realloc((char *)NULL,size) - how standard ?

[Dave P. Schaumann]

In article <15112:Feb2419:11:4391 at kramden.acf.nyu.edu> brnstnd at kramden.acf.nyu.edu (Dan Bernstein) writes:
>In article <1991Feb24.071716.409 at athena.mit.edu> scs at adam.mit.edu writes:
>>      Passing an initially-null pointer to realloc can make it very easy
>>      to write a self-starting incremental allocation algorithm.
>
>I find this advice counterproductive. [...]
>it is simply not portable. It's just as easy---and much more
>portable---to start by allocating one element.

Actually, if you want to port code that passes NULL to realloc to a machine
that doesn't like that, all you have to do is this:

void *Realloc( void *ptr, size_t size ) {

  if( ptr == NULL ) return malloc ( size ) ;
  else		    return realloc( ptr, size ) ;

} /* Realloc */

Then, just #define realloc Realloc anywhere you need to.  I was going to post
this when this question first came up, but I thought it was so obvious, it
would be a waste of bandwidth...

-- 
Dave Schaumann      | Is this question undecidable?
dave at cs.arizona.edu |