On Sunday, July 18, 2010, alfC <alfredo.correa@gmail.com> wrote:
Hi, The STL has an implementation of std::map<T1, T2>. It has some designs drawbacks in my opinion. For example, the fact that T2 has to have a default copy constructor. Even if for T2, by design, doesn't make sense to have a copy constructor.
The problem boils down to the fact that, in the STL design, if an key element of the map is referenced with the operator[] and it doesn't exist then an 'empty' (default) object T2 is created. In my opinion this feature is independent of the other features of a map. For example if the element doesn't exists and the context is not assignment then it could give an exception.
Easy solution: use find and insert instead of operator[]. HTH -- -- Dave Abrahams BoostPro Computing http://www.boostpro.com