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From: "Alex Vinokur" <alexvn AT foot DOT com>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Trouble of using very large arrays
Date: Fri, 23 Apr 2004 12:00:28 +0300
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"Brian Inglis" <Brian DOT Inglis AT SystematicSw DOT Invalid> wrote in message news:urih80l3b6om4kbblr8jthpjbm1i7cp6gc AT 4ax DOT com...
> On Thu, 22 Apr 2004 20:10:08 +0300 in comp.os.msdos.djgpp, "Alex
> Vinokur" <alexvn AT big DOT foot DOT com> wrote:
>
> >  a = (unsigned int*)malloc (rows * columns * sizeof (unsigned int));
>
> Nitpicks:
>
> -- avoid casting malloc results, as it is unnecessary to cast a void
> pointer to any other type of pointer, but the explicit cast will mask
> not declaring malloc or including stdlib.h, and also mask assignment
> to a non-pointer type;

I prefer to compile C-program with C++ compiler.

So, if foo.c contains
-----------------------------------------------------------
a = malloc (rows * columns * sizeof (unsigned int));
-----------------------------------------------------------

We have
$ gpp foo.c
error: invalid conversion from `void*' to `unsigned int*'

>
> -- avoid using types for sizes, in case someone later changes the
> assigned pointer type; use object sizes instead;
Good point! Thanks.

>
> this is cleaner and more maintainable:
>
------ With C-compiler ------
>    a = malloc(rows * columns * sizeof *a);

------ With C++-compiler ------
      a = (unsigned int*)malloc(rows * columns * sizeof *a);
>
[snip]

--
   Alex Vinokur
     mailto:alexvn AT connect DOT to
     http://mathforum.org/library/view/10978.html