Howard Hinnant wrote:
On Aug 22, 2007, at 2:37 PM, Emil Dotchevski wrote:
Today I don't use list::size() in portable code. Why? Because we gave the vendor too much freedom.
How do you compute the size of a std::list in portable code then? :)
I try not to. If I find I must, I write my own replacement list. It is one of the simpler containers to write.
I think that given a std::list object, the best way for user code to compute its size is to call .size(). It would be a user error to assume that .size() is O(1), but it wouldn't be a mistake to assume that the implementation of size() will use the strategy that makes the most sense on that platform.
Howard Hinnant wrote:
Vendor C, with the best of intentions, decides that the release build of the std::lib should contain this checking (std::lib vendors including debug checks in release builds should sound familiar to many of you). Now we have goal #3, but have lost goal #1, and there is no wrapper we can use to get it back.
We haven't lost goal #1. What has happened is that the vendor decided that the benefits of supplying debug checks (goal #3) outweight the performance cost of those checks, on that platform. I don't see harm in that, as long as it doesn't violate the standard. Consider that this decision was made by experts in the problem domain targeting a specific platform. Emil Dotchevski http://www.revergestudios.com/reblog/index.php?n=ReCode