Re: std::list unique
On 5/25/2013 12:12 PM, Mihai Vasilian wrote:
I have this code:
#include <iostream>
#include <list>
int main()
{
typedef std::list<int> list;
int i0t[5]={-1, 2, 3, 3, 5};
list list_1(i0t, i0t+5);
list::reverse_iterator ri0 = ++list_1.rbegin();
list_1.unique();
list_1.remove(3);
int val = *ri0; // why is this valid ?
std::cout << "val = " << val << "\n";
return 0;
}
My intuition was that ri0 iterator would become invalid after
list_1.unique();
list_1.remove(3);
but it didn't happen (I guess).
How do you gather?
Is there something in the standard about this?
An iterator becomes invalid if you erase from the collection the element
to which the iterator points by means of 'remove'. See [list.ops]/15.
Since you've removed all elements with value '3', any iterators that
might have been obtained to point to an element with that value *are
invalid* after that operation.
V
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