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Boost General Interest mailing list
by Jon Kalb 06 Jan '05

06 Jan '05

Boosters, This message announces the Boost General Interest mailing list, called Boost-Interest. This list is a moderated low-traffic announcement-only list of interest to the Boost community. On topic messages will include announcements of books, magazine articles, papers, talks, seminars, products, tools, events, or conferences on advanced uses of C++, generic/generative/meta-programming, and, of course, the Boost libraries. Off topic will be discussion of any kind and job postings. Yes, this is an opt-in list for announcements, but it is a moderated list and the moderators make you two promises. This list will be low volume and all messages will be on-topic (as defined by the charter above). Subscribe or unsubscribe at the Boost-Interest home page: http://lists.boost.org/mailman/listinfo.cgi/boost-interest Anyone may post to this list, but due to the high potential for abuse, each message is individually moderated. Please anticipate some delays in posting and understand that the list moderators have the final say on what is or is not on-topic. -- Jon Kalb Boost-Interest Moderator Kalb(a)LibertySoft.com

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Serialization with NaN and infinity
by Austin Bingham 06 Jan '05

06 Jan '05

I saw a thread on this topic from a few months ago, and I was wondering if there had been any progress or new thought on the topic. Essentially, it appears that the serialization library can't reliably deserialize the serialized version of NaN and infinity for doubles and floats. This seems to be a result of relying on the, AFAIK, undefined behavior of writing NaN/infinity to a stream; it will work correctly with some standard library implementations, but not all. I think the problem can be addressed with these changes: basic_text_oprimitive::save(float or double): on NaN or Infinity, write out some known, stable string (i.e. "nan" or "inf"); don't rely on std implementation. basic_text_iprimitive::load(float or double): look for the "known values" printed by save(), generating the correct values when they're seen. That's a lot of hand waving, to be sure, but something like this would really help out. Of course, a better solution would be fine with me, but there are definitely cases where it's necessary to serialize these values. Currently, there doesn't seem to be a way to reliably to it. Austin Bingham

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Problem compiling the libraries with Dev-C++
by Phantom 06 Jan '05

06 Jan '05

Greetings, I've hit apon a slight problem when it comes to building the latest version of boost (1.32.0) with the tools which come with Dev-C++ (distro 4.9.9.1). When attempting to build the library with the command line; G:\Programming\SDKs\boost_1_32_0>bjam "-sTOOLS=mingw" "-sMINGW_ROOT_DIRECTORY=D:\Dev-Cpp" install the build process fails with the error : spawn: Invalid argument I googled around for a bit and hit apon putting -d+4 onto the command line, which after building the .obj files (via aload of bat files) reported back; Executing raw command directly Executing command ["D:\Dev-Cpp\bin\g++"] ["-Wl,--enable-auto-image-base"] ["-Wl,--exclude-symbols,_bss_end__:_bss_start_ _:_data_end__:_data_start__"] ["-Wl,--out-implib,bin\boost\libs\date_time\build\boost_date_time.dll\mingw\ debug\boost_da te_time-mgw-d-1_32.lib"] [-g] [-shared] [-Wl,--allow-multiple-definition] [-mno-cygwin] [-o] ["bin\boost\libs\date_time\ build\boost_date_time.dll\mingw\debug\boost_date_time-mgw-d-1_32.dll"] [-L"D:/Dev-Cpp/lib"] ["bin\boost\libs\date_time\b uild\boost_date_time.dll\mingw\debug\greg_month.obj"] ["bin\boost\libs\date_time\build\boost_date_time.dll\mingw\debug\g reg_weekday.obj"] ["bin\boost\libs\date_time\build\boost_date_time.dll\mingw\debug\date_genera tors.obj"] spawn: Invalid argument On the advise of someone from gamedev.net I tried the cleaned up version of the command line myself, and it built the lib and dll ok. the cleaned up version was : D:\Dev-Cpp\bin\g++ -Wl,--enable-auto-image-base -Wl,--exclude-symbols,_bss_e nd__:_bss_start__:_data_end__:_data_start__ -Wl,--out-implib,bin\boost\libs\ date_time\build\boost_date_time.dll\mingw\debug\boost_date_time-mgw-d-1_32.l ib -g -shared -Wl,--allow-multiple-definition -mno-cygwin -o bin\boost\libs\date_time\build\boost_date_time.dll\mingw\debug\boost_date_ti me-mgw-d-1_32.dll -LD:/Dev-Cpp/lib bin\boost\libs\date_time\build\boost_date_time.dll\mingw\debug\greg_month.ob j bin\boost\libs\date_time\build\boost_date_time.dll\mingw\debug\greg_weekday. obj bin\boost\libs\date_time\build\boost_date_time.dll\mingw\debug\date_generato rs.obj So, the tools work fine, just for some reason the bjam building doesnt. Bjam has been used by me to build the VC7.1 version of the library back when the current boost version was released. So, the questionis, does anyone have any idea what I might have done wrong to cause such sillyness? The output directory of C:\boost and the "bin" directory the build makes were both deleted prior to trying to build the libraries with mingw32. For completeness the output from the g++ --version is; D:\Dev-Cpp\bin>g++ --version g++ (GCC) 3.3.1 (mingw special 20030804-1) Any tips or help would be appricated, I dont fancy having to try to link everything by hand... Cheers, Rob

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libboost_regex-vc6-sgd-1_32.lib
by Asha V.G. 06 Jan '05

06 Jan '05

Hi When I try to link the test sample, I am getting the error cannot open file "libboost_regex-vc6-sgd-1_32.lib" I am using vc6 to compile. Could any one please help in getting source compiled? Regards Asha

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RE: [Boost-users] Re: a question on boost::is_function
by Foster, Gareth 06 Jan '05

06 Jan '05

Interesting stuff, thanks all that replied. I think was just trying to related the function type to the syntax seen in other types, the fact is that the function type is a bit special I suppose, so I should really just take it by itself. I think I've seen all the possible uses for it thanks to the replies I've had here anyway. It's always interesting to see syntax from the murkier corners of the C++ repertoire :) Thanks again, Gaz -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of John Maddock Sent: 06 January 2005 10:45 To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] Re: a question on boost::is_function > Could I do ... > > int (int) * p_my_function_pointer; > > Or some other such madness? I'm reading MSDN about the indirection > operator > at the moment, maybe that will help to clear this up in my head. Can you > recommend a page on "function types". You can certainly do it via a typedef: typedef int mysig(int); mysig* p_my_function; // declares function pointer mysig myproc; // declares a function called myproc with signature mysig. John. _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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boost::intrusive_ptr and std::list::iterator
by Ernst Murnleitner 06 Jan '05

06 Jan '05

Hello Readers, I have a question regarding boost::intrusive_ptr and std::list::iterator. I have a std::list<boost::intrusive_ptr<CDataset> > which holds my datasets. My question: Is the increment counter of the intrusive_ptr incremented only by doing the following (assigning a iterator to a dataset)? (I could try myself, but I do not know what happens with other compilers/libraries) typedef List std::list<boost::intrusive_ptr<CDataset> >; List list; ... // List holds datasets ... // Get an iterator: List::iterator iter = list.begin(); // Is the Increment counter of the dataset incremented by this action? // Or does the iterator not necessarily keep a pointer to the dataset directly? It would be nice, if somebody could answer this question. In the meantime I try out, what my implementation makes (gcc, linux). Greetings Ernst

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RE: [Boost-users] Re: a question on boost::is_function
by Foster, Gareth 06 Jan '05

06 Jan '05

> boost::is_function<int(int)>::value > I know it's confusing. Most C++ programmers never see a function type > in the wild. You can use remove_pointer to turn a pointer-to-function > into a function. Could I do ... int (int) * p_my_function_pointer; Or some other such madness? I'm reading MSDN about the indirection operator at the moment, maybe that will help to clear this up in my head. Can you recommend a page on "function types". Gaz -- Dave Abrahams Boost Consulting http://www.boost-consulting.com _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Boost Logo Contest
by Joel 06 Jan '05

06 Jan '05

Hello, Boost (www.boost.org) is an open, collaborative effort that includes thousands of programmers from the C++ community at large. Boost is hoping to retire the existing logo (http://www.boost.org/boost.png) and adopt a new one. We are now launching a competition for the creation of a new logo. The competition is open to all designers, both professional and non- professional. The final design must be submitted as a scalable vector format, preferably SVG or EPS. A free, open source, scalable vector graphics editor can be found here: http://inkscape.org/. Alternative bitmap versions (small, medium and large icons, web graphics, etc.) of the logo may also be submitted to augment the main vector format. A JPEG or PNG version, to be placed in a web page, must also be submitted for judging. The Boost community will vote on submitted entries. Voting shall be based on Instant Runoff Voting (http://www.fairvote.org/irv/whatis2.htm) meaning that each individual voter shall choose 5 favorites, in order of preference. In addition to proper acknowledgement, the winning designer will receive: + the Boost Logo Designer T-shirt (printed with the winning logo design), plus, + a signed copy of the MPL book by David Abrahams and Aleksey Gurtovoy, C++ Template Metaprogramming: Concepts, Tools, and Techniques from Boost and Beyond (http://www.awprofessional.com/titles/0321227255) Entries will be accepted on or before February 15, 2005. I will act as the logo contest manager. Please email all entries to me (djowel at gmail dot com). I shall post all submitted entries to Boost's web site. The competition will close on March 1, 2005 and the winning entry will be announced soon thereafter. + The logo must be immediately identifiable with the spirit of Boost. + The logo's concept must be simple and clear and should have relevance to the organization. + The logo should not be too detailed and should work in low resolution. + Any logo submission that is blatantly racist, sexist, obscene, or otherwise discriminatory will be rejected. + The logo must be the original work of the submitter. + The logo must be free of any copyright or other intellectual property claims. + The winning logo shall be distributed under the Boost Software License, Version 1.0. (www.boost.org/LICENSE_1_0.txt) Regards, Joel de Guzman http://www.boost-consulting.com http://spirit.sf.net _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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RE: [Boost-users] status of boost::signal multi-threading support
by Frank Maddin 05 Jan '05

05 Jan '05

> If you're using a signal from two threads concurrently, you will most > likely see random crashes and other bad behavior. Signals keep a lot of > state, even when they are being invoked, so just about anything can > trip it up. > > > I am curious because, I am wondering in my ignorance, what are the > > components of the boost::signal library and how they can be > > multi-thread > > capable. This ofcourse is answered by reviewing the code. > > Ideally, a thread-safe Signals would allow you to invoke in several > threads at one, disconnect signals in several threads concurrently, > etc. > > Doug Just to make sure I understand, this is only a problem if you are using the *same* signal from two threads concurrently. This is what I've thought, but the phrase *If you're using a signal* makes me want to check. Not trying to nit-pick, just trying to make sure there isn't some situation I don't understand. Thanks, Frank

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bind (excessive?) argument copying
by Trent Hill 05 Jan '05

05 Jan '05

I was recently surprised to find that boost::bind seems to copy arguments a number of times when called. For example, this program: class C { public: C() {} C(const C &c) : data(c.data) { std::cout << "C(const C &c)\n"; } boost::array<char, 4000> data; }; void foo(const C &) {} int main(int a_argc, char **a_argv) { C c; boost::bind(&foo, c); return EXIT_SUCCESS; } results in this output (Visual C++ .NET with /O2): C(const C &c) C(const C &c) C(const C &c) C(const C &c) Four copies - I had hoped to only see a single copy. Logically, there doesn't seem to be a need for more than one copy. Is there an implementation issue that requires this many copies? I was hoping to use bind with some moderately weighted objects, however the number of copies that seem to occur may be prohibitive for me. (I realise that dynamically allocating objects and passing around pointers is an alternative but I'd rather avoid that if possible.) Any thoughts? Thanks, Trent.

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