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Re: [boost] [contract] Contract Programming Library
by Andrzej Krzemienski 19 Feb '10

19 Feb '10

> I am thinking to submit a library for Contract Programming (a.k.a. > Design By Contract (TM) ) for C++. > I have drafted some of the library documentation in Boost-like format: > http://dbcpp.sourceforge.net/boost/libs/contract/doc/html/ > Comments? Hi, I have a couple of questions/suggestions regarding the documentation of the library. (1) Does it execute postconditions when the function body ends with a thrown exception? Obviously it shouldn't. I can see one lie saying It is possible to describe the function postconditions. These are logical conditions that programmers expect to be true when the function has ended **normally**. So I guess it doesn't, but I believe this fact deserves some more room in the documentation, like "public member function is not required to satisfy the postcondition if it ends with exception." (2) Obviously, the expressions in assertions shouldn't change the behaviour of the program when executed. This requirement is stronger than having no side effects. You protect the object itself by allowing only const member functions. Are the function arguments (those passed by mutable reference also protected?). Is it allowed/recommended to refer to global or static data in the assertions? If you are using clever macros, perhaps there is a way to block the references to these. In C++0x lambdas you can specify a list of objects you want to refer to: [this, &max_value, &count, &cache]( int fact1, int fact2 ) {...} perhaps there is a way to do it with current C++ macros. (3) In a similar manner, what happens if one of postcondition's assertions throws an exception? I have troubles answering this question myself (I do not know what should ideally happen), but whatever your answer is, I believe it should be clearly documented. (Note that this is not only the issue of DbC; simple C-assertions also leave this question unanswered). (4) Do the assertions have access to objet's private/protected interfaces? (I believe they shouldn't). (5) Does the library allow defining preand postconditions for "free" functions or static member functions? The examples are so focused on objects/classes that I cannot tell the answer. (6) Similarly, does the library allow defining block invariants? (7) The documentation lists the following sequence for executing a constructor: 1. Initialize member variables via the constructor member initialization list (if such a list is specified). 2. Check preconditions (but not invariants). 3. Execute constructor body. 4. Check invariants. 5. Check postconditions. I believe, one of the reasons for validating arguments of a constuctor is to not allow the incorrect values to initialize objest's sub-objects (members). I believe the sequence of the first two items should be inverse. Am I wrong? (8) Since library usses macros that make the syntax a bit difficult to read/parse, perhaps it would be useful to augment every example with another one that would say how the same thing would be acomplished with fictitious "DbC C++" syntax if we had one. This was done for Boost Interface library (under construction, http://www.cdiggins.com/bil.html) and I think it helps a lot. Regards, &rzej

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[type_traits] is_class not detecting C++0X lambda on Intel 11.1/Windows?
by Jesse Perla 19 Feb '10

19 Feb '10

The boost version of is_class doesn't seem to be compatible with lambdas in my target compiler. Am I missing something? Any patches/fixes you can think of? Sadly, I can't just use the tr1 version since this is being used internally within a boost library (boost::parameter in my case). BOOST_AUTO_TEST_CASE( test_is_class ) { auto f = [](double x){return x;}; // static_assert(boost::is_class<decltype(f)>::value, "Failure"); //Compiler failure line 81 of boost/type_traits/is_class.hpp static_assert(std::tr1::is_class<decltype(f)>::value, "Failure"); //Works using the built in tr1 for the compiler }

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Formal review request: static size matrix/vector linear algebra library (Boost) LA
by Emil Dotchevski 18 Feb '10

18 Feb '10

Documentation and source code complete with comprehensive tests, released under the Boost Software License is available here: http://www.revergestudios.com/boost-la/ Thanks, Emil Dotchevski

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[preprocessor]
by Баграт Асатрян 18 Feb '10

18 Feb '10

Hello. boost.preprocessor library is good, but it does not support in-place preprocessor metafunction composition and argument bindings. I have just implemented such a functionallity as in boost.mpl, and can say that it simplifies preprocessor metaprogramming greatly. If interested, contact me. С уважением, Баграт Асатрян. ---------------------------------------------- Тел.: +(374 94) 69-78-67, E-mail: bagrat_assatrian(a)mail.ru

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[thread] Ticket #3748 ignored for boost-1.42?
by Oliver Kowalke 18 Feb '10

18 Feb '10

As I see the patch for the bug (is it?) was not applied for version 1.42. does somebody know why? Oliver

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boost::property_tree is seriously outdated/incomplete
by Philippe Vaucher 18 Feb '10

18 Feb '10

Hello, Basically boost::property_tree documention is incomplete and outdated. There is simply no documentation on what a "Translator" is, only by digging the source you are able to understand it can be used to convert fetched values before returning them. Same goes for "stream_translator", still no idea what it's useful for. What's worse is that the documentation contains WRONG ways of doings things, like it says to change the default '.' separator one should use: pt.get<float>('/', "p.a.t.h/t.o/v.a.l.u.e"); But this is actually done like this: pt.get<float>(boost::property_tree::ptree::path_type("p.a.t.h/t.o/v.a.l.u.e", '/')); Then there are all the quickbook formatting bugs there and there, I made a ticket summing all I've found here https://svn.boost.org/trac/boost/ticket/3925 I hope someone will look after this because boost::property_tree has a great potential and it's a shame the documentation discourages people from using it. There's also obvious changes that ought to happen like being able to get the parent of a ptree node. My 0.02$ Philippe

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Proposal for new variants of the Boost logo.
by Paul A. Bristow 18 Feb '10

18 Feb '10

After many discussions on the thread "Boost logo variants for use in unofficial or unreleased boost documentation" that many will have tired of, a few with more stamina have agreed the following proposal for wider agreement. Proposal for new variants of the Boost logo. =============================== There are many projects springing up, often with smart documentation using the Boost Logo, and there are many more products, for sale and for free, that use Boost libraries. Many are concerned at the 'Dilution of the Brand Identity': so we propose two new variant logos: 1 For projects that are written with Boost 'in mind', perhaps for submission, but are *not yet reviewed and accepted*. "For use with" - logo for projects having some association with Boost, but are *not 'official'*. (Many like red text to signal strongly that this is NOT (perhaps yet) a Boost approved library). 2 For projects that *use* Boost, and would like to acknowledge this - with thanks: "Powered by" - logo for all projects *using* Boost. (in addition to the 'Using Boost' listing on the website) To see the proposed logos: http://dbp-consulting.com/boostvariantslogo.html (produced by Patrick Hogan). (These logos will be available in bitmap, png and svg formats ready to be used in html and pdf docs). Paul PS Some were also in favour of a "Proposed for Boost" logo to be used only *for libraries in the review queue*, but not yet in a final release. Others felt this was unnecessary. So unless there is strong support for this, it does not form part of this proposal. --- Paul A. Bristow Prizet Farmhouse Kendal, UK LA8 8AB +44 1539 561830, mobile +44 7714330204 pbristow(a)hetp.u-net.com

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"Software Development using the C++ Boost Library", book in preparatiion Options
by Jesse Perla 17 Feb '10

17 Feb '10

Daniel: As a caveat, I am far from an expert. just a library user focused on scientific computing in economics... but here are a few more comments that I hope the experts can correct. > 2. type erasure: I looked this term up but it seems as if it is similar to interface/device independent/ programming. In the past we built homemade Function and used it in combination with OO specialisation with virtual functions, Now boost Function is so much > better. Mathematicians and engineers are used to functions and we adopt the same approach (e.g. using namespaces) boost::function certainly beats any home-spun solution. But type erasure is a way to bridge generic programming to give a common *runtime* interface. I think of it as akin to getting the benefits of dynamic polymorphism with arbitrary generic types - effectively creating a virtual function without inheritance. However, just as with dynamic polymorphism it is not without cost: The boost::function infrastructure puts in a dispatch which could drastically hurt performance if called in an inner loop (or have virtually no effect if the function itself is time consuming). The compiler can't inline the functions, etc. Also, the term "type erasure" should be taken literally. The functions which operate on the boost::function are not able to get any information on the type. For example, a common way to deal with a function and derivatives is to have a single function object with an operator() and a gradient() defined. But if you stuff this in a boost::function you lose the information and can only call a specific overload/template of operator(). You can see some old, stupid questions I had asked on this mailing list a while back about this topic: http://lists.boost.org/boost-users/2009/01/44253.php What I learned eventually was that I was trying to use type erasure when I didn't need it, and I was better off sticking with generic programming... So boost::function is very useful, but you run into the same tradeoffs and questions as static vs. dynamic polymorphism: If you don't need dynamic polymorphism, then consider sticking with compile time templates, etc. for better performance and genericity at the potential cost of code complexity. In the case of scientific computing, I find that almost everything is known at compile time and you are better off keeping the types generic/not using type erasure. If you are just using boost::function because the types of the function objects are complicated, consider the alternatives. See my comments in the previous post on the use of "auto" and "decltype" to make this manageable. > 3. Ideally, we would like TR1 and boost to be as seamless as possible. Check out: http://www.boost.org/doc/libs/1_42_0/doc/html/boost_tr1.html Just remember that boost::tr1 is intended to be used only if the vendor hasn't put in a tr1 library. > 4. Fusion: I think this is useful, especially with Any? While I have never used "any", I believe these are two different ways to deal with the problem. Using something like std::vector<boost::any> is another example of type erasure (just as std::vector<boost::function<double (double)> > would be). boost::fusion allows you to have a tuple-like vector of different types, but while retaining type information. The same types of tradeoffs apply as before... and fusion is only usable if you know the types at design-time. If you end up converting some of your code away from boost::function, you may need something like this. On the other hand, it can be pretty advanced so be careful... std::tr1::tuple is enough unless you need to apply an operation on the vector of types. For example, I have often had the case where I had a vector of functions I needed to evaluate. I was unable to use boost::function since I needed genericity so I had a boost::fusion::vector with the various function types. Then to evaluate the functions at the same point, I used a fusion::for_each, transform, or fold depending on what I was trying to do. Note that this should have very high performance: The fusion::for_each ends up doing something akin to loop unrolling at compiletime, and since I didn't lose any type information everything could be inlined. > 7. Numerical integration: I saw this extensive library in Vault. What is the status? These don't seem to be in active development. I have used http://www.coin-or.org/CppAD/ myself. When using AD you will find it extremely difficult to use boost::function because the function stops being generic when the type is removed (play with these libraries and you will understand quickly). This is a perfect example of why you should be wary of removing type information if you don't need to. I think that Robert is correct that you should make sure you study and work with type erasure/generic programming before writing those chapters, especially if you are intended this to be used for numeric computing. Efficiency is critical for these applications and dynamic polymorphism is often unnecessary. And don't be fooled by the name boost::function: Its primary purpose is to bridge dynamic polymorphism for generic callable types, and not to be a placeholder for mathematical functions. While using it can sometimes simplify code (when auto/decltype are not available), the cost should be considered. boost::phoenix, lambda, and bind do not erase type information and I believe all overhead of function adaptation could be optimized away with these. While a lot of the Template Metaprogramming book was beyond my needs, I found careful study essential reading(especially Chapter 9 which covers these topics) .... and that about exhausts my knowledge. Good luck with the book!

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"Software Development using the C++ Boost Library", book in preparatiion
by Jesse Perla 17 Feb '10

17 Feb '10

Looks great to me. A few comments: ---------- Forwarded message ---------- From: "Daniel J. Duffy" <ddu...(a)datasim.nl> Date: Feb 15, 12:55 am Subject: "Software Development using the C++ Boost Library", book in preparatiion To: Boost Developers Archive > 1. Higher Order Functions I used to use boost::function a lot, but now find myself using templated classes with deduction of the function type instead and haven't used boost::function for a long time . I think when writing this section, it would be nice to have a good sense of when type erasure using boost::function is necessary. I found that the main reason I was using boost::function was not type erasure but rather that the types of the functions I was storing were complicated so it was easier to stuff in a boost::function and then have an easier way to reference the type. After I started using auto, decltype, and make_ functions, this became unnecessary. Of course, you can't count on people having "declype" or "auto", so my proposal would be to see if BOOST_AUTO, etc. should be suggested as a temporary solution for people without C++0X turned on. One other thing worth thinking about here is whether you should plan for standardizing on the tr1 namespace(and explain how to use boost::tr1). This might future proof the book as most mainstream compilers seem to have tr1 already. That said, I had a lot of problem with the tr1 library that comes with the Microsoft compiler mixing boost functional programming libraries and tr1::function/bind, so you might want to try things out before going down this route. > 6. Utilities and other Libraries I would love to see a short section on Fusion. I have found Fusion very useful and a good alternative to using type erasure for my applications. Of course, the numerical computing I do has almost everything known at compile time which may distort my view. Also consider type_traits and enable_if, and a minimalist use of MPL to support managing overloads (mpl::and, not, if, etc.). (a huge part of the superb C++ Template Metaprogramming book is about advanced features like iterators or your own sequences, which isn't necessary for most users)

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define for 32/64 bitness?
by Oliver Kowalke 17 Feb '10

17 Feb '10

Does boost provide an preprocessor define telling if the boost lib is build for 32 or 64 bit? I need this info for the second parameter of posix_memalign(). regards, Oliver

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"Software Development using the C++ Boost Library", book in preparatiion
by Daniel J. Duffy 17 Feb '10

17 Feb '10

Hello, We would like to announce news on our new book in preparation that is based on the Boost library. Below is a description of what the book is about and its focus. We discuss several applications such as computational finance, simulation, maths, engineering as well as examples for a wider audience. The book is pitched at intermediate level and upwards. We would be very interested in receiving feedback from Boost authors (and those who are workinng with the library) concerning the chapters in the book, especially the extensive functionality in the library and possibly examples from areas not discussed above. best regards and thank you! Daniel J. Duffy Robert Demming // Book Proposal "Software Development using the C++ Boost Library" Daniel J. Duffy (dduffy(a)datasim.nl) Robert Demming Datasim Education BV February 2010 Publisher: Datasim Press Ltd. Web site: http://www.datasimfinancial.com/ <http://www.datasimfinancial.com/> What is this book? This book introduces and elaborates the C++ boost library and applies it to creating code and applications for a range of domains such as engineering, computational finance, mathematical physics and other exact disciplines. We have written the book in such a way that the learning process is as seamless as possible; first, for each library we introduces its main features by discussing its syntax and by giving '101' examples to show to use it as quickly as possible. Second, we introduce some of the more advanced features in each library with a view to using and customizing them to suit application needs. Finally, we create small and medium-sized applications and test cases by integrating several libraries to show the usefulness and applicability of boost to support complex software systems. The book is structured into seven major categories, each one of which dealing one particular aspect of software development and its applications. For whom is this Book? We have tried to write the book in such a way that it is accessible to as wide a group of developers as possible (an impossible task!) by the appropriate use of examples at each level of developer expertise and test cases that are of direct relevance in a number of application areas. We assume that the reader has several years of experience of object-oriented and template programming in C++. Application Development using Boost Regarding the test cases and applications we try to model them in such a way that the reader understand the problem and design intent before we discuss the actual coding. To this end, we consider the use of UML class and component diagrams (in the appropriate dosage!) to be essential. In one sense, "UML is C++ in pictures". Some applications that we discuss in the book are: Using Lambda to simplify use of STL algorithms Using Signals to implement, MVC, Observer and PAC patterns (GOF, POSA) Using Bind and Function to semi-discretise partial differential equations (PDE) Random for Monte Carlo simulation, numerical integration and option pricing Any and data-independent parameter passing between modules Interval arithmetic and explicit modelling of numerical imprecision Various text-processing applications Compile-time arrays and matrices using Array Using multi_array to model n-dimensional PDEs uBLAS as data structures for numerical algebra Statistical functions and their applications Accumulators and time series applications Using Flyweight as default in applications Multi-threaded scientific applications Network programming and Asio Mapping GOF patterns to boost (i.e. using boost to implement design blueprints) /// Categories of Libraries 1. Higher Order Functions Function Bind Lambda Signals/Signals2 2. Data Types Any Integer Interval Parameter Rational Smart Pointer Tribool Tuple Variant 3. Text and String Processing Regex String Algo Tokenizer Xpressive 4. Data Structures and Searching Array Date Time Graph Multi-Array Multi-Index 5. Mathematics and Statistics Accumulators Math Common Factor Math/Special Functions Math/Statistical Distributions Random uBLAS 6. Utilities and other Libraries Conversion Dynamic Bitset Filesystem Flyweight Lexical Cast Numeric Conversion Program Options Test 7. Multithreading and Networking Asio Statechart Thread Timer Yours sincerely and thank you Daniel Duffy, PhD Ing. Robert Demming

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Re: [boost] [contract] Contract Programming Library
by Andrzej Krzemienski 17 Feb '10

17 Feb '10

> > it is inevitable, etc., but.. read on. I know at least one library in > > Boost that also spoils function declarations in order to provide > > additional functionality: Concept Check library; they may be others > > too (MPL?). > > My suggestion is that if there are (or will be) libraries that require > > spoiling function declarations, they should all provide the same > > "spoiled" syntax. Otherwise I will be always asking "how do I declare > > a function in this library?". It would be very convenient if Boost > > provided one alternative function definition syntax that when used > > would enable all its libraries to work. > > I agree. However, in the past I did look into harmonizing my library > API with the ones of Boost.ConceptCheck and/or Boost.Parameter but it > did not seem feasible... I will double check it. This is not only about clarity. As a super-correct programmer I may want to apply both concept checking and pre-/post-conditions checking to my functions. Perhaps, if the 'compromise' syntax is possible, it requires changing concept-checking library. Regards, &rzej

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[variadic_templates][mpl]interest in compile time matrix multiplication?
by Larry Evans 17 Feb '10

17 Feb '10

For example, with: > ***domain_matrix: > ( 11 12 13 ) > ( 21 22 23 ) the following: > typedef > outer_product_pack > < plus_times_row_column<arg<1>,arg<2> > > >::apply > < domain_matrix > , domain_matrix > >::type > outer_plus_times_rows_rows; > > std::cout<<"***outer_plus_times_rows_rows:\n"; > for_each<outer_plus_times_rows_rows>(printer); produces: > ***outer_plus_times_rows_rows: > ( 434 794 ) > ( 794 1454 ) The plus and times operations can be replaced with any compile-time binary operation. Any interest? -regards, Larry

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[Boost][gsoc]Intrest - big integer library
by Kamil Witecki 17 Feb '10

17 Feb '10

Hello all, I'd like to propose new library for boost - a Big Integer library. Boost has plenty of applications build upon it and some of them has to use integers greater that those ensured by C++ standard. What is more some of them needs even Pythonlike "unbounded" integers. What I am proposing is library implementing cross-platform library supporting such integers working as standard arithmetic type. Is it a good proposal for GSoC project and who would you recommend as a possible mentor for such project? Pozdrawiam, Kamil Witecki.

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[Boost.Preprocessor] FOREACH( MACRO, ... )
by Daniel Larimer 17 Feb '10

17 Feb '10

Is there a reason why Boost.Preprocessor does not have many (any?) utilities for variadic macros? I have implemented a FOREACH( MACRO, ... ) that results in the following expansion MACRO(ARG1) MACRO(ARG2) ... Implemented as such: #define FOREACH_ARRAY( ... ) (PP_NARG(__VA_ARGS__) , ( __VA_ARGS__ ) ) #define FOREACH( A, ... ) BOOST_PP_REPEAT( PP_NARG(__VA_ARGS__), A, FOREACH_ARRAY(__VA_ARGS__) ) #define CASE(z,n,data) case BOOST_PP_ARRAY_ELEM( n, data ): FOREACH( CASE, a, b, c, d, e) case a: case b: case c: case d: case e: Depends upon this macro: #define PP_NARG(...) \ PP_NARG_(__VA_ARGS__,PP_RSEQ_N()) #define PP_NARG_(...) \ PP_ARG_N(__VA_ARGS__) #define PP_ARG_N( \ _1, _2, _3, _4, _5, _6, _7, _8, _9,_10, \ _11,_12,_13,_14,_15,_16,_17,_18,_19,_20, \ _21,_22,_23,_24,_25,_26,_27,_28,_29,_30, \ _31,_32,_33,_34,_35,_36,_37,_38,_39,_40, \ _41,_42,_43,_44,_45,_46,_47,_48,_49,_50, \ _51,_52,_53,_54,_55,_56,_57,_58,_59,_60, \ _61,_62,_63,N,...) N #define PP_RSEQ_N() \ 63,62,61,60, \ 59,58,57,56,55,54,53,52,51,50, \ 49,48,47,46,45,44,43,42,41,40, \ 39,38,37,36,35,34,33,32,31,30, \ 29,28,27,26,25,24,23,22,21,20, \ 19,18,17,16,15,14,13,12,11,10, \ 9,8,7,6,5,4,3,2,1,0

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[thread] thread_specific_ptr, dangerous conflation of identity and address
by Edd Dawson 16 Feb '10

16 Feb '10

Hi folks, A thread_specific_ptr appears to use its own address as a key. For example, the two tss objects created below will likely share the same key: void f() { thread_specific_ptr<int> ptr; // ... } int main() { f(); f(); } When thread_specific_ptr's destructor is called, it does a reset() which clears the data for the thread doing the destruction. However, data for other threads still remain. I find this asymmetric behaviour a little strange. Why should all threads but one see their old data? The bigger problem though, is that it might not be *their* old data. It can just as easily be someone else's old data due to coincidental alignment of different thread_specific_ptrs on the stack at entirely unrelated points in the program, or even in different libraries that each happen to use boost::thread_specific_ptr! void g() { thread_specific_ptr<float> ptr; // ... } f(); g(); It's easy to see the problem here as the calls are very close to one another. In general, however, this strikes me as being really rather dangerous behaviour. Would it be fair to call it a bug? It seems it is only safe to allocate thread_specific_ptrs in static storage. A complete example is listed at the end. It exhibits the kind of behaviour I'm talking about on my x86 systems, at least. Kind regards, Edd //#define BOOST_ALL_NO_LIB 1 #include <queue> #include <iostream> #include <boost/thread/tss.hpp> #include <boost/thread/thread.hpp> #include <boost/thread/barrier.hpp> #include <boost/thread/condition.hpp> #include <boost/thread/mutex.hpp> #include <boost/bind.hpp> using namespace boost; typedef function<void ()> task_type; // Simple multi-producer-single-consumer job queue. // Manages its own consumer thread. class jobq { public: jobq() : dying_(false), consumer_(bind(&jobq::work_loop, this)) { } ~jobq() { exit_work_loop(); consumer_.join(); } void add(const task_type &task) { unique_lock<mutex> lk(mtx_); tasks_.push(task); arrival_.notify_one(); } private: void exit_work_loop() { unique_lock<mutex> lk(mtx_); dying_ = true; arrival_.notify_one(); } bool wait_for_task(task_type &task) { unique_lock<mutex> lk(mtx_); while (!dying_ && tasks_.empty()) arrival_.wait(lk); if (dying_) return false; task = tasks_.front(); tasks_.pop(); return true; } void work_loop() { task_type task; while (wait_for_task(task)) task(); } private: bool dying_; std::queue<task_type> tasks_; mutex mtx_; condition arrival_; thread consumer_; }; template<typename T> void access_tsp(thread_specific_ptr<T> &tsp, barrier &b) { if (!tsp.get()) tsp.reset(new T(-1)); else std::cout << "Already initialized to " << *tsp << "!\n"; b.wait(); } template<typename T> void f(jobq &q) { barrier b(2); thread_specific_ptr<T> tsp; q.add(bind(&access_tsp<T>, ref(tsp), ref(b))); b.wait(); // wait until it's safe to destroy tsp } int main() { jobq q; f<int>(q); f<unsigned>(q); return 0; }

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Re: [boost] [Boost][gsoc]Intrest - big integer library
by Kamil Witecki 16 Feb '10

16 Feb '10

I see that even a simple, but robust, implementaion covering each case (possibly some of them awaiting implementations of apropriate policy) would be hard, if not infeasible, to be done in such a short period of time as is given in GSoC. On the other hand I would take a deeper look in that topic and meanwhile look for another proposition. Many thanks for all your answers and clarifiyng all the infarmation and possible problems. Kamil Witecki.

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Re: [boost] boost 1.42 - compile toolsset=intel-linux with fPIC
by "Sören Freudiger" 16 Feb '10

16 Feb '10

okay, I got it. Okay, I never cared about the project-config.jam file (maybe because the user_config file is mentioned after bootsrap.sh). I just put the using intel-linux stuff inside projetc-config: if ! intel-linux in [ feature.values <toolset> ] { using intel-linux : 10.1 : /lrz/sys/intel/icc_101/bin/icpc : <compileflags>"-fPIC" <linkflags>"-fPIC" ; } instead of the user_config. That's it. Don't know why it doesn't work for intel with user_config but for the gcc. However, I hope it'll work.. Thank @all, SirAnn -- NEU: Mit GMX DSL über 1000,- ¿ sparen! http://portal.gmx.net/de/go/dsl02

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Re: [boost] boost 1.42 - compile toolsset=intel-linux with fPIC
by "Sören Freudiger" 16 Feb '10

16 Feb '10

@ Normal 0 21 false false false DE X-NONE X-NONE Volodya > Well, just do that in project-config.jam? Or, alternatively, remove project-config.jam -- and have only user-config.jam be used. Okay, but which one is that? (location?) I can see your name in the jam files very often, thus you are to be the one who can help me out, dont' ya? @Dick Normal 0 21 false false false DE X-NONE X-NONE >If you build an executable that will dynamically load (with dlopen) shared libraries, then all of its code, including whatever it gets from static libraries, has to be compiled and linked with -fPIC. >This leads us to compile and link all of our code, including boost libraries, with -fPIC. bullseye! that's the problem that we have.. thus we have to turn on the fPIC option.. But I don't get it work for the intel compiler.... Do you have a solution? -- Sicherer, schneller und einfacher. Die aktuellen Internet-Browser - jetzt kostenlos herunterladen! http://portal.gmx.net/de/go/chbrowser

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boost 1.42 - compile toolsset=intel-linux with fPIC
by "Sören Freudiger" 16 Feb '10

16 Feb '10

Hello I just try to compile boost 1.42 on the Altix-HPC in Munic. Problem is that I need to compile it with turned on -fPIC cxx-flag. Following steps I'd done: 1. run ./bootstrap.h --prefix=... --with-toolset=intel-linux 2. modify tools/build/v2/user_config.jam: ... using intel-linux : : : <cxxflags>-fPIC ; ... (according to http://www.boost.org/boost-build2/doc/html/bbv2/reference/tools.html#bbv2.r…) 3. run ./bjam --> error: error: at /home/hlrb2/pr95gi/lu78wol/libs/boost_1_42_0/tools/build/v2/build/project.jam:884 error: duplicate initialization of intel-linux with the following parameters: error: version = <unspecified> error: previous initialization at /home/hlrb2/pr95gi/lu78wol/libs/boost_1_42_0/tools/build/v2/build/project.jam:884 What's the matter? What point did I miss? Please help ;-) SirAnn -- Sicherer, schneller und einfacher. Die aktuellen Internet-Browser - jetzt kostenlos herunterladen! http://portal.gmx.net/de/go/chbrowser

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Re2: boost 1.42 - compile toolsset=intel-linux with fPIC
by "Sören Freudiger" 16 Feb '10

16 Feb '10

Normal 0 21 false false false DE X-NONE X-NONE > Take a look at project-config.jam -- it already has 'using intel....'. > I suggest you remove whatever setting you've made in tools/build/v2/user-config.jam. But that's especially what I wanna to: add the fPIC flag for the gcc version it works fine!) > Further, why are you even trying to use -fPIC. When building shared libraries, -fPIC is used already. Some of our guys have to link because of certain reasons against the static libs from boost and obtain the error boost should be compiled with turned on fPIC flag... -SirAnn -----Ursprüngliche Nachricht----- Von: boost-bounces(a)lists.boost.org [mailto:boost-bounces@lists.boost.org] Im Auftrag von Vladimir Prus Gesendet: Dienstag, 16. Februar 2010 17:18 An: boost(a)lists.boost.org Betreff: Re: [boost] boost 1.42 - compile toolsset=intel-linux with fPIC "Sören Freudiger" wrote: > Hello > I just try to compile boost 1.42 on the Altix-HPC in Munic. Problem is > that I need to compile it with turned on -fPIC cxx-flag. > > Following steps I'd done: > > 1. run ./bootstrap.h --prefix=... --with-toolset=intel-linux 2. modify > tools/build/v2/user_config.jam: > > ... > using intel-linux : : : <cxxflags>-fPIC ; ... > > (according to > http://www.boost.org/boost- build2/doc/html/bbv2/reference/tools.html#bbv2.reference.tools.compiler.intel) > > 3. run ./bjam > > --> error: > error: at > /home/hlrb2/pr95gi/lu78wol/libs/boost_1_42_0/tools/build/v2/build/proj > ect.jam:884 > error: duplicate initialization of intel-linux with the following > parameters: > error: version = <unspecified> > error: previous initialization at > /home/hlrb2/pr95gi/lu78wol/libs/boost_1_42_0/tools/build/v2/build/proj > ect.jam:884 > > What's the matter? What point did I miss? _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost -- NEU: Mit GMX DSL über 1000,- ¿ sparen! http://portal.gmx.net/de/go/dsl02

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[BGL/PM] Composition of two property maps
by Matthias Walter 16 Feb '10

16 Feb '10

Hi, I currently have a function which gets a graph plus an index-map and want's to call a BFS. Therefore it needs to build a color-map which maps vertex_descriptors to colors. As the user already gives a way to map vertex_descriptor to index, I'd like to use this mapping. What I need is a way to define a property map as a composition: composed-map (vertex_descriptor) -> color via color-map (index-map (vertex_descriptor)) -> color whereas index-map (vertex_descriptor) -> index and color-map (index) -> color Of course this should not be too difficult to implement, so I'd just like to ask whether there already exists some kind of implementation, because I neither found a hint by looking in the docs, nor by digging through some of the code. The actual reason I ask is because there might be other ways to come around the problem, e.g. making the color-map itself use vertex_descriptors as keys, so maybe my suggested solution is not the best. best regards Matthias Walter

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C++0x and MSVC 10
by Zachary Turner 16 Feb '10

16 Feb '10

Playing with the release candidate of MSVC 10, and I'm noticing boost 1.42.0 is not using any C++0x features. Has this been discussed before, or is there a reason for this? Taking a peek at boost/config/compiler/visualc.hpp, I see the following: #if _MSC_VER < 1600 #define BOOST_NO_AUTO_DECLARATIONS #define BOOST_NO_AUTO_MULTIDECLARATIONS #define BOOST_NO_DECLTYPE #define BOOST_NO_LAMBDAS #define BOOST_NO_RVALUE_REFERENCES #define BOOST_NO_STATIC_ASSERT #define BOOST_NO_NULLPTR #endif // _MSC_VER < 1600 // C++0x features not supported by any versions #define BOOST_NO_CHAR16_T #define BOOST_NO_CHAR32_T #define BOOST_NO_CONCEPTS #define BOOST_NO_CONSTEXPR #define BOOST_NO_DEFAULTED_FUNCTIONS #define BOOST_NO_DELETED_FUNCTIONS #define BOOST_NO_EXPLICIT_CONVERSION_OPERATORS #define BOOST_NO_EXTERN_TEMPLATE #define BOOST_NO_FUNCTION_TEMPLATE_DEFAULT_ARGS #define BOOST_NO_INITIALIZER_LISTS #define BOOST_NO_RAW_LITERALS #define BOOST_NO_SCOPED_ENUMS #define BOOST_NO_SFINAE_EXPR #define BOOST_NO_TEMPLATE_ALIASES #define BOOST_NO_UNICODE_LITERALS #define BOOST_NO_VARIADIC_TEMPLATES It almost appears as if the #else was simply forgotten on the first #if. Can't we safely change the first conditional to the following? #if _MSC_VER < 1600 #define BOOST_NO_AUTO_DECLARATIONS #define BOOST_NO_AUTO_MULTIDECLARATIONS #define BOOST_NO_DECLTYPE #define BOOST_NO_LAMBDAS #define BOOST_NO_RVALUE_REFERENCES #define BOOST_NO_STATIC_ASSERT #define BOOST_NO_NULLPTR #else #define BOOST_HAS_AUTO_DECLARATIONS #define BOOST_HAS_AUTO_MULTIDECLARATIONS #define BOOST_HAS_DECLTYPE #define BOOST_HAS_LAMBDAS #define BOOST_HAS_RVALUE_REFERENCES #define BOOST_HAS_STATIC_ASSERT #define BOOST_HAS_NULLPTR #endif // _MSC_VER < 1600 Zach

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boost/cstdint.hpp definition of INTMAX_C conflicts with MPFR
by Vincent Lefevre 16 Feb '10

16 Feb '10

Hi, I'm a MPFR developer and the following problem with Boost has been reported in the MPFR mailing-list. As of Boost 1.42, the macros INTMAX_C and UINTMAX_C (in particular) are always defined, and on a system without <stdint.h> (Microsoft C++ compiler), the build of a program using Boost 1.42 and MPFR failed. The reason is that mpfr.h supports systems with and without intmax_t (so that it does not force <stdint.h> inclusion), thus it must have a way to determine when intmax_t is available, without requiring the user to do anything else than including <stdint.h> first. So, it has several heuristics, one of them being the test of the existence of INTMAX_C and UINTMAX_C. Indeed, in C, which does not have namespaces, it is rather intuitive that the existence of INTMAX_C and UINTMAX_C implies that the corresponding types intmax_t and uintmax_t are available. However, in C++ with Boost, intmax_t and uintmax_t are not necessarily available (in the global namespace). Even though one could specify a macro for MPFR that would allow the user to disable (u)intmax_t support explicitly, I think that Boost's behavior is rather awkward, and may break other software too (in particular libraries that would do the same kind of things as Boost). Indeed (correct me if I'm wrong, I don't know very much about C++), while types have namespaces, macros don't, but there are conventions under which using a prefix such as BOOST_ can be used in place of a namespace (to avoid conflicts with other software). So, I wonder why Boost doesn't do the following: since it defines the intmax_t and uintmax_t types in the boost namespace, it should use the BOOST_ prefix for the corresponding macros, e.g. BOOST_INTMAX_C and BOOST_UINTMAX_C. The only acceptable artifact concerning these types would be that additional types and macros be defined due to the inclusion of standard headers such as <stdint.h>; but in such a case, the behavior would remain consistent (i.e. INTMAX_C and UINTMAX_C would be defined only if intmax_t and uintmax_t are available). If, for some reason, Boost really needs to define the INTMAX_C and UINTMAX_C macros, then it should also define intmax_t and uintmax_t in the global namespace. But I don't think that's a good idea. Regards, -- Vincent Lefèvre <vincent(a)vinc17.net> - Web: <http://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <http://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / Arénaire project (LIP, ENS-Lyon)

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[thread] Moving a `recursive_lock`
by Daniel Trebbien 16 Feb '10

16 Feb '10

Hello all, I have been working on a project that uses the Boost Thread library, and I realized that there is a part of the code that needs to transfer a lock to a thread that has just been started. My idea for implementing this was to use a `boost::recursive_mutex` and pass a non-`const` reference to a `boost::recursive_mutex::scoped_lock` to the thread via `boost::ref`. Also, to ensure that the `scoped_lock` does not go out of scope until until the lock is moved, I thought to use a `boost::barrier`. After writing some test code, I find it interesting that if I use a `recursive_mutex`, then an assertion fails, but if I use a `boost::mutex`, then the code seems to work fine. Here is the test code that I have been experimenting with (the `recursive_mutex` version, which is also attached): #include <iostream> #include <boost/ref.hpp> #include <boost/thread.hpp> static boost::recursive_mutex s_mutex; static boost::barrier s_lockMoveBarrier(2); void thread_fun1(boost::recursive_mutex::scoped_lock& lock_) { //boost::recursive_mutex::scoped_lock testLock(s_mutex); // uncommenting this causes deadlock, as expected std::cout << "in `void thread_fun1(...)`: moving lock..."; boost::recursive_mutex::scoped_lock lock2(boost::move(lock_)); std::cout << "done" << std::endl; s_lockMoveBarrier.wait(); std::cout << "in `void thread_fun1(...)`: after the barrier" << std::endl; } int main() { boost::recursive_mutex::scoped_lock lock(s_mutex); std::cout << "in `int main()`: lock on `s_mutex` acquired" << std::endl; boost::thread(&thread_fun1, boost::ref(lock)); s_lockMoveBarrier.wait(); std::cout << "in `int main()`: after the barrier" << std::endl; } After compiling and running this on Debian Squeeze with Boost 1.42.0, I get: in `int main()`: lock on `s_mutex` acquired in `void thread_fun1(...)`: moving lock...done in `int main()`: after the barrier a.out: /usr/local/include/boost/thread/pthread/recursive_mutex.hpp:62: boost::recursive_mutex::~recursive_mutex(): Assertion `!pthread_mutex_destroy(&m)' failed. Aborted After replacing "boost::recursive_mutex" with "boost::mutex", however, the output is: in `int main()`: lock on `s_mutex` acquired in `void thread_fun1(...)`: moving lock...done in `void thread_fun1(...)`: after the barrier in `int main()`: after the barrier This leads me to wondering: 1. Is it correct and/or safe to move a lock to a new thread in this way? 2. Why does the `recursive_mutex` version fail and the `mutex` version succeed? Daniel Trebbien

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