I've started using the circular_buffer container and I am a little confused by its behavior with regard to start and stop positions for iterators. As implemented, the iterator::begin() call always returns the fixed position at element 0 and the iterator::end() call always returns the fixed position past the last element of the circular_buffer. A more intuitive approach might appear to be that the iterator::begin() should return the oldest element in the buffer and iterator::end should return the newest (most recently pushed) element. Thus, in the case where the circular_buffer were NOT full, begin() would return the position at element 0. After the circular buffer became full, begin() should return the position of the next insertion point, again the oldest element in the buffer. When I think of the context of a circular buffer, it seems that absolute positions (element 1, 2, 3, and so on) have little meaning. Under this behavior, existing iterators would then be invalidated whenever a new element is pushed into the buffer, as is the case for other STL containers. No confusing hard/soft invalidation of iterators that exists now. David