4 ms·

I think you are in agreement with the comment you are replying to.

• paulddraper 8y ago
  The comment suggested the standard make it implementation defined rather than undefined. There's not a meaningful difference here. Even today, an implementation may define unsigned overflow.
  • wyldfire 8y ago
    Oh, I see, I wonder if greenhouse_gas is suggesting a feature similar to sizeof() that can be used to portably adapt your program's design to the target's overflow capability.
    • unwind 8y ago
      C language lawyer in training: sizeof is not a function. The parentheses are part of the operand and only needed for type names, to make them into cast expressions.
  • Someone 8y ago
    Yes, there is. Implementation defined means that a conforming implementation _must_ document its behavior. That means that programmers don’t have to use trial and error to figure out how the compiler behaves and don’t have to _hope_ they found all the corner cases.
    • berti 8y ago
      And that is how we get #if defined(_THIS_THING_SOME_COMPILER_DEFINES) && !defined(__BUT_NOT_THIS_ONE_THAT_COMPILER_X_DEFINES) soup ;)
      • greenhouse_gas 8y ago
        Better than than silently ignoring an if guard preventing an overflow, and then overflowing anyways on addition.