- Boost-users - lists.preview.boost.org

[Fwd: How to print the structure of vector of boost::variant]
by Baba Prasad 11 Jan '12

11 Jan '12

Dear friends, please see the bellow my code and tell me how to get out this problem please.when I try to print values of variant it's giving the error as: std::ostream& operator<<(std::ostream&, const status_rsp&): worked.cpp:33: error: const struct status_rsp has no member named os worked.cpp:33: error: const class boost::variant<int, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_> has no member named channelid worked.cpp:33: error: expected ) before ; token worked.cpp:34: error: const class boost::variant<int, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost #include<vector> #include<iostream> #include<boost/variant.hpp> typedef int cid; typedef int n_queue; typedef boost::variant<chid> link_st_rs; typedef std::vector<link_st_rs> link_st_rs_list; typedef boost::variant<n_queue> link_de_rs; typedef std::vector<link_de_rs> link_de_rs_list; using namespace std; struct lparam { int value; }; typedef vector<lparam> link1; struct link_s_rsp { link1 ll; link_st_rs_list lsrl; link_de_rs_list ldrl; }; struct status_rsp { link_s_rsp rsp; friend std::ostream& operator<<(std::ostream& os , const status_rsp& sr) { os << "the value is " << sr.rsp.ll.front().value; os << "id" << sr.rsp.lsrl.front().chid; os << "val" << sr.rsp.ldrl.front().n_queue; return os; } }; typedef vector<status_rsp> srl; int main() { linkparam lp; lp.value =90; link_de_rs_list ldrl; lsrl.push_back(4); ldrl.push_back(3); status_rsp sr; sr.rsp.ll.push_back(lp); srl srl1; srl1.push_back(sr); link1::iterator iter2 = srl1.begin()->rsp.ll.begin(); cout << "A vlue is: " << iter2->value; link_st_rs_list::iterator iter3 = srl1.begin()->rsp.lsrl.begin(); cout << " B value " << iter3->chid; link_de_rs_list::iterator iter4 = srl1.begin()->rsp.ldrl.begin(); cout << "C value" < iter4->n_queue; cin.ignore(); return 0; } Best Regards BaBu -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.

2 1

Needs advices on design ( mpl or processor )
by Allan Nielsen 11 Jan '12

11 Jan '12

Hi This is not a specific questions directly related to Boost::mpl, but a request for help if somebody has the time... For the last couple of month I have been trying to learn to use the boost::mpl library. To learn to use the library I decided to use it for creating a "compressed-enum" library. The library should make it possible to store several enums in a single variable (for instance an unsigned int) Here is a simple example to give en idea: // example enums to play with struct TagA { enum Size { size = 4 }; enum Max { max = 3 }; enum E { A0 = 0, A1 = 1, A2 = 2, A3 = 3, }; }; struct TagB { enum Size { size = 4 }; enum Max { max = 3 }; enum E { B0 = 0, B1 = 1, B2 = 2, B3 = 3, }; }; struct TagC { enum Size { size = 4 }; enum Max { max = 3 }; enum E { C0 = 0, C1 = 1, C2 = 2, C3 = 3, }; }; struct First{}; struct Second{}; int main() { // using the compressed enums library typedef unsigned short STORAGE; typedef CompressedEnums< STORAGE, CompressedEnum<STORAGE, 1, TagA>, CompressedEnum<STORAGE, 4, TagB, First>, CompressedEnum<STORAGE, 16, TagB, Second>, CompressedEnumArray<STORAGE, 64, TagC, 5> > ENUMS; assert(sizeof(ENUMS) == 2)); ENUMS enums; enums.set<TagA>(TagA::A2); enums.set<Second>(TagB::B2); enums.set<3, TagC>(TagC::C2); cout << enums.get<TagA>() << " " << enums.get<Second>(TagB::B2) << " " << enums.get<3, TagC>(TagC::C2) << endl; } CompressedEnums contains the storage variable, and inherit from all its template arguments, and make their methods available through tags. CompressedEnum and CompressedEnumArray only contains static methods which can find the enum in the storage variable. Here is a snippet of my implementation: template < typename STORAGE_TYPE, int OFFSET, typename ENUM_CONTAINER, typename TAG = typename ENUM_CONTAINER::E > struct CompressedEnum { typedef TAG ACCESS_TAG; typedef typename ENUM_CONTAINER::E INNER_TYPE; enum Offset { offset = OFFSET }; enum Size { size = ENUM_CONTAINER::size }; static INNER_TYPE get(const STORAGE_TYPE& data) { return (INNER_TYPE)((data / OFFSET) % size); } ----%<----%<----%<----%<----%<----%<----%<----%<-- } template < typename STORAGE_TYPE, typename B00 = Dummy< 0>, typename B01 = Dummy< 1>, typename B02 = Dummy< 2>, typename B03 = Dummy< 3> > struct CompressedEnums : public B00, B01, B02, B03 { typedef boost::mpl::map<boost::mpl::pair<typename B00::ACCESS_TAG, B00>, boost::mpl::pair<typename B01::ACCESS_TAG, B01>, boost::mpl::pair<typename B02::ACCESS_TAG, B02>, boost::mpl::pair<typename B03::ACCESS_TAG, B03> > TYPE_MAP; template<typename TAG> typename boost::mpl::at<TYPE_MAP, TAG>::type::INNER_TYPE get() const { return boost::mpl::at<TYPE_MAP, TAG>::type::get(data); } ----%<----%<----%<----%<----%<----%<----%<----%<-- STORAGE_TYPE data; }; The code works and does what it is suppose to (as far as I know) but I'm not very happy with the interface: typedef CompressedEnums< STORAGE, // 1 because it is the first CompressedEnum<STORAGE, 1, TagA>, // 4 because TagA::size == 4 CompressedEnum<STORAGE, 4, TagB, First>, // 16 because TagA::size * TagB::size == 16 CompressedEnum<STORAGE, 16, TagB, Second>, // 64 because TagA::size * TagB::size * TagB::size == 64 CompressedEnumArray<STORAGE, 64, TagC, 5> > ENUMS; These magic numbers makes it very easy to make bugs when the code is restructured or changed, and it should be possible to calculate them automatic. If the magic numbers are replaced with their expresions the code will still break of the arguemnts are reordered. To accomplice this I have considered two solutions: macro or more templating... Using macroes I imagin the interface could look something like this: typedef CompressedEnums< STORAGE, ENUM_PACK( STORAGE, 1, (CompressedEnum, TagA) (CompressedEnum, TagB, First) (CompressedEnum, TagB, Second) (CompressedEnumArray, TagC, 5) ) > ENUMS; Which then would expand to the code manual entered above. Alternative using template I imagin that CompressedEnums could change CompressedEnum<STORAGE, 0, TagB, Second> -> CompressedEnum<STORAGE, 16, TagB, Second> automatic and then derive from that one automatic. I tried both, but non of my idea worked out very well, which is why I hope that one of you c++ experts could give me some hints. Best regards Allan W. Nielsen

5 28

depth_first_visit
by James Lindsay 10 Jan '12

10 Jan '12

Hello, I've found several questions regarding the depth_first_visit algorithm but I can't find a complete example anywhere. I was wondering if someone could post a complete example of the depth_first_visit algorithm in action, including how you created the color map. Thanks

3 2

[BGL / General] member of struct is a reference - why?
by Max Limper 10 Jan '12

10 Jan '12

Hi everybody, I was just going through the "File Dependency" example for the graph library and found this piece of code which is a very simple cycle detector: struct cycle_detector : public dfs_visitor<> { cycle_detector( bool& has_cycle) : _has_cycle(has_cycle) { } template <class Edge, class Graph> void back_edge(Edge, Graph&) { _has_cycle = true; } protected: bool& _has_cycle; }; It takes a reference and manipulates the externally declared variable hasCyle via that reference. I tried to change hasCylce to a "regular" member variable, and I just want to read it afterwards, like cycle_detector detector(); boost::depth_first_search(graph, boost::visitor(detector)); if (detector.foundCycles) { //do something } I also thought about giving the cycle detector other member variables, like a list of back edges that gets filled. However, I found that none of those variables gets set the right way, starting with the very simple "bool hasCycle" member. I guess there must be a reason why the person that made the example chose to use a reference, and it only works that way... any ideas why? Thanks a lot in advance.

2 1

[C++ Now! 2012] Deadline extension: Call for Submissions, new deadline is January 20th, 2012
by Hartmut Kaiser 10 Jan '12

10 Jan '12

INAUGURAL C++ NOW! CONFERENCE 2012 Aspen CO, USA, May 14-18, 2012, www.cppnow.org CALL FOR SUBMISSIONS We invite you to submit session proposals to the Inaugural C++ Now! Conference: C++Now! 2012 (Aspen CO, USA, May 14 - 18, 2012). Based on the successful traditions of 5 years of BoostCon, which was the main face-to-face event for all things C++ and Boost (www.boost.org) C++Now! 2012 will present leading speakers from the whole C++ community. The conference name is changing to C++ Now! to reflect the current value of the language, the focus on its new state (from the new Standard), and the need to continually look to the future so the language remains useful to the C++ community. The focus of this conference will be the new C++11 language Standard and as usual Boost: what's new in C++, its Standard library, and in the Boost libraries, how to write and maintain them, how to evangelize or to deploy Boost within your organization. The new C++ Standard, but also the infrastructure and process of Boost, its vision and mission - no matter what you are interested in, it all comes together in the C++Now! sessions. Meet the colleagues, and feel the inspiration to support your work with C++ and Boost for the next year. The C++ Now! Conference is dedicated to discussion and education about C++, an open and free language and standard. Our Conference will focus on discussion and education about open source software usage and developments in the C++ developer and user community. To reflect the breadth of the C++ and Boost communities, the conference includes sessions aimed at three constituencies: C++ and Boost end-users, hard-core Boost library and tool developers, and researchers pushing the boundaries of computation. The program fosters interaction and engagement within and across those groups, with an emphasis on hands-on, participatory sessions. As a multi-paradigm language, C++ is a melting pot where the most compelling ideas from other programming communities are blended in powerful ways. Historically, some of the most popular sessions at C++Now! have highlighted these concepts, from DSLs to functional programming to transactional memory and more. Bring your C#, Python, Ruby or Haskell influences to bear in an environment that will broaden their exposure. IMPORTANT DATES New proposal submissions due: January 20th, 2012. UPDATED! Proposals decisions sent (tentative program): February 17th, 2012. Fully scheduled program available: February 25th, 2012. Session materials due: April 15th, 2012. BEST PRESENTATION AWARDS We know how much effort it takes to prepare talks for our conference. For this reason we will award the best presentations in the following categories: Best Presentation, Best Short Presentation, Best Tutorial, and Best Workshop. The awards will be given based on the audience's voting. Each award will include the author's name listed on the cover of the C++Now! website for that year and a plaque containing all the C++Now! conference information. SESSION TOPICS Topics of interest include, but are not restricted to, the following: * C++11 and how it changes life for users and library writers * General tutorial sessions on C++11, the C++11 Standardslibrary, and one or more Boost libraries * In-depth sessions on using specific Boost libraries * Case studies on using Boost * Experts panels * Advanced sessions on implementation techniques used within Boost libraries * Development workshops to extend or enhance existing Boost libraries * Workshops on design process * Infrastructure workshops such as Build tools, Website, Testing * Concepts and Generic Programming * Hardware and infrastructure presentations focused on how libraries can make better use of the technology * Software development tools and their application to C++ and or Boost * Other topics likely to be of great interest to Boost users and developers Interactive and collaborative sessions are encouraged, as this is the style of learning and participation that has proven most successful at such events. Sessions can be tutorial based, with an emphasis on interaction and participant involvement, or workshop based, whether hands-on programming or paper-based, discussion-driven collaborative work. SESSION FORMATS Presentations Presentations focus on a practitioner's ideas and experience with anything relevant to C++11, Boost and users. Panels Panels feature three or four people presenting their ideas and experiences relating to C++11 and Boost's relevant, controversial, emerging, or unresolved issues. Panels may be conducted in several ways, such as comparative, analytic, or historic. Tutorials Tutorials are sessions at which instructors teach conference participants specific skills relevant to C++11 and Boost. Workshops Workshops provide an active arena for advancements In Boost-relevant topics. Workshops provide the opportunity for experienced practitioners to develop new ideas about a topic of common interest and experience. Author's Corner These were introduced at BoostCon 2008, and were a great Presentations success They are short (30 minute) sessions, focusing on tips on usage and design. In addition, we're looking to uncover the hidden design gems in Boost libraries. Tool Vendors We actively encourage tool vendors and ISP's to submit presentations proposals for a special Tool Vendors Session Track aimed at products related to Boost and C++ (compilers, libraries, tools, etc.). Other formats may also be of interest. Don't hold back a proposal just because it doesn't fit into a pigeonhole. SUBMITTING A PROPOSAL Standard Sessions are 60 minutes. You may submit a proposal for fractions or multiples of 90-minutes. Fractional proposals will be grouped into 60 minute sessions covering related topics. Longer sessions, such as tutorials and classes, will be assigned 90 minute, three hour (i.e. half day), or six hour (i.e. full day) time slots. Please include: * The working title. * Type of session: presentation, panel, tutorial, workshop, authors corner, vendor track, other. * A paragraph or two describing the topic covered, suitable for the conference web site. * Proposed length: 10-20 minute short talks, 45 minutes, 90 minutes, half day, full day. * Alternate lengths, if you are willing to make adjustments: 10- 20 minute short-talks, 45 minutes, 90 minutes, half-day, full day. * Audience: users, developers, both. * Level: basic, intermediate, advanced. * A biography, suitable for the conference web site. * Your contact information (will not be made public). SUBMISSION DETAILS All submissions should be made through the EasyChair conference management system: http://www.easychair.org/conferences/?conf=cppnow2012. If you have not already registered at EasyChair, you will need to do so in order to submit your proposal. All submissions will go through a peer review process. Authors are invited (but are not required) to submit PDF versions of full papers of up to 10 pages in ACM conference proceedings format (see http://www.acm.org/sigs/publications/proceedings-templates) The full papers are not required unless you want them published in the proceedings. All accepted proposals will be made available in the Association for Computing Machinery (ACM) Digital Library (approval pending). Best papers, after further reviews, will be considered to be book chapters or journal articles in a renowned journal. The session materials go on the C++Now! website and will be available to attendees. For general information on the C++Now! 2012 paper submission or the scope of technical papers solicited, please refer to the conference website at www.cppnow.org. For any other questions about the submission process or paper format, please contact the Program Committee at cppnow2012(a)easychair.com. If you have any technical problems with EasyChair, please contact EasyChair for help. Note: Presenters must agree to grant a non-exclusive perpetual license to publish submitted materials, either electronically or in print, in any media related to C++ Now!. Hartmut Kaiser, email: hartmut.kaiser(a)gmail.com (Program Committee Chair) Dave Abrahams, email: dave(a)boostpro.com (Conference Chair) On behalf of the conference organizers

1 0

Quick Unit Test Question
by Brad Tilley 10 Jan '12

10 Jan '12

Hey everyone, I can make BOOST_CHECK produce a failure message like this: BOOST_AUTO_TEST_CASE( test_case2 ) { BOOST_CHECK( 1+1 == 3 ); } But when I try BOOST_WARN, all tests pass: BOOST_AUTO_TEST_CASE( test_case3 ) { BOOST_WARN( 1+1 == 3 ); } Running 3 test cases... *** No errors detected Perhaps I'm doing something wrong. Can someone point me in the right direction? Both BOOST_REQUIRE and BOOST_CHECK work OK. It's only BOOST_WARN that does not work for my testing. Thanks, Brad

5 7

Boost Review Wizard Report for January 2012
by Ronald Garcia 10 Jan '12

10 Jan '12

============================================== Review Wizard Status Report for January 2012 ============================================== News ==== 1. Type Traits Library Extensions Accepted 2. AutoIndex Tool Accepted 3. Heaps Library Accepted 4. Assign v2 Library Rejected 5. Type Traits Introspection Library Accepted 6. Lockfree Library Accepted 7. Algorithm Library Accepted 8. Atomic Library Accepted 9. Local Library Accepted 10. Context Mini-review Ongoing Open Issues =========== The following libraries have been reviewed and await reports from their review managers: * Conversion - reviewed August 2011; review manager: Gordon Woodhull. The following libraries have been accepted to Boost, but have not yet been submitted to SVN: * Constrained Value - accepted September 2010; author: Robert Kawulak * GIL.IO - accepted January 2011; author: Christian Henning. * Atomic - accepted July 2011; author Helge Bahmann * Lockfree - accepted August 2011; author: Tim Blechmann. * Algorithm - accepted December 2011; author: Marshall Clow The following libraries have been accepted and submitted to SVN, but have not yet appeared in a release: * Heaps - accepted June 2011; author: Tim Blechmann. * Type Traits Introspection - accepted August 2011; author: Edward Diener. The following libraries have been accepted provisionally to Boost, but have not been submitted for mini-review and full acceptance: * Log - accepted provisionally March 2010; author: Andrey Semashev. * Endian - accepted provisionally November 2011; author: Beman Dawes. After repeated failed attempts to contact the author, the following library has been marked as Orphaned. * Switch library, accepted provisionally January 2008 author: Steven Watanabe. General Announcements ===================== As always, we need experienced review managers. Please take a look at the list of libraries in need of managers and check out their descriptions. In general review managers are active boost participants, including library contributors, infrastructure contributors, and other mailing list participants with a substantial track record of constructive participation. If you can serve as review manager for any of them, email Ron Garcia or John Phillips, "rxg at cs dot cmu dot edu" and "phillips at pacific dot mps dot ohio-state dot edu" respectively. We are also suffering from a lack of reviewers. While we all understand time pressures and the need to complete paying work, the strength of Boost is based on the detailed and informed reviews submitted by you. If you are interested in reviewing a library but won't have time during the review period, you can always prepare your review ahead of time. No rule says you can only work on a review during the review period. A link to this report will be posted to www.boost.org. If you would like us to make any modifications or additions to this report before we do that, please email Ron or John. The review schedule is an unordered list of the libraries awaiting review. As such, any library on the schedule can be reviewed once the developer is ready, a review manager has been secured, and the manager, developer, and wizards agree on a date to schedule the review. Review Schedule =============== * Join (M) * Pimpl (M) * Sorting (M) * Quaternions, Vectors, Matrices (M) * Variadic Macro Data (M) * Block Pointer (M) * Network (M) * Singularity (M) * Predef (M) ``(M)`` marks libraries that need review managers. -------------------- Join ---- :Author: Yigong Liu :Review Manager: Needed :Download: http://channel.sourceforge.net/ :Description: Join is an asynchronous, message based C++ concurrency library based on join calculus. It is applicable both to multi-threaded applications and to the orchestration of asynchronous, event-based applications. It follows Comega's design and implementation and builds with Boost facilities. It provides a high level concurrency API with asynchronous methods, synchronous methods, and chords which are "join-patterns" defining the synchronization, asynchrony, and concurrency. Pimpl ----- :Author: Vladimir Batov :Review Manager: Needed :Download: | `Boost Vault <http://www.boost-consulting.com/vault/index.php?action=downloadfile&fil…>`__ | http://www.ddj.com/cpp/205918714 (documentation) :Description: The Pimpl idiom is a simple yet robust technique to minimize coupling via the separation of interface and implementation and then implementation hiding. This library provides a convenient yet flexible and generic deployment technique for the Pimpl idiom. It's seemingly complete and broadly applicable, yet minimal, simple and pleasant to use. Sorting ------- :Author: Steven Ross :Review Manager: Needed :Download: `Boost Vault <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=al…>`__ :Description: A grouping of 3 templated hybrid radix/comparison-based sorting algorithms that provide superior worst-case and average-case performance to std::sort: integer_sort, which sorts fixed-size data types that support a rightshift (default of >>) and a comparison (default of <) operator. float_sort, which sorts standard floating-point numbers by safely casting them to integers. string_sort, which sorts variable-length data types, and is optimized for 8-bit character strings. All 3 algorithms have O(n(k/s + s)) runtime where k is the number of bits in the data type and s is a constant, and limited memory overhead (in the kB for realistic inputs). In testing, integer_sort varies from 35% faster to 2X as fast as std::sort, depending on processor, compiler optimizations, and data distribution. float_sort is roughly 70% faster than std::sort. string_sort is roughly 2X as fast as std::sort. Quaternions, Vectors, Matrices ------------------------------ :Author: Emil Dotchevski :Review Manager: Needed :Download: http://www.revergestudios.com/boost-qvm/ :Description: QVM defines a set of generic functions and operator overloads for working with quaternions, vectors and matrices of static size. The library also defines vector and matrix data types, however it allows users to introduce their own types by specializing the q_traits, v_traits and m_traits templates. Variadic Macro Data ------------------- :Author: Edward Diener :Review Manager: Needed :Download: `Boost Sandbox <http://svn.boost.org/svn/boost/sandbox/variadic_macro_data/>`__ :Description: The variadic_macro_data library adds support and functionality for variadic macros to Boost as well as integrating variadic macros with the Boost PP library without changing the latter library in any way. Block Pointer ------------- :Author: Phil Bouchard :Review Manager: Needed :Download: `Boost Sandbox <https://svn.boost.org/svn/boost/sandbox/block_ptr/>`__ :Description: Deterministic memory manager of constant complexity capable of handling cyclic collections. Network ------- :Author: Dean Michael Berris :Review Manager: Needed :Download: http://cplusplus-soup.com/2011/04/18/cpp-netlib-0-9-0-released/ :Description: This is a library that provides application layer protocol support using modern C++ techniques. It is light-weight, fast, cross-platform and is intended to be as easy to configure as possible. Singularity ----------- :Author: Ben Robinson :Review Manager: Needed :Download: https://github.com/icaretaker/Singularity :Description: The Singularity Design Pattern allows you to restrict any class to a single instance. Unlike the infamous Singleton, Singularity gives you direct control over the lifetime of the object, does not require you to grant global access to the object, nor does it limit you to the default constructor for that object. Predef ------ :Author: Rene Rivera :Review Manager: Needed :Download: http://tinyurl.com/73n6a3k :Description: The Predef library implements two simple tasks: 1. Definition of a single version number macro to provide consistent version number at the preprocessor level. 2. A collection of detected definitions for compilers, standard libraries, architectures, operating systems, and languages. Unlike the Boost Config Library it doesn't define language features and capabilities. But only defines presence of detected compilation context. Documentation and downloads are available in the sandbox.. Libraries under development =========================== See http://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction for a current listing of libraries under development.

1 0

Re: [Boost-users] [Multi Index] equal_range from templated function fails to compile with gcc 4.6.1
by Jacob Metcalfe 10 Jan '12

10 Jan '12

Thanks for the quick reply, 51566 does seem very similar. I do not experience the issue from bug 9810 in any of the compilers where I have managed to reproduce the bug - from a quick look it looks somewhat different - and unfortunately changes to access_specifier.hpp don't solve the issue (changing the inheritance modifier or access modifiers in the derived class also does not seem to help). I experimented with a few changes but the only case that got rid of the error was the obvious change of making node_type public in index_base.hpp. In terms of gcc versions - so far I have reproduced the issue with 4.6.1, 4.6.2 and 4.5.2. Jacob.

2 2

extract objects from vector in shared memory
by Sabine B 09 Jan '12

09 Jan '12

Hello! I have again a question to using the boost vector with shared memory objects. I managed inserting the objects of type "MyType" into the vector with the following code: typedef boost::interprocess::allocator<MyType*, managed_shared_memory::segment_manager> ShmemAllocator; typedef boost::interprocess::vector<MyType*, ShmemAllocator> MyVector; struct shm_remove{ shm_remove(){shared_memory_object::remove("MySharedMemory");} ~shm_remove(){shared_memory_object::remove("MySharedMemory");} }remover; managed_shared_memory segment(create_only, "MySharedMemory", 65536); const ShmemAllocator alloc_inst(segment.get_segment_manager()); MyVector *vector = segment.construct<MyVector>("Vector")(alloc_inst); MyType *mytype = segment.construct<MyType>(anonymous_instance)(); MyVector->push_back(mytype); The problem is that I can't manage to extract the object from the vector. I always get a null pointer or a pointer to somewhere. This is the code for the child process: managed_shared_memory segment(open_only, "MySharedMemory"); vector = segment.find<MyVector>("Vector").first; MyType *mytype = vector->at(1); // program crashes when I try to print members of the object MyType or MyType mytype = (MyType&)vector->at(1); // object is empty Does anybody have any hint or an idea what I'm doing wrong? Thank you very much for your help! Best regards, Sabine

1 0

[Multi Index] equal_range from templated function fails to compile with gcc 4.6.1
by Jacob Metcalfe 09 Jan '12

09 Jan '12

I’m having issues compiling some multi_index_container code after upgrading from gcc 4.3.4 to gcc 4.6.1 and wondering if anyone can shed some light. Perhaps this should be directed to gcc, but I have not been able to reduce this to not include multi_index. The contrived code below is the furthest I have been able to reduce the problem so far:**** ** ** 1 #include <boost/multi_index_container.hpp>**** 2 #include <boost/multi_index/ordered_index.hpp>**** 3 #include <boost/multi_index/member.hpp>**** 4 #include <boost/multi_index/composite_key.hpp>**** 5**** 6 using namespace boost::multi_index;**** 7**** 8 struct Data{**** 9 double _d;**** 10 };**** 11**** 12 typedef multi_index_container< Data,**** 13 indexed_by< ordered_non_unique<**** 14 composite_key< Data, member<Data, double, &Data::_d> >**** 15 > >**** 16 > Map;**** 17**** 18 template <int T>**** 19 void foo(){**** 20 Map mi;**** 21 mi.get<0>().equal_range(boost::make_tuple(0.0));**** 22 }**** 23 int main(){**** 24 foo<5>();**** 25 }**** ** ** The failures from gcc 4.6.1 are:**** ** ** boost/multi_index/detail/index_base.hpp: In function 'void foo() [with int T = 5]':**** boost/multi_index/detail/index_base.hpp:49:47: error: 'typedef struct boost::multi_index::detail::index_node_base<Data, std::allocator<Data> > boost::multi_index::detail::index_base<Data, boost ::multi_index::indexed_by<boost::multi_index::ordered_non_unique<boost ::multi_index::composite_key<Data, boost::multi_index::member<Data, double, &Data::_d> > > >, std::allocator<Data> >::node_type' is protected**** tstmi.cpp:24:10: error: within this context**** ** ** ** ** This code appears to compile fine under 4.3.4 and would compile with 4.6.1 if the useless template at line 18 was removed.**** ** ** Many thanks

2 1