December 2009 - Boost-users - lists.preview.boost.org

Newbie question
by Michael Qi 07 Dec '09

07 Dec '09

Hi, I am trying to start to learn boost. Now, I am learning the getting started guide. And try to build a boost regex program in the guide. But Visual C++ 7.1 tell me error: LINK : fatal error LNK1104: Could not open file "D:\Program.obj" Could you help me? Thank you

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Re: [Boost-users] Updated performance results using Boost Serialization 1.41
by Brian Wood 07 Dec '09

07 Dec '09

Kim Barrett writes: >On Dec 4, 2009, at 7:11 PM, Hartmut Kaiser wrote: >> Our measurements show Boost.Serialization spends most of its time creating >> (constructing) archives and there it's mainly initializing the locale... > > The locale initialization can be avoided if your application can get away with using the > boost::archive::no_codecvt construction flag. (Assuming that's still behaving the same > as when I looked into this performance area back around boost 1.33.) > > These threads may also be of interest: > > http://lists.boost.org/Archives/boost/2005/07/90814.php Based on that link I tried it as follows: int const binary_archive_flags = boost::archive::no_header | boost::archive::no_codecvt; filebuf fb; fb.open("ofile", ios_base::out); binary_oarchive oa(fb, binary_archive_flags); clock_t start(clock()); oa << lst; clock_t end(clock()); I didn't discern any improvement to the performance of this test from adding those flags. > http://lists.boost.org/Archives/boost/2006/03/102133.php I don't see how that is relevant. > > I keep promising myself that I will soon collect sufficient round tuits to do something > about this, but so far those promises remain broken. Maybe once I upgrade my team to boost 1.41. -- Brian Wood Ebenezer Enterprises http://www.webEbenezer.net

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Re: [Boost-users] Updated performance results using Boost Serialization 1.41
by Brian Wood 07 Dec '09

07 Dec '09

Hartmut Kaiser writes: > Our measurements show Boost.Serialization spends most of its time creating > (constructing) archives and there it's mainly initializing the locale... That seems a little different from what I've been testing. The test looks like this: filebuf fb; fb.open("ofile", ios_base::out); binary_oarchive oa(fb); clock_t start(clock()); oa << lst; clock_t end(clock()); The time to construct an oarchive is not included in the test. -- Brian Wood Ebenezer Enterprises http://www.webEbenezer.net

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boost::tuple and boost.interprocess
by Michal 07 Dec '09

07 Dec '09

Hallo Group Members I need to use shared memory to communicate between two processes. is boost::tuple ready to be used by boost.interprocess? best regards, Michal

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[serialization] Observation regarding xml archives and library version
by Pfligersdorffer, Christian 07 Dec '09

07 Dec '09

Hi folks, hi Robert, did anyone notice that xml archives can be loaded where other archive types throw an "unsupported version" exception? I was rather surprised when I was able to read in an xml archive created by 1.41 using 1.34! The internal library version changed twice since then, so ... ... are you a magician, Robert? :-) Or is this an undocumented virtue of xml archives? Or is this just a bug nobody seems to have noticed before? Regards, -- Christian Pfligersdorffer Software Engineering http://www.eos.info

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boost::interprocess - checking for a scoped lock
by Brenda Orlin 07 Dec '09

07 Dec '09

I am using scoped_lock with interprocess_mutex. I suspect that I have one of my threads trying to lock the mutex multiple times before it is unlocked. Is there a way to check and see if a mutex has already been locked by the current thread? _________________________________________________________________ Windows 7: Unclutter your desktop. Learn more. http://www.microsoft.com/windows/windows-7/videos-tours.aspx?h=7sec&slideid…

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[Pool] correct usage for optimal performance
by Igor R 07 Dec '09

07 Dec '09

Hello, In my application I use singleton pools for the 2 most common allocation scenarios: 1) Frequent allocation of small objects (one by one, tens to hundreds per second). Every object is disposed soon after its allocation, so that only few objects are alive simultaniously. Since the objects are accessed through shared_ptr, I allocate them as follows: allocate_shared<Obj>(boost::fast_pool_allocator<Obj>()); Is this the appropriate use of Pool for this scenario? Should I use pool_allocator (i.e. ordered_malloc()) instead? 2) Frequent (same as in (1) frequency and lifetime) allocation of memory blocks that look like this: [10Kb, 1Kb, 1.1Kb, 0.9Kb,... 10.5Kb...] - i.e. 1 big block, then several small ones. Each block is stored in shared_array, and I allocate it this way: shared_array<char> data_; //... typedef boost::singleton_pool<my_alloc_tag, 1024> allocator; int chunks = blockSize / allocator::requested_size + 1; // rough aproximation data_.reset(static_cast<char *>(allocator::malloc(chunks)), bind(&allocator::free, _1, chunks)); Again, should I use here ordered_xxx? Or probably it's worth using allocator::maloc for the case of chunks==1, and ordered_malloc for chunks > 1? Thanks!

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bidirectional socket
by pedro chaparro 07 Dec '09

07 Dec '09

hi, i have a basic question, for implementing a bidirectional communication can i do it just using one socket , i mean just open one port? or do i need to implement a client and a server in each end point? im realli confuse with this issue =( -- Ing Pedro Alonso Chaparro Valero Ciudad Politecnica de la Innovación iTEAM - Mobile Communications Group Polytechnic University of Valencia C\ Camino de Vera S/N, Edificio 8G 46022 Valencia, Spain

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Problem using Boost regex
by John Emmas 07 Dec '09

07 Dec '09

If my previous post makes it to the mailing list, please ignore it (I figured out some of the original confusion). Here's the problem I'm left with:- A couple of days ago I installed libboost (v1.40) using the Windows setup.exe file. To get myself started I decided to build the regex example that I found here:- http://www.cs.brown.edu/~jwicks/boost/libs/regex/doc/introduction.html My installation contains DLLs called:- boost_regex-vc80-mt-1_40.dll and boost_regex-vc80-mt-gd-1_40.dll along with their associated link libs - and here's the example, as I built it:- #include <string> #include <boost/regex.hpp> using namespace std; using namespace boost; bool validate_card_format(const string s) { static const boost::regex e("(\\d{4}[- ]){3}\\d{4}"); return regex_match(s, e); } // and further on, I call the above function.... bool bb = validate_card_format("1111 2222 3333 4444"); If I link my app to boost_regex-vc80-mt-gd-1_40.lib (or if I don't link it to boost at all) the app won't run. In either case if I try to launch my app I see a dialog box telling me that the configuration is incorrect (possibly a problem with manifests?) OTOH If I link my app to boost_regex-vc80-mt-1_40.lib, I get a crash at the above call - i.e. at 'bb = validate_card_format("1111 2222 3333 4444");' The crash is caused by an unhandled exception in 'basic_regex::assign'. The exception occurs at the call to 'do_assign()' and I get this message:- boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<std::runtime_error> > at memory location 0x0012f4e4. I'm guessing that I should have configured something between installing boost and starting to use it. Have I missed a step out somewhere? Thanks, John

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boost::date input facet
by Hicham Mouline 07 Dec '09

07 Dec '09

Hello, I have a txt file with a 1st column as a date and a 2nd column as data. I am trying to read this file into a STL sequence. The format of the date varies. Is there a utility function to try different(all) dates formats until it finds a valid date when it attempts to read that 1st column? Or should I just construct a list of possible date_input_facets and try each of them until >> succeeds? Regards,

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