3 Jun
2005
3 Jun
'05
8:28 p.m.
christopher diggins wrote:
From: "Peter Dimov" <pdimov@mmltd.net>
Neal Becker wrote:
Here's my version:
[...]
One interesting problem with strided iterators is coming up with end values. Suppose you have
int x[ 4 ];
and you want to iterate over x[1] and x[3] with stride 2. Your begin iterator will be x+1, and your end iterator will be x+5 - an invalid address.
I am very confused, isn't x+4 also an invalid address? What is the difference between x+4 and x+5 or any other address not within the range x to x+3 ?
x+4 is valid but not dereferenceable. x+5 is invalid, it can't be copied or used in comparisons. None of today's platforms enforce this for pointers, but other random access iterators might.