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Re: [Boost-users] [Test] How to treat memory leaks as errors?
by Василий Старостин 27 Sep '09

27 Sep '09

Hi! >> However, Boost.Test doesn't return non-zero error code when leaks >> detected (as it does this when tests fail). >> How can I make my testing program to return non-zero error code if memory leaked? >Because Boost.Test does not contain anything that can test for memory >leaks. You might want to use something like Google's tcmalloc and so >forth as it can tell you about all that, and you can just add a >Boost.Test testcase at the end of the tests to check for memory leaks >using it. Boost.Test does contain something to test memory leaks since I get such warnings when I loose memory in my Boost.Test-based program :) I know this is _CRT functions (I use MSVC9). And the function, which Boost.Test uses to inform about leaks under Windows, SIGNALS that we have m-leaks in a program. Moreover, Boost.Test can control this function using (to use or not to use). So I expected that Boost.Test can use this function return code and increase errors counter for leaks. If it cannot, this can be improvement for the future. WBR, Vasily P.S. _CrtDumpMemoryLeaks?

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Re: [Boost-users] Sockets and structures?
by Brian Wood 27 Sep '09

27 Sep '09

Daniel F. Savarese writes: > To the OP, I would advise you not take statements such as the above as > gospel without performing measurements yourself. My experience[1] is > directly contrary to the above. I find boost::serialization execution > time to be negligible (for binary archives) and entirely suitable for high > performance networking applications even if that was not the creator's > original objective (a credit to Robert Ramey's skill). With respect for the library and Ramey, I'd like to point out that results obtained with the Boost Serialization library are frequently less efficient than those from the C++ Middleware Writer -- http://webEbenezer.net/comparison.html<http://webebenezer.net/comparison.html> . Additionally, the C++ Middleware Writer automates the job of writing serialization functions for structs/classes unless it is directed not to do so. Regards, Brian Wood Ebenezer Enterprises www.webEbenezer.net "Then Samuel took a rock and set it up between Mizpah and Shen. He named it Ebenezer [Rock of Help] and said, 'Until now the L-RD has helped us.'"

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[Test] Compiler error/missing entry point?
by Michael Spece Ibanez 26 Sep '09

26 Sep '09

I installed the Boost.Test library binary using bootstrap.sh. Is the following a valid program? If not, what is wrong? Is there a missing entry point and, if so, how do I run the test? Source: #define BOOST_TEST_MODULE ExampleTestModule #include <boost/test/unit_test.hpp> BOOST_AUTO_TEST_CASE( my_test ) { BOOST_CHECK(1); } Error: /cygdrive/c/DOCUME~1/M/LOCALS~1/Temp/ccIao0DX.o:TestExample.cc:(.text+0x155): undefined reference to `boost::unit_test::framework::master_test_suite()' /cygdrive/c/DOCUME~1/M/LOCALS~1/Temp/ccIao0DX.o:TestExample.cc:(.text+0x232): undefined reference to `boost::unit_test::unit_test_log_t::set_checkpoint(boost::unit_test::basic_cstring<char const>, unsigned int, boost::unit_test::basic_cstring<char const>)' /cygdrive/c/DOCUME~1/M/LOCALS~1/Temp/ccIao0DX.o:TestExample.cc:(.text+0x317): undefined reference to `boost::test_tools::tt_detail::check_impl(boost::test_tools::predicate_result const&, boost::unit_test::lazy_ostream const&, boost::unit_test::basic_cstring<char const>, unsigned int, boost::test_tools::tt_detail::tool_level, boost::test_tools::tt_detail::check_type, unsigned int, ...)' /cygdrive/c/DOCUME~1/M/LOCALS~1/Temp/ccIao0DX.o:TestExample.cc:(.text+0x4e0): undefined reference to `boost::unit_test::ut_detail::auto_test_unit_registrar::auto_test_unit_registrar(boost::unit_test::test_case*, unsigned long)' /cygdrive/c/DOCUME~1/M/LOCALS~1/Temp/ccIao0DX.o:TestExample.cc:(.text$_ZN5boost9unit_test14make_test_caseERKNS0_9callback0INS0_9ut_detail6unusedEEENS0_13basic_cstringIKcEE[boost::unit_test::make_test_case(boost::unit_test::callback0<boost::unit_test::ut_detail::unused> const&, boost::unit_test::basic_cstring<char const>)]+0x54): undefined reference to `boost::unit_test::ut_detail::normalize_test_case_name(boost::unit_test::basic_cstring<char const>)' /cygdrive/c/DOCUME~1/M/LOCALS~1/Temp/ccIao0DX.o:TestExample.cc:(.text$_ZN5boost9unit_test14make_test_caseERKNS0_9callback0INS0_9ut_detail6unusedEEENS0_13basic_cstringIKcEE[boost::unit_test::make_test_case(boost::unit_test::callback0<boost::unit_test::ut_detail::unused> const&, boost::unit_test::basic_cstring<char const>)]+0xa6): undefined reference to `boost::unit_test::test_case::test_case(boost::unit_test::basic_cstring<char const>, boost::unit_test::callback0<boost::unit_test::ut_detail::unused> const&)' /cygdrive/c/DOCUME~1/M/LOCALS~1/Temp/ccIao0DX.o:TestExample.cc:(.text$_ZN5boost9unit_test15unit_test_log_tD1Ev[boost::unit_test::unit_test_log_t::~unit_test_log_t()]+0xb): undefined reference to `vtable for boost::unit_test::unit_test_log_t' /cygdrive/c/DOCUME~1/M/LOCALS~1/Temp/ccIao0DX.o:TestExample.cc:(.text$_ZN5boost9unit_test15unit_test_log_tC1Ev[boost::unit_test::unit_test_log_t::unit_test_log_t()]+0x21): undefined reference to `vtable for boost::unit_test::unit_test_log_t' /usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../libcygwin.a(libcmain.o):(.text+0xab): undefined reference to `_WinMain@16' collect2: ld returned 1 exit status

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[Test] catch_system_errors default value ...
by Georg Sauthoff 26 Sep '09

26 Sep '09

Hi, the default of 'catch_system_errors = yes' when using the boost unit testing framework is a bit problematic. Apparently, it installs a signal handler for SIGCHILD. I didn't notice this under Linux. But under Solaris I've got an interrupted waitpid system call in one test case[1]. Well, and the trace looks really funny, if waitpid is interrupted by ... SIGCHILD! (the testcase basically does a fork/exec/waitpid) Thus, the default of this parameter is at least a bit counter-intuitive. Perhaps, you[2] consider to change this default in the future. Best regards Georg Sauthoff [1] I assume, that utf does this on Linux in such a way, that waitpid is automatically resumed [2] I mean the utf maintainer, using gmane, I am not able to CC ...

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[Intrusive] List Manipulation and Management
by Freddie Witherden 26 Sep '09

26 Sep '09

Hi all, I am moderningising/porting some old Pascal code. The code makes extensive use of an intrusive singly-linked structure termed a node. In order to replicate this idiom in C++ I have been investigating the Intrusive library. However, I have several questions about list manipulation and memory management. Firstly, in the code being ported all nodes can be thought of as being heap allocated. The following is extremely common (pseudo-code): Node* afunction(...); [...] Node* tail; link(tail, afunction(...)); This is rather nice as in O(1) you can append a returned list to your current list. However, I am unsure how I would accomplish this in Boost Intrusive. I can not seem to find a way to create the somewhat fragile intrusive::list from just a node (be it singly or doubly linked). The list class also seems to take T& as opposed to T* when pusing to the front/back of the list. My experience of intrusive structure in C was that you'd always take a pointer when adding a new link. Secondly, when dealing with heap allocated items, which need to be deleted, the current code uses a while loop to call each nodes destructor. What is the intrusive equivalent? Of course, I am open to ideas/suggestions about better ways to accomplish the above tasks :) Regards, Freddie.

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[random]: several issues
by Thomas Mang 26 Sep '09

26 Sep '09

HI, After some time I came back to the boost random library, and several things I noticed earlier have not changed since years ago. I hereby ask what the present state of ideas regarding these ideas is. Here's my list: a) The library itself provides files for random deviates of distributions not given in the documentation (e.g. poisson, gamma) etc. I find it truly sad that implementation and documentation is that out of synchronisation b) Several distributions require the engine to return a uniform deviate between [0,1), while other's don't have this prerequisite. I find this extremely error prone and purely documented (it is documented, but it should be so clearer, and especially, louder). Worse, I find it even harder (or impossible) to find out which range the engines return. I am not sure if there is any engine returning this range per se, or if I have always to go through uniform_01. Worst of all, there is neither a compile time check nor a runtime check if that [0,1) result-requirement of the engine holds (as far as I have seen the code) - I absolutely fail to see why such a critical assert is completely missing, also given the poor state of the documentation. The poisson and gamma for example also fall in this category, but are not documented at all. I consider this highly dangerous. c) Random numbers are tightly linked to statistical distributions, offered by the library of it's own. Wouldn't it be convenient to try to integrate the whole distribution part of the random numbers more closely into that library? Presently they are too confusingly standalone. d) Is there anyone actually responsible for the random library at the moment? Is it still under active development / maintained, or is old code simply propagating from release to release ? [No offense intended, but above issues let me have doubts regarding active management). thanks, Thomas

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[Test] Test suite timeout.
by Dmitry V. Krivenok 26 Sep '09

26 Sep '09

Hello! I have a question about timeouts implementation in Boost::Test. Please take a look at a simple example I wrote to demonstrate the problem: krivenok@develop2 16:50:52 /tmp/boost_test $ cat main.cpp #include <boost/test/unit_test.hpp> using namespace boost::unit_test; using boost::unit_test::framework::master_test_suite; //////////////////////////////////////////////////////////////////////////////// void some_test_case() { BOOST_TEST_CHECKPOINT("About to enter an infinite loop!"); while(1); } ////////////////////////////////////////////////////////////////////////////// void another_test_case() { BOOST_TEST_CHECKPOINT("About to enter an infinite loop 2!"); while(1); } ////////////////////////////////////////////////////////////////////////////// boost::unit_test::test_suite* create_test_suite() { boost::unit_test::test_suite *ts = new boost::unit_test::test_suite("Some test suite"); if(!ts) return 0; ts->add(BOOST_TEST_CASE(&some_test_case), 0, 5); ts->add(BOOST_TEST_CASE(&another_test_case), 0, 10); return ts; } /////////////////////////////////////////////////////////////////////////////// test_suite* TestSuitesInit(int argc, char* argv[]) { master_test_suite().add(create_test_suite(), 0, 3); return 0; } /////////////////////////////////////////////////////////////////////////////// int main(int argc, char** argv) { return unit_test_main(&TestSuitesInit, argc, argv); } /////////////////////////////////////////////////////////////////////////////// krivenok@develop2 16:50:53 /tmp/boost_test $ I compiled it as follows: krivenok@develop2 16:56:12 /tmp/boost_test $ g++-4.4.1 -Wall -I/usr/local/dev/boost-1.40.0/include main.cpp /usr/local/dev/boost-1.40.0/lib/libboost_unit_test_framework-mt.a krivenok@develop2 16:56:15 /tmp/boost_test $ And the run: krivenok@develop2 16:58:17 /tmp/boost_test $ time ./a.out Running 2 test cases... unknown location(0): fatal error in "some_test_case": signal: SIGALRM (timeout while executing function) main.cpp(10): last checkpoint: About to enter an infinite loop! unknown location(0): fatal error in "another_test_case": signal: SIGALRM (timeout while executing function) main.cpp(18): last checkpoint: About to enter an infinite loop 2! *** 2 failures detected in test suite "Master Test Suite" real 0m15.002s user 0m14.920s sys 0m0.030s krivenok@develop2 16:58:36 /tmp/boost_test $ According to timings measurement I concluded that Boost::Test supports timeouts on per-test-case basis. Test suite timeout (3 sec) is ignored. Is it a bug? P.S. I also found that timeouts are implemented using alarm system call: krivenok@develop2 16:58:36 /tmp/boost_test $ strace -fF ./a.out 2>&1 | grep alarm alarm(0) = 0 alarm(5) = 0 alarm(0) = 0 alarm(0) = 0 alarm(10) = 0 alarm(0) = 0 krivenok@develop2 17:02:03 /tmp/boost_test $ As I know you can't start two or more timers using alarm since alarm uses exactly one internal timer. The following simple program demonstrates the problem: krivenok@develop2 17:06:38 /tmp/boost_test/alarm $ cat main.c #include <unistd.h> int main() { alarm(2); alarm(5); while(1); return 0; } krivenok@develop2 17:06:42 /tmp/boost_test/alarm $ gcc-4.4.1 main.c krivenok@develop2 17:06:44 /tmp/boost_test/alarm $ time ./a.out Alarm clock real 0m5.001s user 0m4.990s sys 0m0.000s krivenok@develop2 17:06:51 /tmp/boost_test/alarm $ strace -fF ./a.out 2>&1 | grep alarm alarm(2) = 0 alarm(5) = 2 krivenok@develop2 17:07:00 /tmp/boost_test/alarm $ This makes the implementation of mixed timeouts difficult and unreliable. For example, consider the following test tree: MasterTestSuite (timeout = T0) -- TestSuite1 (timeout = T1) -- TestCase11(timeout = T11) -- TestCase12(timeout = T12) -- TestSuite2 (timeout = T2) -- TestCase21(timeout = T21) -- TestCase212(timeout = T22) Actual timeout of any test case depends on timeouts of all nodes in the path. -- Sincerely yours, Dmitry V. Krivenok Orange System Co., Ltd. Saint-Petersburg, Russia work phone: +7 812 332-32-40 cellular phone: +7 921 576-70-91 e-mail: krivenok(a)orangesystem.ru web: http://www.orangesystem.ru skype: krivenok_dmitry jabber: krivenok_dmitry(a)jabber.ru icq: 242-526-443

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unit test: BOOST_FIXTURE_TEST_CASE_TEMPLATE
by Hicham Mouline 26 Sep '09

26 Sep '09

Hello, I would like to request for the addition of this macro to the boost unit tests library. I have a mpl::vector_c<....> and I would like to run a test case for the type being each of the mpl integrals. and test case instantiations would have the same fixture. I don't see a workaround but for now I'll just use a runtime loop. Rds,

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fork in boost?
by pedro chaparro 26 Sep '09

26 Sep '09

hi, there is some function in boost libraries equivalent to "fork" in linux? thanks -- Ing Pedro Alonso Chaparro Valero Ciudad Politecnica de la Innovación iTEAM - Mobile Communications Group Polytechnic University of Valencia C\ Camino de Vera S/N, Edificio 8G 46022 Valencia, Spain

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Argument error after upgrading to Snow Leopard
by s seelenluft 26 Sep '09

26 Sep '09

Hi, after upgrading to Snow Leopard I get following error message compiling even a simple Hello World program with bjam: *** argument error * rule SHELL ( command : * ) * called with: ( ) * missing argument command (builtin):see definition of rule 'SHELL' being called ... The .cpp file is: #include <iostream> int main() { cout "Hello World!" << endl; return 0; } The Jamroot file contains: exe HelloWorld : HelloWorld.cpp ; I have: - bjam installed in /usr/local/bin - boost-build libraries in /usr/share/boost-build - in /usr/share/boost-build/user-config.jam the line: using darwin; This is as far as I know exactly the same as I had it under Leopard. What am I missing here? Thanks. Markus

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[python] Passing pointers as arguments without copying.
by Germán Diago 26 Sep '09

26 Sep '09

Hello. The question is simple, but reading the documentation I cannot understand how to do this: class MyClass : boost::noncopyable { void f(MyClass2 * c2); }; MyClass2 is not copyable either. So I want to be able to wrap that function, but avoid the copying of MyClass2 when called from python. I want to pass the c++ object directly, not a copy of it. I'm not sure if this can be done with ptr() or some kind of call policy, but I don't understand the documentation 100%. Any help will be appreciated. Thanks.

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Week of the Year calculations?
by Ramon F Herrera 26 Sep '09

26 Sep '09

I looked at the Date_Time library but couldn't find this. Need to convert a date into the corresponding week of the year and vice versa. I realize that such thing varies and plan to use the standard most common in the USA. TIA, -Ramon

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[exception] nested exceptions: lost information?
by Pascal Z. 26 Sep '09

26 Sep '09

Hello I'm trying to nest exceptions using boost.Exception, but it seems like some information (in this case the message returned via what() ) is lost on the way. #include <iostream> #include <boost/exception.hpp> typedef boost::error_info<struct tag_nested_exception, boost::exception_ptr> nested_exception; struct file_open_error : public boost::exception, public std::exception {}; int open_file(const std::string& filename) { try { // ... throw std::runtime_error("Some internal error."); } catch(const std::exception& error) { throw file_open_error() << nested_exception(boost::copy_exception(error)); } } int main(int argc, char* argv[]) { try { int file = open_file("foo.txt"); file++; } catch(const boost::exception& error) { try { boost::rethrow_exception(*boost::get_error_info<nested_exception>(error)); } catch(const std::exception& nested) { std::cout << "the nested error is: " << nested.what() << std::endl; } } return 0; } I except the output to be "the nested error is: Some internal error." but it outputs "the nested error is: std::exception". What can I do to make it work? Greetings Pascal

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std::accumulate with condition?
by Archie14 26 Sep '09

26 Sep '09

If a given class defines operator + and there is a vector of instances of that class: how I can use std::accumulate to count sum against this vector for the elements that satisfy certain conditions? class A { public: A(useinsum) : _useinsum(useinsum) {}; bool useinsum() {return _useinsum;} int operator + (int a) {return _i + a;} private bool _useinsum; int _i; } std::vector<A> lst; will that work? std::accumulate(lst.begin(), lst.end(), 0, boost::lambda::bind(&A::useinsum, boost::lambda::_1) == false)

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[graph] Optimizing graph definition
by Maxime van Noppen 26 Sep '09

26 Sep '09

Hi, I'm using a quite large boost::graph (~ 100 000 vertices with 8 to 10 edges each) and am trying to get the best of the structure to be able to increase vertices & edges. The graph is mainly read-only. I add 99.99% of the vertices & edges in a big loop at the beginning. I never delete vertices or edges. After that I mainly use dijkstra and A* algorithms with some full traversals. I use very often the edge(v1, v2, g) function to get the edge (if it exists) between two vertices. My priority is to optimize the use of the graph rather than the creation but I'd like to keep the creation time reasonable. For now I use : typedef boost::adjacency_list< boost::vecS, boost::vecS, boost::directedS, my_vertex, my_edge > graph_t; I didn't find enough informations about complexity of functions and algorithms regarding to the graph definition to find out be myself what would be the best parameters for my use case. Is something improvable here ? Thanks ! -- Maxime

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Re: [Boost-users] Sockets and structures?
by OvermindDL1 26 Sep '09

26 Sep '09

On Fri, Sep 25, 2009 at 6:49 PM, Daniel F. Savarese <dfs(a)savarese.org> wrote: > > In message <3f49a9f40909251225p28d497b6i6d73c2dd53e3ba3e(a)mail.gmail.com>, Overm > indDL1 writes: >>Boost.Serialization is good if you are going to serialize up vast >>hierarchies with lots of pointers that can be self referencing and >>such, but it tends to be very costly in execution speed. Something >>like Boost.Spirit2.1 can serialize things up to a binary format as >>well, and *very* fast. Although something like Google's open source >>message system could serialize up messages even better (we need a >>Boost implementation of that system... hmm...). > > To the OP, I would advise you not take statements such as the above as > gospel without performing measurements yourself. My experience[1] is > directly contrary to the above. I find boost::serialization execution > time to be negligible (for binary archives) and entirely suitable for high > performance networking applications even if that was not the creator's > original objective (a credit to Robert Ramey's skill). > > No tool is suitable for all purposes. So figure out your requirements > and do some testing to see what works best before choosing a solution. > Just because boost::serialization works great for me in a particular > application doesn't mean it's going to work great for someone else with > a different set of requirements. Also, talking about performance > cost/overhead is pointless without precise quantification. Run your > own tests in the context of your anticipated usage and see how it > works out. > > daniel > > [1] www.igfip.com: All interprocess communication and object serialization > uses boost::serialization. Play a game of Reversi or Chess (against the > computer or another player) or chat with another player and see if > boost::serialization in any way impacts the real-time/instantaneous > response to your actions. Behind the scenes, boost::serialization's > impact on CPU time isn't even measurable. It is quite slow when you need speed though. You will not notice it in those times, but compared to other methods it tends to be many many orders of magnitude slower. It is the registery that slows it down though (I have profiled it, AMD Code Analyst). It is, however, *wonderful* for like save/load functionality, I still use it for that, but for heavy network utilization on never idle programs (say a real-time 3d action game), I never would. Use the proper tools for the proper purposes. :)

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Re: [Boost-users] [boost user list] Portal Web Design Support of Boost C++
by OvermindDL1 25 Sep '09

25 Sep '09

Do not send this message to me, send it to boost. :) On Fri, Sep 25, 2009 at 1:51 PM, Ray Burkholder <ray(a)oneunified.net> wrote: >> > >> > Does boost C++ support the design of portal web pages or processing >> of >> > database data from web pages depending on user selection of controls >> on the >> > web page? >> >> That has 'nothing' to do with your chosen language, rather with the >> web library you use, the most popular of which is (Fast)CGI, which >> does support it all (what do you think PHP/Python/Java/etc... are all >> built to use, CGI, it can do it all). >> >> Thus, this is not a boost question. > > You may instead be looking for something like http://www.webtoolkit.eu/wt > which makes use of some boost functionality. I however have been looking for something like that, thanks for the link!

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Sockets and structures?
by pedro chaparro 25 Sep '09

25 Sep '09

hi, i'm wondreing if using asio library can i send a structure and not just string messages using the boost::asiio:write command? or how could i do to send a structure which have many information fields? thanks -- Ing Pedro Alonso Chaparro Valero Ciudad Politecnica de la Innovación iTEAM - Mobile Communications Group Polytechnic University of Valencia C\ Camino de Vera S/N, Edificio 8G 46022 Valencia, Spain

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[boost user list] Portal Web Design Support of Boost C++
by Boost lzw 25 Sep '09

25 Sep '09

Hi there, Does boost C++ support the design of portal web pages or processing of database data from web pages depending on user selection of controls on the web page? Thanks in advance, Robert

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Boost serialization libray 1.32 & 1.39 compatibility issue ( from "To DO" list)
by sam p 25 Sep '09

25 Sep '09

Hi, I am facing backward compatibility problem with boost serialization library 1.39. My setup is something like this, (1) I have one version of my program that is built using boost 1.32 serialization library, lets call it 1_32.exe (2) I have another version of my program that is built using boost 1.39 serialization library, lets call it 1_39.exe (3) These two versions of my program communicate with each other over network and they use boost text serialization to exchange data. (4) Program 1_39.exe is able to deserialize data sent by 1_32.exe but 1_32.exe is not able to deserialize data sent by 1_39.exe While debugging this problem I realized that program 1_39.exe is putting archive version as “5” and 1_32.exe is putting archive version as “3”. This results into 1_32.exe throwing “Unknown version” exception. While going through boost documentation I read about “Back Versioning” description provided at http://www.boost.org/doc/libs/1_39_0/libs/serialization/doc/todo.html#backv… Looks like its not very difficult to address this issue if we modify some code in boost serialization library. Are you planning to address this in near future or can you please advice me on the files those need to be changed? Or is there any simple workaround as a stop gap measure to fix this issue? Thanks, Sameer

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Passing reference params to boost::thread, parameter copies.
by Jason Cipriani 25 Sep '09

25 Sep '09

At the end of this message is a test program that uses boost::thread to create two threads. The first is one that takes a parameter by value, the second takes a parameter by reference. I have a couple of questions about some behavior here: 1) When passing by value, why are so many copies of the data made? The program output indicates that there are 9 (!) objects created (at most 5 exist simultaneously), when ideally there would be only 2 (the original and the copy passed to the thread). 2) When passing by reference, why is the data being copied? The copying behavior when passed by reference is identical to when the param is passed by value (9 objects created, 5 simultaneously). Also, and this isn't shown in the program below, but I would therefore expect the program to crash if the boost::thread outlived the referenced object (of course, it does not, since the object is copied). So, I'm surprised by the number of copies, this seems unreasonable, and also I'm confused about why by value and by reference behave identically. Thanks, Jason === BEGIN EXAMPLE === #include <boost/thread/thread.hpp> #include <cstdio> using namespace std; class test { public: test () { printf("%p\n", (void *)this); } test (const test &t) { printf("%p from %p\n", (void *)this, (void *)&t); } ~test () { printf("~%p\n", (void *)this); } }; void expected_copy (test) { printf("in expected_copy\n"); } void expected_nocopy (const test &) { printf("in expected_nocopy\n"); } int main () { printf("expected_copy:\n"); { test t; boost::thread thr(expected_copy, t); thr.join(); } printf("expected_nocopy:\n"); { test t; boost::thread thr(expected_nocopy, t); thr.join(); } printf("complete\n"); getchar(); } === END EXAMPLE ===

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Boost unit_test.cpp problem when try to compile simple program
by Robert Matusewicz 25 Sep '09

25 Sep '09

I tried to use Boost test module in my project but I have a little problem. When I try to compile simple program: #define BOOST_TEST_MAIN #include <boost/test/included/unit_test.hpp> it fails to compile on Visual Studio 2008 with three errors: c:\program files (x86)\boost\boost_1_39\boost\test\impl\exception_safety.ipp(513) : error C2491: 'boost::itest::exception_safety' : definition of dllimport function not allowed c:\program files (x86)\boost\boost_1_39\boost\test\impl\logged_expectations.ipp(228) : error C2491: 'boost::itest::logged_expectations' : definition of dllimport function not allowed c:\program files (x86)\boost\boost_1_39\boost\test\impl\unit_test_main.ipp(174) : error C2491: 'boost::unit_test::unit_test_main' : definition of dllimport function not allowed On Linux machines everything works OK. So, anybody could help me with that? Need more data? Robert

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import boost cstdint into default namespace
by V S P 25 Sep '09

25 Sep '09

Can I somehow import the boost/cstdint definitions into the default namespace without importing any other things from the boost namespace (I am trying to compile a source code that relies on having stdint.h but VC 2008 does not have it so I want to use boost/cstdint but without much modifications to the source at question) thank you -- Vlad P author of C++ ORM http://github.com/vladp/CppOrm/tree/master -- http://www.fastmail.fm - Access your email from home and the web

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BOOST_SYSTEM_NO_DEPRECATED and boost/filesystem/convenience.hpp
by Paul 25 Sep '09

25 Sep '09

Hi, If i compile with -DBOOST_SYSTEM_NO_DEPRECATED and #include <boost/filesystem/convenience.hpp> The compile will fail with the message: boost/filesystem/convenience.hpp: In function ‘typename boost::enable_if<boost::filesystem::is_basic_path<Path>, bool>::type boost::filesystem::create_directories(const Path&)’: boost/filesystem/convenience.hpp:48: error: ‘posix’ is not a member of ‘boost::system’ BOOST_FS_FUNC(bool) create_directories(const Path& ph) { if (ph.empty() || exists(ph)) { if ( !ph.empty() && !is_directory(ph) ) boost::throw_exception( basic_filesystem_error<Path>( "boost::filesystem::create_directories", ph, make_error_code( boost::system::posix::file_exists ) ) ); return false; } The line with boost::system::posix::file_exists is the key problem. In boost/system/error_code.hpp, posix is defined as a namespace # ifndef BOOST_SYSTEM_NO_DEPRECATED namespace posix = errc; namespace posix_error = errc; # endif but ONLY if I don't define NO_DEPRECATED... Maybe time for regression tests with BOOST_SYSTEM_NO_DEPRECATED defined? thanks, Paul

1 0

boost::filesystem::rename() documentation incorrect
by Paul 25 Sep '09

25 Sep '09

Hi all, this documentation is incorrect: Otherwise, if to_p resolves to an existing file, it is removed. This is from Boost 1.40.0, and yet the code for rename() calls rename_api() which then does the following: if ( fs::exists( status_api( to, dummy ) ) ) return error_code( EEXIST, system_category ); ie, if to_p resolves to an existing file, it will always return/throw an error... NOT remove the existing file, as was documented. Or am I reading things wrong? cheers Paul

1 0

A problem on using boost timer (different time intervals were showed). Can any one with kindness help me?
by fmingu 25 Sep '09

25 Sep '09

I am using boost timer in C++ builder 2009 to test the time used in my program.there are the lines: .................... boost::timer t; double timeresult; ................... t.restart(); ........... //my program main body timeresult=t.elapsed(); ShowMessage( " the time consumed by my program is "+FloatToStr(timeresult)); ......................... the program was compiled and linked and worked well. But I find a problem: every time the message showed is not the same time interval, sometimes it is 0.015 and sometimes it is 0.016 and sometimes it is 0. I do not know how it was happened. Does it happen due to the multi-process and multi-thread mode by windows? I do not know how to solve it. My program is quite strict on the time consumed by the computer. Can any one with kindness help me?

7 8

[lambda] Defining a predicate for std::find_if if the key to a std::map is std::pair
by Ryan McConnehey 25 Sep '09

25 Sep '09

I have the following std::map signature. typedef std::pair<std::string, int> cPair; typedef std::map<cPair, std::vector<classA> > cMap; cMap myMap; When entering values into the map, the std::string is the only part of the key that needs to be unique. Upon retrieving map values both values of the key need to be compared. I've tried to define my insert comparison as follows, but am uncertain how to define the predicate with boost::lambda. std::string givenName = "some_text_value"; int givenInt = 3; cMap::const_iterator itor = std::find_if( myMap.begin(), myMap.end(), boost::lambda::bind( ??? , _1) == givenName ); What goes at the question marks? Ryan

5 12

[spirit] parsing vsv files with embedded quotes/line breaks
by Sean Farrow 25 Sep '09

25 Sep '09

Hi: I know there is a spirit example to parse csv or any list-separated file. What I need to do is to be able to parse files with embedded "," characters, quotes and line breaks in. How would i go about doing this? Regards Sean.

2 1

[MPL] at<> function with too many arguments
by Ryan McConnehey 25 Sep '09

25 Sep '09

I have a mpl::map as follows, with a template parameter of a passed in type and a template parameter of "supported_type" that is a class. using boost::mpl; enum { value = 1 + supported_type::value }; typedef typename insert<typename supported_type::type_map, pair<T, int_<value> > >::type type_map; I'm trying to create a function that searches the map for a given type and returns a numeric value if it's found or -1 if it's not found. template <typename S> int typeValue(void) { return at< type_map, S, int_<-1> >::type::value; } The documentation says I can specify a default value for "at" that is returned if the given key isn't found. The compiler, though, says that I've provided too many arguments. Have I called "at" incorrectly? Is the documentation incorrect? Is the fault with the compiler (VS 2005)? Ryan

2 1

[python] Ownership of python objects.
by Germán Diago 24 Sep '09

24 Sep '09

Hello. I'm trying to do the following thing: 1.- Create an object 2.- Put it in an scene (for a game) 3.- To be able to delete it from the scene (this is done from C++) My problem is that if I do the following: p = Object("blabla") Scene.addToScene("myobject", p) //Here, the object is deleted by C++, which is causing problems p.removeFromScene("myobject") I know a workaround for this. It would be to make a wrapper for objects created from python and not deleting the object if it was created from there. But I would like if there is some other (more general) way to avoid this. Thanks in advance.

2 1

[MultiIndex] documentation for macros
by Igor R 24 Sep '09

24 Sep '09

Hello, Is there any description of the various macros that control MI behavior, like BOOST_MULTI_INDEX_ENABLE_SAFE_MODE etc.? I tried to search through the library reference, but haven't managed to find any. Thanks.

3 4

Re: [Boost-users] [Regex] Group of number at line end
by Roland Bock 24 Sep '09

24 Sep '09

Reiner Hutsch wrote: > -----Ursprüngliche Nachricht----- > Von: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] Im Auftrag von John Maddock > Gesendet: Mittwoch, 23. September 2009 18:45 > An: boost-users(a)lists.boost.org > Betreff: Re: [Boost-users] [Regex] Group of number at line end > >> i am looking for a regular expression which extracts a group of number >> from >> the end of a line like the following: >> >> "This line may contain digits (9) but ends with numbers like 1 2 3 4 5" >> >> When using a regex like "^(.+)(\\s+(\\d+))+$" I receive >> "This line may contain digits (9) but ends with numbers like 1 2 3 4" and >> "5". >> >> Can someone help me? > > What about: "^(.+)[^\\d\\s](\\s+\\d+)+$" > > HTH, John. > > Hi John, > > sorry, but this gives also only the last number. > > Reiner. If you want the group, not the each number separately, this should work: ^.*[^ 0-9] *([ 0-9]+)$ Testing with perl: perl -e '$x = "This line may contain digits (9) but ends with numbers like 1 2 3 4 5"; $x =~ s/^.*[^ 0-9] *([ 0-9]+)$/$1/g; print "$x\n";' Output: 1 2 3 4 5 Regards, Roland

1 0

redirect flow with Breadth-First-Search - problems with the residual capacities
by Benjamin Rupp 24 Sep '09

24 Sep '09

Hi, I want to redirect Flow, which I have earlier calculated with Edmonds-Karp, with Breadth-First-Search (Aim is to determine the maximal free capacity of an edge by redirecting all possible flow to other edges) When I call Edmonds-Karp the Maximal Flow is calculated. If I then print out the values of the residual capacities of the edges, all edges with a capacity of 0 (this are the reverse edges) have a residual capacity of 0 instead of a capacity equal to the flow of the reverse edge. I wrote the following code to correct the values: long speicher[num_edges(g)]; for(tie(e_iter,e_end)=edges(g); e_iter!=e_end; ++e_iter) if(get(e_index,*e_iter) < num_edges(g)/2){ speicher[e_index[*e_iter]] = residual_capacity[*e_iter]; speicher[e_index[*e_iter]+(num_edges(g)/2)] = flow[*e_iter]; } for(tie(e_iter,e_end)=edges(g); e_iter!=e_end; ++e_iter) put(residual_capacity,*e_iter,speicher[e_index[*e_iter]]); But this is very time inefficient. Does anyone have an idea why the reverse edges do not have the correct residual capacity? Another strange phenomenon is that if I allocate the correct residual capacity only to the reverse edges because the others are correct this change to the residual capacities is not saved. for(tie(e_iter,e_end)=edges(g); e_iter!=e_end; ++e_iter) if(get(e_index,*e_iter) < num_edges(g)/2){ put(residual_capacity,reverse_edge[*e_iter],flow[*e_iter]); Thanks Benjamin

1 0

[bind/function] memory allocation question
by Tim Blechmann 24 Sep '09

24 Sep '09

hi all, i would like to use boost.bind and boost.function in a real-time application, where heap memory allocation is not allowed. according to the docs, boost.function may allocate memory on the heap, but uses a small object optimization, to avoid heap allocation. i'd be curious, if there is a way to figure out, whether heap allocation may occur or not ... i would like to be able to use boost::function objects, initialized by boost::bind, something like: void callme (int some, int args) {} boost::function<void (void)> fn = boost::bind(callme, 1, 2); fn(); thanks, tim -- tim(a)klingt.org http://tim.klingt.org Which is more musical, a truck passing by a factory or a truck passing by a music school? John Cage

1 0

Serialization demo program crashes trying to free an unallocated block
by Jean-Denis Muys 24 Sep '09

24 Sep '09

Hi, Warning: noob inside. I am new to boost, and quite a bit rusty with C+ +, having spent the past few years with other languages. Nonetheless. I downloaded, built and installed Boost 1.40 just fine on Mac OS X 10.6 (Snow Leopard). I set up a XCode 3.2 project to compile and run the demo.cpp program delivered with the Serialization library. It crashes deep inside this line: restore_schedule(new_schedule, filename.c_str()); GDB gives the following error message: malloc: *** error for object 0x1000581a0: pointer being freed was not allocated The stack crawl shows: #0 0x7fff81202ff6 in __kill #1 0x7fff812a4072 in abort #2 0x7fff811bb095 in free #3 0x7fff836031e8 in std::string::reserve #4 0x7fff836032fe in std::string::append #5 0x10028ccac in boost ::archive::text_iarchive_impl<boost::archive::text_iarchive>::load at text_iarchive_impl.ipp:55 #6 0x100024a5e in boost ::archive::load_access::load_primitive<boost::archive::text_iarchive, std::string> at iserializer.hpp:109 #7 0x100024a83 in boost ::archive ::detail::load_non_pointer_type<boost::archive::text_iarchive, std::string>::load_primitive::invoke at iserializer.hpp:332 #8 0x100024aa8 in boost ::archive ::detail::load_non_pointer_type<boost::archive::text_iarchive, std::string>::invoke at iserializer.hpp:417 #9 0x100024acd in boost::archive::load<boost::archive::text_iarchive, std::string> at iserializer.hpp:542 #10 0x100024afe in boost ::archive ::detail ::common_iarchive <boost::archive::text_iarchive>::load_override<std::string> at common_iarchive.hpp:61 #11 0x100024b2b in boost ::archive ::basic_text_iarchive <boost::archive::text_iarchive>::load_override<std::string> at basic_text_iarchive.hpp:62 #12 0x100024b59 in boost ::archive ::text_iarchive_impl <boost::archive::text_iarchive>::load_override<std::string> at text_iarchive.hpp:66 #13 0x100024b8c in boost ::archive ::detail ::interface_iarchive <boost::archive::text_iarchive>::operator>><std::string> at interface_iarchive.hpp:61 #14 0x100024bc3 in boost ::archive ::detail ::interface_iarchive <boost::archive::text_iarchive>::operator&<std::string> at interface_iarchive.hpp:68 #15 0x100026688 in bus_stop_corner::serialize<boost::archive::text_iarchive> at main.cpp: 123 #16 0x1000266c3 in boost::serialization::access::serialize<boost::archive::text_iarchive, bus_stop_corner> at access.hpp:109 and so on... The last frame for which I have source code is #5. There the crashes occurs in the following routine: template<class Archive> BOOST_ARCHIVE_DECL(void) text_iarchive_impl<Archive>::load(std::string &s) { std::size_t size; * this->This() >> size; // skip separating space is.get(); // borland de-allocator fixup #if BOOST_WORKAROUND(_RWSTD_VER, BOOST_TESTED_AT(20101)) if(NULL != s.data()) #endif s.resize(size); // <============== crash here if(0 < size) is.read(&(*s.begin()), size); } In that frame, s is the empty string (its internal buffer points to a 0 byte), and size is 11. Suspecting a bug in OS X std::string class, I checked that the following program works fine: int main() { std::string s; std::size_t size = 11; std::cout << s << std::endl; s.resize(size); std::cout << s << std::endl; } So I tried to follow the stack up tracking the string object to see where and how it was created. I lost track of it in frame #15 on the following line: ar & street1 & street2; Note that this is back to the sample code. I decided to split that line into two lines, and surely now the crashes occurs there: ar & street1; I'm going to go on tracing through that, but maybe this rings a bell with someone, that would save me time... I can post more info if needed. Best regards and thanks, Jean-Denis

2 4

[interprocess] Memory deallocation doesn't seem to work
by Stephan Menzel 24 Sep '09

24 Sep '09

Hi there, I seem to get a strange behavior with 1.40 on windows concerning deallocation. Basically, I have a managed shared memory segment and I allocate several blocks of mem in it typedef boost::interprocess::managed_windows_shared_memory shared_segment; typedef boost::shared_ptr<shared_segment> shared_segment_ptr; ... shared_segment_ptr p = new shared_segment(create_only, buffername.c_str(), begin_size); ... Now I have several allocate_aligned operations: ptr = m_segment->allocate_aligned(static_cast<size_t>(rawsize), 128); Now after a while the segment will have no more room for further blocks. So I delete some of them to gain more room: m_segment->deallocate(raw.get()); (raw is an interprocess::offset_ptr) I debugged into this and there's indeed deallocation functionality called but when I try to allocate afterwards... ptr = m_segment->allocate_aligned(static_cast<size_t>(rawsize), 128); ... I get an interprocess::bad_alloc This makes me believe that either deallocate didn't do a good job or I have to do something after the deallocate() to really make it happen. I looked into the docs for this but there was nothing mentioned so I suppose deallocate() should suffice. I think fragmentation is not really a problem here. We're talking about a few >1MB blocks in a 30MB segment. Plus some administrative overhead. Any ideas what's going on here? Cheers, Stephan

2 3

Boost-regex: Weird behaviour with non-greedy matching operator in regex_replace in boost 1.40?
by Florian Schwarz 24 Sep '09

24 Sep '09

Hi, the non-greedy matching seems to have a weird behaviour (maybe non-determeterministic?) to work if the pattern is preceeded with something. E.g. when I want to get all characters in a string except the last on, if its an 'o', I would use regex matchExpr("(.*?)o?"); So if I write string text("hallo"); regex matchExpr("(.*?)o?"); string valueExpr("$1"); string result; regex_replace(back_inserter(resul), text.begin(), text.end(), matchExpr, valueExpr); cout << "Match \"" << result << "\"" << endl; it will print the expected "hall". If I now use instead string text(" hallo"); regex matchExpr(" (.*?)o?"); it will print "hallo". And for string text("hhallo"); regex matchExpr("h(.*?)o?"); string valueExpr("$1"); regex_replace(back_inserter(resul), text.begin(), text.end(), matchExpr, valueExpr); cout << "Match \"" << result << "\"" << endl; it will print "allo" which seems even more strange to me. I'm using boost1.40 on ubuntu with g++ 4.2.4 To give you a complete example: #include <boost/regex.hpp> #include <iostream> using namespace std; using namespace boost; void test(string& text, regex& matchExpr, string valueExpr){ if (regex_match(text, matchExpr)){ string result; regex_replace(back_inserter(result), text.begin(), text.end(), matchExpr, valueExpr); cerr << "Match \"" << result << "\"" << endl; } } int main(){ { // Test 1 string text("hallo"); regex matchExpr("(.*?)o?"); string valueExpr("$1"); test(text, matchExpr, valueExpr); } { // Test 2 string text(" hallo"); regex matchExpr(" (.*?)o?"); string valueExpr("$1"); test(text, matchExpr, valueExpr); } {// Test 3 string text(" hallo"); regex matchExpr("^ (.*?)o?$"); string valueExpr("$1"); test(text, matchExpr, valueExpr); } { // Test 4 string text("hhallo"); regex matchExpr("h(.*?)o?"); string valueExpr("$1"); test(text, matchExpr, valueExpr); } { // Test 5 string text("hhallo"); regex matchExpr("^h(.*?)o?$"); string valueExpr("$1"); test(text, matchExpr, valueExpr); } } The program will print Match "hall" Match "hallo" Match "hall" Match "allo" Match "hall" I have the following questions: - why does test 1 match the expected "hall" while test 2 matches "hallo" - why does test 1 match the whole string while test 4 matches only a part of it. Many thanks for your help and best regards Florian Schwarz

3 5

Object Pool Usage
by david.weber＠l-3com.com 24 Sep '09

24 Sep '09

So, I'm investigating Object Pools, and I think I'm not getting something. The documentation isn't great, hence the question We have a lot of small objects that we will use throughout our application's lifespan, and I'm trying to see if ObjectPool is a good fit for us. Heck, I'm just trying to look at performance of it in general. So, I have the following code: -------------------------------------------------------------- void testNormal() { common::Timer t; t.start(); for(int i = 0; i < MAX_NUM_TESTS; i++) { testClass t; t.doWork(); } t.stop(); std::cout << "No Pool: Creating " << MAX_NUM_TESTS << " took " << str_cast(t.getTotalElapsedTime()) << std::endl; } void testPool() { common::Timer t; t.start(); boost::object_pool<testClass> pool; for(int i = 0; i < MAX_NUM_TESTS; i++) { testClass::ptr tc = pool.construct(); tc->doWork(); } t.stop(); std::cout << "Pool: Creating " << MAX_NUM_TESTS << " took " << str_cast(t.getTotalElapsedTime()) << std::endl; } int main(int argc, char* argv[]) { testNormal(); testPool(); return 0; } ------------------------------------------------ When run, I am getting: No Pool: Creating 500000 took 00:00:00.187785 Pool: Creating 500000 took 00:00:00.281679 So, I guess I'm not understanding the advantage of the pools. Could someone write/modify my example to make it make more sense? Thanks --dw

4 3

Re: [Boost-users] [Regex] Group of number at line end
by John Maddock 24 Sep '09

24 Sep '09

> i am looking for a regular expression which extracts a group of number > from > the end of a line like the following: > > "This line may contain digits (9) but ends with numbers like 1 2 3 4 5" > > When using a regex like "^(.+)(\\s+(\\d+))+$" I receive > "This line may contain digits (9) but ends with numbers like 1 2 3 4" and > "5". > > Can someone help me? What about: "^(.+)[^\\d\\s](\\s+\\d+)+$" HTH, John.

2 1

boost::filesystem::exists question
by Steven White 23 Sep '09

23 Sep '09

I am working on building a project that relies on OpenSG2 and VR Juggler 2.2 for various reasons between the two I am building Boost 1_37 for the boost co dependency. While working with VR Juggler I noticed the error that boost::filesystem::exists was not defined in libboost_filesystem-xgcc40-mt.dylib. Which I found a little odd. After looking in to it I noticed that it is indeed not defined in either on of my release libs, but was defined in all of the debug libraries. In case I had done something wrong when I compiled boost I started a recompile with the following options. bjam --tool-set=darwin --prefix=$HOME/usr -- build-type=complete -a stage It currently looks like the build will yield the same results. I have a few nm | grep | c++filt below for the new libs. So I have two questions. Is the behavior below normal. If not what might be the cause? nm bin.v2/libs/filesystem/build/darwin-4.0.1/release/link-static/runtime-link-static/threading-multi/libboost_filesystem-xgcc40-mt-s-1_37.a | grep exists | c++filt 000003b0 T boost::filesystem::detail::symbolic_link_exists_api(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) 0002cc00 S __ZN5boost10filesystem6detail24symbolic_link_exists_apiERKSs.eh nm bin.v2/libs/filesystem/build/darwin-4.0.1/debug/link-static/runtime-link-static/threading-multi/libboost_filesystem-xgcc40-mt-sd-1_37.a | grep exists | c++filt 000005a4 T boost::filesystem::detail::symbolic_link_exists_api(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) 00025cf4 S __ZN5boost10filesystem6detail24symbolic_link_exists_apiERKSs.eh 00021fe8 S boost::files nm stage/lib/libboost_filesystem-xgcc40-mt-d-1_37.dylib |grep exists | c++filt 00002822 T boost::filesystem::detail::symbolic_link_exists_api(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) 00004872 T boost::filesystem::exists(boost::filesystem::file_status) volcano boost_1_37_0]$ nm stage/lib/libboost_filesystem-xgcc40-mt-1_37.dylib | grep exists | c++filt 00002010 T boost::filesystem::detail::symbolic_link_exists_api(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)

1 0

[enable_if] Doesn't work for static member functions ?
by Jean-Louis Leroy 23 Sep '09

23 Sep '09

Consider : template<typename U> struct Test { template<typename T> typename enable_if<is_same<T, int>, void>::type test() { cout << "int" << endl; } template<typename T> typename enable_if<is_same<T, char>, void>::type test() { cout << "char" << endl; } }; template<typename T> typename enable_if<is_same<T, int>, void>::type test() { cout << "int" << endl; } template<typename T> typename enable_if<is_same<T, char>, void>::type test() { cout << "char" << endl; } int _tmain(int argc, _TCHAR* argv[]) { test<int>(); test<char>(); Test<int>::test<double>(); // error return 0; } MSVC9 will give a compilation error (see below) where marked. Am I missing something obvious ? Thanks, J-L 1>c:\users\jll\documents\visual studio 2008\projects\boost_1_40_0\libs\rdb\test\test.cpp(325) : error C2143: syntax error : missing ';' before '<' 1> c:\users\jll\documents\visual studio 2008\projects\boost_1_40_0\libs\rdb\test\test.cpp(333) : see reference to class template instantiation 'Test<U>' being compiled 1>c:\users\jll\documents\visual studio 2008\projects\boost_1_40_0\libs\rdb\test\test.cpp(325) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int etc etc etc

2 1

[[value_initialized] when T is const
by Edward Diener 23 Sep '09

23 Sep '09

I like the idea of using value_initialized for a variable to initialize a value to its value intialized value when no initial value is given. But if an initial value is given it does not work if the T is a const type. Was this intended ? Essentially if a variable is a non-const object, one can say, for example: boost::value_initialized<int> data; // data initialized to its value initialized value boost::value_initialized<int> data; boost::get(data) = arg; // data is initialized to value arg For a const value we have: boost::value_initialized<int const> data; // data initialized to its value initialized value but we can not do: boost::value_initialized<int> data; boost::get(data) = arg; // ERROR // try to initialize data to value arg So there is no way to initialize a const T to a value when using boost::value_initialized<T>. This presents a problem in a template class where T can be a const type: template <class T> struct SomeTemplate<T> { boost::value_initialized<T> data; SomeTemplate() { } // always good SomeTemplate(T arg) { boost::get(data) = arg; // FAILS with a const T, // such as if SomeTemplate<int const> is instantiated with any int value // as in 'SomeTemplate<int const> st(4);' } }; In this case boost::value_initialized can not be used. This makes it much less usable in my estimation since the creator of a template class wanting to use boost::value_initialized can only do so if he restricts that template type to a non-const value. If he does not make that restriction then he must go back to initialization by hand and forgo the advantages of value_initialized entirely. It would seem that this limitation could be lifted if the boost::value_initialized template had a constructor which enabled one to initialize the value in cases where initialization to a value initialized state was not desired. Then, despite T being a const type, one could initialize the variable to a specific value.

2 11

[intrusive] list traversing by list_base_hooks
by Tim Blechmann 23 Sep '09

23 Sep '09

hi all, is there a way to traverse a boost::intrusive::list directly from the list_base_hook? i'd like to traverse the list directly from the node something like: my_node: public list_base_hook<> { my_node * previous_node(); my_node * next_node(); }; is it possible to implement something like that? thnx, tim -- tim(a)klingt.org http://tim.klingt.org /"\ ASCII Ribbon Campaign \ / no HTML in email & vCards X no proprietary attachments / \ use open standards

2 1

Calling boost::_mfi::dm on temporaries (e.g. in transform_iterator)
by Sebastian Theophil 23 Sep '09

23 Sep '09

I've encountered a problem when using boost::mem_fn in transform_iterators. In the attached example, I've chained two transform_iterators. The first iterator returns an Obj by value and the second extracts a member of the temporary object. The example shows that the return value is not quite what is expected. boost::mem_fn(&Obj::m_member) returns an int const&. The transform_iterator uses the return value of the UnaryFunction template parameter to initialize his value_type. In the given example, this logic seems too simple. At least if the UnaryFunction is of type boost::_mfi::dm the transform_iterator could do better: If Reference is boost::use_default If UnaryFunction is boost::_mfi::dm && Iterator::value_type is not a reference itself reference = boost::remove_reference( result_of(UnaryFunction) ) Else reference = result_of(UnaryFunction) Else reference = Reference Is this too much of a special case to fix it in the transform_iterator? The same logic would apply to all (unknown) functors that returned references to member variables. In general, the transform_iterator can probably not decide if a reference returned from a UnaryFunction will cease to exist when the temporary is destroyed. It could have been a global object. On the other hand, transform_iterators should work correctly if only boost objects are used, shouldn't they? I'd like to hear what you think, Sebastian #include "boost/iterator/transform_iterator.hpp" #include <vector> struct Obj { Obj(int n) : m_member(n) {} Obj(Obj const& obj) : m_member(obj.m_member) {} ~Obj() { m_member=INT_MIN; } int m_member; }; static Obj GetObjByValue( int n ) { return Obj(n); } void main() { std::vector<int> v(1, 5); int n=*boost::make_transform_iterator( boost::make_transform_iterator( v.begin(), GetObjByValue ), boost::mem_fn(&Obj::m_member) ); _ASSERT(n==INT_MIN); } -- Sebastian Theophil . stheophil(a)think-cell.com Software Engineer think-cell Software GmbH . Invalidenstr. 34 . 10115 Berlin, Germany http://www.think-cell.com . phone +49-30-666473-10 . toll-free (US) +1-800-891-8091 Directors: Dr. Markus Hannebauer, Dr. Arno Schoedl . Amtsgericht Berlin-Charlottenburg, HRB 85229

1 0

[Regex] Group of number at line end
by Reiner Hutsch 23 Sep '09

23 Sep '09

Hallo regex gurus, i am looking for a regular expression which extracts a group of number from the end of a line like the following: "This line may contain digits (9) but ends with numbers like 1 2 3 4 5" When using a regex like "^(.+)(\\s+(\\d+))+$" I receive "This line may contain digits (9) but ends with numbers like 1 2 3 4" and "5". Can someone help me? RHutsch

1 0

wget
by Matthew Galati 23 Sep '09

23 Sep '09

Is there a way to get boost libraries with wget via some ftp server? I am on linux and want to write a script to grab the source directly.

5 6

BGL - read_graphviz and subgraph
by Giuseppe Di Guglielmo 22 Sep '09

22 Sep '09

Dear all, I read on the 'read_graphviz()' page in BGL library doc http://www.boost.org/doc/libs/1_40_0/libs/graph/doc/read_graphviz.html * read_graphviz treats subgraphs as syntactic sugar. It does not reflect subgraphs as actual entities in the BGL. Rather, they are used to shorten some edge definitions as well as to give a subset of all nodes or edges certain properties. For example, the DOT graphs digraph { a -> subgraph {b -> c} -> e } and digraph { a -> b -> e ; a -> c -> e ; b -> c} are equivalent. Is this actually true? Can I read sub-graph from DOT description and obtain a subgraph object? http://www.boost.org/doc/libs/1_40_0/libs/graph/doc/subgraph.html Eventually are subgraph supported by 'read_graphml()' function? http://www.boost.org/doc/libs/1_40_0/libs/graph/doc/read_graphml.html Thanks, G.

1 0

Fwd: Sockets & acceptors
by Wes Alvaro 22 Sep '09

22 Sep '09

I've looked at the examples and tutorials and have destroyed my code trying to get this to work: * I want to connect to a server on a shared port and get a new port number and a unique ID. * The server should accept connections on a shared port and then open a new port to continue communication. * This happens synchronously. Currently, I can connect to the server: tcp::resolver resolver(io); tcp::resolver::query query(server, port); tcp::resolver::iterator endpoint_iterator = resolver.resolve(query); tcp::resolver::iterator end; boost::system::error_code error = boost::asio::error::host_not_found; while (error && endpoint_iterator != end) { serverSocket.close(); serverSocket.connect(*endpoint_iterator++, error); } if (error) { throw boost::system::system_error(error); } int messageSize = sizeof(ident) * 2 + sizeof(int); // ID and port void *message = malloc(messageSize); boost::asio::read(serverSocket, boost::asio::buffer((char *) message, messageSize)); The server code, ripped from the example: tcp::endpoint endpoint( tcp::v4(), this->listenPort ); tcp::acceptor a( io, endpoint ); do { boost::shared_ptr<tcp::socket> sock(new tcp::socket( io )); this->listenSocket = sock; a.accept( *this->listenSocket ); } while(true); As you can see, the server does nothing with the client connection. However, the client reads the 12 bytes as requested in the last line with boost::asio::read. The information received here is junk (to my program) and causes it to crash. What am I doing wrong? What should I be doing? Any help is much appreciated! Thanks, Wes

2 1

Re: [Boost-users] boost zlib problem on linux (works fine onwindows)
by ChristinaDRS 22 Sep '09

22 Sep '09

Hey Steven, Can you post example code to do this? I'm very new to boost! Thanks, Christina >>Try calling flush on the streambuf. >>In Christ, >>Steven Watanabe ChristinaDRS wrote: > This code works fine on Windows, but I get the exception when running in > linux.. any ideas why? The code, how its compiled, and error are below: > > #include <iostream> > #include <sstream> > #include <boost/iostreams/copy.hpp> > #include <boost/iostreams/device/back_inserter.hpp> > #include <boost/iostreams/filter/bzip2.hpp> > #include <boost/iostreams/filter/zlib.hpp> > #include <boost/iostreams/filtering_stream.hpp> > using namespace std; > > int main() > { > string message = "this is a test message!"; > cout << "message: " << message << endl; > string compressed; > boost::iostreams::filtering_streambuf<boost::iostreams::output> > out; > out.push(boost::iostreams::zlib_compressor()); > out.push(boost::iostreams::back_inserter(compressed)); > boost::iostreams::copy(boost::make_iterator_range(message), out); > cout << "compressed message: " << compressed << endl; > > boost::iostreams::filtering_streambuf<boost::iostreams::input> in; > in.push(boost::iostreams::zlib_decompressor()); > in.push(boost::make_iterator_range(compressed)); > string decompressed; > boost::iostreams::copy(in, > boost::iostreams::back_inserter(decompressed)); > cout << "decompressed message: " << decompressed << endl; > } > > > # g++ zlib.cpp zlib_test2.cpp -o zlib_test2 -lz > # ./zlib_test2 > message: this is a test message! > compressed message: > terminate called after throwing an instance of > 'boost::iostreams::zlib_error' > what(): zlib error > Aborted > # > Try calling flush on the streambuf. In Christ, Steven Watanabe _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users -- View this message in context: http://www.nabble.com/Re%3A--Boost-users--boost-zlib-problem-on-linux-%28wo… Sent from the Boost - Users mailing list archive at Nabble.com.

2 1

boost zlib problem on linux (works fine on windows)
by ChristinaDRS 22 Sep '09

22 Sep '09

Hello all, This code works fine on Windows, but I get the exception when running in linux.. any ideas why? The code, how its compiled, and error are below: #include <iostream> #include <sstream> #include <boost/iostreams/copy.hpp> #include <boost/iostreams/device/back_inserter.hpp> #include <boost/iostreams/filter/bzip2.hpp> #include <boost/iostreams/filter/zlib.hpp> #include <boost/iostreams/filtering_stream.hpp> using namespace std; int main() { string message = "this is a test message!"; cout << "message: " << message << endl; string compressed; boost::iostreams::filtering_streambuf<boost::iostreams::output> out; out.push(boost::iostreams::zlib_compressor()); out.push(boost::iostreams::back_inserter(compressed)); boost::iostreams::copy(boost::make_iterator_range(message), out); cout << "compressed message: " << compressed << endl; boost::iostreams::filtering_streambuf<boost::iostreams::input> in; in.push(boost::iostreams::zlib_decompressor()); in.push(boost::make_iterator_range(compressed)); string decompressed; boost::iostreams::copy(in, boost::iostreams::back_inserter(decompressed)); cout << "decompressed message: " << decompressed << endl; } # g++ zlib.cpp zlib_test2.cpp -o zlib_test2 -lz # ./zlib_test2 message: this is a test message! compressed message: terminate called after throwing an instance of 'boost::iostreams::zlib_error' what(): zlib error Aborted # Thanks! Christina -- View this message in context: http://www.nabble.com/boost-zlib-problem-on-linux-%28works-fine-on-windows%… Sent from the Boost - Users mailing list archive at Nabble.com.

2 1

Using boost::serialization in real-time without allocating memory
by Peter Soetens 22 Sep '09

22 Sep '09

Hi, I'm trying to find out if boost::serialization can be used in real-time applications to stream data into a fifo to another process. It is mandatory that no memory allocations happen during the serialization. I tested this with a std::vector<double> of 10 elements in combination with the boost::iostreams library. The aim is that all memory allocations happen during construction of the archive object, while the serialisation itself causes none. <code> #include <boost/archive/binary_oarchive.hpp> #include <boost/serialization/vector.hpp> #include <boost/iostreams/stream.hpp> #include <boost/iostreams/device/array.hpp> namespace io = boost::iostreams; int main(int argc, char *argv[]) { vector<double> d(10, 1.1); char sink[1000]; memset( sink, 0, 1000); io::stream<io::array_sink> out(sink,1000); boost::archive::binary_oarchive oa(out); //oa << d; // should not allocate return 0; } </code> The setup code does 10 memory allocations according to valgrind: ==12995== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 8 from 1) ==12995== malloc/free: in use at exit: 0 bytes in 0 blocks. ==12995== malloc/free: 10 allocs, 10 frees, 913 bytes allocated. ==12995== For counts of detected errors, rerun with: -v ==12995== All heap blocks were freed -- no leaks are possible. If we uncomment 'oa << d' we get 2 more (unwanted) allocations: ==13010== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 8 from 1) ==13010== malloc/free: in use at exit: 0 bytes in 0 blocks. ==13010== malloc/free: 12 allocs, 12 frees, 1,001 bytes allocated. ==13010== For counts of detected errors, rerun with: -v ==13010== All heap blocks were freed -- no leaks are possible I'm guessing that the 2 allocations in the serialisation path come from a temporay std::string object, when writing the 'serialization::archive' string into the archive. Wouldn't it be possible to rewrite this library code as such that there are no allocations / strings created ? A similar pattern is observed for deserializing: 2 allocs in the serialisation path. Peter PS: I tried to find out who defines the macro BOOST_ARCHIVE_SIGNATURE() but I couldn't find the definition/#define !?

3 25

typelist using mpl::list
by noman javed 22 Sep '09

22 Sep '09

Hi I want to implement typelist concept through mpl::list or mpl::vector. The idea is that for every call to some functor i want to store its type in a mpl::list e.g suppose we have struct A { }; A callA() {}; struct B {}; B callB() {}; main() { callA(); callB(); } this program should create a compile time mpl::list containing {B,A}. How can I implement this concept using mpl::list or mpl::vector ? Thanks in advance Regards Noman

2 1

[program_options] vector parameters not working.
by aiooua 22 Sep '09

22 Sep '09

hello, I recently picked up boost to make use of the various libraries it includes. Unfortunately, I got stuck with the very first one (program_options) I used in my code. Any help would be appreciated very much. I want an option "bunch" which goes along with a bunch of numbers. I thought the following code would do the job: --------------------------------------------------------------------------------------- #include <iostream> #include <string> #include <vector> #include <boost/program_options.hpp> using namespace std; namespace po = boost::program_options; int main(int argc, char* argv[]) { try { vector<int> numbers; po::options_description params("parameters"); po::variables_map options; params.add_options() ("bunch,b", po::value< vector<int> >(&numbers), "a bunch of numbers"); po::store(po::parse_command_line(argc, argv, params), options); po::notify(options); if(options.count("bunch")!=0) { copy (numbers.begin(), numbers.end(), std::ostream_iterator<int>(cout, "\n")); } } catch(exception & e) { cerr << e.what() << endl; } return 0; }; --------------------------------------------------------------------------------------- However, it doesn't seem to work as it should. When I run this as follows: --------------------------------------------------------------------------------------- > test --bunch 4 2 42 4 --------------------------------------------------------------------------------------- It is just printing the first value - Am I doing something wrong here? I'm using 'boost_1_40_0' which I compiled using MS Visual Studio 2005. thanks,

2 2

Status inquiry on Boost.Move
by Phil Deets 22 Sep '09

22 Sep '09

Hello, I am looking for a way to support move semantics with a few of my classes in a personal project I am working on. As soon as Visual C++ 2010 Express Edition comes out, I plan to convert the code to use R-value references, but I would prefer to have move semantics now so I can avoid needless expensive copies now. The Boost.Move code in the sandbox (http://svn.boost.org/svn/boost/sandbox/move/) seems to meet my needs, but I have not tried it yet; so I do not know whether it is stable or not. Does anyone know the status of this implementation. Is it relatively bug-free or should I not use it right now? If there is another move library that you would recommend, feel free to let me know. Thanks, Phil Deets II -- Using Opera's revolutionary e-mail client: http://www.opera.com/mail/

1 0

Re: [Boost-users] Usingboost::serializationinreal-timewithoutallocating memory
by Brian Wood 22 Sep '09

22 Sep '09

Stefan Strasser writes: > that's the same approach. > code seems to be written by an external code generator instead of a c++ > compiler, but there is no difference beyond that, is there? > .NET for example implements serialization based on its reflection mechanism. > it iterates at runtime through the (reflected) fields of a class and extracts > the data. > I don't think an external code generator is "cleaner". I don't claim that an external code generator is cleaner, but that the Ebenezer approach is cleaner, since it (usually) writes marshalling functions at build time. C++ compilers should have been able to do that for 10 years now, but for whatever reason that isn't being developed. Regards, Brian Wood http://webEbenezer.net <http://webebenezer.net/> "Then Samuel took a rock and set it up between Mizpah and Shen. He named it Ebenezer [Rock of Help] and said, 'Until now the L-RD has helped us.'"

1 0

Re: [Boost-users] Usingboost::serializationinreal-timewithoutallocating memory
by Brian Wood 22 Sep '09

22 Sep '09

Stefan Strasser writes: > sure, it's the best serialization solution I know and the template > technique trumps any reflection based solution (even if c++ had > reflection). In what way? The "Usage" section of this page, http://webEbenezer.net/comparison.html<http://webebenezer.net/comparison.html>, gives an example of how it's possible to produce a cleaner solution than that afforded by the Boost Serialization library. The Ebenezer approach to the bus_stop example is twelve lines less than the Boost Serialization approach. Regards, Brian Wood www.webEbenezer.net <http://www.webebenezer.net/> "Then Samuel took a rock and set it up between Mizpah and Shen. He named it Ebenezer [Rock of Help] and said, 'Until now the L-RD has helped us.'"

2 1

boost::proto user guide - compile error creating a lazy function
by Tom Babbin 21 Sep '09

21 Sep '09

Hi, I am going through proto user guide. I am getting compiling error for the following piece code (it's pretty much copy and pasted from the guide). I used 1.40 and gcc. #include <iostream> #include <boost/mpl/int.hpp> #include <boost/proto/core.hpp> #include <boost/proto/context.hpp> #include <boost/proto/debug.hpp> #include <cmath> #include <vector> namespace proto = boost::proto; template<int I> struct placeholder {}; // Define some placeholders proto::terminal< placeholder< 1 > >::type const _1 = {{}}; proto::terminal< placeholder< 2 > >::type const _2 = {{}}; struct calculator_context : proto::callable_context< calculator_context const > { // Values to replace the placeholders std::vector<double> args; // Define the result type of the calculator. // (This makes the calculator_context "callable".) typedef double result_type; // Handle the placeholders: template<int I> double operator()(proto::tag::terminal, placeholder) const { return this->args[I]; } }; // Define a pow_fun function object template<int Exp> struct pow_fun { typedef double result_type; double operator()(double d) const { return std::pow(d, Exp); } }; // Define a lazy pow() function for the calculator DSEL. // Can be used as: pow< 2 >(_1) template<int Exp, typename Arg> typename proto::function< typename proto::terminal<pow_fun<Exp> >::type , Arg const & >::type pow1(Arg const &arg) { typedef typename proto::function< typename proto::terminal<pow_fun<Exp> >::type , Arg const & >::type result_type; result_type result = {{{}}, arg}; return result; } int main() { calculator_context ctx; ctx.args.push_back(3); std::cout << boost::proto::eval( pow1<2>( _1 ), ctx ); return 0; } The error says: calc2.cpp: In function 'int main()': calc2.cpp:116: error: no matching function for call to 'eval(boost::proto::exprns_::expr<boost::proto::tag::function, boost::proto::argsns_::list2<boost::proto::exprns_::expr<boost::proto::tag::terminal, boost::proto::argsns_::term<pow_fun<2> >, 0l>, const boost::proto::exprns_::expr<boost::proto::tag::terminal, boost::proto::argsns_::term<placeholder<1> >, 0l>&>, 2l>, calculator_context&)' /auto/cigprod/spg/lx86_64/opt/boost_1_40_0/boost/proto/eval.hpp:91: note: candidates are: typename boost::proto::result_of::eval<Expr, Context>::type boost::proto::eval(Expr&, Context&) [with Expr = boost::proto::exprns_::expr<boost::proto::tag::function, boost::proto::argsns_::list2<boost::proto::exprns_::expr<boost::proto::tag::terminal, boost::proto::argsns_::term<pow_fun<2> >, 0l>, const boost::proto::exprns_::expr<boost::proto::tag::terminal, boost::proto::argsns_::term<placeholder<1> >, 0l>&>, 2l>, Context = calculator_context] /auto/cigprod/spg/lx86_64/opt/boost_1_40_0/boost/proto/eval.hpp:100: note: typename boost::proto::result_of::eval<Expr, Context>::type boost::proto::eval(Expr&, const Context&) [with Expr = boost::proto::exprns_::expr<boost::proto::tag::function, boost::proto::argsns_::list2<boost::proto::exprns_::expr<boost::proto::tag::terminal, boost::proto::argsns_::term<pow_fun<2> >, 0l>, const boost::proto::exprns_::expr<boost::proto::tag::terminal, boost::proto::argsns_::term<placeholder<1> >, 0l>&>, 2l>, Context = calculator_context] Thanks. -- View this message in context: http://www.nabble.com/boost%3A%3Aproto-user-guide---compile-error-creating-… Sent from the Boost - Users mailing list archive at Nabble.com.

2 4

[graph] : newbie question on brandes_betweenness_centrality
by Matthew Walker 21 Sep '09

21 Sep '09

Hi, I am very much a newbie at this and would greatly appreciate some help on how I could get the brandes_betweenness_centrality function to work for me. I have the following code that compiles without error, but seg faults when I run it: #include <map> #include <boost/graph/graph_traits.hpp> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/graph_utility.hpp> #include <boost/graph/betweenness_centrality.hpp> #include <boost/graph/exterior_property.hpp> int main() { ... // I am reading a network from a file and storing it into lEdges and lNumVertices typedef adjacency_list<vecS, vecS, undirectedS > Graph; Graph g(lEdges.begin(), lEdges.end(), lNumVertices); typedef boost::exterior_vertex_property<Graph, float> BetweennessProperty; typedef BetweennessProperty::map_type BetweennessMap; BetweennessMap lMap; brandes_betweenness_centrality(g, lMap); } If I could get this to work, I then have aspirations that the helper function central_point_dominance(g, lMap) might give me the betweenness centralization measure that I'm after. Thanks in advance for your help! Matthew

2 2

Hierarchical enumeration?
by Archie14 21 Sep '09

21 Sep '09

Does boost (or any other lib in C++) have facility to support smth that resembles hierarchical enumeration? I would like to have something like the following: enum Hierarchy { Store::Clothing = 1 Store::Electronics, Building::Residential, Building::Commercial } ... Hierarchy h = Hierarchy::Building::Commercial; ... if (h == Hierarchy::Store) { if (h == Hierarchy::Store::Clothing) std::cout<<"clothing"; } ...

3 2

ASIO newbie: Passing parameters from a TCP client to a server
by Ramon F Herrera 21 Sep '09

21 Sep '09

Hello all, I have studying the ASIO examples, and experimenting with them. Still, I could benefit from the guidance of experienced programmers. This is my first client-server set of apps. I need the client to pass a few arguments to the server, lets say four. Should I pass them in 4 different lines? Being synchronous I suppose the client blocks until the server performs a read? (that seems to be what I am seeing now). I heard that there are ways to attach the debugger (gdb) to a server process when it starts? (that feat seems to be major wizardry). Sample code would be very appreciated. TIA, -Ramon

3 2

[fusion] transform a heterogeneous vector
by Jean-Louis Leroy 20 Sep '09

20 Sep '09

In the example from the documentation : struct triple { typedef int result_type; int operator()(int t) const { return t * 3; }; }; ... assert(transform(make_vector(1,2,3), triple()) == make_vector(3,6,9)); ...all the elements have the same type. How can it work with heterogeneous vectors ? What would be typedef'ed to result_type ? Jean-Louis

2 4

Can Regex callback function arguments be modified?
by Ramon F Herrera 20 Sep '09

20 Sep '09

I am having some trouble with the Regex callback architecture. Fist of all for, for a variable number of matches, the only way to code is with a callback function and for_each iterator, correct? To make it more interesting, I have a callback calling another callback. This could obviously go deeper and deeper. Due to the inflexibility (perhaps by me perceived?) of the callback architecture, I am forced to use a lot of global variables. To be fair, this is highly manageable within my current application, but I am concerned that this "implicit number and types of parameters" restriction may become a stumbling block in future code. At this stage, what I am trying to determine whether I should base my program(s) on (from simplest to more complex): - Regex - eXpressive - Spirit So far, I prefer Regex because it is much more stable than Spirit. The latter seems to have great potential, but when when I find that I am unable to even build the test examples properly, and the specs vary from one version to the next, I conclude that it is best to allow the good people of Spirit ("spirited people"? :-) time to deliver a more polished product. Don't know anything about eXpressive yet. Regards, -Ramon

5 9

[Test] How to treat memory leaks as errors?
by Василий Старостин 19 Sep '09

19 Sep '09

Hi! I use Boost.Test as testing facility and get "memory leak detected" messages every time this happens. And this is good. However, Boost.Test doesn't return non-zero error code when leaks detected (as it does this when tests fail). How can I make my testing program to return non-zero error code if memory leaked? WBR, Vasily

2 1

How to find Boost 1.40.0 with cmake 2.6?
by Ingolf Steinbach 19 Sep '09

19 Sep '09

Hi, maybe this is a bit off-topic as it is probably a cmake problem, but it could turn out that the correct solution also involves suitable invocation of bjam. As there seems to be no Windows/VC9.0 installer for Boost 1.40.0 (yet), I have built and installed the libraries myself as follows: ...\boost_1_40_0> bootstrap ...\boost_1_40_0> .\bjam --prefix=C:\Programme\boost\boost_1_40_0 ...\boost_1_40_0> .\bjam --prefix=C:\Programme\boost\boost_1_40_0 install Now, there is the following tree in C:\Programme\boost: C:\Programme\boost +-boost_1_40_0 +-include | +-boost-1_40 | +-boost | +.... +-lib +-libboost....-vc90-mt-1_40.lib +-... What is the correct way to teach the FindBoost module in cmake where to search for the boost installation? I have found that I need to at least set(Boost_ADDITIONAL_VERSIONS "1.40" "1.40.0") However, cmake does not yet find Boost. According to the debugging output of the module, the situation seems to improve slightly when I additionally specify set(BOOST_ROOT C:/Programme/boost) Now, cmake reports "Boost version: 1.40.0" but does not find any libraries. Would I have to supply different options to bjam in order to find the libraries? Is it possible to avoid having to specify BOOST_ROOT in the CMakeLists.txt file? TIA for your support! Ingolf

5 5

Mersenne twister problem
by ruya 19 Sep '09

19 Sep '09

Hello I've built a meta-heuristics library in which I use the boost random library. I am using several independent generators through the application. The problem is in the core of my library. The tricky part is that I have three different algorithms using the core, all of them using the class where a segmentation fault happens, but only one of them crashes when it tries to use the class, the others run as expected. Gdb points to the boost library, as you can see in the snippet bellow. I couldn't find any information on this issue, and I cannot see something wrong with my code (the relevant part is bellow). The parent class where generators are declared: template< class SType, typename MemP > class SearchFunctor{ (...) public: virtual SPtr operator()( SPtr s, int iter ) = 0; SearchFunctor(){ (...) //This is how I initialize teh generators, being MASTER SEED 666 generator1 = base_generator_type(MASTER_SEED*13); uni_dist1 = boost::uniform_real<>(0,1); uniEmp = new GeneratorI(generator1, uni_dist1); generator2 = base_generator_type(MASTER_SEED*17); uni_dist2 = boost::uniform_real<>(0,1); uniRes = new GeneratorI(generator2, uni_dist2); } protected: base_generator_type generator1, generator2; boost::uniform_real<> uni_dist1, uni_dist2; GeneratorI* uniEmp; GeneratorI* uniRes; }; The derived class using the generators: template< class SType, typename MemP > struct SwapSearch : public SearchFunctor<SType,MemP>{ typedef SearchFunctor<SType,MemP> Parent; (...) SPtr operator()( SPtr s, int iter ){ assert(s != NULL); assert(s->GetDomain()!= NULL); assert(s->GetDomain()->GetTotalEntities()>1); (...) d1 = (*Parent::uniEmp)() * (s->GetDomain()->GetTotalEntities()-1); d2 = (*Parent::uniEmp)() * (s->GetDomain()->GetTotalEntities()-1); (...) return 0; } }; The output of the debugger has a lot of lines because of meta-programming but starts and finishes with this: #0 0x08071a57 in brickheuristics::SwapSearch (...) (...) at /usr/include/boost/random/mersenne_twister.hpp:279 279 UIntType z = x[i]; Thanks -- View this message in context: http://www.nabble.com/Mersenne-twister-problem-tp25382114p25382114.html Sent from the Boost - Users mailing list archive at Nabble.com.

2 13

[units] CODATA constant for electron charge?
by Manoj Rajagopalan 19 Sep '09

19 Sep '09

Hi developers, Could you please include the electron charge in the codata constants? Right now it has to calculated using codata::e_over_m_e*codata::m_e or set using quantity<electric_charge>::from_value() which is inconvenient. thanks, Manoj

2 1

[Interprocess] deadlocking race condition in emulation interprocess_condition.hpp
by Young, Zachariah L 18 Sep '09

18 Sep '09

This appears related to the discussion found here: http://lists.boost.org/boost-users/2009/03/46051.php Bug: There is a set of conditions where a process can manage to enter do_timed_wait, increment m_num_waiters, and exit without decrementing it. Boost 1.39.0 Sequence of events: We join our hero, Process A (P_A), in boost/interprocess/sync/emulation/interprocess_condition.hpp. P_A is executing a do_timed_wait(true, lock, abs_time) call, and is spinning at the while loop at line 124. tout_enabled == true, and abs_time is a microsecond in the future (about to expire but hasn't yet). Process B, P_A's trusty sidekick, sends a notify_all on the conditional, breaking P_A out of the while loop at line 124. abs_time arrives (ie, P_A got to line 149 with microsec_clock::universal_time() >= abs_time and timed_out = false). With these conditions, P_A gets to line 163 and calls the constructor for scoped_lock. P_A jumps to boost/interprocess/sync/scoped_lock.hpp line 114. P_A executes mp_mutex->timed_lock(abs_time) at line 115. P_A jumps to boost/interprocess/sync/emulation/interprocess_condition.hpp line 49. P_A takes a reading of now at line 56. P_A finds that (now >= abs_time) at line 58 and is sent packing with a return value of false. P_A arrives back in boost/interprocess/sync/emulation/interprocess_condition.hpp on line 163. P_A gets to line 171 and finds lock is false. He panics! He sets timed_out to true and unlock_enter_mut to true, but in his haste to break out of evil Dr. while(1)'s clutches, he forgot to atomically decrement m_num_waiters! Manic laughter can be heard behind him as he tries in vein to acquire the lock on line 214. "You fool! You fell into my trap!", shouts Dr. while(1). "Process B grabbed that very lock and attempted to free you again! He is at line 56 of this very header file, waiting for a call from you that will never come, and he's holding your precious lock! Your deadlock is complete! HAHAHAHAHAHAH!!" Ahem. I do not know the proper way to fix this problem. My straightforward idea is to add the following line at line 172 of boost/interprocess/sync/emulation/interprocess_condition.hpp: if(!lock){ detail::atomic_dec32(const_cast<boost::uint32_t*>(&m_num_waiters)); timed_out = true; unlock_enter_mut = true; break; } However, the commment inlcuded with the block in question: //Notification occurred, we will lock the checking interprocess_mutex so that //if a notify_one notification occurs, only one thread can exit ...makes me wary. One thing seems certain to me: there's something not quite right here. I could increase my timeout window to lower the chances of this occurring, but that is not a solution. That is masking a problem. Anyone got a take on this? Am I missing something obvious? That whole block with the comment really makes me suspicious.

2 6

Using Boost Mutex
by Wesley Bland 18 Sep '09

18 Sep '09

This is firmly in n00b territory. I'm trying to use a boost::mutex to lock a STL queue. The mutex is stored in a class in a map. When I pass the mutex to the boost::mutex::scoped_lock constructor, I get this error: /usr/local/include/boost/noncopyable.hpp: In copy constructor ‘boost::mutex::mutex(const boost::mutex&)’: /usr/local/include/boost/thread/pthread/mutex.hpp:31: instantiated from ‘_Tp& std::map<_Key, _Tp, _Compare, _Alloc>::operator[](const _Key&) [with _Key = int, _Tp = boost::mutex, _Compare = std::less<int>, _Alloc = std::allocator<std::pair<const int, boost::mutex> >]’ SwitchBox.cpp:15: instantiated from here /usr/local/include/boost/noncopyable.hpp:27: error: ‘boost::noncopyable_::noncopyable::noncopyable(const boost::noncopyable_::noncopyable&)’ is private /usr/local/include/boost/thread/pthread/mutex.hpp:31: error: within this context /usr/include/c++/4.2.1/bits/stl_map.h: In member function ‘_Tp& std::map<_Key, _Tp, _Compare, _Alloc>::operator[](const _Key&) [with _Key = int, _Tp = boost::mutex, _Compare = std::less<int>, _Alloc = std::allocator<std::pair<const int, boost::mutex> >]’: /usr/include/c++/4.2.1/bits/stl_map.h:350: note: synthesized method ‘boost::mutex::mutex(const boost::mutex&)’ first required here This appears to be complaining about me passing the mutex into the scoped_lock. Can anyone give me some help here? I've included a much shortened version of the code that otherwise compiles. Thanks for your help, Wesley SwitchBox.hpp ----- #include <map> #include <queue> #include <boost/thread/mutex.hpp> #include <boost/asio.hpp> using boost::asio::ip::tcp; using namespace std; namespace Network { typedef struct Message { int type; unsigned long sender; unsigned long destination; int size; void *body; char *PackHeader(); void UnpackHeader(char *); } Message; class SwitchBox { protected: unsigned long myID; int headerSize; map< int, queue< Message > > sendQueues; map< int, boost::mutex > sendMutexes; bool Initialize(); void SendThread(unsigned long id, tcp::socket sock); }; } SwitchBox.cpp ------ #include "Switchbox.hpp" using namespace Network; bool SwitchBox::Initialize() { myID = 0; headerSize = sizeof(int) + sizeof(unsigned long) * 2 + sizeof(int); return true; } void SwitchBox::SendThread(unsigned long id, tcp::socket sock) { // Set up the lock so it can be locked and unlocked as we need boost::mutex::scoped_lock sendLock(sendMutexes[id], boost::defer_lock); while (true) { // First get the message off of the message queue // Lock the message queue so nothing is moved unexpectedly sendLock.lock(); Message m = sendQueues[id].front(); sendQueues[id].pop(); // Unlock the message queue so everyone else can get to it now sendLock.unlock(); // Next send the message through the socket boost::asio::write(sock, boost::asio::buffer(m.PackHeader(), headerSize)); boost::asio::write(sock, boost::asio::buffer((char *) m.body, m.size)); } }

2 2

Can the Regex code be placed into a class?
by Ramon F Herrera 18 Sep '09

18 Sep '09

The following sample program comes with the Boost Regex distribution. It compiles and runs fine. Its purpose is to count the number of classes in the input text file. http://patriot.net/~ramon/regex_iterator_example.cpp.txt I am having a real hard time trying to convert the code to a class (named "Pairs"). The compilation problem occurs in this statement: std::for_each(m1, m2, &regex_callback); The compiler suggests to use this statement, which does not compile either: std::for_each(m1, m2, &Pairs::regex_callback); Thanks, -Ramon http://www.parashift.com/c++-faq-lite/pointers-to-members.html

2 1

boost::function typename Signature
by veerus 18 Sep '09

18 Sep '09

How to extract the return type and the argument type list from the type Signature in boost::function<Signature> ? More specifically if I have a object of type boost::function< int ( double) >, the thing "int (double)" is matched with a type. What type is that ? Where can I find it? Thanks -- View this message in context: http://www.nabble.com/boost%3A%3Afunction-typename-Signature-tp25507953p255… Sent from the Boost - Users mailing list archive at Nabble.com.

2 1

[Regex] Which sub-expression did participate in a partial match?
by Kay-Michael Wuerzner 18 Sep '09

18 Sep '09

Hello, I wonder if it is possible to find out which sub-expression of a regex is responsible for a partial match? Consider the following example: int main ( int argc, char** argv ) { std::string input ( argv[1] ); boost::regex test ( "((?:Apple )?iPhone)|(Sony Vaio)" ); boost::sregex_iterator it ( input.begin(), input.end (), test, boost::match_default | boost::match_partial ); boost::sregex_iterator none; if ( it != none ) { std::cout << (*it).size () << std::endl; if ( (*it)[0].matched ) std::cout << "full match\n"; else std::cout << "partial match\n"; for ( unsigned int i = 1; i < (*it).size (); ++i ) { if ( (*it)[i].matched ) // this should in principle also be true for partial matches std::cout << i << " " << (*it).position () << std::endl; } } return 0; } The problem is that the if-condition in the for loop is not met in case of a partial match on the sub-expression: $> ./regex_test "Apple" partial match $> ./regex_test "iPhone" full match 1 0 In the first case I would expect the output of the sub-expression and the position of the match. Are you aware of any method to achieve this behavior? Many thanks in advance, Kay

2 1

shared_ptr and pass by value
by Marat Abrarov 18 Sep '09

18 Sep '09

Dear Boost C++ Libraries Developers, According to http://cpp-next.com/archive/2009/08/want-speed-pass-by-value/ why Boost use this (not the only example): ~~~~~~~~~~~~~~~~~~~ shared_ptr & operator=( shared_ptr const & r ) { this_type(r).swap(*this); return *this; } ~~~~~~~~~~~~~~~~~~~ and not such: ~~~~~~~~~~~~~~~~~~~ shared_ptr & operator=( shared_ptr r ) { r.swap(*this); return *this; } ~~~~~~~~~~~~~~~~~~~ Regards, Marat.

2 1

[format] compilation error
by Johan Råde 18 Sep '09

18 Sep '09

Hi, I'm using Boost 1.38 and Visual Studio 2008. The following code #include <boost/format.hpp> #include <ostream> #include <vector> using boost::format; using std::ostream; using std::vector; ostream& operator<<(ostream& os, const vector<int>& v) { os << '['; for(size_t i = 0; i < v.size(); ++i) { if(i > 0) os << ' '; os << v[i]; } os << ']'; return os; } void f() { vector<int> v; str(format("%1%") % v); } fails to compile with the error message 1>c:\libraries\boost\boost_1_38_0\boost\format\feed_args.hpp(100) : error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'const std::vector<_Ty>' (or there is no acceptable conversion) 1> with 1> [ 1> _Ty=int 1> ] Why? How do I fix this? Thank you, Johan Råde

3 2

[Math] Bug in example code / doc (Binomial Distr.)
by Ralf M. 18 Sep '09

18 Sep '09

On p.66 (Binomial distribution, "Binomial Quiz Example") of the Math Toolkit pdf-file, and also at http://www.boost.org/doc/libs/1_40_0/libs/math/doc/sf_and_dist/html/math_to… it is written: "Probability of getting exactly 11 answers right by chance is 2.32831e-010" I think this is wrong. It rather should be one of these below: "Probability of getting exactly 11 answers right by chance is 0.000247132" or "Probability of getting exactly 16 answers right by chance is 2.32831e-010" I have'n checked the underlying source code of this yet; ie. maybe it is only a doc error... And this code there seems IMHO to be problematic too: " int questions = 16; // All the questions in the quiz. int answers = 4; // Possible answers to each question. double success_fraction = (double)answers / (double)questions; // If a random guess. // Caution: = answers / questions would be zero (because they are integers)! binomial quiz(questions, success_fraction); " Shouldn't the second param not simply be the constant p of each item, ie. here 0.25, even if # of questions is set to a different value, for example 32 ? Because 32 / 4, as done above, wouldn't be 0.25 anymore...

3 4

Parallel BGL status in Boost
by Mathieu Malaterre 18 Sep '09

18 Sep '09

Hi there, I am getting lost with the status of PBGL in boost. Is it officially in Boost now ? I am reading some documentation such as: http://charm.cs.uiuc.edu/charmWorkshop/slides/2009_PBGL_Lumsdaine.pptx And it appears there are multiple implementations (see slide #54), namely 'the Parallel BGL' (is there only one?) and the (Parallel) BGL-VTK. Documentation links to : http://www.osl.iu.edu/research/pbgl but this page has not been updated in years, and recent commit AFAIK did happen directly within boost, right ? Is there some threads I am missing, I have been following boost users list but could not find any thread relevant. Basically all I am interested in is how do you provide an iterator interface in a parallel environment where vertex/edge are not local to the machine. Thanks -- Mathieu

3 5

[Regex] Problem with optionality operator
by Kay-Michael Wuerzner 18 Sep '09

18 Sep '09

Hello, I have got a problem with the interpretation of the optionality operator '?' in boost::regex. Consider the following example (regex_test.cpp): #include <iostream> #include <boost/regex.hpp> int main ( int argc, char** argv ) { boost::regex test ( "(Apple)? Iphone 3g" ); boost::match_results<std::string::const_iterator> what; std::string input ( argv[1] ); if ( 0 == boost::regex_match ( input, what, test, boost::match_default | boost::match_partial ) ) { std::cerr << "No Match\n"; } if ( what[0].matched ) { std::cerr << "Full Match\n"; } else { std::cerr << "Partial Match\n"; } return 0; } Test runs are: ./regex_test "Apple Iphone" Output: Partial Match (as expected) ./regex_test "Apple Iphone 3g" Output: Full Match (as expected) ./regex_test "Iphone" Output: No Match and Partial Match (Why is that? "Apple" is optional should only be "Partial Match") ./regex_test "Iphone 3g" Output: No Match and Partial Match (Why is that? "Apple" is optional should be "Full Match") Probably, I am only missing a flag but tests with "\A" and friends do not help. Any comments are appreciated. Many thanks in advance. Cheers, Kay

3 2

Can I use Boost.Regex with multilne text to be recognized?
by Ramon F Herrera 18 Sep '09

18 Sep '09

More accurately, my question should be: How hard (or easy) is it to deal with multiple lines of parsed text in Regex? Is there anything special to do? (such as defining an end of line character(s)) Perhaps the best advice is to stay away from Regex and use something more powerful (such as Xpressive)? TIA, -Ramon

3 4

How to compile boost regex
by manish4gupta 18 Sep '09

18 Sep '09

I am compiling the program using the following option g++ -ggdb -lboost_regex -o regex regex.cpp but it is giving error. #include <boost/regex.hpp> #include <iostream> void print_captures(const std::string& regx, const std::string& text) { boost::regex e(regx); boost::smatch what; std::cout << "Expression: \"" << regx << "\"\n"; std::cout << "Text: \"" << text << "\"\n"; if(boost::regex_match(text, what, e, boost::match_extra)) { unsigned i, j; std::cout << "** Match found **\n Sub-Expressions:\n"; for(i = 0; i < what.size(); ++i) std::cout << " $" << i << " = \"" << what[i] << "\"\n"; std::cout << " Captures:\n"; for(i = 0; i < what.size(); ++i) { std::cout << " $" << i << " = {"; for(j = 0; j < what.captures(i).size(); ++j) { if(j) std::cout << ", "; else std::cout << " "; std::cout << "\"" << what.captures(i)[j] << "\""; } std::cout << " }\n"; } } else { std::cout << "** No Match found **\n"; } } int main(int , char* []) { print_captures("(([[:lower:]]+)|([[:upper:]]+))+", "aBBcccDDDDDeeeeeeee"); print_captures("(.*)bar|(.*)bah", "abcbar"); print_captures("(.*)bar|(.*)bah", "abcbah"); print_captures("^(?:(\\w+)|(?>\\W+))*$", "now is the time for all good men to come to the aid of the party"); return 0; } Error message: regex.cpp: In function ‘void print_captures(const std::string&, const std::string&)’: regex.cpp:20: error: ‘class boost::smatch’ has no member named ‘captures’ regex.cpp:26: error: ‘class boost::smatch’ has no member named ‘captures’ How can i avoid that. Please help me. -- View this message in context: http://www.nabble.com/How-to-compile-boost-regex-tp25447212p25447212.html Sent from the Boost - Users mailing list archive at Nabble.com.

3 4

Re: [Boost-users] PBGL vs (Parallel) BGL-VTK
by Randy Heiland 18 Sep '09

18 Sep '09

On Sep 17, 2009, at 1:19 PM, Jeff Baumes wrote: >> Just out of curiosity what are the main differences in between PBGL >> and (Parallel) BGL-VTK ? What I am looking for is why not use PBGL >> directly ? What was the actual issue ? > > The goal of PBGL in VTK is to integrate PBGL with VTK's data > structures and pipeline model. It includes a wrapper around PBGL > algorithms to conveniently use them from VTK, along with extending > vtkGraph to be an implementation of PBGL concepts. > > Will/Randy may have more to say about it. > > Jeff Jeff has summarized nicely. I'd only add that we've not wrapped all of the PBGL algs yet. -Randy

2 1

[mpi] enviroment constructor different from MPI_Init
by alfC 18 Sep '09

18 Sep '09

I am using MPI in combination with BLACS and apparently it works with MPI_Init but not with boost.MPI when I use #include "blacs.h" int main(int argc, char* argv[]) { MPI_Init(&argc,&argv); int nprocs=0; int mype=0; Cblacs_pinfo( &mype, &nprocs ); // overwrites the pointee, that is how Cblacs_pinfo works std::cout<<mype<<" "<<nprocs<<std::endl; the program output (correctly): "0 1" But when I use boost::mpi::environment env(argc, argv); //instead of MPI_Init(argc, argv); the programs outputs (incorrectly): "0 -1". The point being that apparently boost::mpi::environment is not equivalent to MPI_Init/MPI_Finalize. Any idea of what is difference between MPI_Init and boost::mpi::environment? Thank you, Alfredo

4 5

Having trouble with a callback function (converted to a class) in Regex
by Ramon F Herrera 18 Sep '09

18 Sep '09

Hello, This is my first non-trivial, multi-file C++ program with classes and I bumped into a problem. See example from the Regex library below. The problem occurred after I converted the simple code below to a class (called "Pairs"). The troublesome statement is this one, where we attempt to take the address of a function. std::for_each(m1, m2, &regex_callback); My first compilation attempt produces an error message from the compiler, which is nice enough to offer a solution: pairs.cpp:247: error: ISO C++ forbids taking the address of an unqualified or parenthesized non-static member func tion to form a pointer to member function. Say `&Pairs::assignment_callback' So, following the compiler's suggestion, I changed the line above to this: std::for_each(m1, m2, &Pairs::assignment_callback); Now, I am getting an inscrutable (for me, anyway) error message: stl_algo.h:158: error: must use .* or ->* to call pointer-to-member function in `__f (...)' Thanks for your kind assistance, -Ramon =================================================== int main(int argc, const char** argv) { std::string text; for(int i = 1; i < argc; ++i) { cout << "Processing file " << argv[i] << endl; std::ifstream fs(argv[i]); load_file(text, fs); // construct our iterators: boost::sregex_iterator m1(text.begin(), text.end(), expression); boost::sregex_iterator m2; std::for_each(m1, m2, &regex_callback); // copy results: cout << class_index.size() << " matches found" << endl; map_type::iterator c, d; c = class_index.begin(); d = class_index.end(); while(c != d) { cout << "class \"" << (*c).first << "\" found at index: " << (*c).second << endl; ++c; } class_index.erase(class_index.begin(), class_index.end()); } return 0; }

2 2

[units] Proposal for generalizing scales
by Manoj Rajagopalan 17 Sep '09

17 Sep '09

Hi boost::units developers I am interested in extending the scale system for units. Here I present a short explanation, my initial hack to get this working, and questions on a small re-engineering issue that will crop up if this proposal is accepted. *** WHY *** Existing boost-units code allows scales which have factors as integral powers of a base, b^e, eg. 10^3, 2^10 etc. I'd like to use scales that have factors of the form a*b^e, Examples: (a) electron-Volt (eV) = 1.602*10^{-19} J (b) bohr = 0.528 Angstroms = 5.28*10^{-11} m In quantum chemistry, for example, such an "atomic units system" is typically used. *** HOW *** To achieve this using templates (which don't (yet) recognize floating point constants), I borrowed the idea from the 'dimnum' package. I, (1) added two more parameters of type long to the scale<> template which are the numerator and denominator of the rational approximation to a, (2) added static const value_type factor() member function which returns the value 'a' evaluated as double, (3) modified the value() static member to return factor() * b^e instead of simply b^e --------------- Code snippet (scale.hpp): template<long Base, class Exponent, long FactorNumerator=1L, long FactorDenominator=1L> struct scale { // ... static const double factor() { return double(FactorNumerator)/double(FactorDenominator); } static value_type value() { return(factor() * detail::static_rational_power<Exponent>(static_cast<double>(base))); } // ... }; ---------------- I modified the defintion of the apply<> template class in the boost::mpl::plus_impl, boost::mpl::negate_impl classes in unscale.hpp so that the scale<> return template-type now includes the correct FactorNumerator and FactorDenominator results based on the operands. This seems to be the place where arithmetic on scales is being performed for inter-conversion of quantities. I couldn't modify boost::mpl::times_impl because I'd have to statically exponentiate the numerator/denominator here and this doesn't fit cleanly into the existing mechanism. *** WHAT *** I do have the following questions/observations - please answer/comment. 1. The current implementation assumes that the scales being multiplied have the same base and differ only in the exponent? I just see T0::base being copied as the new base. This can be fixed with the generalized scale approach where if the bases are different (eg. 2 and 10), the resulting base is a default (10?) with exponent=static_rational<0,1> and a new factor f=(2^e1)*(10^e2). Of course, this will work only if there are no overflows. A conceivable use-case for this feature is when calculating, say, price-per-GB that is incurred in setting up a data-center. $<--->c interconversion will require 10^2 scale along the currency dimension while MB<--->GB<--->TB interconversions will require 2^10 scale along the memory dimension (assume they can be created). Here, currency interconversion will necessitate a generalized scale. 2. For simple scales like the existing one, multiplication of scales leads to addition of the exponents and therefore I can understand the static-overload of the plus_impl template to allow MPL to add the exponents. But with generalized scales we will have to switch to a different mechanism. Could you advise me on what all will need to be changed? I have a fair idea and I could use your input to cross-check. 3. When I complete this, can I submit the patch? I would like to add the atomic units system to the existing list of systems http://en.wikipedia.org/wiki/Atomic_units thanks, Manoj

2 3

hash<pair<...
by John Dlugosz 17 Sep '09

17 Sep '09

I just moved a project that was using VC8, with TR1 supplied via BOOST, to VC9 with its own TR1 implementation. I was surprised that a unordered_map failed to compile with a great deal of verboseness because it didn't like my key type. I used a pair of two primitive types as the key. Boost took that just fine. But looking at the current Boost documentation for the hash object, (<http://www.boost.org/doc/libs/1_40_0/doc/html/boost_tr1/subject_list.html#b…>) I see that the hash specializations include primitive types, strings, but not tuples. Is this something that changed between Boost 1_38 and 1_40, or an undocumented extension, or what? Why would the standard leave out that, when everyone and his neighbor will just supply their own generic definition. That is, is there a good reason for not doing it? --John TradeStation Group, Inc. is a publicly-traded holding company (NASDAQ GS: TRAD) of three operating subsidiaries, TradeStation Securities, Inc. (Member NYSE, FINRA, SIPC and NFA), TradeStation Technologies, Inc., a trading software and subscription company, and TradeStation Europe Limited, a United Kingdom, FSA-authorized introducing brokerage firm. None of these companies provides trading or investment advice, recommendations or endorsements of any kind. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.

2 2

boost multi-index container find method.
by Ramesh 17 Sep '09

17 Sep '09

Hello Joaquin, I have a class like below that uses mult-index container's find method. I have a record pattern as below initially: Idx : 100 Flag : 5 Idx : 200 Flag : 5 Idx : 300 Flag : 5 Idx : 400 Flag : 5 I modify the flag for index 100 to 6 & take a dump, the change is OK Idx : 100 Flag : 6 Idx : 200 Flag : 5 Idx : 300 Flag : 5 Idx : 400 Flag : 5 I modify the flag for 100 back to 5 and take a dump, which is also fine. Idx : 100 Flag : 5 Idx : 200 Flag : 5 Idx : 300 Flag : 5 Idx : 400 Flag : 5 Now I do a find based on flag value set to 5 I get the results as below: Idx : 200 flag : 5 While find functionally is correct in picking up the correct data, but I am wondering why it doesnt pick the first record (100) which has the flag value set to 5? am I missing something in the indexing definition in the container itself? Thanks /R ========================= using namespace std; #include <boost/lambda/lambda.hpp> #include <boost/multi_index_container.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/member.hpp> #include <iostream> #include <iterator> #include <iostream> #include <string> struct Token { unsigned long mIdx; unsigned char mflag; public: Token(unsigned long pIdx, unsigned char pflag): mIdx(pIdx), mflag(pflag){} void Update(unsigned char pflag) { mflag = pflag; } ~Token() { mIdx = 0; mflag = 1; } }; struct mIdx{}; struct mflag{}; using namespace boost::multi_index; namespace ll = boost::lambda; typedef multi_index_container< Token, indexed_by< ordered_unique< tag <mIdx>, BOOST_MULTI_INDEX_MEMBER(Token,unsigned long,mIdx)>, ordered_non_unique< tag <mflag>, BOOST_MULTI_INDEX_MEMBER(Token,unsigned char,mflag)> > > tToken; class TokenMaster { tToken TokenContainer; public: unsigned long getByFlag(unsigned long useFlag); bool modify(unsigned long idx, unsigned char flag); bool insert(unsigned long, unsigned char); void dump(); }; unsigned long TokenMaster::getByFlag(unsigned long useFlag) { typedef tToken::index<mflag>::type itflag; itflag& mflag_index = TokenContainer.get<mflag>(); tToken::index_iterator<mflag>::type flagit = mflag_index.find(useFlag); if (flagit == mflag_index.end()) { return 0; } printf("Idx : %d flag : %d\n", flagit->mIdx, flagit->mflag); return flagit->mIdx; } bool TokenMaster::modify(unsigned long idx, unsigned char flag) { tToken::iterator itIp=TokenContainer.find(idx); if (itIp == TokenContainer.end()) return false; return TokenContainer.modify(itIp,(&ll::_1)->*&Token::mflag=flag); } bool TokenMaster::insert(unsigned long idx, unsigned char flag) { tToken::iterator it; bool secres; std::pair<tToken::iterator, bool> result = TokenContainer.insert(Token(idx, flag)); it = result.first; secres = result.second; if (secres) return true; else return false; } void TokenMaster::dump() { unsigned long count = 0; printf("\n\n List of indexes\n"); for (tToken::iterator it = TokenContainer.begin(), it_end=TokenContainer.end(); it != it_end; ++it, count++) { printf("Idx : %d Flag : %d\n", it->mIdx, it->mflag); } printf("\n"); } main() { TokenMaster T1; T1.insert(100, 5); T1.insert(200, 5); T1.insert(300, 5); T1.insert(400, 5); T1.dump(); printf("Modifiying 100 to 6\n"); T1.modify(100, 6); T1.dump(); printf("Modifiying 100 back to 5\n"); T1.modify(100, 5); T1.dump(); printf("\n\nGet by flag \n"); T1.getByFlag(5); } ==========================

3 6

using my sink to write to the file.
by Patel, Anand 17 Sep '09

17 Sep '09

Hello All, I have been trying to implement Sink device that I would like to use with boost::iostreams. I have used Sink class example and now I am trying to use that as my sink device for the stream object. char* file_name = "c:/devel/output/file_one.txt"; typedef container_sink <std::iostream> some_sink; stream<some_sink, std::char_traits<char>> my_file_stream; last line I get many errors as following: 1>c:\documents and settings\user\my documents\visual studio 2008\projects\filereaderwriter\sink.h(11) : error C2039: 'value_type' : is not a member of 'std::basic_iostream<_Elem,_Traits>' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\boost\boost_1_39\boost\iostreams\traits.hpp(176) : see reference to class template instantiation 'foobar::container_sink<Container>' being compiled 1> with 1> [ 1> Container=std::iostream 1> ] 1> c:\program files\boost\boost_1_39\boost\iostreams\traits.hpp(188) : see reference to class template instantiation 'boost::iostreams::detail::member_char_type<T>' being compiled 1> with 1> [ 1> T=foobar::container_sink<std::iostream> 1> ] 1> c:\program files\boost\boost_1_39\boost\iostreams\stream.hpp(108) : see reference to class template instantiation 'boost::iostreams::char_type_of<T>' being compiled 1> with 1> [ 1> T=some_sink 1> ] 1>c:\documents and settings\user\my documents\visual studio 2008\projects\filereaderwriter\sink.h(11) : error C2146: syntax error : missing ';' before identifier 'char_type' 1>c:\documents and settings\user\my documents\visual studio 2008\projects\filereaderwriter\sink.h(11) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int 1>c:\documents and settings\user\my documents\visual studio 2008\projects\filereaderwriter\sink.h(11) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int 1>c:\documents and settings\user\my documents\visual studio 2008\projects\filereaderwriter\sink.h(23) : error C2061: syntax error : identifier 'char_type' 1>c:\program files\boost\boost_1_39\boost\iostreams\traits.hpp(176) : error C2039: 'char_type' : is not a member of 'foobar::container_sink<Container>' 1> with 1> [ 1> Container=std::iostream 1> ] 1>c:\program files\boost\boost_1_39\boost\iostreams\traits.hpp(176) : error C2146: syntax error : missing ';' before identifier 'type' 1>c:\program files\boost\boost_1_39\boost\iostreams\traits.hpp(176) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int 1>c:\program files\boost\boost_1_39\boost\iostreams\traits.hpp(176) : error C2208: 'boost::type' : no members defined using this type 1>c:\program files\boost\boost_1_39\boost\iostreams\traits.hpp(176) : fatal error C1903: unable to recover from previous error(s); stopping compilation Thanks,

2 3

Interprocess condition and process crashes
by Gabriel Burca 17 Sep '09

17 Sep '09

I'm using Boost 1.39 on WindowsXP and I noticed that if a process crashes while waiting on an interprocess condition variable, the signaling process blocks forever in subsequent calls to notify_all(). It looks to me like boost is not using the native facilities, but some emulation, so is this scenario not supported by the emulation? The code is very simple: Process A: while (1) { { scoped_lock<named_mutex> lock(mut); cond.wait(lock); // Process A might be killed or die while in this call // do some work } } Process B: void notifyOthers() { scoped_lock<named_mutex> lock(mut); cond.notify_all(); } I've actually omitted one small detail in the description above. After process A dies, process B can execute notifyOthers() again only once. The second time it never makes it out of the notify_all(). -- Gabriel Burca

2 1

BGL: Very dense adjacency_matrix
by Mathieu Malaterre 17 Sep '09

17 Sep '09

Hi there, Has anyone worked on very dense graph ? Basically the relation is implicitly given by the position in the grid: Eg, consider the following structured grid A B C D E F G H I it would lead to the following (undirected) graph: Graph g(9); add_edge(A, B, g); add_edge(A, D, g); add_edge(B, C, g); add_edge(B, E, g); add_edge(C, F, g); add_edge(D, E, g); add_edge(D, G, g); add_edge(E, F, g); add_edge(E, H, g); add_edge(F, I, g); add_edge(G, H, g); add_edge(H, I, g); When the structured grid is full (no broken link) I would think there are better data structure (ie. no data at all) suited to represent the graph. And as we break link (say, edge(A,B)), we would use an opposite definition of adjacency_list, to list what edge is actually *missing*. As far as I know adjacency_matrix is not implemented in PBGL, so I'll need to work around that issue /real time soon/. Thanks for your help, -- Mathieu

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PBGL vs (Parallel) BGL-VTK
by Mathieu Malaterre 17 Sep '09

17 Sep '09

Just out of curiosity what are the main differences in between PBGL and (Parallel) BGL-VTK ? What I am looking for is why not use PBGL directly ? What was the actual issue ? Thanks, -- Mathieu

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Multiple async operations on a socket
by Kyle Tarplee 17 Sep '09

17 Sep '09

I have a rather simple question that I can't find in the boost::asio documentation. I have a boost::asio::ip::tcp::socket that I want to write to. Can I have multiple outstanding async_write() requests for a single socket? Are the writes performed in the order in which they are submitted? Or is this undefined behavior? How about multiple async_read() requests on the same socket? I know that I need to write to the socket from at most one thread but that doesn't preclude me from not waiting until the first one is done to put on the second async write or read. The reason I ask is because there seems to be two ways to write data to a socket. 1) The "fire and forget" approach (no queue, simply call async_write() when you want to write and ignore the completion handler callback) 2) Push on a queue when you want to write something. Pop from the queue when the preceeding async_write() operation completed. Thus at most one async_write() operation is associated with the socket at any point in time. Thanks in advance, Kyle

4 6

quaternion component access
by gtsml owevwr 17 Sep '09

17 Sep '09

Hi, Is there a way to set a boost::math::quaternion on an component basis? Also, is there to randomly access an component (operator [])? Finally, the current way to access compenents looks a bit too long to me: "R_component_1()". Is there a shorter way? Thanks, Frank

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Re: [Boost-users] building boost 1_33_1 now 1_37_0
by Dan Smithers 17 Sep '09

17 Sep '09

> Message: 1 > Date: Wed, 16 Sep 2009 17:04:46 +0400 > From: Vladimir Prus <vladimir(a)codesourcery.com> > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] building boost 1_33_1 now 1_37_0 > Message-ID: <h8qnpe$j3a$1(a)ger.gmane.org> > Content-Type: text/plain; charset=us-ascii > > Dan Smithers wrote: > >>>> How do I change the includes in jam? >>> Sorry, I don't understand the above. Boost.Build does not pass any >>> "intel includes" nor any "gcc 2.95 includes". Can you provide the commands >>> lines and errors in question and explain how exactly the command lines >>> should be altered. >> I've now found that as long as I make sure that gcc 3.4.3 is ahead of >> 2.95 in the search path I can get past the first hurdle. > > So, is there anything that still needs to be solved? > >> The command line that comes out is >> >> "icpc" -c -xc++ -O3 -Ob2 -w1 -fPIC -DBOOST_ALL_NO_LIB=1 >> -DBOOST_MATH_TR1_DYN_LINK -DNDEBUG -I"." -c -o >> "bin.v2/libs/math/build/intel-linux-release/threading-multi/hypot.o" >> "libs/math/build/../src/tr1/hypot.cpp" >> >> /usr/lib/pthread.h(163): error: expected a ")" >> extern int pthread_create(pthread_2 *__restrict __thread, > > Do you actually have file named /usr/lib/pthread.h? That is very strange > location for a header file. > >> I have written a short test program that includes pthread.h and that >> compiles. > > Anyway, it does not seem like anything wrong is passed to icpc. So, > this error suggests that it's not installed correctly, or some other > configuration issue. Do docs for the intel compiler say anything about > gcc version that is required? Update - I have managed to get this file (hypot.cpp) to build using the Intel 8 compiler. I wonder what they changed? thanks for your help dan

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[serialization] some of the serialization docs are infected with a random single quote replacement
by Todd Day 17 Sep '09

17 Sep '09

The following files have a single character replaced by a ' (that's a single quote) at a fairly regular interval. This is in the latest trunk via SVN. serialization.html - Changeset 56240 special.html - Changeset 44743 traits.html - Changeset 55676

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[serialization] 1.40.00 BOOST_CLASS_EXPORT_GUID creates memory leak
by Todd Day 17 Sep '09

17 Sep '09

MSVC 8.0 BOOST_CLASS_EXPORT_GUID is used to create some static objects for using in serialization. These memory errors are not too big a deal since they aren't runaway - ie, these objects are created at startup before main() is even called, and the objects are not created over and over again. They are just not deleted at program exit, which causes my debugger to complain about memory leaks. I tracked the source of these leaks to two spots in the code. Unfortunately, the code is so complicated at these points that I can't suggest a fix or workaround. Hopefully, the maintainers know what this is about. The first leak is created in \boost_1_40_0\boost\smart_ptr\detail\shared_count.hpp line @ line 124 pi_ = new sp_counted_impl_pd<P, D>(p, d); I could be wrong, but it appears to me that the above problem only occurs for serialized objects that are derived from other objects at least twice. For example, if B is derived from A, and C is derived from B, then BOOST_CLASS_EXPORT_GUID(B, "B") BOOST_CLASS_EXPORT_GUID(C, "C") results in a memory leak for C, but not for B. I think, at least it looks that way. The second leak is created in \boost_1_40_0\libs\serialization\src\void_cast.cpp @ line 205 if(* (*it)->m_derived == * m_base) new void_caster_shortcut( m_derived, (*it)->m_base, m_difference + (*it)->m_difference, includes_virtual_base ); Again, it appears the these leaks only happen for classes which are derived at least twice. The above allocations are not deleted at shutdown. In the second case, it almost appears to me as if a registration function is accidentally getting called twice, and a pointer is getting set first to one allocation and then to a second allocation, which means the first allocation is lost track of. Thanks for any help, -todd- PS - Just pulled down the latest trunk from SVN. It appears that many changes in the areas I've mentioned above have occurred, so maybe this issue is fixed. If so, I'm hoping I can just pull over the include and source file changes made to the serialization library by themselves, but I don't know if those changes rely on other changes in other Boost libraries.

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Re: [Boost-users] building boost 1_33_1 now 1_37_0
by Dan Smithers 17 Sep '09

17 Sep '09

> > Message: 1 > Date: Wed, 16 Sep 2009 17:04:46 +0400 > From: Vladimir Prus <vladimir(a)codesourcery.com> > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] building boost 1_33_1 now 1_37_0 > Message-ID: <h8qnpe$j3a$1(a)ger.gmane.org> > Content-Type: text/plain; charset=us-ascii > > Dan Smithers wrote: > >>>> How do I change the includes in jam? >>> Sorry, I don't understand the above. Boost.Build does not pass any >>> "intel includes" nor any "gcc 2.95 includes". Can you provide the commands >>> lines and errors in question and explain how exactly the command lines >>> should be altered. >> I've now found that as long as I make sure that gcc 3.4.3 is ahead of >> 2.95 in the search path I can get past the first hurdle. > > So, is there anything that still needs to be solved? > >> The command line that comes out is >> >> "icpc" -c -xc++ -O3 -Ob2 -w1 -fPIC -DBOOST_ALL_NO_LIB=1 >> -DBOOST_MATH_TR1_DYN_LINK -DNDEBUG -I"." -c -o >> "bin.v2/libs/math/build/intel-linux-release/threading-multi/hypot.o" >> "libs/math/build/../src/tr1/hypot.cpp" >> >> /usr/lib/pthread.h(163): error: expected a ")" >> extern int pthread_create(pthread_2 *__restrict __thread, > > Do you actually have file named /usr/lib/pthread.h? That is very strange > location for a header file. no, it's in /usr/include I am working on a computer that is not connected to the internet and had type the email. > >> I have written a short test program that includes pthread.h and that >> compiles. > > Anyway, it does not seem like anything wrong is passed to icpc. So, > this error suggests that it's not installed correctly, or some other > configuration issue. Do docs for the intel compiler say anything about > gcc version that is required? Nothing wrong is passed, but it doesn't compile. I don't have this problem building the non-boost code. thanks dan

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Re: [Boost-users] Finding documentation for individual functions (uintmax_t)? An answer.
by s seelenluft 17 Sep '09

17 Sep '09

> in which library do I find documentation for the 'function': uintmax_t? > Since uintmax_t is such ubiquitous any search finds everything except its > actual description. Some more googling found the answer here: http://www.dinkumware.com/manuals/default.aspx Does such an equivalent, ie, a search function for functions/types only and not which does a full-text search, exist for Boost?

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Finding documentation for individual functions (uintmax_t)?
by s seelenluft 17 Sep '09

17 Sep '09

Hi, in which library do I find documentation for the 'function': uintmax_t? Since uintmax_t is such ubiquitous any search finds everything except its actual description. Thanks, Markus

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How to convert std::string into basic_string
by manish4gupta 17 Sep '09

17 Sep '09

#include <boost/interprocess/managed_shared_memory.hpp> #include <boost/interprocess/allocators/allocator.hpp> #include <boost/interprocess/containers/map.hpp> How to convert std::string into boost string. I am doing some benchmarking by inserting the std::string value instead of char_string(ypedef of basic_string) but i am getting error message. #include <boost/interprocess/containers/vector.hpp> #include <boost/interprocess/containers/string.hpp> #include <iostream> using namespace boost::interprocess; //Typedefs of allocators and containers typedef managed_shared_memory::segment_manager segment_manager_t; typedef allocator<void, segment_manager_t> void_allocator; typedef allocator<int, segment_manager_t> int_allocator; typedef vector<int, int_allocator> int_vector; typedef allocator<int_vector, segment_manager_t> int_vector_allocator; typedef vector<int_vector, int_vector_allocator> int_vector_vector; typedef allocator<char, segment_manager_t> char_allocator; typedef basic_string<char, std::char_traits<char>, char_allocator> char_string; class complex_data { int id_; char_string char_string_; int_vector_vector int_vector_vector_; public: //Since void_allocator is convertible to any other allocator<T>, we can simplify //the initialization taking just one allocator for all inner containers. complex_data(int id, const char *name, const void_allocator &void_alloc) : id_(id), char_string_(name, void_alloc), int_vector_vector_(void_alloc) {} //Other members... }; //Definition of the map holding a string as key and complex_data as mapped type typedef std::pair<const char_string, int> map_value_type; typedef std::pair<char_string, int> movable_to_map_value_type; typedef allocator<map_value_type, segment_manager_t> map_value_type_allocator; typedef map< char_string, int , std::less<char_string>, map_value_type_allocator> complex_map_type; int main () { //Remove shared memory on construction and destruction struct shm_remove { shm_remove() { shared_memory_object::remove("MySharedMemory"); } ~shm_remove(){ shared_memory_object::remove("MySharedMemory"); } } remover; //Create shared memory managed_shared_memory segment(create_only,"MySharedMemory", 65536); //An allocator convertible to any allocator<T, segment_manager_t> type void_allocator alloc_inst (segment.get_segment_manager()); //Construct the shared memory map and fill it complex_map_type *mymap = segment.construct<complex_map_type> //(object name), (first ctor parameter, second ctor parameter) ("MyMap")(std::less<char_string>(), alloc_inst); string s = "hello"; char y = (char_string)s; for(int i = 0; i < 100; ++i) { char_string key_object(alloc_inst); map_value_type value(key_object, i); mymap->insert(value); } return 0; } error: no matching function for call to ‘boost::interprocess_container::basic_string<char, std::char_traits<char>, boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0u>, boost::interprocess::iset_index> > >::basic_string(boost::interprocess_container::string&)’ /usr/include/boost/interprocess/containers/container/string.hpp:591: note: candidates are: boost::interprocess_container::basic_string<CharT, Traits, Alloc>::basic_string(typename A::size_type, CharT, const A&) [with CharT = char, Traits = std::char_traits<char>, A = boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0u>, boost::interprocess::iset_index> >] /usr/include/boost/interprocess/containers/container/string.hpp:584: note: boost::interprocess_container::basic_string<CharT, Traits, Alloc>::basic_string(const CharT*, const A&) [with CharT = char, Traits = std::char_traits<char>, A = boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0u>, boost::interprocess::iset_index> >] /usr/include/boost/interprocess/containers/container/string.hpp:577: note: boost::interprocess_container::basic_string<CharT, Traits, Alloc>::basic_string(const CharT*, typename A::size_type, const A&) [with CharT = char, Traits = std::char_traits<char>, A = boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0u>, boost::interprocess::iset_index> >] /usr/include/boost/interprocess/containers/container/string.hpp:564: note: boost::interprocess_container::basic_string<CharT, Traits, Alloc>::basic_string(const boost::interprocess_container::basic_string<CharT, Traits, Alloc>&, typename A::size_type, typename A::size_type, const A&) [with CharT = char, Traits = std::char_traits<char>, A = boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0u>, boost::interprocess::iset_index> >] /usr/include/boost/interprocess/containers/container/string.hpp:557: note: boost::interprocess_container::basic_string<CharT, Traits, Alloc>::basic_string(boost::interprocess::rv<boost::interprocess_container::basic_string<CharT, Traits, Alloc> >&) [with CharT = char, Traits = std::char_traits<char>, A = boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0u>, boost::interprocess::iset_index> >] /usr/include/boost/interprocess/containers/container/string.hpp:548: note: boost::interprocess_container::basic_string<CharT, Traits, Alloc>::basic_string(const boost::interprocess_container::basic_string<CharT, Traits, Alloc>&) [with CharT = char, Traits = std::char_traits<char>, A = boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0u>, boost::interprocess::iset_index> >] /usr/include/boost/interprocess/containers/container/string.hpp:539: note: boost::interprocess_container::basic_string<CharT, Traits, Alloc>::basic_string(const A&) [with CharT = char, Traits = std::char_traits<char>, A = boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0u>, boost::interprocess::iset_index> >] /usr/include/boost/interprocess/containers/container/string.hpp:532: note: boost::interprocess_container::basic_string<CharT, Traits, Alloc>::basic_string(boost::interprocess_container::basic_string<CharT, Traits, Alloc>::reserve_t, size_t, const A&) [with CharT = char, Traits = std::char_traits<char>, A = boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0u>, boost::interprocess::iset_index> >] Thanks in advance. -- View this message in context: http://www.nabble.com/How-to-convert-std%3A%3Astring-into-basic_string-tp25… Sent from the Boost - Users mailing list archive at Nabble.com.

5 14

boost concept to make int template parameter available at runtime?
by Sebastian Weber 17 Sep '09

17 Sep '09

Hi! I am wondering if some boost library (like fusion) or similar may help me solve an awkward problem. In principle I have a class which has an int template parameter, for example: template <int VAL> class A { void print_val() { std::cout << "my value is " << VAL << std::endl; } }; Now I want to make the parameter VAL of class A available at runtime (of course only a limited range, but still), like this class Aruntime { void set_val(int v) { val = v; } int val; ... and again same stuff from A<val> ... }; I am sure there is an easy solution to it. One solution would be to use an object factory, I guess. There I would register for each integer the respective class A which I had to wrap into some other class in order to get rid of the template parameter and virtualize the print_val function. This may not be a boost-problem directly, but any help would be great. Thanks a lot, Sebastian

2 2

error in getting shared vector
by manish4gupta 17 Sep '09

17 Sep '09

I am woking on IPC shared memory where i am loading one vector in memory by process1 and using the same with another program. but in process2 i am getting one error whie this code is same as given http://www.boost.org/doc/libs/1_38_0/doc/html/interprocess/quick_guide.html…. I am just doing benchmarking. May i know what is the reason behind this? Process1. #include <boost/interprocess/managed_shared_memory.hpp> #include <boost/interprocess/containers/vector.hpp> #include <boost/interprocess/allocators/allocator.hpp> int main () { using namespace boost::interprocess; try{ //Shared memory front-end that is able to construct objects //associated with a c-string. Erase previous shared memory with the name //to be used and create the memory segment at the specified address and initialize resources shared_memory_object::remove("MySharedMemory"); managed_shared_memory segment (create_only ,"MySharedMemory" //segment name ,65536); //segment size in bytes //Alias an STL compatible allocator of ints that allocates ints from the managed //shared memory segment. This allocator will allow to place containers //in managed shared memory segments typedef allocator<int, managed_shared_memory::segment_manager> ShmemAllocator; //Alias a vector that uses the previous STL-like allocator typedef vector<int, ShmemAllocator> MyVector; //Initialize shared memory STL-compatible allocator const ShmemAllocator alloc_inst (segment.get_segment_manager()); //Construct a shared memory MyVector *myvector = segment.construct<MyVector>("MyVector") //object name (alloc_inst);//first ctor parameter //Insert data in the vector for(int i = 0; i < 100; ++i){ myvector->push_back(i); } } catch(...){ shared_memory_object::remove("MySharedMemory"); throw; } shared_memory_object::remove("MySharedMemory"); return 0; } Process2 #include <boost/interprocess/managed_shared_memory.hpp> #include <boost/interprocess/containers/vector.hpp> #include <boost/interprocess/allocators/allocator.hpp> #include <algorithm> #include <iostream> int main () { using namespace boost::interprocess; try{ //A special shared memory where we can //construct objects associated with a name. //Connect to the already created shared memory segment //and initialize needed resources managed_shared_memory segment (open_only ,"MySharedMemory"); //segment name //Alias an STL compatible allocator of ints that allocates ints from the managed //shared memory segment. This allocator will allow to place containers //in managed shared memory segments typedef allocator<int, managed_shared_memory::segment_manager> ShmemAllocator; //Alias a vector that uses the previous STL-like allocator typedef vector<int, ShmemAllocator> MyVector; //Find the vector using the c-string name MyVector *myvector = segment.find<MyVector>("MyVector").first; for (MyVector::iterator it = myvector->begin(); it!=myvector->end(); it++) { std::cout << *it << "\n"; } //Use vector in reverse order std::sort(myvector->rbegin(), myvector->rend()); // . . . //When done, destroy the vector from the segment segment.destroy<MyVector>("MyVector"); } catch(...){ shared_memory_object::remove("MySharedMemory"); throw; } shared_memory_object::remove("MySharedMemory"); return 0; } Error Message: terminate called after throwing an instance of 'boost::interprocess::interprocess_exception' what(): No such file or directory Aborted -- View this message in context: http://www.nabble.com/error-in-getting-shared-vector-tp25485820p25485820.ht… Sent from the Boost - Users mailing list archive at Nabble.com.

1 0

Concerning kolmogorov_max_flow
by townofpig Mei Ting 17 Sep '09

17 Sep '09

Hello, I am the newbie in Boost. I am actually not quite familiar with C++ but I have to employ source code for implementing kolmogorov_max_flow. When I am trying to find the input of the kolmogorov-eg.cpp, I know there is a max_flow.dat as input. However, I want to know if it is possible for me to change the input values of weight of the arcs in the graph. Where can I change it? I've spent a lot of time to find but I can't since I am really not so good at programming. Looking to forward to your replies~~ Yahoo!香港提供網上安全攻略，教你如何防範黑客! 請前往 http://hk.promo.yahoo.com/security/ 了解更多!

1 0