Tell HN: C Experts Panel – Ask us anything about C

Post by DougGwyn » Tue, Apr 14, 2020, 2:47 PM UTC

pcr910303 wrote: post #148

As there are a lot of C-masters lurking in this thread: How can one process unicode (UTF-8) properly in C? As a CJK person, I wish there was a robust solution. Are there any standardized ways or proposals? (Using wchar doesn't count.)

Post by eqvinox » Tue, Apr 14, 2020, 2:47 PM UTC

rwmj wrote: post #171

AaronBallman wrote: post #139

Earlier quoted context omitted.

Funny you should mention that, as that feature has come up recently in mailing list discussions. We have not seen an actual proposal for adopting it yet, but features similar semantics are being discussed as a possible idea (no promises). FWIW, I don't think it would wind up being spelled with attribute syntax because we would likely want programmers to have a guarantee that the cleanup will happen (and attributes ca…

I believe the last proposal was in 2008 (ignore the try..finally stuff here): http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1298.pdf So I guess it needs someone to take that and update it, also to pull up a full list of current Linux software which is using this feature (which as I say these days is a surprising amount).

  #define frr_with_privs(privs)                                                  \
          for (struct zebra_privs_t *_once = NULL,                               \
                                    *_privs __attribute__(                       \
                                            (unused, cleanup(_zprivs_lower))) =  \
                                            _zprivs_raise(privs, __func__);      \
               _once == NULL; _once = (void *)1)

  frr_with_privs(privs) {
    ... whatever ...
    break;  /* exit block, drop privileges */
    return; /* return, drop privileges */
  }

Post by a-bit-of-code » Tue, Apr 14, 2020, 2:47 PM UTC

Post by dktoao » Tue, Apr 14, 2020, 2:48 PM UTC

pantalaimon wrote: post #23

Will C eventually get something like C++' constexpr?

Post by pantalaimon » Tue, Apr 14, 2020, 2:49 PM UTC

darepublic wrote: post #130

pantalaimon wrote: post #87

Earlier quoted context omitted.

Do you find the learning curve for C to be high? I find it quite the opposite. It's a simple language with only a few concepts to learn, once you got those, that's it. There might be some preprocessor tricks you'll pick up later, but the base language and library is pretty comprehensive IMHO.

Coming from python/js I found it to be high. Mostly because of the memory management/ making sure I call free correctly etc. In many cases where I would plow ahead in programming, with C I had to stop and would feel dread. A lifesaver for me was using C/C++ Repl environments where I could quickly prototype or sanity check things I was doing.