AFAIK.
CHAR_BITS is defined to be *at least* 8 bits. No guarantee that it is *exactly* 8 bits. This is not just a historical artifact to support strange ancient processors with odd addressing unit sizes either. There are modern C/C++ implementations for modern DSP processors where, for example, sizeof(char) == sizeof(int) == 1, and CHAR_BITS is 16 or 32 (or perhaps even 64, though I haven't actually run across that last case myself). Of course, the vast majority of even purportedly portable code ignores this fact, because it can be a real PITA to deal with, usually for little or no benefit.