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numeric_cast<float> throws for double infinity
by Dmitry Volosnykh 09 Mar '16

09 Mar '16

When I try to cast variable of type double (which is equal to std::numeric_limits<double>::inifinity()) to float I get exception: std::bad_cast: bad numeric conversion: positive overflow. I expected to get std::numeric_limits<float>::inifinity(). The same is true for negative infinity. Is it intended behavior or bug? In case this should be considered as bug, maybe it was fixed in more recent versions of Boost? PS. I am using stock Boost 1.54 on Ubuntu 14.04 Regrads, Dmitry.

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Re: [Boost-users] [boost] [Fit] formal review starts today
by Paul Fultz II 09 Mar '16

09 Mar '16

On Monday, March 7, 2016 at 2:52:09 AM UTC-6, Edward Diener wrote: > > On 3/7/2016 12:15 AM, Paul Fultz II wrote: > > > > > > On Sunday, March 6, 2016 at 9:42:19 PM UTC-6, Edward Diener wrote: > >> > >> On 3/3/2016 6:43 AM, Vicente J. Botet Escriba wrote: > >>> Dear Boost community, sorry for the late anounce > >>> > >>> The formal review of Paul Fultz II's Fit library starts today, 2nd > March > >>> and ends on 13th March. > >>> > >>> Fit is a header-only C++11/C++14 library that provides utilities for > >>> functions and function objects. > >> > >> These are some comments/queries about the Fit documentation. > >> > >> Introduction > >> > >> The introduction says that Fit "provides utilities for functions and > >> function objects." But it seems as if Fit works only with lambda > >> functions and function objects. > > > > > > Fit works with any generalized Callable: > > > > http://en.cppreference.com/w/cpp/concept/Callable > > Please document this. A generalized Callable is a much bigger set of > functionality than just lambda functions and function objects. > > > > > > >> The term 'function' normally encompasses > >> a much larger definition in C++ which includes global functions, static > >> functions, member functions, and lambda functions. > > > > > > Which is what Callable encompasses, but I used "function" since more > > people are familiar with that than Callable. > > A 'function' and a Callable in C++ are two entirely different things. > Use the one that is precise and don't worry what people are familiar > with. Explain what a Callable is early on ( I know you explain it later > ) if you feel that people do not know what it means. > > > > > > >> Fit needs to be more > >> precise in what it says it works with. It repeatedly refers to function > >> objects and lambda functions as 'functions'. I think this vagueness of > >> terminality is really confusing in the documentation. > >> > > > > Perhaps, I should refer to the Callable concept early on then. > > See above. > > > > > > >> > >> Quick Start:Function Objects > >> > >> "We can make it behave like a regular function if we construct the > class > >> as a global variable." > >> > >> What about a non-global > >> > >> sum_f sum = sum_f(); > >> > >> makes 'sum' not behave like a regular function other than the fact that > >> the variable 'sum' may eventually go out of scope ? > >> > > > > In C++, a regular function is always global, there is no such thing as > local > > function(sans gcc extensions). > > My point is that the non-global 'sum' in my example above behaves just > as much like a regular function as your global 'sum'. You may want to > promote the idea of global function objects but I think that this is > personally a bad idea. IMO global variables of any kind are to be avoided. It is quite common in several modern C++ libraries to declare functions as global objects. There are many advantages to this. Why do you believe it should be avoided? Especially since it has the same effect as a free function. DO you believe free function should be avoided as well? > > > > > > > >> > >> Quick Start:Lambdas > >> > >> Why do we need both BOOST_FIT_STATIC_LAMBDA and > >> BOOST_FIT_STATIC_LAMBDA_FUNCTION ? I would seem that > >> BOOST_FIT_STATIC_LAMBDA_FUNCTION would be adequate and > >> BOOST_FIT_STATIC_LAMBDA is just redundant, mimicking lambda syntax to > no > >> purpose. > >> > > > > BOOST_FIT_STATIC_LAMBDA_FUNCTION and BOOST_FIT_STATIC_FUNCTION both > define a > > function at global scope, and can only be used at global scope, whereas > > BOOST_FIT_STATIC_LAMBDA can be used to constexpr initialize local > variables > > as > > well. > > It might be good to add that when the end-user first encounters > BOOST_FIT_STATIC_LAMBDA, because the name does not suggest > initialization of local objects. Furthermore I cannot imagine why one > would want to use it to initialize a local object, Really? You just said that you would prefer avoiding global functions. > so you might want to > explain the benefit of doing so as opposed to the normal syntax for > creating a lambda function. > Maybe the quick start guide isn't the place for this in the first place. > > > In fact, BOOST_FIT_LIFT uses this since it is not always clear what > > context the user might call BOOST_FIT_LIFT. > > > > > >> > >> Quick Start:Overloading > >> > >> The overloading adaptors show two or more lambda functions. Can they > >> also work with function objects ? Or a mix of lambda functions and > >> function objects ? In fact all the reamining Quick Start topics show > >> examples with lambda functions. Do they also work with function objects > ? > >> > > > > Yes it can be used with function objects. I probably should show an > example > > of > > that as well. I used the lambdas because of the terseness of them. > > Evidently the adaptors can be used with any Callable. I think you should > make that point very strongly and show that in examples also. > Agreed. > > > > > > >> > >> Quick Start:Variadic > >> > >> I do not understand what 'We can also make this print function > varidiac, > >> so it prints every argument passed into it.' means ? > >> > > > > I'll try to explain that better, but basically it will print each > argument, > > so: > > > > print("hello", 5); // Will print "hello" and 5 > > I wouldn't associate that with the word 'Variadic' but I do think you > need to explain that more clearly. > I always understood variadic to mean taking a variable number of arguments. What do you understand variadic to mean? > > > > > > >> > >> I do not think the Quick Start explains very much since it is dealing > >> with adaptors of which we know almost nothing and the explanation for > >> these adaptors and what they actually do is very terse. > > > > > > Probably can expand the explanation of adaptors a little more. > > Good idea. What do adaptors create ? They create a function. > Different function objects I would > imagine ? In that case how about the explanation that adaptors take > Callables as input and generate function object types that adapt the > original functionality of one or more Callables to some other purpose. > The examples are already show taking Callables. Are you suggesting I show an example taking a member function or something? > > > > >> > >> In the 'Signatures' section of the Overview I read: > >> > >> "All the functions are global function objects except where an explicit > >> template parameter is required." I honestly don't know what this is > >> supposed to mean. Does this refer to when function objects are referred > >> to as parameters to the adaptors, functions, and utilities of the > library > >> ? > >> > > > > I don't understand what you are asking. It means that the function is > > written > > like this in the documentation: > > > > template<class IntegralConstant> > > constexpr auto if_(IntegralConstant); > > > > But its actually a function object like this in the code: > > > > struct if_f > > { > > template<class IntegralConstant> > > constexpr auto operator()(IntegralConstant) const; > > }; > > const constexpr if_f if_ = {}; > > > > However, `if_c` is written like this in the documentation: > > > > template<bool B, class F> > > constexpr auto if_c(F); > > > > It requires the bool `B` template parameter explicity. So in the code it > is > > written as a function and not as a function object. > > I don't understand to what you are referring when you say 'function'. > Are you talking about adaptors in your library, functions in your > library, or what ? I am talking about all functions that are defined in the library, that includes adaptors as well. I am not sure how to make that clearer. > Please try to understand that your use of the word > 'function' is very broad but that the word 'function' in C++ has a much > narrower meaning. > By function, I mean something like in the example: template<class IntegralConstant> constexpr auto if_(IntegralConstant); I think everyone agrees that is a function in C++.

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Command Line Options Questions
by Jon Lederman 09 Mar '16

09 Mar '16

Hi, I have two questions re: the boost command line options library: 1) I am compiling a dynamic library that links to the boost command line options library as a shared library. When I try to unload the dynamic library, I find that it isn’t properly unloaded and the boost library seems to be causing the issue. I did find that things were helped somewhat when I linked to the boost static libraries. However, it still feels unstable. Are there any particular things I should know about in this context in terms of how my makefile should be linking to boost? Or are there other things I should look at. 2) When using program options, I am getting the following error. For some reason this seemed to work with the dynamic libraries (or it may be a coincidence). Am I required to implement the << and >> operators? It had been compiling previously and stopped. After googling this issue there seems to be a lot of confusion. Any help would be greatly appreciated. in file included from /usr/include/boost/any.hpp:27:0, from /usr/include/boost/program_options/value_semantic.hpp:12, from /usr/include/boost/program_options/options_description.hpp:13, from /usr/include/boost/program_options.hpp:15, from /usr/local/src/freeswitch/src/mod/applications/mod_sc_dsp/mod_sc_dsp.cpp:23: /usr/include/boost/lexical_cast.hpp: In instantiation of 'struct boost::detail::deduce_target_char_impl<boost::detail::deduce_character_type_later<dsp_type> >': /usr/include/boost/lexical_cast.hpp:415:89: required from 'struct boost::detail::deduce_target_char<dsp_type>' /usr/include/boost/lexical_cast.hpp:674:92: required from 'struct boost::detail::lexical_cast_stream_traits<std::basic_string<char>, dsp_type>' /usr/include/boost/lexical_cast.hpp:2363:19: required from 'static Target boost::detail::lexical_cast_do_cast<Target, Source>::lexical_cast_impl(const Source&) [with Target = dsp_type; Source = std::basic_string<char>]' /usr/include/boost/lexical_cast.hpp:2543:50: required from 'Target boost::lexical_cast(const Source&) [with Target = dsp_type; Source = std::basic_string<char>]' /usr/include/boost/program_options/detail/value_semantic.hpp:89:38: required from 'void boost::program_options::validate(boost::any&, const std::vector<std::basic_string<charT> >&, T*, long int) [with T = dsp_type; charT = char]' /usr/include/boost/program_options/detail/value_semantic.hpp:170:55: required from 'void boost::program_options::typed_value<T, charT>::xparse(boost::any&, const std::vector<std::basic_string<charT> >&) const [with T = dsp_type; charT = char]' /usr/local/src/freeswitch/src/mod/applications/mod_sc_dsp/mod_sc_dsp.cpp:484:1: required from here /usr/include/boost/lexical_cast.hpp:388:13: error: static assertion failed: Target type is neither std::istream`able nor std::wistream`able BOOST_STATIC_ASSERT_MSG((result_t::value || boost::has_right_shift<std::basic_istream<wchar_t>, T >::value), desc.add_options() ("help", "Generates help message") ("dsp_type", po::value<dsp_type>(&params.dsp_type)->required(), “") where dsp_type is this: struct dsp_type { dsp_type() {} dsp_type(std::string const& val): value(val) { } std::string value; }; and I have a validator defined as this: void validate(boost::any& v, std::vector<std::string> const& values, dsp_type* /* target_type */, int) { using namespace boost::program_options; //namespace po = boost::program_options; // Make sure no previous assignment to 'v' was made. validators::check_first_occurrence(v); // Extract the first string from 'values'. If there is more than // one string, it's an error, and exception will be thrown. std::string const& s = validators::get_single_string(values); if (s == "ladspa" || s == "audioweaver" || s == "gstreamer" || s == "lv2") { v = boost::any(dsp_type(s)); } else { throw validation_error(validation_error::invalid_option_value); } } /usr/local/src/freeswitch/build/modmake.rules:214: recipe for target 'mod_sc_dsp.lo' failed make[1]: *** [mod_sc_dsp.lo] Error 1

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[Fit] review - ends next 13th Mars
by Vicente J. Botet Escriba 08 Mar '16

08 Mar '16

Hi, we are on the middle of the Fit review stated on 2 Mars and that ends 13th Mars. We have not received a lot of comments, only 4 or 5 people have commented and only a formal review (reject now). I understand that the documentation needs a lot of improvements, nevertheless, this review is the occasion to give as much feedback as possible. If you want to improve this library, please take the time to do a review and share your point of view. Best, Vicente

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Re: [Boost-users] [boost] [Fit] formal review starts today
by Paul Fultz II 07 Mar '16

07 Mar '16

On Sunday, March 6, 2016 at 9:42:19 PM UTC-6, Edward Diener wrote: > > On 3/3/2016 6:43 AM, Vicente J. Botet Escriba wrote: > > Dear Boost community, sorry for the late anounce > > > > The formal review of Paul Fultz II's Fit library starts today, 2nd March > > and ends on 13th March. > > > > Fit is a header-only C++11/C++14 library that provides utilities for > > functions and function objects. > > These are some comments/queries about the Fit documentation. > > Introduction > > The introduction says that Fit "provides utilities for functions and > function objects." But it seems as if Fit works only with lambda > functions and function objects. Fit works with any generalized Callable: http://en.cppreference.com/w/cpp/concept/Callable > The term 'function' normally encompasses > a much larger definition in C++ which includes global functions, static > functions, member functions, and lambda functions. Which is what Callable encompasses, but I used "function" since more people are familiar with that than Callable. > Fit needs to be more > precise in what it says it works with. It repeatedly refers to function > objects and lambda functions as 'functions'. I think this vagueness of > terminality is really confusing in the documentation. > Perhaps, I should refer to the Callable concept early on then. > > Quick Start:Function Objects > > "We can make it behave like a regular function if we construct the class > as a global variable." > > What about a non-global > > sum_f sum = sum_f(); > > makes 'sum' not behave like a regular function other than the fact that > the variable 'sum' may eventually go out of scope ? > In C++, a regular function is always global, there is no such thing as local function(sans gcc extensions). > > Quick Start:Lambdas > > Why do we need both BOOST_FIT_STATIC_LAMBDA and > BOOST_FIT_STATIC_LAMBDA_FUNCTION ? I would seem that > BOOST_FIT_STATIC_LAMBDA_FUNCTION would be adequate and > BOOST_FIT_STATIC_LAMBDA is just redundant, mimicking lambda syntax to no > purpose. > BOOST_FIT_STATIC_LAMBDA_FUNCTION and BOOST_FIT_STATIC_FUNCTION both define a function at global scope, and can only be used at global scope, whereas BOOST_FIT_STATIC_LAMBDA can be used to constexpr initialize local variables as well. In fact, BOOST_FIT_LIFT uses this since it is not always clear what context the user might call BOOST_FIT_LIFT. > > Quick Start:Overloading > > The overloading adaptors show two or more lambda functions. Can they > also work with function objects ? Or a mix of lambda functions and > function objects ? In fact all the reamining Quick Start topics show > examples with lambda functions. Do they also work with function objects ? > Yes it can be used with function objects. I probably should show an example of that as well. I used the lambdas because of the terseness of them. > > Quick Start:Variadic > > I do not understand what 'We can also make this print function varidiac, > so it prints every argument passed into it.' means ? > I'll try to explain that better, but basically it will print each argument, so: print("hello", 5); // Will print "hello" and 5 > > I do not think the Quick Start explains very much since it is dealing > with adaptors of which we know almost nothing and the explanation for > these adaptors and what they actually do is very terse. Probably can expand the explanation of adaptors a little more. > I realize that > is why it is called a 'Quick Start' is because it is just giving the > end-user a quick review of the sort of functionality that the library > entails, but I would much rather see a good Overview first before I look > at anything else in the documentation. > > More Examples > > The more examples section looks at useful cases for the library. Since I > haven't had an overview for the library yet it is disappointing that > this section comes before I really understand how the library is > organized with at least general functionality. I am now given a series > of some highly complicated library syntax without the least idea of why > any of this syntax should be as it is, what it means, or how it works. > That doesn't convince me to use the library at all. It just convinces me > that the library has some showy functionality which does clever things > for particular use cases which the library author wants to convince me I > am going to encounter in my own programming. > Probably more explanation about each of the components used to build the example will be helpful. > > Overview > > The overview section consists of explaining what a function adaptor, > static function adaptor, and decorator are. It also give me some notes > about the syntax of the documentation. I would call this section > 'Definitions' and "Documentation Syntax'. One thing it is not is an > overview of the Fit library as far as I can understand what an overview > is. I also note that following large scale sections deal in Adaptors, > Decorators, Functions, and Utilities. Since 'Functions' and 'Utilities' > are not "defined" in this Overview I am left to wonder if 'Functions' > and 'Utilities' just mean anything in the library which is not an > adaptor or a decorator, and what distinguishes a function from a utility. > This is a good point, the current overview should be called "Definitions". > > In the 'Signatures' section of the Overview I read: > > "All the functions are global function objects except where an explicit > template parameter is required." I honestly don't know what this is > supposed to mean. Does this refer to when function objects are referred > to as parameters to the adaptors, functions, and utilities of the library > ? > I don't understand what you are asking. It means that the function is written like this in the documentation: template<class IntegralConstant> constexpr auto if_(IntegralConstant); But its actually a function object like this in the code: struct if_f { template<class IntegralConstant> constexpr auto operator()(IntegralConstant) const; }; const constexpr if_f if_ = {}; However, `if_c` is written like this in the documentation: template<bool B, class F> constexpr auto if_c(F); It requires the bool `B` template parameter explicity. So in the code it is written as a function and not as a function object. > > The rest of the general About section is fairly straightforward. I still > have no idea of the general functional of the library and why I should > use it. I will only gain an idea of what the library does by reading the > specifics of each adaptor, decorator, function, and utility. This seems > to be the gist of the documentation to me. If I want to understand what > the library does for me in working with function objects and lambda > functions I have to read the specific documentation of each entity in > the library and then go back to the Quick Start and More Examples > sections to further understand how some of these entities are used. > > I think the library documentation would have been much better if there > were a discussion of what the adaptors, decorators, functions, and > utilities of the library were meant to do to enhance user programming > rather than give examples here and there of usage and then leave it up > to the end-user to figure out what, why, and how these entities are to > be used. Quite frankly I don't have a use for a library that does not > attempt to present itself as offering functionality that would be useful > for me in the domain in which the library operates. if I have little or > no idea of that domain I see no reason to think of using a library. > > Since Boost has a number of other libraries dealing with function > objects, most notable the Boost Phoenix library, which is a sort of > successor to the Boost Lambda library, I would think it would be > advantage to the library author to stress functionality in the Fit > library which goes beyond, improves on, or is different from the > functionality in Boost Phoenix, in order to 'sell' end-users on the use > of the Fit library in their code. I do realize that the Fit library > deals with C++11/C++14 idioms, which means that it may be difficult for > many end-users to understand, but I don't think it presents its > documentation in such a way that makes its functionality easier to > understand and I think it should do so. This does not mean that I will > vote right now for Fit to be accepted or not accepted as a Boost > library. I have to look much more carefully at the individual > functionality of the adaptors, decorators, functions, and utilities of > the library to understand what it actually does, before I can vote one > way or another. But I hope my comments and questions about the > documentation to the library will aid the library author in improving > the documentation for end users like me, who are very interested in > library enhancements to function object/lambda function functionality, > but who find the documentation difficult and limiting in certain ways. > Thanks for your feedback, and it will be very helpful in improving the documentation.

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Re: [Boost-users] [boost] [Fit] formal review - should we propose some parts to Boost.Config/Boost.Core
by Vicente J. Botet Escriba 07 Mar '16

07 Mar '16

Le 06/03/2016 09:59, Andrey Semashev a écrit : > On 2016-03-06 05:21, Vicente J. Botet Escriba wrote: >> >> Others could be considered also as function.hpp, lambda.hpp and >> lift.hpp, as the macros are there to workaround some missing language >> features, but those are much more specialized (Boost.Core?) > > I don't think Boost.Core is the right place for them as this library > is for small generally useful components used by many libraries. The > components you pointed out seem too specialized to me, and Boost.Fit > looks like the right place for them. > |Andrey, I was thinking in Boost.Core as these are language-like emulation features, like e.g. addressof, enable_if, explicit_operator_bool, ignorunused, no_exception_support, noncopyanble, scoped_enum, typeinfo. IIUC, BOOST_FIT_STATIC_FUNCTION try to fix a standard Core issue (pending issue 2104 in CWG) identified by Eric Nibler, with the a solution based on proposal's Eric (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4381.html) The library has also a macro BOOST_FIT_DECLARE_STATIC_VAR to do it for any data variable. I would like something that solves this problem in Boost. BOOST_FIT_STATIC_LAMBDA try to covers the C++17 feature constexpr lambdas. I suspect that Boost.Hana should have something like that. Louis, could you tell us how do you manage with these issues? IMO, The fiw of those issues is independent from a functional utilities library, even if Fit can not work without them.|| This is way I believe that it should be extracted and Boost.Core seems the good place to me. Best, Vicente |

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Visual Studio C++ and Boost Multiprecision float128
by Michel Lamoureux 06 Mar '16

06 Mar '16

Hi, I use « Visual Studio Express 2013 for Desktop » to do my C++ programming. When I come tu use Boost Multiprecision header « float128.hpp », I get the following message : Fatal error C1189 : #error : « Sorry compiler is neither GCC, not Intel, don’t know how to configure this header. » However, when I use Boost Multiprecision header « cpp_dec_float », it works well but much slowly. I guess « float128.hpp » is faster : Am I right? Is it possible to fix « float128.hpp » to suit C++ from Visual Studio? Thank you for your answer. Michel Lamoureux Envoyé par Courrier<https://go.microsoft.com/fwlink/?LinkId=550986> pour Windows 10

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[Fit] review - github issuess
by Vicente J. Botet Escriba 06 Mar '16

06 Mar '16

Hi, we have started to create some issues in https://github.com/pfultz2/Fit/issues, and sometimes there are some interesting discussion. I will try to add post on the MLs the issues that are conflicting so that other are aware of the discussion. Anyway, if you are curious you can always take a look at and participate also. If you want to receive the updates I believe that you just need to click on watch (top right). Best, Vicente

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Re: [Boost-users] [boost] [Fit] formal review - should we propose some parts to Boost.Config/Boost.Core
by Glen Fernandes 06 Mar '16

06 Mar '16

On Sat, Mar 5, 2016 at 9:21 PM, Vicente J. Botet Escriba wrote: > Others could be considered also as function.hpp, lambda.hpp and lift.hpp, as > the macros are there to workaround some missing language features, but those > are much more specialized (Boost.Core?) > Boost.Core is where we move code from existing Boost libraries that enables breaking cyclic dependencies between different Boost libraries. I'm not so sure new libraries will need to (or want to) put code there. Glen

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Boost.Spirit Karma: debug() alters result
by Matwey V. Kornilov 05 Mar '16

05 Mar '16

Hello, I am using boost 1.58 and I see the following. template <class Iterator> struct test_generator: karma::grammar<Iterator, std::string()> { test_generator(): test_generator::base_type(start) { using karma::ascii::string; using boost::spirit::ascii::char_; using karma::lit; using karma::buffer; using karma::debug; value2 = +(~char_(' ')); value1 = value2; value = lit('=') << value1; start = buffer[-value]; } karma::rule<Iterator, std::string()> start; karma::rule<Iterator, std::string()> value; karma::rule<Iterator, std::string()> value1; karma::rule<Iterator, std::string()> value2; }; template <class Iterator> struct test_generator2: karma::grammar<Iterator, std::string()> { test_generator2(): test_generator2::base_type(start) { using karma::ascii::string; using boost::spirit::ascii::char_; using karma::lit; using karma::buffer; using karma::debug; value2 = +(~char_(' ')); value1 = value2; value = lit('=') << value1; debug(value); start = buffer[-value]; } karma::rule<Iterator, std::string()> start; karma::rule<Iterator, std::string()> value; karma::rule<Iterator, std::string()> value1; karma::rule<Iterator, std::string()> value2; }; template<class It> bool do_generate(It it, const std::string& x) { test_generator<It> g; return karma::generate(it, g, x); } template<class It> bool do_generate2(It it, const std::string& x) { test_generator2<It> g; return karma::generate(it, g, x); } //... std::string x2,x3; do_generate(std::back_inserter(x2), std::string("")); do_generate2(std::back_inserter(x3), std::string("")); std::cerr << "|" << x2 << "|" << std::endl; std::cerr << "|" << x3 << "|" << std::endl; //... The code prints: <unnamed-rule> <try> <attributes>[[]]</attributes> </try> <fail/> </unnamed-rule> |=| || I.e. introduction of debug() alters result of the generator. Could you please explain me where I am wrong? I am stuck now.

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[Fit] upcoming formal review for Boost.Fit
by Vicente J. Botet Escriba 05 Mar '16

05 Mar '16

Dear Boost community, The formal review of Paul Fultz II's Fit library starts on Wednesday, 2nd March and ends on 13th March. Fit is a header-only C++11/C++14 library that provides utilities for functions and function objects. Fit is: - Modern: Fit takes advantages of modern C++11/C++14 features. It support both `constexpr` initialization and `constexpr` evaluation of functions. It takes advantage of type deduction, variadic templates, and perfect forwarding to provide a simple and modern interface. - Relevant: Fit provides utilities for functions and does not try to implement a functional language in C++. As such, Fit solves many problems relevant to C++ programmers, including initialization of function objects and lambdas, overloading with ordering, improved return type deduction, and much more. - Lightweight: Fit builds simple lightweight abstraction on top of function objects. It does not require subscribing to an entire framework. Just use the parts you need. Fit is divided into three components: * Function Adaptors and Decorators: These enhance functions with additional capability. * Functions: These return functions that achieve a specific purpose. * Utilities: These are general utilities that are useful when defining or using functions Fit has been tested on gcc 4.6-4.9, clang 3.4-3.7, and Visual Studio 2015. For more information see: Github:https://github.com/pfultz2/Fit/tree/boost Documentation:http://pfultz2.github.io/Fit/doc/html/ Note that, as Fit is a functional library, the semantic of the functions is given in the form of `equations` instead of the classic effects, returns schema. This is because most of the functions have no side effects. E.g. the semantic of the function flip is defined as |assert(flip(f)(x, y, xs...) == f(y, x, xs...));| and the semantic of compose as |assert(compose(f, g)(xs...) == f(g(xs...)));| We await your feedback! Best regards, Vicente J. Botet Escriba P.S. Paul, now it is time to freeze the version that will be reviewed. I suggest you to create a branch on which you could fix the review issues.

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[Preprocessor] MSVC nonstandard macro expansion workaround?
by rleigh＠codelibre.net 04 Mar '16

04 Mar '16

Hi folks, I've been trying to get Boost.Preprocessor to run a nested for loop over two sequences to output nested switch blocks and case statements. This works fine with GCC and clang. Unfortunately it's broken with MSVC. If anyone had any thoughts on what I might need to tweak to enable the code to work with MSVC, I'd be very appreciative. Even if it's as nasty as a big ifdef with an alternative set of macros! This is the test case: -------- #include <boost/preprocessor.hpp> #include <iostream> #define LASERTYPE_VALUES (EXCIMER)(GAS)(METALVAPOR)(SOLIDSTATE)(DYE)(SEMICONDUCTOR)(FREEELECTRON)(OTHER) enum LaserType { BOOST_PP_SEQ_ENUM(LASERTYPE_VALUES) }; #define PP_SEQ_FOR_EACH_R_ID() BOOST_PP_SEQ_FOR_EACH_R #define PP_DEFER(x) x BOOST_PP_EMPTY() #define LT_NESTED(maR, maToplevelType, maNestedType) \ std::cout << "Test nested: first=" << LaserType(maToplevelType) << " second=" << LaserType(maNestedType) << " \n"; #define LT_TOPLEVEL(maR, maUnused, maType) \ std::cout << "Test toplevel: " << LaserType(maType) << " \n"; \ PP_DEFER(PP_SEQ_FOR_EACH_R_ID)()(maR, LT_NESTED, maType, LASERTYPE_VALUES); int main() { BOOST_PP_EXPAND(BOOST_PP_SEQ_FOR_EACH(LT_TOPLEVEL, %%, LASERTYPE_VALUES)); } -------- On MSVC, I get this: > cl /EHsc /I \path\to\boost-1_60 /Fe:test-pp.exe test-pp.cpp Microsoft (R) C/C++ Optimizing Compiler Version 18.00.40629 for x64 Copyright (C) Microsoft Corporation. All rights reserved. test-pp.cpp test-pp.cpp(22) : warning C4003: not enough actual parameters for macro 'BOOST_PP_VARIADIC_ELEM_3' test-pp.cpp(22) : warning C4003: not enough actual parameters for macro 'BOOST_PP_BOOL' test-pp.cpp(22) : warning C4003: not enough actual parameters for macro 'BOOST_PP_BOOL_I' test-pp.cpp(22) : warning C4003: not enough actual parameters for macro 'BOOST_PP_VARIADIC_ELEM_2' test-pp.cpp(22) : warning C4003: not enough actual parameters for macro 'BOOST_PP_DEC' test-pp.cpp(22) : warning C4003: not enough actual parameters for macro 'BOOST_PP_DEC_I' test-pp.cpp(22) : error C2065: 'BOOST_PP_SEQ_FOR_EACH_M' : undeclared identifier test-pp.cpp(22) : error C2065: 'BOOST_PP_TUPLE_EAT_2' : undeclared identifier test-pp.cpp(22) : error C2065: 'LT_NESTED' : undeclared identifier test-pp.cpp(22) : error C2064: term does not evaluate to a function taking 1 arguments test-pp.cpp(22) : error C2146: syntax error : missing ';' before identifier 'BOOST_PP_IIF_BOOST_PP_BOOL_' test-pp.cpp(22) : error C3861: 'BOOST_PP_IIF_BOOST_PP_BOOL_': identifier not found test-pp.cpp(22) : error C2065: 'BOOST_PP_FOR_3' : undeclared identifier test-pp.cpp(22) : error C2065: 'BOOST_PP_TUPLE_EAT_4' : undeclared identifier test-pp.cpp(22) : error C2059: syntax error : ',' test-pp.cpp(22) : error C3861: 'BOOST_PP_EXPAND': identifier not found test-pp.cpp(22) : error C2065: 'BOOST_PP_FOR_4' : undeclared identifier test-pp.cpp(22) : error C2065: 'BOOST_PP_FOR_5' : undeclared identifier test-pp.cpp(22) : error C2065: 'BOOST_PP_FOR_6' : undeclared identifier test-pp.cpp(22) : error C2065: 'BOOST_PP_FOR_7' : undeclared identifier test-pp.cpp(22) : error C2065: 'BOOST_PP_FOR_8' : undeclared identifier test-pp.cpp(22) : error C2065: 'BOOST_PP_FOR_9' : undeclared identifier test-pp.cpp(22) : error C2065: 'BOOST_PP_FOR_10' : undeclared identifier I've spent hours tweaking the testcase to try to make this work, but so far without success. It doesn't help that I don't fully understand what specifically is broken with the MSVC preprocessor, or how to work around whatever is behaving in a non-stanadard way. Many thanks, Roger

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PBGL in shared memory
by Ярослав 04 Mar '16

04 Mar '16

Hi guys, I need to write some graph parallel algorithms and I decided to use boost graph library for this. There are also PBGL. So my question is, is PBGL works great in shared memory environment. My algorithms will be used in a competition, so I know that it will be launched on a single machine, but with quite high number of cores. Is it worth to use sequential BGL with OpenMP or something, PBGL can handle shared memory and prevent overhead from copying data from one process space to another (as I get it is using MPI)?

2 1

Turning Boost.Multi-Index ordered_non_unique index into ordered_unique one, with custom comparator
by Dominique Devienne 03 Mar '16

03 Mar '16

I would like to support a slightly unusual use-case. We have a class with a integer member, and a BMI container for instances of this class. That member is supposed to be unique, *except* for a special "invalid" value (-1), which several instances can use. Right now, we use an ordered_non_unique index, because of the -1's, but that leaves the door open for other duplicate "valid" values, which should be forbidden. So my question is whether one can index this member uniquely, thanks to a custom comparator, such that the comparator does not violate the usual strict-weak-ordering requirement of ordered containers? I'm thinking kinda like SQL NULLs, which don't compare equal to each other, i.e. in this case -1 would never equal another -1, and use another arbitrary (but stable) ordering specifically for those -1's. This assumes though I can know which instance the int member is part of, i.e. will the comparator get the integer by value or reference, and if a reference, is that a reference to the "internal" element, such that the arbitrary order can be the address of the element for example? Or to avoid element movement in case of reallocs in the container, can the comparator access an iterator to project it into another random-access index of the same container, to use that index's integer-index as the arbitrary order? I'd appreciate some feedback/insights into the above. Thanks, --DD

4 7

Boost.Spirit Karma: Alternative generator
by Matwey V. Kornilov 03 Mar '16

03 Mar '16

Hello, I am construction karma::rule<OutputIterator, std::string()> which I would like to be either a string or quoted string if the string contains spaces. Now I think that the rule should be something like: rule = (&true[...] << string) | (lit("\"") << string << lit("\"")); but I've failed to write proper semantic action. How could I obtain std::string object reference to write something like: (obj.find(" ") == std::string::npos) ? Or maybe is there a better way to do the same?

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[gsoc16] An update on GSoC 2016 contingency plans
by Niall Douglas 03 Mar '16

03 Mar '16

Dear Boost, We've been collecting a list of veteran Summer of Code students where "veteran" means students whom have previously done a Google Summer of Code for Boost. It /may/ be possible for us to acquire enough funding from a number of contributors to tide over ongoing GSoC projects this summer during our year off from Google funding for veteran students only. The stipend to the student would be the same as with Google, $5,500. The mentor stipend would likely need to be waived under any substitute programme. We would therefore appreciate an update from student and/or mentor as to whether they were intending to submit a continuing GSoC this summer and would be willing to continue work on their Boost library under any funding we find. If we have forgotten any students or projects, please get in touch. Extant ongoing summer of code projects known to us are (please send corrections of any mistakes): * Boost Document, mentored by Antony Polukhin. https://anuragxel.github.io/boost-document/ Student: Anurag Ghosh Status: Not peer reviewed * Boost.Compute, mentored by Kyle Lutz. https://boostorg.github.io/compute/ Student: Jakub Szuppe Status: Official Boost library * Boost.Hana, mentored by Joel Falcou. https://boostorg.github.io/hana/ Student: Louis Dionne Status: Official Boost library * Boost.Http, mentored by Bjorn Reese. https://boostgsoc14.github.io/boost.http/ Student: Vinícius dos Santos Oliveira Status: One peer review held * Boost.Fixed-Point, mentored by Paul Bristow. https://github.com/BoostGSoC15/fixed_point Student: Nikhar Agrawal Status: Not peer reviewed We are aware of the following Boost libraries who have strong but new-to-Boost potential student candidates in the pipeline for summer of code 2016: * Boost.odeint, mentored by Karsten Ahnert and Mario Mulansky There is even less chance we can find funding for these, but if any of the veteran students or mentors has to suddenly pull out before the summer, we would substitute one of these projects instead. Therefore, if mentors had a really excellent student lined up for 2016, please let us know. None of the above should be read that summer of code 2016 is going ahead. We just need some hard numbers with which to lobby for funding. We will get back to the community as soon as we know more. We need all this information requested above back BEFORE this weekend as we will be making use of the Jacksonville ISO WG21 meeting currently happening to grab the right people to ask them for donations from their corporate bodies. If YOUR corporate org would be willing to help sponsor a summer of code student, either partially or in full, PLEASE get in touch. Donations to Boost are tax deductible for US taxpayers. Thank you all very much in advance! Niall --- Boost C++ Libraries Google Summer of Code 2016 admin https://svn.boost.org/trac/boost/wiki/SoC2016

2 1

boost::asio::read_until Segmentation Fault & Third Party Signal Handler
by Craig, Tom 01 Mar '16

01 Mar '16

My Linux application sis using bool::asio::read_until() to read data from a socket. The application also uses commercial, 3rd party hardware. Occasionally my program crashes due to a SIGSEGV violation. The core dump stack trace is shown below. It indicates that the 3rd party signal handler is invoked while my thread is waiting for socket I/O, and that the crash is occurring during signal handler execution. While I recognize that this is an issue with the 3rd party vendor (and I am currently engaged in discussions with them), I'm wondering if my usage of boost is incorrect, or if there is something that I should be doing differently in performing socket I/O? I am using boost v1.43. [cid:image001.png@01D17303.98B2DD10] E. Thomas Craig Principal Software Engineer SWIFT Division KLA-Tencor Corporation 408-875-7909 (work) 650-799-4787 (cell)

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Boost.Spirit. Karma: Kleene star with space separator
by Matwey V. Kornilov 01 Mar '16

01 Mar '16

Hello There is an example of usage Keele star with Karma generator: http://www.boost.org/doc/libs/1_60_0/libs/spirit/doc/html/spirit/karma/refe… std::vector<double> v; v.push_back(1.0); v.push_back(2.0); v.push_back(3.0); test_generator_attr_delim("1.0 2.0 3.0 ", *double_, space, v); How could the remaining space be omitted? Is (double_ % space) supposed to be used instead for such cases?

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Re: [Boost-users] [boost] [Fit] upcoming formal review for Boost.Fit
by Paul Fultz II 29 Feb '16

29 Feb '16

On Sunday, February 28, 2016 at 5:28:39 PM UTC-6, Edward Diener wrote: > > On 2/28/2016 4:23 PM, paul Fultz wrote: > > > > > > > > > > On Sunday, February 28, 2016 12:23 PM, Edward Diener < > eldi...(a)tropicsoft.com <javascript:>> wrote: > > > > > >> > >> > >> On 2/27/2016 11:16 AM, Vicente J. Botet Escriba wrote: > >>> Dear Boost community, > >>> > >>> The formal review of Paul Fultz II's Fit library starts on Wednesday, > 2nd March and ends on 13th March. > >> > >> How do I generate the docs or run the tests for my local copy of Fit ? > > > >> > > > > You can build and run the tests by building the check target. For those > > unfamiliar with cmake, first configure the build directory with cmake: > > > > mkdir build > > cd build > > cmake .. > > cd .. > > > > Next build the check target using the native build system(such as make > or > > msbuild). CMake can call the native build system to build the target > 'check', > > like so: > > > > cmake --build build --config Release --target check > > > > Also, the library can be installed by invoking the 'install' target. > > Why is the CMakeLists.txt not in the 'test' subdirectory, since it > appears from your explanation that the file is used for the tests ? > Its used to install the library as well. > > > > > The documentation needs to be built using mkdocs. You can install mkdocs > and > > the boost theme with pip like this: > > > > pip install mkdocs mkdocs-boost > > > > Then to build the documentation, first `setup.py` must be run to extract > the > > documentation and examples from the source code, then `mkdocs` can be > invoked, > > like this: > > > > python setup.py > > mkdocs build -t boost > > > > And the documentation will be in the 'doc/html' directory. > > Please add these explanations to Fit as you are not using Boost build to > build the doc or run the tests. > I will add them. Also, I tried to add an initial Jamfile to build and run the tests as well. I just modified the Jamfile from other boost libraries. However, I haven't figured out how to run the tests yet using bjam to test my Jamfile. I get "error: Did not find Jamfile.jam or Jamroot.jam in any parent directory". I am not sure how I am supposed to run the tests. > > > _______________________________________________ > Unsubscribe & other changes: > http://lists.boost.org/mailman/listinfo.cgi/boost >

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[gsoc16] Boost rejected as GSoC 2016 org
by Niall Douglas 29 Feb '16

29 Feb '16

Dear Boost, It is with a heavy heart I write to say that Boost was rejected as an org for Google Summer of Code 2016 by Google. We had our application submitted in time, it was reviewed by three members of the Boost leadership, our ideas list had six solid ideas with an especially solid seventh on the way, we were in very good standing with Google and there was no reason to expect rejection. We have asked for clarification as to why we were rejected, and we shall try to improve our application next year to improve our chances. We recognise that many students and mentors will be extremely disappointed by this news. We share in that disappointment, and all we can say is please try again next year. For those students and mentors who are continuing a previous GSoC on an existing Boost library, there may be a possibility that Boost may be able to fund those continuations this year. Each case will be approached by the steering committee on a case by case basis, and be aware that the standard required for funding by Boost is considerably above that of Google's with an accompanying high and detailed standard of funding application to the steering committee. Contact us privately if you want to know more. On other news we had been expecting to announce today that Bryce Adelstein Lelbach has generously agreed to take over as secondary GSoC admin from Boris Schäling who has served Boost GSoC for something like four years now, so he has definitely earned himself a rest! Our thanks to Boris for his service, and welcome Bryce to the team! Finally, I'd like to thank Jon Kalb who moved heaven and earth as he always does to get the GSoC application submitted in time. Yours, Niall Douglas -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

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C++Now Student/Volunteers Call for Applications
by Jon Kalb 29 Feb '16

29 Feb '16

The Call for Applications for Student/Volunteers for C++Now 2016 (AKA BoostCon X) has been released: http://cppnow.org/2016-conference/announcements/2016/02/23/student-volunteer -program-accepting-applications.html The application submission deadline is March 16th. We are looking for students with a strong interest in C++. The opportunity is open to student of any level or any field of study. Jon Kalb Chair, C++Now 2016

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Re: [Boost-users] Boost.Context stack growing inwards
by Thomas Ziegenhagen 29 Feb '16

29 Feb '16

Hi again, just noticed that the make_fcontext() documentation says that it expects the stack pointer to be at the end or at the beginning, depending on the architecture. So please re-read my last mail as a feature request: If Boost.Context is a platform-independent context switching library, please make its stack pointer parameter also platform-independent. Rationale: Booost.Context knows best on which platform it runs. If the API is supposed to work the same on all supported systems, its parameter should do so, too. Other than that: Sorry for wasting your time. Bye, Thomas

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Boost.Context stack growing inwards
by Thomas Ziegenhagen 29 Feb '16

29 Feb '16

Hi there, I get regular crashes when using Boost.Context after just a few calls to make_fcontext(). I built a minimal example as follows: ---- #include <iostream> #include <vector> #include <boost/context/all.hpp> struct Context { boost::context::fcontext_t c_outside, c_inside; }; Context gContext = { nullptr, nullptr }; void DoIt( intptr_t /*pt*/) { uint8_t test[64]; memset( test, 0xaf, sizeof( test)); std::cout << "DoIt(), Point 1" << std::endl; boost::context::jump_fcontext( &gContext.c_inside, gContext.c_outside, 0, true); std::cout << "DoIt(), Point 2" << std::endl; boost::context::jump_fcontext( &gContext.c_inside, gContext.c_outside, 0, true); std::cout << "DoIt(), Point 3" << std::endl; boost::context::jump_fcontext( &gContext.c_inside, gContext.c_outside, 0, true); } int main() { const size_t StackSize = 16384; std::vector<uint8_t> stack( StackSize, 0xf1); gContext.c_inside = boost::context::make_fcontext( stack.data() + 256, stack.size() - 512, DoIt); std::cout << "main(), Point 1" << std::endl; boost::context::jump_fcontext( &gContext.c_outside, gContext.c_inside, 0, true); std::cout << "main(), Point 2" << std::endl; boost::context::jump_fcontext( &gContext.c_outside, gContext.c_inside, 0, true); std::cout << "main(), Point 3" << std::endl; boost::context::jump_fcontext( &gContext.c_outside, gContext.c_inside, 0, true); std::cout << "main(), Point 4" << std::endl; return 0; } ------ This notable thing is that I provide a stack with additional 256 bytes of safety borders. And it turns out: the provided memory is overwritten way beyond the beginning. The actual designated area is not touched at all, but instead the area before the beginning is overwritten. The only thing I found in the documentation is this: "sp Member: Pointer to the beginning of the stack (depending of the architecture the stack grows downwards or upwards)." which hints that on some system the stack might grow to negative addresses. But up to now I thought that boost.context knows which direction is correct, and adjusts the given pointer accordingly. But apparently it doesn't. Or the environment underwent a drastic change. Here it is Windows 10 64bit, Visual Studio 2015. For readers remembering my last mails: I have verified this also with an "classic" boost build using this command line: b2.exe -a --reconfigure variant=debug,release link=static runtime-link=static --with-context So I'm pretty sure it's not a build issue. Question: is this a bug? Probably not, I'm surely not the first to use Boost.Context, so I wonder what the correct way is to handle this issue. So what do I do about this? Thanks in advance Bye, Thomas

1 0

Boost.Spirit Karma: how to store generator?
by Matwey V. Kornilov 28 Feb '16

28 Feb '16

Hello, After reading Karma tutorial, I still don't understand whether there a way to store generator except auto my_generator = ... I would like to generate text representation for many similar objects and I think that it is worth to use single generate object and pass it to generate_delimited() by const reference. Are there such things like qi::rule<> and qi::grammar for Karma?

2 1

[ sorting_view ] -do not sort arrays, sort iterators instead
by Boris Kats 27 Feb '16

27 Feb '16

The sorting procedure is one of the most usable routine in programming.And all sorting template functions have the same signature:template< class RandomIt, class Compare >void sort( RandomIt first, RandomIt last, Compare comp );with conditions: the type of dereferenced RandomIt must meet the requirements of MoveAssignable and MoveConstructible.It is clear that in the sorting process a lot of records are moving in the memory andwhen these records have a big size, these movements, together with calling constructors, can be very expensive.Solution.The proposed template function sorting_view is free of that problem - the sorting procedureis working (and moving) on tiny objects - iterators. As result of that procedure,the initial array of records is remaining intact; however provided std::vector<int> viewallows indirect access to the sorted array. On many occasions user does not need the sortedarray at all and he/she has a luxury to iterate through sorted and unsorted arrays simultaneously.In case of real needs of sorted array, it can be obtained via other template function apply_view with exactly 2*N movements of the records, where N is the size of initial array.For getting sorted view of arrays of user's defined records the appropriate Compare template function should be supplied.Happy sorting, Boris Kats.

1 0

Help: Errors compiling SESHAT project
by C. Ichongiri 26 Feb '16

26 Feb '16

Hey there, I've been at this for days now and can't seem to find anything to help with this: I got the project at https://github.com/falvaro/seshat and followed the instructions exactly as-is: - Got the *Boost* headers - Have got *g++ *compiler ( versions 5.2, 4.9, 4.7, 4.5, 4.3) and my default *clang++* *- Makefile *is present *P.S.* I'm on *OS X Mavericks*; Used *MacPorts* to install all above gcc versions *except *5.2, which was manually done following this tutorial: https://solarianprogrammer.com/2015/05/01/compiling-gcc-5-mac-os-x/#comment… However, when I attempt to compile it, I get the following errors (attached in the Textfile below). A screenshot image also attached shows the filesystem and path I am working with, from where the error file was created. Honestly, I'm at my wits end now, especially with my being new to C++. ANY helpful insight into this would be MOST APPRECIATED. Much thanks in advance, chiich.

1 0

Build Boost.Context with Visual Studio
by Thomas Ziegenhagen 26 Feb '16

26 Feb '16

Hi there, I'm building the required portions of Boost myself, along with all my other projects. It turned out that even the smallest compiler setting changes lead to strange crashes, some of which only occured on 5% of the client's systems, so I will not use externally built boost libraries anymore. So now I'm building the parts of boost which I require, which works fine so far. The trouble starts when I tried to use Boost.Context. It also contains ASM code, which I now need to build in Visual Studio 2015. VS2015 does not have builtin Asm support, for x64 it never had. So I'm invoking the Microsoft assembler as a custom build step. Command line is as follows: ml64 /Fo path/to/obj/file.obj /c path/to/source/jump_x86_64_ms_pe_masm.asm Documentation is as scarce as usual, but I figured from the filename that jump_x86_64_ms_pe_masm.asm is the correct file for Microsoft Visual Studio, x64. But assembling failed, and to add insult to injury, the error messages are lost somewhere in the output piping process. The complete output reads like this: ------ 1>------ Erstellen gestartet: Projekt: boost, Konfiguration: Debug x64 ------ 1> Microsoft (R) Macro Assembler (x64) Version 14.00.23506.0 1> Copyright (C) Microsoft Corporation. All rights reserved. 1> 1> Assembling: C:\Projekte\DeadPlanet\SourceExt\boost\context\asm\jump_x86_64_ms_pe_masm.asm 1> C:\Projekte\DeadPlanet\SourceExt\boost\context\asm\jump_x86_64_ms_pe_masm.asm(80)ied size 1>: error A2008 : syntax error : FRAME 1> C:\Projekte\DeadPlanet\SourceExt\boost\context\asm\jump_x86_64_ms_pe_masm.asm(81)ied size 1>CUSTOMBUILD : warning A4020: directive ignored outside a procedure 1> C:\Projekte\DeadPlanet\SourceExt\boost\context\asm\jump_x86_64_ms_pe_masm.asm(215 1>CUSTOMBUILD : fatal error A1010: unmatched block nesting : jump_fcontext ------ Please note that the actual error messages are overwritten by the filename - I can only guess at what buffer magic happens there, but I'm pretty sure it's not intended. But that's just a funny anecdote. My actual question is: how do I build Boost.Context in Visual Studio? Is there maybe some way to see the effective command line when building using Boost.Jam? Is this even the right ASM file for x86_64, Visual Studio? Thanks in advance! Bye, Thomas

4 5

Spherical Bessel function (nu, x as real) implementation
by campagne 26 Feb '16

26 Feb '16

Dear developpers, 1) Does you use this reference to compute Spherical Bessel Functions for real argument? Accurate recursive generation of spherical Bessel and Neumann functions for a large range of indices E. Gillman <http://scitation.aip.org/content/contributor/AU0510272>^1 and H. R. Fiebig <http://scitation.aip.org/search?value1=H.+R.+Fiebig&option1=author&option91…>Comput. Phys. 2, 62(1988); http://dx.doi.org/10.1063/1.168296 2) is there a way to speed up the computation of j_nu(x) if one wants 10 digits accuracy for instance? Best regards J.E

2 1

[ASIO] Resolver question
by Davies, John 25 Feb '16

25 Feb '16

I have some pretty simple UPD code. (It has to be simple, I'm new at ASIO) boost::asio::ip::udp::resolver::query query(boost::asio::ip::udp::v4(), addr, port); m_receiverEndpoint = *m_resolver.resolve(query); If my address is 192.168.1.112 everything works If my address is 192.168.001.112 it doesn't work and throws an exception about not finding the host. It's not a big deal, but it sure took me a long time to track down. Is there some sort of Boost magic I can do to convert the bad address into a good address? Thanks, John ________________________________ The information contained in this message may be confidential and legally protected under applicable law. The message is intended solely for the addressee(s). If you are not the intended recipient, you are hereby notified that any use, forwarding, dissemination, or reproduction of this message is strictly prohibited and may be unlawful. If you are not the intended recipient, please contact the sender by return e-mail and destroy all copies of the original message.

6 11

Boost Thread Compile Issue
by Len Za 25 Feb '16

25 Feb '16

When simply including into C++ project and attempting to compile causes the following compile error: Environment: - Visual Studio 2010 Pro (Project Configuration: DLL project) - boost v1.60.0 C:\src\SDK\Boost\boost_1_60_0\boost_1_60_0\boost/date_time/microsec_time_clock.hpp(99): error C2146: syntax error : missing ';' before identifier 'curr' C:\src\SDK\Boost\boost_1_60_0\boost_1_60_0\boost/date_time/microsec_time_clock.hpp(81) : while compiling class template member function 'boost::posix_time::ptime boost::date_time::microsec_clock<time_type>::create_time(boost::date_time::microsec_clock<time_type>::time_converter)' with [ time_type=boost::posix_time::ptime ] C:\src\SDK\Boost\boost_1_60_0\boost_1_60_0\boost/thread/thread_time.hpp(22) : see reference to class template instantiation 'boost::date_time::microsec_clock<time_type>' being compiled with [ time_type=boost::posix_time::ptime ] C:\src\SDK\Boost\boost_1_60_0\boost_1_60_0\boost/date_time/microsec_time_clock.hpp(99): error C2065: 'curr' : undeclared identifier C:\src\SDK\Boost\boost_1_60_0\boost_1_60_0\boost/date_time/microsec_time_clock.hpp(100): error C2065: 'curr_ptr' : undeclared identifier C:\src\SDK\Boost\boost_1_60_0\boost_1_60_0\boost/date_time/microsec_time_clock.hpp(100): error C2065: 'curr' : undeclared identifier C:\src\SDK\Boost\boost_1_60_0\boost_1_60_0\boost/date_time/microsec_time_clock.hpp(101): error C2065: 'curr_ptr' : undeclared identifier C:\src\SDK\Boost\boost_1_60_0\boost_1_60_0\boost/date_time/microsec_time_clock.hpp(101): error C2227: left of '->tm_year' must point to class/struct/union/generic type type is ''unknown-type'' C:\src\SDK\Boost\boost_1_60_0\boost_1_60_0\boost/date_time/microsec_time_clock.hpp(102): error C2065: 'curr_ptr' : undeclared identifier C:\src\SDK\Boost\boost_1_60_0\boost_1_60_0\boost/date_time/microsec_time_clock.hpp(102): error C2227: left of '->tm_mon' must point to class/struct/union/generic type type is ''unknown-type'' C:\src\SDK\Boost\boost_1_60_0\boost_1_60_0\boost/date_time/microsec_time_clock.hpp(103): error C2065: 'curr_ptr' : undeclared identifier C:\src\SDK\Boost\boost_1_60_0\boost_1_60_0\boost/date_time/microsec_time_clock.hpp(103): error C2227: left of '->tm_mday' must point to class/struct/union/generic type type is ''unknown-type'' C:\src\SDK\Boost\boost_1_60_0\boost_1_60_0\boost/date_time/microsec_time_clock.hpp(111): error C2065: 'curr_ptr' : undeclared identifier C:\src\SDK\Boost\boost_1_60_0\boost_1_60_0\boost/date_time/microsec_time_clock.hpp(111): error C2227: left of '->tm_hour' must point to class/struct/union/generic type type is ''unknown-type'' C:\src\SDK\Boost\boost_1_60_0\boost_1_60_0\boost/date_time/microsec_time_clock.hpp(112): error C2065: 'curr_ptr' : undeclared identifier C:\src\SDK\Boost\boost_1_60_0\boost_1_60_0\boost/date_time/microsec_time_clock.hpp(112): error C2227: left of '->tm_min' must point to class/struct/union/generic type type is ''unknown-type'' C:\src\SDK\Boost\boost_1_60_0\boost_1_60_0\boost/date_time/microsec_time_clock.hpp(113): error C2065: 'curr_ptr' : undeclared identifier C:\src\SDK\Boost\boost_1_60_0\boost_1_60_0\boost/date_time/microsec_time_clock.hpp(113): error C2227: left of '->tm_sec' must point to class/struct/union/generic type type is ''unknown-type''

1 0

(no subject)
by Виктория Доможакова 24 Feb '16

24 Feb '16

Hello. I have template class. I want to serialize it. But I don't know how. template <class T> class AverDayVisTask : public DrawTask, public AverDayVisMathTask <T> { public: // some functions private: friend class boost::serialization::access; //! boost::serialize template <class Archive> void serialize(Archive& ar, const unsigned int /*version*/) { ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(DrawTask); ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(AverDayVisMathTask<T>); //<----- error } }; // class AverDayVisTask BOOST_CLASS_VERSION(AverDayVisTask<SphericalModel>, 1); BOOST_CLASS_VERSION(AverDayVisTask<SphericalNutModel>, 1); BOOST_CLASS_VERSION(AverDayVisTask<WGS84Model>, 1); BOOST_CLASS_IMPLEMENTATION(AverDayVisTask<SphericalModel>, boost::serialization::object_class_info); BOOST_CLASS_IMPLEMENTATION(AverDayVisTask<SphericalNutModel>, boost::serialization::object_class_info); BOOST_CLASS_IMPLEMENTATION(AverDayVisTask<WGS84Model>, boost::serialization::object_class_info); How fix my problem? -- Виктория Доможакова

2 1

[graph] abort algorithm execution from a visitor
by Frank Tetzel 23 Feb '16

23 Feb '16

Hi all, i played around with the bfs example calculating distances to all vertices. Now i just want to calculate the distance between two vertices, so i want to stop when the target vertex is visited. If i understood the visitor concept correctly it's not really possible to change the behaviour of the algorithm from a visitor. Does anybody know of any workaround to do early exit? Do i have to implement a new algorithm for this? In a different thread on this list Paolo Bolzoni wrote that he aborts in a custom visitor by throwing an exception. Is this the only way? I'm using bfs here and not dijkstra because i have uniform edge weights. Btw, if someone could fix the documentation that would be really nice: http://www.boost.org/doc/libs/1_60_0/libs/graph/doc/bfs_visitor.html The code snippet there did not work for me. I had to wrap make_bfs_visitor() in visitor() like it is done in examples/bfs.cpp too. Regards, Frank

2 2

Boost 1.60 Raspberry Pi lockfree::queue compilation error
by Alexander Simpson 23 Feb '16

23 Feb '16

Hello, I’m trying to compile a project that makes use of boost::lockfree::queue on a Raspberry Pi 2 running Jessie. I built version 1.60 of Boost myself (apt-get was out of date) with sudo ./bjam install. I’m not cross-compiling. When I attempt to compile a project that uses the boost library I get the error listed below (where boostreader.cpp is the file written by me). I found a patch suggested two years ago here (https://svn.boost.org/trac/boost/ticket/9041 <https://svn.boost.org/trac/boost/ticket/9041>) but the changes in that patch seem to have already applied in 1.60, so I’m at a loss as to what to do. Assistance would be greatly appreciated. Alexander Simpson Error message: In function `boost::lockfree::detail::freelist_stack<boost::lockfree::queue<int, boost::parameter::void_, boost::parameter::void_, boost::parameter::void_>::node, std::allocator<boost::lockfree::queue<int, boost::parameter::void_, boost::parameter::void_, boost::parameter::void_>::node> >::~freelist_stack()': main.cpp:(.text._ZN5boost8lockfree6detail14freelist_stackINS0_5queueIiNS_9parameter5void_ES5_S5_E4nodeESaIS7_EED2Ev[_ZN5boost8lockfree6detail14freelist_stackINS0_5queueIiNS_9parameter5void_ES5_S5_E4nodeESaIS7_EED5Ev]+0x18): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' main.cpp:(.text._ZN5boost8lockfree6detail14freelist_stackINS0_5queueIiNS_9parameter5void_ES5_S5_E4nodeESaIS7_EED2Ev[_ZN5boost8lockfree6detail14freelist_stackINS0_5queueIiNS_9parameter5void_ES5_S5_E4nodeESaIS7_EED5Ev]+0x24): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' main.o: In function `boost::lockfree::queue<int, boost::parameter::void_, boost::parameter::void_, boost::parameter::void_>::queue(unsigned int)': main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC2Ej[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC5Ej]+0x6c): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC2Ej[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC5Ej]+0x78): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC2Ej[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC5Ej]+0xb0): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC2Ej[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC5Ej]+0xbc): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC2Ej[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC5Ej]+0xd8): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC2Ej[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC5Ej]+0xe4): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC2Ej[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC5Ej]+0x148): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC2Ej[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC5Ej]+0x170): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC2Ej[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC5Ej]+0x1ec): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC2Ej[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC5Ej]+0x1f8): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC2Ej[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC5Ej]+0x224): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC2Ej[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_EC5Ej]+0x230): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' main.o: In function `boost::lockfree::queue<int, boost::parameter::void_, boost::parameter::void_, boost::parameter::void_>::~queue()': main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x58): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x64): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x90): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x9c): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0xc8): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0xd4): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x128): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x134): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x164): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x170): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x180): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x18c): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x1c8): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x1d4): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x1e8): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x1f4): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x218): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x224): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x260): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x26c): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x278): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' main.cpp:(.text._ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED2Ev[_ZN5boost8lockfree5queueIiNS_9parameter5void_ES3_S3_ED5Ev]+0x284): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' boostreader.o: In function `BoostReader::run()': boostreader.cpp:(.text+0x84): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' boostreader.cpp:(.text+0x90): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' boostreader.cpp:(.text+0xb8): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' boostreader.cpp:(.text+0xc4): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' boostreader.cpp:(.text+0xf0): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' boostreader.cpp:(.text+0xfc): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' boostreader.cpp:(.text+0x11c): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' boostreader.cpp:(.text+0x128): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' boostreader.cpp:(.text+0x1ac): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' boostreader.cpp:(.text+0x1dc): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' boostreader.cpp:(.text+0x204): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' boostreader.cpp:(.text+0x210): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' boostreader.cpp:(.text+0x264): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' boostreader.cpp:(.text+0x288): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()' boostreader.cpp:(.text+0x438): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::scoped_lock(void const volatile*)' boostreader.cpp:(.text+0x454): undefined reference to `boost::atomics::detail::lockpool::scoped_lock::~scoped_lock()'

2 1

boost 1.54: problem with building documentation.
by Paul K 22 Feb '16

22 Feb '16

Hallo people. I need to have documentation in man pages format on my ubuntu 14.04. Unfortunatelly, I fail with this task. The following are the steps I've performed. In step 11 I do "../b2" instead "../b2 man" just to highlight that the problem is not related to building the man pages. Of course "../b2 man" fails as well Could You please help me with it? 1. install following packages for man pages build. lubuntu.14.04$ sudo apt-get install xsltproc lubuntu.14.04$ sudo apt-get install doxygen 2. lubuntu.14.04$ dpkg --list | grep libboost-all ii libboost-all-dev 1.54.0.1ubuntu1 i386 Boost C++ Libraries development files (ALL) (default version) 3. download boost_1_54_0.tar.bz2, unpack to ~/ 4. cd ~/boost_1_54_0 5. ./bootstrap prepares build configuration and puts it to project-config.jam. 6. ./b2 builds whole the boost libraries, but does not install them into the system. 7. lubuntu.14.04$ export BOOST_ROOT=/home/userp/boost_1_54_0 8. lubuntu.14.04$ cd ~/boost.doc/ 9. lubuntu.14.04$ ~/boost_1_54_0/tools/boostbook/setup_boostbook.sh Downloading DocBook XSLT Stylesheets version 1.75.2... Expanding DocBook XSLT Stylesheets into /home/userp/boost.doc/docbook-xsl-1.75.2...done. Downloading DocBook XML DTD version 4.2... Expanding DocBook XML DTD into /home/userp/boost.doc/docbook-dtd-4.2... done. Searching for xsltproc... /usr/bin/xsltproc. Searching for Doxygen... /usr/bin/doxygen. Searching for Java... /usr/bin/java. Downloading FOP distribution version 0.94... Expanding FOP distribution into /home/userp/boost.doc/fop-0.94... done. Updating Boost.Jam configuration in /home/userp/user-config.jam... done. Done! Execute "bjam --v2" in a documentation directory to generate documentation with BoostBook. If you have not already, you will need to compile Boost.Jam. 10. lubuntu.14.04$ cd ~/boost_1_54_0/doc 11. lubuntu.14.04$ ../b2 Performing configuration checks - has_icu builds : yes (cached) /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:1099: in virtual-target.register-actual-name from module virtual-target error: Duplicate name of actual target: <p../bin.v2/libs/filesystem/build/gcc-4.9.3/release/link-static>libboost_filesystem.a error: previous virtual target { gcc%gcc.archive-libboost_filesystem.a.STATIC_LIB { gcc%gcc.compile.c++-codecvt_error_category.o.OBJ { codecvt_error_category.cpp.CPP } } { gcc%gcc.compile.c++-operations.o.OBJ { operations.cpp.CPP } } { gcc%gcc.compile.c++-path.o.OBJ { path.cpp.CPP } } { gcc%gcc.compile.c++-path_traits.o.OBJ { path_traits.cpp.CPP } } { gcc%gcc.compile.c++-portability.o.OBJ { portability.cpp.CPP } } { gcc%gcc.compile.c++-unique_path.o.OBJ { unique_path.cpp.CPP } } { gcc%gcc.compile.c++-utf8_codecvt_facet.o.OBJ { utf8_codecvt_facet.cpp.CPP } } { gcc%gcc.compile.c++-windows_file_codecvt.o.OBJ { windows_file_codecvt.cpp.CPP } } } error: created from ../libs/filesystem/build/boost_filesystem error: another virtual target { gcc%gcc.archive-libboost_filesystem.a.STATIC_LIB { gcc%gcc.compile.c++-codecvt_error_category.o.OBJ { codecvt_error_category.cpp.CPP } } { gcc%gcc.compile.c++-operations.o.OBJ { operations.cpp.CPP } } { gcc%gcc.compile.c++-path.o.OBJ { path.cpp.CPP } } { gcc%gcc.compile.c++-path_traits.o.OBJ { path_traits.cpp.CPP } } { gcc%gcc.compile.c++-portability.o.OBJ { portability.cpp.CPP } } { gcc%gcc.compile.c++-unique_path.o.OBJ { unique_path.cpp.CPP } } { gcc%gcc.compile.c++-utf8_codecvt_facet.o.OBJ { utf8_codecvt_facet.cpp.CPP } } { gcc%gcc.compile.c++-windows_file_codecvt.o.OBJ { windows_file_codecvt.cpp.CPP } } } error: created from ../libs/filesystem/build/boost_filesystem error: added properties: <auto-index-internal>off <auto-index-no-duplicates>off <auto-index-section-names>on <auto-index-verbose>off <auto-index>off <format>docbook error: removed properties: <format>html /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:484: in actualize-no-scanner from module object(file-target)@3468 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:134: in class(a)virtual-target.actualize from module object(file-target)@3468 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:815: in actualize-source-type from module object(action)@3786 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:836: in actualize-sources from module object(action)@3786 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:776: in class(a)action.actualize from module object(action)@3786 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:311: in actualize-action from module object(file-target)@3787 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:493: in actualize-no-scanner from module object(file-target)@3787 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:134: in class(a)virtual-target.actualize from module object(file-target)@3787 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:815: in actualize-source-type from module object(action)@3793 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:834: in actualize-sources from module object(action)@3793 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:776: in class(a)action.actualize from module object(action)@3793 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:311: in actualize-action from module object(file-target)@3794 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:493: in actualize-no-scanner from module object(file-target)@3794 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:134: in class(a)virtual-target.actualize from module object(file-target)@3794 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:815: in actualize-source-type from module object(action)@7122 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:834: in actualize-sources from module object(action)@7122 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:776: in class(a)action.actualize from module object(action)@7122 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:311: in actualize-action from module object(file-target)@7123 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:493: in actualize-no-scanner from module object(file-target)@7123 /home/userp/boost_1_54_0/tools/build/v2/build/virtual-target.jam:134: in class(a)virtual-target.actualize from module object(file-target)@7123 /home/userp/boost_1_54_0/tools/build/v2/build-system.jam:720: in load from module build-system /home/userp/boost_1_54_0/tools/build/v2/kernel/modules.jam:289: in import from module modules /home/userp/boost_1_54_0/tools/build/v2/kernel/bootstrap.jam:139: in boost-build from module /home/userp/boost_1_54_0/boost-build.jam:17: in module scope from module regards

1 0

boost::any constructors
by David 22 Feb '16

22 Feb '16

Hi, boost::any has a perfect forward constructor declared as: template<typename ValueType> any(ValueType&& value , typename boost::disable_if<boost::is_same<any&, ValueType> >::type* = 0 // disable if value has type `any&` , typename boost::disable_if<boost::is_const<ValueType> >::type* = 0) // disable if value has type `const ValueType&&` : content(new holder< typename decay<ValueType>::type >(static_cast<ValueType&&>(value))) {} The is_const SFINAE exclusion forces const types to the regular copy constructor: template<typename ValueType> any(const ValueType & value) : content(new holder< BOOST_DEDUCED_TYPENAME remove_cv<BOOST_DEDUCED_TYPENAME decay<const ValueType>::type>::type >(value)) {} What is different about how the regular copy constructor treats a constant value than what the perfect forward construct would do if the is_const exclusion were removed? Thanks, David

2 1

Nested BOOST_FOREACH crash
by peyman＠ausdia.com 22 Feb '16

22 Feb '16

Good Day Boosters! I am experiencing sporadic crashes that look like memory problem when I have nested (2 level) BOOST_FOREACH loops. Reason I say it looks like memory problem is because slightest change will make it crash or not crash. For example, adding a simple cout would change it! I cannot provide a testcase. So I am just wondering if anybody has experienced the same, or know what could be going on. I am using Boost 1.57. Cheers, Peyman

2 1

Need help when adapting boost 1.59.0 to WinRT
by Nguyễn Trung Duy 22 Feb '16

22 Feb '16

Dear Boost team, I need your help with adapting boost 1.59 to WinRT. I am working on boost and reSIProcate. I built boost and integrated it with reSIProcate project. However, when build reflow project, I got stuck with bellow bugs. I wonder with your great experiences, could you please give me some advice. The error happens at line 96 : #if defined(BOOST_ASIO_WINDOWS_RUNTIME) const int max_addr_v4_str_len = 256; const int max_addr_v6_str_len = 256; typedef unsigned __int32 u_long_type; typedef unsigned __int16 u_short_type; struct in4_addr_type { u_long_type s_addr; }; // error at here And the logs: *\boost-msvc-14.0-store\boost/asio/detail/socket_types.hpp(96): error C3927: '->': trailing return type is not allowed after a non-function declarator (compiling source file MediaStream.cxx)\boost-msvc-14.0-store\boost/asio/detail/socket_types.hpp(96): error C3484: syntax error: expected '->' before the return type (compiling source file MediaStream.cxx)\boost-msvc-14.0-store\boost/asio/detail/socket_types.hpp(96): error C3613: missing return type after '->' ('int' assumed) (compiling source file MediaStream.cxx)\boost-msvc-14.0-store\boost/asio/detail/socket_types.hpp(96): error C3646: 'S_addr': unknown override specifier (compiling source file MediaStream.cxx)\boost-msvc-14.0-store\boost/asio/detail/socket_types.hpp(98): error C3927: '->': trailing return type is not allowed after a non-function declarator (compiling source file MediaStream.cxx)\boost-msvc-14.0-store\boost/asio/detail/socket_types.hpp(98): error C3484: syntax error: expected '->' before the return type (compiling source file MediaStream.cxx)\boost-msvc-14.0-store\boost/asio/detail/socket_types.hpp(98): error C3613: missing return type after '->' ('int' assumed) (compiling source file MediaStream.cxx)\boost-msvc-14.0-store\boost/asio/detail/socket_types.hpp(98): error C3646: 'Byte': unknown override specifier (compiling source file MediaStream.cxx)\boost-msvc-14.0-store\boost/asio/detail/socket_types.hpp(98): error C2143: syntax error: missing ',' before '[' (compiling source file MediaStream.cxx)\boost-msvc-14.0-store\boost/asio/detail/socket_types.hpp(98): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int (compiling source file MediaStream.cxx)\boost-msvc-14.0-store\boost/asio/detail/socket_types.hpp(98): error C2143: syntax error: missing ')' before ';' (compiling source file MediaStream.cxx)\boost-msvc-14.0-store\boost/asio/detail/socket_types.hpp(98): error C2143: syntax error: missing ';' before ')' (compiling source file MediaStream.cxx)\boost-msvc-14.0-store\boost/asio/detail/socket_types.hpp(98): error C2059: syntax error: ')' (compiling source file MediaStream.cxx)\boost-msvc-14.0-store\boost/asio/ip/address_v4.hpp(61): error C2039: 'S_addr': is not a member of 'default::uint32' (compiling source file MediaStream.cxx)\boost-msvc-14.0-store\boost/asio/ip/address_v4.hpp(147): error C2039: 'S_addr': is not a member of 'default::uint32' (compiling source file MediaStream.cxx)\boost-msvc-14.0-store\boost/asio/ip/address_v4.hpp(153): error C2039: 'S_addr': is not a member of 'default::uint32' (compiling source file MediaStream.cxx)* Thanks you so much!!!! *--* *Best Regards,* *NGUYEN TRUNG DUY* *Android Developer* *Mobile*: (+84)977 46 12 23 *Skype :* trungduy150388 *Website*: http://nguyentrungduy.com/ *Blog*: http://dbox.nguyentrungduy.com/ *Github*: https://github.com/nguyentrungduy

2 2

Newbie
by Shan Wijesinghe 22 Feb '16

22 Feb '16

Hi all, I'm a new member to C++ boost and I have a fairly good knowledge in programming in C++. I'm very much excited to join this group and I need directions from the senior members on how to start myself. Please help me here. Thanks in advance. regards, DilSHAN.

6 11

Query on Boost.DLL
by Leo Carreon 21 Feb '16

21 Feb '16

Hi, I have been reading the Boost.DLL documentation. Can a single plugin support multiple API’s? If yes, when the multiple API’s are used at the same time; will there be only one instance of the plugin loaded or will there be multiple instances loaded? Regards, Leo

2 1

Boost.DLL
by Leo Carreon 21 Feb '16

21 Feb '16

Hi, Can anyone please let me know what the status of the Boost.DLL library is? Regards, Leo

2 1

[coroutine] - only std exceptions are caught from coroutines
by Tamas.Ruszkai＠leica-geosystems.com 21 Feb '16

21 Feb '16

3 4

[Interprocess] Communication between x86 and x64 issue
by Toni Neubert 19 Feb '16

19 Feb '16

I want to communicate between different platforms using boost interprocess. I am using vc12 and boost 1.58 on windows 7. My code below is a very simple example, that should work. But it doesn't for communications between different platforms... If I create it in x64 and open in win32, the process stuck at a lock at function try_based_lock in boost/int/sync/detail/common_algorithms.hpp In the other way around: win32 create, x64 open: the process crashes at name_length in segment_manager_helper.hpp while trying to find the name in index (priv_generic_find in segment_manager). #include <iostream> #include <boost/interprocess/managed_shared_memory.hpp> int main() { namespace bip = boost::interprocess; // open in WIN32, create in x64 #ifdef _WIN32 bip::managed_shared_memory msm(bip::open_only, "TestIPC"); #elsif X64 bip::shared_memory_object::remove("TestIPC"); bip::managed_shared_memory msm(bip::create_only, "TestIPC", 4096); msm.construct<uint32_t>("Data")[1](10); #endif // Get Data and print it auto data = msm.find<uint32_t>("Data"); if (data.second == 1) { std::cout << *data.first << std::endl; } std::cin.ignore(); return 0; } Does anybody have experience in this? Thank you in advance!

3 2

Re: [Boost-users] [Serialization] This compiles; but does it work?
by Bjorn Reese 19 Feb '16

19 Feb '16

On 02/19/2016 04:20 AM, Merrill Cornish wrote: > Can anyone tell me if this will work, or do I need to implement the > serialize() function? When you are doing different things for the input and output archives then it is better to split serialization into load and save: #include <boost/filesystem/path.hpp> #include <boost/serialization/split_free.hpp> namespace boost { namespace serialization { template <typename Archive> void serialize(Archive& ar, filesystem::path& p, const unsigned int version) { split_free(ar, p, version); } template<class Archive> void save(Archive & ar, const filesystem::path& p, unsigned int version) { ar << p.string(); } template<class Archive> void load(Archive & ar, filesystem::path& p, unsigned int version) { std::string data; ar >> data; p = data; } }}

2 1

[graph] Search algorithm using quality metric rather than distance
by rleigh＠codelibre.net 19 Feb '16

19 Feb '16

I have an adjacency_list graph (shown in attached dot file). Each edge has an attached "quality metric" as a bundled property. Similar to the dijkstra_shortest_paths algorithm, I'd like to determine the optimal path. However, this algorithm sums the distance along each edge, and finds the shortest path. What I'd like to do is *multiply* the quality metric for each edge in the path, and find the largest one. A perfect path will have a quality metric of 1.0, while suboptimal paths will have values tending towards zero, and the more "bad" edges the smaller the number. I'll likely then look at the number of edges and then select the shortest of the candidates. It seems like a simple algorithm that might already be included, but I just haven't found it yet not knowing its formal name. If anyone has any suggestions, I'd be very grateful. Many thanks, Roger

5 4

[Serialization] This compiles; but does it work?
by Merrill Cornish 19 Feb '16

19 Feb '16

mGraphFile is a data member of type boost:filesystem::path, which isn't (as I understand) handled natively by Boost Serialization. I could define template<class Archive> void serialize(Archive& ar, boost::filesystem::path& p, const unsigned int version); but it is needed in only one place. Below is an excerpt from an inline serialization function that I'm already using. While it has a redundant step not needed for loading and a different redundant step not needed for storing, it would seem to do what I need. (The minor inefficiency of the redundant statements is of no concern here.) ... std::string str = mGraphFile.string(); // redundant if loading ar & BOOST_SERIALIZATION_NVP(str); mGraphFile = str; // redundant if saving ... Can anyone tell me if this will work, or do I need to implement the serialize() function? Merrill Cornish

1 0

boost::msm usage: how to set properties of target states
by spiritwalker 18 Feb '16

18 Feb '16

States in my fsm has different properties. I define a event which will invoke a transition to a target state. I want to set properties of target by event data. My choices are: 1. set properties in the action or guard: but it is still in the source state. I fill not good if i set the target state properties at the time 2. set properties in the target entry: but the value of properties have been calculated in guard on receiving the event so i should recalculated again :( Any one can give me more ideas. Thanks ! -- View this message in context: http://boost.2283326.n4.nabble.com/boost-msm-usage-how-to-set-properties-of… Sent from the Boost - Users mailing list archive at Nabble.com.

2 1

SERIALIZE: Registering derived templete classes serialized via base ptr
by Unger, Jörg 17 Feb '16

17 Feb '16

I'm trying to serialize a derived class via a base ptr using boost serialize. The example to illustrate the problem (without templates) is as follows //****************** Main.cpp ********************** #include <fstream> #include <boost/archive/text_iarchive.hpp> #include <boost/archive/text_oarchive.hpp> #include "Derived.h" int main(int argc, char* argv[]) { std::string fileName = "Out.txt"; Derived myDerived; Base* myBasePtr = &myDerived; //myDerived.foo(); // serialize it as txt std::ofstream ofs(fileName.c_str(), std::ios_base::binary ); boost::archive::text_oarchive ota ( ofs, std::ios::binary ); //ota & boost::serialization::make_nvp(std::string("directly derived").c_str(), myDerived);; ota & boost::serialization::make_nvp(std::string("via base ptr").c_str(), myBasePtr);; return 0; } //*********************************************** //*************** Base.h ************************* #pragma once #include <boost/serialization/access.hpp> #include <boost/serialization/export.hpp> class Base { friend class boost::serialization::access; public: Base(){}; virtual ~Base(){}; template<class Archive> void serialize(Archive & ar, const unsigned int version) {}; }; BOOST_CLASS_EXPORT_KEY(Base) //*********************************************** //**************** Derived.h ********************** #pragma once #include <boost/serialization/access.hpp> #include <boost/serialization/export.hpp> #include "Base.h" class Derived : public Base { friend class boost::serialization::access; public: Derived(){}; void foo(); template<class Archive> void serialize(Archive & ar, const unsigned int version); }; BOOST_CLASS_EXPORT_KEY(Derived) //*********************************************** //**************** Derived.cpp ******************** #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include "Derived.h" //Derived::Derived() //{} void Derived::foo() { } // serializes the class template void Derived::serialize(boost::archive::text_oarchive & ar, const unsigned int version); template void Derived::serialize(boost::archive::text_iarchive & ar, const unsigned int version); template<class Archive> void Derived::serialize(Archive & ar, const unsigned int version) { ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(Base); } BOOST_CLASS_EXPORT_IMPLEMENT(Derived) //*********************************************** When compiling the above code and linking the object files, everything works fine. When I combine everything in a library (in this example it is essentially only Derived.o) and link the main file with the library, I get an error what(): unregistered class - derived class not registered or exported The problem seems to be that the registration in the linked library is not activated. The problem is simplified here, because in our implementation, the derived class is essentially a template class that does not have any cpp-files. We have just added another otherwise empty cpp file with the registration of all possible instantiations of the class. There are several possibilities to solve the problem · The macro BOOST_CLASS_EXPORT_IMPLEMENT(Derived) could be moved to the main.cpp. This workaround is not my preferred options, since the registration has to be done in every main file we want to use the library for. · The macro BOOST_CLASS_EXPORT_IMPLEMENT(Derived) could be moved to the Base.cpp (the constructor for the base class has to be implemented in this file as well). This is another option, but this requires the header files of the derived classes to be included in Base.cpp, which is not convenient either. · Serialize one object of the derived class before serialization through the pointer, but that's only a workaround. (see the commented line in Main.cpp) · Call the foo method in Main.cpp. Surprisingly, this does not depend on whether the foo function is implemented in Derived.cpp, but also if it is called in Main.cpp. Surprisingly, if "myDerived.foo();" in Main.cpp is uncommented the program works fine, which is something I do not understand. It seems that the registration is only performed, if one of the functions in this cpp file is actually called, or am I wrong? · Implement the constructor of Derived in Derived.cpp. This approach works fine for the current example (somehow similar to the previous solution). However, in our case, Derived is a template and thus the constructor can't be implemented in the cpp file. · Another option is to always link the main file with the library and the object file Derived.o, but this is also not a convenient option. · Finally, a manual registration with register_type is possible. This could be moved to a separate subroutine that is always called in different main files. What is the recommended way of registering derived template classes that are serialized through a base ptr within a library. Best regards, Jörg F. Unger

2 1

[Timer] unresolved external symbol boost::chrono::time_point
by Aman Wardak 17 Feb '16

17 Feb '16

Env: Win7 32-bit running in VirtualBox on Macbook Pro Compiler: MS Visual Studio 14 It's my first time working with Boost. I've followed the instructions here: http://www.boost.org/doc/libs/1_60_0/more/getting_started/windows.html I've compiled Boost successfully: ============================ The Boost C++ Libraries were successfully built! The following directory should be added to compiler include paths: C:\Users\IEUser\Documents\boost_1_60_0 The following directory should be added to linker library paths: C:\Users\IEUser\Documents\boost_1_60_0\stage\lib ============================================== I've added the above paths in Visual Studio and was able to run the test in step 6 of the instructions linked above to verify my environment is set up correctly. MY PROBLEM: I'm trying to compile the very first sample code at this link: http://www.boost.org/doc/libs/1_60_0/libs/timer/doc/cpu_timers.html I get the following error: ------ Build started: Project: BoostExample, Configuration: Debug Win32 ------ Source.cpp libboost_timer-vc140-mt-gd-1_60.lib(cpu_timer.obj) : error LNK2019: unresolved external symbol "public: static class boost::chrono::time_point<class boost::chrono::steady_clock,class boost::chrono::duration<__int64,class boost::ratio<1,1000000000> > > __cdecl boost::chrono::steady_clock::now(void)" (?now@steady_clock @chrono@boost@@SA?AV?$time_point@Vsteady_clock@chrono@boost@@V?$duration@ _JV?$ratio@$00$0DLJKMKAA@@boost@@@23@@23@XZ) referenced in function __catch$??1auto_cpu_timer@timer@boost@@QAE@XZ$0 C:\Users\IEUser\Documents\Visual Studio 2015\Projects\CS2370\Debug\BoostExample.exe : fatal error LNK1120: 1 unresolved externals ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ========== Thanks, Aman

1 0

[Test] BOOST_CHECK_EXCEPTION error message still vague
by Merrill Cornish 17 Feb '16

17 Feb '16

In BOOST_1_59_0, I complained that the error message from BOOST_CHECK_EXCEPTION was indecipherable. In BOOST_1_60_0, things improved a lot. But it still leave you hanging. I use the function fail_msg() as the predicate argument to BOOST_CHECK_EXCEPTION. If it finds a specified substring in the exception message, it returns true. Otherwise, it returns false. Below is an error message from BOOST_CHECK_EXCEPTION when the predicate returned false: exception "std::runtime_error" raised as expected: validation on the raised exception through predicate "fail_msg" The first clause says my code raised the expected exception class. That part of the message is clear and unambiguous. The second clause, however, is a non-sequitur. It seems to only acknowledge that there was a predicate named "fail_msg" without saying whether it returned true or false. Overall, the whole message doesn't say whether BOOST_CHECK_EXCEPTION passed or failed. Since a message was output, the user can assume things did not go well, but it seems like the message could be more explicit. Merrill Cornish

2 2

multiprecision max and et_on
by Daniel Brake 16 Feb '16

16 Feb '16

Hi Boost, I would like to be able to use the Eigen linear algebra library with Boost.Multiprecision with et_on. However, as noted here: https://svn.boost.org/trac/boost/ticket/11149 for max, et_on isn't compatible out of the box. Aside from writing my own little overload for max for the particular form being produced in my line of code from within Eigen, does anyone have a fix for enabling max with expression templates on? MWE: { using mpfr = boost::multiprecision::mpfr_float; // et_on by default, which is what i want using std::max; mpfr a(1), b(2), c(4); auto q = b*b+c; mpfr r = max(a,q); } Thanks a lot, Daniel

1 0

[GIL] Why doesn't pixel assignment color-convert?
by Stonewall Ballard 16 Feb '16

16 Feb '16

I've just started using boost.gil, though I've been looking at it for a while. It seems odd to me that assignment doesn't do an implicit color_convert() when the pixels are of different types. Instead, it just copies matching channels. That's the wrong thing to do when assigning an rgba pixel to an rgb pixel, since the former is straight and the latter is premultiplied. It also seems wrong that you can assign an rgba pixel to an rgb pixel, but not vice-versa. It looks like this is caused by pixels_are_compatible in gil_concept.hpp, where it fails to check that both pixels have the same number of channels. Instead, it matches channels of the output pixel against the input pixel, ignoring any extra input pixel channels. It also ignores scoped_channel_value usage. This seems like an error waiting to happen. Comments? - Stoney

1 0

ASIO: add work and remove immed., will ignore further handler_requests???
by aj neu 16 Feb '16

16 Feb '16

Hi, below is some code where boost::asio::io_service::work is added, and then immediately removed. After that, I call async_wait on a steady_timer, but it does not work: io.run() RETURNS IMMEDIATELY, and IGNORES the async_wait. Is this intended? (I was rather surprised, because I thought that the async_wait would schedule new work, but it does not work). If I cange the code-line #define WEIRD_BEHAVIOUR to #undef WEIRD_BEHAVIOUR then I have my expected behaviour. Thanks, ajneu #include <iostream> #include <chrono> #include <experimental/optional> #include <boost/asio.hpp> #include <boost/asio/steady_timer.hpp> #define WEIRD_BEHAVIOUR int main() { boost::asio::io_service io; std::experimental::optional<boost::asio::io_service::work> work; #ifdef WEIRD_BEHAVIOUR work.emplace(io); work = std::experimental::nullopt; #endif boost::asio::steady_timer timer(io, std::chrono::milliseconds{1000}); timer.async_wait([](const boost::system::error_code &ec) { std::cout << ((!ec) ? "done" : "err") << std::endl; }); io.run(); }

1 0

Writing a stratum client using boost:asio
by Jan Willem Penterman 11 Feb '16

11 Feb '16

Hi, I'm trying to write a stratum client for a cryptocurrency mining application. The mining application connects to a stratum server to receive new work to mine on and submit solutions. The stratum protocol is a simple TCP based line protocol with JSON payload. Documentation here: https://mining.bitcoin.cz/help/#!/manual/stratum-protocol I've chosen to use boost::asio, as boost is already heavily used in the fork of the project I'm building the miner for. But I'm having difficulties to understand why my current implementation doesn't work. The basic flow is as follows: 1. connect to the server. this works 2. send subscribe method. this also works 3. authorize worker(s). doesn't work. 4. stratum server should start pushing new work periodically. doesn't work. 5. submit solution when found. not implemented yet. Without authorization, the server should still start pushing work. So I've skipped step 3 for now. The source code as I have it now is available here: https://github.com/Genoil/cpp-ethereum/blob/stratum/libstratum/ The output I get from this is as follows: i 12:19:14|<unknown> Connected to stratum server coinotron.com : 3344 i 12:19:15|<unknown> {"error": null, "id": 1, "result": [["mining.notify", "91d0025c5ea54509977e3475d065169e"], "080016D0", 4]} i 12:19:15|<unknown> Subscribed i 12:19:15|<unknown> { "id": null, "method": "mining.set_difficulty", "params": [32768]} i 12:19:15|<unknown> mining.set_difficulty i 12:19:15|<unknown> {"params": ["31065", "0xc09361c52e9dddd141040cc79c52eaed382e92c1dd350324c040482a4c4ac0fa","0x5a46dd85298b0beff65ccf3006c4b5d2f7fa6ca8a5885a7f2132714fe7a48602","0x0000000200000000000000000000000000000000000000000000000000000000", true], "id": null, "method": "mining.notify"} i 12:19:15|<unknown> mining.notify >From this I can conclude that the subscription call works. Then at the end of handleResponse, I simply queue up a new async_read_until to wait for the next line of JSON to come in from the server. This also kind of works, but the idea is that after a few seconds, new work should come in as a "mining.notify". This never happens. Can anybody explain what I'm doing wrong? Regarding the mining.authorize call on line 113. I've understood from the documentation that I can send that whenever I want, so I tried to do this immediately after the subscribe method returned. But if I do this, it a) doesn't return and b) all lines after "Subscribed" don't come in any longer. This is the second problem I'm trying to figure out. I'm using this as reference, but my Python is even worse than my C++ https://github.com/slush0/stratum-mining-proxy But when I run the binaries connecting to the same host (coinotron.com:3344), I do get new work coming in... Thanks for having a look at this.

1 0

[ASIO] Newbie question - Bidirectional communication example
by Davies, John 11 Feb '16

11 Feb '16

For a simple explanation I have two processes that run on the same computer. Process 1 sends messages to Process 2 by putting the messages into an Interprocess message queue that Process 2 created. Process 2 sends messages to Process 1 by putting the messages into an Interprocess message queue that Process 1 created. The messages can be sent at any time and are not in response to each other. Very symmetrical. Now I want to put Process 1 and Process 2 on separate computers. My intent is to transfer the messages over TCP to the opposite computer without changing Process 1 or 2. So I thought I'd create two connector programs. Connector 1 creates a message queue that pretends to be the Process 2 message queue. When it gets a message, it send it over TCP the Connector 2. Connector 2 gets the message and puts it into the real Process 2 message queue. And the reverse if Process 2 has an outgoing message. I just can't find a good example to steal from. Everything I can find are more like Process 1 makes a request and Process 2 responds. So I think I have a fundamental misunderstanding of how ASIO works. ________________________________ The information contained in this message may be confidential and legally protected under applicable law. The message is intended solely for the addressee(s). If you are not the intended recipient, you are hereby notified that any use, forwarding, dissemination, or reproduction of this message is strictly prohibited and may be unlawful. If you are not the intended recipient, please contact the sender by return e-mail and destroy all copies of the original message.

2 1

[Test] Funny Business with vector::at() out-of-range
by Merrill Cornish 11 Feb '16

11 Feb '16

I posted a question a couple of days ago: "Throws 'Escaping' both BOOST_CHECK_THROW and try{}". I found that BOOST_CHECK_EXCEPTION which is working for me elsewhere fails the same way. So, an out-of-range std::vector::at() seems to be the common element. In the definition of at(), the out-of-range response is handled by __throw_out_of_range_fmt(). When I looked up that one, I found void __throw_out_of_range_fmt(const char*, ...) __attribute__((__noreturn__)) __attribute__((__format__(__gnu_printf__, 1, 2))); in functexcept.h. To my admittedly less-than-expert eye, there doesn't seem to be an actual throw() here. On the other hand, the entire file are entries like this for various exceptions. There are a lot of Google hits for __throw_out_of_range_fmt, but they are for unresolved references in links, apparently caused by mixed version of libraries and object. Everything I've got is compiled linked for MinGW 64-bit, GCC 5.3.0, 64-bit --std=C++14, BOOST 1_60_1 64-bit so I get none of those errors. The problem I'm seeing with my test code is that wrapping a try{} around BOOST_CHECK_THROW shows that [1] the body of the try doesn't complete; but at the same time [2] not even a catch(...) can catch the presumed throw--as if a throw isn't actually being done. So, where did the throw go? Merrill Cornish

2 1

[TEST] Throws "Escaping" both BOOST_CHECK_THROW and try{}
by Merrill Cornish 11 Feb '16

11 Feb '16

I'm running Windows 10, 64-bit; MinGW 64-bit; GCC 5.3 64-bit; and BOOST 1_60_1 Here is the relevant test code: [319] BOOST_CHECK_THROW(throw std::out_of_range("BOOST_CK_THROW test"), std::out_of_range); [320] try { [321] std::cerr << "arcsSize()" << std::endl; [322] empty1.arcsSize(Operand::DEFAULT_ARC_SET+1); [323] std::cerr << "arcsSize() did not throw" << std::endl; [324] }//try [325] catch (const std::out_of_range& ex) [326] { std::cerr << "out_of_range caught=|" << ex.what() << "|" << std::endl; } [327] catch (...) { std::cerr << "something else caught" << std::endl; } [328] [329] BOOST_CHECK_THROW(empty1.arcsSize(Operand::DEFAULT_ARC_SET+1), std::out_of_range); The original code was just the last line, line [329]. [319]-[327] was added in an attempt to characterize the problem. The error [329] got by itself was: terminate called after throwing an instance of 'std::out_of_range' what(): vector::_M_range_check: __n (which is 1) >= this->size() (which is 1) This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information. SIGABRT intercepted; converted to exit(EXIT_FAILURE). arcSize() is implemented with std::vector::at() and the index is out-of-range, so it's supposed to throw std::out_of_range. That's what was detected, so why did it terminate the program? (The last line comes from my SIGABRT handler. Without it, the test executable ends up locked and can't be deleted.) Adding in all of the test lines shown above gives; [319] Operand_Test.cpp(319): info: check 'exception "std::out_of_range" raised as expected' has passed [321] arcsSize() terminate called after throwing an instance of 'std::out_of_range' what(): vector::_M_range_check: __n (which is 1) >= this->size() (which is 1) This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information. SIGABRT intercepted; converted to exit(EXIT_FAILURE). Notice the explicit throw in line [319] is detected and handled properly. However, the arcSize() call from inside the try block throws, but is not caught by even catch(...) {}. Can anyone help me see what's going on here? Merrill Cornish

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[Container] Regarding Trac #11957, static_vector::max_size() is higher than the capacity
by Gagan Kumar 10 Feb '16

10 Feb '16

I tried a simple fix for https://svn.boost.org/trac/boost/ticket/11957 here https://github.com/boostorg/container/pull/37/files . Can someone please review it. Regards,Gagan Kumar

1 0

Boost Variant Type Interfaces
by Ali Nakipoglu 09 Feb '16

09 Feb '16

Hi, In our project we are using boost, boost.variant very extensively. We was using methods provided by the library to interface with Variant types. Mainly : get<T>( variant ) for accessing stored values and variant.which() == Index for checking currently stored type. Overtime we realized we can improve this as : variant.getT() for accessing stored values much more nicer to write and variant.isT() or variant.which() == WHICH_T for checking currently stored type which does not depend on order of template paramters in the Variant definition. Also in some cases we wanted to be able to add type specific methods for example in our case we are using subscript operator to access recursively stored Variants variant[ "a" ].isT() or variant[ 0 ].asT() We generalized this solution for our project and published at https://github.com/FictionIO/WrappedVariant I would like to hear your comments. Do you think its a correct approach or useful? Any suggestions are welcome! Kind Regards, Ali

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[Multiprecision] Runtime assertion failure with clang++3.6.0 but not g++4.9.2
by mbw_bst＠mailbox.org 09 Feb '16

09 Feb '16

Dear all, this is my first post on this mailing list, so hopefully this will all be by the book. Executing the following minimal working example, which is supposed to calculate "3! == 6" via (1) a template function (2) a class template and save the result in a boost::multiprecision::mpz_int, results in unexpected behavior for clang++3.6.0, with the version of my boost library being 1.59.0. The program displays the correct result using g++4.9.2 however: #include <iostream> #include <boost/multiprecision/gmp.hpp> namespace bm = boost::multiprecision; template <std::size_t N> bm::mpz_int factorial() { return N * factorial<N-1>(); } template<> bm::mpz_int factorial<0>() { return 1; } template <std::size_t N> struct factorial2 { static const bm::mpz_int value; }; template<std::size_t N> const bm::mpz_int factorial2<N>::value = N * factorial2<N-1>::value; template<> struct factorial2<0> { static const bm::mpz_int value; }; const bm::mpz_int factorial2<0>::value = 1; int main () { std::cout << factorial<3>() << '\n'; std::cout << factorial2<3>::value << '\n'; return 0; } The output for clang, having been compiled via clang++ -std=c++14 -stdlib=libc++ -DNDEBUG -o main main.cpp -lgmp will result in: 6 0 However, omitting the NDEBUG flag will trigger an assertion failure: main: /usr/include/boost/multiprecision/gmp.hpp:1296: const mpz_t &boost::multiprecision::backends::gmp_int::data() const: Assertion `m_data[0]._mp_d' failed. Aborted (core dumped) Compiling the same program with g++4.9.2 (with or without "-DNDEBUG") yields the expected result: 6 6 What did I miss? Can this behavior indeed be traced down to Boost.Multiprecision, or does it have to do with the initialization order of static const class members? Or something else? Additionally, both variants work correctly with clang when using a built-in type like 'int'. Any help in understanding the problem on hand would be greatly appreciated! Best Regards, mbw

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Re: [Boost-users] [Multiprecision] Runtime assertion failure with clang++3.6.0 but not g++4.9.2
by mbw_bst＠mailbox.org 09 Feb '16

09 Feb '16

Hello again and thanks for your replies! Taking the following two statements into account: > For type int, the values are computed recursively at compile time, for a > user-defined-type the values are computed at runtime and you hit > initialization-order issues. > Seems to be that Multiprecision relies on static data that haven't > (necessarily) been initialized before your own static members. Works > fine > if the members are made non-static: Does that mean that, since a) boost::multiprecision::number<gmp_int> is not constexpr enabled, and b) static initialization can't happen at compile-time for user-defined types, that there is no way for me to initialize a variable of this type at compile-time? Does b) follow logically from a) ? I (believe to have) confirmed runtime-initialization by running valgrind, which showed the presence of dynamic memory allocations (and also jumps depending on uninitialized variables, which probably corresponds to the assertion failure). I am mentioning this because initially my little test program looked somewhat like this: #include <iostream> #include <vector> #include <boost/multiprecision/gmp.hpp> namespace bm = boost::multiprecision; template<std::size_t N> struct factorial { static const bm::mpz_int value; static void add_values(std::vector<bm::mpz_int>& vec) { factorial<N-1>::add_values(vec); vec.push_back(value); } }; template<std::size_t N> const bm::mpz_int factorial<N>::value = N * factorial<N-1>::value; template<> struct factorial<std::size_t{0}> { static const bm::mpz_int value; static void add_values(std::vector<bm::mpz_int>& vec) { vec.push_back(value); } }; const bm::mpz_int factorial<0>::value = 1; int main () { std::vector<bm::mpz_int> fac_table{}; factorial<10'000>::add_values(fac_table); std::cout << "Enter a number between 0 and 10'000 to calculate factorial:"; std::size_t number; std::cin >> number; std::cout << '\n' << number << "! == " << fac_table[number] << '\n'; return 0; } This still includes the "unsafe" static initialization of a user-defined type. However it compiles and runs via g++ -ansi -std=c++14 -O3 -Wall -Wextra -pedantic -static -save-temps -ftemplate-depth-50000 -DNDEBUG -o main main.cpp -lgmp -pthread This was what made me believe in the compile-time computation of the factorials in the first place, since using this version, valgrind does not show any dynamic memory allocation at all. On the other hand, I don't understand what's going on here really, especially since std::vector<> is supposed to allocate memory at run-time. Now I'm not sure whether the last example has anything to do with Boost.Multiprecision anymore, so while it would really make my day if you could help me better understand this, I will understand if this is not the right place to ask these questions. Thanks again for your replies so far, they have been of great help! Cheers, Max

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[gsoc16] ATTN: Project ideas deadline 19th Feb
by Niall Douglas 07 Feb '16

07 Feb '16

Tomorrow 8th February the application period for Google Summer of Code 2016 begins, and yet we have just *one* idea on the ideas page: https://svn.boost.org/trac/boost/wiki/SoC2016 We need *plenty* more if we are to be approved again this year as a Google Summer of Code org, the deadline for which is the 19th February. So if you have some project ideas and think you could mentor a student this summer, *please* consider adding a project idea to the ideas list or stepping forward with a list of Boost libraries or topics you'd be willing to mentor. Our thanks in advance. --- Boost C++ Libraries Google Summer of Code 2016 admin https://svn.boost.org/trac/boost/wiki/SoC2016

1 0

download from sourceforge?
by Dan Bloomquist 07 Feb '16

07 Feb '16

I followed the link form boost.org and then through sourceforge. But sourceforge directed me to: <http://downloadbud.com/?adprovider=sourceforge_fwint&source=fw36_300x250-do…> The link is an executable! I've never heard of 'downloadbud'. Not a big deal for now, I'm running with 1.58. But I'd like to get the latest of spirit x3 before I ask questions on the spirit list that may not need asking. Is there another source for boost? Or, is this executable actually a safe extractor? Sourceforge handing over an exe when it should be be a package seems just wrong... Thanks, Dan.

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Boost and v8
by Daniel Burchardt 06 Feb '16

06 Feb '16

Hi, I try create v8 module to python used boost and i have problem: #include <iostream> using namespace std; #include <stdio.h> #include <stdlib.h> #include <string.h> #include "include/libplatform/libplatform.h" #include "include/v8.h" using namespace v8; const char* say_hello(const char* name) { return name; } #include <boost/python/module.hpp> #include <boost/python/def.hpp> #include <boost/python/class.hpp> using namespace boost::python; BOOST_PYTHON_MODULE(hello) { class_<V8, boost::noncopyable>("V8", no_init) .def("Initialize", &V8::Initialize).staticmethod("Initialize"); def("say_hello", say_hello); } compile process is ok but when i try import hello in python i see error: /hello.so: undefined symbol: _ZN2v82V810InitializeEv Thanks for help

2 1

[MSM][MPL] Can't compile FSM with > 20 transitions (solved)
by Carlos Santos 05 Feb '16

05 Feb '16

Hi there, I am using boost v1.59 and I am having trouble in compiling a MSM state machine with more than 20 transitions. I followed the Q&A and added the following lines BEFORE any boost include: #define BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS #define BOOST_MPL_LIMIT_VECTOR_SIZE 30 // or whatever you need #define BOOST_MPL_LIMIT_MAP_SIZE 30 // or whatever you need but now instead of getting the previous error: error: wrong number of template arguments (21, should be 20) I get this one: /usr/local/include/boost/multi_index/tag.hpp:75:67: error: wrong number of template arguments (30, should be 20) mpl::vector<BOOST_PP_ENUM_PARAMS(BOOST_MULTI_INDEX_TAG_SIZE,T)>, I was just finishing this email when I found a solution. Adding only the following header #include "boost/mpl/vector/vector30.hpp" and explicitly declaring the transition table as a numbered mpl::vector (yep you have to count the rows...) struct transition_table : mpl::vector21< ... > solves the problem. Can you suggest me a better solution for this? Thanks! *Carlos Santos *

1 0

[Test] BOOST_CHECK_EQUAL can't compare scoped enumerations
by Merrill Cornish 05 Feb '16

05 Feb '16

I'm running Windows 10, 64-bit, MinGW64 with GCC 5.3 64-bit, and BOOST_1_60_0 64-bit. Here is the stripped down version of what's failing: enum class UsedFor { NOTIFY_INPUT, CONST_INPUT, VAR_INPUT, NOTIFY_RESULT, VAR_RESULT}; UsedFor mUse = UsedFor::NOTIFY_INPUT; BOOST_CHECK(mUse == Operand::UsedFor::NOTIFY_INPUT); // BOOST_CHECK_EQUAL(mUse, Operand::UsedFor::NOTIFY_INPUT); If BOOST_CHECK_EQUAL() is commented out, BOOST_CHECK() complies and executes without error. However, // BOOST_CHECK(mUse == Operand::UsedFor::NOTIFY_INPUT); BOOST_CHECK_EQUAL(mUse, Operand::UsedFor::NOTIFY_INPUT); If BOOST_CHECK() is comment out, BOOST_CHECK_EQUAL() gets a template barf with the general comment, " template argument deduction/substitution failed:". Here are some of the complaints: D:\Boost_1_60_0/boost/test/tools/detail/print_helper.hpp:50:14: note: cannot convert 't' (type 'const DiGSE::Operand_Class_Test_Suite::Operand_Default_Constructor_Test::test_method()::UsedFor') to type 'std::_Setw' ostr << t; ^ D:/Program Files/mingw-w64/x86_64-5.3.0-posix-seh-rt_v4-rev0/mingw64/x86_64-w64-mingw32/include/c++/iomanip:208:5: note: candidate: template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, std::_Setprecision) operator<<(basic_ostream<_CharT, _Traits>& __os, _Setprecision __f) D:\Boost_1_60_0/boost/test/tools/detail/print_helper.hpp:50:14: note: cannot convert 't' (type 'const DiGSE::Operand_Class_Test_Suite::Operand_Default_Constructor_Test::test_method()::UsedFor') to type 'std::_Setprecision' ostr << t; ^ At this point, it seems to be complaining about every io manipulator in existence. D:\Boost_1_60_0/boost/test/tools/detail/print_helper.hpp:50:14: note: mismatched types 'const std::piecewise_linear_distribution<_RealType>' and 'const DiGSE::Operand_Class_Test_Suite::Operand_Default_Constructor_Test::test_method()::UsedFor' ostr << t; Then it gets to the point of, apparently, dragging out all of the error messages it doesn't get to use very often: mismatched types*'const std::chi_squared_distribution<_RealType>' *and 'const DiGSE::Operand_Class_Test_Suite::Operand_Default_Constructor_Test::test_method()::UsedFor' ostr << t; ^ For the time being, I can simply use the explicit == check, but it looks like there's a problem here. Merrill Cornish

2 3

[ANN] build2 - C++ build toolchain
by Boris Kolpackov 03 Feb '16

03 Feb '16

Hi, build2 is an open source, cross-platform toolchain for building and packaging C++ code. It includes a build system, package manager, and repository web interface. We've also started cppget.org, a public repository of open source C++ packages. This is the first alpha release and currently it is more of a technology preview rather than anything that is ready for production. We have tested this version on various Linux'es, Mac OS, and FreeBSD. There is no Windows support yet (but cross-compilation is supported). The project's page is: https://build2.org For those who need to see examples right away, here is the introduction: https://build2.org/build2-toolchain/doc/build2-toolchain-intro.xhtml Enjoy, Boris

1 0

BOOST_LOG_TRIVIAL destination change
by Marc Paschover 02 Feb '16

02 Feb '16

I am working on a native Excel add-in (using XLW+), and I have been using Boost.Logging to output some diagnostic information, using BOOST_LOG_TRIVIAL. I would like to see this information in the Output window of Visual Studio. It seems like I somehow need to change the destination to boost::logging::destination::dbg_window, but I haven't been able to figure out a way to do this globally. Is there a way to do this? Thanks, Marc.

1 0

Boost 1.60: boost::archive::iterators bug?
by Ernest Zaslavsky 02 Feb '16

02 Feb '16

Hi, Recently I've noticed that Base64 encoded data produced by implementation I use and implementation used by chromium project sometimes are not the same. It happened only once but it was enough for me to start worrying. The implementation is quite simple, and I guess borrowed it from somewhere, like SO or something. The code as following: using it_base64_t = bai::base64_from_binary<bai::transform_width<std::string::const_iterator, 6, 8>>; namespace bai = boost::archive::iterators; auto writePaddChars = (3 - input.length() % 3) % 3; std::string base64(it_base64_t(input.begin()), it_base64_t(input.end())); base64.append(writePaddChars, '='); simple and elegant. However, today I wrote a short test which takes a chapter from 'Alice's Adventures in Wonderland' and encodes it. As well, I used two different online encoder to encode the same text, both online encoders produce the same data. However above code produced the same code until character 1029 and then it is different from what it should be. Then later, it gets back to the same output as produced by online encoders. So my question is, any chance it is a bug in archive::iterators or it is something in the above code? Coliru is down, so, full code is here http://pastebin.com/JxMsMeV2 [Read More]<http://feeds.feedburner.com/~r/sizmek-blog/~6/1> [http://www.sizmek.com/Sizmek.png]<http://www.sizmek.com/>

1 0

Building Boost 1.60 with VS2015 - 32 bit compiler is always selected
by Tiago Gehring 01 Feb '16

01 Feb '16

Hi, I'm trying to build Boost 1.60 with Visual Studio 2015 Update 1 in 64-bit mode but it seems to be ignoring the address-model=64 parameter and always builds a 32-bit version (I called b2 from the VS2015 Native tools for x64 command prompt): -- C:\Users\Tiago\code\boost_1_60_0>*b2 --toolset=msvc-14.0 variant=release link=static threading=multi address-model=64 architecture=x86* Performing configuration checks *- 32-bit : yes* - arm : no - mips1 : no - power : no - sparc : no - x86 : yes .... C:\Users\Tiago\code\boost_1_60_0>*cl* Microsoft (R) C/C++ Optimizing Compiler *Version 19.00.23506 for x64* Copyright (C) Microsoft Corporation. All rights reserved. usage: cl [ option... ] filename... [ /link linkoption... ] --- I saw in some ond discussion mentions to explicitly select the compiler version (I also have VS2010 and VS2012 installed) and environment variables batch file (in the project-config.jam file) but this didn't help either. Any help is really appreciated. Best regards, Tiago Gehring

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Re: [Boost-users] asio: implementing sock->receive like behavior eith async_read_some
by Bjorn Reese 01 Feb '16

01 Feb '16

On 01/28/2016 01:56 PM, Lloyd wrote: > I am using asio to read some data from SSL socket. asio tcp socket > implements a "receive" function, but ssl socket doesn't have an > implementation for "receive". In the code sample given below I wish to > implement this kind of behavior. > > eg > > { > ... > sock.async_read_some(...); > //continue the execution only after the above call finishes. > } Why are you using an asynchronous operation instead of simply calling ssl::stream::read_some()?

2 1

C++Now 2016 Registration is Open
by Jon Kalb 28 Jan '16

28 Jan '16

Boost Users, Registration is now open for this year¹s C++Now (put on by Boost). http://cppnow.org/2016-conference/announcements/2016/01/28/registration-is-o pen.html The conference has sold out the last three years and is expect to do say again this year. Do not put off registering. Note that session submitters should not register until they receive instructions from Marshall Clow, our conference registrar. See you in Aspen! Jon

1 0

asio: implementing sock->receive like behavior eith async_read_some
by Lloyd 28 Jan '16

28 Jan '16

Hi, I am using asio to read some data from SSL socket. asio tcp socket implements a "receive" function, but ssl socket doesn't have an implementation for "receive". In the code sample given below I wish to implement this kind of behavior. eg { ... sock.async_read_some(...); //continue the execution only after the above call finishes. } Whats the best way to do this? I tried "future" but the code blocks/dead locks some how, The I tried "spawn", but in this case also I don't know the method to wait for the coroutine to finish. Some tips are greatly appreciated. Thanks, Lloyd

1 0

[Boost.LexicalCast] problem with 1.59 in Solaris
by dariomt＠gmail.com 28 Jan '16

28 Jan '16

Trying to compile file libs/date_time/src/gregorian/greg_month.cpp I get an error related to Boost.LexicalCast. I have reduced the problem to a minimal test case: #include <string> #include <boost/lexical_cast.hpp> void f(const char* s) { std::string s1(boost::lexical_cast<std::string>(s)); } My feeling is that this compiler has problems in the specializations for boost::detail::is_stdstring and boost::detail::is_char_array_to_stdstring. If I remove all those specializations the error goes away. I assume this is not the perfect solution because I guess this will miss some optimization of lexical_cast, but at least I can compile it this way :( Is there a better solution for this? Has this problem been fixed in 1.60? Error message (full instantiation stack available if needed): "/ThirdPartyLibs/boost/1_59_0/boost/lexical_cast/try_lexical_convert.hpp", line 146: Error: Ambiguous partial specialization for boost::detail::is_char_array_to_stdstring<std::string, const char*>, boost::detail::is_char_array_to_stdstring<boost::container::basic_string<boost::detail::CharT, boost::detail::Traits, boost::detail::Alloc>, const boost::detail::CharT*> and boost::detail::is_char_array_to_stdstring<std::basic_string<boost::detail::CharT, boost::detail::Traits, boost::detail::Alloc>, const boost::detail::CharT*>. "/ThirdPartyLibs/boost/1_59_0/boost/lexical_cast.hpp", line 42: Where: While instantiating "boost::conversion::detail::try_lexical_convert<std::string, const char*>(const char*const&, std::string &)". "/ThirdPartyLibs/boost/1_59_0/boost/lexical_cast/try_lexical_convert.hpp", line 134: Error: Ambiguous partial specialization for boost::detail::is_stdstring<std::string>, boost::detail::is_stdstring<boost::container::basic_string<boost::detail::CharT, boost::detail::Traits, boost::detail::Alloc>> and boost::detail::is_stdstring<std::basic_string<boost::detail::CharT, boost::detail::Traits, boost::detail::Alloc>>. "/ThirdPartyLibs/boost/1_59_0/boost/lexical_cast.hpp", line 42: Where: While instantiating "boost::conversion::detail::try_lexical_convert<std::string, const char*>(const char*const&, std::string &)".

5 9

Regression with boost::python 1.60
by Emmanuel 28 Jan '16

28 Jan '16

Hello, I am not sure if this is the right place to do it, but I will try :-). I am having a regression in boost 1.60, I documented a small reproducer here: http://stackoverflow.com/questions/35056398/typeerror-when-iterating-over-a… Does anyone have a clue ? Cheers, Emmanuel

1 0

[Odeint] Stiff System of differential equations
by jules 25 Jan '16

25 Jan '16

Hi all, I am currently working with a very large set of differential equations; it is a disease model with 20160 classes depending on which vaccine has been admnistered, history of infection, and age. To solve this I have been using the runge_kutta_fehlber78 controlled stepper with the integrate_const function. There I need to set the absolute_error, relative_error and the step_size. My issue is that the results from the solver seems to depend highly on the step_size and whether or not an observer is provided. Since the solver is adaptive I feel like the results should not depend on step_size and they should definitely not depend on the presence of an observer. My question is why would the results be related to the step_size or the observer? How would it be possible to get the same results regardless of the step_size and the presence of an observer? Could this be related to the system being stiff and if so how would it be possible to solve it (The jacobian is too complicated to calculate because of the population dynamics)? Any help would be appreciated. Many thanks, Jules

3 5

BGL, shortest path between two nearby nodes in a huge graph
by Paolo Bolzoni 25 Jan '16

25 Jan '16

Dear list, I am a happy user of BGL, but recently I got stuck in a strange problem. I think I am missing the obvious, so I'll be happy to read the fine manual if it's the case. Just point me to the right direction. I need to find the shortest path between two nodes, for doing so I am using dijkstra with a custom visitor that stops the search (throwing an exception) when examine_vertex is called on the destination node. It worked fine, but it run strangely slow. After some profiling, it is clear that most of the time is used in the initialize_vertex function. The graph is fairly large, but the path I am looking for are fairly small (10 edges tops usually). It is possible to skip the initialize phase? Cheers, Paolo

3 5

Some help for betweenness centrality for undirected weighted graph
by Xinran Wang 25 Jan '16

25 Jan '16

Hi everyone, this is from Jason. I am a new user of Boost library. Nowadays, I am doing a research about betweenness centrality measure. I am very confused about how to use boost to calculate the betweenness centrality. I need to calculate the centrality score based on a undirected and weighted graph. The following code is what I tried to do. But this block of code can only be used for calculated for unweighted graph. Could anyone here can offer me examples? Thanks for any reply. #include <boost/graph/betweenness_centrality.hpp> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/graphviz.hpp> typedef boost::property<boost::edge_weight_t, float> EdgeWeightProperty; typedef boost::adjacency_list < boost::listS, boost::vecS, boost::undirectedS, boost::no_property, EdgeWeightProperty > Graph; typedef boost::graph_traits < Graph >::vertex_descriptor vertex_descriptor; typedef boost::graph_traits < Graph >::edge_descriptor edge_descriptor; typedef std::pair<int, int> Edge; typedef std::map<Edge, int> StdEdgeIndexMap; void betweennessCentrality() { Graph g; Graph::vertex_descriptor a1 = boost::add_vertex(g); Graph::vertex_descriptor a2 = boost::add_vertex(g); Graph::vertex_descriptor a3 = boost::add_vertex(g); Graph::vertex_descriptor a4 = boost::add_vertex(g); Graph::vertex_descriptor a5 = boost::add_vertex(g); Graph::vertex_descriptor a6 = boost::add_vertex(g); Graph::vertex_descriptor a7 = boost::add_vertex(g); EdgeWeightProperty weight0 = 1; boost::add_edge(a1, a2, weight0, g); EdgeWeightProperty weight1 = 1; boost::add_edge(a1, a3, weight1, g); EdgeWeightProperty weight2 = 1; boost::add_edge(a2, a3, weight2, g); EdgeWeightProperty weight3 = 1; boost::add_edge(a3, a4, weight3, g); EdgeWeightProperty weight4 = 1; boost::add_edge(a4, a5, weight4, g); EdgeWeightProperty weight5 = 1; boost::add_edge(a5, a6, weight5, g); EdgeWeightProperty weight6 = 1; boost::add_edge(a5, a7, weight6, g); EdgeWeightProperty weight7 = 1; boost::add_edge(a6, a7, weight7, g); typedef boost::property_map< Graph, boost::vertex_index_t>::type VertexIndexMap; VertexIndexMap v_index = get(boost::vertex_index, g); std::vector< double > v_centrality_vec(boost::num_vertices(g), 0.0); boost::iterator_property_map< std::vector< double >::iterator, VertexIndexMap > v_centrality_map(v_centrality_vec.begin(), v_index); brandes_betweenness_centrality( g, v_centrality_map); }

1 0

[math/stat] generating t-distributed random numbers
by U.Mutlu 22 Jan '16

22 Jan '16

Hi, I've an old code that creates a normal-distributed random number between 0 and 1 (by using the polar method). Is it possible to convert this number to a t-distributed number (with v=5) using boost? Or, alternatively: how to generate t-distributed random numbers in the range 0 to 1 with v=5 (ie. degrees of freedom = 5) in boost?

1 1

[fusion] [mpl] binary MPL transform on empty fusion vectors
by Nathan Ridge 22 Jan '16

22 Jan '16

Hi, I've run into an error in code involving MPL and Fusion which I've reduced to the following: #include <boost/mpl/transform.hpp> #include <boost/fusion/container/vector.hpp> #include <boost/fusion/mpl.hpp> struct predicate { template <typename T, typename U> struct apply { typedef T type; }; }; typedef boost::mpl::transform< boost::fusion::vector<>, boost::fusion::vector<>, predicate> ::type Result; This simple piece of code tries to perform a binary MPL transform on two fusion vectors of size 0. It produces the error reproduced below, with both gcc 5.1 and clang 3.7. My boost version is 1.60. I'm quite sure that this used to work with an older boost and compiler version combination, though I don't recall which exactly (something in the vicinity of boost 1.54 / gcc 4.8). Did I run into a regression, or should I not be expecting this to work in the first place? Should I be special-casing zero-length vectors? Thanks, Nate In file included from test.cpp:2: In file included from boost/include/boost/fusion/container/vector.hpp:12: In file included from boost/include/boost/fusion/container/vector/vector.hpp:28: In file included from boost/include/boost/fusion/container/vector/detail/at_impl.hpp:12: boost/include/boost/fusion/container/vector/detail/value_at_impl.hpp:50:57: error: no matching function for call to 'value_at_impl' typedef typename mpl::identity<decltype(seq::template value_at_impl<N::value>(boost::declval<seq*>()))>::type::type type; ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ boost/include/boost/fusion/container/vector/detail/value_of_impl.hpp:30:61: note: in instantiation of template class 'boost::fusion::extension::value_at_impl<boost::fusion::vector_tag>::apply<boost::fusion::vector<>, mpl_::int_<0>>' requested here typedef typename value_at_impl<vector_tag>::template apply<vector, index>::type type; ^ boost/include/boost/fusion/iterator/value_of.hpp:52:15: note: in instantiation of template class 'boost::fusion::extension::value_of_impl<boost::fusion::vector_iterator_tag>::apply<boost::fusion::vector_iterator<boost::fusion::vector<>, 0>>' requested here : extension::value_of_impl<typename detail::tag_of<Iterator>::type>:: ^ boost/include/boost/fusion/iterator/mpl/fusion_iterator.hpp:47:45: note: in instantiation of template class 'boost::fusion::result_of::value_of<boost::fusion::vector_iterator<boost::fusion::vector<>, 0>>' requested here typedef typename fusion::result_of::value_of<Iterator>::type type; ^ boost/include/boost/mpl/iterator_category.hpp:27:22: note: in instantiation of template class 'boost::mpl::fusion_iterator<boost::fusion::vector_iterator<boost::fusion::vector<>, 0>>' requested here typedef typename Iterator::category type; ^ boost/include/boost/mpl/pair_view.hpp:152:20: note: in instantiation of template class 'boost::mpl::iterator_category<boost::mpl::fusion_iterator<boost::fusion::vector_iterator<boost::fusion::vector<>, 0>>>' requested here typename iterator_category<iter1_>::type ^ boost/include/boost/mpl/aux_/has_tag.hpp:20:1: note: in instantiation of template class 'boost::mpl::pair_view<boost::fusion::vector<>, boost::fusion::vector<>>' requested here BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(has_tag, tag, false) ^ boost/include/boost/mpl/has_xxx.hpp:245:65: note: expanded from macro 'BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF' , boost::mpl::aux::type_wrapper<BOOST_MSVC_TYPENAME U::name>* = 0 \ ^ boost/include/boost/mpl/aux_/has_tag.hpp:20:1: note: while substituting deduced template arguments into function template 'test' [with U = boost::mpl::pair_view<boost::fusion::vector<>, boost::fusion::vector<>>] BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(has_tag, tag, false) ^ boost/include/boost/mpl/has_xxx.hpp:253:18: note: expanded from macro 'BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF' sizeof(gcc_3_2_wknd::test(static_cast<t_*>(0))) \ ^ boost/include/boost/config/suffix.hpp:394:72: note: expanded from macro 'BOOST_STATIC_CONSTANT' # define BOOST_STATIC_CONSTANT(type, assignment) static const type assignment ^ boost/include/boost/mpl/sequence_tag.hpp:112:30: note: in instantiation of template class 'boost::mpl::aux::has_tag<boost::mpl::pair_view<boost::fusion::vector<>, boost::fusion::vector<>>, mpl_::bool_<false>>' requested here ::boost::mpl::aux::has_tag<Sequence>::value ^ boost/include/boost/mpl/O1_size.hpp:30:30: note: in instantiation of template class 'boost::mpl::sequence_tag<boost::mpl::pair_view<boost::fusion::vector<>, boost::fusion::vector<>>>' requested here : O1_size_impl< typename sequence_tag<Sequence>::type> ^ boost/include/boost/mpl/fold.hpp:34:25: note: in instantiation of template class 'boost::mpl::O1_size<boost::mpl::pair_view<boost::fusion::vector<>, boost::fusion::vector<>>>' requested here ::boost::mpl::O1_size<Sequence>::value ^ boost/include/boost/mpl/transform.hpp:75:7: note: in instantiation of template class 'boost::mpl::fold<boost::mpl::pair_view<boost::fusion::vector<>, boost::fusion::vector<>>, boost::fusion::vector<>, boost::mpl::bind2<boost::mpl::push_back<mpl_::na, mpl_::na>, mpl_::arg<1>, boost::mpl::bind2<predicate, boost::mpl::bind1<boost::mpl::first<mpl_::na>, mpl_::arg<2>>, boost::mpl::bind1<boost::mpl::second<mpl_::na>, mpl_::arg<2>>>>>' requested here : fold< ^ boost/include/boost/mpl/transform.hpp:114:1: note: in instantiation of template class 'boost::mpl::aux::transform2_impl<boost::fusion::vector<>, boost::fusion::vector<>, predicate, boost::mpl::back_inserter<boost::fusion::vector<>>>' requested here BOOST_MPL_AUX_INSERTER_ALGORITHM_DEF(4, transform2) ^ boost/include/boost/mpl/aux_/inserter_algorithm.hpp:52:7: note: expanded from macro 'BOOST_MPL_AUX_INSERTER_ALGORITHM_DEF' : if_< has_push_back< typename clear<P1>::type> \ ^ boost/include/boost/mpl/eval_if.hpp:38:22: note: in instantiation of template class 'boost::mpl::transform2<boost::fusion::vector<>, boost::fusion::vector<>, predicate, mpl_::na>' requested here typedef typename f_::type type; ^ boost/include/boost/mpl/transform.hpp:138:1: note: in instantiation of template class 'boost::mpl::eval_if<boost::mpl::or_<boost::mpl::is_na<predicate>, boost::mpl::is_lambda_expression<boost::fusion::vector<>>, boost::mpl::not_<boost::mpl::is_sequence<boost::fusion::vector<>>>, mpl_::bool_<false>, mpl_::bool_<false>>, boost::mpl::transform1<boost::fusion::vector<>, boost::fusion::vector<>, predicate>, boost::mpl::transform2<boost::fusion::vector<>, boost::fusion::vector<>, predicate, mpl_::na>>' requested here AUX778076_TRANSFORM_DEF(transform) ^ boost/include/boost/mpl/transform.hpp:125:22: note: expanded from macro 'AUX778076_TRANSFORM_DEF' typedef typename eval_if< \ ^ test.cpp:13:17: note: in instantiation of template class 'boost::mpl::transform<boost::fusion::vector<>, boost::fusion::vector<>, predicate, mpl_::na>' requested here boost::mpl::transform< ^ boost/include/boost/fusion/container/vector/vector.hpp:275:30: note: candidate template ignored: could not match 'store' against 'vector' mpl::identity<U> value_at_impl(store<N, U>*); ^

2 2

Boost Log: Use of operator<<
by Florian Lindner 21 Jan '16

21 Jan '16

Hello, I want to put a custom object called DynamicVector on the BOOG_LOG_SEV stream. For that I defined an operator<< template<typename Vector> typename std::enable_if<tarch::la::IsVector<Vector>::value, std::ostream&>::Type operator<< (std::ostream & os, const Vector & vector); IsVector<Vector> will be true, since template<typename Scalar> struct IsVector<DynamicVector<Scalar> > { static const int value = true; }; The operator itself is working: // getCoords returns a DynamicVector<double> std::cout << inMesh->vertices()[j].getCoords(); // compiles just fine. but BOOST_LOG_SEV(_log, boost::log::trivial::severity_level::error) << inMesh->vertices()[j].getCoords(); gives an compile error: /usr/include/boost/log/utility/formatting_ostream.hpp:799:19: error: invalid operands to binary expression ('ostream_type' (aka 'basic_ostream<char_type, traits_type>') and 'const tarch::la::DynamicVector<double>') strm.stream() << value; str.stream() seems to be an ostream_type which is an basic_ostream<char_type, traits_type>. I wonder why this isn't convertible to std::ostream, like http://stackoverflow.com/questions/17269499/overloading-operator-for-boost-… and the comment at http://www.boost.org/doc/libs/1_54_0/boost/log/utility/formatting_ostream.h… suggest. Any help appreciated! Thanks, Florian

1 0

Re: [Boost-users] [boost] Boost.Operators issue: polluting namespace of caller through argument-dependent lookup
by John M. Dlugosz 21 Jan '16

21 Jan '16

On 1/20/2016 10:41 AM, Daniel Frey wrote: > In a way it makes library collections like Boost harder and I still think you should use > qualified lookup in your specific case, No, I specifically don't want to qualify every use, as explained originally. The code needs compatibility with some configurations that require the tr1 namespace and others that prohibit it. Qualifying every reference is bad; rather, import them in one place. You are basically saying that `using N::foo;` is never right because someone may happen to use the name foo in an unrelated library and ADL is a misfeature? I think that doesn't scale. It should be SOP to isolate classes that are meant to be used as base classes by library consumers, and treat unqualified lookup of names pulled in to the local scope via `using` as something that is a useful feature that ought to work. > but as I already said in another mail I’m willing to fix it. I just need to figure out > where to commit and merge stuff as the last time I worked on it we were still using svn > and the branching model was different. I hope to be able to find the time somewhere in > the next days. Regards, Daniel Looking forward to it in 1.62 or whatever. Thanks! —John

1 0

[locale] boost::locale::format number formatting on OS X and Windows
by Michael Smith 21 Jan '16

21 Jan '16

Using Boost.Locale from Boost 1.60.0 (installed via homebrew, so it uses icu) on Mac OS X 10.11.2, I seem to be getting unexpected behavior for some of the boost::format number formatting. A short example program #include <boost/locale.hpp> int main(int argc, char** argv) { boost::locale::format fmt("{1,number} should be 1,25."); fmt % 1.25; boost::locale::generator gen; std::cout << fmt.str(gen("fr-fr.UTF-8")) << std::endl; return 0; } That produces 1,25 on Linux, and 1.25 on Windows (using mingw-w64) and Mac. Any idea why they'd represent it differently?

1 0

Re: [Boost-users] Using Coroutines in the Visitor Pattern (use-case: BGL event visitor)
by alex 20 Jan '16

20 Jan '16

>-----Original Message----- >From: Boost-users [mailto:boost-users-bounces@lists.boost.org] On Behalf Of >Daniel Hofmann >Sent: 17 November 2015 15:55 >To: boost-users(a)lists.boost.org >Subject: [Boost-users] Using Coroutines in the Visitor Pattern (use-case: BGL >event visitor) > >(Disclaimer: this is not only specific to BGL, I can think of similar >use-cases where the visitor pattern is used --- I will still explain it >in the BGL context, as it is probably easier to understand) > > >Suppose you have a BGL graph and want to implement s-t shortest path >queries. It is possible to do this by using a bi-directional approach, >that is starting a Dijkstra search [1] from the start and starting a >additional Dijkstra search from the target. As soon as they "meet in the >middle", you can unpack the two sub-paths. > >[snip] > >It then came to my mind that I could use Coroutines for cooperative >multitasking, without the downsides that come with threading. > >My idea was to invert the callbacks using Coroutines as it is shown in >the SAX parsing example [3], in order to get a lazy range of vertices >each visitor examines. I then could simply walk the two ranges, >terminating as soon as there is the same element in both. Jeremiah Willcock gave a good description of how this could work: http://lists.boost.org/Archives/boost/2012/07/195300.php The way he describes it is really using coroutines instead of the visitor pattern. > > >But due to way the dijkstra_shortest_path function adds an additional >level of indirection I failed to implement this, and I have strong >doubts that it is possible with Coroutines at all. I> >I'm mainly struggling with wrapping my head around stopping and resuming >the dijkstra_shortest_path function, when all I can modify is the >visitor it takes. That is, the reason I can not make it work is that I >can not launch two dijkstra_shortest_path functions asynchronously with >just Coroutines. > I think there are two options: 1. Let your visitor throw an exception to get out of the dijkstra shortest path function; use some version of the function that skips initialization to resume again (the existing dijkstra_shortest_path_no_init is not good enough, so you would have to make one). 2. Reimplement the dijkstra function as a coroutine. I have implemented both, but have only really used option 1; whereas option 2 remained a toy experiment. In both cases the tricky part was to properly initialize and keep track of(and not re-initialize on resume) all parameters that are input to the dijkstra function, i.e. color_map, queue, distance_map, etc. https://github.com/ahhz/resumable_dijkstra I used the lightweight stackless coroutine of Boost ASIO. http://www.boost.org/doc/libs/1_59_0/doc/html/boost_asio/reference/coroutine .html >The control flow I need would probably look like this: start the first >Dijkstra search, on its first vertex it visits, "jump back out" and >start the second Dijkstra visitor. From there on ping-pong between the >two visitors exclusively. And I'm not sure this is possible with the >Coroutine approach. > It depends how much you are willing to re-implement. It is possible in principle >I appreciate any tips in this regard, even if it's a "just use your 15 >lines of threading code instead of trying to be fancy" :) > I think it would be great to have a fancy solution for this in BGL.

3 14

boost serialization
by Виктория Доможакова 20 Jan '16

20 Jan '16

I use boost serialization in my project. I I conducted f an experiment: 1) I removed one line with the data in the boost archive file. 2) I started my project. 3) All variables initialized in the constructor. 4) Value of variables loaded from boost archive in order . 5) When queue comes to removing values , I get exeption (I handle exeption with try-catch ) and file didn't read to end and close. 6) But this variable is equal to the value next after removal . My question: why this variable is equal to the value next after removal . if this variable has value from constructor than it is more logic. -- Виктория Доможакова

1 0

[gsoc16] Attn: We need 2016 mentors and project ideas for Boost!
by Niall Douglas 20 Jan '16

20 Jan '16

Dear Boost community, We are now within one month of the beginning of Google Summer of Code 2016! Last year's GSoC was a particularly momentus one as we witnessed the approval by the community for Boost.Hana to enter Boost - congratulations to Louis and his mentor Joel for bringing to Boost a very exciting new C++ library which pushes C++ compilers to their limits. We have also seen greatly improved retention of GSoC students in the community thanks to the improved student selection procedures introduced last year, and the fresh blood brought into Boost has been very evident on the mailing list this year. As part of filling in our application for 2016, we must supply to Google a list of potential GSoC mentors and potential GSoC projects for summer 2016 in order to be approved as an organisation this year. Therefore a lengthy page of awesome project ideas at https://svn.boost.org/trac/boost/wiki/SoC2016 before *February 8th* would be an enormous help to getting us approved again this year and bringing to Boost another US$35,000 of Google funding. 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 had more slots awarded to us by Google than we had good combinations of student and mentor, so we had to return slots which I believe has not happened here at Boost GSoC in at least a decade. That means that your project ideas have a better chance than ever of receiving funding if you can find a good student, and that is best done by getting project ideas floated *early*. 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 or via gsoc-admin(a)boost.org. Thank you in advance for your time. --- Boost C++ Libraries Google Summer of Code 2016 admin https://svn.boost.org/trac/boost/wiki/SoC2016

2 1

Using Coroutines in the Visitor Pattern (use-case: BGL event visitor)
by Daniel Hofmann 19 Jan '16

19 Jan '16

(Disclaimer: this is not only specific to BGL, I can think of similar use-cases where the visitor pattern is used --- I will still explain it in the BGL context, as it is probably easier to understand) Suppose you have a BGL graph and want to implement s-t shortest path queries. It is possible to do this by using a bi-directional approach, that is starting a Dijkstra search [1] from the start and starting a additional Dijkstra search from the target. As soon as they "meet in the middle", you can unpack the two sub-paths. In terms of the BGL this would roughly look like the following (simplified, with synchronization and visitor omitted): Vertex middle; async(dijkstra_shortest_paths(g, start, visitor(v{middle}))); async(dijkstra_shortest_paths(g, target, visitor(v{middle}))); where the visitors single-step all vertices in their examine_vertex callback [2] and check if they met in the middle. While this is quite easy to implement with threading, is has its downsides, mainly in synchronization for this ping-pong play between the two visitors, resulting in contention on the synchronization locks. But also the overhead of using threads might be too high for smaller graphs. It then came to my mind that I could use Coroutines for cooperative multitasking, without the downsides that come with threading. My idea was to invert the callbacks using Coroutines as it is shown in the SAX parsing example [3], in order to get a lazy range of vertices each visitor examines. I then could simply walk the two ranges, terminating as soon as there is the same element in both. But due to way the dijkstra_shortest_path function adds an additional level of indirection I failed to implement this, and I have strong doubts that it is possible with Coroutines at all. I'm mainly struggling with wrapping my head around stopping and resuming the dijkstra_shortest_path function, when all I can modify is the visitor it takes. That is, the reason I can not make it work is that I can not launch two dijkstra_shortest_path functions asynchronously with just Coroutines. The control flow I need would probably look like this: start the first Dijkstra search, on its first vertex it visits, "jump back out" and start the second Dijkstra visitor. From there on ping-pong between the two visitors exclusively. And I'm not sure this is possible with the Coroutine approach. I appreciate any tips in this regard, even if it's a "just use your 15 lines of threading code instead of trying to be fancy" :) Cheers, Daniel J H [1] http://www.boost.org/doc/libs/1_59_0/libs/graph/doc/dijkstra_shortest_paths… [2] http://www.boost.org/doc/libs/1_59_0/libs/graph/doc/DijkstraVisitor.html [3] http://www.boost.org/doc/libs/1_59_0/libs/coroutine/doc/html/coroutine/moti…

2 4

Re: [Boost-users] boost.dll winapi compile error
by Elod G 18 Jan '16

18 Jan '16

I was missing the latest winapi module, duh. ElodG On 1/18/2016 19:00, boost-users-request(a)lists.boost.org wrote: > Message: 1 > Date: Sun, 17 Jan 2016 23:12:32 +0200 > From: Elod G <gyelod(a)gmail.com> > To: boost-users(a)lists.boost.org > Subject: [Boost-users] boost.dll winapi compile error > Message-ID: <569C03BF.9030305(a)gmail.com> > Content-Type: text/plain; charset=utf-8 > > Hello All, > > I cloned origin/master of https://github.com/boostorg/dll and copied > include/ to the 1.60 release of boost to give boost.DLL a go. > > I am getting the following compile error when including: "boost/dll.hpp" > boost\dll\detail\windows\shared_library_impl.hpp:140: error: C2039: > 'get_proc_address' : is not a member of 'boost::detail::winapi' > > I am using VS2013. > > What am I missing? > > -- > ElodG

1 0

boost.dll winapi compile error
by Elod G 17 Jan '16

17 Jan '16

Hello All, I cloned origin/master of https://github.com/boostorg/dll and copied include/ to the 1.60 release of boost to give boost.DLL a go. I am getting the following compile error when including: "boost/dll.hpp" boost\dll\detail\windows\shared_library_impl.hpp:140: error: C2039: 'get_proc_address' : is not a member of 'boost::detail::winapi' I am using VS2013. What am I missing? -- ElodG

1 0

multiprecision thread safety
by Daniel Brake 14 Jan '16

14 Jan '16

Hi Boost, I have a couple of questions regarding thread safety and Boost.Multiprecision. I am writing a library, and would like to be able to use mpfr_float (packed into my own complex class) in differing variable precisions on multiple threads simultaneously. 1. Is this supported? I looked in documentation, but didn't find comments to that end. 2. Must I manually call mpfr_free_cache when terminating threads, as recommended by the mpfr documentation? see http://www.mpfr.org/mpfr-current/mpfr.html, section 4.7 memory handling. If so, since Boost.Multiprecision claims to not change the default precision of mpfr_t, do I need to access the particular back end for the thread, and free its cache? Thanks, Daniel Brake danielthebrake(a)gmail.com

2 1

boost 1.55 asio tcp cpp03 chat_server example memory leaks
by Hung Ruo Han 14 Jan '16

14 Jan '16

Hi all i hope someone could give me a clue where to investigate... i'm running the chat_server example from boost http://www.boost.org/doc/libs/1_55_0/doc/html/boost_asio/example/cpp03/chat… on visual studio 2010, windows 10 and i downloaded boost binaries from : http://sourceforge.net/projects/boost/files/boost-binaries/1.55.0/boost_1_5… i used a script to simulate 30 tcp clients, each thread behavior basically: 1. connect to tcp server 2. start a loop 3. send a message to tcp server 4. receive a message from tcp server 5. sleep 6. back to step 2 the strange fact is when i use windows task manager to monitor the memory consumption. The numbers from columns *private working set* and *shared working set* remains "stable" for almost 18 minutes and after that the values of *private working set* starts to increase almost 5 MB by minute. So my doubts are: 1. Does anyone ever seen anything similar before? 2. What could cause this? Regards -- Hung Ruo Han <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> This email has been sent from a virus-free computer protected by Avast. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> <#DDB4FAA8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

1 0

[phoenix] [clang] error assigning function object
by Nathan Ridge 12 Jan '16

12 Jan '16

Hi there, I'm experiencing a compiler error in code that tries to assign a Boost.Phoenix function object returned by invoking a phoenix::function with a std::string as one of the bound parameters. I've reduced my error to the following minimal code: #include <string> #include <boost/phoenix/core/argument.hpp> #include <boost/phoenix/function.hpp> struct S { void operator()(std::string, int) const; }; boost::phoenix::function<S> lazy; auto func1 = lazy(std::string(), boost::phoenix::placeholders::_1); auto func2 = func1; void foo() { func2 = func1; } My compiler version is clang 3.7; the error does not occur with gcc 5.1. The error also goes away if I change the type of the first argument from std::string to a different type (like int). The compiler error is shown below. Any ideas as to what is going on? Am I doing something wrong, or did I run into a bug in Phoenix? Thanks, Nate In file included from test.cpp:81: In file included from /home/nr/dev/dist/boost/include/boost/phoenix/core/argument.hpp:13: In file included from /home/nr/dev/dist/boost/include/boost/phoenix/core/actor.hpp:25: In file included from /home/nr/dev/dist/boost/include/boost/proto/make_expr.hpp:100: In file included from /home/nr/dev/dist/boost/include/boost/proto/detail/make_expr_.hpp:3: /home/nr/dev/dist/boost/include/boost/proto/detail/preprocessed/make_expr_.hpp:73:88: error: no type named 'type' in 'boost::proto::transform<boost::proto::switch_<boost::phoenix::phoenix_generator, boost::proto::tag_of<boost::proto::_> ()>, void>::result<boost::phoenix::phoenix_generator (boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::assign, boost::proto::argsns_::list2<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>>, 2>)>' typedef typename proto_generator::template result<proto_generator(expr_type)>::type result_type; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~ /home/nr/dev/dist/boost/include/boost/proto/make_expr.hpp:180:34: note: in instantiation of template class 'boost::proto::detail::make_expr_<boost::proto::tagns_::tag::assign, boost::phoenix::phoenix_domain, boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, const boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>, void, void, void, void, void, void, void, void, void>' requested here typename detail::make_expr_< ^ /home/nr/dev/dist/boost/include/boost/phoenix/core/actor.hpp:225:36: note: in instantiation of template class 'boost::proto::result_of::make_expr<boost::proto::tagns_::tag::assign, boost::phoenix::phoenix_domain, boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, const boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>, void, void, void, void, void, void, void, void, void>' requested here typename proto::result_of::make_expr< ^ /home/nr/dev/dist/boost/include/boost/phoenix/core/actor.hpp:185:12: note: while substituting deduced template arguments into function template 'operator=' [with A0 = const boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>] struct actor ^ /home/nr/dev/dist/boost/include/boost/proto/matches.hpp:830:44: note: in instantiation of template class 'boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::assign, boost::proto::argsns_::list2<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>>, 2>' requested here : Cases::template case_<typename Expr::proto_tag>::template impl<Expr, State, Data> ^ /home/nr/dev/dist/boost/include/boost/proto/transform/impl.hpp:238:13: note: in instantiation of template class 'boost::proto::switch_<boost::phoenix::phoenix_generator, boost::proto::tag_of<boost::proto::_> ()>::impl<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::assign, boost::proto::argsns_::list2<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>>, 2>, int, boost::proto::envns_::empty_env>' requested here : PrimitiveTransform::template impl<Expr, empty_state, empty_env> ^ /home/nr/dev/dist/boost/include/boost/proto/transform/impl.hpp:255:9: note: in instantiation of template class 'boost::proto::detail::apply_transform<boost::phoenix::phoenix_generator (boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::assign, boost::proto::argsns_::list2<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>>, 2>)>' requested here BOOST_PROTO_TRANSFORM_(PrimitiveTransform, X) ^ /home/nr/dev/dist/boost/include/boost/proto/transform/impl.hpp:194:48: note: expanded from macro 'BOOST_PROTO_TRANSFORM_' typedef typename boost::proto::detail::apply_transform<Sig>::result_type type; \ ^ /home/nr/dev/dist/boost/include/boost/proto/detail/preprocessed/make_expr_.hpp:73:43: note: in instantiation of template class 'boost::proto::transform<boost::proto::switch_<boost::phoenix::phoenix_generator, boost::proto::tag_of<boost::proto::_> ()>, void>::result<boost::phoenix::phoenix_generator (boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::assign, boost::proto::argsns_::list2<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>>, 2>)>' requested here typedef typename proto_generator::template result<proto_generator(expr_type)>::type result_type; ^ /home/nr/dev/dist/boost/include/boost/proto/make_expr.hpp:180:34: note: in instantiation of template class 'boost::proto::detail::make_expr_<boost::proto::tagns_::tag::assign, boost::phoenix::phoenix_domain, boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>, void, void, void, void, void, void, void, void, void>' requested here typename detail::make_expr_< ^ /home/nr/dev/dist/boost/include/boost/phoenix/core/actor.hpp:213:36: note: in instantiation of template class 'boost::proto::result_of::make_expr<boost::proto::tagns_::tag::assign, boost::phoenix::phoenix_domain, boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>, void, void, void, void, void, void, void, void, void>' requested here typename proto::result_of::make_expr< ^ test.cpp:96:8: note: while substituting deduced template arguments into function template 'operator=' [with A0 = boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>] func2 = func1; ^ 1 error generated.

2 3

[Statechart] Implementing an internal timeout in an asynchronous state machine
by John Buonassisi 07 Jan '16

07 Jan '16

Hi there, I am looking for some advice on the best way to implement an internal timeout in an asynchronous state machine using the Boost Statechart library. My project requires an asynchronous state machine that multiple threads can queue events to. The asynchronous state machine will react to events and execute callback functions that are registered on creation of the state machine. So far, this hasn't been a problem, but I have hit a bit of a roadblock when handling timeouts. I need my asynchronous state machine class to start a timer in a certain reaction method, when this timer expires I need the scheduler to queue a timeout event. Basically, the timer will act as an interrupt, when it expires I need a timeout event to be immediately queued to the state machine event queue. Since asynchronous state machines are created and managed by a scheduler class (in my case boost::statechart::fifo_scheduler<>) how can I get the asynchronous state machine to queue a timeout event? If possible, I would like to encapsulate this timeout functionality, so client code that uses my derived asynchronous state machine does not have to deal with managing timeouts. My first thought is to have the asynchronous state machine class create a thread when the timer is started. The thread will continually check if the timer has expired and if it has, will queue a timeout event. The issue with this approach is that I would need to pass the scheduler and state machine handler to the thread function in order to queue the event. Obviously, the state machine does not have access to these objects and I am unsure if this is a safe approach. Any suggestions or help with this matter would be greatly appreciated! This is my first post to the mailing list so I hope this is the right arena for my question. Thanks, John Buonassisi

1 0

*newbie* 'BOOST_INTRUSIVE_HAS_MEMBER_FUNCTION_CALLABLE_WITH_ITERATION' : undeclared identifier
by Gregory Werner 07 Jan '16

07 Jan '16

Hi all new to the list. When trying to build a rather large project which uses boost, I get the following few lines 12 times during the build process: 7>c:\local\boost_1_60_0\boost\intrusive\detail\has_member_function_callable_with.hpp(303): error C2065: 'BOOST_INTRUSIVE_HAS_MEMBER_FUNCTION_CALLABLE_WITH_ITERATION' : undeclared identifier 7>c:\local\boost_1_60_0\boost\intrusive\detail\has_member_function_callable_with.hpp(320): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int 7>c:\local\boost_1_60_0\boost\intrusive\detail\has_member_function_callable_with.hpp(320): error C2143: syntax error : missing ';' before ''template<'' Others can build this same project just fine and I can't find anything on the internet which would indicate others having problems with this file. I am using VS2010 Professional Version with SP1. My compiler and boost libraries are both 32 bit. I tried uninstalling and reinstalling everything but same errors. These are the only errors which prevent my project from successful build. Any ideas as to what could cause this? -Greg

2 1

Feedback boost conan binary packages
by Luis 07 Jan '16

07 Jan '16

Dear Boost Users, Disclaimer: I am founder and developer of conan.io C++ package manager. Please note that it is just a FOSS project, MIT license, fully decentralized, and although I'd like to promote the tool and receive feedback about it, there are already channels for that conversation in the github repos. What I'd really like is to get feedback about the Boost packages I am creating and maintaining in conan. I have generated almost 190 different binary packages for Boost versions 1.57-1.60 ( https://www.conan.io/search?q=Boost%20AND%20user:lasote) for Linux, Win, Mac and different flavours of compilers (gcc 4.7-5.3, VS12-14) and settings (Debug, Release). You can read a quick getting started on such Boost packages in: http://docs.conan.io/en/latest/examples/boost.html If someone has been able to try it, I'd like to know several things: - whether it is interesting to have pre-compiled packages or you always prefer to build from source (i.e. always using the --build option in conan). So far there are about 200 downloads of binary packages, but probably many people prefer to build from source. - It has dependencies to already existing zlib and bzip2 conan packages (can be shared or static). Are you fine with these? Any other Boost dependencies missing that you would like to automate? - It is probably the largest package so far, have you experienced slow downloads? You can report issues and feedback in the conan-boost repo: https://github.com/lasote/conan-boost/issues. Thanks very much, Luis

2 2

boost variant is not a literal type
by Robert Ramey 07 Jan '16

07 Jan '16

I want to use Boost.Variant constexpr function. In order to do this it has to be a literal type - which apparently it isn't. The rule for being a literal type are summarized here: http://en.cppreference.com/w/cpp/concept/LiteralType a boost::variant isn't default constructable so it fails to qualify. Has anyone else had this problem before and managed to solve it in a convenient way? Robert Ramey

3 7

Re: [Boost-users] boost program options
by avib369 . 06 Jan '16

06 Jan '16

With reference to boost 1.59 and program options. The following test passes on boost 1.53, but fails on boost 1.59. I need to able to handle. --arg1 10 and --arg1=10 boost 1.59 now fails on '--arg1 10', with test below with option value being empty. #include <string> #include <iostream> #include <fstream> #include <boost/test/unit_test.hpp> #include <boost/foreach.hpp> #include <boost/program_options.hpp> using namespace std; namespace po = boost::program_options; BOOST_AUTO_TEST_SUITE( BaseTestSuite ) BOOST_AUTO_TEST_CASE( test_program_options_implicit_value ) { cout << "Base:: ...test_program_options_implicit_value\n"; // Declare the supported options. po::options_description desc("Allowed options"); desc.add_options() ("help", "produce help message") ("arg1", po::value<string>()->implicit_value( string("") ), "optional arg1 description") ; { char* argv[] = { const_cast<char*>("test_program_options_implicit_value"), const_cast<char*>("--help"), const_cast<char*>("--arg1") }; po::variables_map vm; po::store(po::parse_command_line(3, argv, desc), vm); po::notify(vm); BOOST_CHECK_MESSAGE(vm.count("help"), "Expected help"); BOOST_CHECK_MESSAGE(vm.count("arg1"), "Expected arg1"); BOOST_CHECK_MESSAGE(vm["arg1"].as<string>() == "", "Expected arg1 to be empty"); } { // ****** This fails on boost 1.59 bit passes in boost 1.53 ******* char* argv[] = { const_cast<char*>("test_program_options_implicit_value"), const_cast<char*>("--arg1"), const_cast<char*>("10") }; po::variables_map vm; po::store(po::command_line_parser(3, argv, desc), vm); po::notify(vm); BOOST_CHECK_MESSAGE(vm.count("arg1"), "Expected arg1"); BOOST_CHECK_MESSAGE(vm["arg1"].as<string>() == "10", "Expected arg1 with value of 10 but found '" << vm["arg1"].as<string>() << "'"); } { char* argv[] = { const_cast<char*>("test_program_options_implicit_value"), const_cast<char*>("--arg1=11") }; po::variables_map vm; po::store(po::parse_command_line(2, argv, desc), vm); po::notify(vm); BOOST_CHECK_MESSAGE(vm.count("arg1"), "Expected arg1"); BOOST_CHECK_MESSAGE(vm["arg1"].as<string>() == "11", "Expected arg1 with value of 11 but found " << vm["arg1"].as<string>()); } } Ta, Avi

2 1

boost program_options
by avib369 . 06 Jan '16

06 Jan '16

There seems to be change/regression in boost program options. In boost/1.53. I used boost::program_options::variables_map vm; po::store( po::parse_command_line( argc, argv, desc_ , po::command_line_style::unix_style ^ po::command_line_style::allow_short), vm ); po::notify( vm ); This could handle arguments like: ./exe --help all ./exe --help summary However from boost 1.59, this no longer works, instead I have to use: ./exe --help=all ./exe --help=summary Is this a known change ? how do i get back to the old functionality ? Ta, Avi

2 1

Boost 1.60.0 breaks Boost.Log formatter on MSVC11
by Robert Rumpf 06 Jan '16

06 Jan '16

I’ve been happily using Boost.Log (and much of the rest of Boost) for years, but on upgrading to 1.60, I find that I get runtime errors on MSVC 11. I’ve tracked the problem back to a simple representative example (as provided with the Boost.Log library): http://www.boost.org/doc/libs/1_60_0/libs/log/example/doc/tutorial_fmt_stre… The problematic portion of the example is the usage of character arrays when setting up the formatter, specifically: << ": <" << "> " The code compiles fine but then throws an exception at runtime, seemingly due to uninitialized data. Removing the strings in the formatter configuration makes the error disappear. I would guess that it has something to do with xvalues going into the formatter unintentionally, but this code has functioned fine on prior versions of Boost 1.59-1.54, and I can find nothing in the release notes that points me at where the problem might be. I am compiling with BOOST_SPIRIT_USE_PHOENIX_V3. Before I start doing lots of diffs, has anyone else experienced this problem, and is there any known solution or workaround? Thanks for all of the excellent work and support, Rob

1 0

[regex] link errors on 1.60 update
by James Walker 06 Jan '16

06 Jan '16

When I tried to convert my project from Boost 1.58.0 to 1.60.0, I got some link errors. This is using Xcode 4.6.3 on Mac OS X 10.7.5. I'm compiling all the sources in libs/regex/src. Help? Undefined symbols for architecture i386: "boost::re_detail_106000::perl_matcher<char const*, std::allocator<boost::sub_match<char const*> >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::construct_init(boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags)", referenced from: boost::re_detail_106000::perl_matcher<char const*, std::allocator<boost::sub_match<char const*> >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::perl_matcher(char const*, char const*, boost::match_results<char const*, std::allocator<boost::sub_match<char const*> > >&, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags, char const*) in BVHJointMap.o boost::re_detail_106000::perl_matcher<char const*, std::allocator<boost::sub_match<char const*> >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::perl_matcher(char const*, char const*, boost::match_results<char const*, std::allocator<boost::sub_match<char const*> > >&, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags, char const*) in AnimationsManager.o "boost::re_detail_106000::perl_matcher<char const*, std::allocator<boost::sub_match<char const*> >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::find()", referenced from: bool boost::regex_search<char const*, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >(char const*, char const*, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags) in BVHJointMap.o "boost::re_detail_106000::perl_matcher<char const*, std::allocator<boost::sub_match<char const*> >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::match()", referenced from: bool boost::regex_match<char const*, std::allocator<boost::sub_match<char const*> >, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >(char const*, char const*, boost::match_results<char const*, std::allocator<boost::sub_match<char const*> > >&, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags) in AnimationsManager.o

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Boost 1.60.0 rc1 is now available
by Marshall Clow 05 Jan '16

05 Jan '16

Release candidate files for 1.60.0 are available at: http://boost.cowic.de/rc/ As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. This helps ensure the candidates build OK before we push them out to SourceForge. The files (and associated md5s) are: MD5 (boost_1_60_0_rc1.7z) = 7ce7f5a4e396484da8da6b60d4ed7661 MD5 (boost_1_60_0_rc1.tar.bz2) = 65a840e1a0b13a558ff19eeb2c4f0cbe MD5 (boost_1_60_0_rc1.tar.gz) = 28f58b9a33469388302110562bdf6188 MD5 (boost_1_60_0_rc1.zip) = 0cc5b9cf9ccdf26945b225c7338b4288 Thanks! -- The release managers P.S. Release notes are here: http://www.boost.org/users/history/version_1_60_0.html

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