From: broeker AT acp3bf DOT knirsch DOT de (Hans-Bernhard Broeker)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Complex Numbers
Date: 24 Sep 1999 03:50:52 +0200
Organization: RWTH Aachen, III. physikalisches Institut B
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Andrew Hurrell (andrew AT amh-consulting DOT freeserve DOT co DOT uk) wrote:
[...]
> 1)    The complex math stuff appears to use a _complex_ data type within
> gcc.  Have I missed this completly in the docs, or is it not supported under
> DJGPP.

You have missed it in the docs. Among some other extensions to the core
standard C language, gcc supports complex numbers as a compiler-integrated
datatype. It's documented in

	info gcc 'C Extensions' complex

In a nutshell:

	__complex__ double a = 1 + 5i;

defines a complex variable 'a' with value 1 + 5i.

> 2)    Also the Cephes docs talk about C9X which I get the impression is
> going to be new standard for C, and again according to these docs, this new
> implementation will support Complex math.  Does anyone know what the state
> of play on C9X - does DJGPP conform to this standard ?

C9x is still a moving target, and no efforts in the DJGPP community
have yet been made to implement any of its changes. Quite a large part
of it will have to be done by the gcc developers, not in DJGPP,
anyway.  The standardized set of library functions hasn't changed all
that much, in comparison to the language itself.

> 3)    When I try to debug anything (from within RHIDE) that uses complex
> math I am unable to see what data my variables contain (all variables report
> as being void - yet printf's give the correct answers).  What am I doing
> wrong ?

Nothing, I think. The gcc documentation page I already mentioned has
details about how to display these variables in a debugger.

-- 
Hans-Bernhard Broeker (broeker AT physik DOT rwth-aachen DOT de)
Even if all the snow were burnt, ashes would remain.