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

newbie question - how to test
by Saibal Ghosh 30 Jan '09

30 Jan '09

Hi, I am building BOOST (the libraries) on solaris platform using SunStudio 11 compiler. But how to test whether all libraries are build properly? Does BOOST has some tests which i can run to verify the build ? regards, Saibal

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serialization deserialization through the pointer
by niranjan bangera 30 Jan '09

30 Jan '09

hi all, i am facing some problem in my code. Please help me to tackle it. BOOST Version : 1.36.0 compliler : gnu-gcc-/4.1.1-binutils-2.16.1/x86_64-pc-linux2.4/bin/gcc example of my prog: header: my.h ---- class my { int var1; int var2; structure object; // structure is the some other structure which is defined(i have defied the serialization function for this also... /*serialization function*/ friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int file_version) { ar & var1; ar & var2; ar & object; } }; mymain.cpp ---------- #include "boost/archive/text_iarchive.hpp" #include "boost/archive/text_oarchive.hpp" #include "boost/serialization/access.hpp" #include "boost/serialization/serialization.hpp" #include "boost/serialization/collection_traits.hpp" #include "boost/serialization/utility.hpp" #include "my.h" class mymain { protected: my * ptr; public: void mytake_arch(); void myretrive_arch(); }; void mymain::mytake_arch() { std::ofstream ofs("filename"); { boost::archive::text_oarchive oa(ofs); oa << ptr; } } void mymain::myretrive_arch() { mymain *ptr = NULL; //// Confused in this, This is correct or wrong, if wront what else i can use std::ifstream ifs("filename"); boost::archive::text_iarchive ia(ifs); ia >> ptr; } int main() { mymain obj; obj.mytake_arch(); obj.myretrive_arch(); } Problem: ------- I have some confusion in retriving, Whether the way in which i retrieved is correct or wrong. Any other replacement or modification can be done for the retriving part(myretrive_arch() function). Please let me know. because the retrived ptr(pointer retrived) causes segmentation fault whenenver i use it for some other application. Any suggestions will be apprciated. Thanks, Niranjan

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Cross compiling
by Yepez, Esteban 30 Jan '09

30 Jan '09

Hello, I am trying to cross compile boost for an embedded processor that has its own gcc and g++ compiler. What are the options I need to invoke so that the make uses these compilers instead of gcc? Also, can you tell me the simpliest way to test it? Thanks, Esteban

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Compiler Error With boost::bind and boost::signals
by KERSAM 30 Jan '09

30 Jan '09

Hello. I have a compiler error when I try to use boost::bind and boost::signals. Here is the code: -------------------- #include<boost/bind.hpp> #include<boost/signals.hpp> class MyBoostTest { public: void testFunction(int x, int y) {} }; void doConnect() { boost::signal2<void, int, int> signal; signal.connect(boost::bind<void>(&MyBoostTest::testFunction, new MyBoostTest, _1)); } ----------------------------------- The compiler gives me the following error: c:\3rdparty\boost\boost\bind.hpp(289) : error C2064: term does not evaluate to a function taking 2 arguments class does not define an 'operator()' or a user defined conversion operator to a pointer-to-function or reference-to-function that takes appropriate number of arguments What am I doing wrong? Regards -- View this message in context: http://www.nabble.com/Compiler-Error-With-boost%3A%3Abind-and-boost%3A%3Asi… Sent from the Boost - Users mailing list archive at Nabble.com.

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Re: [Boost-users] RBGL use with BGL minCut() function
by Gianni Loiacono 30 Jan '09

30 Jan '09

Thanks another time Mr. Sutton for the answer. This is my goal: "I have made a project that use efficiently BGL library. Now I have the necessity to use the Gomory-Hu algorithm......then I have searched on the net some source "boost compatible" that makes this algorithm ;)" But nothing, on the net there isn't this function.....I'm surprised because it is a fundamental algorithm of graph theory :o) Thanks a lot and sorry for my eng :) Bye.

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Re: [Boost-users] [BGL] Bundled properties and property maps
by Andrew Sutton 30 Jan '09

30 Jan '09

On Tue, Jan 13, 2009 at 9:56 AM, Andrew Sutton <andrew.n.sutton(a)gmail.com>wrote: > Hi Andrew, apologies for writing directly to you, I just thought I'd try to >> get your attention this way since you hadn't yet replied to my last post on >> the above topic in the mailing list. >> > > Sorry about that, I've been swamped since new years. I'm going to bounce > this back to the list > > I would avoid declaring property maps as const. Somewhere in your posted > code you have: > > const property_map<...>::const_type map; // or something similar. > > For all property maps, map = get(...) is a valid expression, regardless of > whether your map is a ::type or ::const_type. By declaring it const, and > then instantiating a template with the const pmap, you're going to run into > problems - probably the problem you reported earlier. > > Andrew Sutton > andrew.n.sutton(a)gmail.com >

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Boost 1.38.0 beta 2 available
by Beman Dawes 30 Jan '09

30 Jan '09

Boost 1.38.0 beta 2 available is available from SourceForge. http://sourceforge.net/project/showfiles.php?group_id=7586&package_id=8041&… Please report any problems or comments to the users or developers mailing lists. ------------- Version 1.38.0 New Libraries * Flyweight: + Design pattern to manage large quantities of highly redundant objects, from Joaquín M López Muñoz. * ScopeExit: + Execute arbitrary code at scope exit, from Alexander Nasonov. * Swap: + Enhanced generic swap function, from Joseph Gauterin. Updated Libraries * Accumulators: + Add rolling_sum, rolling_count and rolling_mean accumulators. * Date_Time: + Added support for formatting and reading time durations longer than 24 hours with new formatter: %0. + Removed the testfrmwk.hpp file from the public include directory. + Fixed several bugs and compile errors. + For full details see the change history * Exception: + Improved and more customizable diagnostic_information output. * Hash: + boost/functional/detail/container_fwd.hpp has been moved to boost/detail/container_fwd.hpp. The current location is deprecated. + For more detail, see the library changelog. * Interprocess: + Updated documentation to show rvalue-references funcions instead of emulation functions. + More non-copyable classes are now movable. + Move-constructor and assignments now leave moved object in default-constructed state instead of just swapping contents. + Several bugfixes (#2391, #2431, #1390, #2570, #2528). * Intrusive: + New treap-based containers: treap, treap_set, treap_multiset. + Corrected compilation bug for Windows-based 64 bit compilers. + Corrected exception-safety bugs in container constructors. + Updated documentation to show rvalue-references funcions instead of emulation functions. * Math: + Added Johan Råde's optimised floating point classification routines. + Fixed code so that it compiles in GCC's -pedantic mode (bug report #1451). * Multi-index Containers: Some redundant type definitions have been deprecated. Consult the library release notes for further information. * Proto: + Fix problem with SFINAE of binary operators (Bug 2407). + Fix proto::call transform for callable transforms with >3 arguments. + result_of::value changed behavior for array-by-value terminals. + unpack_expr requires only Forward Sequences rather than Random Access Sequences. + Deprecate legacy undocumented BOOST_PROTO_DEFINE_(VARARG_)FUNCTION_TEMPLATE macros. + Add BOOST_PROTO_REPEAT and BOOST_PROTO_LOCAL_ITERATE macros to help with repetitive code generation + Support for nullary expressions with tag types other than proto::tag::terminal + Allow 0- and 1-argument variants of proto::or_ and proto::and_ * Regex: + Breaking change: empty expressions, and empty alternatives are now allowed when using the Perl regular expression syntax. This change has been added for Perl compatibility, when the new syntax_option_type no_empty_expressions is set then the old behaviour is preserved and empty expressions are prohibited. This is issue #1081. + Added support for Perl style ${n} expressions in format strings (issue #2556). + Added support for accessing the location of sub-expressions within the regular expression string (issue #2269). + Fixed compiler compatibility issues #2244, #2514, and #2458. * Unordered: + Use boost::swap. + Use a larger prime number list for selecting the number of buckets. + Use aligned storage to store the types. + Add support for C++0x initializer lists where they're available. + For more detail, see the library changelog. * Xpressive: + basic_regex gets nested syntax_option_flags and value_type typedef, for compatibility with std::basic_regex + Ported to Proto v4; Proto v2 at boost/xpressive/proto has been removed. + regex_error inherits from boost::exception Other Changes Experimental support for building Boost with CMake has been introduced in this version. For more details see the wiki, Discussion is taking place on the Boost-cmake mailing list. Compilers Tested Boost's primary test compilers are: * TODO * GCC 4.0.1 on OS X 10.4.10 and 10.5.2 on Intel and 10.4.9 on Power PC. * GCC 4.3.2 on Ubuntu Linux. * GCC 4.3.3 on Unstable Debian. * GCC 4.2.1 on HP-UX 64-bit. * HP C/aC++ B3910B A.06.17 on HP-UX 64-bit. * Visual C++ 7.1 SP1, 8.0 SP1 and 9.0 SP1 on Windows XP. Boost's additional test compilers include: * OS X: + GCC 4.0.1 on OS X 10.4.10 and 10.5.2 on Intel, OS X 10.4.9 on PowerPC + Intel 9.1, 10.0 on OS X 10.4.10 + Intel 10.1, 11.0 on OS X 10.5.2 * On Linux: + GCC 4.1.1, 4.2.1 on 64-bit Red Hat Enterprise Linux + GCC 4.1.2 on 64-bit Redhat Server 5.1 + GCC 3.4.3, GCC 4.0.1, GCC 4.2.4 and GCC 4.3.2 on Red Hat Enterprise Linux + GCC 4.3.2 with C++0x extensions + GCC 4.2.1 on OpenSuSE Linux + pgCC 8.0-0a 64-bit target on Red Hat Enterprise Linux + QLogic PathScale(TM) Compiler Suite: Version 3.1 on Red Hat Enterprise Linux * IBM XL C/C++ Enterprise Edition for AIX, V10.1.0.0, on AIX Version 5.3.0.40 * GCC 4.2.1 on FreeBSD 7. * GCC 4.2.1 on HP-UX Integrity * HP C/aC++ B3910B A.06.17 on HP-UX 64-bit. Acknowledgements TODO

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BGL: Vertex or Vertex& ?
by Roger House 30 Jan '09

30 Jan '09

I've just started using the Boost Graph Library (which is proving to be a very nice tool) and I've encountered an issue: When vertex descriptors are passed as parameters, stored in vectors, etc., is it better to use Vertex&, or is Vertex alone okay. I've been assuming that a vertex descriptor is probably a pointer, so I've been using Vertex. But then is occurred to me that my assumption could be all wrong and I should be using Vertex&. Here are the Graph, Vertex, and Edge definitions I've been using: typedef adjacency_list < vecS, // edge container type vecS, // vertex container type undirectedS, VertexProperties, EdgeProperties, GraphProperties > Graph; typedef graph_traits<Graph>::vertex_descriptor Vertex; typedef graph_traits<Graph>::edge_descriptor Edge; Roger House

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David M Garza is out of the office.
by David M Garza 30 Jan '09

30 Jan '09

I will be out of the office starting 01/30/2009 and will not return until 02/03/2009. I will respond to your message when I return.

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[ASIO] random crashes
by Axel 30 Jan '09

30 Jan '09

Hello I m using ASIO library (from boost 1.35) in a network daemon (running on a Debian Etch system). The code structure is almost the same as the one described in the HTTP Server example (http://tenermerx.com/Asio/boost_asio_1_3_1/doc/html/boost_asio/examples.htm…) One io_service is used, async_accept() creates new "sessions" and so on. The daemon can run flawlessly for weeks (or only some hours), and crash randomly (segmentation fault). The "network" load isn't really high, every 5 minutes, a few megabytes of data (characters) are sent to the daemon. I didn't noticed any memory leaks or null pointers accesses. Among many crashes, I found 2 kind of crashes. Since core are dumped, I tried to debug it, but I don't know how to interpret the core result. The binary wasn't linked against debug libraries and I just can get debug data from the binary itself. Here's the gdb output on "bt full" command. The daemon has 4 threads, here s the gdb output of the one which causes the crash (I assume this is this one) First kind of crash : (only the relevant part is pasted, the output is huge). It seems to be related to the way I handle the timeout on a timer. In my daemon, the io_service thread may call close() function on the socket object when another thread may call cancel() on the socket object. Could this lead to a crash ? (I can post source code if needed) What is the best way to handle receive timeout *and* socket & timer close from another thread ? Thread 1 (process 27120): Program terminated with signal 11, Segmentation fault. #0 0xb7c7c024 in pthread_mutex_lock () from /lib/tls/i686/cmov/libpthread.so.0 No symbol table info available. #1 0xb7d5f0c6 in pthread_mutex_lock () from /lib/tls/i686/cmov/libc.so.6 No symbol table info available. #2 0x08060438 in boost::asio::detail::posix_mutex::lock (this=0x16) at /usr/include/boost/asio/detail/posix_mutex.hpp:71 error = 0 #3 0x08060559 in scoped_lock (this=0xb796807c, m=@0x16) at /usr/include/boost/asio/detail/scoped_lock.hpp:36 No locals. #4 0x08060ad0 in boost::asio::detail::epoll_reactor<false>::close_descriptor (this=0x2, descriptor=-1291829448) at /usr/include/boost/asio/detail/epoll_reactor.hpp:297 lock = {<boost::noncopyable_::noncopyable> = {<No data fields>}, mutex_ = @0x16, locked_ = 212} ev = {events = 6, data = {ptr = 0x25, fd = 37, u32 = 37, u64 = 8589934629}} #5 0x0809b189 in boost::asio::detail::reactive_socket_service<boost::asio::ip::tcp, boost::asio::detail::epoll_reactor<false> >::close (this=0xb3004358, impl=@0xb3037f1c, ec=@0xb7968128) at /usr/include/boost/asio/detail/reactive_socket_service.hpp:210 No locals. #6 0x0809b277 in boost::asio::stream_socket_service<boost::asio::ip::tcp>::close (this=0xb3000098, impl=@0xb3037f1c, ec=@0xb7968128) at /usr/include/boost/asio/stream_socket_service.hpp:145 No locals. #7 0x0809b2c5 in boost::asio::basic_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> >::close (this=0xb3037f18) at /usr/include/boost/asio/basic_socket.hpp:253 ec = {m_val = 0, m_cat = 0xb7c74c10} #8 0x08091129 in Session::handleTimeout (this=0xb3037f18, error=@0xb796821c) at Session.cc:80 Could someone bring me some explainations about this crash ? Second kind of crash : (I really have no idea from where could come the crash, the backtrace isn't very useful) (gdb) bt full #0 boost::asio::detail::scoped_lock<boost::asio::detail::posix_mutex>::unlock (this=0xb5631dac) at /usr/include/boost/asio/detail/scoped_lock.hpp:58 No locals. #1 0x00000000 in ?? () No symbol table info available. Could someone give me some advices about how to handle these crashes ? How could I get more data in backtrace ? Thanks in advance for your help. Regards

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seg fault on windows with Boost threads, istringstream, mingw
by Tod Courtney 30 Jan '09

30 Jan '09

Hi I am working on a multithreaded application for linux and windows using Boost threads. For windows, we have been developing with MinGW G++ 3.4.4 (packaged in cygwin). My application uses a producer-consumer model where one thread produces tasks definitions and multiple worker threads complete the tasks. I discovered that our application runs fine on linux but crashes with a SIGSEGV fault on windows, at least when compiled with MinGW. When compiling the same application with MSVC it works fine. The SIGSEGV crash is not always in the exact same place in the code, but is very likely to occur -- it happens 99% of the time when there are 3 or more worker threads. The code runs fine if there is only 1 worker thread. If I try to use the debugger to get a stack trace, I find the stack is corrupted so I can not see the method or source code lines that caused the crash. I have tried boost 1.36 and 1.37. I have tried MinGW g++ 3.4.4 (from cygwin), 3.4.5 (main release) and 4.3 (alpha). I get the same results in all cases. I have added the -mthreads flag to the compile and link options for my application. I believe the problem is related to this code, which uses a istringstream to convert a string to a basic type (say a double): template <typename T> bool FromString(T &t,const std::string &s, std::ios_base &(*f)(std::ios_base &)=std::dec) { std::istringstream iss(s); return !(iss >> f >> t).fail(); } The istringstream object is local to the conversion function, and each istringstream is unique for each thread. So I wouldn't expect a thread-related problem, unless istringstream has internal state stored in static variables. However, if I replace that code with equivalent calls to C-lib functions like 'atof', the problem goes away. I have attached a test application, along with the makefile I use to build it, that demonstrates this problem. This test application fails for with a SIGSEGV when run with MinGW GCC 3.4.4 (from cygwin), MinGW 3.4.5 (current MinGW release) or MinGW GCC 4.3 alpha. It works fine when I compile with MSVC or Cygwin GCC (non-mingw version based on cygwin1.dll and pthreads). I hope there is a solution but at this point and hope for some help answering these questions: 1) Is there a multi-thread bug in the MinGW implementation istringstream? 2) Is there a problem with my build process? Am I missing a flag or using the wrong variation of a library? 3) Is this problem unique to my machine or reproducible by others? 4) Has anyone else encountered a similar issue? If you have experience with using Boost threads with MinGW I would love to hear any pointers or suggestions you can share. If you try this test application with MinGW G++ and it works I would love to know it. If multiple people can confirm this is a bug, I want to submit it to either the MinGW or Boost threads dev. teams. Thanks in advance for your help, Tod Courtney -- Tod Courtney Delcross Technologies LLC tcourtney(a)delcross.com, www.delcross.com (217) 363-3396 ext 103 mingw34: test.cpp c:\\MinGW\\bin\\g++ -mthreads -o mingw34 test.cpp -I c:\\boost\\boost_1_37_0 -L c:\\boost\\boost_1_37_0\\stage\lib -lboost_thread-mgw34-mt newmingw43: test.cpp c:\\mingw4\\bin\\g++ -mthreads -o newmingw43 test.cpp -I c:\\boost\\boost_1_37_0 -L c:\\boost\\boost_1_37_0\\stage\\lib -lboost_thread-mgw43-mt nocygwin: test.cpp /usr/bin/g++ -mthreads -o nocygwin test.cpp -I /cygdrive/c/boost/boost_1_37_0 -L /cygdrive/c/boost/boost_1_37_0/stage/lib -mno-cygwin -lboost_thread-mgw34-mt cygwin: test.cpp /usr/bin/g++ -o cygwin test.cpp -I /cygdrive/c/boost/boost_1_37_0 -L /cygdrive/c/boost/boost_1_37_0/stage/lib -lboost_thread_pthread-gcc34-mt-1_37 #include <string> #include <vector> #include "boost/bind.hpp" #include "boost/thread.hpp" #include "boost/thread/barrier.hpp" using namespace std; boost::mutex msgMutex; //////////////////////////////////////////////////////////////////////// /// threadsafe tracing method void msg(const std::string &str) { boost::mutex::scoped_lock lock(msgMutex); cout<<str<<endl; } //////////////////////////////////////////////////////////////////////// /// method run by each worker thread bool exec(std::vector<string> * vec) { char buff[256]; // wait here until all threads have been created msg(string("START THREAD: ")); // now do the work for(size_t n=0;n<vec->size();n++) { string val=(*vec)[n]; double d=0; d=atof(val.c_str()); // COMMENTING OUT THE NEXT TWO LINES AVOIDS THE SIGSEGV istringstream iss(val); iss>>d; sprintf(buff,"value=%lf",d); msg(string(buff)); } msg("EXEC DONE: "); return true; } //////////////////////////////////////////////////////////////////////// /// main method: parse inputs and create worker threads int main(int argc, char **argv) { int numThreads=0; if (argc==2) numThreads=atoi(argv[1]); else cout<<"USAGE: "<<argv[0]<<" <numthreads>"<<endl; boost::thread **worker; vector<string> **vec; worker=new boost::thread*[numThreads]; vec=new vector<string>*[numThreads]; for(int n=0;n<numThreads;n++) { vec[n]=new vector<string>; for(int m=0;m<10;m++) { ostringstream oss; oss<<n<<"."<<m; vec[n]->push_back(oss.str()); } worker[n]=new boost::thread(boost::bind(&exec,vec[n])); } // wait until all threads to end for(int n=0;n<numThreads;n++) { worker[n]->join(); delete worker[n]; delete vec[n]; } delete [] worker; delete [] vec; }

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[serialization] Can access::destroy (please) be removed?
by Maarten Nieber 30 Jan '09

30 Jan '09

Hi, my compiler (Visual Studio 2003) gives an error in access.hpp when I try to serialize an object that has a protected destructor (see summarized compiler output below). If I comment out the call to delete in access::destroy, the compiler does no longer complain and my code seems to work. Is the destroy function (or: the delete call) really needed? Thanks!, Maarten MyClass::MyClass' : cannot access protected member declared in class 'MyClass' boost\archive\detail\iserializer.hpp(105) : see reference to function template instantiation 'void boost::serialization::access::destroy<T>(const T *)' being compiled

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[boost][asio] deadline_timer doesn't delays - async_wait invokes handler at once
by tomasz jankowski 30 Jan '09

30 Jan '09

Hello, I would like to add timeout to my server which is based on "http server 3" example. But I don't know why but I can't force deadline_timer to work properly. deadline_timer doesn't delays invoking of handler. please look how I modified source code of connection::start() in "http server 3" example. I did it according to suggestion placed on http://lists.boost.org/Archives/boost/2007/04/120339.php Could someone tell me what I.m doing wrong? tom void set_result(boost::optional<boost::system::error_code>* a, boost::system::error_code b) { a->reset(b); } void connection::start() { boost::optional<boost::system::error_code> timer_result; boost::asio::deadline_timer timer(socket_.io_service(),boost::posix_time::seconds(5)); timer.async_wait(boost::bind(set_result, &timer_result, _1)); boost::optional<boost::system::error_code> read_result; socket_.async_read_some(boost::asio::buffer(buffer_), strand_.wrap( boost::bind(&connection::handle_read, shared_from_this(), boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred))); socket_.io_service().reset(); while (socket_.io_service().run_one()) { if (read_result){ timer.cancel(); }else if(timer_result) { socket_.cancel(); } } if (*read_result) { throw boost::system::system_error(*read_result); } } ---------------------------------------------------- Pierwszy w Polsce profesjonalny serwis o modelkach! Zobacz zdjęcia, video i piękne kobiety. - Kliknij: http://klik.wp.pl/?adr=http%3A%2F%2Fcorto.www.wp.pl%2Fas%2Falemodelki.html&…

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Bug in Ublas' Inner Product between Matrix and Vector?
by Gundala Viswanath 30 Jan '09

30 Jan '09

Hi all, I am trying to perform an inner product multiplication with ublas between this Matrix and Vector: ublas::matrix <double> inputMat (5,5,0); [5,5]((0.994704,0.000882587,0.000882587,0.000882587,0.00264776),(0.00527045,0.989459,0.00263523,0.00263523,0),(0,0,0.00528298,0,0),(0,0,0,1,0),(0,0,0,0,1)) ublas::vector <double> inputVec (5); [5](0.4,0.2,0.2,0.2,0.2) The result I get is this: [5](0.398941,0.201054,0.0010566*,0.2,0.2) Where as the correct one should be (using R): 0.3999707,0.1981258,0.2007013*,0.2007013,0.2005310 Note the significant discrepancy in the 3rd element (*). The product command I use is this: ublas::vector <double> Result (5); Result = ublas::prod(inputMat,inputVec); Is there anything wrong with my way of doing inner product or it is a bug? - Gundala Viswanath Jakarta - Indonesia

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linking boost in a shared library using -fPIC
by jono 30 Jan '09

30 Jan '09

hi. i'm building a shared library under gcc 4.1.1 which links some boost 1.33.1 libraries. a predecessor added the -fPIC switch to the Jamfiles of boost 'thread', 'date_time' and 'regex', and i have had no problems linking them. i've added the boost 'filesystem' library to the project and similarly patched the Jamfile... . . . lib boost_filesystem : ../src/$(SOURCES).cpp : # build requirements <define>BOOST_FILESYSTEM_STATIC_LINK <include>$(BOOST_ROOT) <sysinclude>$(BOOST_ROOT) <no-warn>exception.cpp <no-warn>operations_posix_windows.cpp #******************** <gcc><*><cxxflags>"-fPIC" #******************** # common-variant-tag ensures that the library will # be named according to the rules used by the install # and auto-link features: common-variant-tag : debug release # build variants ; . . . ... and recompiled boost. but i still get the following linker error. ------------------------------------------------------------- gcc-Link-action bin/blablabla/libinterpreter.so/gcc/debug/shared-linkable-true/threading-multi/libinterpreter.so /usr/bin/ld: /home/jono/lib/boost/bin_linux/debug/libboost_filesystem.a(operations_posix_windows.o): relocation R_X86_64_32 against `a local symbol' can not be used when making a shared object; recompile with -fPIC /home/jono/lib/boost/bin_linux/debug/libboost_filesystem.a: could not read symbols: Bad value ------------------------------------------------------------- can anyone spot my deliberate mistake? cheers Jono

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from range_iterator to range_value
by er 29 Jan '09

29 Jan '09

Hello, Is this, or a class that achieves the same goal, already defined somewhere in the boost? template<typename R> struct range_value{ typedef typename iterator_value<typename boost::range_iterator<R0>::type>::type type; }; Thanks.

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[serialization] Support for smart pointers?
by Robert Dailey 29 Jan '09

29 Jan '09

Hi, The documentation for Boost.Serialization states that support for loading/saving pointers is fully supported out of the box. However, what if I want to use smart pointers, such a boost::scoped_ptr? Right now I believe I would have to do this: Foo* foo1; archive & foo1; boost::scoped_ptr<Foo> foo2( foo1 ); I was thinking it would be convenient to avoid the extra variable (foo1) and do this: boost::scoped_ptr<Foo> foo2; archive & foo2; Is this possible?

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[lambda] lambda member access
by Michał Nowotka 29 Jan '09

29 Jan '09

In function: void clean_data (MyMap& map) { remove_if(map.begin(), map.end(), (&lambda::_1 )->*(&pair< X* const, double >::second) <= m_epsilon); } where: typedef std::map<const X*,double> MyMap; I get error: c:\program files\microsoft visual studio 9.0\vc\include\algorithm(1240) : error C2582: 'operator =' function is unavailable in 'std::pair<_Ty1,_Ty2>' with [ _Ty1=const hapl::Haplotype *const , _Ty2=double ] c:\program files\microsoft visual studio 9.0\vc\include\algorithm(4949) : see reference to function template instantiation '_OutIt std::_Remove_copy_if<std::_Tree<_Traits>::iterator,_OutIt,_Pr>(_InIt,_InIt,_OutIt,_Pr,std::_Range_checked_iterator_tag)' being compiled with [ _OutIt=std::_Tree<std::_Tmap_traits<const hapl::Haplotype *,double,std::less<const hapl::Haplotype *>,std::allocator<std::pair<const hapl::Haplotype *const ,double>>,false>>::iterator, _Traits=std::_Tmap_traits<const hapl::Haplotype *,double,std::less<const hapl::Haplotype *>,std::allocator<std::pair<const hapl::Haplotype *const ,double>>,false>, _Pr=boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::relational_action<boost::lambda::lessorequal_action>,boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::action<2,boost::lambda::other_action<boost::lambda::member_pointer_action>>,boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::other_action<boost::lambda::addressof_action>,boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::placeholder<1>>,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>>>,double std::pair<hapl::Haplotype *const ,double>::* const ,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>>>,const double,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>>>, _InIt=std::_Tree<std::_Tmap_traits<const hapl::Haplotype *,double,std::less<const hapl::Haplotype *>,std::allocator<std::pair<const hapl::Haplotype *const ,double>>,false>>::iterator ] c:\program files\microsoft visual studio 9.0\vc\include\algorithm(1309) : see reference to function template instantiation '_OutIt stdext::unchecked_remove_copy_if<std::_Tree<_Traits>::iterator,_FwdIt,_Pr>(_InIt,_InIt,_OutIt,_Pr)' being compiled with [ _OutIt=std::_Tree<std::_Tmap_traits<const hapl::Haplotype *,double,std::less<const hapl::Haplotype *>,std::allocator<std::pair<const hapl::Haplotype *const ,double>>,false>>::iterator, _Traits=std::_Tmap_traits<const hapl::Haplotype *,double,std::less<const hapl::Haplotype *>,std::allocator<std::pair<const hapl::Haplotype *const ,double>>,false>, _FwdIt=std::_Tree<std::_Tmap_traits<const hapl::Haplotype *,double,std::less<const hapl::Haplotype *>,std::allocator<std::pair<const hapl::Haplotype *const ,double>>,false>>::iterator, _Pr=boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::relational_action<boost::lambda::lessorequal_action>,boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::action<2,boost::lambda::other_action<boost::lambda::member_pointer_action>>,boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::other_action<boost::lambda::addressof_action>,boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::placeholder<1>>,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>>>,double std::pair<hapl::Haplotype *const ,double>::* const ,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>>>,const double,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>>>, _InIt=std::_Tree<std::_Tmap_traits<const hapl::Haplotype *,double,std::less<const hapl::Haplotype *>,std::allocator<std::pair<const hapl::Haplotype *const ,double>>,false>>::iterator ] c:\users\kott\documents\visual studio 2008\projects\mbi\implementation\src\main.cpp(631) : see reference to function template instantiation '_FwdIt std::remove_if<std::_Tree<_Traits>::iterator,boost::lambda::lambda_functor<T>>(_FwdIt,_FwdIt,_Pr)' being compiled with [ _FwdIt=std::_Tree<std::_Tmap_traits<const hapl::Haplotype *,double,std::less<const hapl::Haplotype *>,std::allocator<std::pair<const hapl::Haplotype *const ,double>>,false>>::iterator, _Traits=std::_Tmap_traits<const hapl::Haplotype *,double,std::less<const hapl::Haplotype *>,std::allocator<std::pair<const hapl::Haplotype *const ,double>>,false>, T=boost::lambda::lambda_functor_base<boost::lambda::relational_action<boost::lambda::lessorequal_action>,boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::action<2,boost::lambda::other_action<boost::lambda::member_pointer_action>>,boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::other_action<boost::lambda::addressof_action>,boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::placeholder<1>>,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>>>,double std::pair<hapl::Haplotype *const ,double>::* const ,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>>>,const double,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>>, _Pr=boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::relational_action<boost::lambda::lessorequal_action>,boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::action<2,boost::lambda::other_action<boost::lambda::member_pointer_action>>,boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::other_action<boost::lambda::addressof_action>,boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::placeholder<1>>,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>>>,double std::pair<hapl::Haplotype *const ,double>::* const ,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>>>,const double,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>>> ] I don't get it because i found somewhere (http://www.lukaszczerwinski.pl/boost_lambda_member_access.html) similar example that (should) work fine: std::map< std::string , int > someMap; using boost::lambda::_1; std::for_each( someMap.begin(), someMap.end(), std::cout << ( & _1 ) ->* ( & std::pair< std::string const, int >::first ) << std::endl ); -- Michał Nowotka

2 1

[Thread] How to invoke a memory fence?
by Radosavljevic, Branko 29 Jan '09

29 Jan '09

I have a newbie question about using Boost.Thread to invoke a memory fence operation. What are the memory fence guarantees associated with the synchronization concepts in Boost.Thread? My specific use case involves one writer and several readers. For example, something like: bool available = false; int value; // Writer thread value = getValue(); available = true; // A reader thread while (!available) yield(); doSomething(value); In other words, the write to available should have release semantics, and the read from available should have acquire semantics. I realize I can use platform-specific commands, but I'd rather not. I assume that if I want to use Boost.Thread, I'll need to use a mutex, but I don't see any discussion of memory fence issues in the documentation. Thanks, Branko Any information contained in or attached to this e-mail is intended solely for the use of the intended recipient(s), is confidential and may contain information that is legally privileged. If you are not an intended recipient of this e-mail, please notify the sender of the delivery error and then please delete and destroy all copies and attachments, and be advised that any review or dissemination of, or the taking of any action in reliance on, the information contained in or attached to this e-mail is expressly prohibited. See http://www.bankofamerica.com/emaildisclaimer (if this link is not clickable, please copy and paste the link into your browser address bar) for further important information on confidentiality, the risks inherent in electronic communication (including the possibility that e-mail messages cannot be guaranteed to be secure or free of errors or viruses), some of our policies regarding transactions and pricing and certain other matters.

3 3

BOOST_NO_EXCEPTIONS problem when C++ Exceptions are disabled
by rroc 29 Jan '09

29 Jan '09

Hi, I 'm trying to create a msvc project with C++ Exceptions disabled, as well as defined BOOST_NO_EXCEPTIONS and _HAS_EXCEPTIONS=0. This requires me to define a custom exception routine. All of this goes smoothly, but there is a problem with boost. Even when the BOOST_NO_EXCEPTIONS is set, the following boost files: exception\diagnostic_information.hpp exception_ptr.hpp ...are using try-catch blocks and because of this give a warning: warning C4530: C++ exception handler used, but unwind semantics are not enabled. Am I using this somewhat wrong or should I just modify the files to for example always ::boost::throw_exception()? Thanks, Johannes Rajala -- View this message in context: http://www.nabble.com/BOOST_NO_EXCEPTIONS-problem-when-C%2B%2B-Exceptions-a… Sent from the Boost - Users mailing list archive at Nabble.com.

2 1

[partly: Boost.Function] typesafe (templated) wrapper around class with void* API
by Christoph Duelli 29 Jan '09

29 Jan '09

[This question has a Boost.Function relation later on. Sorry if too off topic.] I have a class that works on some data structures. This class' API uses void* to be general and avoid code duplication that using a template here would incur. Basically: class A // simplification { // Assume A to be a "fat" class there are more methods // working on void* // and lots of code put away into a .cpp file. We don't // want that duplicated by many template instantiations. public: // Most of the work is generic and independent from the // data types worked on. void do_something(void*); protected: // some work has to be done be the subclass virtual bool help_me(const void*) =0; }; I do not like using void* all that much. Thus I would like to create a type-safe (generic) thin wrapper class. Using inline functions,the idea is that the run time penalty (at least for do_something) is low and casts from/and to void are all 'hidden' here. template<typename T> class B : public A { public: void do_something(T* t) { A::do_something(t); } protected: // Force user to provide a correctly typed callback. virtual bool help_me(const T*) =0; private: // call the user's safe callback bool help_me(const void* t) { return help_me(static_cast<const T*>(t)); } }; and finally class C : public B<MyStruct> { bool help_me(const MyStruct* ms) { ... } }; Is this a good way to do that? More specific questions: i) I assume the penalty for my callback "help_me" is one more indirection. Can't see that optimized away. ii) Assuming A's interface gets passed a real callback function (a Boost.Function) instead: class A { public: typedef boost::function<bool(const void*)> helper_func; void do_something(void*, helper_func); }; is it somehow possible to get a typesafe templated B such that template<typename T> class B : public A { public: typedef boost::function<bool(const T*)> helper_func; void do_something(T* t, helper_func hf) { // this makes my compiler unhappy (when instanced). // I do understand that... can it be worked around somehow? A::do_something(t, hf); } }; I would like to be able to pass a function working on T* rather than void*. While writing this posting have found the following to compile: template<typename T> struct ToVoidWrapper { typedef boost::function<bool(const T*)> helper_func; helper_func hf_; ToVoidWrapper(const helper_func &hf) : hf_(hf) {} bool func(const void *t) const { return hf_(static_cast<const T*>(t)); } }; with do_something in B: void do_something(T* t, helper_func hf) { ToVoidWrapper<T> vw(hf); A2::do_something(t, boost::bind(&ToVoidWrapper<T>::func, &vw, _1)); } I am not really looking forward to writing such "forwarding to void*" functions. Are there alternatives? Maybe something in Boost that I have overlooked? Or a standard C++ idiom I am not aware of? I have attached compilable code that sums up the above code snippets so far. Thank you for looking into this and best regards Christoph

2 2

Help with (possibly MPL) pattern for a viewer that may contain a copy of statically allocated data
by Jesse Perla 29 Jan '09

29 Jan '09

I am wondering what the best pattern/approach for a data structure that may contain either a reference or a copy of some data used in a constructor. I would love the opportunity to have the data structure capable of conditionally storing the data for the data copy on the stack. Are there any fancy generic tricks/patterns to do this using boost::mpl, etc.? So to put in some pseudocode notes for discussion to get the point across of what I think I want: boost::array< boost::array<double, M>, N> myaxis; //creates axis in a stack allocated data structure. regular_grid<M, N, COPYDATA> my_grid(axis_values); regular_grid<M, N, REFDATA> my_grid(axis_values); template<int M, int N, int ConstructionPolicy> class regular_grid { boost::array< boost::array<double, M>, N>& axis_ref_; //Reference to the axis, either static or actual reference. All code in the class would use this, not axis_ STATIC_IF(ConstructionPolicy == COPYDATA) { boost::array< boost::array<double, M>, N> axis_; regular_grid(const boost::array< boost::array<double, M>, N>& axis) : axis_(axis), axis_ref_(axis_) //constructor makes copy, sets ref to copy. { } } STATIC_ELSE(ConstructionPolicy == REFDATA) { regular_grid(const boost::array< boost::array<double, M>, N>& axis) : axis_ref_(axis) {} //constructor just uses the ref. } }; Is this possible? any ideas on code to look at to see how to do it?

7 7

[lambda] newbie: lambda to help in std::accumulate
by Michał Nowotka 29 Jan '09

29 Jan '09

I want to compute sum of logarithms so i wrote: #include <cmath> double evaluate(const vector<double>& win_probabls) { return accumulate (win_probabls.begin(), win_probabls.end(), 0, lambda::_1 + log(lambda::_2) ); } but this code doesn't compile. Does anyone know why? -- Michał Nowotka

3 4

RBGL use with BGL minCut() function
by Gianni Loiacono 29 Jan '09

29 Jan '09

Hi all, sorry for my poor english. I want to use RBGL http://bioconductor.org/packages/2.3/bioc/html/RBGL.html into my project (I use BGL) for to use the function minCut() for to obtain the minimum cut and **the list of two subsets (S and V-S) cutted from the algorithm** (for me this is an import "thing"). I have readed all pdfs all docs, but I don't understand how I can use this library/dll in my project. Also, I have tried to add the sources files to my project (mincut.cpp, mincut.hpp, RBGL.hpp) and rebuild all, but the compiler don't find the Rdefines.h include file :°(. Please, somebody can help me with some example? I use C++ Mingw compiler and Code::block editor. Thanks a lot :-)

2 1

Simple serialization of int*
by Sahrah 29 Jan '09

29 Jan '09

Hi all, I am looking for a solution to do this: int p1 = 5; int* test; test = &p1; std::ofstream out("test.bin"); boost::archive::binary_oarchive ar(out); ar << test; it does not compile. I get: Error 9 error C2228: left of '.serialize' must have class/struct/union c:\...\boost_1_37_0\boost\serialization\access.hpp I am using MSVC9. Boost 1.37.0 thanks, Sahrah -- View this message in context: http://www.nabble.com/Simple-serialization-of-int*-tp21713482p21713482.html Sent from the Boost - Users mailing list archive at Nabble.com.

4 4

Boost.Asio 1.37 - can't compile with VC++ 2003 (version 1.35 is fine)
by lipik 29 Jan '09

29 Jan '09

Hi, I just upgraded my Boost distribution, and have immediately run into a compilation problem: both Intel and VC++ compilers complain that: - 'QueueUserAPC' : is not a member of 'operator``global namespace''' - 'QueueUserAPC': identifier not found, even with argument-dependent lookup 1.35 compiles fine. I checked and this API is available in Winbase.h. Can't figure out why it is not being found - there don't seem to be be any C++ version directives hiding it inside winbase. I am on XP, and _WIN32_WINNT is set to 0x0501, so this is not the culprit either. Pre-compiled headers are turned off, and I have defined WIN32_LEAN_AND_MEAN (to avoid winsock conflict). Any help greatly appreciated. Thanks Amit

2 1

Function for Replace NaN with Zero and Vector2Vector Concordance
by Gundala Viswanath 29 Jan '09

29 Jan '09

Dear all, I have two questions: 1. What's the way in Ublas to replace Nan with Zero, be it in Vector or Matrix? 2. What's the way to check vector 2 vector concordance. E.g. vector <int> V1 += 1,2,3; vector <int> V2 + =1,2,3; if we do that_func(V1,V2), it will returns true. - Gundala Viswanath Jakarta - Indonesia

1 0

Re: [Boost-users] Extending boost::function for mathematics?
by Jesse Perla 29 Jan '09

29 Jan '09

Thanks as always Stephen (who I still refuse to accept is either a single individual or human): Sorry to all if this is getting so long and specific, this project is justified later. Your comments generated a lot of thought about what my main problems are. I think I distracted myself by the generation of derivatives here before I had worked out some other issues. But your implementation looks very elegant. For now lets assume that people supply the gradient/jacobian directly or from their own finite_difference/autodifferentiation. So here are some, more basic, questions. Question 1: Based on your template, how do I forward a function to the boost::function's operator() in this wrapper? Why might we want to do this? Because we are trying to implement a concept with operator() and .gradient(..) with a function wrapper here. Library writers may want to write generic code that operates on any of these, not just ones wrapped in math_function... Then we may end up with true inlining of operator() and .gradient(...) when a full differentiable function object is implemented, instead of always going through an indirection pointer in boost::function. template<class Signature> class math_function { public: typedef boost::function<Signature>::result_type result_type; template<class F> math_function(const F& f, const G& f) : f_(f) : g_(g) {} result_type operator()(How to extract from the signature the input parameters? myvalues...) { return f_(myvalues....); } result_type gradient()(How to extract from the signature the input parameters???????) { return g_(myvalues...); } private: boost::function<Signature> f_; boost::function<Signature> g_; }; void test_mathfunctions() { using lambda::_1; using lambda::_2; math_function<double (double)> myfunc(_1*_1, 2* _1); //simple quadratic cout << myfunc(.1); cout << myfunc.gradient(.1); } Question 2: How can this wrapping interact with binding? void test_mathfunctions_binding() { using lambda::_1; using lambda::_2; //But you might also want a constant thrown in there... Why a separate parameter? Because you don't take the derivative over the other stuff. And you want to keep your functions pure so you can bind, not force them to be stateful, etc. math_function<double (double, double)> myfunc(_1*_1 + _2, 2* _1); //simple quadratic translated by a constant //But how would you work with bind? Would these following work immediately? boost::function<double (double)> myfunc_bound = bind(myfunc, _1, 2.0); boost::function<double (double)> myfuncderiv_bound = bind(myfunc::gradient, _1, 2.0); //or something like this... I always forget member function notation. //Any way to bind that entire structure back to a math_function? Very useful since we would bind parameters before calling optimizers, etc. With dynamic programming we usually have a grid of values and call the optimizer binding over the entire grid. math_function<double (double)> myfunc_bound = math_bind(myfunc, _1, 2.0); cout << my_func_bound.gradient(1.0); //Note that the binding can now use the gradient. } Question 3: How would we adapt a structure implementing the operator() and gradient() to be stored here? Just like boost::function accepting any function object? struct square { double operator()(double x) {return x * x;} double gradient(double x){return 2 * x;} }; math_function<double (double)> myfunc(square); Given the previous code, would we write a constructor like?: template<class F> math_function(const F& f) : f_(f), g_(bind(F::gradient, f, _1...?) //Here I don't see how to bind to the arbitrary signature, extracting the inputs from the Signature which (may) be more than 1 Question 3: What are the thoughts on whether/how this is extensible to higher dimensions? Lets start on the gradient with mapping functions: f : R^N -> R It is perfectly reasonable for these types of problems for the first parameter in the function to be the only one that the derivative is taken over. The dimensionality of the derivative/gradient/jacobian would come out of a combination of the result_type from the signature and the dimensionality of the domain. For example, something like: template<int DomainDim, class Signature> class math_function { public: typedef boost::function<Signature>::result_type result_type; typedef boost::array<DomainDim, result_type> gradient_result_type; //Note that this adds the dimensionality, the data structure could be a template parameter. template<class F> math_function(const F& f, const G& f) : f_(f) : g_(g) {} result_type operator()(How to extract form the signature the input parameters???????) { return f_(Signature); } gradient_result_type gradient()(How to extract form the signature the input parameters???????) { return g_(Signature); } private: boost::function<Signature> f_; boost::function<gradient result_type with OLD INPUT Signature> g_; }; void test_mathfunctions_multidim() { using lambda::_1; using lambda::_2; boost::array<double, 2> mygrad(boost::array<double, 2> x, double a) {boost::array<double, 2> ret; ret[0] = 2*x[0]; ret[1] = 2*x[1]; }; //I put this separately since I don't know how to construct arrays in lambda math_function<2, double (boost::array<double, 2> , double)> myfunc(pow(_1[0]*, 2) + pow(_1[1], 2) + _2, mygrad); cout << myfunc.gradient({{0.0, 0.0}}); //etc. } Question 4: Now lets say that what we really want is to manage f: R^N -> R^M functions. Here, we could potentially use ublas::matrix as a default data structure. template<class Signature, class SecondDimStructure = ublas::matrix, template <class T, int N> class NDimStructure = boost::multi_array > //We really don't need the dim's here since we are using heap based data structures. class math_function { public: typedef boost::function<Signature>::result_type result_type; typedef SecondDimStructure gradient_result_type; //This really is a jacobian, size N * M typedef NDimStructure<result_type::value_type, 4> hessian_result_type; //This really is size (N*M) ^2 if I remember my calculus.... template<class F> math_function(const F& f, const G& f) : f_(f) : g_(g) {} result_type operator()(How to extract form the signature the input parameters???????) { return f_(Signature); } gradient_result_type gradient()(How to extract form the signature the input parameters???????) { return g_(Signature); } private: boost::function<Signature> f_; boost::function<gradient result_type with OLD INPUT Signature> g_; //should add in the higher dimensional hessian of the function if I remember }; Question 5: I want to also associate information about the nature of the function. Whether it is convex/concave, increasing, strictly increasing, etc. These tend to have an inheritance structure, but it isn't absolutely necessary. I was thinking about using trait classes. But I assume that we would lose all those traits when we use type erasure? Are we better off storing a bunch of enums in this data structure? Increasing the size of the class shouldn't be an issue. Question 6: Let me justify why this is all very useful and a general problem: Right now, everyone writing non-linear algorithms in C++ has their own structures for managing mathematical functions that contain derivatives, jacobians, hessians. I am running into this right now because I am trying to wrap a bunch of other people's algorithms for my own work. A few comments: 1) Everyone is using dynamic polymorphism for these overloading a virtual operator() and some type of gradient/jacobian... I assume this is because there is no agreed upon concept for functions objects with gradients... In reality, none of these seem to require dynamic polymorphism. Why shouldn't a newton's method optimizer have inlining of the operator() and derivative through static polymorphism where possible? 2) Most of these guys have conflated functionality/settings specific to their optimizers/solves with the evaluation of the function/gradient. This makes generic code difficult without wrappers/adapters. 3) Many use their own data structures for arrays, matrices, multidim results. This may be inevitable, but means that you need to have these types parameterized in any mathematical callback routine. 4) While a lot could be gained from having people agree on a static concept for mathematical applications akin to standardizing on operator() for functors, it is also very useful to have a generic callback wrapper akin to boost;:function. The main reason for this is that you will tend to write parameterized, pure functions where you want to bind parameters. Worst case, people could write their own functions with this mathematical callback structure and adapters could be written for the different libraries. 5) Not to disparage these superb libraries, but a few examples to see what I mean: http://quantlib.org/reference/class_quant_lib_1_1_cost_function.html and http://trilinos.sandia.gov/packages/docs/r6.0/packages/didasko/doc/html/nox… and http://www.coin-or.org/CppAD/Doc/ipopt_cppad_simple.cpp.xml If anyone is interested in working with me on this very interesting and useful problem, please give me an email. I think it has a lot of potential for general use. -Jesse

11 19

Re: [Boost-users] Boost and K-Cuts
by Gianni Loiacono 29 Jan '09

29 Jan '09

Hi mr. Zeljko Vrba, I have downloaded and readed the soruce file for build the GoHu tree. It uses a different implement approch from Boost....;°( I don't understand very well the source, but I have understand that if I want to add it to my project I must "revolutionize" my source :( :( Sorry for my eng. ;) Bye.

1 0

Re: [Boost-users] top posting, was boost::proto helpful for a compiler project?
by raindog＠macrohmasheen.com 29 Jan '09

29 Jan '09

I know its a rule, but I think it is dumb. My phone does not even support botting posting for example, does that mean I'm not allowed to post to this newgroup? my guess is that it started off with a few people wanting to separate themselves from others by usage of arbitrary rules in order to obtain some form of "l33tn3$$" without having actually considering the merits or lack thereof ubtil after their motives were question in which scenario artificial ones were created to support the habbit. Modern mail clients (my phone not one of them) support threaded mail anyways and so what you get is the same email. 100 times in a thread. There has been the argument that if you were ob a forum that they go by bottom posting but again modern mail clients support threading anyways, and I don't know about you, but I can't recall the last time I was reading a forum and every post included included the entirety of the posts to the thread prior. Lastly, why would you ever want to pick up a thread by reading the middle of it? Using the forum analogy, one would be hard pressed to find someone whose month was to always read a thread by starting on page 12, so, group by thread and read from the start ------Original Message------ From: Eric Niebler Sender: boost-users-bounces(a)lists.boost.org To: boost-users(a)lists.boost.org ReplyTo: boost-users(a)lists.boost.org Sent: Jan 26, 2009 4:42 PM Subject: Re: [Boost-users] boost::proto helpful for a compiler project? Please don't top-post. See http://www.boost.org/community/policy.html#effective peter_foelsche(a)agilent.com wrote: > Eric Niebler wrote: >> peter_foelsche(a)agilent.com wrote: >>> How can boost proto help me in my compiler project? >>> >>> Is it another way to write a grammar and parse it? >> >> If by "compiler" you mean something that reads a text file, parses >> it according to a grammar and Does Something, then Proto is *not* >> what you are looking for. Use Boost.Spirit. >> > ok. Can you give me an application area for boost::proto? In short I > don't understand what DomainSpecificEmbeddedLanguage means. The term is defined in Proto's documentation, and many examples are given there. http://boost-sandbox.sf.net/libs/proto HTH, -- Eric Niebler BoostPro Computing http://www.boostpro.com _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users Sent from my Verizon Wireless BlackBerry

6 5

Boost.Parameters: are static member functions possible somehow?
by Joost Kraaijeveld 28 Jan '09

28 Jan '09

Hi, I can generate global and ordinary member functions with Boost.Parameters. But I would like to create static member functions. IS that somehow possible? I have looked at the macros of the library but I did not get any wiser :-(. So is it possible, and if so, how? TIA -- Groeten, Joost Kraaijeveld Askesis B.V. Molukkenstraat 14 6524NB Nijmegen tel: 024-3888063 / 06-51855277 fax: 024-3608416 web: www.askesis.nl

2 1

Install on Mac OS
by rolf ngondo 28 Jan '09

28 Jan '09

Hi all! I'm developping an application using boost on MAC OS X, using CMake as system compiler. I succesfully built the same application with CMake on windows and it works fine. But on Mac OS, the build fails. It sounds like CMake failed finding boost include directory. I tried the bjam command : bjam --builddir=anydir --toolset=gcc --with-some_boost_lib install. I got libs but it skipps creating any directory on /usr/local/. If anyone succeeded on installing boost properly in /usr/loal... please help. One more thing, since I'm using CMake, I can't use boost version later than 1.36.0. Thanks to all.

3 5

[BGL] - deriving from filtered_graph
by Michael Fawcett 28 Jan '09

28 Jan '09

When using a type that I derived from filtered_graph, if I use operator[] on the instance, e.g. derived_from_filtered_graph_instance[descriptor].foo = bar; I get the following error: C:\dev\vendor\boost\1.37.0\boost/graph/graph_traits.hpp(124) : error C2039: 'edge_bundled' : is not a member of 'btra::restricted_graph<Graph>' 1> with 1> [ 1> Graph=btra::undirected_graph 1> ] 1> C:\dev\vendor\boost\1.37.0\boost/graph/graph_traits.hpp(137) : see reference to class template instantiation 'boost::edge_bundle_type<G>' being compiled 1> with 1> [ 1> G=btra::restricted_graph<btra::undirected_graph> 1> ] 1> C:\dev\btra\trunk\btra/two_way/esri_io.h(186) : see reference to class template instantiation 'boost::graph::detail::bundled_result<Graph,Descriptor>' being compiled 1> with 1> [ 1> Graph=btra::restricted_graph<btra::undirected_graph>, 1> Descriptor=boost::detail::edge_desc_impl<boost::undirected_tag,__w64 unsigned int> 1> ] and if I typedef edge_bundled in the derived class, everything seems to work okay. filtered_graph doesn't contain the typedef, the Graph type does, so does this mean that to be more correct I should specialize graph_traits for my derived type, or is just having the typedef enough? Also, in the filtered_graph documentation, it says it models VertexAndEdgeListGraph and PropertyGraph, but neither of those concepts mention edge_bundled as an associated type. Thanks in advance, --Michael Fawcett

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[serialization]Runtime Exception While Loading Old Serialized XML Files w/ 1.38
by Yaser Zhian 28 Jan '09

28 Jan '09

Hello list, I have a bunch of XML files that have been serialized using Boost.Serialization (the standard XML archive) and were working fine until we upgraded to the boost trunk a few days ago (unfortunately, I can't tell exactly what repository revision were used to generate the archives, but I know they were custom builds of pre-release 1.37 trunk, and the file_version attribute in the XML is set to 4.) Also, we use MSVC9.0sp1 for building everything. As soon as we upgraded to the trunk, we started getting runtime exceptions (invalid archive format) on some of our larger files. I think I have tracked it down to an incompatibility between version 4 and version 5 files that the newer build fails to take into consideration, the details of which (as far as I could find out) follows. In our data structures there is an std::list of pointers to objects previously serialized in the same serialization operation (which means these repeated pointers are stored as a reference to the previous object and the data is not duplicated.) Using the old library, when this list was being serialized, apparently the "item_version" was not being written (only the "count" filed and the "item"s were.) The old library apparently didn't expect to read this either, so everything worked out nicely. The new library however, expects an "item_version" field and throws when it doesn't find one. As I trace into the serialization library, I can see that there is logic there for new libraries to be able to handle archive format changes through time. Now my question is whether this "discrepancy" is actually a bug in either the older or the new code, or failing to handle the format change is a bug, or this issue has already come up and been dealt with in some other way? (how?) I should also mention that it is quite probably that the problem be in our code, but I have no idea how. I would appreciate any help in locating it. Any pointers, help, clues and general wisdom is greatly appreciated. -yzt

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need help building boots
by Vincenzo Calo' 28 Jan '09

28 Jan '09

Hi, my log file was scrubbed in my previous post. So I'm posting it again, sorry. I'm a newbie and I'm trying to build boost on a Mac OS X 10.4.11. I'm not able to generate the dylib files so something is going wrong. dhcp25:/usr/local/lib/boost_1_37_0 root# ./configure --with- libraries=iostreams Building Boost.Jam with toolset darwin... tools/jam/src/bin.macosxx86/ bjam Unicode/ICU support for Boost.Regex?... not found. Backing up existing Boost.Build configuration in user-config.jam.4 Generating Boost.Build configuration in user-config.jam... Generating Makefile... dhcp25:/usr/local/lib/boost_1_37_0 root# make install ./tools/jam/src/bin.macosxx86/bjam --user-config=user-config.jam -- prefix=/usr/local --exec-prefix=/usr/local --libdir=/usr/local/lib -- includedir=/usr/local/include --with-iostreams install ...patience... ...found 14372 targets... ...updating 21 targets... MkDir1-quick-fix-for-unix bin.v2/libs/iostreams MkDir1-quick-fix-for-unix bin.v2/libs/iostreams/build MkDir1-quick-fix-for-unix bin.v2/libs/iostreams/build/darwin-4.0.1 MkDir1-quick-fix-for-unix bin.v2/libs/iostreams/build/darwin-4.0.1/ release MkDir1-quick-fix-for-unix bin.v2/libs/iostreams/build/darwin-4.0.1/ release/threading-multi darwin.compile.c++ bin.v2/libs/iostreams/build/darwin-4.0.1/release/ threading-multi/file_descriptor.o /var/tmp//cc3iqlUI.s:7843:Complex expression. Absolute segment assumed. /var/tmp//cc3iqlUI.s:7845:Complex expression. Absolute segment assumed. /var/tmp//cc3iqlUI.s:7850:Complex expression. Absolute segment assumed. /var/tmp//cc3iqlUI.s:7852:Complex expression. Absolute segment assumed. /var/tmp//cc3iqlUI.s:7856:Complex expression. Absolute segment assumed. ... "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline - Wall -dynamic -no-cpp-precomp -gdwarf-2 -Wno-long-double -fPIC - DBOOST_ALL_NO_LIB=1 -DBOOST_IOSTREAMS_DYN_LINK=1 -DNDEBUG -I"." -c - o "bin.v2/libs/iostreams/build/darwin-4.0.1/release/threading-multi/ file_descriptor.o" "libs/iostreams/src/file_descriptor.cpp" ...failed darwin.compile.c++ bin.v2/libs/iostreams/build/darwin-4.0.1/ release/threading-multi/file_descriptor.o... darwin.compile.c++ bin.v2/libs/iostreams/build/darwin-4.0.1/release/ threading-multi/mapped_file.o /var/tmp//ccuFxoHi.s:15391:Complex expression. Absolute segment assumed. /var/tmp//ccuFxoHi.s:15393:Complex expression. Absolute segment assumed. /var/tmp//ccuFxoHi.s:15398:Complex expression. Absolute segment assumed. /var/tmp//ccuFxoHi.s:15400:Complex expression. Absolute segment assumed. .... "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline - Wall -dynamic -no-cpp-precomp -gdwarf-2 -Wno-long-double -fPIC - DBOOST_ALL_NO_LIB=1 -DBOOST_IOSTREAMS_DYN_LINK=1 -DNDEBUG -I"." -c - o "bin.v2/libs/iostreams/build/darwin-4.0.1/release/threading-multi/ mapped_file.o" "libs/iostreams/src/mapped_file.cpp" ...failed darwin.compile.c++ bin.v2/libs/iostreams/build/darwin-4.0.1/ release/threading-multi/mapped_file.o... darwin.compile.c++ bin.v2/libs/iostreams/build/darwin-4.0.1/release/ threading-multi/zlib.o darwin.compile.c++ bin.v2/libs/iostreams/build/darwin-4.0.1/release/ threading-multi/bzip2.o ...skipped <pbin.v2/libs/iostreams/build/darwin-4.0.1/release/ threading-multi>libboost_iostreams-xgcc40-mt-1_37.dylib for lack of <pbin.v2/libs/iostreams/build/darwin-4.0.1/release/threading- multi>file_descriptor.o... ...skipped <p/usr/local/lib>libboost_iostreams-xgcc40-mt-1_37.dylib for lack of <pbin.v2/libs/iostreams/build/darwin-4.0.1/release/ threading-multi>libboost_iostreams-xgcc40-mt-1_37.dylib... ...skipped <p/usr/local/lib>libboost_iostreams-xgcc40-mt.dylib for lack of <p/usr/local/lib>libboost_iostreams-xgcc40-mt-1_37.dylib... MkDir1-quick-fix-for-unix bin.v2/libs/iostreams/build/darwin-4.0.1/ release/link-static MkDir1-quick-fix-for-unix bin.v2/libs/iostreams/build/darwin-4.0.1/ release/link-static/threading-multi darwin.compile.c++ bin.v2/libs/iostreams/build/darwin-4.0.1/release/ link-static/threading-multi/file_descriptor.o /var/tmp//ccgEKwgZ.s:7843:Complex expression. Absolute segment assumed. / "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline - Wall -no-cpp-precomp -gdwarf-2 -Wno-long-double -DBOOST_ALL_NO_LIB=1 -DNDEBUG -I"." -c -o "bin.v2/libs/iostreams/build/darwin-4.0.1/ release/link-static/threading-multi/file_descriptor.o" "libs/ iostreams/src/file_descriptor.cpp" ...failed darwin.compile.c++ bin.v2/libs/iostreams/build/darwin-4.0.1/ release/link-static/threading-multi/file_descriptor.o... darwin.compile.c++ bin.v2/libs/iostreams/build/darwin-4.0.1/release/ link-static/threading-multi/mapped_file.o /var/tmp//ccDow0aV.s:15391:Complex expression. Absolute segment assumed. /var/tmp//ccDow0aV.s:15393:Complex expression. Absolute segment assumed. /var/tmp//ccDow0aV.s:15398:Complex expression. Absolute segment assumed. /var/tmp//ccDow0aV.s:15400:Complex expression. Absolute segment assumed. /var/tmp//ccDow0aV.s:15404:Complex expression. Absolute segment assumed. /var/tmp//ccDow0aV.s:35405:Complex expression. Absolute segment assumed. "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline - Wall -no-cpp-precomp -gdwarf-2 -Wno-long-double -DBOOST_ALL_NO_LIB=1 -DNDEBUG -I"." -c -o "bin.v2/libs/iostreams/build/darwin-4.0.1/ release/link-static/threading-multi/mapped_file.o" "libs/iostreams/ src/mapped_file.cpp" ...failed darwin.compile.c++ bin.v2/libs/iostreams/build/darwin-4.0.1/ release/link-static/threading-multi/mapped_file.o... darwin.compile.c++ bin.v2/libs/iostreams/build/darwin-4.0.1/release/ link-static/threading-multi/zlib.o darwin.compile.c++ bin.v2/libs/iostreams/build/darwin-4.0.1/release/ link-static/threading-multi/bzip2.o ...skipped <pbin.v2/libs/iostreams/build/darwin-4.0.1/release/link- static/threading-multi>libboost_iostreams-xgcc40-mt-1_37.a for lack of <pbin.v2/libs/iostreams/build/darwin-4.0.1/release/link-static/ threading-multi>file_descriptor.o... ...skipped <p/usr/local/lib>libboost_iostreams-xgcc40-mt-1_37.a for lack of <pbin.v2/libs/iostreams/build/darwin-4.0.1/release/link- static/threading-multi>libboost_iostreams-xgcc40-mt-1_37.a... ...skipped <p/usr/local/lib>libboost_iostreams-xgcc40-mt.a for lack of <p/usr/local/lib>libboost_iostreams-xgcc40-mt-1_37.a... ...failed updating 4 targets... ...skipped 6 targets... ...updated 11 targets... Not all Boost libraries built properly. Thanks a lot for your help. Best, Vincenzo

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help building boost
by Vincenzo Calo' 28 Jan '09

28 Jan '09

Hi, I'm a newbie and I'm trying to build boost on a Mac OS X 10.4.11. I'm not able to generate the dylib files so something is going wrong. I've attached the output log file. Thanks a lot for your help. Best, Vincenzo

2 1

[date_time] new local_date_time constuctor
by a k 28 Jan '09

28 Jan '09

Hi, This is a request to add a third constructor of the class boost::local_time::local_date_time. THE PROBLEM: The following piece of code throws an exception. date d(2008, Oct, 26); time_duration td( 2, 30, 0 ); // 2:30 a.m. time_zone_ptr tz( new posix_time_zone("CET-1CEST,M3.5.0,M10.5.0/3") ); local_date_time myLtime( d, td, tz, EXCEPTION_ON_ERROR ); // last line throws This is because the date and time I chose happens to be located in the "vulnerble" moment when the wall clock gets moved back by an hour. In human terms, time 2:30am appears twice on 26-Oct-2008 in CET time zone because at 3:00 am we go back to 2:00 am and arrive at point 2:30 once more. In terms of boost::date_time library, the following condition appears: (local_date_time::check_dst(d, td, tz) == ambiguous); I would like to be able to write something like "On creating date/time infer the DST flag; on ambiguity assume no DST". In fact I can do that currently by replacing the last line from my above example with: bool inDST = (local_date_time::check_dst(d, td, tz) == is_in_dst); local_date_time myLtime(d, td, tz, inDST); This has two drawbacks however. First, check_dst gets called twice: first by me, second by the constructor, to check it once more. Second, it is too (IMO) verbose. THE REQUEST: Would it be possible to add a third constructor of local_date_time class that would accept a hint how to solve an ambiguity (if we have one). It would read like: local_date_time myLtime( d, td, tz, ASSUME_NOT_DST_ON_ERROR ); In the boost code I found it was already thought of, but got into a TODO state. Is there any chance that it gets implemented? Regards, &rzej

1 0

[BGL] Segfaults when switching from digraph to undirected graph
by Grzegorz Slodkowicz 28 Jan '09

28 Jan '09

Hi, I ran into trouble after changing my directed adjacency_list into an undirected graph. The following code causes a segfault: for (set<Node>::iterator n = nodes.begin(); n != nodes.end(); ++n) { graph_traits<Graph>::out_edge_iterator edges_begin, edges_end; tie(edges_begin, edges_end) = out_edges(*n, g); for (graph_traits<Graph>::out_edge_iterator ne = edges_begin; ne != edges_end; ++ne) { Node nn1 = target(*ne, g); // ... K_o = out_degree(nn1, g); graph_traits<Graph>::out_edge_iterator nn1edges_begin, nn1edges_end; tie(nn1edges_begin, nn1edges_end) = out_edges(nn1, g); int k; graph_traits<Graph>::out_edge_iterator nn1e; for (nn1e = nn1edges_begin; nn1e != nn1edges_end; ++nn1e) { k = 0; if (nodes.count(target(*nn1e, g))) // !!! k++; } } } I cut out most of the stuff not directly related to accessing the graph. It segfaults in the line marked by !!!, so it would seem that out_edges returns an invalid range (I did some debugging and the this line executes quite a few times before the iterator becomes invalid. I can't seem to force gdb to recognise nn1e as a symbol so I can't tell which edge/node is causing the problem. All this is ran after the graph is initialised (it's quite large, ab. 22k nodes and 900k edges). Best regards, Greg

2 2

multi_index: changing elements?
by Olaf Leidinger 28 Jan '09

28 Jan '09

Hello! I'm quiet new to boost and especially multi_index. I want to get a non-constant reference to elements I inserted into this container, but when dereferencing the iterator all I get is a const reference. What am I doing wrong? Please have a look at the attached example. Thanks a lot, Ciao, Olaf Leidinger

2 1

Howto check Matrix Byte Size in Boost's Ublas Object
by Gundala Viswanath 28 Jan '09

28 Jan '09

Dear All, I have the following matrix implementation using Ublas. One is plain old matrix ('m') and the other is sparse matrix ('sm') My question is how can I check the byte size of 'sm' and 'm'? If my implementation is correct 'sm' byte size should give much smaller byte size than 'm'. Since both 'm' and 'sm' print the same output here. //____ BEGIN__ matrix<double> m(matDim[0], matDim[1], 0); coordinate_matrix<double> sm(matDim[0],matDim[1], 0); for (size_t i = 0; i < realValue.size(); ++i){ m(rowIndex[i]-1,colIndex[i]-1) = realValue[i]; sm(rowIndex[i]-1,colIndex[i]-1) = realValue[i]; } // End The full and compilable code can be found here: http://cpp.codepad.org/MbPm3OuK - Gundala Viswanath Jakarta - Indonesia

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[asio] still weird crashes with asio using libpion on windows
by Stephan Menzel 28 Jan '09

28 Jan '09

Hi all, I have been experiencing problems with weird crashes on Windows using libpion (http://www.pion.org/projects/pion-network-library) and the problem is still there with pion 1.0.10 but it changed a little and might shed some new light on the Let me just outline the situation. I have a simple project with an app and two libs, both using boost 1.36 at this time. The app links against those two libs, and one of the libs links against pion. So does the app of course. I've built pion as debug dll with boost 1.36. This runs on Windows and Linux. Now on Linux everything is fine, no problem at all, no dangerous valgrind output, nothing. On Windows however, the application crashes as soon as I do something with pion, and the callstack leads me to believe it's got something to do with boost asio. Usually it happens within asio win_mutex and looks a lot like this: http://trac.atomiclabs.com/ticket/32 To me this looks like an uninitialized mutex is being used. Not entirely however. I get this: First-chance exception at 0x7c91100b in myapp.exe: 0xC0000005: Access violation reading location 0x00000028. it's in win_mutex.hpp int do_lock() { #if defined(__MINGW32__) // Not sure if MinGW supports structured exception handling, so for now // we'll just call the Windows API and hope. ::EnterCriticalSection(&crit_section_); return 0; #else __try { -> ::EnterCriticalSection(&crit_section_); // CRASH } __except(GetExceptionCode() == STATUS_INVALID_HANDLE || GetExceptionCode() == STATUS_NO_MEMORY ? EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH) { if (GetExceptionCode() == STATUS_NO_MEMORY) return ERROR_OUTOFMEMORY; return ERROR_INVALID_HANDLE; } return 0; #endif } This exception repeats many times until eventually the app crashes because 'this' is invalid, pointing somewhere it shouldn't. The Bug occurs several seconds after the application has started, but I don't have to actually access pion's http socket for that. I think it might not be pion's fault at all. The whole thing only happens on Windows and renders both pion useless on that system. I know, it's only Windows but I've been debugging around that for some months now and I'd really like that solved at some point. Any ideas? Thanks a lot... Stephan PS: I can't go to boost 1.37 because of: https://svn.boost.org/trac/boost/ticket/2541 With Chris apparently not responding or posting about ASIO any more is there any chance of this being fixed in the next release? Is ASIO maintained at all? Cause nobody seems to care about that bug. Again, I know it's only Windows but as long as Windows is officially a supported system an imporant lib like ASIO should work on it.

1 0

Regex & Multiple Iterations in single string?
by John D 28 Jan '09

28 Jan '09

Hi I am building something that does multiple random search and replaces across a single text file read line by line. This is just underway and already a snag. I need to know if there is a lightweight to identify and as important handle multiple regex matches in a single string. >From what I am aware BOOST_REGEX_MATCH_EXTRA exists but adds overhead and is maybe overkill. Anyone know how I can run a regex of "e" on "ececece" and deal with the 4 occurences on an individual basis. Much thanks to you all keep up the hard work, John

3 2

Re: [Boost-users] Boost and K-Cuts
by Gianni Loiacono 28 Jan '09

28 Jan '09

Thanks Mr. Zeljko Vrba for the help and for the link :) :) Now I'm reading some docs to understand if the k-way is the best solution for my project ;) Thanks another time. Bye.

1 0

Example program that fails to compile (boost::bind and boost::function called for collection)
by Archie14 28 Jan '09

28 Jan '09

Below is a a test program with the purpose of calling member function for each element of the collection. Argument of this member function is a boost::function. I put compilation error after the source code. Any help will be greatly appreciated. #include <boost/bind.hpp> #include <boost/function.hpp> #include <boost/ptr_container/ptr_vector.hpp> typedef boost::function<void (int, int, const char*) > delegate; class A : public boost::noncopyable { public: commandhandler(delegate& f) {} }; template <typename C> class Acoll { typedef boost::ptr_vector<C> ptr_container; ptr_container m_data; public: typedef C CLIENT; ptr_container& operator() (){return m_data;} }; template <typename CLIENTS> class Test { CLIENTS& m_clients; public: delegate dosomething; Test(CLIENTS& val) : m_clients(val) {} void run() { std::for_each(m_clients().begin(), m_clients().end(), boost::bind(&CLIENTS::CLIENT::commandhandler, boost::ref(dosomething), _1 )); } }; int _tmain(int argc, _TCHAR* argv[]) { Acoll<A> coll; Test<Acoll<A> > test(coll); test.run(); return 0; } Error: 1>e:\libraries\boost\boost_1_37_0\boost\bind.hpp(292) : error C2664: 'R boost::_mfi::mf1<R,T,A1>::operator ()<boost::function<Signature>>(const U &,A1) const' : cannot convert parameter 2 from 'A' to 'boost::function<Signature> ' 1> with 1> [ 1> R=void, 1> T=A, 1> A1=delegate &, 1> Signature=void (int,int,const char *), 1> U=delegate 1> ] 1> and 1> [ 1> Signature=void (int,int,const char *) 1> ] 1> e:\libraries\boost\boost_1_37_0\boost\bind\bind_template.hpp(32) : see reference to function template instantiation 'void boost::_bi::list2<A1,A2>::operator ()<F,boost::_bi::list1<A &>>(boost::_bi::type<T>,F &,A &,int)' being compiled 1> with 1> [ 1> A1=boost::reference_wrapper<delegate>, 1> A2=boost::arg<1>, 1> F=boost::_mfi::mf1<void,A,delegate &>, 1> T=void, 1> A=boost::_bi::list1<A &> 1> ] 1> e:\program files\microsoft visual studio 9.0\vc\include\algorithm(29) : see reference to function template instantiation 'void boost::_bi::bind_t<R,F,L>::operator ()<T>(A1 &)' being compiled 1> with 1> [ 1> R=void, 1> F=boost::_mfi::mf1<void,A,delegate &>, 1> L=boost::_bi::list2<boost::reference_wrapper<delegate>,boost::arg<1>>, 1> T=A, 1> A1=A 1> ] 1> c:\test\t458\t458\t458.cpp(39) : see reference to function template instantiation '_Fn1 std::for_each<boost::void_ptr_iterator<VoidIter,T>,boost::_bi::bind_t<R,F,L>>(_ InIt,_InIt,_Fn1)' being compiled 1> with 1> [ 1> _Fn1=boost::_bi::bind_t<void,boost::_mfi::mf1<void,A,delegate &>,boost::_bi::list2<boost::reference_wrapper<delegate>,boost::arg<1>>>, 1> VoidIter=std::_Vector_iterator<void *,std::allocator<void *>>, 1> T=A, 1> R=void, 1> F=boost::_mfi::mf1<void,A,delegate &>, 1> L=boost::_bi::list2<boost::reference_wrapper<delegate>,boost::arg<1>>, 1> _InIt=boost::void_ptr_iterator<std::_Vector_iterator<void *,std::allocator<void *>>,A> 1> ] 1> c:\test\t458\t458\t458.cpp(37) : while compiling class template member function 'void Test<CLIENTS>::run(void)' 1> with 1> [ 1> CLIENTS=Acoll<A> 1> ] 1> c:\test\t458\t458\t458.cpp(47) : see reference to class template instantiation 'Test<CLIENTS>' being compiled 1> with 1> [ 1> CLIENTS=Acoll<A> 1> ]

2 3

Boost MPI and threads
by Clément Rezvoy 28 Jan '09

28 Jan '09

Hi all, I have a question regarding boost MPI and thread support. boost::mpi::environment uses MPI::Init to initialize MPI. I would like to be able to assess the supported thread level using MPI::Init_thread. Is it possible to first initialize MPI via MPI::Init_thread and then create a boost::mpi::environment ? the documentation reads: If the MPI environment has not already been initialized, initializes MPI with a call to MPI_Init does that also work if the initialisation is not carried out via boost::mpi::environment? Assuming the underlying MPI implementation supports it, is it safe to mix boost threads with boost MPI, at least at a FUNNELED level, carrying out all the MPI communications in the main thread? thanks for your help, Clément Rezvoy.

2 1

Build Boost 1.37 under Solaris 10 - what is the best way
by Georg Sauthoff 27 Jan '09

27 Jan '09

Hi, I built boost under Solaris with the Sun C++ compiler 12. To summarize the experience: informations are very much scattered around in the boost documentation/web pages and you have to learn bjam Finally I did it like this: $ ./configure --prefix=/my/prefix \ --with-libraries=test,program_options --with-toolset=sun $ cat > user-config.jam using sun : 5.9 : CC : <cxxflags>"-library=stlport4 -features=tmplife -features=tmplrefstatic -O" <linkflags>-library=stlport4 ; ^D $ ./tools/jam/src/bin.solaris/bjam -sICU_PATH=/usr \ --user-config=user-config.jam --with-test --with-program_options \ address-model=64 -d3 $ ./tools/jam/src/bin.solaris/bjam -sICU_PATH=/usr \ --user-config=user-config.jam --with-test --with-program_options \ address-model=64 \ -d3 --prefix=/my/prefix install My software works so far with this compiled version of boost under Solaris 10. Well, is this the right/best/official/boost/bjam-way to build boost on Solaris 10? The default sun toolset-settings does not seem to include even '-library=stlport4' option, although the Sun CC is infamous for its nonconforming STL implementation which is selected by default. Is it possible to improve the sun bjam toolset in such a way, that it selects -features=tmplife by default, if it detects that CC is of version 5.9? And is it possible to select the addresss-model=64 property via the ./configure command line? Is there is a './configure --help' aequivalent for bjam to display the options of the current toolset without reading the bjam toolset source? Best regards Georg Sauthoff

1 0

boost::signals - can't generate assignment op.
by Noah Roberts 27 Jan '09

27 Jan '09

I know that signals can't be assigned or copied, and as far as I can tell I have made sure that never happens. However, I'm still getting the warning. We have no warning policy here. Code followed by compiler output, what do I need to do?: ------------------------------------------- #include <boost/signal.hpp> #include <boost/function.hpp> struct rect {}; struct document { document() : changed_sig() {} virtual rect extents() const = 0; virtual ~document() {} boost::signals::connection attach(boost::function<void (document&)> const& slot) { return changed_sig.connect(slot); } private: boost::signal<void (document&)> changed_sig; document(document const&) {} document& operator=(document const&) { return *this;} protected: void changed(document & d) { changed_sig(d); } }; int main() { } ------------------------------------------------ 1>e:\boostvs2\include\boost\signals\trackable.hpp(163) : warning C4512: 'boost::signals::detail::bound_objects_visitor' : assignment operator could not be generated 1> e:\boostvs2\include\boost\signals\trackable.hpp(66) : see declaration of 'boost::signals::detail::bound_objects_visitor' 1>e:\boostvs2\include\boost\signals\signal_template.hpp(71) : warning C4512: 'boost::signals::detail::args1<T1>' : assignment operator could not be generated 1> with 1> [ 1> T1=document & 1> ] 1> e:\boostvs2\include\boost\signals\signal_template.hpp(344) : see reference to class template instantiation 'boost::signals::detail::args1<T1>' being compiled 1> with 1> [ 1> T1=document & 1> ] 1> e:\boostvs2\include\boost\signals\signal_template.hpp(335) : while compiling class template member function 'void boost::signal1<R,T1,Combiner,Group,GroupCompare,SlotFunction>::operator ()(T1)' 1> with 1> [ 1> R=void, 1> T1=document &, 1> Combiner=boost::last_value<void>, 1> Group=int, 1> GroupCompare=std::less<int>, 1> SlotFunction=boost::function<void (document &)> 1> ] 1> e:\boostvs2\include\boost\signal.hpp(335) : see reference to class template instantiation 'boost::signal1<R,T1,Combiner,Group,GroupCompare,SlotFunction>' being compiled 1> with 1> [ 1> R=void, 1> T1=document &, 1> Combiner=boost::last_value<void>, 1> Group=int, 1> GroupCompare=std::less<int>, 1> SlotFunction=boost::function<void (document &)> 1> ] 1> e:\dev_workspace\experimental\scratch\scratch\main.cpp(19) : see reference to class template instantiation 'boost::signal<Signature>' being compiled 1> with 1> [ 1> Signature=void (document &) 1> ] 1>Linking...

2 2

Boost.MPL: Is it possible to apply a variable substitution without evaluating the lambda-expression?
by Luke Simon 27 Jan '09

27 Jan '09

I am using BOOST_MPL_ASSERT to assert a lambda-expression applied to a sequence of types by folding the lambda-expression onto a sequence of types (see code and continue discussion below). template<class predicate, class argument> struct mpl_assert { typedef typename apply<predicate, argument>::type type; BOOST_MPL_ASSERT((type)); }; template<class pred, class xs> struct assert_for_all : foldr< mpl_assert<typename lambda<pred>::type, _>, true_, xs > {}; The foldr metafunction is a strict version of Haskell's foldr, i.e., MPL's reverse_fold with parameters passed in the order that Haskell's foldr passes parameters. The distinction isn't important for this discussion, so don't dwell on that detail. My intent is that if the lambda-expression is false for one of the types in the sequence, then the lambda-expression applied to the "bad" argument is printed in a compile-time error. However, what gets printed is the result of the lambda-expression applied to the bad argument: integral_constant<bool, false>, which is very uninformative. If the definition of mpl_assert is changed to the following: template<class predicate, class argument> struct mpl_assert { typedef typename apply<predicate, argument>::type type; BOOST_MPL_ASSERT((apply<predicate, argument>)); }; ...then what gets printed is the unevaluated application of a lambda-expression to the bad argument. While this is more informative, it is still too messy because the type is a lambda-expression containing placeholders. The most desirable type to have printed would be the lambda-expression after placeholder substitution, but before further evaluation. For example, imagine: typedef assert_for_all<is_same<foo, _>, boost::mpl::vector<foo, bar> >::type type; ...the first definition of mpl_assert prints the following uninformative type in the displayed error: boost::integral_constant<bool, false> ...the second definition of mpl_assert prints the more descriptive but overly messy type: boost::mpl::apply<boost::mpl::protect<boost::mpl::bind2<boost::mpl::quote2<boost::is_same, mpl_::void_>, foo, mpl_::arg<-0x000000001> >, 0>, bar, mpl_::na, mpl_::na, mpl_::na, mpl_::na> ...but what I want to have printed is the type: boost::is_same<foo, bar> Boost.MPL is already calculating such a type, because apply<is_same<foo, _>, bar> returns is_same<foo, bar>::type, so the needed type is there... but does Boost.MPL provide a means of accessing it as opposed to accessing its ::type field?

2 1

[boost.bind] How to retrieve the function type of a boost::bind result
by Olaf Krzikalla 27 Jan '09

27 Jan '09

Hi, The following snippet won't compile since the compiler can't deduce the template argument: template<typename T> void foo(boost::function<T> func) { /*...*/ } void bar() {} void baz() { foo(boost::bind(&bar)); // error foo<void()>(boost::bind(&bar)); // OK foo(boost::function<void()>(boost::bind(&bar))); // OK } So how do I get the first line of baz to work? That is, is there a generic way to compute the boost::function type from the bind result? Background code follows here: template<typename T> T getArg(int i) { /*...*/ } template<typename T> struct arity_dispatch; template<> struct arity_dispatch< boost::function<void()> > { static void call(const boost::function<void()>& f) { f(); } }; template<class T> struct arity_dispatch< boost::function<void(T)> > { static void call(const boost::function<void(T)>& f) { f(getArg<T>(0)); } }; template<class T, class U> struct arity_dispatch< boost::function<void(T, U)> > { static void call(const boost::function<void(T, U)>& f) { f(getArg<T>(0), getArg<T>(1)); } }; //aso. template<typename T> void generic_call(boost::function<T> func) { arity_dispatch< boost::function<T> >::call(func); } Neither is it possible for me to call "generic_call" with a boost::bind result nor is it possible to (partial) specialize for the _bi::_bind_t types as these types are internal ones. Also it seems that I can't even statically compute the arity of a boost::bind result (which would indeed help a lot). Any suggestions? If not I propose the introduction of a type function_type in the return type of a bind expression (I already needed it once before). Thanks in advance Olaf Krzikalla

3 5

Maximum Size of Matrix in Boost
by Gundala Viswanath 27 Jan '09

27 Jan '09

Hi, I have a matrix withn 10^7 * 10^7 rows, each with double value like 0.333. All this printed in text file. I want to slurp all of them in Boost Matrix, with 6GB RAM, can it handle such matrix? - Gundala Viswanath Jakarta - Indonesia

5 5

[boost.build] no best alternative error
by Sandeep Gupta 27 Jan '09

27 Jan '09

Hi, I am missing something obvious but i am at lost extending bjam. I want to chain two rules Rule 1 : generate t.gp --> x.mp Rule 2 : x.mp --> x.mps My original attempts failed (discussed here http://tinyurl.com/dg7hle)*. * I would greatly appreciate any suggestions. thanks sandeep

1 0

Re: [Boost-users] Looking for a book on graph algorithms
by Roger House 27 Jan '09

27 Jan '09

Thanks to everyone who replied to my request for pointers to books, etc., on graph algorithms. I now have several books on order. Roger House

3 2

Using Boost.Test on 64-bit OSX
by Michael Dickey 27 Jan '09

27 Jan '09

I can't seem to get Boost's unit test framework to work on OS X Leopard (10.5) when using "-arch x86_64" for 64-bit builds (note: the programs I build using boost seem to work fine, but the unit tests blow up). I have Xcode 3.1.2 installed, and the results are the same if I'm using gcc 4.0 or 4.2. I used the 32_64.diff patch from trac to make 4-way Universal boost libraries (https://svn.boost.org/trac/boost/ticket/1679 ). Any ideas would be greatly appreciated =) Thanks, -Mike Without "-arch x86_64" (defaults to 32-bit intel): Mikes-Mac-Pro:~ mdickey$ g++ -DBOOST_TEST_DYN_LINK -I/usr/local/ include/boost-1_37 -L/usr/local/lib -lboost_unit_Test_framework-xgcc42- mt -o test test.cpp Mikes-Mac-Pro:~ mdickey$ ./test Running 5 test cases... *** No errors detected With "-arch x86_64": Mikes-Mac-Pro:~ mdickey$ g++ -arch x86_64 -DBOOST_TEST_DYN_LINK -I/usr/ local/include/boost-1_37 -L/usr/local/lib -lboost_unit_Test_framework- xgcc42-mt -o test test.cpp Mikes-Mac-Pro:~ mdickey$ ./test --log_level=all Running 5 test cases... Entering test suite "simple-unit-test" Entering test suite "SimpleTests_S" Entering test case "test1" Test case test1 doesn't include any assertions Leaving test case "test1"; testing time: 22mks Entering test case "test2" Test case test2 doesn't include any assertions Leaving test case "test2"; testing time: 15mks Entering test case "test3" Test case test3 doesn't include any assertions Leaving test case "test3"; testing time: 16mks Entering test case "test4" Test case test4 doesn't include any assertions Leaving test case "test4"; testing time: 15mks Entering test case "test5" Test case test5 doesn't include any assertions Leaving test case "test5"; testing time: 14mks Leaving test suite "SimpleTests_S" Leaving test suite "simple-unit-test" *** No errors detected test(93789) malloc: *** error for object 0x30001001004d0: Non-aligned pointer being freed (2) *** set a breakpoint in malloc_error_break to debug test(93789) malloc: *** error for object 0x30001001005d0: Non-aligned pointer being freed (2) *** set a breakpoint in malloc_error_break to debug test(93789) malloc: *** error for object 0x30001001006c0: Non-aligned pointer being freed (2) *** set a breakpoint in malloc_error_break to debug test(93789) malloc: *** error for object 0x30001001007c0: Non-aligned pointer being freed (2) *** set a breakpoint in malloc_error_break to debug gdb backtrace to malloc_error_break (note above that it's happening after completion of all tests): #0 0x00007fff810a9a11 in malloc_error_break () #1 0x00007fff810a4a90 in szone_error () #2 0x00000001000156ec in ~framework_impl [inlined] () at impl/ framework.ipp:133 #3 0x00000001000156ec in __tcf_1 () at impl/framework.ipp:222 #4 0x00007fff8100131c in __cxa_finalize () #5 0x00007fff81001232 in exit () #6 0x0000000100001057 in start () Confirm test program is a 64-bit executable: Mikes-Mac-Pro:~ mdickey$ file test test: Mach-O 64-bit executable x86_64 Dynamic linkage of test program: Mikes-Mac-Pro:~ mdickey$ otool -L test test: libboost_unit_test_framework-xgcc42-mt-1_37.dylib (compatibility version 0.0.0, current version 0.0.0) /usr/lib/libstdc++.6.dylib (compatibility version 7.0.0, current version 7.4.0) /usr/lib/libgcc_s.1.dylib (compatibility version 1.0.0, current version 1.0.0) /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 111.1.3) Confirm Universal/FAT build of Boost libraries: Mikes-Mac-Pro:~ mdickey$ file /usr/local/lib/ libboost_unit_test_framework-xgcc42-mt.dylib /usr/local/lib/libboost_unit_test_framework-xgcc42-mt.dylib: Mach-O universal binary with 4 architectures /usr/local/lib/libboost_unit_test_framework-xgcc42-mt.dylib (for architecture i386): Mach-O dynamically linked shared library i386 /usr/local/lib/libboost_unit_test_framework-xgcc42-mt.dylib (for architecture ppc7400): Mach-O dynamically linked shared library ppc /usr/local/lib/libboost_unit_test_framework-xgcc42-mt.dylib (for architecture x86_64): Mach-O 64-bit dynamically linked shared library x86_64 /usr/local/lib/libboost_unit_test_framework-xgcc42-mt.dylib (for architecture ppc64): Mach-O 64-bit dynamically linked shared library ppc64 Source code for test.cpp (note that if I have just one or two test cases it doesn't crash.. having several IS significant): #define BOOST_TEST_MODULE simple-unit-test #include <boost/test/unit_test.hpp> class SimpleFixture { public: SimpleFixture() {} virtual ~SimpleFixture() {} }; BOOST_FIXTURE_TEST_SUITE(SimpleTests_S, SimpleFixture) BOOST_AUTO_TEST_CASE(test1) {} BOOST_AUTO_TEST_CASE(test2) {} BOOST_AUTO_TEST_CASE(test3) {} BOOST_AUTO_TEST_CASE(test4) {} BOOST_AUTO_TEST_CASE(test5) {} BOOST_AUTO_TEST_SUITE_END()

2 1

[test] test_case_filter not building on Solaris
by David Graham 27 Jan '09

27 Jan '09

Hello, We are having trouble with boost::unit_test::test_case_filter while using boost 1.37 on Solaris 10 (x86) with Sun's own C++ compiler (5.9). We're using Sun's own STL implementation, *not* stlport. $ CC -V CC: Sun C++ 5.9 SunOS_i386 Patch 124864-09 2008/12/16 The problem occurs in the constructor of test_case_filter, specifically at this line: ------- m_filters.push_back( std::vector<single_filter>( string_token_iterator( *tit, (dropped_delimeters = ",", kept_delimeters = dt_none) ), string_token_iterator() ) ); ------- Here is the compiler's complaint: ------- "[...]boost-1.37.0/include/boost/test/impl/unit_test_main.ipp", line 116: Error: Could not find a match for std::vector<boost::unit_test::test_case_filter::single_filter>::vector(boost::unit_test::basic_string_token_iterator<char, boost::unit_test::ut_detail::default_char_compare<char>>, boost::unit_test::basic_string_token_iterator<char, boost::unit_test::ut_detail::default_char_compare<char>>) needed in boost::unit_test::test_case_filter::test_case_filter(boost::unit_test::basic_cstring<const char>). "[...]boost-1.37.0/include/boost/test/impl/unit_test_main.ipp", line 116: Error: Formal argument x of type const std::vector<boost::unit_test::test_case_filter::single_filter>& in call to std::vector<std::vector<boost::unit_test::test_case_filter::single_filter> >::push_back(const std::vector<boost::unit_test::test_case_filter::single_filter>&) is being passed int. ------- It would appear that, even though Sun's definition of std::vector does include a (template) constructor that takes two iterators (see /opt/sunstudio12/SUNWspro/prod/include/CC/Cstd/vector), the compiler is unable to match the boost code to this constructor. In fact, it seems unable to infer a match for this constructor even with some simple test code: ------- std::list<int> l; std::vector<int> v(l.begin(), l.end()); ------- ...which results in this error: ------- Error: Could not find a match for std::vector<int>::vector(std::list<int>::iterator, std::list<int>::iterator) ------- Apologies for the length of this post so far. I have two ensuing questions: 1. Is using Sun's C++ compiler and STL implementation with boost a bad idea? (unfortunately, due to other library dependencies, we cannot use gcc and/or stlport) 2. If we provide some workaround code for this particular problem, is it likely that it would be accepted as an addition to boost? Naturally we don't want to maintain our own local boost patches, so if our workaround would be accepted then it would hopefully benefit others as well as saving us from having to maintain local patches. many thanks in advance for any responses, David Graham Senior Software Engineer CR2 Ltd - http://www.cr2.com/ CR2

3 2

[BGL] - Undocumented Predicates for filtered_graph
by Michael Fawcett 27 Jan '09

27 Jan '09

In filtered_graph.hpp there appear to be a number of predefined predicates for general use (they are no in the detail namespace). One of them that I'd like to use is is_in_subset, but it appears that set_contains is not defined anywhere, not even for the most common case (std::set). Shouldn't Boost provide something like template <typename T, typename L, typename A, typename E> bool set_contains(const std::set<T, L, A> &s, const E &e) { return s.find(e) != s.end(); } and vice-versa for is_not_in_subset so that users don't have to open up the boost namespace and define it themselves? Thanks, --Michael Fawcett

2 2

Inner Product and Sparse Matrix in Boost
by Gundala Viswanath 27 Jan '09

27 Jan '09

Hi all, Is there a boost library that allow inner product between sparse matrix and vector? - Gundala Viswanath Jakarta - Indonesia

2 1

boost filesystem path questions
by Sean Farrow 27 Jan '09

27 Jan '09

Hi: I have a few questions re boost::filesystem paths: 1. if I have a path: device1\windows\system32, can I ranslate this using the boost filesystem library to c:\windows\system32"? 2. Does the boost filesystem library accept/use uincode i.e LPWSTR and std::wstring? 3. is the a method for just obtaining the filename from a full path that has been supplied. Any help apreciated. Sean.

2 2

boost::proto helpful for a compiler project?
by peter_foelsche＠agilent.com 27 Jan '09

27 Jan '09

How can boost proto help me in my compiler project? Is it another way to write a grammar and parse it? Peter Foelsche "The first point (using an init() function in preference to a constructor) is bogus. Using constructors and exception handling is a more general and systematic way of dealing with resource acquisition and initialization errors. This style is a relic of pre-exception C++." -- Stroustrup

5 7

Re: [Boost-users] Looking for a book on graph algorithms
by Alan M. Carroll 27 Jan '09

27 Jan '09

I still reference the Melhorn book. Data Structures and Algorithms 2: Graph Algorithms and NP-Completeness Kurt Melhorn EATCS Monographs on Theoretical Computer Science

1 0

Numeric_cast from int to float
by Hermann Rodrigues 27 Jan '09

27 Jan '09

Hi, I am using boost::numerical_cast to cast different numerical types in my code. Everything always seems to work as I expected except for a small thing: I always thought that the conversion from int to float could raise an exception when the int can not be properly represented as a float. However, this is not what I am gettingn in version 1.33.1. For example, in my opinion, casting -2147483647 to a float should be raising an exception but boost::numerical_cast always says that the conversion is valid and well-formed. Obviously, my boost version is a little outdated, but I can not upgrade at this time due to several constraints. My question is: is this behavior either a bug (even in newer versions of boost) or a feature? Thank you in advance. -- Hermann Rodrigues hermann(a)csr.ufmg.br Centro de Sensoriamento Remoto / UFMG http://www.csr.ufmg.br/dinamica

4 7

Looking for a book on graph algorithms
by Roger House 27 Jan '09

27 Jan '09

I'm looking for a good book on graph algorithms, perhaps something a bit different than the usual introductory book. For example, I would like an algorithm for finding all paths from vertex v to vertex u, not necessarily the shortest one or the longest one. Also, algorithms for determining the girth, diameter, and other properties of graphs are of interest. Or perhaps I should be looking at journal papers? Any pointers will be appreciated. Roger House

6 10

Re: [Boost-users] Looking for a book on graph algorithms
by Rodolfo Federico Gamarra 26 Jan '09

26 Jan '09

I give two other references: Network Flows: Theory, Algorithms, and Applications (Hardcover) by Ravindra K. Ahuja (Author), Thomas L. Magnanti (Author), James B. Orlin (Author) This book is quite big (~850 pages), many applications, problems and algorithmic variations. Graph Theory by Frank Harary (Author) This more focused on, so to say, the math side: properties and theorems about graphs, less than 300 pages. -- Rodolfo Federico Gamarra

1 0

[boost-build]how to configure custom targets
by Sandeep Gupta 26 Jan '09

26 Jan '09

Hello, I am trying to roll out my own main target (essentially to create plots using gnuplots). The tutorial example/customization was helpful and modifications at appropriate places does the required job. However the output-file is generated on "bin/gcc-4.2/debug". How can I change this so that it outputs to plots/ subdirectory. My second concern is that bjam executes the rule even if the end target is up-to-date. How to fix this. Thanks, Sandeep

1 0

[Bind] bind to member functions
by Rutger ter Borg 26 Jan '09

26 Jan '09

Hello, this works fine, struct A { template< typename X > void f( bool ) { bind(&A::f<X>, this, _1)( true ); } }; whereas template< typename Z > struct A { template< typename X > void f( bool ) { bind(&A<Z>::f<X>, this, _1)( true ); } }; gives me trouble in the at the line of bind form of "expected primary-expression before ‘>’ token". I've tried numerous typedefs, but that didn't do the trick. Many thanks in advance for help on this, Rutger

2 2

[serialization] Creating temporary archive objects
by Robert Dailey 26 Jan '09

26 Jan '09

Hi, What would be a good technique to deserialize an object without using 2-phase initialization? In other words, I want to avoid first default constructing the object and *then* streaming it out of the archive object. I was thinking of a factory for this but a good code example would help a great deal since I'm not extremely familiar with Boost.Serialization. I was looking through the Boost.Serialization documentation but I was unable to find information on this. Help is greatly appreciated!

2 3

[Smart Ptr] explicit checked_delete specialization ?
by Alexander 26 Jan '09

26 Jan '09

Is this OK to specialize boost::checked_delete to control deletion with scoped_ptr ? Or to specialize some boost::scoped_ptr members for the same purpose ?

2 1

how to get available disk space value via boost?
by boost001 26 Jan '09

26 Jan '09

I want to get free disk space via boost. How can I do it? thanks -- View this message in context: http://www.nabble.com/how-to-get-available-disk-space-value-via-boost--tp21… Sent from the Boost - Users mailing list archive at Nabble.com.

4 4

asio multicast cross-platform issues
by Birju Prajapati 26 Jan '09

26 Jan '09

Hi, On WinXP, I successfully implemented an application that listens to multiple multicast groups (different IPs same port). When I recompiled that app on Linux, on another box, I started getting duplicate datagrams. After messing around for a long while, I got it working. I had to change two things: socket.bind was changed so that it no longer was given 'any' and the port, but the multicast address and port. socket.set_option was changed so that it no longer was given only the multicast address, but both the multicast address and local address. Moving this code back to Windows stops it working! I then stumbled across this while researching my issue: http://osdir.com/ml/lib.boost.asio.user/2007-04/msg00135.html I could not find this information anywhere in the documentation. Could someone point me in the right place? Does it also mean that the statement "Boost.Asio is a cross-platform C++ library for network and low-level I/O programming that provides developers with a consistent asynchronous model using a modern C++ approach." In the docs is inaccurate for multicast? If not, is there a cross-platform, asio way? Cheers, Birju Schneider Trading 4th Floor, 25 Copthall Avenue London EC2R 7BP -------------------------------------------------------- Message from: Birju.Prajapati(a)schneidertrading.com Message to: boost-users(a)lists.boost.org Attached files: 0 This e-mail and any files transmitted with it are confidential, may be legally privileged, and are for the sole use of the intended recipient. Copyright in this e-mail and any accompanying document created by us is owned by us. If you are not the intended recipient of this e-mail or any part of it please telephone our IT Department at the number shown above or by e-mail at info(a)schneidertrading.com. You should not use or disclose to any other person the contents of this e-mail or its attachments (if any), nor take copies. This e-mail is not a representation or warranty and is not intended nor should it be taken to create any legal relations, contractual or otherwise. Schneider Trading Associates Ltd (Registration No. 3692131) is incorporated in England and Wales and the registered office is at 25 Copthall Avenue, London EC2R 7BP. The company is authorised and regulated by the Financial Services Authority

1 0

Re: [Boost-users] Using different compilers with boost
by Dan Smithers 26 Jan '09

26 Jan '09

>> I need to use several compilers for my project for different target >> computers. I have built boost 1.37 for gcc 4.1.2 and 3.4.3 and >> everything seems to be nicely set up as >> <boost_dir>/lib/libboost_xxx-gcc34-mt-1_37.so and >> <boost_dir>/lib/libboost_xxx-gcc41-mt-1_37.so. >> >> Is there anyway of automatically detecting which version to link? I >> suppose that gcc --version and some sort of awk script could do this. >> > > gcc -dumpversion is more useful for automated processing. > > For example, > gcc -dumpversion | perl -p -e > 's/(\d)\.(\d)\.\d/-lboost_xxx-gcc$1$2-mt-1_37/' Thanks Steven, just what I was looking for. dan

1 0

Re: [Boost-users] Fwd: Newbie: Eclipse and Boost
by raindog＠macrohmasheen.com 26 Jan '09

26 Jan '09

Based on your eloquent description I'm guessing you're running ms-dos 6.5 and have eclipse 0.5 beta installed in text mode. Perhaps the situation is different, in which case I would need correcting. ------Original Message------ From: n0b0dy-at-home Sender: boost-users-bounces(a)lists.boost.org To: boost-users(a)lists.boost.org ReplyTo: boost-users(a)lists.boost.org Sent: Jan 25, 2009 4:25 AM Subject: [Boost-users] Fwd: Newbie: Eclipse and Boost Hiya, i'm about to make my first steps with boost... unfortunately eclipse says "boost/shared_ptr.hpp: No such file or directory"; i've included the boost-path, so what's my mistake? Greetings n0b0dy@home _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users Sent from my Verizon Wireless BlackBerry

2 1

[program options] No value option in config file not allowed.
by Rodolfo Federico Gamarra 26 Jan '09

26 Jan '09

Hi all! I'm using parse_config_file to read my options from a file. Some of them are only a flag (ie no value given), like -z (--gzip), -h (--help) or -v (--verbose). What I see is that those options can be specified with the file only if some dummy value is given. For concreteness, let's say that the option is gzip. If I put gzip= the result is "Error: no value given in 'gzip='". If the = isn't put, then the message is "Error: unrecognized line in 'gzip'". Using spaces doesn't help because they are trimmed away. The method common_config_file_iterator::get() (config_file.cpp) seems to be involved: else if ((n = s.find('=')) != string::npos) { string name = m_prefix + trim_ws(s.substr(0, n)); string value = trim_ws(s.substr(n+1)); if (!allowed_option(name)) boost::throw_exception(unknown_option(name)); //// Doesn't allow empty values for an option. if (value.empty()) boost::throw_exception(invalid_syntax(s, "no value given")); found = true; this->value().string_key = name; this->value().value.clear(); this->value().value.push_back(value); break; } else { boost::throw_exception(invalid_syntax(s, "unrecognized line")); } The trimming may be handy, but it seems useful to allow empty values; on the other hand, it seems that whether an empty value is legal or not should be checked on a higher level. Thanks a lot. -- Rodolfo Federico Gamarra

1 0

[ublas] warning on VC9 about checked iterators
by Peter Barker 25 Jan '09

25 Jan '09

Hello, Using Boost 1.37.0, I compile the following program under VC9 (VS .NET 2008 Express Edition): #include <boost/numeric/ublas/vector.hpp> class Host { public: Host(const boost::numeric::ublas::bounded_vector<double,3>& normal) : normal_(normal) {} private: boost::numeric::ublas::bounded_vector<double,3> normal_; }; int main() { return 0; } and I get the following warning: 1>c:\boost\boost_1_37_0\boost\numeric\ublas\storage.hpp(337) : warning C4996: 'std::copy': Function call with parameters that may be unsafe - this call relies on the caller to check that the passed values are correct. To disable this warning, use -D_SCL_SECURE_NO_WARNINGS. See documentation on how to use Visual C++ 'Checked Iterators' 1> c:\program files\microsoft visual studio 9.0\vc\include\xutility(2576) : see declaration of 'std::copy' 1> c:\boost\boost_1_37_0\boost\numeric\ublas\storage.hpp(334) : while compiling class template member function 'boost::numeric::ublas::bounded_array<T,N>::bounded_array(const boost::numeric::ublas::bounded_array<T,N> &)' 1> with 1> [ 1> T=double, 1> N=3 1> ] 1> c:\boost\boost_1_37_0\boost\numeric\ublas\vector.hpp(36) : see reference to class template instantiation 'boost::numeric::ublas::bounded_array<T,N>' being compiled 1> with 1> [ 1> T=double, 1> N=3 1> ] 1> c:\boost\boost_1_37_0\boost\numeric\ublas\vector.hpp(524) : see reference to class template instantiation 'boost::numeric::ublas::vector<T,A>' being compiled 1> with 1> [ 1> T=double, 1> A=boost::numeric::ublas::bounded_array<double,3> 1> ] 1> c:\newsystem\readdisplaystlascii\readdisplaystlascii\main.cpp(10) : see reference to class template instantiation 'boost::numeric::ublas::bounded_vector<T,N>' being compiled 1> with 1> [ 1> T=double, 1> N=3 1> ] Should I compile with -D_SCL_SECURE_NO_WARNINGS? Is there a fix coming for ublas? What do others do? Regards, Pete

2 2

Fwd: Newbie: Eclipse and Boost
by n0b0dy-at-home 25 Jan '09

25 Jan '09

Hiya, i'm about to make my first steps with boost... unfortunately eclipse says "boost/shared_ptr.hpp: No such file or directory"; i've included the boost-path, so what's my mistake? Greetings n0b0dy@home

2 1

Boost and K-Cuts
by Gianni Loiacono 25 Jan '09

25 Jan '09

Hi all, sorry for my poor english. I want to know if the algorithm explained in this paper:http://www.cc.gatech.edu/~vazirani/k-cut.ps for finding the k-cuts (algorithm efficient) was been development in boost. In other words: There is in BGL some procedure that can cuts minimal a graph? Thanks a lot for the help :) Bye

2 1

Is there any internal mechanics to add support for regular expression checks to output_test_stream? (UTF)
by Pauli Nieminen 25 Jan '09

25 Jan '09

Hello! So long description is that. I'm trying to write unit test for log subsystem to my project. The logging sub system outputs timestamps which would be easiest to match with regular expression in unit tests. Of course I could disable the timestamp output for unit test but I think there might be many others test cases where regular expression would be the simplest solution. I tried to search for existing solution but it seems like none has been looking for this kind of support in unit test library.So my idea for implementing the regular expression support in my project is extending current output_test_stream class with my own code. So example test case should look something like (of course using a fixture in real code): BOOST_AUTO_TEST_CASE ( stream_check ) { output_test_stream stream; log::logger log(stream); log.log_entry(<level>, <component>) << "test log messange."; boost::regex validator("\\d{8,8} \\d\\d:\\d\\d:\\d\\d <level> <component>: test log message."); BOOST_CHECK( stream.is_equal(validator) ); } Pauli PS. "Detailed specification of class output_test_stream is covered in reference section. " (documentation/Output testing tool) Where is that reference section for detailed specification? The best I could find is the source code. :)

1 0

[lambda] std::sort problem
by Michał Nowotka 25 Jan '09

25 Jan '09

Following code does not compile: sort(m_results->begin(), m_results->end(), lambda::_1->second > lambda::_2->second); where: m_result is type of std::vector<std::pair<const SomeClass*,double>* > vs2008 compiler says: error C2780: 'void std::sort(_RanIt,_RanIt)' : expects 2 arguments - 3 provided, see declaration of 'std::sort' but in lamda documentation there is similar example: sort(vp.begin(), vp.end(), *_1 > *_2); so what's wrong with my code? -- Michał Nowotka

3 5

Re: [Boost-users] boost geometry lib
by Andruit＠gmx.de 25 Jan '09

25 Jan '09

Thanks Pete for your answer, but I can't manage to compile my source. I tried to compile one of the example programs but it failed. I am using a gcc compiler. Did you manage to compile the example programs? The following command failed: gcc -I/path-to-geometrielib 1_point_example.cpp -o point_example Do you know what is wrong??? Thank you. Andreas -- Psssst! Schon vom neuen GMX MultiMessenger gehört? Der kann`s mit allen: http://www.gmx.net/de/go/multimessenger

5 5

Newbie: Partial Problem with link
by Paul Campbell 25 Jan '09

25 Jan '09

OK: method A in section 6 # SUCCESS g++ -I /usr/local/boost_1_36_0 regex_test.cpp -o regex \ /usr/local/boost_1_36_0/bin.v2/libs/regex/build/gcc-4.1.2/release/link-static/threading-multi/libboost_regex-gcc41-mt-1_36.a ./regex < jayne.txt > Will Success Spoil Rock Hunter? NG: method B in section 6 #FAILURE http://www.boost.org/doc/libs/1_37_0/more/getting_started/unix-variants.html #link-your-program-to-a-boost-library This is a snip from my make file do_regex_not_working: g++ -I /usr/local/boost_1_36_0 regex_test.cpp -o regex \ -L /usr/local/boost_1_36_0/bin.v2/libs/regex/build/gcc-4.1.2/release/threading-multi/ \ # don't worry about my mail wrap problem -lboost_regex-gcc41-mt-1_36 Execution: g++ -I /usr/local/boost_1_36_0 regex_test.cpp -o regex \ -L /usr/local/boost_1_36_0/bin.v2/libs/regex/build/gcc-4.1.2/release/threading-multi/ \ -lboost_regex-gcc41-mt-1_36 Error Message: /usr/bin/ld: cannot find -lboost_regex-gcc41-mt-1_36 collect2: ld returned 1 exit status make: *** [do_regex_not_working] Error 1 Can you see what could be in error ?

2 1

Extending boost::function for mathematics?
by Jesse Perla 25 Jan '09

25 Jan '09

Steven: beautifully simple code on your previous post. I just fear that MPL is beyond the reach of mortals such as myself because I could never come up with that solution. If people are in the mood for this kind of stuff, let me post on a set of questions coming up in my libraries: 1) QUESTION 1: MANAGING DERIVATIVES FOR FUNCTIONS * I am doing a lot of work with functions that may have an associated derivative analytically or numerically determined. * This is the tip of the iceberg in associating a bunch of information with a mathematical function that all needs to be bundled. * I have been creating functors like the following: template <class ParamType> struct square{ typedef double result_type; //For adaptors double operator()(double x, const ParamType& params ) { return x*x;} double gradient(double x, const ParamType& params ){return 2 * x;} boost::function<double (double,const ParamType& params)> gradient(){return boost::bind(&square::gradient, *this, _1, _2)}; //I forget the exact notation for bind with member functions, but the idea is that it would return a boost::function. }; //Analytical derivative But I would also love the ability to use finitedifference or autodifferentiation algorithms for more complicated examples. Perhaps something like: struct square : finite_differences<int Order>{ double operator()(double x, const ParamType& params ) { return x*x;} }; //Analytical derivative * Ideally here, finite_differences<int Order> would be able to generate the derivative using order taylor series approx and the operator() to evaluate the function. Even here I am not sure the best way to organize it. 2) QUESTION 2: ADAPTATION AND USE LIKE BOOST::FUNCTION Now, lets say that there was something similar to boost::function but which had the "derivative" concept to call.gradient(...) to evaluate grad, or return a functor which is the gradient as another function.. Lets call it math_function for now. The behavior is things like the following: using lambda::_1; using lambda::_2; math_function<double (double)> mysquare(_1 * _1); //This will generate a math_function with the finite differences as its derivative. assert(mysquare(1) == 1); math_function<double (double)> mysquaregrad = mysquare.gradient(); //Gets the derivative, which was generated through finite differences. This could then be used to get the .gradient again for example. assert(mysquare.gradient(.1) == mysquaregrad(.1)); math_function<double (double, int)> myfunc(_1 + _2); math_function<double (double)> myboundfunc = bind(my_func, _1, 3); assert(myboundfunc.gradient(1.0) == 4.0); //And then to create one with an analytical derivative math_function<double (double)> mysquare(_1 * _1, 2 * _1); assert(mysquare.gradient(1.0) == 2.0); //evaluated through the analytical derivative. boost::function<double (double)> myboostsquare = mysquare.as_function(); //would be nice for interoperability... or something similar. //Then we can create a class such as polynomial which subclasses math_function polynomial_function<3> mypoly({{2, 3, 5}}); //Creates a third order polynomial. The operator() uses fancy algorithms for polynomial evaluation. math_function<double (double)> mypoly2 = mypoly; //Can adapt to a math_function for use in generic algorithms. math_function<double (double)> mypolygrad1 = mypoly.gradient(); polynomial_function<2> mypolygrad2 = mypoly.gradient(); //Maybe this is getting too fancy... 3) QUESTION 3: WHY DO I WANT ALL THIS STUFF? For the same reason that boost::function is so useful for functional programming. I am going to have a million permutations on this kind of pattern, am writing very generic algorithms, and would prefer not to have to write a superclass for every permutation of parameters. I want to be able to freely bind to it, easily use lambdas, and eventually want to add a bunch of other traits such as # of derivatives, range/domain, continuity, hessians, etc. that can be uniformly managed. 4) QUESTION 4: AM I INSANE? Is this at all possible or has something similar been done? It seems to me that it might be, but I am likely not be capable of doing it. Is piggybacking boost::function in some smart way here the best approach? Even if we can't subclass directly, can we copy the source code and intelligently add in a few extra functions, etc.?

2 1

Re: [Boost-users] boost::interprocess::message_queue::timed_receive, bug or mistake? (Ion Gazta?aga)
by nacitar＠ubercpp.com 24 Jan '09

24 Jan '09

> From: Ion Gazta?aga <igaztanaga(a)gmail.com> > Subject: Re: [Boost-users] > boost::interprocess::message_queue::timed_receive, bug or mistake? > To: boost-users(a)lists.boost.org > Message-ID: <497ADAC1.9090204(a)gmail.com> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Use universal time instead of local time. Maybe this is not documented, > and maybe this might be severe limitation. I've seen that boost::thread > uses boost::system_time so maybe Interprocess should go this way. > > Regards, > > Ion > That makes sense, given my timezone, why it was acting as such. Works now, but you should definitely add that to the documentation. If you have knowledge of the boost's date/time features beforehand, it would seem obvious. But, as in my case, I only looked at boost's date/time features in order to get the timeout to work with interprocess, so I lacked the entire picture. A small footnote would have made it a lot clearer. Great library, thanks for the help.

1 0

reversible_ptr_container question
by Archie14 24 Jan '09

24 Jan '09

I am using ptr_vector and tried to get last element from the vector using rbegin() - which apparently is not supported by ptr_vector unless I missed smth. After some search I found "reversible_ptr_container" in #include <boost/ptr_container/detail/reversible_ptr_container.hpp> I have my doubts if this is the one I should use because it is not easily found in the documentation and buried in the "details". The questions are: 1. For rbegin() relative to ptr_vector - should I employ reversible_ptr_containier? If yes then short example will be highly appreciated. 2. How to get last element from ptr_vector (not using --end())?

2 2

Use of socket
by Johan Mazel 24 Jan '09

24 Jan '09

Hi I'm trying to create some code based on the code of the socket tutorial of the boost website. The code to create a UDP socket which will send datagram is the following one : boost::asio::io_service io_service; udp::resolver resolver(io_service); udp::resolver::query query(udp::v4(), argv[1], "daytime"); udp::endpoint receiver_endpoint = *resolver.resolve(query); udp::socket socket(io_service); socket.open(udp::v4()); But, to send something else than a Daytime request, I need to know what are the avalaible option to put instead of "daytime" in this line : udp::resolver::query query(udp::v4(), argv[1], "daytime"); Unfortunately and as far sa I know, the documentation is quite light about that. The only that I found is this one : http://www.boost.org/doc/libs/1_37_0/doc/html/boost_asio/reference/ip__basi… it is quite empty. Eventually, my goal is to use a specified port instead of a name of service. Thanks in advance for the help. Johan

2 3

[asio] Reading datagram packets
by Chard 24 Jan '09

24 Jan '09

Is it possible to read the extra data that wasn't added to the buffer when a datagram is received ? E.g. given an initial receive instruction something like: char m_buf[10]; udp::endpoint m_endpoint; <--> udpSocket.async_receive_from(buffer(buf), m_endpoint, bind(ReadHandler, ...)); service.run(); If more than 10 characters were in the datagram packet, how can they be accessed? Calling other read methods (after processing in the ReadHandler) just appears to block (I guess it is looking for another packet). Surely I don't have to ensure the buffer is as large as I'll ever need it to be?

2 3

event loop
by Jens Luedicke 24 Jan '09

24 Jan '09

Hello, is there something like a generic event loop library in boost? Jens -- Jens Luedicke web: http://perldude.de

1 0

Re: [Boost-users] Tree library?
by joel falcou 24 Jan '09

24 Jan '09

Le Sam 24 janvier 2009 10:51, Thomas Klimpel a écrit : > Are you sure? The original poster seems to have a "rooted tree" in mind, > which is a special "directed acyclic graph" (DAG). I just looked at the > TOC of the boost::graph documentation, and the only DAG algorithm I could > find was "topological_sort". There is also the transitive_closure > algorithm, which could be used to compute the "partial order" relation of > the DAG, but I'm not sure whether this is really the appropriate way to > compute the "partial order" relation of a DAG (because the number of > edges could increase to O(V^2) and DAG's are not mentioned in the > corresponding documentation). Indeed, I wasn't thinking of the related algorithm. So yeah, boost::tree seems to lack then

1 0

boost::interprocess::message_queue::timed_receive, bug or mistake?
by nacitar＠ubercpp.com 24 Jan '09

24 Jan '09

I'm using boost svn 50746 (latest at time of writing), on 32-bit Ubuntu Intrepid Ibex, with gcc/g++ 4.3.2 This is a simple test case showing that for some reason, message_queue::timed_receive is returning immediately for me, not throwing an exception, but just returning false which signifies that the timeout has been reached. The output of the program is as follows: Current time: 2009-Jan-23 17:40:29 After delay: 2009-Jan-23 17:40:34 Timeout at 2009-Jan-23 17:40:29 Note that the timeout occurs before it is supposed to, it returns instantly. Is this a bug, or am I doing something wrong? MINIMAL CODE: #include <iostream> #include <boost/interprocess/ipc/message_queue.hpp> #include <boost/date_time/posix_time/posix_time.hpp> // Link with boost_date_time int main(void) { char buf[1024]; std::size_t uSize; unsigned int priority; // Create a queue boost::interprocess::message_queue::remove("SOME_QUEUE"); boost::interprocess::message_queue mq(boost::interprocess::create_only,"SOME_QUEUE",1024,1024); // 5 second delay boost::posix_time::time_duration delay(boost::posix_time::seconds(5)); // current time boost::posix_time::ptime timeout = boost::posix_time::ptime(boost::posix_time::second_clock::local_time()); std::cout << "Current time: " << boost::posix_time::to_simple_string(timeout) << std::endl; timeout += delay; std::cout << "After delay: " << boost::posix_time::to_simple_string(timeout) << std::endl; if (mq.timed_receive(buf,sizeof(buf),uSize,priority,timeout)) { std::cout << "Got a message!" << std::endl; } else { std::cout << "Timeout at " << boost::posix_time::to_simple_string(boost::posix_time::ptime(boost::posix_time::second_clock::local_time()))<< std::endl; } return 0; }

2 2

Preserving mtime with filesystem lib
by Brad Schick 24 Jan '09

24 Jan '09

Is there a portable way to use the boost filesystem library to copy files and preserve mtimes? I am writing a tool that moves media files around and mtime can be significant when other sources of metadata are absent (like exif, iptc, xmp). It would be a bummer to have to add platform specific code to do that. Thanks, -Brad

1 1

Using different compilers with boost.
by Dan Smithers 23 Jan '09

23 Jan '09

Hi, I need to use several compilers for my project for different target computers. I have built boost 1.37 for gcc 4.1.2 and 3.4.3 and everything seems to be nicely set up as <boost_dir>/lib/libboost_xxx-gcc34-mt-1_37.so and <boost_dir>/lib/libboost_xxx-gcc41-mt-1_37.so. Is there anyway of automatically detecting which version to link? I suppose that gcc --version and some sort of awk script could do this. thanks dan

2 1

How does one build a "release" version of Boost with the -Zi or /Zi compiler flag enabled?
by Joseph A. Marks 23 Jan '09

23 Jan '09

How does one build a "release" version of Boost with the -Zi or /Zi compiler flag enabled? Please e-mail answer directly to josephamarks(a)yahoo.com As well as to this list! Thanks Very much. Joseph A. Marks PHONE: 612-788-9658 e-mail: josephamarks(a)yahoo.com

2 1

Re: [Boost-users] 1.37: boost::enable_shared_from_this fails whil estd::tr1 succeed s
by Daniel Lidström 23 Jan '09

23 Jan '09

> Daniel Lidström: > > I have already found a workaround, but it is a little bit annoying: > > > > struct Sub : public Base, > > public tr1::enable_shared_from_this<Sub> > > { > > void f() > > { > > BasePtr basePtr = > > tr1::dynamic_pointer_cast<Base>(shared_from_this()); > > } > > }; > > > > I would like to avoid explicit type casts like this. > > You don't need the cast. Of course. Sorry I didn't see the obvious this time. /Daniel

1 0

[date time] Querying current time zone settings.
by Rodolfo Federico Gamarra 23 Jan '09

23 Jan '09

Hi all! I'm using boost::posix_time::second_clock::local_time() to retrieve my current local time, and then using operator<< to stream the resulting ptime. I'd like to add to the output my local time zone (as configured in the underlying OS). Be it just a time difference or (better) a region (like "America/New_York"). I have been looking but didn't find how to to it. The class ptime doesn't include the time zone; and all the other examples I've seen in to docs work with an explicitly used time zone in the code. For example: time_zone_ptr zone( new posix_time_zone("MST-07") ); local_date_time ldt = local_sec_clock::local_time(zone); And, for instance, in the docs about I/O it can be seen "%q ISO time zone (output only). This flag is ignored when using the time_facet with a ptime.". There's also a boost::date_time::c_local_adjustor (which warns about "This class assumes that timezone settings of the machine are correct. This can be a very dangerous assumption."), but doesn't help me much. By now, I can use (also) boost::posix_time::second_clock::universal_time() to infer my time zone. Is there any alternative to this? Thanks a lot. -- Rodolfo Federico Gamarra

1 0

how to make a vector to derivedClass::create() methods
by Victor.Whiskey.Yankee 23 Jan '09

23 Jan '09

Hi, I wish to make a std::vector to some create() methods from several different derived classes (same ABC). I could instead use the ctors if necessary. lambda::bind<> and lambda::constructor<> maybe?, but I fail getting syntax. Thank you, Vic

2 4

1.37: boost::enable_shared_from_this fails while std::tr1 succeed s
by Daniel Lidström 23 Jan '09

23 Jan '09

Hello, this sample does not compile when using the boost version: #if 1 #include <boost/enable_shared_from_this.hpp> namespace tr1 = boost; #else #include <memory> namespace tr1 = std::tr1; #endif namespace { struct Base { virtual void f() = 0; }; typedef tr1::shared_ptr<Base> BasePtr; struct Sub : public Base, public tr1::enable_shared_from_this<Base> { void f() { BasePtr basePtr = shared_from_this(); } }; } int main() { return 0; } boost\enable_shared_from_this.hpp(50) : error C2446: '==' : no conversion from 'boost::enable_shared_from_this<T> *const ' to '`anonymous-namespace'::Base *' with [ T=`anonymous-namespace'::Base ] Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast boost\enable_shared_from_this.hpp(48) : while compiling class template member function 'boost::shared_ptr<T> boost::enable_shared_from_this<T>::shared_from_this(void)' with [ T=`anonymous-namespace'::Base ] test.cpp(23) : see reference to class template instantiation 'boost::enable_shared_from_this<T>' being compiled with [ T=`anonymous-namespace'::Base ] The tr1 version compiles though. I am using Visual Studio 2008 with SP1 installed. I have already found a workaround, but it is a little bit annoying: struct Sub : public Base, public tr1::enable_shared_from_this<Sub> { void f() { BasePtr basePtr = tr1::dynamic_pointer_cast<Base>(shared_from_this()); } }; I would like to avoid explicit type casts like this. Why does the boost version fail? Thanks in advance! Regards, Daniel Lidström Stockholm, Sweden

2 1

[boost][interprocess] upgradable_mutex is semi-recursive...
by Lars Hagström 23 Jan '09

23 Jan '09

The subject is misleading, but hopefully eye-catching :-) I do understand that this is not an interprocess bug, but more of a result of how upgradeable locks work. But the behavior can be dangerous, as will be seen. What I've got happening is that one process locks the mutex recursively (sharable, of course). And this works (most of the time), since it is okay to lock the mutex shareably any number of times (even if it is within the same thread). But the problem occurs when a writer (in another thread) manages to get inbetween these lockings, when we get this sequence thread A locks mutex shareably thread B waits for exclusive lock thread A waits for sharable lock Since the upgradable mutex is written so that if there is an exclusive locker waiting it doesnt let any more sharable lockers in this will deadlock. Something that explains this could be useful in the interprocess documentation. Or, maybe the problem could be solved. I see two ways: 1. Detect recursive sharable locking, so that my thread A would always get an exception when trying to lock a lock that I've already got (it is a recipe for disaster) 2. Allow recursive sharable locks. If you've got the lock it's okay to take it again. Since I'm not really a fan of recursive locking (the above locking is a mistake, really) I think I would prefer solution 1 of these two. (I'm fixing my code to not be recursive now, but I thought this might be of interest to either Ion or anyone using boost interprocess.) Cheers Lars

2 2

[boost program options] missing value validation
by Andy F 23 Jan '09

23 Jan '09

If I have a parameter which needs a value, but the value is not specified in the command line, I get an unknown exception in VisualStudio 2005. Meaning, if I declare a --compression=something, but then call the program with just --compression, the exception is thrown at the po::store() method. How do I intercept this and validate? I am just using the code from the example program: po::options_description desc("Allowed options"); desc.add_options() ("help", "produce help message") ("compression", po::value<std::string>(), "set compression level") ; po::variables_map vm; po::store(po::parse_command_line(ac, av, desc), vm); po::notify(vm); if (vm.count("help")) { std::cout << desc << "\n"; return 1; } if (vm.count("compression")) { std::cout << "Compression level was set to " << vm["compression"].as<std::string>() << ".\n"; } else { std::cout << "Compression level was not set.\n"; }

2 5

[BGL] Remove vertices/edges from a subgraph
by Grzegorz Slodkowicz 23 Jan '09

23 Jan '09

What is the reason for vertex/edge removal functions in subgraphs being unimplemented? Is it simple oversight / lack of demand or would that pose some problems? Regards, Greg

2 4

Help with a boost::lambda problem and boost::array?
by jesseperla＠gmail.com 23 Jan '09

23 Jan '09

> Is there a solution? It appeared to me that the likely winner was: http://www.boost.org/doc/libs/1_37_0/doc/html/lambda/extending.html Then it seems we would use the boost array's typedef value_type to get the return type. However, I do not see operator[] overloading in the list of supporting operators here. But the following code compiles: //Testing lambda and vectors/arrays. using lambda::_1; std::vector<Real> vec(1); vec[1] = 0; boost::function<Real (std::vector<Real>)> vec_f = _1[0]; //Returns the 0'th element. Hence, it seems that this type of action is supported. Any idea where the sourcecode for the std::vector lambda operators are? might be useful to just copy/paste. Also, I wonder if there is any way to do this generically for all vector/array types supporting the Container concept? (I use a lot of ublas::vectors). And if operator() is also supported, I use a lot of ublas::matrix as well, so this would be nice to have in lambda. Jesse

3 4

Help with a boost::lambda problem and boost::array?
by jesseperla＠gmail.com 23 Jan '09

23 Jan '09

Does anyone have an idea why the following doesn't compile: using lambda::_1; using lambda::_2; boost::function<double (const boost::array<double, 2>&)> f = lambda::ret<double>(_1[0] * _1[1]); But the following does as a double-check: using lambda::_1; using lambda::_2; boost::function<double (const double&, const double&)> f2 = lambda::ret<double>(_1 * _2); Thanks, Jesse

5 8

WinCE family
by Marat Abrarov 22 Jan '09

22 Jan '09

Does anybody can describe what happens with the development process of support of WM 5-6x and WinCE 5-6? What is the current state of affairs? It would make boost more popular if boost supports (either particular, but official) such modern and famous mobile platforms like Symbian (S60), WM (5 and above), WinCE (5 and especially 6), Android. I understand that it's rather difficult to support such a different case of platforms, but boost (for me) ~ Standard C++ Library, and if Qt supports S60 3rd edition, WM 5-6, WinCE 5-6, Linux Embedded - why boost can't? Best regards, Marat Abrarov.

3 2

boost::interprocess shared memory performance
by Andy Wiese 22 Jan '09

22 Jan '09

This is my first experience with using shared memory for anything more than trivial IPC. Thanks again to Ion Gaztañaga for getting the library working on FreeBSD. I'm developing initially on OS-X 10.5.6 with boost_trunk, but the eventual target platform is FreeBSD--I'm just an old mac programmer used to cushy development tools. I originally used managed_mapped_file, and got everything working, but I was disappointed by performance. Profiling with shark, I found that the application was spending a lot of time in msync, which according to man(2) is used to synchronize mapped memory with the filesystem. It makes sense to me that the interprocess containers I was creating could have a lot of file I/O overhead, and managed_mapped_file was probably not a good choice. So I rewrote the code to use managed_shared_memory instead of managed_mapped_file, thinking that it would eliminate the file I/O and therefore be faster. However, I am surprised that it is not much faster, and when I profile with Shark on os-x I see that it is still spending a lot of time in msync, specifically whenever a managed_shared_memory object is destroyed. (in boost::interprocess::mapped_region::flush(unsigned long, unsigned long), which is called within basic_managed_shared_memory's destructor) Does managed_shared_memory really need to call msync? I see that I should optimize my code to cache the managed_shared_memory objects so that fewer create/deletes are necessary, but this is still going to happen fairly frequently and I wonder if this expensive msync call is necessary. In the tradition of coder forums everywhere, someone will probably ask what I'm trying to accomplish and whether there may be a better way. Suggestions welcome. I'm writing a little cgi driven database utility that queries data stored in a filesystem directory using a simple query language. I would like to keep indexes of the data to speed query resolution. The utility is old-school cgi, so all its resources (such as indexes) have to be instantiated into memory each time the cgi process is started. I could write indexes to files, but then I incur a de/serialization overhead that is expensive. My intention was to keep the indexes as ready-to-use interprocess::maps in shared memory, to be used by all invocations of the cgi. It works, but the performance of the shared memory is poor enough that I'm not getting much increase over just doing a brute force search through the datafiles. All suggestions appreciated! Andy

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