Re: VS 2005 should allows this, why?

"Bo Persson" <>
Sun, 9 Jul 2006 10:57:50 +0200
"Ian Collins" <> skrev i meddelandet

Lighter wrote:

red floyd wrote:

At this point, you have undefined behavior, and ANYTHING can

I'm sorry for my careless. I made a typying mistake. The actual
fragment is as follows:

That's why you should always copy and paste, not retype.

#include <set>

using namespace std;

int main()

typedef set<int> INTSET;

INTSET coll;

coll.insert(9); // This line was omitted before

INTSET::iterator pos = coll.begin();

*pos = 9; // VS 2005 should allowes this, why?

Again, I ask why VS 2005 and why should it allow it?

I think the OP might be referring to this defect report for C++

which asks if you are allowed to change the value of the map elements.

The original standard is obviously a bit unclear on this, which
explains why implementations behave inconsistently.

So, my attempt to answer the question is:

It might (right now) be ok to do *pos=9, if pos is a valid iterator,
and assigning the value 9 doesn't change the order of the elements in
the set.

It seems like the next revision of the standard will contain the
sentence "Keys in an associative container are immutable.", which will
change the rule.

Bo Persson

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