September 2014 - Boost-users

[interprocess] Determine size of managed_shared_memory
by Kai Benndorf 12 Oct '19

12 Oct '19

Hi all, I want to create a managed_shared_memory in exactly the size I needed. Therefore I do something like this: size = sizeof( common_managed_shared_memory ); size += sizeof( MyClassInSharedMem ); managed_shared_memory segment(create_only, "name", size ); MyClassInSharedMem allocates itself some memory by segment->allocate(). I added this also to the size, but get a boost::interprocess::bad_alloc exception on allocating this additional memory. Are there some magic bytes I forgot to add? Many thanks in advance Kai

3 2

[Range, Phoenix] What am I missing...
by Robert Jones 25 Apr '17

25 Apr '17

Hi Folks Can anyone explain the output of this program... #include <iostream> #include <boost/range/algorithm/copy.hpp> #include <boost/range/counting_range.hpp> #include <boost/range/adaptor/reversed.hpp> #include <boost/range/adaptor/transformed.hpp> #include <boost/phoenix/bind/bind_function.hpp> #include <boost/phoenix/core/argument.hpp> int f( int i ) { return i * 2; } int main( ) { using boost::adaptors::reversed; using boost::adaptors::transformed; using boost::counting_range; using boost::copy; using boost::phoenix::arg_names::_1; copy( counting_range( 1, 5 ) | reversed | transformed( f ), std::ostream_iterator<int>( std::cout, " " ) ); std::cout << std::endl; copy( counting_range( 1, 5 ) | reversed | transformed( bind( f, _1 ) ), std::ostream_iterator<int>( std::cout, " " ) ); std::cout << std::endl; } Which is... 8 6 4 2 1768406272 1768406272 1768406272 1768406272 I'm using Gcc 4.6.2 & Boost 1.53 Thx All.

3 4

[statechart] Passing parameters from event to State Local Storage
by Christophe Bourez 16 Nov '16

16 Nov '16

I need to maintain a parameter into the state local storage. This parameter is initially contained in the event that causes the transition to the target state. I give hereafter a small illustrative example. typename sc = boost::statechart; class EvTest : public sc::event<EvTest> { public: EvTest(std::size_t val) : value(val) {} std::size_t getValue() const { return this->value; } private: std::size_t value; }; class MyStateMachine; class StSource; class StTarget; class StSource : public sc::simple_state<StSource, MyStateMachine> { public: typedef sc::custom_reaction<EvTest> reactions; sc::result react(const EvTest &event) { // How to pass event.getValue() to the target state ? transit<StTarget>(); } }; class StTarget : public sc::simple_state<StTarget, MyStateMachine> { public: StTarget(std::size_t val) : val(value) {} private: std::size_t value; }; Thanks, Christophe

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Re: [Boost-users] lexical_cast between double and string slow in Visual Studio 2013
by David Roberts 07 May '15

07 May '15

> That issue is unknown. I'd really appreciate the investigation. I have done some more investigation, and there are two factors that only cause the slowness when they both occur together. > Try excluding the lexical_cast from test, I have a feeling that this is only MSVC related issue: > > #include <sstream> > #include <string> > > int main (int, char **) > { > for (double count = 0.0; count < 1000000.0; count += 1.41) > { > std::stringstream ss; > ss << count; > std::string result = std::move(ss.str()); > ss.str(std::string()); > > ss << result; > ss >> count; > } > > return 0; > } > Running your test program does not exhibit the problem. It runs in around 3 seconds on my machine when built with either Visual Studio 2010 or Visual Studio 2013. However, changing it very slightly to match more closely what lexical_cast does internally does recreate the problem: #include <sstream> #include <string> int main (int, char **) { for (double count = 0.0; count < 1000000.0; count += 1.41) { std::stringstream ss; ss.unsetf(std::ios::skipws); ss.precision(17); ss << count; std::string result = std::move(ss.str()); ss.str(std::string()); ss << result; ss >> count; } return 0; } The effect of setting the precision to 17 is that lots of 9s appear in the string representations. (The number 17 is what boost::detail::lcast_get_precision(double*) chooses.) Without the precision call the contents of the string called result start off like this: 0 1.41 2.82 4.23 5.64 7.05 8.46 9.87 11.28 12.69 With precision set to 17 they start off like this: 0 1.4099999999999999 2.8199999999999998 4.2299999999999995 5.6399999999999997 7.0499999999999998 8.4599999999999991 9.8699999999999992 11.279999999999999 12.69 This happens for both Visual Studio 2010 and Visual Studio 2013. Then the next difference is that Visual Studio 2013 spends a lot longer handling all the extra 9s. Changing the program so that the double is converted to a string using std::stringstream without a precision call and then back to double using lexical_cast takes about 3 seconds for both Visual Studio 2010 and Visual Studio 2013. It is the combination of having all the extra 9s to parse and using Visual Studio 2013 that makes the test using lexical_cast to go both ways slow. Both Visual Studio 2010 and Visual Studio 2013 do the conversion by calling std::num_get<char,std::istreambuf_iterator<char,std::char_traits<char> > >::do_get() which then calls a function called _Stodx() which is implemented in xstod.c. This function is very different for the two versions. In Visual Studio 2010 it's a relatively thin wrapper around the C function strtod(). In Visual Studio 2013 _Stodx() has got a completely new implementation that's generated by #including xxstod.h with some macros defined. The original C function strtod() is much faster than the new _Stodx() when there are lots of 9s at the end of the strings being parsed. This modification to the program: #include <sstream> #include <string> #include <stdlib.h> int main (int, char **) { for (double count = 0.0; count < 1000000.0; count += 1.41) { std::stringstream ss; ss.unsetf(std::ios::skipws); ss.precision(17); ss << count; std::string result = std::move(ss.str()); ss.str(std::string()); ss << result; char *endptr; count = strtod(ss.str().c_str(), &endptr); } return 0; } has a runtime of about 3 seconds even though it's got to cope with all the 9s. I guess only someone from Microsoft or Dinkumware could comment on why _Stodx() was reimplemented. But the other thing is that by setting precision to 17 lexical_cast is bloating the string representations of the doubles with lots of 9s in both Visual Studio 2010 and Visual Studio 2013. Setting precision to 15 instead prevents this, and makes the original test run faster even with Visual Studio 2013 (about 4 seconds rather than 10). Regards, David

5 4

Statechart serialization
by mbrodeur65 04 Mar '15

04 Mar '15

Hi, I'm looking for a solution to serialize boost::statechart objects. I'm aware that this feature is on the statechart library todo list but was wondering if there are any workaround to achieve this with the latest boost release (1.34) ? thanks for your help ! mbrodeur65 -- View this message in context: http://www.nabble.com/Statechart-serialization-tf4131326.html#a11749139 Sent from the Boost - Users mailing list archive at Nabble.com.

4 4

[multi state machine/ MSM] execute_queued_events
by Steve Hickman 26 Jan '15

26 Jan '15

In the MSM doc section "Enqueueing events for later processing", you state that "Calling execute_queued_events() will then process all enqueued events (in FIFO order)." You also said in a previous post that MSM is not thread safe, thus requiring an external mechanism to insure thread safety. I don't see a mechanism to execute a single event at a time, which would be preferable if I have to lock the queue while processing events. Having said that, a cursory examination of the "execute_queued_events" code makes me think it only processes one event per call. Which is correct? Is the documentation correct that it actually processes all queued events? If not, can the documentation be corrected? If so, is there a publicly usable call to process a single queued event? If there is no publicly available call for processing a single queued event, how do you recommend processing queued events in a thread safe manner that won't lock the queue for extended periods of time?

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[endian] Boost.Endian library added for 1.57.0
by Beman Dawes 14 Dec '14

14 Dec '14

The library provides integer and floating point types and conversion functions for portable byte ordering regardless of processor endianness. Although the primary uses are for file or network I/O, it is also useful for unaligned integers or floats, or for 3, 5, 6, and 7 byte integers. The library's predecessors have been in use for thirty years and developed independently multiple times. The repository is https://github.com/boostorg/endian The documentation is online at https://boostorg.github.io/endian/ See https://boostorg.github.io/endian/index.html#Release-history for changes since the Formal Review. No need to report "Inspection Report" problems; those will be cleaned up before 1.57.0 ships. Please do report any other problems or concerns, since the time between now and when the 1.57.0 beta ships in effect acts a mini-review period. If anyone has access to a big-endian platform with a modern C++ compiler, please, please run the endian test suite and report the results. All testing and use in recent years has been on little-endian platforms, so big-endian platform testing is a worry. Thanks for you patience, --Beman

3 2

Fusion Move Semantics
by Ovanes Markarian 04 Dec '14

04 Dec '14

Hi! I would like to ask does fusion supports move semantics, or are all the values going to get copied. I use C++11 (clang with libstdcxx) and boost 1.54 (but can upgrade). In my use case I have boost::fusion::map and was wondering, that in case of moving of that map, is it going to forward the move call to contained values or not. Many thanks for help, Ovanes

3 2

NT² 3.0 and Boost.SIMD - Stable release
by Joel Falcou 21 Nov '14

21 Nov '14

The first stable release of the 3.x series of MetaScale’s open-source software is available: NT² 3.0. It also includes its spin-off project, Boost.SIMD (not yet a Boost library). Many Issues have been closed since last beta. The main focus of this release cycle was to fix performances issues and to stabilize some parts of the API. Next step will be to separate NT2 and Boost.SIMD into separate repositories, thus making one more step toward Boost.SIMD submission into review. [ http://www.metascale.org/nt%C2%B2-3-0-and-boost-simd ] *Changes & Bug Fixes:* - Major performance improvements in both libraries - Added experimental support for the HPX runtime for parallelization on shared memory systems - Optimizations of many elemental functions, in particuler log/ex, frexp/ldexp and cbrt - More advanced shuffle pattern recognition for SIMD - Fixed issues with Visual Studio 2013 - More functions are force-inlined to ensure good performance - New functions for conversion between types and mixing of vectors of different sizes - Demo applications usable as benchmarks - Better handling of errors when an unsupported function is called - New API for custom memory allocators Full changelog is available at https://github.com/MetaScale/nt2/releases/tag/3.0.0. *How to get it ?* - Source and binary packages can be downloaded here: http://nt2.metascale.org/downloads - The release is also available on Github : https://github.com/MetaScale/nt2/releases - The main master branch is still under development : https://github.com/MetaScale/nt2

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[property_tree] Failure with Boost 1.56
by beet 10 Oct '14

10 Oct '14

Dear all, with the release of Boost 1.56, on Ubuntu 14.04 (g++ 4.8.2, 64 bit), code like the following suddenly fails to compile: pt::xml_writer_settings<char> settings('\t', 1); pt::write_xml(someFileName, ptr_out, std::locale(), settings); "pt" is obviously an alias for boost::property_tree. The error message I'm getting is /opt/boost156/include/boost/property_tree/detail/xml_parser_writer_settings.hpp:38:35: error: 'char' is not a class, struct, or union type typedef typename Str::value_type Ch; I can see the following possibly relevant change in property_tree: In Boost 1.55, from xml_parser.hpp: ----------------------------------- template<typename Ptree> void write_xml( const std::string & , const Ptree & , const std::locale & = std::locale() , const xml_writer_settings<typename Ptree::key_type::value_type >& = xml_writer_settings<typename Ptree::key_type::value_type >() ); In Boost 1.56, same header: --------------------------- template<typename Ptree> void write_xml( const std::string & , const Ptree & , const std::locale & = std::locale() , const xml_writer_settings<typename Ptree::key_type > & = xml_writer_settings<typename Ptree::key_type >() ); So xml_writer_settings is now given a Ptree::key_type instead of a Ptree::key_type::value_type which I assume is the reason for the above error. Is there a portable way to specify the type of indention character in write_xml ? Best Regards, Beet

2 1

[Threads] and OpenMP
by Stephan Menzel 01 Oct '14

01 Oct '14

Hi all, I would like to ask around about a strategy on how to tacke the following threading problem: I am maintaining a boost intensive portable C++ client-server application and recently have included a highly complex 3rd party algorithm into my application that does CPU intense stuff. Long running stuff. Often in the range of days. While at the same time being heavy in OpenMP usage. Now of course requirements are that the user has to be able to cancel this. The algorithm runs in a boost threads controlled background thread. Now I began to place interruption points throughout the 3rd party code but soon had to realize that a lot of CPU time is being handled in OpenMP threaded code regions. So the question is: How can I more or less gracefully shut this down? How do interruption points work in an omp parallel for loop? Do I have a chance at all? My constraints here are a bit forgiving. Given the complexity of the 3rd party code I have already accepted the notion that this is gonna be a memleak monster. Luckily, there's no disk or other hardware access so I'm ready to live with a certain amount of mem not being cleaned up. Yet the backend thread communicates with the spawning class by calling a mutexed callback when it's ready so the user knows it's cancelled. This is protected by a boost mutex as well. And juding from the horrible threading "clogs" that I observed in my first trials I suppose this is gonna be a problem as well. And input is appreciated. And yes, I am aware that this is gonna be an ugly mess. Cheers, Stephan

3 3

[bimap] Mapping a set into itself
by Arindam Mukherjee 30 Sep '14

30 Sep '14

Is there a way to represent a mapping from a set to itself using boost::bimap? Regards, Arindam

1 0

choosing source ip on multihomed computer
by David Frank 30 Sep '14

30 Sep '14

Hi, I'm wondering how to make boost::asio::connect(<socket>, ...) connect from the source interface/ip address I choose on a multihomed computer. Thanks, Dave

2 1

[serialization] serialize type-erasure
by oswin krause 30 Sep '14

30 Sep '14

Hi list, i am currently trying to serialize a type-erasure, but i am not sure how this should be done exactly. Before boost 1.56 we used the polymorphic archives and a base class to implement serialization, but since they are broken in 1.56 and a few users are nagging me (plus i can't compile the library myself any more after a mandatory upgrade...), i have to get it right. my setup looks like this class ErasureBase{ .... }; template<class T> class Erasure{ public: Erasure (T& foo):m_foo(foo){} template<class Archive> void serialize(Archive & ar, const unsigned int){ ar & m_foo; } private: T& m_foo; }; class MyClass{ public: template<class T> MyClass(T& foo):m_wrapper(new Erasure<T>(foo)){} template<class Archive> void serialize(Archive & ar, const unsigned int){ ar & *m_wrapper; } private: boost::scoped_ptr<ErasureBase> m_wrapper; }; in the usage of MyClass i assume that serialisation/deserialisation is only to be called on constructed objects of type MyClass, therefore i do not need capabilities to deserialize from pointers. The question is: how do I tell the archive which Erasure<T> exist? The solutions in the tutorial pages only look at the cases where Erasure<T> is serialized directly or where it is known which classes are to be serialized (and i don't assume my users to know which Erasure<T> are instantiated...). If there exists a solution for this: is the solution also stable wrt the order of registration of classes? Best, Oswin The ques

1 1

[multi_index] Couple of questions on multi-index containers
by Aaron Levy 29 Sep '14

29 Sep '14

If I erase elements in a multi_index_container, how are iterators invalidated? 1. For other than random_access index, only iterators to the deleted element? 2. For random_access index, potentially any iterator? What are the data structures used internally for this container and its indexes. -- Aaron Levy aaron.levy(a)yandex.com

4 5

[msm] & typeerasure / any
by Raj Sambasivan 28 Sep '14

28 Sep '14

HI Boost-users/christophe, I'm trying to make use of type erasure for fsm based on suggestion from an earlier mail thread http://boost.2283326.n4.nabble.com/msm-access-to-root-fsm-td4649632.html but hitting compilation errors. Can you pls help? while the any works as expected for push back e.g for vector (bottom of email) it doesnt work for MSM.. *Doesn't Work for MSM:* BOOST_TYPE_ERASURE_MEMBER((has_process_event), process_event, 1) typedef any<has_process_event<HandledEnum(Event1 const &)>, _self&> any_fsm; struct AnyFSM { AnyFSM(any_fsm afsm_) : _afsm(afsm_) {} void process(Event1& e) { _afsm.process_event(e); } any_fsm _afsm; }; TestFSM test; test.start(); AnyFSM(test); test.process(Event1()); *error:* *test.cpp:47:43: **error: **'Event1' does not refer to a value* typedef any<has_process_event<HandledEnum(Event1 const &)>, _self&> any_fsm; *Works for vector:* BOOST_TYPE_ERASURE_MEMBER((has_push_back), push_back, 1) typedef any<has_push_back<void(int)>, _self&> any_container; void append_many(any_container container) { for(int i = 0; i < 10; ++i) container.push_back(i); } struct AnyContainer { AnyContainer(any_container cont_) : _cont(cont_) {} void append() {append_many(_cont); } any_container _cont; }; AnyContainer m(v); m.append(); for(auto i : v) { std::cout << i << std::endl; } Thanks -Raj

1 1

[Log] [ASIO with ssl] windows service crash on windows server 2008
by Pritesh Acharya 27 Sep '14

27 Sep '14

Details: OS: Windows Server 2008 SP2 Boost 1.56.0 (shared library) OpenSSL: Win32OpenSSL-1_0_1i I have a windows service application written in C++. As a minimal test case, I have created a small demo code to show the problem. The service just log some information to a file and does nothing. The same code has no problem in my Development machine(windows7) and window Server 2003. Also on Windows Server 2008, when the service is run as LocalSystem privilege, it crashes, but when run as Administrator it works. Additionally, when I remove the asio ssl header from the code, it works. or when I remove the log header, it works. The problem seems to be related to when ASIO ssl and LOG are used together. Below I've included 1. Code 2. User Mode Crash dump 3. Call Stack obtained from running Crash Dump *1. Code:* *#include <boost/log/trivial.hpp>* *#include <boost/log/sources/severity_logger.hpp>* *#include <boost/asio/ssl.hpp>* *#include <windows.h>* *#include <stdio.h>* *#define SLEEP_TIME 5000* *#define LOGFILE "C:\\AASSLInstaller_D_56\\memstatus.txt"* *SERVICE_STATUS ServiceStatus; * *SERVICE_STATUS_HANDLE hStatus; * *void ServiceMain(int argc, char** argv); * *void ControlHandler(DWORD request); * *int InitService();* *int WriteToLog(char* str)* *{* * FILE* log;* * log = fopen(LOGFILE, "a+");* * if (log == NULL)* * return -1;* * fprintf(log, "%s\n", str);* * fclose(log);* * return 0;* *}* *//void ThreadFunction()* *//{* *// WriteToLog("at ThreadFunction");* *// //std::cout << "hello World " << std::endl;* *// //getchar();* *//}* *int main() * *{ * * using namespace boost::log::trivial; //for logging* * boost::log::sources::severity_logger_mt< boost::log::trivial::severity_level > lg;* * //WriteToLog("at main");* * //return 1;* * SERVICE_TABLE_ENTRY ServiceTable[2];* * ServiceTable[0].lpServiceName = "MemoryStatus";* * ServiceTable[0].lpServiceProc = (LPSERVICE_MAIN_FUNCTION)ServiceMain;* * ServiceTable[1].lpServiceName = NULL;* * ServiceTable[1].lpServiceProc = NULL;* * // Start the control dispatcher thread for our service* * StartServiceCtrlDispatcher(ServiceTable); * * return 0;* *}* *void ServiceMain(int argc, char** argv) * *{ * * int error; * * ServiceStatus.dwServiceType = SERVICE_WIN32; * * ServiceStatus.dwCurrentState = SERVICE_START_PENDING; * * ServiceStatus.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;* * ServiceStatus.dwWin32ExitCode = 0; * * ServiceStatus.dwServiceSpecificExitCode = 0; * * ServiceStatus.dwCheckPoint = 0; * * ServiceStatus.dwWaitHint = 0; * * hStatus = RegisterServiceCtrlHandler(* * "MemoryStatus", * * (LPHANDLER_FUNCTION)ControlHandler); * * if (hStatus == (SERVICE_STATUS_HANDLE)0) * * { * * // Registering Control Handler failed* * return; * * } * * // Initialize Service * * //error = InitService(); * * error = 0;* * if (error) * * {* * // Initialization failed* * ServiceStatus.dwCurrentState = SERVICE_STOPPED; * * ServiceStatus.dwWin32ExitCode = -1; * * SetServiceStatus(hStatus, &ServiceStatus); * * return; * * } * * // We report the running status to SCM. * * ServiceStatus.dwCurrentState = SERVICE_RUNNING; * * SetServiceStatus (hStatus, &ServiceStatus);* * MEMORYSTATUS memory;* * // The worker loop of a service* * //boost::thread t(&ThreadFunction);* * while (ServiceStatus.dwCurrentState == SERVICE_RUNNING)* * {* * char buffer[16];* * GlobalMemoryStatus(&memory);* * sprintf(buffer, "%d", memory.dwAvailPhys);* * int result = WriteToLog(buffer);* * if (result)* * {* * ServiceStatus.dwCurrentState = SERVICE_STOPPED; * * ServiceStatus.dwWin32ExitCode = -1; * * SetServiceStatus(hStatus, &ServiceStatus);* * return;* * }* * Sleep(SLEEP_TIME);* * }* * return; * *}* *// Service initialization* *int InitService() * *{ * * int result;* * result = WriteToLog("Monitoring started.");* * return(result); * *} * *// Control handler function* *void ControlHandler(DWORD request) * *{ * * switch(request) * * { * * case SERVICE_CONTROL_STOP: * * WriteToLog("Monitoring stopped.");* * ServiceStatus.dwWin32ExitCode = 0; * * ServiceStatus.dwCurrentState = SERVICE_STOPPED; * * SetServiceStatus (hStatus, &ServiceStatus);* * return; * * case SERVICE_CONTROL_SHUTDOWN: * * WriteToLog("Monitoring stopped.");* * ServiceStatus.dwWin32ExitCode = 0; * * ServiceStatus.dwCurrentState = SERVICE_STOPPED; * * SetServiceStatus (hStatus, &ServiceStatus);* * return; * * default:* * break;* * } * * // Report current status* * SetServiceStatus (hStatus, &ServiceStatus);* * return; * *} * *2. Dump* *Dump Summary* *------------* *Dump File: with_ssl_56.exe.4208.dmp : C:\Dumps\with_ssl_56.exe.4208.dmp* *Last Write Time: 9/26/2014 11:59:38 AM* *Process Name: with_ssl_56.exe : C:\lpa_c\wix_for_service\build_win\src\with_ssl_56\Debug\with_ssl_56.exe* *Process Architecture: x86* *Exception Code: 0xC0000005* *Exception Information: The thread tried to read from or write to a virtual address for which it does not have the appropriate access.* *Heap Information: Not Present* *System Information* *------------------* *OS Version: 6.0.6002* *CLR Version(s): * *Modules* *-------* *Module Name Module Path Module Version* *----------- ----------- --------------* *with_ssl_56.exe C:\lpa_c\wix_for_service\build_win\src\with_ssl_56\Debug\with_ssl_56.exe 0.0.0.0* *ntdll.dll C:\Windows\System32\ntdll.dll 6.0.6002.18881* *kernel32.dll C:\Windows\System32\kernel32.dll 6.0.6002.19034* *advapi32.dll C:\Windows\System32\advapi32.dll 6.0.6002.18005* *rpcrt4.dll C:\Windows\System32\rpcrt4.dll 6.0.6002.18882* *boost_log-vc100-mt-gd-1_56.dll C:\boost_1_56_0_dyn\stage\lib\boost_log-vc100-mt-gd-1_56.dll 0.0.0.0* *boost_date_time-vc100-mt-gd-1_56.dll C:\boost_1_56_0_dyn\stage\lib\boost_date_time-vc100-mt-gd-1_56.dll 0.0.0.0* *MSVCP100D.dll C:\Windows\System32\MSVCP100D.dll 10.0.30319.1* *MSVCR100D.dll C:\Windows\System32\MSVCR100D.dll 10.0.30319.1* *boost_system-vc100-mt-gd-1_56.dll C:\boost_1_56_0_dyn\stage\lib\boost_system-vc100-mt-gd-1_56.dll 0.0.0.0* *boost_filesystem-vc100-mt-gd-1_56.dll C:\boost_1_56_0_dyn\stage\lib\boost_filesystem-vc100-mt-gd-1_56.dll 0.0.0.0* *boost_chrono-vc100-mt-gd-1_56.dll C:\boost_1_56_0_dyn\stage\lib\boost_chrono-vc100-mt-gd-1_56.dll 0.0.0.0* *boost_thread-vc100-mt-gd-1_56.dll C:\boost_1_56_0_dyn\stage\lib\boost_thread-vc100-mt-gd-1_56.dll 0.0.0.0* *psapi.dll C:\Windows\System32\psapi.dll 6.0.6000.16386* *ws2_32.dll C:\Windows\System32\ws2_32.dll 6.0.6001.18000* *msvcrt.dll C:\Windows\System32\msvcrt.dll 7.0.6002.18551* *nsi.dll C:\Windows\System32\nsi.dll 6.0.6001.18000* *user32.dll C:\Windows\System32\user32.dll 6.0.6002.18005* *gdi32.dll C:\Windows\System32\gdi32.dll 6.0.6002.19171* *3. Call Stack* * 00000000() * * user32.dll!76659ce4() * * [Frames below may be incorrect and/or missing, no symbols loaded for user32.dll] * * advapi32.dll!77b84158() * * advapi32.dll!77b840f6() * * advapi32.dll!77b8430d() * * ws2_32.dll!7670ab6d() * * ws2_32.dll!7670aa95() * * ws2_32.dll!7670a3b2() * * ws2_32.dll!7670ae3f() * * ws2_32.dll!7670ad7a() * * ws2_32.dll!7670acc3() * * ws2_32.dll!7670ac2b() * * boost_log-vc100-mt-gd-1_56.dll!boost::asio::detail::winsock_init_base::startup(boost::asio::detail::winsock_init_base::data & d, unsigned char major, unsigned char minor) Line 39 + 0x2d bytes C++* * boost_log-vc100-mt-gd-1_56.dll!boost::asio::detail::winsock_init<2,0>::winsock_init<2,0>(bool allow_throw) Line 57 + 0xe bytes C++* *> boost_log-vc100-mt-gd-1_56.dll!boost::asio::detail::`dynamic initializer for 'winsock_init_instance''() Line 116 + 0x1c bytes C++* * MSVCR100D.dll!_initterm(void (void)* * pfbegin, void (void)* * pfend) Line 873 C* * boost_log-vc100-mt-gd-1_56.dll!_CRT_INIT(void * hDllHandle, unsigned long dwReason, void * lpreserved) Line 284 + 0xf bytes C* * boost_log-vc100-mt-gd-1_56.dll!__DllMainCRTStartup(void * hDllHandle, unsigned long dwReason, void * lpreserved) Line 506 + 0x11 bytes C* * boost_log-vc100-mt-gd-1_56.dll!_DllMainCRTStartup(void * hDllHandle, unsigned long dwReason, void * lpreserved) Line 476 + 0x11 bytes C* * ntdll.dll!77a112f4() * * ntdll.dll!779f906b() * * ntdll.dll!77a016d2() * * ntdll.dll!779fbf5a() *

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[thread] Specific old move semantics usage
by Vicente J. Botet Escriba 27 Sep '14

27 Sep '14

Hi all, I would like to remove the specific move semantics included in Boost.Thread as it was flawed. This has been replaced by the Boost.Move one long time ago. Is there someone still using it? Could I at least define by the default (even for BOOST_THREAD_VERSION 2) BOOST_THREAD_USES_MOVE for Boost 1.57? Best, Vicente

1 0

Using boost::xpressing on Windows Store
by Paula Stanciu 27 Sep '14

27 Sep '14

Hello, I'm trying to use boost::xpressive on Windows Store and I ran into the following problem: Because _WIN32 is defined BOOST_XPRESSIVE_HAS_MS_STACK_GUARD gets defined and that causes the use of _resetstkoflw() that is not defined for windows sore ( http://msdn.microsoft.com/library/windows/apps/jj606124.aspx ) and so I cannot compile the code that uses boost::xpressive. I think BOOST_XPRESSIVE_HAS_MS_STACK_GUARD should not be defined for Windows store since it does not support _resetstkoflw() ? Any idea how I can solve this issue? Would it be the right thing to undefine this for Windows Store ? Thanks, Paula

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Re: [Boost-users] Using boost::xpressive on Windows Store
by Paula Stanciu 27 Sep '14

27 Sep '14

Thanks Eric. Yes, it's if the WINAPI_FAMILY is set to WINAPI_PARTION_APP. Should I submit a patch with the changes I think should be done in this case ? It's actually just adding and extra check in xpressive_fwd.hpp before BOOST_XPRESSIVE_HAS_MS_STACK_ GUARD is defined. ( e.g. (WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP)) ) Best regards, Paula On Fri, Sep 26, 2014 at 6:19 PM, Eric Niebler <eniebler(a)boost.org> wrote: > On 9/26/2014 8:03 AM, Paula Stanciu wrote: > > Hello, > > > > I'm trying to use boost::xpressive on Windows Store and I ran into the > > following problem: > > > > Because _WIN32 is defined BOOST_XPRESSIVE_HAS_MS_STACK_GUARD gets > > defined and that causes the use of _resetstkoflw() that is not defined > > for windows sore ( > > http://msdn.microsoft.com/library/windows/apps/jj606124.aspx ) and so I > > cannot compile the code that uses boost::xpressive. > > > > I think BOOST_XPRESSIVE_HAS_MS_STACK_GUARD should not be defined for > > Windows store since it does not support _resetstkoflw() ? Any idea how I > > can solve this issue? Would it be the right thing to undefine this for > > Windows Store ? > > Sure. Is there some #define a program can check to see if it's being > compiled for Windows Store? > > Eric > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

1 0

BOOST_PP_ERROR(0x0003, BOOST_PP_REPEAT_OVERFLOW) with multiply nested BOOST_PP_REPEATS
by Colin Fowler 26 Sep '14

26 Sep '14

I'm having a problem with multiple nested repeats. I need to generate int x_0_0_0_0 to int x_a_b_c_d. Attempting to do so results in a BOOST_PP_ERROR. For readability, a few shorter defines #define TUPLE_ELEM BOOST_PP_TUPLE_ELEM #define REPEAT BOOST_PP_REPEAT and I also neglect the necessary BOOST_PP_CAT statements in DECL4D in this example #define DECL4D(z, n, text) TUPLE_ELEM(3, text) TUPLE_ELEM(0, text) TUPLE_ELEM(1, text) TUPLE_ELEM(2, text) n; #define DECL4C(z, n, text) REPEAT(TUPLE_ELEM(0, text), DECL4D, (TUPLE_ELEM(1, text), TUPLE_ELEM(2, text), n, TUPLE_ELEM(3, text))) #define DECL4B(z, n, text) REPEAT(TUPLE_ELEM(0, text), DECL4C, (TUPLE_ELEM(1, text), TUPLE_ELEM(2, text), n, TUPLE_ELEM(3, text))) #define DECL4A(z, n, text) REPEAT(TUPLE_ELEM(0, text), DECL4B, (TUPLE_ELEM(1, text), TUPLE_ELEM(2, text), n, TUPLE_ELEM(3, text))) #define decl4(a, b, c, d, text) REPEAT(a, DECL4A, (b, c, d, text)) decl4(1, 1, 1, 1, int x_) Am I hitting a nesting depth limit or something else? Is there a way around this? Ideally I want to write a decl5 macro and have successfully written a decl1, decl2 and decl3 so far Regards, Colin

2 3

[fusion] problem converting the result of a transform of a set into a map
by Christian Kerl 26 Sep '14

26 Sep '14

Hello everybody, I've a problem with the boost fusion library. I try to convert a fusion set into a map using the transform algorithm. Here is a example: typedef typename boost::fusion::result_of::as_map< typename boost::fusion::result_of::transform<BoundMembers, map_name_to_member>::type >::type Content; where BoundMembers is a boost::fusion::set and map_name_to_member is defined as: struct map_name_to_member { template <typename T> struct result; template <class F, typename T> struct result<F(T)> { typedef boost::fusion::pair<typename T::Name, typename T::Member> type; }; }; With boost 1.56 and gcc 4.8.1 I get the following compilation error: include/boost/fusion/iterator/key_of.hpp:36:16: error: invalid use of incomplete type ‘struct boost::fusion::extension::key_of_impl<boost::fusion::transform_view_iterator_tag>’ struct key_of ^ include/boost/fusion/iterator/key_of.hpp:21:16: error: declaration of ‘struct boost::fusion::extension::key_of_impl<boost::fusion::transform_view_iterator_tag>’ struct key_of_impl; However, this code used to work with Boost 1.48. I found a workaround to fix this, by converting the result of transform to a fusion list before coverting it to a map, i.e.: typedef typename boost::fusion::result_of::as_map< typename boost::fusion::result_of::as_list< typename boost::fusion::result_of::transform<BoundMembers, internal::map_name_to_member>::type >::type >::type Content; Am I doing something wrong or is this intended behavior? Thanks for your support. Best regards, Christian Kerl

1 0

Re: [Boost-users] boost logger architecture
by Savva Kuznetsov 26 Sep '14

26 Sep '14

Hi, Tony. It would be great to have an opportunity to know which file is currently being used for logging and set another, for example. Also, we want to control logs rotation and set conditions in which current file must be stored into collection, and create new file with the same name. It would be much easier task and I guess it would be the true boost-style, if boost\log\sinks\text_file_backend.cpp was not hiding a lot of definitions and class interfaces. S.K.

1 0

boost logger architecture.
by Savva Kuznetsov 25 Sep '14

25 Sep '14

Hello, guys. This post is almost the entire duplicate of my Ticket #10524. We're using boost logger in our application and it's really great boost library part. But, we need to change some of it's functionality. Actually, we need to add some lines of code in a method of collector class (for example, file_collector from boost\log\sinks\text_file_backend.cpp) I guess the right way to do this is inheritance from file_collector class and redefinition of it's members functions. But, since it's entire declaration and definition are in text_file_backend.cpp file in an anonymous namespace, it's impossible. Also, it would be cool to use some functions that this class uses (these functions are in text_file_backend.cpp file too for some unknown reason). The only solution I see is to copy-and-paste the entire file_collector class code from boost\log\sinks\text_file_backend.cpp and rewrite some of it's methods content, but, it's obviously wrong and not beautiful way (not boost-way). I guess boost must provide an extensible way to do things. Is there any reason that the entire class is in text_file_backend.cpp file or maybe I am missing something? My ticket have been closed by the author of logger with the comment: "file_collector in text_file_backend.cpp is not designed to be extensible because the interface for the extension is not clear. This made the implementation simpler." It's kinda strange reason, is it?

3 2

List of supported locales and time-zones
by niXman 25 Sep '14

25 Sep '14

Hi, Can somebody tell me please, how can I get a list of supported locale names and time-zones using boost.locale? Thanks. -- Regards, niXman ___________________________________________________ Dual-target(32 & 64-bit) MinGW-W64 compilers for 32 and 64-bit Windows: http://sourceforge.net/projects/mingw-w64/ ___________________________________________________ Another online IDE: http://liveworkspace.org/

1 0

boost.python built with VC2010
by Mohammed El-Afifi 25 Sep '14

25 Sep '14

Hello, I have successfully built boost.python with visual c++ 2010(dynamic library, 64-bit). I have python 2.7.8 64-bit installed on windows 7 64-bit. I've read here https://docs.python.org/2/distutils/apiref.html#module-distutils.msvccompil… that python extensions should be built with the same compiler that was used to build python itself. My question is, since python 2.7.8 was built with visual c++ 2008 64-bit compiler, can I have the following mix a) my python extension built with VC2008 64-bit(to match python itself) b) 64-bit boost.python dll built with VC2010 64-bit c) python 64-bit, built itself with VC2008 64-bit? I've noticed that boost.python dll depends on python dll and that's why I'm quite worried about the mix. Appreciating your insights.

1 0

[boost/config] BOOST_LIKELY argument requirements
by Stephan Bergmann 25 Sep '14

25 Sep '14

Looking at the definition of BOOST_LIKELY as #define BOOST_LIKELY(x) __builtin_expect(x, 1) in boost/config/compiler/{clang,intel,gcc}.hpp, and given that at lest the GCC and Clang __builtin_expect has a first parameter of type long, I wonder (1) whether it would be better to define it as #define BOOST_LIKELY(x) __builtin_expect(bool(x), 1) so that > $ cat test.cc > #include "boost/config.hpp" > #include "boost/logic/tribool.hpp" > int f(boost::tribool b1, boost::tribool b2) { > if (b1) return 1; > else if (BOOST_LIKELY(b2)) return 2; > else return 3; > } > > $ g++ -c test.cc > In file included from .../boost_1_56_0/boost/config.hpp:39:0, > from test.cc:1: > test.cc: In function ‘int f(boost::logic::tribool, boost::logic::tribool)’: > .../boost_1_56_0/boost/config/compiler/gcc.hpp:90:46: error: cannot convert ‘boost::logic::tribool’ to ‘long int’ for argument ‘1’ to ‘long int __builtin_expect(long int, long int)’ > #define BOOST_LIKELY(x) __builtin_expect(x, 1) > ^ > test.cc:5:14: note: in expansion of macro ‘BOOST_LIKELY’ > else if (BOOST_LIKELY(b2)) return 2; > ^ would not fail (effectively changing the requirement for the argument to BOOST_LIKELY from "[the] expression should result in a boolean value" to "it should be contextually convertible to bool"). (2) if not that, whether to at least wrap the expansion of x in parentheses, #define BOOST_LIKELY(x) __builtin_expect((x), 1) Stephan

1 0

[assign][ptr_container] Exception safety of ptr_list_of, ptr_push_back, ptr_map_insert, etc.
by Aaron Levy 24 Sep '14

24 Sep '14

I am trying to understand how ptr_list_of or ptr_push_back provide more exception safety. I can write something like: boost::ptr_vector<Foo> vec; push_back(vec)(new Foo)(new Foo); Is the order of evaluation of the two "new Foo" expressions indeterminate here? If not, then if the second new throws, the destructor of vec should be invoked. The Foo object allocated by the first new and now part of vec should also get released as part of that. -- Aaron Levy aaron.levy(a)yandex.com

3 3

[Log] reversed file rotation order...
by Ovanes Markarian 24 Sep '14

24 Sep '14

Hi *, We use file rotation with boost log, since I work more and with Python I use Python's logging as well. One interesting feature I observed was that Python's logger does reversed file rotation. Is that sort of feature implemented with boost::log library? In boost the rotation is: whatever_0.log < oldest file whatever_1.log whatever_2.log < newest file In Python the rotation order is: whatever_0.log < newest file whatever_1.log whatever_2.log < oldest file I think this is a very cool how Python does it, since I am able to endlessly "tail" in the shell the log file: tail -f whatever_0.log will not stop until I cancel the tail operation. With boot it is like, logger writes a new file and tail hangs with the file which is no longer written. This is a bit unusable and confusing. Would be great if that'd be possible in boost. Thanks, Ovanes

1 0

Problems Linking with Boost Serialization
by Isaac Lascasas 24 Sep '14

24 Sep '14

I have found this on boost 1.56 with msvc12: Error 119 error LNK2005: "bool __cdecl boost::archive::detail::is_whitespace<char>(char)" (??$is_whitespace@D @detail@archive@boost@@YA_ND@Z) already defined in libboost_wserialization-vc120-mt-1_56.lib(basic_text_wiprimitive.obj) C:\supernova\sb6\src\supernova_clr\libboost_serialization-vc120-mt-1_56.lib(basic_text_iprimitive.obj) Error 120 error LNK2005: "bool __cdecl boost::archive::detail::is_whitespace<wchar_t>(wchar_t)" (??$is_whitespace@ _W@detail@archive@boost@@YA_N_W@Z) already defined in libboost_wserialization-vc120-mt-1_56.lib(basic_text_wiprimitive.obj) C:\supernova\sb6\src\supernova_clr\libboost_serialization-vc120-mt-1_56.lib(basic_text_iprimitive.obj) This code used to link fine with previous boost versions. Now it looks like you can't use both archive and warchive at the same time. I'm using xml warchives for serializing in my code. Regards. Isaac Lascasas.

2 2

Boost::Locale jam file seems to be outdated for ICU ver. 53.1
by Caroline Beltran 24 Sep '14

24 Sep '14

I'm using Boost::Locale (and ICU) for the first time but I strongly believe that the jam file is referencing old ICU dll filenames. Current ICU dlls: icuucd53.dll icudt53.dll icuind53.dll icuin53.dll Relevant snippet from jam file (Boost 1.56): searched-lib icuuc : : <toolset>msvc <variant>debug <name>icuucd <search>$(ICU_PATH)/lib <link>shared <runtime-link>shared ; To me it appears that the snippet above is referring to icuucd when it should be referring to icuucd53. I've been trying really hard to get Boost::Locale going on my system. I updated all references to dlls and this is the result of the config test. As you can see, I am not linking with ICU (even though ICU was installed correctly and ICU test results were successful). I think that the jam file may need further changes. Please advise. D:\boost_1_56_0\stage\lib>test_config - Backends: std winapi - Without iconv - Environment LANG= LC_ALL= LC_CTYPE= TZ= - C locale: English_United States.1252 - C++ locale: English_United States.1252 - Testing locales availability on the operation system: locale C C++ en_US.UTF-8 No No en_US.ISO8859-1 No No English_United States.1252 Yes Yes he_IL.UTF-8 No No he_IL.ISO8859-8 No No Hebrew_Israel.1255 Yes Yes ru_RU.UTF-8 No No Russian_Russia.1251 Yes Yes tr_TR.UTF-8 No No Turkish_Turkey.1254 Yes Yes ja_JP.UTF-8 No No ja_JP.SJIS No No Japanese_Japan.932 Yes Yes - Testing timezone and time Local Time :%c=09/23/14 15:18:07; %Z=Central Daylight Time (Mexico); %z=Central Daylight Time (Mexico) Universal Time:%c=09/23/14 20:18:07; %Z=Central Standard Time (Mexico); %z=Central Standard Time (Mexico) - Boost.Locale's locale: en_US.UTF-8

2 1

Adding more than 20 rows in transition table for Boost::MSM
by Yechiel Levi 23 Sep '14

23 Sep '14

Hi, I tried defining: #define BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS #define BOOST_MPL_LIMIT_VECTOR_SIZE 30 // or whatever you need #define BOOST_MPL_LIMIT_MAP_SIZE 30 // or whatever you need /// Boost-MSM Includes // back-end #include "boost/mpl/vector/vector30.hpp" #include <boost/msm/back/state_machine.hpp> //front-end #include <boost/msm/front/state_machine_def.hpp> #include <boost/msm/front/functor_row.hpp> #include <boost/any.hpp> // for And_ operator #include <boost/msm/front/euml/operator.hpp> And i still get the following errors: builder1: In file included from /usr/local/include/boost/mpl/erase.hpp:19, builder1: from /usr/local/include/boost/fusion/mpl/erase.hpp:10, builder1: from /usr/local/include/boost/fusion/mpl.hpp:20, builder1: from /usr/local/include/boost/fusion/include/mpl.hpp:11, builder1: from /usr/local/include/boost/msm/back/state_machine.hpp:30, builder1: from File_Meta_FSM.h:18, builder1: from Open_Files_Mng.h:5, builder1: from Open_Files_Mng.cpp:1: builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:56: error: ‘_’ was not declared in this scope builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:56: error: ‘_’ was not declared in this scope builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:56: error: template argument 1 is invalid builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:56: error: template argument 2 is invalid builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:57: error: template argument 3 is invalid builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:62: error: ‘_’ was not declared in this scope builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:62: error: ‘_’ was not declared in this scope builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:62: error: template argument 1 is invalid builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:62: error: template argument 2 is invalid builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:63: error: template argument 3 is invalid and more of the same errors.. -- Kind regards, Yechiel Levi

5 7

Graph concepts for Dijkstra shortest-path searches
by Clayton Davis 22 Sep '14

22 Sep '14

Hi, I am somewhat uncertain on which concepts are required for the Dijkstra searches in the BGL and parallel BGL. For the sequential BGL, documentation at http://www.boost.org/doc/libs/1_56_0/libs/graph/doc/dijkstra_shortest_paths… would seem to indicate that a VertexListGraph is required, even when the no_init version is used. Looking at the code, I think that is accurate - use of the index map at https://github.com/boostorg/graph/blob/master/include/boost/graph/dijkstra_… seems to require vertex list traversal - but I would also think that defeats the purpose of the no_init option. Conversely, for the parallel BGL documentation at http://www.boost.org/doc/libs/1_56_0/libs/graph_parallel/doc/html/dijkstra_… says only that DistributedGraph is required, which is a refinement of Graph but not VertexListGraph or IncidenceGraph. However, just a little bit of searching seems to show that the parallel Dijkstra search requires both, along with perhaps PropertyGraph (see for instance https://github.com/boostorg/graph_parallel/blob/master/include/boost/graph/… and https://github.com/boostorg/graph_parallel/blob/master/include/boost/graph/…) I won't pretend to understand the code; but I would expect these functions to require something stronger than the documentation indicates. Could someone please clarify what the requirements are for these functions? Any help is greatly appreciated. Thanks, Clayton

1 0

BOOT_PP_REPEAT simple nesting problem
by Colin Fowler 22 Sep '14

22 Sep '14

Hi all, I'm trying to use BOOST_PP to generate some code. I can generate the sequence int x_0 to int x_4 using the code below. #include <boost/preprocessor/repetition/repeat.hpp> #define DECL1(z, n, text) text ## _ ## n = n; #define decl1(text, count) BOOST_PP_REPEAT(count, DECL1, text) decl1 (int x, 5) What I'd like to do is write a decl2 that can be used something like this: decl2 (int x, 5, 2) to generate int x_0_0 to int x_4_1 I've tried nesting BOOST_PP_REPEAT but so far I've been unable to produce the desired behaviour unless I hardcode one of the iteration counts. I'd like to also eventually write a decl3(int x, 5, 3, 4) when I understand how a decl2 would work. Any help much appreciated! Regards, Colin

4 6

[assign][cref_list_of] Creating anonymous list of pairs
by Aaron Levy 22 Sep '14

22 Sep '14

Is there a way to generate a list of value pairs using ref_list_of or cref_list_of. Maybe such a list could be assigned to a map. Something like: ref_list_of<size, std::pair<std::string, std::string>>("foo", "bar")("foo1", "bar1")...; or std::map<string, string> names = ref_list_of<size, std::pair<std::string, std::string>>("foo", "bar")("foo1", "bar1")...; -- Aaron Levy aaron.levy(a)yandex.com

3 2

[ptr_container][ptr_map]
by Aaron Levy 22 Sep '14

22 Sep '14

Consider the following code: class Base { public: virtual ~Base() = 0 {}; virtual double get() = 0; }; class D1 : public Base { public: D1(double n) : val_(n) {} double get() const { return val_; } private: double val_; }; class D2 : public Base { D2(double n) : val_(n) {} double get() const { return val_; } private: double val_; }; bool operator < (const Base& left, const Base& right) { return (left.get() < right.get()); } I can create a ptr_set of Base like this: boost::ptr_set<Base> set; But I can't create a ptr_map with Base as key, like this: boost::ptr_map<Base, Base> map; The problem is that Base is abstract and so the key cannot be instantiated by ptr_map. What is the cause for this distinction between ptr_set and ptr_map. -- Aaron Levy aaron.levy(a)yandex.com

2 1

Boost.Test multiple linkage question
by Rob Harris 21 Sep '14

21 Sep '14

All, I've been ripping out my hair all day, and I can't seem to determine a straight answer from the Googles. Can I link _multiple_ boost unit test dynamic libraries into a single binary and have all of them detected? For instance... src lib liba foo.cpp liba_unittests.cpp libb bar.cpp libb_unittests.cpp libd baz.cpp libd_unittests.cpp lib liba.so liba_ut.so libb.so libb_ut.so libd.so libd_ut.so bin ut unittest_driver When I build this infrastructure out, everything compiles. I've checked the compilation command and it looks like everything is on the command line, but there's explicit indication that unittest_driver actually read or linked any of the lib*_ut.so files. If I make individual unit test drivers in, say, liba, the driver works fine. If I link everything into a single unittest_driver binary, I keep getting the dreaded empty test tree. I have -DBOOST_ALL_DYN_LINK set in my CXXFLAGS so that shouldn't be the problem. And I only have BOOST_TEST_MAIN set in the driver; still no joy. Any help (or a definitive, "no you idiot, you can't do that!") would be greatly appreciated. Thanks. -RMH

2 1

Utah C++ User Group started
by legalize+jeeves＠mail.xmission.com 21 Sep '14

21 Sep '14

[Please do not mail me a copy of your followup] I'm booting up a C++ User Group in Utah. We're bootstrapping out first meeting to decide a regular meeting time and location. Join the Utah C++ Programmers MeetUp group to hear about meetings: <http://www.meetup.com/Utah-Cpp-Programmers/> Follow related evens on the Utah C++ Users Group blog: <http://utahcpp.wordpress.com> -- "The Direct3D Graphics Pipeline" free book <http://tinyurl.com/d3d-pipeline> The Computer Graphics Museum <http://computergraphicsmuseum.org> The Terminals Wiki <http://terminals.classiccmp.org> Legalize Adulthood! (my blog) <http://legalizeadulthood.wordpress.com>

1 0

[lockfree] stack needs undocumented trivial assignment
by Norbert Wenzel 21 Sep '14

21 Sep '14

I'm trying to replace some computation intensive loops in legacy code with parallel loops and thus tried to store the results in a lockfree stack. I've chosen stack over queue because of the requirements stated in the documentation, where stack only needs a copy ctor and queue additionally needs trivial assignment and trivial dtor. My result struct I want to store in the stack is *not* trivially assignable. When trying to compile the code containing my lockfree::stack the static assertion in line 75 of stack.hpp because it requires trivial assignment and trivial dtor. My question would be if this is simply an error in the documentation ie. if the requirements section should be copied over from lockfree::queue or if these static assertions should only be checked in some special case, eg. where the stack is of fixed size? thanks, Norbert

1 0

[context] How to set stack pointer in a platform-independent way?
by TONGARI J 21 Sep '14

21 Sep '14

Hi, The problem had been discussed here: https://groups.google.com/forum/#!topic/boost-devel-archive/cl8B1oUPrVM But it's still not clear how to set the stack pointer portably, even after examining the code of Boost.Coroutine. For now, Boost.Context only supports downward stack, and Boost.Coroutine, which happened to be written by the same author, just assumes that the stack always grows downward, which is not really a portable implementation, if future Boost.Context supports upward stack, Boost.Coroutine has to be changed as well. Even than that, what does "beginning of the stack" really means? Suppose we have a stack of size 3, starting at [s]: [s-1][s][s+1][s+2][s+3] Why the beginning of a downward stack is [s+3], not [s+2]? If it's a upward stack, is beginning [s] or [s-1]? Thanks.

5 12

from: giridhar
by giridhar 20 Sep '14

20 Sep '14

Salutations boost http://ariasking.com/morning.php/ttqhx3144vcfnpry/ giridhar

1 0

[ASIO] [SSL] [SOCKS4] Layers
by Maciej Miszczak 19 Sep '14

19 Sep '14

Hello, I have been successfully using ASIO for a long time, but recently I try to use SSL over SOCKS 4 and I'm struggling with short read while asynchronous SSL handshaking. I have come across this: http://stackoverflow.com/questions/9943541/boost-asio-how-to-read-write-on-…] but it's only partially helpful. I haven't find any good explanation, what the layers really are (ex. I can't assign next_layer and lowest_layer to any of OSI layers). Could someone explain the meaning of next_layer and lowest_layer and how to use SSL stream with SOCKS 4 proxy. Best regards, Maciej Miszczak

2 2

Re: [Boost-users] Boost XML Serialization
by Manasi Deshpande 19 Sep '14

19 Sep '14

Hello All, Currently I am working on DB Driven C++ API, where it also involves XML processing functionalities. That's where I came across Boost Serialization. We have a very peculiar story here, and it goes like this: We have 2 identical APIs. One in C# and another in C++. Both are DB driven similar APIs. There are instances, where any XML data serialized on C++ platform needs to be de serialized on C# and vice versa. In C# life is straight forward; one needs no bothering about serialization and de serialization. I think in boost you can de serialize the XML document only if it is built using Boost Serialization. I think it is the case in C# also. Is there any way out, where Boost Serialization can be customized? Please forgive me if I am not clear in stating my problem statement! -------------------------------------------------------------------------------------------------- This email and any attachments are confidential and are for the use of the addressee only. If you are not the addressee, you must not use or disclose the contents to any other person. Please immediately notify the sender and delete the email. Statements and opinions expressed here may not represent those of the company. Email correspondence is monitored by the company. This information may be subject to export control regulation. You are obliged to comply with such regulations. Renishaw plc (company number 1106260) and Wotton Travel Limited (company number 01973158) are companies registered in England and Wales with a registered office at New Mills, Wotton-under-Edge, Gloucestershire, GL12 8JR, United Kingdom, Telephone +44 1453 524524. --------------------------------------------------------------------------------------------------

2 1

[logging+unittest]
by Witold E Wolski 19 Sep '14

19 Sep '14

Hi, I need to integrate some loggin into my unit to some extend bein integration tests (hardware). How best to call this function which sets up boost logging void init() { boost::log::add_file_log("sample.log"); boost::log::core::get()->set_filter ( boost::log::trivial::severity >= boost::log::trivial::info ); } if I have a test Runner looking like: #define BOOST_TEST_MODULE MasterTestSuite #include <boost/test/unit_test.hpp> Is there a way not have to add the suites manually Thanks. -- Witold Eryk Wolski

1 1

[thread] memory synchronization multiple mutexes
by firespot 18 Sep '14

18 Sep '14

Hi, How does memory synchronization and visibility behave when multiple mutexes are involved? I have two groups of threads (boost::thread_group) and two mutexes (boost::mutex m1, boost::mutex m2) + associated condition variables, with each thread group being responsible to write to some variables (here Ptr, run) and consistently using "its" mutex for locking. However there is a piece of code that looks - much simplified - like this: void f() { { boost::unique_lock<boost::mutex> Lock(m1); Ptr = someAddress; // set the Ptr from 0 to some memory address } { boost::unique_lock<boost::mutex> Lock(m2); run = 1; // was 0, inform that execution can proceed condVar2.notify_all(); } ... // wait until Ptr has been reset to 0 { boost::unique_lock<boost::mutex> Lock(m1); while (Ptr != 0) condVar1.wait(Lock); } } and another function: void g() { { boost::unique_lock<boost::mutex> Lock(m2); while (run == 0) condVar2.wait(Lock); } // run the execution, e.g. std::copy(Ptr, Ptr + 100, Target); // finally all finished, signal back that Ptr is not needed any more { boost::unique_lock<boost::mutex> Lock(m1); Ptr = 0; condVar1.notify_all(); } } f() is only invoked from a thread of the first group, and g() only from a thread of the second group. Whenever Ptr might get changes the first mutex (m1) and its associated condition-variable is used, and whenver run might get changed the second mutex and its associated conditional variable is used. The control flow guarantees that run is not set to 1 prior to Ptr being set, and thus in g() the "running" itself (here the std::copy) cannot commence earlier. However, what puzzles me now: I used a different mutex for setting Ptr and setting/checking run. Does this have any impact whatsoever on memory visibility across the threads in the two thread-groups? Specifically, is it always guaranteed that when g() continues its execution (because run == 1) that it must see the correct value of Ptr (a non-NULL value)? Or is it possible that it still sees 0 and I'd have to make a separate locking involving m1 to guarantee a proper read for Ptr as anything written under a lock of m1 is also only guaranteed to be later properly read if the locking also used m1? thanks!

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[mpl] simple mpl::transform with placeholder?
by Andrew King 18 Sep '14

18 Sep '14

Hi, Lets say I have an mpl vector defined as : template <typename Traits> struct A { }; template <typename Traits> struct B { }; typedef mpl::vector<A<mpl::_>, B<mpl::_> > MyVec; struct MyTraits {}; How do I 'apply' or transform MyVec with MyTraits? ie. I want the mpl::vector ... boost::mpl::vector<A<MyTraits>, B<MyTraits>>; I realise I can do mpl::apply<A<mpl::_>, MyTraits> to get A<MyTraits> but I can't work out how to do the equivalent to the entire vector. mpl::transform seems like what I should be using. Transform seems to do apply internally, but I can't work out the syntax to do something like: using substituted = typename boost::mpl::transform<MyVec, boost::mpl::apply<boost::mpl<_>, MyTraits> >::type; (This isn't right!) It may be I am confused because inside the transform, boost::mpl::_1 is the item in the vector, not the 'inner' placeholder. Sorry if this is a basic question ... Regards, Andrew

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[Thread] Read-write locks
by lfrfly＠icqmail.com 17 Sep '14

17 Sep '14

I'm trying to create a standard read/write lock using Boost Threads, and I'm having a bit of difficulty mapping the Boost concepts onto the usual ones. A read/write lock should have several states: Locked for reading (multiple threads may lock at once), locked for writing (only one thread may lock, and no threads may be locked for reading at the same time), and unlocked. Ideally it would be nice if an RWL which is locked for reading may temporarily upgrade to locked for writing, then return to the locked for reading state. Boost supports several relevant notions of locking: shared locking, upgrade locking, and exclusive locking. This to me is a confusing distinction. In particular, a shared_mutex seems appropriate as the basis for a RWL, but is lock_upgrade() the equivalent of a write lock and lock_shared the equivalent of a read lock? This is unclear. If "upgrade locking" is not the same as "exclusive locking", then is an upgrade lock actually exclusive? Could someone please clarify this.

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Numeric Cast from integer to floating point
by dariomt＠gmail.com 17 Sep '14

17 Sep '14

Hi, Quoting the docs for boost::numeric_cast: "There are several situations where conversions are unsafe: [...] Conversions from floating point types to integral types." What about conversions from integral types to floating point types? E.g. from 64bit int to double. The following example shows what I mean: #include <iostream> #include <cmath> #include <boost/numeric/conversion/cast.hpp> int main() { const uint64_t i = 123445678911188878; std::cout << "i=" << i << std::endl; const double d = i; std::cout << "d=" << std::fixed << d << std::endl; std::cout << "next=" << std::fixed << std::nextafter(d, std::numeric_limits<double>::max() ) << std::endl; std::cout << "prev=" << std::fixed << std::nextafter(d, -std::numeric_limits<double>::max()) << std::endl; // I'd expect the following cast to fail const double dd = boost::numeric_cast<double>(i); std::cout <<"dd=" << std::fixed << dd << std::endl; return 0; } prints i=123445678911188878 d=123445678911188880.000000 next=123445678911188896.000000 prev=123445678911188864.000000 dd=123445678911188880.000000 because that integer cannot be represented in double precision Is there something in Boost to help here? Thanks in advance

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value_type in Typed In Place Factory
by Adam Badura 17 Sep '14

17 Sep '14

According to header file boost/utility/typed_in_place_factory.hpp (as linked from documentation: http://www.boost.org/doc/libs/1_55_0/boost/utility/typed_in_place_factory.h…) typed_in_place_factory has member type value_type which is the constructed type. Yet documentation ( http://www.boost.org/doc/libs/1_55_0/libs/utility/in_place_factories.html) fails to mention it. Why? Is it not part of the interface (I would assume so based on not mentioning it in documentation...)? Or was it just forgotten? I find such value_type quite useful... And since I'm already writing let me note that the mentioned documentation has also another minor issue. In Specification section the sample in_place_factory and typed_in_place_factory should be named in_place_factory1 and typed_in_place_factory1. As this is how they are really named. Or it should be stated explicitly that the actual name is implementation dependent. Adam Badura

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Boostlog and ASIO crash in shared library
by Ray Cheng 16 Sep '14

16 Sep '14

Hi, My project use a simple main using dlopen to "run" the real main function in target shared library. I use both Boost Log and ASIO (for threadpool) in the project. In Linux I found the ASIO got weird behavior with some un-initialized variables and crashing all the time. I am able to trim down my problem into a small program as below: // *** threadpool.cpp *** #include <iostream> #include <memory> #include <boost/asio/io_service.hpp> #include <boost/bind.hpp> #include <boost/thread/thread.hpp> void print() { std::cout << "print" << std::endl; } struct ThreadPool { void start() { boost::asio::io_service ioService; boost::thread_group threadpool; std::unique_ptr<boost::asio::io_service::work> work = std::make_unique<boost::asio::io_service::work>(ioService); threadpool.create_thread(boost::bind(&boost::asio::io_service::run, &ioService)); for (int i=0; i<100; ++i) { ioService.post(&print); } std::cout << "Post all calculation tasks" << std::endl; work.reset(); threadpool.join_all(); ioService.stop(); std::cout << "Finished all calculation tasks" << std::endl; } }; extern "C" void createthreadpool() { ThreadPool pool; pool.start(); } // *** threadpool.cpp *** g++ -O0 -std=gnu++1y -fPIC -c -g -DLinux -DGNU_GCC -I${BOOST_HOME}/include threadpool.cpp g++ -shared -o libthreadpool.so threadpool.o -L${BOOST_HOME}/lib -lboost_system -lboost_date_time -lboost_thread -lboost_filesystem -lboost_regex -lboost_chrono -ldl -lstdc++ // *** main.cpp *** #include <dlfcn.h> #include <iostream> int main(int argc, char** argv) { typedef void* createProcess(); auto service = dlopen("libthreadpool.so", RTLD_LAZY); createProcess* make = reinterpret_cast<createProcess*>(dlsym(service, "createthreadpool")); std::cout << "dlsym" << std::endl; make(); return 0; } // *** main.cpp *** g++ -O0 -std=gnu++1y -fPIC -c -g -DLinux -DGNU_GCC main.cpp // Link against boost_log to simulate my problem (although it is not using any boost_log). This version will crash g++ -o main.bad main.o -L${BOOST_HOME}/lib -lboost_system -lboost_date_time -lboost_thread -lboost_filesystem -lboost_regex -lboost_chrono -lboost_log -ldl -lstdc++ // it works fine If link against libthreadpool, surprising me g++ -o main main.o -L/home/sysmmbuild/dev/boost -lthreadpool -L${BOOST_HOME}/lib -lboost_system -lboost_date_time -lboost_thread -lboost_filesystem -lboost_regex -lboost_chrono -lboost_log -ldl -lstdc++ One more finding is, if compile boost_log without thread support, the main.bad also working fine. I have attached the code and make.sh as make script. Software version Redhat enterprise 6.5 g++ 4.9.1 Boost 1.56.0 Rgds, Ray

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