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[thread] basic question
by Sean Farrow 12 Sep '10

12 Sep '10

Hi: I am writing a cross platform application, I need to do the following: Firstly Launch a thread, which seems simple enough. Secondly, the thread function pols a port for input (midi, does assio support this?) Thirdly, I need someway of transferring data between the thread waiting for input and the main thread, what is the best way of doing this, in win32 I'd use Events. Finally, what is the best way of terminating the thread cleanly, in win32, I'd probably use a while loop of some sort.Any help appreciated! Regards Sean.

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fusion transform_view
by Hicham Mouline 12 Sep '10

12 Sep '10

Hello After I invoke the result_of::transform<Seq, UnaryFct> metafunction, the result type I get, printed out by typeid(...).name() gives transform_view< Seq, UnaryFct, void_ > is there a way to print out the actual resulting type, forcing the view to "evaluate" ? regards,

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[boost] [constrained_value] Constrained Value review results
by Gordon Woodhull 11 Sep '10

11 Sep '10

Greetings, Substituting for Jeff Garland, I am pleased to present the results from the constrained_value review. The library is available at http://rk.dl.pl/f/constrained_value.zip The documentation is at http://rk.dl.pl/r/constrained_value Enjoy! Gordon 1. History The idea for a constrained value library goes back to at least 2004; Christopher Diggins proposed a mini-library at that time. In 2007 Joe Gottman suggested that Jeff Garland's constrained_value.hpp in date_time could be a top-level library. Concurrently, Robert Kawulak (henceforth RK) was working on his own library for the purpose, which he also started in 2004, unaware of the others. RK announced his library on November 11, 2007. Discussion continued into 2008; on June 19, RK announced his library was ready for review and it was put in the queue. The review began on December 1 2008 and continued until around December 15 (with some trailing discussion of the definition of invariant and why exceptions should not be used to check invariants). Gordon Woodhull reviewed the thread's 260 messages in the summer of 2010 and produced this report, dividing the issues raised between those where there was consensus on a change, those where no resolution was found, and those where the author and requesters (mostly) agreed that no change was needed. 2. Votes Eight people voted for acceptance of the library; there were no "no" votes. However, many people stated conditions on acceptance. Thanks to Chris (indy271828(a)sympatico.ca) Vicente Botet, Zach Laine, John Maddock, Thorsten Ottosen, Stjepan Rajko, Daryle Walker, and Gordon Woodhull for providing reviews. (In addition, Paul Bristow provided a review which looks like a yes but does not explicitly say so.) Thanks also to David Abrahams, Kim Barrett, Neal Becker, Paul Bristow, Edward Diener, Jeff Flinn, Joe Gottman, Mathias Guanard, Mika Heiskanen, Giovanni Pierro Deretta, Thomas Klimpel, Michael Marcin, OvermindDL1, John Phillips, raindog, Ravi (lists_ravi(a)lavabit.com) Johan Råde, Sebastian Redl, Peter Simons, Steven Watanabe, Utku Yaman, and Deane Yang for participating in a very active discussion. 3. Issues to be Addressed Floating point By far the most contentious issue in the review was the statement in the library documentation that floating point is not supported, and a few reviewers made fixing this a condition on acceptance. The issue is that the x87 math instructions (which are the default for 32-bit Intel compiles) utilize 80-bit registers which are then rounded down to 64 bits when a double value is written to memory. This can cause two values which were not equal to become equal later, with fairly unpredictable behavior depending on optimization and what code intervenes between calculating a value and comparing it. One solution is simply not to use the x87 math instructions by enabling the SSE2 math instructions instead. However, users may want the extra precision, and there is no way for a library to control this option. A few reviewers confused this issue with the frequent need for fuzzy comparison with epsilon; it was shown that the bug can still appear with epsilon-based comparisons. Jeff Garland points out that the Boost Numeric Interval library, http://www.boost.org/doc/libs/1_42_0/libs/numeric/interval/doc/interval.htm has also dealt with the x87 and NaN problems. It uses the round-trip-to-memory approach for x87. There is potential to create constraints for constrained_value using numeric::interval, and perhaps any other fixes for floating point belong in that library. Many solutions were proposed; after debate there were four left standing: * Force the new value to be written to memory Kim Barrett suggested the following function, noting that it should not force a memory write unless the value is in a register. inline double exact(double const& x) { return *const_cast<double const volatile*>(&x); } Gordon Woodhull has tested this against example provided by Thomas Klimpel in a message titled "floating point FUD" of January 23, 2010 (http://article.gmane.org/gmane.comp.lib.boost.devel/198817) and it does work. However, many people objected to this solution because of efficiency concerns: it requires a round-trip to memory (or at least to cache) for every assignment. * Only allow >= or <= for floating point types, and make sure the bounds are truncated 80- to 64-bit truncation can cause two values to become equal, but if one of them is already truncated, it cannot cause them to swap order. Since it is likely that the value will be changed much more frequently than the bound, it would suffice to apply truncation just to the bounds when they are set, e.g. with the exact() function above. However it does not seem that this solution can work if the bounds are dynamically calculated; the library supports bounds being returned by an inlined function. Johan Råde also suggested that it might be possible to implement < and > in terms of <= and >= and the std::nextafter function. * Force the processor to use 64-bit precision Johan Råde mentions a floating point control register which could be used in http://article.gmane.org/gmane.comp.lib.boost.devel/183760 There were also mentions of possible assembly code solutions, but none were provided and this was generally unpopular because it requires someone very knowledgeable to maintain it. John Phillips argued that reducing the precision will "lose significance faster than expected". * Another interesting solution was suggested by Stjepan Rajko: that the test might not be the same as the invariant. This is what testing with epsilon would guarantee. If the value passes the test it is guaranteed to satisfy the invariant, but only the test and not the invariant is in code. So some values might be rejected which are okay, but no bad value is accepted. RK felt that any floating point solution should be implemented separately from constrained_value, because he does not have the expertise. But he should be willing to document the scope of the problem better, including the SSE2 compiler flags that avoid the problem altogether. The first solution (truncation of the value) does not seem to require any changes to the library. Truncating the bounds might require some extra customization points. NaN Another problem with floating point is NaN, which compares false with everything. It might be okay if the bounds inclusion test always returned false. But the closed range is implemented as !(x < lower) && !(upper < x). Stjepan Rajko suggested that it should always be compare(lower, x) && compare(x, upper) where compare is < for excluded bounds and <= for included. It seems like this solution would work well for floats but not necessarily for user-defined types, which might only define operator<(). Substitutability with the underlying type A few people requested the ability to set a compiler flag in order to substitute the constrained_value with the underlying type. This is not exactly possible, unless the user is willing to explicitly extract the value using static_cast<T>(cv). The library does provide unconstrained<> which in most cases optimizes away, but the interface is not perfectly compatible with the underlying type. Constraints not copied when operators used The use of operators invokes implicit conversion to the underlying type, which means that in a statement like constrained_value x(10, constraint(...)), y(-x); y ends up with uninitialized constraints. Steven Watanabe suggested that the operators could be overloaded, but RK argued that the behavior would be application-specific: "For some applications returning a constrained value would be OK (but again there is the problem that the constraint may reject the modified value) while for others it's better to return the underlying type." Constrained strings Jeff Garland offered that he has written constrained_string classes for allowing values from a set of strings, and for validation against a regex. RK said he might add a constraint type which validates against set<T>, and affirmed that a regex validator would be nice too. Bounding on only one side Utku Yaman and others requested a way to bound integers on only one side. RK noted that you could set one of the bounds to the maximum or minimum possible integer, but this is verbose. Default arguments would be confusing, and RK thought maybe he would supply lower_saturating_int and upper_saturating_int. Note that there is a more general problem, especially if floating point is allowed. (Also consider e.g. fixed point, rational.) Recoverable error policy - error policy changing the value There were some objections to the error policy taking three parameters - the new value, the member value, and the constraint. Does it really need to change the member value? Yes, RK explained, because this is a recoverable error policy. Vicente Botet asked that the concept be called RecoverableErrorPolicy. Serialization Neal Becker requested support for serialization. RK agreed this is worth looking into and pointed out a couple of difficulties. One, a way to not serialize empty (or static) policies is needed. Two, non-default constructible types such as odd_number might require use of load_construct_data() / save_construct_data() instead of serialize(). Rename bounded_int This class name does not convey the fact that the bounds are specified at compile time. Neal Becker suggested compile_time_bounded or static_bounded. RK says the first name is too long, and the second might imply that the bounds are static members (which is also a legitimate use case). sizeof static constrained types == sizeof underlying type Assuming that the empty base class optimization is being applied correctly, which seems to be the case, if the constraint and the error policy are empty, the size of the constrained value should be the same as the size of the underlying type. However, this was not the case on all platforms, at least at the time of the review. The library should include sizeof tests in its test suite so that potential users know if there is unexpected overhead on their platform. Specify static bounds as open<0>, closed<100> for bounded<> and bounded_int<> Requested by Vicente Botet. If possible, this would reduce the number of template arguments and would be more clear than the current bounds exclusion boolean parameters. Some default constructions may throw If zero does not satisfy the constraint, then a default-constructed constrained value may throw an exception. (There are other examples, like non-empty string.) Many reviewers requested a means to provide a default value, which can be done by wrapping the underlying type, but RK felt a default value class was out of scope. At the very least this should be documented and probably an example given. Examples Vicente Botet requested: * an example showing how to create a constrained class by derivation and/or containment which adds/removes methods from the constrained value interface * a date example where changing the month affects the bounds for the day. * example of static bounding on only one side * example of bounds calculated at runtime by a function ("runtime dynamic bounding") Others: * example of constraints with static members - allows shared mutable constraints with no overhead per instance. Tests! Many reviewers were offended that there were no tests in the review version. RK said he would write some. Documentation * document the concepts and provide tests with concept archetypes. It turns out that these are documented briefly in the doxygen documentation of constrained<> at http://tinyurl.com/39v8o6r, but many reviewers were expecting a section in the main document. * Stjepan Rajko pointed out that the constraint can't depend on mutable members of the underlying type, and wondered if there were other implicit requirements, such as the way copy construction or swapping works. He requested these be documented. * Gordon Woodhull suggests a section on space efficiency and which configurations should allow the size to be optimized to the same size as the underlying type, and spelling out in each example what the cost in space is. * Thorsten Ottosen requested benchmarks of non-checking unconstrained against just using the underlying type. RK offered that he had looked at the generated assembly on some platforms. 4. Unresolved debates Error policy is allowed to change constraint Vicente Botet objected to the "bounded object with memory" example, which tracks extremal values by setting the bounds to include any new values. And Thorsten Ottosen objected to the inefficiency of change_constraint using construct-and-swap: it's not necessary to swap the constraint unless it might be changed by the error policy. This seems to be an example of a monitored value, which RK does not want to write himself, so does it belong in this library? RK argued that it does no harm, so why not allow? Double-checking and disabling assertions A number of people were concerned with the inefficiency of first checking the constraint, and then also asserting that the constraint is satisfied after the assignment has happened or the error handler has been called. But RK argued that it was necessary to check the invariant to make sure that the assignment operator and the error handler are doing their job. Besides, it is possible to disable the asserts with either BOOST_DISABLE_ASSERTS or NDEBUG. There was some discussion of adding an assert policy or a specific macro (with no clear conclusion). Disabling checks There is unconstrained, which offers a way to replace one constrained type with an unconstrained type, but Chris (indy271828(a)sympatico.ca) requested a way to disable all checks with a single macro. It might not be good enough to use a single error policy and select between throwing version and an assign-anyway version, because the compiler won't always optimize this away. More members, less free functions Thorsten Ottosen thought that any functions which change the state of the object should be members, not free functions. In particular, change_constraint might be less efficient than possible because the construct-and-swap requires copying the constraint. This does seem to be partly an ideological debate. Specific classes instead of a general super-template Vicente Botet requested that the interface use specific classes instead of typedefs: currently many of the specializations, like bounded<>, are metafunctions that apply some parameters to the generic constrained_value and return a new type, and then the specific operations are free functions. Instead these could be full classes with member functions. RK argued that this would result in unnecessary duplication. Way to disable the arithmetic operators Vicente Botet requested a solution in code or in documentation for users who don't want the arithmetic operators defined. 5. Ideas not requiring any action Monitored Values Stjepan Rajko suggested (and Vicente Botet expanded on the idea) that constrained value is really a special case of a more general "monitored value" class, in which a monitor policy decides how to handle any assignment. So constrained value would be a monitored value where the monitor policy checks a constraint, possibly calls an error policy, and then asserts the constraint. RK did not want to implement this and resisted suggestions to allow the assertion to be disabled in order to allow this use case, because without an invariant, it's not really a constrained value. But he suggested that monitored value could be implemented by someone else and constrained value could be re-implemented in terms of it. "Monitored value" might not be the best name for the general class, because "monitor" suggests something passive, rather than something which controls the outcome of assignment. A way to run a function on a constrained value Stjepan Rajko requested a way to make a copy of the value, run a function on it, and then reassign back, preferring the syntax call_using_copy(f, x) to x = f(x). But he notes this could be written as a free function. Multiple ranges Edward Diener requested a way to supply multiple ranges, but agreed that the syntax would be unattractive. Assertions instead of exceptions Thorsten Ottosen requested a way to have only assertions and no exceptions, and RK pointed out that this can be done either by specifying an error policy which asserts, or even with an assign-anyway error policy, which leaves the invariant checking in place. Exclude bounds parameter Vicente Botet found it confusing that bounded_int takes false to mean include bounds and true to mean exclude the bounds. RK explained that this is an artifact of the way within_bounds is templated on a type which can be either a compile-time or a runtime value, e.g. mpl::true_ or bool; this technique means there can be no default argument to the constructor and thus the more common option must be false, the default constructed value of bool. Constraints between several variables. Vicente Botet suggested a sort of constrained_tuple where if you set one field it would affect the constraints for the other fields. E.g. a date object where the month and year would affect the valid range for the day. With the current interface you'd have to set the whole date at once. Constrained values as sets of instances Exploring the problem domain, Vicente Botet suggested another possible implementation of constrained value where the constrained value type keeps track of which instances satisfy the constraint. This class would offer a split operation which moves any instances which satisfy a more specific constraint into the new set. Changing the constraint would similarly return the set of instances which are now excluded. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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basic_file_source copy to filtering_streambuf
by Kraus Philipp 11 Sep '10

11 Sep '10

Hi, I have got a basic_file_source for reading a file. Can I copy the whole file into a filtering_streambuf, whithout closing the stream? I do this at this time with: std::ifstream l_file( "filename", std::ifstream::in | std::ifstream::binary ); std::copy( std::istream_iterator<char>(l_file), std::istream_iterator<char>(), std::ostreambuf_iterator<char>(&l_target) ) I would like to switch std::ifstream to basic_file_source. I can't use boost::copy because it close after writing my target stream. Do the basic_file_source hold a iterator, which I can use with std::copy? How can I do this? Thanks Phil

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Interaction between boost::timer and boost::thread
by Matthieu Brucher 11 Sep '10

11 Sep '10

Hi, I've decided to use boost::thread to run a background thread in my MPI application. Only one rank has a timer, and I only make some calls to elapsed(). Here is what I get if I print the values I retrieve from this single rank: 2.98 (...) 6.58 6.6 6.6 6.61 6.71 6.73 6.75 2.69 2.69 6.78 2.77 2.77 2.83 6.91 2.87 2.87 6.94 6.96 6.97 2.91 2.91 2.91 2.94 7.02 2.99 3.01 3.01 3.02 3.05 3.05 (...) You may notice that the values are not incresing, which leads to very bad total time in my case. Is there a known interaction between these two classes? I'm trying to create a simple example, but I can't get boost::timer to count sleep() time :| Matthieu Brucher -- Information System Engineer, Ph.D. Blog: http://matt.eifelle.com LinkedIn: http://www.linkedin.com/in/matthieubrucher

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[phoenix] function with reference implementation
by alfC 11 Sep '10

11 Sep '10

I noticed that in some contexts I have both the object class and the corresponding phoenix function class impl; ... impl f_impl; boost::phoenix::function<impl> f(f_impl); now to avoid the copying I could use: boost::phoenix::function<impl&> f(f_impl); which works. Although boost::phoenix::function<impl const&> f(f_impl); //doesn't work. (error below) Is there any problem with using references at all, in the first place? -- Thanks, Alfredo /home/correaa/usr/include/boost/spirit/home/phoenix/function/ function.hpp:31: error: conversion from ‘boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::detail::function_eval<1>, boost::fusion::vector<boost::phoenix::value<gsl::interpolation::spline>, boost::phoenix::argument<0>, > > >’ to non-scalar type ‘boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::detail::function_eval<1>, boost::fusion::vector<boost::phoenix::value<const gsl::interpolation::spline>, boost::phoenix::argument<0> > > >’ requested

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some problems about shared_ptr
by Samurai Deeper 11 Sep '10

11 Sep '10

I am a newbie of C++ and I have some question about the shared_ptr I think the best way to explain it is with an example: /*******beginning of CValue.h*************/ #ifndef TVALUE_H #define TVALUE_H template< typename tvalue > class CValue { public: CValue( tvalue value ) : value_(value) {}; private: tvalue value_; }; #endif /****end*************/ /*****Type.h***********/ #ifndef TYPE_H #define TYPE_H #include<boost/shared_ptr.hpp> /*template< typename tvalue > struct Type{ typedef boost::shared_ptr< CValue< tvalue > > pValue; };*/ template<typename T, template <typename> class Value> struct Type { typedef boost::shared_ptr< Value<T> > pValue; }; #endif /********end************/ what if I want to make it as a composition class? by example /***************example**********/ #include "Type.h" #include "CValue.h" template<typename T> class DIP //digital image processing { public: DIP(); virtual ~DIP(); shared_ptr < Type<T, filter> >createMediumFilter(); }; template<typename T> DIP<T>::DIP() {} template<typename T> DIP<T>::~DIP() {} template<typename T> shared_ptr< Type<T, filter> > DIP<T>::createMediumFilter() { typename Type<T, filter>::pValue c(new mediumFilter< T >); return c; } /*****************end**************/ I want to create the instance of mediumFilter like this in the main function int main() { Type<matrix<double>, Composition>::pValue C(new Composition<matrix<double> >); Type<matrix<double>, CValue>::pValue D; D = C->createCValue(); cout<<"system pause"<<endl; cin.get(); } how could I fix the problems? thanks -- View this message in context: http://old.nabble.com/some-problems-about-shared_ptr-tp29674340p29674340.ht… Sent from the Boost - Users mailing list archive at Nabble.com.

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How to manage the internal memory allocation in boost libraries?
by Tang Jiang Jun 11 Sep '10

11 Sep '10

Hello, I am seeking a way to manage the internal memory allocation in boost libraries, and it seems that most of boost libraries do not support allocator parameter, so they can not be handled like STL library. But for my project, our memory management need to control all the memory allocation even it happens in the third-party libraries. Could somebody give me some suggestions to accomplish that? Regards, Tang Jiang Jun

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[Unordered] Penultimate Iterator
by Hossein Haeri 11 Sep '10

11 Sep '10

Dear all, What is the quickest way to get hold of the penultimate iterator in an unordered_map? I'm aware of this one -- which is O(n), where n == container_.size(): container_type::const_iterator i = container_.begin(); advance(i, container_.size() - 1); Is there no O(1) solutions? TIA, --Hossein

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[Boost.Test] Understanding the correct use of BOOST_CHECK_CLOSE and BOOST_CHECK_CLOSE_FRACTION
by Torri, Stephen CIV NSWCDD, W15 10 Sep '10

10 Sep '10

I am trying to understand how to be use BOOST_CHECK_CLOSE and BOOST_CHECK_CLOSE_FRACTION for my problem. My problem is being able to check that two floating point values agree within 12 decimal digits. That is the difference between the two values is smaller than 1e-12. I see from the documentation that BOOST_CHECK_CLOSE requires a percent of agreement while BOOST_CHECK_CLOSE_FRACTION requires a fraction value. So when I used BOOST_CHECK_CLOSE_FRACTION to compare two value I got output that I didn't know how to read: /test_sgp4_orbit_data.cpp(52): error in "default_calculate_semi_major_test": difference{1e-12} between result{1.1219271770198256} and 1.1219271773271688{1.1219271773271688} exceeds 9.9999999999999998e-13 I used BOOST_CHECK_CLOSE_FRACTION as: BOOST_CHECK_CLOSE_FRACTION ( result, 1.1219271773271688, 1e-12 ); What I am intending is if 'result' and the value differ by more than 1e-12 then I have an error. If the difference is smaller than 1e-12 I wish to have the comparison succeed. From the output I don't know why the exceeds value is not written as '1e-12' since that is what I used. Where am I going wrong in my use of BOOST_CHECK_CLOSE_FRACTION? Stephen Stephen Torri, PhD NAVAL SURFACE WARFARE CENTER DAHLGREN 17214 Ave B Suite 121 Dahlgren, Va. 22448 540-653-1082 I am not a contracting officer. I cannot modify or initiate contracts, nor do I have the authority to financially commit the government in any way.

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[python] python 3 with boost 1.44, without using bjam
by Geoff Hilton 10 Sep '10

10 Sep '10

I'm working on a DLL that I would like to expose to Python as a module, but as I came into Python only when Python 3 was available, that's what I know and therefore would like to use. A while ago I took a stab at learning bjam, but for now I've reverted to regular msvc projects, I was able to compile boost.python initially with bjam when I updated to Boost 1.44, the result generated the following files of relevance: libboost_python3-vc90-mt-1_44.lib libboost_python3-vc90-mt.lib libboost_python3-vc90-mt-sgd-1_44.lib libboost_python3-vc90-mt-sgd.lib which is great.. but when I try to compile my project it looks for libboost_python-vc90-mt-1_44.lib or libboost_python-vc90-mt-gd-1_44.lib as appropriate. How can I make msvc compile it successfully? I know bjam is a compiler driver, so I imagine there's a way... (FYI, here are the compilation commands I use from a batch file when compiling a new boost release. I used to use the recommended commands but they stopped working when boost changed the naming conventions to use version-independent naming, probably because I hadn't modified project settings in some way, but a lot of projects would get effected, so after some fiddling this is what I came up with). start bjam --toolset=msvc variant=debug link=static threading=multi runtime-link=static stage start bjam --toolset=msvc variant=release link=static threading=multi runtime-link=shared stage Many thanks, Geoff Unrelatedly, a comment I think might be interesting (if only speculative): from what I recall, I think boost was partially influenced to switch to version-independent naming because (among other reasons) Microsoft was using the version-independence way of thinking via the .Net model with the GAC, but I found an article at one point (which I can no longer find) saying that they realized after much experience with .Net that it's actually still quite possible to get version/DLL conflicts as a result of the version-independence naming (I believe it had to do with GUID generation or some such thing, but don't quote me on that), and quite a lot harder to debug. As a result they would be rethinking .Net and/or changing to a model where version-dependence plays a more prominent role at some point in the future. I wish I could point out the article, but at any rate I know I remember thinking it was funny (if possibly unfortunate) that boost was switching to this new naming convention, a move partially influenced by Microsoft's current methodology in some capacity, after Microsoft had discovered this issue and would eventually be (as I understand it) reverting to what essentially equates to the traditional pre-.Net DLL where versioning can be a more important issue.

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Boost.accumulators : weighted_median
by Maximilian Matthe 10 Sep '10

10 Sep '10

Hi! I want to calculate the median color (along some other data) of the pixels of an image from its histogram: std::vector<int> m_Hist; // m_Hist[i] contains number of pixels with color i. using namespace boost::accumulators; accumulator_set<double, features<tag::weighted_mean, tag::weighted_median(with_p_square_quantile), tag::weighted_variance(lazy), tag::weighted_skewness >, double> acc; for(int i = 0; i < 256; i++) acc(i, weight = m_Hist[i]); float mm = weighted_mean(acc); float stdD = sqrtf(weighted_variance(acc)); float med = weighted_median(acc); float sk = weighted_skewness(acc); mean und stdD work correctly, but the median is too large. It gives me about 200, but the real value should be around 75 (I checked that manually). The skewness is around 11000 (which also seems quite large to me). So, what am I doing wrong with accumulators?

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[boost-users][serialization]Linking time problems with a class hierarchy
by Laszlo Orban 10 Sep '10

10 Sep '10

Currently we are having a class hierarchy consisting of 50+ class definitions (all descendants of one class) along with some assistant structures; the typical you would expect from a 'real' application, and this base is growing each day. We are serializing and deserializing objects from these classes in a kind of client-server application. Everything works fine (testing on both linux and windows platform using gcc 4.4.1), however we are experiencing a rather weird issue. It started quite some time ago, but only starting to get really annoying nowadays: the compile and linking time of the projects that uses these classes are starting to get ridiculous and we could trace this back to serialization. As usual for polymorphic archives, we are using the BOOST_CLASS_EXPORT_GUID macro for creating the necessary singletons for the class definitions. To narrow down the problem we have tried the following checks: 1.) If we comment out all the BOOST_CLASS_EXPORT_GUID macros, the problem is gone, linking and compiling time is reduced to some seconds, the length of the executable and the object files are 'normal', but of course the serialization doesn't work. If I put the macros back, the compiling of the source file that contains them skyrockets to 2-3 minutes, also the linking time to around the same time on a Core2Duo 2 GHz machine, and the length of the object file (and thus the executable) goes from several hundred Kbs to 15+ Mb-s. (A bit varied values on the same code depending if it is linux or windows, but the same behaviour nonetheless.) 2.) We have tried to mess around with the number of macros running, and it seems the increase of the compile time is linear, linking time is more like exponential. 3.) We have tried to 'clean' the class structure and reduced the members in the classes to only some basic booleans and integers (even purged the std::string-s), in most classes completely eliminating all members just let the 'skeleton' there, and still: no significant change in compile and linking time. 4.) We have tried to do all this is in a 'clean' project with only a "void main() {}" method and the class hierarchy, to ensure that not somehow the usage of it causes the problem: negative, the problem still exists. Now it is not a great problem that the compile is so slow, as that causes a problem only when the class hierarchy is changed. Also the executable size is only a bit irritating, but not a serious problem. However the linking time is something we need to solve asap, as it is hindering our development a lot, especially as this class hierarchy is used in several applications (naturally, we wouldn't need serialization otherwise), thus the linking problem affects all of them. (And this will be worse later, as the class hierarchy is growing each day.) Any ideas about how to go on from here? Is there any way I can change the BOOST_CLASS_EXPORT_GUID macro to a more simple? effective? one? Or maybe all this is normal and we have to live with it? (This is a strongly reduced snippet on how we are using the polymorphic serialization with boost_1_42, but as I mentioned, it is working nicely: class Mess { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & messageId; } protected: int messageId; public: (...) }; class CMess : public Mess { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & boost::serialization::base_object<Mess>(*this); ar & cma; } protected: int cma; (...) }; (...) BOOST_CLASS_EXPORT_GUID(CMess, "CMess") Thanks for reading it!

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[serialization] simple binary archive problem
by Paul Graphov 10 Sep '10

10 Sep '10

Hello Boost users! I've upgraded to boost-1.44 and got a problem with binary serialization archives. This code sample http://pastebin.com/Uv465sGt worked well with 1.43 but doesn't work with 1.44 This is a program that creates a struct, serializes it, deserealizes back and compares, archive file name should be supplied as command line parameter. After switching from binary_*archive to text_*archive it works well. With binary_*archive it fails with terminate called after throwing an instance of 'std::bad_alloc' Stack trace is quite huge. p.s. [druid@druid-desktop tmp]$ uname -a Linux druid-desktop 2.6.32-24-generic #42-Ubuntu SMP Fri Aug 20 14:21:58 UTC 2010 x86_64 GNU/Linux [druid@druid-desktop tmp]$ gcc --version gcc (Ubuntu/Linaro 4.4.4-13ubuntu2) 4.4.5 20100902 (prerelease)

5 10

Help with shared_ptr and template
by Mario Chacon 10 Sep '10

10 Sep '10

Hello: I have this problem and I do not how to fix it, I know I cannot write template typedefs, its a limitiation of the C++ syntax, right? or I'm wrong? I saw that the best way is to wrap your typedefs in a struct, which can be templated, but I'm still stack with problems. The best way to explain it's with an example: #include <cstdlib> #include <iostream> #include <boost/shared_ptr.hpp> template< typename tvalue > class CValue { public: CValue( tvalue value ) : value_(value) {}; private: tvalue value_; }; template< typename tvalue > struct Type{ typedef boost::shared_ptr< CValue< tvalue > > pValue; }; int main(int argc, char *argv[]) { Type<bool>::pValue a; return EXIT_SUCCESS; } How can I create a shared_ptr for the template class "CVALUE"?? Please I do not know what else I can prove... :( Thank you.. Mario.. Salu2...

6 8

Warnings when I include posix_time.hpp
by André Santee 10 Sep '10

10 Sep '10

I'm getting the following warning just by including the <boost/date_time/posix_time/posix_time.hpp> header file in my msvc express 2008 project: c:\program files (x86)\microsoft visual studio 9.0\vc\include\iosfwd(607) : warning C4996: 'std::char_traits<char>::copy': Function call with parameters that may be unsafe - this call relies on the caller to check that the passed values are correct. To disable this warning, use -D_SCL_SECURE_NO_WARNINGS. See documentation on how to use Visual C++ 'Checked Iterators' I know that the reason why it's giving me the warning is self explanatory but boost headers aren't supposed to give us warnings. In fact, the warning is not even in the boost header file, but it seems to be included/caused by it. I just want to know if I'm doing something wrong or this is the MSVC header that is messed up. Thanks, André.

2 1

Date Time header only
by Mohamed Bana 10 Sep '10

10 Sep '10

Hi Folks, What parts of the Date Time library is header only? Our applications run on several platforms and it's quite troublesome to get date time to compile on all of them. In my attempt, I was to get it to work on all our platforms except Solaris. I'm aware that I need to use stlport on Solaris, but we can't because we need to interface with another library which doesn't use stlport. To summarise, the whole situation is rather messy and I'm looking for a header only library. If there isn't any, are there any other date and time libraries aside from boost that doesn't require a very strict C++ compliant compiler? If you need more info, just ping me.

1 0

[Boost.Test] How to reuse test results?
by Torri, Stephen CIV NSWCDD, W15 10 Sep '10

10 Sep '10

I tried to use BOOST_FIXTURE_TEST_SUITE to use a fixture in multiple tests. Of course it works fine yet the behavior was not as I expected. What I was expecting which I learned from testing was that the fixture was setup and torn down on each test rather than when the suite ended. In my present problem I have a class which represents the initialization steps of an simulation. There are various algorithms that need to be executed and the results of one can be used in another. So what I was hoping to learn how to do is have a fixture which I can use in the tests of a suite which is only setup and torn down once respectively. So something like: #define BOOST_TEST_MODULE long_life_fixture #include <boost/test/unit_test.hpp> struct CommonData { CommonData() : i ( 0.0 ) { BOOST_TEST_MESSAGE("setup CommonData"); } ~CommonData() { BOOST_TEST_MESSAGE("tear down CommonData"); } double i; }; BOOST_FIXTURE_TEST_SUITE ( class_tests, CommonData ) BOOST_AUTO_TEST_CASE ( function1_test ) { i = 5.0; BOOST_CHECK_EQUAL ( i, 5.0 ); } BOOST_AUTO_TEST_CASE ( function2_test ) { double j = i * 5; BOOST_CHECK_EQUAL ( j, 25.0 ); } BOOST_AUTO_TEST_SUITE_END() Stephen Stephen Torri, PhD NAVAL SURFACE WARFARE CENTER DAHLGREN 17214 Ave B Suite 121 Dahlgren, Va. 22448 540-653-1082 I am not a contracting officer. I cannot modify or initiate contracts, nor do I have the authority to financially commit the government in any way.

2 1

Boost on BG systems, how to compile?
by Filippo Spiga 09 Sep '10

09 Sep '10

Dear Users, does someone have any experience on compiling boost for BlueGene systems? I need to compile the library both for the compute-node and the frontend-node but I have (a lot of) problems to find the right way to do that. Boost follows a completely different compile strategy than other libraries/packages, I am feeling as I have no control on what really happen. At this point I can only read all the documentation but I would like to avoid to waste hours on that. Any help, suggestion, tutorial will be appreciate. Thank you in advance. Regards. -- Filippo SPIGA, MSc «Nobody will drive us out of Cantor's paradise.» -- David Hilbert

1 0

[Thread] MinGW 4.5.1
by Paul Mensonides 09 Sep '10

09 Sep '10

I'm trying to build Boost on Windows with the 32-bit binaries supplied by http://www.equation.com/servlet/equation.cmd?call=fortran. Aside from about 10 billion "visibility attribute" warnings, everything appears to compile correctly except the Thread library: (running from a Windows command prompt) bjam toolset=gcc link=static runtime-link=static stage The build output that I get is below, but it looks like something is wrong with the macro configuration when including boost/detail/interlocked.hpp. Any help? ----- Performing configuration checks - has_icu builds : no warning: Graph library does not contain MPI-based parallel components. note: to enable them, add "using mpi ;" to your user-config.jam - ../config//has_long_double_support builds : yes warning: skipping optional Message Passing Interface (MPI) library. note: to enable MPI support, add "using mpi ;" to user-config.jam. note: to suppress this message, pass "--without-mpi" to bjam. note: otherwise, you can safely ignore this message. warning: Unable to construct ./stage-unversioned warning: Unable to construct ./stage-unversioned Component configuration: - date_time : building - filesystem : building - graph : building - graph_parallel : building - iostreams : building - math : building - mpi : building - program_options : building - python : building - random : building - regex : building - serialization : building - signals : building - system : building - test : building - thread : building - wave : building ...patience... ...patience... ...patience... ...patience... ...found 7329 targets... ...updating 8 targets... gcc.compile.c++ bin.v2\libs\thread\build\gcc-mingw-4.5.1\debug\link-static\runtime-link-static\threading-multi\win32\thread.o In file included from ./boost/thread/once.hpp:14:0, from libs\thread\src\win32\thread.cpp:17: ./boost/thread/win32/once.hpp: In function 'void boost::call_once(boost::once_flag&, Function)': ./boost/thread/win32/once.hpp:136:20: error: '_InterlockedCompareExchange' is not a member of 'boost::detail' ./boost/thread/win32/once.hpp:152:25: error: '_InterlockedIncrement' is not a member of 'boost::detail' ./boost/thread/win32/once.hpp:155:21: error: '_InterlockedExchange' is not a member of 'boost::detail' ./boost/thread/win32/once.hpp:169:21: error: '_InterlockedExchange' is not a member of 'boost::detail' ./boost/thread/win32/once.hpp:184:17: error: '_InterlockedIncrement' is not a member of 'boost::detail' "g++" -ftemplate-depth-128 -O0 -fno-inline -Wall -g -mthreads -Wno-long-long -DBOOST_ALL_NO_LIB=1 -DBOOST_THREAD_BUILD_LIB=1 -I"." -c -o "bin.v2\libs\thread\build\gcc-mingw-4.5.1\debug\link-static\runtime-link-static\threading-multi\win32\thread.o" "libs\thread\src\win32\thread.cpp" ...failed gcc.compile.c++ bin.v2\libs\thread\build\gcc-mingw-4.5.1\debug\link-static\runtime-link-static\threading-multi\win32\thread.o... ...skipped <pbin.v2\libs\thread\build\gcc-mingw-4.5.1\debug\link-static\runtime-link-static\threading-multi>libboost_thread-mgw45-mt-sd-1_44.a(clean) for lack of <pbin.v2\libs\thread\build\gcc-mingw-4.5.1\debug\link-static\runtime-link-static\threading-multi>win32\thread.o... ...skipped <pbin.v2\libs\thread\build\gcc-mingw-4.5.1\debug\link-static\runtime-link-static\threading-multi>libboost_thread-mgw45-mt-sd-1_44.a for lack of <pbin.v2\libs\thread\build\gcc-mingw-4.5.1\debug\link-static\runtime-link-static\threading-multi>win32\thread.o... ...skipped <pstage\lib>libboost_thread-mgw45-mt-sd-1_44.a for lack of <pbin.v2\libs\thread\build\gcc-mingw-4.5.1\debug\link-static\runtime-link-static\threading-multi>libboost_thread-mgw45-mt-sd-1_44.a... gcc.compile.c++ bin.v2\libs\thread\build\gcc-mingw-4.5.1\release\link-static\runtime-link-static\threading-multi\win32\thread.o In file included from ./boost/thread/once.hpp:14:0, from libs\thread\src\win32\thread.cpp:17: ./boost/thread/win32/once.hpp: In function 'void boost::call_once(boost::once_flag&, Function)': ./boost/thread/win32/once.hpp:136:20: error: '_InterlockedCompareExchange' is not a member of 'boost::detail' ./boost/thread/win32/once.hpp:152:25: error: '_InterlockedIncrement' is not a member of 'boost::detail' ./boost/thread/win32/once.hpp:155:21: error: '_InterlockedExchange' is not a member of 'boost::detail' ./boost/thread/win32/once.hpp:169:21: error: '_InterlockedExchange' is not a member of 'boost::detail' ./boost/thread/win32/once.hpp:184:17: error: '_InterlockedIncrement' is not a member of 'boost::detail' In file included from ./boost/thread/shared_mutex.hpp:14:0, from ./boost/thread/detail/thread_group.hpp:9, from ./boost/thread/thread.hpp:24, from libs\thread\src\win32\thread.cpp:10: ./boost/thread/win32/shared_mutex.hpp: In member function 'T boost::shared_mutex::interlocked_compare_exchange(T*, T, T) [with T = boost::shared_mutex::state_data]': ./boost/thread/win32/shared_mutex.hpp:110:103: instantiated from here ./boost/thread/win32/shared_mutex.hpp:50:99: warning: dereferencing type-punned pointer will break strict-aliasing rules ./boost/thread/win32/shared_mutex.hpp:50:99: warning: dereferencing type-punned pointer will break strict-aliasing rules ./boost/thread/win32/shared_mutex.hpp:51:52: warning: dereferencing type-punned pointer will break strict-aliasing rules ./boost/thread/win32/shared_mutex.hpp:51:52: warning: dereferencing type-punned pointer will break strict-aliasing rules "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -mthreads -Wno-long-long -DBOOST_ALL_NO_LIB=1 -DBOOST_THREAD_BUILD_LIB=1 -DNDEBUG -I"." -c -o "bin.v2\libs\thread\build\gcc-mingw-4.5.1\release\link-static\runtime-link-static\threading-multi\win32\thread.o" "libs\thread\src\win32\thread.cpp" ...failed gcc.compile.c++ bin.v2\libs\thread\build\gcc-mingw-4.5.1\release\link-static\runtime-link-static\threading-multi\win32\thread.o... ...skipped <pbin.v2\libs\thread\build\gcc-mingw-4.5.1\release\link-static\runtime-link-static\threading-multi>libboost_thread-mgw45-mt-s-1_44.a(clean) for lack of <pbin.v2\libs\thread\build\gcc-mingw-4.5.1\release\link-static\runtime-link-static\threading-multi>win32\thread.o... ...skipped <pbin.v2\libs\thread\build\gcc-mingw-4.5.1\release\link-static\runtime-link-static\threading-multi>libboost_thread-mgw45-mt-s-1_44.a for lack of <pbin.v2\libs\thread\build\gcc-mingw-4.5.1\release\link-static\runtime-link-static\threading-multi>win32\thread.o... ...skipped <pstage\lib>libboost_thread-mgw45-mt-s-1_44.a for lack of <pbin.v2\libs\thread\build\gcc-mingw-4.5.1\release\link-static\runtime-link-static\threading-multi>libboost_thread-mgw45-mt-s-1_44.a... ...failed updating 2 targets... ...skipped 6 targets...

1 0

Graphviz and Boost Problem
by ef 09 Sep '10

09 Sep '10

Hello I am using the dot language to create a graph using Boost. My Graphs are huge and I am trying to delete* vertices *and edges that are no longer used in my program. Under boost/graph/graphviz.hpp I added a function to remove a vertex and its edges in the mutate_graph class, I then go ahead and implement it under the mutate_graph_impl class: virtual void do_remove_vertex( const node_t& node) { bgl_vertex_t v = bgl_nodes[node]; clear_vertex(v,graph_); remove_vertex(v,graph_); } However I keep getting a segfault on the call to clear vertex, I ran it into gdb and here is the back trace (i hope this is not to long) Program received signal SIGSEGV, Segmentation fault. 0x000000000040b87f in std::_List_base<boost::detail::sep_<void*, boost::property<boost::edge_weight_t, int, boost::no_property> >, std::allocator<boost::detail::sep_<void*, boost::property<boost::edge_weight_t, int, boost::no_property> > > >::_M_clear (this=0x0) at /usr/include/c++/4.4/bits/list.tcc:68 68 _Node* __cur = static_cast<_Node*>(this->_M_impl._M_node._M_next); (gdb) bt #0 0x000000000040b87f in std::_List_base<boost::detail::sep_<void*, boost::property<boost::edge_weight_t, int, boost::no_property> >, std::allocator<boost::detail::sep_<void*, boost::property<boost::edge_weight_t, int, boost::no_property> > > >::_M_clear (this=0x0) at /usr/include/c++/4.4/bits/list.tcc:68 #1 0x00000000004119d2 in std::list<boost::detail::sep_<void*, boost::property<boost::edge_weight_t, int, boost::no_property> >, std::allocator<boost::detail::sep_<void*, boost::property<boost::edge_weight_t, int, boost::no_property> > > >::clear (this=0x0) at /usr/include/c++/4.4/bits/stl_list.h:1132 #2 0x000000000040fac4 in boost::clear_vertex<boost::detail::adj_list_gen<boost::adjacency_list<boost::listS, boost::listS, boost::directedS, boost::property<boost::vertex_name_t, std::string, boost::no_property>, boost::property<boost::edge_weight_t, int, boost::no_property>, boost::no_property, boost::listS>, boost::listS, boost::listS, boost::directedS, boost::property<boost::vertex_name_t, std::string, boost::no_property>, boost::property<boost::edge_weight_t, int, boost::no_property>, boost::no_property, boost::listS>::config> (u=0x0, g_=...) at boost_1_43_0/boost/graph/detail/adjacency_list.hpp:633 #3 0x000000000040e7a5 in boost::detail::graph::mutate_graph_impl<boost::adjacency_list<boost::listS, boost::listS, boost::directedS, boost::property<boost::vertex_name_t, std::string, boost::no_property>, boost::property<boost::edge_weight_t, int, boost::no_property>, boost::no_property, boost::listS> >::do_remove_vertex (this=0x7fffffffe520, node=...) at boost_1_43_0/boost/graph/graphviz.hpp:767 #4 0x00007ffff7b6ab12 in boost::read_graphviz_detail::translate_results_to_graph (r=..., mg=0x7fffffffe520) at ../../../libs/graph/src/read_graphviz_new.cpp:782 #5 0x00007ffff7b6b314 in boost::detail::graph::read_graphviz_new (str=..., mg=0x7fffffffe520) at ../../../libs/graph/src/read_graphviz_new.cpp:830 #6 0x000000000040bc1f in boost::read_graphviz_new<boost::adjacency_list<boost::listS, boost::listS, boost::directedS, boost::property<boost::vertex_name_t, std::string, boost::no_property>, boost::property<boost::edge_weight_t, int, boost::no_property>, boost::no_property, boost::listS> > (str=..., graph=..., dp=..., node_id=...) at boost_1_43_0/boost/graph/detail/read_graphviz_new.hpp:103 #7 0x000000000040b243 in boost::read_graphviz<std::istream_iterator<char, char, std::char_traits<char>, long>, boost::adjacency_list<boost::listS, boost::listS, boost::directedS, boost::property<boost::vertex_name_t, std::string, boost::no_property>, boost::property<boost::edge_weight_t, int, boost::no_property>, boost::no_property, boost::listS> > ( user_first=..., user_last=..., graph=..., dp=..., node_id=...) at boost_1_43_0/boost/graph/graphviz.hpp:910 #8 0x000000000040aa18 in boost::read_graphviz<boost::adjacency_list<boost::listS, boost::listS, boost::directedS, boost::property<boost::vertex_name_t, std::string, boost::no_property>, boost::property<boost::edge_weight_t, int, boost::no_property>, boost::no_property, boost::listS> > (in=..., graph=..., dp=..., node_id=...) at boost_1_43_0/boost/graph/graphviz.hpp:922 #9 0x00000000004086a9 in test_graph_read_write (filename=...) at graphviz.cpp:41 #10 0x0000000000408814 in main () at graphviz.cpp:52 In my main program my graph is declared like this: adjacency_list<listS, listS, directedS,property<vertex_name_t, std::string>, property<edge_weight_t, int> > Graph; and go ahead and initiate graphviz like this: read_graphviz(in, g, dp, "id"); Am I breaking some pretty obvious rules? As I am pretty lost. Any advice/suggestions and comments is very much appreciated. Thanks in advance!

2 10

Regex Design trap
by Sven Bauhan 09 Sep '10

09 Sep '10

Dear Developers, I found a possible trap in the design of the syntax of the Regex library. Consider the following code: std::string text( "blabla123xyz" ); boost::regex expression( "\\w+(\\d+)\\w+" ); boost::smatch matches; boost::regex_search( text, matches, expression ); text = "asdfghjkl"; std::string value = matches[1]; Although this code is not very useful, it can lead to inpredictable behaviour. As far as i know the matches just reference the string position in the original string. so when the string is changed the matches don't fit any more. This may be a quite good performance but it requires to be very careful. Especially if the string is just referenced somewhere and the matches are given to somewhere else. Furthermore as i saw the Regex library I wondered about its interface. It seems more like a C library interface than C++ code. I also code in Ruby and the Regex class is much more convenient. The pattern matching is done there by a method of class Regex and returns the matches: expression = Regex.new( "\w+(\d+)\w" ) matches = expression.match( "blabla123xyz" ) if ( matches ) ... Would it be possible to implement such a more object oriented interface to boost::regex? Greetings, Sven -- Dipl.-Ing. Sven Bauhan DFS Deutsche Flugsicherung GmbH

2 3

[serialization] Implementation in mutliple DLLs
by Guy Premont 09 Sep '10

09 Sep '10

Hi, I've done research on the list and could not find any pointer about my problem so here it is. I'm using windows, boost 1.40, and vc9, i am not using polymorphic archives, and i'm using member function serialization. In a big project, separated in different modules, I want to spread serialization also into different DLLs. Typically, i have a base class Base, implemented in Base.dll and the serialization is in BasePersistence.dll. The serialization member functions are marked with ddlexport or dllimport, explicit template instantiation is done to force inclusion in the dll. So far everything is working. Now I have a class Derived, derived from Base, implemented in Derived.dll. If i have only one serialization library that handle all classes, it works fine, but I want the serialization to be split with the same module as the implemention. So, I want the serialization of class Derived to be in DerivedPersistence.dll. It compiles but fails to link, There are a lot of undefined symbols, most are in boost::serialization::archive namespace. Is there a special BOOST_DLL flag to use? It seems like the DerivedPersistence.dll does not find in BasePersistence.dll the functions it should find. Is it at all possible to spread the serialization code into multiple dependent DLLs? Just having something to hint at a possible solution would be a big help. Thanks Guy -- Guy Prémont, D.Sc. Architecte logiciel senior / Senior software architect CM Labs Simulations Inc. http://www.cm-labs.com/ Tel. 514-267-1166 ext. 237

3 2

[Fusion, maybe?] Workings of ADL.
by Robert Jones 09 Sep '10

09 Sep '10

I expected this to work #include <boost/fusion/include/vector.hpp> #include <boost/fusion/include/at_c.hpp> typedef boost::fusion::vector<int, int> V; int first( const V & v ) { return at_c<0>( v ); } but I find I need a "using namespace boost::fusion;". Why isn't this covered by ADL? Thx - Rob.

2 6

[test] Windows Vista: "The application failed to initialize properly (0xc0000005)."
by Daniel Trebbien 09 Sep '10

09 Sep '10

I am using MinGW on Windows to try to compile a working shared binary of Unit Test Framework. My GCC version is the latest for MinGW, 4.5.0, and I used the following line to compile libboost_unit_test_framework-mgw45-mt-1_44.dll: bjam toolset=gcc link=shared --with-test release I have tried both Boost 1.43.0 and 1.44.0 beta 1 sources, but with each, bjam succeeds and my test program that uses UTF fails with the message dialog: The application failed to initialize properly (0xc0000005). Click OK to terminate the application. My test program compiles and runs fine on Debian Linux using Boost 1.42. Is anyone else experiencing this problem?

5 8

Compilation error's while building Boost 1_43_0 on HP-UX Re: Compilation error's while building Boost 1_43_0 on HP-UX 11.11 with gcc version 3.3.1
by Avi Bahra 09 Sep '10

09 Sep '10

You may not be aware but boost is not supported on HP-UX this was quite a while ago. However I have built with boost using gcc a while ago. Using gcc 4.3.1 on HP_UX itanium B.11.23, boost 1.38 My own application/boost had problems gcc with later boost versions, so I tried HPUX acc compiler. This seem to cope better. However be aware that aCC is very slow at compiles, but does work. Currently using Acc version 6, with boost 1.43 However regardless of the compiler, you will have problems. So be prepared for a world of pain, if you want to use boost on HPUX. Depending on which libraries you use. I have had to manually hack some of boost files, to get it too work, in particular for boost asio, and one other lib, I forget. Best regards, Ta, Avi

1 0

[tuples] sorting vector of boost-tuples
by Christian Meesters 09 Sep '10

09 Sep '10

Hi, Don't know whether this is a boost-thing or C++ ... hope to put the problem the right way. Anyway, I have a tuple: //! tuple of <marker id, r2, allele> typedef boost::tuple<std::string, double, char> Proxy; and a map like //! map of <marker id, <vector of Proxies> > typedef std::map<std::string, std::vector<Proxy> > ProxyLT; Now, ProxyLT proxies; proxy = boost::tuple<std::string, double, char>(some string id, some double, some character); // pushing this tuple into the map/vector construct proxies[some other string id].push_back(proxy); And now I would like to sort these vectors within the map vector by vector according to the double in the tuple. For this I have the function (within a header file): inline bool proxy_gt(Proxy first, Proxy second) { return (first.get<1>() > second.get<1>()); } and then the actual sorting: for (yamas::ProxyLT::iterator pit = proxies.begin(); pit != proxies.end(); pit++) { sort((*pit).second.begin(), (*pit).second.end(), proxy_gt); } Problem is that g++ keeps telling me /usr/include/c++/4.4/bits/stl_heap.h:180: error: must use '.*' or '->*' to call pointer-to-member function in '__comp (...)', e.g. '(... ->* __comp) (...)' when 'sort' is called. Whatever I do to the inline function - I cannot solve this problem. Any hints? TIA Cheers Christian

1 0

asio multicast receiver takes all traffic addressed to the same port (example/multicast/receiver.cpp)
by Yuri T. 09 Sep '10

09 Sep '10

Hi, In my network there are multiple multicast streams with different addresses, but with the same port. I tried to run an example from the asio library (example/multicast/receiver.cpp). In Windows it works fine but in linux if you run multiple copies of the application they receive all packets arriving on the specified port and ignore the broadcast address. How to filter packets by multicast address? (senderEndpoint contain real IP, not multicast)

2 1

issues when linking a library that uses boost classes
by Sean Farrow 09 Sep '10

09 Sep '10

Hi: I've recently written a library that uses boost classes internally. The library (the release version) uses the visual studio multi-threaded static library. When I try to use the class in another program that uses boost classes it appears the relevant parts of the library don't get linked in. After specifying the lib on the linker tab (i.e the one that I've built) the build goes fine, but I get an excdeption when the app is run. Any ideas? I can replicate this with two projects, visual studio 2008, boost 1.44 release. If anybody wants to take a look at the solution, I'm happy to send off-list. Cheers Sean.

2 3

Re: [Boost-users] fusion::vector with 1 element, fusion::transform, boost::variant and boost::optional
by Hicham Mouline 09 Sep '10

09 Sep '10

> -----Original Message----- > From: Hicham Mouline [mailto:hicham@mouline.org] > Sent: 09 September 2010 04:49 > To: 'boost-users(a)lists.boost.org' > Subject: fusion::vector with 1 element, fusion::transform, > boost::variant and boost::optional > > Hello, > I have this error w msvc2008: I attach here a compilable cpp file. same error with g++4.4 regards,

1 0

Incorrect handling of synthesized attributes in Spirit.
by Preeti Khurana 09 Sep '10

09 Sep '10

I am trying to parse the lines :: 10.1.1.1/32 10.10.1.1 29/nolabel 10.7.7.7/32 150.2.2.2 nolabel/30 Which are space separated and putting them in a vector of strings :: sp %= lit(' '); ip_address %= +char_("0-9") >> char_('.') >> +char_("0-9") >> char_('.') >> +char_("0-9") >> char_('.') >> +char_("0-9") >> *char_("/") >> *char_("0-9"); data %= *sp >> ( xr_special | ip_address | +lit("/") | +char_("0-9A-Za-z()")); start %= +(data ) >> *sp >> eoi; qi::rule<Iterator, void()> sp; qi::rule<Iterator, std::string()> ip_address; qi::rule<Iterator, std::string()> data; qi::rule<Iterator, test::Parsed_Rec()> start; (Parsed Rec carries a vector of strings ) Grammar is able to parse the lines but while parsing 29 in first line & 30 in last line, the attributes are incorrectly filled. The attributes are filled twice ( Debug File for this is debug_file_incorrect). Snippet :: <data> <try> 29/nolabel</try> <xr_special> <try>29/nolabel</try> <fail/> </xr_special> <ip_address> <try>29/nolabel</try> <fail/> </ip_address> <success>/nolabel</success> <attributes>[[2, 9, 2, 9]]</attributes> </data> While if I change my grammar to explicitly fill the attributes, they are filled correctly. File attached : debug_file_correct data = *sp >> ( xr_special | ip_address[_val= _1] | +lit("/") | +char_("0-9A-Za-z()")[_val+= _1] ); <data> <try> 29/nolabel</try> <xr_special> <try>29/nolabel</try> <fail/> </xr_special> <ip_address> <try>29/nolabel</try> <fail/> </ip_address> <success>/nolabel</success> <attributes>[[2, 9]]</attributes> </data> Thanks Preeti

1 0

fusion::vector with 1 element, fusion::transform, boost::variant and boost::optional
by Hicham Mouline 09 Sep '10

09 Sep '10

Hello, I have this error w msvc2008: error C2664: 'nicohich::systems::make_parameters_for_simulate<parameters_t>::type::type(c onst boost::fusion::vector1<T0> &)' : cannot convert parameter 1 from 'const parameters_1_n_seq_t' to 'const boost::fusion::vector1<T0> &' 1> with 1> [ 1> parameters_t=my_ns::systems::ns1::parameters, 1> T0=boost::variant<std::vector<double>, my_ns::range_incr<double>, my_ns::range<double>,double> 1> ] 1> and 1> [ 1> T0=boost::variant<std::vector<double>, my_ns::range_incr<double>, my_ns::range<double>,double> 1> ] 1> Reason: cannot convert from 'const parameters_1_n_seq_t' to 'const boost::fusion::vector1<T0>' 1> with 1> [ 1> T0=boost::variant<std::vector<double>, my_ns::range_incr<double>, my_ns::range<double>,double> 1> ] 1> No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called where parameters_1_n_seq_t which is a result of a metafunction invocation is: (as determined at runtime by typeid(parameters_1_n_seq_t).name(), I manually edited out the namespaces and trailing boost templates args ): fusion::transform_view< fusion::vector1< optional< variant< std::vector<double>, my_ns::range_incr<double>, my_ns::range<double>, double > > >, deoptionalize_item, void_ > where struct deoptionalize_item { typedef deoptionalize_item Self; template<typename Sign> struct result; // primary template template<typename T> // template spec struct result<Self( const boost::optional<T>& )> { typedef const T& type; }; template <typename T> const T& operator()( const boost::optional<T>& rhs ) const { return *rhs; } }; my_ns::systems::ns1::parameters is defined as: namespace systems { struct base_parameters { double x; }; namespace ns1 { struct parameters : public base_parameters { // double y }; } } // at global namespace BOOST_FUSION_ADAPT_STRUCT( my_ns::systems::ns1::parameters, (double, x) // (double, y) ) Previously, parameters held the field y, and this error didn't happen. Regards,

1 0

trick to print a type at compile-time
by Hicham Mouline 09 Sep '10

09 Sep '10

Hello, Is there a way to print the type returned by a metafunction typedef some_metafunction<T>::type result_type; during compile-time (probably via triggering a compilation error). I almost recall some sort of static assertion (mpl ?) to do this. regards,

5 7

serialization of c++0x or boost unordered_map
by William Oquendo 08 Sep '10

08 Sep '10

Dear all, I would like to know if is there a canonical way to use serialization for c++0x or boost unordered_map, like the provided for standards vectors with the file boost/serialization/vector.hpp . Thanks in advance. Best regards / Cordialmente, -- William Oquendo Phd Candidate Simulation Of Physical Systems Group Universidad Nacional de Colombia Linux User # 321481 ********************* Este correo puede carecer de tildes o eñes ya que el teclado no contiene estos caracteres. Presento excusas por eso. *********************

2 1

[Random] uniform_real, min/max at end of value range
by Ruediger Berlich 08 Sep '10

08 Sep '10

Hi there, from what I can see, uniform_real(min,max) essentially does this: fp_type result = uniform_fp_between_0_and_1 * (max - min) + min; // (1) (1) will fail e.g. if the distance between min and max is > std::numeric_limits<fp_type>::max() While writing unit tests for my code I have come across exactly this situation. My application would not suffer much from reducing the allowed value range for my variables to < +/-0.5*std::numeric_limits<fp_type>::max() . However I feel that this would be a bit artificial. Hence I was wondering whether code like the following made more sense (although it is certainly not as efficient): /**********************************************************/ fp_type uniform_real(const fp_type& min, const fp_type& max) { // Check that min and max have appropriate values assert(min<=max); if(min >= fp_type(0.) || max <= fp_type(0.)) { // (max-min) is valid return uniform_01() * (max - min) + min; } else { // Some values will fail (max-min) // We know: min<0., max>0. assert(min<0); assert(max>0); // Calculate a random number in the range [0,1[ fp_type fraction = uniform_01(); // Calculate the fraction of the distance of min from 0. volatile fp_type minFraction = -fraction*min; // Calculate the fraction of the distance of max from 0. volatile fp_type maxFraction = fraction*max; // // The start of the scale volatile fp_type result = min + minFraction; // Add maxFraction to the result. result += maxFraction; return result; } } /**********************************************************/ Essentially, in cases where (max-min) could be larger than the allowed value range, the distance to 0 of each max and min is individually multiplied with a fp random number in the range [0,1[ . The resulting values are then added seperately to min. There should be no situation where an attempt is made to create a value larger than the allowed value range ... unless the compiler optimizes this to "result=min+minFraction+maxFraction;" or worse. volatile might or might not prevent this, I am not sure (seems to work with g++ 4.4.3, though). What is your view on this ? Are there different/better approaches in Boost that I could use ? Best Regards, Ruediger

2 1

insert_iterator() for Unordered Containers
by Hossein Haeri 08 Sep '10

08 Sep '10

Dear all, Is there any insert_iterator (the std Iterator Adaptor) for unordered containers? I am especially interested in unordered_map. TIA, --Hossein

2 1

BOOST_FUSION_ADAPT_STRUCT for empty structs
by Hicham Mouline 08 Sep '10

08 Sep '10

Hello I have this situation: namespace X { struct base_parameters { double skid; }; namespace XX { struct derived_parameters: public base_parameters { double old_field; }; } } // at global namespace BOOST_FUSION_ADAPT_STRUCT( X::XX::parameters, (double, skid) //(double, old_field) ) boost 1.44 Is this supposed to work? I'm getting a compile error which I can't understand and 1 change that I've done is remove the only field that was before in derived_parameters. Regards,

2 2

Building Boost on Mac Snow Leopard
by Andrew Maclean 08 Sep '10

08 Sep '10

Hi All, If I build boost using bjam (no problems there) and set in .bashrc: export DYLD_LIBRARY_PATH="$DYLD_LIBRARY_PATH:${BOOST_ROOT}/stage/lib" Things seem to work OK when when calling applications from the command line in a terminal. However if I invoke the application e.g. x.app from the Finder the boost dynamic libraries are not found. If I run for example, otool -D /Users/andrewmaclean/Code/GeneralLibraries/boost_1_44_0/stage/lib/libboost_date_time.dylib /Users/andrewmaclean/Code/GeneralLibraries/boost_1_44_0/stage/lib/libboost_date_time.dylib: libboost_date_time.dylib Clearly no absolute path is set. It seems to me that Finder is ignoring the DYLD_LIBRARY_PATH variable, I even changed it to DYLD_FALLBACK_LIBRARY_PATH to see if it would make any difference. So the only solution I have is to install boost into the default system libraries, where it works perfectly. Now comes the interesting question. If I build VTK then the absolute paths are put into the dynamic libraries. So something in CMake/gcc actually adds these paths into the dynamic libraries. Why doesn't bjam do this? Is there a parameter I am missing? Rgeards Andrew -- ___________________________________________ Andrew J. P. Maclean Centre for Autonomous Systems The Rose Street Building J04 The University of Sydney 2006 NSW AUSTRALIA Ph: +61 2 9351 3283 Fax: +61 2 9351 7474 URL: http://www.acfr.usyd.edu.au/ ___________________________________________

4 4

Compilation error's while building Boost 1_43_0 on HP-UX 11.11 with gcc version 3.3.1
by Nakul Virmani 08 Sep '10

08 Sep '10

HI All, I am trying to build boost 1_43_0 on HP-UX box (HP-UX 11.11) using gcc verision 3.3.1, but i am running into compilation errors. The gcc version details are as below -bash-3.2$ ./gcc -v Reading specs from ./../lib/gcc-lib/hppa2.0w-hp-hpux11.11/3.3.1/specs Configured with: ../src/configure --enable-languages=c,c++ --prefix=/usr/local/pa20_32 --with-local-prefix=/usr/local/pa20_32 --with-gnu-as --with-as=/usr/local/pa20_32/bin/as --with-ld=/usr/ccs/bin/ld --disable-shared --disable-nls Thread model: single gcc version 3.3.1 The following error are thrown and not even a single file is built ...patience... ...patience... ...patience... ...found 5243 targets... ...updating 747 targets... common.mkdir stage common.mkdir stage/lib common.mkdir /export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost common.mkdir /export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2 common.mkdir /export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs common.mkdir /export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs/math common.mkdir /export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs/math/build common.mkdir /export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs/math/build/gcc-3.3.1 common.mkdir /export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs/math/build/gcc-3.3.1/release common.mkdir /export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs/math/build/gcc-3.3.1/release/threading-multi common.mkdir /export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs/math/build/gcc-3.3.1/release/threading-multi/.. common.mkdir /export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs/math/build/gcc-3.3.1/release/threading-multi/../src common.mkdir /export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs/math/build/gcc-3.3.1/release/threading-multi/../src/tr1 gcc.compile.c++.pch /export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs/math/build/gcc-3.3.1/release/threading-multi/../src/tr1/pch.hpp.gch g++: unrecognized option `-pthread' g++: language c++-header not recognized g++: libs/math/build/../src/tr1/pch.hpp: linker input file unused because linking not done gcc.compile.c++ /export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs/math/build/gcc-3.3.1/release/threading-multi/assoc_laguerre.o g++: unrecognized option `-pthread' cc1plus: error: unrecognized option `-Winvalid-pch' "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pthread -fPIC -Winvalid-pch -DBOOST_ALL_NO_LIB=1 -DBOOST_BUILD_PCH_ENABLED -DBOOST_MATH_TR1_DYN_LINK=1 -DNDEBUG -I"/export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs/math/build/gcc-3.3.1/release/threading-multi/../src/tr1" -I"." -I"libs/math/src/tr1" -c -o "/export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs/math/build/gcc-3.3.1/release/threading-multi/assoc_laguerre.o" "libs/math/build/../src/tr1/assoc_laguerre.cpp" ...failed gcc.compile.c++ /export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs/math/build/gcc-3.3.1/release/threading-multi/assoc_laguerre.o... gcc.compile.c++ /export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs/math/build/gcc-3.3.1/release/threading-multi/assoc_legendre.o g++: unrecognized option `-pthread' cc1plus: error: unrecognized option `-Winvalid-pch' "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pthread -fPIC -Winvalid-pch -DBOOST_ALL_NO_LIB=1 -DBOOST_BUILD_PCH_ENABLED -DBOOST_MATH_TR1_DYN_LINK=1 -DNDEBUG -I"/export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs/math/build/gcc-3.3.1/release/threading-multi/../src/tr1" -I"." -I"libs/math/src/tr1" -c -o "/export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs/math/build/gcc-3.3.1/release/threading-multi/assoc_legendre.o" "libs/math/build/../src/tr1/assoc_legendre.cpp" ...failed gcc.compile.c++ /export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs/math/build/gcc-3.3.1/release/threading-multi/assoc_legendre.o... gcc.compile.c++ /export/home/devuser/Boost_1_43_0/boost_1_43_0/tmp/libs/boost/bin.v2/libs/math/build/gcc-3.3.1/release/threading-multi/beta.o g++: unrecognized option `-pthread' cc1plus: error: unrecognized option `-Winvalid-pch' Am i missing something?Is there any specific HP-UX version or any minimum gcc version that is required to build boost 1_43_0? Regards, Nakul Virmani

1 0

Using subscript operator with interprocess map
by Michi Mutsuzaki 08 Sep '10

08 Sep '10

El 03/09/2010 9:18, Michi Mutsuzaki escribió: > char_string needs an allocator in its constructor (not tested code): > (*mymap)[char_string("key", alloc_inst)] = 1; Thanks Ion, that fixed the compilation error. Now I'm trying create a map from char_string to char_string, and that's failing. Here is the code and the error message I'm getting (I'm really sorry I keep posting about compilation errors, but I'm having hard time parsing the error message): #include <functional> #include <iostream> #include <algorithm> #include <boost/interprocess/managed_mapped_file.hpp> #include <boost/interprocess/containers/map.hpp> #include <boost/interprocess/containers/string.hpp> #include <boost/interprocess/allocators/allocator.hpp> namespace bi = boost::interprocess; typedef bi::allocator<char, bi::managed_mapped_file::segment_manager> char_alloc; typedef bi::basic_string<char, std::char_traits<char>, char_alloc> char_string; typedef std::pair<const char_string, char_string> ValueType; typedef bi::allocator<ValueType, bi::managed_mapped_file::segment_manager> map_alloc; typedef bi::map<char_string, char_string, std::less<char_string>, map_alloc> MyMap; int main () { bi::managed_mapped_file segment(bi::open_or_create, "/tmp/test", 65536); map_alloc alloc_inst (segment.get_segment_manager()); char_alloc alloc_inst2 (segment.get_segment_manager()); MyMap *mymap = segment.find_or_construct<MyMap>("MyMap") (std::less<char_string>(), alloc_inst); (*mymap)[char_string("key", alloc_inst2)] = char_string("val", alloc_inst2); return 0; } /usr/local/include/boost/interprocess/containers/map.hpp: In instantiation of `T& boost::interprocess::map<Key, T, Pred, Alloc>::operator[](const typename boost::interprocess::detail::rbtree<Key, std::pair<const Key, T>, boost::interprocess::detail::select1st<std::pair<const Key, T> >, Pred, Alloc>::key_type&) [with Key = char_string, T = char_string, Pred = std::less<char_string>, Alloc = map_alloc]': boost_test.cc:27: instantiated from here /usr/local/include/boost/interprocess/containers/map.hpp:325: error: no matching function for call to `boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0u>, boost::interprocess::iset_index> >::allocator()' /usr/local/include/boost/interprocess/allocators/allocator.hpp:135: note: candidates are: boost::interprocess::allocator<T, SegmentManager>::allocator(const boost::interprocess::allocator<T, SegmentManager>&) [with T = char, SegmentManager = boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0u>, boost::interprocess::iset_index>] /usr/local/include/boost/interprocess/allocators/allocator.hpp:130: note: boost::interprocess::allocator<T, SegmentManager>::allocator(SegmentManager*) [with T = char, SegmentManager = boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0u>, boost::interprocess::iset_index>]

1 0

Re: [Boost-users] [MSM] stack overflow happens when there is a false-guard anonymous transition
by Christophe Henry 07 Sep '10

07 Sep '10

<snip previous discussion> > Thanks for getting me on the same page. I think completion events are > peculiar only in the sense that their event is implicitly generated. > Run-to-completion step semantics must still be obeyed as well as guards > must be evaluated only once. Yes, I agree on this. This is now the trunk state. > If the completion event has been dispatched and it fails to take a > transition I believe the state is now quiescent (for reasons articulated > earlier). I also see it that way after re-reading the standard. > So... how do we exit? The *only* way to exit via the completion > transition is for a completion event to be dispatched again. How can > this happen? Via a self transition (or compound transition that returns) > or via hierarchical search and a return to history. > > > ----------- ----------- > ----->| | [g] | | > | S1 |--------->| S2 | > -->| entry/F1 | | | > | | exit/F2 | | | > | |__________| |_________| > |____| > E You are probably right from a Standard perspective (IIUC) but it is not a very elegant solution. Worse, those using completion events often write a complete state machine this way, and this method will almost double their number of transitions, which will cost much in compile-time. > I think executing process_completion is actually a violation of the > model (UML). Completion events occur based on a well defined set of > rules. Failure to take a completion transition because of a guard is by > design or implementation (intentional or a flaw). A new event must be > processed that results in a completion event to be dispatched for the > evaluation to occur again. It also rubs me wrong because > run-to-completion steps are always initiated via an event being > dispatched. process_completion would produce a second "interface" for > injecting behavior. > > My recommendation would be to stick with the standard. Typically the > side affects of entry F1 or transition E will result in the evaluation > of g to true. If simply calling process_completion again results in g > becoming true it means significant state changes outside of the state > machine (or in a parallel machine). In my opinion, this would be an > indicator of a bad design. The one place where I do something similar is > when "polling" real hardware; however, I use the above configuration and > trigger E to evaluate g in a predictable manner. As msm is used in embedded systems, there is plenty of hardware and it seems a valid use case. Anyway, thinking about it again today, I realized that we do not need process_completion. I'm wondering how I could miss this. As completion events are defined for msm as having the event "none", the same effect can be achieved by simply calling: fsm.process_event(none()); And now we are UML-conform. We have our completion semantics for the first time the source state becomes active, and our standard event semantics using "none" as event. And this costs us no extra transition. Now this is a win-win scenario :) So, process_completion is out :) > As for the "wildcard" or any trigger, ROOM had this notion and I have > used it extensively over the years. In 13.3.1 you will find > AnyReceiveEvent. A transition trigger can be associated with this > message event which would specify the transition should be triggered by > receipt of any message. I don't think MSM encompasses the Communications > Package models and this may be a stretch to get working. BTW, MSM does not have the wildcard concept (yet) but is coming pretty close using a base event. If you define in your fsm an event called "any_event" and all your other events inherit from any_event: struct eventA : public any_event{}; struct eventB : public any_event{}; The following transition: Row<State1, any_event, State2> Will fire if you throw at it an any_event, an eventA or an eventB. It's not perfect but it will help until I find a better solution. Thanks for your very useful insights! Regards, Christophe

2 1

Boost::config
by Jean-Sebastien Stoezel 07 Sep '10

07 Sep '10

Hello, Could somebody suggest a good tutorial for the Boost::config library. More precisely, how to parse from files, and use section names: http://www.boost.org/doc/libs/1_44_0/doc/html/program_options/overview.html… Thanks! Jean

1 0

How do I use random_device?
by Raphael MD 07 Sep '10

07 Sep '10

Hi everyone! I need to use random_device for generating non deterministic random numbers, but I don't know how to use this class, it's very confusing, I don't understand it. I'm using linux. My example code: using namespace std; #include <iostream> #include <string> #include <boost/timer.hpp> #include <boost/nondet_random.hpp> int main() { boost::random_device::result_type min(1); boost::random_device::result_type max(60); boost::random_device dev; } Thanks for help.

2 1

[Fusion] The real, real basics!
by Robert Jones 07 Sep '10

07 Sep '10

Ok, I know this is going to be laughably simple, but I think I'm making a right hash of it... For the cerebrally challenged, how do you write the specification of a function which takes any fusion vector, but only a fusion vector, as a parameter? Thx - Rob.

2 2

[Boost.Test] TestDox output format
by Martin Moene 07 Sep '10

07 Sep '10

Dear Gennadiy and other readers, Recently I've been looking around for TestDox support for various programming languages and testing frameworks (http://en.wikipedia.org/wiki/TestDox) TestDox provides an agile way to document a project's evolving design and code by giving an overview of the suite names and test names (with test success or failure) as sentences as in: prompt>main.exe --log_level=all Running 4 test cases... example [x] Passing test reports x [ ] Failing test reports space [ ] Throwing test reports space MySuite [x] Passing test in my suite reports x *** 2 failures detected in test suite "example" To learn how this may work out under Boost.Test, I transformed the compiler_log_formatter into a simple testdox_log_formatter, see http://www.eld.leidenuniv.nl/~moene/Home/projects/testdox/. Now my question is: Would it be worthwile to add a testdox_log_formatter to the Boost.Test library itself? Best regards, Martin

1 0

looking for some help to find some functionality
by Jeff T 07 Sep '10

07 Sep '10

Dear All, I'm new to boost, and trying to use it in an on-going development. I'm looking for some functionality but I was not able to find them in boost. I appreciate your help, comments, and suggestions. Functionality I'm looking for: 1. A way determine whether a value is not a number (eg. System.Double.IsNaN(double) in C#) 2. A way to determine if a number if infinity (eg. System.Double.IsInfinity(double) in C#) 3. Availability of Normal Density Function, Cumulative Normal Density Function, and Inverse Cumulative Normal Density. Thank you. Jeff

4 4

thread mutex problem
by Kraus Philipp 07 Sep '10

07 Sep '10

Hi, I'm new with boost thread, I have some problems. I have got two methods, one for writing and one for reading my data and I would do this thread-safe. I have tried to do this with boost::unique_lock<boost::shared_mutex> lock(...), but I have created a deadlock. For example my methods are called within the threads and set / get data to / from a ublas matrix. void setData( const size_t row, const size_t col, const size_t data) { (1*) _matrix(row, col) = data (2*) } and getData( const size_t row, const size_t col, size_t& a, size_t& b) { a = _matrix(row, col); b = _matrix(col, row); } How can I do both methods in the correct way thread-safe? By reading the matrix data the write method need not to change the values. I have created a unique lock on (1*) and do the unlock on (2*) but this creates the deadlock. Then I have tried it with a scoped_lock on (1*) but the data in the matrix is wrong. I hope that someone can explain me the correct solution. Thanks a lot Phil

3 2

[any] Is it possible to support polymorphism in boost::any?
by Tang Jiang Jun 07 Sep '10

07 Sep '10

Hello, It seems that boost::any does not support polymorphism in the following sample. class A {}; class B : public A {}; void foo( boost::any& _any ) { try { A* p = any_cast< A* >( _any ); <-- Only succeed when _any contain a pointer to a object that is exactly class A, but not any object that is descendant of class A, like B. do_some_thing( p ); } catch( const bad_any_cast& ) { } } void goo() { A* pa = new B; boost::any a = pa; foo( a ); } Is it possible to make it support this polymorphism usage? Because boost::any is a type-safe replacement of void*, I hope that boost::any has the same polymorphic behavior as void*. Regards, Tang Jiang Jun

5 9

How to store on exception object ?
by Timothy Madden 07 Sep '10

07 Sep '10

Hello In a callback function I need to store and save an exception object for until the callback is finished and the control is returned to my application code. The callback is invoked by the C language code in minizip library from zlib-1.2.3 contrib directory, and I need to throw the exception when control returns to my application invoking minizip functions. This is true for any exception that might get thrown and caught in my callback, so I would like to do that for any exception type. However how can I store a thrown object for later re-throw without the actual exception type ? Is there a way to do that ? Thank you, Timothy Madden

6 14

Re: [Boost-users] [MSM] stack overflow happens when there is a false-guard anonymous transition
by Christophe Henry 06 Sep '10

06 Sep '10

Hi Michael, It's always nice to hear from you and have an interesting UML discussion with an expert! > I hope you are well. You know how I like to dig into this stuff... so > I'll give my thoughts. They are tainted by the the UML predecessor; > however, I think there is good logic and possibly even a specification > argument for my point of view. > > UML 2.2 Superstructure section 15.3.14 [Transition] provides the > associations for: > > trigger : Trigger[0..*] -- I am assuming that no trigger is what > you are referring to as > an anonymous transition. I don't see > that term used in current > specifications anymore. > > guard: Constraint[0..1] -- "A guard is a constraint that provides > a fine-grained control > over the firing of the transition. The > guard is evaluated > when an event occurrence is dispatched > by the state machine. > If the guard is true at that time, the > transition may be > enabled; otherwise, it is disabled. > Guards should be > pure expressions without side effects. > Guard expressions > with side effects are ill formed." > > > I would argue that the definition of the guard constraint requires that > the transition is evaluated when an event is dispatched and is only > evaluated once for that event. Because the transition is disabled if the > guard evaluates false, then the transition cannot be evaluated again > until another event is dispatched. I think your interpretation makes sense. Agreed. > I would also argue that the system is considered stable once evaluation > of an event begins. Guards are not allowed to cause side effects; > therefore, the 'state' of the system when evaluation begins should be > the same as when evaluation has completed if no transition is taken. Agreed again. > Personally, the least surprising thing (imnsho) would be that: > > 1. event is dispatched > 2. internal transitions are evaluated for current state > 3. external transitions are evaluated for current state > 4. hierarchy is followed up and 2/3 repeated > 5. if top is reached without satisfying event ... an error has > occurred and is acted upon as normal This is what is implemented for all events except for what the standard calls "Completion Events" (also called anonymous transitions in an UML book from the Booch/Rumbaugh collection). > I do not think whether a trigger is defined or not for a transition will > affect this behavior. Transitions without a trigger are simply > candidates for any event. The steps outlined above are those used for > transitions with triggers, no? I agree on the first part and disagree on the second. So, I took from the standard: "A completion transition is a transition originating from a state or an exit point but which does not have an explicit trigger, although it may have a guard defined. A completion transition is implicitly triggered by a completion event. In case of a leaf state, a completion event is generated once the entry actions and the internal activities (“do” activities) have been completed. If no actions or activities exist, the completion event is generated upon entering the state. If the state is a composite state or a submachine state, a completion event is generated if either the submachine or the contained region has reached a final state and the state’s internal activities have been completed. This event is the implicit trigger for a completion transition. The completion event is dispatched before any other events in the pool and has no associated parameters. For instance, a completion transition emanating from an orthogonal composite state will be taken automatically as soon as all the orthogonal regions have reached their final state. If multiple completion transitions are defined for a state, then they should have mutually exclusive guard conditions." So you are right and I should handle them like any other event. OTOH, the standard does not see them as a candidate for any event but as an implicit event which I have to trigger after the target state entry behavior. If a transition without an explicit trigger (event) is defined, it fires. And I should generate it only once, thus avoiding the overflow. What you suggest is a kind of an "any" take-all event, which I also find a good idea (I do not remember seeing it in the standard, but a good idea should be implemented if possible). The part of the standard which I find unpracticable is, if the guard rejects the completion event, how do we move out of this case? If I follow the standard, we would need to reenter a state, which means we would need a dummy event (not nice). This is why I suggest a process_completion() which would simply resend a completion event. Ok? Thanks for your (as usual) helpful insights, Christophe PS: reading again, I see that there is another implementation error in the current implementation, completion events have a lower priority than the event queue, I will change this on the way too.

2 1

[asio] Close file descriptors on exec.
by Rok Breulj 06 Sep '10

06 Sep '10

Why does boost.asio not set its file descriptors to close on exec? (in 1.42, but didn't see any changelogs or tickets mentioning it).

1 0

[MSM] stack overflow happens when there is afalse-guard anonymous transition
by Christophe Henry 06 Sep '10

06 Sep '10

>When start() got called in main(), it will enter a endless reentering between state_machine::process_event() and >state_machine::handle_eventless_transitions_helper::process_completion_event(). Finally it caused a stack overflow. > > >Could somebody please help me to fix this problem? I just committed a tentative fix into the trunk: - completion events are only tried if the previous transition was successful. This should prevent the overflow and some border cases. - calling fsm.process_completion() will retry the completion event if the guard returned false. The event is sent only once for every call of process_completion() - the completion events are, standard conforming, tried before the event queues If it works and we all agree this is the right solution, I will keep it. Thanks, Christophe

1 0

A question about "prim_minimum_spanning_tree.hpp"
by 王伟 06 Sep '10

06 Sep '10

Hi, I'm studying MST algorithms in GPU recently.I need BGL implementation as coparison,But I have a problem in using prim_minimum_spanning_tree.hpp.The problem is:when I use large input(e.g. >1M),there's a "segmnetation error" problem.But when the input(e.g. 1K) is small,the result is noproblem. I haven't found know the reason yet.My complier is gcc 4.1.2,OS is RHEL5. Help would be appreciated. Thanks in advance. Wang wei The complete code is in the attachment.

3 4

[MSM] stack overflow happens when there is afalse-guard anonymous transition
by Christophe Henry 06 Sep '10

06 Sep '10

<snip> >When start() got called in main(), it will enter a endless reentering between state_machine::process_event() and >state_machine::handle_eventless_transitions_helper::process_completion_event(). Finally it caused a stack overflow. > > >Could somebody please help me to fix this problem? Hi, The problem is that UML does not specify how often an anonymous transition should be "tried" and I probably chose the wrong solution (to try again and again). So, as your guard always returns false, msm keeps trying, which means calls to process_event() until the stack overflows. The solution probably is to try just once but it will force you to manually try to reprocess by calling, say a process() function without event, but it arguably simply means passing the buck to you. Please let me think about it a bit more, I'd like to think this out a bit more. For the moment, I suggest you to either write a useful guard or revert to a named event, which you will process when it makes sense in your application. Regards, Christophe

2 1

How to work with large files in boost ?
by Timothy Madden 06 Sep '10

06 Sep '10

Hello Can I open and work with 64bit files (over 2Gb) in boost ? I see iostreams library has a stream<file_descriptor>off_type of long, which is 32 bit ... Thank you, Timothy Madden

1 0

Can I create and open a file only if it does not exist ?
by Timothy Madden 05 Sep '10

05 Sep '10

Hello I see file_descriptor_sink uses the openmode flags from std::ios_base, and also file class actually calls the open function standard C++ basic_filebuf. I would like to open a temporary file (generated with unique_path) only if it does not exist, as if by POSIX open() with O_CREAT | E_EXCL, and no combination of ios_base::openmode flags allows for that. Is there a way in boost to create and open a file only if it does not exist ? Thank you, Timothy Madden

1 0

combining mpl sequences
by Karsten Ahnert 05 Sep '10

05 Sep '10

Hi, I have a templatized mpl-vector template< class T > class containers : public mpl::vector< std::vector< T > , std::list< T > , std::deque< T > > { }; and a mpl-vector holding some types: typedef mpl::vector< float , double , long double >::type my_types; Is there a simple way to build a mpl vector which contains the elements of the first vector with template arguments of the second vector, hence mpl:vector< std::vector< float > , std::vector< double > , std::vector< long double > , std::list< float > , std::list< double > , std::list< long double > , std::deque< float > , std::deque< double > , std::deque< long double > > I can do this manually with mpl::insert_range typedef mpl::insert_range< mpl::vector0<> , mpl::end< mpl::vector0<> >::type , containers< mpl::at< my_types , mpl::int_<0> >::type > >::type first; typedef mpl::insert_range< first , mpl::end< first >::type , containers< mpl::at< my_types , mpl::int_<1> >::type > >::type second; typedef mpl::insert_range< second , mpl::end< second >::type , containers< mpl::at< my_types , mpl::int_<2> >::type > >::type all_containers; But this way is not very elegant. Does some has any hints how to do this automatically? Best regards, Karsten

3 4

cstdint.hpp on MSVC inconsitency ?
by joel falcou 05 Sep '10

05 Sep '10

In cstdint.hpp, the logic is that , if sizeof(long) == 4 then int32_t = long elseif sizeof(int) == 4 then int32_t = int. However, boost::detail::int_least_helper assumes sizeof(long) > sizeof(int). The consequence is that int_t<32>::fast is not the same as int32_t on MSVC while MSVC always garantee that int == long. Is there any rationale we missed or should I try to fix that as it currently prevent nT2 from compiling on MSVC . Regards

2 1

Mingw: The input line is too long
by Joost Kraaijeveld 05 Sep '10

05 Sep '10

Hi, When I compile Boost i get the following error (for several libraries): F:\boost_1_42_0>"g++" "-Wl,--out-implib,bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\boost_serialization-mt-d.lib" -o "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\boost_serialization-mt-d.dll" -shared -Wl,--start-group "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_archive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_iarchive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_iserializer.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_oarchive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_oserializer.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_pointer_iserializer.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_pointer_oserializer.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_serializer_map.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_text_iprimitive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_text_oprimitive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_xml_archive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\binary_iarchive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\binary_oarchive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\extended_type_info.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\extended_type_info_typeid.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\extended_type_info_no_rtti.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\polymorphic_iarchive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\polymorphic_oarchive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\stl_port.o" "bin.v2\libs\se The input line is too long. "g++" "-Wl,--out-implib,bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\boost_serialization-mt-d.lib" -o "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\boost_serialization-mt-d.dll" -shared -Wl,--start-group "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_archive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_iarchive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_iserializer.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_oarchive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_oserializer.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_pointer_iserializer.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_pointer_oserializer.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_serializer_map.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_text_iprimitive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_text_oprimitive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\basic_xml_archive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\binary_iarchive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\binary_oarchive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\extended_type_info.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\extended_type_info_typeid.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\extended_type_info_no_rtti.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\polymorphic_iarchive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\polymorphic_oarchive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\stl_port.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\text_iarchive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\text_oarchive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\void_cast.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\archive_exception.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\xml_grammar.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\xml_iarchive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\xml_oarchive.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\xml_archive_exception.o" "bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\shared_ptr_helper.o" -Wl,-Bstatic -Wl,-Bdynamic -Wl,--end-group -g -mthreads ...failed gcc.link.dll bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\boost_serialization-mt-d.lib bin.v2\libs\serialization\build\gcc-mingw-4.5.0\debug\threading-multi\boost_serialization-mt-d.dll... I have tried to compile Boost in the directory "b" and/or with the options "--md5" and/or "--abbreviate-paths" but nothing helped. As mingw is advertised in the "Boost's additional test compilers include:" section I guess that i (in theory) should be possible to compile it. Does anyone hav any idea how to achieve this? How can I compile Boost 1.42 using Mingw both static AND dynamic? TIA -- Groeten, Joost Kraaijeveld Askesis B.V. Molukkenstraat 14 6524NB Nijmegen tel: 024-3888063 / 06-51855277 fax: 024-3608416 web: www.askesis.nl

1 0

How to use %e for the format of time_input_facet?
by xiada74＠sina.com 05 Sep '10

05 Sep '10

I tried the below code:   #include <boost/date_time.hpp> #include <boost/date_time/posix_time/ptime.hpp> #include <iostream> using namespace boost::posix_time; int main() {     std::string _format1 = "%Y-%m-%d %H:%M:%S";     std::string _format2 = "%Y-%m-%e %H:%M:%S";     std::string teststring = "2010-09-10 10:01:01";     ptime time1, time2;     time_input_facet facet1(_format1, 1);     time_input_facet facet2(_format2, 1);     std::stringstream ss1(teststring);     std::stringstream ss2(teststring);     ss1.imbue(std::locale(ss1.getloc(), &facet1));     ss1 >> time1;     ss2.imbue(std::locale(ss2.getloc(), &facet2));     ss2 >> time2;     std::cout << "Time1: " << time1 << std::endl;     std::cout << "Time2: " << time2 << std::endl;     return 0; } The output is:   Time1: 2010-Sep-10 10:01:01 Time2: not-a-date-time Who can help to fix the issue for the format using "%e"?   Thanks in advance!

1 0

Boilerplate generated code
by Ryan McConnehey 05 Sep '10

05 Sep '10

I have a class that mostly remains the same except for the variables and functions to retrieve the variables. I've looked at boost preprocessor and it seems more designed to create classes that have a fixed number of variables but different defaults. Could any of the boost libraries turn the included class into boilerplate code that allows an arbitrary number of variables? The example below only has three variables but I could have used any number. Ryan //Minimal detail. Not complete class struct Arguments { Arguments(void) { xxx = false; yyy = 3; zzz = 4530; } bool operator== (Arugments const& rhs) { return ( (xxx == rhs.xxx) && (yyy == rhs.yyy) && (zzz == rhs.zzz)); } bool getXXX(void) const { return xxx; } int getYYY(void) const { return yyy; } long getZZZ(void) const { return zzz; } bool xxx; int yyy; long zzz; }; //Would like to be able to call it instead something like this Create( Arguments, //Class name ((bool, xxx, getXXX, false), (int, yyy, getYYY, 3), (long, zzz, getZZZ, 4530)));

2 3

How to disable the check or the error after checking for ICU (for regex lib) when building boost ?
by Timothy Madden 05 Sep '10

05 Sep '10

Hello I get the following message when compiling boost from trunk: 1>Building the Boost C++ Libraries. 1>has_icu_test.cpp 1>libs\regex\build\has_icu_test.cpp(12) : fatal error C1083: Cannot open include file: 'unicode/uversion.h': No such file or directory 1>Performing configuration checks 1> - has_icu builds : no Although the build succeeds (as this is a test) Visual Studio recognizes the error in the output and stops compiling the project and reports the build as failed. Is there a way for me to suppress this message ? Or this test ? Attempting to redirect output with &>outfile.txt do not work as the error messages still gets output in VS. Are there and build options to disable this check ? Thank you, Timothy Madden

5 17

boost interprocess library and concurrency
by Shane Miller 04 Sep '10

04 Sep '10

Hi, After reading through the BOOST interprocess library documentation I cannot workout whether - its STL set/hash/vector containers are multi-threaded safe. (Seeming, no, is the answer) - if a program cores in the middle of write operation to a STL container in shared memory then clearly the container is in an undefined state. Locks might be left locked (if this BOOST library uses locks say in a STL set or hash map insert/update). Now what? We just throw away the shared memory segment and start again? Has anybody solved these issues using CAS, transactions, or some other lock free solution? - aside from these issues, suppose one allocates a 2GB shared memory segment and all 2GB is used by a STL set. Does this BOOST interprocess library support adding more shared memory segments so this STL set can grow larger? Does doing so require relocating it which is a slow operation? What are the details here. I am looking for a crash recoverable, concurrent shared memory implementation of STL. Mainly I have a cache of items that will be read-intensive with some periodic updates and insertions throughout the day. Key-value pairs won't work; it must operate on pointers to C++ structs. Shane

2 1

Run all Boost.Test cases simulteniously
by Gaurav N Shah 04 Sep '10

04 Sep '10

Hi, As far as I know, boost::test behaior is to execute each test case by the sequence those are added. However, I want to execute all test cases simulteniously. Is there any way for it? This communication is for informational purposes only. It is not intended as an offer or solicitation for the purchase or sale of any financial instrument or as an official confirmation of any transaction. All market prices, data and other information are not warranted as to completeness or accuracy and are subject to change without notice. Any comments or statements made herein do not necessarily reflect those of JPMorgan Chase & Co., its subsidiaries and affiliates. This transmission may contain information that is privileged, confidential, legally privileged, and/or exempt from disclosure under applicable law. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or use of the information contained herein (including any reliance thereon) is STRICTLY PROHIBITED. Although this transmission and any attachments are believed to be free of any virus or other defect that might affect any computer system into which it is received and opened, it is the responsibility of the recipient to ensure that it is virus free and no responsibility is accepted by JPMorgan Chase & Co., its subsidiaries and affiliates, as applicable, for any loss or damage arising in any way from its use. If you received this transmission in error, please immediately contact the sender and destroy the material in its entirety, whether in electronic or hard copy format. Thank you. Please refer to http://www.jpmorgan.com/pages/disclosures for disclosures relating to European legal entities.

3 2

[MSM] stack overflow happens when there is a false-guard anonymous transition
by Tang Jiang Jun 04 Sep '10

04 Sep '10

Hello guys, I met a stack overflow crash in the following MSM sample (boost 1.44). struct Some_Event {}; struct State0 : public msm::front::state<> {}; struct State1 : public msm::front::state<> {}; struct State2 : public msm::front::state<> {}; struct State_Machine_ : public msm::front::state_machine_def< State_Machine_ > { typedef State0 initial_state; template< typename Event > bool is_possible( const Event& ) { return false; } struct transition_table : public mpl::vector< _row< State0, Some_Event, State1 >, g_row< State0, msm::front::none, State2, &State_Machine_::is_possible > > {}; }; struct State_Machine : public msm::back::state_machine< State_Machine_ > {}; void main() { State_Machine state_machine; state_machine.start(); state_machine.process_event( Some_Event() ); } When start() got called in main(), it will enter a endless reentering between state_machine::process_event() and state_machine::handle_eventless_transitions_helper::process_completion_event(). Finally it caused a stack overflow. Could somebody please help me to fix this problem? Many thanks! Regards, Tang

1 0

Using subscript operator with interprocess map
by Michi Mutsuzaki 04 Sep '10

04 Sep '10

Hello, I'm using a map from basic_string to int on managed_mapped_file (boost 1.35.0). Everything works except that I get a compilation error if I use subscript operator. I'm trying something like this: #include <boost/interprocess/managed_mapped_file.hpp> #include <boost/interprocess/containers/map.hpp> #include <boost/interprocess/containers/string.hpp> #include <boost/interprocess/allocators/allocator.hpp> namespace bi = boost::interprocess; typedef bi::allocator<char, bi::managed_mapped_file::segment_manager> char_alloc; typedef bi::basic_string<char, std::char_traits<char>, char_alloc> char_string; typedef std::pair<const char_string, int> ValueType; typedef bi::allocator<ValueType, bi::managed_mapped_file::segment_manager> map_alloc; typedef bi::map<char_string, int, std::less<char_string>, map_alloc> MyMap; int main () { bi::managed_mapped_file segment(bi::open_or_create, "/tmp/test", 65536); map_alloc alloc_inst (segment.get_segment_manager()); MyMap *mymap = segment.find_or_construct<MyMap>("MyMap") (std::less<bi::string>(), alloc_inst); (*mymap)[char_string("key")] = 1; return 0; } What am I doing wrong? Thanks! --Michi

2 1

[BGL] Can't set non-const edge_descriptor = const edge_descriptor
by John Robertson 04 Sep '10

04 Sep '10

I have struct edge_properties { Traits::edge_descriptor ePredecessor; } some_function ( const Graph g ) { e = edge(vertex_a, vertex_b, g).first; //fails here g[e].ePredecessor = e; } compiler gives ./Includes/Utilities.cpp:451: error: passing ‘const boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int>’ as ‘this’ argument of ‘boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int>& boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int>::operator=(const boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int>&)’ discards qualifiers make: *** [pl] Error 1 My guess is that e is returned as a const but g[e].ePredecessor is declared a variable. How can I fix this? Thanks John

2 1

Understanding of Boost License
by Ronghui Yu 03 Sep '10

03 Sep '10

Hi, All, If I have a software developed based on Boost library, does it mean I have to open source this software? Thanks in advance -- =========================== Regards Ronghui Yu

2 1

[filesystem] v3 recursive_directory_iterator does not enumerate entries
by Timothy Madden 03 Sep '10

03 Sep '10

Hello I use recursive_directory_iterator in my project and the dereference operarator on the iterator object always returns the the base directory that I am iterating over, and not the directory entries, each one in turn. Am I doing something wrong ? int iLevel = -1; // loop over and copy each file from the source directory for ( recursive_directory_iterator it(tmpName); it != recursive_directory_iterator(); it++ ) { //if (it.level() != iLevel) if (true) { // recursion just entered a new directory, create it #ifdef _DEBUG boost::filesystem::path dir_entry(*it); cout << "Entry: " << dir_entry << endl; cout << "\tas:"; for ( boost::filesystem::path::iterator p_it = dir_entry.begin(); p_it != dir_entry.end(); p_it++ ) { if (p_it != dir_entry.begin()) cout << "/"; cout << *p_it; } cout << endl; #endif iLevel = it.level(); } } Thank you, Timothy Madden

1 0

Is there a way for a library to add symbols to the standard headers ?
by Timothy Madden 03 Sep '10

03 Sep '10

Hello To write a library to add a POSIX emulation layer on Windows, is there a way to add symbols from my library to C/C++ standard library headers, without getting into recursive inclusion ? For example, is there a way to get the 'Additions to fstream' from the boost::filesystem library, actually look like they are added to the standard <fstream> header ? I know users can use #include "cstdio" (with quotes instead of brackets) throughout a project, in order to later be able to include some local version of the header, if the need for it arise during during some porting at a later time for example. However this works for user-level code, while for a library it is not that simple any more ... Thank you, Timothy Madden

5 7

gcc refuses to compile Boost.Extension example
by René Tschirley 03 Sep '10

03 Sep '10

Dear Boost experts, I struggle to get Jeremy Pack's Boost.Extension going. I want to use the platform independent way to explicitly load shared libraries. Starting with the tutorial, it took me some time to find this out: boost::extensions::shared_library lib("mylib.dll"); boost::function<void (int)> fun1(lib.get<void, int>("DoSomething")); works, but boost::function<void (void)> fun2(lib.get<void, void>("DoSomething")); does not work as the compiler (Eclipse CDT Helios using gcc 4.4.0 on Windows with MinGW) complains: somefile.cpp:74: error: no matching function for call to 'boost::extensions::shared_library::get(const char [12])' I'm a bit confused. Am I blind? Is this a bug? Weird feature? User-too-dumb-error? Sincerely, Rene

2 2

BOOST_IS_MPI_DATATYPE macro and std::vector
by Prevrhal, Sven 03 Sep '10

03 Sep '10

I have a class whose data I want to send/recv and which are of type std::vector. However, once it's allocated the size of this vector is fixed during runtime. Can I use BOOST_IS_MPI_DATATYPE to speed up data transfer and how would I do it? Thanks, Sven ________________________________ The information contained in this message may be confidential and legally protected under applicable law. The message is intended solely for the addressee(s). If you are not the intended recipient, you are hereby notified that any use, forwarding, dissemination, or reproduction of this message is strictly prohibited and may be unlawful. If you are not the intended recipient, please contact the sender by return e-mail and destroy all copies of the original message.

2 1

boost::shared_ptr vs std::shared_ptr
by Raindog 03 Sep '10

03 Sep '10

I was just watching the video here: http://channel9.msdn.com/shows/Going+Deep/C9-Lectures-Stephan-T-Lavavej-Sta… And was wondering if anyone had written up a brief guide about the differences between boost::shared_ptr and std::shared_ptr.

1 0

treat a range of ranges as a single range?
by Nathan Ridge 03 Sep '10

03 Sep '10

Hello, Is it possible, using the facilities in Boost.Range, to treat a range whose elements are themselves ranges, as a range whose elements are the elements of the component ranges? For example, I would like to treat a range of strings as a range of characters. A detokenizer in essence. Thanks, Nate.

1 0

replace_range already declared in this scope?
by Nathan Ridge 03 Sep '10

03 Sep '10

Hello, It seems the following two headers do not play nicely with each other: #include <boost/algorithm/string.hpp> #include <boost/range/adaptors.hpp> When both are included in a source file, I get the error: boost/range/adaptor/replaced.hpp:102: error: ‘replace_range’ is already declared in this scope Removing either of the headers fixes the problem, but I cannot do that since I need functionality from both. What can I do to fix this? I am using Boost 1.43. Thanks, Nate.

1 0

Re: [Boost-users] Problem using serialization::xml_archive with polymrphic classes
by przemyslaw.sliwa＠uk.bnpparibas.com 03 Sep '10

03 Sep '10

Hello, thanks for help with this. This has fixed the problem. However, I have got a much more complicated example which fails. I have a simple inheritance structure with 4 classes, they derive a->b->c->d nothing complex. say a is the mose base and d is the most derived class, Each class has got a virtual destructor. I can easily serialize object of type d but I cannot do this with a pointer to a this class. Basicaly invoking in the code std::vector<b*> tmpCcys; ar & boost::serialization::make_nvp("currencyEvents", tmpCcys); does not work at all! I can get to the point // retrieve the true type of the object pointed to // if this assertion fails its an error in this library assert(NULL != this_type); const boost::serialization::extended_type_info * true_type = i.get_derived_extended_type_info(t); // note:if this exception is thrown, be sure that derived pointer // is either registered or exported. if(NULL == true_type){ boost::serialization::throw_exception( archive_exception( archive_exception::unregistered_class, true_type->get_debug_info() ) ); } in the oserializer.hpp where each element of the vector is dumped to the archive but call to i.get_derived_extended_type_info(t) throws an exception of an unknown type. It is not archive or event std::exception onlt catch(...) {...} can handle it and therefore it is not possible to see what is going on. The data under t looks fine but const extended_type_info * get_derived_extended_type_info(const T & t) const { // note: this implementation - based on usage of typeid (rtti) // only does something if the class has at least one virtual function. BOOST_STATIC_WARNING(boost::is_polymorphic<T>::value); return typeid_system::extended_type_info_typeid_0::get_extended_type_info( typeid(t) ); } simply throws something which is not possible to handle correctly. I cannot step into typeid(t) on windows and VC++2005. As mentioned i have no problems at all with serializing object. Serializing pointers deos not work att all! I am exporting the class using BOOST_CLASS_EXPORT_GUID(d, "CurrencyEvent") I have to mention that the most base class is a template and I export it as well using BOOST_CLASS_EXPORT_GUID(a<Currency>, "EventCurrency") BOOST_CLASS_EXPORT_GUID(a<CurrencyCouple>, "EventCurrencyCouple") similar BOOST_CLASS_EXPORT_GUID(b, "BaseCurrencyEvent") BOOST_CLASS_EXPORT_GUID(c, "RealCurrencyEvent") the classes a,b,c and d are within a namespace Events and defined/declared within a dll but this should not be a problem at all since I can serialize objects of the most derived class. Could someone help me with this issue? Thanks a lot in advance ___________________________________________________________ This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and delete this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is prohibited. Please refer to http://www.bnpparibas.co.uk/en/information/legal_information.asp?Code=ECAS-… for additional disclosures.

2 1

[Test] BOOST_*_EQUAL_COLLECTIONS ostream problem
by Thomas Suckow 02 Sep '10

02 Sep '10

I am attempting to compare two std::map<string,string> objects in Boost.Test but am finding that it is trying to stream the std::pair< const string, string > that results from dereferencing the iterator. /* Simplified Example */ AUTO_TEST_CASE( Map_Same ) { std::map< std::string, std::string > x; std::map< std::string, std::string > y; BOOST_CHECK_EQUAL_COLLECTIONS( x.begin(), x.end(), y.begin(), y.end() ); } Results in: /usr/include/boost/test/utils/wrap_stringstream.hpp: In function 'boost::basic_wrap_stringstream<CharT>& boost::operator<<(boost::basic_wrap_stringstream<CharT>&, const T&) [with CharT = char, T = std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >]': /usr/include/boost/test/test_tools.hpp:641: instantiated from 'boost::test_tools::predicate_result boost::test_tools::tt_detail::equal_coll_impl(Left, Left, Right, Right) [with Left = std::_Rb_tree_iterator<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, Right = std::_Rb_tree_iterator<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >]' In my application the values a particular entry in the map will not reveal the problem, so I chose to suppress printing of the pair: typedef std::pair< const std::basic_string<char>,std::basic_string<char> > pair_type; BOOST_TEST_DONT_PRINT_LOG_VALUE( pair_type ); But alas, this did absolutely nothing. Confused, I tried: BOOST_CHECK_EQUAL( *x.begin(), *y.begin() ); And it compiled. Remove the suppression and the error returns. So the suppression works, just not in conjunction with BOOST_*_EQUAL_COLLECTIONS. Searching the mailing list revealed a post from 2005. http://article.gmane.org/gmane.comp.lib.boost.user/13146 He mentions as I also found that equal_coll_impl uses the stream operator directly on the dereferenced iterators. This *appears* to be bypassing the code that allows suppression. Though I may be wrong (I can rarely tell with boost). Can someone check on this and see if I am crazy? In the mean time I guess I just have to overload the stream operator. Regards, Thomas Suckow

1 0

Re: [Boost-users] Problem using serialization::xml_archive withpolymrphic classes
by przemyslaw.sliwa＠uk.bnpparibas.com 02 Sep '10

02 Sep '10

Thanks for reply, All classes a, b, c and d are actually defined within one dll (one module). I forgot to mention it. I can do this following thing: d* pD = mew d(); and then ar & boost::serialization::make_nvp("item", pD); but c* pD = new D(); ar & boost::serialization::make_nvp("item", pD); does not work at all! It throws this strange type of exceptions which I cannot handle at all. Another problem is that if I do the first version the member m_key variable of true_type in the call const boost::serialization::extended_type_info * true_type = i.get_derived_extended_type_info(t); is a null pointer which is not right. Do you have any idea what could be wrong? Thanks a lot for help ___________________________________________________________ This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and delete this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is prohibited. Please refer to http://www.bnpparibas.co.uk/en/information/legal_information.asp?Code=ECAS-… for additional disclosures.

2 1

Boost.Functional/Hash
by Andrej van der Zee 02 Sep '10

02 Sep '10

Hi, I have a question that I hope can be answered by using Boost. I have the following datastructure: struct ip_info { const u_int8_t _ifile_index; const unsigned long _src_ip; const unsigned long _dst_ip; const u_int16_t _id; const u_int16_t _length; const u_int16_t _src_port; const u_int16_t _dst_port; const u_int32_t _seq; const u_int32_t _ack_seq; }; The object is identified by all its members. Now I want to count duplicates. But I have MANY of these objects, I mean billions. I have to reduce the memory footprint of my program, because it soon grows over 4GB and boom! So I rather not keep all the objects in memory and why would I, because I do not need them. I just need to count duplicates. My idea was to hash such objects to a smaller values and use that hash value as key_type in a map. The value_type of the map would be an integer. This something like std::map<int32_t, u_int16_t> or something. Then I though maybe use Boost.Functional/Hash, but are there any guarantees that the hash value is unique? How unique are they? Are there better alternatives? Thank you, Andrej

4 3

[BGL] Using pointers as indexes in graphs
by Bruno Barberi Gnecco 02 Sep '10

02 Sep '10

Hi, I want to store pointers in a graph. Can I somehow use their pointers as indexes? Here's the code I'm trying to execute. It does not work correctly, however; apparently graph add other nodes in the vector storage (to fill the holes?). I suppose I could use listS instead of vecS, but then I can't get the topological_sort code to work (I know I have to provide some form of indices, but I don't understand how to do that). Any suggestions to solve this? Thanks! #include <iostream> #include <boost/graph/graph_traits.hpp> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/topological_sort.hpp> class Plugin { public: // some data here int x; Plugin(int a) : x(a) {} }; typedef std::list< std::pair<Plugin *, Plugin *> > EdgeList; typedef boost::adjacency_list<boost::setS, boost::vecS, boost::directedS, Plugin *> PipelineGraph; typedef boost::graph_traits<PipelineGraph>::vertex_descriptor PipelineVertex; void graph(EdgeList edges) { PipelineGraph graph; for (EdgeList::iterator it(edges.begin()); it != edges.end(); it++) { PipelineVertex a(boost::vertex(reinterpret_cast<unsigned long> (it->first), graph)); PipelineVertex b(boost::vertex(reinterpret_cast<unsigned long> (it->second), graph)); boost::add_edge(a, b, graph); } // sort by topology, so we run the plugins in the correct order std::vector<PipelineVertex> sorted; boost::topological_sort(graph, std::back_inserter(sorted)); std::cout << sorted.size() << std::endl; // REVERSE topological order std::vector<PipelineVertex> vl(sorted.rbegin(), sorted.rend()); // loop for (std::vector<PipelineVertex>::iterator it(vl.begin()); it != vl.end(); it++) { Plugin *p = reinterpret_cast<Plugin *>(*it); std::cout << p->x << std::endl; } } int main() { EdgeList edges; Plugin *a = new Plugin(1); Plugin *b = new Plugin(2); Plugin *c = new Plugin(3); Plugin *d = new Plugin(4); edges.push_back(std::pair<Plugin*, Plugin*>(a, b)); edges.push_back(std::pair<Plugin*, Plugin*>(b, c)); edges.push_back(std::pair<Plugin*, Plugin*>(b, d)); graph(edges); return 0; }

2 3

how to get std::min_element() working with boost::multi_array?
by Valmor de Almeida 02 Sep '10

02 Sep '10

Hello, Could someone help getting std::min_element() (or a variation of) to work with multi_array? boost::multi_array<int, 2> A; // code for dimensioning A and filling in; deleted cout << *min_element(A.begin(),A.end()) << endl; Thanks, -- Valmor

1 1

Looking for Halfedge or other topologic representation library
by Lang Stefan 02 Sep '10

02 Sep '10

Hello everyone, While looking for an existing implementation of halfedge data structures or similar topological representations of 2-dimensional manifolds I found one article pointing to boost:graph. I've checked the documentation, but it seem that this library is way to generic/abstract for my purpose, and yet seems to miss a number of important functions that probably only make sense when working with a topological representation of a two-dimensional oriented manifold. Conceptually, Half-edge data structures would fit my needs very well, and I've found several sites with half-done or half-documented implemetations. But those that actually had code were either too specific to be useful for my purposes, or half of the site couldn't be retrieved, probably because the relevant pages are no longer hosted. So I was wondering, if there is, maybe, another library within boost that is dealing more with the topological aspect of graphs, whether or not based on boost::graph? What I am looking for is a topological framework for oriented surfaces that lets me retrieve adjacency information regarding faces, edges and vertices, disregardful of whether or not the set of surfaces represent the full surface of a 3D object or just a part of it. I also need to directly navigate between the objects defining the actual 3D points, curves, and surfaces, and the corresponding topological objects. But that, I hope, is just a minor detail. I suspect it won't be so hard to implement myself, but building on a well-designed library is so much less error prone... Cheers, Stefan

3 2

Re: [Boost-users] does pool::release_memory() really require an ordered
by Lang Stefan 02 Sep '10

02 Sep '10

-----Ursprüngliche Nachricht----- Message: 5 Date: Wed, 1 Sep 2010 17:32:46 -0400 From: Mark Rajcok <mrajcok(a)gmail.com> To: boost-users(a)lists.boost.org Subject: [Boost-users] does pool::release_memory() really require an ordered pool? Message-ID: <AANLkTim0t9KTDJowTbn2viBu+RSTqnwfKA1c7qRbv_X2(a)mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 On page http://www.boost.org/doc/libs/1_44_0/libs/pool/doc/interfaces/pool.html there is this precondition for release_memory(): "t must be ordered". Does that mean that ordered_malloc() must always be used, if I want to use release_memory()? Looking at the implementation for release_memory(), it appears to be iterating through chunks in each block, which I wouldn't expect if ordered_malloc() were always used. What I'm really after: I want to use object_pool, but periodically I'd like to reclaim/release any memory blocks that are no longer in use. In my application, I may have traffic spikes, where I allocate a lot of memory, but then later (after spiking) I'd like to release it. (The object pools will persist for the life of the application, and there will probably always be some "active objects" -- i.e., allocated from the pool and not free()d yet.) (I'm hoping the documentation may be out of date, and release_memory() can be used on pools that don't use ordered_malloc() and on object_pools.) -- Mark ------------------------------ Mark, I cannot check the repository right now, but last time I did there were no changes to the version of boost::pool since I last tried to work with it, about three years ago. Back then I found that memory wasn't released at all due to a relevant part of the code being commented out. But even uncommenting it didn't help all that much: just like you, I found that the effort of releasing a single object was, essentially, proportional to the size of the pool, at best at an order of O(log(N)), maybe even worse. So just using standard new and delete operators would at some point outperform this pool implementation! I've done my own implementation in the meantime, with all operations at constant time, and using shared pointers to objects from the pool, which would make sure unused memory blocks can be released ASAP. Never got around to actually use it though, so I cannot say for sure if it has errors still. The tests and benchmarks I ran did look rather good, but I found that using malloc/free instead of new/delete got me about the same performance boost, which is why I ultimately discarded it. (malloc and free were already being used anyway, not that I was happy with it. But unfortunately I ran out of arguments to replace them...) Cheers, Stefan

1 0

[BGL] Segmentation fault in clear_vertex
by Daniel Trebbien 02 Sep '10

02 Sep '10

I am attempting to modify my implementation of the Stoer–Wagner min-cut algorithm to modify the input graph. In the code sample below, t and s are vertex_descriptors that were calculated by a call to boost::detail::stoer_wagner_phase: boost::tie(s, t, w) = boost::detail::stoer_wagner_phase(g, assignments, weights, pq); assert(s != t); // ... std::multimap<vertex_descriptor, edge_descriptor> sOutEdges; BGL_FORALL_OUTEDGES_T(s, e, g, UndirectedGraph) { const vertex_descriptor u = target(e, g); if (t != u) { sOutEdges.insert(std::make_pair(u, e)); } } BGL_FORALL_OUTEDGES_T(t, e, g, UndirectedGraph) { const vertex_descriptor u = target(e, g); const weight_type eWeight = get(weights, e); typename std::multimap<vertex_descriptor, edge_descriptor>::iterator sOutEdgesIt, sOutEdgesEnd; boost::tie(sOutEdgesIt, sOutEdgesEnd) = sOutEdges.equal_range(u); if (sOutEdgesIt != sOutEdgesEnd) { for(; sOutEdgesIt != sOutEdgesEnd; ++sOutEdgesIt) { put(weights, sOutEdgesIt->second, get(weights, sOutEdgesIt->second) + eWeight); } } else if (t != u) { // need to update e to set the source to s edge_descriptor ePrime; boost::tie(ePrime, boost::tuples::ignore) = add_edge(s, u, g); put(weights, ePrime, eWeight); } } clear_vertex(t, g); The segmentation fault occurs in the call to clear_vertex, but does not occur if I comment out the line that adds an edge to the graph g. The type of g, by the way, is: boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS, boost::no_property, boost::property<boost::edge_weight_t, int> > Why does adding an edge between vertices s and target(e, g), both of which are not equal to t, cause a segmentation fault? For reference, gdb says that the fault occurs on line 999 of boost/graph/detail/adjacency_list.hpp: // O(E/V * E/V) template <class Config> inline void clear_vertex(typename Config::vertex_descriptor u, undirected_graph_helper<Config>& g_) { typedef typename Config::global_edgelist_selector EdgeListS; BOOST_STATIC_ASSERT((!is_same<EdgeListS, vecS>::value)); typedef typename Config::graph_type graph_type; typedef typename Config::edge_parallel_category Cat; graph_type& g = static_cast<graph_type&>(g_); typename Config::OutEdgeList& el = g.out_edge_list(u); typename Config::OutEdgeList::iterator ei = el.begin(), ei_end = el.end(); for (; ei != ei_end; ++ei) { detail::erase_from_incidence_list (g.out_edge_list((*ei).get_target()), u, Cat()); g.m_edges.erase((*ei).get_iter()); *// line 999* } g.out_edge_list(u).clear(); } Program received signal SIGSEGV, Segmentation fault. std::_List_node_base::unhook (this=0x3d7a38) at ../../../../gcc-4.4.0/libstdc++-v3/src/list.cc:134 134 ../../../../gcc-4.4.0/libstdc++-v3/src/list.cc: No such file or director y. in ../../../../gcc-4.4.0/libstdc++-v3/src/list.cc (gdb) bt #0 std::_List_node_base::unhook (this=0x3d7a38) at ../../../../gcc-4.4.0/libstdc++-v3/src/list.cc:134 #1 0x0045fa26 in std::list<boost::list_edge<unsigned int, boost::property<boost ::edge_weight_t, int, boost::no_property> >, std::allocator<boost::list_edge<uns igned int, boost::property<boost::edge_weight_t, int, boost::no_property> > > >: :_M_erase (this=0x22fa9c, __position=...) at c:/mingw/bin/../lib/gcc/mingw32/4.4.0/include/c++/bits/stl_list.h:1424 #2 0x0045fa0c in std::list<boost::list_edge<unsigned int, boost::property<boost ::edge_weight_t, int, boost::no_property> >, std::allocator<boost::list_edge<uns igned int, boost::property<boost::edge_weight_t, int, boost::no_property> > > >: :erase (this=0x22fa9c, __position=...) at c:/mingw/bin/../lib/gcc/mingw32/4.4.0/include/c++/bits/list.tcc:111 #3 0x00413ec9 in boost::clear_vertex<boost::detail::adj_list_gen<boost::adjacen cy_list<boost::listS, boost::vecS, boost::undirectedS, boost::no_property, boost ::property<boost::edge_weight_t, int, boost::no_property>, boost::no_property, b oost::listS>, boost::vecS, boost::listS, boost::undirectedS, boost::no_property, boost::property<boost::edge_weight_t, int, boost::no_property>, boost::no_prope rty, boost::listS>::config> (u=5, g_=...) at c:/mingw/bin/../lib/gcc/mingw32/4.4.0/../../../../include/boost/graph/det ail/adjacency_list.hpp:999 #4 0x0041b0cc in boost::detail::stoer_wagner_min_cut<boost::adjacency_list<boos t::listS, boost::vecS, boost::undirectedS, boost::no_property, boost::property<b oost::edge_weight_t, int, boost::no_property>, boost::no_property, boost::listS> , boost::adj_list_edge_property_map<boost::undirected_tag, int, int&, unsigned i nt, boost::property<boost::edge_weight_t, int, boost::no_property>, boost::edge_ weight_t>, boost::associative_property_map<std::map<int, bool, std::less<int>, s td::allocator<std::pair<int const, bool> > > >, boost::shared_array_property_map <unsigned int, boost::vec_adj_list_vertex_id_map<boost::no_property, unsigned in t> >, boost::d_ary_heap_indirect<unsigned int, 4u, boost::shared_array_property_ map<unsigned int, boost::vec_adj_list_vertex_id_map<boost::no_property, unsigned int> >, boost::shared_array_property_map<int, boost::vec_adj_list_vertex_id_map <boost::no_property, unsigned int> >, std::greater<int>, std::vector<unsigned in t, std::allocator<unsigned int> > > > (g=..., weights=..., parities=..., assignments=..., pq=...) ...

1 1

does pool::release_memory() really require an ordered pool?
by Mark Rajcok 02 Sep '10

02 Sep '10

On page http://www.boost.org/doc/libs/1_44_0/libs/pool/doc/interfaces/pool.html there is this precondition for release_memory(): "t must be ordered". Does that mean that ordered_malloc() must always be used, if I want to use release_memory()? Looking at the implementation for release_memory(), it appears to be iterating through chunks in each block, which I wouldn't expect if ordered_malloc() were always used. What I'm really after: I want to use object_pool, but periodically I'd like to reclaim/release any memory blocks that are no longer in use. In my application, I may have traffic spikes, where I allocate a lot of memory, but then later (after spiking) I'd like to release it. (The object pools will persist for the life of the application, and there will probably always be some "active objects" -- i.e., allocated from the pool and not free()d yet.) (I'm hoping the documentation may be out of date, and release_memory() can be used on pools that don't use ordered_malloc() and on object_pools.) -- Mark

2 1

Struggling to implement bzip2 on windows
by Jared James Thompson 02 Sep '10

02 Sep '10

Hi All, I'm a VS2008 user, trying to use the ESBTL library for a project, which implements Boost to do many operations. ESBTL #includes <boost/iostreams/filter/bzip2.hpp>, which has been disabled for the Boostpro installation of windows. Quite simply, I'm struggling to get bzip2 installed and set up so that boost runs with bzip2 enabled. Has anybody done this before? Can anyone offer me more information than "compile from source?" best, Jared -- Jared James Thompson Department of Medicinal Chemistry and Molecular Pharmacology Laboratory for Computational Drug Design and Biology RHPH 504C Heine Pharmacy Building 575 Stadium Mall Drive West Lafayette, IN 47907-2091

3 3

lamba: QStringList <<
by Hicham Mouline 02 Sep '10

02 Sep '10

Hello, the following for_each call with _1 fails to compile #include <QStringList.h> #include <boost/lambda/lambda.hpp> using namespace boost::lambda; QStringList items_list; std::for_each(begin_items(),end_items(), items_list << _1 ); QStringList has these << operators defined: QStringList& operator<< ( const QString& str ); QStringList& operator<< ( const QStringList& other ); the type of item iterator returned by begin_items() is: const char* const* QString has a ctor: QString (const char * str) The compilation error is: error C2678: binary '<<' : no operator found which takes a left-hand operand of type 'const QStringList' (or there is no acceptable conversion) I don't see why it tries to find a << that takes a ***const*** QStringList left-hand operand? Regards,

2 1

Boost.Random and Dieharder et al.
by Patricia Hawley 02 Sep '10

02 Sep '10

Hi, I am working with a team developing some utilities for a simulation, and one of our requirements is to test the quality of the random generators. We based the utility on Boost.Random, but now have to show that that was a good decision. Has anyone verified the generators (e.g. Mersenne Twister or Linear Congruential ) in Boost.Random pass the Dieharder, Ent, and/or TestU01 suites? Any comments or suggestions on this are appreciated, Pat

2 1

Re: [Boost-users] Boost-users Digest, Vol 2466, Issue 3
by Clarke, Carus V 01 Sep '10

01 Sep '10

Steven Watanabe wrote: > AMDG > > Clarke, Carus V wrote: > >> It looks like stat is setting errno to ENOENT. > >> Do you get the same behavior if the file exists before > starting the > >> program? > > > > Yes, the behavior is the same whether the program writes > the file or if the file had been previously written. > > > > Okay. Try using stat directly, instead of using Boost.Filesystem. > If that works, then can you use a debugger to find exactly > what arguments Boost.Filesystem is passing to stat? > > In Christ, > Steven Watanabe > Actually, the Boost.Filesystem library for Boost 1.44 uses the Windows API GetFileAttributes functions for reading file status on Cygwin, and it was in calls to these functions that things were failing. Since my last post, the Cygwin developers have updated the base Cygwin system (to 1.7.7-1). Updating my Cygwin installation to the new version has fixed the problem. Apparently, the 1.7.6-1 version had some bugs that were inadvertently introduced in an attempt to improve Cygwin functionality. I do have a question that might be better asked in a new thread, but here it is. Why does the Boost.Filesystem library force the use of Windows-style paths for Cygwin? The Cygwin system prefers Posix or mixed paths with forward slashes as separators. The use of Win32 paths on Cygwin is now deprecated, and Cygwin actually issues a warning the first time it encounters a Windows-style path. See http://cygwin.com/cygwin-ug-net/using.html#using-pathnames for more information. The Cygwin GCC 4.3.4 compiler no longer supports the -mno-cygwin option that was supported under Cygwin 1.5 and earlier. This means that any application created with this compiler depends on the Cygwin dll. Also, Boost does not appear to have a Cygwin platform for regression testing. Would it help if I or someone else could set one up? Thanks for your help. Carus V. (Bud) Clarke carus.v.clarke(a)boeing.com

1 0

Problem using serialization::xml_archive with polymrphic classes
by przemyslaw.sliwa＠uk.bnpparibas.com 01 Sep '10

01 Sep '10

HelloHello, I have written code below and it works fine when using text archives. However, when I try to run it with the xml archives it is throwing a strange error saying "Invalid XML tag name". I have no idea what that means and could not find it in the documentation of the serialization library. Could someone tell me what I am doing wrong in this code? Thanks a lot for help! #include <boost/smart_ptr/shared_ptr.hpp> #include <boost/archive/xml_oarchive.hpp> #include <boost/archive/xml_iarchive.hpp> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/serialization/vector.hpp> #include <boost/serialization/string.hpp> #include <boost/serialization/shared_ptr.hpp> #include <boost/date_time/local_time/local_time.hpp> #include <boost/serialization/export.hpp> #include <iostream> using namespace boost; using namespace std; class Actor { public: Actor( void ) {} Actor( char gender ) : gender( gender ) {} virtual ~Actor() {} char Gender( void ) const { return gender; } private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & BOOST_SERIALIZATION_NVP(gender); } char gender; }; class Crit: public Actor { public: Crit( void ) {} Crit( int age ) : age( age ) { } int Age( void ) const { return age; } private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & BOOST_SERIALIZATION_NVP(boost::serialization::base_object< Actor >( *this )); ar & BOOST_SERIALIZATION_NVP(age); } int age; }; class Food: public Actor { public: Food( void ) {} Food( int energy ) : energy( energy ) { } int Energy( void ) const { return energy; } private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & BOOST_SERIALIZATION_NVP(boost::serialization::base_object< Actor >( *this )); ar & BOOST_SERIALIZATION_NVP(energy); } int energy; }; BOOST_CLASS_EXPORT_GUID( Actor, "Actor") BOOST_CLASS_EXPORT_GUID( Crit, "Crit") BOOST_CLASS_EXPORT_GUID( Food, "Food") template< typename T > void save( T& data, string filename ) { ofstream ofs( filename.c_str() ); boost::archive::xml_oarchive oa( ofs ); oa & BOOST_SERIALIZATION_NVP(data); } template< typename T > void load( T& data, string filename ) { ifstream ofs( filename.c_str() ); boost::archive::xml_iarchive ia( ofs ); ia & BOOST_SERIALIZATION_NVP(data); } void TestAlpha( void ) { shared_ptr< Crit > critAlpha( new Crit( 18 ) ); shared_ptr< Crit > critBravo( new Crit( 19 ) ); shared_ptr< Food > foodAlpha( new Food( 20 ) ); shared_ptr< Food > foodBravo( new Food( 21 ) ); vector< shared_ptr< Actor > > conAlpha; vector< shared_ptr< Actor > > conBravo; conAlpha.push_back( critAlpha ); conAlpha.push_back( foodAlpha ); // save string filename = "sav.sav"; save( conAlpha, filename ); // test assert( critBravo->Age() == 19 ); assert( foodBravo->Energy() == 21 ); // load load( conBravo, filename ); // test critBravo = dynamic_pointer_cast< Crit >( conBravo[ 0 ] ); assert( critBravo->Age() == 18 ); foodBravo = dynamic_pointer_cast< Food >( conBravo[ 1 ] ); assert( foodBravo->Energy() == 20 ); } int main() { try { TestAlpha(); } catch(boost::archive::archive_exception& e) { return -1; } return 0; } ___________________________________________________________ This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and delete this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is prohibited. Please refer to http://www.bnpparibas.co.uk/en/information/legal_information.asp?Code=ECAS-… for additional disclosures.

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mpl::set and mpl::fold
by Paul Graphov 01 Sep '10

01 Sep '10

Hello Boost Users, I've encountered a problem while using mpl::fold with mpl::set I've defined a template to check if one sequence contains all elements of the other: namespace mpl = boost::mpl; template<class A, class B> struct subset : mpl::fold< A, mpl::true_, mpl::and_<mpl::_1, mpl::contains<B, mpl::_2> > > {}; It works fine with lists and vectors but when first template parameter (A) is set or set_c it fails to compile. Did I miss something? Why is it impossible to iterate through a set via fold? p.s. tested on gcc and clang under linux. p.p.s. compilation error is quite huge, the main message is /usr/local/include/boost/mpl/eval_if.hpp:38: error: no type named ‘type’ in ‘struct boost::mpl::next<boost::mpl::s_iter<boost::mpl::set_c<int, 1l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l>, boost::mpl::set0_c<int> > >’

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[gil] bit_aligned_pixel_iterator
by Christian Henning 01 Sep '10

01 Sep '10

Hi there, I have a problem with extracting the correct values out of a 3bit gray image. The test code below displays my problem. Here, there is a vector of unsigned chars which create a particular bit pattern though all pixels in the image should have the same values. The bit pattern is: 1011 0110 0110 1101 1101 1011 0000 0000. On my machine ( x86 ) this should be read out in values of 110b ( which is 6 ) for all pixels. Instead my code reads out: 6, 6, 2, 6, 6, 0, 6, 6, 0. Here is the code: #include <cassert> #include <vector> #include <boost/gil/gil_all.hpp> using namespace std; using namespace boost; using namespace gil; int main() { typedef bit_aligned_image1_type< 3, gray_layout_t >::type gray3_image_t; typedef gray3_image_t image_t; typedef image_t::view_t view_t; typedef view_t::reference ref_t; typedef view_t::value_type pixel_t; typedef bit_aligned_pixel_iterator< ref_t > iterator_t; vector< unsigned char > buf( 4 ); buf[0] = 182; buf[1] = 109; buf[2] = 219; buf[3] = 0; iterator_t it( &buf[0], 0 ); ref_t p1 = *it; it++; ref_t p2 = *it; it++; ref_t p3 = *it; it++; ref_t p4 = *it; it++; ref_t p5 = *it; it++; ref_t p6 = *it; it++; ref_t p7 = *it; it++; ref_t p8 = *it; it++; ref_t p9 = *it; it++; unsigned char v1 = get_color( p1, gray_color_t() ); unsigned char v2 = get_color( p2, gray_color_t() ); unsigned char v3 = get_color( p3, gray_color_t() ); unsigned char v4 = get_color( p4, gray_color_t() ); unsigned char v5 = get_color( p5, gray_color_t() ); unsigned char v6 = get_color( p6, gray_color_t() ); unsigned char v7 = get_color( p7, gray_color_t() ); unsigned char v8 = get_color( p8, gray_color_t() ); unsigned char v9 = get_color( p9, gray_color_t() ); return 0; } The first two values are correct since they covered by the first byte. The third value doesn't seem to take in account the first bit of the second byte. I think this is incorrect. The stepping of the bits of by the iterator seems correct. Each value that is covered by one byte completely is correct but when a value is stretched over two bytes there seems to be a problem. Regards, Christian

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[type_traits]: is_boost_optional?
by Roland Bock 01 Sep '10

01 Sep '10

Hi, is there something in Boost.TypeTraits (or somewhere else) that allows me to check if a type is a boost::optional? I'd like to do something like this: template<typename T> typename enable_if<is_boost_optional<T> >, T::value_type>::type foo(const T&); Thanks and regards, Roland

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Boost.Filesystem: question about code conversion for char16_t with version 3
by Yasuhiro Hara 01 Sep '10

01 Sep '10

Hello, I am studying Boost.Filesystem version 3, but I got a couple of questions. I am wondering if someone helps me to understand version 3. I saw the reference document and path.hpp header file, I am not sure how to specify a code conversion API for char16_t or char32_t. It looks like only code conversion API between wchar_t and char can be specified. Since version 3 tries to support char16_t and char32_t, I am a little puzzled. I would appreciate if someone helps me to understand how I can use char16_t with version 3. Best regrads, /yasu

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compressed fusion::vector?
by Cory Nelson 01 Sep '10

01 Sep '10

Hello, Is there a compressed fusion::vector that minimizes the size if the types passed in are empty, like compressed_pair? Thanks! -- Cory Nelson http://int64.org

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[iostreams] filtering_ostream does not flush std::cout.
by Duncan Smith 01 Sep '10

01 Sep '10

I'm using Boost 1.43.0, and I've found that filtering_ostream does not flush "std::cout". I found a relevant (and recent) ticket against Boost 1.44.0, but my issue is slightly different. https://svn.boost.org/trac/boost/ticket/4590 I'm using GCC 4.3.4 on Gentoo Linux. I'm hoping that I'm just doing something wrong, but if you think there's a bug, I'll add my testcase to the ticket. The basic recipe: filtering_ostream out; out.push(any_filter_at_all()); out.push(std::cout); out << "Hello World!" << std::flush; sleep(10); // Observe an empty console. std::cout << std::flush; sleep(10); // Observe printed text on console. This problem is quite bad for me when doing the following on the command-line (for a more complicated program): ./program 2>&1 | tee some-file.log Because stdout is not getting flushed, the stdout and stderr get intermingled strangely. However, disabling buffering on stdout works around the problem: stdbuf --output=0 ./program 2>&1 | tee some-file.log Please tell me if you think there's a bug in my code. If it's a bug in Boost.Iostreams (or I'm expecting the wrong behaviour), I would appreciate any ideas for workarounds (I tried cout.setf(unitbuf), and that doesn't seem to do the trick). Here's the full text of my code: ------------------ // Test case for flushing a filtering_ostream based on the // boost_iostreams_filtering_ostream.cpp attached to ticket #4950: // https://svn.boost.org/trac/boost/ticket/4590 // https://svn.boost.org/trac/boost/attachment/ticket/4590/boost_iostreams_fil… // changed to use "cout" as the sink. // // Flushing a filtering_ostream using the flush() global function does not work // in Boost 1.43. I suspect it also does not work in Boost 1.44. // // Using GCC-4.3.4 on Gentoo Linux. // #include <cassert> #include <string> #include <boost/iostreams/categories.hpp> #include <boost/iostreams/operations.hpp> #include <boost/iostreams/filtering_stream.hpp> #include <iostream> // Included for "sleep()" call below. #include <unistd.h> namespace io = boost::iostreams; // Simple output filter forwarding just forwarding the put chars to // the sink. struct transparent_output_filter { typedef char char_type; typedef io::output_filter_tag category; template <typename Sink> bool put(Sink& snk, char c) { return io::put(snk, c); } }; int main(int argc, char *argv[]) { using namespace std; io::filtering_stream<io::output> out; // Transparent filter just forward the characters to the sink. // // Note: I observe this behaviour with and without this line. out.push(transparent_output_filter()); // Sink appends characters to "cout". out.push(cout); // Write test string to filtering_ostream. out << "Hello World!"; // On my system, this will flush the buffer iff I'm on an // interactive console. "\n" and endl have the same effect. I believe // that my shell sets "stdout" to be line-buffered if it's interactive. // out << "\n"; bool wasFlushed = false; // The flush does *not* work in Boost 1.43. wasFlushed = io::flush(out); // This assertion does not go off, though. assert(wasFlushed); // This also doesn't work. wasFlushed = out.flush(); assert(wasFlushed); // This also doesn't work. out << std::flush; // Demonstrate that none of the above flush calls had any effect on "cout". sleep(10); // Now we finally get the characters on the console. cout << flush; // Demonstrate that the direct flush call works when called directly on // "cout". sleep(10); return 0; }

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Can I use both filesystem versions v2 and v3 in a program ?
by Timothy Madden 01 Sep '10

01 Sep '10

Hello Can I include <boost/filesystem.hpp> but use the BOOST_FILESYSTEM_V... macro to include one version in on of my cpps and another version in another cpp ? Do both versions get compiled when boost is built ? Thank you, Timothy Madden

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Re: [Boost-users] Boost.Serialization: Restoringobjectstate(preventcreation of a new object)?
by ray＠maya-studio.com 01 Sep '10

01 Sep '10

I've ended up with the following solution: #include <fstream> #include <iostream> #include <boost/archive/xml_iarchive.hpp> #include <boost/archive/xml_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/archive/text_oarchive.hpp> #include <boost/serialization/export.hpp> #include <boost/foreach.hpp> #define _SERIALIZATION_FUNC(CLASS_NAME, ARCH_TYPE) \ public: \ virtual void Serialize(ARCH_TYPE& ar) \ { \ CLASS_NAME& x = *static_cast<CLASS_NAME*>(this); \ ar & BOOST_SERIALIZATION_NVP(x); \ } #define SERIALIZATION(CLASS_NAME) \ public: \ _SERIALIZATION_FUNC(CLASS_NAME, boost::archive::text_iarchive) \ _SERIALIZATION_FUNC(CLASS_NAME, boost::archive::text_oarchive) \ _SERIALIZATION_FUNC(CLASS_NAME, boost::archive::xml_iarchive) \ _SERIALIZATION_FUNC(CLASS_NAME, boost::archive::xml_oarchive) \ private: \ friend class boost::serialization::access; \ template<typename TArchive> \ void serialize(TArchive & ar, const unsigned int version /*file_version*/) class A { public: A() : m_a(0) {} protected: int m_a; private: SERIALIZATION(A) { ar & BOOST_SERIALIZATION_NVP(m_a); } }; class B : public A { public: B() : m_b(0) {} protected: int m_b; private: SERIALIZATION(B) { ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(A); ar & BOOST_SERIALIZATION_NVP(m_b); } }; BOOST_CLASS_EXPORT(B) int main(int argc, char* argv[]) { // ... A a; B b; std::list<A*> lst; // List of A* pointers lst.push_back(&a); // Base class lst.push_back(&b); // Derived //... // Save { std::ofstream ofs("c:/test.xml"); boost::archive::xml_oarchive oa(ofs); BOOST_FOREACH(A* pA, lst) { pA->Serialize(oa); } } //... // Restore { std::ifstream is("c:/test.xml"); boost::archive::xml_iarchive ia(is); BOOST_FOREACH(A* pA, lst ) { pA->Serialize(ia); } } //... } Everything works as expected (my classes can live with a few additional virtual functions :). And thank you for creating this excellent serialization library! Ray

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Using Boost.MPI with gather , data becomes overwritten after gather operation
by hgc-01134＠hkedcity.net wong 01 Sep '10

01 Sep '10

Hi, I am trying to use Boost.MPI to do a very simple program that 1. Processes from different ranks do a gather operation 2. The gather operation will gather the CoProcessInfo ( which is just a data structure of rank# and hostname) into a vector 3. After the gather operation, Rank 0 will print the CoProcessInfo one by one in the vector. ------------------------------------------------------------------------------------------------------------------------------------------------------ My testing environment consists of TWO virtual machine ( each of the machine has two cores ): Centos 5.5 mpich2 Boost.mpich2 Boost 1.41 mpiexec ------------------------------------------------------------------------------------------------------------------------------------------------------ The expected output of the program should be something like ( just an example order of ranks ): Host VM1, Rank 0 Host VM1, Rank 1 Host VM2, Rank 2 Host VM2, Rank 3 ---------------------------------------------------------------------------------------------------------------------------------------------------------- However, I got something like: ( just an example order of ranks ), the hostname is incorrect after gather operation ( three VM2 appears!) Host VM1, Rank 0 Host VM2, Rank 1 Host VM2, Rank 2 Host VM2, Rank 3 I found that each process CAN correctly found out the hostname and rank#, however, the data will become a bit like overwritten, after the gather operation. Thank you very much. ------------------------------------------- Source Code ------------------------------------------------------------------- #include <boost/asio/ip/host_name.hpp> #include <iostream> #include <vector> #include <string> #include <boost/mpi/environment.hpp> #include <boost/mpi/communicator.hpp> #include <boost/mpi.hpp> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <sstream> #include <fstream> using namespace std; namespace mpi = boost::mpi; class CoProcessInfo { private: string hostname; int rank; friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int /* version */) { ar & hostname & rank; } public: CoProcessInfo() { hostname = boost::asio::ip::host_name(); rank = 0; } void setRank(int _rank) { rank = _rank; } string getHostname() const { return hostname; } int getRank() const { return rank; } }; int main(int argc, char* argv[]) { int myrank; mpi::environment env(argc, argv); mpi::communicator world; myrank = world.rank(); CoProcessInfo localInfo; localInfo.setRank( myrank ); std::vector<CoProcessInfo> coProcInfo; mpi::gather(world, localInfo, coProcInfo, 0); if( myrank == 0 ){ for (std::vector<CoProcessInfo>::const_iterator it = coProcInfo.begin(); it !=coProcInfo.end(); ++it) { cout << endl << " Host : " << it->getHostname() << " , Rank : " << it->getRank() << endl; } } return 0; } ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Regards, Joseph

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boost::addressof
by Stanisław Findeisen 31 Aug '10

31 Aug '10

Hi! In the latest boost release (1.44) boost::addressof is defined as follows (boost/utility/addressof.hpp): namespace detail { template<class T> struct addr_impl_ref { T & v_; inline addr_impl_ref( T & v ): v_( v ) {} inline operator T& () const { return v_; } private: addr_impl_ref & operator=(const addr_impl_ref &); }; template<class T> struct addressof_impl { static inline T * f( T & v, long ) { return reinterpret_cast<T*>( &const_cast<char&>(reinterpret_cast<const volatile char &>(v))); } static inline T * f( T * v, int ) { return v; } }; } // namespace detail template<class T> T * addressof( T & v ) { #if defined( __BORLANDC__ ) && BOOST_WORKAROUND( __BORLANDC__, BOOST_TESTED_AT( 0x610 ) ) return boost::detail::addressof_impl<T>::f( v, 0 ); #else return boost::detail::addressof_impl<T>::f( boost::detail::addr_impl_ref<T>( v ), 0 ); #endif } Q1: What is volatile in the cast needed for? Q2: Could anyone please explain to me what are the 2nd parameters in each of the f functions in struct addressof_impl for? Q3: What is struct addr_impl_ref::operator T& () const ??! I understand it is there to get called when passing addr_impl_ref<T>(v) instead of v to addressof_impl<T>::f, but I've never seen such a thing before. I would understand T& struct addr_impl_ref::operator(), or something, but this one is different. Sorry if this is a newbie question. Q4: I can see that in 1.34.1 boost::addressof was much more simple: // VC7 strips const from nested classes unless we add indirection here # if BOOST_WORKAROUND(BOOST_MSVC, == 1300) template<class T> struct _addp { typedef T * type; }; template <typename T> typename _addp<T>::type # else template <typename T> T* # endif addressof(T& v) { return reinterpret_cast<T*>( &const_cast<char&>(reinterpret_cast<const volatile char &>(v))); } so I wonder what was the problem with this design?... -- http://eisenbits.homelinux.net/~stf/ OpenPGP: DFD9 0146 3794 9CF6 17EA D63F DBF5 8AA8 3B31 FE8A Like Hardship, Risk & Challenge? --- Follow Jesus!!

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