[Discuss] Casting the return value of malloc bad?

[Paul Nienaber]

Do it this way:

foo = malloc(n * sizeof(*foo));

(the parentheses around *foo are unnecessary, but more readable, IMO)

ISO/ANSI/IEC C provides (since 1989) assignment between pointer-to-void
and other pointer types without the need for a cast.  The exception to
this is function pointers, which aren't required to be representable by
a pointer-to-void.  Of course, you're usually hard-pressed to find an
implementation that doesn't allow you to, and SUS/POSIX requires that
you can.

If you're wondering about sizeof(*foo), consider what happens if you
change the type of "foo" =)

~p

Andrew Resch wrote:
> This link seems to explain it:
> http://faq.cprogramming.com/cgi-bin/smartfaq.cgi?answer=1047673478&id=1043284351
>
>
> Basically, there is no need and it will just cause problems if you
> decide to
> change the type of pointer.
>
> On 7/11/06, Adam Parkin <pzelnip at telus.net> wrote:
>>
>> Okay a question for the C gurus on the list: I've heard from a few
>> people that casting the return value from malloc is bad practice, is
>> this true, and if so, why?  And more importantly, if it is bad practice,
>> then what is a better practice (and why)?
>>
>> -- 
>> Adam Parkin
>> E-mail: pzelnip at telus.net
>> ----------------------
>> To an optimist the glass is half-full.
>> To a pessimist the glass is half-empty.
>> To a computer scientist the glass is twice as big as it needs to be.
>>
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