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boost bind, issue moving from 1.57 to 1.60
by Jason Mancini 16 Jun '16

16 Jun '16

Hello, The following minimized program works under 1.57 but no longer under 1.60, as the second bind results in calling of a member function with nullptr at run-time. Is the code mal-formed? Is it a boost bind bug? It still works fine with raw pointers, but no longer works correctly with boost::shared_ptr. Same result with gcc 4.8.1 and gcc 6.1.0 on Linux. Thanks, Jason ------------------- #include <stdio.h> #include <boost/shared_ptr.hpp> #include <boost/make_shared.hpp> #include <boost/bind.hpp> #include <boost/function.hpp> struct Boom { bool Oops() const { printf("Boom::Oops @ %p\n", this); return true; } }; int main() { boost::shared_ptr<const Boom> obj = boost::make_shared<Boom>(); using tMatcher = boost::function<bool(boost::shared_ptr<const Boom>)>; tMatcher Func = boost::bind(&Boom::Oops, _1); Func = boost::bind(Func, _1) && boost::bind(&Boom::Oops, _1); Func(obj); } ------------------- Expected output: Boom::Oops @ 0x11f6d79 Boom::Oops @ 0x11f6d79 Actual output: Boom::Oops @ 0x11f6d79 Boom::Oops @ (nil) -------------------

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Handling process termination
by Shaginesh P.K.(NeSTIT) 12 Jun '16

12 Jun '16

Hi All, I am using boost library for logger. Seems pretty good. Am using boost with asynchronous sink. Hence require a close down of sink explicitly. But this is not possible when process crashes. Do boost have any mechanism for the same (Like handling the signals of OS and like stack dumps)? What does boost prefer for unexpected termination of process where the logs will go out uncollected? Could you please help me out of this? Thanks and Regards Shaginesh PK ________________________________ Confidentiality Statement / Disclaimer : This message and any attachments is intended for the sole use of the intended recipient. It may contain confidential information. Any unauthorized use, dissemination or modification is strictly prohibited. If you are not the intended recipient, please notify the sender immediately then delete it from all your systems, and do not copy, use or print. Internet communications are not secure and it is the responsibility of the recipient to make sure that it is virus/malicious code exempt. The company/sender cannot be responsible for any unauthorized alterations or modifications made to the contents. If you require any form of confirmation of the contents, please contact the company/sender. The company/sender is not liable for any errors or omissions in the content of this message. ________________________________

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Re: [Boost-users] Another query on Boost DLL Library
by Leo Carreon 11 Jun '16

11 Jun '16

Please ignore this question, I found out the answer with a bit more understanding of the example. From: Leo Carreon Sent: Thursday, June 09, 2016 2:07 PM To: Boost Users Mailing List Subject: Another query on Boost DLL Library Hi, When using the factory method when creating a plugin, is it possible to pass an argument to the factory method? If yes, how? Kinds regards, Leo

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Trouble Updating Boost to run OpenFOAM
by Blair Climenhaga 10 Jun '16

10 Jun '16

Hello Everyone, I have recently begun using OpenFOAM which requires boost for some of its functions, however upon installing OpenFOAM it appears that some of the needed Boost contents are not in my usr/include/boost such as the directories container, move, intrusive, core and many others. I have attempted to update boost in multiple ways so that these directories are added to the boost directory however I have had no success. The two types of attempts I have made are listed below. 1. Using sudo apt-get install libboost-all-dev, however this seems to just update the lib and provide me with the needed directories 2. Download the .zip of the newest boost version and follow the steps listed on the boost website. I have been downloading and installing the files to a directory in the home rather than usr and it seems that the product is not on the Path of the computer, as it is does not appear when I use the echo or whereis commands. If anyone has any advice for how to solve this issue or any recommendations I would greatly appreciate the assistance. Thank you for your time and for your help in advance. All the best, Blair Climenhaga

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[boost] [thread] thread handling question
by Markus Pieper 09 Jun '16

09 Jun '16

Hi, this may be a very dumb question… My boost version is 1.56.0. In my program I use a database logging technique. To avoid blocking the main thread, I coded this: int main() { while(bDoCalculations == true) { // calculate some stuff m_Logger->doLogging(); } } void CLoggingData::doLogging() { std::vector<float>* Result; // fill Result boost::thread (&CLoggingData::doStoreData, this, Result); } void CLoggingData::doStoreData(std::vector<float>* dataVector) { // pass pointer to database writer instance delete dataVector; } I do not use join() in the doLogging method because I don’t want the main thread to block if the database is busy and will not respond immediately. But then, after a long run I get a boost::thread_resource_error exception. You may say: Of course, you never join your thread and after a few thousands new threads you blow your stack. Well, but what can I do to get my desired behavior? In the documentation I found this which I think of might help: You can use a thread_joiner to ensure that the thread has been joined at the thread destructor. int main() { boost::thread t(my_func); boost::thread_joiner g(t); // do someting else } // here the thread_joiner destructor will join the thread before it is destroyed. But where is the thread_joiner class implemented? Or do I have to add something inside my doStoreData method to end the thread properly? Thanks in advance, Markus Gesendet mit AquaMail für Android http://www.aqua-mail.com

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Another query on Boost DLL Library
by Leo Carreon 09 Jun '16

09 Jun '16

Hi, When using the factory method when creating a plugin, is it possible to pass an argument to the factory method? If yes, how? Kinds regards, Leo

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Re: [Boost-users] Query on Boost DLL Library
by Leo Carreon 09 Jun '16

09 Jun '16

After a bit more reading of the documentation, my understanding is std::shared_ptr can be used but not std::experimental::filesystem because boost::filesystem is an argument to boost::dll::import_alias. In light of this, can I request a revision to the Boost DLL Library. Can boost::filesystem be replaced with either std::experimental::filesystem or std::filesystem. whichever is available on the version of the compiler being used? The reason for this is so that there is only one version of the filesystem library to be used in your application. From: Leo Carreon Sent: Thursday, June 09, 2016 11:06 AM To: Boost Users Mailing List Subject: Query on Boost DLL Library Hi, In Boost DLL Library factory method example it uses boost::shared_ptr and boost::filesystem, can these be replaced by std::shared_ptr and std::experimental::filesystem? Kind regards, Leo

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Query on Boost DLL Library
by Leo Carreon 09 Jun '16

09 Jun '16

Hi, In Boost DLL Library factory method example it uses boost::shared_ptr and boost::filesystem, can these be replaced by std::shared_ptr and std::experimental::filesystem? Kind regards, Leo

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Re: [Boost-users] [boost] RFC : About forking a C++11 standard library and adapt it to C++98 compilers
by Vicente J. Botet Escriba 08 Jun '16

08 Jun '16

Le 06/06/2016 à 11:16, Joseph Van Riper a écrit : > On Thu, Jun 2, 2016 at 6:09 PM Vicente J. Botet Escriba < > vicente.botet(a)wanadoo.fr> wrote: > >> Hi, >> >> Some of us have to work yet with C++98 compiler at work (due to well >> know reasons) and this for a long time. This is a reality. >> >> I was wondering about forking a public domain C++11/14/17 standard >> library and adapt it to C++98 compilers. This library could be seen as >> another TR1, an extension of the C++03 standard library. >> >> Does this make any sens? Would this project be of interest for the >> Boost/C++ community? >> > Yes. At least for what we do where I work. > > The cyber-security field works with very old machines, either for forensics > (people forget they have some old machine until it gets hacked and some old > process that always "just worked" stops working), teaching (teaching old, > outmoded techniques helps to illustrate cyber security problems without > giving people tools for modern exploitation), or competitions. > > I kind of hate having to work with clunky, antediluvian C++ compilers that > magnify the level of woe required to deal with old machinery. Especially > while the rest of the C++ world moves on to the spiffy-shiny features found > in the later compilers. Having at least a library that helps us use some > of those nifty features can help us use our skills on more modern projects > when we move on to another job, while easing the efforts required to do our > work. A library wouldn't change your compiler ;-), but it could change the way you program :). > > Anyway, if you find that this will be useful to you at your work we will >> need your participation. Would you be interested in working on it? > > Hmmm... am I even knowledgeable enough? > > While I may find myself learning quite a lot about C++ by studying the > boost code people write, I am also humbled by what I see there. I fear I > am only beginning to dip into some of the intermediate meta-programming > techniques that seem to confer tremendous power to this language. > > as a Boost community project? >> outside Boost, as an independent project? >> > Hmmm... > > The boost 'brand' confers a certain gravitas. If you wish to maintain this > gravitas in the new library, I'd say keep the boost brand, but require the > same rigor. We have a License issue, so it couldn't be a Boost library :( Vicente P.S. Please, contact me privately if you are interested.

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[BGL] breadth_first_search with distance record and predecessors?
by The Maschine 06 Jun '16

06 Jun '16

Hi all, Im trying to cover the dijkstra_shortest_paths call I usually do with a BFS. Id like to get back the predecessors so I can rebuild the paths and the distance to each vertex. The dijkstra_shortest_paths work for me fine! I tried a couple of BFS calls but I always get errors. What am I missing? std::vector<Vertex> predecessors(boost::num_vertices(m_ugraph)); // To store parents std::vector<Weight> distances(boost::num_vertices(m_ugraph), std::numeric_limits<double>::max() ); // To store distances IndexMap indexMap = boost::get(boost::vertex_index, m_ugraph); PredecessorMap predecessorMap(&predecessors[0], indexMap); DistanceMap distanceMap(&distances[0], indexMap); boost::dijkstra_shortest_paths(m_ugraph, s_vertex, boost::predecessor_map(predecessorMap).distance_map(distanceMap).weight_map(boost::get(&EdgeProperties::m_weight, m_ugraph)) ); //breadth_first_search(m_ugraph, s_vertex, visitor( make_bfs_visitor( record_predecessors( &predecessors, on_tree_edge() ) ) ).vertex_index_map( identity_property_map() ).record_distances(&distances.begin(),boost::on_tree_edge()) ); //boost::breadth_first_search(m_ugraph, s_vertex, boost::visitor(boost::make_bfs_visitor(std::make_pair(boost::record_distances(&distances.begin(),boost::on_tree_edge()),boost::record_predecessors(&predecessors.begin(),boost::on_tree_edge{}))))); Thanks a lot!

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