January 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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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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[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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problems building
by Nathan Ridge 28 Feb '15

28 Feb '15

Hi list, I'm trying to build Boost for the first time in a while, and getting unexpected errors. I have a git checkout of the 'master' branch, but I've also tried with the 'boost-1.57.0' tag and had the same problem. The build command I'm running is './b2 --with-filesystem', and the errors I'm getting are of the following form: gcc.compile.c++ bin.v2/libs/system/build/gcc-4.9.0/release/threading-multi/error_code.o In file included from libs/system/src/error_code.cpp:16:0: ./boost/system/error_code.hpp:18:39: fatal error: boost/utility/enable_if.hpp: No such file or directory #include <boost/utility/enable_if.hpp> ^ compilation terminated. "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pthread -fPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_SYSTEM_DYN_LINK=1 -DNDEBUG -I"." -c -o "bin.v2/libs/system/build/gcc-4.9.0/release/threading-multi/error_code.o" "libs/system/src/error_code.cpp" Full output is here: http://pastebin.com/fgReAxTE Looking at [1], boost/system/error_code.hpp does indeed include <boost/utility/enable_if.hpp>, and looking at [2], there is indeed no 'enable_if.hpp' in boost/utility, so I'm not sure how it's _supposed_ to work. What am I missing? Thanks, Nate [1] https://github.com/boostorg/system/blob/master/include/boost/system/error_c… [2] https://github.com/boostorg/utility/tree/master/include/boost/utility

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[Units] Heterogeneous unit for pressure per time
by Dina Goldshtein 28 Feb '15

28 Feb '15

Hi, I asked about this in StackOverflow<http://stackoverflow.com/questions/27519186/boost-heterogeneous-unit-bar-pe…> but didn't get any answers so I thought I'd try here as well. I need to create a unit which represents pressure per time, specifically Bar per Minute. I tried creating it in the same way as I created similar units before: typedef boost::units::derived_dimension<boost::units::length_base_dimension, -1, boost::units::mass_base_dimension, 1, boost::units::time_base_dimension, -3>::type pressure_roc_dimension; typedef boost::units::unit<pressure_roc_dimension, boost::units::make_system<boost::units::metric::bar_base_unit, boost::units::metric::minute_base_unit>::type> bar_per_minute_unit; BOOST_UNITS_STATIC_CONSTANT(BarPerMinute, bar_per_minute_unit::unit_type); typedef boost::units::quantity<bar_per_minute_unit, double> BarPerMinuteRoC; And then I try to use it: BarPerMinuteRoC bpm = 5.0 * BarPerMinute; But this line doesn't compile with quite a long error trail which I'm having a bit of trouble understanding fully. 1>c:\workspace\externals\boost_1_57_0\include\boost\units\detail\linear_algebra.hpp(197): error C2039: 'item' : is not a member of 'boost::units::dimensionless_type' 1> c:\workspace\externals\boost_1_57_0\include\boost\units\dimensionless_type.hpp(37) : see declaration of 'boost::units::dimensionless_type' 1> c:\workspace\externals\boost_1_57_0\include\boost\units\detail\linear_algebra.hpp(259) : see reference to class template instantiation 'boost::units::detail::determine_extra_equations_skip_zeros_impl<true,false>::apply<RowsBegin,1,1,3,Result>' being compiled 1> with 1> [ 1> RowsBegin=boost::units::list<boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::detail::make_zero_vector<0>::type>>,boost::units::detail::determine_extra_equations_skip_zeros_impl<false,true>::apply<boost::units::list<boost::units::list<boost::units::static_rational<-1,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::list<boost::units::static_rational<-2,1>,boost::units::detail::expand_dimensions<0>::apply<boost::units::dimensionless_type,boost::units::dimensionless_type>::type>>>,boost::units::dimensionless_type>,1,0,3,boost::units::list<boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::detail::make_zero_vector<0>::type>>>,boost::units::list<boost::units::list<boost::units::static_rational<-1,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::list<boost::units::static_rational<-2,1>,boost::units::detail::expand_dimensions<0>::apply<boost::units::dimensionless_type,boost::units::dimensionless_type>::type>>>,boost::units::dimensionless_type>>>::next_equations> 1> , Result=boost::units::list<boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::detail::make_zero_vector<0>::type>>>,boost::units::list<boost::units::list<boost::units::static_rational<-1,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::list<boost::units::static_rational<-2,1>,boost::units::detail::expand_dimensions<0>::apply<boost::units::dimensionless_type,boost::units::dimensionless_type>::type>>>,boost::units::dimensionless_type>> 1> ] 1> c:\workspace\externals\boost_1_57_0\include\boost\units\detail\linear_algebra.hpp(264) : see reference to class template instantiation 'boost::units::detail::determine_extra_equations<2,false>::apply<boost::units::list<boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::detail::make_zero_vector<0>::type>>,boost::units::detail::determine_extra_equations_skip_zeros_impl<false,true>::apply<boost::units::list<boost::units::list<boost::units::static_rational<-1,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::list<boost::units::static_rational<-2,1>,boost::units::detail::expand_dimensions<0>::apply<boost::units::dimensionless_type,boost::units::dimensionless_type>::type>>>,boost::units::dimensionless_type>,1,0,3,Result>::next_equations>,3,Result>' being compiled 1> with 1> [ 1> Result=boost::units::list<boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::detail::make_zero_vector<0>::type>>>,boost::units::list<boost::units::list<boost::units::static_rational<-1,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::list<boost::units::static_rational<-2,1>,boost::units::detail::expand_dimensions<0>::apply<boost::units::dimensionless_type,boost::units::dimensionless_type>::type>>>,boost::units::dimensionless_type>> 1> ] 1> c:\workspace\externals\boost_1_57_0\include\boost\units\detail\linear_algebra.hpp(538) : see reference to class template instantiation 'boost::units::detail::determine_extra_equations<3,false>::apply<Matrix,3,Matrix>' being compiled 1> with 1> [ 1> Matrix=boost::units::list<boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::detail::make_zero_vector<0>::type>>>,boost::units::list<boost::units::list<boost::units::static_rational<-1,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::list<boost::units::static_rational<-2,1>,boost::units::detail::expand_dimensions<0>::apply<boost::units::dimensionless_type,boost::units::dimensionless_type>::type>>>,boost::units::dimensionless_type>> 1> ] 1> c:\workspace\externals\boost_1_57_0\include\boost\units\detail\linear_algebra.hpp(828) : see reference to class template instantiation 'boost::units::detail::make_square_and_invert<boost::units::list<boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::detail::make_zero_vector<0>::type>>>,boost::units::list<boost::units::list<boost::units::static_rational<-1,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::list<boost::units::static_rational<-2,1>,boost::units::detail::expand_dimensions<0>::apply<boost::units::dimensionless_type,boost::units::dimensionless_type>::type>>>,boost::units::dimensionless_type>>>' being compiled 1> c:\workspace\externals\boost_1_57_0\include\boost\units\detail\linear_algebra.hpp(1032) : see reference to class template instantiation 'boost::units::detail::normalize_units<T>' being compiled 1> with 1> [ 1> T=boost::units::list<boost::units::scaled_base_unit<boost::units::si::second_base_unit,boost::units::scale<60,boost::units::static_rational<1,1>>>,boost::units::list<boost::units::metric::bar_base_unit,boost::units::dimensionless_type>> 1> ] 1> c:\workspace\externals\boost_1_57_0\include\boost\units\detail\linear_algebra.hpp(1051) : see reference to class template instantiation 'boost::units::detail::calculate_base_unit_exponents_impl<false>::apply<T,Dimensions>' being compiled 1> with 1> [ 1> T=boost::units::list<boost::units::scaled_base_unit<boost::units::si::second_base_unit,boost::units::scale<60,boost::units::static_rational<1,1>>>,boost::units::list<boost::units::metric::bar_base_unit,boost::units::dimensionless_type>> 1> , Dimensions=BSII::Units::pressure_roc_dimension 1> ] 1> c:\workspace\externals\boost_1_57_0\include\boost\units\heterogeneous_system.hpp(243) : see reference to class template instantiation 'boost::units::detail::calculate_base_unit_exponents<boost::units::list<boost::units::scaled_base_unit<boost::units::si::second_base_unit,boost::units::scale<60,boost::units::static_rational<1,1>>>,boost::units::list<T,boost::units::dimensionless_type>>,Dimensions>' being compiled 1> with 1> [ 1> T=boost::units::metric::bar_base_unit 1> , Dimensions=BSII::Units::pressure_roc_dimension 1> ] 1> c:\workspace\externals\boost_1_57_0\include\boost\units\unit.hpp(92) : see reference to class template instantiation 'boost::units::detail::make_heterogeneous_system<Dim,System>' being compiled 1> with 1> [ 1> Dim=BSII::Units::pressure_roc_dimension 1> , System=boost::units::homogeneous_system<boost::units::list<boost::units::scaled_base_unit<boost::units::si::second_base_unit,boost::units::scale<60,boost::units::static_rational<1,1>>>,boost::units::list<boost::units::metric::bar_base_unit,boost::units::dimensionless_type>>> 1> ] 1> c:\workspace\externals\boost_1_57_0\include\boost\units\unit.hpp(99) : see reference to class template instantiation 'boost::units::reduce_unit<S1>' being compiled 1> with 1> [ 1> S1=BSII::Units::bar_per_minute_unit 1> ] 1> c:\workspace\foundations\sw_foundations\bsii_common\test\src\units\units_pressure_test.cpp(97) : see reference to class template instantiation 'boost::units::is_implicitly_convertible<BSII::Units::bar_per_minute_unit,Unit>' being compiled 1> with 1> [ 1> Unit=BSII::Units::bar_per_minute_unit 1> ] According to the Boost documentation a homogeneous system can only be composed of linearly independent base units. In my case, I'm trying to mix bars (which in turn "contain" seconds as the time element) with minutes. This sounds problematic to me. But on the other hand, since I don't include mass and length base units in my system it seems to me that the base is independent after all. In any case, I searched online for an example of creating such a heterogeneous unit but didn't find anything comprehensible. Also, I read in the Boost documentation that a heterogeneous unit doesn't preserve information about how it was created. Does this mean I won't be able to, for instance, multiply BarPerMinuteRoC by Minute and get Bar back? Thanks a lot! Dina This message (including any attachments) is intended only for the use of the individual or entity to which it is addressed and may contain materials protected by copyright or information that is non-public, proprietary, privileged, confidential, and exempt from disclosure under applicable law or agreement. If you are not the intended recipient, you are hereby notified that any review use, dissemination, distribution, or duplication of this communication is strictly prohibited. If you are not the intended recipient, please contact the sender immediately by reply email and destroy all copies of the original. Thank you.

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[gsoc15] Attn: We need 2015 mentors and project ideas for Boost!
by Niall Douglas 10 Feb '15

10 Feb '15

Dear Boost community, We are now within one month of the beginning of Google Summer of Code 2015! Last year's GSoC furthered the continuing success of the Boost GSoC programme with the first ever Boost funded extension to a GSoC project (that being Boost.Hana by Louis Dionne mentored by Joel Falcou, congrats to both of them on passing an exceptionally tough selection process), and over $50,000 of Google funding brought to Boost in 2014. We also sent three representatives to last year's mentor summit, including one student whose entire expenses the Boost Steering Committee very generously covered. As part of filling in our application for 2015, we must supply to Google a list of potential GSoC mentors and potential GSoC projects for summer 2015. There are a number of changes to how we design project ideas for students this year intended to improve the GSoC experience for both students and mentors, so please examine the ideas page which outlines those changes at https://svn.boost.org/trac/boost/wiki/SoC2015 and if you have any questions or concerns about those changes, please ask now rather than just before the GSoC deadline. If you think yourself able to mentor a student doing some work on Boost this summer, *please* consider adding a description of the proposed work item and your name to the list. Last year we acquired eight slots from Google and had to disappoint two mentors and students, we hope with the improved selection process we can get back to the ten annual slots we once had. If you want to know more about mentoring a Google Summer of Code funded student work before you nominate yourself, please feel free to ask on the main Boost developers mailing list boost(a)lists.boost.org. Thank you in advance for your time. Niall Douglas (Boost Google Summer of Code admin) Boris Schäling (Boost Google Summer of Code admin) --- Boost C++ Libraries Google Summer of Code 2014 admin https://svn.boost.org/trac/boost/wiki/SoC2014

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[Serialization] XML: float format is scientific instead of human-readable since Boost 1.57
by Frank Stähr 09 Feb '15

09 Feb '15

Hello Boost guys, when I switched from Boost 1.55 to 1.57 there was a change in the formation of floats and doubles for xml archives. Look at this example: #include <fstream> #include <boost/archive/xml_oarchive.hpp> class MyClass { friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & boost::serialization::make_nvp("accuracy", accuracy); } double accuracy = 0.03; }; int main() { MyClass obj; std::ofstream ofs("sample.xml"); boost::archive::xml_oarchive oa(ofs); oa & boost::serialization::make_nvp("myclass", obj); } I compiled it with VS 2013 for 32 bit. The output file has the line: <m_accuracy>2.99999999999999990e-002</m_accuracy> In Boost 1.55 it was much better human-readable: 0.03. Is this behaviour (this change) intended? In any case, what is the best way to format floats and doubles? (i. e. a manipulator for the ofstream?) Thanks, Frank -- Frank Stähr Technische Universität Berlin Communication Systems Group Sekr. EN1 Einsteinufer 17 10587 Berlin, Germany

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[msm] multi thread access
by Sam Fisher 05 Feb '15

05 Feb '15

Hi Christophe, Did you consider adding build-in multi-thread support? (via policies maybe?) For example, I can guaranteed that all access to sub-fsm within its handlers (process_event()) will be synchronized. The problem is, sub-fsm "knows" about its parent and internally communicates with it (forwarding events etc). I can't control it from my side. typical scenario: an action from sub-fsm struct A_Init { template <typename Evt, typename FSM, typename SourceState, typename TargetState> void operator()(Evt&, FSM& fsm, SourceState&, TargetState&) const { std::thread([=]() mutable { std::lock_guard<std::mutex> l(access); fsm.process_event(some_event()); }).detach(); } }; locking proccess_event() in sub-fsm doesn't help if it alters the root.

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[Variant] Assertion fails at variant/detail/visitation_impl.hpp:207
by Attila Rajmund Nohl 02 Feb '15

02 Feb '15

Hello! I'm using boost-1.55 on Linux. When I run a specific testcase, I get an abort at line 207 in the visitation_impl.hpp file. The comment says that "should never be here at runtime". Unfortunately I don't really understand under what circumstances could runtime end up here - could someone explain how? The variant has a recursive element, i.e. looks something like this: struct Resp; struct SR { } struct AR { std::vector<Resp> resp; } typedef variant< SR, recursive_wrapper<AR> > RMType; struct Resp { RMType rm; }

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boost::ptr_container library question ?
by Danny K 02 Feb '15

02 Feb '15

The ptr_container supports an overload for std::auto_ptr. I was curious if there was a way to add the same functionality for std::unique_ptr. ie an overload that allows a std::unique_ptr to be added to a ptr_vector for example?

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[type_erasure] Problem with iterators
by Marco Guazzone 31 Jan '15

31 Jan '15

Hi, I'm new to the Type Erasure library. I need to write a base class with type-erased forward iterators. To do so I've taken inspiration from the print_sequence.cpp example I've found in the Type Erasure source tree. At the end of the email there is the whole code of my tentative, called "erasure.cpp". Unfortunately, I've problems (presumably) with const iterators which cause the following compile error: $ g++ -Wall -Wextra -pedantic -std=c++11 -I$HOME/sys/src/git/boost -o erasure erasure.cpp -lm *** [begin error] *** In file included from /home/sguazt/sys/src/git/boost/boost/type_erasure/iterator.hpp:20:0, from erasure.cpp:2: /home/sguazt/sys/src/git/boost/boost/type_erasure/operators.hpp: In instantiation of ‘static R boost::type_erasure::dereferenceable<R, T>::apply(const T&) [with R = double&; T = __gnu_cxx::__normal_iterator<const double*, std::vector<double> >]’: /home/sguazt/sys/src/git/boost/boost/type_erasure/detail/instantiate.hpp:91:9: required from ‘static void boost::type_erasure::detail::instantiate_concept7::apply(Concept*, Map*) [with Concept = boost::mpl::vector<boost::type_erasure::forward_iterator<>, boost::type_erasure::same_type<boost::type_erasure::deduced<boost::type_erasure::iterator_value_type<boost::type_erasure::_self> >, double>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>; Map = boost::mpl::map1<boost::mpl::pair<boost::type_erasure::_self, __gnu_cxx::__normal_iterator<const double*, std::vector<double> > > >]’ /home/sguazt/sys/src/git/boost/boost/type_erasure/any.hpp:225:13: required from ‘boost::type_erasure::any<Concept, T>::any(U&&) [with U = __gnu_cxx::__normal_iterator<const double*, std::vector<double> >&; Concept = boost::mpl::vector<boost::type_erasure::forward_iterator<>, boost::type_erasure::same_type<boost::type_erasure::deduced<boost::type_erasure::iterator_value_type<boost::type_erasure::_self> >, double>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>; T = boost::type_erasure::_self]’ erasure.cpp:36:40: required from ‘std::vector<_RealType> base<T>::foo(IterT, IterT) [with IterT = __gnu_cxx::__normal_iterator<const double*, std::vector<double> >; T = double]’ erasure.cpp:77:73: required from here /home/sguazt/sys/src/git/boost/boost/type_erasure/operators.hpp:134:44: error: invalid initialization of reference of type ‘double&’ from expression of type ‘const double’ static R apply(const T& arg) { return *arg; } *** [/end error] *** The GCC version is 4.9.2. Here below is the content of "erasure.cpp". If I comment lines below the comment "THE FOLLOWING WON'T COMPILE" I get no error. So the problem is due to the use of cbegin/cend. *** [erasure.cpp] *** #include <boost/type_erasure/any.hpp> #include <boost/type_erasure/iterator.hpp> #include <boost/type_erasure/operators.hpp> #include <boost/type_erasure/same_type.hpp> #include <boost/mpl/vector.hpp> #include <boost/smart_ptr.hpp> #include <cmath> #include <cstddef> #include <iostream> #include <iterator> #include <vector> namespace mpl = boost::mpl; namespace te = boost::type_erasure; template <typename T> using fwd_iter_impl_t = te::any< mpl::vector< te::forward_iterator<>, te::same_type<te::forward_iterator<>::value_type,T>>>; template <typename T> class base { protected: typedef fwd_iter_impl_t<T> fwd_iter_type; public: virtual ~base() { } template <typename IterT> std::vector<T> foo(IterT first, IterT last) { return this->do_foo(first, last); } private: virtual std::vector<T> do_foo(fwd_iter_type first, fwd_iter_type last) = 0; }; // base template <typename T> class derived: public base<T> { private: typedef typename base<T>::fwd_iter_type fwd_iter_type; std::vector<T> do_foo(fwd_iter_type first, fwd_iter_type last) { const std::ptrdiff_t n = std::distance(first, last); std::vector<T> res(n); for (std::size_t i = 0; first != last; ++first, ++i) { res[i] = std::pow(*first,i)/n; } return res; } }; // derived int main() { std::vector<double> dv; dv.push_back(5); dv.push_back(8); dv.push_back(11); boost::scoped_ptr< base<double> > p_base(new derived<double>()); // begin/end const std::vector<double> foos = p_base->foo(dv.begin(), dv.end()); for (std::size_t i = 0; i < foos.size(); ++i) { std::cout << "foos[" < cfoos = p_base->foo(dv.cbegin(), dv.cend()); for (std::size_t i = 0; i < cfoos.size(); ++i) { std::cout << "cfoos[" << i << "]: " << cfoos[i] << std::endl; } } *** [/erasure.cpp] *** Thank you very much for your help. Best, -- Marco

3 9

[Asio] Handlers of asycn_send_to are called in which order?
by Attila Rajmund Nohl 30 Jan '15

30 Jan '15

Hello! My code sends UDP packets using async_send_to. If all packets are successfully sent, are their handlers called in the same order as the async_send_to calls happened? I mean if my code looks something like this: socket.async_send_to(buffer1, destination, handler1); socket.async_send_to(buffer2, destination, handler2); Is it guaranteed that handler2 is always called after handler1?

3 2

[iostreams] Devices and WOULD_BLOCK
by David Hawkins 30 Jan '15

30 Jan '15

Hi all, Boost newcomer here ... I have an application where I need to encode/decode a serialized data stream. I have used Boost.Iostreams filtering_stream filter to implement encoding and decoding function of each layer. The device interface is via a USB device, eg., think USB-to-Serial device, but without the classic Virtual COM Port or ttyUSB0 layer available. For example, the FTDI FT232H USB-to-MPSSE interface is a suitable cable http://www.ftdichip.com/Products/Cables/USBMPSSE.htm The cable can be used to implement either JTAG or SPI mode access (the mode selection introduces different filters into the filtering_stream stack). I have the filters working, and am working on getting a device working. Rather than deal with the details of the final hardware, I figured I'd simplify the design by creating a client/server design via sockets; the client code matches what I would use with real hardware, while the server code emulates the hardware. I started with this example for a socket device http://stackoverflow.com/questions/12023166/is-there-a-boostiostreams-bidir… The "problem" with the protocol I need to decode (which I have no choice to change) is that the data stream possibly contains escaped characters, so there is no way to know the read data length at the socket layer - its up to the filtering_stream layers to request data from the device layer until a complete packet is decoded. This all sounds good in theory, but in practice the filter layers attempt to read in blocks, and the read size is often larger than the read data that the device layer will supply. This lead to higher-level layers blocking in read(). I figured (perhaps incorrectly) that I could deal with this using non-blocking socket reads. After reading Boost.Iostreams non-blocking support in Section 3.6 http://www.boost.org/doc/libs/1_57_0/libs/iostreams/doc/index.html http://www.boost.org/doc/libs/1_57_0/libs/iostreams/doc/guide/asynchronous.… I modified the socket device example in the link above to; * put the socket in non-blocking mode before constructing the device * change the device 'read' procedure to return WOULD_BLOCK rather than throw an exception This does not work, and its not due to the filter layers. There is an issue with the device layer. Here's the issue ... given a design with a filtering_stream created only with a socket_device and no filters, if I trace the code in a debugger (Boost 1.57.0 source, Visual Studio 2012 under Win7), the socket_device read method call return sequence is boost/iostreams/read.hpp - read_device_impl read template at line 187 - read at line 52 boost/iostreams/detail/adapter/concept_adapter.hpp - device_wrapper_impl read at line 169 - read at line 77 boost/iostreams/detail/streambuf/indirect_streambuf.hpp - line 258 i.e., this source file https://github.com/boostorg/iostreams/blob/master/include/boost/iostreams/d… and this particular block of code // Read from source. std::streamsize chars = obj().read(buf.data() + pback_size_, buf.size() - pback_size_, next_); if (chars == -1) { this->set_true_eof(true); chars = 0; } setg(eback(), gptr(), buf.data() + pback_size_ + chars); The code tests for EOF (-1), but not WOULD_BLOCK (-2), so after this point, since chars is -2, things go bad. So I guess my question now is; Have I just bumped into the as-yet-unsupported part of Boost.Iostreams support for asynchronous I/O? Cheers, Dave PS. I can post example code if anyone wants to trace the code for themselves, I just figured I'd post the question to start with.

4 15

Joining boost::asio::strands
by Cesar Mello 29 Jan '15

29 Jan '15

Hi, After spawning several paralell jobs through calls to boost::asio::spawn inside a loop, is there an easy way to wait for all of them to finish? I would like to join them to aggregate the results. Please can you give me any clue? Thank you a lot! Best regards Cesar

1 0

ProgramOptions: explicit empty string argument
by Akim Demaille 29 Jan '15

29 Jan '15

Hi, I would like to be able to support an empty optional argument for long options. This is something that is supported by gnu getopt_long and argp. Consider for instance a simplified version of the first simple example program: #include <iostream> #include <boost/program_options.hpp> int main(int ac, char* av[]) { namespace po = boost::program_options; using namespace std; po::options_description desc("Allowed options"); desc.add_options() ("help", "produce help message") ("compression", po::value<string>()->implicit_value(""), "set compression level") ; po::variables_map vm; po::store(po::parse_command_line(ac, av, desc), vm); po::notify(vm); if (vm.count("help")) cout << desc << "\n"; else if (vm.count("compression")) cout << "Compression level was set to " << vm["compression"].as<string>() << ".\n"; else cout << "Compression level was not set.\n"; } when I run it, in "typical cases", I have: $ ./a.out Compression level was not set. $ ./a.out --compression=foo Compression level was set to foo. $ ./a.out --compression foo Compression level was set to foo. $ ./a.out --compression Compression level was set to . all of this is fine. However, how can I explicitly pass the empty string? $ ./a.out --compression= libc++abi.dylib: terminating with uncaught exception of type boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::program_options::invalid_command_line_syntax> >: the argument for option '--compression' should follow immediately after the equal sign zsh: abort ./a.out --compression= Of course I could simply to my user that there is a special token, say '-', that means "empty", but it is still more complex than simply accepting the empty string to mean the empty string. Thanks! (There are some stack overflow questions, but they do not address this particular point, --foo='').

1 0

[interprocess] Bizarro File Names (Windows)
by Aaron_Wright＠selinc.com 28 Jan '15

28 Jan '15

I have a service that is running in Windows Server 2008 R2 SP1 that uses shared memory. It runs fine for a month or so, but then stops working correctly. When I check the C:\ProgramData\boost_interprocess\*\ folder, I get a bunch of weird file names, such as: 88C861CD6DE2CF01EBA2F0CC1200D001A4070000EBFFFFFF 88C861CD6DE2CF01EBA2F0CC1200D001A4070000ECFFFFFF 88C861CD6DE2CF01EBA2F0CC1200D001A4070000EDFFFFFF 88C861CD6DE2CF01EBA2F0CC1200D001A4070000EEFFFFFF 88C861CD6DE2CF01EBA2F0CC1200D001A4070000EFFFFFFF 88C861CD6DE2CF01EBA2F0CC1200D001A4070000F0FFFFFF 88C861CD6DE2CF01EBA2F0CC1200D001A4070000F1FFFFFF 88C861CD6DE2CF01EBA2F0CC1200D001A4070000F2FFFFFF 88C861CD6DE2CF014B04F3CC1200D001A40700000AFFFFFF 88C861CD6DE2CF014B04F3CC1200D001A40700000BFFFFFF 88C861CD6DE2CF014B04F3CC1200D001A40700000CFFFFFF 88C861CD6DE2CF014B04F3CC1200D001A40700000DFFFFFF ... (and so on) These are not even close to the names that are supposed to be used. They seem to increment a bit, then shift slightly, and start incrementing again. When I restart the service I get similar named files and patterns, and my services crashes because it can't grow shared memory (presumably because the file names are not correct). I have to restart the box in order to get the correct behavior. Has anyone seen this behavior before? --------------------------------------------------------- Aaron Wright

1 1

[mpl] lazy condition in enable_if
by Sam Fisher 28 Jan '15

28 Jan '15

Hi, I need to run boost::mpl::for_each<> function with template condition, like: boost::mpl::for_each< vector_of_types, boost::mpl::make_identity<boost::mpl::_1> > (Functor< condition >()); I'm trying to implement lazy binding in enable_if. Visual studio fails with error "'X<IsFoo<boost::mpl::_>>::operator ()' : ambiguous call to overloaded function" minimal test code which fail on boost 1.57 #include <boost/mpl/for_each.hpp> #include <boost/mpl/lambda.hpp> #include <boost/mpl/bind.hpp> #include <boost/mpl/vector.hpp> #include <boost/core/enable_if.hpp> #include <iostream> #include <type_traits> template <int> struct dummy { dummy(int) {} }; // from doc struct Foo {}; struct Bar {}; template <typename T> struct IsFoo { typedef typename std::is_same<T, Foo>::type type; }; #define generate_type(_fn) \ typename boost::mpl::apply<boost::mpl::bind< \ boost::mpl::lambda< _fn <boost::mpl::_> >::type, \ boost::mpl::bind<typename boost::mpl::lambda<_Pred>::type, U> \ > >::type #define enable_type generate_type(boost::enable_if) #define disable_type generate_type(boost::disable_if) template <typename _Pred> struct X { template <typename U> enable_type operator()(boost::mpl::identity, dummy<0> = 0) const { std::cout << "enable: " << typeid(U).name() << std::endl; } template <typename U> disable_type operator()(boost::mpl::identity, dummy<1> = 0) const { std::cout << "disable: " << typeid(U).name() << std::endl; } }; int main() { X<IsFoo<boost::mpl::_> > x; x(boost::mpl::identity<Foo>()); x(boost::mpl::identity<Bar>()); return 0; }

1 0

[release] Release schedule changes..
by Rene Rivera 27 Jan '15

27 Jan '15

After some discussion in the Boost Release Team we've decided on an ongoing schedule for releases. Taking into account the realities of how long it takes for authors and the release team to work on a release we've decided to move to *three* releases a year. The targets for the releases will now be: * Spring release on the second Wednesday of April. * Summer release on the second Wednesday of August. * Fall/Winter release on the second Wednesday of December. There will be no January release. This will allow for the fact that most people are on extended holidays during Winter. It will also allow for people to work on larger changes that require more testing time during the longer Winter period. We are also moving to Wednesday release to allow the release managers non-weekend time to work before and after the release. Please consult the Boost calendar for specific dates and merge schedule for the next release. Thanks, the Boost Release Team. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

1 0

[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?

4 7

[multi_index] recursive declaration of MIC with a value which contains references of its kind
by Nick Stokes 26 Jan '15

26 Jan '15

I have a value type (Foo) which is supposed to contain references to some multi_index_container of its type, like so: struct Foo { int property1; int property2; FooMIC* other; // this (the pointer value) may or may not be indexed upon }; typedef multi_index_container< Foo, indexed_by < sequenced<> , ordered_unique< member<Foo, int, &Foo::property1> > , ... >> FooMIC; Due to recursive nature of this, I wasn't able to figure out how do declare such a thing (other than unsafely using void* references in Foo). Any ideas? Thanks many, Nick

2 2

Re: [Boost-users] [boost] [Review] Boost.Endian mini-review
by Beman Dawes 26 Jan '15

26 Jan '15

On Sun, Jan 25, 2015 at 6:12 PM, Jason Newton <nevion(a)gmail.com> wrote: > On Sun, Jan 25, 2015 at 8:21 AM, Beman Dawes <bdawes(a)acm.org> wrote: > >> On Sat, Jan 24, 2015 at 2:25 AM, Jason Newton <nevion(a)gmail.com> wrote: >> > I think the only thing that I have no interest in using - a kind way of >> > saying its probably unneeded bloat IMO is the arithmetic types. I prefer >> > native types and using conversion functions. But maybe they could >> improve >> > my code - its something I toss back and forth a little and haven't >> > attempted embracing. >> >> Because even the endian buffer and arithmetic types that appear most >> expensive generate only short sequences of code, the optimizing >> compilers often generate exactly the same instructions regardless of >> endian approach. On Intel machines, that often distills down to a >> single bswap instruction since the value is already in a register. >> >> That isn't always true, so you do need to measure performance of >> various approaches in the context of your actual application. But if >> use of the buffer or arithmetic types would otherwise improve your >> code, please don't reject them without actually testing performance >> first. >> > > Allow me to clarify: I meant code bloat, not speed. Sorry - your original post was clear, but I misinterpreted. I have not systematically measured code bloat. Maybe I can do that at least for some common use cases. Thanks, --Beman

1 0

Re: [Boost-users] [boost] [Review] Boost.Endian mini-review
by Beman Dawes 25 Jan '15

25 Jan '15

On Sat, Jan 24, 2015 at 2:25 AM, Jason Newton <nevion(a)gmail.com> wrote: ... > As a long time user of the Boost.Endian library (applying patches to the > distribution I maintain), I am happy to see it finally up for uh... > mini-review. Hoping to see it get to formal review and included... further > hoping it makes it into the next C++ standard! The library went through formal review in 2011, so will go into Boost as soon as the mini-review is over. And, yes, I do plan to propose it to the standards committee. > It is ready in my opinion. I've seen it go through some topical changes > over the years but the only thing I've used from it are the conversion > functions which have been great for implementing proper io in the range of > network socket io / serial with various protocols and stored data from > varies devices/sensors) if a specification enforces byte order. It > fullfills my needs and always did fairly well on performance with gcc/clang. Depending on what version you have been using, the performance may now be even better. > I think the only thing that I have no interest in using - a kind way of > saying its probably unneeded bloat IMO is the arithmetic types. I prefer > native types and using conversion functions. But maybe they could improve > my code - its something I toss back and forth a little and haven't > attempted embracing. Because even the endian buffer and arithmetic types that appear most expensive generate only short sequences of code, the optimizing compilers often generate exactly the same instructions regardless of endian approach. On Intel machines, that often distills down to a single bswap instruction since the value is already in a register. That isn't always true, so you do need to measure performance of various approaches in the context of your actual application. But if use of the buffer or arithmetic types would otherwise improve your code, please don't reject them without actually testing performance first. > > This library should not be looked at as fulfilling an uncommon need - and > should even be part of future C++ standards because the usual > macro/functions (e.g. htons) in the in arpa/inet.h are widely used outside > of inet related code (see above examples) and have the types encoded in the > name making them not easily usable/composable in contrast to something > template based which the library offers. Further IEEE 754 support - > especially for double floating point types. The library definitely fills > that gap and has for years IMO. Thanks for the kind words! --Beman

1 0

[thread] await hangs when using boost::promise/future
by TONGARI J 25 Jan '15

25 Jan '15

Hi, The sample code is here: https://gist.github.com/jamboree/3b8716ad1922749e77ae The boost::future adaption code is adapted from N4286. Tested with VS2015 preview. If std::promise is passed, the code works fine. Any clue why it hangs if boost::promise is passed? Thanks.

3 10

[Graph] source vertex colour at start of BFS or DFS
by Jeremy Murphy 24 Jan '15

24 Jan '15

Hi, I'm wondering, why do the BFS and DFS algorithms not inspect the colour of the source vertices given to them? If a source vertex is already black, shouldn't the search effectively be a no-op? Currently the source vertex is 'discovered' and coloured grey regardless of its previous colour. I know it might seem weird to pass a black vertex as the source, but I guess I see it as similar to passing an empty range to an algorithm: it's valid but nothing happens. Thanks, cheers. Jeremy

1 0

Re: [Boost-users] unit test BOOST_CHECK_CLOSE absolute
by Dave Gomboc 24 Jan '15

24 Jan '15

Gennadiy Rozental <rogeeff <at> gmail.com> writes: > > Paul A. Bristow <pbristow <at> hetp.u-net.com> writes: > > FWIW I've also wanted the *values* in a message (rather > > than just a test fail). > > I do not follow this comment. Which message and which tool do you refer to? Perhaps he meant that he'd like the error message when a BOOST_CHECK_CLOSE fails to show the value that was rejected, and also the range of values that would have been accepted? Dave

2 1

[Review] Boost.Endian mini-review
by Joel FALCOU 23 Jan '15

23 Jan '15

The mini-review of Boost.Endian starts today and runs through Sunday, February 1. The library repository is available on GitHub at https://github.com/boostorg/endian The docs for the library can be viewed online at https://boostorg.github.io/endian/ The objective of the mini-review is to verify that the issues raised during the formal review have been addressed. Those issues are documented at https://boostorg.github.io/endian/mini_review_topics.html which also describes the resolution of each issue. Comments and suggestions unrelated to the mini-review issues are also welcome, but the key question the review manager needs your opinion on is this: Is the library ready to be added to Boost releases? -- Joel Falcou, Endian Review Manager

1 0

Review Wizard Status Report for January 2015
by Ron Garcia 23 Jan '15

23 Jan '15

============================================== Review Wizard Status Report for January 2015 ============================================== News ==== 1. Boost 1.56 Released November 2014. New Libraries: none 2. Sort Accepted. November 2014. 3. Compute Accepted. December 2014. Open Issues =========== The following libraries have review managers, but have not yet been scheduled for review: * Range Extensions - added May 2012; review manager: Neil Groves. The following libraries have been accepted to Boost, but have not yet been integrated into Boost Git: * Contract - accepted September 2012; author: Lorenzo Caminiti. * Sort - accepted November 2014: author: . * Compute - accepted December 2014: author: . The following libraries have been accepted and submitted to Boost Git, but have not yet appeared in a release: * Convert - accepted June 2014; author: Vladimir Batov. The following libraries have been accepted provisionally to Boost, but have not been submitted for mini-review and full acceptance: * Endian - accepted provisionally September 2011; author Beman Dawes. * Fiber - accepted provisionally January 2014; author Oliver Kowalke. General Announcements ===================== As always, we need experienced review managers. Please take a look at the list of libraries in need of managers and check out their descriptions. In general review managers are active boost participants, including library contributors, infrastructure contributors, and other mailing list participants with a substantial track record of constructive participation. If you can serve as review manager for any of them, email Ron Garcia or John Phillips, "rxg at cs dot ubc dot ca" and "johnphillipsithica at gmail dot com" respectively. We are also suffering from a lack of reviewers. While we all understand time pressures and the need to complete paying work, the strength of Boost is based on the detailed and informed reviews submitted by you. If you are interested in reviewing a library but won't have time during the review period, you can always prepare your review ahead of time. No rule says you can only work on a review during the review period. A link to this report will be posted to www.boost.org. If you would like us to make any modifications or additions to this report, please email Ron or John. The review schedule is an unordered list of the libraries awaiting review. As such, any library on the schedule can be reviewed once the developer is ready, a review manager has been secured, and the manager, developer, and wizards agree on a date to schedule the review. Review Schedule =============== * Join (M) * Sorting (M) * Quaternions, Vectors, Matrices (M) * Block Pointer (M) * Singularity (M) * Extended Complex Numbers (M) * Metaparse (M) * Boost.Range Extensions * Nowide (M) * Array (M) * STL Extensions (M) * Countertree (M) * Process (M) * Asynchronous File I/O (M) * Application (M) * Edit Distance (M) * Mixin (M) * Dependency Injection (M) * DLL (M) ``(M)`` marks libraries that need review managers. -------------------- Join ---- :Author: Yigong Liu :Review Manager: Needed :Download: http://channel.sourceforge.net/ :Description: Join is an asynchronous, message based C++ concurrency library based on join calculus. It is applicable both to multi-threaded applications and to the orchestration of asynchronous, event-based applications. It follows Comega's design and implementation and builds with Boost facilities. It provides a high level concurrency API with asynchronous methods, synchronous methods, and chords which are "join-patterns" defining the synchronization, asynchrony, and concurrency. Sorting ------- :Author: Steven Ross :Review Manager: Needed :Download: https://github.com/boost-vault/Sorting :Description: A grouping of 3 templated hybrid radix/comparison-based sorting algorithms that provide superior worst-case and average-case performance to std::sort: integer_sort, which sorts fixed-size data types that support a rightshift (default of >>) and a comparison (default of <) operator. float_sort, which sorts standard floating-point numbers by safely casting them to integers. string_sort, which sorts variable-length data types, and is optimized for 8-bit character strings. All 3 algorithms have O(n(k/s + s)) runtime where k is the number of bits in the data type and s is a constant, and limited memory overhead (in the kB for realistic inputs). In testing, integer_sort varies from 35% faster to 2X as fast as std::sort, depending on processor, compiler optimizations, and data distribution. float_sort is roughly 70% faster than std::sort. string_sort is roughly 2X as fast as std::sort. Quaternions, Vectors, Matrices ------------------------------ :Author: Emil Dotchevski :Review Manager: Needed :Download: http://www.revergestudios.com/boost-qvm/ :Description: QVM defines a set of generic functions and operator overloads for working with quaternions, vectors and matrices of static size. The library also defines vector and matrix data types, however it allows users to introduce their own types by specializing the q_traits, v_traits and m_traits templates. Block Pointer ------------- :Author: Phil Bouchard :Review Manager: Needed :Download: https://svn.boost.org/svn/boost/sandbox/block_ptr/ :Description: Deterministic memory manager of constant complexity capable of handling cyclic collections. Singularity ----------- :Author: Ben Robinson :Review Manager: Needed :Download: https://github.com/cppmaven/Singularity :Description: The Singularity Design Pattern allows you to restrict any class to a single instance. Unlike the infamous Singleton, Singularity gives you direct control over the lifetime of the object, does not require you to grant global access to the object, nor does it limit you to the default constructor for that object. Extended Complex Numbers ------------------------ :Author: Matthieu Schaller :Review Manager: Needed :Download: http://code.google.com/p/cpp-imaginary-numbers/ :Description: The library is an extension of the std::complex class addressing two issues: 1. The standard does not guaranty the behaviour of the complex class if instantiated with types other than float/double/long double. 2. Some calculation where pure imaginary numbers (i.e. multiples of sqrt(-1)) appear are unnecessarily slowed down due to the lack of support for these numbers. The code I submit contains two interleaved classes boost::complex and boost::imaginary which can be instantiated with any type T provided T overloads the usual arithmetic operators and some basic (real) mathematical functions depending on which complex function will be used. It is thus an extended version of Thorsten Ottosen's n1869 proposal (http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2005/n1869.html) Metaparse --------- :Author: Abel Sinkovics :Review Manager: Needed :Download: http://abel.web.elte.hu/metaparse/metaparse.zip :Description: Metaparse is a library for constructing parsers parsing at compile-time based on template metaprogramming. The parsers built with the library take boost::mpl::strings as input and can produce - types - objects (types with public static members) - callable C++ functions (types with public static method) - template metafunction classes as output (based on the input being parsed). On compilers supporting constexpr the library provides the following syntactic sugar for writing the input of the parsers: BOOST_STRING("this is a string") The library can be used for implementing DSLs in C++, including DSLs making C++ template metaprogramming easier (see examples). Range Extensions ---------------- :Author: Akira Takahashi :Review Manager: Neil Groves :Download: https://github.com/faithandbrave/OvenToBoost :Description: This project adds some features of the Oven Range Library to Boost.Range. Features: - Additional Range Adaptors (taken, taken_while, dropped, dropped_while, elements, elements_key, memoized, outdirected) - Extensions for using Lambda (regular function, regular operator) - Infinite Range (iteration function) - and additional range utilities. Nowide ------ :Author: Artyom Beilis :Review Manager: Needed :Download: http://cppcms.com/files/nowide/ :Description: This library makes cross platform Unicode aware programming easier. It provides an implementation of standard C and C++ library functions, such that their inputs are UTF-8 aware on Windows without requiring to use Wide API. Array ----- :Author: Brian Smith :Review Manager: Needed :Download: https://github.com/BrianJSmith/Array :Description: The array class is a C++11 compatible implementation of static multidimensional arrays. STL Extensions -------------- :Author: Vadim Stadnik :Review Manager: Needed :Download: https://github.com/vstadnik/stl_ext_adv_review :Description: The proposed library [stl_ext_adv] offers augmented array based B+ trees and STL containers that support the interfaces of the C++03 sequences and associative containers. The library offers a number of extensions and performance improvements that are not available in C++03 and C++11 standard containers. Countertree ----------- :Author: Francisco Jose Tapia :Review Manager: Needed :Download: https://dl.dropbox.com/u/8437476/works/countertree_code_doc.zip :Description: This library is an implementation of a binary red-black counter tree. This tree have an additional counter in each leaf. This permit the access to the elements by the position, like in a vector. It is a random access container with random access iterators. COUNTERTREE This kind of trees have an additional counter in each leaf. This permit the access to the elements by the position, like in a vector. It is a random access container with random access iterators. With unordered information we have a vector with the same speed inserting and deleting in any position (O(log N)). With ordered information, we have the classes set, multiset, map and multimap, with identical interface than the STL classes, with the plus of access to the elements by position, like in a vector. The iterators are random access , and you can subtract them. SUBALLOCATOR The suballocator is a layer between the allocator and the data structures, compatible with any allocator with the STL definition. The suballocator replace to the allocator in the allocation of equal size elements. It provides speed, return the unused memory and decrease the memory used by the program and improve the cache performance due to the data locality improvement ( 30% of improvement of speed respect the std::allocator with GCC 4.7) Process ------- :Author: Boris Schaeling :Review Manager: Needed :Download: http://www.highscore.de/boost/process0.5/process.zip :Description: Boost.Process is a library to manage system processes. It can be used to: * create child processes * setup streams for child processes * communicate with child processes through streams (synchronously or asynchronously) * wait for processes to exit (synchronously or asynchronously) * terminate processes Asynchronous File I/O --------------------- :Author: Niall Douglas and Paul Kirth :Review Manager: Needed :Download: https://github.com/BoostGSoC/boost.afio/archive/boost-peer-review.tar.gz :Description: Boost.AFIO is a linear scalable, batch, chainable, asynchronous closure execution engine with an almost wait free implementation extending Boost.ASIO and Boost.Thread specialised as a portable asynchronous file i/o implementation library. Implementation of this first version has been kept as simple as possible (~ 1000 active LOC) at the cost of some performance, though with a good compiler you can expect 25-50% of the performance of using raw Boost.ASIO. Application ----------- :Author: Renato Tegon Forti :Review Manager: Needed :Download: https://github.com/retf/Boost.Application :Documentation: http://www.dokfile.com/appbeta4/docs/libs/application/doc/html/index.html :Description: Application provides an application environment, or start point to any people that want a basic infrastructure to build an system application on Windows or Unix Variants (e.g. Linux, MacOS). Application uses behaviours modeled using 'aspects' concept proposed by 'Vicente J. Botet Escriba', that allow easy extension and customization of library components. The application modes uses these components internally to achieve the user desirable behaviours. Application provide many useful ready-to-use features, e.g: * Run application as Windows Service; * Run application as UNIX/POSIX Daemon; * Plugin extension system; * Process(executable) Single instance Instantiation support; * Application SIGNAL/Callbacks customization; * Windows Service Setup feature; * And many others. Edit Distance ------------- :Author: Erik Erlandson :Review Manager: Needed :Download: https://github.com/erikerlandson/algorithm/tree/edit_distance/sequence :Description: The edit distance is the length of the shortest (or least-cost) edit script from one sequence to another, where an edit script is defined as a sequence of insertion, deletion and (optionally) substitution operations. The function implementing the edit distance is named edit_distance. This function will return the edit distance between two sequences, where sequences may be any valid range object supporting forward iteration. The edit_distance function will also, if requested, return the edit script. Mixin ----- :Author: Borislav Stanimirov :Download: https://github.com/iboB/boost.mixin :Documentation: http://ibob.github.io/boost.mixin/ :Review Manager: Needed :Description: Boost.Mixin is a library that allows the composition and modifications of polymorphic types at run time. Types and objects are constructed out of building blocks called mixins. The library uses the type boost::mixin::object as a placeholder, whose instances can be extended with existing classes (mixins), thus providing a particular instance with the functionality of all those types. Accessing the newly formed type's interface is made through messages: stand-alone functions generated by the library, which can be thought of as methods. This is given while also having full abstraction between the interface and the definition of types. An existing feature in another language similar to Boost.Mixin and also an inspiration for the library are the mixins in Ruby. The library also has similarities with the pattern entity-component-system. Dependency Injection -------------------- :Author: :Download: https://github.com/krzysztof-jusiak/di :Documentation: http://krzysztof-jusiak.github.io/di/boost/libs/di/doc/html :Incubator: http://rrsd.com/blincubator.com/bi_library/di-dependency-injection/?gform_p… :Review Manager: Needed :Description: Boost.DI is a dependency injection library improving manual dependency injection by simplifying object instantiation with automatic dependencies injection. Using Boost.DI has many advantages over manual dependency injection. * Reduce boilerplate code (No factories, no objects creation in specific order) * Reduce cost of maintenance effort (Constructor signature change won't affect di configuration) * Reduce testing effort * Give better control of what and how is created (Policies, Providers) * Give better understanding about objects hierarchy (UML Dumper) DLL --- :Author: Antony Polukhin :Download: https://github.com/apolukhin/Boost.DLL :Documentation: http://apolukhin.github.io/Boost.DLL/index.html :Review Manager: Needed :Description: This library was designed to simplify plugin development using C++ in a portable cross-platform manner. Library provides a portable across platforms way to: * load libraries * import any native functions and variables * make alias names for C++ mangled functions and symbols * query libraries for sections and exported symbols * self loading and self querying * getting program and module location by exported symbol Libraries under development =========================== See The Boost Library Incubator Project at http://blincubator.com for discussion of libraries currently under development.

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problems building Boost-1.55.0 in 32b machines with c++11
by Patricia Mendez Lorenzo 22 Jan '15

22 Jan '15

Dear Boost experts, since a while I am trying to compile Boost from the source in a 32b linux machine with c++11 enabled. The compiler version used is gcc4.8.1 This is performed through cmake as follows: --> Configuration: bootstrap.sh --with-python=<path to /bin/python> --with-toolset=gcc --> Build: /b2 -j4 variant=release --layout=versioned --debug-configuration --toolset=gcc --user-config=<path to a user-config.jam> Where user-config.jam contains the following information: using gcc : : : <linkflags>-m32 <compileflags>-m32 -std=gnu++0x also tested it with -std=c++11 And finally installed which basically contains the same options as the build adding --prefix=<installation dir> The libraries built following this procedure does not seem to have been created with c++11. If I compare the signatures of the same library build in 64 against 32 the result are In 64: nm --defined-only --demangle libboost_filesystem-gcc48-mt-1_55.so | grep copy_file boost::filesystem::detail::copy_file(boost::filesystem::path const&, boost::filesystem::path const&, boost::filesystem::copy_option, boost::system::error_code*) In 32, the same produces: boost::filesystem::detail::copy_file(boost::filesystem::path const&, boost::filesystem::path const&, boost::filesystem::copy_option::enum_type, boost::system::error_code*) The difference seems to come from wrong i686 build options. Could you please help me to find the good options to build these libs in 32b with c+=11 enabled? Thank you so much,

2 2

Question about subgraph isomorphism function
by Shouwei Li 20 Jan '15

20 Jan '15

Hi Guys, I am using boost graph library in my research project about graph theory. One object is testing whether graph G1 has a subgraph isomorphic to another graph G2. I only care about the result, "yes" or "no", and don't expected to find out a isomorphism pattern. I use the library function vf2_subgraph_iso(), but the third parameter is a callback function which will print out the isomorphic pattern all the time. Is there any way to omit this parameter or eliminate the output pattern. Here is my code snippet: ----------------------------------------------------- vf2_print_callback<Graph, Graph> callback(C4, g); if (!vf2_subgraph_iso(C4, g, callback) { // something; } else { // something; } __________________________________ Thanks for you attention! Best Regards! Shouwei

1 0

How to build modular boost for android?
by Robert Dailey 19 Jan '15

19 Jan '15

How do I build modular boost for android? I have it checked out from github at the 1.57 tag. I don't see a user-config.jam file, except for at "tools/build/example/user-config.jam". The structure is completely changed, where do I need to make changes? What changes do I make? Any guidance is appreciated. I'm no where near an expert here, I just need a quick ad-hoc solution. Thanks.

2 1

[interval] Guaranteed interval arithmetic for "long double"
by Александров Петр 15 Jan '15

15 Jan '15

Hello. Is guaranteed interval arithmetic for "long double" supported by Boost Interval library on x86-64 CPU, Linux, Clang or GCC? Kind regards, Petr.

1 0

[Coroutine] Migrating coroutines between different threads
by lin li 15 Jan '15

15 Jan '15

Hi, people. I have a question about the coroutines in boost (both the normal Coroutine and the asio couroutine). Can I suspend a coroutine in one thread, then later on resume it in another thread? I have been googling about this and found some (outdated) documents saying that this is not possible ( http://www.crystalclearsoftware.com/soc/coroutine/coroutine/coroutine_threa… ). However, I did not find this warning in the document of the current release. Is this limitation still there or not?

2 1

init log with BOOST_LOG_INLINE_GLOBAL_LOGGER_DEFAULT
by Bill Tian 15 Jan '15

15 Jan '15

Hi guys, I want to define a global logger that can be used in other place. The severity level always be "info". I init the log like this: #include <cstdlib> #include <boost/log/trivial.hpp> #include <boost/log/core.hpp> #include <boost/log/sources/global_logger_storage.hpp> #include <boost/log/sources/severity_logger.hpp> #include <boost/log/sources/record_ostream.hpp> #include <boost/log/sources/severity_feature.hpp> // Here we define our application severity levels. enum severity_level { normal, notification, warning, error, critical }; // The formatting logic for the severity level template< typename CharT, typename TraitsT > inline std::basic_ostream< CharT, TraitsT >& operator<< (std::basic_ostream< CharT, TraitsT >& strm, severity_level lvl) { static const char* const str[] = { "normal", "notification", "warning", "error", "critical" }; if (static_cast<std::size_t>(lvl) < (sizeof(str) / sizeof(*str))) strm << str[lvl]; else strm << static_cast<int>(lvl); return strm; } // Global logger declaration BOOST_LOG_INLINE_GLOBAL_LOGGER_DEFAULT(test_lg, boost::log::sources::severity_logger_mt<severity_level>) void try_logging() { boost::log::sources::severity_logger_mt<severity_level>& lg = test_lg::get(); // TODO: // always write "info" record, Unknown reason! BOOST_LOG_SEV(lg, normal) << "This is a normal severity record"; BOOST_LOG_SEV(lg, notification) << "This is a notification severity record"; BOOST_LOG_SEV(lg, warning) << "This is a warning severity record"; BOOST_LOG_SEV(lg, error) << "This is a error severity record"; BOOST_LOG_SEV(lg, critical) << "This is a critical severity record"; } int main(int argc, char* argv[]) { try_logging(); return EXIT_SUCCESS; } In the log i got this: [2015-01-14 19:00:34.800935] [0x40000300] [info] This is a normal severity re cord [2015-01-14 19:00:34.805935] [0x40000300] [info] This is a notification sever ity record [2015-01-14 19:00:34.806935] [0x40000300] [info] This is a warning severity r ecord [2015-01-14 19:00:34.806935] [0x40000300] [info] This is a error severity rec ord [2015-01-14 19:00:34.806935] [0x40000300] [info] This is a critical severity record What do i miss? Thank you! Bill

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Re: [Boost-users] unit test BOOST_CHECK_CLOSE absolute
by lepere renaud 14 Jan '15

14 Jan '15

>> For example, I am comparing coordinates in 2d spaces and the relative >> value is not important, the meaningfull value is the absolute difference >> between coordinates. > > It is almost never true. Related error gives you much better estimate of > closeness. I agree with that most of the time but this is not always true. Just imagine the case you compare lattitude, longitude. In this case, only absolute values make sense. > >> I have seen that I can do a >> BOOST_CHECK_SMALL(fabs(x - expected_x), 1e-3); >> >> but in this can I don't have a good message when the test fails (it does >> not show the value of x and the expected_x). >> >> In fact I would like to have something like BOOST_CHECK_CLOSE_ABSOLUTE ? >> Is there something equivalent or how can I do something like this ? > > Don't. Specify relative tolerance (or percent tolerance) and keep using > BOOST_CHECK_CLOSE. Relative tolerance will give me false bug report, I want a point to be equal to (0, 0) with a small absolute error and I don't care if it is -1e-15 or +1e-10 so BOOST_CHECK_CLOSE is not an option here and I have to use BOOST_CHECK_SMALL with the absolute difference. The problem with BOOST_CHECK_SMALL(fabs(x - expected_x), 1e-3); Is that when it fails with the message that does not print the values "x" and "expected_x" and does not say something like x(2.0) is not equal to "expected_x(0.0)" with an difference of 1e-3. I can probably write my own macro combining BOOST_TEST_MESSAGE() and some glues to obtain what I want but I was wondering if someone had the same problem and a solution. Thanks Renaud

2 1

[Boost.build] Building for ARM64
by mefyl 14 Jan '15

14 Jan '15

Hi, In my quest cross-compiling Boost.Context for ARM64, I encounter the following problem (using develop since ARM64 support is not in 1.57): $ ./bootstrap.sh --with-libraries=context [...] $ ./b2 -d2 -q toolset=clang architecture=arm abi=aapcs address-model=64 binary-format=mach-o [...] "clang++" -o "bin.v2/libs/system/build/clang-darwin-4.2.1/release/abi- aapcs/address-model-64/architecture-arm/threading-multi/libboost_system.dylib" -single_module -dynamiclib -install_name "libboost _system.dylib" "bin.v2/libs/system/build/clang-darwin-4.2.1/release/abi- aapcs/address-model-64/architecture-arm/threading-multi/error_code.o" Despite asking for arm, the "-arch arm64" I would expect is not passed to clang which thus compile to x86_64. However Boost.Context DOES understand I'm targeting arm since it picks the right ASM file: "clang++" -x assembler-with-cpp -O3 -O3 -finline-functions -Wno-inline - Wall -fPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_CHRONO_DYN_LINK=1 - DBOOST_CONTEXT_DYN_LINK=1 -DBOOST_CONTEXT_SOURCE -DBOOST_SYSTEM_DYN_LINK=1 - DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_THREAD_BUILD_DLL=1 -DBOOST_THREAD_POSIX - DBOOST_THREAD_USE_DLL=1 -DNDEBUG -I"." -c -o "bin.v2/libs/context/build/clang- darwin-4.2.1/release/abi-aapcs/address-model-64/architecture-arm/threading- multi/asm/make_arm64_aapcs_macho_gas.o" "libs/context/src/asm/make_arm64_aapcs_macho_gas.S" Which yields assembly errors of course since "-arch arm64" is not passed. Other sources seem to manage to build Boost for ARM64 using darwin toolset forcing clang as the compiler and passing many additional options, but their setup fails to build Boost.Context since it either picks the wrong ASM file, either complains the platform is not supported. Thanks in advance ! -- Quentin "mefyl" Hocquet CTO @ infinit.io

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Ambiguous overload for boost::blank when using optional & variant
by Berteun Damman 14 Jan '15

14 Jan '15

Hi, I'm using boost 1.57 after upgrading from 1.50, and the following innocuous looking program does not compile with either GCC (4.9) or Clang (3.5); tested both on Mac & Linux: #include <boost/optional.hpp> // This header triggers the problem #include <boost/variant.hpp> int main() { boost::variant<boost::blank> a, b; swap(a,b); // a.swap(b) does not make a difference } Both GCC and Clang give the same error: /opt/local/include/boost/variant/detail/move.hpp:60:5: error: call to 'swap' is ambiguous swap(lhs, rhs); [....] /opt/local/include/boost/core/swap.hpp:54:8: note: candidate function [with T1 = boost::blank, T2 = boost::blank] void swap(T1& left, T2& right) ^ /opt/local/include/boost/variant/detail/move.hpp:44:13: note: candidate function [with T1 = boost::blank, T2 =boost::blank] inline void swap(T1& lhs, T2& rhs) In this case one could remove the Optional header, but in a larger project this is of course not a solution; a better solution seems to add an overload for swap taking two boost blanks. I feel this is a bug in Boost, can someone confirm and tell me where I should file the bug request? Finally I noticed due to the above error messages that boost::variant will never use variadic templates when you use Clang. For GCC it uses them (in C++11 mode), but for Clang it refuses. Why is this? Thanks, -Berteun

1 0

[Context] Boost.Context ARM64 support
by mefyl 14 Jan '15

14 Jan '15

Hi, We currently use boost context on iOS, and as you may know Apple is making it mandatory for application to bundle a 64bits version starting February 1 (https://developer.apple.com/news/?id=10202014a) It is thus crucial for us - and anyone using Boost Context on iOS - to get a working ARM64 backend working. Looking at github, I see code has been contributed, but the build system still bounces to unsupported.hh when building with clang for ARM64. Is that code acutally working but not-yet-released, or is it still incomplete ? In the latter case, is anyone still working on it and do we have any rough idea of the delay before a working version get pushed ? Happy to read some ARM64 doc and contribute if it's in a stale state, of course. Cheers, -- Quentin "mefyl" Hocquet CTO @ infinit.io

2 7

unit test BOOST_CHECK_CLOSE absolute
by Renaud Lepère 12 Jan '15

12 Jan '15

I am doing unit tests using boost utf but I have sometimes problems with BOOST_CHECK_SMALL because it checks relative value. For example, I am comparing coordinates in 2d spaces and the relative value is not important, the meaningfull value is the absolute difference between coordinates. I have seen that I can do a BOOST_CHECK_SMALL(fabs(x - expected_x), 1e-3); but in this can I don't have a good message when the test fails (it does not show the value of x and the expected_x). In fact I would like to have something like BOOST_CHECK_CLOSE_ABSOLUTE ? Is there something equivalent or how can I do something like this ?

3 3

[GIL] Problem trying to use scoped_channel_value with copy_and_convert_pixels
by Gabriel Marcano 12 Jan '15

12 Jan '15

I have been experimenting with Boost.GIL, and I have run into something that I'm not sure if it's a problem on my end or with Boost.GIL. In essence, I'm trying to make a grayscale image with channels limited to 14 bits. I am using scoped_channel_value to do this. The problem happens when I try to convert the 14 bit image to a 16 bit grayscale image I get compilation errors. I am including the code I am using below: //START CODE #include <boost/gil/gil_all.hpp> #include <cstdint> using namespace std; using namespace boost::gil; namespace detail { struct bits14_min { static std::uint16_t apply() { return 0;} }; struct bits14_max { static std::uint16_t apply() { return 0x3FF;} }; } typedef scoped_channel_value <std::uint16_t, ::detail::bits14_min, ::detail::bits14_max> bits14_t; typedef pixel<bits14_t, gray_layout_t> Pixel1; typedef image<Pixel1> Frame1; int main() { Frame1 image( Frame1::point_t(100, 100), Frame1::value_type((1 << 14)-1), 0); gray16_image_t image2(image.dimensions()); Frame1::view_t view1(view(image)); gray16_image_t::view_t view2(view(image2)); copy_and_convert_pixels(view1, view2); return 0; } //END CODE The interesting thing is that the program compiles if change typedef scoped_channel_value <std::uint16_t, ::detail::bits14_min, ::detail::bits14_max> bits14_t; to typedef scoped_channel_value <float, ::detail::bits14_min, ::detail::bits14_max> bits14_t; I think the relevant error in the log is this: /usr/include/boost/gil/channel_algorithm.hpp:54:8: error: ‘struct boost::gil::scoped_channel_value<short unsigned int, detail::bits14_min, detail::bits14_max>’ is not a valid type for a template non-type parameter struct unsigned_integral_max_value : public mpl::integral_c<UnsignedIntegralChannel,-1> {}; I am attaching the full compile log to this email. Thank you for any help with this matter! Sincerely, Gabriel E. Marcano

2 2

Initializing of Boost.Log
by Igor Mironchik 11 Jan '15

11 Jan '15

Hi guys, I want to initialize simple log. I do the next: #include <boost/log/utility/setup/file.hpp> #include <boost/log/trivial.hpp> #include <boost/log/utility/setup/common_attributes.hpp> void init() { boost::log::add_file_log ( boost::log::keywords::file_name = "sample_%Y%m%d.log", boost::log::keywords::auto_flush = true, boost::log::keywords::open_mode = (std::ios::out | std::ios::app), boost::log::keywords::format = "[%TimeStamp%] [%Severity%]: %Message%" ); boost::log::add_common_attributes(); } int main(int, char*[]) { init(); BOOST_LOG_TRIVIAL( trace ) << "A trace severity message"; BOOST_LOG_TRIVIAL( debug ) << "A debug severity message"; BOOST_LOG_TRIVIAL( info ) << "An informational severity message"; BOOST_LOG_TRIVIAL( warning ) << "A warning severity message"; BOOST_LOG_TRIVIAL( error ) << "An error severity message"; BOOST_LOG_TRIVIAL( fatal ) << "A fatal severity message"; return 0; } But in log I receive: [2015-Jan-11 09:51:04.082221] []: A trace severity message [2015-Jan-11 09:51:04.082221] []: A debug severity message [2015-Jan-11 09:51:04.082221] []: An informational severity message [2015-Jan-11 09:51:04.092221] []: A warning severity message [2015-Jan-11 09:51:04.092221] []: An error severity message [2015-Jan-11 09:51:04.092221] []: A fatal severity message And my question is how to initialize logging to write severity level in messages? What do I miss? Thank you. -- Best Regards, Igor Mironchik.

1 2

Building boost under solaris
by Raphael Fuchs 10 Jan '15

10 Jan '15

Hello, I am trying to compile boost 1.57 under Solaris for the second day now, please help. Here is my setup: - Solaris Sparc 5.10 - gcc 4.9.2 What I did: ./bootstrap.sh --without-icu --prefix=/usr/local/ -n Building Boost.Build engine with toolset gcc... ./b2 This results in two errors like the following: gcc.compile.asm bin.v2/libs/context/build/gcc-4.9.2/release/threading-multi/asm/make_sparc64_sysv_elf_gas.o /usr/ccs/bin/as: "/var/tmp//cc3IBrs7.s", line 13: error: invalid character (0x40) /usr/ccs/bin/as: "/var/tmp//cc3IBrs7.s", line 34: warning: detect global register use not covered .register pseudo-op /usr/ccs/bin/as: "/var/tmp//cc3IBrs7.s", line 52: error: unknown "%"-symbol /usr/ccs/bin/as: "/var/tmp//cc3IBrs7.s", line 52: error: quoted-string operand required /usr/ccs/bin/as: "/var/tmp//cc3IBrs7.s", line 52: error: statement syntax "g++" -x assembler-with-cpp -O3 -finline-functions -Wno-inline -Wall -fPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_CONTEXT_DYN_LINK=1 -DBOOST_CONTEXT_SOURCE -DNDEBUG -D_XOPEN_SOURCE=600 -I"." -c -o "bin.\ v2/libs/context/build/gcc-4.9.2/release/threading-multi/asm/make_sparc64_sysv_elf_gas.o" "libs/context/src/asm/make_sparc64_sysv_elf_gas.S" Question 1: the /usr/css/bin directory is not in my PATH. How can I tell b2 to use the gnu-utils assembler? I also get a lot of errors like this: "g++" -x assembler-with-cpp -O3 -finline-functions -Wno-inline -Wall -fPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_CONTEXT_DYN_LINK=1 -DBOOST_CONTEXT_SOURCE -DNDEBUG -D_XOPEN_SOURCE=600 -I"." -c -o "bin.\ v2/libs/context/build/gcc-4.9.2/release/threading-multi/asm/jump_sparc64_sysv_elf_gas.o" "libs/context/src/asm/jump_sparc64_sysv_elf_gas.S" ...failed gcc.compile.asm bin.v2/libs/context/build/gcc-4.9.2/release/threading-multi/asm/jump_sparc64_sysv_elf_gas.o... gcc.compile.c++ bin.v2/libs/context/build/gcc-4.9.2/release/threading-multi/unsupported.o libs/context/src/unsupported.cpp:7:2: error: #error "platform not supported" #error "platform not supported" ^ "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pthreads -fPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_CONTEXT_DYN_LINK=1 -DBOOST_CONTEXT_SOURCE -DNDEBUG -D_XOPEN_SOURCE=600 -I"."\ -c -o "bin.v2/libs/context/build/gcc-4.9.2/release/threading-multi/unsupported.o" "libs/context/src/unsupported.cpp" ...failed gcc.compile.c++ bin.v2/libs/context/build/gcc-4.9.2/release/threading-multi/unsupported.o... ...skipped <pbin.v2/libs/context/build/gcc-4.9.2/release/threading-multi>libboost_context.so.1.57.0 for lack of <pbin.v2/libs/context/build/gcc-4.9.2/release/threading-multi>asm/make_sparc64_sysv_\ elf_gas.o... Question 2:Why does the compiler complain, even though the -D_XOPEN_SOURCE=600 flag is specified? Your support is very much appreciated Best regards Raphael

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rolling log file directory not effective after two files
by David Frank 10 Jan '15

10 Jan '15

Greetings, I'm using the following call to set the rolling log files in dir directory: // Set up where the rotated files will be stored sink->locked_backend()->set_file_collector(sinks::file::make_collector( keywords::target = dir, // where to store rotated files keywords::max_size = 16 * 1024 * 1024, // maximum total size of the stored files, in bytes keywords::min_free_space = 100 * 1024 * 1024 // minimum free space on the drive, in bytes )); But, after two files, the log files get created in the current running directory, I'm wondering if anyone has seen this. Thanks,Dave

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double free when both shared library and executable linked to boost libraries
by Eric Roller 09 Jan '15

09 Jan '15

I've run into a run-time error (double free) with my software which uses a plug-in architecture. The main executable (a.out) uses dlopen to load a shared library (mylib.so). Both a.out and mylib.so utilize the boost libraries (version 1.54) and are therefore linked separately to them. Depending on whether I use static or dynamic linking to the boost libraries I encounter the double free error as confirmed by address sanitizer using gcc 4.9.2 on linux x86_64. Here is a summary of the results: a.out link mylib.so link double free? static dynamic YES static static NO dynamic dynamic NO dynamic static NO So you can see, only when the main executable used static linking to boost and the shared library used dynamic linking to boost is when I saw the double free error at run time. My question is, why is the error only triggered under that condition and what is the recommended link configuration when using boost libraries for both a shared library and an executable. Ideally, the shared library plug-in should be free to use any boost version with either static or dynamic linking, and it should be independent from (i.e. not conflict with) the main executable's boost version and link type. What compiler/link settings would be necessary to achieve this, if it is even possible at all? -- Eric Roller

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Trouble compiling from git repository (VS2013)
by Cesar Mello 09 Jan '15

09 Jan '15

Hi! I cloned the git repository following the instructions from the wiki. But I get the following error on Windows using VS2013 and the command "b2 address-model=64 link=static". Can someone please give me a clue? Thank you very much! Best regards Mello "Name clash for '<pstage\lib>libboost_system-vc120-mt-1_58.lib' Tried to build the target twice, with property sets having ..." Building the Boost C++ Libraries. Performing configuration checks - symlinks supported : no - junctions supported : yes - hardlinks supported : yes - arm : no (cached) - mips1 : no (cached) - power : no (cached) - sparc : no (cached) - x86 : yes (cached) - has_icu builds : no warning: Graph library does not contain MPI-based parallel components. note: to enable them, add "using mpi ;" to your user-config.jam - zlib : no - iconv (libc) : no - iconv (separate) : no - icu : no - icu (lib64) : no - message-compiler : yes - compiler-supports-ssse3 : yes - compiler-supports-avx2 : yes - gcc visibility : no - long double support : yes warning: skipping optional Message Passing Interface (MPI) library. note: to enable MPI support, add "using mpi ;" to user-config.jam. note: to suppress this message, pass "--without-mpi" to bjam. note: otherwise, you can safely ignore this message. - zlib : no (cached) error: Name clash for '<pstage\lib>libboost_system-vc120-mt-1_58.lib' error: error: Tried to build the target twice, with property sets having error: these incompabile properties: error: error: - <warnings>all error: - <architecture>x86 <warnings>on error: error: Please make sure to have consistent requirements for these error: properties everywhere in your project, especially for install error: targets.

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Using static code checkers against the Boost code base
by Hickman, Steve (AdvTech) 08 Jan '15

08 Jan '15

I don't know if there is a policy yet on using static code checkers on the Boost code base as part of the release cycle. Given that the Visual Studio 2012 Analyzer tool I'm using just picked up 3 issues in the 1.57 release (I've posted TRAC items on them already), I suspect not. I would like to encourage such a policy. Boost is, among other things, about quality. This is a way to enhance quality. For people like me who work in safety critical fields, it is vital. I cannot use Boost libraries if they can't be certified. Static analyzers can help insure quality, which makes it easier to qualify these tools. There are many tools available. Some, like CppCheck, are open source. Others are built into development environments (aforementioned VS Analyzer, Clang tools, etc.). Further, I suspect that tool vendors could be convinced it would be good PR to have their tools used by Boost, so I suspect even those with paid licenses can be made available for free. Steve Hickman System Architect, Flight Deck of the Future 480-236-8367

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iostreams gzip/zlib: different behavior with msvc 32 bit vs 64 bit (boost 1.53)
by Simon Haegler 07 Jan '15

07 Jan '15

dear boost users if i compile & run the test code below with msvc 2010 SP1 *64 bit*, both variants (gzip/zlib) work as expected. however, compiling the same with msvc 2010 SP1 *32 bit*, the gzip_decompressor aborts with Assertion failed: 0, file libs\iostreams\src\gzip.cpp, line 127 looking at the debug stack trace, the decompressor chokes on some header byte. i tested with boost 1.53. did anybody encounter the same? TIA, simon here is my test code: BOOST_AUTO_TEST_SUITE(CompressionTests) const std::string SOME_DATA = "yadda yadda duh"; BOOST_AUTO_TEST_CASE(boost_zlib) { const std::string p = "C:\\temp\\compressed.zlib"; { boost::iostreams::filtering_ostream out; out.push(boost::iostreams::zlib_compressor()); out.push(boost::iostreams::file_sink(p, std::ios_base::binary)); out << SOME_DATA; boost::iostreams::close(out); } std::string result; { boost::iostreams::filtering_istream in; in.push(boost::iostreams::zlib_decompressor()); in.push(boost::iostreams::file_source(p, std::ios_base::binary)); result.assign((std::istreambuf_iterator<char>(in)), (std::istreambuf_iterator<char>())); boost::iostreams::close(in); } BOOST_CHECK_EQUAL(result, SOME_DATA); } BOOST_AUTO_TEST_CASE(boost_gzip) { const std::string p = "C:\\temp\\compressed.gzip"; { boost::iostreams::filtering_ostream out; out.push(boost::iostreams::gzip_compressor()); out.push(boost::iostreams::file_sink(p, std::ios_base::binary)); out << SOME_DATA; boost::iostreams::close(out); } std::string result; { boost::iostreams::filtering_istream in; in.push(boost::iostreams::gzip_decompressor()); in.push(boost::iostreams::file_source(p, std::ios_base::binary)); result.assign((std::istreambuf_iterator<char>(in)), (std::istreambuf_iterator<char>())); boost::iostreams::close(in); } BOOST_CHECK_EQUAL(result, SOME_DATA); } BOOST_AUTO_TEST_SUITE_END()

1 0