On Sun, Jan 23, 2011 at 1:01 PM, Thorsten Ottosen <nesotto@cs.aau.dk> wrote:
As for the conjectured extra indirection, then I'm not sure it can become any major performance problem, nor do I see how one can avoid it when we need to go for the heap in certain cases.
Clearly the extra indirection is the only potential problem, otherwise a stack-based vector implementation could probably be replaced by a stack-based std::vector allocator. However, the cost of the extra indirection is platform-dependent and difficult to measure in the abstract. In my experience, most cases when someone has complained about inefficiencies in std::vector boil down to incorrect use: - not using reserve(); - calling push_back()/insert() in a loop (which is inefficient even with reserve); - iterating by redundantly calling end() each time; - using operator[] for sequential access to the elements. So the only meaningful way to evaluate the benefits of a std::vector alternative is to discuss specific use cases, considering other alternatives as well. Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode