Newsgroups:	comp.os.msdos.djgpp
From:	Peter Berdeklis <peter AT atmosp DOT physics DOT utoronto DOT ca>
Subject:	Re: complex numbers, correct ??
Message-ID:	<Pine.SGI.3.91.970827160403.12574A-100000@atmosp.physics.utoronto.ca>
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Organization:	University of Toronto - Dept. of Physics
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Date:	Wed, 27 Aug 1997 20:07:00 GMT
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Lines:	31
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

On 25 Aug 1997, Jos Bergervoet wrote:

> I installed djgpp 2.721, read the FAQ (for v2.01) and still don't
> see why the following does not work. Other compiler have no problem
> with it. I noticed that using complex<double> in the declaration
> makes the compiler accept it, but still it computes (0,0) instead
> of ( 0.981, 0.018). Have I missed recent changes in the C++ syntax?
> 
> Greetings,
> Jos Bergervoet
> 
>     complex    a, b, c;
>     a = complex(23.4, 26.9);
>     b = (a+2)/(a+3);
>     printf( "Hello: result = (%10.4g,%10.4g)\n", b );

printf() is a C function, not a C++ function.  C knows nothing about 
complex types, or any C++ class type for that matter.  The g in the format 
code causes it interpret b as a float.  Since it isn't you get undefined 
results.

Try this:
	cout << "Hello: result = " << b << endl;

By the way, if the code fragment you give above works on other compilers 
dump them!  This would be a compiler bug.

---------------
Peter Berdeklis
Dept. of Physics, Univ. of Toronto

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