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[lambda][1.33.1] Lambda warnings after installing VS2005 SP1
by john.wismar＠autozone.com 01 Aug '07

01 Aug '07

I have just installed Service Pack 1 for VS2005, and am now getting a warning in some code using lambda::bind. There wasn't a warning previously, but I don't know if the issue is due to an update to the C++ standard library, a legitimate warning that they weren't flagging before, or a spurious warning. It looks like the issue is that I'm passing a function pointer, to bind. Is this a warning I should just ignore, or is this a legitimate issue? Thanks for your help! Here's a sample app, followed by the warnings I'm seeing. #include <boost/lambda/bind.hpp> using boost::lambda::bind; using boost::lambda::_1; #include <vector> #include <map> #include <algorithm> int main() { enum choice { select, reject }; std::vector<long> questions; std::map<long, choice> answers; std::transform(questions.begin(), questions.end(), std::inserter(answers, answers.begin()), bind(std::make_pair<long, choice>, _1, select)); return 0; } c:\boost\boost\lambda\detail\lambda_traits.hpp(389) : warning C4180: qualifier applied to function type has no meaning; ignored c:\boost\boost\lambda\detail\lambda_traits.hpp(458) : see reference to class template instantiation 'boost::lambda::detail::bind_traits<T>' being compiled with [ T=std::pair<long,main::choice> (long,main::choice) ] c:\temp\lambda_warning_test\lambda_warning_test.cpp(20) : see reference to class template instantiation 'boost::lambda::detail::bind_tuple_mapper<T0,T1,T2,T3,T4,T5,T6,T7,T8,T9>' being compiled with [ T0=std::pair<long,main::choice> (long,main::choice), T1=boost::lambda::placeholder1_type, T2=const main::choice, T3=boost::tuples::null_type, T4=boost::tuples::null_type, T5=boost::tuples::null_type, T6=boost::tuples::null_type, T7=boost::tuples::null_type, T8=boost::tuples::null_type, T9=boost::tuples::null_type ] -------------------------------- John Wismar john.wismar(a)autozone.com

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Boost.Foreach performance
by Thomas Matelich 01 Aug '07

01 Aug '07

So, I'm loving Foreach and as I watch it spread throughout our codebase, of course it runs across the desk of our optimization obsessed team member. So, I was curious if you could address runtime performance of Foreach. I would expect it to be essentially equivalent to a hand written for loop with caching of end(). But what's the overhead of the auto_any_t, etc.? Thanks, Tom

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[1.34.0 thread] vc8: "R6030 CRT not initialized" error with static executable
by Markus Werle 01 Aug '07

01 Aug '07

Hi! After some nightmare chasing a bug within my code I boiled it down to a dummy MFC MDI project including nothing else but <boost/thread/tss.hpp> the line static boost::thread_specific_ptr<void *> tld_helper; in InitInstance() triggers an "R6030 - CRT not initialized" error, but only on one single windows XP platform. The app runs fine on all others. If you have any idea what might have gone wrong, please give me a hint. I put some simplified code below. Excluding the init() line in boost::details::tss(boost::function1<void, void*>* pcleanup) removes the initializing error in the executable :-( best regards, Markus My compiler settings: Microsoft Visual Studio 2005 Version 8.0.50727.762 (SP.050727-7600) Microsoft .NET Framework Version 2.0.50727 Installed Edition: Professional [...] Microsoft Visual C++ 2005 77626-009-0000007-41492 Microsoft Visual C++ 2005 Microsoft Visual Studio 2005 Professional Edition - ENU Service Pack 1 (KB926601) Compiler flags: /Ox /Ob2 /Oi /Ot /I "D:\FEV-Data\Sourcen\cpp\VC8\Common\DLLs\boost_1_34_0" /D "WIN32" /D "_WINDOWS" /D "NDEBUG" /D "_CRT_SECURE_NO_DEPRECATE" /D "_MBCS" /FD /EHsc /MT /Yu"stdafx.h" /Fp"Release\MaximumCM_Dummy.pch" /Fo"Release\\" /Fd"Release\vc80.pdb" /W3 /nologo /c /TP /errorReport:prompt /bigobj /wd4996 Linker flags /OUT:"D:\FEV-Data\ExperimentalCode\WerleShowBug\Release\MaximumCM_Dummy.exe" /INCREMENTAL:NO /NOLOGO /LIBPATH:"d:\FEV-Data\Sourcen\cpp\VC8\Common\DLLs\boost_1_34_0\stage\lib" /MANIFEST /MANIFESTFILE:"Release\MaximumCM_Dummy.exe.intermediate.manifest" /DELAYLOAD:"OleAcc.dll" /DEBUG /PDB:"d:\FEV-Data\ExperimentalCode\WerleShowBug\release\MaximumCM_Dummy.pdb" /SUBSYSTEM:WINDOWS /OPT:REF /OPT:ICF /MACHINE:X86 /ERRORREPORT:PROMPT nafxcw.lib DelayImp.lib <snip> // WerleShowBug.cpp : Defines the class behaviors for the application. // #include "stdafx.h" #include "WerleShowBug.h" #include "MainFrm.h" #include "ChildFrm.h" #include "WerleShowBugDoc.h" #include "WerleShowBugView.h" // #include <boost/utility.hpp> #include <boost/function.hpp> #include <boost/thread/detail/config.hpp> #include <stdexcept> namespace boost { class BOOST_THREAD_DECL my_exception : public std::exception {}; namespace detail { class BOOST_THREAD_DECL tss // : private noncopyable { public: tss(boost::function1<void, void*>* pcleanup) { if (pcleanup == 0) { } try { // remove this code and it runs init(pcleanup); // } catch (...) { delete pcleanup; } } private: unsigned int m_slot; //This is a "pseudo-slot", not a native slot void init(boost::function1<void, void*>* pcleanup); }; template <typename T> struct tss_adapter { template <typename F> tss_adapter(const F& cleanup) : m_cleanup(cleanup) { } void operator()(void* p) { m_cleanup(static_cast<T*>(p)); } boost::function1<void, T*> m_cleanup; }; } // namespace detail template <typename T> class thread_specific_ptr // : private noncopyable { public: thread_specific_ptr() : m_tss(new boost::function1<void, void*>( boost::detail::tss_adapter<T>( &thread_specific_ptr<T>::cleanup))) { } thread_specific_ptr(void (*clean)(T*)) : m_tss(new boost::function1<void, void*>( boost::detail::tss_adapter<T>(clean))) { } ~thread_specific_ptr() { reset(); } T* get() const { return static_cast<T*>(m_tss.get()); } T* operator->() const { return get(); } T& operator*() const { return *get(); } T* release() { T* temp = get(); if (temp) m_tss.set(0); return temp; } void reset(T* p=0) { // T* cur = get(); // if (cur == p) return; // m_tss.set(p); // if (cur) m_tss.cleanup(cur); } private: static void cleanup(T* p) { delete p; } detail::tss m_tss; }; #ifdef BOOST_MSVC # pragma warning(pop) #endif } // namespace boost #ifdef _DEBUG #define new DEBUG_NEW #endif // CWerleShowBugApp BEGIN_MESSAGE_MAP(CWerleShowBugApp, CWinApp) ON_COMMAND(ID_APP_ABOUT, &CWerleShowBugApp::OnAppAbout) // Standard file based document commands ON_COMMAND(ID_FILE_NEW, &CWinApp::OnFileNew) ON_COMMAND(ID_FILE_OPEN, &CWinApp::OnFileOpen) // Standard print setup command ON_COMMAND(ID_FILE_PRINT_SETUP, &CWinApp::OnFilePrintSetup) END_MESSAGE_MAP() // CWerleShowBugApp construction CWerleShowBugApp::CWerleShowBugApp() { // TODO: add construction code here, // Place all significant initialization in InitInstance } // The one and only CWerleShowBugApp object CWerleShowBugApp theApp; // CWerleShowBugApp initialization BOOL CWerleShowBugApp::InitInstance() { // This one killes the app static boost::thread_specific_ptr<void *> tld_helper; // InitCommonControlsEx() is required on Windows XP if an application // manifest specifies use of ComCtl32.dll version 6 or later to enable // visual styles. Otherwise, any window creation will fail. INITCOMMONCONTROLSEX InitCtrls; InitCtrls.dwSize = sizeof(InitCtrls); // Set this to include all the common control classes you want to use // in your application. InitCtrls.dwICC = ICC_WIN95_CLASSES; InitCommonControlsEx(&InitCtrls); CWinApp::InitInstance(); // Initialize OLE libraries if (!AfxOleInit()) { AfxMessageBox(IDP_OLE_INIT_FAILED); return FALSE; } AfxEnableControlContainer(); // Standard initialization // If you are not using these features and wish to reduce the size // of your final executable, you should remove from the following // the specific initialization routines you do not need // Change the registry key under which our settings are stored // TODO: You should modify this string to be something appropriate // such as the name of your company or organization SetRegistryKey(_T("Local AppWizard-Generated Applications")); LoadStdProfileSettings(4); // Load standard INI file options (including MRU) // Register the application's document templates. Document templates // serve as the connection between documents, frame windows and views CMultiDocTemplate* pDocTemplate; pDocTemplate = new CMultiDocTemplate(IDR_WerleShowBugTYPE, RUNTIME_CLASS(CWerleShowBugDoc), RUNTIME_CLASS(CChildFrame), // custom MDI child frame RUNTIME_CLASS(CWerleShowBugView)); if (!pDocTemplate) return FALSE; AddDocTemplate(pDocTemplate); // create main MDI Frame window CMainFrame* pMainFrame = new CMainFrame; if (!pMainFrame || !pMainFrame->LoadFrame(IDR_MAINFRAME)) { delete pMainFrame; return FALSE; } m_pMainWnd = pMainFrame; // call DragAcceptFiles only if there's a suffix // In an MDI app, this should occur immediately after setting m_pMainWnd // Enable drag/drop open m_pMainWnd->DragAcceptFiles(); // Enable DDE Execute open EnableShellOpen(); RegisterShellFileTypes(TRUE); // Parse command line for standard shell commands, DDE, file open CCommandLineInfo cmdInfo; ParseCommandLine(cmdInfo); // Dispatch commands specified on the command line. Will return FALSE if // app was launched with /RegServer, /Register, /Unregserver or /Unregister. if (!ProcessShellCommand(cmdInfo)) return FALSE; // The main window has been initialized, so show and update it pMainFrame->ShowWindow(m_nCmdShow); pMainFrame->UpdateWindow(); return TRUE; } // CAboutDlg dialog used for App About class CAboutDlg : public CDialog { public: CAboutDlg(); // Dialog Data enum { IDD = IDD_ABOUTBOX }; protected: virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support // Implementation protected: DECLARE_MESSAGE_MAP() }; CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD) { } void CAboutDlg::DoDataExchange(CDataExchange* pDX) { CDialog::DoDataExchange(pDX); } BEGIN_MESSAGE_MAP(CAboutDlg, CDialog) END_MESSAGE_MAP() // App command to run the dialog void CWerleShowBugApp::OnAppAbout() { CAboutDlg aboutDlg; aboutDlg.DoModal(); } // CWerleShowBugApp message handlers

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boost 1.34.1 string algorithm.
by chun ping wang 01 Aug '07

01 Aug '07

I was wondering is it really necessary to use string algorithms to find in variable str2 the last occurence that does not contain a number between 1 and 9 and create a substr base on that. regulary i would use std::string strNew = str2.substr(str2.find_last_not_of("123456789")); So 2 questions. 1.) Whats the benefit of the string algorithm version of boost in this case. 2.) How would I do this using string algorithm instead.

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newbie question
by Mike Gagnon 31 Jul '07

31 Jul '07

Hi Boost experts, I'm writing code in Visual C++ 6.0 and I'm trying to replace text in a string using a regular expression to match the text. I know there is a replace function in boost - but I don't think it's accessible from the regex++ API (or am I too much of a newbie to realize this)? Is there a way for me to use boost in Visual C++ 6.0 to do what I want? Thanks for any help! Best, Mike

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Useful macro
by Pavel Syomin 31 Jul '07

31 Jul '07

Hello! I don't sure, that I choose right mail list for my ofer... So, don't beat me much... :) I often use such macro for testing function parameters: #define THROW_INVALID_ARGUMENT_IF_FAIL(expression) \ do { \ using std::invalid_argument; \ using std::string; \ \ if(!(expression)) \ throw invalid_argument(string(BOOST_CURRENT_FUNCTION) + \ " : Assertion '" #expression "' failed"); \ } while(false) I think, that this macro is very useful and can be part of <boost/utility.hpp>.

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Re: [Boost-users] [1.34.1]quesion about b uild the lib
by hongleij＠126.com 31 Jul '07

31 Jul '07

1. > bjam --help >in Boost's top-level dir will show the --libdir and the like. >The threading and the list are documented in the "Builtin features" >section of Boost.Build manual. i spent quit a few hours on bbv2 document to get learn how to configure bjam to build boost libs. for it quite differnt from 1.33. but when i get an example bjam toolset=gcc-4.1.2 variant=release runtime-link=static threading=multi --without-regex --build-dir=/c/temp/gcc/build --stagedir=/c/temp/gcc/dest stage help with the bjam --help and the example ,i compile and installed boost successesful. so, i think an example in the very "getting started" for the usage of bjam with config option is nesesary. especially for those people just want to build boost ,not want to use bjam to manage building process of their project . 2, i use --with option in the root dir of boost,get all correct libs for rebuild a special lib. libboost_iostreams-mgw41-mt-sd-1_34_1.a libboost_iostreams-mgw41-1_34_1.a libboost_iostreams-mgw41-d-1_34_1.a libboost_iostreams-mgw41-mt-1_34_1.a libboost_iostreams-mgw41-mt-d-1_34_1.a boost_iostreams-mgw41-1_34_1.dll boost_iostreams-mgw41-1_34_1.a boost_iostreams-mgw41-mt-1_34_1.dll boost_iostreams-mgw41-mt-1_34_1.a boost_iostreams-mgw41-mt-d-1_34_1.dll boost_iostreams-mgw41-mt-d-1_34_1.a boost_iostreams-mgw41-d-1_34_1.dll boost_iostreams-mgw41-d-1_34_1.a libboost_iostreams-mgw41-s-1_34_1.a libboost_iostreams-mgw41-sd-1_34_1.a libboost_iostreams-mgw41-mt-s-1_34_1.a but in the diretary boost_1_34_1\libs\iostreams\build i use bjam -a --toolset=gcc -sNO_ZLIB -sZLIB_BINARY=zdll -sZLIB_LIBPATH=C:\MinGW\lib -sZLIB_INCLUDE=C:\MinGW\include just got . boost_iostreams-mgw41-d-1_34_1.a boost_iostreams-mgw41-d-1_34_1.dll not all files. mingw will compile with libboost_iostreams-mgw41-d-1_34_1.a when using -lboost_iostreams-mgw41-d-1_34_1 3. if add "with MinGW,MSYS is not needed, see..." seems more clear. may your help iPod、万点巨额点卡、奖学金……海量奖品，想拿就拿！

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boost::regex_match throws exception
by mildaiv＠centrum.cz 31 Jul '07

31 Jul '07

I build boost::regex 1.34 using Borland BDS 2006. Simple regular expresions works fine, but I have problem with this regular expresion: ^[_a-zA-Z0-9-]+(\.[_a-zA-Z0-9-]+)*(a)[a-zA-Z0-9-]+(\.[a-zA-Z0-9-]+)+$ if a try to match it with any string longer then 22 bytes, regex throws exception. After some investigations i simplified regular expresion to ^[10+]*@$ and it still throws exception code I use: boost::regex e("^[10+]*@$"); boost::match_results<std::string::const_iterator> what; if(0 == boost::regex_match(input, what, e, boost::match_default | boost::match_partial)) // here function throw exception { throw std::runtime_error("Invalid data entered - this could not possibly be a valid card number"); } if(what[0].matched) { return true; } return false; Milan Bacik

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[1.34.1]quesion about build the lib
by hongleij＠126.com 31 Jul '07

31 Jul '07

as a person familiar with usage of boost,yet a green man of building the lib,i just want build the boost lib, . i have such questions: 1, how could i know the bjam config options for building boost, such as runtime-link ,threading ,--libdir, --includedir . should i must read the total bbv2 document? 2,after build the total boost lib and installed in mingw bjam --toolset=gcc --build-dir="E:\tmp" install --libdir="C:\MinGW\lib" --includedir="C:\MinGW\include" ,i want to build the iostream with zlib support and aready installed zlib in mingw. according to the libs/iostreams/doc/index.html, i use command bjam -a --toolset=gcc -sNO_ZLIB -sZLIB_BINARY=zdll -sZLIB_LIBPATH=C:\MinGW\lib -sZLIB_INCLUDE=C:\MinGW\include get boost_iostreams-mgw41-d-1_34_1.a boost_iostreams-mgw41-d-1_34_1.dll yet cannot get libboost_iostreams-mgw41-1_34_1.a libboost_iostreams-mgw41-d-1_34_1.a and so on. thus, i still cann't use zlib with boost::iostream. 3.we know we can build the boost in mingw without MSYS by using bjam,yet the get start does not give such information. 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. i think how to build the boost libs using bjam should more well documented with so many configure options as possible.and how to build a perticular lib .1.33 did more than 1.34 many thanks iPod、万点巨额点卡、奖学金……海量奖品，想拿就拿！

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use PATH environment variable to search for libraries and include files on windows with mingw
by mattknox_ca 31 Jul '07

31 Jul '07

I don't see any obvious way to make bjam look in my PATH environment variable on windows (using gcc) when trying to locate header files and such. Is this possible? I have a directory "C:\c_libs" , which underneath I have two subfolders: "include" and "lib". I would like to modify user-config.jam (or if there is a more appropriate file to modify, please suggest) such that all my projects will always have access to the files in these folders without having to explictly reference these folders in each project's Jamroot file. Right now those folders are in my path environment variable, but I am open to the idea of creating explicity environment variables for each of those folders if that makes the task easier. But either way, I don't know how to do it. I banged my head against the keyboard for a few hours, and that didn't help. Any assistance is greatly appreciated. Thanks, - Matt -- View this message in context: http://www.nabble.com/use-PATH-environment-variable-to-search-for-libraries… Sent from the Boost - Users mailing list archive at Nabble.com.

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[Important] Reminder: CVS closes at 8am EDT tomorrow
by Douglas Gregor 30 Jul '07

30 Jul '07

This is a friendly reminder that Boost CVS will be shutting down permanently tomorrow, July 31st, at 8:00AM EDT. We will be converting the entire CVS repository to Subversion and expect to have the new Subversion repository up by the end of the day. For more information about the move to Subversion, see http://lists.boost.org/Archives/boost/2007/07/125148.php - Doug

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Using boost graphic lib (newbie)
by E B 30 Jul '07

30 Jul '07

I need to display a graph . Therefore I need to compute coordinate of each node (XY) and I plan to use BGL which provide algorithms for this purpose. After having looked at the test examples, I can not see how to implement a graph and run one of the layout algorithms. Does anybody have any experience on using BGL ? My node stuct is struct { string name; int x; int y; } and I have a vector of pair that contain the edges (vector<pair<node*,node*> >). I need to feed the node.x and node.y by using my own struct or another ones provided I get the X Y.

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Stupid ostringstream question
by Bill Lear 30 Jul '07

30 Jul '07

I have been searching the world in vain for a stringstream that works with a static buffer, and does not use the heap for memory allocation. We have an application that uses lots (12-16Gb) of memory. This puts a strain on the memory allocation routines, and when we want to create a small string we find that stringstream is very, very expensive, and sprintf into a static buffer much, much faster. Does boost provide anything like this? This actually came up when we realized that boost lexical_cast was using stringstream. When we replaced it with sprintf, our runtimes (when memory usage was very high) went down significantly. I should also point out that ANYTHING we did with dynamic memory at that point in the application (vector::push_back, for example) was hideously slow. I'd like to have the best of both worlds: the relatively clear syntax of the ostringstream inserters, working on a static buffer. Any help (code samples especially) appreciated. Bill

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[Boost.Build v2] Please help updating my build process from v1 (1.33.1) to v2 (1.34.1)
by Ames, Andreas (Andreas) 30 Jul '07

30 Jul '07

Hi all, as most of my colleagues insist on using Visual Studio, I have made a vcproj-wrapper around Boost.Build v1 for 1.33.1. The Jamfile looks like this: <Jamfile> project-root ; BOOST_LOCAL_STAGE_DIR ?= stage ; rule Pseudo ( target : libname : kind : variant : name_prefix ? ) { LIBNAME = $(libname) ; LIBKIND = $(kind) ; VARIANT = $(variant) ; REALNAME = $(name_prefix)$(LIBNAME) ; REALNAME ?= $(LIBNAME) ; NOTFILE $(target) ; DEPENDS $(target) : $(BOOST_LOCAL_STAGE_DIR)/$(LIBKIND)/$(LIBNAME)/$(VARIANT) ; stage $(BOOST_LOCAL_STAGE_DIR)/$(LIBKIND)/$(LIBNAME)/$(VARIANT) : <$(LIBKIND)>@boost/libs/$(LIBNAME)/build/boost_$(REALNAME) : <sysinclude>../../../boost <debug-symbols>on <debug-store>database <runtime-build>$(VARIANT) <runtime-link>dynamic <native-wchar_t>on : $(VARIANT) ; } Pseudo signals_lib_debug : signals : lib : debug ; Pseudo signals_lib_release : signals : lib : release ; </Jamfile> Furthermore I've created a Jamrules and a boost-build.jam like follows: <Jamrules> project boost : ../../../boost ; </Jamrules> <boost-build.jam> boost-build ../../../boost/tools/build/v1 ; </boost-build.jam> From my vcproj-files I can then just invoke bjam with the appropriate target and TOOLS-spec. 1) Unfortunately this doesn't work any longer with Boost.Build v2. After changing boost-build.jam in the obvious way, I just get bjam to display: error: Could not find parent for project at '.' error: Did not find Jamfile or project-root.jam in any parent directory. although the Jamfile is definitely there. The same thing happens, when I change the name to Jamfile.v2. 2) Skimming over the docs, I don't see Jamrules (which was previously needed) mentioned. Is it still necessary? 3) Finally, the build wrapper needs to be selfcontained (we get it from our repository), so site-config.jam and user-config.jam must not be mandatory. I just wonder, where to specify my 'using' rule(s) (like 'using msvc : 8.0 ;'). TIA, aa -- Andreas Ames | Programmer | Comergo GmbH | ames AT avaya DOT com Sitz der Gesellschaft: Stuttgart Registergericht: Amtsgericht Stuttgart - HRB 22107 Geschäftsführer: Andreas von Meyer zu Knonow, Udo Bühler, Thomas Kreikemeier

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[filesystem] Using path in shared library fault (?)
by Hughes, James 30 Jul '07

30 Jul '07

Hello all, I am using filesystem::path is a shared library called 'common', to initialise a static var. static boost::filesystem::path p("/home/me"); However, this give a seg fault (Linux, gcc) when the shared library is loaded. I am guessing this is an issue with the filesytem library not being loaded in at the time of the loading of 'common' (when the static var is initialised) - hence the seg fault. Its only an issue with the static variable, as all other uses of path in the library work fine. Is there any way round this? James This message (including any attachments) contains confidential and/or proprietary information intended only for the addressee. Any unauthorized disclosure, copying, distribution or reliance on the contents of this information is strictly prohibited and may constitute a violation of law. If you are not the intended recipient, please notify the sender immediately by responding to this e-mail, and delete the message from your system. If you have any questions about this e-mail please notify the sender immediately.

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stream + file_descriptor_source + closing
by Tomasz Noiński 30 Jul '07

30 Jul '07

Hi, I'm trying to use boost::iostreams for a project I'm writing and I have a problem: It seems that the destructor of boost::iostreams::stream<boost::iostreams::file_descriptor_source> closes the file descriptor. I really need to be able to close this file descriptor manually and I can't find any way to do it. Note that file_descriptor_source has a constructor parameter specifying if the descriptor should be closed in file_descriptor_source destructor or not. It perfectly works - it's boost::iostreams::stream destructor that forces closing the description, not file_descriptor_source destructor. A short code illustrating this problem (for Linux): --- 8< --- #include <iostream> #include <boost/iostreams/device/file_descriptor.hpp> #include <boost/iostreams/stream.hpp> #include <cstring> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <errno.h> using namespace std; using namespace boost::iostreams; int main() { int fd = open("/etc/fstab", O_RDONLY); clog << "fd=" << fd << endl; { file_descriptor_source source(fd, false); stream<file_descriptor_source> strm(source); string s; strm >> s; clog << "first line: " << s << endl; } int closeRet = close(fd); int closeErrno = errno; clog << "closing result: " << closeRet << ", " << strerror(closeErrno) << endl; } --- 8< --- The behaviour I would expect is the close() at the end succeeding. However, it returns -1 with errno=EBADF. Is this the expected behaviour or a bug? TIA, Noix

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boost thread read_write_mutex
by Fei Liu 30 Jul '07

30 Jul '07

Just a question, I don't see any big bold note that the related read/write mutex or locks should not be used...What's the story of reader/writer's mutex in boost::thread? Fei

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[Boost.Graph] Compiler warning in dijkstra_shortest_paths
by Ewgenij Sokolovski 30 Jul '07

30 Jul '07

Hello. I use the Boost.Graph with the dijkstra_shortest_paths algorithm in my graph application. All works fine. But while compiling with the options -Wall -W I get a strange compiler warning: /usr/include/boost/graph/dijkstra_shortest_paths.hpp:80: Warning: »bfs_vis$m_decreased« is used in this function uninitialised This was the last line of the warning because it is quite long in its complete version. I translated the line above from German because I use a German version of g++, so maybe it sounds in the English version a little bit different. But the meaning remains the same:) Does anybody know what that is supposed to mean? Is something wrong with my program or is it a bug in dijkstra_shortest_paths? Here is the warning in the complete version: /usr/include/boost/graph/dijkstra_shortest_paths.hpp: In function »void boost::detail::dijkstra_dispatch2(const VertexListGraph&, typename boost::graph_traits<G>::vertex_descriptor, DistanceMap, WeightMap, IndexMap, const Params&, ColorMap) [with VertexListGraph = boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, boost::no_property, float, boost::no_property, boost::listS>, DistanceMap = float*, WeightMap = boost::adj_list_edge_property_map<boost::undirected_tag, float, float&, long unsigned int, boost::property<boost::edge_bundle_t, float, boost::no_property>, boost::edge_bundle_t>, IndexMap = boost::vec_adj_list_vertex_id_map<boost::no_property, long unsigned int>, Params = boost::bgl_named_params<boost::adj_list_edge_property_map<boost::undirected_tag, float, float&, long unsigned int, boost::property<boost::edge_bundle_t, float, boost::no_property>, boost::edge_bundle_t>, boost::edge_weight_t, boost::bgl_named_params<float*, boost::vertex_distance_t, boost::no_property> >, ColorMap = boost::iterator_property_map<__gnu_cxx::__normal_iterator<boost::default_color_type*, std::vector<boost::default_color_type, std::allocator<boost::default_color_type> > >, boost::vec_adj_list_vertex_id_map<boost::no_property, long unsigned int>, boost::default_color_type, boost::default_color_type&>]«: /usr/include/boost/graph/dijkstra_shortest_paths.hpp:80: Warning: »bfs_vis$m_decreased« is used in this function uninitialised Greetings Ewgenij -- Ist Ihr Browser Vista-kompatibel? Jetzt die neuesten Browser-Versionen downloaden: http://www.gmx.net/de/go/browser

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Problem Bjam
by question boost 30 Jul '07

30 Jul '07

Hi, using Code Blocks i got the folowing message: ld.exe "Cannot find -lboost_filesystem-mgw-mt-s-l_33_l". So I did :cd /jam source location/then build.bat Then, i put the following variables: path=C:\Program Files\CodeBlocks\bin BOOST_BUILD_PATH=C:\Documents and Settings\Administrateur\Bureau\boost_1_33_1\boost_1_33_1\tools\build\v2 BOOST_ROOT=C:\Documents and Settings\src\boost It is not the right things to do => i get the message again. My question is: What are the right things to do in order not to get the message any more? Thank You _________________________________________________________________ Windows Live Messenger vous offre 30 nouvelles émoticônes gratuites, installées directement dans votre Messenger ! http://www.emoticones-messenger.fr/

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How to build only Boost.Iostreams with compression filter support on Windows XP using MinGW
by Benjamin Lau 30 Jul '07

30 Jul '07

Good evening, Pardon my ignorance, or my poor documentation reading skills, but I am unable to build Boost.Iostreams with compression filter support on Windows XP using MinGW. I am using Boost 1.34.1, zlib 1.2.3 and bzip2 1.0.4. I tried the following command lines but to no avail: bjam --toolset=gcc -sNO_COMPRESSION=0 -sNO_BZIP2=0 -sBZIP2_LIBPATH=C:\bzip2-1.0.4 -sBZIP2_SOURCE=C:\bzip2-1.0.4 -sNO_ZLIB=0 -sZLIB_LIBPATH=C:\zlib-1.2.3 -sZLIB_SOURCE=C:\zlib-1.2.3 stage or bjam --toolset=gcc --NO_COMPRESSION=0 --NO_BZIP2=0 --BZIP2_LIBPATH=C:\bzip2-1.0.4 --BZIP2_SOURCE=C:\bzip2-1.0.4 --NO_ZLIB=0 --ZLIB_LIBPATH=C:\zlib-1.2.3 --ZLIB_SOURCE=C:\zlib-1.2.3 stage I searched through the Boost.Iostreams documentation, the Boost.Jam documentation, and the Boost.Build V2 documentation. Boost.Jam documentation indicates that the former should work, but Boost.Build V2 seems to use very little of or not at all of the -s flag for Boost.Jam, so I tried the latter. The result of both commands were the same, Boost.Iostreams was built without the compression filters. However, I do get 12 "warning: Unable to construct ./stage-unversioned" as the first output from Boost.Jam, after which it says "...patience..." and continues with the building process. Thank you in advance for assisting me in my problem, and in case I have missed out something critical yet obvious, and hence resulting in my failure, I apologise for not reading carefully enough. Thank you and have a nice day Benjamin Lau

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Zhang has Tagged you :)
by Zhang Shenpeng 29 Jul '07

29 Jul '07

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[asio] when deadline_timer::cancel() returns
by Yuval Ronen 29 Jul '07

29 Jul '07

The Asio docs for deadline_timer::cancel say that "This function forces the completion of any pending asynchronous wait operations against the timer". Let's say I have a thread executing io_service::run, and is now invoking a completion handler of a deadline_timer. While this completion handler is underway, a second thread is calling cancel() on that deadline_timer. Is the cancel() call supposed to block until the completion handler is finished? To my best understanding, both according to the docs, and according to what seems to be logical to me, the answer is "yes, it should block". However, it doesn't. Is it a bug, or by design? Yuval

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[mpl] what is not a placeholder expression
by "JOAQUIN LOPEZ MU?Z" 29 Jul '07

29 Jul '07

According to the MPL reference, a placeholder expression X<a1,..,an> must satisfy (among others) the following condition: "All of X's template parameters, including the default ones, are types." According to that the following should then compile without errors: #include <boost/mpl/apply.hpp> #include <boost/mpl/assert.hpp> #include <boost/type_traits/is_same.hpp> using namespace boost; using namespace boost::mpl; template<typename T,int=0> struct foo { template<typename Q> struct apply{ typedef Q type; }; }; typedef apply1<foo<_1>,int>::type t1; BOOST_MPL_ASSERT((is_same<t1,int>)); int main(){} However, I've tried with GCC 3.4.4 and the static assertion fails! I'd like to know: 1. Whether I'm right in assuming that the code above should compile without assertion failures. 2. What the behavior is for other versions of GCC and compilers: reports most welcome!! 3. Whether this is a known problem specific to GCC or, more generally, what the status of this issue is. Thank you, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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Trac / Register User
by Olaf van der Spek 28 Jul '07

28 Jul '07

On 7/27/07, Chris Weed <chrisweed(a)gmail.com> wrote: > > Where are the links to Trac from http://boost.org/? > > I've been trying to find Trac before but didn't succeed. > > Report Bugs -> Bug tracking facility > > http://svn.boost.org/trac/boost/report Thanks. But where is the register user link? I only see login.

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[BGL] Parameter: CompareFunction - dijkstra_shortest_paths
by Leandro T. C. Melo 28 Jul '07

28 Jul '07

Hello all. It is clear for me the reason for template parameter CombineFunction in dijkstra_shortest_paths. For instance, prim_minimum_spanning_tree makes use of it to correct compute the MST. Basically, in Dijkstra's it is something like this: distance = distance of vertex v + weight of edge e; And in Prim's only the weight is considered: distance = weight of edge e; This is reflected on the argument used for the CombineFunction in Prim's function (from file prim_minimum_spanning_tree.hpp): prim_minimum_spanning_tree(...) { typedef typename property_traits<WeightMap>::value_type W; std::less<W> compare; detail::_project2nd<W,W> combine; dijkstra_shortest_paths(...); } Where _project2nd is: template <class U, class V> struct _project2nd { V operator()(U, V v) const { return v; } }; However, it is not clear the reason of the CompareFunction template parameter (which is a predicate). First, because, I don't see a situation where not using std::less<Some_type> would make any sence, because of the way the Dijkstra's algorithm is constructed. Second, because the value_type of the DistanceMap must be the same of the value_type of WeightMap (according to the documentation). Therefore, why the following two lines of code in Prim's implementation (from the function I pointed at beginning of the email)? typedef typename property_traits<WeightMap>::value_type W; std::less<W> compare; Since, in Dijkstra's algorithm the only difference is that DistanceMap is used as an argument for the definition of the value_type from property_traits. Am I loosing something here? If yes, would anyone explain it to me? Thank you, Leandro.

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