- Boost-users - lists.boost.org

[MPL] - for_each operators with decision branching
by Noah Roberts 19 May '10

19 May '10

I have a project in which I use these things I call "records" to attach data to edges and vertexes in a boost::graph. They are visitable (acyclic visitor described by Alexandrescu) and I have metafunctions that will take their most derived type and give me a list of "fields" that they contain. I can then write generic processors to do things like build editors for them or perform operations that can effect any field of a particular type or concept. Thus I often find myself using mpl::for_each and writing things like this: struct operator { template < typename MetaField > void operator()(MetaField const&, boost::enable_if< some_test >::type * = 0); template < typename MetaField > void operator()(MetaField const&, boost::disable_if<some_test>::type * = 0); }; I imagine that this is common enough that there may already be a utility to write things like this but I don't see one in the docs. Is it out there? What about something that would make this type of thing easy: struct operator { template < typename MetaField > void operator()(MetaField const&, boost::enable_if< test_a >::type * = 0); template < typename MetaField > void operator()(MetaField const&, boost::enable_if< and_< not_ <test_a>, test_b>>::type * = 0) void operator()(MetaField const&, boost::enable_if<not_<or_<test_a, test_b>>>::type * = 0); }; That's supposed to be an if, elseif, else construct. -- http://crazyeddiecpp.blogspot.com/

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Re: [Boost-users] [proto, fusion] Segfault in for_each
by Eric Niebler 19 May '10

19 May '10

On 5/19/2010 10:01 AM, David Greene wrote: > On Thursday 13 May 2010 23:16:31 David A. Greene wrote: >> On Monday 10 May 2010 21:15:42 Eric Niebler wrote: >>>> I've been wrestling with this for days. Any ideas on how to debug >>>> this? >>> >>> Nope. But it'd probably help if you sent around a self-contained repro. >> >> Ok, here's a smallish testcase. gdb shows the same problem: an invalid >> proto expression reference. > > Hey Eric, > > No rush to take a look at this, but I wanted to make sure you got the > testcase since I haven't seen a reply. Sorry for not responding sooner. I got it. This came in during the melee of BoostCon. And now I'm down with a cold. I hope to look at it soon. -- Eric Niebler BoostPro Computing http://www.boostpro.com

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Boost.Regex Can't compile / link programs..
by John Mc Murray 19 May '10

19 May '10

Hello all, I am trying to evaluate boost, I've heard some good things about it... I've managed to set it up mostly successfully. On boosts page: http://www.boost.org/doc/libs/1_43_0/more/getting_started/windows.html#get-… I've managed to compile the first program which does not use any separately compiled libs.. When I try to compile the second program which uses the regex lib, I get a link error... There are many link errors, but I am only posting the first one from gcc's output: C:\DOCUME~1\John\LOCALS~1\Temp\ccgmT8rw.o:reg.cpp:(.text$_ZN5boost9re_detail27cpp_regex_traits_char_layerIcEC2ERKNS0_21cpp_regex_traits_baseIcEE[boost::re_detail::cpp_regex_traits_char_layer<char>::cpp_regex_traits_char_layer(boost::re_detail::cpp_regex_traits_base<char> const&)]+0x55): undefined reference to `boost::re_detail::cpp_regex_traits_char_layer<char>::init()' When I comment out the 3 lines in the code snippet below (marked with //comment out), but I leave the one line boost::smatch matches; it does compile.. Does that mean that I have Regex installed correctly, but I am maybe missing a lib when I try to compile Here is how I'm trying to compile: g++ -I ../boost_1_43_0 -L ../boost_1_43_0/stage/lib -luser32 -lpthread -lboost_program_options-mgw44-mt-1_43 -lboost_regex-mgw44-mt-1_43 -lboost_thread-mgw44-mt-1_43 -o r reg.cpp Maybe I don't need to include all those libs, but I keep adding libs, hoping that something will work Also, if I remove the args to boost::regex, boost::regex pat("^Subject: (Re: |Aw: )*(.*)"); to boost::regex pat(); then the software compiles with no warnings... Anyone know what's up here? Oh, I'm using this on windows (MinGW - g++) now, but once its working here I'll need to redo it all on Linux (Mandriva). Thanks... John /***************************************************************************/ #include <boost/regex.hpp> #include <iostream> #include <string> int main() { std::string line; boost::regex pat("^Subject: (Re: |Aw: )*(.*)"); //comment out while (std::cin) { std::getline(std::cin, line); boost::smatch matches; if (boost::regex_match(line, matches, pat)) //comment out std::cout << matches[2] << std::endl; // comment out } } /***************************************************************************/ -- John Mc Murray john(a)softsmart.co.za www.softsmart.co.za Cell: 083 784 6313 Tel: 011 083 7085 Fax: 086 650 5573 Make money from your website or blog. Join our affiliate program now! www.softsmart.co.za/affiliates

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Product between a matrix row and a complete matrix
by Alex34 19 May '10

19 May '10

I need to multiply a matrix <double> single row with a complete matrix <double> to obtain an accessible vector of values with uBLAS Can someone very kindly provide me a snippet on how to do this (in the previous post I tried without success: "Problem with prod function") or a paper about matrix operations with uBLAS? I need matrix calculations with uBLAS but the documentation is really lacking in explaining a lot of things. Please help me or provide me a guide or a tutorial or anything I can study to solve my problem Sincerely, Paul

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boost::any, string conversion and serialization
by Archie14 19 May '10

19 May '10

How to get a string representation of of boost::any value? for example, is the following approach correct? boost::any t(2); std::string str = boost::any_cast<std::string>(t); In addition, from searching archieves I understand that there is no serialization for boost::any. Currently I plan to examine "name" in type_info returned from boost::any::type() and serialize accordingly. I'll appreciate any advise for better approach.

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Serialization of a class which contains a pointer
by Nguyen Kim Son 19 May '10

19 May '10

Hello, I've tried a simple example with the serialization of a class that contains an int and a pointer to int (named "nothing" in the code) but after having tried both ar & (*b) and ar & b (b is the second variable), I have not been succeeded to send the class via the call "send" (in boost::mpi). My code is found at: http://www.copypastecode.com/29170/ Does anyone has an idea of why it doesn't work? Thank you in advance! Son. -- --------------------------------------------------------- Son NGUYEN KIM Antibes 06600 Tel: 06 48 28 37 47

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Get IP address of a client
by Rouven Walter 19 May '10

19 May '10

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Problems linking statically under linux
by Vial, Florent 19 May '10

19 May '10

Hi all, I recently need to link my application statically to the boost libraries. I am on a RHEL 5.3 (x86_64) system and compiling/linking with gcc 4.1.2. I built my boost 1.43.0 static libraries using follwing command line: ./bjam --build-dir="/tmp/boost_143.gcc41" threading=multi link=static runtime-link=static --prefix="/usr/local/boost1430-gcc41" --without-mpi --without-python --without-serialization --without-test --without-wave address-model=64 -d+2 --layout=tagged cxxflags="-fPIC -pipe -march=nocona -msse2 -pthread -Wno-multichar -DLINUX" My tools/build/v2/user-config.jam contains only using gcc ; I'll just take the example of the thread library for describing my problem. I can see that the all the wished libraries built fine, with a typical compile line being: "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pthread -m64 -fPIC -pipe -march=nocona -msse2 -pthread -Wno-multichar -DLINUX -DBOOST_ALL_NO_LIB=1 -DBOOST_THREAD_BUILD_LIB=1 -DBOOST_THREAD_POSIX -DNDEBUG -I"." -c -o "/tmp/boost_143.build.gcc41/boost/bin.v2/libs/thread/build/gcc-4.1.2/rel ease/address-model-64/link-static/runtime-link-static/threading-multi/pt hread/thread.o" "libs/thread/src/pthread/thread.cpp" When i "su" and add "install" to the bjam command line above, all files install properly and /usr/local/boost1430-gcc41/lib is populated with static libraries like libboost_thread-mt-s.a Now i build my library that uses the boost thread library. A typical compile line is : /usr/bin/g++ -Wall -g -O3 -g -g -pipe -march=nocona -msse2 -pthread -Wno-multichar -DLINUX -fPIC -pthread -c -o obj/myfile.o myfile.cpp -I../include -I./ -I/usr/local/boost1430-gcc41/include/boost-1_43 -I/usr/local/cppunit1121-gcc41/include -I../include/mylib AR ../lib/libmylib.a Now i try to build the unit test for that library using : ar -rsc ../lib/libmylib.a obj/myfile.o LD /home/florent/dev/mylib/MylibTestMain /usr/bin/g++ -o /home/florent/dev/mylib/MylibTestMain obj/MylibTestMain.o obj/AUnitTest.o obj/AnotherUnitTest.o -L../lib -lmylib -L/usr/local/cppunit1121-gcc41/lib -lcppunit -ldl -L/usr/local/lib64 -L/usr/local/boost1430-gcc41/lib -lboost_thread-mt-s And i get a lot of undefined references: obj/AUnitTest.o: In function `AUnitTest::testAFunction()': undefined reference to `boost::thread_group::thread_group()' undefined reference to `boost::thread_group::join_all()' undefined reference to `boost::thread_group::~thread_group()' undefined reference to `boost::mutex::~mutex()' ... <snip> So my question is: how do i link properly statically with the boost libraries ? Is there any defined that i should be aware of while compiling my unit tests ? Thank you in advance, Florent Arnold & Richter Cine Technik GmbH & Co. Betriebs KG Sitz: Munchen - Registergericht: Amtsgericht Munchen - Handelsregisternummer: HRA 57918 Personlich haftender Gesellschafter: Arnold & Richter Cine Technik GmbH Sitz: Munchen - Registergericht: Amtsgericht Munchen - Handelsregisternummer: HRB 54477 Geschaftsfuhrer: Franz Kraus; Dr. Martin Prillmann A new star is born - ALEXA the most versatile digital camera system. Get all the latest information from arridigital.com and YouTube.

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Serialization: C4308 warning with MSVC9
by Political Confusion 19 May '10

19 May '10

I'm using Boost 1.43 with MSVC9 SP1 and Windows SDK v7 on Windows 7. I've created a class like the "A Very Simple Case" example (i.e. added 'access' as friend and a templated serialize function). In serialize, I just archive 10 ints (signed and unsigned). It compiles fine, but when I add program code to save my class to a text_oarchive, I get a warning: c:\third-party\boost_1_43_0\boost\mpl\print.hpp(51) : warning C4308: negative integral constant converted to unsigned type Line 51 of print.hpp is: enum { n = sizeof(T) + -1 }; Calling sizeof() on my class gives a 44. I do not get any warning when I load my class with text_iarchive. And both save and load appear to work fine.

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BoostCon 2011 Hotel Reservation Billing
by David Abrahams 19 May '10

19 May '10

FYI, last year the Meadows' move to an automated reservation system caused some issues with the amount people were charged for reservations. After inquiring specifically into billing for 2011 reservations, this is what I heard back from Doug Crawford: > I met with our reservations team. > For your group, we'll go back to manual deposits. > Aspen Meadows will agree to the following: > Room reservations will be accepted with 1 night deposit > > Balance due 30 days prior to arrival > > Reservations made 30 days or less prior to arrival will be > charged in full. > > Standard reservations cancellations policies apply - > reservations are non refuncable less than 14 days of arrival. ^----------------sounds intriguing, but I think this is meant to say “non-refundable.” ;-) Cheers, -- Dave Abrahams Meet me at BoostCon: http://www.boostcon.com BoostPro Computing http://www.boostpro.com

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