- Boost - lists.preview.boost.org

[config] Changes to reflect Visual C++ "15" preview 5
by Beman Dawes 21 Oct '16

21 Oct '16

Boost.Config is current reporting these macros for msvc 14.0 update 3 and later: BOOST_NO_COMPLETE_VALUE_INITIALIZATION Xiang Fan of the VC++ compiler team kindly tested "15" preview 5 against boost without this macro is still getting errors. So this one is still needed. BOOST_NO_CXX11_HDR_CODECVT That's wrong. <codecvt> has been supplied at least since msvc 10.0. I'll submit a P/R. BOOST_NO_CXX14_AGGREGATE_NSDMI Here is a test program, based on the config docs: #include <cassert> struct Foo { int x, y = 42; }; int main() { Foo foo = { 1234 }; assert(foo.y == 42); assert(foo.x == 1234); } That now passed on "15" preview 5, so I'll summit a P/R. BOOST_NO_CXX14_CONSTEXPR The "15" preview 5 release notes say "The most notable compiler changes include complete support for generalized constexpr" I know from conversations with msft folks that they put a lot of effort into constexpr fixes, and that they would like bug reports if anyone is finds constexpr bugs with "15" preview 5. I'll submit a P/R. BOOST_NO_TWO_PHASE_NAME_LOOKUP This one still applies. The backstory has changed a lot, however. Enough progress has been made on the new parser that two phase name lookup should ship next year, and maybe even early next year. But don't hold your breath quite yet. Thanks to Andrew Pardoe for fact checking a draft of this post. --Beman

9 26

Review Manager needed for the C++14 Reflections Library that works Without Macro nor Markup (ex magic_get)
by Antony Polukhin 20 Oct '16

20 Oct '16

Hello, PFR is a C++14 library that represents POD structures as tuples and provides tuple-like methods for PODs. Library has a set of predefined operators for PODs and useful functions for everyday use. Works with user-defined types without any macro nor boilerplate code. Has additional (theoretical) features for C++17. Library: https://github.com/apolukhin/magic_get Docs: http://apolukhin.github.io/magic_get/ Boost Library Incubator: http://blincubator.com/bi_library/pfr-pod-flat-reflection/?gform_post_id=16… Anyone wishing to become the Review Manager for the library? -- Best regards, Antony Polukhin

3 3

[spirit][qi] How to write a boost::spirit::qi parser to do what '?' does in regex?
by Han Wang 19 Oct '16

19 Oct '16

Let's say we have a regex "start:(?: ([0-9]{1,2}))? ([0-9].*)". It will match std::string string1 = "start: 01 0ab"; and std::string string2 = "start: 0ab"; We can also get the 2 matched string respectively. I try to use boost::spirit::qi parser to parse string2 but it couldn't match. qi::rule<std::string::const_iterator, std::string()> rule1 = qi::repeat(1,2)[qi::digit]; qi::rule<std::string::const_iterator, std::string()> rule2 = qi::digit >> *qi::char_; std::vector<std::string> attr; auto it_begin = string2.begin(); auto it_end = string2.end(); if (qi::parse( it_begin, it_end, qi::lit("start:") >> -(qi::lit(" ") >> rule1) >> qi::lit(" ") >> rule2 >> qi::eoi, attr)) std::cout<<"match"<<std::endl; else std::cout<<"not match"<<std::endl; We can of course use a look-ahead operator to check what's behind rule1, but is there a more generic approach to implement regex operator '?' ? Thanks!

2 1

[container] small_flat_set and small_flat_map
by Sam Kellett 19 Oct '16

19 Oct '16

Given that Boost.Container has a small_vector now, would a piece of work that changed flat_set and flat_map to use small_vector<0> internally be feasible? I ask because I feel like if this was the case it would be almost trivial to expose flat_tree<N> through small_flat_set<N> and small_flat_map<N> types to provide the small size optimisation for these two containers.

5 8

Error in Review Schedule
by Emil Dotchevski 19 Oct '16

19 Oct '16

It seems like the entry for the Callable Traits library in http://www.boost.org/community/review_schedule.html links the PODs Flat Reflection documentation. Emil

2 1

Re: [boost] [fixed_point] First presentation from GSoC 2015 and more
by John McFarlane 19 Oct '16

19 Oct '16

> > Date: Thu, 13 Oct 2016 20:41:27 +0000 (UTC) > From: Christopher Kormanyos <e_float(a)yahoo.com> > > > I discuss P0106R0 (a revision to N3352) in my paper, the latest draft of > > which is always available here: https://github.com/ > > johnmcfarlane/fixed_point/blob/master/doc/p0037.md#p0106 > > I'm honestly not sure which approach is preferable overall. The set of > > features and qualities requested during SG14 and SG6 meetings is large > and > > conflicting. It includes minimal build times, minimal run-time overhead, > > every rounding and overflow strategy listed in P0105, decimal radix and > > support for specialized fixed-point instructions on embedded > architectures. > Hi John. Thanks for visiting this thread. > > My recommendation would be to limit the scope of the proposal > to a realistic level in the SGs so that we can end up with anything > at all within a reasonable time scale. We could consider back porting > some (but probably not all) of SG14's specified interface to Boost > if that helps move anything along. > A second pair of implementor eyes would be a huge help. I should point out that although it hasn't seen much attention lately, P0106 may still be active. (Frankly, the evolution of my design has been largely a process of slowly copying or facilitating all the most popular from Lawrence's proposal!) One problem P0037 faces - even if it were to be standardized - would be that alone, it only provides fixed-point arithmetic. It's designed to work with types that also solve arbitrary width, rounding and overflow but those types are not part of any proposal. In particular, without an arbitrary-width integer type, it's very difficult to use fixed_point<> safely. > > I was also wondering about decimal radix, but I don't know if it > might simply be better to identify those 80% of the most popular use cases and simply specify these. At least it would get the library > moving forward and people could use fixed-point in C++. This is basically what we tried to do with the GSoC project. > That makes sense. I at least want to have a solution which doesn't close the door on decimal in future additions. Here's my current plan: https://github.com/johnmcfarlane/fixed_point/blob/master/doc/p0037.md#non-b… > > >> In your work I've been experiencing some trouble with>> the division > routine. > > Can you elaborate? Was this recently? I've been trying out numerous > > strategies for arithmetic operators. My current preferred approach is to > > pad the left-hand operand before performing the division but that's only > > been checked in for a few months. > > I'm not sure about the design, and error on my side is a likely possibility. But division operator in the master branch seems like it does not pad before divide. This might give the wrong result. > I hope that's not the case but it's a tough operator to get right - especially with 32-bit operands. If you ever find a good example of this happening I'd be very interested in it. At least when using the elastic alias, precision loss should be avoidable (beyond inevitable approximation of rational numbers and x/0). tl;dr: The details of padding in the division operator follow... The padding is done on this line: https://github.com/johnmcfarlane/fixed_point/blob/91c3f2e272f9fd5e33ffb4dc2… It's on display in this test: https://github.com/johnmcfarlane/fixed_point/blob/1cc7ceaaff5422667ae962995… In the above test, the two operands have a single fractional digits. If operator/ did not pad the LHS, then the integer operation would be 126/8 which would lose precision. Instead, the LHS is promoted and shifted left by 8 bits. Then, integer division occurs and the value is stored with (hopefully!) no further shifts. > For division, I have used the following approach. * handle sign * extend n bits to 2n bits > * shift left by radix split plus one round bit * divide 2n / n -> n bits > * handle round and sign > So you're right this requires 64-bit extension for a 32-bit fixed-point unless you tackle the problem of two-component division, which I have done using a simplified version of Knuth long division. At the moment, this is only in develop branch. The compiler switch is BOOST_FIXED_POINT_DISABLE_WIDE_INTEGER_MATH. > This is core to the difference in approach between P0037 and P0106. I guarantee to use built-in integer math for any type specialized on built-in integers. I believe that types with arbitrary width can then be built upon this foundation using novel integer types. Here is an example using Boost.Multiprecision to express a Googol: http://johnmcfarlane.github.io/fixed_point/#boost fixed_point<> uses the same algorithm regardless of whether the `Rep` integer is an uint8_t or a 400-bit custom type. > > >> I also had some problems compiling on VC12 (but you don't target that > >> compiler anyway). So that's no big deal. > > > You will need a C++11-compliant compiler as sg14::fixed_point<> creates > > literal types. Lack of support for features like constexpr constructors > is > > the main obstacle to compiling under VC++ 2013 and earlier. > I actually agree with that approach. Either it uses C++11 or it does not. I don't see the need to cater to a specific older compiler for new library work. > It's a pragmatic choice. Three reasons are: * C++11 has everything I need to implement (with difficulty) a literal type. In particular, I can write most of my unit tests using `static_assert` which is the best thing ever! * Once you start returning novel specializations from your arithmetic operators, `auto` type deduction is essential to usability. * Many of my target users in SG14 are stuck with compilers which are behind the curve. > >> In your work you are using wrapped versions of elementary transcendental > >> functions designed for built-in float. You might appreciate our > hand-crafted > >> functions designed to be highly efficient in several digit ranges. > > > Yes! I would be very interested in seeing if I could adapt those > function. > We worked hard on these. And there are many good algorithms available in boost/fixed_point/fixed_point_negatable_cmath.hpp > > Having spent a non-trivial amount of time writing the simplest sqrt I could find, I appreciate the effort this must have involved. > Mine are placeholders and I've deliberately postponed the non-trivial task > > of adding cmath equivalents. It's come up - maybe a couple of times - > > whether these functions are desired and the response has been to just > keep > > the proposal narrow so they are not included. > > > There are interesting questions regarding how to implement some > functions. > > For example, you surely don't always want the same inputs and outputs > from > > functions involving angles. And hopefully these functions can be > constexpr > > - unlike existing functions. > I agree. > > Also, how have you approached the trade-off between speed and accuracy? I > > went for a very simple sqrt function which is adequate if the value is > > calculated at compile time but is likely not desirable at run-time. This > > isn't a problem that floating-point variants face. > > The elementary transcendental functions use many techniques including polynomial approximation, Pade approximation, Taylor series, > Newton iteration. For low digit counts, mostly polynomial approximation. We > express the coefficients directly as integral values of the fixed_point > representation and avoid as much as possible full division and multiply, > favoring integer div and mul. These functions are quite efficient. We have > not constexpr-ed them. But it looks like there is potential for that. > Writing constexpr functions in C++11 can be a big challenge. > > >> I have also benched our fixed_point on bare-metal embedded systems both > >> 8-bit and 32-bit with very satisfying efficiency results. This is a key > >> feature for our embedded users that might also be interesting for SG14. > > > My current aim is to match integer performance for common arithmetic > > operations when using built-ins. This leads to some situations where > > overflow is a big problem - but no worse than dealing with raw integers. > > I'm curious how you deal with multiplying two int-sized values together > > without resorting to wider, slower types.I was under the impression that > > P0106 types always widen to fit their values. > We have resorted to wider integer for internal mul and div or used higher > level algorithms when the compiler switch BOOST_FIXED_POINT_DISABLE_WIDE_INTEGER_MATH > is activated as mentioned above (develop branch only). > In our approach, full multiplication requires: * sign conversion > * left shift for round bit > * multiply n*n --> 2n bits * right shift and round * sign conversion > On a 32-bit system, a full 32*32 -> 64 mul is required. > This full multiplication approach can not achieve your desired efficiency > goal on 8-bit and 32-bitCPUs. Division uses similar approach. > > Multiplication and division with plain int or unsigned can achieve the > efficiency goal --- if it were not for handling rounding and overflow. > > In my current branch, I'm actually trying to get even closer to integer-level efficiency. No longer does 32-bit multiplication result in 64-bit results on systems with 32-bit integer. This means that overflow on 32-bit arithmetic operations is even more common. The solution is explicit casting to 64-bit or use of an integer type which auto-widens: http://johnmcfarlane.github.io/fixed_point/#elastic This is the toughest design issue I face - especially when combined with division. > > >> Thank you and best regards, Chris > > And thank you. Keep up the good work! > > John > Thanks again and best regards, Chris > > Cheers, John

4 7

[serialization]
by alainm 19 Oct '16

19 Oct '16

Hi, I have a few blocking compilation/link problems on the develop branch for which to fixes are pending (46 (3 lines) & 45(1 line)). 45 is a bug in the code I thin, 46 probably works just fine on most platform, but not on mine (recent Intel compiler on CentOS 6.5, which mean advanced features, but old headers). Boths are breaking are breaking some tests on Boost.MPI. Could someone have a look at it ? Regards Alain

1 0

[Serialization] check failed ???
by alainm 17 Oct '16

17 Oct '16

Hi, If I got on: https://github.com/boostorg/serialization/pull/46 I see a message "All checks have failed". If I follow the link "details" I see stuff regarding rake (?) and unfound "rakefiles", What is this all about ? Regards -- Alain Miniussi Pole Génie Logiciel Scientifique Observatoire de la Côte d'Azur Blv de l'Observatoire, Nice

1 0

Read only attributes in C++ (class proposal)
by Daniel Illescas Romero 17 Oct '16

17 Oct '16

Hello, I wanted to make some read only attributes on C++ so I made a class, named ReadOnly. This class will contain an internal private value, only “friend” classes could change this internally. Description: · A read only object will contains an internal value that can’t be changed outside the class. For example: ReadOnly<string> name = “Daniel”; To access its value: object.name, if you try: object.name = “other”, it won’t change it’s value because it’s a read only variable; you can change it’s value only inside the class the object is declared, you could change it like: name.value = “whatever”; · To set a value (outside the class) to a read only attribute you MUST specify a setter function (which can be static and contained inside the class), like: ReadOnly<int> age {ReadOnly::setAge, 1}; (optionally you can also set a default value to the attribute). Example of setter function: static bool setAge(const int& value) { return (value > 0 && value <= 150); } So if you you have an object and you want to change its value like this: object.age = 100; it will change its internal value only if the setter function (which is called internally) returns true. · The idea of doing all of this instead private variables and getters & setters is because this approach is closer to OOP than what is normally used; I mean if you have an object and you want to get an attribute value, what you need to do in most cases is something like: object.getAttribute(), you are calling a function to just take a look at an attribute, that shouldn’t make sense in OOP, that’s why I made all of this. It’s also similar to how you manage getters and setters in Swift, because they are embedded in the attribute and you don’t need to make other functions. :) I uploaded the project to github so everyone can take a look: https://github.com/illescasDaniel/ReadOnly <https://github.com/illescasDaniel/ReadOnly> — I wanted to know your opinion about the idea of the class and also about the implementation, I’d love to upload it to boost libraries but I want to know people opinion and make the class better. Thank you!

2 1

How can I detect if a template static member function exists?
by Vinnie Falco 16 Oct '16

16 Oct '16

I'd like to write a trait: template<class T> struct has_content_length : std::integral_constant<bool, ...>{}; which detects whether or not a template static member function is present in T. Here's a typical T: struct X { template<bool isRequest, class Body, class Headers> static std::uint64_t content_length( message<isRequest, Body, Headers> const& m); }; How can I detect if X::content_length(m) is callable for any m of type message template?

2 1

Re: [boost] [config] Changes to reflect Visual C++ "15" preview 5
by Tom Kent 15 Oct '16

15 Oct '16

I've now added a runner to the test suite with msvc-15.0 (preview 5 installed), it should show up in a couple hours as "teeks99-09o-win2012R2-64on64" (the far right column). The run only took a few minutes instead of an hour or two, so I'm expecting it to look pretty broken. Just glancing at the logs it looks like the compiler isn't even being found. Does this require b2 updates? Tom

2 1

[algorithm] New search algorithms
by Зайцев Александр 14 Oct '16

14 Oct '16

Hello. Now in Boost. Algorithm there are 3 algorithms for searching: Knuth-Morris-Prata, Boyer-Moore, Boyer-Moore-Horspool. They are good algorithms, but there are other efficient algorithms like Turbo-Boyer-Moore, Quick Search, etc. You can find some more here: http://www-igm.univ-mlv.fr/~lecroq/string/index.html Now i am working on new search algorithms for Boost.Algorithm. Maybe are there anybody,who familiar with string search algorithms? -- Best regards, Alexander Zaitsev

1 0

[program_options] -d directory is falling into positional input-files 1_62_0
by Roger Martin 14 Oct '16

14 Oct '16

Hi, Pulled this from a larger application to isolate to the problem: -d ./tmp or -d "./tmp" doesn't go to directory string but is with the positionals: #include <stdlib.h> #include <iostream> #include <exception> #include <string> #include <cstring> #include <memory> #include <fstream> #include "boost/program_options.hpp" int main(int argc, char** argv) { try { boost::program_options::positional_options_description p; p.add("input-file", -1); std::string directory = "./"; boost::program_options::options_description visible("Allowed options"); visible.add_options() ("input-file", boost::program_options::value<std::vector<std::string>>(), "input files can be *.xml, *.pdb, *.mol2, *.mtz, *.cif, *.csv, and *.sdf. Csv and sdf formats are for NMR calculations. csv lists the atoms for which the shifts will be computed. 1st line containts the Header: \"Chain\",\"Residue ID\",\"Sequence\",\"Atom Name\",\"Unbound ppm\",\"Bound ppm\". Then atoms may be listed i.e \"A\",\"MET\",231,\"CE\",10.30,10.50. sdf file contains the ligands for a CSP calculation. ") ("directory,d", boost::program_options::value<std::string>(&directory)->implicit_value("./"), "Directory for publishing output.") ; boost::program_options::options_description all("Allowed options"); all.add(visible);//.add(hidden); boost::program_options::variables_map vm; boost::program_options::store(boost::program_options::command_line_parser(argc, argv).options(all).positional(p).run(), vm); boost::program_options::notify(vm); std::vector<std::string> fileList = vm["input-file"].as < std::vector < std::string >> (); for (unsigned int fileListIndex = 0; fileListIndex < fileList.size(); fileListIndex++) { std::cout<<" "<<fileList[fileListIndex]<<" "<<std::endl; } } catch (std::exception& e) { std::cout << e.what() << std::endl; } return 0; } Built with g++ 4.9.0 on Linux frodo.quantumbioinc.com 2.6.32-573.7.1.el6.centos.plus.x86_64 #1 SMP Wed Sep 23 03:02:55 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux g++ -fPIE -std=c++11 -I${BOOST_HOME}/include -Wl,--allow-multiple-definition -MT main.o -MMD -MP -O3 -c -o main.o main.cpp g++ -pie -Wl,--allow-multiple-definition -o main main.o -L${BOOST_HOME}/lib -lboost_program_options -lc -lm -lpthread -lz -lstdc++ -ldl -lrt And run as ./main 2-aminoethanol.pdb -d ./tmp which results in 2-aminoethanol.pdb ./tmp This code had been working with 1_57_0. Some change in the API I need to adjust for?

1 0

[algorithm] Longest palindromic substring in Boost.Algorithm
by Зайцев Александр 14 Oct '16

14 Oct '16

Hello I want to add to Boost.Algorithm algorithm for finding all palindromes in a sequence in O(N). https://en.wikipedia.org/wiki/Longest_palindromic_substring Is it useful algorithm for Boost? Have you any suggestions? -- Best regards, Alexander Zaitsev

3 2

Re: [boost] [fixed_point] First presentation from GSoC 2015 and more
by John McFarlane 13 Oct '16

13 Oct '16

Hi Christopher. I'm actually the main culprit behind P0037. :) Date: Wed, 12 Oct 2016 18:32:26 +0000 (UTC) > From: Christopher Kormanyos <e_float(a)yahoo.com> > To: "boost(a)lists.boost.org" <boost(a)lists.boost.org> > Subject: Re: [boost] [fixed_point] First presentation from GSoC 2015 > and more > Message-ID: <1026507022.4306136.1476297146580(a)mail.yahoo.com> > Content-Type: text/plain; charset=UTF-8 > > > I'm a bit surprised I didn't see this work before. > > Are you aware that SG14, the gamedev, real-time simulations, embedded > > software and financing study group for the standard > > is working on fixed point real proposal too? > > Here is a version of the proposal:>http://johnmcfarlane > .github.io/fixed_point/papers/p0037r2.html and>http://johnmcfarlane.githu > b.io/fixed_point/papers/p0381r0.html > > I will notify SG14 in case they missed your work too. > Thanks for the information. > We became aware of your work unfortunately very late inthe project. Much > of our fixed_point work stems from myearly prototyping dating from 2011 - > 2013. > I see a lot of similarities in the two bodies of work.Maybe we could > identify the strengths of each work.I don't know if it makes sense to > combine them,but maybe share some concepts or interface ideaswould make > sense. > I discuss P0106R0 (a revision to N3352) in my paper, the latest draft of which is always available here: https://github.com/ johnmcfarlane/fixed_point/blob/master/doc/p0037.md#p0106 I'm honestly not sure which approach is preferable overall. The set of features and qualities requested during SG14 and SG6 meetings is large and conflicting. It includes minimal build times, minimal run-time overhead, every rounding and overflow strategy listed in P0105, decimal radix and support for specialized fixed-point instructions on embedded architectures. > > In your work I've been experiencing some trouble withthe division routine. Can you elaborate? Was this recently? I've been trying out numerous strategies for arithmetic operators. My current preferred approach is to pad the left-hand operand before performing the division but that's only been checked in for a few months. > I also had some problems compilingon VC12 (but you don't target that > compiler anyway).So that's no big deal. > You will need a C++11-compliant compiler as sg14::fixed_point<> creates literal types. Lack of support for features like constexpr constructors is the main obstacle to compiling under VC++ 2013 and earlier. > In your work you are using wrapped versions of elementarytranscendental > functions designed for built-in float.You might appreciate our hand-crafted > functionsdesigned to be highly efficient in several digit ranges. > Yes! I would be very interested in seeing if I could adapt those function. Mine are placeholders and I've deliberately postponed the non-trivial task of adding cmath equivalents. It's come up - maybe a couple of times - whether these functions are desired and the response has been to just keep the proposal narrow so they are not included. There are interesting questions regarding how to implement some functions. For example, you surely don't always want the same inputs and outputs from functions involving angles. And hopefully these functions can be constexpr - unlike existing functions. Also, how have you approached the trade-off between speed and accuracy? I went for a very simple sqrt function which is adequate if the value is calculated at compile time but is likely not desirable at run-time. This isn't a problem that floating-point variants face. > I have also benched our fixed_point on bare-metalembedded systems both > 8-bit and 32-bit with verysatisfying efficiency results. This is a key > featurefor our embedded users that might also be interestingfor SG14. > My current aim is to match integer performance for common arithmetic operations when using built-ins. This leads to some situations where overflow is a big problem - but no worse than dealing with raw integers. I'm curious how you deal with multiplying two int-sized values together without resorting to wider, slower types.I was under the impression that P0106 types always widen to fit their values. > > Thank you and best regards, Chris > > And thank you. Keep up the good work! John > > On Tuesday, October 11, 2016 11:37 PM, Klaim - Jo?l Lamotte < > mjklaim(a)gmail.com> wrote: > > > On 6 October 2016 at 12:07, Paul A. Bristow <pbristow(a)hetp.u-net.com> > wrote: > > > > -----Original Message----- > > > From: Boost [mailto:boost-bounces@lists.boost.org] On Behalf Of > > Christopher Kormanyos > > > Sent: 05 October 2016 23:07 > > > To: boost(a)lists.boost.org > > > Subject: Re: [boost] [fixed_point] First presentation from GSoC 2015 > and > > more > > > > > > >> A partial implementation of fixed-point in a Boost-like > > > >> style based on proposal N3352 is now available. > > > > > > > ... But your links don't work, > > > > Indeed :-( ( > > > > The correct link to the docs for some years used to be > > > > https://dl.dropboxusercontent.com/u/43940943/modular-boost/ > > libs/fixed_point/doc/html/index.html > > > > but sadly this no longer works for reasons that so far escape me (but I > > suspect some change at Dropbox?). > > > > Meanwhile here is a PDF version to whet your appetite until I get a html > > version publicly available. > > > > https://dl.dropboxusercontent.com/u/43940943/modular-boost/ > > libs/fixed_point/doc/fixed_point.pdf > > > > Boost.Fixed_point ? > > =============== > > > > A partial implementation of fixed-point in a Boost-like style based on > > proposal N3352 is now available. > > > > This work is the result of developments from 2013-2016, including efforts > > from GSoC 2015. > > > > The source code is available at: https://github.com/ > > BoostGSoC15/fixed_point > > > > (The master branch will be stable for a while but the develop branch may > > be updated in the light of your feedback). > > > > Preliminary docs are available at: > > > > https://dl.dropboxusercontent.com/u/43940943/modular-boost/ > > libs/fixed_point/index.html > > > > We are potentially interested in submitting this work for inclusion in > > Boost. > > > > We are now requesting comments and suggestions for improvements, > > corrections and any > > further test results if these become available. > > > > Some key library features include: > > > > * proper C++ header-only implementation > > * full numeric_limits and <cmath> functions > > * flexible template choice of split between resolution and range > > * automatic selection of underlying integral representation > > * portability and high efficiency for bare metal microcontrollers > > * interoperation with Boost.Math > > * seamless extension to high-precision using Boost.Multiprecision > > * extensive test suite > > > > Thank you for your consideration. > > Best regards, > > > > Christopher Kormanyos > > > > And apologies from Paul. > > > > > Hi, > > I'm a bit surprised I didn't see this work before. > Are you aware that SG14, the gamedev, real-time simulations, embedded > software and financing study group for the standard > is working on fixed point real proposal too? > Here is a version of the proposal: > http://johnmcfarlane.github.io/fixed_point/papers/p0037r2.html and > http://johnmcfarlane.github.io/fixed_point/papers/p0381r0.html > I will notify SG14 in case they missed your work too. > > Jo?l Lamotte > > _______________________________________________ > Unsubscribe & other changes: http://lists.boost.org/mailman > /listinfo.cgi/boost > > > >

2 1

Re: [boost] : Curiousity question
by Brian Wood 13 Oct '16

13 Oct '16

Edward Diener writes: > I would like to ask a design question for any Boost developers or anyone > on this mailing list who might care to answer. > > You are designing or working on a library, perhaps for Boost, perhaps > for fun, and part of the design of the library has some public > functionality taking a shared pointer as input. You: > > 1) Use boost::shared_ptr > 2) Use std::shared_ptr > 3) Use both boost::shared_ptr and std::shared_ptr with the same > functionality > 4) Use neither, you roll your own shared pointer-like functionality > 5) You don't lke shared pointers and use raw pointers instead > > I really am curious about this. I haven't put any limitation on your > library or made any presumption on who your library is for, on purpose. > Thanks for anyone answering ! I avoid shared pointers. I'll use a unique_ptr if a raw pointer won't work. -- Brian Ebenezer Enterprises - In G-d we trust. http://webEbenezer.net

2 1

[qvm] Doesn qvm contain any sse/avx etc optimizations?
by Viktor Sehr 12 Oct '16

12 Oct '16

If not, is it planned for utilizing it? /Viktor

2 1

Boost library incubator URL address
by Edward Diener 12 Oct '16

12 Oct '16

Is the Boost Library Incubator web site down or removed ? I cannot get to it anymore via a URL. I have this URL, http://www.rrsd.com/software_development/blincubator/index.htm, but it just hangs on me.

2 1

Announcing version 3 of the cxx_dual library
by Edward Diener 11 Oct '16

11 Oct '16

I have created version 3 of the cxx_dual library. version 3 is a large rewrite of the documentation to simplify the use of the library, as well as a change in the directory structure so that the basic usage of the library is through a single header file and the use of a namespace alias, and not through the macro interface. As in: #include <boost/cxx_dual/regex.hpp> void SomeFunction() { cxxd_regex_ns::regex re("A regular expression etc."); bool result(cxxd_regex_ns::regex_match("Some string...",re)); // etc. } What ! No macros ! Actually a few macros still exist for testing which dual library has been chosen and overriding the dual library chosen, but the basic functionality means almost no macros in user code. The library is available at https://github.com/eldiener/cxx_dual.git. What is it ? The Cxx Dual library, or CXXD for short, is a C++ macro header-only library which chooses between using a Boost library or its C++ standard equivalent library for a number of different C++ implementations, while allowing the end-user to use the same code to program either choice. An implementation is a Boost library which has a C++ standard library equivalent whose public interfaces are nearly the same in both cases. An 'implementation' is called a 'mod' for short and each of the possible Boost or C++ standard implementations for that mod are called a 'dual library'. The Cxx Dual library does this by automatically choosing either the Boost library or the C++ standard library for a particular mod, including the correct header file(s) needed for the dual library chosen, and creating a namespace alias for the namespace of the dual library chosen. CXXD also provides a macro-based solution for distinguishing between the Boost version and the C++ standard version of a dual library so that specific code for a particular dual library choice may be written in those cases where the public interfaces diverge.

1 0

Announcing version 3 of the cxx_dual library
by Edward Diener 11 Oct '16

11 Oct '16

I have created version 3 of the cxx_dual library. version 3 is a large rewrite of the documentation to simplify the use of the library, as well as a change in the directory structure so that the basic usage of the library is through a single header file and the use of a namespace alias, and not through the macro interface. As in: #include <boost/cxx_dual/regex.hpp> void SomeFunction() { cxxd_regex_ns::regex re("A regular expression etc."); bool result(cxxd_regex_ns::regex_match("Some string...",re)); // etc. } What ! No macros ! Actually a few macros still exist for testing which dual library has been chosen and overriding the dual library chosen, but the basic functionality means almost no macros in user code. What is it ?

1 0

Re: [boost] [beast] Request for Discussion
by Vinnie Falco 10 Oct '16

10 Oct '16

There's some great programming and design discussion related to Beast and HTTP going on in the GitHub issues for the project. And there are some interface changes looming. Stakeholders and interested parties should consider participating in these discussions if they would like to influence the outcome: Some of the discussions: HTTP 1 versus 2 namespacing https://github.com/vinniefalco/Beast/issues/121 HTTP/2 design https://github.com/vinniefalco/Beast/issues/122 Expect: 100-continue https://github.com/vinniefalco/Beast/issues/123 `basic_headers` to make better use of allocators and string_ref https://github.com/vinniefalco/Beast/issues/124

1 0

[git] some fetch errors
by Raffi Enficiaud 09 Oct '16

09 Oct '16

Hi all, I see the following errors: """ Fetched in submodule path 'libs/python', but it did not contain 0ca7db361b8a70540c5683ae3ba2219c3352f721. Direct fetching of that commit failed. """ while my agents were checking out version aa407db3a22120496d6c49d2e3bc0b494b5ceb76 of the boost superproject. Does anyone know why am I seeing this? I cannot find rev 0ca7db361b8a70540c5683ae3ba2219c3352f721 in libs/python Thanks, Raffi

5 6

[python] Missing test file.
by Rene Rivera 09 Oct '16

09 Oct '16

FYI.. The testing CI sanity check is failing with this missing file error: error: Unable to find file or target named error: 'printer.py' error: referred to from project at error: '../libs/python/test' <https://travis-ci.org/boostorg/boost/jobs/166196326#L6960> Please fix ASAP. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

2 1

Re: [boost] [beast] Request for Discussion
by Vinnie Falco 09 Oct '16

09 Oct '16

To get this topic hopping again, I'll share a bit of news. With help from Howard Hinnant I've opened an issue against the Networking TS to make sure that its algorithms do not place unnecessary requirements on user-defined types: http://cplusplus.github.io/LWG/lwg-active.html#2779 This will affect Beast's buffer sequence adapters (such as buffer_cat).

1 1

Boost.Python NumPy extension
by Stefan Seefeld 09 Oct '16

09 Oct '16

Hello, I'm happy to announce that I just merged the NumPy C++ wrappers from https://github.com/ndarray/Boost.NumPy into Boost.Python's development branch. (Online documentation for it can be browsed here: http://boostorg.github.io/python/develop/doc/html/numpy) I'd very much like to be able to merge this into the master branch for the next Boost release (version 1.63). At present I'm using SCons to build Boost.Python (stand-alone, against a separately installed Boost), which is also the infrastructure I use for CI testing (https://travis-ci.org/boostorg/python) I would like to ask for help with integrating the new NumPy extension into the Boost.Build-based build system, such that this will also be picked up by the regular Boost infrastructure. Please refer to https://github.com/boostorg/python/issues/89 if you'd like to help with this. Many thanks ! Stefan -- ...ich hab' noch einen Koffer in Berlin...

1 0

Build: Trying to get Boost.Build to see my OpenSSL on Windows
by Vinnie Falco 07 Oct '16

07 Oct '16

I'm trying to build the Asio SSL examples but bjam can't find my OpenSSL installation on Windows (using Visual Studio 2015). Everything else builds. And I am having the dickens of a time finding any information on the web about mixing Windows, OpenSSL, and bjam. As a last resort I've thrown a hail mary to StackOverflow: http://stackoverflow.com/questions/39800333/how-do-i-get-bjam-to-set-includ… I'm not clear on what this line does on Windows using MSVC: lib ssl ; The line appears in Asio Jamfiles that use OpenSSL. Any help is appreciated, thank you.

7 38

[doc] Doc directory for a library
by Edward Diener 07 Oct '16

07 Oct '16

If a library does not have a 'doc' subdirectory, because the doc is not buildable but is rather hardcoded into an HTML file, what is the best way to satsify Boost and the boost_check_library regression test for that library ?

2 2

Upcoming changes to _MSC_VER
by Gabriel Dos Reis 07 Oct '16

07 Oct '16

Hi, This is a heads up. I spoke with Beman at CppCon about this: the upcoming release of Visual Studio (VS "15") has some changes to how _MSC_VER will be defined at every (future) update. These changes are already implemented in 'VS "15" Preview 5'. The full details are here https://blogs.msdn. microsoft.com/vcblog/2016/10/05/visual-c-compiler-version/ Internal testing showed that some components of Boost source code needed a few changes to use inequalities instead of equalities with _MSC_VER. Thanks, PS: The formal documentation of _MSVC_LANG is coming. -- Gaby

3 3

Review request: Beast
by Vinnie Falco 04 Oct '16

04 Oct '16

Can Beast please be added to the review queue? Michael Caisse has volunteered to act as the review manager. Beast provides C++11, header-only implementations of the HTTP and WebSocket protocols using Boost.Asio and presenting a consistent, modern synchronous and asynchronous interface style. Beast project repository https://github.com/vinniefalco/Beast HTML documentation http://vinniefalco.github.io/beast Boost incubator link: http://blincubator.com/bi_library/beast-2/?gform_post_id=1579 Thanks!

3 3

Extending Boost.Python with NumPy support
by Stefan Seefeld 04 Oct '16

04 Oct '16

Hello, I'm presently working on a few improvements to the Boost.Python module. As part of this I'm refactoring the numeric API to actually support NumPy. There has been quite a lot of effort we put into this in the past (notably a GSoC project I mentored a few years ago), but we never managed to include this into the Boost master branch, so it's never been formally released. As I'm now getting ready to polish this work off, I wonder whether any of this would require a formal submission as a new Boost library, or whether it can just be done under the Boost.Python umbrella ? I reckon this is somewhat of a gray area, so I'd like to clarify whether there are concrete rules for what changes / additions require a formal review process. Thanks, Stefan -- ...ich hab' noch einen Koffer in Berlin...

5 8

Re: [boost] [Boost-users] Need help with errors while building boost for clang on android NDK
by Robert Dailey 04 Oct '16

04 Oct '16

On Wed, Sep 28, 2016 at 10:49 AM, Robert Dailey <rcdailey.lists(a)gmail.com> wrote: > On Mon, Sep 26, 2016 at 11:55 AM, Robert Dailey > <rcdailey.lists(a)gmail.com> wrote: >> On Mon, Sep 26, 2016 at 11:09 AM, Oliver Kowalke >> <oliver.kowalke(a)gmail.com> wrote: >>> 2016-09-26 17:57 GMT+02:00 Robert Dailey <rcdailey.lists(a)gmail.com>: >>>> >>>> >> > clang-linux.compile.asm >>>> >> > >>>> >> > >>>> >> > bin.v2\libs\context\build\clang-linux-android\release\link-static\runtime-link-static\target-os-linux\threading-multi\asm\make_i386_ms_pe_gas.o >>>> >> > libs\\context\\src\\asm\\make_i386_ms_pe_gas.asm:30:1: error: unknown >>>> >> > directive >>>> >> > .def _make_fcontext; .scl 2; .type 32; .endef >>>> > >>>> > >>>> > you try to build for i386 instead arm >>>> >>>> How can I make it use arm instead? >>> >>> >>> I assume you try to cross compile : >>> http://www.boost.org/doc/libs/1_61_0/libs/context/doc/html/context/architec… >> >> I am indeed trying to cross compile, however I am not familiar with b2 >> nor do I much care to learn it (since it's a means to an end for me to >> build boost). >> >> Can you provide an example of how I can specify the documented >> settings to b2 for my build? Do I provide the values to those in my >> project-config file? > > Would really love help with this guys. I literally can't find info on > this anywhere else. Surely someone has had success getting 1.61 > building with NDK + ARM + Clang. > > I made a best-guess using the context cross compiling settings linked > earlier. Does this seem correct? It doesn't build at the moment saying > it can't find locale-related symbols. That doesn't help me at all so I > guess I'm going to have to dig into the llvm STL code and find out > what preprocessor flags I'm missing (assuming it's that simple). Also > I still don't know how to specify 'ar' and 'ranlib' executables to > boost from NDK. > > > using clang : android : > $(androidNDKRoot)/toolchains/llvm/prebuilt/$(androidPlatform)/bin/clang++ : > <compileflags>--sysroot=$(androidNDKRoot)/platforms/android-15/arch-arm > <compileflags>-Os > <compileflags>-fno-strict-aliasing > <compileflags>-O2 > <compileflags>-DNDEBUG > <compileflags>-g > <compileflags>-I$(androidNDKRoot)/sources/cxx-stl/llvm-libc++abi/libcxxabi/include > <compileflags>-I$(androidNDKRoot)/sources/cxx-stl/llvm-libc++/libcxx/include > <compileflags>-I$(androidNDKRoot)/sources/cxx-stl/llvm-libc++/libs/armeabi-v7a > <compileflags>-I$(androidNDKRoot)/sources/android/support/include > <compileflags>-DANDROID > <compileflags>-D__ANDROID__ > <compileflags>-D__arm__ > <compileflags>-D_REENTRANT > <architecture>arm > <address-model>32 > <binary-format>pe > <abi>aapcs > ; FYI: I still haven't gotten this working. Sorry to keep bumping this thread but I have absolutely zero options yet. I need help from the boost developers at this point, I think.

2 2

[concept_check] convert Concept to trait?
by Vinnie Falco 04 Oct '16

04 Oct '16

I don't see a place to open issues on https://github.com/boostorg/concept_check so I am posting this here. What I want to do is convert a concept into a trait. For example, given the ForwardIterator concept checking class, I would like to write: template<T> using is_ForwardIterator = std::integral_constant<bool, ...>; Which aliases to std::true_type if T meets the requirements of ForwardIterator and false otherwise. Or perhaps a general purpose alias: template<t> using is_concept<T, C> = std::integral_constant<bool, ...>;l Which aliases to std::true_type if T meets the requirements of concept C. Are such things possible, or perhaps already in the library? My preliminary analysis suggests the answers to these questions are no and no. Has this point been brought up elsewhere, and if so where could I find it? Regards

3 2

preparation for Gsoc 2017
by Prashant Kumar 04 Oct '16

04 Oct '16

Hello Boost community, I need some help for preparing effectively for Gsoc 17 with Boost community. I have been through the boost gsoc webpage and for getting selected in Gsoc an aspirant need to provide competency Test. I want to know that apart from competency test what other projects would be helpful in making my proposal strong. Should I be writting more programs using boost library ? , should I be aware of all boost libraries ?. I want your suggestions as I'm very serious regarding the matter. thanks!! and sorry if the question is quite nooby.

2 1

How to build Boost with VS15
by Olaf van der Spek 04 Oct '16

04 Oct '16

Hi, How does one build Boost (1.62) with VS15 (Preview 4)? I know it's not officially supported.. C:\VC\boost>bootstrap.bat Building Boost.Build engine 'cl' is not recognized as an internal or external command, operable program or batch file. Failed to build Boost.Build engine. Please consult bootstrap.log for further diagnostics. -- Olaf

6 10

Review Request: Synapse
by Emil Dotchevski 03 Oct '16

03 Oct '16

I'm requesting a formal review for the Synapse library. Edward Diener has kindly offered to serve as the review manager for Synapse. Synapse is a signal programming library, similar to Boost Signals2 and the signals-slots system in Qt. The main difference is that Synapse is non-intrusive: the address of any object of any static type whatsoever can be passed to synapse::emit to emit a signal. This makes it possible to emit Synapse signals from objects of third-party types as well as system objects (e.g. standard FILE pointers, HWNDs, etc.) or any other object that can be converted to a pointer. The library has been formatted to fit the Boost directory and namespace structure. To get Synapse, clone https://github.com/zajo/boost-synapse.git into a directory called synapse under your boost/libs directory. See the tutorial at http://zajo.github.io/boost-synapse/Tutorial.html, or read full documentation at http://zajo.github.io/boost-synapse/index.html. Thanks, Emil

1 0

CMake Modularization
by Philip Woods 03 Oct '16

03 Oct '16

CMake is a widely used build system and has become for many the de facto standard. Boost is a widely used collection of modules and has become for many part of the de facto standard. However, the two do not play very well together. I know there is another port of boost to CMake, but it has lain dormant for years and uses an old version of boost; plus I chose to take a different route. The old project attempted to completely replace Boost.Build with CMake. My example port simply allows people to more easily use boost modules in their projects. I created an example project https://github.com/Elzair/cmake-boost-filesystem-test to demonstrate my ideas. I added CMake build support to the minimum number of modules needed to support this demo: https://github.com/Elzair/assert https://github.com/Elzair/config https://github.com/Elzair/core https://github.com/Elzair/filesystem/tree/master and https://github.com/Elzair/system I even added CMake build support to the header only boost libraries. I did this for two reasons. First, I did not want users to have to fool with CMake's find_package(). Second, I wanted to add helpful error messages in case a user has not included all of a module's dependencies (or added them in the wrong order). Would the community be interested in modular CMake support for more modules? Any comments, questions, critiques or suggestions are welcome.

8 16

Cannot open include file: 'pyconfig.h'
by Olaf van der Spek 30 Sep '16

30 Sep '16

Hi, Boost 1.62 @ VC15, no Python installed: call "C:\Users\W7\AppData\Local\Temp\b2_msvc_default_vcvarsall_x86.cmd" >nul cl /Zm800 -nologo @"bin.v2\libs\python\build\msvc\debug\link-static\threading-multi\import.obj.rsp" ...failed compile-c-c++ bin.v2\libs\python\build\msvc\debug\link-static\threading-multi\import.obj... compile-c-c++ bin.v2\libs\python\build\msvc\debug\link-static\threading-multi\exec.obj exec.cpp C:\VC\boost\boost/python/detail/wrap_python.hpp(50): fatal error C1083: Cannot open include file: 'pyconfig.h': No such file or directory Should it be trying to build Python stuff? -- Olaf

1 0

[release] Boost 1.62.0 release available
by Rene Rivera 30 Sep '16

30 Sep '16

Release 1.62.0 of the Boost C++ Libraries is now available. These open-source libraries work well with the C++ Standard Library, and are usable across a broad spectrum of applications. The Boost license encourages both commercial and non-commercial use. This release contains two new libraries and numerous enhancements and bug fixes for existing libraries. New Libraries * Fiber: Framework for userland-threads/fibers, from Oliver Kowalke. * QVM: Boost QVM is a generic library for working with quaternions, vectors and matrices of static size with the emphasis on 2, 3 and 4-dimensional operations needed in graphics, video games and simulation applications, from Emil Dotchevski. For details, including download links, see http://www.boost.org/users/ news/version_1.62.0 You can also download directly from SourceForge: http://sourceforge.net/ projects/boost/files/boost/1.62.0/ The SHA256 checksums are as follows: b91c2cda8bee73ea613130e19e72c9589e9ef0357c4c5cc5f7523de82cce11f7 boost_1_62_0.7z 36c96b0f6155c98404091d8ceb48319a28279ca0333fba1ad8611eb90afb2ca0 boost_1_62_0.tar.bz2 440a59f8bc4023dbe6285c9998b0f7fa288468b889746b1ef00e8b36c559dce1 boost_1_62_0.tar.gz 084b2e0638bbe0975a9e43e21bc9ceae33ef11377aecab3268a57cf41e405d4e boost_1_62_0.zip Tom Kent has made pre-built windows binaries, and they are available at: https://sourceforge.net/projects/boost/files/boost-binaries/1.62.0/ To install this release on your system, see http://www.boost.org/doc/libs/ release/more/getting_started/index.html Thanks, --The Boost release team

6 5

[release] Master open for changes.
by Rene Rivera 30 Sep '16

30 Sep '16

FYI.. Master branches are now open for changes for the next release. Note that because of the late 1.62.0 release the window for the next release is shorter than usual. And there is now less than a month before master closes again for new libraries. Please consult the calendar for further dates. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

1 0

[asio] inefficiency in the polling
by Tatsuyuki Ishi 29 Sep '16

29 Sep '16

The current run/poll_one does polling regardless if there's task in the queue. If there's task in the queue, polling is just a waste of system call, since there's already a job to do. Also, my common use case is "wait and consume all work", which is not covered efficiently by current design. (run_one+poll takes two system calls) Side note: on Windows asio performs even worse, it only retrieve one event per syscall... Not sure if it's intended. Friendly note: please use "Reply to All" when replying to me.

4 3

Population count procedure in dynamic_set
by Wojciech Muła 28 Sep '16

28 Sep '16

Hello! The library dynamic_bitset contains a slow population count procedure: https://github.com/boostorg/dynamic_bitset/blob/340822f979371973fe4a8436362… There are several better, faster and (more or less) portable algorithms. Daniel Lemire, Nathan Kurz and I work on a library which provides fastest possible implementations for CPU having AVX2 instruction set, you can check out its current state: https://github.com/CountOnes/hamming_weight. I also did an extensive comparison of different algorithms on different machines: https://github.com/WojciechMula/sse-popcount, one example https://github.com/WojciechMula/sse-popcount/blob/master/results/skylake/sk… As I mentioned these algorithms are different, the fastest use SIMD instructions, other depends on a CPU instruction. However, some approaches are portable, machine-independent, like this https://github.com/WojciechMula/sse-popcount/blob/master/popcnt-bit-paralle… It's possible to provide better solution at small cost, a lot of work has already been done. Would you be interested in including such boosted procedures as part of dynamic_bitset (or a new library)? Popcount itself is used in number of fields: I've found it in DNA matching (Jaccard index), computer vision, databases, and Daniel recently reported application in machine learning. best regards Wojciech

2 1

[container] Trie data structure
by Зайцев Александр 28 Sep '16

28 Sep '16

Hi! My implementation of Aho-Corasick uses my own implementation of trie data structure. But i want something to use from Boost. Is there trie in Boost? If not, can I start work on trie for Boost? -- Best regards, Alexander Zaitsev

6 9

Re: [boost] [Boost-users] [release] Boost 1.62.0 Release Candidate 1
by Marshall Clow 28 Sep '16

28 Sep '16

On Tue, Sep 27, 2016 at 7:14 PM, Edward Diener <eldiener(a)tropicsoft.com> wrote: > On 9/27/2016 9:24 PM, Marshall Clow wrote: > >> >> >> On Mon, Sep 26, 2016 at 5:52 PM, Marshall Clow <mclow.lists(a)gmail.com >> <mailto:mclow.lists@gmail.com>> wrote: >> >> On Mon, Sep 26, 2016 at 7:36 AM, Rene Rivera <grafikrobot(a)gmail.com >> <mailto:grafikrobot@gmail.com>> wrote: >> >> The release candidates for the 1.62.0 release are now available >> at: >> >> >> [snip] >> >> >> >> Now to run some tests.... >> >> -- Marshall >> >> >> The test "vmd/test/test_doc_modifiers_return_type.cpp" hangs clang. >> Reported as https://llvm.org/bugs/show_bug.cgi?id=30546 >> > > Evidently clang runs out of memory. Note that with VC++ and gcc the test > passes. > > I don't know why clang would run out ot memory while VC++ and gcc do not > but I have not queried the clang mailing list further about it. An educated > guess is that clang calculates some fixed size for the preprocessor and > when macro expansions cause that fixed size to overrun you get an out of > memory condition. I can hardly believe that the preprocessor is really > running out of virtual memory, no matter how complicated the preprocessor > code gets in VMD. > > When I was discussing the problem with Richard, he opined that that might be a problem, if the preprocessed source exceeded 1 GB in size - which it doesn't. (GCC expands this test to about 700K) So I suspect it is "just a bug" -- Marshall

1 0

[release] Boost 1.62.0 Release Candidate 1
by Rene Rivera 28 Sep '16

28 Sep '16

The release candidates for the 1.62.0 release are now available at: https://sourceforge.net/projects/boost/files/boost/1.62.0.rc.1/boost_1_62_0… https://sourceforge.net/projects/boost/files/boost/1.62.0.rc.1/boost_1_62_0… https://sourceforge.net/projects/boost/files/boost/1.62.0.rc.1/boost_1_62_0… https://sourceforge.net/projects/boost/files/boost/1.62.0.rc.1/boost_1_62_0… The SHA256 checksums are as follows: b91c2cda8bee73ea613130e19e72c9589e9ef0357c4c5cc5f7523de82cce11f7 boost_1_62_0_rc1.7z 36c96b0f6155c98404091d8ceb48319a28279ca0333fba1ad8611eb90afb2ca0 boost_1_62_0_rc1.tar.bz2 440a59f8bc4023dbe6285c9998b0f7fa288468b889746b1ef00e8b36c559dce1 boost_1_62_0_rc1.tar.gz 084b2e0638bbe0975a9e43e21bc9ceae33ef11377aecab3268a57cf41e405d4e boost_1_62_0_rc1.zip 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. Thanks, the release managers. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

6 9

[dll] Problem building documentation on Windows
by Vinnie Falco 27 Sep '16

27 Sep '16

I am trying to build the Boost documentation on Windows and I am encountering this error bash-4.3$ pwd /d/lib/boost_1_62_0/libs/dll/doc bash-4.3$ bjam Jamfile.v2:66: in modules.load *** argument error * rule doxygen ( target : sources + : requirements * : default-build * : usage-requirements * ) * called with: ( autodoc_shared_library_core : : <doxygen:param>HIDE_UNDOC_MEMBERS=YES <doxygen:param>HIDE_UNDOC_CLASSES=YES <doxygen:param>HIDE_SCOPE_NAMES=YES <doxygen:param>EXTRACT_ALL=NO <doxygen:param>EXTRACT_PRIVATE=NO <doxygen:param>BUILTIN_STL_SUPPORT=YES <doxygen:param>ENABLE_PREPROCESSING=YES <doxygen:param>MACRO_EXPANSION=YES <doxygen:param>ALIASES= \ "forcedlink{1}=\xmlonly<link linkend='boost.dll.\1'>boost::dll::\1</link>\endxmlonly" \ "forcedmacrolink{1}=\xmlonly<link linkend='\1'>\1</link>\endxmlonly" <doxygen:param>PREDEFINED= \ "BOOST_RV_REF(T)=T&&" \ "BOOST_RV_REF(shared_library)=shared_library&&" \ "BOOST_COPY_ASSIGN_REF(shared_library)=const shared_library&" \ "BOOST_MOVABLE_BUT_NOT_COPYABLE(shared_library)= \ shared_library(const shared_library&) = delete; \ shared_library& operator=(const shared_library&) = delete; " \ "BOOST_DLL_IMPORT_RESULT_TYPE=result_type" \ "BOOST_DLL_MANGLED_IMPORT_RESULT_TYPE=result_type" \ "BOOST_EXPLICIT_OPERATOR_BOOL()=explicit operator bool() const noexcept;" \ "BOOST_DLL_DOXYGEN" <xsl:param>boost.doxygen.reftitle=Shared Library Reference ) * missing argument sources D:/lib/boost_1_62_0/tools/build/src/tools\doxygen.jam:622:see definition of rule 'doxygen' being called D:/lib/boost_1_62_0/tools/build/src/build\project.jam:325: in load-jamfile D:/lib/boost_1_62_0/tools/build/src/build\project.jam:64: in load D:/lib/boost_1_62_0/tools/build/src/build\project.jam:145: in project.find D:/lib/boost_1_62_0/tools/build/src\build-system.jam:535: in load D:\lib\boost_1_62_0\tools\build\src/kernel\modules.jam:295: in import D:\lib\boost_1_62_0\tools\build\src/kernel/bootstrap.jam:139: in boost-build D:\lib\boost_1_62_0\boost-build.jam:17: in module scope I get the same error when I try to build the full documentation from boost_1_62_0/doc/ My doxygen is at version 1.8.12 -- Follow me on Github: https://github.com/vinniefalco

2 5

[fiber] design fault with multithreading
by Tatsuyuki Ishi 27 Sep '16

27 Sep '16

The current design doesn't allow a work-stealing algorithm to distribute work perfectly. Unfortunately, the use of sleep queue and remote ready queue made it insufficient for schedulers like shared_work. Instead here, I'd like to propose it as non-pure virtual function in the algorithm class. This allows schedulers to override the queues, and enables the use of underlying implementation's timer manager, which is included in Asio. Friendly notice: please use "Reply All" when replying to me.

1 0

Boost should not be saying "_FPOSOFF"
by Billy O'Neal (VC LIBS) 27 Sep '16

27 Sep '16

Hello, Boost folks. :) I tried to remove this undocumented internal macro from our STL because we used it in only one place, but this broke Boost: #define _FPOSOFF(fp) ((long long)(fp)) ...patience... ...found 722 targets... ...updating 18 targets... common.mkdir build\boost\bin.v2\libs common.mkdir build\boost\bin.v2\libs\iostreams common.mkdir build\boost\bin.v2\libs\iostreams\build common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99 common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99\debug common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi\file_descriptor.obj file_descriptor.cpp d:\src\vc\wcfb01\qa\vc\FE\3rdpartycomp\boost_1_60_0\boost/iostreams/positioning.hpp(107): error C3861: '_FPOSOFF': identifier not found libs\iostreams\src\file_descriptor.cpp(265): warning C4244: 'argument': conversion from 'std::streamsize' to 'DWORD', possible loss of data libs\iostreams\src\file_descriptor.cpp(289): warning C4244: 'argument': conversion from 'std::streamsize' to 'DWORD', possible loss of data cl /Zm800 -nologo @"build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi\file_descriptor.obj.rsp" ...failed compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi\file_descriptor.obj... compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi\mapped_file.obj mapped_file.cpp d:\src\vc\wcfb01\qa\vc\FE\3rdpartycomp\boost_1_60_0\boost/iostreams/positioning.hpp(107): error C3861: '_FPOSOFF': identifier not found libs\iostreams\src\mapped_file.cpp(59): warning C4244: 'return': conversion from 'const boost::iostreams::stream_offset' to '::size_t', possible loss of data libs\iostreams\src\mapped_file.cpp(325): warning C4244: 'argument': conversion from 'boost::iostreams::stream_offset' to 'SIZE_T', possible loss of data cl /Zm800 -nologo @"build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi\mapped_file.obj.rsp" ...failed compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi\mapped_file.obj... ...skipped <pbuild\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi>libboost_iostreams-vc-mt-gd-1_60.lib for lack of <pbuild\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi>file_descriptor.obj... ...skipped <pstage\lib>libboost_iostreams-vc-mt-gd-1_60.lib for lack of <pbuild\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi>libboost_iostreams-vc-mt-gd-1_60.lib... common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99\release common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi\file_descriptor.obj file_descriptor.cpp .\boost/iostreams/positioning.hpp(107): error C3861: '_FPOSOFF': identifier not found libs\iostreams\src\file_descriptor.cpp(265): warning C4244: 'argument': conversion from 'std::streamsize' to 'DWORD', possible loss of data libs\iostreams\src\file_descriptor.cpp(289): warning C4244: 'argument': conversion from 'std::streamsize' to 'DWORD', possible loss of data cl /Zm800 -nologo @"build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi\file_descriptor.obj.rsp" ...failed compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi\file_descriptor.obj... compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi\mapped_file.obj mapped_file.cpp .\boost/iostreams/positioning.hpp(107): error C3861: '_FPOSOFF': identifier not found libs\iostreams\src\mapped_file.cpp(59): warning C4244: 'return': conversion from 'const boost::iostreams::stream_offset' to '::size_t', possible loss of data libs\iostreams\src\mapped_file.cpp(325): warning C4244: 'argument': conversion from 'boost::iostreams::stream_offset' to 'SIZE_T', possible loss of data cl /Zm800 -nologo @"build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi\mapped_file.obj.rsp" ...failed compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi\mapped_file.obj... ...skipped <pbuild\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi>libboost_iostreams-vc-mt-1_60.lib for lack of <pbuild\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi>file_descriptor.obj... ...skipped <pstage\lib>libboost_iostreams-vc-mt-1_60.lib for lack of <pbuild\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi>libboost_iostreams-vc-mt-1_60.lib... ...failed updating 4 targets... ...skipped 4 targets... ...updated 10 targets... failed Billy3

8 18

[iterator] Is there any interest in Null Iterator Adaptor ?
by Rahman Salim Zengin 27 Sep '16

27 Sep '16

Hi! It would be pleasure for me to hear about your precious thoughts. https://github.com/rszengin/null_iterator Best regards.

3 5

Re: [boost] [fiber] Suggestions regarding asio
by Tatsuyuki Ishi 27 Sep '16

27 Sep '16

It would be better if you used "Reply to All", since I disabled the delivery from the list. > When considering using multiple threads with an io_service passed to a custom Boost.Fiber scheduler, I keep bumping into the problem that a given fiber scheduler instance must always run on its original thread -- but I know of no way to give an Asio handler "thread affinity." How do we get processor cycles to the scheduler on the thread whose fibers it is managing? Since we only poll on one master thread, we can easily get affinity. Maybe pseudocode is easier: * We have two class, one for main polling, others waiting for job. * The first one, polls from asio using the same way as the example (poll, or run_one). while(true) { if(!run_one()) stop_other_threads(); // No more work in asio, give up waiting poll(); // flush the queue // Now we should have some fibers in the queue. yield(); // continue execution } * Other threads, uses condvar to wait on the ready queue. awakened(){queue.push_back(f); cv.notify_[one,all](); iosvc.post([]{});} pick_next(){while(!jobs_available){cv.wait();} return job;}

5 7

Code complexity
by Vard Antinyan 27 Sep '16

27 Sep '16

Dear Boost developers, We have undertaken a task to assess code complexity triggers and generate recommendations for developing simple and understandable code. Our intension is to share the results with you, developers, so everyone can learn the triggers behind complex software. We need your help for rigorous results. My request to you is - if you get 5-10 min. time, would you please consider to answer the questions of this survey on code complexity? https://goo.gl/forms/h9WXZ8VSEw7BUyHg1 You are welcome to learn preliminary results through this link: https://www.facebook.com/SoftwareCodeQuality/photos/?tab=album&album_id=163… The results will be shared in a public webpage and everyone possible will be invited to learn and discuss them. Your knowledge and experience is vital for achieving substantial and generalizable results, and your effort is much appreciated! Sincerely Vard Antinyan PhD candidate in University of Gothenburg, Sweden Tel: 0046317725707

2 1

(Boost) Synapse update
by Emil Dotchevski 27 Sep '16

27 Sep '16

(Synapse is not part of Boost. I appreciate feedback as well as looking for someone willing to volunteer as review manager when Synapse is submitted for formal review.) Synapse is a signal-programming library similar to the Qt signal/slot system and Boost Signals 2. The difference is that Synapse is non-intrusive: any object of any static type whatsoever can serve as an emitter. I've just updated Synapse with support for interthread communication. It is available on github: http://zajo.github.io/boost-synapse/index.html. Thanks, Emil

3 5

Need help with errors while building boost for clang on android NDK
by Robert Dailey 26 Sep '16

26 Sep '16

I'm using NDK r11 and I'm setting up project-config.jam to build boost using clang + llvm STL. I'm running into a few errors that I do not know how to solve. I will post my config file at the bottom. First problem is that boost does not know where to find tools 'ar' and 'ranlib': clang-linux.archive bin.v2\libs\container\build\clang-linux-android\release\link-static\runtime-link-static\target-os-linux\threading-multi\libboost_container-clang-mt-s-1_61.a '"ar"' is not recognized as an internal or external command, operable program or batch file. '"ranlib"' is not recognized as an internal or external command, operable program or batch file. How can I explicitly specify the NDK path to these executables? Second problem is related to some assembler stuff, I think. I get these errors while compiling boost thread: clang-linux.compile.asm bin.v2\libs\context\build\clang-linux-android\release\link-static\runtime-link-static\target-os-linux\threading-multi\asm\make_i386_ms_pe_gas.o libs\\context\\src\\asm\\make_i386_ms_pe_gas.asm:30:1: error: unknown directive .def _make_fcontext; .scl 2; .type 32; .endef ^ libs\\context\\src\\asm\\make_i386_ms_pe_gas.asm:30:22: error: unknown directive .def _make_fcontext; .scl 2; .type 32; .endef ^ libs\\context\\src\\asm\\make_i386_ms_pe_gas.asm:30:36: error: expected identifier in directive .def _make_fcontext; .scl 2; .type 32; .endef ^ libs\\context\\src\\asm\\make_i386_ms_pe_gas.asm:30:40: error: unknown directive .def _make_fcontext; .scl 2; .type 32; .endef ^ libs\\context\\src\\asm\\make_i386_ms_pe_gas.asm:136:1: error: unknown directive .def __exit; .scl 2; .type 32; .endef ^ How can I solve this? I have no idea at this point. I'm invoking the build using: b2 --without-python threading=multi link=static runtime-link=static toolset=gcc-android target-os=linux threadapi=pthread --stagedir=android stage And my project-config.jam looks like: import option ; option.set keep-going : false ; androidNDKRoot = E:/android/ndk ; androidAbiVer = 4.9 ; androidPlatform = windows-x86_64 ; using clang : android : $(androidNDKRoot)/toolchains/llvm/prebuilt/$(androidPlatform)/bin/clang++ : <compileflags>--sysroot=$(androidNDKRoot)/platforms/android-15/arch-arm <compileflags>-Os <compileflags>-fno-strict-aliasing <compileflags>-O2 <compileflags>-DNDEBUG <compileflags>-g <compileflags>-I$(androidNDKRoot)/sources/cxx-stl/llvm-libc++abi/libcxxabi/include <compileflags>-I$(androidNDKRoot)/sources/cxx-stl/llvm-libc++/libcxx/include <compileflags>-I$(androidNDKRoot)/sources/cxx-stl/llvm-libc++/libs/armeabi-v7a <compileflags>-I$(androidNDKRoot)/sources/android/support/include <compileflags>-DANDROID <compileflags>-D__ANDROID__ <compileflags>-D__arm__ <compileflags>-D_REENTRANT ;

1 1

[Math/Special Functions] Is there any interest in the Lambert W function?
by Balázs Cziráki 26 Sep '16

26 Sep '16

Greetings! I'm working on a C++ implementation of the Lambert W (a.k.a. product logarithm or Omega function) and I wanted to ask the Boost developer community if there is interest in adding it to the library. The current version can be found on GitHub: https://github.com/CzB404/lambert_w/ I've successfully tested it with Cygwin GCC v5.4, v6.2 and with MinGW GCC that is supplied with Code::Blocks, and also on Visual Studio 2015. A test on a Linux based OS (probably Ubuntu) is also going to happen. Any suggestions or constructive criticism is welcome. Best regards, Balázs Cziráki

4 5

[range] sub_range of istream_range
by Andrew Hundt 26 Sep '16

26 Sep '16

I’m trying to iterate through a file using sub_ranges of an istream_range of an ifstream. However, it seems if I construct sub ranges of various subsets of the full istream_range, try to adjust the limits with advance_begin and advance_end, and then access them I get null dereferences. Any thoughts? I can produce an example if needed. Cheers! Andrew Hundt

1 0

markable -- informal review request
by Andrzej Krzemienski 24 Sep '16

24 Sep '16

Hi Everyone, I would like to ask your opinion, suggestions, and perhaps an informal review of the 'markable' library. An alternative to boost::optional when performance really matters. It is the second incarnation of the 'compact_optional' library that I have presented last year. The main differences from the previous version: * name change: it is called 'markable' so that it is not confused with 'optional'. It uses "mark values" and mark policies" * it has the ability to mark an empty state even for the types with strong invariants, by marking a bit pattern rather than any proper value of T (an idea by Matt Calabrese) An example use case: typedef markable<mark_int<int, -1>> opt_int; opt_int oi; opt_int o2 (2); assert (!oi.has_value());assert (o2.has_value());assert (o2.value() == 2); static_assert (sizeof(opt_int) == sizeof(int), ""); The github repository: https://github.com/akrzemi1/markable And documentation therein: https://github.com/akrzemi1/markable/tree/master/documentation Any comments, suggestions or critique are most welcome. Regards, &rzej;

4 8

[fiber] Suggestions regarding asio
by Tatsuyuki Ishi 22 Sep '16

22 Sep '16

The current example seems non-flexible and very hacky. 1. The timer handler has no problem, since it's expected to be called from any thread. (Description in "Deeper Dive into asio" is meaningless) 2. Possible alternatives: * A post(empty lambda) is a little bit waste but solves the threading problem. It wakes up one thread by doing interrupt of epoll etc. Maybe adding a interrupt method to asio codebase could be more efficient. * One thread doing event polling and the other doing condvar is enough. Since we're not expecting a slow handler (most times, it just make a fiber ready), this should be sufficient. Correct me if I'm wrong.

2 1

[interprocess] Improved shared_memory lifetime using file locks?
by Sebastian Theophil 21 Sep '16

21 Sep '16

Hi, coming from Windows, the filesystem persistence of basic_managed_shared_memory is giving us headaches. When we have N processes accessing the same shared memory, and one of them crashes, the other N-1 are in an undefined state. That’s the same on Windows and POSIX platforms and is ok for us. On Windows, the problem resolves itself when the other N-1 processes are all closed and then restarted, because Windows deletes the shared memory automatically. On POSIX systems, I think we can use file locks to make sure that the shared memory is reinitialized by the first process to access it. I’d appreciate any feedback, especially if it points out the problems with this approach: - basic_managed_shared_memory(boost::interprocess::open_or_create, …) opens the backing file with flags O_CREAT | O_EXLOCK | O_NONBLOCK - if that succeeds: - we are the first - (re-) initialize shared memory - also a good time to unlink/open the named POSIX semaphore that’s hanging around in an invalid state too! - degrade exclusive lock using flock(LOCK_SH) - else - open file with flag O_SHLOCK (open only, and blocking!) - when that succeeds, open shared memory Problems I can see: - Only works when (advisory) shared and exclusive locking and the degradation of one to the other is supported (at least flock not supported on Windows, e.g.) - What about other file systems? NFS? - Somebody could lock all your files. (OTOH, sb could also delete all my backing files all the time. My application would run, but not have any shared memory. Might be an advantage that my application does *not* run when the file is locked.) - What else? Is this worth implementing in boost.interprocess? I appreciate any feedback, Sebastian PS: I’ve googled previous discussions about shared memory lifetime in boost.interprocess. I don’t claim that my proposal gives the same semantics as Windows shared memory. It doesn’t and it seems impossible to achieve. I’m looking for, erm, usable semantics on POSIX systems. Clearly, everybody has to implement some lifetime tracking. It would be nice if boost.interprocess provided one or more solutions. -- Dr. Sebastian Theophil | stheophil(a)think-cell.com Senior Software Engineer We are looking for C++ Developers: https://www.think-cell.com/career think-cell Software GmbH | Chausseestr. 8/E | 10115 Berlin | Germany https://www.think-cell.com | phone +49 30 666473-10 | US phone +1 800 891 8091 Amtsgericht Berlin-Charlottenburg, HRB 180042 Directors: Dr. Markus Hannebauer, Dr. Arno Schödl

1 0

[release] 1.62.0 Master branch is closed
by Rene Rivera 21 Sep '16

21 Sep '16

The master branch is now closed for all changes, except by permission from a release manager. Thanks, The Release Team -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

1 0

[release] Boost 1.62.0. Beta 2
by Rene Rivera 20 Sep '16

20 Sep '16

The packages for 1.62.0 beta 2 are now available: <https://sourceforge.net/projects/boost/files/boost/1.62.0.beta.2/> The SHA256 checksums are as follows: 95feae3620b3e604e93f14d97195fc04a4b67063692859af8df19657d41b82d5 boost_1_62_0_b2.7z 27bc9b328ff73d7dbf80cd9d4b5f79b0878221e5d8e4b6c47444b135edc1080a boost_1_62_0_b2.tar.bz2 3939d5efa683449e87b374d7e92e3eeb6490063ddb2877919f0fad26e3a0f53e boost_1_62_0_b2.tar.gz cff9ab5db0928244c4c836cf3da5140e6e93db7756e2791ba99a21104ad3aa72 boost_1_62_0_b2.zip As always, the release managers would appreciate it if you download the archive of your choice and give building and using it a try. Please report both success and failure, and anything else that is noteworthy. Thanks! -- The release managers -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

4 9

Re: [boost] first steps to submitting - boost :: observers
by Bjorn Reese 19 Sep '16

19 Sep '16

On 09/17/2016 08:10 PM, Robert McInnis wrote: > https://github.com/tiny/boost_observers.git What are the advantages of this library over Boost.Signals2 [1]? Same question with regards to the Boost.Synapse [2] proposal. My impression from a brief look at your repository is that you need to focus more on thread-safety. Is there any way to avoid the overhead of thread synchronization in a single-threaded application? Observers are invoked while the mutex is locked, so observers cannot make calls on the subject. How does the lock-free mutex perform, especially when congested? Why is the lock-free mutex recursive? There are several member variables that are used as if they are atomic but they are not declared as such, e.g. Subject::_block, Numeric<T>::_x (think T == long long.) The Scope template can be replaced by lock_guard if you model the LockFreeMutex after the BasicLockable concept [3]. The thread_self() and thread_pid() functions can be replaced by this_thread::get_id(). Replace the hAtomic macro with a type alias. Use <cstdint> instead of <stdint.h> to reduce polution of the global namespace. [1] http://www.boost.org/doc/html/signals2.html [2] http://zajo.github.io/boost-synapse/ [3] http://en.cppreference.com/w/cpp/concept/BasicLockable

4 6

[density] version 7
by Giuseppe Campana 19 Sep '16

19 Sep '16

Hi to all, I’ve just merged to the master branch a major review of density, an header-only library of heterogeneous dense containers. Unfortunately this update includes some renamings. Anyway the new names are simpler and more explicative: heterogeneous_array, heterogeneous_queue, function_queue, lifo_array. The update consists of fixes and optimizations. The results of the benchmarks are included in the documentation. The container function_queue gives the best results, being many times faster than an std::queue of std::function’s (http://peggysansonetti.it/tech/density/html/func_queue_bench.html) The library is not yet ready for asking a formal review, but hopefully it will be in a few months. Html overview (now a little more schematic) and reference doc at http://peggysansonetti.it/tech/density/html/index.html Repository at https://github.com/giucamp/density/tree/master Giuseppe Campana.

1 0

Fuzzy string search to the Boost String Algortihm
by Зайцев Александр 19 Sep '16

19 Sep '16

Hello. I want to discuss about some proposals. I am working on Levenshtein distance and Damerau-Levenshtein distance algortihms. I hope, that these implementations will be pulled to the Boost String library. But i think that we can add to the Boost String Library some more algorithms for fuzzy searhing. I mean these algortihms: Levenshtein distance Damerau-Levenshtein distance Bitap algorithm with modifications by Wu and Manber Spell-checker method N-gram method Signature hashing method BK-trees What do you think about this idea? If you think that it can be implemented to the Boost String Algo, i will start work on this list immediately. Best regards, Zaitsev Alexander.

2 2

first steps to submitting - boost :: observers
by Robert McInnis 19 Sep '16

19 Sep '16

G'afternoon, This is my first time submitting to a public repo, please be gentle I'd like to submit a series of classes I have been using since '90. The initial set implements a thread safe subject/observer pattern. I have included a handful of example programs, two fairly trivial and the third more in-depth. All examples are single file examples to make compilation trivial. This is the first re-work of my original tools, making them more boost-friendly. I expect to add more default observer templates and observable objects, but that will come with time. WHY? -- The reason for these classes is to help insure the mathematical integrity of your data model in relation to your business rules. If at any time you were to change one of your data elements without updating all those dependent on it, then your data integrity would be compromised. These classes look to solve that. As an example: -- using namespace boost::observers ; Numeric<long> x, y, z ; // rules: y = x + 2; z = y * 3 ; x = 5 ; printf( "%d \n", z ) ; x = 1 ; printf( "%d \n", z ) ; -- Setting the rules properly, the classes allow for 'z' to be correct each time it's printed using code almost exactly like this. This will remove the possibility of accidently forgetting to trigger the rule update. WHERE? -- The repo can be found here: git clone https://github.com/tiny/boost_observers.git Any input on how to continue from this point would also be much appreciated. I have skype and ventrilo servers available if that helps. Thanks in advance, Rob -- Robert McInnis

5 7

[release] Boost 1.62.0 - One week to close.
by Rene Rivera 16 Sep '16

16 Sep '16

Reminder.. Next week, on the 21st, the release will close for all changes. Except for extra ordinary and approved changes. Please exercise caution when merging changes to master branches. Remember that changes need to be well tested on the develop branches before going into master. And that changes at this point should be for critical problems. Thanks, the Release Team. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

2 2

[uuid] PR to remove auto-linking to advapi32 when BOOST_ALL_NO_LIB is defined
by Edward Diener 15 Sep '16

15 Sep '16

I don't know how to resolve a PR for uuid ( https://github.com/boostorg/uuid/pull/11 ). If a library exists only as a DLL and not as a static library should BOOST_ALL_NO_LIB still be considered in effect ? My viewpoint is 'no' but the person who created the PR believes that the BOOST_ALL_NO_LIB config macro should turn off any #pragma auto-linking in code even when their is no other way to use a library other than as a shared library. What I am afraid of is breaking user code even if BOOST_ALL_NO_LIB is defined by producing link errors. But perhaps I am wrong and this should be considered justified when BOOST_ALL_NO_LIB is being used.

5 7

[algorithm] Musser-Nishanov sequence search algorithm
by Jeremy Murphy 15 Sep '16

15 Sep '16

Dear Boost community, most of you are probably familiar with Dave Musser, well known for his work on generic programming, introsort and more. What you maybe didn't know, and I didn't until not that long ago, is that he and Gor Nishanov also designed (based off KMP) and wrote a generic sequence search algorithm to compete with Boyer-Moore, etc, which apart from being competitively fast is ostensibly more generic than the others. You can read for yourself on Dave Musser's website: http://www.cs.rpi.edu/~musser/gp/algorithms.html By "more generic" I mean it has a fallback algorithm if the corpus does not have random-access iterators, and its behaviour can easily be tuned for the alphabet size to dramatic effect. (I haven't looked into the 'tunability' of BM, BMH, KMP, etc, so I'm not sure if this is a unique feature.) But at face value, it appears to have powerful features that the others lack without compromising performance, which is pretty neat. So I've been in contact with the original authors and with their permission am just playing the messenger to bring the algorithm to wider attention with the expectation that it is something we could really benefit from. What I hope for now is to have discussion on whether indeed it is an algorithm that we want, presumably alongside the others in Boost.Algorithm. My slightly more controversial thought is that, if no shortcomings or weaknesses are revealed, this could up being the superior search algorithm. I've opened a pull request on Boost.Algorithm with the code so everyone can play around with it if they want. https://github.com/boostorg/algorithm/pull/25 Looking forward to hearing what everyone thinks. Cheers. Jeremy

1 0

[uuid][rational] Pushed bug fixes to 'master'
by Edward Diener 15 Sep '16

15 Sep '16

I pushed some bug fixes from 'develop' to 'master' for the uuid and rational libraries. The fixes had been tested on the 'develop' branch for a long time and the results showed that the fixes were fine. While none of the fixes were major I felt that the fixes were important enough to go in the upcoming Boost release if they are going to be picked up. I, and probably other members of CMT, should have been more proactive in pushing these fixes to 'master' sooner, once they showed green on the develop test matrix.

2 3

Final Call for Extended Abstracts and Posters: International Conference on Information Society (i-Society 2016), Technical Co-Sponsored by IEEE UK/RI Chapter!
by David Brown, i-Society 2016 14 Sep '16

14 Sep '16

1 0

[log] Boost 1.62 cannot compile log with Oracle Developer Studio 12.5
by Aparna Kumta 14 Sep '16

14 Sep '16

Compiling Boost.log with Oracle Developer Studio 12.5, we see the following failure: % "CC" -std=c++11 -library=stdcpp,CrunG3 -xO4 -mt -erroff=%none -m32 -KPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_ATOMIC_DYN_LINK=1 -DBOOST_CHRONO_DYN_LINK=1 -DBOOST_DATE_TIME_DYN_LINK=1 -DBOOST_FILESYSTEM_DYN_LINK=1 -DBOOST_LOG_BUILDING_THE_LIB=1 -DBOOST_LOG_DLL -DBOOST_LOG_HAS_PTHREAD_MUTEX_ROBUST -DBOOST_LOG_WITHOUT_DEBUG_OUTPUT -DBOOST_LOG_WITHOUT_EVENT_LOG -DBOOST_SPIRIT_USE_PHOENIX_V3=1 -DBOOST_SYSTEM_DYN_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_THREAD_BUILD_DLL=1 -DBOOST_THREAD_DONT_USE_CHRONO=1 -DBOOST_THREAD_POSIX -DBOOST_THREAD_USE_DLL=1 -DDATE_TIME_INLINE -DNDEBUG -D_XOPEN_SOURCE=500 -D__EXTENSIONS__ -D__STDC_CONSTANT_MACROS -D__typeof__=__typeof__ -I"../../.." -I"../../../libs/log/src" -c -o "../../../bin.v2/libs/log/build/sun/release/stdlib-gnu/threading-multi/posix/ipc_reliable_message_queue.o" "../../../libs/log/src/posix/ipc_reliable_message_queue.cpp" "../../../libs/log/src/posix/ipc_reliable_message_queue.cpp", line 61: Error: #error Boost.Log: Native 32-bit atomic operations are required but not supported by Boost.Atomic on the target platform. This seems to be a configuration issue. The following changes seems to work: 1) In boost/atomic/detail/platform/platform.hpp % !diff diff ./platform.hpp ./platform.hpp_orig 46c46 < #elif (defined(__GNUC__) || (__SUNPRO_CC >= 0x5130)) && (defined(__i386__) || defined(__x86_64__)) --- > #elif defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) 68c68 < #elif (defined(__GNUC__) || (__SUNPRO_CC >= 0x5130)) && defined(__sparc) --- > #elif defined(__GNUC__) && defined(__sparc_v9__) The above change causes the compilation to proceed further, however, it fails again with another configuration issue causing failure to build atomic library "CC" -std=c++11 -library=stdcpp,CrunG3 -xO4 -mt -erroff=%none -m32 -KPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_ATOMIC_DYN_LINK=1 -DBOOST_ATOMIC_SOURCE -DNDEBUG -I"../../.." -c -o "../../../bin.v2/libs/atomic/build/sun/release/stdlib-gnu/threading-multi/lockpool.o" "../../../libs/atomic/src/lockpool.cpp" "../../../boost/atomic/detail/ops_gcc_sparc.hpp", line 69: Error: The function "fence_before_store" must have a prototype. In boost/atomic/detail/ops_gcc_sparc.hpp, the following change seems to resolve the issue % !diff % diff ./ops_gcc_sparc.hpp ./ops_gcc_sparc.hpp_orig 69c69 < fence_before(order); --- > fence_before_store(order); 71c71 < fence_after(order); --- > fence_after_store(order); 110c110 < fence_before(order); --- > base_type::fence_before(order); 118c118 < fence_after(order); --- > base_type::fence_after(order); I will submit a PR for this change. Thanks, Aparna

1 0

[filesystem] How to remove specific files from a directory?
by Andrzej Krzemienski 14 Sep '16

14 Sep '16

Hi, I wonder what is boost::filesystem recommendation for solving the following problem. I want to remove all files from a given directory that satisfy a certain predicate, e.g., only these whose names start with letter "s". It is my understanding that the calling filesystem::remove may invalidate the iterator, and therefore the following solution is incorrect: fsys::directory_iterator it{path}, itEnd{}; for ( ; it != itEnd ; ++it ) { if (predicate(*it)) fsys::remove(it->path()); } But, is the following guaranteed to work?: fsys::directory_iterator it{path}, itEnd{}; for ( ; it != itEnd ; ) { if (predicate(*it)) fsys::remove((it++)->path()); else ++it; } If not, does there exist a dedicated solution for solving this problem that would not require of me N traversals through the directory? Thanks, &rzej;

6 11

[release] Boost 1.62.0 Beta 1
by Rene Rivera 14 Sep '16

14 Sep '16

The first beta packages for 1.62.0 beta 1 are now available: <https://sourceforge.net/projects/boost/files/boost/1.61.0.beta.1/> The SHA256 checksums are as follows: f7cc83e6a3b03cd7aa8822992aa3e36422cc2214644d69277ef55a4db51f44bd boost_1_62_0_b1.7z 4057993811e40b1fd4719675e44c2550b6c2379546192da2299c17fec9a3dddf boost_1_62_0_b1.tar.bz2 fb0c10b625c5ec47cc837b54740540e400c59571b2eabf427c00f32bffc6ca70 boost_1_62_0_b1.tar.gz b38ef21c43c5ff814a2144bc23871c134164e7f51c71672d0f49a44636fb50b5 boost_1_62_0_b1.zip As always, the release managers would appreciate it if you download the archive of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. Thanks! -- The release managers -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

4 4

Re: [boost] [Boost-users] [release] Boost 1.62.0 Beta 1
by Rene Rivera 13 Sep '16

13 Sep '16

On Mon, Sep 12, 2016 at 12:44 AM, Oliver Kowalke <oliver.kowalke(a)gmail.com> wrote: > 2016-09-12 0:00 GMT+02:00 Tom Kent <lists(a)teeks99.com>: > >> Since the fiber build was a failure, >> > > should be fixed > Could someone try a build of the master snapshot to see if it's really fixed? I'm still in favor of a beta 2 build to make sure that gets flushed out >> before going to RCs. >> > > +1 > We can certainly do that. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

2 1

[math] Undefined reference to promote_args
by Florian Lindner 13 Sep '16

13 Sep '16

Hello, when compiling a file that uses float_distance from #include <boost/math/special_functions/relative_difference.hpp> I get a linking error: undefined reference to `boost::math::tools::promote_args<double, double, float, float, float, float>::type boost::math::float_distance<double, double>(double const&, double const&)' I try to add all boost_math libs I could find, but none helped: -lboost_system -lboost_filesystem -lboost_math_tr1 -lboost_math_c99 -lboost_math_c99 Since float_distance is not a C99 / TR1 function, shouldn't boost.math work as header only? What is the problem here? Thanks, Florian

2 1

[qi][endian]BOOST_ENDIAN_FORCE_PODNESS is defined in Qi
by Takatoshi Kondo 12 Sep '16

12 Sep '16

Hi, I'm using Boost.Endian with Boost.Qi. It seems that BOOST_ENDIAN_FORCE_PODNESS is defined at boost/spirit/home/support/detail/endian.hpp http://www.boost.org/doc/libs/1_61_0/boost/spirit/home/support/detail/endia… And boost/spirit/include/qi.hpp includes boost/spirit/home/support/detail/endian.hpp According to the Boost.Endian document, endian_buffer's constructors are disappeared by BOOST_ENDIAN_FORCE_PODNESS. http://www.boost.org/doc/libs/1_61_0/libs/endian/doc/buffers.html I'd like to use both endian_buffer's constructors and Boost.Qi. Is there any good way to do that? I don't know much abour Boost.Qi, but defining BOOST_ENDIAN_FORCE_PODNESS in the header file makes big side effects. For my workaround, I changed my include order. Sucessfully compiled http://melpon.org/wandbox/permlink/gSijxeBFJorWpzSd Error ocuured http://melpon.org/wandbox/permlink/FVffqcw8JEKGFXU0 --- Takatoshi Kondo

1 0

[property_tree] arrays in info files ?
by alainm 11 Sep '16

11 Sep '16

Hi, Is there a simple way to specify an array value with the info format, something like arr { 42 "" 43 "" 44 "" } but without the empty strings. thanks

1 0

docca: C++ Documentation XSLT library
by Vinnie Falco 09 Sep '16

09 Sep '16

Hi. When I developed Beast for Boost.Asio (https://github.com/vinniefalco/Beast) I lifted the xsl transforms from Boost.Asio (thanks Chris!) and adapted them. These scripts take the output of Doxygen and transform them into Boost.Book code (or QuickBook code or whatever its called). In other words, it creates a file called reference.qbk. This file is included in the documentation, which gets processed through a Jamfile to produce the HTML documentation that you see here: http://vinniefalco.github.io/beast/index.html This is great, and I am using the same system for my new key/value database engine (https://github.com/vinniefalco/NuDB/) The problem is that now I want to start another project and use the same documentation, but there is a considerable amount of copying going on here. The entire reference.xsl file is copied and placed in the new project: https://github.com/vinniefalco/NuDB/blob/master/doc/reference.xsl This file has to be edited significantly because it has references to project-specific namespaces, prefixes, and various other annoying minutiae. Therefore, I have started a new project called "docca:" https://github.com/vinniefalco/docca This project aims to refactor my variant of Boost.Asio's reference.xsl file so that it can be re-used in other projects. The procedure would be to create your own empty .xsl file, and include docca's xsl file after defining some variables. For example: <?xml version="1.0" encoding="utf-8"?> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0"> <xsl:variable name="namespace" select="'ripple::'"/> <xsl:include href="../include/docca/doxygen.xsl"/> </xsl:stylesheet> Above is the file you provide, while include/docca/doxygen.xsl is provided by docca (This is very much a work in progress). By this point many of you have fallen asleep, XSLT is a great cure for insomnia. If you're still awake you're probably very excited at the prospects of a turn-key solution for making great looking docs out of Javadoc comments in your C++ headers so I'll move right on to the questions: 1. Is there already a system for doing this? 2. If not, is there any interest in such a system? Is this project worth the effort? 3. Is this approach viable? Or is there a different approach? 4. Are these the right tools for the job? 5. Is there anyone out there who is fairly knowledgeable with XSLT and Boost.Book / QuickBook? Disclaimer: I am by no means an expert at either Boost.Book, Quick.Book, XSLT, or bjam. My only experience with these tools is recently, to put the Beast repository together. -- Follow me on Github: https://github.com/vinniefalco

2 1

Header-only singletons (was Re: [config] RFC PR 82)
by Vinnie Falco 09 Sep '16

09 Sep '16

On Mon, Aug 1, 2016 at 4:13 PM, Vinícius dos Santos Oliveira >...I want my library header only and Boost.System requires the category to > be a single static object and it'll even use address comparison to test if the > categories are the same: > ... > Is it guaranteed the above code will return the same object even if this > code was included in different libraries used by the same program? Sorry for the late reply. This header-only idiom works: inline boost::system::error_category const& my_category() { struct my_error_category : boost::system::error_category { ... }; static my_error_category cat; return cat; } This idiom also works: template<class = void> boost::system::error_category const& my_category() { struct my_error_category : boost::system::error_category { ... }; static my_error_category cat; return cat; } Justification: >From the C++ standard (see https://isocpp.org/std/the-standard) 7.1.6 describes inline functions. It says they must exist in every TU that they are used in, and must be the same in all TUs (no diagnostic required). 7.1.6 p6 also states that the address of an (extern) inline function shall be the same in all TUs. Elsewhere, the standard specifies that inline functions are extern by default. Empirical evidence also supports these claims, both of the aforementioned idioms have been used extensively in my projects under gcc, clang, and msvc. This likely upcoming feature (maybe its already in?) further cements support for global variables in header-only libraries: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4424.pdf However, even in the absence of additional language features, the ability to have global variables in header-only libraries exists today, with nothing more than C++11 support. Hope this helps!

1 0

[config] recent change to suffix.hpp causing several failures for Oracle Developer Studio 12.5
by Aparna Kumta 09 Sep '16

09 Sep '16

A recent change to suffix.hpp seems to cause several tests to fail when compiling with Oracle Developer Studio12.5. The error is: "CC" -std=c++11 -xO4 -mt -erroff=%none -m32 -DBOOST_ALL_NO_LIB=1 -DBOOST_CHRONO_STATIC_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_SYSTEM_STATIC_LINK=1 -DBOOST_TEST_NO_AUTO_LINK=1 -DBOOST_TIMER_STATIC_LINK=1 -DNDEBUG -D__typeof__=__typeof__ -I".." -c -o ./count.o" "../libs/accumulators/test/count.cpp" "../boost/config/suffix.hpp", line 628: Error: Badly formed constant expression. <snipped> See: http://www.boost.org/development/tests/develop/developer/output/oracle-spar… % diff ./suffix.hpp ./suffix.hpp_orig 626a627,630 > # elif defined(__has_cpp_attribute) > # if __has_cpp_attribute(noreturn) > # define BOOST_NORETURN [[noreturn]] > # endif % Thanks, Aparna

2 1

[test] Test failures for gcc 4.6
by Andrey Semashev 09 Sep '16

09 Sep '16

Hi, I'm seeing these test failures for gcc 4.6 (MinGW): http://www.boost.org/development/tests/develop/developer/output/igaztanaga-… Looks like the error originates from Boost.Test, and I can also see lots of failures in Boost.Test itself for that compiler. Is this a known problem? Any fixes planned?

2 5

Gmane going away
by Tom Kent 07 Sep '16

07 Sep '16

So it looks like Gmane is under attack and the guy who runs it is thinking about just turning it off (that would be sad). https://lars.ingebrigtsen.no/2016/07/28/the-end-of-gmane/ Anyway, I know a lot of boost users use is as the gnu mailman archive pages are really hard to use. I would like to propose that we (specifically the list owner(s)) mirror the boost mailing lists to the mail-archive.com site. It has good search features and decent thread browse-ability. Thoughts? Tom

8 9

[release] documentation of 1.62 betaX
by Raffi Enficiaud 06 Sep '16

06 Sep '16

Hi, I cannot see the documentation of any of the libraries from http://www.boost.org/doc/libs/1_62_0_beta1/ . Can anyone please indicate me where I may check the generated online documentation for the betaX/RCX? Thanks, Raffi

2 3

[release] 1.62 Open for fixes.
by Rene Rivera 06 Sep '16

06 Sep '16

Reminder.. The master branch is open for bug fixes, and doc changes, without permission. Any other changes need the permission of a release manager. The release team. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

2 2

boost.Test: new patch for 11756
by André Draszik 05 Sep '16

05 Sep '16

Hi, I have attached a patch to https://svn.boost.org/trac/boost/ticket/11756 can somebody comment and/or apply it please? I'm not trying to be pushy, just writing here since it seems that it can happen that people see traffic on a bug, but don't realise that a patch was attached. Thanks! Andre'

2 2

Boost-1.62: How to get list of all dirs under 'run-tests libs:' target from status/Jamfile?
by Sergey Sprogis 04 Sep '16

04 Sep '16

I use latest Boost versions to test new C++ compiler in development stage. It's important for me to know what would be "pass rate" for every library which Boost.org reports on its Regression Testing website. To calculate all those pass rates I created script which goes inside every library's 'test', 'example' or whatever subdirectory and launches bjam from there. It creates a separate logfile(s) for every library which I then analyze to calculate "pass rate". But before launching my script I need to know the whole list of dirs which Boost.org uses for its Regression testing. In the previous Boost-1.61.0 version I was able to easily produce such list by extracting it from 'status/Jamfile.v2'. It looked like this: run-tests libs : accumulators/test # test-suite accumulators algorithm/test # test-suite algorithm algorithm/minmax/test # test-suite algorith/minmax ... concept_check # test-suite concept_check config/test # test-suite config container/bench # test-suite container benchmarks container/example # test-suite container_example ..... As you may see this list contains not only 'test' subdirs, but also some others: 'example', 'bench', etc. But now the problem is that in Boost-1.62.0 'status/Jamfile.v2' does not have such full list anymore. Could anyone suggest me some hack how to produce the full list of tested libraries for Boost-1.62.0, similar to one which Boost-1.61.0 has? It would be nice if bjam will eventually have a special option which will allow to produce such list, but for now I'd appreciate just a hack which will help me to solve this issue. Thanks, Sergey

2 1

[test] Unrecognized option -u
by Andrey Semashev 03 Sep '16

03 Sep '16

Hi, I'm seeing test errors about unrecognized option -u presumably from Boost.Test, see here for example: http://www.boost.org/development/tests/develop/developer/output/teeks99-09b… The test in question is not mine, and I don't know what the -u option is supposed to be for, but I assume it was supported by Boost.Test at some point and now it isn't. Is this an intended change in Boost.Test, an oversight or just a mistake in the Jamfile? If it was supported by Boost.Test, what did the option do and is it ok to just remove it?

3 4

[release] Can I push a bug fix?
by Andrzej Krzemienski 01 Sep '16

01 Sep '16

Hi all, Do I need permission now to push a bug fix to master? I intend to put this fix: https://github.com/boostorg/optional/commit/5d5d1f46baac851c8ec0ca15059d3e7… Regards, &rzej;

2 1

Please add component "dll" to track
by Antony Polukhin 31 Aug '16

31 Aug '16

Subj. Thanks! -- Best regards, Antony Polukhin

1 0

compiling boost using C++11 atomics
by André Draszik 30 Aug '16

30 Aug '16

Hi, Is there any particular reason that boost isn't being compiled with BOOST_AC_USE_STD_ATOMIC and BOOST_SP_USE_STD_ATOMIC (by default) when C++11 support in g++ is available (g++ >= 4.7)? Thanks, Andre'

3 5

[PropertyTree] Pull request removing usage of typeid()
by Chris Glover 29 Aug '16

29 Aug '16

Hi, In February, I submitted a pull request that removes the usage of typeid from property_tree and replaces it with boost.type_index. This allows me to use property_tree with rtti disabled, which I need sometimes. https://github.com/boostorg/property_tree/pull/20 I've had no feedback on the change. Can it be merged? Thanks, -- chris

2 2

[graph] Dinic's algorithm and BGL
by Зайцев Александр 29 Aug '16

29 Aug '16

Hello. In the Boost Graph Library i can't find Dinic's algorithm (https://en.wikipedia.org/wiki/Dinic%27s_algorithm) I think there isn't implementation of this algo in the library. Why? Best regards, Alexander Zaitsev.

2 2

[algorithm] Adding suffix automata, suffix array
by Зайцев Александр 29 Aug '16

29 Aug '16

Hello. I implemented Aho-Corasick to Boost.Algorithm. It's very useful algorithm, but i think that there are more useful algorithms, like suffix automata and suffix array. They can solve a lot of specific task on sequences of values: searching subsequences, count number of different subsequence, etc. Can i start work on it? ----- Best regards, Alexander Zaitsev.

2 3

[Boost.Book] How to go full-bleed on documentation image headers?
by Vinnie Falco 29 Aug '16

29 Aug '16

On the Boost website, the image in documentation headers is full bleed (no white border). For example: http://www.boost.org/doc/libs/1_61_0/doc/html/boost_asio.html How do I achieve this in my own documentation? I have set the image in the Jamfile, but I have no idea how to adjust the border: http://vinniefalco.github.io/beast/index.html The Jamfile and supporting source files are here: https://github.com/vinniefalco/Beast/tree/master/doc Thanks

2 1

[predef] macro to detect OS version on Solaris
by Aparna Kumta 28 Aug '16

28 Aug '16

I looked at the predef documentation and see BOOST_OS_SOLARIS macro to detect the Solaris OS. Is there a way I can detect the Solaris version? Thanks, Aparna | | <http://www.boost.org/doc/libs/1_61_0/libs/predef/doc/html/predef/reference/…>

3 2

[algorithm] Discuss about Aho-Corasick implementation
by Зайцев Александр 28 Aug '16

28 Aug '16

Hello. I implemented Aho-Corasick for Boost.Algorithm. I think that a lot of developers are interested in this and can look through my code and guess some suggestions. You are welcome: https://github.com/ZaMaZaN4iK/algorithm/blob/feature_branch/aho_corasik/inc… -- Best regards, Alexander Zaitsev

1 0

[Root.Ptr] Review Schedule Listing Fix
by Phil Bouchard 27 Aug '16

27 Aug '16

Greetings, In the formal review schedule page: http://www.boost.org/community/review_schedule.html Is it possible for somebody to: - Change the name of the submission "Block Pointer" to "Root Pointer" - Point the source code to: https://github.com/philippeb8/root_ptr - Point the documentation to: http://philippeb8.github.io/root_ptr This way people will at least be able to read something about Root.Ptr! ;) Regards, -Phil

2 2

[test] request to integrate a bugfix to master
by Raffi Enficiaud 26 Aug '16

26 Aug '16

Dear all, Please move boost.test to rev f68df446a4a5a3873e262364b56c5c2446216ae6 as it contains an important bug fix in case header only version of boost.test is used. Thanks and sorry for the noise, Raffi

2 1

[test] All geometry regression tests failing in develop and master
by Rene Rivera 25 Aug '16

25 Aug '16

Tagging subject for visibility. But this obviously needs to get resolved ASAP.. On Wed, Aug 24, 2016 at 3:53 AM, Barend Gehrels <barend(a)xs4all.nl> wrote: > Hi, > > It seems that nearly all regression tests are failing for us in both > develop and master: > > http://www.boost.org/development/tests/master/developer/geometry.html > > With the messages like: > > disjoint.obj : error LNK2001: unresolved external symbol > "public: virtual void __cdecl boost::unit_test::output::juni > t_log_formatter::log_start( > class std::basic_ostream<char,struct std::char_traits<char> > &,unsigned > long)" > (?log_start@junit_log_formatter@output@unit_test@boost@@ > UEAAXAEAV?$basic_ostream@DU?$char_traits@D@std@@@std@@K@Z) > > > We use Boost.Test (header-only), is there something changed there? Do we > need to change our Jam file? (of course we want to keep it header-only). > > The failures are new, before my one-week holiday it was still all OK. > > Regards, Barend -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

3 4

]dynamic_bitset] develop change never merged to master
by Edward Diener 25 Aug '16

25 Aug '16

In going through the CMT libraries for the upcoming release I noticed a longstanding change to dynamic_bitset on the 'develop' branch that added capacity, reserve, and shrink_to_fit functionality which had never been merged to the 'master' branch. The change is purely to add functionality rather than a bug fix, but it has been tested successfully on the 'develop' branch for a long while now. Do we want this functionality in the upcoming release ? If not, this change can be merged to 'master' after the release is out for the next release.

2 2

[release] Boost 1.62 now closed.
by Rene Rivera 25 Aug '16

25 Aug '16

Reminder.. The Boost 1.62 release, i.e. master branches, are now closed. Any change requires approval from a release manager. The release will reopen for bug fixes a week from now after the beta is posted. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

6 8

All geometry regression tests failing in develop and master
by Barend Gehrels 24 Aug '16

24 Aug '16

Hi, It seems that nearly all regression tests are failing for us in both develop and master: http://www.boost.org/development/tests/master/developer/geometry.html With the messages like: disjoint.obj : error LNK2001: unresolved external symbol "public: virtual void __cdecl boost::unit_test::output::junit_log_formatter::log_start( class std::basic_ostream<char,struct std::char_traits<char> > &,unsigned long)" (?log_start@junit_log_formatter@output@unit_test@boost@@UEAAXAEAV?$basic_ostream@DU?$char_traits@D@std@@@std@@K@Z) We use Boost.Test (header-only), is there something changed there? Do we need to change our Jam file? (of course we want to keep it header-only). The failures are new, before my one-week holiday it was still all OK. Regards, Barend

1 0

[Quickbook] Quickbook, SVG, graphviz dot
by Matt Calabrese 23 Aug '16

23 Aug '16

This is something of a stretch, but I'm hoping someone has a simple solution to my problem. I'm using Quickbook and in my docs I'm including an SVG that I generated from a graphviz dot file, which was also automatically generated from code that I'm documenting. Inside each of the nodes in the graph contained in the SVG, I would like to have source code snippets that are formatted in a way that is consistent with code snippets that are embedded in Quickbook files. Ideally, I'd like to even include Quickbook links in that source code, though I think that's likely a bit harder (my Quickbook code snippet files are usually written in a way that compiles in C++ but on the Quickbook end also replaces known functions with links to their corresponding docs -- I'd like to have that even in the nodes of the generated graph). I'm not certain where precisely to start as I'm rather far outside of my usual domain here. I pretty sure that it must be feasible in some way, as I know that SVG can embed links and use css, etc. but I'm not sure precisely how I should try to tackle this. Perhaps I can create some kind of post-process to run on the SVG that was generated from the dot file? Is there something simpler than this? Any ideas are appreciated. -- -Matt Calabrese

1 0

Re: [boost] double_ended - request formal review
by Mathias Gaunard 23 Aug '16

23 Aug '16

On 15 July 2016 at 16:51, Benedek Thaler <thalerbenedek(a)gmail.com> wrote: > Dear Boost, > > I'd like to request the review of the double_ended library. > > Code: https://github.com/erenon/double_ended > Documentation: http://erenon.hu/double_ended > > The library contains two classes. Excerpt from the documentation: > > * `devector` is a hybrid of the standard vector and deque containers, as > well as the small_vector of Boost.Container. It offers cheap (amortized > constant time) insertion at both the front and back ends, while also > providing the regular features of std::vector, in particular the contiguous > underlying memory. In contrast to the standard vector, however, devector > offers greater control over its internals. Like small_vector, it can store > elements internally without dynamically allocating memory. Not related to your request per-se, but I think this occasion is as good as any to discuss the library. devector is an interesting variant of vector, but it gives the illusion that is could be used as a queue. However given the implementation, it seems elements removed from either end will never be reclaimed. I suggest documenting that limitation or having a threshold above which memory is actually freed.

4 5

[CallableTraits] Seeking Review Manager
by Barrett Adair 23 Aug '16

23 Aug '16

Boost Developers, CallableTraits is a C++11/14/17 library for the inspection, synthesis, and decomposition of callable types. CallableTraits aims to be the "complete type manipulation facility for function types" mentioned in the final paragraph of C++17 proposal p0172. Library: https://github.com/badair/callable_traits Docs: http://badair.github.io/callable_traits/doc/html/index.html Boost Library Incubator: http://blincubator.com/bi_library/callabletraits-2/?gform_post_id=1574 Current Version: 1.0.1 I've received some great feedback on the mailing list. I consider the current version to be production-ready, which includes excellent cross-platform test coverage and thorough documentation filled with examples. Does anyone wish to be a review manager for this library? It is not a very large codebase, although the implementation is config-heavy and relatively noisy. The Library Submissions page on the Boost website indicates that a library manager should be found before requesting a formal review, but I noticed that there are many "scheduled reviews" that do not have a library manager. May I request a review as well? Thank you, Barrett

3 3

[release] Boost 1.62 closed for major changes.
by Rene Rivera 19 Aug '16

19 Aug '16

Reminder Boost 1.62, i.e. the master branches, are now closed for major changes. The only changes that should be going in at this time should be bug fixes for serious problems. Any documentation changes are fine to go in. And remember... Boost 1.62 will close for all changes a week from today. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

4 8

[odeint ] Can fix for ticket #12034 be merged into master branch?
by Aparna Kumta 19 Aug '16

19 Aug '16

The fix for Boost ticket #12034 has been in the develop branch for about 6 months now. Could this please be merged into the master branch so it makes it in for Boost 1.62 release? Thanks, Aparna

1 0

[circular_buffer] Synchronize master with develop
by Andrey Semashev 18 Aug '16

18 Aug '16

Hi, I've created this PR to synchronize master with develop for Boost.CircularBuffer: https://github.com/boostorg/circular_buffer/pull/10 Rene has given the permission to merge in the "[boost] [release] Boost 1.62 closed for major changes." thread. I would appreciate if someone with permissions could merge the PR. Thanks.

1 0

Status on Travis
by Raffi Enficiaud 18 Aug '16

18 Aug '16

Hi dear list, Hi Rene, I would like to know more about Travis and its status. From what I understand, a lot of efforts have been made recently for making things running per commit on Travis and have a quick feedback. * Naturally the first question is: is the status given by Travis the "official" one? so we consider the status given by Travis an official source of information, especially wrt. to its competing regression dashboard. * What are the development plans for Travis? Right now I see 3 types of builds, and I do not fully understand what they cover (platform, compiler) nor their differences. * For boost.test, I am testing each feature branch before merging to develop, by 1. cloning boost superproject on develop 2. switching only boost.test to the feature branch This is for preventing the breakages on develop that we observed in the past since several libraries are depending on boost.test. Would it be possible to have that as well on Travis or any continuous CI? That would be per library then. Would it also be possible to have like a template .travis.yml coming from the boost.superproject which can partly be overiden by a library? (if we want to build things slightly differently) * The CI I am using is able to parse the junit files generated by the test framework, and summarizes the information of each build nicely (also tracks the tests history). Is there anything similar in Travis? Right now, apart from looking at the full logs (which is hard), is there any intermediate information than red/green overall status? * I can see many project under the boostorg of Travis https://travis-ci.org/boostorg/ . How do we do that? Thanks, Raffi

3 4

[Beast] Status: HTTP+WebSocket for Boost
by Vinnie Falco 17 Aug '16

17 Aug '16

I’m reporting on the status of Beast, a C++11 header-only library implementing HTTP and WebSocket which is submitted to the boost incubator. The official repository for Beast is at: https://github.com/vinniefalco/Beast It has been a few months since the last update and the number of users measured on GitHub has grown steadily. There is robust, active development with bug fixes and improvements. Unfortunately there hasn’t been much of in terms of attention from the Boost community, no feedback from the incubator was provided. If anyone would like to help out by checking out Beast in the incubator and leaving some comments that would be a tremendous help. Incubator link: http://blincubator.com/bi_library/beast-2/?gform_post_id=1579 The most exciting news is that Beast HTTP and WebSockets have been deployed in the production server environment for the company I work for, Ripple (http://ripple.com) On a side note, my co-worker David Schwartz is giving a CppCon 2016 Keynote speech on the relationship of C++ to public blockchain systems and cryptocurrencies: http://cppcon.org/schwartz-keynote-turner-plenary/ You can see the Beast integration in “rippled”, an open source server application that implements Ripple’s decentralized ledger: https://github.com/ripple/rippled/tree/develop/src/ripple/server/impl I will be doing a 15 minute lightning talk introducing CppCon 2016 conference attendees to Beast. The talk will have 8 minutes of presentation with the remainder of the time allocated for questions (if there are no questions I have additional materials which can be presented). At the conference I would love to meet anyone who is interested in the library or wants to have their questions answered - feel free to reach out to me through my email address vinnie.falco(a)gmail.com (also listed on my GitHub profile) if you’d like to get in contact. Thanks! -- Follow me on Github: https://github.com/vinniefalco/Beast

2 1

[contract] Contracts for constexpr functions
by Lorenzo Caminiti 16 Aug '16

16 Aug '16

Hello all, A couple of the proposals I read on adding Contract Programming to the C++ standard raise the question if contracts should be supported for constexpr functions or not. I tough about this question a bit... but I am still not sure of the answer. I wanted to discuss this topic with this mailing list, especially with respect to what Boost.Contract can currently do. My general impression is that preconditions, postconditions, and class invariants should useful for constexpr functions but noting that: * Probably old values will not be useful in constexpr functions because constexpr prevents its functions from having side-effects (so it seems there will no variable visible outside of the function that the function body can change, and those variables are usually the candidates for making old copies). * Subcontracting will never apply to constexpr functions because they cannot be virtual. For example: struct conststr { // No virtual function so no subcontracting. [[invariant: empty() == (size() == 0)]] // Useful class invariants. [[invariant: data() != nullptr]] template<unsigned N> constexpr conststr(char const (&s)[N]) [[requires: s != nullptr]] // Useful preconditions. : data_(s), size_(N - 1) {} constexpr char back() const [[ensures(result): result == data()[size() - 1]]] // Useful postconditions. // Old values never useful because constexpr has no side-effects? { return data_[size_ - 1]; } constexpr unsigned size() const { return size_; } constexpr bool empty() const { return size_ == 0; } constexpr char const* data() const { return data_; } private: char const* data_; unsigned size_; }; That said, if I understand it correctly, the following are not allowed from within constexpr functions: 1. (Literal) type local variables with non-trivial constexpr destructors (see N3597 and subsequent proposals). 2. Try-catch statements (see N3597 and subsequent proposals). 3. Lambda functions (see N4487). Reading a few proposals, it seems that supporting the above from constexpr functions would be technically possible, but difficult to implement (see N3597 and its subsequent proposals, N4487, etc.). I'm not really familiar with these constexpr restrictions and plans/discussions to relax them in future revisions of the standard... Boost.Contract implementation uses all the above 1-2-3 respectively to: a. Check class invariants and postconditions at function exit (using RAII). b. Catch assertion failures as well as any other exception that might occur while evaluating an asserted conditions and then call the appropriate contract failure handler. c. Conveniently program functors that check pre- and postconditions within the contracted function. Therefore Boost.Contract implementation does not currently support contracts for constexpr functions. --Lorenzo

2 1

'is_palindrome' and 'const char*'
by Зайцев Александр 14 Aug '16

14 Aug '16

Hello. I have some question about some case for 'is_palindrome' algo. 'is_palindrome' algorithm checks a sequence - if sequence is a palindromeor empty, function returns true, in other cases returns false. But in case e.g. "a" (is_palindrome("a")) result is false, because "a" = {'a', '\0'}. And maybe this behaviour is unexpected for users. So... what do you think about it? Should I implement special version for const char* or not? -- Best regards, Zaitsev Alexander

3 4

filesystem 1.61.0 and cygwin: Windows assumed, posix expected
by Frédéric Bron 12 Aug '16

12 Aug '16

Hi, On cygwin, the following program #include <iostream> #include <boost/filesystem.hpp> int main() { auto p = boost::filesystem::path{"foo"}; p /= "bar"; std::cout << p.string() << '\n'; return 0; } outputs: foo\bar but cygwin is a posix system and I expect: foo/bar I read in the doc that "User-defined BOOST_POSIX_API and BOOST_WINDOWS_API macros are no longer supported." So how can I have posix support on cygwin? Thanks, Frédéric

1 1

[graph] Sync develop with master?
by Murray Cumming 12 Aug '16

12 Aug '16

Now that Boost 1.61 is out, it would be great if the various fixes in boost graph's develop branch could be merged/cherry-picked/whatever to master, please. There seem to be a couple of years of fixes that have not appeared in a release. -- Murray Cumming murrayc(a)murrayc.com www.murrayc.com

5 21

[thread][circular_buffer] Unmerged changes for 1.62
by Andrey Semashev 12 Aug '16

12 Aug '16

Hi, There are a couple of my PRs hanging for quite some time that I'd like to be merged before 1.62 is released: https://github.com/boostorg/circular_buffer/pull/9 Changes the default implementation of circular_buffer in debug mode to the thread-safe by default. https://github.com/boostorg/thread/pull/92 Fixes compilation of Boost.Thread with MSVC-8. There is also https://github.com/boostorg/thread/pull/94, which is not mine but it looks like it fixes a genuine problem. Could someone have a look at them and merge? Thanks.

2 3

[interprocess] weirdest bug with offset_ptr equality comparison
by Joaquin M López Muñoz 11 Aug '16

11 Aug '16

The following is a distilled testcase after the ticket reported at https://svn.boost.org/trac/boost/ticket/12367 #include <boost/interprocess/allocators/allocator.hpp> #include <boost/interprocess/managed_shared_memory.hpp> template<typename Allocator> struct node_base { using allocator_type=Allocator; }; template<typename Allocator> struct node_impl { using value_type= typename Allocator::template rebind<node_impl>::other::value_type; }; template<typename Super> struct trampoline:node_impl<typename Super::allocator_type>{}; template<typename Super> struct node:Super,trampoline<Super>{}; int main() { using node_type= node< node< node_base< boost::interprocess::allocator< int, boost::interprocess::managed_shared_memory::segment_manager > > > >; using pointer=boost::interprocess::offset_ptr<node_type>; pointer p=nullptr; bool b=(p==p); // here's the problem } This works fine with GCC. When compiled with Visual Studio 2015, we get: 1>------ Build started: Project: borrame2015, Configuration: Debug x64 ------ 1> sandbox.cpp 1>d:\usr\joaquin\proyectos\boost-repo\trunk\boost\interprocess\detail\mpl.hpp(74): error C2594: 'argument': ambiguous conversions from 'node<node<node_base<boost::interprocess::allocator<int,boost::interprocess::segment_manager<CharType,MemoryAlgorithm,IndexType>>>>> ' to 'node_impl<boost::interprocess::allocator<int,boost::interprocess::segment_manager<CharType,MemoryAlgorithm,IndexType>>> ' 1> with 1> [ 1> CharType=char, 1> MemoryAlgorithm=boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,ptrdiff_t,size_t,0x00>,0x00>, 1> IndexType=boost::interprocess::iset_index 1> ] 1> d:\usr\joaquin\proyectos\borrame2015\sandbox.cpp(39): note: see reference to class template instantiation 'boost::interprocess::ipcdetail::is_convertible<node_type *,PointedType *>' being compiled 1> with 1> [ 1> PointedType=node_impl<boost::interprocess::allocator<int,boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,ptrdiff_t,size_t,0x00>,0x00>,boost::interprocess::iset_index>>> 1> ] ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ========== Note that it is the line bool b=(p==p); // here's the problem that triggers the problem; if removed, compilation goes fine. Almost anything in the testcase program is needed for the problem to arise: - using node_type=node<node<...>> --> using node_type=node<...> (just one node level): compilation OK - remove using value_type=... in node_impl: compilation OK - rebind<node_mpl> --> rebind<char>: compilation OK - use std::allocator rather than boost::interprocess::allocator: compilation OK Ion, I'm totally puzzled by this and unable to navigate through the internals of Boost.Interprocess. Totally at your disposal if you need further info or assistance running tests etc. Thank you, Joaquín M López Muñoz

2 3

[contract] noexcept and throwing handlers
by Lorenzo Caminiti 10 Aug '16

10 Aug '16

Hello all, I would like to discuss contracts and exception specifications (e.g., noexcept) specifically with respect to what Boost.Contract does. On one hand, it seems silly to allow a contract failure handler to throw an exception to only translate such an exception into a call to terminate() for noexcept functions. However, noexcept can be considered part of the function contract (namely, the contract that says the function shall not throw) and contract failure handlers should not be allowed to break such contract, not even when they are allowed to throw. For example consider a noexcept function fclose() that is called from a destructor without a try-catch statement (correctly so because fclose is declared noexcept). If fclose() is now allowed to throw when its preconditions fail, that will cause the destructor ~x() to throw as well?! void fclose(file& f) noexcept [[requires: f.is_open()]] ... class x { ~x() noexcept { fclose(f_); // f_ might not be open because of some bug... ... } file f_; }; (A point similar to the above is also made in N4160, in contrast with what argued in N4110.) Functions should honor their exception specifications (noexcept, etc.) even when their contracts fail and contract failure handlers are configured to throw. That is what Boost.Contract does (given that contract checking code appears within the function definition so it is subject to the exception specifications that appear in the enclosing function declaration): void fclose(file& f) noexcept { // This will call terminate()... boost::contract::guard c = boost::contract::function() .precondition([&] { BOOST_CONTRACT_ASSERT(f.is_open()); // ...even if this throws. } ; ... } int main() { boost::contract::set_precondition_failure( [] (boost::contract::from where) { // Re-throw exceptions (assertion_failure, user-defined, etc.). if(where != boost::contract::from_destructor) throw; std::terminate(); // But destructors never throw. } ); ... } Also note that a contract framework that allows to install failure handlers that throw exceptions should also pass some sort of parameter to the handler function to indicate if the contract failure happened in a destructor or not. That is so the failure handlers can choose to never throw for destructors, not even if class invariants (or postconditions) fails when checked by destructors. --Lorenzo

3 4

[release] Continuous release archives.
by Rene Rivera 09 Aug '16

09 Aug '16

Starting with this release the archives for the prospective beta and release candidates are continuously built from the master branch and uploaded to SourceForge [1] (and to Bintray [2]). The release team would really appreciate if authors would download the archives and check the contents. In particular that the archives contain all the content you expect of your library, or libraries. And if you can also try building in your system that would stupendous. The more eyes we have on the final release products the smoother the process will be. And result in more time that the master branch is not blocked. Please report any problems sooner rather than later. So that we can try and address them before it's took late. Thank you, The Release Team [1] <https://sourceforge.net/projects/boost/files/boost/snapshots/master/> [2] <https://bintray.com/boostorg/master/snapshot#files> -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

5 7

Feature suggestions for Boost's program_options
by Eyal Rozenberg 09 Aug '16

09 Aug '16

Greetings Boost developers, [ Disclaimer: I'm new to this list - I joined by Vladimir Prus' suggestion that I raise my feature ideas here on the list. I've read the posting guidelines, and I haven't seen any discussion of program_options (at least not by Vladimir himself) for at least a year back in the list archives, so I think my post is legit. ] I've been using Boost's program_options library for several months now. It mostly does the job (that's a compliment...) - but there are some features whose lack is really bugging me. For some of them (especially Feature Idea 1) I actually work around by taking some options as unparsed remainders, sticking them in a string->string map and parsing them myself. Without further ado, and in decreasing order of importance to me: -------------------------------- Feature Idea 1: Support specifying multiple alternative long option names, using comma-separation. Right now we can specify, for example, "include-path,I" - one short form, one long form. Why not allow specifying "include-path,include-dir,headers-path,I" ? Only the first long option name would be printed as part of the usage information, to not complicate things overmuch, and merely tolerate alternative phrasing. Feature Idea 2: Have a (new?) parser which supports taking "semi-parsed command-line options" as input: A map from string keys to string values, or to optional<string> values to represent options without an argument as well. This is actually very close to environment parsing, except that the environment parser gets its "map" from, well, the environment variables. So the implementation might be simply exposing the existing functionality with a slightly richer interface. Feature Idea 3: A facility for pretty-printing parsed options to an std::ostream, in which the option description starts the line, and the option value (not the name used for parsing) is printed after it. There is some pretty-printing for the usage info to the console, so why not this? (Argument against this idea: Choosing a default is a very touchy subject. Counter-argument: ... but that's also somewhat true of printing usage information; and nobody has to use this default, it would be entirely optional.) Feature Idea 4: Support three rather than just two levels of describing options: name, for the command line; short description, for listing values (see Feature Idea 3; long description for the usage info. Feature Idea 5: Create a variant of update_with which doesn't just set the option value, but creates a link of sorts between the variable which the app would use and the variable_map entry. With this in place, further changes to the variable map automagically affect the app variable. -------------------------------- So, - What do you think about these suggestions, in principle? - If you find some of them relevant, can you help estimate the necessary development effort and possible negative implications/caveats to consider? - Assuming a feature idea is both relevant and feasible, is it customary to request implementation by the maintainer? Commit yourself to implementing it vis-a-vis statement of statement of partiality to accepting a patch? Some other practice? Thank you for getting through the long(ish) email and for your hard work, Eyal Rozenberg DB architecture group CWI Amsterdam

3 4

[release] Boost 1.62 closing for new libraries this week
by Rene Rivera 07 Aug '16

07 Aug '16

Hopefully everyone has had a good Summer and has gotten all the new libraries and breaking changes in.. As we are closing the release window for that this week. Please consult the calendar [1] for the full release schedule. And take this as a reminder to merge your changes that you want in the next release as soon as possible. [1] <http://www.boost.org/development/index.html> -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

1 0

[boost-process] Beta & Review
by Klemens Morgenstern 07 Aug '16

07 Aug '16

Hi, boost-process is now in beta, you can check it out here: https://github.com/klemens-morgenstern/boost-process and read the doc here: http://klemens-morgenstern.github.io/process/ It will probably be in review in the beginning of November, Antony Polukhin will be the review manager. I really hope I'll get some feedback before that, so I can work on the weak points and also get more detailed in the documentation. Thanks, Klemens

4 10

[boost-spirit-qi] Support for n-ary operators PR
by Frank Hein 06 Aug '16

06 Aug '16

Hello, some days ago I raised an PR (https://github.com/boostorg/spirit/pull/200) which adds support for a new class of parsers, in particular named n-ary operators. Joel de Guzman reviewed that. The code is ok. Because this addition touches the inner core of qi, the metagrammar, Joel asked me to drum for support in the community. So if you are in qi, may I kindly ask you to review this PR, the code, the discussion so far, and respond, if you want to support this PR or if you think, it's not needed. Thank you very much. I highly appreciate your feedback. The PR description is very detailled, so this mail has not to be. :) Regards, Frank

1 0

Review Schedule and Review Manager for PODs Flat Reflection (ex magic_get)
by Antony Polukhin 05 Aug '16

05 Aug '16

Hello, PODs Flat Reflection (or PFR) is a C++14 library that represents POD structures as tuples and provides tuple-like methods for PODs. Library has a set of predefined operators for PODs and useful functions for everyday use. Works with user-defined types without any macro or boilerplate code. Library: https://github.com/apolukhin/magic_get Docs: http://apolukhin.github.io/magic_get/ Boost Library Incubator: http://blincubator.com/bi_library/pfr-pod-flat-reflection/?gform_post_id=16… Could the PODs Flat Reflection library be put on review schedule? Anyone wishing to become a Review Manager for the library? -- Best regards, Antony Polukhin

6 9

[config] RFC PR 82
by Domagoj Saric 01 Aug '16

01 Aug '16

Hi everyone, I am finally getting back to (trying to) contributing some of my personal projects to Boost. For two of those, Err (https://github.com/psiha/err) and especially Functonoid (a C++11 generalization and rewrite of my previous Boost.Function related work) I need some lower level codegen and/or optimiser control functionality (i.e. portable macros wrapping toolset specific attributes and pragmas) that I've added to my personal fork of Boost.Config and which I've now submitted in the subject PR (https://github.com/boostorg/config/pull/82) I don't expect this PR to be accepted as is/'just like that' so I'm opening this thread where we can discuss which of those changes/macros are welcome, which need more work and which, for some reason, should not be part of Boost.Config (and which, in turn then, I have to move to some 'internal implementation headers' in libraries that will need them). To avoid 'spamming' (and save time;) I'll skip the explanation of the individual macros as I expect them to mostly be self-explanatory (if not from their name then from the minimal Boost.Config documentation additions that are part of th PR). ps. I'll be on the (off) road for the next three weeks so I don't know when I'll be able to respond until I get back... -- "What Huxley teaches is that in the age of advanced technology, spiritual devastation is more likely to come from an enemy with a smiling face than from one whose countenance exudes suspicion and hate." Neil Postman

8 31

constexpr, cmath functions and other functions and distributions
by Paul A. Bristow 01 Aug '16

01 Aug '16

After much head scratching (and some head banging) - against a string of "Computer Says No" inscrutable diagnostic messages. I believe that I have now produced a (partial) version of Boost.Math normal_distribution that can be a constexpr using GCC6.1.1. (diagnosis has got to improve if constexprizing existing code is to become popular? ) constexpr normal_distribution<double> n01(0., 1.); producing this code 960 .loc 1 47 0 961 000d 660FEFC0 pxor %xmm0, %xmm0 # tmp89 962 0011 F20F1145 movsd %xmm0, -32(%rbp) # tmp89, n01.m_mean 962 E0 963 0016 F20F1005 movsd .LC1(%rip), %xmm0 #, tmp90 963 80080000 964 001e F20F1145 movsd %xmm0, -24(%rbp) # tmp90, n01.m_sd 964 E8 and more interestingly, a PDF can be calculated at compile-time constexpr double p = pdf(n01, 0.5); 965 .loc 1 56 0 966 0023 F20F1005 movsd .LC2(%rip), %xmm0 #, tmp91 966 88080000 967 002b F20F1145 movsd %xmm0, -8(%rbp) # tmp91, p 967 F8 Perhaps the assembler whizzes can confirm that this looks like a compile-time computation? This relies on lots of C++14 and 17 constexpr features, and Most crucially it relies on being able to use several cmath functions as constexpr. For a couple of trivially simple examples: abs(x) and isfinite(x). constexpr double ax42 = abs(-42.); // Unspecified version of abs. constexpr double ax42g = ::abs(-42.); // C double version? constexpr double ax42b = __builtin_abs(-42.); // builtin GCC only constexpr double ax42s = std::abs(-42.); // std:: version Without most cmath functions it seems to me impossible to write any reasonable (so-called special or not) mathy function or statistical distribution that can be constexpr. At present, only GCC 6.1.1 authors have foreseen this need and provided these so-called built_in_* cmath function versions that are constexpr, see https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html. (Aside on other compilers: · Clang 3.8 has some problem deep inside type_traits that I haven't yet investigated. · VS2015 update 3 still doesn't compile many essential C++17 features from my experiments so far, and doesn't provide any constexpr cmath functions. ) The many potential benefits of compiler-time computations are quite enticing to contemplate :-) * No run-time where possible * Errors caught at compile-time * Improved code readability * Reduce executable footprint and potentially most important * Avoid global initialization order issues * Avoid initialization thread races See · Scott Schurr, C++ Developer, Ripple Labs https://cppnow2015.sched.org/event/2oLK/constexpr-c-at-compile-time · Dietmar Khul Constant Fun https://www.youtube.com/watch?list=PL9hrFapz4dsM1B9bI8VmEE4JJlR0m-dvo <https://www.youtube.com/watch?list=PL9hrFapz4dsM1B9bI8VmEE4JJlR0m-dvo&v=T37…> &v=T37ElKPICvo&app=desktop Is there any support for making std::abs and friends constexpr where possible in future versions of the C++ Standard? Paul PS I can't conceive of any UDT using or providing floating-point without some function like frexp to get and set exponent and significand. I also note that making constexpr frexp and ldexp and other functions passing a pointer to a variable to be updated may be more difficult/impossible, and is very likely to require at least initialization of the to-be-updated variable before calling frexp. I've investigated overcoming this by writing a naïve new constexpr version of frexp returning a std::pair (significand and exponent) but, of course, it can never be a 'drop-in' replacement because it has a different signature, so lots of code changes are inevitable. --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830

5 6

[type_erasure] Do we have a maintainer (minor fix needed)?
by John Maddock 31 Jul '16

31 Jul '16

This trivial PR is open for type_erasure and fixes an issue introduced by changes to Boost.Config (enabling constexpr support for VC14up3). https://github.com/boostorg/type_erasure/pull/11 BTW the failure is not caused by buggy constexpr support, there's some other issue going on once that code path is enabled. Anyhow, since we really should be merging Config to master soon, I'd like to see this collateral-damage fixed if possible. Thanks, John.

1 0

[contract] Template types
by Lorenzo Caminiti 29 Jul '16

29 Jul '16

Hello all, I would like to discuss the extra type requirements that contracts can impose of generic types and how Boost.Contract handles that. I think I mentioned some of this already in different emails to this list, but I wanted to summarize this topic in one email. For example, note that the following code will not compile when the old value template parameter T is not copyable: template<typename T> void swap(T& a, T& b) [[ensures: a == old(b)]] ... In Boost.Contract (approach 1): template<typename T> void swap(T& a, T& b) { boost::contract::old_ptr<T> old_b = BOOST_CONTRACT_OLDOF(b); boost::contract::guard c = boost::contract::function() .postcondition([&] { BOOST_CONTRACT_ASSERT(a == *old_b); }) ; ... } In some cases, that might be what the contract writers want: the generic old value type T is not copyable so postconditions cannot be checked and the program should not compile. However, in some other cases the contract writes might not want to add the extra copyable requirement on T and check the related postconditions only when callers specify a template parameter T that happens to be copyable. That can be done allowing some sort of static-if in contracts: template<typename T> void swap(T& a, T& b) [[ensures: static if(is_copyable<T>::value) a == old(b)]] ... In Boost.Contract (approach 2): template<typename T> void swap(T& a, T& b) { boost::contract::old_ptr_if_copyable<T> old_b = BOOST_CONTRACT_OLDOF(b); boost::contract::guard c = boost::contract::function() .postcondition([&] { if(old_b) BOOST_CONTRACT_ASSERT(a == *old_b); }) ; ... } Both approach 1 and 2 above are valid and should be supported by the framework. The decision between which approach to use for a specific contract should be left up to the programmers. Like old values can introduce the extra copyable type requirement, any contract assertion can in general introduce an number of extra requirements on generic types, namely the type requirements necessary to support the operations used to program the contract assertions. For example, the following code will not compile if T is not equality comparable (which is not a type requirement vector normally imposes on T): template<typename T> class vector { void push_back(T const& value) [[ensures: back() == value]] ... }; In Boost.Contract (approach 1): template<typename T> class vector { void push_back(T const& value) { boost::contract::guard c = boost::contract::public_function(this) .postcondition([&] { BOOST_CONTRACT_ASSERT(back() == value); }) ; ... } }; Again, that might be what contract writes want in some case but in other cases they might want to just skip the assertion when T does not meet all the type requirements needed by the operations used in the assertion: template<typename T> class vector { void push_back(T const& value) [[ensures: static if(has_equal_to<T>::value) back() == value]] ... }; In Boost.Contract (approach 2): template<typename T> class vector { void push_back(T const& value) { boost::contract::guard c = boost::contract::public_function(this) .postcondition([&] { BOOST_CONTRACT_ASSERT( boost::contract::check_if<has_equal_to<T>::value >( boost::bind(equal_to<T>, cref(back()), cref(value)) ) ); }) ; ... } }; --Lorenzo

1 0

Gmane going away
by Tom Kent 29 Jul '16

29 Jul '16

So it looks like Gmane is under attack and the guy who runs it is thinking about just turning it off (that would be sad). https://lars.ingebrigtsen.no/2016/07/28/the-end-of-gmane/ Anyway, I know a lot of boost users use is as the gnu mailman archive pages are really hard to use. I would like to propose that we (specifically the list owner(s)) mirror the boost mailing lists to the mail-archive.com site. It has good search features and decent thread browse-ability. Thoughts? Tom

1 0

Boost Social Event at CppCon 2016
by Jon Kalb 28 Jul '16

28 Jul '16

Boost Developers, Because a lot of Boosters are going to be attending CppCon, we¹d like to arrange a social event for Boosters/C++Now attendees. http://cppcon.org/ If you are planning to attend CppCon or even If you are just going to be in or around Bellevue, Washington between September 17th and 23rd and you¹d like to join us for dinner, please let us know so we can get a count. Please send mail to: social(a)boost.org Once we settle on a date, etc, we¹ll let everyone who responded know when and where, so please let us know, even if you are a ³maybe.² If you are attending, please make your hotel reservations soon. We are likely to sell out of our room block. http://cppcon.org/lodging/ I hope to see you at CppCon. Jon

2 1

Approximate matching to Boost.Algorithm
by Зайцев Александр 27 Jul '16

27 Jul '16

Hello. I want to discuss about some proposals. I am working on Levenshtein distance and Damerau-Levenshtein distance algortihms. I hope, that these implementations will be pulled to the Boost String library. But i think that we can add to the Boost String Library some more algorithms for fuzzy searhing. You can find this list here: https://fuzzystring.codeplex.com/ List: 1)Hamming Distance 2)Jaccard Distance 3)Jaro Distance 4)Jaro-Winkler Distance 5)Levenshtein Distance 6)Longest Common Subsequence 7)Longest Common Substring 8)Overlap Coefficient 9)Ratcliff-Obershelp Similarity 10)Sorensen-Dice Distance 11)Tanimoto Coefficient Maybe something else... What do you think about this idea? If you think that it can be implemented to the Boost String Algo, i will start work on this list immediately. Best regards, Zaitsev Alexander.

2 1

I am working on Aho-Corasik
by Зайцев Александр 27 Jul '16

27 Jul '16

Hello. FYI: Now i am working on Aho-Corasik algorithm. Best regards, Alexander Zaitsev.

1 0

Fast nth-elemnt on the segment
by Зайцев Александр 26 Jul '16

26 Jul '16

Hello. What do you think about algorithm of fast searching nth-elemnt on the segment with O(logN), where N is count of elements. I would implement it to Boost.Algorithm. Best regards, Alexander Zaitsev

1 0

[type_erasure] Conflict with private member called data
by Nigel Pattinson 22 Jul '16

22 Jul '16

Hi I'm running into a problem with the type erasure library when trying to declare a member called 'data', e.g. BOOST_TYPE_ERASURE_MEMBER((has_data), data) using SomeClass = any< vector< copy_constructible<>, typeid_<>, relaxed, has_data<void*()> > >; This conflicts with the private member variable called 'data' in the any class. SomeClass does compile, but attempting to call the data() does not compile due to the conflict, with the error message being 'cannot access private member ... ' . I'm not sure if this is a limitation in the library or a compiler bug - I'm using Visual Studio 2015 Update 1. Using boost 1.57.0 at present, I could use a more recent version if that would help. Does anyone know of a possible workaround ? Thanks Nigel Pattinson

2 2

Update for the Cxx dual library
by Edward Diener 22 Jul '16

22 Jul '16

The Cxx dual library, or CXXD for short, is a C++ macro header-only library which chooses between using a Boost library or its C++ standard equivalent library for a number of different C++ implementations, while using the same code to program either choice. An 'implementation', called a 'dual library', is a Boost library which has a C++ standard library equivalent whose public interfaces are nearly the same in both cases. I have updated the Cxx dual library, for those who prefer to minimize their use of macros in source code, by providing an alternate method to the use of macros for including the appropriate header files and specifying the appropriate namespace for a dual library. In this alternate method including the appropriate header files is done by including an implementation header file, and specifying the appropriate namespace is done by using a C++ namespace alias. The alternate method, called the alias mode, is fully documented. You can get the latest version of the Cxx dual library at https://github.com/eldiener/cxx_dual. Instructions for using the library are in the README.md file. PDF documentation is available in cxx_dual.pdf, HTML doc is availavble online at http://eldiener.github.io/cxx_dual and you can generate local HTML documentation using the doc jam file. Questions, comments, bug reports are always welcome.

1 0

does boost support multimedia framework
by qw 22 Jul '16

22 Jul '16

Hi, Does boost support multimedia framework, just like gstreamer? Thanks! Regards Andrew

2 1

[contract] Class invariants (also for static and volatile/const-volatile public functions)
by Lorenzo Caminiti 21 Jul '16

21 Jul '16

Hello all, I would like to discuss class invariants, but also for static and volatile/const-volatile public member functions, and specifically with respect to how Boost.Contract handles them. Class invariants are important... almost as important as preconditions. For example for a vector container, class invariants specify among other things the equivalence relationship `(size() == 0) == empty()` that could be found useful by static analyzers and optimizes (also discussed in N4160): template<typename T> class vector { [[invariant: (size() == 0) == empty()]] [[invariant: size() <= capacity()]] public: void push_back(T const& value) ... { ... } }; The above contract cannot be programmed using preconditions and postconditions unless: it is repeated (together with all other invariant assertions) in pre- and postconditions of each public member functions, it is asserted with try-catches also when those functions throw, it is repeated in constructor postconditions, in destructor preconditions, and with try-catches also when destructors throw... Even if invariants are programmed in some `bool invariant() const` function to avoid repeating all invariant assertions in each pre- and postcondition, the code will be cluttered by boiler-plate code (try-catch to assert invariants on throw, etc.) and an invariant failure will just report that the invariant() function returned false, but it will not report which specific invariant condition actually failed (plus static analyzers and optimizes will not be able to parse the conditions from the invariant function): template<typename T> class vector { bool invariant() const { // But cannot distinguish which of the two assertions failed... // and cannot be used by static analyzers and optimizers. return (size() == 0) == empty() && size() <= capacity(); } public: void push_back(T const& value) ... [[requires: invariant()]] [[ensures: invariant()]] { try { ... } catch(...) { [[assert: invariant()]]; throw } } }; Class invariants cannot be effectively emulated using pre- and postconditions... they should be added to a contract framework as their own feature. In Boost.Contract: template<typename T> class vector { void invariant() const { BOOST_CONTRACT_ASSERT((size() == 0) == empty()); BOOST_CONTRACT_ASSERT(size() <= capacity()); } public: void push_back(T const& value) { boost::contract::guard c = boost::contract::public_function(*this) ... ; ... } }; Note that the above invariant function `void invariant() const` cannot be declared static or const-volatile because it will need to call queries like size(), empty(), capacity(), etc. that are const and not static or const-volatile. Thus the above invariant function, being const, cannot be called at entry and exit of static and volatile/const-volatile public functions. A contract framework for C++ should support also static and const-volatile class invariants to properly handle static and volatile/const-volatile public functions (even if static and const-volatile class invariants are not mentioned in any C++ contract proposal): * Static public functions check static class invariants at entry, at exit, and if body throws. * Volatile and const-volatile public functions check static and const-volatile class invariants (in that order) at entry, at exit, and if body throws. * Non cv-qualified and const public functions check static, const-volatile, and const class invariants (in that order) at entry, at exit, and if body throws. * Constructors check static class invariants at entry, at exit, and if body throws (because those do not require the object to be constructed). Then constructors check const-volatile and const class invariants (in that order) at exit (if body does not throw, because those require the object to be constructed). * Destructors check static class invariants at entry, at exit, and if body throws (because those do not require a constructed object). Then destructors check const-volatile and const class invariants (in that order) at entry and if body throws (because those require a constructed object). In Boost.Contract: struct a { static void static_invariant() { BOOST_CONTRACT_ASSERT(...); } void invariant() const volatile { BOOST_CONTRACT_ASSERT(...); } void invariant() const { BOOST_CONTRACT_ASSERT(...); } // Following check all static_invariant(), invariant() const volatile, and invariant() const (in that order). a() { boost::contract::guard c= boost::contract::constructor(this); } virtual ~a() { boost::contract::guard c = boost::contract::destructor(this); } void m() /* no cv qualifiers */ { boost::contract::guard c = boost::contract::public_function(*this); } void c() const { boost::contract::guard c = boost::contract::public_function(*this); } // Following check both static_invariant() and invariant() const volatile (in that order). void v() volatile { boost::contract::guard c = boost::contract::public_function(*this); } void cv() const volatile { boost::contract::guard c = boost::contract::public_function(*this); } // Following check only static_invariant(). static void s() { boost::contract::guard c = boost::contract::public_function<a>(); } }; Maybe volatile member functions are rarely used in C++ so const-volatile class invariants will also be used rarely if at all... Nevertheless, if const-volatile class invariants are not supported, it will not be possible to specify invariants for classes with volatile public functions so const-volatile class invariants should be supported for completeness. Static class invariant could instead be useful when programming contracts for the static part of the object state. In particular, Boost.Contract also supports postconditions for destructors (those should be checked by a static function because they should not access the object `this` that has been destroyed after the execution of the destructor body). Destructor postconditions are not mentioned in any contract proposal... but together with constructor and other function pre- and postconditions, and together with static class invariants, they can specify contracts for the static part of the object state. For example, consider the contracts for a class that counts the number of its object instances: struct a : private noncopyable, private nonmovable { static void static_invariant() { BOOST_CONTRACT_ASSERT((instances() != 0) == exists()); } a() { boost::contract::old_ptr<unsigned> old_instances = BOOST_CONTRACT_OLDOF(instances()); boost::contract::guard c = boost::contract::constructor(this) .postcondition([&] { BOOST_CONTRACT_ASSERT(instances() == old_instances + 1); }) ; ++instances_; } virtual ~a() { boost::contract::old_ptr<unsigned> old_instances = BOOST_CONTRACT_OLDOF(instances()); boost::contract::guard c = boost::contract::destructor(this) .postcondition([&] { // Must never use object `this`. BOOST_CONTRACT_ASSERT(instances() == old_instances - 1); }) ; --instances_; } static unsigned instances() { boost::contract::guard c = boost::contract::public_function<a>(); return instances_; } static bool exists() { boost::contract::guard c = boost::contract::public_function<a>(); return instances_ != 0; } private: static unsigned instances_; }; unsigned a::instances_ = 0; --Lorenzo

1 0

double_ended - request formal review
by Benedek Thaler 21 Jul '16

21 Jul '16

Dear Boost, I'd like to request the review of the double_ended library. Code: https://github.com/erenon/double_ended Documentation: http://erenon.hu/double_ended The library contains two classes. Excerpt from the documentation: * `devector` is a hybrid of the standard vector and deque containers, as well as the small_vector of Boost.Container. It offers cheap (amortized constant time) insertion at both the front and back ends, while also providing the regular features of std::vector, in particular the contiguous underlying memory. In contrast to the standard vector, however, devector offers greater control over its internals. Like small_vector, it can store elements internally without dynamically allocating memory. * `batch_deque` is very similar to the standard deque, with a slight twist. It lets you specify its segment size: The size of the contiguous memory segments it uses to store its elements. This provides a consistent layout across platforms, and lets you iterate over the segments with batch operations. I'm also looking for a review manager. Thanks, Benedek

2 1

[contract] Friend functions
by Lorenzo Caminiti 19 Jul '16

19 Jul '16

Hello all, I would like to discuss contracts for friend functions and specifically how they are handled in Boost.Contract. Consider the following example: class a; class b; class data { ... friend bool deep_equal(a*, b*); bool equal(data const&); }; class a { ... friend bool deep_equal(a*, b*); data data_; }; class b { ... friend bool deep_equal(a*, b*); data data_; }; bool deep_equal(a* x, b* y) { return x->data_.equal(y->data_); } Via friendship, deep_equal can be considered to extend a and b public interfaces, but not data's public interface (in fact, deep_equal does not take instance of data as an argument). Therefore, it is reasonable to think that deep_equal should check a and b class invariants (if so... in which order?), but not data's class invariants. As discussed in N4160, that would probably require some new language feature to specify which subset of friend functions also extend a class public interface. Plus such a feature should identify some preferred order in which class invariants should be checked for a friend function that extends public interfaces of multiple classes. That seems rather complicated so I think a language proposal (like N1962) is better off going with the general rule that friends functions do not check class invariants (even if that might not always be ideal in all cases): bool deep_equal(a* x, b* y) [[requires: x && y]] // Does not check a and b (and c) invariants... even if arguably it should. { return x->data_.equal(y->data_); } In Boost.Contract: bool deep_equal(a* x, b* y) { boost::contract::guard c = boost::contract::function() .precondition([&] { BOOST_CONTRACT_ASSERT(x && y); }) ; // Does not check a and b (and c) invariants... even if arguably it should. return x->data_.equal(y->data_); } Maybe programmers could manually check a and b invariants (but then also from the function body when it throws) when those checks are truly essential for friend function: bool deep_equal(a* x, b* x) [[requires: x && y]] // Check a and b invariants in that order (if contract writes decide to), does not check c invariants. [[requires: x->invariant() && y->invariant()] [[ensures: x->invariant() && y->invariant()] { try { return x->data_.equal(y->data_); } catch(...) { [[assert: x->invariant() && y->invariant()]]; throw; } } (That seems somewhat verbose... plus it assumes that class invariants are somehow specified in a `bool invariant() const function (that can be private), or using a set of [[invariant: ...]] attributes that automatically generate such a callable `bool invariant() const` function.) This is possible in Boost.Contract: bool deep_equal(a* x, b* y) { boost::contract::guard c = boost::contract::function() .precondition([&] { BOOST_CONTRACT_ASSERT(x && y); }) ; // Check a and b invariants in that order (if contract writers decide to), does not check c invariants. boost::contract::guard inv_x = boost::contract::public_function(*x); boost::contract::guard inv_y = boost::contract::public_function(*y); return x->data_.equal(y->data_); } Finally, note that in this case preconditions are checked before entry invariants (while usually public functions check preconditions after entry invariants). That is desirable/needed for friend functions because the class object is not *this (which is always well defined and therefore subject to no precondition). For friend functions, the class object can be any computation of the friend function arguments and those arguments must be validated by preconditions before they can be used to access the class object. In the examples above, the arguments are checked to be not null by preconditions so they can be safely dereferenced to get the objects *x and *y (and in general the computations required might be even much more complex than dereferencing pointers). Thank you. --Lorenzo

1 0

[contract] Without the macros
by Lorenzo Caminiti 19 Jul '16

19 Jul '16

Hello all, In the last few years my professional and personal lives changed quite a bit limiting my ability to contribute to Boost. However, in my spare time I slowing continued to revise Boost.Contract hoping to be able to commit it to a Boost release someday (after the library was accepted 3+ years ago... https://groups.google.com/forum/?fromgroups=#!topic/boost-list/jQ7OjAmos_Y) While doing so I realized that leveraging C++11 lambda functions, Boost.Contract could be re-implemented without its crazy macros that alter C++ function declaration syntax. Boost.Contract still remains the only C++ library that implements *all* features of Contract Programming (a.k.a., Design by Contract or DbC): subcontracting, class invariants (also static and volatile), postconditions (with old and return values), preconditions, customizable actions on assertion failure (terminate, throw, etc.), optional assertion compilation, disable assertion checking while already checking other assertions (to avoid infinite recursion), etc. Furthermore, in its new incarnation Boost.Contract no longer uses crazy macros so it is easier to use, faster to compile, and gives readable compiler errors. For example: #include <boost/contract.hpp> int inc(int& x) { int result; boost::contract::old_ptr<int> old_x = BOOST_CONTRACT_OLDOF(x); boost::contract::guard c = boost::contract::function() .precondition([&] { BOOST_CONTRACT_ASSERT(x < std::numeric_limits<int>::max()); }) .postcondition([&] { BOOST_CONTRACT_ASSERT(x == *old_x + 1); BOOST_CONTRACT_ASSERT(result == *old_x); }) ; return result = x++; // Function body. } Or with subcontracting: #include <boost/contract.hpp> #include <vector> template<typename T> class pushable; // Arbitrary base to demo subcontracting. template<typename T> class vector #define BASES public pushable<T> : BASES { public: typedef BOOST_CONTRACT_BASE_TYPES(BASES) base_types; // Subcontracting. #undef BASES void invariant() const { // Checked in AND with base class invariants. BOOST_CONTRACT_ASSERT(size() <= capacity()); // Line 25. } virtual void push_back(T const& value, boost::contract::virtual_* v = 0) /* override */ { boost::contract::old_ptr<unsigned> old_size = BOOST_CONTRACT_OLDOF(v, size()); // Old values. boost::contract::guard c = boost::contract::public_function< override_push_back>(v, &vector::push_back, this, value) .precondition([&] { // Checked in OR with base preconditions. BOOST_CONTRACT_ASSERT(size() < max_size()); // Line 35. }) .postcondition([&] { // Checked in AND with base postconditions. BOOST_CONTRACT_ASSERT(size() == *old_size + 1); // Line 38. }) ; vect_.push_back(value); // Function body. } BOOST_CONTRACT_OVERRIDE(push_back) // For `override_push_back`. // Could program contracts for those as well. unsigned size() const { return vect_.size(); } unsigned max_size() const { return vect_.max_size(); } unsigned capacity() const { return vect_.capacity(); } private: std::vector<T> vect_; }; Full documentation and examples at: https://lcaminiti.github.io/boost-contract What do you think? Thanks, --Lorenzo P.S. The library can also be used without C++11 lambda functions (or any C++11 specific feature) but programmers have to write a fare amount of extra code to program the precondition and postcondition functors (using non-local functions, Boost.LocalFunction, Boost.Funsion, Boost.Lambda, or some other approach) so that might not useful in practice.

6 14

[graph] Compilation error with adjacency_list and C++11
by Sebastien Loriot (GeometryFactory) 18 Jul '16

18 Jul '16

Hello, the program below does not compile at least with g++ 5.3.1 and clang++ 3.5.2-1 when using c++11 standard. If I comment line #1 it compiles. If I change #2 to undirectedS it compiles. Is there anything wrong in my code or is it a problem in boost's? Thanks, Sebastien. #include <boost/graph/adjacency_list.hpp> struct A { A(){} A(const A& ){} // #1 A& operator=(const A&){return *this;} }; typedef boost::adjacency_list<boost::listS, boost::vecS, boost::directedS, //#2 A > Graph; int main() { Graph g; boost::add_vertex(g); return 0; }

2 2

[type_index] Interest in dynamic_cast emulation?
by Chris Glover 17 Jul '16

17 Jul '16

Hi, I reached for Boost.TypeIndex the other day expecting to find a kind of dynamic_cast I could use in the absence of Rtti. I didn't find it, so I wrote something to emulate it using type_index internally. It's working, but before I go too far and clean this up and possibly submit a pull request, I would like to gauge if there's interest in such a thing or if there's some fundamental reason why it doesn't exist. So, thoughts? Thanks, -- chris

5 8

[contract] Strong exception safety guarantees
by Lorenzo Caminiti 15 Jul '16

15 Jul '16

Hello all, I've been considering adding a .except(...) construct to Boost.Contract that will allow to specify conditions to check at function exit but when the function body throws (in contrast to postconditions that are checked at function exit but only when the function body does not throw). I think .except(...) could be used to assert strong exception safety guarantees... (note that class invariants are already checked at exit of public functions and also when the public function bodies throw, but invariants are suited to assert only basic, and not strong, exception safety guarantees). That might help addressing a point made in P0147R0 under the "Contracts and Exceptions" section: ``Some operations make stronger exception safety claims. In particular, they claim that an exception thrown from a member function will leave the state of an object unchanged from its state on function entry. If we invalidate postconditions on exceptions, we appear to have no mechanism to describe strong exception safety.'' For example, the following swap ensures to leave its arguments unchanged when it throws: void swap(std::string& a, std::string& b) { boost::contract::old_ptr<std::string> old_a = BOOST_CONTRACT_OLDOF(a); boost::contract::old_ptr<std::string> old_b = BOOST_CONTRACT_OLDOF(b); boost::contract::guard c = boost::contract::function() .postcondition([&] { // Checked at function exit but only if body does not throw. BOOST_CONTRACT_ASSERT(a == *old_b); BOOST_CONTRACT_ASSERT(b == *old_a); }) .except([&] { // Checked if body throws (strong exception safety guarantees). BOOST_CONTRACT_ASSERT(a == *old_a); BOOST_CONTRACT_ASSERT(b == *old_b); }) ; ... // Body implementation (which might throw). } Would this be beneficial? Thanks, --Lorenzo

2 5

smartptr maintained
by Karolin Varner 15 Jul '16

15 Jul '16

Hi, is smartptr still being maintained? There are four pull requests, one more than a year old. Best, Karolin Varner

2 3

[graph] A* implementation doesn't follow the algorithm
by Nick Lamprianidis 14 Jul '16

14 Jul '16

For the A* algorithm holds that when a new vertex v is reached through a shorter path, then v is added to the open set. But looking at the boost graph's A* implementation, which is based on the BFS algorithm, one can see that a target vertex is added to the priority queue, regardless of whether the relevant edge is being relaxed. This creates the following situation: The execution starts and you get to a point where you know you cannot reach the goal: no vertices with finite cost in the priority queue. Normally, you would expect that the priority queue is empty and thus the execution ends. Instead, the execution continues, since the priority queue is filled with all those vertices (with infinite cost) that got added for no reason. In an application where the state of a target vertex v gets set when an associated edge is being relaxed, a problem arises. In the situation mentioned above, uninitialized vertices reach the visitor's examine_vertex method. Unless you know what's really happening, so you can take care to add a test condition to exit, it leaves you wondering what's going wrong. I propose that you either change the implementation or at least update the documentation (pseudocode). -- Nick Lamprianidis http://paign10.me

3 2

[log][regression] Error with Boost.Lob build jamfile breaks MinGW regression tester in develop
by Ion Gaztañaga 13 Jul '16

13 Jul '16

Hi, My develop branch regression runner fails whereas the master one works fine. The develop runner fails with all Mingw targets (msvc 7.1 works fine), with this error: ************************************ # Starting tests ("c:\boost\develop\boost_bb\src\engine\bin.ntx86\bjam.exe" "-sBOOST_BUILD_PATH=c:\boost\develop;c:\boost\develop\boost_bb\src" "-sBOOST_ROOT=c:\boost\develop\boost_root" "--boost=c:\boost\develop\boost_root" "--boost-root=c:\boost\develop\boost_root" "--boost-build=c:\boost\develop\boost_bb\src" "--debug-configuration" -l300 toolset=gcc-6.1c++14 -d2 preserve-test-targets=off --dump-tests -j3 --abbreviate-paths debug-symbols=off -m64 "--build-dir=c:\boost\develop\results" >>"c:\boost\develop\results\bjam.log" 2>&1)... c:\boost\develop\boost_root\status> "c:\boost\develop\boost_bb\src\engine\bin.ntx86\bjam.exe" "-sBOOST_BUILD_PATH=c:\boost\develop;c:\boost\develop\boost_bb\src" "-sBOOST_ROOT=c:\boost\develop\boost_root" "--boost=c:\boost\develop\boost_root" "--boost-root=c:\boost\develop\boost_root" "--boost-build=c:\boost\develop\boost_bb\src" "--debug-configuration" -l300 toolset=gcc-6.1c++14 -d2 preserve-test-targets=off --dump-tests -j3 --abbreviate-paths debug-symbols=off -m64 "--build-dir=c:\boost\develop\results" 1>>"c:\boost\develop\results\bjam.log" 2>&1 # Running Boost.Build tests Traceback (most recent call last): File "run.py", line 71, in <module> runner(root) File "c:\boost\develop\boost_regression_src\regression.py", line 287, in __init__ self.main() File "c:\boost\develop\boost_regression_src\regression.py", line 624, in main getattr(self,action_m)() File "c:\boost\develop\boost_regression_src\regression.py", line 589, in command_regression self.command_test() File "c:\boost\develop\boost_regression_src\regression.py", line 368, in command_test self.command_test_boost_build() File "c:\boost\develop\boost_regression_src\regression.py", line 410, in command_test_boost_build "boost/bin.v2/libs/any/test/any_test.test")); WindowsError: [Error 3] The system cannot find the path specified: 'c:\\boost\\develop\\results\\boost/bin.v2/libs/any/test/any_test.test/*.*' ************************************ That path ("..libs/any/test/any_test.test/) is hardcoded in regression.py, but it's not generated in my bin.v2 so it's reasonable an error saying that the system can't find the path ;-) It seems that error occurs before boost.build tests, as bjam.log shows: ************************************ C:/boost/develop/boost_bb/src/build\targets.jam:1077: in evaluate-requirements from module targets error: Can not evaluate conditional properties <conditional>@Jamfile<C:\boost\develop\boost_root>%Jamfile<C:\boost\develop\boost_root>.handle-static-runtime <conditional>@Jamfile<C:\boost\develop\boost_root>%boostcpp.deduce-address-model <conditional>@Jamfile<C:\boost\develop\boost_root>%boostcpp.deduce-architecture <conditional>@Jamfile<C:\boost\develop\boost_root\libs\log\build>%Jamfile<C:\boost\develop\boost_root\libs\log\build>.check-instruction-set <conditional>@Jamfile<C:\boost\develop\boost_root\libs\log\build>%Jamfile<C:\boost\develop\boost_root\libs\log\build>.check-message-compiler <conditional>@Jamfile<C:\boost\develop\boost_root\libs\log\build>%Jamfile<C:\boost\develop\boost_root\libs\log\build>.check-pthread-mutex-robust <conditional>@Jamfile<C:\boost\develop\boost_root\libs\log\build>%Jamfile<C:\boost\develop\boost_root\libs\log\build>.check-visibility <conditional>@Jamfile<C:\boost\develop\boost_root\libs\log\build>%Jamfile<C:\boost\develop\boost_root\libs\log\build>.select-arch-specific-sources <conditional>@Jamfile<C:\boost\develop\boost_root\libs\log\build>%Jamfile<C:\boost\develop\boost_root\libs\log\build>.select-platform-specific-sources <conditional>@Jamfile<C:\boost\develop\boost_root\libs\log\build>%Jamfile<C:\boost\develop\boost_root\libs\log\build>.select-regex-backend <link>shared:<define>BOOST_LOG_DLL <target-os>cygwin:<define>BOOST_USE_WINDOWS_H <target-os>cygwin:<define>NOMINMAX <target-os>cygwin:<define>SECURITY_WIN32 <target-os>cygwin:<define>WIN32_LEAN_AND_MEAN <target-os>cygwin:<define>__USE_W32_SOCKETS <target-os>cygwin:<library>/boost/log//advapi32 <target-os>cygwin:<library>/boost/log//mswsock <target-os>cygwin:<library>/boost/log//ws2_32 <target-os>freebsd:<library>/boost/log//rt <target-os>hpux:<define>_XOPEN_SOURCE=600 <target-os>hpux:<library>/boost/log//ipv6 <target-os>linux:<define>_XOPEN_SOURCE=600 <target-os>linux:<library>/boost/log//rt <target-os>qnxnto:<library>/boost/log//socket <target-os>solaris:<define>_XOPEN_SOURCE=500 <target-os>solaris:<define>__EXTENSIONS__ <target-os>solaris:<library>/boost/log//nsl <target-os>solaris:<library>/boost/log//socket <target-os>windows:<define>BOOST_USE_WINDOWS_H <target-os>windows:<define>NOMINMAX <target-os>windows:<define>SECURITY_WIN32 <target-os>windows:<define>WIN32_LEAN_AND_MEAN <target-os>windows:<library>/boost/log//advapi32 <target-os>windows:<library>/boost/log//mswsock <target-os>windows:<library>/boost/log//ws2_32 <threading>multi:<library>/boost/atomic//boost_atomic <threading>multi:<library>/boost/thread//boost_thread <threading>single:<define>BOOST_LOG_NO_THREADS <toolset>clang:<cxxflags>-ftemplate-depth-1024 <toolset>como-linux:<define>_GNU_SOURCE=1 <toolset>como:<link>static <toolset>darwin:<cxxflags>-ftemplate-depth-1024 <toolset>gcc,<target-os>cygwin:<linkflags>-Wl,--enable-auto-import <toolset>gcc,<target-os>windows:<linkflags>-Wl,--enable-auto-import <toolset>gcc:<cxxflags>-fno-strict-aliasing <toolset>gcc:<cxxflags>-ftemplate-depth-1024 <toolset>intel-darwin:<cxxflags>-wd177,780,2196,1782,193,304,981,1418,411,734,279 <toolset>intel-linux:<cxxflags>-wd177,780,2196,1782,193,304,981,1418,411,734,279 <toolset>intel-win:<cxxflags>/Qwd177,780,2196,1782,193,304,981,1418,411,734,279 <toolset>intel-win:<define>_CRT_SECURE_NO_DEPRECATE <toolset>intel-win:<define>_CRT_SECURE_NO_WARNINGS <toolset>intel-win:<define>_SCL_SECURE_NO_DEPRECATE <toolset>intel-win:<define>_SCL_SECURE_NO_WARNINGS <toolset>msvc,<runtime-link>shared:<threading>multi <toolset>msvc:<cxxflags>/bigobj <toolset>msvc:<cxxflags>/wd4003 <toolset>msvc:<cxxflags>/wd4456 <toolset>msvc:<cxxflags>/wd4459 <toolset>msvc:<cxxflags>/wd4503 <toolset>msvc:<define>_CRT_SECURE_NO_DEPRECATE <toolset>msvc:<define>_CRT_SECURE_NO_WARNINGS <toolset>msvc:<define>_SCL_SECURE_NO_DEPRECATE <toolset>msvc:<define>_SCL_SECURE_NO_WARNINGS <toolset>pgi:<library>/boost/log//rt C:/boost/develop/boost_bb/src/build\targets.jam:1112: in common-properties2 from module targets C:/boost/develop/boost_bb/src/build\targets.jam:977: in targets.common-properties from module targets C:/boost/develop/boost_bb/src/build\targets.jam:1303: in class(a)basic-target.generate from module object(typed-target)@1504 C:/boost/develop/boost_bb/src/build\targets.jam:774: in generate-really from module object(main-target)@49045 C:/boost/develop/boost_bb/src/build\targets.jam:746: in class(a)main-target.generate from module object(main-target)@49045 C:/boost/develop/boost_bb/src/build\targets.jam:895: in targets.generate-from-reference from module targets C:/boost/develop/boost_bb/src/build\targets.jam:1266: in generate-dependencies from module object(typed-target)@14269 C:/boost/develop/boost_bb/src/build\targets.jam:1320: in class(a)basic-target.generate from module object(typed-target)@14269 C:/boost/develop/boost_bb/src/build\targets.jam:774: in generate-really from module object(main-target)@49008 C:/boost/develop/boost_bb/src/build\targets.jam:746: in class(a)main-target.generate from module object(main-target)@49008 C:/boost/develop/boost_bb/src/build\targets.jam:895: in targets.generate-from-reference from module targets C:/boost/develop/boost_bb/src/build\targets.jam:1266: in generate-dependencies from module object(alias-target-class)@36618 C:/boost/develop/boost_bb/src/build\targets.jam:1323: in class(a)basic-target.generate from module object(alias-target-class)@36618 C:/boost/develop/boost_bb/src/build\targets.jam:774: in generate-really from module object(main-target)@36634 C:/boost/develop/boost_bb/src/build\targets.jam:746: in class(a)main-target.generate from module object(main-target)@36634 C:/boost/develop/boost_bb/src/build\targets.jam:272: in class(a)project-target.generate from module object(project-target)@2141 c:/boost/develop/boost_bb/src\build-system.jam:714: in load from module build-system C:\boost\develop\boost_bb\src/kernel\modules.jam:295: in import from module modules C:\boost\develop\boost_bb\src/kernel/bootstrap.jam:139: in boost-build from module C:\boost\develop\boost_root\boost-build.jam:17: in module scope from module ************************************ I can't see why this Jamfile from Boost.Log is accepted when MSVC-7.1 is the target but fails when MinGW is the selected target. I could neither t deduce what is the failing piece of the configuration. The same error happens with a wide range of MINGW targets: GCC-3.4, GCC-4.1, GCC-4.2, GCC-4.3, GCC-4.4, GCC-4.5, GCC-4.6, GCC-4.7, GCC-4.8, GCC-4.9, GCC-5.1, GCC-5.2, GCC-5.3 and GCC-6.1. Any clue on what can be happening and how can it be fixed? Attached regression logs for a failed MINGW regression with GCC 6.1. Best, Ion

3 8

[regression][winapi] Tests not being run
by Andrey Semashev 11 Jul '16

11 Jul '16

Hi, I wrote about it before, but now the problem becomes more weird. The problem is that the tests for Boost.WinAPI are not being run for some reason. What's weird is that now there is one test in the matrix (http://www.boost.org/development/tests/develop/developer/winapi.html) that isn't part of the Boost.WinAPI test suite. I assume that entry is part of the formal checks for the library conformance, since it is present for all libraries. Could someone please have a look why the tests for Boost.WinAPI are not being executed? PS: The link for the __boost_check_library__ entry is broken: https://github.com/boostorg/winapi/blob/developstatus/boost_check_library.py I believe, there's a slash missing between develop and status, and also the repository name should be boost rather than winapi.

2 2

[TypeErasure] Merging pull-requests
by Deniz Bahadir 11 Jul '16

11 Jul '16

Hello everyone, Hello Steven, a view weeks ago I reported some bugs of Boost.TypeErasure [1,2] and provided pull-requests [3,4] which fix these. I just wanted to bring these to attention so that they might get merged and find their way into the next Boost release. Thanks, Deniz PS: There is another open pull-request [5] (by John Maddock) which seems to be even more urgent. [1] https://svn.boost.org/trac/boost/ticket/12291 [2] https://svn.boost.org/trac/boost/ticket/12292 [3] https://github.com/boostorg/type_erasure/pull/9 [4] https://github.com/boostorg/type_erasure/pull/10 [5] https://github.com/boostorg/type_erasure/pull/11 -- BENOCS GmbH Dipl.-Inform. Deniz Bahadir Winterfeldtstr. 21 10781 Berlin Germany Phone: +49 - 30 / 577 0004-22 Email: deniz.bahadir(a)benocs.com www.benocs.com Board of Management: Michael Wolz, Dr.-Ing. Oliver Holschke, Dr.-Ing. Ingmar Poese Commercial Register: Amtsgericht Bonn HRB 19378

2 1

[Hana/Fit] about constexpr/noexcept on equivalent functions to std::overload
by Vicente J. Botet Escriba 08 Jul '16

08 Jul '16

Hi, On the C++ standard meating in Oulu, we decided to make the std::overload function constexpr and conditionaly noexcept and ensure that the overloaded functions shall be constexpr if the stored finctions are. I don't find in the reference documentation of Hana and Fit any reference of whether the overloaded functions preserve constexpr or not. There is a reedit post [1] and CWG issue 1581 [2] that are related. Could the authors clarify? What other think? Best, Vicente [1] https://www.reddit.com/r/cpp/comments/35g7f6/c17_progress_update/cr4mvid [2] http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#1581

3 6

[config] msvc-14 config changes heads up
by John Maddock 08 Jul '16

08 Jul '16

I've just pushed some changes to develop so that MSVC-14.0 update 3 no longer defines: BOOST_NO_CXX14_VARIABLE_TEMPLATES BOOST_NO_SFINAE_EXPR BOOST_NO_TWO_PHASE_NAME_LOOKUP As far as I can tell, these cause no new regressions in develop, please let me know if I've missed something. I haven't stopped defining BOOST_NO_CXX11_CONSTEXPR as it causes new failures: * Multiprecision, one new failure when using constexpr features, looks harmless. * Metaparse, causes the compiler to run out of resources on a couple of tests - these test non-default values of BOOST_METAPARSE_LIMIT_STRING_SIZE and are probably harmless. * Type_erasure, causes one new runtime failure. * Chrono, nothing much compiles - this one is the showstopper and needs investigating - any takers? Best, John.

7 13

[qvm] help with tests
by Emil Dotchevski 06 Jul '16

06 Jul '16

It appears that the QVM tests are broken somehow but it isn't clear to me what might be wrong. It shows "pass" next to __boost_check_library__, but there are no results for the actual tests. It used to work fine earlier -- this issue might be related somehow to a previous problem, where I had a build directory without realizing that the test framework recognized that name and did things I did not intend; so I renamed the build directory to bld. Can someone help me fix this? Thanks, Emil

3 7

Re: [boost] Boost numeric conversion - unary function deprecated or removed for C++17
by Brandon Kohn 06 Jul '16

06 Jul '16

Sent from Mail for Windows 10 From: Paul A. Bristow Sent: Monday, July 4, 2016 12:48 PM To: boost(a)lists.boost.org Subject: [boost] Boost numeric conversion - unary function deprecated or removed for C++17 >Can anyone help please. I’ve pushed fixes for this. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

3 4

Boost numeric conversion - unary function deprecated or removed for C++17
by Paul A. Bristow 06 Jul '16

06 Jul '16

I need to use C++17 (or MSVC std:c++latest) for other reasons, but I am blocked on MSVC by failure to compile converter.hpp It works OK on GCC 6.1.1 but not on VS2015 update 3 http://stackoverflow.com/questions/33114656/replacement-for-binary-function http://stackoverflow.com/questions/33114656/replacement-for-binary-function I suspect that GCC has not yet removed the deprecated unary_function but that MSVC correctly has removed it? Updating this looks above my pay grade. Can anyone help please. Paul --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830

3 2

[1.61.0][container] Error compiling alloc_lib.c with -std=c++11
by Richard Hadsell 05 Jul '16

05 Jul '16

I am trying to build Boost 1.61.0 with Clang and C++11 features. Other parts of the library warn about using C++11 features, if I do not build with the option -std=c++11. However, this C source file gives an error, and I assume it does not build at all: clang-linux.compile.c.without-pth bin.v2/libs/container/build/clang-linux-3.5.0/release/instruction-set-core2/threading-multi/alloc_lib.o error: invalid argument '-std=c++11' not allowed with 'C/ObjC' "[snip]clang++" -c -x c -O3 -Wno-inline -Wall -std=c++11 -fPIC -gcc-toolchain [snip]gcc/4.8.3 -Wno-[snip] -march=core2 -pthread -fPIC -m64 -DBOOST_ALL_NO_LIB=1 -DBOOST_CONTAINER_DYN_LINK=1 -DNDEBUG -I"." -c -o "bin.v2/libs/container/build/clang-linux-3.5.0/release/instruction-set-core2/threading-multi/alloc_lib.o" "libs/container/src/alloc_lib.c" ...failed clang-linux.compile.c.without-pth bin.v2/libs/container/build/clang-linux-3.5.0/release/instruction-set-core2/threading-multi/alloc_lib.o... These are the options from my user-config: using clang : 3.5.0 : [snip]/clang++ : <compileflags>"-std=c++11 -fPIC -gcc-toolchain [snip]/gcc/4.8.3 -Wno-[snip]" <linkflags>"-fPIC -gcc-toolchain [snip]/gcc/4.8.3" ; I don't see a way to provide C++-only flags or C-only flags. Actually, I thought that all Boost source files would be C++. -- Dick Hadsell 203-992-6320 Fax: 203-992-6001 Reply-to: hadsell(a)blueskystudios.com Blue Sky Studioshttp://www.blueskystudios.com 1 American Lane, Greenwich, CT 06831-2560

2 2

[meta] Hidden libraries.
by Daniel James 04 Jul '16

04 Jul '16

I just noticed that 'detail' and 'winapi' have started turning up in the library lists because they've added metadata files. We've always hidden these libraries in the past, so I'm thinking of adding an extra field to mark them as private/hidden libraries. Probably just something like: { "key": "detail", "name": "Detail", "private": true /* the rest.... */ } Any opinions?

4 4

[release] please add fiber to master
by Oliver Kowalke 03 Jul '16

03 Jul '16

Hello admins, I'd like to ask you to add boost.fiber to the master branch so that it will become part of the next boost release (1.62). thank you in advance, Oliver

3 7

What kind of algorithms/data structures can enter in Boost
by Зайцев Александр 03 Jul '16

03 Jul '16

Hello. I am interested in developing data structures and some algorithms in Boost library. But one of the requierement for library is: "The library should be generally useful". What does it mean? I think, that i can add to the library some more data structures: suffix tree/array/automata, palindromic tree, modifications of stack/queue for getting min/max with O(1), Aho–Corasick(maybe it's algo already exist in Boost Library), maybe something else (kd-tree, for example). And algortihms: Manacker's algo for calculating palindromes number, Longest increasing subsequence, palindromic check. There are many algorithms, which i can implement to the Boost library. Also Boost.Math versus GNU MP library is very simple. In GNU MP there are many useful features. And i don't know? we need to provide these features to the Boost.Math or not. Ok, Who can explain me, what algorithms of those that i mentioned, is generally useful? What is useful for Boost, and what is useless? Thanks. -- Best regards, Zaitsev Alexander

3 4

defect macro for thread_local?
by Oliver Kowalke 02 Jul '16

02 Jul '16

Hi, does boost provide a defect macro for thread_local (like BOOST_NO_CXX11_THREAD_LOCAL)? I couldn't find something similar int the boost macro reference. The macro would be helpful together with the feature-check to exclude compilers, that do not support the keyword thread_local (as gcc-4.7. and apple's compiler), from unit-tests. Oliver

4 7

[1.61.0] building with Clang and c++11
by Richard Hadsell 02 Jul '16

02 Jul '16

I have downloaded 1.61.0 and want to build it with Clang. This is in my user-config: using clang : 3.5.0 : /netDISKS/master/netmt/LINUX_C65/app/clang/3.5.0/bin/clang++ : <compileflags>"-fPIC -gcc-toolchain /netDISKS/master/netmt/LINUX_C65/app/gcc/4.8.3 -Wno-overloaded-virtual -Wno-unused-function -Wno-unused-variable -Wno-c99-extensions -Wno-variadic-macros" <linkflags>"-fPIC -gcc-toolchain /netDISKS/master/netmt/LINUX_C65/app/gcc/4.8.3" ; When I build, I see warnings like these: ./boost/mpl/print.hpp:50:19: warning: in-class initialization of non-static data member is a C++11 extension [-Wc++11-extensions] const int m_x = 1 / (sizeof(T) - sizeof(T)); ^ ./boost/timer/timer.hpp:44:43: warning: 'long long' is a C++11 extension [-Wc++11-long-long] void clear() { wall = user = system = 0LL; } ^ ./boost/regex/v4/instances.hpp:124:34: warning: unknown warning group '-Wkeyword-macro', ignored [-Wunknown-pragmas] #pragma clang diagnostic ignored "-Wkeyword-macro" ^ When I add '-std=c++11' to the <compileflags> and <linkflags>, I get errors and warnings like these: clang-linux.compile.c.without-pth bin.v2/libs/container/build/clang-linux-3.5.0/release/instruction-set-core2/link-static/threading-multi/alloc_lib.o error: invalid argument '-std=c++11' not allowed with 'C/ObjC' "/netDISKS/master/netmt/LINUX_C65/app/clang/3.5.0/bin/clang++" -c -x c -O3 -Wno-inline -Wall -std=c++11 -fPIC -gcc-toolchain /netDISKS/master/netmt/LINUX_C65/app/gcc/4.8.3 -Wno-overloaded-virtual -Wno-unused-function -Wno-unused-variable -Wno-c99-extensions -Wno-variadic-macros -march=core2 -pthread -m64 -DBOOST_ALL_NO_LIB=1 -DBOOST_CONTAINER_STATIC_LINK=1 -DNDEBUG -I"." -c -o "bin.v2/libs/container/build/clang-linux-3.5.0/release/instruction-set-core2/link-static/threading-multi/alloc_lib.o" "libs/container/src/alloc_lib.c" libs/locale/src/shared/localization_backend.cpp:54:22: warning: 'auto_ptr' is deprecated [-Wdeprecated-declarations] std::auto_ptr<localization_backend> res(new actual_backend(backends,default_backends_)); ^ ./boost/regex/v4/instances.hpp:124:34: warning: unknown warning group '-Wkeyword-macro', ignored [-Wunknown-pragmas] #pragma clang diagnostic ignored "-Wkeyword-macro" ^ What options do I need to add or remove to build and use boost with no errors and as few warnings as possible? -- Dick Hadsell 203-992-6320 Fax: 203-992-6001 Reply-to: hadsell(a)blueskystudios.com Blue Sky Studios http://www.blueskystudios.com 1 American Lane, Greenwich, CT 06831-2560

5 6

New library? CallableTraits
by Barrett Adair 01 Jul '16

01 Jul '16

I posted about this a month ago, but I did not receive much response. Since then, I added an extended example use case, and I added a documentation section [1] that compares CallableTraits and Boost.FunctionTypes. I received some positive feedback this week in Aspen, and r/cpp also seemed to respond well [2], so I thought I'd give this another shot. Here are my questions for you: 1. Is there any interest in reviewing a future version of this for inclusion in Boost? 2. If so, does this belong in its own library, or should it be incorporated into Boost.TypeTraits or something similar? 3. What you like to see added, removed, renamed, or redesigned? I'd say CallableTraits is about 85% finished. Here's what's left: * Add INVOKE semantics to a couple of things for consistency (arity, etc) * Remove unused/undocumented code * Account for transaction_safe and C++17 noexcept * Finish/test the calling convention features * Finish/update the reference documentation * Write even more tests Cheers, Barrett [1] http://badair.github.io/callable_traits/doc/html/index.html#callable_traits… [2] https://www.reddit.com/r/cpp/comments/4ffmfs/callabletraits_never_write_ano… GitHub: https://github.com/badair/callable_traits Documentation from the top: http://badair.github.io/callable_traits/doc/html/index.html (reference section under construction)

5 11

[build] Running 1 per N tests
by Adam Wulkiewicz 30 Jun '16

30 Jun '16

Hi, At Boost.Geometry we're using CircleCI for testing. They allow to run the tests concurently on N virtual machines. I'd like to alter my script to automatically redistribute the tests evenly across all of the machines, i.e. to run 1/N of the tests on each machine. The problem is that at Boost.Geometry we have a lot of nested project directories, i.e. b2 executed for some upper directory runs the tests in the test-suite in this directory and then follows nested projects defined by build-project directives, so runs the tests recursively. So e.g. if b2 was executed on some virtual machine for the most-top-level directory all of the tests would be built anyway. Do you have an idea how this could be solved without altering the tests structure? Is it currently somehow possible (though AFAIK it isn't) or would be possible to implement options allowing to e.g.: - run b2 only for a certain directory/Jamfile, e.g. --non-recursive - ignore arbitrary Jamfile directive, e.g. --ignore-build-project - run only 1 per N tests, an option used together with -jX but running tests only for one thread, e.g. b2 -i2 -j4 running only 1 per 4 commands starting from 2nd command ? The last option would be the most convenient for me. The tests would be divided as evenly as possible. It wouldn't require to use some workarounds i.e. traversing test directories recursively and running b2 manually for them which could result in low-quality redistribution, e.g. if some directory contained many tests and other small number of tests. Regards, Adam

2 2

boost regression run.py fails with, fatal: Not a git repository
by Blower, Melanie 29 Jun '16

29 Jun '16

I'm trying to run.py on develop to report results with the Intel compiler. The script I use first downloads run.py. The git is failing partway through with this message Cloning into 'tools/quickbook'... Submodule path 'tools/quickbook': checked out 'c7cb99ac029593024f3f31a1ab2503820f1300d5' # Cleaning up "/localext3/mblower/sandbox/_try_dev/boost_root/bin" directory ... # Cleaning up "/localext3/mblower/sandbox/_try_dev/boost_root/bin.v2" directory ... # Cleaning up "/localext3/mblower/sandbox/_try_dev/results" directory ... # Getting sources (2016-06-29T12:24:07Z)... # Executing GIT command: /localext3/mblower/sandbox/_try_dev/boost_root> git submodule foreach "cd $toplevel && git submodule deinit $path" Entering 'libs/accumulators' fatal: Not a git repository (or any parent up to mount point /localext3) Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set). Stopping at 'libs/accumulators'; script returned non-zero status. # git_source_checkout failed with message "GIT command "git submodule foreach "cd $toplevel && git submodule deinit $path"" failed with code 256" I'm using a new server, the "master" results completed successfully last night. There's plenty of disk space. Any ideas?

2 1

[boost-git] fiber not contained?
by Oliver Kowalke 29 Jun '16

29 Jun '16

Hi, I was asked several times why boost.fiber is not contained if boost's git-repo is cloned with git clone --recursive http://github.com/boostorg/boost.git. I'm wondering because boost.fiber is already included in the regression tests (master/develop). Oliver

4 8

Attention library authors.. Library requirements testing is now active.
by Rene Rivera 29 Jun '16

29 Jun '16

As part of continued efforts to move testing to CI, to facilitate release management, and to provide more information to authors I've now implemented some testing changes: 1. Most libraries are now tested automatically if they have a usable test directory. There are still libraries that do not follow the requirements of having all their tests in just the single test directory. You can see which ones those are here < https://github.com/boostorg/boost/blob/develop/status/Jamfile.v2#L101>. Library authors should IMMEDIATELY make changes to their test/Jamfile's to follow the library requirements for testing. Before the next release I plan to blindly remove that custom list of extra test targets. 2. Most structure library requirements are now checked both in the regular full testing and in the CI testing. I've implemented a script to check for most of the library directory structure and integration requirements. The script runs as an additional CI job, currently in Travis. Here's one of those jobs < https://travis-ci.org/boostorg/boost/jobs/137506433>. At the moment it reports 17 libraries as having errors. There are also some warnings, i.e. not requirement violations but just some stuff that may be wrong. The script also runs as part of the general full testing and any problems are reported in each library's results as a single entry at the top of the tables. Here's how one of the test failures looks like < http://tinyurl.com/zbe9gal> [1] [2]. It would be great if library authors address those errors in some form ASAP. I know that for some of those reported libraries there will need to be some discussions as to how to best address the errors. Feel free to start additional threads for those as needed. [1] < http://www.boost.org/development/tests/develop/developer/output/teeks99-09f… > [2] Note there are currently some false failures in this aspect from a build system "bug". The bug is already fixed but tests will take some time to cycle to reflect the bug fix. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

11 23

Query: ADL vs MSVC2013 support
by Soul Studios 28 Jun '16

28 Jun '16

I have transplanted the advance/next/prev/distance member functions into ADL non-member functions in a current unreleased version of colony (plflib.org) My question is whether MSVC2013 support for these functions is more important to the boost community than them being ADL. There's a bug in MSVC2013 (fixed in MSVC2015, never backported to MSVC2013) that causes a compiler crash under certain template configurations - unfortunately the way that the ADL has to be implemented (I have tried several methods) causes this bug. The workaround would be to disable these functions in MSVC2013 only, as everything works fine in MSVC2010, MSVC2015, Clang 3.6-3.8 (have not tested earlier) and GCC 4.6-5.1 (have not tested earlier).

1 1

message: Build #2 is still failing.
by Robert Ramey 26 Jun '16

26 Jun '16

I'm getting these messages on aregular basis. They point to the url https://travis-ci.org/boostorg/serialization/builds/140270355 I can see the utility of this. It seems that this is due to some requirement that I'm not fulfillng in the serialization library test directory.... or something. What, if anything, should I do about this. Robert Ramey

2 1

enabling constexpr with Visual studio 2015 Update 3 (RC)
by Paul A. Bristow 24 Jun '16

24 Jun '16

I am trying to use the enhanced constexpr features and have (perhaps unwisely) downloaded the latest Visual Studio Update 3 (RC) to get as great a chance of achieving this as possible. https://blogs.msdn.microsoft.com/vcblog/2015/12/02/constexpr-in-vs2015-upda… (and later posts) I am unsure what I need to do to ensure that the compiler is enabled for use the latest features. I have added /std:c++14 to the options of the property for the project. (aside I also tried /std:C++latest but that works for some tasks but failed to compile with odd-looking errors in converter.hpp Error C2518 keyword 'typename' illegal in base class list; ignored \modular-boost\boost\numeric\conversion\detail\converter.hpp 453 // Trivial Converter : used when (cv-unqualified) T == (cv-unqualified) S // template<class Traits> struct trivial_converter_impl : public std::unary_function< BOOST_DEDUCED_TYPENAME Traits::argument_type ,BOOST_DEDUCED_TYPENAME Traits::result_type > ,public dummy_range_checker<Traits> {...} So I stopped trying that /std:c++latest option. What else should it do?) Running the modular-boost/libs/config/config_info.cpp program BOOST_NO_CXX14_CONSTEXPR [no value] BOOST_CONSTEXPR [no value] BOOST_CONSTEXPR_OR_CONST =const BOOST_STATIC_CONSTEXPR =static const These don't seem to be what I think that I would expect (constexpr and static constexpr). I want especially to use BOOST_STATIC_CONSTEXPR to get static constexpr. Do I need to also add #define BOOST_CXX14_CONSTEXPR in my program or elsewhere? (Doing this doesn't change BOOST_CONSTEXPR_OR_CONST from const to constexpr) Thanks for any suggestions. Paul --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830

8 16

[typeof] Pull requests
by Adam Wulkiewicz 23 Jun '16

23 Jun '16

Hi, There are trivial pull requests in TypeOf waiting for merging (https://github.com/boostorg/typeof/pulls) One of them is more than 2 yo. Would it be possible to merge them? At least #3 or #4 should be merged. Regards, Adam

1 0

Additional Test Configurations
by Tom Kent 22 Jun '16

22 Jun '16

About a month ago I got three new machines dedicated to testing boost online (thanks to Boost Community/Steering Committee/Conservancy!). These three machines are currently running tests along with a couple other machines that I have. Now that things are up and running, I'm looking for some community input as to how best utilize them. Here's the current setup: teeks99-01 - Ubuntu 14.04 + Docker - gcc-4.4 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.5 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.6 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.7 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.8 (master + develop) Docker trusty + ubuntu-toolchain-r/test - gcc-4.9 (master + develop) Docker trusty + ubuntu-toolchain-r/test - gcc-5 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.0 (master + develop) Docker trusty + h-rayflood/llvm - clang-3.1 (master + develop) Docker trusty + h-rayflood/llvm - clang-3.2 (master + develop) Docker trusty + h-rayflood/llvm - clang-3.3 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.4 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.5 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.6 (master + develop) Docker trusty - clang-3.7 (master + develop) Docker trusty + llvm.org/apt teeks99-02 - Ubuntu 16.04 + Docker - gcc-4.4 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.5 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.6 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.7 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.8 (master + develop) Docker trusty + ubuntu-toolchain-r/test - gcc-4.9 (master + develop) Docker trusty + ubuntu-toolchain-r/test - gcc-5 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.0 (master + develop) Docker trusty + h-rayflood/llvm - clang-3.1 (master + develop) Docker trusty + h-rayflood/llvm - clang-3.2 (master + develop) Docker trusty + h-rayflood/llvm - clang-3.3 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.4 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.5 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.6 (master + develop) Docker trusty - clang-3.7 (master + develop) Docker trusty + llvm.org/apt teeks99-03 - Ubuntu 16.04 + Docker - gcc-5 (develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.7 (develop) Docker trusty + llvm.org/apt teeks99-05 - Ubuntu 14.04 (Azure VM) - gcc-4.8 (master) - clang-3.4 (master) teeks99-08 - Windows 2012 (KVM VM) - msvc-8.0 (master + develop) SP1 - msvc-9.0 (master + develop) SP1 - msvc-10.0 (master + develop) SP1 - msvc-11.0 (master + develop) Update 4 - msvc-12.0 (master + develop) Update 5 - msvc-14.0 (master + develop) Update 2 teeks99-09 - Windows 2012 (KVM VM) - msvc-8.0 (master + develop) SP1 - msvc-9.0 (master + develop) SP1 - msvc-10.0 (master + develop) SP1 - msvc-11.0 (master + develop) Update 4 - msvc-12.0 (master + develop) Update 5 - msvc-14.0 (master + develop) Update 2 I'm currently working on getting gcc-6 and clang 3.8, sorry they aren't in the list yet. I'm planning to retire the teeks99-01 shortly and converting the ancient teeks99-05 to something newer, still doing boost testing. All these configurations and the scripts that keep them cycling are on github at: https://github.com/teeks99/boost-build For each platform there are a couple configurations that I try to run frequently to give 'rapid' results as developers are committing code. The configurations for windows are set so that every few runs it will run the msvc-12.0 (develop) test, so that is never more than ~10hrs old. Similarly on linux, the gcc-5 and clang-3.7 (develp) tests get run every few hours. Just to give a feeling of the timing, Linux runs take .75-3 hrs and Windows runs take 1.5-4hrs, depending on compiler, os, hardware, etc. All these configurations have minimal compiler options set. MSVC + GCC builds have no options set, clang has `<cxxflags>-Wno-c99-extensions`. >From a lot of the discussing I've seen on the lists, it seems that there's a lot of work going into C++ 11/14/1z development. I was thinking it would be good to add some of those switches. Which ones? How many? Baseline Standard -std=c++98 (I believe this is the default for all the g++/clang++ instances above) -std=c++11/0x -std=c++14/1y -std=c++1z GNU Standard -std=gnu++98 -std=gnu++11/0x -std=gnu++14/1y -std=gnu++1z Clang Library -stdlib=libc++ -stdlib=libstdc++ Optimization -O2? Warnings -Wall -Wextra Others? I'm guessing that most of these will be of interest to at least a small subset of developers. There probably isn't a need to apply all possible combinations to all possible compilers however. (Not to mention that it would make the results matrix even more overwhelming.) Which combinations are important for you to see in the matrix? What do you think should be the 'rapid' configurations? I'm also thinking about additional compilers (in addition to gcc-6/clang-3.9 mentioned above), though these will take a bit of work on my part, so will only get implemented as I have time available. - gcc HEAD from GIT - clang HEAD from GIT - cygwin/gcc - mingw - clang on windows - Other? Thanks in advance for your input! Tom

6 12

[boost.process] 0.6 Alpha
by Klemens Morgenstern 21 Jun '16

21 Jun '16

Hi all, the boost.process 0.6 library is now in alpha, that is: it has some (compiling) examples, a documentation and tests that pass on windows as well as on linux. It basically allows you to manage a process like this: pstream pipe; child c("some_prog", "--some-arg", env["PATH"]+="C:/stuff", std_in < "data.csv", std_out > pipe, std_err > null, start_dir="./bin"); std::string data; pipe >> data; c.wait(); cout << c.exit_code() << endl; You can find the documentation here: http://klemens-morgenstern.github.io/process/ Get the source code from here: https://github.com/klemens-morgenstern/boost-process If you want to use it on windows, you currently would need to clone my boost.winapi fork also: https://github.com/klemens-morgenstern/winapi As for the scope of the library, it is meant to implement a small, portable layer to allow platform-independent process management. Thereby it's functionality is (unless I missed something) basically what is possible on posix as well as on windows. There are some platform extension, but I would not recommend to use them. It is also possible (though not yet documented) to write extensions, and if they work on both platforms I will gladly add them. It is however not the goal of the library, to be the be-all and end-all of process management; in past disscussions, different ideas where brought up, like implementing a DSEL for that or only allowing asynchronous communication. This library will never be that, since it would be much more fitting to build this on-top of it. E.g. a DSEL could be written (e.g. boost.shell) using boost.process underneath, so the library could concentrate only on the DSEL. It doesn't depend on boost.iostreams anymore, though it still uses boost.asio, boost.fusion and boost.filesystem. As for the open issues: some error handling is still lacking (but that'd be something like being unable to duplicate a handle), which would be required for proper extension, which is also why it's not documented. Also there's still an open discussion about the naming of the class and functions (child, system, spawn), so that may change also. But I consider this simple enough for a easy refactoring. If anyone has naming ideas, please tell me. One Idea was 'subprocess' but 'process::subprocess' just looks too strange to me. I hope you try it out, and give me some feedbacks. Or write angry error reports, both helps. Thanks! Klemens

8 32

Checking interest in stacktrace library
by Antony Polukhin 21 Jun '16

21 Jun '16

Hi, I've got some prototype for getting stack traces: https://github.com/apolukhin/stacktrace It's design is based on the idea that class for stacktrace must be fully noexcept, without dynamic allocations in constructors and as simple as possible. Is there interest in it? What functionality would you like to have in it? -- Best regards, Antony Polukhin

9 10

Re: [boost] proposed new library "histogram"
by Bjorn Reese 20 Jun '16

20 Jun '16

On 05/05/2016 12:21 AM, Hans Dembinski wrote: > https://github.com/HDembinski/histogram I suggest that you use non-intrusive serialization and place that in separate headers, so there is no dependency on Boost.Serialization unless you need it.

2 4

Checking interest in clang-{format, tidy} configurations
by jerry.c.t＠web.de 19 Jun '16

19 Jun '16

Hi, is there an interest for common boost clang-format and clang-tidy (only the module readability-identifier-naming) configurations to inforce consistent layout and naming style? For clang-format there are predefined styles like llvm, google etc. I think about adding a new predefined style 'boost' to clang-format. But first i would start with a separate _clang-format file. For clang-tidy there are no predefined styles thus i would simply create a _clang-tidy file. Best regards, Jerry

2 1

Feature request: variant::view
by TONGARI J 19 Jun '16

19 Jun '16

Hi, Sometimes we need to view a value as a variant and we don't want to copy the value into a variant. It'd be great if there's a variant::view that works like a variant but holds a reference to the value instead. The constructor should allow any reference to the types as in the variant, and a constructor that takes a reference to the variant, e.g. template<class T1, class T2...> class variant<T1, T2...>::view { view(T1&); view(T2&); ... view(variant&); }; And we can use apply_visitor/get on a view as on a variant. Thoughts? Thanks.

2 2

Boost's List of improvements
by Зайцев Александр 19 Jun '16

19 Jun '16

Hello. I will prepared Boost's list of improvements. I can realize it. Maybe, some algorithms I only can't find in Boost. And i think, that if i will implement algorithms from this list, it's will be great. Improvement list for Boost.Algorithm Boost.Algorithm(String) 1) Manacker's Algorithm: finding all palindromes in string O(N). 2) Different algortihms based on suffix arrays and suffix trees: Boost.Algorithm(Numbers) 1) Checking for number's simplicity by BPSW test. O(logN). 2) Effective factorization algorithms: Po, Po-1, Bents algo, Po-Monte-Carlo, Ferms algo. 3) Longest increasing subsequence Boost. Container 1) Modifications of queue and stack for searching min/max element with O(1). Maybe, I forgot something. -- Best regards, Zaitsev Alexander

1 0

Book
by Robert Ramey 18 Jun '16

18 Jun '16

I've attached an epub version of my "book". You should be able to just click on it and have the apple book reader popup and then be able to read it. The apple book reader has some interesting features. a) the book looks pretty good considering I didn't have to put to much effort into the formatting etc. b) For our purposes the best part is that you can easily annotate the book! There are three icons in the upper left corner. One to display the table of contents and other one for "notes" You can highlight text and add a note to it then save the book !. This is perfect as far as I'm concerned. Please don't spend time "copy editing" it. The whole thing needs to be gone over with a fine tooth comb with the idea of making the text more readable and clear, that the examples are in sync with the text, probably more narrative etc. etc. I'm really mostly concerned that the concepts are readable and explained to the target reader. Since I discovered the notion of semiring I understand the my C++ type algebra fulfills all the requirements of a semiring. And there is a large list of theorms which apply to semirings. I don't intend to add too much to the section, at least for now. It is very interesting but but right not it doesn't yet have a practical application. I'm hoping that will change but for now I it's as far as I want to go with this. This section will also need some work as far at the math is concerned. There are some issues with the notion of an inverse of a type etc which are still not really finished. But for now I think I've got the concepts outlined. It generates a book 60 pages long.

4 4

Re: [boost] [Boost-users] Checking interest in stacktrace library
by Antony Polukhin 18 Jun '16

18 Jun '16

2016-06-18 17:49 GMT+03:00 Edward Diener <eldiener(a)tropicsoft.com>: > On 6/18/2016 6:34 AM, Antony Polukhin wrote: > >> Is there interest in it? >> What functionality would you like to have in it? >> > > Documentation is always helpful. > Yeep, that's currently missing :( If in short: namespace boost { namespace stacktrace { class stacktrace { public: BOOST_STATIC_CONSTEXPR std::size_t max_symbol_width = 256; typedef boost::array<char, max_symbol_width> frame_t; stacktrace() BOOST_NOEXCEPT; stacktrace(const stacktrace& bt) BOOST_NOEXCEPT; stacktrace& operator=(const stacktrace& bt) BOOST_NOEXCEPT; ~stacktrace() BOOST_NOEXCEPT; std::size_t size() const BOOST_NOEXCEPT; frame_t operator[](std::size_t frame) const BOOST_NOEXCEPT; }; template <class CharT, class TraitsT> std::basic_ostream<CharT, TraitsT>& operator<<(std::basic_ostream<CharT, TraitsT>& os, const stacktrace& bt); }} So you can construct stacktraces, copy them and output them to streams: std::cerr << stacktrace(); -- Best regards, Antony Polukhin

1 0

Library addition request
by Gerrit Daniels 18 Jun '16

18 Jun '16

Hello, I've written a library that implements automatic serialization of user defined types. You can find it here: https://github.com/gerritdaniels/ctrl. I was wondering if this is something that could be added to the boost library. Kind regards, Gerrit Daniels.

6 10

Stand-alone Boost.Python
by Stefan Seefeld 18 Jun '16

18 Jun '16

Hello, I have started working on a new SCons-based build infrastructure for Boost.Python that allows the Boost.Python code to be compiled stand-alone against a pre-installed Boost. I have checked in a first version to the develop branch, and have enabled Travis-CI to use that. While this works reasonably well, and provides a much simpler workflow for developers wanting to contribute to Boost.Python, it isn't (yet) entirely feature-complete. Notably, running this on Windows (using MSVC) produces errors. I'd appreciate any help with this, especially from Windows users who are more familiar with MSVC than I am (that shouldn't be hard, given I have next to no experience with using MSVC :-) ). Building Boost.Python is now very simple: * clone the repo via `git clone https://github.com/boostorg/python.git` and switch to the 'develop' branch * configure a build via `scons config --python=... --boost-prefix=...` * build and test via `scons test` Hopefully this will make it much simpler to contribute and test patches, so we can work down the list of accumulated PRs and issues. (For avoidance of doubt: for the immediate future I have no intentions to replacing the official bjam-based build system. But once the new one has proven to be stable enough, I expect to actually build stand-alone releases for Boost.Python.) Thanks, Stefan -- ...ich hab' noch einen Koffer in Berlin...

1 0

Using Boost with VS 14.0 update 3 RC and Clang 3.8.0 (from CodeBlocks IDE) compile fails in MS type_traits is_assignable
by Paul A. Bristow 15 Jun '16

15 Jun '16

I am trying to check a program that compiles on VS with 14.0 update 3 RC and on Codeblocks IDE GCC 5.3 compile OK, but CodeBlocks Clang 3.8.0 fails: C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\include\type_traits:524:45: error: '_To' does not refer to a value : integral_constant<bool, __is_assignable(_To, _From)> I:\modular-boost\boost\mpl\aux_\preprocessed\plain\or.hpp|58|error: pasting formed 'BOOST_PP_TUPLE_ELEM_O_3(', an invalid preprocessing token [-Winvalid-token-paste] and terminally many more. clang++.exe -Wall -std=c++14 -m64 -fexceptions -O4 -m64 -std=c++14 -fms-extensions -Wall -m64 -fms-compatibility-version=19.00 -II:\modular-boost -c J:\Cpp\hellos\fixed_point_constexpr\fixed_point_constexpr.cpp -o obj\Release\fixed_point_constexpr.o I see some discussion of similar problem on https://groups.google.com/forum/#!topic/boost-list/MvqaK4SDy_c and a possible apparent fix on https://github.com/boostorg/type_traits/pull/24 Any suggestions for working around this problem? Paul PS I may try to use a *nix platform for this. --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830

2 1

[density] new library
by Giuseppe Campana 14 Jun '16

14 Jun '16

Hi to all, I'm working to density, a C++11 header-only library for heterogeneous containers and lifo memory management. It is not complete, but it is very close (and usable already). Just to avoid confusion, the test project of density contains a sub-module called testity, that in a near future will become a separate library. I'm wondering if it may become a valid proposal for a new library. In any case, any kind of feedback is welcome. Source code at https://github.com/giucamp/density Documentation at http://peggysansonetti.it/tech/density/html/index.html Regards, Giuseppe Campana.

6 9

[property_tree] Quoting documentation
by alainm 13 Jun '16

13 Jun '16

Hi, I am using property_tree for a project, and I'd like to provide a description of the format. That text is exactly what I need: http://www.boost.org/doc/libs/1_61_0/doc/html/property_tree/parsers.html#pr… I am going to provide a link to the doc, but would need to insert the text into the documentation pdf too (some people actually still read paper). Is it possible and what kind of copyright text should I use ? Thanks Alain

2 1

Start to contribute to Boost.
by Зайцев Александр 11 Jun '16

11 Jun '16

Hello. I very want to start contribute to Boost library. I want to help this project. And... maybe for start i can try to fix some bugs. Can you give me some pieces of advice, what i can do at start? Thanks. -- С уважением, Зайцев Александр.

3 2

Pimpl Again?
by Vladimir Batov 10 Jun '16

10 Jun '16

Don't laugh but it is only fairly recently at work that I managed to move all our supported platforms to C++11. So, then, I started moving our code to C++11 (what a delight!) and stumbled upon my old pimpl which is used quite a bit around my workplace for all its good properties... :-) Now C++11-ed piml turned out to be very small and very basic. So basic it felt it did not have the right to exist. Still, it encapsulates and enforces the "proper" pimpl properties and behavior, reduces implementation minutia and offers a recognizable deployment pattern (helps other people reading the code). Over the years IMO the technique has been proven as legitimate and useful, a basic but important building block... rather than a curiosity item. Unfortunately, despite many articles and a few Sutter's GotWs about it there is nothing ready-to-go like std::unique_ptr. I feel that pimpl and its deployment pattern need to be codified, described, "standardized" and in our toolboxes to stop/avoid everyone re-inventing the pimpl and making the same mistakes. IMO Boost is best positioned for that. Do you think we might review what I've got and/or maybe collectively come up with something better... It's no MPL or Hana but as std::unique_ptr it's one of the first "little things" I personally reach out for in my everyday work. IMO having pimpl in Boost would save quite a few hours of frustration for many. Thoughts? No pressure. I am easy either way. :-) https://github.com/yet-another-user/pimpl Docs are freshened up but still somewhat out of date. Apologies.

15 84

[config] Changes needed for VC++ 2015 Update 3?
by Beman Dawes 09 Jun '16

09 Jun '16

The VS 2015 Update 3 release candidate has been announced. See https://blogs.msdn.microsoft.com/vcblog/2016/06/07/compiler-improvements-in… (The following is partially for Boost developers who care about msvc, and partially to remind myself of what may need to be done to support update 3. It will be several weeks before I can work on this, so if any of the other config maintainers want to step in, please do so.) Update 3 supports standards versioning switches similarly to gcc, clang, and other compilers. We probably want to update Boost.Config accordingly. See https://blogs.msdn.microsoft.com/vcblog/2016/06/07/standards-version-switch… Update 3 fixes lots of constexpr bugs, so we need to review whether or not BOOST_NO_CXX11_CONSTEXPR is still required. Note that in develop there is an undocumented config macro BOOST_MSVC_CXX11_CONSTEXPR that turns off BOOST_NO_CXX11_CONSTEXPR to facilitate testing. Update 3 fixes the expression SFINAE issues that were causing most of the Boost develop test failures. https://blogs.msdn.microsoft.com/vcblog/2016/06/07/expression-sfinae-improv… Quoting from that: There are still three failing tests in the Boost [develop] test suite when compiling with MSVC. Two test failures relate to using the noexcept operator in a template type argument. We currently parse it immediately, even in a dependent context. One test failure is a Boost library issue that we’ve reported to the [library's] maintainers. There are still known update 3 expression SFINAE issues (see "What remains to be done?" in the blog article) so do we continue to define BOOST_NO_SFINAE_EXPR? There is an undocumented BOOST_MSVC_SFINAE_EXPR macro in develop that turns off BOOST_NO_SFINAE_EXPR, so it is easy for developers to use msvc expression SFINAE if the want to. But our usual criteria for a _NO_ macro is not full compliance, but whether or not Boost code works with a feature. So using that criteria for update 3 we would remove BOOST_NO_SFINAE_EXPR. Opinions? --Beman <aside> We always urged Microsoft to test their releases against Boost. For update 3 expression SFINAE, they did exactly that. Thanks to Microsoft's Andrew Pardoe for coordinated the effort and to Xiang Fan for running the tests and tracking down the reason for each test failure. An undocumented Boost.Config macro BOOST_MSVC_SFINAE_EXPR to support their testing. The approach was to run tests for all libraries with the normal test setup, and then run again with BOOST_MSVC_SFINAE_EXPR defined. If the problem was with the Boost library, Xiang then reported it to me. I need to review a long series of email exchanges with him to make sure I alerted library maintainers to any Boost problems. </aside>

5 9

Boost Best Practice text download option fails.
by Fletcher, John P 08 Jun '16

08 Jun '16

This is a very interesting item to me. https://svn.boost.org/trac/boost/wiki/BestPracticeHandbook This has an option at the end to download as plain text. This fails on my browser (Firefox) with "Corrupted Content Error" which I have never seen before. Please sort this out someone. John

2 1

[variant] spirit broken
by Jürgen Hunold 08 Jun '16

08 Jun '16

Hi Antony, according to git bisect, your commit ----------- commit b3650685f941a0c35cadfd878a185f274e132788 Author: Antony Polukhin <antoshkka(a)gmail.com> Date: Sat May 28 01:29:52 2016 +0300 Variant constructors and assignment operators now do not participate in overload resolutions if variant can not hold the input type (trac 5871, trac 11602) ------------ broke Boost.Spirit. The test failures can be seen in the regression matrix. For example: http://www.boost.org/development/tests/develop/developer/output/Flast-FreeB… fails with ../boost/variant/variant.hpp:1152:7: note: while substituting deduced template arguments into function template 'operator=' [with T = boost::variant<boost::spirit::info::nil_, std::__1::basic_string<char>, boost::recursive_wrapper<boost::spirit::info>, boost::recursive_wrapper<std::__1::pair<boost::spirit::info, boost::spirit::info> >, boost::recursive_wrapper<std::__1::list<boost::spirit::info, std::__1::allocator<boost::spirit::info> > > >] class variant ^ ../boost/spirit/home/support/info.hpp:29:12: note: definition of 'boost::spirit::info' is not complete until the closing '}' struct info It seems that the commit somehow disabled support for recursive variant usage. To reproduce this, just run the Spirit regression test. Yours, Jürgen -- * Dipl.-Math. Jürgen Hunold ! * voice: ++49 4257 300 ! Fährstraße 1 * fax : ++49 4257 300 ! 31609 Balge/Sebbenhausen * jhunold(a)gmx.eu ! Germany

2 5

[Spirit] real_policies<> and 1.0#NAN
by Pete Bartlett 08 Jun '16

08 Jun '16

Hi, Boost.Spirit is not sure of itself when it comes to parsing representations of infs and nans such as “1.0#NAN”. The docs [1] for the default real_policies<T> for parsing numbers say: “[…] with the additional detection of NaN and Inf as mandated by the C99 Standard and proposed for inclusion into the C++0x Standard: nan, nan(...), inf and infinity (the matching is case-insensitive). This corresponds to the following grammar:” The first sentence suggests that 1.0#NAN etc will not be parsed. But the grammar itself then says: <quote> nan = -lit("1.0#") >> no_case["nan"] >> -('(' >> *(char_ - ')') >> ')') ; inf = no_case[lit("inf") >> -lit("inity")] ; </quote> suggesting that "#1.0NAN" is intended to parsed, but "#1.0INF" is not! Then the in-code docs [2] however suggest that both "1.0#NAN" and "1.0#INF" are intended to be parsed: <quote> // The second call allows to recognize representation formats starting // with a 1.0 (such as 1.0#NAN or 1.0#INF etc.). </quote> However, the actual code fails to parse either of these these. This is because in [3] the presence of the "0" causes frac_digits to be non-zero and so the "traits::is_equal_to_one(..)" condition is never tested. In the case "1.#NAN" (without a zero) frac_digits is zero so the condition is tested and we enter the traits::parse_nan code, but now the text parsed to this sub-parser is "#NAN" and the parser does not cater for the initial "#". Could the maintainers state which behaviour is intended...hopefully I may be able to supply a patch to docs/code/tests knowing that. Regards, Pete [1] http://www.boost.org/doc/libs/1_61_0/libs/spirit/doc/html/spirit/qi/referen… [2] <boost/spirit/home/qi/numeric/real_policies.hpp> [3]<boost/spirit/home/qi/numeric/detail/real_impl.hpp>

2 1

RFC : About forking a C++11 standard library and adapt it to C++98 compilers
by Vicente J. Botet Escriba 07 Jun '16

07 Jun '16

Hi, Some of us have to work yet with C++98 compiler at work (due to well know reasons) and this for a long time. This is a reality. I was wondering about forking a public domain C++11/14/17 standard library and adapt it to C++98 compilers. This library could be seen as another TR1, an extension of the C++03 standard library. Does this make any sens? Would this project be of interest for the Boost/C++ community? I have not a clear idea of the cost of doing this work, how it should be done, what would be the limitations, ... but I'm sure that this would be quite useful on the projects that are forced to use C++98 and an excellent bridge to those that will move from C++98 to C++11 compilers. There are some Boost libraries that could be used to reduce the limitations, as Boost.Config/Predef, Boost.Move, ...and others that could be used as inspiration on how to implement them using C++98. Anyway, if you find that this will be useful to you at your work we will need your participation. Would you be interested in working on it? as a Boost community project? outside Boost, as an independent project? Comments and suggestion welcome. Best, Vicente P.S. The same can be done for C++14 standard libraries and the future standard C++17 libraries P.S.S. The same can be done for C++14 libraries and the future C++17 libraries but this time adapting to C++11 compilers (this will be much easier but the concerned community will be quite different ).

5 7

Make libs/maintainers.txt a template file
by Daniel James 07 Jun '16

07 Jun '16

Hi, If you haven't noticed, on develop libs/libraries.htm is now a template which gets filled in as part of the documentation build. You can see the template and generated files at: https://github.com/boostorg/boost/blob/develop/libs/libraries.htm http://www.boost.org/doc/libs/develop/libs/libraries.htm This will be merged to master pretty soon. The only obstacle is updating the website automatically from the latest build, which should be happening very soon. The file libs/maintainers.txt is also automatically updated, but that's done in the repo itself, so that you have the full copy in you normal checkout. But I'm finding that people don't realise this, and we've had a few pull requests to update it manually. So instead, I think it might be a good idea to convert it to a template as well. This means you won't have a local copy, but will still be able to see a reasonably up to date copy online at: http://www.boost.org/doc/libs/develop/libs/maintainers.txt Any objections? I'm think of using similar templates for some other files, such as the root index.html (for the version number and new libraries). thanks, Daniel

2 2

Cxx dual library
by Edward Diener 06 Jun '16

06 Jun '16

I have finished all the main work on the Cxx dual library at https://github.com/eldiener/cxx_dual. The library is also in the Boost Library Incubator at http://rrsd.com/blincubator.com/bi_library/cxx_dual-2/?gform_post_id=1597. The Cxx dual library, or CXXD for short, is a C++ macro header-only library which chooses between using a Boost library or its C++ standard equivalent library for a number of different C++ implementations, while using the same code to program either choice. An 'implementation' is a Boost library which has a C++ standard library equivalent whose public interfaces are nearly the same in both cases. An 'implementation' is called a 'dual library' in this documentation, or 'CXXD-mod' for short. The library does this by defining object-like macros for including the appropriate header file and namespace or using either the Boost library version or the C++ standard library version of a particular dual library. CXXD currently supports twenty eight different dual libraries, where the Boost version and the C++ standard version is nearly interchangeable in some respects. CXXD also provides a macro-based solution for distinguishing between the Boost version and the C++ standard version of a dual library so that specific code for a particular dual library choice may be written in those cases where the public interfaces diverge. The library came out of my initial PR to add such a feature to Boost.Config, and then I decided to create a separate library and expand on the functionality. The gist of the library is to write a single set of code for a particular implementation and have it work whether or not that code targets a Boost implementation or its C++ standard equivalent. The default algorithm will choose the C++ standard implementation if it is available, otherwise it chooses the Boost implementation. The default can be overriden for any of the 28 different implementations which CXXD supports. With all the talk about supporting C++11 or C++14 in new code, the library offers a way of supporting C++11 or C++14 standard libraries if available whether one writes in C++03 dialect or uses the new language features of C++11 on up. The Cxx dual library itself, being macro based, should work with any C++ code at that code's language level. The library itself is NOT, repeat NOT, an attempt to enforce a C++ language level for anybody who wants to use it. I have a little more work I am doing on increasing the support for Boost Build in the library, but all the central implementation of the library is complete in my mind. Questions, comments, or bug reports are always welcome, either here in this mailing list, in the Boost Library Incubator, or as Github issues, by those who are interested in trying the library out or reading the documentation. I will be using CXXD in another library on which I am working but hopefully others will find a use for it in their own code.

5 30

[exception] Broken in master?
by John Maddock 06 Jun '16

06 Jun '16

Anything that includes Boost.Exception is currently broken on master for all compilers, for example: http://www.boost.org/development/tests/master/developer/output/teeks99-09j-… http://www.boost.org/development/tests/master/developer/output/Flast-FreeBS… The cause is the use of a partial-template specialization in info.hpp with no previous definition of class set_info_rv. Thanks, John.

2 1

Boost.Fiber mini-review May 23 - June 1: review report
by Nat Goodspeed 05 Jun '16

05 Jun '16

The Boost.Fiber mini-review is now closed. Results: Bjorn Reese: YES Niall Douglas (private): YES Agustín K-ballo Bergé: YES Niall Douglas reminds me that in a previous mini-review he already voted to accept the Fiber library. Unless he stated that he had changed his mind, it would be reasonable to carry forward that "yes" vote. However, he did reaffirm his previous stance. In that spirit, let me remind the community of another couple previous positive votes: Eugene Yakubovich Antony Polukhin Significantly, there were no remaining NO votes. I therefore conclude that the Boost community ACCEPTS the Fiber library into the Boost family of libraries. On behalf of the Boost community, I would like to congratulate Oliver Kowalke not only for his engineering work, but for considerable patience in working to improve the library and its documentation. Thank you, Oliver!

3 2

Re: [boost] Checking interest in std::get for PODs
by Bjorn Reese 04 Jun '16

04 Jun '16

On 06/03/2016 08:27 AM, Antony Polukhin wrote: > There's a C++14 library that is able to do basic reflections for PODs > without any macro magic or markup: https://github.com/apolukhin/magic_get Could the "Enums will be returned as their underlying type" limitation be partially worked around by allowing users to register their own enums?

3 2

Checking interest in std::get for PODs
by Antony Polukhin 04 Jun '16

04 Jun '16

Hi, There's a C++14 library that is able to do basic reflections for PODs without any macro magic or markup: https://github.com/apolukhin/magic_get Would it be interesting for Boost? Could it pass Boost review if it has a reinterpret_cast in it? -- Best regards, Antony Polukhin

8 16

Re: [boost] Cxx dual library
by Thomas Heller 04 Jun '16

04 Jun '16

Am 02.06.2016 8:56 nachm. schrieb "Edward Diener" <eldiener(a)tropicsoft.com>: > > I have finished all the main work on the Cxx dual library at https://github.com/eldiener/cxx_dual. The library is also in the Boost Library Incubator at > http://rrsd.com/blincubator.com/bi_library/cxx_dual-2/?gform_post_id=1597. > > The Cxx dual library, or CXXD for short, is a C++ macro header-only library which chooses between using a Boost library or its C++ standard equivalent library for a number of different C++ implementations, while using the same code to program either choice. An 'implementation' is a Boost library which has a C++ standard library equivalent whose public interfaces are nearly the same in both cases. An 'implementation' is called a 'dual library' in this documentation, or 'CXXD-mod' for short. > > The library does this by defining object-like macros for including the appropriate header file and namespace or using either the Boost library version or the C++ standard library version of a particular dual library. CXXD currently supports twenty eight different dual libraries, where the Boost version and the C++ standard version is nearly interchangeable in some respects. CXXD also provides a macro-based solution for distinguishing between the Boost version and the C++ standard version of a dual library so that specific code for a particular dual library choice may be written in those cases where the public interfaces diverge. Personally, I'm not a big fan of such a solution, especially when those macros "leak" into the public interface. We had a similar interface which would automatically switch between std and boost function. The result looked nice at first sight, however the subtle differences between the two led to various problems, one of which was that documenting the public interfaces containing this macro was very difficult, where does it point to know? Where should we send users to who look for more information about this function type? Should they be aware of both? Switching compilers or even boost version and now suddenly everything seems broken? The solution for us was to just decide which one to use and go with it, setting the requirements to the used standard library/boost version as needed.

4 9

A retrospect on 'CMakeLists.txt' policy review
by David Sankel 04 Jun '16

04 Jun '16

Hello all, I wanted to thank everyone who participated in the CMakeLists.txt and related threads. I'm sorry I wasn't able to participate all the way through, but I found the majority of the posts to be civil and constructive (some of my own heated posts being notable exceptions). Here is my take away. No one is arguing that the current guidelines disallow authors from placing a CMakeLists.txt in the root of their library's directory. Some pointed out drawbacks of placing them there and recommended 'build/' or 'CMake/' instead. Others saw value in having CMakeLists.txt in the root directory, but felt these should be short wrappers where the real work is done in the 'build/' directory. Louis and Paul, I know you felt it important for your gitHub distribution to have 'CMakeLists.txt' in the root directory as is typical for CMake projects. Does this result satisfy your concerns? -- David Sankel

9 18

[announcement] GitHub permission changes
by Daniel Pfeifer 03 Jun '16

03 Jun '16

Hi all, GitHub finally allows us to set permissions on the level of granularity that we always wanted. When we moved to GitHub, we received many request like "can I please get admin rights to my repository?" We wanted to do that, but it just was not possible. As a workaround, we have created a team per repository and many of those teams had just one member. That way, we could at least give you write access to individual repositories. Not quite what you requested, but at least something. Anyway, it is now possible to set permissions on a per repository level. I have started to delete the teams with a single member and added the member as the owner of the repository. How do those changes affect you? As the owner of a repository you have write access as before, but you can also add collaborators, modify the repository descriptions, enable/disable issue tracking and wiki, and so forth. I will continue this cleanup soon, but I need your input. For teams with multiple members, I don't know whether you want to share ownership or whether you prefer to have a single owner and additional contributors. Please create new issues for that matter: https://github.com/boostorg/admin/issues Cheers, Daniel

3 2

Boost.Fiber mini-review May 23 - June 1
by Nat Goodspeed 02 Jun '16

02 Jun '16

Hi all, The Boost.Fiber candidate library by Oliver Kowalke begins a mini-review today, Monday May 23, which will close Wednesday June 1. It was last reviewed in September 2015; the verdict at that time was "not yet." Oliver has been working steadily to address review comments and to improve the library in other ways, and has brought the library back for mini-review. The updated documentation is here: http://olk.github.io/libs/fiber/doc/html/index.html The code is on the master branch of this repository: https://github.com/olk/boost-fiber/tree/master I believe it is Oliver's intention to respond to review feedback on the develop branch, leaving the master branch stable during the review. I will monitor reviews and discussion on both the boost-users@ list and the boost@ developers' list. Please include at least "fiber" and "review" in the subject line of your mail, e.g. by replying to this message. (Please reply to only ONE list, however.) I will also check the Boost Library Incubator for Fiber reviews: http://rrsd.com/blincubator.com/bi_library/fiber/?gform_post_id=859 though I check that less frequently than email. Please do remember to state in your review whether you think the library should be accepted as a Boost library. Thank you for your interest and your feedback! ----------------------------------------------------- Here follows a synopsis of issues raised during the September 2015 review: Cross-thread fiber migration: Evidently the community strongly desires the ability to transfer a suspended fiber from one thread to another. Now supported, with documentation. Cross-thread migration support implies a requirement to document the thread safety requirements of the customization API. Addressed. Standard required timing specifications: meet (30.2.4 Timing specifications [thread.req.timing]). Addressed. Adapt one or more existing test suites for thread facilities to validate the correctness of the Fiber library's synchronization constructs. The requester clarified in private mail that I misstated his suggestion: he wanted Oliver to review one or more such test suites to discover the kinds of issues that can arise with thread synchronization constructs. He has professed himself satisfied with the current state of the Fiber library's synchronization constructs. std::chrono support: ensure that wait_until() can accept any supported time_point specialization. Addressed. C++11 compatibility. Addressed. Document that this_fiber::yield() (et al.) are valid from main(), or in general from a thread function, as well as from explicitly-launched fibers. Addressed. Make shared_state lock requirements explicit: for example, make mark_ready_and_notify_() accept a std::unique_lock<>& (or &&) to force its caller to provide one. Addressed. Avoid holding mutex during condition_variable::notify_*() calls. Addressed. packaged_task must not decay-copy its task arguments. Addressed. Align fibers::async() signature, result description and invoke_helper implementation with std::async(). Avoid returning std::move(...). Addressed. Wait list implementation: try an intrusive linked list of fiber_context objects. Addressed. Avoid sleeping thread when no fibers are ready -- block on external event. Better handling of waiting tasks (decentralized wait queues?). Addressed. Optimization to resume awakened fiber on the thread that awakens it. Hooks provided. Template redundancy: eliminate duplication between specializations for T, T& and void. The future, shared_future, shared_state, promise and task_object templates were specifically cited. Addressed. Leverage predicate-based condition::wait() overload internally. Addressed. Nested schedulers: make schedulers be schedulable entities themselves. Not implemented. Improve robustness of `promise' handling in Asynchronous Callbacks documentation. Avoid overconfident remarks about it. Addressed. Fix Note overstating the requirements on condition_variable::wait(). Addressed.

2 3

[optional] using name boost::in_place -- need your opinion/advice
by Andrzej Krzemienski 30 May '16

30 May '16

Hi Everyone, I have stumbled upon a problem that I do not know how to address. I would like to seek an advice from the people in this list. I am trying to make boost::optional resemble std::optional (where it is reasonably easy to achieve). std::optional has this nice and useful "placement" constructor: std::optional<std::mutex> m {std::in_place}; std::in_place is a tag type, that instructs std::optional to create an object using placement-new syntax, from the provided arguments (zero in the example), without incurring any move construction. I cannot easily copy 1-to-1 this solution, because in namespace boost name in_place is reserved for the in-place factories: http://www.boost.org/doc/libs/1_61_0/libs/utility/in_place_factories.html I could simply go with a different name for a tag, but something tells me it would introduce an unnecessary complications for users that want to migrate from one optional to another. I could hack in-place factories so that they can also be used as a tag, although, I am not sure it is doable in a type-safe manner, and if it would not confuse people to have this boost::in_place do a number of different things. I could use a different namespace, but again, this might look surprising.I am a bit torn. I wonder if anyone here needed to face a similar problem, and if you can think of an elegant solution. Thanks, &rzej

4 12

[Boost.Test][Boot.Timer v2] header only boost.test conflicts with Boot.Timer V2
by Tan, Tom (Shanghai) 30 May '16

30 May '16

This following simple snippet would yield an error with visual studio 2015 for both boost1.60.61: boost/timer/timer.hpp(32): error C2757: 'timer': a symbol with this name already exists and therefore this name cannot be used as a namespace name // compiled with cl.exe /EHsc #define BOOST_TEST_MODULE test #include <boost/test/included/unit_test.hpp> #include <boost/timer/timer.hpp> The following variants are ok // compiled with cl.exe /EHsc #define BOOST_TEST_MODULE test #include <boost/test/unit_test.hpp> #include <boost/timer/timer.hpp> Or // compiled with cl.exe /EHsc #define BOOST_TEST_MODULE test #include <boost/test/included/unit_test.hpp> #include <boost/timer.hpp> It looks like Boost.Test is relying on boost.timer v1, which is deprecated in documentation and conflict with V2.

3 2

[boost.timer v2] auto_cpu_timer does not compile
by Tan, Tom (Shanghai) 29 May '16

29 May '16

This following snippet generates an error with VS2015 both fo 1.60&1.61: libboost_timer-vc140-mt-s-1_61.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 "public: struct boost::timer::cpu_times __cdecl boost::timer::cpu_timer::elapsed(void)const " (?elapsed@cpu_timer@timer@boost@@QEBA?AUcpu_times@23@XZ) // compile with cl.exe /EHSc #include <boost/timer/timer.hpp> int main() { boost::timer::auto_cpu_timer t; } What's interesting is that uncommenting line #14 in file boost/timer/timer.hpp would get rid of this error. - Why is there such a line but commented out there? - Is there a better way to get it through without modifying this file - the binary is downloaded from sourceforge, not a custom build. - Thanks.

1 0

Re: [boost] Boost.Fiber mini-review May 23 - June 1
by Bjorn Reese 28 May '16

28 May '16

On 05/23/2016 06:20 PM, Nat Goodspeed wrote: > Please do remember to state in your review whether you think the > library should be accepted as a Boost library. Yes, I vote for unconditional acceptance of Boost.Fiber. I did not participate in the formal review (due to time constraints), so I am not going to address the individual issues. I happened to have studied Boost.Fiber recently because I came across limitations of the inter-coroutine interaction in Boost.Coroutine, and Boost.Fiber addresses these limitations rather nicely. I especially like the message passing channels, which makes Boost.Fiber an obvious choice for building a coroutine-based actor framework. The only finding I have is that several Boost.Fiber headers include detail headers from Boost.Context. While this is not a problem per se (because Oliver is the maintainer of both libraries), it may be an idea to consider if these detail headers should be made public.

1 0