Why does gcc4 dislike this code?

[Christopher Layne]

On Wed, Jun 18, 2008 at 03:45:07PM -0700, walt wrote:
> Hi all,
>
> This is a snippet of code that compiles nicely with gcc3 but not
> with gcc4 (4.1.2 to be exact):
>
>  *((unsigned long int *) tmp)++ = *((unsigned long int *) b1)++;
>
> error: invalid lvalue in increment

http://www.google.com/search?q=gcc+lvalue+cast

-cl