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Date: Sat, 4 May 2002 07:16:14 -0700 (PDT)
From: PEDRO IZECKSOHN <izecksohn AT yahoo DOT com>
Subject: Re: Can double negations get optimized out?
To: djgpp AT delorie DOT com
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   For me your code worked this way: ( b= !!a ) == ( b==a )
.
   I would write it this way:

//...
int a;
do {
scanf("%d",&a);
} while ( (a!=0) && (a!=1) );
//...

   or

//...
int a;
scanf("%d",&a);
if ( (a!=0) && (a!=1) ) { /* ... */ }
//...

--- Martin Steuer <martinSteuer AT gmx DOT de> wrote:
> For example:
> 
> [...]
> int a,b;
> scanf("%d",&a);
> b = !!a;
> [...]
> 
> I want to be sure that b can only be 1 or 0. Do i have to
> worry that this 
> is optimized out by a compiler? In my opinion i dont
> think so...
> 
> Thanks in advance for the info
> 


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