Re: Problem with iterators
On Jun 7, 3:39 pm, desktop <f...@sss.com> wrote:
I have this code:
std::list<int> mylist;
mylist.push_back(1);
mylist.push_back(2);
mylist.push_back(3);
mylist.push_back(4);
std::list<int>::iterator it_p = mylist.begin();
std::list<int>::iterator it_q = mylist.end();
std::set<int> myset(it_p,it_q);
int first = *myset.begin();
int second = *myset.end();
std::cout << "first = " << first << std::endl;
std::cout << "second = " << second << std::endl;
I copy the elements from the "list" to the "set" with the two
iterators: "it_p" and "it_q". When I print "first" and
"second" I get 1 and 4. But should:
int second = *myset.end();
not return the value of the element *after* the last which is
undefined? I thought that I had to decrement myset.end() by
one to get the value 4.
It's undefined behavior, of course. Just for the record, this
code core dumps with both g++ and VC++, at least in "debug"
mode.
Another thing. As I understand each container supports a specific
iterator. Eg. list only supports forward iterators while set supports
bidirectional iterators.
But where (have tried) google do I find a list of each iterator that a
container supports?
The Dinkumware site has some very good documentation, try:
http://www.dinkumware.com/manuals/.
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