March 2015 - 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] Crashing Issue
by swati upadhyaya 04 Nov '15

04 Nov '15

hi I am using like this where RunningThreads_ is vector containing boost thread object pointer(handler).I am using interrupt() for the interruption of thread interruption_point() catching that interruption then joining.everytime its crashing in join() for me but for others who have the same configuration its working fine all of us has windos 8. For me also it was working last week but this week the same piece of code is crashing. :( RunningThreads_[i].handle->interrupt(); RunningThreads_[i].handle->join(); delete RunningThreads_[i].handle; On Thu, Feb 5, 2015 at 9:31 AM, swati upadhyaya <swatiupadhyaya(a)gmail.com> wrote: > RunningThreads_[i].handle->interrupt(); > LOG4CPLUS_INFO(root, "Thread Interrupted for " << > RunningThreads_[i].app_name << " successful"); > RunningThreads_[i].handle->join(); > LOG4CPLUS_INFO(root, "Waiting for thread to exit " << > RunningThreads_[i].app_name << " successful"); > delete RunningThreads_[i].handle; > LOG4CPLUS_INFO(root, "Thread handle for " << > RunningThreads_[i].app_name << " successfully deleted"); > //RunningThreads_.erase(i); > > On Wed, Feb 4, 2015 at 12:10 AM, Vicente J. Botet Escriba < > vicente.botet(a)wanadoo.fr> wrote: > >> Le 03/02/15 09:10, swati upadhyaya a écrit : >> >> In my code join() timed_joined() is crashing, I am using these API >> after interrupt(),Same piece of code is working for others but in my system >> its crashing, >> Is there some dependency problem I am using >> Boost version: 1.55.0 >> OS: Windows 8 >> IDE: Visual Studio 2010 >> >> Hi, >> >> it could help if you post the example and the backtrace. >> >> Which version/OS/compiler use others for which this works? >> >> Vicente >> >> _______________________________________________ >> Boost-users mailing list >> Boost-users(a)lists.boost.org >> http://lists.boost.org/mailman/listinfo.cgi/boost-users >> > >

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Some strange boost headers errors
by alfonso santimone 15 May '15

15 May '15

Hi guys, i'm a boost newbie. I've got to include boost libraries in the include path of a VisualStudio 2012 project. When i try to compile i have all these errors. Every errors is related to missing headers ( boost ones and even standard Win ones ) and to synthax errors depending on missing headers i guess. Do someone have any idea on what's wrong here? I just post here a few lines of errors, but the other ones are all of the same kind Error 1 error C2061: syntax error : identifier 'boost' C:\boost_1_57_0\boost\core\ checked_delete.hpp 24 1 csound~ Error 2 error C2059: syntax error : ';' C:\boost_1_57_0\boost\core\checked_delete.hpp 24 1 csound~ Error 3 error C2449: found '{' at file scope (missing function header?) C:\boost_1_57_0\boost\core\checked_delete.hpp 25 1 csound~ Error 4 error C2059: syntax error : '}' C:\boost_1_57_0\boost\core\checked_delete.hpp 67 1 csound~ Error 5 error C2054: expected '(' to follow 'using' C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\cstddef 19 1 csound~ Error 6 error C2061: syntax error : identifier 'using' C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\cstddef 19 1 csound~ Error 7 error C2061: syntax error : identifier 'boost' C:\boost_1_57_0\boost\smart_ptr\detail\sp_nullptr_t.hpp 23 1 csound~ Error 8 error C2059: syntax error : ';' C:\boost_1_57_0\boost\smart_ptr\detail\sp_nullptr_t.hpp 23 1 csound~ Error 9 error C2449: found '{' at file scope (missing function header?) C:\boost_1_57_0\boost\smart_ptr\detail\sp_nullptr_t.hpp 24 1 csound~ Error 10 error C2059: syntax error : '}' C:\boost_1_57_0\boost\smart_ptr\detail\sp_nullptr_t.hpp 41 1 csound~ Error 11 error C2054: expected '(' to follow 'using' C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\cstdlib 19 1 csound~ Error 12 error C2061: syntax error : identifier 'using' C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\cstdlib 19 1 csound~ Error 13 error C2061: syntax error : identifier 'abort' C:\Program Files (x86)\Microsoft Visual Studio many thanks in advance bests alfonso www.elgallorojorecords.com soundcloud.com/alfonsosantimone www.facebook.com/alfonsosantimone

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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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Re: [Boost-users] [boost] [test] boost.test owner unresponsive to persistent problems for multiple years
by Paul A. Bristow 24 Apr '15

24 Apr '15

> -----Original Message----- > From: Boost [mailto:boost-bounces@lists.boost.org] On Behalf Of Richard > Sent: 17 March 2015 17:20 > To: boost(a)lists.boost.org > Subject: Re: [boost] [test] boost.test owner unresponsive to persistent problems for multiple years > > Another quarter has gone by and another Boost release is prepared for beta and I see *no* changes to > Boost.Test listed in the release notes.> > So here we are, waiting another 3 months for *simple* changes to be reflected in this library while the > maintainer insists that the fixes are available, yet they continue not to be deployed into any shipping release. It is indeed really deplorable that we don't have Boost.Test updates in a release. Though in mitigation I note that we are really struggling to get out a GIT-driven release at all, (and some of the new troubles are with asynch-exceptions in Boost.Test. See this thread Re: [boost] Running b2 on develop needs asynch-exceptions=on.) However, Richard's hard work on improved docs have been refined and completed by Raffi Enficiaud. Many bug fixes are in the develop branch (including some very new and prompt bug fixes, for example https://svn.boost.org/trac/boost/ticket/11054). I also understand that the fear of Boost.Test updates causing trouble with other libraries, and worse with users test, is a cause for caution in a release version. So it would be really good if *lots more users could download and use the version in the Boost.Test develop branch* so we can get current user feedback. (My experience is good using this, and the test matrix is also good). You can download just Boost.Test either using GIT or as a zip from https://github.com/boostorg/test/tree/develop and substitute it for the contents of the current release modular-boost/libs/test folder (Don't forget to rebuild the Boost.Test library unless you only use the included version). If nothing else, you will find Raffi's shiny new Boostbook docs finally allow you to find what you want to know without frustration. I'd very much like to see this new docs version in the 1.58 documentation release (despite any new features not being in the code release). Paul --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830

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SSL certificate expired
by Martin Honermeyer 10 Apr '15

10 Apr '15

Hi, I just wanted to post a note in case administrators are not yet aware: The SSL certificate for *.boost.org has expired and needs to be replaced. This affects e.g. https://svn.boost.org/. Best, Martin

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[polygon] Voronoi diagram: weird results
by Jeremy Murphy 03 Apr '15

03 Apr '15

Hi, I started using the voronoi_diagram functionality recently and am getting some weird results that I need help interpreting. Here is an example: https://drive.google.com/open?id=0B9-L1xN12iKVYUlMb1hLY0FEMWs&authuser=0 What you can see here is a salmon (?) coloured layer of polygons (input) underneath a semi-transparent layer of pale blue polygons (output) and a boundary. So you can see that some of the output looks 'good', as in, regular and usable, but on the right-hand side there is some obvious 'bad' results that I cannot completely explain. The missing polygons are almost certainly because I have culled any polygons from the output that included points outside the boundary. But there are also appears to be some 'bad' polygons in the output that overlap 'good' ones. So I guess my initial question is: is this a typical symptom of something that other users of the voronoi_diagram recognize? I'm using Boost.Geometry for all other geometric processing. Thanks, cheers. Jeremy

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Cross compiling boost 1.55 static libs
by Pham Ngoc Hai 01 Apr '15

01 Apr '15

Hi guys, I'm trying to cross compile boost for armhf but some of the functions seem to be missed.I'm using croos-tool ng, gcc-4.8 =================================For example in file system, boost::filesystem::detail::status is not there: nm stage/lib/linux_armv7/libboost_filesystem.a | grep status [returns nothing] ================================= I take a look on an existing ubuntu.14.04 armhf nm libboost_filesystem.a | grep status 00000048 t _ZN12_GLOBAL__N_113dir_itr_firstERPvS1_PKcRSsRN5boost10filesystem11file_statusES8_.isra.29.constprop.49 00001cf4 T _ZN5boost10filesystem6detail14symlink_statusERKNS0_4pathEPNS_6system10error_codeE 000019c0 T _ZN5boost10filesystem6detail6statusERKNS0_4pathEPNS_6system10error_codeE 00001b54 T _ZNK5boost10filesystem15directory_entry12m_get_statusEPNS_6system10error_codeE 00001e98 T _ZNK5boost10filesystem15directory_entry20m_get_symlink_statusEPNS_6system10error_codeE ================================= my project-config.jam: # Boost.Build Configuration # Automatically generated by bootstrap.sh import option ; import feature ; # Compiler configuration. This definition will be used unless # you already have defined some toolsets in your user-config.jam # file. #if ! gcc in [ feature.values <toolset> ] #{ using gcc : armhf : arm-unknown-linux-gnueabi-g++ : <compileflags>-fexpensive-optimizations <compileflags>-O3 <compileflags>-march=armv7-a <compileflags>-mtune=cortex-a9 <compileflags>-mfpu=neon <compileflags>-mfloat-abi=hard <compileflags>-ftree-vectorize <compileflags>-ffast-math <compileflags>-funsafe-math-optimizations <compileflags>-pipe <compileflags>-fwhole-program <compileflags>-fpermissive <compileflags>-fPIC ; #} project : default-build <toolset>gcc ; # Python configuration using python : 2.7 : ; # List of --with-<library> and --without-<library> # options. If left empty, all libraries will be built. # Options specified on the command line completely # override this variable. libraries = ; # These settings are equivivalent to corresponding command-line # options. option.set prefix : /usr/local ; option.set exec-prefix : /usr/local ; option.set libdir : /usr/local/lib ; option.set includedir : /usr/local/include ; # Stop on first error option.set keep-going : false ; ================================= I use this patch to fix the zlib problem in boost_1.55 cat no_zlib.diff Index: libs/iostreams/build/Jamfile.v2 --- libs/iostreams/build/Jamfile.v2 (revision 6521) +++ libs/iostreams/build/Jamfile.v2 (working copy) @@ -159,8 +159,6 @@ : $(sources) : <link>shared:<define>BOOST_IOSTREAMS_DYN_LINK=1 <define>BOOST_IOSTREAMS_USE_DEPRECATED - [ ac.check-library /zlib//zlib : <library>/zlib//zlib - <source>zlib.cpp <source>gzip.cpp ] : : <link>shared:<define>BOOST_IOSTREAMS_DYN_LINK=1 ; ================================= my b2 command: ./b2 link=static threading=multi --tool-set=gcc-armhf --without-python -sNO_COMPRESSION=1

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