3 ms·

tl;dr #include <stdckdint.h> bool ckd_add(type1 result, type2 a, type3 b); bool ckd_sub(type1 result, type2 a, type3 b); bool ckd_mul(type1

tl;dr #include <stdckdint.h> bool ckd_add(type1 *result, type2 a, type3 b); bool ckd_sub(type1 *result, type2 a, type3 b); bool ckd_mul(type1 *result, type2 a, type3 b); #include <stdckdint.h> #include <limits.h> /* ... */ int x; int a = INT_MAX; int b = INT_MAX; if (!chk_add(&x, a, b)) { /* error! */ } Other stuff on the table for C23 - https://thephd.dev/c-the-improvements-june-september-virtual-c-meeting https://thephd.dev/c-the-improvements-june-september-virtual... - (PDF) https://open-std.org/jtc1/sc22/wg14/www/docs/n3054.pdf https://open-std.org/jtc1/sc22/wg14/www/docs/n3054.pdf

heywhatupboys 4y ago
> if (!chk_add(&x, a, b)) { > /* error! */ > } does it return non-zero on success???
- EdSchouten 4y ago
  It returns a boolean.
- tinglymintyfrsh 4y ago
  They're using a bool, so it violates the old-school C paradigm used for library calls. This is more of a macro rather than a syscall or standard library function call.
  - comex 4y ago
    It returns a bool, but true means error, not false.
    - ronsor 4y ago
      It's not really an error. The function is just "check if this addition overflows" and tells you true, it does overflow, or false, it doesn't.
comex 4y ago
You have it backwards: it returns true on error.
RustyRussell 4y ago
Let's take this as evidence that the proposal is counter-intuitive?