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From: ghoti+@andrew.cmu.edu (Adam Stoller)
Newsgroups: comp.std.c
Subject: [m]allocation question
Message-ID: <UaxqffS00Vtq8akksB@andrew.cmu.edu>
Date: 19 Sep 90 12:56:11 GMT
Organization: Information Technology Center, Carnegie Mellon, Pittsburgh, PA
Lines: 32

I've been looking at a book, "Algorithms in C" by Robert Sedgewick - and
although some of the coding examples are fairly sloppy (in terms of
error checking) I can understand that since that isn't the focus of the
book.  

However there is at least one piece of code where he allocates pointers
in a way I've never seen before -- and it isn't clear to me whether it
should work -- and was wondering if anyone could clarify it for me (in
regards to whether it works according to the Standard).

Example:

    static struct node
      { int key; struct node *next; };
    static struct node *head, *z, *t;
.....
    push (int v)
      {
        t = (struct node *) malloc(sizeof *t);
.....

Isn't *t garbage at the time the sizeof is performed - isn't this
[almost?] de-referencing a NULL pointer.

Traditionally, I believe, the above line is written:
        t = (struct node *) malloc (sizeof (struct node));
so my question is not how to correctly write the allocation, but whether
his method of writing it is at all acceptable?

Primarilly curious,

--fish