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text_file_backend with append and rotate
by Victor Yankee 06 Dec '12

06 Dec '12

Hello everyone! How to create a text_file_backend that appends to existing log file and also has rotation. The init function below always creates a new file every time I run my program no matter the rotation settings. I am using svn version 774 (latest as of Dec 5, 2012. I tried many ways but no joy. There is not an example like this, and there does not seem to be a test for appending either, so maybe it is not supported, but that would be bad. So I must be doing something wrong. Here is my function to set up the logger (using my custom severity levels): void init() { typedef boost::log::sinks::synchronous_sink< boost::log::sinks::text_file_backend > FileSink_t; boost::shared_ptr< FileSink_t> mySink( new FileSink_t( boost::log::keywords::file_name = "%Y%m%d_%H%M%S_%5N.log" , boost::log::keywords::rotation_size = 16 * 1024 * 1024 /3 , boost::log::keywords::time_based_rotation = boost::log::sinks::file::rotation_at_time_point(0,0,0) , boost::log::keywords::auto_flush = true , boost::log::keywords::open_mode=(std::ios::out | std::ios::app) // seems to have no effect )); // this method of setting append does not seem to work either, so I must be doing something wrong mySink->locked_backend()->set_open_mode(std::ios::out|std::ios::app); mySink->locked_backend()->set_file_collector(boost::log::sinks::file::make_collector( boost::log::keywords::target = "logs" , boost::log::keywords::max_size = 16 * 1024 * 1024 , boost::log::keywords::min_free_space = 2 * 16 * 1024 * 1024 )); mySink->set_filter(boost::log::filters::attr< LOGGING::LOG_LEVEL >("Severity", std::nothrow) >= LOGGING::warning); mySink->locked_backend()->scan_for_files(); mySink->set_formatter( boost::log::formatters::format("[%1% | %2%] %3%") % boost::log::formatters::date_time< boost::posix_time::ptime >("TimeStamp") % boost::log::formatters::attr< LOGGING::LOG_LEVEL >("Severity", std::nothrow) % boost::log::formatters::message() ); boost::log::core::get()->add_sink(mySink); boost::log::core::get()->add_global_attribute("TimeStamp", boost::log::attributes::local_clock()); }

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Why does gcc require explicit template arguments with my boost::bind
by Chris Stankevitz 06 Dec '12

06 Dec '12

Hello, Below I implement a function "Chain" that takes two functions and executes them both. The first approach succeeds: direct function call. The second approach succeeds: call via bind with explicit template arguments The third and fourth approaches fail: call via bind without explicit template arguments (with/without boost::protect) Question: Why do I have to use explicit template arguments when using bind with Chain? Thank you, Chris === #include <boost/bind.hpp> #include <boost/function.hpp> template <typename TAFunc1, typename TAFunc2> void Chain(const TAFunc1& Func1, TAFunc2& Func2) { Func1(); Func2(); } void f() { } void foo() { boost::function<void()> x = boost::bind(f); boost::function<void()> y = boost::bind(f); Chain(x, y); boost::bind(Chain<boost::function<void()>, boost::function<void()> >, x, y)(); boost::bind(Chain, x, y)(); boost::bind(Chain, boost::protect(x), boost::protect(y))(); }

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Experience with dealing with warnings from the Clang toolset?
by Paul A. Bristow 06 Dec '12

06 Dec '12

I have added a little information on dealing with warnings when using the Clang toolset at https://svn.boost.org/trac/boost/wiki/Guidelines/WarningsGuidelines but I am sure there are people using Clang who can provide more detailed information and suggestions from their experiences. Please tell me if you have anything to add. Paul --- Paul A. Bristow, Prizet Farmhouse, Kendal LA8 8AB UK +44 1539 561830 07714330204 pbristow(a)hetp.u-net.com

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Boost::Asio read_until and streambuf usage
by Gonzalo Garramuno 06 Dec '12

06 Dec '12

I have a server that sends three lines, each of which have to be parsed independently. I am using read_until but have a problem with its usage. When read_until reads once, the streambuf seems to contain the three lines but not in the istream and only when I call read_until several times, I get the lines. I am wondering how can I safely read_until the buffer is empty (the 3 or more lines are read) and then exit the loop. boost::asio::streambuf buf; while( 1 ) { size_t reply_length = boost::asio::read_until( socket_, buf, '\n' ); std::istream is(&buf); std::string reply; std::getline(is, reply); // only 1 line obtained }

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Re: [Boost-users] boost msm - differed events
by Kamel Zaarouri, Mr 05 Dec '12

05 Dec '12

Hi guys, I realized that I asked a very unclear question yesterday. I will try to reformulate :) Let's say I have 2 states, an Active state and an Idle state. If I receive some events in Active state I would like to defer them and execute them when I go back to Idle state. But when I go back to Idle State is there a way to chose which previously deferred event to process? or is there a way to prioritize them or even ignore few of them? Thank you!

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C++11, boost::filesystem::path, no std::hash specialization
by Benjamin Kircher 05 Dec '12

05 Dec '12

Hi there, I cannot use boost::filesystem::path with an e.g. unordered_set because std::hash seems not to be specialized for this type. Is this intended? Should I file a bug? Or am I completely misguided? I use 1.52 libraries with -DBOOST_FILESYSTEM_NO_DEPRECATED. I searched the bug database but did not find anything relevant (other than this https://svn.boost.org/trac/boost/ticket/5650 ticket). Thanks in advance, -Benjamin

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Boost.Serialization type-dependent serialization
by Roman Suvorov 05 Dec '12

05 Dec '12

Hi! I have a list of objects of the following structure: > class Obj > { > // a number simple fields > int field1() const; > > // ... > > // reference to an object containing large amount of data > const blob_type & mega_blob() const; > }; The list is to be serialized in the following way: 1) simple fields of each object are to be serialized into a single xml file; 2) mega_blobs' are to be serialized into separate binary files. The idea of doing it is to write custom archive that has operator<< specialized for blob_type which does the magic. Following the Boost.Serialization reference (http://www.boost.org/doc/libs/1_52_0/libs/serialization/doc/archive_referen…) I wrote the code in order to proof the concept: http://pastebin.com/ekbXXvxF My test project is built using CMake and G++-4.6.3 (Debian Wheezy) (that seems to be ok - other code that uses Boost.Serialization compiles well): http://pastebin.com/WVRUKLD2 As a result I get the following linker errors: http://pastebin.com/rM05nkqw The questions: 1) am I using xml_oarchive_impl wrong way or that problem is not boost-related? 2) maybe there are more elegant ways of solving my task? Cheers, Suvorov Roman.

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Re: [Boost-users] Boost-users Digest, Vol 3288, Issue 1
by Shcherbina Vladimir 05 Dec '12

05 Dec '12

Hi, Could you try it with MS compiler and any release prior to the 1.52.0? -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of boost-users-request(a)lists.boost.org Sent: 04 December 2012 17:29 To: boost-users(a)lists.boost.org Subject: Boost-users Digest, Vol 3288, Issue 1 Send Boost-users mailing list submissions to boost-users(a)lists.boost.org To subscribe or unsubscribe via the World Wide Web, visit http://lists.boost.org/mailman/listinfo.cgi/boost-users or, via email, send a message with subject or body 'help' to boost-users-request(a)lists.boost.org You can reach the person managing the list at boost-users-owner(a)lists.boost.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Boost-users digest..." Today's Topics: 1. Re: Boost 1.49.0 compilation issue (Marshall Clow) 2. Re: boost msm - Multiple differed events (Kamel Zaarouri, Mr) 3. [serialization] versioning for class nested within template class (Gabriel Redner) 4. Re: Asio and software interrupts (Steve Lorimer) 5. Spirit guidance needed (Arkadiy and Marina Vertleyb) 6. [boost][polygon]Errors with minkowski sum (renaud lepere) 7. Re: Spirit guidance needed (Igor R) 8. Experience with dealing with warnings from the Clang toolset? (Paul A. Bristow) ---------------------------------------------------------------------- Message: 1 Date: Mon, 3 Dec 2012 09:29:59 -0800 From: Marshall Clow <mclow.lists(a)gmail.com> To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] Boost 1.49.0 compilation issue Message-ID: <BA420D66-6A77-4CF9-AB4C-E1005A770684(a)gmail.com> Content-Type: text/plain; charset=us-ascii On Dec 2, 2012, at 1:47 AM, Shcherbina Vladimir <Vladimir.Shcherbina(a)elbitsystems.com> wrote: > I tried to compile this boost dependent class with VS2008 and VS2010 > (error lines are in bold) Another data point: I was able to successfully compile your code with clang. and the 1.52.0 release. -- Marshall Marshall Clow Idio Software <mailto:mclow.lists@gmail.com> A.D. 1517: Martin Luther nails his 95 Theses to the church door and is promptly moderated down to (-1, Flamebait). -- Yu Suzuki ------------------------------ Message: 2 Date: Mon, 3 Dec 2012 21:08:57 +0000 From: "Kamel Zaarouri, Mr" <kamel.zaarouri(a)mail.mcgill.ca> To: "boost-users(a)lists.boost.org" <boost-users(a)lists.boost.org> Subject: Re: [Boost-users] boost msm - Multiple differed events Message-ID: <E7E49CA8DA97024ABF8B81BBF85E325412D63A(a)EXMBX2010-3.campus.MCGILL.CA> Content-Type: text/plain; charset="us-ascii" Hi Guys, Let's say that we have 2 states, S1 and S2. with this transition table: S1 -> S2 on event Es2 S2 -> S1 on event Es1 also let's say that S1 can also accept Ev1 and Ev2 but S2 cannot accept them so it differs them. Now when let's say that S2 receives 2 events Ev1 and Ev2 and differs them. Now, when S2 goes back to S1 would S1 handle both events in order? or how does it work? Thanks, ------------------------------ Message: 3 Date: Mon, 3 Dec 2012 17:51:40 -0500 From: Gabriel Redner <gredner(a)gmail.com> To: boost-users <boost-users(a)lists.boost.org> Subject: [Boost-users] [serialization] versioning for class nested within template class Message-ID: <CAO0m-H+t-bfAOe7JoV27MEMeHPXs6pVzDV9yqJC1Csp2Av6ESA(a)mail.gmail.com> Content-Type: text/plain; charset=windows-1252 Hi folks, I am having trouble incrementing the serialization version of a regular class nested within a template class. I'm not sure if the problem is with boost or with my own understanding of the issue. My code looks like: ============================== template <typename A, typename B> struct Foo { struct Bar { int data1; int data2; private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, unsigned int version) { ar & data1; if (version >= 2) { ar & data2; } else { data2 = 0; } } }; }; ============================== My attempt at setting the version looks like: ============================== namespace boost { namespace serialization { template <typename A, typename B> struct version<typename Foo<A, B>::Bar> { BOOST_STATIC_CONSTANT(unsigned int, value = 2); }; } // namespace serialization } // namespace boost ============================== However, g++ gives an error: ============================== main.cpp:31:8: error: template parameters not used in partial specialization: main.cpp:31:8: error: ?A? main.cpp:31:8: error: ?B? ============================== Strangely, clang 3.0 compiles the code but issues some warnings: ============================== main.cpp:31:8: warning: class template partial specialization contains template parameters that can not be deduced; this partial specialization will never be used struct version<typename Foo<A, B>::Bar> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.cpp:30:20: note: non-deducible template parameter 'A' template <typename A, typename B> ^ main.cpp:30:32: note: non-deducible template parameter 'B' template <typename A, typename B> ^ 1 warning generated. ============================== I'd appreciate any pointers! Thanks, -Gabe ------------------------------ Message: 4 Date: Tue, 4 Dec 2012 10:17:33 +1100 From: Steve Lorimer <steve.lorimer(a)gmail.com> To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] Asio and software interrupts Message-ID: <CAE-NPOiR0Z3rGhmfBftGxpRLrJHTBW=6eMjGac27SaW+OvgJVw(a)mail.gmail.com> Content-Type: text/plain; charset="iso-8859-1" On 4 December 2012 01:51, Joseph Sulewski <joemacher(a)gmail.com> wrote: > *When I call socket->bind I provide it with an endpoint. When I > create the endpoint I'm currently using the multicast address, what > should I use for the address? * > If you bind to INADDR_ANY then the OS will use its ip routing tables to work out which the best local nic to use is. You can force it to use a specific local nic by providing its address. Most applications will use INADDR_ANY *If I'm binding to multiple multicast addresses it doesn't make sense to > bind to one of them.* > Because UDP is connectionless there is no way for the kernel / network stack to know which pid to deliver datagrams to for a particular port unless you bind your socket's file descriptor to that port. (note, if you want to allow other file descriptors to be able to bind to that port you need to set SO_REUSEADDR to 1) > *Finally, it appears I can join multiple multicast groups but they > need to be the same port. Is this correct?* > The reason for this is as my previous point above. What you would do is create as many sockets as there are different ports, and have each socket join the multicast addresses which are on that port > >

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[Filesystem] Movable fstreams
by Szymon Gatner 04 Dec '12

04 Dec '12

Hi, Could move (via boost.move) support be added to file streams provided by filesystem library? Would be very useful when returning for example ifstream from function. Cheers, Simon -- Szymon Gatner The Lordz Games Studio www.thelordzgamesstudio.com

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Boost.Math - Statistical Distribution Explorer - updated to Boost 1.52
by Paul A. Bristow 04 Dec '12

04 Dec '12

Just to note that I have recently updated the Microsoft Windows C# 'app' that allows one to explore various properties of statistical distributions and calculate their Cumulative Distribution Function CDF, Probability Distribution Function PDF, or quantiles/percentiles. This revision includes some new distributions and all the bug fixes and improvements in Boost.Math for 1.52. I have also now aligned the application version numbering with Boost release numbering. For full information and download http://sourceforge.net/projects/distexplorer/ It works on all the 'this-millennium' versions of Windows. If anyone knows how to produce a *nix version, please contact me. Paul --- Paul A. Bristow, Prizet Farmhouse, Kendal LA8 8AB UK +44 1539 561830 07714330204 pbristow(a)hetp.u-net.com

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