On Thu, May 15, 2008 at 9:29 PM, Jan Gaspar <jano_gaspar@yahoo.com> wrote:
OK, will see what can I do with the 1.35.1. release.
Great, thanks. :)
Btw on the 4th line I don't see a problem to explicitly set the capacity like this: circular_buffer<char> buffer(0); // nothing will be allocated
True, I understand. Actually, the problem is also a little more subtle than just that. Consider also the case: map<int, circular_buffer<int> > buffers; circular_buffer<int> buffer(buffers[rand() % 10]); In this case doing buffers[rand() % 10] will cause an implicit creation of a default constructed circular_buffer<int>. There are a lot of cases (especially in STL containers) that when circular_buffer<...>'s can be contained, the implicit requirement of default constructability of items be maintained. It is a subtle issue, and is really hard to trace (i.e., it took me a while to figure out why suddenly when I decided to use a circular_buffer<...>, it kept throwing an std::bad_alloc). I think instead of (mis)behaving in the case of the default constructed buffer, there should be some considerably sane default. I personally chose 0, where adding items to the buffer would most probably fail afterwards, which can be expected behavior. It could also be another number, like how the STL vector chooses a default number of elements and grows accordingly -- but in this case of the circular buffer, it may be hard to determine that default. We can make it degenerate to a 1 element circular buffer where there's really only one value ever in the buffer, but I think that is also wasteful. I hope this helps! -- Dean Michael C. Berris Software Engineer, Friendster, Inc. [http://blog.cplusplus-soup.com] [mikhailberis@gmail.com] [+63 928 7291459] [+1 408 4049523]