On 11/11/2011 23:23, Steven Schveighoffer wrote:
Ali Çehreli Wrote:
On 11/11/2011 01:42 PM, Steven Schveighoffer wrote:
On Fri, 11 Nov 2011 16:10:12 -0500, Simon<s.d.hamm...@gmail.com> wrote:
On 11/11/2011 19:04, Steven Schveighoffer wrote:
On Fri, 11 Nov 2011 14:01:42 -0500, Steven Schveighoffer
<schvei...@yahoo.com> wrote:
There should be no bounds error in any case, an empty slice is valid.
By "in any case" I meant in either debug or release mode.
-Steve
even when you index beyond the bounds of the slice?
you may not actually be reading memory because it's zero length, but
it's still logically invalid; you've gone outside the valid range.
You are not reading beyond the valid range. A zero-length slice is
perfectly legal to point at the end of an array or other slice. Reading
any data from a zero-length slice will cause an out-of-bounds error in
debug mode, because it has no elements.
in vc9, if you increment an iterator beyond the valid range you get a
debug assert. that's caught quite a few bugs where I work when we
upgraded to vc9.
I think you are misunderstanding what the $ actually means.
It's the equivalent in C++ iterators to x.end.
The pair of iterators x.end, x.end is a valid range. Going *beyond*
x.end would be illegal. But iterating *to* x.end is legal (which would
be the equivalent of [$..$] range), and you will not be able to convince
me that vc9 doesn't allow it.
-Steve
How about Jonathan's this comment: "It wouldn't surprise me if arr[500
.. 500] worked exactly the same way. Because the array is empty, it
doesn't really matter what values you gave it."
I think Simon is objecting to 500..500 being accepted (if at all). I
agree that $..$ is correct.
Ali
Oh my mistake! I thought we were talking about arr[$..$]!
Yes, arr[500..500] would result in bounds errors if the array is only 7
elements. When I read it I thought it was just an arbitrary example to show
another way to get an empty slice with an assumption that 500 is a valid index.
-Steve
Yup, that was what I was on about. Should have been a bit clearer on
that. Ta.
--
My enormous talent is exceeded only by my outrageous laziness.
http://www.ssTk.co.uk
