June 2008 - Boost - lists.preview.boost.org

bad include guards
by Steven Watanabe 26 Jan '17

26 Jan '17

AMDG The following pairs of files have identical include guards ./boost/concept_check/general.hpp ./boost/concept/detail/msvc.hpp ./boost/concept_check/msvc.hpp ./boost/concept/detail/msvc.hpp ./boost/filesystem/cerrno.hpp ./boost/cerrno.hpp ./boost/interprocess/containers/tree.hpp ./boost/interprocess/containers/detail/tree.hpp ./boost/mpl/min_max.hpp ./boost/mpl/max.hpp ./boost/mpl/vector/aux_/front.hpp ./boost/mpl/list/aux_/front.hpp ./boost/multi_index/identity_fwd.hpp ./boost/multi_index/identity.hpp ./boost/python/pointee.hpp ./boost/python/detail/pointee.hpp ./boost/spirit/phoenix/closures.hpp ./boost/lambda/closures.hpp ./boost/xpressive/proto/v1_/proto_typeof.hpp ./boost/xpressive/proto/proto_typeof.hpp ./libs/config/test/boost_no_dep_nested_class.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/config/test/boost_no_mem_templates.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/config/test/boost_no_std_allocator.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/conversion/test.hpp ./libs/any/test.hpp ./libs/interprocess/example/print_container.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/interprocess/test/expand_bwd_test_template.hpp ./libs/interprocess/test/allocation_test_template.hpp ./libs/interprocess/test/printcontainer.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/interprocess/test/print_container.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/iostreams/test/detail/utf8_codecvt_facet.hpp ./boost/detail/utf8_codecvt_facet.hpp ./libs/regex/test/regress/test_regex_search.hpp ./libs/regex/test/regress/test_partial_match.hpp ./libs/serialization/test/C.hpp ./libs/serialization/test/A.hpp ./libs/xpressive/perf/regex_comparison.hpp ./libs/regex/performance/regex_comparison.hpp ./tools/inspect/time_string.hpp ./tools/common/time_string.hpp In Christ, Steven Watanabe

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Why no non-null smart pointers?
by Ross MacGregor 29 Apr '14

29 Apr '14

I just created a very small smart pointer libary for our project. It will contain two types of shared pointers: SharedHandle and NullableSharedHandle. SharedHandle will be a shared pointer that cannot be null by ensuring a non-null construction while NullableSharedHandle will basically be a typedef for boost::shared_ptr. I firmly believe that code can be made more reliable by minimizing the use of nullable pointers. To this end, I think it is important that we start using non-null pointer types. Ideally the compiler would be able to understand a non-null pointer and catch bugs at compile time, but I think we can still improve things with a few runtime checks. If we make sure that a shared pointer is constructed with a non-null pointer and ban any reset() type methods, we guarentee that it points to something. This can be beneficial for the following reasons: 1. Any function that uses this type will no longer be burdened with precondition checks to make sure variables of this type are not null. 2. It's type is simply more explicit and better explains its function. 3. Moving the non-null check to the creation phase will reduce the possibility of encountering null pointer exceptions at runtime (assuming there are many more pointer references than constructor calls). So my little pointer library seems to make a lot of sense, but if so why hasn't this simple smart pointer variation made it into boost yet? Has this been discussed somewhere already? My search on non-null smart pointers is not revealing much discussion on the topic. Regards, Ross

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[asio] read_until -- possibly misleading documentation?
by Richard Smith 15 Apr '10

15 Apr '10

The documentation for Boost.ASIO (which is otherwise very comprehensive) says of the boost::asio::read_until set of overloads: | Read data into a streambuf until a delimiter is | encountered. <http://www.boost.org/doc/libs/1_35_0/doc/html/boost_asio/reference/read_unt…> What the function actually does is to read blocks of data into the streambuf, and stop when the delimiter is found. This means that frequently data beyond the delimiter will be read into the streambuf. (And this is elaborated in more detail on the individual function's pages, if a reader looks there.) I appreciate that this behaviour is compatible with the documentation, but someone less familiar with ASIO could easily assume that the function will read as far as the delimiter and no further. (And I have just spent a fair amount of time debugging a piece of code where the author had made this assumption.) Could we change the summary documentation to read something like: | Read data into a streambuf at least until a delimiter is | encountered. The implementation may read beyond the | delimiter, but will not block when doing so. While I'm on the subject of ASIO documentation, I can't see any documentation on whether the service_name parameters to the basic_resolver_query constructors are allowed to be port numbers (e.g. "80") or whether they have to be symbolic names (e.g. "http"). Port numbers work, at least on Linux, but it's not clear whether this is something that I should be relying on. Similarly for IPv4 and IPv6 addresses in the host_name parameter. Richard Smith

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Proposed addition to the iterator library for iterating over all tuples.
by Alex Mendes da Costa 19 Jun '09

19 Jun '09

Hi folks: I quite often have to write code to do the following: Given N sequences, generate all the N-tuples s.t. the i'th element in each tuple is drawn from the i'th sequence. For example, if sequence S1 is { 1, 2, 3 } and sequence S2 is { 10, 20 }, I need to generate these tuples: (1, 10), (2, 10), (1, 20), (2, 20). I think this problem could be solved elegantly with a iterator similar to zip_iterator. I have some questions: (1) Is there already a way to do this in boost? (2) If not, would this be a worthwhile addition to the iterator library? (3) If so, could I contribute code for this, or must the existing library owners write it? (4) If so, how would I go about getting my code added? Most of the docs seem to be about submitting entire libraries, rather than extensions to existing libraries. Thanks, Alex

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[mpl] is there a or_seq like logical metafunction?
by vicente.botet 17 Jun '09

17 Jun '09

Hello, I needs calculate the mlp::or_ of a sequence of nullary logical metafunction. This seams quite simple. I have do the following: <code> template <typename Seq> struct or_seq; template <typename Seq, long N> struct or_seq_aux : mpl::or_< typename mpl::front<Seq>::type, or_seq<typename mpl::pop_front<Seq>::type> > {}; template <typename Seq> struct or_seq_aux<Seq, 1> : mpl::front<Seq>::type {}; template <typename Seq> struct or_seq : or_seq_aux<Seq, mpl::size<Seq>::value> {}; </code> Is there a boost or_seq like logical metafunction? Is there a better way to do it? I would be extremely interested in any suggestions. Best regards --------------------------- Vicente Juan Botet Escriba

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Proposed templated integer_sort
by Steven Ross 25 Apr '09

25 Apr '09

Would there be interest in an integer_sort call that is faster than std::sort? Spreadsort is an in-place hybrid radix-based and comparison-based algorithm with better worst-case and average-case (roughly 20-50%) performance than introsort on random integer data. The worst-case advantage is algorithmic, with Spreadsort taking the better of O(n(square_root(bit_sizeof(data) - log(n)))) and O(nlog(n)) time. For 32-bit integers, that's O(n(square_root(32 - log(n)))), so for a log(n) of 16 (65536 items), it's 4n (plus a small constant times n), vs 16n for introsort. For larger n, the advantage vs. pure comparison-based algorithms increases. In effect, Spreadsort smoothly transitions from pure MSB Radix sort to std::sort with its data cut up by a couple iterations of MSB Radix sort (reducing the size of the log(n) factor), depending upon the distribution and size of the data. I could write a templated version of Spreadsort for the Boost library if there is interest. It would work for anything that supports the << and - operators. It could also handle standard floats sorted as integers. Functors supporting << and - could make it more general. Multi-dimensional sorting is also sped up by Spreadsort. I could also write a similar string_sort, that should also be significantly faster than std::sort. This would look much like postal sort, just using introsort after a certain number of iterations. Is this of interest? http://sourceforge.net/projects/spreadsort

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Profiling template instantiations
by Steven Watanabe 12 Feb '09

12 Feb '09

AMDG Over the last few days, I've been working on a tool that counts the number of class template instantiations in a translation unit. To use it from a jamfile import profile_templates : : directory of the tool ; template-profile result : some_file.cpp : <include>some_directories ; If everything works, this will create a file with the extension .tp which will contain the number of times each class template was instantiated, with the most common templates at the top. I've put a zip of a rough version in the vault. http://www.boost-consulting.com/vault/index.php?action=downloadfile&filenam… Caveats: I've only tested with Visual C++ 9.0 and gcc 3.4.4 on cygwin so far. Other compilers won't work, yet. Other versions of these compilers may or may not work. It may be necessary to add link=static to the bjam command line. In Christ, Steven Watanabe

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Re: [boost] Profiling template instantiations (Steven Watanabe)
by PORKOLAB Zoltan 12 Feb '09

12 Feb '09

Hi Steven, We have created a framework for debugging/profiling template metaprograms in 2006. It might give you a few tips. It works based on the same idea you have. We instrument all template codes, both at the begining and at the end of each template we insert a special piece of code emitting warning messages of a well-defined form. Before instrumentation we create an XML file to remember the template positions in the source file. When we parse the warning, using this information we can reconstruct the instantiation stack knowing the original line numbers, identifiers, etc.. At the end we produce another XML for possible front-ends. The framework uses boost::spirit and boost::wave. We have also implemented and tested a visual studio plug-in. An overview of the whole idea: http://gsd.web.elte.hu/templight/ There is also a GPCE article about the framework, you can find it here: http://portal.acm.org/citation.cfm?id=1173746&coll=portal&dl=ACM&CFID=47731… or here: http://gsd.web.elte.hu/contents/articles/gpce06.pdf You can download both the VS binaries and the source from: http://people.inf.elte.hu/pocok Please feel free to use the code or any of the ideas. For technical question you can find Jozsef: jmihalicza(a)gmail.com or me. Regards, Zoltan

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[thread/interprocess] could we improve recursive_mutex constructor
by vicente.botet 24 Jan '09

24 Jan '09

Hi, the recursive_mutex constructor initialize/set/destroy the pthread_mutexattr_t every time. I'm wondering if we can improve the efficiency storing this on a static variable which will be initialized once. What could be the better way to initialize this static variable? Note: the same applies to interprocess mutexes. recursive_mutex() { // begin code that can be initialized only once pthread_mutexattr_t attr; int const init_attr_res=pthread_mutexattr_init(&attr); if(init_attr_res) { throw thread_resource_error(); } int const set_attr_res=pthread_mutexattr_settype(&attr,PTHREAD_MUTEX_RECURSIVE); if(set_attr_res) { throw thread_resource_error(); } // end code that can be initialized only once int const res=pthread_mutex_init(&m,&attr); if(res) { throw thread_resource_error(); } // begin code that can be removed BOOST_VERIFY(!pthread_mutexattr_destroy(&attr)); // end code that can be removed } Regards, Vicente

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manipulators for filtering_stream s
by Roland Schwarz 22 Jan '09

22 Jan '09

Surprisingly I was not able to find on the net code that would give me a smart way to indent a stream. So I wrote a little filter based on the boost iostreams library. My first attempt was: boost::iostreams::filtering_ostream out; indent_filter ind(4); out.push(ind); out.push(std::cout); However trying to control it via e.g. ind.in() ind.out() turns out to be problematic interface since, 1) out.push() takes a copy of ind 2) the interface ind.in() is suboptimal. With my attached example it is possible to: #include "indent.hpp" ... boost::iostreams::filtering_ostream out; indent_filter::push(out,2); out.push(std::cout); ... And use it like so: out << "Hello Filter!\n" << indent_in << "this is\n" << "indented\n" << indent_out << "until here\n" ; Which will result in output: Hello Filter! this is indented until here The state is stored in the ios base class of the stream, by way of the pword mechanism. Consequently the filter stream even may be downcast to a basic_ostream, and the indenter will still work. E.g. with out defined as above: ... foo(out); ... void foo(std::ostream& out) { out << indent_in << "out is a downcast filter_stream\n" << indent_out << "end of indentation\n" ; } If you want to try it out, you just need to include the header indent.hpp. If someone thinks the snippet is usable either as an example for the iostreams library or the filter streams manipulator idea is worth generalizing to make it usable for other filters too, I would be glad to hear from you. -- _________________________________________ _ _ | Roland Schwarz |_)(_ | aka. speedsnail | \__) | mailto:roland.schwarz@chello.at ________| http://www.blackspace.at

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[thread] proposal to manage portable and non portable thread attributes
by vicente.botet 22 Jan '09

22 Jan '09

Hello, Boost.thread has already a non portable interface to get the thread handle class thread { public: ... typedef np_native_handle_type native_handle_type; native_handle_type native_handle(); ... }; Boost.Thread do not allow to pass thread attributes on the thread constructor. I supose that this is due to portable issues. Could we identifiy which attributes are portable and which one not? The portable attributes (as stack size, ...) can be grouped on a thread_attributes class. In order to be able to pass whatever attribute to the thread constructor we can add the setting of non portable attributes to this thread_attributes class, and making the thread constructor take a thread_attributes in addition to the existing parameters. class thread { public: class thread_attributes { // portable attributes public: // set/get of attributes // .. #if defined(BOOST_THREAD_PLATFORM_WIN32) // ... window version #elif defined(BOOST_THREAD_PLATFORM_PTHREAD) private: pthread_attr_t native_attributes; public: set_np_attributes(const pthread_attr_t* h); // ... other #else #error "Boost threads unavailable on this platform" #endif }; thread(const thread_attributes*p, F f,A1 a1); ... }; The portable application needing some specific configuration can construct portable threads using the following schema thread::thread_attributes attr; // set portable attributes // ... #if defined(BOOST_THREAD_PLATFORM_WIN32) // ... window version #elif defined(BOOST_THREAD_PLATFORM_PTHREAD) // ... pthread version pthread_attr_t native_attributes; pthread_attr_init(&native_attributes); pthread_attr_setstacksize(&native_attributes, 1000000); attr.set_np_attributes(&native_attributes); #else #error "Boost threads unavailable on this platform" #endif thread th(attr, f,ctx); What do you think? Vicente

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[proto][design]why unary_expr,binary_expr; but no nullary_expr?
by Larry Evans 14 Dec '08

14 Dec '08

Although there's unary_expr<Tag,*>, binary_expr<tag.*,*> in traits.hpp there's no nullary_expr<Tag>. I realize this would be a replacement to the current terminal template but with a user specified tag. After all, if a user specified tag for n-ary (where n>0) expressions *is* desirable, why is a user specified tag for 0-ary expressions *not* desirable? On case where this would be useful is for algebraic morphisms where n-ary ops in a source algebra are mapped to n-ary ops in a target algebra. This *includes* 0-ary ops. An op would be the equivalent to proto tags. I think this could be done by another transform similar to the pass_through transform but allowing transformation of the tag. Currently pass_through just uses the source tag in the target expression. It seems like it should be pretty easy to allow transformation on the tag also.

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[integer] Promotion of endian library code from vault
by Neil Mayhew 01 Oct '08

01 Oct '08

On 2006-07-22 12:21:01, Beman Dawes wrote: > [boost] [integer] endian-0.6 posted w/ names changed > endian-0.6.zip has been posted in the integer directory of the file > vault at http://boost-consulting.com/vault/ This code is still in the vault, but I'd like to see it in the main part of boost. What needs to be done to make this happen? The endian library is exactly what I've been looking for, and I would really like to use it in my work, but I can't justify that to my colleagues if it's not an official part of boost. I would hate to become yet another person that reinvents this particular wheel. However, I notice there was a lot of discussion <http://lists.boost.org/Archives/boost/2006/07/108125.php> about PODs vs constructors, because of unions, so maybe not enough consensus was reached? There were some interesting proposals but no agreed-upon solution. In which case, I suspect that people will need to copy the code and each hack it to suit their own purposes, which is not what boost is all about. I have two use cases from my own work: TrueType fonts, and Mac HFS+ file systems. Both of these are big-endian file formats that need to be read into memory and processed, so (FWIW) I would support the POD approach. Currently, I can't use the code as-is because of the need to use the types in unions. References: http://lists.boost.org/Archives/boost/2000/03/2495.php http://lists.boost.org/Archives/boost/2006/05/105621.php http://lists.boost.org/Archives/boost/2006/06/105695.php http://lists.boost.org/Archives/boost/2006/06/105779.php http://lists.boost.org/Archives/boost/2006/06/105968.php http://lists.boost.org/Archives/boost/2006/06/106655.php http://lists.boost.org/Archives/boost/2006/07/108125.php http://lists.boost.org/Archives/boost/2006/07/108202.php --Neil

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[BENUM] Any interest in auto-generated enum-to/from-string functions, without longer/more-complex usage?
by Tony D 15 Sep '08

15 Sep '08

Anyone think this functionality belongs in boost? (I have working code) ENUM(X, B = N, C, D = B + C }; // or whatever X x1 = C; cout << x1 << '\n'; // outputs "C\n" X x2("D"); // construct from string... if (x2 == D) { will do } Tony __________________________________________________________ Sent from Yahoo! Mail. A Smarter Email http://uk.docs.yahoo.com/nowyoucan.html

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Proto<markus>::review()(proto::accept);
by Markus Werle 30 Aug '08

30 Aug '08

Hi! I think Proto should be accepted for inclusion into boost. A general purpose Expression Template library is hard to write. Proto is the most sophisticated and closest approach to perfection available today. - What is your evaluation of the design? Proto is well-designed in many aspects, though I got the impression that some beauty and purity was sacrificed on the altar of compile-time efficiency, but that's OK. (And yes, I hate BOOST_PP_MACROS!) Proto catches the most important issues of a general purpose expression template library, I especially like the way how expression storage and expression evaluation is strictly separated and the way I can add my own functionality. Proto covers the most important aspects of an ET library, sometimes in very elegant ways. Proto's design adressed compile time issues. That's a value in itself. OTOH: Transforms leave me with mixed feelings. I am not very good at catching ideas without good step-by-step documentation and I got messed up with grammars vs. transforms. This part of proto is new and it looks like a candidate for rework. I'd like to have an extra review in half a year only on the grammar and transform part of proto (*)[comment below]. That's a DSEL all by itself and I guess that interface may have some pitfalls. Larry Evans has worked that out in detail. There may be issues in the naming convention used there, e.g. I am unsure whether and_ is the appropriate name for what it does. - What is your evaluation of the implementation? None. Not enough time. Steven Watanabe did it for us all. Code looks clean. For my taste too many levels of nested namespaces, but that's the boost trend at the moment. I may appreciate this style later in my life, once I understand why you need it. - What is your evaluation of the documentation? The quality varies from excellent to hard to read. I agree with all what David writes about the docs. There is some potential for improvement, but that should not hinder the inclusion into boost: we need a community effort here since Eric's skill level probably is way too high in order to have some feeling for why the unaware might have problems with parts of the doc. The teacher should be one step ahead, not too far ahead. - What is your evaluation of the potential usefulness of the library? We really, really need this. Better today than tomorrow. The whole world is waiting for this to come. And C++ again rocks - Did you try to use the library? A couple of hours, but only for some of the examples. - With what compiler? VC8, Intel 10.1 - Did you have any problems? Nope. Eric-faster-than-lightning fixed those before I could run into them ... - How much effort did you put into your evaluation? I read the docs three times and worked through some details. I investigated the type representation of expressions by reading purposely generated compiler error messages and tried to figure out the design. - Are you knowledgeable about the problem domain? I had several attempts to write some kind of ET library on my own, some parts published at daixtrose.sourceforge.net. I also planned to write something like proto myself, but due to lack of time and programming skills I lost the race before it began. (rm -rf /work/markus/ideas/expresion_templates_revisited) Eric, thanks for the time saved by the publication of proto. Markus P.S. This review is short, sorry. I had some unexpected tasks to do the last week which hindered further investigation. I'll put some more effort into this in the future. (*) I'd like to have an extra review on _every_ boost library in a 2-year-cycle. By this boost::multi_array could probably be forced to model assignable like any other STL container and ::_1 from boost::bind will move into its own namespace - just to mention my two favourite change requests ...

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Re: [boost] UTF-8 conversion etc. (Sebastian Redl) (Sebastian Redl)
by Graham 28 Aug '08

28 Aug '08

>> As I said to Phil, Rogier and I completed a Unicode character library >> for >> >> Release under boost, but never submitted it to Boost as we had intended >> to >> >> release it with a string library built on it, and never had time to do >> the >> >> second part of the work. >> >Post it, and we'll do the second part. It's open-source. > >Sebastian Sebasian, As requested, I have posted a Unicode character support library in the boost vault as Unicode_lib.zip. Please feel free to use this under the boost license. It would be great if somebody had the time to develop the existing character support to ad the string wrappers that we had intended to - but ran out of time doing. It should be well documented, but if you want any questions answered, please feel free to ask and I'll try and help! Thanks. Yours, Graham

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[asio]: extending asio
by Andreas Pokorny 17 Aug '08

17 Aug '08

Hello, I would like to add more asynchronous event sources to asio, like: - input events for mouse, keyboard and joystick .. - window exposure, move, resize events in some generic form, - generic "quit" events - file alteration With directFB/X11/Unix/Linux most of that can be done directly through select or epoll. But since reading the message and parsing events is mostly done by a third party library, I would only need the reactor part for these. Is this possible with asio? According to msdn it seems to be possible to create so called event objects for direct input devices. I am no win32 expert so I do not know if one can combine that with completion ports? Regards Andreas Pokorny

7 16

Why I hate subversion
by Eric Niebler 02 Aug '08

02 Aug '08

U boost/indirect_reference.hpp U boost/parameter.hpp svn: In directory 'boost' svn: Can't move 'boost/.svn/tmp/foreach.hpp.2.tmp' to 'boost/foreach.hpp': Permission denied ericne@ericne-xps ~/boost/org/trunk $ svn up svn: Checksum mismatch for 'boost/.svn/text-base/enable_shared_from_this.hpp.svn-base'; recorded: '12d8c5183a709a7699c13b312073c36c', actual: 'c89a6b23045ff8c89d2de74213d1649a' Does this ever happen to anybody else? I get this random corruption of my local subversion repository about once a month. -- Eric Niebler Boost Consulting www.boost-consulting.com

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Possible library submissions: fuzzy logic library, new container
by Alex Shafir 01 Aug '08

01 Aug '08

I am trying to determine if there might be any interest in a couple of possible library submissions. Both ideas were very useful and instrumental for many C++ development projects that I was doing for the last years. The fuzzy logic library is a simple, pure C++, optimized for speed, practical implementation of the fuzzy logic calculations that DOES NOT attempts to comply with the FCL(Fuzzy Control Language) standard (like IEC 1131). It CANNOT load FCL files. Instead similar to the Boost Spirit framework it provides a syntax that enables fuzzy logic rules to be written exclusively in C++. Compiled fuzzy model specifications are immediately executable. A snippet of what this syntax currently looks like is at the end of this message. The other idea is the “sparse array” container. Working for securities trading industry I used it innumerable number of times. It is useful in situations where there is a set of entities identified by integer(unsigned) numbers. Most often the numbers are identity keys in a database, a protocol field ids, etc. The potential range of the numbers makes it impractical to use a C++ array or the STL <vector>. On the other hand the average percentage of the keys that are really used in an application relative to the potential range is often less then 5% and there are huge holes of unused keys between zero and max(used key). The data elements or pointers to objects are kept in a structure similar to a balanced B-tree. Elements are directly accessed by an index operator. Access involves only a few arithmetic and redirection operations. When storing a new element that is outside of the range provided by exiting data structure the structure bilds itself up extending the indes range enough to accommodate a new index value. Existing data are never physically moved like in the STL vector. So, all references/pointers/iterators referencing existing elements are never invalidated. Feel free to comment. Fuzzy model syntax sample: ======================================== #include "TestModel.h" using namespace Fuzzy; // test model definition TestModel::TestModel(string file): Model(file), angle(-1), velocity(-1), speed(-1) { // fuzzy variables definitions created by the base class (Fuzzy::Model) // Input/Output methods; Input/Output arguments are refs // to double scalar variables Var& Angle = Input(angle); Var& Vlcty = Input(velocity); Var& Speed = Output(speed); // membership functions definitions created by fuzzy variables // Term method; Term method takes curve name as an argument; // cureve names are defined in the Fuzzy::Model curve definition // file MemFun& AngleNegHigh = Angle.Term("AngleNegHigh"); MemFun& AngleNegLow = Angle.Term("AngleNegLow"); MemFun& AngleZero = Angle.Term("AngleZero"); MemFun& AnglePosLow = Angle.Term("AnglePosLow"); MemFun& AnglePosHigh = Angle.Term("AnglePosHigh"); MemFun& VlctyNegHigh = Vlcty.Term("VelocityNegHigh"); MemFun& VlctyNegLow = Vlcty.Term("VelocityNegLow"); MemFun& VlctyZero = Vlcty.Term("VelocityZero"); MemFun& VlctyPosLow = Vlcty.Term("VelocityPosLow"); MemFun& VlctyPosHigh = Vlcty.Term("VelocityPosHigh"); MemFun& SpeedNegHigh = Speed.Term("AngleNegHigh"); MemFun& SpeedNegLow = Speed.Term("AngleNegLow"); MemFun& SpeedZero = Speed.Term("AngleZero"); MemFun& SpeedPosLow = Speed.Term("AnglePosLow"); MemFun& SpeedPosHigh = Speed.Term("AnglePosHigh"); // these are the model rules; syntax is pretty strightforward; // rules look like operator >> where lhs is the condition and // rhs is the conclusion; // lhs and rhs have to be in parens if they contain more then // one term because of the c++ operators precedence rules; // conclusion may be a comma separated list of output terms // in parens ((AngleZero and VlctyZero)or(AnglePosLow and VlctyNegLow)or(AngleNegLow and VlctyPosLow)) >> SpeedZero; ((AngleZero and VlctyNegLow)or(AngleNegLow and VlctyZero)) >> SpeedNegLow; ((AnglePosLow and VlctyZero)or(AngleZero and VlctyPosLow)) >> SpeedPosLow; ((AngleZero and VlctyNegHigh)or(AngleNegHigh and VlctyZero)) >> SpeedNegHigh; ((AnglePosHigh and VlctyZero)or(AngleZero and VlctyPosHigh)) >> SpeedPosHigh; } TestModel::~TestModel() { } void TestModel::run(double a, double v, double &s) { // we assign scalar variables to class members angle = a; velocity = v; speed = s; // then run the model // it should be pretty fast as it all designed to preallocate // all the needed large objects in the model constructor Model::run(); // and assign the values of output variables s = speed; }

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range_ex: status?
by Mathias Gaunard 30 Jul '08

30 Jul '08

I'm writing some piece of software working that does a lot of data structures traversal and that really needed filtering of traversal etc. I thought I'd get that from Boost.Range, but I was surprised to see Boost.Range provides very little: all the good stuff (the range-based algorithms and adaptors) are in another library, range_ex, which isn't in the main distribution yet. Will this library be included in Boost soon? It's really great. As for the open issues, here are my opinions: - Output ranges: don't adaptors already output ranges? - Two input ranges, or a range and an iterator?: two ranges can do more - For any algorithm foo(container, args...), if foo(args...) is valid then it should be called - Null-termination of C-style strings: Isn't that up to Boost.Range to decide whether it's a range or not?

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Mac OS universal builds: testers needed
by Mat Marcus 25 Jul '08

25 Jul '08

I've made a number of changes to my universal-binary supporting darwin.jam patch (shipping with the Adobe Source Library) in order to address the concerns raised by Rene and others at http://svn.boost.org/trac/boost/ticket/989 : My current version supports invocations like: bjam architecture={combined,x86,power} link={shared,static} address-model={64,32} That is, universal builds are now supported, along with 64 bit builds. I'd like to ask for the help from a few volunteers who'd be willing to test it out, before I submit my patch for consideration. Anyone interested in helping me test it? If so, please contact me off list and I'll send you a couple of boost build files to replace. I still have a bit of cleanup to do. Specifically, on the mac, if a build doesn't specify an -arch parameter, the architecture (and perhaps the address model) of the host machine is used. I'm not really comfortable with the same folder path meaning different things on different machines. So, I plan to do something like the following in darwin.jam (in invented pseudo code) SWITCH(on result of /usr/bin/arch) { # host machine's architecture CASE(ppc) use <architecture>power/<address-model>32 as the default CASE(i386) use <architecture>x86/<address-model>32 as the default CASE(ppc64) use <architecture>power/<address-model>64 as the default CASE(x86_64) use <architecture>x86/<address-model>64 as the default DEFAULT error, unknown arch Thanks, Mat

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Re: [boost] Is our subversion server/archive 1.5 yet?
by Douglas Gregor 18 Jul '08

18 Jul '08

On Sun, 2008-06-29 at 16:12 -0400, Daryle Walker wrote: > Last week, a was bouncing around sites and found out that Subversion > 1.5.0 has gone final. I've downloaded it because I want to try its > built-in merging support (to fix up Boost.Integer in a branch). Has > our subversion system been updated to 1.5? No, we're still using Subversion 1.4 on the server. > Obviously, if the client and server use subversion versions 1.x and > 1.y respectively, the transactions will proceed as the lower of those > versions. Therefore, both individual clients and the server must be > at least the 1.5 level to use built-in merging. There's another > requirement, though: if the server is upgraded to 1.5, the > repositories it manages aren't automatically upgraded. If a > repository isn't upgraded to the 1.5 format, then the server will act > in 1.4-compatibility mode as needed. > > Is there a schedule for these upgrades to be done (if not done > already)? Is it possible to tell from the client side which mode a > server/repository uses? I actually don't know how to tell from the client-side which version of Subversion the server is running. As for the upgrade... we're looking into Subversion 1.5, but it appears to be a nontrivial process to perform the upgrade and migrate svnmerge.py merge information appropriately, so we need to read more, do some test runs, check that other projects haven't run into serious problems, etc. So much depends on the Subversion repository that we need to be careful. When we're ready to move, we'll send out an e-mail to the mailing list. - Doug

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Possible MingW ASIO bug with Boost 1.35.0 g++ 4.2.1
by Jason Turner 17 Jul '08

17 Jul '08

Some ASIO test code is crashing in a way that I do not understand. GDB is unable to debug it (no stack available on crash) and the error is a rather obtuse "This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information." Test code which crashes: #include <boost/asio/ip/address.hpp> #include <iostream> int main() { std::cout << boost::asio::ip::address::from_string("1.1.2.3") << std::endl; } By changing the asio file included, the code no longer crashes: #include <boost/asio.hpp> #include <iostream> int main() { std::cout << boost::asio::ip::address::from_string("1.1.2.3") << std::endl; } This is windowsxp professional, gcc version 4.2.1-dw2. I'm unable to test this on Linux at the moment, so I do not know if it affects other platforms. -Jason -- http://emptycrate.com Games, Programming, Travel & other stuff

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[intrusive] Problem with EDG base compilers in strict Ansi mode.
by Markus Schöpflin 14 Jul '08

14 Jul '08

Hello, currently any_test and doc_any_hook fail on Tru64/CXX with the following errors: cxx: Error: ../boost/intrusive/detail/any_node_and_algorithms.hpp, line 276: class template "boost::intrusive::any_algorithms<VoidPointer>" has no member "unlink_not_available_for_any_hooks" (notmember) any_algorithms<VoidPointer>::unlink_not_available_for_any_hooks(); -----------------------------------^ cxx: Error: ../boost/intrusive/detail/any_node_and_algorithms.hpp, line 283: class template "boost::intrusive::any_algorithms<VoidPointer>" has no member "swap_nodes_not_available_for_any_hooks" (notmember) any_algorithms<VoidPointer>::swap_nodes_not_available_for_any_hooks(); -----------------------------------^ AFAICT this is the only EDG based compiler which tests in strict Ansi mode, adding -strict_ansi to the other EDG based compilers (acc for example) would probably lead to the same error. Attached patch contains a proposed fix for this. It checks for __EDG__ and __STD_STRICT_ANSI to enable the fix and works for me locally. The patch should replace the compile error by a link error, because in strict Ansi mode EDG doesn't allow you to refer to non-existing names. OK to apply? Regards, Markus Index: detail/any_node_and_algorithms.hpp =================================================================== --- detail/any_node_and_algorithms.hpp (revision 46676) +++ detail/any_node_and_algorithms.hpp (working copy) @@ -269,6 +269,11 @@ static bool unique(const_node_ptr node) { return 0 == node->node_ptr_1; } + +#if defined(__EDG__) && defined(__STD_STRICT_ANSI) + static void unlink(node_ptr); + static void swap_nodes(node_ptr l, node_ptr r); +#else static void unlink(node_ptr) { //Auto-unlink hooks and unlink() call for safe hooks are not @@ -282,6 +287,7 @@ //what algorithm they must use from unlink them from the container any_algorithms<VoidPointer>::swap_nodes_not_available_for_any_hooks(); } +#endif }; } //namespace intrusive

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[thread] lockable traits and concepts classes adding proposal
by vicente.botet 14 Jul '08

14 Jul '08

Hello boosters , While writtig a generic library I have needed some lockable traits and concepts to be chacked with BCCL. If you think that these classes are of general use it will be a pleasure for me, if Anthony accepts, to included them on the Boost.Thread library. Otherwise I will left them in my Sync library. For the moment all is defined in a sync (as synchronization) namespace and directory but this is without importance. Attached a short introduction (in quickbook format- sorry I can not attach the html file) as well as the header files (which should with gcc 3.4 on cygwin) Of course all this is subject to discusion, naming and file structure changes, ... For each one of the mutex in the thread library, we need to * make the mutex inherit from the helper lock_traits_base or * have nested typedefs or * specialize each one of the traits templates As an external library I have do this in a non-intrusive way as for example: template<> struct timed_interface_tag<boost::mutex> { typedef hasnt_timed_interface_tag type; }; template<> struct reentrancy_tag<boost::mutex> { typedef non_recursive_tag type; }; template<> struct category_tag<boost::mutex> { typedef exclusive_lock_tag type; }; template<> struct scope_tag<boost::mutex> { typedef multi_threaded_tag type; }; But if included in the Thread library it will be better to use one of the intrusive methods. I have also defined other classes that could be of general interest. * A make_lockable class will make Lockable/ShareLocakble/UpgradeLocable the derived class depending on the Lock parameter. This class could be the base of a monitor class. It can be used as follows: class X : public make_lockable<boost::mutex> { } X x; unique_lock<X> lock(x); * a ..._synchronization_family set of classes that can be used as follows: template <class SyncFamily> message_queue; typedef message_queue<thread_synchonization_family> my_mt_message_queue; typedef message_queue<null_synchonization_family> my_st_message_queue; The null_synchonization_family needs a null_mutex and a null_condition classes. There is already something similar in Boost::Interprocess. * To finish, I'm working on a filter_matching_lockables meta-function which take as parameter a vector of lockables types and will filter the lockables types not satisfying a list of traits. The use shoul be somthing like typedef filter_matching_lockables<vector<boost::mutex, boost::recursive_mutex, ...>, mpl::and_<is_exclusive_lock<_>, mpl::not_<is_recursive_lock<_> > >::type candidates. and a find_best_lock which choose between the lockables given as parameter the best one following a given criteria. Of course, there is yet a lot of work to do, add lock concepts, lockable and lock concept traits, document, tests, document, tests ... between others. As you see there is nothing new, neither complex, only some helper classes making easier the construction of higher abstraction levels, and that currently are missing in boost. Have a good code reading and please let me know what do you think. _____________________ Vicente Juan Botet Escriba

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