Robot Dreams

Here we are a day before the end of BoostCon07, and I finally have time to post new pictures. It's been a busy and exciting few days. This has got to be the most talking I've done ever. What better way to start, than with the entrance to the Flug Forum building:

Tomorrow will be a long day with some morning sessions, lunch, the drive to Denver, and on to the flight to Chicago. Enjoy the small sampling of the pictures, and see you all on the Boost lists.

For those who are interested in C++, and in particular Boost C++ Libraries, BoostCon 2007 is approaching quickly. The conference is the week of May 13th. And early, as in reduced price, registration ends this week. I'll be going to both enjoy the Aspen scenery and to learn about new stuff going on in the C++ world. I'll even be running a session for engineering the testing system for Boost. If you can't be bothered to grace us with your presence. perhaps you know someone else who might be, so go tell them about it!

Shortly before I went on vacation to Kaua'i North Shore, Princeville Google started it's second Summer of Code foray. Like usual I can't resist making suggestions and put together a very short page in the Boost Wiki with two project ideas, the first two Boost.Build ones. Like the proverbial snowball rolling down, many other people added ideas. And at some point, one day past the deadline, Boost was accepted into the SoC. And right before I left for Hawaii, I joined the mentor list for Boost SoC projects. So here I am in vacation, having fun, except for the part of loosing my wallet at the beach, and the Boost SoC wheels keep grinding.

So I come back a week later, one week ago now, and a few thousand emails of all kinds have accumulated (yes I got more than 3000 emails in one week). After quickly parsing a small percentage of the email, I go look at how the Boost SoC applications from students and find 130 still active applications to go through (44 of them had already been tossed out by the other mentors). Yikes I would have never expected so many students wanting to do work for Boost. As it turns out Boost is one of the top projects in the SoC, in terms of number of submissions. So here I am, late at night evaluating more applications. In this case for 2D Geometry Computation, and I've already gone through and evaluated the Boost.Build related ones (turns out there where a small number of those), and the ones for a Generic Tree Container.

I have my own theories as to why students would gravitate to wanting to work on Boost libraries. But I'd like to hear from others, since I haven't been a student for a long time now. What drives students to Boost and C++?

PS. I'll get around to posting the pictures, mostly underwater ones, from the vacation soon.

First off, a general update. It's been a slow start to the blog, sorry about that. But I'm still recovering from a total drive failure of the machine I do most of my development work from. So it's been a hard slog to reinstall everything, especially that initial Windows install with at least 15 reboots (I was counting them and that's when I gave up). On to the subject at hand...

One of the data structures in C++ I make use of most are the associative standard containers. I use them because of the bounded algorithmic guarantees they provide. But one of the most nagging problems with them is that it is hard to do any meaningful searching once one has arranged to keep the sorted elements. Sure it's easy to find equivalent elements with for example std::set::equal_range. But if how you are sorting is anything but the element itself as a value it's rather painful to come up with the usual convoluted special value elements to do the searching for you. For example having:

struct A
{
    int type;
    std::string label;
    std::string description;
};

struct S
{
    bool operator()(
        boost::shared_ptr<A> const & a,
        boost::shared_ptr<A> const & b ) const
    {
        return a->type < b->type;
    }
};

std::multiset<boost::shared_ptr<A>,S> db;

And wanting to find out how many A's of type #2 there are. So even though the set is arrange in the most optimal way for getting that answer one is thwarted in using the property of the set only because std::multiset::count, and others, don't take anything but the an element.