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

[integer] what is the fastest integer type which can hold an 8 bit number?
by Robert Ramey 11 Sep '15

11 Sep '15

Reading the documentation at http://www.boost.org/doc/libs/1_59_0/libs/integer/doc/html/boost_integer/in… I invoke the following using temp_integer = typename boost::int_t<8>::fast; With the idea of getting the fastest integer type which will hold an 8 bit signed number. But I get temp_integer equal to a char type. This surprises me. I don't believe that the fastest integer type which can hold an 8 bit signed integer is a char. I looked into the boost/integer.hpp and I can't really figure it out. It doesn't seem to to have any processor specific code in it - which I would think would be necessary to implement the function. What am I missing here? Robert Ramey

3 3

Boost.Fiber mini-review September 4-13
by Nat Goodspeed 11 Sep '15

11 Sep '15

Hi all, The mini-review of Boost.Fiber by Oliver Kowalke begins today, Friday September 4th, and closes Sunday September 13th. It was reviewed in January 2014; the verdict at that time was "not in its present form." Since then Oliver has substantially improved documentation, performance, library customization and the underlying implementation, and is bringing the library back for mini-review. The substance of the library API remains the same, which is why a mini-review is appropriate. The Fiber library now requires a C++14-conforming compiler. I will monitor reviews and discussion on both the boost-users@ list and the boost@ developers' list. Please include at least "fiber" and "review" in your mail subject, e.g. by replying to this message. (Please reply to only ONE list, however.) Thank you for your interest and your feedback! ----------------------------------------------------- About the library: Boost.Fiber provides a framework for micro-/userland-threads (fibers) scheduled cooperatively. The API contains classes and functions to manage and synchronize fibers similar to Boost.Thread. Each fiber has its own stack. A fiber can save the current execution state, including all registers and CPU flags, the instruction pointer, and the stack pointer and later restore this state. The idea is to have multiple execution paths running on a single thread using a sort of cooperative scheduling (versus threads, which are preemptively scheduled). The running fiber decides explicitly when it should yield to allow another fiber to run (context switching). Boost.Fiber internally uses execution_context from Boost.Context; the classes in this library manage, schedule and, when needed, synchronize those contexts. A context switch between threads usually costs thousands of CPU cycles on x86, compared to a fiber switch with a few hundred cycles. A fiber can only run on a single thread at any point in time. docs: http://olk.github.io/libs/fiber/doc/html/index.html git: https://github.com/olk/boost-fiber --------------------------------------------------- Please always state in your review whether you think the library should be accepted as a Boost library! Additionally please consider giving feedback on the following general topics: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Nat Goodspeed Boost.Fiber Review Manager ________________________________

6 51

[Accumulators] Compiler error when compiling examples: extractor.hpp:36:74: error: no type named 'result_type' in 'boost::fusion::void_'
by Bernhard Wagner 11 Sep '15

11 Sep '15

When compiling: #include <boost/accumulators/framework/accumulator_set.hpp> #include <boost/accumulators/statistics/covariance.hpp> #include <boost/accumulators/statistics/variates/covariate.hpp> #include <boost/test/unit_test.hpp> #include <boost/test/floating_point_comparison.hpp> using namespace boost::accumulators; int main() { accumulator_set<double, stats<tag::covariance<double, tag::covariate1> > > acc; acc(1., covariate1 = 2.); acc(1., covariate1 = 4.); acc(2., covariate1 = 3.); acc(6., covariate1 = 1.); assert(covariance(acc) == -1.75); } using: clang++ -std=c++11 -stdlib=libc++ -Weverything accum_covariance.cpp -L /usr/local/Cellar/boost/1.55.0_2/lib/ -l boost_unit_test_framework (on OSX 10.8.5) I get following error. Same error when I try using rolling_sum or rolling_mean. In file included from accum_covariance.cpp:1: In file included from /usr/local/include/boost/accumulators/framework/accumulator_set.hpp:27: In file included from /usr/local/include/boost/accumulators/framework/accumulators/external_accumulator.hpp:13: /usr/local/include/boost/accumulators/framework/extractor.hpp:36:74: error: no type named 'result_type' in 'boost::fusion::void_' typedef typename mpl::apply<AccumulatorSet, feature_type>::type::result_type type; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~

2 2

xpressive: regex to catch HTML generic tag with back reference to tag name
by Mia 10 Sep '15

10 Sep '15

Hello,I am quite new to Boost Xpressive, I am using C++ on Visual Studio 2013 and Boost 1_58_0I need to clean up some text from all HTML tagsI an trying to use this regex:wsregex html_any_tag_regex = wsregex::compile("^([^<]*)?<([A-Za-z][A-Za-z0-9]*)[^>]*>(.+)<\\/(\\2)>(.*)?$");this regex causes compilation error: error C2664: 'int boost::mpl::assertion_failed(boost::mpl::assert::type)' : cannot convert argument 1 from 'boost::mpl::failed ************boost::is_same<wchar_t,char>::* ***********' to 'boost::mpl::assert::type'I tested my regex here:http://www.myezapp.com/apps/dev/regexp/show.wsand it is parsed exactly to my needs.What am I doing wrong?Thank youMia -- View this message in context: http://boost.2283326.n4.nabble.com/xpressive-regex-to-catch-HTML-generic-ta… Sent from the Boost - Users mailing list archive at Nabble.com.

1 0

Linker error with boost::serialization
by Stephen Gray 10 Sep '15

10 Sep '15

Using Debian Jessie (64bit) I've just built Boost 1.56 from source. Whilst compiling an application I'm getting the error; g++ -o ./Release/sdCloneServer @"sdCloneServer.txt" -L. -L/usr/local/lib -L/usr/lib/x86_64-linux-gnu -lpthread -lzmq -lboost_date_time -lboost_serialization./Release/sdCloneServer_sdCloneServer.cpp.o: In function `boost::archive::detail::common_iarchive<boost::archive::text_iarchive>::vload(boost::archive::class_name_type&)':sdCloneServer.cpp:(.text._ZN5boost7archive6detail15common_iarchiveINS0_13text_iarchiveEE5vloadERNS0_15class_name_typeE[_ZN5boost7archive6detail15common_iarchiveINS0_13text_iarchiveEE5vloadERNS0_15class_name_typeE]+0x1): undefined reference to `boost::archive::text_iarchive_impl<boost::archive::text_iarchive>::load_override(boost::archive::class_name_type&)'collect2: error: ld returned 1 exit status I've tried manipulating the order in which the libraries are listed in the complier command but without success. Can anyone please offer suggestions on what is wrong and how to resolve this? With thanks.

1 0

Compilation problem with fedora 22
by Pierre Daye 10 Sep '15

10 Sep '15

Hello, I recently installed Fedora 22 and I decided to use boost 1.59.0. I also have a little server with Centos 7 on it. On both system, I installed boost 1.58.0. I also installed the Intel cluster studio XE 2016 on each machine. I can compile (and run) with no problem my code on the Centos 7 but I can not compile it under fedora 22. The relevant lines of code are: void GABAB::compCumSum(double* out,double T_in,double dur) > { > double dt=0.01; > int NStep=(int) floor(dur/dt); > > int tmpstartInd=startInd; > > startInd=0; > > StateVector x(2 * NState); > > controlled_runge_kutta< runge_kutta_cash_karp54 < StateVector, double, > StateVector, double, vector_space_algebra, mkl_operations > > > stepper_cumsum; > > compInitState(x, 0.0, 0.0); > > for (int ii = 0; ii < NState; ii++) > x[ ii + NState ] = 0.0; > > for (int ii = 0; ii < NState; ii++) > out[ii] = x[ii]; > > setInput(T_in, T_in); > > cumsum_GABAB tmp(*this); > > size_t steps = integrate_adaptive( stepper_cumsum, tmp , x , 0.0 , dur , > dt ); > > for (int ii = 0; ii < NState; ii++) > out[ii] = x[ii + NState]; > > startInd=tmpstartInd; > } StateVector is a typedef in another header file: typedef boost::numeric::ublas::vector< double > StateVector; If I comment the line starting with "integrate_adaptive(...", I can compile the code. Otherwise, I got a tons of errors, starting with: /usr/include/c++/5.1.1/functional(78): error: class > "boost::numeric::odeint::controlled_runge_kutta<boost::numeric::odeint::runge_kutta_dopri5<StateVector, > double, StateVector, double, boost::numeric::odeint::vector_space_algebra, > boost::numeric::odeint::default_operations, > boost::numeric::odeint::initially_resizer>, > boost::numeric::odeint::default_error_checker<double, > boost::numeric::odeint::vector_space_algebra, > boost::numeric::odeint::default_operations>, > boost::numeric::odeint::initially_resizer, > boost::numeric::odeint::explicit_error_stepper_fsal_tag>" has no member > "result_type" > { typedef typename _Functor::result_type result_type; }; I emphasize the fact that the code can easily be compiled under Centos 7 with the same installation procedure of boost and the intel cluster xe suite. Any clue of what is happening? Thanks, Pierre -- "It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong." Richard P. Feynman

1 0

Boost.Test - problems overriding main
by ramonpadilla1＠yahoo.co.uk 10 Sep '15

10 Sep '15

I want to provide my own main function while using Boost.Test. So I have included the following macros: #define BOOST_TEST_ALTERNATIVE_INIT_API #define BOOST_TEST_NO_MAIN In my main function I have a call to: ::boost::unit_test::unit_test_main(&registering_all_tests, argc, argv) but this gives me the following error when build on OS X using Xcode 6: Undefined symbols for architecture x86_64: "boost::unit_test::unit_test_main(bool (*)(), int, char**)", referenced from: _main in main.o I found out that including the following file: #include <boost/test/included/unit_test.hpp> resolves this problem but I'm confused about the implications. The description of this file states that it uses the included (vs. linked) version of Unit Test Framework. The Boost getting started guide states that: > Boost.Test can be used in “header-only” or “separately compiled” mode,> although **separate compilation is recommended for serious use**. I have built the library separately. The Boost doc also states: > Including the UTF directly into your test module> > If you prefer to avoid the standalone library compilation you can> either include all files that constitute the static library in your> test module's makefile or include them as a part of a test module's> source file. To facilitate the later variant the UTF presents the> single-header usage variant. In either case no special build options> or macro definitions are required to be added to your compilation> options list by default. But the same flags that can be used for the> standalone library compilation are applicable in this case. Though,> obviously, neither BOOST_TEST_DYN_LINK nor BOOST_TEST_NO_LIB are> applicable. This solution may not be the best choice in a long run,> since it requires the UTF sources recompilation for every test module> you use it with and for every change of a test module you are working> on. In a result your testing cycle time may increase. If it become> tiresome, I recommend switching to one of the prebuilt library usage> variants. It seems that by choosing to include the included (vs. linked) version of Unit Test Framework I am dong the wrong thing. Can someone please clarify the correct approach. The examples of overriding main don't mention the need to do this.

2 4

Boost serializing abstract base class
by John King 08 Sep '15

08 Sep '15

I'm having trouble serializing a few classes with boost serialization. I've looked through different documentation and I've found it pretty confusing. Some say that you have to include certain libraries in a certain order, others say you have to use BOOST_SERIALIZATION_BASE_OBJECT_NVP, others boost::serialization::base_object, etc. I've also seen some use BOOST_CLASS_EXPORT() but I don't want to have to list every single possible derived class... The code: *main.cpp:* #include <iostream> #include <memory> #include <boost/archive/binary_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> #include <fstream> #include "model.h" #include "c1.h" int main() { std::shared_ptr<C1> c1 = std::make_shared<C1>(); Model m(c1); std::cout << "TYPE: " << m.which_type_in_use() << std::endl; std::ofstream out_stream("test.bin", std::ios::out | std::ios::binary | std::ios::trunc); boost::archive::binary_oarchive oar(out_stream); oar << (m); Model m2; std::ifstream in_stream("test.bin", std::ios::in | std::ios::binary); boost::archive::binary_iarchive iar(in_stream); iar >> (m2); std::cout << "TYPE: " << m2.which_type_in_use() << std::endl; } *p1.h:* #ifndef P1_H_ #define P1_H_ #include <string> #include <boost/archive/binary_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> class P1 { protected: int size = 100; std::string type; public: int get_size() { return size; } virtual std::string get_type() = 0; friend class boost::serialization::access; template<typename Archive> void serialize(Archive &ar, const unsigned int version) { ar & size; ar & type; } }; #endif *c1.h:* #ifndef C1_H_ #define C1_H_ #include "p1.h" #include <string> #include <boost/serialization/serialization.hpp> class C1 : public P1 { public: bool is_child = true; C1() { int r = 10; } std::string get_type(); template<typename Archive> void serialize(Archive &ar, const unsigned int version) { ar & is_child; ar & boost::serialization::base_object<P1>(*this); } }; #endif *c1.cpp:* #include "c1.h" std::string C1 :: get_type() { return "c1"; } *model.h:* #ifndef MODEL_H_ #define MODEL_H_ #include <memory> #include <boost/archive/binary_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> #include "p1.h" class Model { public: bool is_model = true; //int *nums; std::shared_ptr<P1> p; Model(std::shared_ptr<P1> p1); Model() = default; std::string which_type_in_use(); template<typename Archive> void serialize(Archive &ar, const unsigned int version); }; #endif *model.cpp:* #include "model.h" Model :: Model(std::shared_ptr<P1> p1) : p(p1) { //nums = (int*)malloc(10*sizeof(int)); //nums[5] = 123; } std::string Model :: which_type_in_use() { return p->get_type(); } template<typename Archive> void Model :: serialize(Archive &ar, const unsigned int version) { ar & is_model; ar & p; }

1 0

[test] upgrading from 1.58 to 1.59
by Mathieu Champlon 07 Sep '15

07 Sep '15

Hello, Prior to boost 1.59 I had code using the floating point comparisons of Boost.Test as in if( boost::test_tools::check_is_close( v1, v2, boost::test_tools::percent_tolerance( tolerance ) ) ) ... if( boost::test_tools::check_is_close( v1, v2, boost::test_tools:: Snippet fraction_tolerance( tolerance ) ) ) ... As these seem to have been replaced/generalized starting with boost 1.59 I need to upgrade my code. Surely this involves using boost::test_tools::tolerance() but I'm getting a bit lost in the internals of Boost.Test. Could someone shed some light ? Thanks ! MAT.

2 3

Static linking program_options on ARM
by Pau Garcia i Quiles 07 Sep '15

07 Sep '15

Hello, I am having trouble when linking Boost::Program_Options statically on Linux ARM 32-bit: it spits an error about a duplicate symbol for a guard-variable. It works fine on Linux ARM 32-bit (same compiler) if using shared libraries, and also on Linux x86-64 both with static and shared libraries. I can reproduce the problem with the examples included in the libs/program_options/examples: real.cpp and custom_syntax.cpp compile and run fine but first.cpp, multiple_sources.cpp options_description.cpp, option_groups.cpp and regex.cpp fail: $ armv7a-openelec-linux-gnueabi-g++ -std=c++11 -o option_groups option_groups.cpp -L $SYSROOT/usr/lib -lboost_program_options /tmp/cch3i9Yf.ltrans0.ltrans.o:(.bss._ZGVZN5boost15program_options10validators17get_single_stringIcEERKSbIT_St11char_traitsIS3_ESaIS3_EERKSt6vectorIS7_SaIS7_EEbE5empty[_ZGVZN5boost15program_options10validators17get_single_stringIcEERKSbI T_St11char_traitsIS3_ESaIS3_EERKSt6vectorIS7_SaIS7_EEbE5empty]+0x0): multiple definition of `guard variable for std::basic_string<char, std::char_traits<char>, std::allocator<char> > const& boost::program_options::validators::get_single_ string<char>(std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > const&, bool)::empty' /tmp/ccORpK3T.o:(.bss._ZGVZN5boost15program_options10validators17get_single_stringIcEERKSbIT_St11char_traitsIS3_ESaIS3_EERKSt6vectorIS7_SaIS7_EEbE5empty[_ZGVZN5boost15program_options10validators17get_single_stringIcEERKSbIT_St11char_trai tsIS3_ESaIS3_EERKSt6vectorIS7_SaIS7_EEbE5empty]+0x0): first defined here /tmp/cch3i9Yf.ltrans0.ltrans.o:(.bss._ZZN5boost15program_options10validators17get_single_stringIcEERKSbIT_St11char_traitsIS3_ESaIS3_EERKSt6vectorIS7_SaIS7_EEbE5empty[_ZZN5boost15program_options10validators17get_single_stringIcEERKSbIT_St 11char_traitsIS3_ESaIS3_EERKSt6vectorIS7_SaIS7_EEbE5empty]+0x0): multiple definition of `std::basic_string<char, std::char_traits<char>, std::allocator<char> > const& boost::program_options::validators::get_single_string<char>(std::vecto r<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > const&, bool)::empty' /tmp/ccORpK3T.o:(.bss._ZZN5boost15program_options10validators17get_single_stringIcEERKSbIT_St11char_traitsIS3_ESaIS3_EERKSt6vectorIS7_SaIS7_EEbE5empty[_ZZN5boost15program_options10validators17get_single_stringIcEERKSbIT_St11char_traitsIS 3_ESaIS3_EERKSt6vectorIS7_SaIS7_EEbE5empty]+0x0): first defined here collect2: error: ld returned 1 exit status Compiling Boost with or without C++11 does not affect either (it happens on both cases). Has anyone faced something like this? Thank you -- Pau Garcia i Quiles http://www.elpauer.org (Due to my workload, I may need 10 days to answer)

2 2