September 2010 - Boost-users - lists.preview.boost.org

[test] crash with the following test
by Felipe Magno de Almeida 22 Sep '10

22 Sep '10

With boost 1.44.0 (the same happens with 1.43) the following test causes a crash in framework.ipp:388 with a dereference of a NULL pointer. The test_unit* res returns NULL from s_frk_impl().m_test_units[id] where id is 1. id is equal to 1 because when unit_test::framework::run is ran, id is INV_TEST_UNIT_ID is passed to it. Then in framework.ipp:399 if id == INV_TEST_UNIT_ID id is assigned the value in master_test_suite().p_id which is 1. I've verified that when master_test_suite is constructed it assigns INV_TEST_UNIT_ID to p_id, so I'm lost why this is 1 here. Then, back in framework.ipp:386 s_frk_impl().m_test_units there's only one element in the map and the id is 65535 and not one. -- test.cpp -- #define BOOST_TEST_MODULE parse_empty_import_documents #include <boost/test/included/unit_test.hpp> BOOST_AUTO_TEST_CASE (parse_empty_import_documents) { } -- test.cpp -- Any help would be appreciated. -- Felipe Magno de Almeida

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[Test] Unit test for const suggestion.
by MA 22 Sep '10

22 Sep '10

Hi there! I have been having some trouble unit testing const variables/types in my code. The problem I had was basically: The compiler stops the compilation with an error if you try to change a const variable/type. Still you want to write a unit test that checks that the variable cannot be changed. So to check that the variable/type cannot be changed we can just check if the variable/type is const or not. By doing so we indirectly check that the variable/type cannot be changed. So the suggestion for the Boost.Test library is to create a BOOST_CHECK_IS_CONST that works something like the code below but with the BOOST_CHECK_EQUAL syntax: ------ #include <iostream> #include <boost/type_traits.hpp> template<typename T > bool isconst(T&, typename boost::enable_if<boost::is_const< T >, T >::type* = 0 ) { return true; } template< typename T > bool isconst(T&, typename boost::disable_if<boost::is_const< T >, T>::type* = 0 ) { return false; } int main() { const int const_int = 0; int plain_int = 0; std::cout << isconst(const_int) << std::endl; std::cout << isconst(plain_int) << std::endl; } ----- By doing this you can check for const in a unit test like this: BOOST_CHECK_EQUAL(isconst(const_int), true); But it would be nicer with a BOOST_CHECK_IS_CONST. Regards, anlmat

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Problem with boost archive. Cannot solve in any way.
by Germán Diago 22 Sep '10

22 Sep '10

Hello. I have this code, which throws an exception and I cannot find in any way why. It throws an invalid_signature exception. I'm sure that the serialized data where it comes this data from is correct. The code: std::string data_bytes(std::get<1>(*datos).begin(), std::get<1>(*datos).end()); std::istringstream stream(data_bytes); MensajeRed msg; //FIXME: This constructor throws boost::archive::binary_iarchive archive(stream); archive >> msg; Throws in the constructor of boost::binary_iarchive. Thanks in advance.

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[test] inconsistent dll linkage warnings and BOOST_TEST_DECL and unit_test_main.ipp
by Felipe Magno de Almeida 22 Sep '10

22 Sep '10

Hi, When I compile /boost//unit_test_framework as a dependency in a boost.build project I get errors with BOOST_TEST_DECL with some definitions in .ipp files. It seems BOOST_TEST_DECL is suppose to be used in functions that aren't defined for the user and that must be exported/imported depending if included by test's source or the user's source files. But .ipp files use BOOST_TEST_DECL which are included by the user with msvc-8.0 compiler and then it gives errors about that __declspec(dllimport) doesn't allow definition. To fix it I just changed BOOST_TEST_DECL for BOOST_TEST_CALL_DECL in the .ipp files. It works correctly with gcc in linux though. Regards, -- Felipe Magno de Almeida

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[ASIO] Access violation on io_service::work destructor
by Daniele Barzotti 22 Sep '10

22 Sep '10

Hi, In my code I have a io_Service and a work object shared among my classes: // Main io_service static boost::asio::io_service io_service; static boost::scoped_ptr<boost::thread> io_service_thread; static boost::asio::io_service::work* p_work; static BOOL thread_started; void io_worker_thread(void) { #if(WIN32 && _WIN32_DCOM) struct com_init { com_init() { CoInitializeEx(NULL, COINIT_APARTMENTTHREADED); } ~com_init() { CoUninitialize(); } } initializer_object; #endif io_service.run(); io_service.reset(); thread_started = false; }; void Init(....) { if (!thread_started) { try { // create the work object on the heap p_work = new boost::asio::io_service::work(io_service); // run the IO service as a separate thread: // Instead of start the worker thread directly // by passing the io_service object, // I call the io_worker_thread function where // I can do some initialization tasks like // calling CoInitializeEx for COM io_service_thread.reset(new boost::thread(io_worker_thread)); thread_started = !thread_started; } catch (boost::thread_resource_error e) { // Failed to create the new thread return 0; } } } When my application ends and the io_service.run() returns I get: First-chance exception at 0x09299c18 (AxEuroATLib_debug.dll) in EuroSvr.exe: 0xC0000005: Access violation reading location 0xf0f0f0fc. at the following line (io_service.ipp): inline io_service::work::~work() { io_service_.impl_.work_finished(); } I wrong something? Regards, Daniele

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Boost.PropertyTree - Iterating over child items with same name
by RUOFF, LARS (LARS)** CTR ** 22 Sep '10

22 Sep '10

Hello, concerning Boost.PropertyTree: First: Taking the example file from the Tutorial: <debug> <filename>debug.log</filename> <modules> <module>Finance</module> <module>Admin</module> <module>HR</module> </modules> <level>2</level> </debug> The module entries are parsed using BOOST_FOREACH(ptree::value_type &v, pt.get_child("debug.modules")) m_modules.insert(v.second.data()); But reading the documentation for "get_child" confuses me: --------------- self_type & get_child(const path_type & path); Get the child at the given path, or throw ptree_bad_path. Notes: Depending on the path, the result at each level may not be completely determinate, i.e. if the same key appears multiple times, which child is chosen is not specified. [...] --------------- So how is it garantueed that BOOST_FOREACH will iterate over all the children? Second: (This is my actual problem) If for example i extend the file a bit like this: <debug> <filename>debug.log</filename> <modules> <module>Finance</module> <param1>100</param1> <param2>200</param2> <module>Admin</module> <param1>100</param1> <param2>200</param2> <module>HR</module> <param1>100</param1> <param2>200</param2> </modules> <level>2</level> </debug> Now the "modules" have sub-items. How would i go to iterate over the modules and children if i'd need to create an object for each module and associate the right params to each? Thanks, regards, Lars

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[PtrContainer] Inserting "this" Pointers
by Hossein Haeri 22 Sep '10

22 Sep '10

Dear all, Is inserting "this" pointers into pointer containers valid? If so, what are the consequences? Would that need special care for example? TIA, --Hossein

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circular_buffer iterators
by Bosko Markovic 22 Sep '10

22 Sep '10

I have a simple use case for circular_buffer but I need a few advices. There is one producer and one consumer which only inspects elements and circular buffer will only be keeping history of last CB_SIZE elements. As far as I have understood there are two ways to access buffer elements, using indexes and operator[] or using iterators. I have chosen iterators. Since adding elements to buffer can invalidate iterators what is the proper way to check if they are still valid? Is it comparing it to .end() and .begin()? typedef boost::circular_buffer<data_type> CircularBuffer; CircularBuffer cb(CB_SIZE); CircularBuffer::iterator it = cb.begin(); ... if( it >= cb.begin() && it < cb.end() ){ cout << *it; } Regards, BoskoM.

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Compiling boost::regex v4 with VC8 on Windows
by Wolfgang Goldbach 22 Sep '10

22 Sep '10

Hi, In my current project boost::regex was used previously from version v3 (boost 1.30.2) and there was no problem. Because I use a third party SDK that contains boost 1.33.1 I want to use boost and regex (v4) from this SDK. In the project there is a source file that includes "boost/regex.hpp". In the release version the file compiles, but in the debug version I get a lot of errors like: char_regex_traits.hpp(34) : error C2976: 'boost::regex_traits' : too few template arguments /basic_regex.hpp(186) : error C2825: 'traits': must be a class or namespace when followed by '::' basic_regex.hpp(186) : error C2039: 'size_type' : is not a member of '`global namespace'' I have now removed the preprocessor definition '_DEBUG' from the VC8 project that contains the source file but this makes no difference. Is there any idea what's going on here ? Wolfgang

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boost thread, shared_mutex deadlock
by George George 22 Sep '10

22 Sep '10

threadA owns a shared_lock on the mutex, threadB tries to get a unique lock on the mutex and blocks, threadC tries to get a shared_lock on the mutex and blocks also!! I guess there is a LIFO kind of stack serving the mutex to the requesting locks. But what happens if threadA depends on threadC in order to complete and release the lock?I n this case I have got a deadlock. Is this a design flow of my app or boost?

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