August 2011 - Boost-users - lists.preview.boost.org

adding elements to a std::container in a single expression
by Peter Foelsche 14 Aug '11

14 Aug '11

until now I've usually written my own template to do this: template<typename T> struct push_back_container:T { push_back_container &_push_back(const typename T::value_type &_r) { push_back(_r); return *this; } }; one can use this like this: push_back_container<std::vector<something> >()._push_back(something1)._push_back(_something2) Is there some more elegant way to do this? Peter

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[C++0x] ISO/IEC approves C++0x standard!
by Beman Dawes 13 Aug '11

13 Aug '11

The C++0x standard has been approved by ISO/IEC. The vote was unanimous; all 21 National Bodies voting were in favor. That means the dozen or so Boost libraries that were in TR1 are now part of the standard itself. Good work, Boosters! --Beman

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[serialization] unregistered class exception when using BOOST_CLASS_EXPORT_GUID
by Ron Hashimshony 13 Aug '11

13 Aug '11

Hi all boost users, We have been using boost.serialization for years. We want to move from 1.33 to 1.47 and encountered a problem. Many of our classes are abstract, and the derived are defined with BOOST_CLASS_EXPORT_GUID. At one point in time, a new class (B) was added that derives from a class that was defined with the BOOST_CLASS_EXPORT_GUID macro (A). It all worked well in 1.33. In 1.47, when we get to de-serialize class A, we get an exception of unregistered class. We traced it down, and found out that if we remove the derived class (B), it works fine, but this is not an option, and then the derived class (B) cannot be de-serialized from the file... If there any way to bypass this problem? was there a change made that broke this functionality? Many Thanks! Ron

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Re: [Boost-users] [!! SPAM] [Boost.Wave] util::file_position<> and asserted !is_escaped_lit(..) requirement
by Hartmut Kaiser 13 Aug '11

13 Aug '11

> (Using namespace boost::wave here on.) > > It seems that util::file_position<> has an assertion that checks if a > given filename contains any following sequences: <\\>, <\"> or <\?> (using > util::debug::is_escaped_lit). > > I wonder why file_position<> does need to check this and if it's so > crucial why it's done using a mere BOOST_ASSERT? > > Now, here's comes the reason why I'm asking this: At least with MSVC9's > remote debugger (or some other lowlevel component; not really the > interesting part > here) translates all network shares on a remote computer to UNC-paths. > This is correct behaviour and actually a very neat feature. However, as > you might be already aware at this point this leads to the actual problem: > Any UNC-path triggers (consider <\\foo\path\file>) the assertion and > things go boom. > > It is not possible to easily work around this by refactoring user code > and/or input values as provided filenames are completed internally using > util::complete_path (after which <file> becomes <\\foo\path\file> etc. in > this case). > > I tried to disable this assertion (actually, there's two; one in the > constructor and one in the set_file member function) and didn't see any > strange behaviour. E.g. std::ifstream handling with UNC-paths in > iteration_context_policies::load_file_to_string::inner<> worked just fine, > as expected from a native STL. > > Goes without saying that I'm using the latest Boost version (1.47.0). I > would be very pleased if anyone could shed some light on this matter or > better still > - fix it permanently. Right, that's apparently a leftover from old boost.filesystem times, when it did not support UNC paths. I'll remove the checks asap. Regards Hartmut --------------- http://boost-spirit.com

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[serialization] overloading load_construct_data: no accessible constructor at all
by Griffin Howlett 13 Aug '11

13 Aug '11

Hey, so I'm using the boost::serialization library, and I'm trying to override how a class is constructed, since it has no default constructor. This is demonstrated here<http://www.boost.org/doc/libs/1_47_0/libs/serialization/doc/serialization.h…>. To me it appears the function ONLY takes the `class* t` and then sets it to point to a newly constructed object. If I'm wrong, this is definitely the source of my error. However, the only way to construct my class is by using another classes `create()` function, meaning I need to stray from the code in the example (this is stated in the boost::serialization namespace): `::new(t)my_class(attribute);` I tried simply calling the create function and setting `t` equal to the returned pointer, but this doesn't seem to work because right after the `load_construct_data function`, and in the `serialization function`, the given `myClass&` is not the same as what I set 't' to. *How do I do whatever ::new(t) is doing so the object created using the create function follows through into the serialize/other functions?* [1]: http://www.boost.org/doc/libs/1_47_0/libs/serialization/doc/serialization.h…

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JSON Property file reader compile problem
by Scott Smith 13 Aug '11

13 Aug '11

I'm trying to use the boost property tree to read a json file. I'm using 1.46 on gcc 4.6 (Fedora 15). I'm also running on Eclipse (Indigo) which is relevant for something I mention below. Here's the issue . I have a JSON file which has an array of parameters which looks something like: { "config": { "modules": [ { "name": "somename0", "param1": "someparam", "param2":"someotherparm" }, { "name": "somename1", "param1": "someparam", "param2":"someotherparm" }, { "name": "somename2", "param1": "someparam", "param2":"someotherparm" } ] } } So, I wrote the following code (Note that I can't use boost:FOR_EACH because of some bug in eclipse (#332278) which causes an error-or so I believe): ptree v = pt.get<ptree>("config.modules"); for (ptree::iterator it = v.begin() ; it != v.end ; ++it) { ptree module = ???; } The first two lines seem to compile fine. I'm assuming that what I get from v is the "root" ptree (the parent) for the various "modules" objects and that the iterator will walk through them. However, I've tried all sorts of things trying to get at the module data (e.g., it->second, (*it)->second, ...) and clearly I don't know what it is I need to tell the compiler I want. All I get are compile errors. The compiler is giving me no hints as to what I need to tell it. Can someone tell me what I'm missing here? Thanks Scott

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(no subject)
by Hasanul Ferdaus 12 Aug '11

12 Aug '11

living paycheck to paycheck wasnt working for me I told myself to stay positive without this id still be completely distraught! <a href="http://salanowyswiat.home.pl/PhilipBennett68.html">http://salanowyswiat.home.pl/PhilipBennett68.html</a> I waited so long for my time to shine

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[ASIO] Send data on a socket
by Claude 12 Aug '11

12 Aug '11

I created a socket with BOOST asio and I use it in a server process that accepts connections from "remote" client. It is possible from the process that created the socket, send data to the same socket simulating the arrival of data from a client process? -- View this message in context: http://boost.2283326.n4.nabble.com/ASIO-Send-data-on-a-socket-tp3738099p373… Sent from the Boost - Users mailing list archive at Nabble.com.

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[Boost.Wave] util::file_position<> and asserted !is_escaped_lit(..) requirement
by Pekka Seppänen 12 Aug '11

12 Aug '11

Hello. (Using namespace boost::wave here on.) It seems that util::file_position<> has an assertion that checks if a given filename contains any following sequences: <\\>, <\"> or <\?> (using util::debug::is_escaped_lit). I wonder why file_position<> does need to check this and if it's so crucial why it's done using a mere BOOST_ASSERT? Now, here's comes the reason why I'm asking this: At least with MSVC9's remote debugger (or some other lowlevel component; not really the interesting part here) translates all network shares on a remote computer to UNC-paths. This is correct behaviour and actually a very neat feature. However, as you might be already aware at this point this leads to the actual problem: Any UNC-path triggers (consider <\\foo\path\file>) the assertion and things go boom. It is not possible to easily work around this by refactoring user code and/or input values as provided filenames are completed internally using util::complete_path (after which <file> becomes <\\foo\path\file> etc. in this case). I tried to disable this assertion (actually, there's two; one in the constructor and one in the set_file member function) and didn't see any strange behaviour. E.g. std::ifstream handling with UNC-paths in iteration_context_policies::load_file_to_string::inner<> worked just fine, as expected from a native STL. Goes without saying that I'm using the latest Boost version (1.47.0). I would be very pleased if anyone could shed some light on this matter or better still - fix it permanently. Br, Pekka

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async_read_some() not found??
by Claude 12 Aug '11

12 Aug '11

I have this code (from async_read_until boost documentation): boost::asio::streambuf b; void handler(const boost::system::error_code& e, std::size_t size) { if (!e) { std::istream is(&b); std::string line; std::getline(is, line); // ... } } boost::asio::async_read_until(s, b, "\r\n", handler); But I obtain this error on Ubuntu 11.04 (boost 1.45.0): boost/asio/impl/read_until.hpp|388|*error: request for member ‘async_read_some’* in ‘((boost::asio::detail::read_until_delim_op<boost::asio::basic_stream_socket<boost::asio::ip::tcp>*, std::allocator<char>, void (*)(const boost::system::error_code&, unsigned int)>*)this)->boost::asio::detail::read_until_delim_op<boost::asio::basic_stream_socket<boost::asio::ip::tcp>*, std::allocator<char>, void (*)(const boost::system::error_code&, unsigned int)>::stream_’, which is of non-class type ‘boost::asio::basic_stream_socket<boost::asio::ip::tcp>*’ I Included in my project: libpthread libboost_system -- View this message in context: http://boost.2283326.n4.nabble.com/async-read-some-not-found-tp3732368p3732… Sent from the Boost - Users mailing list archive at Nabble.com.

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[filesystem] misidentifies file type on Solaris x86 64-bit
by Will Mason 11 Aug '11

11 Aug '11

Hello, I'm using Boost 1.46.1 with filesystem v3. Code that I've been running successfully on Windows, Linux and FreeBSD started producing very mysterious results on Solaris. I boiled it down to this: boost::filesystem will not identify a directory as a directory. Here's a test program: #include <boost/filesystem.hpp> int main() { try { boost::filesystem::path d(boost::filesystem::absolute("dir")); if (boost::filesystem::exists(d)) { std::cout << d << " already exists" << std::endl; } else { boost::filesystem::create_directory(d); std::cout << d << " is " << (boost::filesystem::is_directory(d) ? "" : "not") << " a directory" << std::endl; } } catch (std::exception& e) { std::cout << "Exception: " << e.what() << std::endl; } return 0; } And here is a snippet of a terminal session compiling and running the program: $ CC -o fstest fstest.cpp -library=stlport4 -Iexternal/solaris/x86/64/suncc/5.11/include external/solaris/x86/64/suncc/5.11/lib/libboost_filesystem.a external/solaris/x86/64/suncc/5.11/lib/libboost_system.a $ ./fstest "/export/home/will/Projects/cap/dir" is not a directory $ file /export/home/will/Projects/cap/dir /export/home/will/Projects/cap/dir: directory $ Thanks for any help, Will

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Boost Unit test on Eclipse
by Yong Qin 11 Aug '11

11 Aug '11

I have tried to use boost unit test on Eclipse CDT w/ MinGW and VC++. But I can not link to the static boost library: libboost_unit_test_framework-vc100-mt-1_47.lib. The code I used: #defineBOOST_TEST_MAIN #defineBOOST_TEST_MODULEMasterTestSuite #include<boost/test/unit_test.hpp> BOOST_AUTO_TEST_SUITE(FooTests) BOOST_AUTO_TEST_CASE(ctor_test1) { Fooa; BOOST_CHECK_EQUAL(a.name(),MY_PROJECT_NAMESPACE::Foo::DEF_NAME); } BOOST_AUTO_TEST_CASE(ctor_test2) { conststd::stringtheName("Blah"); Fooa(theName); BOOST_CHECK_EQUAL(a.name(),theName); } BOOST_AUTO_TEST_SUITE_END() What is wrong?

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program_options: accepting NaNs for doubles
by Rhys Ulerich 11 Aug '11

11 Aug '11

Hi all, program_options does not accept NaN or Inf as valid double input. For example, the following sequence modifies the "Getting Started" first.cpp [1] to accept double input: cp $BOOST_SOURCE/libs/program_options/example/first.cpp . perl -pi -e 's/<int>/<double>/;' first.cpp LDFLAGS="-lboost_program_options" make first # ...or whatever The modified example indeed barfs on NaN or Inf input: $ ./first --compression=5.5 Compression level was set to 5.5. $ ./first --compression=Inf error: in option 'compression': invalid option value 'Inf' $ ./first --compression=NaN error: in option 'compression': invalid option value 'NaN' Two questions: 1) Does this count as a bug? 'std::cin >> foo' doesn't grok Inf or NaNs (on my system anyhow) but methods like strtod() do. Users providing explicit infinities or not-a-numbers as options parameters likely don't do so accidentally. This Inf/NaN behavior is not mentioned in the active tickets. 2) Can anyone suggest a workaround (shy of using string-based parameters and calling strtod myself)? Thanks, Rhys [1] http://www.boost.org/doc/libs/1_47_0/doc/html/program_options/tutorial.html…

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Re: [Boost-users] Boost-users post acknowledgement
by Yong Qin 11 Aug '11

11 Aug '11

for VC, I try to link to: libboost_test_exec_monitor-vc100-mt-1_47.lib and got error: LNK1561: entry point must be defined VCApp_Test line 0 C/C++ Problem for MinGW, I try to link to: libboost_test_exec_monitor-mgw46-mt-1_47.a and got error: undefined reference to `__chkstk_ms' MinGWApp_Test line 0, external location: D:\boost_1_47_0-MinGW\stage\static\lib\libboost_unit_test_framework-mgw46-mt-1_47.a(unit_test_parameters.o):unit_test_parameters.cpp C/C++ Problem undefined reference to `std::__detail::_List_node_base::_M_hook(std::__detail::_List_node_base*)' MinGWApp_Test line 0, external location: D:\boost_1_47_0-MinGW\stage\static\lib\libboost_unit_test_framework-mgw46-mt-1_47.a(unit_test_suite.o):unit_test_suite.cpp C/C++ Problem undefined reference to `std::__detail::_List_node_base::_M_unhook()' MinGWApp_Test line 0, external location: D:\boost_1_47_0-MinGW\stage\static\lib\libboost_unit_test_framework-mgw46-mt-1_47.a(unit_test_suite.o):unit_test_suite.cpp C/C++ Problem

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question about Boost naming
by Yong Qin 11 Aug '11

11 Aug '11

I am using Boost test library now and find there are several libraries there: libboost_unit_test_framework-mgw46-1_47.a libboost_unit_test_framework-mgw46-mt-1_47.a libboost_unit_test_framework-mgw46-s-1_47.a what are differences between the 3 libraies (with "s", or with "mt", or no "mt" and "s")? also, for VC++ compiler, there is: boost_unit_test_framework-vc100-mt-1_47.dll but MinGW have: libboost_unit_test_framework-mgw46-mt-1_47.dll libboost_unit_test_framework-mgw46-1_47.dll Why MinGW have more?

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[boost-build] Dynamic linking dependency propagation on mac os x
by Tim Odenthal 11 Aug '11

11 Aug '11

Dear list, i'm trying to compile an existing project which compiles fine on Windows (where we link statically) and linux (where linking is default, i.e. dynamic) on Mac OS X (10.7). I'm essentially trying to use the same configuration as on linux, since darwin ~ gcc… The project makes use of (and therefore links to) several boost libraries including system, filesystem, serialization,… We create several libraries which depend upon each other: - lib1depends on serialization,filesystem,… - lib2 depends on lib1 - lib3 depends on lib1 and lib2 -> here's the first problem: the (implicit) dependence on system, filesystem and serialization is not automatically resolved anymore. At least, the linker complains about missing symbols, since the "g++"-command-line doesn't include the libraries. I could solve that by adding those libraries to the requirements with <use>/boost/serialization, etc. -lib4 depends on lib3 -> here's the real problem: again, the implicit dependence on (specifically) lib1 and the boost-libs is lost. I can use the same trick as before with the boost-libs, but whatever I do, I cannot make the "lib1.dylib" appear in the "g++" command-line. When I execute the command by hand - adding lib1.dylib - it executes fine & the linker does not complain. How/why does that happen? My user-config.jam simply consists of: using darwin : : : <compileflags>-DBOOST_WAVE_SUPPORT_THREADING=0 ; What else do I need to configure differently on Mac OS X? Thanks a lot in advance for any suggestions Tim

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Windows Installer Build
by asif saeed 11 Aug '11

11 Aug '11

Hi, I installed Boost 1.47 using Windows Installer. I have Visual C++ 2010 Express installed and I installed Platform SDK for 2003 and Windows Driver Kit, that give me MFC/ATL, etc., separately. However, I have to set the directories in each project before I build anything otherwise the VC++ 2010 picks up the Windows SDK 7.0 that gets installed by default by Visual C++ 2010 Express. So Boost installer, I suspect, too picked up the wrong SDK, Windows SDK 7, directories instead of the those of the platform SDK. I suspect so because upon including ASIO header and just getting an IP Address string, I get build warnings like these: Please define _WIN32_WINNT or _WIN32_WINDOWS appropriately. For example: - add -D_WIN32_WINNT=0x0501 to the compiler command line; or - add _WIN32_WINNT=0x0501 to your project's Preprocessor Definitions. Assuming _WIN32_WINNT=0x0501 (i.e. Windows XP target). File0001.cpp Please define _WIN32_WINNT or _WIN32_WINDOWS appropriately. For example: - add -D_WIN32_WINNT=0x0501 to the compiler command line; or - add _WIN32_WINNT=0x0501 to your project's Preprocessor Definitions. Assuming _WIN32_WINNT=0x0501 (i.e. Windows XP target). File0002.cpp Second_test.cpp Please define _WIN32_WINNT or _WIN32_WINDOWS appropriately. For example: - add -D_WIN32_WINNT=0x0501 to the compiler command line; or - add _WIN32_WINNT=0x0501 to your project's Preprocessor Definitions. Assuming _WIN32_WINNT=0x0501 (i.e. Windows XP target). Any idea how I can fix this? Best, Asif

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Re: [Boost-users] [asio] user defined composed operations and strands
by Marat Abrarov 11 Aug '11

11 Aug '11

Hi, Tacheon. > If async_write_data is called and io_service::run is called from multiple threads, strands are should > be necessary to avoid raced. > The question is: How do I support handlers wrapped in a strand and how do I get this strand forwarded > to async_read? > As far as I understand this should be somehow possible by using asio_handler_invoke but the > documentation is a bit too fuzzy on the topic for me to understand. There is no such info in Asio docs. You may look at asio-samples (http://sourceforge.net/projects/asio-samples) There is ma::context_wrapped_handler class (and ma::make_context_wrapped_handler helper function) that makes such a wrapper for intermediate handler. But you shouldn't use > typedef boost::function<void (error_t const &)> completion_handler_t; because it hides asio_hanlder_invoke defined for the original (user supplied) handler. You may write something like this: class io_port { public: //Ctors and so on... template<typename Handler> void async_read_data ( raw_buffer_t & buffer , Handler const & handler) { //uses a composed operation itself... boost::asio::async_read ( socket , boost::asio::buffer(header) , ma::make_context_wrapped_handler(handler, boost::bind ( &io_port::handle_header_received<Handler> , this , boost::ref(buffer) , handler , boost::asio::placeholders::error))); } //first intermediate handler template<typename Handler> void handle_header_received ( raw_buffer_t & data , Handler const & handler , boost::system::error_code const & error { if(error) { handler(error_t(error)); } else { prepare_buffer(data, header.perparation_data()); //pseudo-code //uses a composed operation itself... boost::asio::async_read ( socket , boost::asio::buffer(data) , ma::make_context_wrapped_handler(handler, boost::bind(&io_port::handle_data_received<Handler> , this , boost::ref(buffer) , handler , boost::asio::placeholders::error) ); } } //second intermediate handler template<typename Handler> void handle_data_received ( raw_buffer_t & data , Handler const & handler , boost::system::error_code const & error ) { if(error) { handler(error_t(error)); } else { handler(error_t()); } } }; Also, it will be very helpful to read Asio sources: /boost/asio/impl/read.hpp: 339 and 145 (Boost 1.47). May be it' will be better to implement io_port class similar to boost::asio::detail::read_op. Regards, Marat Abrarov.

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question about changing permission with boost
by rudy b 11 Aug '11

11 Aug '11

Hi, I am trying to copy a file from one folder to another, but I am also trying to access to the last_write_time of the file, BEFORE copying it to the other folder, And I notice, whenever I am inside a Read-only directory, and trying to access the "last_write_time" of a Read-only file, I get the following error message: what(): boost::filesystem::last_write_time: Permission denied: "src/ temp1/methodologies.ppt" In this scenario "temp1" is a Read-only directory, also methodologies.ppt is a Read-only file as well. Does anyone know how to get around this? Is there a way to change the directory/file permission (to write) prior to copying, and then change the permission back again? I need to access the time-stamp before copying the file, because right after I copy the file, the date-stamp will be updated. I would really appreciate some help, please advise, thanks, RB

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[BGL] bundled properties and forward declarations (changes from 1.42 -> 1.46.1 ?)
by Anders Wallin 10 Aug '11

10 Aug '11

I have code using bundled properties roughly like this that compiles with boost 1.42: struct EdgeProperty; typedef adjacency_list< ... , EdgeProperty , ...> MyGraph; typedef graph_traits<MyGraph>::edge_descriptor Edge; struct EdgeProperty { Edge next; }; When trying to compile this with boost 1.46.1 I get "error: forward declaration of EdgeProperty’". I am not sure why. The obvious solution would be to move the definition of EdgeProperty before the MyGraph typedef, but then I run into a circular dependency problem as I want to store an edge_descriptor in EdgeProperty. any ideas? Anders

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[bimap] Problem with finding elements in a vector_of
by Teto 10 Aug '11

10 Aug '11

Hi, I've a peculiar bimap defined as such: bbi::bimap< bbi::unordered_set_of< TFullId>, bbi::vector_of<CBindDescriptor>> And I want to find all the TFullId matching a certain CBindDescriptor. but I can't succeed in compiling. Here are 10 lines of code: http://boost.codepad.org/99V38S9U Thx for any hint matt

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[BGL] resize/reserve on graph?
by Geoff Hilton 10 Aug '11

10 Aug '11

If I know that during the execution of the algorithm the graph size must be grown by X number of vertices in one go, is there a way this can be done to avoid multiple allocations such as when using std::vector's reserve(..) or resize(..) member functions without subverting the BGL's documented interface? Currently I use a for loop which iterates over add_vertex(vertex_property, graph). Can a reserve and/or resize equivalent otherwise please be added somewhere? Thank you, Geoff

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installing boost_1_47_0
by rudy b 10 Aug '11

10 Aug '11

Hi, I am newb in using boost. And, I am having so much trouble installing and running a simple example. I would REALLY appreciate some help. I tried to install boost_1_47_0.tar.gz on my unix machine, and I followed the stpes http://www.boost.org/doc/libs/1_47_0/more/getting_started/unix-variants.html to first build, and install the libraries. I had no problem running some the examples (provided on the link above, that was using some of its already built libraries), and they all worked. The problem is when I try to run an example that is using a boost_filesystem. I tried uninstalling/installing different boost versions, cause I thought the error may be version dependent, but it wasn't. I also tried to built the entire library using different versions of gcc (3.4.6, 4.3.5, 4.4.0, 4.5.0, 4.5.1, 4.5.2, 4.6.0), and I get the same error messages. I even made sure that when compile, I have the boost_1_4x_0 path in my compile script. I also made sure that I have appended boost_1_4x_0 path to my $path. I even tried to have -lboost_filesystem in my compile script, but this didn't help either !!! This is the type of error that I am getting: /tmp/cczDoDOU.o: In function `__static_initialization_and_destruction_0(int, int)': sync.cpp:(.text+0xe03): undefined reference to `boost::system::generic_category()' sync.cpp:(.text+0xe1e): undefined reference to `boost::system::generic_category()' sync.cpp:(.text+0xe39): undefined reference to `boost::system::system_category()' /tmp/cczDoDOU.o: In function `boost::filesystem3::last_write_time(boost::filesystem3::path const&, long)': And, when I change the version of compiler, I get something like: /tmp/ccw1Sepi.s: Assembler messages: /tmp/ccw1Sepi.s:408: Error: unknown pseudo-op: `.cfi_personality' /tmp/ccw1Sepi.s:409: Error: unknown pseudo-op: `.cfi_lsda' /tmp/ccw1Sepi.s:531: Error: unknown pseudo-op: `.cfi_personality' /tmp/ccw1Sepi.s:532: Error: unknown pseudo-op: `.cfi_lsda' /tmp/ccw1Sepi.s:722: Error: unknown pseudo-op: `.cfi_personality' /tmp/ccw1Sepi.s:723: Error: unknown pseudo-op: `.cfi_lsda' /tmp/ccw1Sepi.s:1046: Error: unknown pseudo-op: `.cfi_personality' Please advise, thanks, RB

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Program_Options - Is there anyway to get the name of executable?
by asif saeed 10 Aug '11

10 Aug '11

Hi, Is it possible to get name of the executable that started the program using program_options? Thanks in advance, Asif

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More problems with boost::asio and async_read
by Allan Nielsen 10 Aug '11

10 Aug '11

Hi I posted on this a couple of hours ago with some problems. It turned out that some of the problems I had might have been due to buggy hardware. But there is still some thing I do not understand... So, now I have reproduced some of of the problems I have with out any hardware (except from a PC). Basically I'm trying to read from a input source (in this case stdin) with a timeout. Due to the design of the existing application where this have to fit is it not possible to call run on my io_service. Here is my try so far: #include <boost/asio.hpp> #include <boost/bind.hpp> #include <boost/optional.hpp> using namespace std; void set_result( boost::optional<boost::system::error_code> * a, boost::system::error_code b ) { if( b == 0) a->reset( b ); } void receive(boost::asio::io_service & io, boost::asio::posix::stream_descriptor & stream, boost::asio::streambuf & result){ boost::optional<boost::system::error_code> timer_result; boost::optional<boost::system::error_code> read_result; boost::asio::deadline_timer timer( io ); timer.expires_from_now( boost::posix_time::milliseconds(5000) ); // allow up to 50ms of timeout for every char timer.async_wait( boost::bind(&set_result, &timer_result, _1) ); boost::asio::async_read( stream, result, boost::asio::transfer_at_least(1), boost::bind( &set_result, &read_result, _1 )); boost::system::error_code ec; while(1) { io.reset(); io.poll_one(ec); if ( read_result ) { timer.cancel(); return; } else if ( timer_result ) throw std::runtime_error("timeout"); } } void receive(boost::asio::io_service & io, boost::asio::posix::stream_descriptor & stream, size_t size, boost::asio::streambuf & result){ while( result.size() < size ) receive(io, stream, result); } int main(int argc, const char *argv[]) { boost::asio::io_service io; boost::asio::posix::stream_descriptor in(io, ::dup(STDIN_FILENO)); for(int i = 0; i < 5; i++){ std::cout < "; std::cout.flush(); try { boost::asio::streambuf buf; receive(io, in, 5, buf); std::cout << "out> "; std::copy(boost::asio::buffer_cast<const char *>(buf.data()), boost::asio::buffer_cast<const char *>(buf.data()) + buf.size(), ostream_iterator<char>(std::cout)); } catch (const std::exception & e) { std::cout << e.what() << endl; } } return 0; } At my first look, I thought that it was working, but after playing more around with the test app, I got some segmentations faults. I found that something bad happens if I wait for the first query to timeout, and then enter 5 chars the next. Here is what valgrind says: ==17848== Memcheck, a memory error detector ==17848== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al. ==17848== Using Valgrind-3.6.1 and LibVEX; rerun with -h for copyright info ==17848== Command: ./ccTalkScan ==17848== ==17848== 0 Type in 4 chareters and press enter in> ==17848== Invalid read of size 8 ==17848== at 0x546EB4A: ??? (setcontext.S:60) ==17848== by 0x425847: receive(boost::asio::io_service&, boost::asio::posix::basic_stream_descriptor<boost::asio::posix::stream_descriptor_service>&, unsigned long, boost::asio::basic_streambuf<std::allocator<char> >&) (ccTalkScan.cxx:3 20) ==17848== by 0x425982: main (ccTalkScan.cxx:334) ==17848== Address 0x7feffdf68 is not stack'd, malloc'd or (recently) free'd ==17848== ==17848== Invalid read of size 8 ==17848== at 0x546EB52: ??? (setcontext.S:63) ==17848== by 0x425847: receive(boost::asio::io_service&, boost::asio::posix::basic_stream_descriptor<boost::asio::posix::stream_descriptor_service>&, unsigned long, boost::asio::basic_streambuf<std::allocator<char> >&) (ccTalkScan.cxx:3 20) ==17848== by 0x425982: main (ccTalkScan.cxx:334) ==17848== Address 0x7feffdf58 is not stack'd, malloc'd or (recently) free'd ==17848== ==17848== Invalid read of size 8 ==17848== at 0x546EB59: ??? (setcontext.S:64) ==17848== by 0x425847: receive(boost::asio::io_service&, boost::asio::posix::basic_stream_descriptor<boost::asio::posix::stream_descriptor_service>&, unsigned long, boost::asio::basic_streambuf<std::allocator<char> >&) (ccTalkScan.cxx:320) ==17848== by 0x425982: main (ccTalkScan.cxx:334) ==17848== Address 0x7feffdf28 is not stack'd, malloc'd or (recently) free'd ==17848== ==17848== Invalid read of size 8 ==17848== at 0x546EB4A: ??? (setcontext.S:60) ==17848== by 0x5E4BD2C: (below main) (in /lib64/libc-2.12.2.so) ==17848== Address 0x7feffdfd8 is not stack'd, malloc'd or (recently) free'd ==17848== ==17848== Invalid read of size 8 ==17848== at 0x546EB52: ??? (setcontext.S:63) ==17848== by 0x5E4BD2C: (below main) (in /lib64/libc-2.12.2.so) ==17848== Address 0x7feffdfc8 is not stack'd, malloc'd or (recently) free'd ==17848== ==17848== Invalid read of size 8 ==17848== at 0x546EB59: ??? (setcontext.S:64) ==17848== by 0x5E4BD2C: (below main) (in /lib64/libc-2.12.2.so) ==17848== Address 0x7feffdf98 is not stack'd, malloc'd or (recently) free'd ==17848== timeout 1 Type in 4 chareters and press enter in> asdf ==17848== Syscall param readv(vector[...]) points to unaddressable byte(s) ==17848== at 0x5EF7A81: readv (in /lib64/libc-2.12.2.so) ==17848== by 0x42AF1C: boost::asio::detail::descriptor_ops::non_blocking_read(int, iovec*, unsigned long, boost::system::error_code&, unsigned long&) (descriptor_ops.ipp:153) ==17848== by 0x4360BF: boost::asio::detail::descriptor_read_op_base<boost::asio::mutable_buffers_1>::do_perform(boost::asio::detail::reactor_op*) (descriptor_read_op.hpp:55) ==17848== by 0x427CE4: boost::asio::detail::reactor_op::perform() (reactor_op.hpp:40) ==17848== by 0x429003: boost::asio::detail::epoll_reactor::run(bool, boost::asio::detail::op_queue<boost::asio::detail::task_io_service_operation>&) (epoll_reactor.ipp:286) ==17848== by 0x429C81: boost::asio::detail::task_io_service::do_one(boost::asio::detail::scoped_lock<boost::asio::detail::posix_mutex>&, boost::asio::detail::task_io_service::idle_thread_info*) (task_io_service.ipp:264) ==17848== by 0x42986F: boost::asio::detail::task_io_service::poll_one(boost::system::error_code&) (task_io_service.ipp:188) ==17848== by 0x42A0C2: boost::asio::io_service::poll_one(boost::system::error_code&) (io_service.ipp:103) ==17848== by 0x4255E1: receive(boost::asio::io_service&, boost::asio::posix::basic_stream_descriptor<boost::asio::posix::stream_descriptor_service>&, boost::asio::basic_streambuf<std::allocator<char> >&) (ccTalkScan.cxx:307) ==17848== by 0x425847: receive(boost::asio::io_service&, boost::asio::posix::basic_stream_descriptor<boost::asio::posix::stream_descriptor_service>&, unsigned long, boost::asio::basic_streambuf<std::allocator<char> >&) (ccTalkScan.cxx:320) ==17848== by 0x425982: main (ccTalkScan.cxx:334) ==17848== Address 0x65ba4f0 is 0 bytes inside a block of size 512 free'd ==17848== at 0x4C25C4F: operator delete(void*) (vg_replace_malloc.c:387) ==17848== by 0x432D07: __gnu_cxx::new_allocator<char>::deallocate(char*, unsigned long) (new_allocator.h:95) ==17848== by 0x4316BF: std::_Vector_base<char, std::allocator<char> >::_M_deallocate(char*, unsigned long) (stl_vector.h:146) ==17848== by 0x42FD64: std::_Vector_base<char, std::allocator<char> >::~_Vector_base() (stl_vector.h:132) ==17848== by 0x42D6A4: std::vector<char, std::allocator<char> >::~vector() (stl_vector.h:313) ==17848== by 0x42B657: boost::asio::basic_streambuf<std::allocator<char> >::~basic_streambuf() (basic_streambuf.hpp:114) ==17848== by 0x425A77: main (ccTalkScan.cxx:336) ==17848== out> 2 Type in 4 chareters and press enter in> timeout 3 Type in 4 chareters and press enter in> timeout 4 Type in 4 chareters and press enter in> timeout ==17848== ==17848== HEAP SUMMARY: ==17848== in use at exit: 168 bytes in 3 blocks ==17848== total heap usage: 65 allocs, 62 frees, 22,246 bytes allocated ==17848== ==17848== LEAK SUMMARY: ==17848== definitely lost: 0 bytes in 0 blocks ==17848== indirectly lost: 0 bytes in 0 blocks ==17848== possibly lost: 0 bytes in 0 blocks ==17848== still reachable: 168 bytes in 3 blocks ==17848== suppressed: 0 bytes in 0 blocks ==17848== Rerun with --leak-check=full to see details of leaked memory ==17848== ==17848== For counts of detected and suppressed errors, rerun with: -v ==17848== Use --track-origins=yes to see where uninitialised values come from ==17848== ERROR SUMMARY: 27 errors from 9 contexts (suppressed: 4 from 4) I have tried different things to fix, but I that I might have mis understood a thing or two here. So some help would be most appreciated. -- Allan W. Nielsen

2 8

unlocatable infinite loop when using boost::serialization
by Griffin Howlett 10 Aug '11

10 Aug '11

Ok so i've set up boost::serialization to work with objects whose constructor and destructors are private (forcing you to make them through "factories"), but after doing the coming steps, the << operator of a boost::oarchive never returns. I've followed what was happening exactly in a debugger, but don't know what's happening *after the ending brackets of the object's serialization function. It's not even reaching the overloaded destroy function*. I think it's some internal business. - To do this i've overided the `load/save_construct_data function` and the `access::destroy template function` with the appropriate parameters. - I also defined a serialization function for each factory-built object, but it doesn't do anything as to force you to pass a pointer instead. - You'll also notice i've added my own Save() function as so the user can specify a different factory to use for recreating (loading) the object back up if needed. **Why would this be happening and how do i fix it?** here's the source: oa << WallBody2; //this is the call in main, wallBody2 is a b2Body* template<> static void access::destroy( const b2Body * t) // const appropriate here? { // the const business is an MSVC 6.0 hack that should be // benign on everything else const_cast<b2Body*>(t)->GetWorld()->DestroyBody(const_cast<b2Body*>(t)); } template<> static void access::destroy( const b2Fixture * t) // const appropriate here? { // the const business is an MSVC 6.0 hack that should be // benign on everything else const_cast<b2Fixture*>(t)->GetBody()->DestroyFixture(const_cast<b2Fixture*>(t)); } template<class Archive> inline void save_construct_data( Archive & ar, const b2Body * t, const unsigned int file_version) { // save data required to construct instance b2World* WorldPtr= const_cast<b2Body*>(t)->GetWorld(); ar & WorldPtr; Save(ar, const_cast<b2Body*>(t), file_version); } template<class Archive> inline void save_construct_data( Archive & ar, const b2Fixture * t, const unsigned int file_version) { // save data required to construct instance b2Body* BodyPtr= const_cast<b2Fixture*>(t)->GetBody(); ar & BodyPtr; Save(ar, const_cast<b2Fixture*>(t), file_version); } template<class Archive> void serialize(Archive & ar, b2Fixture& b2, const unsigned int version) { std::cout << "b2Fixture is not serializable, only b2Fixture pointers are" << std::endl;}; template<class Archive> void serialize(Archive & ar, b2Body& b2, const unsigned int version) { std::cout << "b2Fixture is not serializable, only b2Fixture pointers are" << std::endl;}; template<class Archive> void Save(Archive & ar, b2Body* b2, const unsigned int version) { b2World* World = b2->GetWorld(); ar & World; b2BodyDef InitialBodyDef; InitialBodyDef.inertiaScale= b2->GetInertia(); // QUESTION: Is there any way to get/set this from a body (not def) ar & InitialBodyDef; // QUESTION: wtf is inertiaScale? any relation to MassData? b2BodyDef BodyDef; BodyDef.angle= b2->GetAngle(); BodyDef.position= b2->GetPosition(); BodyDef.active= b2->IsActive(); BodyDef.angularDamping= b2->GetAngularDamping(); BodyDef.angularVelocity= b2->GetAngularVelocity(); BodyDef.awake= b2->IsAwake(); BodyDef.bullet= b2->IsBullet(); BodyDef.fixedRotation= b2->IsFixedRotation(); BodyDef.linearDamping= b2->GetLinearDamping(); BodyDef.linearVelocity= b2->GetLinearVelocity(); BodyDef.type= b2->GetType(); BodyDef.userData= b2->GetUserData(); ar & BodyDef; // number of fixtures saved first so when loaded we know // how many fixturedefs to extract unsigned int numbFixtures=0; for (b2Fixture* fixture = b2->GetFixtureList(); fixture; fixture = fixture->GetNext()) numbFixtures++; ar & numbFixtures; //TODO: find out if boost will detect this as a list for (b2Fixture* fixture = b2->GetFixtureList(); fixture; fixture = fixture->GetNext()) ar & fixture; } template<class Archive> void Save(Archive & ar, b2Fixture* b2, const unsigned int version) { b2Body* Body = b2->GetBody(); ar & Body; //Registered so boost can differentiate types of "shapes" ar.register_type(static_cast<b2CircleShape *>(NULL)); ar.register_type(static_cast<b2PolygonShape *>(NULL)); b2Shape* Shape= b2->GetShape(); ar & Shape; b2FixtureDef FixtureDef; FixtureDef.density= b2->GetDensity(); FixtureDef.filter= b2->GetFilterData(); FixtureDef.friction= b2->GetFriction(); FixtureDef.isSensor= b2->IsSensor(); FixtureDef.restitution= b2->GetRestitution(); FixtureDef.userData= b2->GetUserData(); ar & FixtureDef; }

1 0

Boost system library error
by Abbas Banaiyan 10 Aug '11

10 Aug '11

Hi, I installed Boost 1.4.47 on a Linux x86_64 server with gcc 4.4.4. When I try to make a simulator which uses Boost libraries I get the following error message: /home/abanaiya/local//include/boost/system/error_code.hpp:316: note: candidates are: boost::system::error_code::error_code(int&, const boost::system::error_category&) /home/abanaiya/local//include/boost/system/error_code.hpp:315: note: boost::system::error_code::error_code() /home/abanaiya/local//include/boost/system/error_code.hpp:311: note: boost::system::error_code::error_code(const boost::system::error_code&) ../../src/boost.task-0.4.2/boost/task/detail/bind_processor_linux.hpp: In function âvoid boost::this_thread::bind_to_processor(unsigned int)â: ../../src/boost.task-0.4.2/boost/task/detail/bind_processor_linux.hpp:41: error: no matching function for call to âboost::system::error_code::error_code(int&, const boost::system::error_category& (&)())â /home/abanaiya/local//include/boost/system/error_code.hpp:316: note: candidates are: boost::system::error_code::error_code(int&, const boost::system::error_category&) /home/abanaiya/local//include/boost/system/error_code.hpp:315: note: boost::system::error_code::error_code() /home/abanaiya/local//include/boost/system/error_code.hpp:311: note: boost::system::error_code::error_code(const boost::system::error_code&) ../../src/boost.task-0.4.2/boost/task/detail/bind_processor_linux.hpp: In function âvoid boost::this_thread::bind_to_any_processor()â: ../../src/boost.task-0.4.2/boost/task/detail/bind_processor_linux.hpp:59: error: no matching function for call to âboost::system::error_code::error_code(int&, const boost::system::error_category& (&)())â /home/abanaiya/local//include/boost/system/error_code.hpp:316: note: candidates are: boost::system::error_code::error_code(int&, const boost::system::error_category&) /home/abanaiya/local//include/boost/system/error_code.hpp:315: note: boost::system::error_code::error_code() /home/abanaiya/local//include/boost/system/error_code.hpp:311: note: boost::system::error_code::error_code(const boost::system::error_code&) /home/abanaiya/local//include/boost/system/error_code.hpp: At global scope: /home/abanaiya/local//include/boost/system/error_code.hpp:214: warning: âboost::system::posix_categoryâ defined but not used /home/abanaiya/local//include/boost/system/error_code.hpp:215: warning: âboost::system::errno_ecatâ defined but not used /home/abanaiya/local//include/boost/system/error_code.hpp:216: warning: âboost::system::native_ecatâ defined but not used make[2]: *** [sim.o] Error 1 make[1]: *** [all-recursive] Error 1 make: *** [all-recursive] Error 1 I also received the following error that I removed it by disabling the corresponded line at api_config.hpp file. /home/abanaiya/local//include/boost/system/api_config.hpp:28:5: error: #error user defined BOOST_POSIX_API or BOOST_WINDOWS_API not supported I also tried version 1.4.42 and got the same error. Would you please let me know hot to resolve it. I run the following command to install the Boost: ./bjam --prefix=$HOME/local install Thanks, Abbas

1 0

Public Encryption with ASIO SSL
by David McCallum 09 Aug '11

09 Aug '11

I'm trying to create a system where clients can encrypt messages, but only the server can decrypt them. I'm configuring the context on the server-side like so: context_.set_options(boost::asio::ssl::context::default_workarounds | boost::asio::ssl::context::no_sslv2); context_.set_password_callback(boost::bind(&server::get_password, this)); context_.use_private_key_file("server.pem", boost::asio::ssl::context::pem); However, I can't find any way to load the public key on the clients. Can I create a connection that relies on public-key encryption? Or do the SSL classes expect me to use public-key encryption only to generate symmetrical keys, ie with Diffie-Hellman? -David

1 0

Boost::Test Samples?
by Jeffrey Walton 09 Aug '11

09 Aug '11

Hi All, I'm not sure I have chosen the right testing architecture (external runner for a DSO), and I am having problems getting Boost::Test to run properly. I have print statements which are not printing in functions registered with BOOST_TEST_SUITE. And I have spiked a test would should print an error message. I thought it would be a good idea to look at [sample] projects that work rather than code snippets. Unfortunately, the link for "collection of examples" at [1] is broken. Does anyone know where to find Boost::Test samples? Thanks in advance, Jeff [1] http://www.boost.org/doc/libs/1_44_0/libs/test/doc/html/utf/intro.html

5 10

[mpl] Safe to instantiate mpl classes for tag-dispatch-by-instance?
by Gabriel Redner 09 Aug '11

09 Aug '11

Hi all, Say I have a functor which accepts a tag instance: struct tagA {}; struct tagB {}; struct MyFunc { template <typename TTag> void operator()(TTag, int other_stuff) {...} }; In some cases I want to pass multiple tags at once. Is it safe to just instantiate mpl::pair, mpl::vector, etc. and use them for this purpose, since from a runtime perspective they're just empty classes? Or, is this a Bad Idea for some reason? Thanks, -Gabe

1 0

Segmentation fault when using asio and poll_one
by Allan Nielsen 09 Aug '11

09 Aug '11

Hi I'm using Boost 1.46.1 asio for doing serial communication. About 1/1000 times when I run the poll_one I get this segmentation fault: Program received signal SIGSEGV, Segmentation fault. 0x0000000000434a7a in boost::asio::detail::reactor_op::perform (this=0x402010af1010004) at /usr/include/boost-1_46/boost/asio/detail/reactor_op.hpp:40 40 return perform_func_(this); (gdb) bt #0 0x0000000000434a7a in boost::asio::detail::reactor_op::perform (this=0x402010af1010004) at /usr/include/boost-1_46/boost/asio/detail/reactor_op.hpp:40 #1 0x0000000000435da6 in boost::asio::detail::epoll_reactor::run (this=0x6625c0, block=false, ops=...) at /usr/include/boost-1_46/boost/asio/detail/impl/epoll_reactor.ipp:286 #2 0x0000000000436a24 in boost::asio::detail::task_io_service::do_one (this=0x6624e0, lock=..., this_idle_thread=0x0) at /usr/include/boost-1_46/boost/asio/detail/impl/task_io_service.ipp:264 #3 0x0000000000436612 in boost::asio::detail::task_io_service::poll_one (this=0x6624e0, ec=...) at /usr/include/boost-1_46/boost/asio/detail/impl/task_io_service.ipp:188 #4 0x0000000000436e65 in boost::asio::io_service::poll_one (this=0x7fffffffe240, ec=...) at /usr/include/boost-1_46/boost/asio/impl/io_service.ipp:103 #5 0x000000000043b69b in CcTalkPort::receive (this=0x7fffffffe240) at /home/awn/git/gamblify/hardware/gmbio/software/test/ccTalkScan.cxx:382 #6 0x000000000043b7dc in CcTalkPort::receive (this=0x7fffffffe240, size=5) at /home/awn/git/gamblify/hardware/gmbio/software/test/ccTalkScan.cxx:396 #7 0x000000000043bcb5 in CcTalkPort::_ask (this=0x7fffffffe240, req=...) at /home/awn/git/gamblify/hardware/gmbio/software/test/ccTalkScan.cxx:411 #8 0x000000000043ac6e in CcTalkPort::ask (this=0x7fffffffe240, req=...) at /home/awn/git/gamblify/hardware/gmbio/software/test/ccTalkScan.cxx:317 #9 0x000000000043daef in CcTalkDevice::ask_hex (this=0x7fffffffe300, v=..., m=..., s=...) at /home/awn/git/gamblify/hardware/gmbio/software/test/ccTalkScan.cxx:583 #10 0x000000000043ce69 in CcTalkDevice::request_software_revision (this=0x7fffffffe300) at /home/awn/git/gamblify/hardware/gmbio/software/test/ccTalkScan.cxx:507 #11 0x000000000043c57f in CcTalkDevice::coreInfo (this=0x7fffffffe300) at /home/awn/git/gamblify/hardware/gmbio/software/test/ccTalkScan.cxx:459 #12 0x00000000004325ff in main (argc=1, argv=0x7fffffffe528) at /home/awn/git/gamblify/hardware/gmbio/software/test/ccTalkScan.cxx:820 Here is the snippet where I call it: while(1) { io_service.reset(); io_service.poll_one(ec); if ( read_result ) { timer.cancel(); return; } else if ( timer_result ) { throw CcTalkTimeOutException(); } } Any hints on how to debug this? -- Allan W. Nielsen

2 1

Working around the restriction in enable_shared_from_this
by kelvSYC 09 Aug '11

09 Aug '11

Suppose I have a class called Group, extending boost::enable_shared_from_this<Group>. Now suppose I have something like this: class Foo { boost::shared_ptr<const Group> G; public: Foo(const Group& G_) : G(G_.shared_from_this()) {} }; This would totally barf if, among other things, G_ was allocated from the stack, say, since I don't have an owning shared_ptr instance. So, it would appear that, at the very least, if you were to allocate a Group on the stack, then you would need a shared_ptr with a null deleter to make use of Foo. This seems inconvenient to whoever may want to use Foo, so is there a way to change this so get around the shared_ptr instance restriction without changing Foo?

1 0

path filesystem
by rudy 09 Aug '11

09 Aug '11

Hi, This is my first post, so please advise me if this is not the correct place to post my question. This is my question: I have the following directory pattern (Dir1 is the parent directory, and the rest are the child files/subdirectories): Dir1 file1 file2 .file3 subdir1 .subdir2 the following code will go through the Dir1, and it will fail in creating the "path" when it reaches ".file3" or ".subdir2" boost::filesystem:ath dir1_path(filepath.c_str()); How should I create a path to a directory that (for example) has the following path? /root/my_docs/pgg/.file1 filesystem::path works just fine if I had to deal with (/root/my_docs/pgg/file1) instead of (/root/my_docs/pgg/.file1) !!! apparently when the file/directory starts with '.', I cannot get filesystem::path to behave properly. please advise, thanks, Rudy

1 0

Boost.Program_options: Parsing arguments like "+a" possible?
by boost_mailinglist＠gmx.de 09 Aug '11

09 Aug '11

Hello, is it possible to parse also arguments like "+a" with the library "Boost.Program_options"? The numbers of arguments are simple to much to use only the "-" or the "--" as a sign for arguments. If it possible, how have I to activate this function? Thank you. -- Empfehlen Sie GMX DSL Ihren Freunden und Bekannten und wir belohnen Sie mit bis zu 50,- Euro! https://freundschaftswerbung.gmx.de

4 11

[asio] user defined composed operations and strands
by Tacheon 09 Aug '11

09 Aug '11

Hello, I am trying to implement some new composed operations (like boost::asio::async_read) with asio. However I am a bit concerned about thread-safety when the run-method of the used io_service object ist called from multiple threads and there are parallel read- and write operations on the same socket. The composed operations look like this: class io_port { public: //Ctors and so on... typedef boost::function<void (error_t const &)> completion_handler_t; void async_read_data ( raw_buffer_t & buffer , completion_handler_t const & handler) { //uses a composed operation itself... boost::asio::async_read ( socket , boost::asio::buffer(header) , boost::bind ( &io_port::handle_header_received , this , boost::ref(buffer) , handler , boost::asio::placeholders::error) ); } //first intermediate handler void handle_header_received ( raw_buffer_t & data , completion_handler_type const & handler , boost::system::error_code const & error { if(error) { handler(error_t(error)); } else { prepare_buffer(data, header.perparation_data()); //pseudo-code //uses a composed operation itself... boost::asio::async_read ( socket , boost::asio::buffer(data) , boost::bind ( &io_port::handle_data_received , this , boost::ref(buffer) , handler , boost::asio::placeholders::error) ); } } //second intermediate handler void handle_data_received ( raw_buffer_t & data , completion_handler_type const & handler , boost::system::error_code const & error ) { if(error) { handler(error_t(error)); } else { handler(error_t()); } } void async_write_data ( raw_buffer_t const & buffer , completion_handler_t const & handler) { ... } //quite similar to async_read_data }; usage may be either port.async_read ( buffer , handler ); or port.async_read ( buffer , strand.wrap(handler) ); //how to forward this to asio::async_read? If async_write_data is called and io_service::run is called from multiple threads, strands are should be necessary to avoid raced. The question is: How do I support handlers wrapped in a strand and how do I get this strand forwarded to async_read? As far as I understand this should be somehow possible by using asio_handler_invoke but the documentation is a bit too fuzzy on the topic for me to understand. -- Empfehlen Sie GMX DSL Ihren Freunden und Bekannten und wir belohnen Sie mit bis zu 50,- Euro! https://freundschaftswerbung.gmx.de

1 0

Re: [Boost-users] Enums to/from Strings
by Benjamin van den Hout 09 Aug '11

09 Aug '11

Hi John, > For the time being, I've made a function called to_string, which seems to be a common > choice. But what's the best way to make it automatically known to those other features? It's not the most pretty solution, but perhaps you could resort to the Boost Preprocessor library to generate both the enum and the 'toString' method for you. Some sample code can be found here on my blog: http://www.smork.info/blog/index.php?entry=entry110809-105615 Kind regards, Benjamin van den Hout

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Re: [Boost-users] [fusion] adapt std::tuple to be a fusion sequence?
by "Claas H. Köhler" 09 Aug '11

09 Aug '11

I was wondering about the status of the above topic: Does a boost implementation of an adaptor exist or is Sebastian's suggestion the best alternative currently available? His solution did not work out of the box for me, since g++-4.6 complained about an "incomplete type std::tuple_size<const std::tuple<..." However, when I replaced each occurence of std::tuple_size<X> by std::tuple_size< typename std::remove_cv<X>::type > everything seemed to work fine. Regards Claas > No docs. Also, this is just for the MSVC 10 (no-variadics) > >implementation. It was just something I hacked up quickly because I > >needed it for something internal. > > >Anyway, here it is. > > >Sebastian

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Boost::Test and streams
by Jeffrey Walton 09 Aug '11

09 Aug '11

Hi All, I'm working form http://www.boost.org/doc/libs/1_47_0/libs/test/doc/html/index.html. I can't seem to find Boost::Test's streams. The discussion of streams begins at [1]. [1] does list macros such as BOOST_TEST_DONT_PRINT_LOG_VALUE, but I'm interested in a C++-centric solution. For example: // test framework output stream using boost_test::tout; tout << loglevel::error << "My error message" << endl; tout << loglevel::warn << "My warning message" << endl; According to [2], I can set the log level from the environment and from the command line. But would like to set it dynamically. For example: tout << setlevel(warn); // warnings and above or tout.setlelvel(error); // errors and above In addition, I would like to be able to tie a file output to screen output, so I can watch the tests roll by and go to the log file for in depth reading. To be fair, redirection is covered at [3], but its not quite what we are looking for. For example: ofstream logfile(...); ... tout.attach(logfile); or tout.tie(logfile); Though the authors did a great job on the documentation, these topics do not appear to be included. Any ideas how one might go about these sorts of things? Thanks in advance, Jeffrey Walton [1] http://www.boost.org/doc/libs/1_47_0/libs/test/doc/html/utf/user-guide/test… [2] http://www.boost.org/doc/libs/1_47_0/libs/test/doc/html/utf/user-guide/runt… [3] http://www.boost.org/doc/libs/1_47_0/libs/test/doc/html/utf/user-guide/test…

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[boost.asio 1.47] : changing host time
by Mathieu Peyréga 08 Aug '11

08 Aug '11

Hello, I would like to know if there are any implications with the fact of having a call to settimeofday in order to change the system time while using boost asio (asynchronous timers). The point of calling settimeofday (software is running on a linux box with super user privileges) is to synchronize the system clock with a GPS receiver clock at some point while the io service is already running. Best regards, Mathieu Peyréga

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Re: [Boost-users] Asio problems with async_read
by Alex Perry 08 Aug '11

08 Aug '11

Allan Nielsen wrote on Mon, 8 Aug 2011 14:13:08 +0200 > Hi > > I have a funciton where we I am using boost::asio to read from the > serial port of my computer. > > I have started out with an implementation which uses read, and I am > now trying to convert it to async_read because I want a time out. > > When I am trying to use the async_read version, I get timeouts after I > have read one or two charterers, even though I know there are more > charterers to be read on the wire. > Not sure that this is much help since I've never really used boost.asio and reading further down the thread it may be a problem with how you are calling it. However having done a lot of serial comms in the past seeing a couple of characters only whilst more data is on the wire I'd guess that the timeout is as a result of the low level serial hardware interrupt. The UART is probably signalling that its internal FIFO buffer is full and you need to read this promptly - quite how that all pans out and what daemon / service has the responsibility of reading this these days I haven't got the faintest - I was writing TSR's when I knew the gory technical details of this so life was much simpler. I'm actually impressed that you've found a computer that still has a serial port on it! Most seem to have gone over to the ubiquitous USB these days - though that may be the easiest solution - use USB and a usb/serial converter which would avoid having to rediscover the lost art of programming UART latch timings etc and give you a decent amount of low level buffering so you could ignore low level stuff and just read the data. http://www.bb-europe.com/tech_articles/USB_converters.asp?gclid=CPvOgur5v6o… or some such. HTH Alex

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Asio problems with async_read
by Allan Nielsen 08 Aug '11

08 Aug '11

Hi I have a funciton where we I am using boost::asio to read from the serial port of my computer. I have started out with an implementation which uses read, and I am now trying to convert it to async_read because I want a time out. When I am trying to use the async_read version, I get timeouts after I have read one or two charterers, even though I know there are more charterers to be read on the wire. Here is the code: void set_result( boost::optional<boost::system::error_code> * a, boost::system::error_code b ) { a->reset( b ); } std::vector<uint8_t> receive(boost::asio::io_service & io, boost::asio::serial_port & cctalk_port){ #if 0 boost::optional<boost::system::error_code> timer_result; boost::optional<boost::system::error_code> read_result; boost::asio::deadline_timer timer( io ); timer.expires_from_now( boost::posix_time::milliseconds(5000) ); timer.async_wait( boost::bind(&set_result, &timer_result, _1) ); boost::asio::streambuf result; boost::asio::async_read( cctalk_port, result, boost::asio::transfer_at_least(1), boost::bind( &set_result, &read_result, _1 )); while(1) { io.poll_one(); if ( read_result ) { timer.cancel(); std::vector<uint8_t> res(boost::asio::buffer_cast<const uint8_t * >(result.data()), boost::asio::buffer_cast<const uint8_t * >(result.data()) + result.size() ); return res; } else if ( timer_result ) { throw runtime_error("timeout"); } } throw runtime_error("Should not happend"); #else uint8_t c; boost::asio::read(cctalk_port, boost::asio::buffer(&c, 1)); std::vector<uint8_t> res; res.push_back(c); return res; #endif }

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need help on compile error about gregorian and regex
by Eric Lin 08 Aug '11

08 Aug '11

Dear Boost experts: when I compile a program(some example code from c++ book) it contain #include <boost/date_time/gregorian/gregorian.hpp> #include <boost/regex.hpp> and I got a lot compile error related about it on my g++ with boost 1.46.1 installed ------- ------- ----------------------------------------------------------------------------------------------------- eric@eric-laptop:~/cppcookbook/download/TESTDIR$ g++ -ltinyxml 14-3.cpp /tmp/cct65iz6.o: In function `unsigned short boost::date_time::month_str_to_ushort<boost::gregorian::greg_month>(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)': 14-3.cpp:(.text._ZN5boost9date_time19month_str_to_ushortINS_9gregorian10greg_monthEEEtRKSs[unsigned short boost::date_time::month_str_to_ushort<boost::gregorian::greg_month>(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)]+0x97): undefined reference to `boost::gregorian::greg_month::get_month_map_ptr()' /tmp/cct65iz6.o: In function `bool boost::regex_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >(__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, __gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > >&, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags)': 14-3.cpp:(.text._ZN5boost11regex_matchIN9__gnu_cxx17__normal_iteratorIPKcSsEESaINS_9sub_matchIS5_EEEcNS_12regex_traitsIcNS_16cpp_regex_traitsIcEEEEEEbT_SD_RNS_13match_resultsISD_T0_EERKNS_11basic_regexIT1_T2_EENS_15regex_constants12_match_flagsE[bool boost::regex_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >(__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, __gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > >&, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags)]+0x4c): undefined reference to `boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::match()' /tmp/cct65iz6.o: In function `boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::assign(char const*, char const*, unsigned int)': ------------------------------------------------------------------------------------------This is only front part of the whole errors------------------- these code is claimed worked on msvc++7.1 on window xp and you can download it from http://examples.oreilly.com/9780596007614/ 14-1.xml 14-2.h 14-3.cpp to test by yourself plz help and thanks a lot in advance, Eric(on g++ 4.5.2, linuxkernel 2.6.38-10)

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boost.preprocessor BOOST_PP_SEQ_FOR_EACH shows strange error messages
by aliko 07 Aug '11

07 Aug '11

Hi! I'm trying to utilize preprocessor library for the first time and my questions probably are too stupid for this list but I have not found another place to ask.:) In series of projects I have a repetitive task with defining many variables and structures based on configuration of embedded platform. First I've tried to generate array of numbers from ADC, the main definition from which all the variables and structures should be created. But I've got a strange error messages which I can't interpret right way. My code is: ********************************************************************** #include <boost/preprocessor/seq.hpp> #include <boost/preprocessor/tuple.hpp> #define POS_NAME 0 #define POS_PIN 1 #define POS_SKIP 2 #define POS_K 3 #define POS_TYPES 4 #define POS_SCALES 5 #define NFIELDS 6 #define NSIGS 5 enum {DISCRETE, ANALOG, CONTROL, MEASURE, END_TYPES}; //NAME, PIN, SKIP, FILTERK, DATATYPES, SCALES #define ADC ( \ (POSITION, 0, 0, 100, (ANALOG, CONTROL, MEASURE), \ (((DISCRETE, ANALOG) (1000, 4000) (0, 20000)) \ ((ANALOG, CONTROL) (4000, 20000) (0, 10000)) \ ((ANALOG, MEASURE) (4000, 20000) (0, 3000)))), \ (CURRENT, 1, 0, 100, (ANALOG, CONTROL), \ (((DISCRETE, ANALOG) (1000, 4000) (0, 20000)) \ ((ANALOG, CONTROL) (4000, 20000) (0, 10000)))), \ (HALL, 2, 0, 100, (ANALOG, CONTROL), \ (((DISCRETE, ANALOG) (1000, 4000) (0, 20000)) \ ((ANALOG, CONTROL) (4000, 20000) (0, 10000)))), \ (PRESSURE, 4, 0, 100, (ANALOG, CONTROL, MEASURE), \ (((DISCRETE, ANALOG), (1000, 4000) (0, 20000)) \ ((ANALOG, CONTROL) (4000, 20000) (0, 10000)) \ ((ANALOG, MEASURE) (4000, 20000) (0, 3000)))), \ (TEMPERATURE, 10, 0, 100, (CONTROL, MEASURE), \ (((DISCRETE, CONTROL) (1000, 4000) (0, 20000)) \ ((CONTROL, MEASURE) (4000, 20000) (0, 3000)))) \ ) #define WITH_NUMBERS(Z0, Z1, SEQ) BOOST_PP_SEQ_ELEM(1, SEQ), BOOST_PP_SEQ_ELEM(2, SEQ), #define TO_NUMBERS(Z0, Z1, SEQ) BOOST_PP_SEQ_FOR_EACH(WITH_NUMBERS, _, SEQ) #define TO_SCALES(Z0, Z1, TUPLE) BOOST_PP_SEQ_FOR_EACH(TO_NUMBERS, _, BOOST_PP_TUPLE_ELEM(NFIELDS, POS_SCALES, TUPLE)) unsigned int bounds[] = {BOOST_PP_SEQ_FOR_EACH(TO_SCALES, _, BOOST_PP_TUPLE_TO_SEQ(NSIGS, ADC))}; ********************************************************************** The errors are: ./test_preprocess.cpp:56:1: error: ‘TO_NUMBERS’ was not declared in this scope ./test_preprocess.cpp:56:1: error: ‘_’ was not declared in this scope ./test_preprocess.cpp:56:1: error: ‘(0, (._74)1u)’ cannot be used as a function ./test_preprocess.cpp:56:1: error: ‘(0, (._74)2u)’ cannot be used as a function ./test_preprocess.cpp:56:1: error: ‘(0, (._74)3u)’ cannot be used as a function ./test_preprocess.cpp:56:1: error: ‘BOOST_PP_SEQ_FOR_EACH’ was not declared in this scope ... end so on Why it's not sees TO_NUMBERS definition?

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99 Bottles of Beer using Boost MPL, feedback invited
by Alastair Rankine 07 Aug '11

07 Aug '11

So inspired by http://programmingpraxis.com/2011/08/05/ninety-nine-bottles-of-beer/ , I decided to attempt to generate the lyrics to the 99 bottles of beer song. To make it interesting I decided to use Boost MPL to generate the lyrics using template metaprogramming. Here is my attempt. https://gist.github.com/1130306 It compiles with gcc 4.2 against boost 1.47. Given that I am pretty inexperienced with MPL I would very much appreciate some constructive criticism. I'd specifically like to know if the code can be cleaned up to be simpler or to perform better. Also I'm not entirely happy with the duplication in the PrintX functors, would definitely like to get a better approach here. Thanks,

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[Fusion] Is there an assignment function for any two conformant sequences?
by someguy 07 Aug '11

07 Aug '11

Is there a function like "assign(dest_fusion_seq,src_fusion_seq)" which does recursive element-wise assignment between any two conformant fusion sequences(including adapted ones)? I didn't find one but I think there should be such functionality. -- View this message in context: http://boost.2283326.n4.nabble.com/Fusion-Is-there-an-assignment-function-f… Sent from the Boost - Users mailing list archive at Nabble.com.

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[Boost.Serialization] Serializing "abstract" classes
by Júlio Hoffimann 06 Aug '11

06 Aug '11

Dear all, I'm using Boost 1.45... I've read Boost.Serialization docs so many times and can't understand why my testcase is not working as expected. According to the following three links, we need to address serialization of derived classes with "abstract" base class by using boost macros: http://www.boost.org/doc/libs/1_47_0/libs/serialization/doc/traits.html#exp… http://www.boost.org/doc/libs/1_47_0/libs/serialization/doc/special.html#ex… http://www.boost.org/doc/libs/1_47_0/libs/serialization/doc/traits.html#abs… I did my testcase ( http://codepad.org/6ETp1Ac0 ) completely based on the demo: http://www.boost.org/doc/libs/1_47_0/libs/serialization/example/demo.cpp Compiling and running shows that the derived class archive contains just the base class data members. What is happening? How can i solve this problem? I really appreciate any help, Júlio.

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Another baffling error message
by Eric Fowler 06 Aug '11

06 Aug '11

Sorry to have to ask the list for help, but I am once again stumped. Perhaps you will find this easy. I have some classes defined: using namespace std; using namespace boost; class POS{..stuff..} class LEN{...stuff...} typedef adjacency_list<vecS, vecS, undirectedS, POS, LEN> DG; typedef graph_traits<DG>::vertex_descriptor Vertex; typedef graph_traits<DG>::edge_descriptor Edge; class DelaunayGraph: public DG { public: void foo() { Edge e = whatever(); remove_edge(e, *this); // <<<<----THIS BLOWS UP ..stuff... } The error I am getting is: c:\documents and settings\eric\my documents\visual studio 2008\projects\shuttle\delaunay\trunk\delaunaygraph.h(371) : error C2661: 'boost::undirected_graph_helper<Config>::remove_edge' : no overloaded function takes 2 arguments with [ Config=boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS,boost::vecS,boost::undirectedS,POS,LEN>,boost::vecS,boost::vecS,boost::undirectedS,boost::property<boost::vertex_bundle_t,POS>,boost::property<boost::edge_bundle_t,LEN>,boost::no_property,boost::listS>::config ] What am I doing wrong in this instance, and what design principle am I violating? Eric

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datetime will not be parsed
by Kraus Philipp 06 Aug '11

06 Aug '11

Hello, I use this code for parsing a string into a datetime: boost::local_time::local_date_time l_datetime(boost::date_time::not_a_date_time); std::istringstream l_datestream("Sat Aug 06 10:52:26 +0000 2011"); l_datestream.imbue( std::locale( std::locale::classic(), new boost::local_time::local_time_input_facet("%a %b %d %H:%M:%S %q %Y")) ); l_datestream >> l_datetime; But the l_datetime is always set to "not a date time". I think the parameter within the input facet are correct, so I don't understand why the string is not be parsed. Can anyone help me please to create a working solution? Thanks Phil

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question about boost::intrusive_ptr
by Mahmood Naderan 06 Aug '11

06 Aug '11

Hi I used boost::intrusive_ptr in a function, say foo(), like this: boost::intrusive_ptr<BranchFeedback> theFeedback ( new BranchFeedback() ); std::vector< std::vector< BPredState > > theFetchState; .... theFeedback->theBPState = &theFetchState[anIndex][!anOne]; The difinition of BranchFeedback and BPredState are: struct BranchFeedback : boost::counted_base { ... boost::intrusive_ptr<BPredState> theBPState; }; struct BPredState : boost::counted_base { ... uint32_t theGShare; uint32_t theSerial; }; The problem is when foo() reaches the end (I mean '}'), I get segmentation fault which points to ~intrusive_ptr() { if(p_ != 0) intrusive_ptr_release(p_); } I thought I used the intrusive_ptr in a correct way. Is there any consideration that I missed? Thanks, // Naderan *Mahmood;

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is boost 1.46.1 contain thread/read_write_mutex.hpp
by Eric Lin 05 Aug '11

05 Aug '11

dear boost progamers: when I tried to compile from my g++4.5.2 a simple file which include #include <boost/thread/read_write_mutex.hpp> ------- root@eric-laptop:/home/eric/cppcookbook/ch12# g++ -lboost_thread Example12-3.cpp Example12-3.cpp:3:45: fatal error: boost/thread/read_write_mutex.hpp: No such file or directory compilation terminated. --------- and I check from / of my ubuntuLinux with boost 1.46.1 I can not find any file name as read_wirte_mutex.hpp --------- root@eric-laptop:/# find . | grep read_write_mutex.hpp root@eric-laptop:/# --- and I can not digout from web how to make it compile under gcc/g++ plz help, Eric

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