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[asio] Thread safety
by Laurent Fert 01 Jul '09

01 Jul '09

Hi, I have a thread that runs io_service::run(). I have another thread that creates a timer and schedules it to fire later. Once the timer has been scheduled, the second thread forgets about it and everything is handled by the thread that runs the service. Is it safe to create/schedule a timer with an io_service from a thread while this services is being run in another thread? Thank you for your replies, Laurent

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[asio] ICMP protocol support
by Chris Miceli 01 Jul '09

01 Jul '09

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 I am attempting to use the ICMP protocol that is "off-the-shelf" in Boost.Asio, but am unable to get any use of it working. Following the code listed here: http://www.boost.org/doc/libs/1_36_0/doc/html/boost_asio/overview/networkin… I immediately run into problems. The DAYTIME protocol is defined to operate on TCP or UDP port 13. ICMP should be used for control messages, not data transmission. Trying to connect to a server supported DAYTIME with ICMP does not work using the code at the previously mentioned site, this error is returned: Service not found Which makes sense because this service is not defined for this protocol. My question is, what is the intended purpose of the current implementation of this protocol? If to use ICMP to tranfer data by using the payload, why? If to construct messages useful for writing a traceroute or ping utility, how would I do this? Has anyone used this library? Online there is a desire to use boost.Asio and ICMP to write ping using boost, but they all reach these same questions. I am appreciative of any help on this topic. - -Chris -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEAREKAAYFAkpK05UACgkQS3i4IU3+Scsw2QCbBAQpHwqzTqIvn3hVunI6bnK9 Z6AAn0EfsRAwPbon8jJYVotEe6awn7Xy =/gWa -----END PGP SIGNATURE-----

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boost::bind with references
by Zachary Turner 01 Jul '09

01 Jul '09

I have a function defined as template<typename T> void foo(const T& x); and then I use boost::bind(foo, x); However, once the code is inside the body of foo, the addresses of x inside foo and the addresses of x when I called bind are different. So somehow a copy is being made. I can get around it by using boost::ref(), but is there a technical reason why it doesn't "just work" and pass it by reference?

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[TypeTraits] Is it possible to detect that type is not exist and use default type?
by Sakharuk, Vlad (GMI Development) 30 Jun '09

30 Jun '09

Here is example: class one { public: typedef someclass internal; }; class two { // No internal class }; class default_internal{ }; I would like to be able to write something if it possible: template<class T, class B = if_exist(T::internal) T::internal else default_internal > class proc { }; So I can use proc with both proc<one> One; proc<two> Two; without specifying derived type? Thanks! \/. -------------------------------------------------------------------------- This message w/attachments (message) may be privileged, confidential or proprietary, and if you are not an intended recipient, please notify the sender, do not use or share it and delete it. Unless specifically indicated, this message is not an offer to sell or a solicitation of any investment products or other financial product or service, an official confirmation of any transaction, or an official statement of Merrill Lynch. Subject to applicable law, Merrill Lynch may monitor, review and retain e-communications (EC) traveling through its networks/systems. The laws of the country of each sender/recipient may impact the handling of EC, and EC may be archived, supervised and produced in countries other than the country in which you are located. This message cannot be guaranteed to be secure or error-free. References to "Merrill Lynch" are references to any company in the Merrill Lynch & Co., Inc. group of companies, which are wholly-owned by Bank of America Corporation. Securities and Insurance Products: * Are Not FDIC Insured * Are Not Bank Guaranteed * May Lose Value * Are Not a Bank Deposit * Are Not a Condition to Any Banking Service or Activity * Are Not Insured by Any Federal Government Agency. Attachments that are part of this E-communication may have additional important disclosures and disclaimers, which you should read. This message is subject to terms available at the following link: http://www.ml.com/e-communications_terms/. By messaging with Merrill Lynch you consent to the foregoing. --------------------------------------------------------------------------

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Serialization of a universal data type
by Gokulakannan Somasundaram 30 Jun '09

30 Jun '09

Hi, I have started using Boost Serialization in one of my project and thanks for the library. I may be asking a question that might have got repeated, but i did my search on the forums but couldn't get the relevant answer. I have a data-type which is more like a universal datatype(unsigned long). Consider a 64 bit system and if the value to be stored in this datatype is greater than 8 bytes, then it is stored as value. If the value to be stored is greater than 8 bytes, then it is stored elsewhere and the pointer is stored here. By using other meta-data information, the data is extracted from this data-type. To be exact, i am referring to the datum implementation in open-source database postgresql. If i have to serialize this data-type, i need more info from other variables which store the metadata. The functions, i am trying to implement in Boost serialization are readDatum and _outDatum(similar to load/save). I don't see, how i can do that in Boost serialization, especially because of the signature of the load/save function. It only takes the version and the object to be serialized. How can i pass the other meta-data? I could always create a new data-type(say SerializableDatum) with all the required info, but then this data-type is being created only for the purpose of serialization. Is there any better way to achieve the same result? Thanks, Gokul.

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Using boost::date_time library with wince
by Matt Schuckmann 30 Jun '09

30 Jun '09

Does anybody have any experience with using boost::date_time (boost version 1.37 or later) with windows ce (aka Windows Mobile 5 or Windows Mobile 6) Specifically I'm trying to figure out the best way to get around the missing functions std::localtime() and std::gmtime(). Yes as hard as it is to believe Microsoft choose to leave these 2 simple functions out of wince, imagine that. I'm actually running into this because I'm trying to use boost::thread which uses mostly the header only parts of date_time. The problem crops up when c_time.hpp is included. Thanks in advance for any help Matt Schuckmann

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Using boost with windows mobile 5 or 6.
by Matt Schuckmann 30 Jun '09

30 Jun '09

I'm currently trying to use boost in my Windows Mobile 5/6 (aka WinCE) project and I'm having some real problems. Note the project is a port of a C++ library that is currently used in a Windows application and a Linux application. First let me say I'm using boost 1.37 and Visual Studio 2005 (VC 8), I'm not currently using STLPort. The specific libraries I'm trying to use are Thread, State machine and to some extent Date Time (mostly because Thread makes use of date_time) I'm not finding much of concrete info on how to go about doing thiss. The most help has come from the VeecoFTC regression build setup but that just got me to the point of building the boost library for the thread project. However, when I try to use thread in my project I run into problems specificly: * Wince does not implement std::localtime or std::gmtime which are used by the boost versions of localtime and gmtime in c_time.hpp. (Thread appears to depend on this via the date_time library) * Wince does not implement the standard library file locale. Most of the problems caused by this are solved be defining BOOST_NO_STD_LOCAL however the files compare.hpp and replace.hpp in boost/algorithm/string/ both don't respect the BOOST_NO_STD_LOCAL and they use std::locale a lot. Has anyone else gotten round these problems and if so what did you do? I've never been clear on why many people appear to be using STLPort with boost with winCE (or at least the VeecoFTC build is) is that something I should be doing? If so can I do it just for my WinCE builds? Does anybody know if I'd have more luck with boost 1.39 or even upgrading to Visual Studio 2008 (VC 9)? Thanks Matt Schuckmann

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[boost][graph] problems using reverse_graph adaptor
by Andrey Torba 30 Jun '09

30 Jun '09

I have a Graph type which satisfies concepts: boost::function_requires<boost::GraphConcept<Graph> >(); boost::function_requires<boost::IncidenceGraphConcept<Graph> >(); boost::function_requires<boost::BidirectionalGraphConcept<Graph> >(); boost::function_requires<boost::VertexListGraphConcept<Graph> >(); boost::function_requires<boost::AdjacencyGraphConcept<Graph> >(); when i make a reverse adaptor: boost::make_reverse_graph(g); i receive such errors: 'edges_size_type' : is not a member of 'boost::graph_traits<Graph>' 'edge_property_type' : is not a member of 'Graph' 'vertex_property_type' : is not a member of 'Graph' Why does reverse_graph requires edges_size_type? edges_size_type isn't in BidirectionalGraph, VertexListGraph, PropertyGraph. it is in EdgeListGraph. reverse_graph requires Graph to be `BidirectionalGraph and optionally VertexListGraph and PropertyGraph`. What does `optionally` mean? My graph is not a PropertyGraph. I want just revert edges. -- Regards, Andrey

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[Interprocess] Custom naming for the managed_external_buffer
by Thomas d'Erceville 30 Jun '09

30 Jun '09

Hello, I'm using a mapped file in order to share my objects between many processes and I already have my own kind of key to identify them. So instead of linking them to a <char *> in the function construct(), I would like to use my own type (providing convenient functions such as less(), operator==, ...) So I mean, instead of : MyObject * my_object = mapped_file.construct<MyObject>("object_name"); I want to known if there is a way to write something like : MyKey *object_key*(...) MyObject * my_object = mapped_file.construct<MyObject>(*object_key*); I'm taking a look at the section "Building custom indexes<http://www.boost.org/doc/libs/1_39_0/doc/html/interprocess/customizing_inte…>" but I am not sure to be able to solve my problem with that. Could someone confirm? Best regards, Thomas 2009/6/29 David Larsson <laserallan(a)gmail.com> > Hi! > I'm outputting the progress from an externally executed command line > application using the windows API call OutputDebugString. > This means that I need to convert all line breaking characters to flush > commands to make sure the text is outputted when a new line is received > rather than when some underlying structure finds it suitable to linebreak. > I've created a sink that writes to OutputDebugString and it works great, > however unless I manually insert lots of std::endl (or flushing some other > way) I won't get any output until the buffer is full. > > Is it possible to write an iostream filter that forces a flush on newlines > or is this something I need to handle before feeding data into my stream? > > /David > > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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Boost Interprocess os_file_functions
by Pascal Kesseli 30 Jun '09

30 Jun '09

Hi everyone For a mutual exclusion on a SerialInterface class, I used a Boost Interprocess Mutex, which compiled on MinGW without any problems. Using the same code on my arm-linux-gcc cross compilation tool chain (Version 3.3.2) renders the following error: g++ -I"/home/othmarsen/Documents/Software/C++/MOXA/UC-7112/ewbmeter" -I"/home/othmarsen/Documents/Software/C++/MOXA/UC-7112/pss" -I/opt/c++/boost/boost_1_39_0 -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"Interface/MockSerialInterface.d" -MT"Interface/MockSerialInterface.d" -o"Interface/MockSerialInterface.o" "../Interface/MockSerialInterface.cpp" In file included from /opt/c++/boost/boost_1_39_0/boost/interprocess/sync/emulation/named_creation _functor.hpp:16, from /opt/c++/boost/boost_1_39_0/boost/interprocess/sync/named_mutex.hpp:22, from /home/othmarsen/Documents/Software/C++/MOXA/UC-7112/ewbmeter/ewbmeter/Interf ace/Interface.h:5, from /home/othmarsen/Documents/Software/C++/MOXA/UC-7112/ewbmeter/ewbmeter/Interf ace/SerialInterface.h:5, from ../Interface/MockSerialInterface.h:4, from ../Interface/MockSerialInterface.cpp:1: /opt/c++/boost/boost_1_39_0/boost/interprocess/detail/mpl.hpp:67: warning: all member functions in class `boost::interprocess::detail::is_convertible<T, U>' are private In file included from /opt/c++/boost/boost_1_39_0/boost/interprocess/sync/posix/semaphore_wrapper. hpp:17, from /opt/c++/boost/boost_1_39_0/boost/interprocess/sync/named_mutex.hpp:26, from /home/othmarsen/Documents/Software/C++/MOXA/UC-7112/ewbmeter/ewbmeter/Interf ace/Interface.h:5, from /home/othmarsen/Documents/Software/C++/MOXA/UC-7112/ewbmeter/ewbmeter/Interf ace/SerialInterface.h:5, from ../Interface/MockSerialInterface.h:4, from ../Interface/MockSerialInterface.cpp:1: /opt/c++/boost/boost_1_39_0/boost/interprocess/detail/os_file_functions.hpp: In function `bool boost::interprocess::detail::delete_subdirectories_recursive(const std::string&, const char*)': /opt/c++/boost/boost_1_39_0/boost/interprocess/detail/os_file_functions.hpp: 461: error: `::' does not have a class or union named `stat' Any ideas on that? Thanks and best regards Kessi

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