• Brad Beveridge <brad.beveridge somewhere.com> Jul 26 2004
• Derek Parnell <derek psych.ward> Jul 26 2004
• Brad Beveridge <brad.beveridge somewhere.com> Jul 26 2004
• Ilya Minkov <minkov cs.tum.edu> Jul 26 2004
• "Vathix" <vathixSpamFix dprogramming.com> Jul 26 2004
• "C. Sauls" <ibisbasenji yahoo.com> Jul 26 2004

Brad Beveridge <brad.beveridge somewhere.com> writes:

Hi all, this sounds like a daft question, but I can't find in the docs where
it is addressed.
The following code on linux with dmd0.94 segfaults.
Object o;
assert (o != null);

Is there another way that I can assert that o is a valid reference before I
use it?

Cheers
Brad

Derek Parnell <derek psych.ward> writes:

On Mon, 26 Jul 2004 19:41:19 +1200, Brad Beveridge wrote:

 Hi all, this sounds like a daft question, but I can't find in the docs where
 it is addressed.
 The following code on linux with dmd0.94 segfaults.
 Object o;
 assert (o != null);
 
 Is there another way that I can assert that o is a valid reference before I
 use it?
 
 Cheers
 Brad


Try 
  assert (o !== null)

or 
 
 assert (!(o === null));

or

 assert (!(o is null));


-- 
Derek
Melbourne, Australia
26/Jul/04 5:43:18 PM

Brad Beveridge <brad.beveridge somewhere.com> writes:

Thank you, now that I see the === operator it rings a bell :)  It has been a
long time since I read the D specs in fine detail.

Cheers
Brad

Derek Parnell wrote:

 On Mon, 26 Jul 2004 19:41:19 +1200, Brad Beveridge wrote:
 
 Hi all, this sounds like a daft question, but I can't find in the docs
 where it is addressed.
 The following code on linux with dmd0.94 segfaults.
 Object o;
 assert (o != null);
 
 Is there another way that I can assert that o is a valid reference before
 I use it?
 
 Cheers
 Brad


 Try
   assert (o !== null)
 
 or
  
  assert (!(o === null));
 
 or
 
  assert (!(o is null));
 
 

Ilya Minkov <minkov cs.tum.edu> writes:

Brad Beveridge schrieb:

 Is there another way that I can assert that o is a valid reference before I
 use it?


assert(o);

-eye

"Vathix" <vathixSpamFix dprogramming.com> writes:

"Ilya Minkov" <minkov cs.tum.edu> wrote in message
news:ce2qo1$quf$3 digitaldaemon.com...
 Brad Beveridge schrieb:

 Is there another way that I can assert that o is a valid reference




 use it?


 assert(o);

 -eye


That's a special case that calls the invariant on the object. If it's null,
you'll get an access violation. I wish a simple o!==null would be
automatically tested before the invariant, but oh well.

"C. Sauls" <ibisbasenji yahoo.com> writes:

Vathix wrote:
 "Ilya Minkov" <minkov cs.tum.edu> wrote in message
assert(o);


 That's a special case that calls the invariant on the object. If it's null,
 you'll get an access violation. I wish a simple o!==null would be
 automatically tested before the invariant, but oh well.
 


You could always do:

   assert(o !== null && o);

But that's kind of... well, ugly, to me.

-Chris S.
-Invironz