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[msm]entry point pseudo states and events (Re: [msm] orthogonal region and event consume)
by Takatoshi Kondo 02 Jun '12

02 Jun '12

Hi Christophe, I changed the subject. Current topic isn't concerned with orthogonal region directly. On Thu, May 31, 2012 at 5:43 AM, Christophe Henry <christophe.j.henry(a)googlemail.com> wrote: > Hi Takatoshi, > > >>> I read your ticket. Note that it's not UML-conform to have 2 transitions >>> originating from Entry1 (11-08-06.pdf §15.3.8 page 551). >>> After reading the Standard again twice, I realized that no example >>> provided >>> there displays any event on both transitions, which is really bad if it's >>> what they mean. I need to have a look at other literature. > > >> I read the section that you mentioned carefully. My interpretation of >> UML specification is different from yours. >> It's really difficult to explain my interpretation. So, I draw the >> diagram. See the attached file. >> Am I misunderstanding? > > > I will not pretend I have the perfect understanding of the Standard. Here's > my take. I also saw the sentence on top of your diagram and didn't fully > understand it when reading the Standard. There is also the following > sentence in the Standard: > > "An entry pseudostate is used to join an external transition terminating on > that entry point to an internal transition > emanating from that entry point". > > Which sounds logical because on your diagram the regions would not be > orthogonal. > > This means you cannot have transitions triggered by different events leading > to the entry point, not can you have different transitions leaving it. You > will need more entry points. > > Caution: I am far from being sure I got it right. That's why I precised my > definition of it in the doc. The implemented solution has the advantage that > you have the normal transition handling, including multiple transitions and > guards, events with data, base events, etc. > What you don't have is entry in multiple regions, which only the fork > currently provides, at the cost of lesser encapsulation. > Correct or not, this is the part of the Standard I chose to implement pseudo > entries. > > To be honest, I'm not of fan of pseudo entries. I prefer the vastly superior > solution of entering a submachine the "normal" way, then letting a > templatized, enable_if'd on_entry of the submachine do something clever with > the event at compile-time. Aha! I completely overlooked such approach. For example, we can choose the initial state in submachine using mpl and initial_state typedef instead of using entry_pseudo_state. I believe that I've understood your design decisions. I also think that following the UML standard blindly is not essential. >> My goal is to improve sub-machines' re-usability. If we want to reuse >> sub-machines in another state machines, sub-machines shouldn't know >> the outside information. > > > I agree but is it the case? I mean, if you send normal events to your > submachine through your outer machine, it also needs to know them, right? > I understand this as: "hi, I'm a submachine and I provide the following > entry points: Entry1 requires Event1, Entry2 requires Event2, etc.". A bit > like function parameters. I wanted to explain that as follows: "hi, I'm a submachine and I provide the following entry points: Entry1 accepts any events. Because I don't care that. " Let me introduce more practical example that requires entry_pseudo_state. ScanFinger.png is a sub-machine. This sub-machine's primary purpose is to scan fingerprint. Before scanning, the sub-machine checks that finger is alive or not. But it's optional. To skip this check procedure, the entry point pseudo state ScanOnly is provided. FingerPrintRegister.png is the parent state machine. It uses ScanFinger as a sub-machine twice. In this scenario, alive checking is not required. So, the parent machine uses ScanOnly enty_pt. In another scenario, not mentioned here, might require the normal entry into ScanFinger to check the finger is alive. ScanFinger machine doesn't care about outer event. In FingerPrintRegister, the states RightScnning and LeftScanning have different incoming events for ScanOnly entry points. But any events are accepted. And then, it's not referred. Based on your suggestion, I introduce the base event class. As long as the incoming event of entry point is not "none", this approach works good. struct AnyEvent {}; struct Completed: public AnyEvent {}; struct StartButtonPressed: public AnyEvent {}; (See 39_FingerPrintExampleBaseEvent.cpp) If the incoming event is "none", the transition is stopped. Sometimes I want to use "none" as incoming event for entry point in the same sub-machine. And it is impossible that msm::front::none inherits user event classes such as AnyEvent. I'm trying to find better approach to solve the above problem. Thanks, Takatoshi >> See my second mail in this thread. My solution using templates >> (entry_pseudo_event_template.cpp) requires the template parameters >> same as the number of entry point pseudo states in sub-machine. It's >> acceptable but if outgoing transition would be able to use none, I >> would remove the template parameters. > > >> In the above case, it is not required to support multiple incoming >> transitions to one entry pseudo state. Because the instances of >> sub-machine are different. > > > In this case, maybe I could interest you in defining a base event class for > Event1 and Event2, then making this base event the event triggering the > inside transition. Your first example would be changed this way: > > struct BaseEvent {}; > struct Event1: public BaseEvent {}; > ... > msmf::Row < Entry1, BaseEvent, State2_2, msmf::none, msmf::none > > > > > Regards, > Christophe > > _______________________________________________ > Unsubscribe & other changes: > http://lists.boost.org/mailman/listinfo.cgi/boost

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Interest in double-ended priority queue? (priority_deque)
by Nathaniel McClatchey 02 Jun '12

02 Jun '12

Details: Template-based container adapter. Mimics std::priority_queue interface and requirements. O(1) read and O(log n) delete of either end of queue. O(n) create and merge. Functions for unordered access and mutating of elements. Remaining development: Further optimization. Note: Implementation is similar to but independent from http://lists.boost.org/Archives/boost/2011/12/188848.php

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Standardization of Boost (and other) libraries
by Beman Dawes 01 Jun '12

01 Jun '12

The C++ standards committee has set up a discussion forum (also accessible via email) to help those preparing language and library proposals. Requests for feedback, help, champions, and anything else related to proposals is on topic. https://groups.google.com/a/isocpp.org/forum/#!forum/std-proposals Note that this is a different URL than mentioned at C++Now! - language and library proposal groups have since been combined into a single group. After some false starts, discussion has started in earnest. The first two requests for feedback were on proposals for Boost.Any and Boost.Optional. If you are interested in proposing a Boost library for standardization, you probably want to check out std-proposals. --Beman

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Re: [boost] [review] Multiprecision review scheduled for June 8th - 17th, 2012
by John Maddock 01 Jun '12

01 Jun '12

>>* What is the type of boost::multiprecision::number_category<B>::type for >>all the provided backends? Could the specialization for >>boost::multiprecision::number_category<B>::type be added in the >>documentation of each backend? and why not add also B::signed_types, >>B::unsigned_types, B::float_types, B::exponent_type? > > OK. On second thoughts, the members of B::signed_types etc are basically implementation details - optimizations if you will. Rather than listing the types explicitly I'd prefer some more weasel wording along the lines of "This type will interoperate natively with any signed or unsigned built in integer type no wider than a long - this means for example that multiplying by a integer literal is more efficient than constructing an mpz_int temporary from the integer and then multiplying. Likewise for the other arithmetic operations." John.

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Re: [boost] [filesystem] Linker error against std::codecvt in VS2012 RC
by Stewart, Robert 01 Jun '12

01 Jun '12

Peter Dimov wrote: > Lars Viklund wrote: > > > [1] 1>libboost_filesystem-vc110-mt-gd-1_50.lib(path.obj) : > > error LNK2001: unresolved external symbol "protected: virtual > > int __thiscall std::codecvt<wchar_t,char,int>::do_length(int > > const &,char const *,char const *,unsigned int)const " > > (?do_length@?$codecvt@_WDH@std@@MBEHABHPBD1I@Z) > > Well, you could start by preparing a simple test program that > calls std::codecvt in the same way path.obj does, to eliminate > Boost as a factor. If do_length is indeed not present in the > dynamic runtime, this would probably be a showstopper bug > against the RC, so it will get noticed. :-) If that's not the problem, verify that you built Boost.Filesystem using the same CRT. _____ Rob Stewart robert.stewart(a)sig.com Software Engineer using std::disclaimer; Dev Tools & Components Susquehanna International Group, LLP http://www.sig.com ________________________________ IMPORTANT: The information contained in this email and/or its attachments is confidential. If you are not the intended recipient, please notify the sender immediately by reply and immediately delete this message and all its attachments. Any review, use, reproduction, disclosure or dissemination of this message or any attachment by an unintended recipient is strictly prohibited. Neither this message nor any attachment is intended as or should be construed as an offer, solicitation or recommendation to buy or sell any security or other financial instrument. Neither the sender, his or her employer nor any of their respective affiliates makes any warranties as to the completeness or accuracy of any of the information contained herein or that this message or any of its attachments is free of viruses.

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Re: [boost] [Boost-users] [review] Multiprecision review scheduled for June 8th - 17th, 2012
by Jeffrey Lee Hellrung, Jr. 31 May '12

31 May '12

Just to preempt this, I think it will be more appropriate for any review discussions to take place on the developers' list (boost(a)lists.boost.org) On Wed, May 30, 2012 at 2:38 PM, Vicente J. Botet Escriba < vicente.botet(a)wanadoo.fr> wrote: > Le 29/05/12 23:08, Jeffrey Lee Hellrung, Jr. a écrit : > > Hi all, > > > > The review of the proposed Boost.Multiprecision library authored by John > Maddock and Christopher Kormanyos has been scheduled for > > > > June 8th - June 17th, 2012 > > > > and will be managed by myself. > > > > I hope everyone interested can reserve some time to read through the > documentation, try the code out, and post a formal review, either during > the formal review window or before. > > > Hi, > > glad to see that the library will be reviewed soon. > > I have spent some hours reading the documentation. Here are some comments > and a lot of questions. > > * As all the classes are at the multi-precision namespace, why name the > main class mp_number and not just number? > > typedef mp::number<mp::mpfr_float_**backend<300> > my_float; > > * I think that the fact that operands of different backends can not be > mixed on the same operation limits some interesting operations: > > I would expect the result of unary operator-() always signed? Is this > operation defined for signed backends? > I would expect the result of binary operator-() always signed? Is this > operation defined for signed backends? what is the behavior of > mp_uint128_t(0) - mp_uint128_t(1)? > > It would be great if the tutorial could show that it is possible however > to add a mp_uint128_t and a mp_int256_t, or isn't it possible? > I guess this is possible, but a conversion is needed before adding the > operands. I don't know if this behavior is not hiding some possible > optimizations. > > I think it should be possible to mix backends without too much complexity > and that the library could provide the mechanism so that the backend > developer could tell to the library about how to perform the operation and > what should be the result. > > * Anyway, if the library authors don't want to open to this feature, the > limitation should be stated more clearly, e.g in the reference documentation > "The arguments to these functions must contain at least one of the > following: > > An mp_number. > An expression template type derived from mp_number. > " > there is nothing that let think mixing backend is not provided. > > * What about replacing the second bool template parameter by an enum class > expression_template {disabled, enabled}; which will be more explicit. That > is > > typedef mp::mp_number<mp::mpfr_float_**backend<300>, false> my_float; > > versus > > typedef mp::mp_number<mp::mpfr_float_**backend<300>, > mp::expression_template::**disabled> my_float; > > * As I posted in this ML already I think that allocators and precision are > orthogonal concepts and the library should allow to associate one for fixed > precision. What about adding a 3rd parameter to state if it is fixed or > arbitrary precision? > > * Why cpp_dec_float doesn't have a template parameter to give the integral > digits? or as the C++ standard proposal from Lawrence Crow ( > http://www.open-std.org/jtc1/**sc22/wg21/docs/papers/2012/**n3352.html<http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3352.html>), > take the range and resolution as template parameters? > > * What about adding Throws specification on the mp_number and backend > requirements operations documentation? > > * Can the user define a backend for fixed int types that needs to manage > with overflow? > > * Why bit_set is a free function? > > * I don't see nothing about overflow for cpp_dec_float backend operations. > I guess it is up to the user to avoid overflow as for integers. what would > be the result on overflow? Could this be added to the documentation? > > * can we convert from a cpp_dec_float_100 to a cpp_dec_float_50? if yes, > which rounding policy is applied? Do you plan to let the user configure the > rounding policy? > BTW, I see in the reference "Type mp_number is default constructible, and > both copy constructible and assignable from: ... Any type that the Backend > is constructible or assignable from. " > I would expect to have this information in some way on the tutorial. I > will appreciate also if section "Constructing and Interconverting Between > Number Types" says something about convert_to<T> member function. > > If not, what about a mp_number_cast function taking as parameter a > rounding policy? > > * Does the cpp_dec_float back end satisfies any of the Optional > Requirements? The same question for the other backends? > > * Is there a difference between implicit and explicit construction? > * On c++11 compilers providing explicit conversion, couldn't the > convert_to function be replaced by a explicit conversion operator? > * Are implicit conversion possible? > > * Do you plan to add constexpr and noexcept to the interface? After > thinking a little bit I'm wondering if this is this possible when using 3pp > libraries backends that don't provide them? > > * Why do you allow the argument of left and right shift operations to be > signed and throw an exception when negative? Why don't just forbid it for > signed types? > > * Why the "Non-member standard library function support" can be used only > with floating-point Backend types? Why not with fixed-point types? > > * What is the type of boost::multiprecision::number_**category<B>::type > for all the provided backends? Could the specialization for > boost::multiprecision::number_**category<B>::type be added in the > documentation of each backend? and why not add also B::signed_types, > B::unsigned_types, B::float_types, B::exponent_type? > > * Why have you chosen the following requirements for the backend? > - negate instead of operator-() > - eval_op instead of operator op=() > - eval_convert_to instead of explicit operator T() > - eval_floor instead of floor > > Optimization? Is this optimization valid for short types (e.g. up to 4/8 > bytes)? > > * As the developer needs to define a class with some constraints to be a > model of backend, which are the advantages of requiring free functions > instead of member functions? > * Couldn't these be optional if the backend defines the usual operations? > * Or could the library provide a trivial backend adaptor that requires the > backend just to provide the usual operations instead of the eval_xxx? > * How the performances of mp_number<this_trivial_**adaptor<float>, false> > will compare with float? > > * And last, I don't see anything related to rvalue references and move > semantics. Have you analyzed if its use could improve the performances of > the library? > > Good luck for the review. A really good work. > Vicente > > > ______________________________**_________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/**mailman/listinfo.cgi/boost-**users<http://lists.boost.org/mailman/listinfo.cgi/boost-users> >

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[nowide] Easy Unicode For Windows: Request For Comments/Preliminary Review
by Artyom Beilis 31 May '12

31 May '12

Hello all Booster, I comments on a library that I want to submit for a formal review. The library provides an implementation of standard C and C++ library functions such that their inputs are UTF-8 aware on Windows without requiring using Wide API to make program work on Windows. Library: Boost.Nowide Download: http://cppcms.com/files/nowide/nowide.zip Documents: http://cppcms.com/files/nowide/html/ Features: http://cppcms.com/files/nowide/html/index.html#main_the_solution Tested On: OS: Windows 7 32/64 bit, Linux Compilers: GCC-4.6, MSVC-10 Artyom Beilis -------------- CppCMS - C++ Web Framework: http://cppcms.com/ CppDB - C++ SQL Connectivity: http://cppcms.com/sql/cppdb/

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Is there interest in typeid(TYPE).name() like function that does not require RTTI
by Antony Polukhin 30 May '12

30 May '12

Hi, Would be there some interest in function for getting class name without RTTI? Such function can be implemented like that: template <class TemplateNameT> std::string template_type(const TemplateNameT& v) { #ifdef _MSC_VER const char* const template_name_begin = strstr(BOOST_CURRENT_FUNCTION, "(const ") + sizeof("(const ") - 1; BOOST_ASSERT(template_name_begin); const char* const template_name_end = template_name_begin + strlen(template_name_begin) - sizeof("&)"); #else // Code for other platforms #endif return std::string(template_name_begin, template_name_end); } If there is some interest, I'll update code to work on other platforms, and change method signature from template_type(instance) to template_type<InstanceTypeT>::name() Usage example: // Function can be compiled with RTTI disabled. template <class T> void foo(const T& val) { std::cerr << template_type<T>::name(); // instead of typeid(T).name(); } -- Best regards, Antony Polukhin

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[msm] orthogonal region and event consume
by Takatoshi Kondo 30 May '12

30 May '12

Hello Christophe, I'm using Boost.MSM version 1.49.0. I bumped on a suspicious behavior. See the attached diagram and code. When Event1 occurs in State1, Action1 is invoked. I think the event isn't consumed correctly. If the transition from State1 to State2 connect State2 directly instead of Entry1, the event seems to be consumed. What do you think? Thanks, Takatoshi

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Memory upgrade of wowbagger
by DongInn Kim 30 May '12

30 May '12

Dear all, My name is DongInn Kim, systems administrator of the current boost server machine, wowbagger. I am sorry for this short notice but we would like to upgrade wowbagger's memory at 2:00pm (E.T.) May 30, 2012. We need to reboot wowbagger and It should not take more than 10 mins to upgrade RAMs. During the memory upgrade, the following services would not be available. - mailing list - mail archives - trac - subversion - official websites Please let me if you have any issues or questions about the outage. Regards, -- - DongInn --------------------------- CREST System administrator dikim(a)cs.indiana.edu Indiana University Bloomington, IN

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