July 2015 - Boost-users - lists.preview.boost.org

Structure size when compiling with and without -std=c++11
by Miloslav Marik 03 Aug '15

03 Aug '15

Hi, I would like to share my experience with boost when combining with c++11. I hope it might help someone. Suppose a simple program: #include <boost/asio.hpp> #include <iostream> using boost::asio::detail::atomic_count; struct Test { // Whether the task has been interrupted. bool task_interrupted_; // The count of unfinished work. atomic_count outstanding_work_; }; int main () { std::cout << "Size is " << sizeof(Test) << std::endl; return 0; } And here is the story: $ /opt/gcc-4.8.4/bin/g++ -std=c++11 -I /opt/boost-1.58.0/include/ -L /opt/boost-1.58.0/lib -lboost_system b.cpp $ ./a.out Size is 16 $ /opt/gcc-4.8.4/bin/g++ -I /opt/boost-1.58.0/include/ -L /opt/boost-1.58.0/lib -lboost_system b.cpp $ ./a.out Size is 8 It means that c++11 program cannot be linked with boost libraries compiled without "-std=c++11" option. It was asio in my case and the program was linked with libboost_log.so.1.58.0. I would really appreciate a short warning somewhere at "Getting Started on Unix Variants" page. It may safe someone a few hours of life. Best Regards, Slavek

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Boost 1_59_0_b1_rc1 is available for testing
by Marshall Clow 02 Aug '15

02 Aug '15

Release candidate files for 1.59.0 beta 1 are available at http://boost.cowic.de/rc/ As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. This helps ensure the candidates build OK before we push them out to SourceForge. The files (and associated md5s) are: MD5 (boost_1_59_0_b1_rc1.7z) = f54a97e5ee7f8e3d04cd9af8396e30f9 MD5 (boost_1_59_0_b1_rc1.tar.bz2) = 9804305aae0c9de9f8cfc02e3de75167 MD5 (boost_1_59_0_b1_rc1.tar.gz) = e584770bd76885c123a0426d24466fe2 MD5 (boost_1_59_0_b1_rc1.zip) = ee34f223aa789a6b3f727cb9480651ed Thanks! -- The release managers

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Need sample for CMakelist.txt with BOOST.test
by Abhay Mhatre 01 Aug '15

01 Aug '15

Hi, I am newbie, and struggling with testing project that is build in CMakeList.txt for using Boost.Test. project builds successfully and runs too, only problem is when unit test fails BOOST_REQUIRE exits without printing fatal exception message on console. It also doesn't show next failure. I tired compiling same library with g++ command and everything works as expected. however with CMakeList project there is no output I tried setting explicit boost::unit_test::unit_test_log_t::instance().set_threshold_level(boost::unit_test::log_all_errors) also tried with setting # define BOOST_TEST_LOG_LEVEL all but there is no output except fatal error on console. also it doesn't show fatal error for multiple tests/ Can some one please suggest some way to investigate this further/ provide sample CMakeList.txt file that I can compare and see if I am missing anything thanks in advance, Abhay

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Map runtime value to type
by dariomt＠gmail.com 31 Jul '15

31 Jul '15

Hi all, Say I have a compile-time map of <value,type> pairs, and I need to access the correct element given a value at runtime and do something with that type. That something would be the same for any of the mapped types (e.g. calling an overloaded function that would then do the right thing depending on the type). The value would typically be an enum. Is there anything in the Boost libraries to help with this? If I used C++11, would there be a simple solution to this? Regards PS: I cannot use Boost.Variant

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Re: [Boost-users] output boost graph parallel issue
by Mayank Bakshi 31 Jul '15

31 Jul '15

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output boost graph parallel issue
by Mayank Bakshi 31 Jul '15

31 Jul '15

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[Asio] [Boost.ASIO] async_read cannot read full data from client
by Sarvagya Pant 30 Jul '15

30 Jul '15

** I have a server created using Boost.ASIO (thanks to sehe from Stackoverflow). The server is supposed to received message from client, parse it as json and correspondingly send the message back to client. To make life easier, i have considered very simple cases: (i) Client can send {"hello":"client"}, server should send response {"hello":"server"} (ii) Client can send {"message" : "Some Message"}, server should send {"response" : "OK"} The server runs, accepts data from client but cannot call the handler of async_read. The doc states that The asynchronous operation will continue until one of the following conditions is true: 1. The supplied buffers are full. That is, the bytes transferred is equal to the sum of the buffer sizes. 2. An error occurred. I think in my case the buffer is not full, thus the handler function is not getting called. How should I change my code so that server can read the message sent by client, process it and send back correct response.? PS: If the code is not attached, http://pastebin.com/pi192t6i is the link to file. *-- Sarvagya PantKathmandu, Nepal+9779803468257*

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how to know which xml_iarchive is parsing
by breadbread1984 30 Jul '15

30 Jul '15

my program serializing and deserializing an object has some problem. I am debugging it. I found it was so hard to debug the code without knowing which line the xml_iarchive is parsing. Is there any way to know which line the xml_iarchive is working on? Thx!

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unsupported version problem of serialization of graph
by breadbread1984 30 Jul '15

30 Jul '15

I am using boost graph library. I can serialize the graph successfully. But when deserialized a graph from the file, an unsupported version exception was throwed out. I created a minimum runnable example and posted it [here] (http://www.rapidshare.com.cn/Bq95n2v) The serialized graph file is enclosed as well. The file is generated with the same version of graph library. Could anyone help me to find the problem? thx!

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problem of deserializing from a xml file
by breadbread1984 30 Jul '15

30 Jul '15

I am having problem deserializing from a file of a serialized object. An exception of input stream error always occurs. The class of the object is pasted [here] (http://pastebin.com/6XEBybWV) The xml file is pasted [here] (http://pastebin.com/e2Ka2kVH) I tried debugging the program. The top few frames of the back trace of the exception is as follows #0 0x00007f8f9be4c267 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:55 #1 0x00007f8f9be4deca in __GI_abort () at abort.c:89 #2 0x00007f8f9c76006d in __gnu_cxx::__verbose_terminate_handler() () from /usr/lib/x86_64-linux- gnu/libstdc++.so.6 #3 0x00007f8f9c75dee6 in ?? () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6 #4 0x00007f8f9c75df31 in std::terminate() () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6 #5 0x00007f8f9c75e149 in __cxa_throw () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6 #6 0x00007f8f9e661734 in void boost::serialization::throw_exception<boost::archive::archive_exception>(boost::archiv e::archive_exception const&) () from /usr/lib/x86_64-linux- gnu/libboost_serialization.so.1.55.0 #7 0x00007f8f9e67e2f7 in boost::archive::basic_xml_iarchive<boost::archive::xml_iarchive>::load_start(char const*) () from /usr/lib/x86_64-linux-gnu/libboost_serialization.so.1.55.0 #8 0x0000000000486ab4 in boost::archive::basic_xml_iarchive<boost::archive::xml_iarchive>::load_override<std::m ap<int, std::deque<Observation, std::allocator<Observation> >, std::less<int>, std::allocator<std::pair<int const, std::deque<Observation, std::allocator<Observation> > > > > > (this=0x7ffe12327440, t=...) at /usr/include/boost/archive/basic_xml_iarchive.hpp:85 It seems the problem occurs when the std::map<int, std::deque<Observation, std::allocator<Observation> > in Status is loaded. I can't step into frame #7 to checkout the detail of the exception. Could anyone give a hint of the problem. Thanks!

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