On Wednesday, 8 July 2009 at 22:55:47 UTC, Jarrett Billingsley wrote:
> I noticed in the spec on arrays that "A [fixed-size] array with a
> dimension of 0 is allowed, but no space is allocated for it. It's
> useful as the last member of a variable length struct.."  This sounds
> like C99's "flexible array members," where a struct can have an array
> as its last element that isn't given a size, specifically for allowing
> variable-sized structs.
>
> Well, the issue with a zero-length fixed-size array is that.. uh, you
> can't access anything out of it.  The compiler disallows any indexing
> of a zero-length array with constant indices, and at runtime, all
> accesses caught by the array bounds checking.  Weirder still, the .ptr
> of any zero-length array is always null, so you can't even do things
> like "arr.ptr[5] = x;" (which would be perfectly acceptable in my
> opinion).
>
> Just a silly issue.

Just thought I'd mention that this works now, since this is the only forum thread that mentions working with C's flexible array members.  You simply define a zero-length array and then access it using .ptr, as in this C binding and example program I recently translated:

https://github.com/joakim-noah/usrsctp/blob/master/usrsctp.d#L185
https://github.com/joakim-noah/usrsctp/blob/master/programs/rtcweb.d#L836