Maxim Yegorushkin <maxim.yegorushkin <at> gmail.com> writes:
On 05/11/10 18:15, JOAQUIN M. LOPEZ MUÑOZ wrote:
________________________________________ De: boost-bounces <at> lists.boost.org [boost-bounces <at> lists.boost.org] En nombre de Stewart, Robert [Robert.Stewart <at> sig.com]
As is, it mirrors std::map's interface.
Correct, this is exactly the rationale behind the difference in the result types of both overloads. Clever as Maxim's suggestion is, I'm reluctant to diverge from the standard without a compelling reason --here the benefit does not seem impressive, since there are efficient ways to determine whether the insertion took place, for instance checking size() before and after trying the insertion.
Performance-wise, it probably requires extra CPU cycles and storage (cache) to check size before and after insertion.
I would still vote for another insert overload, maybe insert2() or something, which returns that bool. Since internally final_insert_ always returns it, there is no good reason to waste it.
The (not explicitly stated) reason why the second overload of insert does not return a pair<iterator,bool> is to make ordered containers compatible with std::insert_iterator: http://www.sgi.com/tech/stl/insert_iterator.html Why don't you propose your auto_cast_pair solution as a modification to the standard? As it stands, seems like insert_iterator can be easily modified to cope with a auto_cast_pair return type. Joaquín M López Muñoz Telefónica, Investigación y Desarrollo