Re: nested while loop computing triangular number - issues

From	Keith Thompson <kst-u@mib.org>
Newsgroups	comp.lang.c
Subject	Re: nested while loop computing triangular number - issues
Date	2015-07-15 13:19 -0700
Organization	None to speak of
Message-ID	<lnd1ztjhqv.fsf@kst-u.example.com> (permalink)
References	(2 earlier) <5abf1a27-ebbf-4c5d-89d9-e0b8fc6efd04@googlegroups.com> <lnmvz2pdd0.fsf@kst-u.example.com> <7e623eb8-4156-443c-b637-ffe06d4e87de@googlegroups.com> <lntwt9mcuf.fsf@kst-u.example.com> <kfnio9lqoy8.fsf@x-alumni2.alumni.caltech.edu>

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Tim Rentsch <txr@alumni.caltech.edu> writes:
> Keith Thompson <kst-u@mib.org> writes:
>> [snip]
>>
>> Incidentally, one thing I dislike about compound literals is
>> that the storage duration of the object depends only on the
>> context in which it appears.  A string literal always creates an
>> array object with static storage duration.  A compound literal
>> creates an object with static storage duration if it occurs
>> outside a function, or with automatic storage duration if it
>> occurs inside a function.  [snip] there are times it would be
>> convenient to have a block-scope compound literal that refers to
>> a static object.
>>
>> I might suggest an enhancement that permits something like:
>>
>>     (static struct foo){1, 0, 1, 0};
>>
>> at block scope.  (Of course non-constant expressions would not
>> be permitted.)
>
> I don't know why you think this would be useful.  If the value is
> used only for its value (ie, and the address is not taken),
> simply leave off the 'static' and let the compiler notice that
> the value can be initialized and kept statically.  If the address
> is made use of, but the contents are not modified, writing the
> compound literal with 'const' in the type should let the compiler
> notice that the value can be allocated statically as well (ie,
> even though there was no mention of 'static').

[...]

I was thinking of compound literals as analogous to string literals.

It's certainly useful to be able to assign a string literal to a
`const char*` object, and for that string to continue to exist outside
the scope in which it appears.

    {
        ...
        obj->name = "Fred";
        ...
    }

It would be awkward of the char array containing "Fred" were to vanish
at the closing brace.  I can imagine something similar for, say, a
structure rather than a character array.

I don't have a concrete example off the top of my head -- and a
non-const static object could cause problems if you're not careful.

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"

Thread

nested while loop computing triangular number - issues Alla _ <modelling.data@gmail.com> - 2015-07-11 06:31 -0700
  Re: nested while loop computing triangular number - issues Alla _ <modelling.data@gmail.com> - 2015-07-11 06:52 -0700
  Re: nested while loop computing triangular number - issues Siri Cruz <chine.bleu@yahoo.com> - 2015-07-11 07:07 -0700
    Re: nested while loop computing triangular number - issues Alla _ <modelling.data@gmail.com> - 2015-07-11 07:27 -0700
      Re: nested while loop computing triangular number - issues Siri Cruz <chine.bleu@yahoo.com> - 2015-07-11 08:19 -0700
  Re: nested while loop computing triangular number - issues Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-07-11 15:28 +0100
    Re: nested while loop computing triangular number - issues Alla _ <modelling.data@gmail.com> - 2015-07-11 08:01 -0700
      Re: nested while loop computing triangular number - issues James Kuyper <jameskuyper@verizon.net> - 2015-07-11 12:24 -0400
      Re: nested while loop computing triangular number - issues Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-07-11 21:24 +0100
        Re: nested while loop computing triangular number - issues Alla _ <modelling.data@gmail.com> - 2015-07-12 09:35 -0700
          Re: nested while loop computing triangular number - issues Keith Thompson <kst-u@mib.org> - 2015-07-12 11:55 -0700
            Re: nested while loop computing triangular number - issues Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-07-12 22:14 +0100
            Re: nested while loop computing triangular number - issues Alla _ <modelling.data@gmail.com> - 2015-07-13 08:05 -0700
    Re: nested while loop computing triangular number - issues David Kleinecke <dkleinecke@gmail.com> - 2015-07-11 10:51 -0700
      Re: nested while loop computing triangular number - issues Keith Thompson <kst-u@mib.org> - 2015-07-11 14:56 -0700
        Re: nested while loop computing triangular number - issues David Kleinecke <dkleinecke@gmail.com> - 2015-07-12 09:32 -0700
          Re: nested while loop computing triangular number - issues James Kuyper <jameskuyper@verizon.net> - 2015-07-12 13:19 -0400
            Re: nested while loop computing triangular number - issues David Kleinecke <dkleinecke@gmail.com> - 2015-07-13 10:16 -0700
          Re: nested while loop computing triangular number - issues Keith Thompson <kst-u@mib.org> - 2015-07-12 11:48 -0700
            Re: nested while loop computing triangular number - issues James Kuyper <jameskuyper@verizon.net> - 2015-07-12 15:23 -0400
            Re: nested while loop computing triangular number - issues Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-15 11:02 -0700
              Re: nested while loop computing triangular number - issues Keith Thompson <kst-u@mib.org> - 2015-07-15 13:19 -0700
                Re: nested while loop computing triangular number - issues Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-20 11:01 -0700
  Re: nested while loop computing triangular number - issues Alla _ <modelling.data@gmail.com> - 2015-07-11 08:45 -0700

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