Robert Ramey wrote:
Ian McCulloch wrote:
Besides, is the boost iostreams library really much slower than a hand-coded buffer?
I'm pretty confident that its much, much slower, but this will remain in dispute until someone runs the code with a profiler.
Anyway, this is a side issue. The main point is:
David Abrahams wrote:
,---- | For many archive formats and common datatypes there exist APIs | that can quickly read or write contiguous sequences of those types | all at once (**). Reading or writing such a sequence by | separately reading or writing each element (as the serialization | library currently does) can be an order of magnitude more | expensive. `----
Sorry - that's NOT the main point.
The main point is - do enhancement for special cases have to be incorporated into the the core code so that everybody else is obligated to use it? What are the advantages and disadvantages of doing so?
Umm, I don't follow - how are others going to be obligated to use those special cases that don't necessarily apply to them?
No one is disputing that it desireable to be able to extend the library for these special circumstances.
Actually it's *very* desirable.
If there is to be any possibility of targetting an archive to this format, then array support is crucial.
Then just make an archive which does it- what's stopping you?
True - but the suggestion is that it's common enough to want as part of the core library. Here we use netCDF (the format brought up by Ian) and HDF-5 data files, and run with MPI on a mosix cluster ... the point being that these data types are integral to industries like ours - where large volumes of data are the norm - and array access is indeed crucial - we see code here that runs in the order of seconds to minutes, or hours depending on how data is read and written - but as a concesion, that is also dependent on the underlying libraries we inherit from 3rd parties (aka netCDF, HDF-5, et al). I've been loosly following this thread and I understand your reluctance to this - but it's a matter of perception as to how needful, and widespread such a need is. ... back to lurker mode Cheers, -- Manfred Doudar MetOcean Engineers www.metoceanengineers.com