- Boost-users - lists.boost.org

Re: [Boost-users] [date_time] timezone rules for different years
by Stephen Turner 09 Jan '07

09 Jan '07

> -----Original Message----- > From: Stephen Turner [mailto:sturner@clicktracks.com] > Sent: 04 January 2007 16:02 > To: 'boost-users(a)lists.boost.org' > Subject: RE: [date_time] timezone rules for different years > > [...snip...] > > Actually, I think the hardest part would be populating the > date_time_zonespec.csv file. Is there already a program to > generate that file from the zoneinfo files, or was it done > semi-by-hand? > Of course, an alternative might be for the library to read the actual zoneinfo files, rather than to extend the intermediate zonespec.csv format. I'm not sure which would be better. -- Stephen Turner, Cambridge, UK http://homepage.ntlworld.com/adelie/stephen/ "The internet is a reflection of our society. If we do not like what we see, the problem is not to fix the mirror, we have to fix society." (Vint Cerf)

1 0

Re: [Boost-users] cross compiling boost
by Hughes, James 09 Jan '07

09 Jan '07

If you are cross compiling boost, you don't need to cross compile bjam - just compile it for your host machine (I assume a PC with Windows or Linux). Then use that bjam to cross compile boost with the command line posted earlier. James > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of remi > Sent: 09 January 2007 11:23 > To: boost-users(a)lists.boost.org > Subject: [Boost-users] cross compiling boost > > > hi, > > I have a problem to create bjam with another toolset called > arm-linux-gcc. I use ./build.sh cc > > CC=arm-linux-gcc > > but it dosen't work ... > > > can anyome help me ?? > > Best regards > > __________________________________________________ > Do You Yahoo!? > En finir avec le spam? Yahoo! Mail vous offre la meilleure > protection possible contre les messages non sollicités > http://mail.yahoo.fr Yahoo! Mail > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users > This message (including any attachments) contains confidential and/or proprietary information intended only for the addressee. Any unauthorized disclosure, copying, distribution or reliance on the contents of this information is strictly prohibited and may constitute a violation of law. If you are not the intended recipient, please notify the sender immediately by responding to this e-mail, and delete the message from your system. If you have any questions about this e-mail please notify the sender immediately.

2 1

Re: [Boost-users] RE : Re: cross compiling boost for ARM
by Hughes, James 09 Jan '07

09 Jan '07

Yes. > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of remi > Sent: 05 January 2007 17:41 > To: boost-users(a)lists.boost.org > Subject: [Boost-users] RE : Re: cross compiling boost for ARM > > > Thank tou for the anwser ! > > So if i want to cross complie boost, i need boost_1_33_1.tar > and boost-jam package ? > > __________________________________________________ > Do You Yahoo!? > En finir avec le spam? Yahoo! Mail vous offre la meilleure > protection possible contre les messages non sollicités > http://mail.yahoo.fr Yahoo! Mail > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users > This message (including any attachments) contains confidential and/or proprietary information intended only for the addressee. Any unauthorized disclosure, copying, distribution or reliance on the contents of this information is strictly prohibited and may constitute a violation of law. If you are not the intended recipient, please notify the sender immediately by responding to this e-mail, and delete the message from your system. If you have any questions about this e-mail please notify the sender immediately.

2 1

Re: [Boost-users] boost::serialization fundamental question about "block read/write"
by Gerd Ritter 09 Jan '07

09 Jan '07

Hi Christian, I have looked at the boost::asio implementation. From what I can see it does use boost::serialization but it wraps each object into it's own archive object inside for every time you call async write (from /example/serialization/connection.hpp): void async_write(const T& t, Handler handler) { // Serialize the data first so we know how large it is. std::ostringstream archive_stream; boost::archive::text_oarchive archive(archive_stream); archive << t; This works fine but has a couple major drawbacks: a) for each object to be sent a new archive is created and destroyed (performance) b) none of the pointer tracking and other boost::serialization features are available and c) especially for small objects this will create serious bandwith "bloat" since each archive contains at least a 27byte header. What I want to achieve is to keep the archive open for the duration of the life time of the connection or logical session which may allow for socket reconnects. I will look into using asio for socket handling though. If I can make it work I'll share the code, maybe it can be included in asio which would be good because I wouldn't have to maintain it ;-) Regards, Gerd > Date: Mon, 8 Jan 2007 15:02:34 -0500 > From: "Christian Henning" <chhenning(a)gmail.com> > Subject: Re: [Boost-users] boost::serialization fundamental question > about "block read/write" > To: boost-users(a)lists.boost.org > Message-ID: > <949801310701081202n5533ba61n41e96dd48945817c(a)mail.gmail.com> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Hi Gerd, I'm sure you know that already. But, have you taken a look at > boost::asio? There is even an example for using the serialization lib > when sending objects over a socket. > > Here a link: > http://asio.sourceforge.net/boost_asio_0_3_7/libs/asio/doc/examples/index.h… > > Just scroll down a bit to the Serialization section. > > Christian > > > On 1/8/07, Gerd Ritter <gerd.ritter(a)googlemail.com> wrote: > > > > Hi, > > > > I have a more fundamental question/inquiry about the serialization library.

1 0

Support for extended Daylight Saving Time in 2007
by Eric Yankowitz 09 Jan '07

09 Jan '07

Been trying to find information describing boost's level of support for the four week Daylight Saving Time extension in the US that will occur this March. (http://geography.about.com/cs/daylightsavings/a/dst.htm) I haven't been able to find very much. A lot of software is having issues and was wondering if Boost was ready for the event? Was able to find these links, which suggested issues: http://sourceforge.net/tracker/index.php?func=detail&aid=1471723&group_id=7… http://sourceforge.net/tracker/index.php?func=detail&aid=1478619&group_id=7… Any idea if these are being resolved? And if any others exist? Thanks, Eric Yankowitz

1 0

Need Help with Using Boost 1.33 w/ .Net 2005
by Allen 09 Jan '07

09 Jan '07

Hello, I'm a newbie to boost & am trying to use the "filesystem" library with .Net 2005. I've gotten boost to compile & produce the following libraries for windows vc-8_0 tool set: (@ bottom of email) The problem I'm having is 2 fold: 1. which ones do I use ( I think I know, but...) 2. I am using C:\boost\lib\boost_filesystem-vc80-mt-1_33_1.lib C:\boost\lib\boost_filesystem-vc80-mt-1_33_1.dll 3. I've got the dll in the directory my executable runs from 4. I'm including the library w/in my project But, every time I run my application, it bombs on the following code: std::cerr << "file selection has changed: Fname/Folder:" << std::endl; Glib::ustring gus_fname = m_filechooserbuttonChooseComponentsFile->get_filename(); std::cerr << "file name:=" << gus_fname << std::endl << std::endl; Glib::ustring gus_fname_foler = m_filechooserbuttonChooseComponentsFile->get_current_folder(); std::cerr << "folder:=" << gus_fname_foler << std::endl << std::endl; m_gusFobComponentsFileFullPath = gus_fname; std::cerr << "using paths..." << std::endl; boost::filesystem::path p(m_gusFobComponentsFileFullPath, boost::filesystem::native); (**** BOMB ****) The variable, m_gusFobComponentsFileFullPath, has the value: C:\projects\cramOSG_console\trunk\CRAMComponents.fob For the life of me, I can not figure out why boost is crashing. An older version of boost works just fine w/ this code and I am wondering if I'm using the correct libraries or perhaps what was compiled is not correct. The error give is not a simple one to debug. The application simply crashes @ the point noted when run. Under the debugger, it simply crashes in a "locked" file and since I'm not using the debug version of the libs, I can't walk into the code. Would someone please help me? Thank you so much ahead of time. I appreciate your advice and comments. --Allen C:\boost\lib\boost_date_time-vc80-mt-gd.lib C:\boost\lib\boost_filesystem-vc80-mt-1_33_1.lib C:\boost\lib\boost_filesystem-vc80-mt.lib C:\boost\lib\boost_filesystem-vc80-mt-gd-1_33_1.lib C:\boost\lib\boost_filesystem-vc80-mt-gd.lib C:\boost\lib\boost_iostreams-vc80-mt-1_33_1.lib C:\boost\lib\boost_iostreams-vc80-mt.lib C:\boost\lib\boost_iostreams-vc80-mt-gd-1_33_1.lib C:\boost\lib\boost_iostreams-vc80-mt-gd.lib C:\boost\lib\boost_program_options-vc80-mt-1_33_1.lib C:\boost\lib\boost_program_options-vc80-mt.lib C:\boost\lib\boost_program_options-vc80-mt-gd-1_33_1.lib C:\boost\lib\boost_program_options-vc80-mt-gd.lib C:\boost\lib\boost_regex-vc80-mt-1_33_1.lib C:\boost\lib\boost_regex-vc80-mt.lib C:\boost\lib\boost_regex-vc80-mt-gd-1_33_1.lib C:\boost\lib\boost_regex-vc80-mt-gd.lib C:\boost\lib\boost_serialization-vc80-mt-1_33_1.lib C:\boost\lib\boost_serialization-vc80-mt.lib C:\boost\lib\boost_serialization-vc80-mt-gd-1_33_1.lib C:\boost\lib\boost_serialization-vc80-mt-gd.lib C:\boost\lib\boost_signals-vc80-mt-1_33_1.lib C:\boost\lib\boost_signals-vc80-mt.lib C:\boost\lib\boost_signals-vc80-mt-gd-1_33_1.lib C:\boost\lib\boost_signals-vc80-mt-gd.lib C:\boost\lib\boost_thread-vc80-mt-1_33_1.lib C:\boost\lib\boost_thread-vc80-mt.lib C:\boost\lib\boost_thread-vc80-mt-gd-1_33_1.lib C:\boost\lib\boost_thread-vc80-mt-gd.lib C:\boost\lib\boost_wserialization-vc80-mt-1_33_1.lib C:\boost\lib\boost_wserialization-vc80-mt.lib C:\boost\lib\boost_wserialization-vc80-mt-gd-1_33_1.lib C:\boost\lib\boost_wserialization-vc80-mt-gd.lib C:\boost\lib\libboost_date_time-vc80-mt-1_33_1.lib C:\boost\lib\libboost_date_time-vc80-mt.lib C:\boost\lib\libboost_date_time-vc80-mt-gd-1_33_1.lib C:\boost\lib\libboost_date_time-vc80-mt-gd.lib C:\boost\lib\libboost_date_time-vc80-mt-s-1_33_1.lib C:\boost\lib\libboost_date_time-vc80-mt-s.lib C:\boost\lib\libboost_date_time-vc80-mt-sgd-1_33_1.lib C:\boost\lib\libboost_date_time-vc80-mt-sgd.lib C:\boost\lib\libboost_filesystem-vc80-mt-1_33_1.lib C:\boost\lib\libboost_filesystem-vc80-mt.lib C:\boost\lib\libboost_filesystem-vc80-mt-gd-1_33_1.lib C:\boost\lib\libboost_filesystem-vc80-mt-gd.lib C:\boost\lib\libboost_filesystem-vc80-mt-s-1_33_1.lib C:\boost\lib\libboost_filesystem-vc80-mt-s.lib C:\boost\lib\libboost_filesystem-vc80-mt-sgd-1_33_1.lib C:\boost\lib\libboost_filesystem-vc80-mt-sgd.lib C:\boost\lib\libboost_iostreams-vc80-mt-1_33_1.lib C:\boost\lib\libboost_iostreams-vc80-mt.lib C:\boost\lib\libboost_iostreams-vc80-mt-gd-1_33_1.lib C:\boost\lib\libboost_iostreams-vc80-mt-gd.lib C:\boost\lib\libboost_iostreams-vc80-mt-s-1_33_1.lib C:\boost\lib\libboost_iostreams-vc80-mt-s.lib C:\boost\lib\libboost_iostreams-vc80-mt-sgd-1_33_1.lib C:\boost\lib\libboost_iostreams-vc80-mt-sgd.lib C:\boost\lib\libboost_prg_exec_monitor-vc80-mt-1_33_1.lib C:\boost\lib\libboost_prg_exec_monitor-vc80-mt.lib C:\boost\lib\libboost_prg_exec_monitor-vc80-mt-gd-1_33_1.lib C:\boost\lib\libboost_prg_exec_monitor-vc80-mt-gd.lib C:\boost\lib\libboost_prg_exec_monitor-vc80-mt-s-1_33_1.lib C:\boost\lib\libboost_prg_exec_monitor-vc80-mt-s.lib C:\boost\lib\libboost_prg_exec_monitor-vc80-mt-sgd-1_33_1.lib C:\boost\lib\libboost_prg_exec_monitor-vc80-mt-sgd.lib C:\boost\lib\libboost_program_options-vc80-mt-1_33_1.lib C:\boost\lib\libboost_program_options-vc80-mt.lib C:\boost\lib\libboost_program_options-vc80-mt-gd-1_33_1.lib C:\boost\lib\libboost_program_options-vc80-mt-gd.lib C:\boost\lib\libboost_program_options-vc80-mt-s-1_33_1.lib C:\boost\lib\libboost_program_options-vc80-mt-s.lib C:\boost\lib\libboost_program_options-vc80-mt-sgd-1_33_1.lib C:\boost\lib\libboost_program_options-vc80-mt-sgd.lib C:\boost\lib\libboost_regex-vc80-mt-1_33_1.lib C:\boost\lib\libboost_regex-vc80-mt.lib C:\boost\lib\libboost_regex-vc80-mt-gd-1_33_1.lib C:\boost\lib\libboost_regex-vc80-mt-gd.lib C:\boost\lib\libboost_regex-vc80-mt-s-1_33_1.lib C:\boost\lib\libboost_regex-vc80-mt-s.lib C:\boost\lib\libboost_regex-vc80-mt-sgd-1_33_1.lib C:\boost\lib\libboost_regex-vc80-mt-sgd.lib C:\boost\lib\libboost_serialization-vc80-mt-1_33_1.lib C:\boost\lib\libboost_serialization-vc80-mt.lib C:\boost\lib\libboost_serialization-vc80-mt-gd-1_33_1.lib C:\boost\lib\libboost_serialization-vc80-mt-gd.lib C:\boost\lib\libboost_serialization-vc80-mt-s-1_33_1.lib C:\boost\lib\libboost_serialization-vc80-mt-s.lib C:\boost\lib\libboost_serialization-vc80-mt-sgd-1_33_1.lib C:\boost\lib\libboost_serialization-vc80-mt-sgd.lib C:\boost\lib\libboost_signals-vc80-mt-1_33_1.lib C:\boost\lib\libboost_signals-vc80-mt.lib C:\boost\lib\libboost_signals-vc80-mt-gd-1_33_1.lib C:\boost\lib\libboost_signals-vc80-mt-gd.lib C:\boost\lib\libboost_signals-vc80-mt-s-1_33_1.lib C:\boost\lib\libboost_signals-vc80-mt-s.lib C:\boost\lib\libboost_signals-vc80-mt-sgd-1_33_1.lib C:\boost\lib\libboost_signals-vc80-mt-sgd.lib C:\boost\lib\libboost_test_exec_monitor-vc80-mt-1_33_1.lib C:\boost\lib\libboost_test_exec_monitor-vc80-mt.lib C:\boost\lib\libboost_test_exec_monitor-vc80-mt-gd-1_33_1.lib C:\boost\lib\libboost_test_exec_monitor-vc80-mt-gd.lib C:\boost\lib\libboost_test_exec_monitor-vc80-mt-s-1_33_1.lib C:\boost\lib\libboost_test_exec_monitor-vc80-mt-s.lib C:\boost\lib\libboost_test_exec_monitor-vc80-mt-sgd-1_33_1.lib C:\boost\lib\libboost_test_exec_monitor-vc80-mt-sgd.lib C:\boost\lib\libboost_thread-vc80-mt-1_33_1.lib C:\boost\lib\libboost_thread-vc80-mt.lib C:\boost\lib\libboost_thread-vc80-mt-gd-1_33_1.lib C:\boost\lib\libboost_thread-vc80-mt-gd.lib C:\boost\lib\libboost_thread-vc80-mt-s-1_33_1.lib C:\boost\lib\libboost_thread-vc80-mt-s.lib C:\boost\lib\libboost_thread-vc80-mt-sgd-1_33_1.lib C:\boost\lib\libboost_thread-vc80-mt-sgd.lib C:\boost\lib\libboost_unit_test_framework-vc80-mt-1_33_1.lib C:\boost\lib\libboost_unit_test_framework-vc80-mt.lib C:\boost\lib\libboost_unit_test_framework-vc80-mt-gd-1_33_1.lib C:\boost\lib\libboost_unit_test_framework-vc80-mt-gd.lib C:\boost\lib\libboost_unit_test_framework-vc80-mt-s-1_33_1.lib C:\boost\lib\libboost_unit_test_framework-vc80-mt-s.lib C:\boost\lib\libboost_unit_test_framework-vc80-mt-sgd-1_33_1.lib C:\boost\lib\libboost_unit_test_framework-vc80-mt-sgd.lib C:\boost\lib\libboost_wave-vc80-mt-1_33_1.lib C:\boost\lib\libboost_wave-vc80-mt.lib C:\boost\lib\libboost_wave-vc80-mt-gd-1_33_1.lib C:\boost\lib\libboost_wave-vc80-mt-gd.lib C:\boost\lib\libboost_wave-vc80-mt-s-1_33_1.lib C:\boost\lib\libboost_wave-vc80-mt-s.lib C:\boost\lib\libboost_wave-vc80-mt-sgd-1_33_1.lib C:\boost\lib\libboost_wave-vc80-mt-sgd.lib C:\boost\lib\libboost_wserialization-vc80-mt-1_33_1.lib C:\boost\lib\libboost_wserialization-vc80-mt.lib C:\boost\lib\libboost_wserialization-vc80-mt-gd-1_33_1.lib C:\boost\lib\libboost_wserialization-vc80-mt-gd.lib C:\boost\lib\libboost_wserialization-vc80-mt-s-1_33_1.lib C:\boost\lib\libboost_wserialization-vc80-mt-s.lib C:\boost\lib\libboost_wserialization-vc80-mt-sgd-1_33_1.lib C:\boost\lib\libboost_wserialization-vc80-mt-sgd.lib C:\boost\lib\boost_date_time-vc80-mt-1_33_1.dll C:\boost\lib\boost_date_time-vc80-mt-gd-1_33_1.dll C:\boost\lib\boost_filesystem-vc80-mt-1_33_1.dll C:\boost\lib\boost_filesystem-vc80-mt-gd-1_33_1.dll C:\boost\lib\boost_iostreams-vc80-mt-1_33_1.dll C:\boost\lib\boost_iostreams-vc80-mt-gd-1_33_1.dll C:\boost\lib\boost_program_options-vc80-mt-1_33_1.dll C:\boost\lib\boost_program_options-vc80-mt-gd-1_33_1.dll C:\boost\lib\boost_regex-vc80-mt-1_33_1.dll C:\boost\lib\boost_regex-vc80-mt-gd-1_33_1.dll C:\boost\lib\boost_serialization-vc80-mt-1_33_1.dll C:\boost\lib\boost_serialization-vc80-mt-gd-1_33_1.dll C:\boost\lib\boost_signals-vc80-mt-1_33_1.dll C:\boost\lib\boost_signals-vc80-mt-gd-1_33_1.dll C:\boost\lib\boost_thread-vc80-mt-1_33_1.dll C:\boost\lib\boost_thread-vc80-mt-gd-1_33_1.dll C:\boost\lib\boost_wserialization-vc80-mt-1_33_1.dll C:\boost\lib\boost_wserialization-vc80-mt-gd-1_33_1.dll C:\boost\lib\boost_date_time-vc80-mt-1_33_1.lib C:\boost\lib\boost_date_time-vc80-mt.lib C:\boost\lib\boost_date_time-vc80-mt-gd-1_33_1.lib -- Sincerely, Allen Gene Allen Saucier, Jr Senior Software Engineer CAS, Inc 100 Quality Circle Huntsville, AL 35806 or PO Box 11190 Huntsville, AL 35814 (256) 922-6453 (w) "As for I and my house, we shall follow the Lord" Joshua 25:14

2 1

Re: [Boost-users] [Test] Auto test timeouts?
by Sohail Somani 08 Jan '07

08 Jan '07

> [mailto:boost-users-bounces@lists.boost.org] On Behalf Of > Gennadiy Rozental > > "Sohail Somani" <s.somani(a)fincad.com> wrote in message > news:1C1EBEF8DBACDC439D038EA051674EC7567695@xbox.financialcad.com... > > Good morning/afternoon/evening good people of the Boost lists, > > > > Does anyone know how to set timeouts on the auto testing > suite of the > > Boost unit test framework? I'm guessing that I'll need to > write my own > > test_main() but if anyone knows of a way to tweak the auto > test suite in > > general, that would be very useful! > > There is no interface to specify the timeout for > automatically registered > test case. For this test case you will have to use manual > registration. Thanks! And thanks for a great lib btw.

1 0

boost::serialization fundamental question about "block read/write"
by Gerd Ritter 08 Jan '07

08 Jan '07

Hi, I have a more fundamental question/inquiry about the serialization library. What I want to do is to use the serialization library to send classes over a socket. Even though archives are not supposed to be used at streams I figured that it should be possible to create a oarchive on the sender side, create a iarchive on the receiver side, and use these for multiple, successive write / read operations in block mode. In order to test that assumption I created a test program to see if it would be possible. Here the pseudo code: void sync_streams(stringstream &os, stringstream& os) { // write data from one sting stream to the other // this emulates sending the data on a socket int rd_avail = os.tellp() - os.tellg(); os.read(buffer, rd_avail); is.write(buffer, rd_avail); } stringstream os, is; boost::archive::text_oarchive oa(os); sync_streams(os, is); // sync preamble boost::archive::text_iarchive ia(is); oa << object1; sync_streams(os, is); // sync object block ia >> rdObject1; oa << object2; sync_streams(os, is); // sync object block ia >> rdObject2; While I made this work, I wonder if it is a hack or if this is a valid use case for the serialization library. I looked at the asio projects example/source, there it was done by using a full archive for each object to be transmitted. Sending an archive every time seems a bit expensive too me, since a full preamble is sent everytime and I would loose all the pointer tracking and other great features from the serialization library. Regards, Gerd

3 2

[Test] Auto test timeouts?
by Sohail Somani 08 Jan '07

08 Jan '07

Good morning/afternoon/evening good people of the Boost lists, Does anyone know how to set timeouts on the auto testing suite of the Boost unit test framework? I'm guessing that I'll need to write my own test_main() but if anyone knows of a way to tweak the auto test suite in general, that would be very useful! Thanks, Sohail

2 1

Performance problem in iostreams::stream
by Jerker Öhman 08 Jan '07

08 Jan '07

We use iostreams::stream to read from a legacy file format. The code that reads from the stream looks a little like this: void ReadStuff(std::istream &stream, Stuff &stuff, OtherStuff &otherStuff) { StreamDirectory streamDir; stream >> streamDir; stream.seekg(streamDir.GetOffset(STUFF_TAG)); stream >> stuff; stream.seekg(streamDir.GetOffset(OTHER_STUFF_TAG); stream >> otherStuff; } I.e. the stream contains a directory that holds information about the items following the directory and the offsets to them. The stream and code is also organized so that the calls to seekg in most cases are to the current position of the stream. In other words, seekg doesn’t have to do anything. If the stream is buffered the code runs into serious performance problems. After a while seekg ends up in this function. template<typename T, typename Tr, typename Alloc, typename Mode> typename indirect_streambuf<T, Tr, Alloc, Mode>::pos_type indirect_streambuf<T, Tr, Alloc, Mode>::seek_impl (stream_offset off, BOOST_IOS::seekdir way, BOOST_IOS::openmode which) { if (pptr() != 0) this->BOOST_IOSTREAMS_PUBSYNC(); // sync() confuses VisualAge 6. if (way == BOOST_IOS::cur && gptr()) off -= static_cast<off_type>(egptr() - gptr()); setg(0, 0, 0); setp(0, 0); return obj().seek(off, way, which, next_); } and as far as I can see it just dumps the internal buffer and passes the call on. After still some calls we end up in the stream source seek function. This wouldn’t be so bad if it wasn’t for the fact that the stream source offset isn’t the same as the streams offset since the stream is buffered. Perhaps a little example would clarify this. Assume that we read 4 bytes from a stream with a 10k buffer. The stream will then fill its buffer from the underlying source which means that after the read, the stream will have a full 10k buffer and an offset into the buffer that is 4. The underlying stream source will have an offset pointer that points to 10k+1 bytes into the underlying stream. If we now call seekg to position the file to offset 4 (which already is the current position), the stream throws away it’s buffer and we end up in the stream source who’s file position is 10k+1 so it also throws away it’s internal buffers and seeks back in the underlying stream to offset 4. In this way, what should have been a NULL operation turns into something very time-consuming. Previously we used a class that inherited directly from std::basic_streambuff that contained horrible code that no one really understood so switching to boost::iostreams was a blessing. Unfortunately the boost::iostreams implementation is 10 times slower when it is buffered and 50% slower when it is unbuffered. When reading files that are a couple of GB that really matters. /Jerker

1 0