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Re: Segmentation Fault

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On 05/17/2012 03:50 PM, pembed2012 wrote:
> On Wed, 16 May 2012 20:17:22 +0000, Ike Naar wrote:
> 
>> On 2012-05-14, pembed2012 <once@was.enough.invalid> wrote:
>>>       if(ctm[qu[i]] == 0);
>>
>> This statement is redundant (it's an if statement with an empty body).
>> Elsethread, you say that the code was written by a "genius programmer"
>> and is super efficient. Including a redundant statement is not what one
>> would expect from such a programmer. Is the code that you posted the
>> real, unmodified code?
> 
> The only thing I can think of is, maybe the condition is being evaluated 
> for its side effects.

Side effects can only result from ++, --, assignment expressions,
certain function calls, or accessing a volatile object. None of those
things happen in this code, so that can't be the reason.

> Of course it may be a bug. How does the behavior of the code change if 
> you delete the ; ?

In the original code, it said:

	if(ctm[qu[i]] == 0);
	atm[qu[i]] = -1;

That's exactly equivalent to

	atm[qu[i]] = -1;

Removing the semicolon would change the code so that it was equivalent to
	if(ctm[qu[i]] == 0)
	{
            atm[qu[i]] = -1;
	}

which is very different.

> I don't feel like I've had a clear answer yet about what this function is 
> doing and how it works!

You haven't, because you've been asking the wrong people. Is there
anyone who's ever written code that uses this function that you can talk to?

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Segmentation Fault pembed2012 <once@was.enough.invalid> - 2012-05-14 16:45 +0000
  Re: Segmentation Fault John Gordon <gordon@panix.com> - 2012-05-14 17:00 +0000
    Re: Segmentation Fault Keith Thompson <kst-u@mib.org> - 2012-05-14 13:44 -0700
      Re: Segmentation Fault Edward Rutherford <edward.p.rutherford79@REMOVETHIS.gmail.com> - 2012-05-14 21:07 +0000
        Re: Segmentation Fault John Gordon <gordon@panix.com> - 2012-05-14 21:10 +0000
  Re: Segmentation Fault James Kuyper <jameskuyper@verizon.net> - 2012-05-14 13:25 -0400
    Re: Segmentation Fault pembed2012 <once@was.enough.invalid> - 2012-05-14 21:00 +0000
      Re: Segmentation Fault James Kuyper <jameskuyper@verizon.net> - 2012-05-14 17:21 -0400
      Re: Segmentation Fault John Gordon <gordon@panix.com> - 2012-05-14 21:24 +0000
        Re: Segmentation Fault John Gordon <gordon@panix.com> - 2012-05-14 21:35 +0000
        Re: Segmentation Fault pembed2012 <once@was.enough.invalid> - 2012-05-15 19:27 +0000
          Re: Segmentation Fault "BartC" <bc@freeuk.com> - 2012-05-15 20:38 +0100
            Re: Segmentation Fault pembed2012 <once@was.enough.invalid> - 2012-05-16 19:56 +0000
              Re: Segmentation Fault James Kuyper <jameskuyper@verizon.net> - 2012-05-16 16:17 -0400
              Re: Segmentation Fault James Kuyper <jameskuyper@verizon.net> - 2012-05-16 16:17 -0400
          Re: Segmentation Fault John Gordon <gordon@panix.com> - 2012-05-15 19:56 +0000
          Re: Segmentation Fault James Kuyper <jameskuyper@verizon.net> - 2012-05-15 15:58 -0400
            Re: Segmentation Fault Jorgen Grahn <grahn+nntp@snipabacken.se> - 2012-05-18 01:02 +0000
          Re: Segmentation Fault Kaz Kylheku <kaz@kylheku.com> - 2012-05-15 20:10 +0000
            Re: Segmentation Fault lawrence.jones@siemens.com - 2012-05-15 17:43 -0400
              Re: Segmentation Fault James Kuyper <jameskuyper@verizon.net> - 2012-05-15 18:27 -0400
            Re: Segmentation Fault gordonb.dxbbb@burditt.org (Gordon Burditt) - 2012-05-19 02:37 -0500
  Re: Segmentation Fault "BartC" <bc@freeuk.com> - 2012-05-14 22:17 +0100
  Re: Segmentation Fault Fred K <fred.l.kleinschmidt@gmail.com> - 2012-05-14 10:02 -0700
  Re: Segmentation Fault Fred K <fred.l.kleinschmidt@gmail.com> - 2012-05-14 11:33 -0700
  Re: Segmentation Fault Ike Naar <ike@sverige.freeshell.org> - 2012-05-16 20:17 +0000
    Re: Segmentation Fault nick_keighley_nospam@hotmail.com - 2012-05-17 03:05 -0700
      Re: Segmentation Fault Ike Naar <ike@iceland.freeshell.org> - 2012-05-17 11:07 +0000
    Re: Segmentation Fault pembed2012 <once@was.enough.invalid> - 2012-05-17 19:50 +0000
      Re: Segmentation Fault James Kuyper <jameskuyper@verizon.net> - 2012-05-17 16:59 -0400
      Re: Segmentation Fault Ike Naar <ike@sverige.freeshell.org> - 2012-05-18 07:22 +0000

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