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

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

3 4

[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

1 0

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.

1 0

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 |

3 3

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

2 1

[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

1 0

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

1 0

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.

2 3

[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.

6 11

[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

5 5

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?

2 2

[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)

3 3

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?

2 3

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 >

2 4

[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/

1 0

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

1 0

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

3 2

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