From:	Martin Ambuhl <mambuhl AT earthlink DOT net>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: enum - Why does true == false?
Date:	Fri, 17 Sep 1999 00:11:53 -0400
References:	<HbrhNzeq9qsy9UvyzT4fDeX4Lrnh AT 4ax DOT com>
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To:	djgpp AT delorie DOT com
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Carl Hover wrote:
> 
> Why does this program print "true == false" when compiled with djgpp
> v2.01, and "true != false" when compiled with Borland C++ 3.1? Are
> enum constants ill-defined during preprocessing?

Try replacing your code with the following and see if it gives you a
clue:
#include <stdio.h>

int main(void)
{
    enum {
        false, true
    };
#if defined(true)
    printf("true is defined\n");
#elif !defined(true)
    printf("true is not defined\n");
#endif
    
#if defined(false)
    printf("false is defined\n");
#elif !defined(false)
    printf("false is not defined\n");
#endif

#if true == false
    printf("true == false\n");
#endif

#if true != false
    printf("true != false\n");
#endif

    return 0;
}


> 
> #include <stdio.h>
> 
> int main(void)
> {
>   enum {false, true};
> 
>   #if true == false
>     printf("true == false\n");
>   #endif
> 
>   #if true != false
>     printf("true != false\n");
>   #endif
> 
>   return 0;
> }

-- 
Martin Ambuhl	mambuhl AT earthlink DOT net

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