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[move] Where is it? when to use it?
by Michael Powell 29 Jul '13

29 Jul '13

Hello, Okay, this is kind of a Boost question, and kind of not. Kind of a C++ question, and kind of not. Depends where I can find a workable solution. First, I am using Sourcery CodeBench in a more recent (not the most recent) version. I believe it is one revision back from most recent. Targeting (Arch)Linux/ARM. I believe I answered my question from online references: http://en.cppreference.com/w/cpp/utility/move, which I've also confirmed is a C++0x experimental feature in the version of CodeBench I am using. It may be more or less up to date when I upgrade to the latest CodeBench. If the experimental doesn't work out, is there a Boost alternative? If so, where do I include it? Thank you... Regards, Michael Powell

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[asio] reconnect without close the socket, is it possible?
by TONGARI J 28 Jul '13

28 Jul '13

Hi, I want to know if the connection is broken up at some point, can I reconnect without shutdown-close the socket. On Windows, I keep getting already_connected error when reconnecting but still fails to do other async read/write... Also, any way to test if the socket is connected? Thanks.

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Re: [Boost-users] serialization of standard unordered containers
by Brian Wood 28 Jul '13

28 Jul '13

niXman writes: > 2013/7/27 D. R. Evans: >> 1. Is serialization of standard unordered containers supported in version >>1.54.0 of the boost libraries? >No. > > Alternatively, look at the YAS: > https://github.com/niXman/yas The C++ Middleware Writer - http://webEbenezer.net has support for the standard unordered containers. -- Brian Wood Ebenezer Enterprises http://webEbenezer.net

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find positions of punctuations with boost regex
by chenyong 27 Jul '13

27 Jul '13

I am trying to find ALL positions of punctuations in a textual string so that I can divide the text into sentence. How to do this with boost regex. Thanks Felix

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[asio] Async (or sync) in threads
by Michael Powell 27 Jul '13

27 Jul '13

Hello, I am having a hard time getting my Asio usage off the ground. I started with what I thought was a nominal (knock on wood) asynchronous server, which runs in a worker thread, but was running into seg fault issues. In the interest of "simplifying" the issue, I decided to simplify to a "blocking" server, hopefully also hosted in a thread, but am also running into seg fault issues. First I am trying to capture the server instance in a lambda passing it to a thread as a runner. Then I am trying to capture a shared pointer to the server thinking there is some move semantic or something. Seg fault in either case. Most of the examples are one main being the sole main thread hosting the io_service. Would that this were the case with me. This has to be one worker among several other workers running in the same process. Wouldn't mind if there were a couple of ideas recommending what I might explore next. Thank you... In the diagnostic routine I've got wired up: boost::shared_ptr<dchem::asio::ip::tcp::server2> server_ = boost::make_shared<dchem::asio::ip::tcp::server2>(17017); boost::thread runner_([&server_]() { server_->start_server(); }); runner_.start_thread(); while (!timer_.has_elapsed_query_wait(wait_timeout_, elapsed_milliseconds_)) { //... } runner_.interrupt(); runner_.join(); And the server itself, header first: class server2 { public: /** * \brief Endpoint type definition. */ typedef boost::asio::ip::tcp::endpoint endpoint_type; /** * \brief Acceptor type definition. */ typedef boost::asio::ip::tcp::acceptor acceptor_type; /** * \brief Service type definition. */ typedef boost::asio::io_service service_type; /** * \brief Socket type definition. */ typedef boost::asio::ip::tcp::socket socket_type; /** * \brief Socket pointer type definition. */ typedef boost::shared_ptr<socket_type> socket_pointer; /** * \brief Port type definition. */ typedef unsigned int port_type; protected: /** * \brief Returns whether bytes are available. * \param s A socket reference. */ static bool are_bytes_readable(socket_type& s); /** * \brief Starts a new session. * \param s Starts running a new session. */ void session(socket_pointer s); public: /** * \brief Constructor * \param port A TCP port. */ server2(port_type port); /** * \brief Destructor */ virtual ~server2(); /** * \brief Starts the server. */ void start_server(); private: /** * \brief Service. */ service_type m_service; /** * \brief Port. */ port_type m_port; }; ///////////////////////////////////////////////////////////////////// server2::server2(port_type port) : m_service(), m_port(port) { } ///////////////////////////////////////////////////////////////////// server2::~server2() { } ///////////////////////////////////////////////////////////////////// bool server2::are_bytes_readable(socket_type& s) { boost::asio::socket_base::bytes_readable cmd_(true); s.io_control(cmd_); std::size_t cmd_result_ = cmd_.get(); return cmd_result_ > 0; } ///////////////////////////////////////////////////////////////////// void server2::start_server() { try { endpoint_type ep_(boost::asio::ip::tcp::v4(), m_port); acceptor_type a_(m_service, ep_); std::cout << "accepting connection" << std::endl; boost::system::error_code ec_; auto s_ = boost::make_shared<socket_type>(m_service); a_.accept((*s_), ec_); if (!ec_) return; std::cout << "starting session" << std::endl; session(s_); } catch (boost::thread_interrupted& tiex) { } catch (...) { } } ///////////////////////////////////////////////////////////////////// void server2::session(socket_pointer s) { auto& s_ = (*s); while (true) { { utils::sleep_for_milliseconds(100); threading::thread_interruption_disabler tid; std::cout << "are bytes readable" << std::endl; if (!are_bytes_readable(s_)) continue; std::cout << "reading some" << std::endl; boost::system::error_code ec_; std::vector<byte> buffer_; size_t length_ = s_.read_some(boost::asio::buffer(buffer_), ec_); //Connection reset cleanly by peer. if (ec_ == boost::asio::error::eof) break; else if (ec_) //Some other error. throw boost::system::system_error(ec_); boost::asio::write(s_, boost::asio::buffer(buffer_, length_)); } } } Regards, Michael Powell

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shared_ptr problem
by Tim Burgess 26 Jul '13

26 Jul '13

Hi, I'm developing an application for Windows and Mac. My source compiles and links fine, but I'm having a problem when building the code on the Mac (OSX 10.8 Mountain Lion, Xcode 4.6 using GCC). The contents of the Issue Navigator are shown below: SurfaceReader Group /Users/tim/developer/libraries/boost_1_54_0/boost/smart_ptr/make_shared_obje ct.hpp /Users/tim/developer/libraries/boost_1_54_0/boost/smart_ptr/make_shared_obje ct.hpp:711: error: no matching function for call to 'AppConfig::AppConfig(const boost::shared_ptr<AppConfig>&)' /Users/tim/developer/libraries/boost_1_54_0/boost/smart_ptr/make_shared_obje ct.hpp:711: error: no matching function for call to 'SurfaceProtocol::SurfaceProtocol(const boost::shared_ptr<SurfaceProtocol>&)' /Users/tim/developer/libraries/boost_1_54_0/boost/smart_ptr/make_shared_obje ct.hpp:711: error: no matching function for call to 'RBSpeech::RBSpeech(const boost::shared_ptr<RBSpeech>&)' I'm using shared_ptr in about half the modules in my application and, given that the above output doesn't refer to compilation errors in particular modules of mine, I'm confused as to how to track this issue down. Obviously, the issue has something to do with the constructors for my AppConfig, SurfaceProtocol and RBSpeech classes, but these don't cause any problems under Windows/VS2010 and only the RBSpeech class has any Mac-specific code blocks. Can anybody advise me how to proceed, please? Best wishes. Tim Burgess Raised Bar Ltd. T: 01827 719822 M: 07989 486976 W: http://www.raisedbar.net

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[iostreams] Some basic questions about filtering_stream
by Stephen Greenfield 25 Jul '13

25 Jul '13

Some basic questions about Boost filtering_streams. I have dozens of functions that presently take a parameter of std::ofstream&. For example: void foo(std::ofstream& outStream) { // lots of operations, like this: outStream << "various bits of text"; } Which then get used as thus: void StreamSomeTextToFile(char* fileName) { ofstream myFileStream(fileName, ios::out | ios::app | ios::binary); foo(myFileStream); myFileStream.close(); } Now I'd like to use the boost filtering_stream to output to a compressed ZIP file. I've compiled, linked and run the commonly cited boost filtering_stream test code for packing and unpacking and it worked perfectly for me. Now I'd like to try to substitute my use of std::ofstream& with the filtering_stream: void StreamSomeCompressedTextToFile(char* fileName) { ofstream myFileStream(destPath, std::ios_base::out | std::ios_base::app | std::ios_base::binary); boost::iostreams::filtering_streambuf<boost::iostreams::output> myCompressedFileStream; myCompressedFileStream.push(boost::iostreams::zlib_compressor()); myCompressedFileStream.push(myFileStream); foo(myCompressedFileStream); // I can't just pass myCompressedFileStream to foo(std::ofstream&), right? myFileStream.close(); } THREE QUESTIONS: 1) Do all my functions that previously accepted std::ofstream& outStream need to now accept a parameter of type boost::iostreams::filtering_streambuf<boost::iostreams::output>& ? Or, is there a proper parameter type so those numerous ("foo") functions could work with EITHER type of stream type? 2) In my simple test cases, I was not able to use stream operator syntax with the filtering_streambuf: myCompressedFileStream << "some text"; this generated the the error: no match for 'operator<<'. I similarly had compile errors with write(): `error: 'class boost::iostreams::filtering_streambuf<boost::iostreams::output, char, std::char_traits<char>, std::allocator<char>, boost::iostreams::public_>' has no member named 'write`' Could this be a missing header? If so, I haven't been able to determine which one. 3) In the common test case example code (below), I was confused that I could not locate the file "hello.z" after it had been created. The unpack code (also below) executed correctly and clearly references the created file -- so where can it be found? void pack() { std::ofstream file("hello.z", std::ios_base::out | std::ios_base::binary); boost::iostreams::filtering_streambuf<boost::iostreams::output> out; out.push(boost::iostreams::zlib_compressor()); out.push(file); char data[5] = {'a', 'b', 'c', 'd', 'e'}; boost::iostreams::copy(boost::iostreams::basic_array_source<char>(data, sizeof(data)), out); file.close(); } void unpack() { std::fstream file("hello.z", std::ios_base::in | std::ios_base::binary); boost::iostreams::filtering_streambuf<boost::iostreams::input> in; in.push(boost::iostreams::zlib_decompressor()); in.push(file); boost::iostreams::copy(in, std::cout); } My code is being developed on XCode 3.2.6, GNU 4.0, Mac OS X 10.6.8

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[multiprecision] serialization support?
by Neal Becker 25 Jul '13

25 Jul '13

Does/will multiprecesion have support for boost::serialization?

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[MultiIndex] How to extract a key-extractor?
by Igor R 25 Jul '13

25 Jul '13

Hello, The following code is expected to get the key-extractor, but it doesn't compile. How to do this correctly? Thanks. #include <boost/multi_index_container.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/mem_fun.hpp> struct A { int f() const { return 0; } }; typedef boost::multi_index::multi_index_container< int, boost::multi_index::indexed_by< boost::multi_index::ordered_unique< boost::multi_index::const_mem_fun<A, int, &A::f> > > > container_type; typedef container_type::key_from_value_type extractor_type; // doesn't compile typedef container_type::nth_index<0>::key_from_value_type extractor_type; // doesn't compile

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multiprecision int - convert to floating type
by Neal Becker 25 Jul '13

25 Jul '13

Any suggestion how to convert a mp int (e.g., int128_t) to a float type (e.g., double)?

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