----- Mensaje original ----- De: David Abrahams <dave@boost-consulting.com> Fecha: Sábado, Diciembre 11, 2004 9:01 pm Asunto: [boost] Re: boost::filter_iterator Model [...]
Is that stretching the definition of an iterator? I'm not sure.
That's too much for me. I tend to think that it's stretching what users might expect when they see "constant time amortized operation".
This is tricky territory. It certainly warrants a note in the documentation, but I'm not exactly sure what to say.
I'm afraid that, generally speaking, filter_iterator<> cannot just guarantee the std-required complexity, and you cannot do anything about it (consider for instance filter_iterator<is_prime<int>, counting_iterator<int> >) To say it bluntly, not all instantiations of filter_iterator<> are iterators. I'd just say it so: "std-mandated complexity guarantees are provided only if the number of skipped elements divided by the length of the base range remains constant in average." Joaquín M López Muñoz Telefónica, Investigación y Desarrollo