On 05/12/12 09:48, Olaf van der Spek wrote:
On Wed, Dec 5, 2012 at 8:53 AM, "Claas H. Köhler" <claas.koehler@dlr.de> wrote:
To be very precise, it was actually the assumption that counting_iterator behaves similar to all other iterators in the standard library, which guarantee a defined behaviour when default constructed. (By guaranteed I mean as far as I have seen so far. Not sure what the standard says about them)
AFAIK you can't expect default constructed iterators to be usable (in general). For example, this will assert in VC11: typedef std::map<int, int> C; C::iterator a; C::iterator b; a == b;
Hi Olaf! Thanks for the info. That's very interesting. So it seems to be implementation dependent. Using gcc-4.7 the following code outputs true/ 1 for all 5 comparisons. std::vector<double>::iterator itv1, itv2; std::string::iterator itstr1, itstr2; std::set<double>::iterator its1, its2; std::map<double, double>::iterator itm1, itm2; std::list<double>::iterator itl1, itl2; std::cout << (its1 == its2) <<std::endl << (itv1 == itv2) <<std::endl << (itstr1 == itstr2) <<std::endl << (itm1 == itm2) <<std::endl << (itl1 == itl2) <<std::endl; Claas