October 2014 - Boost-users - lists.preview.boost.org

[interprocess] Determine size of managed_shared_memory
by Kai Benndorf 12 Oct '19

12 Oct '19

Hi all, I want to create a managed_shared_memory in exactly the size I needed. Therefore I do something like this: size = sizeof( common_managed_shared_memory ); size += sizeof( MyClassInSharedMem ); managed_shared_memory segment(create_only, "name", size ); MyClassInSharedMem allocates itself some memory by segment->allocate(). I added this also to the size, but get a boost::interprocess::bad_alloc exception on allocating this additional memory. Are there some magic bytes I forgot to add? Many thanks in advance Kai

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[Range, Phoenix] What am I missing...
by Robert Jones 25 Apr '17

25 Apr '17

Hi Folks Can anyone explain the output of this program... #include <iostream> #include <boost/range/algorithm/copy.hpp> #include <boost/range/counting_range.hpp> #include <boost/range/adaptor/reversed.hpp> #include <boost/range/adaptor/transformed.hpp> #include <boost/phoenix/bind/bind_function.hpp> #include <boost/phoenix/core/argument.hpp> int f( int i ) { return i * 2; } int main( ) { using boost::adaptors::reversed; using boost::adaptors::transformed; using boost::counting_range; using boost::copy; using boost::phoenix::arg_names::_1; copy( counting_range( 1, 5 ) | reversed | transformed( f ), std::ostream_iterator<int>( std::cout, " " ) ); std::cout << std::endl; copy( counting_range( 1, 5 ) | reversed | transformed( bind( f, _1 ) ), std::ostream_iterator<int>( std::cout, " " ) ); std::cout << std::endl; } Which is... 8 6 4 2 1768406272 1768406272 1768406272 1768406272 I'm using Gcc 4.6.2 & Boost 1.53 Thx All.

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[statechart] Passing parameters from event to State Local Storage
by Christophe Bourez 16 Nov '16

16 Nov '16

I need to maintain a parameter into the state local storage. This parameter is initially contained in the event that causes the transition to the target state. I give hereafter a small illustrative example. typename sc = boost::statechart; class EvTest : public sc::event<EvTest> { public: EvTest(std::size_t val) : value(val) {} std::size_t getValue() const { return this->value; } private: std::size_t value; }; class MyStateMachine; class StSource; class StTarget; class StSource : public sc::simple_state<StSource, MyStateMachine> { public: typedef sc::custom_reaction<EvTest> reactions; sc::result react(const EvTest &event) { // How to pass event.getValue() to the target state ? transit<StTarget>(); } }; class StTarget : public sc::simple_state<StTarget, MyStateMachine> { public: StTarget(std::size_t val) : val(value) {} private: std::size_t value; }; Thanks, Christophe

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Re: [Boost-users] lexical_cast between double and string slow in Visual Studio 2013
by David Roberts 07 May '15

07 May '15

> That issue is unknown. I'd really appreciate the investigation. I have done some more investigation, and there are two factors that only cause the slowness when they both occur together. > Try excluding the lexical_cast from test, I have a feeling that this is only MSVC related issue: > > #include <sstream> > #include <string> > > int main (int, char **) > { > for (double count = 0.0; count < 1000000.0; count += 1.41) > { > std::stringstream ss; > ss << count; > std::string result = std::move(ss.str()); > ss.str(std::string()); > > ss << result; > ss >> count; > } > > return 0; > } > Running your test program does not exhibit the problem. It runs in around 3 seconds on my machine when built with either Visual Studio 2010 or Visual Studio 2013. However, changing it very slightly to match more closely what lexical_cast does internally does recreate the problem: #include <sstream> #include <string> int main (int, char **) { for (double count = 0.0; count < 1000000.0; count += 1.41) { std::stringstream ss; ss.unsetf(std::ios::skipws); ss.precision(17); ss << count; std::string result = std::move(ss.str()); ss.str(std::string()); ss << result; ss >> count; } return 0; } The effect of setting the precision to 17 is that lots of 9s appear in the string representations. (The number 17 is what boost::detail::lcast_get_precision(double*) chooses.) Without the precision call the contents of the string called result start off like this: 0 1.41 2.82 4.23 5.64 7.05 8.46 9.87 11.28 12.69 With precision set to 17 they start off like this: 0 1.4099999999999999 2.8199999999999998 4.2299999999999995 5.6399999999999997 7.0499999999999998 8.4599999999999991 9.8699999999999992 11.279999999999999 12.69 This happens for both Visual Studio 2010 and Visual Studio 2013. Then the next difference is that Visual Studio 2013 spends a lot longer handling all the extra 9s. Changing the program so that the double is converted to a string using std::stringstream without a precision call and then back to double using lexical_cast takes about 3 seconds for both Visual Studio 2010 and Visual Studio 2013. It is the combination of having all the extra 9s to parse and using Visual Studio 2013 that makes the test using lexical_cast to go both ways slow. Both Visual Studio 2010 and Visual Studio 2013 do the conversion by calling std::num_get<char,std::istreambuf_iterator<char,std::char_traits<char> > >::do_get() which then calls a function called _Stodx() which is implemented in xstod.c. This function is very different for the two versions. In Visual Studio 2010 it's a relatively thin wrapper around the C function strtod(). In Visual Studio 2013 _Stodx() has got a completely new implementation that's generated by #including xxstod.h with some macros defined. The original C function strtod() is much faster than the new _Stodx() when there are lots of 9s at the end of the strings being parsed. This modification to the program: #include <sstream> #include <string> #include <stdlib.h> int main (int, char **) { for (double count = 0.0; count < 1000000.0; count += 1.41) { std::stringstream ss; ss.unsetf(std::ios::skipws); ss.precision(17); ss << count; std::string result = std::move(ss.str()); ss.str(std::string()); ss << result; char *endptr; count = strtod(ss.str().c_str(), &endptr); } return 0; } has a runtime of about 3 seconds even though it's got to cope with all the 9s. I guess only someone from Microsoft or Dinkumware could comment on why _Stodx() was reimplemented. But the other thing is that by setting precision to 17 lexical_cast is bloating the string representations of the doubles with lots of 9s in both Visual Studio 2010 and Visual Studio 2013. Setting precision to 15 instead prevents this, and makes the original test run faster even with Visual Studio 2013 (about 4 seconds rather than 10). Regards, David

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[boost.geometry] buffer distance strategies
by gchlebus 09 Mar '15

09 Mar '15

Hi, I am wondering whether it would be possible to achieve anisotropic buffering (distances in neg x, pos x, neg y, pos y can have different values) of a polygon using the buffer function with custom-implemented distance strategy. What I want to achieve is presented on the figure 2-b in the following paper: http://itcnt05.itc.nl/agile_old/Conference/mallorca2002/proceedings/posters… I would be grateful to hear from you whether it is doable, and if positive, how one could implement such a custom distance strategy. Best, -- View this message in context: http://boost.2283326.n4.nabble.com/boost-geometry-buffer-distance-strategie… Sent from the Boost - Users mailing list archive at Nabble.com.

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Statechart serialization
by mbrodeur65 04 Mar '15

04 Mar '15

Hi, I'm looking for a solution to serialize boost::statechart objects. I'm aware that this feature is on the statechart library todo list but was wondering if there are any workaround to achieve this with the latest boost release (1.34) ? thanks for your help ! mbrodeur65 -- View this message in context: http://www.nabble.com/Statechart-serialization-tf4131326.html#a11749139 Sent from the Boost - Users mailing list archive at Nabble.com.

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[multi state machine/ MSM] execute_queued_events
by Steve Hickman 26 Jan '15

26 Jan '15

In the MSM doc section "Enqueueing events for later processing", you state that "Calling execute_queued_events() will then process all enqueued events (in FIFO order)." You also said in a previous post that MSM is not thread safe, thus requiring an external mechanism to insure thread safety. I don't see a mechanism to execute a single event at a time, which would be preferable if I have to lock the queue while processing events. Having said that, a cursory examination of the "execute_queued_events" code makes me think it only processes one event per call. Which is correct? Is the documentation correct that it actually processes all queued events? If not, can the documentation be corrected? If so, is there a publicly usable call to process a single queued event? If there is no publicly available call for processing a single queued event, how do you recommend processing queued events in a thread safe manner that won't lock the queue for extended periods of time?

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[endian] Boost.Endian library added for 1.57.0
by Beman Dawes 14 Dec '14

14 Dec '14

The library provides integer and floating point types and conversion functions for portable byte ordering regardless of processor endianness. Although the primary uses are for file or network I/O, it is also useful for unaligned integers or floats, or for 3, 5, 6, and 7 byte integers. The library's predecessors have been in use for thirty years and developed independently multiple times. The repository is https://github.com/boostorg/endian The documentation is online at https://boostorg.github.io/endian/ See https://boostorg.github.io/endian/index.html#Release-history for changes since the Formal Review. No need to report "Inspection Report" problems; those will be cleaned up before 1.57.0 ships. Please do report any other problems or concerns, since the time between now and when the 1.57.0 beta ships in effect acts a mini-review period. If anyone has access to a big-endian platform with a modern C++ compiler, please, please run the endian test suite and report the results. All testing and use in recent years has been on little-endian platforms, so big-endian platform testing is a worry. Thanks for you patience, --Beman

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Fusion Move Semantics
by Ovanes Markarian 04 Dec '14

04 Dec '14

Hi! I would like to ask does fusion supports move semantics, or are all the values going to get copied. I use C++11 (clang with libstdcxx) and boost 1.54 (but can upgrade). In my use case I have boost::fusion::map and was wondering, that in case of moving of that map, is it going to forward the move call to contained values or not. Many thanks for help, Ovanes

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NT² 3.0 and Boost.SIMD - Stable release
by Joel Falcou 21 Nov '14

21 Nov '14

The first stable release of the 3.x series of MetaScale’s open-source software is available: NT² 3.0. It also includes its spin-off project, Boost.SIMD (not yet a Boost library). Many Issues have been closed since last beta. The main focus of this release cycle was to fix performances issues and to stabilize some parts of the API. Next step will be to separate NT2 and Boost.SIMD into separate repositories, thus making one more step toward Boost.SIMD submission into review. [ http://www.metascale.org/nt%C2%B2-3-0-and-boost-simd ] *Changes & Bug Fixes:* - Major performance improvements in both libraries - Added experimental support for the HPX runtime for parallelization on shared memory systems - Optimizations of many elemental functions, in particuler log/ex, frexp/ldexp and cbrt - More advanced shuffle pattern recognition for SIMD - Fixed issues with Visual Studio 2013 - More functions are force-inlined to ensure good performance - New functions for conversion between types and mixing of vectors of different sizes - Demo applications usable as benchmarks - Better handling of errors when an unsupported function is called - New API for custom memory allocators Full changelog is available at https://github.com/MetaScale/nt2/releases/tag/3.0.0. *How to get it ?* - Source and binary packages can be downloaded here: http://nt2.metascale.org/downloads - The release is also available on Github : https://github.com/MetaScale/nt2/releases - The main master branch is still under development : https://github.com/MetaScale/nt2

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[Test] How to log output to both stdout in HRF and to a file in XML?
by Martin Ba 03 Nov '14

03 Nov '14

As asked on SO: http://stackoverflow.com/questions/26505229/how-to-log-boost-test-output-to… I would like to enable logging of Boost.Test output to *both* the stdout/sterr and to a logfile. However, I would also like to have the stdout logging be in HumanReadableFormat and only the file output be in XML format. Generating a report file seems to be addressed [here][1]. ([official docs][2]) Choosing the format can be done in [various ways][3], but it seems one is stuck with either HRF or XML? ----------- Rationale: When running tests on or [Jenkins][4] server, the [xUnit plugin][5] [requires][6] the **log** XML output (as opposed to the *report* XML output -- `log_level` vs. `report_level`). However, the in-progress log output (in HRF) is highly valuable *while* the tests are running on the server, to detect hanging tests or to a quick manual check of where the tests currently are. So I want an in-progress HRF log for the tests and at the end I need an XML file containing the `<TestLog>...</TestLog>` output of Boost.Test (not the `<TestResult>` output). Do note that we run both unit as well as integration tests via Boost.Test, so some of them are quite long-running. [1]: http://stackoverflow.com/questions/3786639/what-is-the-better-way-to-genera… [2]: http://www.boost.org/doc/libs/1_44_0/libs/test/doc/html/utf/user-guide/test… [3]: http://www.boost.org/doc/libs/1_44_0/libs/test/doc/html/utf/user-guide/runt… [4]: http://jenkins-ci.org/ [5]: https://wiki.jenkins-ci.org/display/JENKINS/xUnit+Plugin [6]: https://issues.jenkins-ci.org/browse/JENKINS-13686

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[1.57.0] Release candidates available
by Marshall Clow 03 Nov '14

03 Nov '14

[ Please disregard previous message; apparently I am brain-dead this morning. The uploaded files are correct, though. ] Release candidate files for 1.57.0 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_57_0_rc1.7z) = 17c98dd78d6180f553fbefe5a0f57d12 MD5 (./boost_1_57_0_rc1.tar.bz2) = 1be49befbdd9a5ce9def2983ba3e7b76 MD5 (./boost_1_57_0_rc1.tar.gz) = 25f9a8ac28beeb5ab84aa98510305299 MD5 (./boost_1_57_0_rc1.zip) = 5e040e578e3f0ba879da04a1e0cd55ff Thanks! -- The release managers P.S. Release notes are here: http://www.boost.org/users/history/version_1_57_0.html

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(no subject)
by Johnny McCullough 01 Nov '14

01 Nov '14

I'm new to boost, and I'm wondering about the best / most efficient way to transfer a large dataset via boost::asio. I've retrieved a datasetfrom a database (Cassandra) and I'm using boost asio to provide a network service that responds to queries. So I have a client socket and a dataset. I have to iterate the dataset, perform some simple formatting (e.g. csv, json, xml), then write it out to the client socket. But there's a lot of data. Perhaps gigabytes. So my initial thoughts were the producer / consumer pattern - the producer writing to a streambuf and the consumer async_write-ing it out to the client's socket. But I'm not sure this is a good approach - I know that streambuf isn't threadsafe and so managing the streambuf with locks may well become a performance bottleneck. Obviously, I don't want to replicate what may be gigabyte(s) of data from a resultset into a buffer just so it can be written out to a socket, So should I write this data synchronously straight to the socket instead? What's the best approach to solving this kind of problem? thanks for your consideration

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From: giridhar
by giridhar 31 Oct '14

31 Oct '14

Hi boost http://mountpleasanthomebuilder.com/brother.php?produce=z3ueg5w3x3gg giridhar Sent from my iPhone

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[1.56.0] Release candidates available
by Marshall Clow 31 Oct '14

31 Oct '14

Release candidate files for 1.65.0 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_57_0_rc1.7z) = 17c98dd78d6180f553fbefe5a0f57d12 MD5 (./boost_1_57_0_rc1.tar.bz2) = 1be49befbdd9a5ce9def2983ba3e7b76 MD5 (./boost_1_57_0_rc1.tar.gz) = 25f9a8ac28beeb5ab84aa98510305299 MD5 (./boost_1_57_0_rc1.zip) = 5e040e578e3f0ba879da04a1e0cd55ff Thanks! -- The release managers P.S. Release notes are here: http://www.boost.org/users/history/version_1_57_0.html

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[PropertyTree][variant] Reading JSON into a recursive variant.
by Arindam Mukherjee 31 Oct '14

31 Oct '14

I have a recursive variant definition that can handle JSON data. Is there a way to read JSON data using PropertyTree into a recursive JSON? Here is the variant defn. #define BOOST_VARIANT_NO_FULL_RECURSIVE_VARIANT_SUPPORT #include <boost/variant.hpp> JSONNullType {}; boost::variant<std::string, double, bool, JSONNullType> jsonToken; typedef boost::make_recursive_variant< std::string, double, JSONNullType, std::map<std::string, boost::recursive_variant_>, std::vector<boost::recursive_variant_> >::type JSONValue; Regards, Arindam

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[Boost.Test]: How I can write custom external main ?
by NtVisigoth 29 Oct '14

29 Oct '14

Hi, Everybody! I've 2 questions about Boost.Test usage. My general cpp-source file appmain.cpp: // more lines with "#include"-constructions #define BOOST_TEST_MODULE TestMain #include <boost/test/unit_test.hpp> My suite-source file suite1.cpp: #include <boost/test/unit_test.hpp> BOOST_AUTO_TEST_SUITE(FooFooSuite) BOOST_AUTO_TEST_CASE(testBarBarBar) { // more lines } BOOST_AUTO_TEST_SUITE_END() Questions #1: How can write external main in my general cpp-file appmain.cpp? I want usage exe-file like : test.exe d:\test-files\ Questions #2: I see these lines in the boost.test documentation: boost::unit_test::framework::master_test_suite().argc boost::unit_test::framework::master_test_suite().argv This args and argv global, are these ? Can I use this in different suites without save to global variable ? P.S.: I sorry for my English.

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[type_traits] Check if implicit conversion from one type to another is possible
by Aaron Levy 29 Oct '14

29 Oct '14

Which is the correct type trait to use to check if an element of type T can be assigned to an element of type U. Is it any of the following: boost::is_convertible<T, U> std::is_assignable<U, T> Now boost::is_convertible<double, int>::value is true while std::is_assignable<int, double>::value is false. What does this signify? -- Aaron Levy aaron.levy(a)yandex.com

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bjam hangs on select (in develop branch)
by Alain Miniussi 28 Oct '14

28 Oct '14

Hi, I am trying to test Boost.MPI with Intel's implementation and I am stuck while trying to run simple tests through bjam. Bjam is hangs on the select (not pselect ?) instruction of the unix exec_wait. As far as processes are concerned: PID USER PR NI S %CPU TIME+ PPID COMMAND ....................... 16882 alainm 20 0 S 0.0 0:01.61 6507 bjam 16899 alainm 20 0 T 0.0 0:00.00 16882 sh 16900 alainm 20 0 Z 0.0 0:00.00 16899 mpiexec.hydra <defunct> ....... bjam calls a generated shell (below) which calls a mpiexe.hydra which work perfectly fine outside bjam. The mpiexec.hydra dies the the shell refuses to let it go. the shell script, generated by bjam, is: =============================================== [alainm@gurney engine]$ more /proc/16899/cmdline /bin/sh LD_LIBRARY_PATH="/gpfs/scratch/alainm/view/boost/bin.v2/libs/mpi/build/intel-linux/debug:/gpfs/scratch/alainm/view/boost/bin.v2/libs/serialization/build/intel-linux/debug:/softs/ intel/composer_xe_2015.0.090/bin/lib:/softs/intel/composer_xe_2015.0.090/lib/intel64:$LD_LIBRARY_PATH" export LD_LIBRARY_PATH status=0 if test $status -ne 0 ; then echo Skipping test execution due to testing.execute=off exit 0 fi mpiexec.hydra -n 2 "../../../bin.v2/libs/mpi/test/broadcast_stl_test-2.test/intel-linux/debug/broadcast_stl_test-2" blob > "../../../bin.v2/libs/mpi/test/broadcast_stl_test-2.te st/intel-linux/debug/broadcast_stl_test-2-run.output" 2>&1 status=$? echo >> "../../../bin.v2/libs/mpi/test/broadcast_stl_test-2.test/intel-linux/debug/broadcast_stl_test-2-run.output" echo EXIT STATUS: $status >> "../../../bin.v2/libs/mpi/test/broadcast_stl_test-2.test/intel-linux/debug/broadcast_stl_test-2-run.output" if test $status -eq 0 ; then cp "../../../bin.v2/libs/mpi/test/broadcast_stl_test-2.test/intel-linux/debug/broadcast_stl_test-2-run.output" "../../../bin.v2/libs/mpi/test/broadcast_stl_test-2.test/intel- linux/debug/broadcast_stl_test-2-run" fi verbose=0 if test $status -ne 0 ; then verbose=1 fi if test $verbose -eq 1 ; then echo ====== BEGIN OUTPUT ====== cat "../../../bin.v2/libs/mpi/test/broadcast_stl_test-2.test/intel-linux/debug/broadcast_stl_test-2-run.output" echo ====== END OUTPUT ====== fi exit $status [alainm@gurney engine]$ ================================================= Note that select only test for the subprocess output, at the hanging point mpiexec.hydra is done with its outputs. Any idea ? Alain PS: there was a cmake based project some time ago, is it still active or is bjam here to stay ?

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[Boost.Polygon] Union filling holes
by Julien Nicoulaud 27 Oct '14

27 Oct '14

Hi all, I am using boost/polygon to do unions of multiple polygons, and I lose holes that were in the input after the assign() operation. Here is code that demonstrates the issue: // Create outer contour Point outer[] = {gtl::construct<Point>(0, 0), gtl::construct<Point>(0, 10), gtl::construct<Point>(10, 10), gtl::construct<Point>(10, 0)}; // Create inner contour Point inner[] = {gtl::construct<Point>(2, 2), gtl::construct<Point>(8, 2), gtl::construct<Point>(8, 8), gtl::construct<Point>(2, 8)}; // Define inner contour as a polygon polygon_with_holes_data<long> input_poly_inner; gtl::set_points(input_poly_inner, inner, inner+4); // Put inner polygon in a list vector<polygon_with_holes_data<long> > inners; inners.push_back(input_poly_inner); // Create input polygon as outer contour + inner polygon list polygon_with_holes_data<long> input_poly; gtl::set_points(input_poly, outer, outer+4); gtl::set_holes(input_poly, inners.begin(), inners.end()); // Create input polygon set, insert input polygon polygon_set_data<long> input_poly_set; input_poly_set.insert(input_poly); // Create output polygon set, assign input polygon set vector<polygon_with_holes_data<long> > output_poly_set; assign(output_poly_set, input_poly_set); // Print result std::cout << output_poly_set.size() << " polys" << std::endl; std::cout << output_poly_set[0].size_holes() << " holes" << std::endl; This prints: 1 polys 0 holes Any idea what I am doing wrong ? Kind regards, Julien Nicoulaud

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1.57.0 beta 1 is in a new location
by Marshall Clow 27 Oct '14

27 Oct '14

Tom Kent pointed out that I put the beta 1 files in a folder that we traditionally use for Windows binaries, so I have moved the beta files to https://sourceforge.net/projects/boost/files/boost/1.57.0.beta.1/ These are the same files as last Monday - merely in a new location. If you have already downloaded and tested the beta, thanks! - no need to do it again. — Marshall

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[Geometry] Packing algorithm for r-tree?
by Jeremy Murphy 27 Oct '14

27 Oct '14

I see that a fourth node splitting algorithm for bulk loading is documented in the Introduction to spatial indexes but not listed elsewhere (such as Creation and Modification). Is it hiding in the library somewhere or is the introduction just a tantalizing sneak preview? Thanks, cheers. Jeremy

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BGL, cut set
by Mads Jensen 27 Oct '14

27 Oct '14

Hi, I'm looking into how you can quickly find the cut set of a graph without having to loop over the colormap as a vector. I'm using the http://www.boost.org/doc/libs/1_56_0/libs/graph/doc/edmonds_karp_max_flow.h… (the example provided does mostly what I want, except that it uses a vector, and not a regular map). Boykov Kolmogorov also has the colormap parameter. It seems that associative_property_map could be used, but I don't really see how? Hints on how to do this will be appreciated. A lot of the examples of the Boost graph library use the preprocessor with a check similar to: #if defined(BOOST_MSVC) && BOOST_MSVC <= 1300 What's so special about this? Thank you, -- Med Venlig Hilsen / Kind regards, Mads Jensen

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[Serialization] Deserialization of base class fails
by Torsten Wylegala 25 Oct '14

25 Oct '14

Hi, I'm currently trying to serialize and deserialize a derived class using boost::archive::xml_iarchive/xml_oarchive Version 1.52. Everything works fine as long as I serialize and deserialize the same class (Example 1). The attributes of the derived class and the base class are both serialized and the deserialized correctly and requestPackageOut equals requestPackageIn (the base-class attributes are equal too). But if I serialize the derived class "RequestPackage" and try to deserialize it into the base-class "Package" (Example 2) I'm getting an "input stream error" exception while trying to deserialize with ia >> BOOST_SERIALIZATION_NVP(*package);. I'm quite new to this topic and found a lot of posting but none of them seems to match and solve my exact problem. It would by very nice if somebody could help me with that. Background information: I want to use xml-serialized objects for data exchange via network and want all the packages to inherit from Package-class which carries "packageId" and therefore give me the chance to identify the incoming xml-objects and handle every package based on this id. If some information is missing I will do my best to provide it later. Torsten Example 1: int main(int argc, char** argv){ std::cout << "Started!" << std::endl; std::string serializedObject; RequestPackage requestPackageOut; RequestPackage requestPackageIn; requestPackageOut.setPackageId(3); requestPackageIn.setPackageId(0); Serializer::serialize(&serializedObject,&requestPackageOut); Serializer::deserialize(&serializedObject,&requestPackageIn); return 0; } Example 2: int main(int argc, char** argv){ std::cout << "Started!" << std::endl; std::string serializedObject; Package package; RequestPackage requestPackageOut; RequestPackage requestPackageIn; requestPackageOut.setPackageId(3); requestPackageIn.setPackageId(0); Serializer::serialize(&serializedObject,&requestPackageOut); Serializer::deserialize(&serializedObject,&package); return 0; } The Rest: namespace Serializer{ template <typename T> int serialize(std::string *serializedObject, T *package){ int returnValue = 0; std::ostringstream objectOss; boost::archive::xml_oarchive oa(objectOss); try { oa << BOOST_SERIALIZATION_NVP(package); } catch (boost::archive::archive_exception const& ex) { returnValue = 1; } serializedObject->assign(objectOss.str()); return returnValue; }; template <typename T> int deserialize(std::string *serializedObject, T *package){ int returnValue = 0; std::istringstream objectIss(*serializedObject); boost::archive::xml_iarchive ia(objectIss); try { ia >> BOOST_SERIALIZATION_NVP(*package); } catch (boost::archive::archive_exception const& ex) { std::cerr << "Error: " << ex.what() << std::endl; std::cerr.flush(); returnValue = 1; } return returnValue; }; } class RequestPackage : public Package{ private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(Package); ar & BOOST_SERIALIZATION_NVP(requestId); } int requestId; public: int getRequestId() const; void setRequestId(int requestId); }; class Package{ private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & BOOST_SERIALIZATION_NVP(packageID); } int packageID; public: int getPackageId() const; void setPackageId(int packageId); };

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Boost Serialization
by Abraham, Marshel 25 Oct '14

25 Oct '14

I am trying to Serialize a class : StartPeerSessionRequest::StartPeerSessionRequest() { mProtocolVersion = 1*10000 + 14*100 + 4; mSessionFlags = 1; mMaxResponseLength = 0; mMake = "MyMake"; mModel = "MyModel"; mSerialNumber = "10000"; mTrackDelay = 0; mHeadUnitModel = "Headunit"; mCarModelYear = "2014"; mVin = "1234567980"; mVehicleMileage = 1000; mShoutFormat = 3; mNotificationInterval = 1; } template <class Archive> void StartPeerSessionRequest::serialize(Archive &ar, const unsigned int version) { ar & mProtocolVersion; ar & mSessionFlags; ar & mMaxResponseLength; ar & mMake; ar & mModel; ar & mSerialNumber; ar & mTrackDelay; ar & mHeadUnitModel; ar & mCarModelYear; ar & mVin; ar & mVehicleMileage; ar & mShoutFormat; ar & mNotificationInterval; } void StartPeerSessionRequest::save() { boost::archive::binary_oarchive oa(serlreq, boost::archive::no_header); oa << (*this); /*cout<<"\n binary_oarchive :"<<serlreq.size();*/ boost::archive::text_oarchive ota(serializedRequest, boost::archive::no_header); ota<<(*this); cout<<"\n text_oarchive :"<<serializedRequest.str()<<"size :"<<serializedRequest.str().size(); } serializedRequest.str.size() provides me a length of 87 actually it should provide me 65 bytes.( I ve counted u can figure that out from the constructor ) I suspect it is appending lengths in between. I have tried using text_archive also it doesnt work. What I need is to just plain serialize class members as it is. I guess i need to use some traits or wrappers, or boost::serialization::binary_object Please let me know Thanks Regards Marshel Abraham 3097146

2 2

"event-driven" async-receive
by Alexander Carôt 25 Oct '14

25 Oct '14

Hello all, I have question regarding the async_receive_from – operation (using UDP): Right now I have a thread, which triggers the receive call in constant intervals. This works allright if the sender sends data in the same interval or larger intervals. However, if the send intervals are (much) smaller (or if multiple senders exist) the receive-operation is not triggered often enough. Eventually I’d like the receiving socket to behave in an „event-driven “ manner – so, whenever data is there the receive-handler should be invoked. I used to work with Qt, which works this way (via signals/slots) but since I moved to boost I wonder how I can reproduce this behavior. Can anyone tell how to approach this ? Thanks in advance, best Alex

3 3

Applying Boost Phoenix to infinite sequence
by Aaron Levy 24 Oct '14

24 Oct '14

Is there a way to use Boost Phoenix to define an infinite sequence and evaluate specific terms of it, compute partial sums, etc? I am looking for pointers to specific libraries or examples. -- Aaron Levy aaron.levy(a)yandex.com

1 1

cross compile for arm setup (solved)
by John Davis 24 Oct '14

24 Oct '14

Hello I appreciate the assistance. Below is the script and results for building boost with a cross compiler. It appears to work. -------------------------- #!/bin/bash # place this script in the $BOOST_ROOT directory and invoke it like so: # ./doit.sh # Clean up any stuff left over from a previous build rm -rf /opt/xxx/boost/include rm -rf /opt/xxx/boost/lib # edit /opt/xxx/yyy/boost/boost_1_51_0/tools/build/v2/user-config.jam to add the following line # using gcc : 4.3arm : arm-linux-gnueabi-g++ : <architecture>arm <target-os>linux ; # edit /opt/xxx/yyy/boost/boost_1_51_0/tools/build/v2/user-config.jam to remove the following line # using gcc ; # Ensure we are in host development environment and not using the cross compiler. # # Later we modify path and CROSS_COMPILE variables. # Here we are just ensuring we start properly, # make sure our path does not use the cross compiler at beginning export PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/opt/java6/bin:/opt/java6/db/bin:/opt/java6/jre/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl export CROSS_COMPILE= # In this stage, we are using the host compiler. # setup env variable for $BOOST_DIR # I'm not sure if this is being used, but set it just in case. export BOOST_ROOT=/opt/xxx/yyy/boost/boost_1_51_0 # Its important that the next step is run from $BOOST_DIR/tools/build/v2 aka /opt/xxx/yyy/boost/boost_1_51_0/tools/build/v2 cd $BOOST_ROOT/tools/build/v2 # NOTE: ask if we have removed gcc and replaced gcc with cross compiler in user-config.jam am I really # invoking gcc-arm below? Its not in my path at this point. ./bootstrap.sh --with-toolset=gcc echo current working directory is $PWD # checkpoint exit # At this point, /opt/xxx/boost is still empty. # # The ./bootstrap.sh script executed above in the tools/build/v2 directory # is complete and gives the following output: # #Bootstrapping the build engine with toolset gcc... engine/bin.linuxx86_64/bjam # #Bootstrapping is done. To build and install, run: # # ./b2 install --prefix=<DIR> # # !!! ERROR # We can't run b2 at this point, because we don't have the cross compiler in # our path yet. It dies looking for arm-linux-gnueabi-g++ # Furthermore, even though we were running in the tools/build/v2 directory # the explicit path of running ./b2 in the current directory is wrong. # Instead it should be run from the root directory. # This command failed at this point, try it again later with different CWD and # different options. #./b2 toolset=gcc install --prefix=/opt/xxx/boost #exit # At this point in the script, we have preconfigured the build of the libraries using # the cross compiler, the build tools which run on the host to build the libraries # are built (according to docs. where they are located is beyond me) , and our original project-config.jam file is still in place since # we issued bootstrap.sh in the v2 subdirectory. We need to change working # directories back to the root. # It builds b2 in the tools driectory. Maybe this is what the docs are referring to above? #cd $BOOST_ROOT #echo current working directory is $PWD #exit # We are switching to the cross compiler at this point, ensure it is in the # path first. # Setup path so that gcc from cross compiler is first in the path # also specify cross_compiler env variable in case its used. # # this will find the cross compiler for those who dont use the prefix, ie. gcc export PATH=/opt/arm/usr/local/arm-linux-gnueabi/bin:$PATH # this will find the cross compiler for those who use the prefix, ie. arm-linux-gnueabi-gcc export PATH=/opt/arm/usr/local/bin:$PATH # this will set the cross compiler prefix for those who use it. This export # is not used by Boost.Build but keep it here for our app which uses boost. export CROSS_COMPILE=arm-linux-gnueabi- # since we installed boost.build stuff to /opt/xxx/boost # in the step above, add that to the path for the next step as well. # Its currently empty but maybe it needs to be set during the next step. export PATH=/opt/xxx/boost/bin:$PATH # build boost.build so that we can build boost or are we building boost at this point? # # WARNING!!! # Specify an install directory so that it doesn't put the results in /usr/local/bin. # Even if you dont specify install as an option to ./b2 it will attempt to copy files to /usr/bin # in the following step! # # /opt/xxx/boost is where we want results. Our code will this dir in order to use boost. # /opt/xxx/yyy/boost/boost_1_51_0 is the top of the boost src. We are building beneath there. #./b2 --toolset=gcc-4.3arm --prefix=/opt/xxx/boost # hmm. I did not get any .a or .so after that last step. Try to add a install parameter. #./b2 toolset=gcc-4.3arm --prefix=/opt/xxx/boost --build-type=complete --layout=versioned # hmm. I did not get any .a or .so after that last step. Try to add a install parameter. # Above we use --with-toolset=, here we use just toolset= # It was suggested to use the additional options below (i'm not sure why, consider them later.) # --without-python # -sNO_BZIP2=1 ./b2 toolset=gcc-4.3arm --without-python --debug-configuration --prefix=/opt/xxx/boost --build-type=complete --layout=versioned install # running b2 using above syntax from the tools/v2/build directory, we have the following in the /opt/xxx/boost dir: # the version of b2 here is x86_64 # /opt/xxx/boost/bin/b2 # /opt/xxx/boost/bin/bjam # /opt/xxx/boost/share/boost-build/ whole subtree cd $BOOST_ROOT echo current working directory is $PWD /opt/xxx/boost/bin/b2 toolset=gcc-4.3arm --without-python --debug-configuration --prefix=/opt/xxx/boost --build-type=complete --layout=versioned install # At this point, we have the cross compiler in our path first. We are good to go for building our code using boost # with the cross compiler. ------------------------------------------------------------- -- John F. Davis 6 Kandes Court Durham, NC 27713 919-888-8358 独树一帜

1 0

Map Binary archive problem May be a bug?
by Joshua Nocturne 24 Oct '14

24 Oct '14

On my phone, so I try my best to describe my problem. std::map<int,int> myMap; for(int i = 0; i != 30; i++) myMap.insert( make_pair(i,i+1) ); ofstream ofs("test"); binary_oarchive oa(ofs); oa<<myMap; ofs.close(); ofs.clear(); myMap.clear(); Ifstream ifs("test"); binary_iarchive ia(ifs); ia>>myMap; This code will throw an exception "input stream error". But if reducing the size of map like this for(int i = 0;i != 20; i++) It will run successful. Cause I can't figure it out so I seek your help. Look forward to your reply.

2 1

Inserting in a boost::interprocess::map
by Hemanth Choudary M V (RBEI/ETA1) 24 Oct '14

24 Oct '14

Hi, I have the following boost::interprocess::map: std::shared_ptr<boost::interprocess::map<size_t,boost::interprocess::managed_shared_memory*> > memoryMap; I insert into the map in the following manner: memoryMap ->insert( std::make_pair (i, new boost::interprocess::managed_shared_memory(boost::interprocess::create_only, "MemoryMap", 128))); Compilation is successful. But there is the following run-time error during insert: "memory access violation occurred at address -----------, while attempting to read inaccessible data" Is there anything missing? Mit freundlichen Grüßen / Best regards Hemanth Choudary M V RBEI/ETA1 Tel. +49 7113423 2875 [cid:image001.gif@01CFEF7A.B28D3180] [cid:image002.gif@01CFEF7A.B28D3180]<https://www.facebook.com/BoschIndia> [cid:image003.gif@01CFEF7A.B28D3180] <https://twitter.com/boschindia> [cid:image004.gif@01CFEF7A.B28D3180] <http://www.linkedin.com/company/bosch-engineering-and-business-solutions?tr…>

1 0

[Boost.TypeTraits] Which was the first Boost release that included make_signed?
by dariomt＠gmail.com 24 Oct '14

24 Oct '14

Looking at Boost.TypeTraits documentation it seems that boost/type_traits/ make_signed.hpp was added in version 1.35.0, but I can't find any reference to that change in the release notes. Which was the first Boost release that included make_signed?

3 2

Pattern issue with boost::regex
by Tal Shnaiderman 24 Oct '14

24 Oct '14

Hi All, I have a question regarding boost::regex pattern recognition and groups I created the following code, in it i created a pattern and a string to match: 1 2 3 4 5 6 p = "((a b (f+\\.))d d(\\3))"; str="a b ffff.d dfff."; boost::regex pattern(p, boost::regex::icase&boost::regex::extended &~boost::regex::no_bk_refs); bool match = boost::regex_match(str, pattern); cout << str << ((match)?"-Pattern is legal":"-Pattern is illegal" )<< endl; Pattern is illegal I'm saw that my result is 'Pattern is illegal' because the group \\3 that refers to (f+\\.) isn't equal to it. if I change the input to str="a b ffff.d dffff."; The pattern is legal. In other words my original plan was to use the \\3 instead of writing the pattern; p = "((a b (f+\\.))d d(f+\\.))"; But I can see that in the original pattern it simply expect the same output to reappear Is there a way I can use the group naming not to copy the (f+\\.) group? Thanks, I hope my Q is clear since I'm new to the regex topic.

3 2

cross compile boost for arm TRY2 (Possibly solved)
by John Davis 24 Oct '14

24 Oct '14

Hello Here is a more succient attempt at building boost with a cross compiler. It appears to work. I'm not certain if it works at this point though. Please take a look and comment. Here is the script: --------------------------------------------------------------- #!/bin/bash # edit /opt/xxx/yyy/boost/boost_1_51_0/tools/build/v2/user-config.jam to add the following line # using gcc : 4.3arm : arm-linux-gnueabi-g++ : <architecture>arm <target-os>linux ; # Later we modify path, make sure our path does not use the cross compiler at beginning export PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/opt/java6/bin:/opt/java6/db/bin:/opt/java6/jre/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl # In this stage, we are using the host compiler. # setup env variable for $BOOST_DIR # I'm not sure if this is being used, but set it just in case. export BOOST_ROOT=/opt/xxx/yyy/boost/boost_1_51_0 # this is run from $BOOST_DIR/tools/build/v2 aka /opt/xxx/yyy/boost/boost_1_51_0/tools/build/v2 # in this case, I do not think you invoke the cross compiler. I think at this point, you are building # code for the host development machine. ./bootstrap.sh --with-toolset=gcc # setup path so that gcc from cross compiler is first in the path # also specify cross_compiler env variable in case its used. # # this will find the cross compiler for those who dont use the prefix, ie. gcc export PATH=/opt/arm/usr/local/arm-linux-gnueabi/bin:$PATH # this will find the cross compiler for those who use the prefix, ie. arm-linux-gnueabi-gcc export PATH=/opt/arm/usr/local/bin:$PATH # this will set the cross compiler prefix for those who use it export CROSS_COMPILE=arm-linux-gnueabi- # build boost.build so that we can build boost or are we building boost at this point? # # WARNING!!! # Specify an install directory so that it doesn't put the results in /usr/local/bin. # Even if you dont specify install as an option to ./b2 it will attempt to copy files to /usr/bin # in the following step! # # /opt/xxx/boost is where we want results. Our code will this dir in order to use boost. # /opt/xxx/yyy/boost/boost_1_51_0 is the top of the boost src. We are building beneath there. ./b2 --toolset=gcc-4.3arm --prefix=/opt/xxx/boost # at this point, we have the cross compiler in our path first. We are good to go for building our code using boost # with the cross compiler. -------------------------- -- John F. Davis 6 Kandes Court Durham, NC 27713 919-888-8358 独树一帜

2 1

[Log] record_ostream too restrictive due to non-copyability, non-assignability?
by Latimerius 23 Oct '14

23 Oct '14

Hello, I'm trying to migrate from an existing solution to Boost.Log. So far I've been able to emulate all important features of the existing library - except one. The existing library supported submitting a log message in multiple statements. This is useful when the message being composed has conditional parts, when a part of it is composed in a loop or even a different function, something like this: auto logmsg = log (Channel::CORE, Severity::DEBUG); logmsg << "unconditional part"; if (condition) logmsg << " conditional part"; for (auto element : container) logmsg << element; logging_subroutine (logmsg); logmsg << endmsg; To that end I extracted a structure from the manual_logging() function from the Boost.Log documentation to hold the state of the message being composed: struct log_msg_state { my_logger & logger; logging::record rec; logging::record_ostream strm; ... <constructor & destructor definition> ... }; Having done this, I can emulate most of the above example fairly easily by defining a bunch of operator<<() overloads for the log_msg_state. However, I've been struggling with record_ostream. It was a bit of a challenge even to initialise it in the constructor - we can't use the initialiser list as we have to make sure first that our logging::record is valid. On the other hand, in the ctor body when the check can be performed, it's too late as record_ostream has already been constructed already and as it turns out, you can't do much with a constructed instance - no usual stuff like if (rec) strm = logging::record_ostream (rec); works! Fortunately, I've been able to hack around it like this: if (rec) new (&strm) logging::record_ostream (rec); Not pretty but has been working well so far! However, I've failed to find a solution for returning my log_msg_state (and thus record_ostream) from a function. The non-copyability, non-assignability, non-moveability are always getting in the way. (Note also that I do NOT want to hold a pointer to record_ostream in my log_msg_state and allocate it dynamically - that would certainly make things easier but I don't want to penalise each and every log message with a dynamic allocation for no good reason.) Could someone please advise me how to get the functionality I need, a solution or a work-around at least? Thanks in advance pvl

1 0

unused parameter warning
by Kevin Molcard 23 Oct '14

23 Oct '14

Hi all, in some boost libraries I am using, there are compilation warnings complaining about unused parameter. For instance: boost/signals2/detail/auto_buffer.hpp:102:45: warning: unused parameter 'size' I'd like to get rid of the warnings. What is the best way to proceed? Should I send a merge request in github or something else? Thanks in advance Kevin

1 0

using boost in cross compiler environment. intel host and arm target
by John Davis 22 Oct '14

22 Oct '14

Hello I have some code for arm which I would like to use with boost. The boost libraries I am interested in are not header only and thus require building. I have downloaded the boost tarfile and I have read the following two webpages relative but I am still confused. Here is a summary of the two urls and where I am confused. http://www.boost.org/doc/libs/1_56_0/more/getting_started/ This url has the following procedure which seems to use the host default compiler to build boost. Easy Method for Building and Installing Boost Binary Libraries. step 1: $ cd $BOOST_DIR step 2: $ ./bootstrap.sh --help step 3: $ ./bootstrap.sh --prefix=path/to/installation/prefix ( Other docs specify for this step: $ ./b2 --build-dir=/tmp/build-boost toolset=gcc stage (optional --build-type=complete) Also says that --stagedir=/path/to/install/special/stage/target/library/binaries I'm not certain what the stage components are or what the stage part is. ) $ ./b2 install “This will leave Boost binaries in the lib/ subdir of the installation prefix.” The only customization mentioned here is for where you want your results to be placed. step 4: Add path/to/installation to my $PATH environment variable. http://www.boost.org/doc/libs/1_51_0/doc/html/bbv2/tasks.html#bbv2.tasks.cr… The section is on common tasks for boost build, in particular in the section is task on cross compilation. Boost.Build supports cross compilation with gcc toolset. When using gcc, you first need to specify your cross compiler in user-config.jam for example: using gcc : arm : arm-none-linux-gnueabi-g++; This looks good, i'm thinking I need to edit a user-config.jam file. After that, if the host and target os are the same, for example linux, you can just repeat this compiler version to be used: b2 toolset=gcc-arm Regarding the user-config.jam file. These are the notes I took while reading: http://www.boost.org/doc/libs/1_51_0/doc/html/bbv2/overview.html#bbv2.overv… On startup, boost.build searches and reads two config files: site-config.jam and user-config.jam. Alternatively, the docs say you can edit the one at the top of the boost.build directory. In my case, I believe that would be $BOOST_DIR/tools/build/v2 directory rather than $BOOST_DIR. This directory has five .jam files: boost-build.jam, bootstrap.jam, build-system.jam, Jamroot.jam, site-config.jam and user-config.jam. Then I started thinking maybe editing this file will build boost.build for running on arm. I don't want to run boost.build on arm. I want it to use the cross compiler to build boost so that the libs will work with code that runs on arm. Summary, this is what I think I need to do. Please correct me where I am wrong. 1. using the tarfile I've downloaded, copy the $BOOST_DIR/tools/build/v2/user-config.jam file to my /home/davis directory. 2. edit the ~/user-config.jam file (I wish I could put this file in the $BOOST_DIR tree rather than my home dir) to use the cross compilers I have in my /opt/arm directory. 3. With the /opt/arm/ compiler directory in my path and in the $BOOST_DIR/tools/build/v2 directory issue the commands to build boost 3.a. $ ./bootstrap.sh --prefix=path/to/installation/prefix --with-toolset=gcc-arm 3.b this should add a b2 program in the path/to/installation/prefix dir. /path/to/installation/prefix will actually be /opt/arm/boot.build. This should have the boost build tool I build that runs on intel but is set to build boost for arm. 4. Change directory to $BOOST_DIR 4.a $ /path/to/installation/prefix/b2 --build-dir=/tmp/build-boost toolset=gcc-arm or literally /opt/arm/boot.build/bin?/b2 -build-dir=/tmp/build-boost toolset=gcc-arm 4.c $ /path/to/installtion/prefix/b2 install -- John F. Davis 6 Kandes Court Durham, NC 27713 919-888-8358 独树一帜

1 0

Flyweight: wrapping shared_ptr
by Akim Demaille 22 Oct '14

22 Oct '14

Hi all, I'd like to add hash-consing on top of my hiearchy-based AST implementation, which uses shared_ptr (I'm in C++11) to guarantee value semantics (the pointee is const). Below is a tiny version that would help me see if using Boost.Flyweight is adequate. It works, but it is not transparent, because I have to explicitly call '.get()' on my flyweights to deference to the pointers. So for instance my code reads: size_t hash() const { size_t res = 0; hash_combine(res, boost::hash_value(op)); hash_combine(res, l.get()->hash()); hash_combine(res, r.get()->hash()); return res; } where I expect to have l->hash(), not l.get()->hash(). I have tried deriving from flyweight to add an operator->, but it fails horribly. I realize that it is suboptimal to use flyweight on top of shared_ptr, as I get two reference counters. Yet this change is less invasive than migrating my AST hierarchy to using variants as is done in the example of the documentation. What would be the right approach? Thanks a lot.

3 11

Problem with bundled BGL properties
by alev mutlu 21 Oct '14

21 Oct '14

Hi all, I am new to BGL and the followings are snippets from my code. When I compile my code I get the following error. Any suggestions, error: no match for ‘operator=’ in ‘city_name.boost::vec_adj_list_vertex_property_map<Graph, GraphPtr, ValueType, Reference, Tag>::operator[] [with Graph = boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, relation, boost::property<boost::edge_name_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::no_property>, boost::no_property, boost::listS>, GraphPtr = boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, relation, boost::property<boost::edge_name_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::no_property>, boost::no_property, boost::listS>*, ValueType = boost::detail::error_property_not_found, Reference = boost::detail::error_property_not_found&, Tag = boost::vertex_name_t](v1) = r’ /home1/mutlu/boost/include/boost-1_37/boost/pending/detail/property.hpp:21: note: candidates are: boost::detail::error_property_not_found& boost::detail::error_property_not_found::operator=(const boost::detail::error_property_not_found&) struct argument{ int is_variable; string value; }; struct relation{ string relation_name; vector<argument> arguments; }; typedef property<edge_name_t, std::string> EdgeNameProperty; typedef adjacency_list<vecS, vecS, directedS, relation, EdgeNameProperty> Graph; int main(){ Graph g; property_map<Graph, vertex_name_t>::type city_name = get(vertex_name, g); property_map<Graph, edge_name_t>::type edge_value = get(edge_name, g); typedef graph_traits<Graph>::vertex_descriptor Vertex; typedef graph_traits<Graph>::edge_descriptor Edge; Vertex v1; v1 = add_vertex(g); city_name[v1]= r; } error: no match for ‘operator=’ in ‘city_name.boost::vec_adj_list_vertex_property_map<Graph, GraphPtr, ValueType, Reference, Tag>::operator[] [with Graph = boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, relation, boost::property<boost::edge_name_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::no_property>, boost::no_property, boost::listS>, GraphPtr = boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, relation, boost::property<boost::edge_name_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::no_property>, boost::no_property, boost::listS>*, ValueType = boost::detail::error_property_not_found, Reference = boost::detail::error_property_not_found&, Tag = boost::vertex_name_t](v1) = r’ /home1/mutlu/boost/include/boost-1_37/boost/pending/detail/property.hpp:21: note: candidates are: boost::detail::error_property_not_found& boost::detail::error_property_not_found::operator=(const boost::detail::error_property_not_found&)

1 0

1.57.0 beta 1 release candidates available for testing
by Marshall Clow 21 Oct '14

21 Oct '14

Release candidate files for 1.57.0 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_57_0_b1_rc1.7z) = 8633fbf5ebb7eaabcb0f309c14646ae3 MD5 (boost_1_57_0_b1_rc1.tar.bz2) = 8e76f98146793f0fbd2492a9151c405b MD5 (boost_1_57_0_b1_rc1.tar.gz) = d41ff3ffb36ac84ff5bf34f799308907 MD5 (boost_1_57_0_b1_rc1.zip) = 8a844dc36284247b2e936f2120e118b2 Thanks! -- The release managers

7 17

1.57.0 beta 1 is now available
by Marshall Clow 20 Oct '14

20 Oct '14

Boost release 1.57.0 beta 1 is now available from SourceForge See http://sourceforge.net/projects/boost/files/boost-binaries/1.57.0.beta.1/ This release contains no new libraries. For details of what's in the release, see http://www.boost.org/users/history/version_1_57_0.html. Note that the links to files on this web page are for the final release - use the SourceForge link above to get the beta files. Please download the beta, give it a try, and report any problems you encounter. Thanks, -- The Boost Release Team P.S. There are a couple of known problems with this beta: * There are problems building with MSVC 8.0 * There are some problems with range/detail/any_iterator.hpp. These will be fixed before the release.

1 0

Boost 1.56 with QT creator, “LNK1104: cannot open file 'libboost_unit_test_framework-vc100-mt-gd-1_56.lib'”
by Kavita 20 Oct '14

20 Oct '14

Hello, I am working on a project of boost unit testing framework using QT creator. I have written a small test program and trying to link "libboost_unit_test_framework-vc100-mt-gd-1_56.lib". This library is present at specified path. But program fails to compile giving said linking error. I searched on net and found that, error should go with "#define BOOST_ALL_NO_LIB". But then, I am getting below error: main.obj:-1: error: LNK2019: unresolved external symbol "class boost::unit_test::test_suite * __cdecl init_unit_test_suite(int,char * * const)" (?init_unit_test_suite@@YAPAVtest_suite@unit_test@boost@@HQAPAD@Z) referenced in function _main The above function is a part of "libboost_unit_test_framework-vc100-mt-gd-1_56.lib". I have written same unit tests using VS 2010 and with the same boost libraries. The program worked properly with expected behavior. What could be possibly going wrong with the usage of boost on QT ? Please help ! -Thanks

6 6

[Log] Writing empty messages with the attributes as the actual payload
by Scott Mueller 17 Oct '14

17 Oct '14

Hello Boost.Users! I'm trying to integrate Boost logging with an existing message infrastructure. In this infrastructure, I have an existing schema that looks like this: Severity Timestamp Process source (much like "channel") Process component (more like a "sub-channel") Message ID A vector of arguments The message is rendered by looking up the message ID to receive the following information: formatting string ("This is an example of %1 message type. The arguments can look like this %4, 3, 2"), the expected argument types which are potentially convertible if the underlying type is different, and so on. I guess what I'm asking is whether or not a logging source can accept the arguments as defined by a compile-time defined schema in the form of attributes with an empty message. Can the logging core route message records defined in this way properly? Is such a thing supported? I'm in the process of writing something up to do this, but I'd like to know in advance whether or not "empty" messages with a bunch of attributes set can get routed to supported sinks. Thanks in advance for your help! Best regards, M. Scott Mueller

1 0

boost serialisation 1.56, why does library version change, when no change in library ?
by avib369 . 16 Oct '14

16 Oct '14

At boost 1.53 the library version was 10, however at boost 1.56 it has jumped to 11. I have not seen any documentation/release notes about boost serialisation changes. What has changed in boost serialisation to merit this change ? The documentation in $BOOST_ROOT/libs/serialization/basic_archive.cpp describes the changes to boost library version, however it does *not* describe why it jumped from 10 -> 11. Any help appreciated. Ta, Avi

2 1

[thread] linux.hpp, BOOST_HAS_PTHREAD_YIELD, BOOST_HAS_SCHED_YIELD
by Rob Conde 16 Oct '14

16 Oct '14

Using boost 1.55, Ubuntu 12.04, gcc 4.6 I'm building boost on linux using the lsb sdk. I was getting the failure (paraphrased): pthread_yield not declared in libs/thread/src/thread.cpp 513 The documentation for pthread_yield (http://man7.org/linux/man-pages/man3/pthread_yield.3.html) says: This call is nonstandard, but present on several other systems. Use the standardized sched_yield(2)<http://man7.org/linux/man-pages/man2/sched_yield.2.html> instead. If I change boost/config/platform/linux.hpp to define BOOST_HAS_SCHED_YIELD instead of BOOST_HAS_PTHREAD_YIELD Then sched_yield is used instead and the build finishes properly. I'm posting this for two reasons: 1. To help others running into the same issue 2. To question whether linux.hpp should be updated officially as I did above 3. If not, why Thanks, Rob Conde

1 0

Boost.Python: Polymorphism downcasting
by Christoff Kok 16 Oct '14

16 Oct '14

Hi, I have a list of base classes in C++, I want to access them in Python as a list of their derived most classes. Is there a build in means to cater for this in Boost.Python? I've made an example the problem I ma facing: // ------------------------------- Code ----------------------------------// #include<memory> #include<iostream> #include<vector> namespace boost { template<class T> T* get_pointer(std::shared_ptr<T>& p){ return p.get(); }} struct Vehicle{ virtual ~Vehicle(){} friend bool operator==(const Vehicle& lhs, const Vehicle& rhs) { return true; }}; struct Boat: public Vehicle{ virtual ~Boat(){} friend bool operator==(const Boat& lhs, const Boat& rhs) { return true; } char const* testBoatSpecificMethod() { return "Floating."; } }; struct Truck: public Vehicle{ virtual ~Truck(){} friend bool operator==(const Truck& lhs, const Truck& rhs) { return true; } char const* testTruckSpecificMethod() { return "Trucking."; } }; class Garage { public: Garage() {}; ~Garage() {}; char const* test() { std::string temp = "Vehicle List Size: " + std::to_string(m_VehicleList.size()); return temp.c_str(); } friend bool operator==(const Garage& lhs, const Garage& rhs) { return true; } std::vector<Vehicle>& vehicleList() { return m_VehicleList; } private: std::vector<Vehicle> m_VehicleList; }; #include <boost/python.hpp> #include <boost/python/suite/indexing/vector_indexing_suite.hpp> BOOST_PYTHON_MODULE(garage_ext) { using namespace boost::python; class_<Garage>("Garage") .def("test", &Garage::test) .def("vehicleList", &Garage::vehicleList, return_internal_reference<1>()); class_<Vehicle,std::shared_ptr<Vehicle>>("Vehicle"); class_<Boat,std::shared_ptr<Boat>,bases<Vehicle>>("Boat") .def("testBoatSpecificMethod", &Boat::testBoatSpecificMethod); class_<Truck,std::shared_ptr<Truck>,bases<Vehicle>>("Truck") .def("testTruckSpecificMethod", &Truck::testTruckSpecificMethod); implicitly_convertible<std::shared_ptr<Boat>,std::shared_ptr<Vehicle>>(); implicitly_convertible<std::shared_ptr<Truck>,std::shared_ptr<Vehicle>>(); class_<std::vector<Vehicle> >("stl_vector_Vehicle") .def(vector_indexing_suite<std::vector<Vehicle> >()); } // --------------------------- Test Script -------------------------------// import garage_ext g = garage_ext.Garage() l = g.vehicleList() l.append(garage_ext.Boat()) print "Expecting a Boat object:" print str(l[0]) print g.vehicleList()[0].testBoatSpecificMethod() garage_ext.f2("Done.") // ------------------------------ Output ---------------------------------// Expecting a Boat object <garage_ext.Vehicle object at 0x7fb17a3bfb50> Traceback (most recent call last): File "test_garage.py", line 7, in <module> print g.vehicleList()[0].testBoatSpecificMethod() AttributeError: *'Vehicle' object has no attribute 'testBoatSpecificMethod'* *'Vehicle' object has no attribute 'testBoatSpecificMethod'* Here I want Vehicle to be a Boat object. If there is not a build in or recommended/known Boost.Python means to handle this problem, I'm thinking of wrapping the list (Lots of accessors to be wrapped in my library.) with a get accessor returning a boost::python::list, storing the derived most types. Getting the derived most type possibly by calling overriden 'getAsDerivedClass' method. I would like to avoid this. I dislike having to add python usage specific methods to the library, for our design and vision values / reasons. Kind Regards, Christoff

1 1

BGL - maximum_adjacency_search - assignedVertices
by Adam Celick 14 Oct '14

14 Oct '14

I was looking at the implementation of maximum_adjacency_search algorithm and got confused by the assignedVertices local variable. It is defined as a set of vertex descriptors and is being iterated over inside the main loop (lines 168-184) but it is never inserted into. So the for loop will always skip. It looks to me as if that part of the code can be eliminated. Am I missing something? Thanks, Adam

1 0

Generating kuratowski subgraph with external edge index map
by Amir Hassan 13 Oct '14

13 Oct '14

Hi! I have a graph which i test for planarity and in case the test fails i want to generate the kuratowski subgraph. I have code that used to compile with boost graph 1.36 but doesn't with 1.56. I guess the problem has to do with the type of the edge index map. you can find code and error messages here: http://stackoverflow.com/questions/26346343/c-boost-graph-generating-kurato… Help is greatly appreciated! greets, amir

1 0

[interprocess 1.42] Copy multiple variables into shared memory
by Michael Behnke 13 Oct '14

13 Oct '14

Hello, I'm trying to write multiple variables one by one into a mapped_region, but somehow I fail. Here is the Code I worked on so far: boost::interprocess::shared_memory_object shm_obj(boost::interprocess::open_or_create, "Test", boost::interprocess::read_write); shm_obj.truncate(1000); boost::interprocess::mapped_region region(shm_obj, boost::interprocess::read_write, 0, 0); uint32_t size = 33; uint32_t type = 666; std::string data("I'm a Test!"); uint32_t* start_ptr_int = &(static_cast<uint32_t*> (region.get_address())[0]); std::memcpy(start_ptr_int, &size, sizeof (uint32_t)); start_ptr_int = &(static_cast<uint32_t*> (region.get_address())[4]); std::memcpy(start_ptr_int, &type, sizeof (uint32_t)); char* start_ptr_char = &(static_cast<char*> (region.get_address())[8]); std::memcpy(start_ptr_char, data.c_str(), data.length()); uint32_t sizeOfData; std::memcpy(&sizeOfData, &(static_cast<uint32_t*> (region.get_address())[0]), sizeof (uint32_t)); uint32_t typeOfData; std::memcpy(&typeOfData, &(static_cast<uint32_t*> (region.get_address())[4]), 4); char* revData = new char[sizeOfData]; std::memcpy(revData, &(static_cast<char*> (region.get_address())[sizeof (uint32_t) * 2]), sizeOfData); First I write an uint32_t into the region at index 0. Afterwards, I'm writing another uint32_t at position 4 (assuming the first uint32_t took the bytes 0 - 3). Last I write a string into the region, at index 8. Reading the first uint32_t again from shared memory works fine, as does reading the string (the last variable). But if I try to read the second variable (uint32_t) the data is not what I expected. I know that the problem is memcpy, somehow my syntax does not work. Unfortunately I could not find a matching example, cause mostly memset is used to explain the functionality of boost::mapped_region. I have to write lots of data into shared memory (structured like size1|type1|data1|...|sizeN|typeN|dataN) but still can't figure out how to do this the right way. Any suggestions are greatly appreciated. Kind regards Michael Behnke -- Bachelorand ________________________________________________________ ADITION technologies AG Schwarzwaldstraße 78b 79117 Freiburg http://www.adition.com T +49 / (0)761 / 88147 - 30 F +49 / (0)761 / 88147 - 77 SUPPORT +49 / (0)1805 - ADITION (Festnetzpreis 14 ct/min; Mobilfunkpreise maximal 42 ct/min) Eingetragen beim Amtsgericht Düsseldorf unter HRB 54076 Vorstände: Andreas Kleiser, Jörg Klekamp, Marcus Schlüter Aufsichtsratsvorsitzender: Joachim Schneidmadl UStIDNr.: DE 218 858 434

1 0

Boost Locale – accessing ICU functions directly
by Caroline Beltran 10 Oct '14

10 Oct '14

I recently began using Boost Locale traversing and boundary analysis of Unicode strings. I’ve used some of the features available for case conversion, i.e.: to_upper(), which appears to wrap ICU’s toUpper() function. I didn’t find Boost Locale wrappers for other ICU functions such as u_isalpha() or u_isalnum(). How can I these ICU functions? Thank you!

1 0

Are shared memory files distributable?
by Rajalakshmi Iyer 10 Oct '14

10 Oct '14

Hello, Is it possible to create a shared memory file using Boost Interprocess (with STL containers) and distribute it to several machines for reading and modifying independently? Thanks Raj -- @BlisMedia <http://twitter.com/BlisMedia> www.blismedia.com <http://blismedia.com> This email and any attachments to it may be confidential and are intended solely for the use of the individual to whom it is addressed. Any views or opinions expressed are solely those of the author and do not necessarily represent those of BlisMedia Ltd, a company registered in England and Wales with registered number 06455773. Its registered office is 3rd Floor, 101 New Cavendish St, London, W1W 6XH, United Kingdom. If you are not the intended recipient of this email, you must neither take any action based upon its contents, nor copy or show it to anyone. Please contact the sender if you believe you have received this email in error.

2 1

[make_shared] How to use boost::make_shared with more than 9 arguments
by dariomt＠gmail.com 10 Oct '14

10 Oct '14

I could patch my local copy with several more overloads (I need up to 12 parameters) but, is there a better way? I cannot change the constructor of the class to group parameters (as recommended in StackOverflow). Of course this is for C++03 Regards

2 1

Re: [Boost-users] Flyweight: wrapping shared_ptr
by Joaquin M Lopez Munoz 10 Oct '14

10 Oct '14

> De: Boost-users [mailto:boost-users-bounces@lists.boost.org] > En nombre de Akim Demaille > Enviado el: martes, 07 de octubre de 2014 18:27 > Para: Boost Users List > Asunto: Re: [Boost-users] Flyweight: wrapping shared_ptr > > Le 7 oct. 2014 à 18:18, Joaquín Mª López Muñoz <joaquin(a)tid.es> a écrit : > > > An alternative would be to use some sort of cloning smart pointer to > > spare the reference count, but it's not clear to me this would be > > faster than > > shared_ptr: > > > > * element exists: shared_ptr creation is slower than clone_ptr > > creation > > * element does not exist: shared_ptr creation and copy is probably > > faster than clone_ptr creation and cloning. > > Yes, indeed. A slightly smarter approach involves a cloning class that accepts a const Base& and does only clone on copy, thus avoiding dynamic memory allocation when the element already exists. This can be nicely wrapped up as follows: template<typename Base> class poly_holder { public: poly_holder(const Base& x):p(&x),dlt(false){} poly_holder(const poly_holder& x):p(x.p->clone()),dlt(true){} poly_holder& operator=(const poly_holder& x) { Base* q=x.p->clone(); if(dlt)delete p; p=q; dlt=true; return *this; } ~poly_holder(){if(dlt)delete p;} operator const Base&()const {return *p;} private: const Base* p; bool dlt; }; template<typename Base> class poly_flyweight:public boost::flyweight<poly_holder<Base>> { public: using super=boost::flyweight<poly_holder<Base>>; using super::super; const Base& operator*() const{return base();} const Base* operator->()const{return &base();} private: const Base& base()const{return this->get();} }; template<typename Base> std::size_t hash_value(const poly_flyweight<Base>& x) { return boost::hash<const Base*>()(&*x); } template<typename Base> bool operator==( const poly_flyweight<Base>& l,const poly_flyweight<Base>& r) { return static_cast<boost::flyweight<poly_holder<Base>>>(l)== static_cast<boost::flyweight<poly_holder<Base>>>(r); } template<typename Base> bool operator!=( const poly_flyweight<Base>& l,const poly_flyweight<Base>& r) { return !(l==r); } I've rewritten your test case to take advantage of this poly_flyweight thing, cleaning up some unnecessary hash and operator== overloads along the way and without resorting to the intermediate Exp_ type; see: http://coliru.stacked-crooked.com/a/76e87531b65d44f9 > Is there anyway Flyweight could have supported the operator-> natively? > It seems that with some SFINAE under the hood, it would work, don't you think? Yep, that would be possible, the only reason I didn't do it is to not clutter the interface. Also, some std classes such as (C++17) std::optional implement operator* differently, without the extra dereference required by smart pointer semantics. Joaquín M López Muñoz Telefónica

3 20

Boost.Geometry, probable bug in point_on_surface
by Petr Doubrava 10 Oct '14

10 Oct '14

#include <boost/geometry.hpp> #include <boost/geometry/geometries/point_xy.hpp> #include <boost/geometry/geometries/polygon.hpp> void test_point_on_surface() { typedef boost::geometry::model::point<double, 2, boost::geometry::cs::cartesian> Point; boost::geometry::model::polygon<Point> poly; boost::geometry::read_wkt("POLYGON((1074699.93 703064.65, 1074702.10 703054.62, 1074704.53 703061.40, 1074703.90 703064.58, 1074699.93 703064.65))",poly); boost::geometry::correct(poly); Point point; boost::geometry::point_on_surface(poly,point); //computed point isn't on the surface of polygon //[0] 1074839.1013086310 double //[1] 703154.77900308778 double bool res = boost::geometry::within(point,poly); // res is false }

2 2

[property_tree] Failure with Boost 1.56
by beet 10 Oct '14

10 Oct '14

Dear all, with the release of Boost 1.56, on Ubuntu 14.04 (g++ 4.8.2, 64 bit), code like the following suddenly fails to compile: pt::xml_writer_settings<char> settings('\t', 1); pt::write_xml(someFileName, ptr_out, std::locale(), settings); "pt" is obviously an alias for boost::property_tree. The error message I'm getting is /opt/boost156/include/boost/property_tree/detail/xml_parser_writer_settings.hpp:38:35: error: 'char' is not a class, struct, or union type typedef typename Str::value_type Ch; I can see the following possibly relevant change in property_tree: In Boost 1.55, from xml_parser.hpp: ----------------------------------- template<typename Ptree> void write_xml( const std::string & , const Ptree & , const std::locale & = std::locale() , const xml_writer_settings<typename Ptree::key_type::value_type >& = xml_writer_settings<typename Ptree::key_type::value_type >() ); In Boost 1.56, same header: --------------------------- template<typename Ptree> void write_xml( const std::string & , const Ptree & , const std::locale & = std::locale() , const xml_writer_settings<typename Ptree::key_type > & = xml_writer_settings<typename Ptree::key_type >() ); So xml_writer_settings is now given a Ptree::key_type instead of a Ptree::key_type::value_type which I assume is the reason for the above error. Is there a portable way to specify the type of indention character in write_xml ? Best Regards, Beet

2 1

[Boost.Polygon] Bug in polygon_set_data, or are my expectations wrong?
by Patrick J. LoPresti 09 Oct '14

09 Oct '14

I have just submitted a bug report: https://svn.boost.org/trac/boost/ticket/10642 ...but I am wondering if the bug is in my understanding rather than in Boost.Polygon. The test case is very simple, so I am appending it to this message. My question is, should I expect polygon_set_data<int> to scramble such a simple figure? It almost looks like some (but not all) of the coordinates are being snapped to multiples of 2. Or something. Note that doubling all of the coordinates avoids the bug. Assuming it is a bug (?) Thanks! - Pat #include <boost/polygon/polygon.hpp> #include <iostream> #include <cstdlib> namespace bp = boost::polygon; using namespace bp::operators; typedef bp::polygon_set_data<int> PolygonSet; typedef bp::polygon_data<PolygonSet::coordinate_type> Polygon; typedef bp::polygon_traits<Polygon>::point_type Point; int main(int argc, char *argv[]) { // Small figure with a little hole. Area should be 32. const Point points[] = { Point(0,0), Point(6,0), Point(6,4), Point(4,6), Point(0,6), Point(0,0), Point(4,4), Point(5,4) }; Polygon poly1(&points[0], &points[sizeof(points)/sizeof(points[0])]); PolygonSet ps1; ps1 += poly1; std::cout << "poly1 area == " << area(poly1) << "\n"; // Boost.Polygon says the area of ps1 is 30. That is because its internal // representation is wrong, as you can confirm by manually // examining the result of ps1.get() or ps1.get_trapezoids(). std::cout << "ps1 area == " << area(ps1) << "\n"; // Doubling the coordinates avoids the bug. Polygon poly2(poly1); scale_up(poly2, 2); PolygonSet ps2; ps2 += poly2; std::cout << "poly2 area == " << area(poly2) << "\n"; std::cout << "ps2 area == " << area(ps2) << "\n"; assert(area(poly2) == area(ps2)); assert(area(poly1) == area(ps1)); }

1 0

[polygon] Incorrect output from get_trapezoids(..., HORIZONTAL)
by Patrick J. LoPresti 08 Oct '14

08 Oct '14

I apologize for sending this to the mailing list, but when I tried to file a bug report via Trac, it said "Trac thinks your submission might be Spam. To prove otherwise please provide a response to the following"... And then there was no "following". Please let me know if there is a better forum to report this sort of issue. I am using Boost 1.56. The following program uses boost::polygon to slice up a figure (with a "hole" cut out of it) into horizontal trapezoids. The output I get is: Output: polygon (4 3) (4 0) (0 0) (0 3) (4 3) ...which is clearly wrong. I am pretty sure my code is correct, because if I replace bg::HORIZONTAL with bg::VERTICAL, I get the correct output of a bunch of vertical trapezoids. For my application, I really want horizontal traps. I suppose I can just swap x and y on input and output... But this seemed worth reporting. Thanks. - Pat #include <boost/polygon/polygon.hpp> #include <iostream> namespace bp = boost::polygon; typedef bp::polygon_set_data<int> PolygonSet; typedef bp::polygon_data<PolygonSet::coordinate_type> Polygon; typedef bp::polygon_traits<Polygon>::point_type Point; std::ostream & operator<<(std::ostream &os, const Point &pt) { return os << "(" << bp::x(pt) << " " << bp::y(pt) << ")"; } std::ostream & operator<<(std::ostream &os, const Polygon &poly) { os << "polygon "; for (Polygon::iterator_type p = poly.begin() ; p != poly.end() ; ++p) os << " " << *p; return os; } std::ostream & operator<<(std::ostream &os, const PolygonSet &ps) { std::vector<Polygon> temp; ps.get(temp); os << "polygonset "; for (std::vector<Polygon>::const_iterator p = temp.begin() ; p != temp.end() ; ++p) os << " " << *p; return os; } int main(int argc, char *argv[]) { const Point points[] = { Point(2,0), Point(4,0), Point(4,3), Point(0,3), Point(0,0), Point(2,0), Point(2,1), Point(1,1), Point(1,2), Point(3,2), Point(3,1), Point(2,1) }; Polygon poly; bp::set_points(poly, &points[0], &points[sizeof(points)/sizeof(points[0])]); std::cout << "Input: " << poly << "\n"; PolygonSet ps; ps.insert(poly); std::cout << "ps = " << ps << "\n"; std::vector<Polygon> traps; // Note: bp::VERTICAL works fine bp::get_trapezoids(traps, ps, bp::HORIZONTAL); std::cout << "Output:\n"; for (std::vector<Polygon>::const_iterator p = traps.begin() ; p != traps.end() ; ++p) std::cout << *p << "\n"; }

2 2

program_options: Make PO not eat argc
by Florian Lindner 08 Oct '14

08 Oct '14

Hello, I have a couple of libraries (MPI, petsc) that also consume my applications argc and argv, which is parsed with boost::program_options before. po seems to eat up argv, i.e. removes all items that it handles. Can I disable that behavior somehow so that po does not touch argc/argv. Or do I need to recreate it, e.g. using collect_unrecognized? Thanks, Florian

2 2

program_options: How to best model two/three pos args
by Florian Lindner 08 Oct '14

08 Oct '14

Hello, my application has positional arguments like that: Run tests : ./app test ConfigurationName PathToSrc Run server : ./app server ParticipantName ConfigurationName Print XML reference: ./app xml Linewidth It has three (if first in [test, server]) or two (if first in [xml]) positional arguments. How to model and test this best using boost? I could add three options and declare them as positional arguments, named like "first", "second", "third". I could also use just one positional argument like: po::positional_options_description pos_dec; pos_dec.add("positionals", 3); and test the resulting vector. What do you think? Thanks, Florian

2 1

MSM to diagram
by Robert Bielik 08 Oct '14

08 Oct '14

Hi all, I want to use MSM in an application, however, for design documentation purposes I'd like to be able to express the state machine in a diagram. And preferably going the route from C++ code -> graphical diagram (i.e. not from UML -> C++ code). Has anyone looked at that, or know of resources on how to accomplish this ? TIA /Robert

1 0

[general] Advice from Bjarne Stroustrup
by legalize+jeeves＠mail.xmission.com 06 Oct '14

06 Oct '14

[Please do not mail me a copy of your followup] At the end of each chapter in "The C++ Programming Language", 4th edition, Bjarne Stroustrup has a list of advice. I found the advice very helpful and decided that the advice should be online somewhere. Initially I put this together as a PPT presentation, but oh my lord, it was too long. Instead, I made a page in my user space on the cppreference.com wiki: <http://en.cppreference.com/w/User:Legalize/Advice_from_Bjarne_Stroustrup> This let me link to other pages on the wiki describing specific language features where possible. Hopefully you will find it useful. -- "The Direct3D Graphics Pipeline" free book <http://tinyurl.com/d3d-pipeline> The Computer Graphics Museum <http://computergraphicsmuseum.org> The Terminals Wiki <http://terminals.classiccmp.org> Legalize Adulthood! (my blog) <http://legalizeadulthood.wordpress.com>

2 1

NT² eand Boost.SIMD release 3.1
by Joel FALCOU 06 Oct '14

06 Oct '14

NT2 is a Matlab inspired, high-level API for scientific computation in C++. Boost.SIMD is a candidate library for inclusion in Boost dealing with the portable encpsulation of SIMD instructions sets. This following releases updates NT2 and Boost.SIMD libraries to version 3.1 This new release of NT2 and Boost.SIMD focused on fixing performance issues and add some new support for architecture and parallel algorithms. The main new features include: - Linear Algebra functions can now use GPGPU through the MAGMA library whenever possible. - Reduction and Scan operations now works with more shared memory back-end - Altivec support is now complete for the VMX ISA We wish to thanks Ian Masliah for his work on MAGMA, Antoine Tran Tan for the shared memory support and Pierre Esterie participation to the Altivec ISA completion. Special thanks to Tim Blenchmann and khegeman for their help and patch submisisons throughout this development. The release Changelog is here : https://github.com/MetaScale/nt2/releases/tag/3.1.0 The files can be download from : http://nt2.metascale.org/downloads/ The Documentation (in progress) is here : http://nt2.metascale.org/doc/html/index.html **Next release announcment** This release is the last C++03 compliant version of both NT2 and Boost.SIMD. The next release - 4.0 - will be C++11 only. The new minimal version of supported compilers will be : - g++ 4.6 - Microsoft Visual Studio 12 (2013) - clang 3.4 - icc 12.1 The main reason for this change is to be able to properly fix the compile-time issue that one may experience. It'll also allow us to use some C++11 feature to simplify or streamline some of the user interface. * The NT2 Team

1 0

[bimap] Look ups on the vector_of collection type
by Arindam Mukherjee 05 Oct '14

05 Oct '14

Would it make sense to define a bimap like this: boost::bimap< boost::bimaps::set_of<std::string>, boost::bimaps::vector_of<std::string>> mymap; And then make the right view (vector_of) more amenable to lookups by performing a sort followed by a binary search on it? Thanks.

1 0

Flat multi set operation costs
by Paolo Bolzoni 03 Oct '14

03 Oct '14

Dear list, In a project of mine I am using a sorted vector as a multimap. The point was that insert, delete and retrieval operations arrived in batches (lots of inserts, lots of retrieval, lots of deletes...) so I essentially saved time sorting the vector when a new kind of operation arrived. I recently noticed boost has the flat multiset implementation, so I was wondering do it follows the same idea? If it does I would be nice to kick-out some code and use the library for ease of maintenance. Your faithfully, Paolo

2 1

boost python wrapping class with getter/setter with const string& arg and return type
by MM 03 Oct '14

03 Oct '14

Hi class C { public: const std::string& get_name() const; void set_name(const std::string&); private: std::string name_; }; given this class C, how would I expose it to python with the class property name? class_<C>("C"). .add_property("name", &C::get_name, &C::set_name); with the proper includes as in the tutorial, it fails to compile. MM

1 0

[Test] Global Fixtures
by Mauricio Carneiro 03 Oct '14

03 Oct '14

I am trying to use global fixtures in my tests but I may be misinterpreting the documentations. The following toy example doesn't work : #include <boost/test/unit_test.hpp> struct TruthFixture { int x = 3; int f (int a) { return a + 3; } }; BOOST_GLOBAL_FIXTURE( TruthFixture ) BOOST_AUTO_TEST_CASE(test_variable) { printf("x = %d\n", x); } BOOST_AUTO_TEST_CASE(test_function) { printf("f(2) = %d\n", f(2)); } the error message I get is the following: test/test.cpp:14:22: error: use of undeclared identifier 'x'; did you mean 'TruthFixture::x'? printf("x = %d\n", x); ^ TruthFixture::x test/test.cpp:4:7: note: 'TruthFixture::x' declared here int x = 3; ^ test/test.cpp:14:22: error: invalid use of non-static data member 'x' printf("x = %d\n", x); ^ test/test.cpp:18:25: error: use of undeclared identifier 'f'; did you mean 'TruthFixture::f'? printf("f(2) = %d\n", f(2)); ^ TruthFixture::f test/test.cpp:6:7: note: 'TruthFixture::f' declared here int f (int a) { ^ test/test.cpp:18:25: error: call to non-static member function without an object argument printf("f(2) = %d\n", f(2)); ^ 4 errors generated. clearly the BOOST_GLOBAL_FIXTURE declaration is not doing anything. But if I drop the global fixture declaration and revert to the per function declaration, it works: #include <boost/test/unit_test.hpp> struct TruthFixture { int x = 3; int f (int a) { return a + 3; } }; BOOST_FIXTURE_TEST_CASE(test_variable, TruthFixture) { printf("x = %d\n", x); } BOOST_FIXTURE_TEST_CASE(test_function, TruthFixture) { printf("f(2) = %d\n", f(2)); } then everything works perfectly as intended. Any input on what I am doing wrong with the *global* fixture declaration? Thank you! Mauricio Carneiro, Ph.D. http://www.broadinstitute.org/~carneiro/

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[Boost] [DateTime] dividing a time_period in N time_periods
by Pablo Madoery 02 Oct '14

02 Oct '14

Hi, I want to make a method which divides a time_period in N time periods, something like this: list<time_period> splitTimePeriod(time_period timePeriod, int n); I actually have made it and although it seems to work it results very inefficient regarding the time it took to divide a large time_period. The method I did is this: list<time_period> splitTimePeriod(time_period timePeriod, int n) { double secsTime = dateTime::diffSeconds(timePeriod.end(), timePeriod.begin()); // tiempo en segundos de cada período de tiempo double ti = secsTime / n; list<time_period> timePeriods; // tiempo de comienzo del primer período de tiempo ptime tpBegin = timePeriod.begin(); // tiempo de fin del último período de tiempo ptime tpLastEnd = timePeriod.end(); for (int i = 0; i < n; i++) { int tUnits = ti * time_duration::ticks_per_second(); // tiempo de comienzo del siguiente período de tiempo ptime tpNextBegin = dateTime::increment(tpBegin, tUnits); // tiempo de fin del período de tiempo ptime tpEnd; if (i == n - 1) { tpEnd = tpLastEnd; } else { tpEnd = dateTime::decrement(tpNextBegin, 1); // guarda para evitar que por cuestiones // de redondeo, el tiempo final de un período // sea mayor que el pasado inicialmente // como argumento de entrada if (tpEnd > tpLastEnd) { tpEnd = tpLastEnd; } } time_period p(tpBegin, tpEnd); // se inserta período de tiempo en la lista timePeriods.push_back(p); // se actualiza el comienzo del siguiente período de tiempo tpBegin = tpNextBegin; } return timePeriods; } Other methods I use are these: double diffSeconds(const ptime &dateA, const ptime &dateB) { time_duration diff = dateA - dateB; return diff.total_seconds(); } ptime increment(const ptime &date, int n) { time_iterator it(date, dateTime::unit); for (int i = 0; i < n; i++) { ++it; } return *it; } ptime decrement(const ptime &date, int n) { time_iterator it(date, dateTime::unit); for (int i = 0; i < n; i++) { --it; } return *it; } const time_duration unit = microseconds(1); ################################################# The question is: is there a better way to accomplish this?

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[mpl] struct definition and mpl sequence in one shot?
by Adam Romanek 01 Oct '14

01 Oct '14

Hi! I have a problem and I'm not sure how to approach it. Currently my code looks like this: struct Definition { typedef boost::mpl::int_<5> A; typedef boost::mpl::int_<3> B; typedef boost::mpl::int_<6> C; typedef boost::mpl::int_<1> D; typedef boost::mpl::vector<A, B, C, D> Seq; }; Here, the number N in mpl::int_< N > denotes some arbitrary decimal number. Then some other code calculates the sum of these numbers up to the type defined by "key", e.g. for Definition::D, the sum is 5 + 3 + 6 (A + B + C). This needs to be done at compile-time. That's why I use mpl::vector and some appropriate meta-programming. I'm wondering whether it would be possible to provide such struct definition without the need to repeat type names in the mpl::vector for Seq type. In other words, I'd probably need a bunch of macros which would allow me to write code like this: struct Definition { FIELD(A, 5); FIELD(B, 3); FIELD(C, 6); FIELD(D, 1); GEN_SEQ() // if needed }; And then Definition::A would still refer to boost::mpl::int_<5>, or would at least allow me to access the boost::mpl::int_<5> somehow, and Definition::Seq would give me the appropriate MPL sequence. Of couse this is just my imagination. The code might look different, I'm just looking for options. Thanks in advance. Adam Romanek

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[Build] -finline-functions no longer supported in clang 3.5
by Mauricio Carneiro 01 Oct '14

01 Oct '14

Hi all, turns out clang 3.5 is no longer supporting <http://llvm.org/klaus/clang/commit/6590426aeb5275ec33dac2877f9349bbbb2d4b2e…> -finline- <http://llvm.org/klaus/clang/commit/6590426aeb5275ec33dac2877f9349bbbb2d4b2e…> functions <http://llvm.org/klaus/clang/commit/6590426aeb5275ec33dac2877f9349bbbb2d4b2e…>, which it claims never did anything anyway, so this is their way to take it out of usage. My release builds (which are done solely through boost build) automatically add this parameter to the compilation command line, and thus is now failing (since I use -Werror). Is there a way to modify the "release" variant not to use that line anymore? Also, is there a way to extend the command line parameters that the release variant will use? Thank you, Mauricio Carneiro, Ph.D. http://www.broadinstitute.org/~carneiro/

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boost::log native syslog sink.
by svante karlsson 01 Oct '14

01 Oct '14

I'm using ubuntu 14.04 with the included boost 1.54 and I'm trying to set up a syslog sink. I've cut this from the samples and added "ident". void init_syslog() { boost::shared_ptr< boost::log::core > core = boost::log::core::get(); // Create a backend boost::shared_ptr< sinks::syslog_backend > backend(new sinks::syslog_backend( keywords::facility = sinks::syslog::local0, keywords::use_impl = sinks::syslog::native, keywords::ident = "mqtt-proxy" )); // Set the straightforward level translator for the "Severity" attribute of type int backend->set_severity_mapper(sinks::syslog::direct_severity_mapping< int >("Severity")); // Wrap it into the frontend and register in the core. // The backend requires synchronization in the frontend. core->add_sink(boost::make_shared< sink_t >(backend)); } The logs end up in syslog but I cant prefix those by program name (and processnumber ) - I've expected the logs to be marked as 'mqtt-proxy' I get logs like Sep 29 03:47:40 ubuntu : ad569c57-780a-431b-bde3-7ede49e7c77f, bridge create but what I would like is similar to Sep 29 03:47:40 ubuntu mqtt-proxy: ad569c57-780a-431b-bde3-7ede49e7c77f, bridge create Am I missing something or is ident not supported? /svante

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[Threads] and OpenMP
by Stephan Menzel 01 Oct '14

01 Oct '14

Hi all, I would like to ask around about a strategy on how to tacke the following threading problem: I am maintaining a boost intensive portable C++ client-server application and recently have included a highly complex 3rd party algorithm into my application that does CPU intense stuff. Long running stuff. Often in the range of days. While at the same time being heavy in OpenMP usage. Now of course requirements are that the user has to be able to cancel this. The algorithm runs in a boost threads controlled background thread. Now I began to place interruption points throughout the 3rd party code but soon had to realize that a lot of CPU time is being handled in OpenMP threaded code regions. So the question is: How can I more or less gracefully shut this down? How do interruption points work in an omp parallel for loop? Do I have a chance at all? My constraints here are a bit forgiving. Given the complexity of the 3rd party code I have already accepted the notion that this is gonna be a memleak monster. Luckily, there's no disk or other hardware access so I'm ready to live with a certain amount of mem not being cleaned up. Yet the backend thread communicates with the spawning class by calling a mutexed callback when it's ready so the user knows it's cancelled. This is protected by a boost mutex as well. And juding from the horrible threading "clogs" that I observed in my first trials I suppose this is gonna be a problem as well. And input is appreciated. And yes, I am aware that this is gonna be an ugly mess. Cheers, Stephan

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Re: [Boost-users] choosing source ip on multihomed computer (Bjorn Reese)
by David Frank 01 Oct '14

01 Oct '14

I did, here is my relevant code segment, but the destination still shows that I sent from another ip than what I set here: tcp::resolver resolver(fIo_service); tcp::resolver::query query(tcp::v4(), host, port); tcp::resolver::iterator iterator = resolver.resolve(query); fpSocket = new tcp::socket(fIo_service); if (fpSocket == nullptr) return ; fpSocket->open(boost::asio::ip::tcp::v4()); fpSocket->bind(boost::asio::ip::tcp::endpoint(boost::asio::ip::address::from_string("<ip>"), 0)); boost::system::error_code errcode; boost::asio::connect(*fpSocket, iterator, errcode); On Tuesday, September 30, 2014 12:00 PM, "boost-users-request(a)lists.boost.org" <boost-users-request(a)lists.boost.org> wrote: Send Boost-users mailing list submissions to boost-users(a)lists.boost.org To subscribe or unsubscribe via the World Wide Web, visit http://lists.boost.org/mailman/listinfo.cgi/boost-users or, via email, send a message with subject or body 'help' to boost-users-request(a)lists.boost.org You can reach the person managing the list at boost-users-owner(a)lists.boost.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Boost-users digest..." Today's Topics: 1. Re: choosing source ip on multihomed computer (Bjorn Reese) 2. Re: [Threads] and OpenMP (Bjorn Reese) ---------------------------------------------------------------------- Message: 1 Date: Tue, 30 Sep 2014 15:58:37 +0200 From: Bjorn Reese <breese(a)mail1.stofanet.dk> To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] choosing source ip on multihomed computer Message-ID: <542AB70D.6060807(a)mail1.stofanet.dk> Content-Type: text/plain; charset=windows-1252; format=flowed On 09/30/2014 03:04 PM, David Frank wrote: > I'm wondering how to make boost::asio::connect(<socket>, ...) > connect from the source interface/ip address I choose on a multihomed > computer. Call bind() before connect(). ------------------------------ Message: 2 Date: Tue, 30 Sep 2014 15:59:43 +0200 From: Bjorn Reese <breese(a)mail1.stofanet.dk> To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] [Threads] and OpenMP Message-ID: <542AB74F.4010303(a)mail1.stofanet.dk> Content-Type: text/plain; charset=windows-1252; format=flowed On 09/30/2014 11:24 AM, Stephan Menzel wrote: > So the question is: How can I more or less gracefully shut this down? > How do interruption points work in an omp parallel for loop? Do I have a > chance at all? One approach is to execute the tasks in a separate process. The process can easily be killed, and it takes care of the memory leaks. ------------------------------ Subject: Digest Footer _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users ------------------------------ End of Boost-users Digest, Vol 3932, Issue 2 ********************************************

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