On 8/9/16 10:09 AM, ciechowoj wrote:
On Tuesday, 9 August 2016 at 14:01:17 UTC, Steven Schveighoffer wrote:
I think this should work:
extern extern(C) int[1] tab;
Then if you want to access the elements, use the tab.ptr[elem]
If it's a global variable, tack on __gshared.
I've already tried this and works (64-bit at least on linux). But is it
portable?
Yes. D is designed to interface with C in certain ways, and this should
be portable.
No other way that allow to access the `tab` directly (without ..ptr
proxy) ?
Well, you can via properties:
@property int* tabp() { return tab.ptr; }
tabp[elem];
Essentially, tab is a symbol that points at some undetermined number of
elements. Since it's undetermined, D doesn't allow safe easy access.
If you did int *tab, then it would think the symbol points at a pointer.
tab.ptr is a shortcut to &tab[0].
You could potentially do int tab, and then use (&tab)[elem].
Or if you know the number of elements, you can just declare them.
If it were me, I'd access it via tab.ptr, because it *is* an unsafe
operation and I'd want to highlight that for future readers.
If something defines tab's length, I'd highly recommend wrapping the two:
extern(C) int tabLength(); // mythical mechanism or no?
@property int[] dtab { return tab.ptr[0 .. tabLength]; }
-Steve
