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[range] can't use boost::any_range with RTTI disabled due to boost::polymorphic_downcast
by Adam Romanek 06 May '14

06 May '14

Hi! I'd like to draw your attention to an issue with boost::any_range that prevents it from being used with RTTI disabled. The problem is that boost::any_range indirectly uses boost::polymorphic_downcast which in turn uses dynamic_cast. Note that the dynamic_cast is only used to ensure the requested cast is valid and it's done only in non-release builds. It would be great if the check was simply skipped in RTTI-disabled environments, as it is done in release builds. This would result in loss of safety that boost::polymorphic_downcast provides but the pieces that use it would at least compile in RTTI-disabled environments. Would it be possible to fix this problem? If you wish I could create a ticket for this issue. BTW, there's a typo in the documentation of boost::any_range [1]. It mentions boost::forward_pass_traversal_tag, which does not exist. It should rather be boost::forward_traversal_tag. WBR, Adam Romanek [1] http://www.boost.org/doc/libs/1_55_0/libs/range/doc/html/range/reference/ra…

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Boost support of MinGW
by Kosta Zertsekel 05 May '14

05 May '14

Hi guys, It is said that MinGW is not supported by Boost because it is not fully POSIX compatible: http://www.boost.org/doc/libs/1_55_0/more/getting_started/windows.html#pch Excerpt: "A note to Cygwin and MinGW users If you plan to use your tools from the Windows command prompt, you're in the right place. If you plan to build from the Cygwin bash shell, you're actually running on a POSIX platform and should follow the instructions for getting started on Unix variants. Other command shells, such as MinGW's MSYS, are not supported-they may or may not work." Does it mean that is some program that uses Boost was compiled with MinGW, then it can randomly crash or has some stability issues? Thanks in advace, --- Kosta

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[TypeIndex 3.0] Review Manager's Report
by Niall Douglas 04 May '14

04 May '14

Dear Boost, The second round of peer review of proposed Boost.TypeIndex finished on Wed 30th, and here is the review manager's report. My thanks to the five reviewers who took the time and trouble to submit full reviews, plus to everyone else who commented. Votes regarding acceptance: 4 voted to accept TypeIndex into Boost immediately. 1 voted to accept into Boost with conditions. Overall: I recommend immediate acceptance into Boost. Conditions: 1. No one liked the present boost::typeind namespace, almost anything else would be better. I see the namespace has already changed in the develop branch to boost::typeindex, so I think this is already solved. Other common comments: * More than one reviewer mentioned how they liked the docs. * More than one reviewer expressed a desire for an ability to programmatically parse through type specifier strings. I agree with Antony that that is another library which isn't TypeIndex (something Boost.Spirit based which works directly with mangled symbol string representations, representing them as a partial AST - preferably also with a libclang compatible backend - would be great, but that is a totally different library and TypeIndex 3.x provides extensibility for such an additional function). * More than one reviewer sought some method of preventing link if you mix up incompatible uses of TypeIndex and/or with RTTI. Niall -- Currently unemployed and looking for work in Ireland. Work Portfolio: http://careers.stackoverflow.com/nialldouglas/

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What's wrong with my code?
by Bill David 04 May '14

04 May '14

Hi all, I meet a problem with some code with boost and want to ask for some help here. To the following code: #include <list> using namespace std; #include "boost/function.hpp" #include "boost/foreach.hpp" #include "boost/bind.hpp" using namespace boost; void InsertItemHelper(list<int>& inContainer, list<int>::iterator& ioPosition, const list<int>::value_type& inItem) { ioPosition = inContainer.insert(ioPosition, inItem); } void WorkerFunction(const list<int>& inContainer, boost::function<void(int)> const& inAddItemCallback) { BOOST_FOREACH(auto item, inContainer) { inAddItemCallback(item); } } void Print(const list<int>& inContainer) { BOOST_FOREACH(auto item, inContainer) { std::cout << item << endl; } } int main() { list<int> sourceContainer; sourceContainer.push_back(1); sourceContainer.push_back(2); sourceContainer.push_back(3); list<int> targetContainer; list<int>::iterator pos = targetContainer.end(); boost::function<void(int)> addItemCallbackFxn(boost::bind(& InsertItemHelper, targetContainer, pos, _1)); WorkerFunction(sourceContainer, addItemCallbackFxn); return 0; } When I run it on Windows with VS2012, I always get a “list insert iterator outside range” error with: inContainer.insert(ioPosition, inItem); It seems targetContainer I passed to boost::bind is copied so that the following debug error of STL is hit: #if _HAS_ITERATOR_DEBUGGING if (_Where._Mycont != this) _DEBUG_ERROR("list insert iterator outside range"); #endif /* _HAS_ITERATOR_DEBUGGING */ But I am passing targetContainer as a reference and after the error, I can correctly get data in it. Does anybody know what’s wrong behind? Thanks, BD

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[Date Time] time_period has not default constructor
by Pablo Madoery 30 Apr '14

30 Apr '14

I am using the library Date Time, in particular the object time_period. I was wondering why (if there is a good reason) this class has not a default constructor. the default constructor result usefull when using for example a map with the operator [] or when using serialization from Boost. ptime class has default constructor. If a time_period is formed by two ptime objects, why time_period has not its default constructor as well. Thanks

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allocating shared memory fails beyond 8 GB
by vipin sachdeva 30 Apr '14

30 Apr '14

Hi, I am using managed_xsi_shared_memory to allocate memory as below: boost::interprocess::managed_xsi_shared_memory shmem(boost::interprocess::create_only, key, atol(argv[2])); For some reason, I cannot allocate more than 8 GB of memory. Both sysctl and ipcs have limits higher than that set (output below). ------ Shared Memory Limits -------- max number of segments = 1874919423 max seg size (kbytes) = 9765624999999 max total shared memory (kbytes) = 39999999999999996 min seg size (bytes) = 1 kernel.shmmax = 9999999999999999 kernel.shmall = 9999999999999999 kernel.shmmni = 1874919423 vm.hugetlb_shm_group = 0 Is there any reason why this allocation should fail ?

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[typeindex v3.0] Peer review begins Mon 21st ends Wed 30th
by Niall Douglas 30 Apr '14

30 Apr '14

Dear Boost, A second round of community review begins for proposed Boost.TypeIndex on Mon 21st, lasting ten days. I should apologise as it's my fault for starting another peer review straight after Boost.Align ends, however I was busy as Google Summer of Code admin until today, and I will be preparing to talk at C++ Now straight after this review ends. I hope that this doesn't affect the community's willingness to contribute to the review. Reminder of the report from the last TypeIndex v2.1 review: https://groups.google.com/forum/#!topic/boost-list/TeiSdkRkUF0 Reminder of the original peer review announcement: http://boost.2283326.n4.nabble.com/TypeIndex-Peer-review-period-for-li brary-acceptance-begins-ending-Thurs-21st-Nov-td4654788.html Source code: https://github.com/apolukhin/type_index/zipball/master Github: https://github.com/apolukhin/type_index Documentation: http://apolukhin.github.com/type_index/index.html Changes in TypeIndex v3.0 since v2.1 (from my own review of it): 1. Documentation is hugely improved over v2.1, lots of side by side examples illustrating the differences and similarities. 2. You can now create your own custom type indices using an extensible framework. 3. boost::typeind::type_info now exports raw_name() and pretty_name() to maximise MSVC-GCC compatibility, and to solve point 1 but not point 2 in the v2.1 report. 4. The undefined behaviour trick used in v2.1 has been replaced with a cast via the placeholder type boost::typeind::detail::ctti_data which can be viewed in https://github.com/apolukhin/type_index/blob/master/include/boost/type _index/ctti_type_index.hpp. There is an explanation in the comments there about this technique's compatibility with the C++ standard. 5. TypeIndex now defines everything in the boost::typeind namespace instead of the boost namespace. So: 1. What is your evaluation of the design? 2. What is your evaluation of the implementation? 3. What is your evaluation of the documentation? 4. What is your evaluation of the potential usefulness of the library? 5. Did you try to use the library? With what compiler? Did you have any problems? 6. How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? 7. Are you knowledgeable about the problem domain? And finally, every review should answer this question: 8. Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. Thanks, Niall -- Currently unemployed and looking for work in Ireland. Work Portfolio: http://careers.stackoverflow.com/nialldouglas/

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update cycle
by Philipp Kraus 30 Apr '14

30 Apr '14

Hello, I try to compile Boost myself under OSX and the thread library runs into compiler errors. I have seen that the fix is inserted into the repo, so I would like to wait to a new Boost release. The last Boost version (1.55.0) was released on November 2013, so my question is in which cycles are new releases created (half a year)? Thanks Phil

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Boost::Interprocess - using variadic template args with managed_shared_memory::construct()
by james 28 Apr '14

28 Apr '14

Hi, I'm trying to write a wrapper over some of boost::interprocess and I want to have a function like this: template <typename T, typename... Args> T* Wrapper::createStruct(const std::string& name, Args&&... args) { return m_shm->construct<T>(name.c_str())(std::forward<Args>(args)...); } This fails to compile as it seems boost::interprocess uses its own varargs scheme when I try to create the following struct in the SHM through this wrapper function: struct Custom { Custom(int a, int b) : m_a(a), m_b(b) { } int a; int b; } int main() { ... Custom* c = shm->createStruct("Custom", 1, 2); } The error message: /usr/include/boost/interprocess/detail/named_proxy.hpp:79:7: error: no matching function for call to ‘test_sharedmemory::sharedmemory_custom::test_method()::Custom::Custom()’ { new((void*)mem)T(boost::forward<Args>(get<IdxPack>(args_))...); } ^ /usr/include/boost/interprocess/detail/named_proxy.hpp:79:7: note: candidates are: /home/james/dev/infinityplus/test/common/shm/sharedmemory/main.cpp:136:7: note: test_sharedmemory::sharedmemory_custom::test_method()::Custom::Custom(int, int) Custom(int one, int two) ^ /home/james/dev/infinityplus/test/common/shm/sharedmemory/main.cpp:136:7: note: candidate expects 2 arguments, 0 provided Is there any way I can get this to work? I'd rather my wrapper's interface used std only. boost 1.55 c++11 g++ 4.8.2 TIA, James

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Announcing the student program for Meeting C++ 2014
by Jens Weller 28 Apr '14

28 Apr '14

Hello C++ and Boost Community, today I have the honor to announce the student program for Meeting C++ 2014: > The Meeting C++ Student program will enable 50 students to attend Meeting C++ 2014 plus 3 exclusive workshops organized by think-cell one day before the conference on December 4th. So, for students this will be a 3 day conference! After the workshops you will be invited to the student dinner by think-cell. Further details at http://meetingcpp.com/index.php/newsreader/items/meeting-cpp-2014-the-stude… kind regards, Jens Weller

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