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[Date_Time] Question about warnings.
by Seweryn Habdank-Wojewódzki 16 Nov '06

16 Nov '06

Hi! Can anyone tell me why the compilation of the program which uses Boost.Date_Time (boost ver. 1.33) displays 3 warnings: /usr/include/boost/date_time/time_facet.hpp:202: warning: unused parameter 'a_ref' /usr/include/boost/date_time/time.hpp:81: warning: unused parameter 'as_offset' /usr/include/boost/date_time/time.hpp:88: warning: unused parameter 'as_offset' I know this are just warnings, but why they appears? Are that wariables really unused? :-). Best regards. -- |\/\/| Seweryn Habdank-Wojewódzki `\/\/'

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[date_time] local_time_period between two different time zones
by Alberto Giannetti 16 Nov '06

16 Nov '06

I want to calculate the time difference between local_date_time objects that I initialized using two different time zones: #include <iostream> #include <boost/date_time/posix_time/posix_time.hpp> #include <boost/date_time/local_time/local_time.hpp> // TZ database int main(int argc, char* argv[]) { using namespace boost::posix_time; using namespace boost::local_time; tz_database tz_db; try { tz_db.load_from_file("tz.csv"); } catch( data_not_accessible& e ) { std::cerr << "Error with time zone data file: " << e.what() << std::endl; exit(EXIT_FAILURE); } catch( bad_field_count& e ) { std::cerr << "Error with time zone data file: " << e.what() << std::endl; exit(EXIT_FAILURE); } time_zone_ptr tzp_nyc = tz_db.time_zone_from_region("America/New_York"); time_zone_ptr tzp_rome = tz_db.time_zone_from_region("Europe/Rome"); local_date_time nyc_time(second_clock::universal_time(), tzp_nyc); std::cout << "Current time in NY is " << to_simple_string(nyc_time.local_time()) << std::endl; local_date_time rome_time(second_clock::universal_time(), tzp_rome); std::cout << "Current time in Rome is " << to_simple_string(rome_time.local_time()) << std::endl; local_time_period tdiff(nyc_time, rome_time); std::cout << "Difference between time zones: " << tdiff.length() << std::endl; return 0; } tdiff.lenth() returns 00:00:00. Why the function can't return the difference between the two local times? ____________________________________________________________________________________ Sponsored Link $420k for $1,399/mo. Think You Pay Too Much For Your Mortgage? Find Out! www.LowerMyBills.com/lre

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Re: [Boost-users] [Serialization] a coupla crashes from hiearchy complexity
by Reusser, Edward 16 Nov '06

16 Nov '06

Robert, The 1/2 megabyte string being converted is pure XML generated by the xml_oarchive and read in using xml_iarchive in the boost serialization library. It is being inserted as a single tag of an XML item serialized entirely by the xml_oarchive and xml_iarchive in the boost serialization library. I believe that there are only 5 characters that need to be converted: less than (<), greater than (>), quote ("), apostrophe ('), and ampersand (&). Changing a block of text containing these characters to their corresponding escape sequences doesn't seem very difficult to me. It is being done completely automatically by the serialization library. Our current solution, which uses a text archive on the front end and stores the internal strings as xml seems to work for now and completely avoids this conversion. I just wanted to let you know that the conversion routine in the boost serialization library doesn't work for large buffers. I had to laugh at your response at sending this library to you. That certainly wouldn't have been MY first choice, but I did want to make the offer. Ed -----Original Message----- From: Robert Ramey [mailto:ramey@rrsd.com] Sent: Wednesday, November 15, 2006 8:33 PM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] [Serialization] acouplacrashesfromhiearchycomplexity "Reusser, Edward" <Edward.Reusser(a)actel.com> wrote in message news:5E916BAE1732F344BAFD713DF2373479016EAAA9@SV-MSG-01.amer.actel.com... Robert, But the same exact problem occurs. Even using boost serialization, a text value within 2 tags cannot exceed about ½ megabyte in length if it contains escaped character sequences, because when it is read back it will not be properly converted to XML. I know the entire XML string is being translated out to the file because I can open the file and see that it is correct. Furthermore, the serialization library doesn't report any errors in reading the key/value pairs. It isn't until I parse the value using the xml_iarchive that it fails. **** I suspect that both serialization and xerces are having the same problem. The problem is that standards for xml/html escape sequences are ambiguous. and not correctly escaped. This occurs when the string includes non-string charactes like null, and who knows what else. Its probably not a hard fix - but would take alot of time to sort the all the varying standardese. If anyone want's todo this let me know. If your doing 1/2 mb of string - its possible it contains some wierd characters that neither xerces nor I know what to do with. So a couple of things to try would be: a) try xml_wachive - this stores data in UTF-8 and might be more robust. b) try stroign the string as a "binary object". This would consume more spaces as it stores the data in binary coded text - but should be bullit proof. c) If you really, really need this, and you want to do your bit for humanity, you can checkout the xml escape/unescape that the serialization library uses. This is a little out of whack as it uses one method - dataflow iterators to escape, and another - spirit parser to unescape. Maybe that should be changed or at lease looked at. When in doubt - I prefer symmetry as should be apparent from the naming conventions used by the serialization library. As for the 2nd crash, using text_iarchive and text_oarchive within Library B, this still gives the internal structure overflow error. When I get time to go back and look at it again, I will probably rewrite it so that all of the shared_ptr's are stored directly and make other simplifications. If you have a mechanism for me to send this DLL directly to you, then I will attempt to get permission to do so. *** Errrr - thanks but no thanks. I woud prefer to run this via through you. Robert Ramey The information contained in or attached to this email may be subject to the Export Administration Regulations (EAR), administered by the U.S. Department of Commerce, or the International Traffic in Arms Regulations (ITAR), administered by the U.S. Department of State, and may require an export license from the Commerce or State Department prior to its export. An export can include a release or disclosure to a foreign national inside or outside the United States. Include this notice with any reproduced portion of this information.

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Re: [Boost-users] BGL: Bundled Properties in subgraphs
by RIVASSEAU Jean Noel 16 Nov '06

16 Nov '06

Hi there, I also remember that I was the first to discover/report this problem, while I was using the BGL a while ago, but I can confirm it has long been fixed. (I made extensive use of bundled properties in subgraph, so it had to work). Jean-Noël -----Message d'origine----- De : boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] De la part de Doug Gregor Envoyé : jeudi 16 novembre 2006 16:07 À : boost-users(a)lists.boost.org Objet : Re: [Boost-users] BGL: Bundled Properties in subgraphs On Nov 13, 2006, at 5:18 PM, Greg Reynolds wrote: > I am trying to use the subgraph class with bundled propeties and > wonder if it is still broken? I found a message on the list saying > that it was broken in March 2005, but would probably be fixed shortly. It should have been fixed in April, 2005. > I include my code below. It compiles cleanly if I don't use subgraph, > i.e. > just declare the adjacency_list. The error I'm seeing is coming from the lack of an edge_index property for the edges. If one adds that edge_index property, subgraph should work. > It also works if use the internal > properties method. Really? I can't get it to compile with internal properties (until I add an edge_index property). Cheers, Doug _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Windows Implementation
by alabi＠thaerocomp.com 16 Nov '06

16 Nov '06

Dear Users, I have downloaded and successfully installed (with bjam) Boost for Visual Studio.NET vc7. I have a rogram using boost with the line: #include <BOOST\path_to_header> The compiler does not find the header. Does nayone know how to make the compiler recognize the boost location so I can place it in angluar bracket as above. If I copied all the BOOST into my subfolder, things work but I dont want to make a copy of BOOST in every project. Ken. ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.

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Re: [Boost-users] Using assign::map_list_of for complex types
by Hughes, James 16 Nov '06

16 Nov '06

Clip.. > >>{ } > >> > > > > > > I did something along these lines but still got a load of compile > > faults. Will post a more accurate code snippet when time > allows, but > > have a deadline end of today!! > > You also need to call the constructor when you call map_list_of(): > > map_list_of(1, data( "hello", list_of(3)(4)(4) ) ); > > -Thorsten > ____ Thanks Thorsten, that did the trick. I had actually tried something along those line when trying to figure it out myself, but didn't know how to handle the range stuff you put in your example. Thanks again. As a sort of aside, this example would make a good addition to the documentation, for those coming to C++ from C where this sort of nested structure initialisation is common (well, in my world it is!). James ___________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users > This message (including any attachments) contains confidential and/or proprietary information intended only for the addressee. Any unauthorized disclosure, copying, distribution or reliance on the contents of this information is strictly prohibited and may constitute a violation of law. If you are not the intended recipient, please notify the sender immediately by responding to this e-mail, and delete the message from your system. If you have any questions about this e-mail please notify the sender immediately.

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Re: [Boost-users] Using assign::map_list_of for complex types
by Hughes, James 16 Nov '06

16 Nov '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of > Thorsten Ottosen > Sent: 15 November 2006 12:00 > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Using assign::map_list_of for complex types > > Hughes, James wrote: > > Hello all, > > > > I've been trying to create an initiliser for the following > > (paraphrased) > > > > struct data > > { > > Char *str; > > const char*? Typo when copying from Linux box to email box - soz! > > > Vector<int> stuff; > > }; > > > > > > map<int, struct data> mapstuff = map_list_of (1, ("hello", > list_of (3) > > (4) (2)), (3, ("goodbye", list_of (1) (3) ); > > > > Etc etc > > > > However, this doesn't work, with a very complex compile error from > > assign. I've tried also... > > > > map<int, struct data> mapstuff = map_list_of > > (1, {"hello", list_of (3) (4) (2) } ), // note curly braces > > (3, {"goodbye", list_of (1) (3) ) } ); > > > > But that doesn't work either. > > > > Is it actually possible to do something like this, and if so, how? > > I suspect that you have to provide a constructor for your data class: > > template< class Range > > data( const char* str, const Range& r ) > : str(str), stuff(boost::begin(r),boost::end(r)) > { } > I did something along these lines but still got a load of compile faults. Will post a more accurate code snippet when time allows, but have a deadline end of today!! > -Thorsten > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users > This message (including any attachments) contains confidential and/or proprietary information intended only for the addressee. Any unauthorized disclosure, copying, distribution or reliance on the contents of this information is strictly prohibited and may constitute a violation of law. If you are not the intended recipient, please notify the sender immediately by responding to this e-mail, and delete the message from your system. If you have any questions about this e-mail please notify the sender immediately.

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Re: [Boost-users] [Serialization] a couplacrashesfromhiearchycomplexity
by Reusser, Edward 16 Nov '06

16 Nov '06

Robert, I reported 2 crashes. As far as the runtime crash is concerned I have performed further analysis and come up with the following conclusions: A complication that I didn't mention seems to be the source of the runtime crash. I have 2 separate DLL libraries, call them Library A, and library B. Inside of A, I have what is essentially a list of key/value pairs. Initially I serialized this data in and out to a file using xerces (someone else did this part). Later, Library B comes along and asks for a value using a key (the value is just a string). This library then uses the boost serialization library (xml_iarchive) to convert it to classes. When I want to persist the state of Lbrary B, I then convert the class structures back to a string using xml_oarchive and store it in the master key/value map of Library A. The difficulty arises because the string I am saving and retrieving is somewhat large, sometimes over a megabyte in length. When the xerces library gets this,. It converts all of the '<' and '> characters into escape sequences like &lt and &gt. So far so good. Except there is a bug in the translation so that any string larger than about ½ megabyte do not get properly converted from XML text into the corresponding string. Thus, the string I am feeding into the boost serialization library is not proper XML because it has been only partially escaped. So we redid the serialization in the first library to serialize the key/value pairs using boost serialization instead of xerces, completely discarding this library. But the same exact problem occurs. Even using boost serialization, a text value within 2 tags cannot exceed about ½ megabyte in length if it contains escaped character sequences, because when it is read back it will not be properly converted to XML. I know the entire XML string is being translated out to the file because I can open the file and see that it is correct. Furthermore, the serialization library doesn't report any errors in reading the key/value pairs. It isn't until I parse the value using the xml_iarchive that it fails. We solved this problem using text_iarchive and text_oarchive for the key/value map of Library A, preventing the XML in Library B from being touched. As for the 2nd crash, using text_iarchive and text_oarchive within Library B, this still gives the internal structure overflow error. When I get time to go back and look at it again, I will probably rewrite it so that all of the shared_ptr's are stored directly and make other simplifications. If you have a mechanism for me to send this DLL directly to you, then I will attempt to get permission to do so. Ed ________________________________ From: Robert Ramey [mailto:ramey@rrsd.com] Sent: Monday, November 13, 2006 2:22 PM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] [Serialization] a couplacrashesfromhiearchycomplexity it would seem to me that a stack trace would be interesting to see. I'm wondering if its just a stack that is too short (I would have expected to see this sooner if it was) or some error somewhere which creates an unterminated recurssion. With VC its easy to see the stack trace. With the Gnu Debuger, one has to back trace from the right point. Robert Ramey "Reusser, Edward" <Edward.Reusser(a)actel.com> wrote in message news:5E916BAE1732F344BAFD713DF2373479016EA233@SV-MSG-01.amer.actel.com... Robert, I would need permission to send you the exact library code. I am reluctant to do this primarily because recreating my exact build environment would be a hassle (we are using gnumake on the PC). I also would need to do this directly to you, as I could not post this code into a public forum. Having said that, any recursive descent parser has complexity limits based on stack size. It would be pretty easy to create test cases that probe these complexity limits for the various archive types. I would like to see how much (approximately) stack space is allocated in the runtime for each level of xml hierarchy, and also for the text archives. The main complexity seems to be because I am using shared_ptr's extensively at all levels of the hierarchy. Thus, I have 2 levels nested for each class, the <px> data </px> and the actual data, which is in turn being represented by a collection of shared_ptr's, etc. I am also using std::map of shared pointers, and std::set of shared_ptr's. I also use enable_shared_from_this<T> for my base classes, then statically cast the resultant shared pointers internally for the derived classes. This is to get around a Linux problem which I can describe more fully if you like (would take a few pages of explanation). So for example: class Base : public boost:enable_shared_from_this<Base> { virtual boost::shared_ptr<Base> GetSharedFromThis() { return shared_from_this(); } }; class Derived1 : public Base { public: virtual boost::shared_ptr<Derived1> GetSharedFromThis() { return static_pointer_cast<Derived1>( shared_from_this() ); } }; class Derived2 : public Base { public: virtual boost::shared_ptr<Derived2> GetSharedFromThis() { return static_pointer_cast<Derived2>( shared_from_this() ); } }; I am assuming that I do not need to call boost::serialization::base_object<boost::enable_shared_from_this<Base> >( *this ); When I serialize the base class. Could that be the problem? I think what I am going to do is go back into the program and simply eliminate all of the shared_ptr serializations. I can serialize to raw pointers, and then just create the shared_ptr's from those pointers explicitly in my case. I simply do not ever have any shared_ptr's with multiple reference counts to worry about. I will let you know what happens. ________________________________ From: Robert Ramey [mailto:ramey@rrsd.com] Sent: Monday, November 13, 2006 8:30 AM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] [Serialization] a coupla crashes fromhiearchycomplexity I would be curious to see your particular case. The fact that different archives give problems that seem related to nesting depth suggest along with the fact that this hasn't been reported suggests that there is some sort of use case or error which hasn't been considered. Robert Ramey "Reusser, Edward" <Edward.Reusser(a)actel.com> wrote in message news:5E916BAE1732F344BAFD713DF2373479016EA059@SV-MSG-01.amer.actel.com... I am using the serialization library in boost 1.33.1. I am compiling on windows using the VC 7.1 compiler. The problem I am having is that when I use xml_iarchive and xml_oarchive, everything works just fine for simple cases, but if the xml gets very deep ( same exact class hierarchy, just more data organized a little more complexly) I am getting runtime stack overflow crashes in the spirit parser. I figured I could solve that by simply substituting text_iarchive and text_oarchive. Please note that I am simply substituting in these archive types instead of using the xml archive headers, which work. There are no other code changes anywhere. Now I am getting the following compiler error: \boost\mpl\eval_if.hpp(40) : fatal error C1204: compiler limit : internal structure overflow Any suggestions? I can try increasing the stack size of my current application to eliminate the xml runtime stack overflow problem, but I am uneasy doing this until I understand how to calculate the stack sizes required, and why it is happening. Furthermore, I would prefer using the text archives, since the data is more compact than the xml ones. Ed Reusser Principal Software Engineer Actel Corporation (408) 318-4972 ________________________________ The information contained in or attached to this email may be subject to the Export Administration Regulations (EAR), administered by the U.S. Department of Commerce, or the International Traffic in Arms Regulations (ITAR), administered by the U.S. Department of State, and may require an export license from the Commerce or State Department prior to its export. An export can include a release or disclosure to a foreign national inside or outside the United States. Include this notice with any reproduced portion of this information. ________________________________ _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users ________________________________ The information contained in or attached to this email may be subject to the Export Administration Regulations (EAR), administered by the U.S. Department of Commerce, or the International Traffic in Arms Regulations (ITAR), administered by the U.S. Department of State, and may require an export license from the Commerce or State Department prior to its export. An export can include a release or disclosure to a foreign national inside or outside the United States. Include this notice with any reproduced portion of this information. ________________________________ _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users The information contained in or attached to this email may be subject to the Export Administration Regulations (EAR), administered by the U.S. Department of Commerce, or the International Traffic in Arms Regulations (ITAR), administered by the U.S. Department of State, and may require an export license from the Commerce or State Department prior to its export. An export can include a release or disclosure to a foreign national inside or outside the United States. Include this notice with any reproduced portion of this information.

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Best practices for boost:signal
by Memfis 15 Nov '06

15 Nov '06

What is the best practice for using boost::signal? Should the signal be a public field? Should an accessor method be used? Should there be some special connection methods for every signal, like the following: private: signal<void()> x; public: void connectX(const signal<void()>::slot_type& slot); void disconnectX(const signal<void()>::slot_type& slot); If you use boost:signal, how do you do it? (Okay, actually connectX should return a connection object and disconnectX should take the it as its parameter, but it's about the general idea) -- Memfis

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[mpl::map] Still problems with map
by Ovanes Markarian 15 Nov '06

15 Nov '06

Ji Dave, Hi Alexey, It seems that at least macro definition for the map of 150 tuples worked. Now I face a new problem. To reduce compilation times we decided to use map10, map20 etc. Unfortunately as we found out this will not compile if I pass to map10 only 7 arguments. With unnumbered map these elements were default initialized with "na" type. Why isn't this the case with numbered maps? I get the following g++ errors: /path/fname.hpp:5945: error: wrong number of template arguments (4, should be 10) /user/some_uname/projects/libs/boost/include/boost/mpl/map/aux_/preprocessed/typeof_based/map10.hpp:141: error: provided for `template<class P0, class P1, class P2, class P3, class P4, class P5, class P6, class P7, class P8, class P9> struct boost::mpl::map10' I assume that the macro generation was successful if I receive the error: /path/fname.hpp:11036: error: wrong number of template arguments (71, should be 150) /user/some_uname/projects/libs/boost/include/boost/mpl/map/aux_/numbered.hpp:41: error: provided for `template<class P0, class P1, class P2, class P3, class P4, class P5, class P6, class P7, class P8, class P9, class P10, class P11, class P12, class P13, class P14, class P15, class P16, class P17, class P18, class P19, class P20, class P21, class P22, class P23, class P24, class P25, class P26, class P27, class P28, class P29, class P30, class P31, class P32, class P33, class P34, class P35, class P36, class P37, class P38, class P39, class P40, class P41, class P42, class P43, class P44, class P45, class P46, class P47, class P48, class P49, class P50, class P51, class P52, class P53, class P54, class P55, class P56, class P57, class P58, class P59, class P60, class P61, class P62, class P63, class P64, class P65, class P66, class P67, class P68, class P69, class P70, class P71, class P72, class P73, class P74, class P75, class P76, class P77, class P78, class P79, class P80, class P81, class P82, class P83, class P84, class P85, class P86, class P87, class P88, class P89, class P90, class P91, class P92, class P93, class P94, class P95, class P96, class P97, class P98, class P99, class P100, class P101, class P102, class P103, class P104, class P105, class P106, class P107, class P108, class P109, class P110, class P111, class P112, class P113, class P114, class P115, class P116, class P117, class P118, class P119, class P120, class P121, class P122, class P123, class P124, class P125, class P126, class P127, class P128, class P129, class P130, class P131, class P132, class P133, class P134, class P135, class P136, class P137, class P138, class P139, class P140, class P141, class P142, class P143, class P144, class P145, class P146, class P147, class P148, class P149> struct boost::mpl::map150' Many thanks for your kind help. With Kind Regards, Ovanes Markarian

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[boost-users][fusion] tuple + io question
by David Klein 15 Nov '06

15 Nov '06

Hi, Is there a reason why fusion/tuple/tuple.hpp includes fusion/sequence/io.hpp? The "normal" boost::tuple, is split into tuple/tuple.hpp and tuple/tuple_io.hpp. I have the problem that just including *stream headers, make my program crash before main, because they rely on static variables that dynamically allocate memory, which isn't available before main. I fixed this for me by commenting out the include line, and now i'm only just wondering why this differs to boost::tuples? -- regards, dave

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[Boost.MultiArray] So many warnings
by Evgeny Yashin 15 Nov '06

15 Nov '06

Hi guys. Just started to use library, and.. #include "boost/multi_array.hpp" void f() { boost::multi_array<int, 2> arr; arr.resize( boost::extents[2][2] ); } Why so many warnings (5 warnings)?? warning C4267: '=' : conversion from 'size_t' to 'boost::const_multi_array_ref<T,NumDims,TPtr>::index', possible loss of data .... Can it be fixed?

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Using assign::map_list_of for complex types
by Hughes, James 15 Nov '06

15 Nov '06

Hello all, I've been trying to create an initiliser for the following (paraphrased) struct data { Char *str; Vector<int> stuff; }; map<int, struct data> mapstuff = map_list_of (1, ("hello", list_of (3) (4) (2)), (3, ("goodbye", list_of (1) (3) ); Etc etc However, this doesn't work, with a very complex compile error from assign. I've tried also... map<int, struct data> mapstuff = map_list_of (1, {"hello", list_of (3) (4) (2) } ), // note curly braces (3, {"goodbye", list_of (1) (3) ) } ); But that doesn't work either. Is it actually possible to do something like this, and if so, how? James This message (including any attachments) contains confidential and/or proprietary information intended only for the addressee. Any unauthorized disclosure, copying, distribution or reliance on the contents of this information is strictly prohibited and may constitute a violation of law. If you are not the intended recipient, please notify the sender immediately by responding to this e-mail, and delete the message from your system. If you have any questions about this e-mail please notify the sender immediately.

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Errors compiling Boost.Python library on Solaris
by chris botos 15 Nov '06

15 Nov '06

Hi, I'm new to this list and to Boost. I'm interested in using Boost to wrap C++ objects in Python. The environment is Solaris 10, x86. I did the following: Downloaded boost_1_33_1.tar and extracted it to /opt/boost. >setenv PYTHON_ROOT /usr/local > cd to /opt/boost/boost_1_33_1/libs/python/build > bjam I get lots of error messages, repeated throughout the compile and tend to be grouped and refer to the same line: '->' cannot appear in a constant-expression '&' cannot appear in a constant-expression template argument 1 is invalid value is not a member of '<declaration errors>' ...failed gcc-C++-action ... is also associated with the above If I "bjam" from /opt/boost/boost_1_33_1, I get the same errors when it gets to the python library. I would most appreciate any help with this! Regards, Chris Botos

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comparing map's key and sorted vector
by Maitre Bart 15 Nov '06

15 Nov '06

Suppose I have a map (m) and a sorted vector of strings (v). The map's key is a string, and the map's value is foobar. I wish to compare map's keys with the vector's values and detect if they all match: (*mit).first == *vit and wish to do it with STL/Boost algo and functors. So I am starting with this: equal(m.begin(), m.end(), v.begin(), boost::bind(std::equa_to<string>(), std::select1st<std::pair<string,foobar> >(_1), _2)); I know 2 parameters are past to bind: *mit and *vit . However, before the equality, I want to extract the key from the map iterator (i.e. (*mit).first) before the comparison. That is this part I have difficulty to concretise. Btw, is there any equivalent to select1st (SGI extension) in Boost? Does anyone have any idea? I must be close to the solution...

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[OT] Strange Subject Line Problem with this Mailing List
by Wu Yinghui, Freddie 14 Nov '06

14 Nov '06

Hi all, Sorry for this post, as it is not related to Boost, but to this mailing list instead. I've been seeing subject lines in a mess for "Re:" posts as illustrated below: ==== snip ==== > Today's Topics: > > 1. BGL: Bundled Properties in subgraphs (Greg Reynolds) > 2. Re: [Serialization] a couplacrashesfromhiearchycomplexity > (Reusser, Edward) ==== snip ==== As seen above, the subject line of the second post was unreadable to me without spending a fair amount of efforts. Has anyone checked out what was the cause of this problem yet? Cheers, Freddie -- Wu Yinghui, Freddie Research & Development Senior Software Engineer Volume Interactions Pte Ltd 1 Kim Seng Promenade, #12-01 Great World City East Tower Singapore 237994 Tel: +65 62226962 (Ext 216) Fax: +65 62226215 Email: yhwu(a)volumeinteractions.com URL: http://www.volumeinteractions.com Important: This message is intended for the recipient(s) addressed above. It contains privileged and confidential information. If you are not the intended recipient, please notify the sender immediately by replying to this message and then delete it from your system. You must not read, copy, use, or disseminate this communication in any form. Thank you.

2 1

[serialization] Richer "tagged" fields and polymorphic archive types
by Caleb Epstein 14 Nov '06

14 Nov '06

Robert, First let me start off by thanking you for the excellent Boost Serialization library. I'm planning to use it as part of a new system I'm building at my place of work as a more flexible replacement for Rogue Wave's "saveGuts/restoreGuts". I've been able to implement my own archive types without too much of a struggle, and have been overall very impressed with the functionality of the library and its documentation. Now some background and then on to the questions :) I'm not sure if you are familiar with TIBCO's "Rendezvous" messaging middleware product (http://tibco.com/) or with the FIX protocol (http://fixprotocol.org/) but these are both commonly used in financial services applications. Rendezvous as a messaging transport and FIX as a general message convention and data dictionary. FIX also specifies a "session" layer used for communication, but thats out of scope here. Both Rendezvous (RV) and FIX support the concept of numeric field identifiers in their messages. In FIX, serialized messages look like TAG=VALUE\x01TAG=VALUE\x01... where TAG is an integer field ID and VALUE is the value associated with that tag and \x01 is an ASCII SOH character. In RV messages, fields may be given a name and/or an integer field ID. So it is pretty straightforward to represent a FIX message as an RV message (or vice-versa) if you always use these numeric IDs. Also, these "tagged" message formats facilitate interchange of data between different systems because they do not place stringent requirements on field ordering or even field presence in some cases. In the system I'm working on, the fundamental object types can all be mapped more or less directly to messages in the FIX specification. OK, so now onto the meat of the question. What I'd like to use in this application is something akin to NVP serialization for my objects, but which I'll call FIELD serialization. Every member of an object can be associated with a FIELD ID which would contain both a name and an integer ID (e.g. "Price" and 44). The universe of field IDs is more or less static and well-known. To this end I've created two utility classes called field_id and field. The field_id class is a std::pair<int, const char*> and the template field class is a std::pair<const field_id*, T*> not unlike the nvp class. It provides methods to get the field's name, id, and value. There is also a template utility function "make_field(const field_id&, T&)" that creates a field object in the same way "make_nvp" creates an nvp. I have implemented a "tibco_oarchive" that provides a template "save_override(const field<T>&, int)" method, and this works fine if I am using template<typename Archive> serialization methods with my archive definition in scope, and if I write my serialization code using "make_field" instead of "make_nvp". But this, naturally, does *not* work if I try to use polymorphic archives, since the base classes here do not know anything about my "field" template, only "nvp". Additionally, my template-based serialization code will fail to compile with archive types that don't provide "save_override"s for my "field" template, which is all of the "standard" archive classes. What I'd like is to figure out some way to implement this tagged-field serialization scheme in a way that would be compatible with the polymorphic archive interface and that would (ideally) still compile with the existing archive implementations that don't know about my "field" class. This latter requirement is less important. The reason I'm leaning toward the polymorphic archive interface is that I'm sure we will need to adopt new wire-formats and middleware interfaces in the future. Keeping all the object serialization code in a library that doesn't require recompilation will make this process very easy. So, do you think you could offer any suggestions on how I might go about achieving this? Let me know if you need more information or clarification, and thanks for your help. -- Caleb Epstein

2 1

Sequence of Types, What For?
by Terry G 14 Nov '06

14 Nov '06

I've just finished reading C++ Template Metaprogramming again. I just don't get it. Why would someone use a type container? I have used enable_if, along with some of the logic functions for managing an overload set. Otherwise, I'm clueless. I'd really like a reference to an MPL primer or some case studies. Too much pain with very little gain. Time to ask for help. Rereading this, it sounds negative. Really, I think the MPL is really cool! terry

13 30

Re: [Boost-users] Serialization problem on 64-bit Windows release
by Sergey Filippov 14 Nov '06

14 Nov '06

Robert Ramey <ramey <at> rrsd.com> writes: > This doesn't seem to be the case in your situation. Anyway, thank you for the information. I'll keep trying to reproduce an issue in test lab. Sergey

2 2

Minor ublas issue
by Daniel Krügler 14 Nov '06

14 Nov '06

Hello, I stumbled about the current cvs HEAD version of exception.hpp, where I found one remaining throw under *_NO_EXCEPTIONS conditions in "singular". Here the proposed fix: Index: exception.hpp =================================================================== RCS file: /cvsroot/boost/boost/boost/numeric/ublas/exception.hpp,v retrieving revision 1.19 diff -u -r1.19 exception.hpp --- exception.hpp 2 Feb 2006 19:27:23 -0000 1.19 +++ exception.hpp 13 Nov 2006 18:54:27 -0000 @@ -175,7 +175,6 @@ explicit singular (const char *) {} void raise () { - throw *this; std::abort (); } #endif I also would like to recommend, that the current exception text of struct non_real should be changed as follows (The prefix "exception:" seems redundant): Index: exception.hpp =================================================================== RCS file: /cvsroot/boost/boost/boost/numeric/ublas/exception.hpp,v retrieving revision 1.19 diff -u -r1.19 exception.hpp --- exception.hpp 2 Feb 2006 19:27:23 -0000 1.19 +++ exception.hpp 13 Nov 2006 19:01:45 -0000 @@ -185,7 +185,7 @@ #if ! defined (BOOST_NO_EXCEPTIONS) && ! defined (BOOST_UBLAS_NO_EXCEPTIONS) // Inherit from standard exceptions as requested during review. : public std::domain_error { - explicit non_real (const char *s = "exception: non real") : + explicit non_real (const char *s = "non real") : std::domain_error (s) {} void raise () { throw *this; Greetings from Bremen, Daniel Krügler

1 0

BJam can't find arguments to gcc-spawn
by Charles Broderick 14 Nov '06

14 Nov '06

I am having problems running even a basic Jamfile consisting only of: Main : main.c ; When running bjam with debugging on, I receive this output (truncated). I looked at allyourbase.jam and gcc-tools.jam, and it looks like OK jam code to me... why won't main.c get passed in as the target? /local/apps/boost/1.33.1/tools/build/v1/allyourbase.jam:1136:>>>>|>>>>|>> switch .c /local/apps/boost/1.33.1/tools/build/v1/allyourbase.jam:1139:>>>>|>>>>|>> Cc : main.c /local/apps/boost/1.33.1/tools/build/v1/allyourbase.jam:624:>>>>|>>>>|>>>> DEPENDS : main.c /local/apps/boost/1.33.1/tools/build/v1/allyourbase.jam:626:>>>>|>>>>|>>>> Cc-platform-specifics : main.c /local/apps/boost/1.33.1/tools/build/v1/allyourbase.jam:593:>>>>|>>>>|>>>>|> local _h = /local/apps/boost/1.33.1/tools/build/v1/allyourbase.jam:634:>>>>|>>>>|>>>> Cc-action : main.c /local/apps/boost/1.33.1/tools/build/v1/gcc-tools.jam:489:>>>>|>>>>|>>>>|> gcc-spawn /local/apps/boost/1.33.1/tools/build/v1/gcc-tools.jam:489: in Cc-action *** argument error * rule gcc-spawn ( targets + ) * called with: ( ) * missing argument targets /local/apps/boost/1.33.1/tools/build/v1/gcc-tools.jam:402:see definition of rule 'gcc-spawn' being called /local/apps/boost/1.33.1/tools/build/v1/allyourbase.jam:634: in Cc /local/apps/boost/1.33.1/tools/build/v1/allyourbase.jam:1139: in Object /local/apps/boost/1.33.1/tools/build/v1/allyourbase.jam:1207: in Objects /local/apps/boost/1.33.1/tools/build/v1/allyourbase.jam:969: in Main Jamfile:2: in load-jamfiles /local/apps/boost/1.33.1/tools/build/v1/bootstrap.jam:21: in boost-build /local/apps/boost/1.33.1//boost-build.jam:16: in module scope

2 1

Re: [Boost-users] [Serialization] a couplacrashesfromhiearchycomplexity
by Reusser, Edward 13 Nov '06

13 Nov '06

Robert, After more analysis, I am getting evidence that this error might be on my end (something seems to corrupt the XML text itself). More to follow... Ed ________________________________ From: Robert Ramey [mailto:ramey@rrsd.com] Sent: Monday, November 13, 2006 2:22 PM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] [Serialization] a couplacrashesfromhiearchycomplexity it would seem to me that a stack trace would be interesting to see. I'm wondering if its just a stack that is too short (I would have expected to see this sooner if it was) or some error somewhere which creates an unterminated recurssion. With VC its easy to see the stack trace. With the Gnu Debuger, one has to back trace from the right point. Robert Ramey "Reusser, Edward" <Edward.Reusser(a)actel.com> wrote in message news:5E916BAE1732F344BAFD713DF2373479016EA233@SV-MSG-01.amer.actel.com.. . Robert, I would need permission to send you the exact library code. I am reluctant to do this primarily because recreating my exact build environment would be a hassle (we are using gnumake on the PC). I also would need to do this directly to you, as I could not post this code into a public forum. Having said that, any recursive descent parser has complexity limits based on stack size. It would be pretty easy to create test cases that probe these complexity limits for the various archive types. I would like to see how much (approximately) stack space is allocated in the runtime for each level of xml hierarchy, and also for the text archives. The main complexity seems to be because I am using shared_ptr's extensively at all levels of the hierarchy. Thus, I have 2 levels nested for each class, the <px> data </px> and the actual data, which is in turn being represented by a collection of shared_ptr's, etc. I am also using std::map of shared pointers, and std::set of shared_ptr's. I also use enable_shared_from_this<T> for my base classes, then statically cast the resultant shared pointers internally for the derived classes. This is to get around a Linux problem which I can describe more fully if you like (would take a few pages of explanation). So for example: class Base : public boost:enable_shared_from_this<Base> { virtual boost::shared_ptr<Base> GetSharedFromThis() { return shared_from_this(); } }; class Derived1 : public Base { public: virtual boost::shared_ptr<Derived1> GetSharedFromThis() { return static_pointer_cast<Derived1>( shared_from_this() ); } }; class Derived2 : public Base { public: virtual boost::shared_ptr<Derived2> GetSharedFromThis() { return static_pointer_cast<Derived2>( shared_from_this() ); } }; I am assuming that I do not need to call boost::serialization::base_object<boost::enable_shared_from_this<Base> >( *this ); When I serialize the base class. Could that be the problem? I think what I am going to do is go back into the program and simply eliminate all of the shared_ptr serializations. I can serialize to raw pointers, and then just create the shared_ptr's from those pointers explicitly in my case. I simply do not ever have any shared_ptr's with multiple reference counts to worry about. I will let you know what happens. ________________________________ From: Robert Ramey [mailto:ramey@rrsd.com] Sent: Monday, November 13, 2006 8:30 AM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] [Serialization] a coupla crashes fromhiearchycomplexity I would be curious to see your particular case. The fact that different archives give problems that seem related to nesting depth suggest along with the fact that this hasn't been reported suggests that there is some sort of use case or error which hasn't been considered. Robert Ramey "Reusser, Edward" <Edward.Reusser(a)actel.com> wrote in message news:5E916BAE1732F344BAFD713DF2373479016EA059@SV-MSG-01.amer.actel.com.. . I am using the serialization library in boost 1.33.1. I am compiling on windows using the VC 7.1 compiler. The problem I am having is that when I use xml_iarchive and xml_oarchive, everything works just fine for simple cases, but if the xml gets very deep ( same exact class hierarchy, just more data organized a little more complexly) I am getting runtime stack overflow crashes in the spirit parser. I figured I could solve that by simply substituting text_iarchive and text_oarchive. Please note that I am simply substituting in these archive types instead of using the xml archive headers, which work. There are no other code changes anywhere. Now I am getting the following compiler error: \boost\mpl\eval_if.hpp(40) : fatal error C1204: compiler limit : internal structure overflow Any suggestions? I can try increasing the stack size of my current application to eliminate the xml runtime stack overflow problem, but I am uneasy doing this until I understand how to calculate the stack sizes required, and why it is happening. Furthermore, I would prefer using the text archives, since the data is more compact than the xml ones. Ed Reusser Principal Software Engineer Actel Corporation (408) 318-4972 ________________________________ The information contained in or attached to this email may be subject to the Export Administration Regulations (EAR), administered by the U.S. Department of Commerce, or the International Traffic in Arms Regulations (ITAR), administered by the U.S. Department of State, and may require an export license from the Commerce or State Department prior to its export. An export can include a release or disclosure to a foreign national inside or outside the United States. Include this notice with any reproduced portion of this information. ________________________________ _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users ________________________________ The information contained in or attached to this email may be subject to the Export Administration Regulations (EAR), administered by the U.S. Department of Commerce, or the International Traffic in Arms Regulations (ITAR), administered by the U.S. Department of State, and may require an export license from the Commerce or State Department prior to its export. An export can include a release or disclosure to a foreign national inside or outside the United States. Include this notice with any reproduced portion of this information. ________________________________ _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users The information contained in or attached to this email may be subject to the Export Administration Regulations (EAR), administered by the U.S. Department of Commerce, or the International Traffic in Arms Regulations (ITAR), administered by the U.S. Department of State, and may require an export license from the Commerce or State Department prior to its export. An export can include a release or disclosure to a foreign national inside or outside the United States. Include this notice with any reproduced portion of this information.

1 0

Re: [Boost-users] [Serialization] a coupla crashes fromhiearchycomplexity
by Reusser, Edward 13 Nov '06

13 Nov '06

Robert, I would need permission to send you the exact library code. I am reluctant to do this primarily because recreating my exact build environment would be a hassle (we are using gnumake on the PC). I also would need to do this directly to you, as I could not post this code into a public forum. Having said that, any recursive descent parser has complexity limits based on stack size. It would be pretty easy to create test cases that probe these complexity limits for the various archive types. I would like to see how much (approximately) stack space is allocated in the runtime for each level of xml hierarchy, and also for the text archives. The main complexity seems to be because I am using shared_ptr's extensively at all levels of the hierarchy. Thus, I have 2 levels nested for each class, the <px> data </px> and the actual data, which is in turn being represented by a collection of shared_ptr's, etc. I am also using std::map of shared pointers, and std::set of shared_ptr's. I also use enable_shared_from_this<T> for my base classes, then statically cast the resultant shared pointers internally for the derived classes. This is to get around a Linux problem which I can describe more fully if you like (would take a few pages of explanation). So for example: class Base : public boost:enable_shared_from_this<Base> { virtual boost::shared_ptr<Base> GetSharedFromThis() { return shared_from_this(); } }; class Derived1 : public Base { public: virtual boost::shared_ptr<Derived1> GetSharedFromThis() { return static_pointer_cast<Derived1>( shared_from_this() ); } }; class Derived2 : public Base { public: virtual boost::shared_ptr<Derived2> GetSharedFromThis() { return static_pointer_cast<Derived2>( shared_from_this() ); } }; I am assuming that I do not need to call boost::serialization::base_object<boost::enable_shared_from_this<Base> >( *this ); When I serialize the base class. Could that be the problem? I think what I am going to do is go back into the program and simply eliminate all of the shared_ptr serializations. I can serialize to raw pointers, and then just create the shared_ptr's from those pointers explicitly in my case. I simply do not ever have any shared_ptr's with multiple reference counts to worry about. I will let you know what happens. ________________________________ From: Robert Ramey [mailto:ramey@rrsd.com] Sent: Monday, November 13, 2006 8:30 AM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] [Serialization] a coupla crashes fromhiearchycomplexity I would be curious to see your particular case. The fact that different archives give problems that seem related to nesting depth suggest along with the fact that this hasn't been reported suggests that there is some sort of use case or error which hasn't been considered. Robert Ramey "Reusser, Edward" <Edward.Reusser(a)actel.com> wrote in message news:5E916BAE1732F344BAFD713DF2373479016EA059@SV-MSG-01.amer.actel.com.. . I am using the serialization library in boost 1.33.1. I am compiling on windows using the VC 7.1 compiler. The problem I am having is that when I use xml_iarchive and xml_oarchive, everything works just fine for simple cases, but if the xml gets very deep ( same exact class hierarchy, just more data organized a little more complexly) I am getting runtime stack overflow crashes in the spirit parser. I figured I could solve that by simply substituting text_iarchive and text_oarchive. Please note that I am simply substituting in these archive types instead of using the xml archive headers, which work. There are no other code changes anywhere. Now I am getting the following compiler error: \boost\mpl\eval_if.hpp(40) : fatal error C1204: compiler limit : internal structure overflow Any suggestions? I can try increasing the stack size of my current application to eliminate the xml runtime stack overflow problem, but I am uneasy doing this until I understand how to calculate the stack sizes required, and why it is happening. Furthermore, I would prefer using the text archives, since the data is more compact than the xml ones. Ed Reusser Principal Software Engineer Actel Corporation (408) 318-4972 ________________________________ The information contained in or attached to this email may be subject to the Export Administration Regulations (EAR), administered by the U.S. Department of Commerce, or the International Traffic in Arms Regulations (ITAR), administered by the U.S. Department of State, and may require an export license from the Commerce or State Department prior to its export. An export can include a release or disclosure to a foreign national inside or outside the United States. Include this notice with any reproduced portion of this information. ________________________________ _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users The information contained in or attached to this email may be subject to the Export Administration Regulations (EAR), administered by the U.S. Department of Commerce, or the International Traffic in Arms Regulations (ITAR), administered by the U.S. Department of State, and may require an export license from the Commerce or State Department prior to its export. An export can include a release or disclosure to a foreign national inside or outside the United States. Include this notice with any reproduced portion of this information.

2 1

[Boost.Test} exit codes
by Christoph 13 Nov '06

13 Nov '06

Hi, I am experimenting with the Boost.Test framework. I have stumbled upon the exit code of the test program. I have not found the documentation on the exit code (maybe I have overlooked it) and am somewhat baffled how to interpret it: i) what is the semantic of the exit code? It seems to be 0 when all tests are passed (as expected), but I get 201 if some tests fail. What does 201 mean? Are there further possibilities? ii) is it possible have the exit code return the number of failed test cases? Thank you Christoph

2 1

[enable_if][type_traits] Overload resolution question
by Michael Marcin 13 Nov '06

13 Nov '06

Hello, I have a fixed point math class and I want to enable some optimized operator overloads. for instance: fixed& fixed::operator /= ( const fixed &rhs ); fixed& fixed::operator /= ( int n ); it seems however to me that what I really want is an overload like: template< typename T > fixed& operator /= ( typename boost::enable_if<boost::is_integral<T>,T>::type n ); However I can't seem to get that function considered for overload resolution instead it goes through the following constructor and calls the /= that takes a const fixed &. template< typename T > fixed::fixed( T n, typename boost::enable_if< boost::is_integral<T> >::type* = 0 ); Speaking of which I don't understand why the following doesn't work in place of the previous constructor. template< typename T > fixed::fixed( typename boost::enable_if< boost::is_integral<T>,T>::type n ); Finally I'm using this class to replace a lot of hardcoded / macro logic and often as an optimization the code uses binary shifts to represent power of 2 multiply/divides. Going forward these divides need to work with both fixed and floating point types so f >> 1 needs to change to f / 2. Is it possible to create an overload for the / and * operators that determine if the operand is an integral constant and is a power of 2 and use a binary shift internally? Thanks, Michael Marcin

3 5

Re: [Boost-users] [Serialization] unexpected assert registeringclasses
by Reusser, Edward 13 Nov '06

13 Nov '06

Robert, Thanks for the quick response. I have ensured that the serialization for each type is located in exactly one place. The header files where the serialization code resides for the derived classes are not global, that is, our build system is set up to ensure that no other library or DLL can reference them. I believe that I can make the serialization completely independent and contained inside the DLL without much difficulty. However, unless I statically link the serialization library, I don't think I can prevent the macro: BOOST_CLASS_EXPORT_GUID( class, "ClassNameText" ) from initializing the global table inside the serialization DLL (which is dynamically linked). I noticed that when I tried to use the other registration technique you describe, register_type<T>(), this also calls the registration code in the serialization DLL on load, so that doesn't solve the problem. It doesn't seem very practical to serializing in/out a prototype of each derived class into the archive initially because it would increase the archive size by a lot. Too bad there isn't a mechanism for creating a registration table specific to the DLL where the classes are serialized. If the global table was of the following structure: using namespace std; map< HMODULE, map<string, ETI*> >; Then the above macro would simply use AfxGetInstanceHandle (in the case of windows, I am unsure what the corresponding calls in other OS's would be), to pass the HMODULE handle. Ed -----Original Message----- From: Robert Ramey [mailto:ramey@rrsd.com] Sent: Monday, November 13, 2006 8:24 AM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] [Serialization] unexpected assert registeringclasses Having serialization code in DLLS has raised some stick issues. The basic problem is the existence of a global table of information about types being serialized. Among other thngs, this global type table contains the export string name (GUID) that is shared among programs to identify the type. This table also points to functions via a virtual function mechnamism to implementations required by serialization. Entries are added to this table when code is loaded and deleted when code is unloaded. in version 1.33 I included the indicated assert - as it seemed to me that this must be unique. I was concerned that multiple entries in the table might point to different function implementations - as indeed they will. So I included this assertion. This started to create problems as you have found. Also I've now come to thnk that the having multiple entries for the same type is harmless - and difficult to avoid in the presence of dynamically loaded/unloaded DLLS. So in 1.34 - I commmented out the assertion. In addition, I've augmented the code to make sure that the correct entry in the table is deleted when the corresponding DLL is unloaded. So I believe that starting in 1.34 this problem will be resolved. I really don't know for sure because its very hard to come up with a good test for this. So, I think this problem is addressed. But in the face of dynamically loaded DLLs - which are not all guarenteed to be in sync ( some could have older versions of code), I think that the best policy would be to be sure that serialzation code for a particular type should be found in one and only one place. Also, doing this will result in smaller DLLS and applications. Doing this requires that one explicitly orgranize his code so to achieve this. This means avoiding instantiation of serialization code in applications and by explicitly instantiation such code in the DLLS. The closest guide I have for doing this is demo_pimpl which shows how to do this. Robert Ramey "Reusser, Edward" <Edward.Reusser(a)actel.com> wrote in message news:5E916BAE1732F344BAFD713DF2373479016EA054@SV-MSG-01.amer.actel.com.. . I am using the boost 1.33.1 distribution, and the xml_iarchive and xml_oachive to serialize a rather deep and complex data structure to xml. I am using make_nvp directly in all cases (not the macro). I am sometimes getting the following assert (line 71 in extended_type_info.cpp) when I load previously serialized data: assert( lookup(eti) == m_self->m_map.end() ); It seems obvious that what is happening is that somehow I am calling self_register more than once for a specific class. Tracing through the code however I am puzzled exactly how this could happen, since the registration should only happen once when the libraries are loaded. This never happens on save by the way, only on load. It also never happens if I do the save, followed by a load immediately. It only happens if I do the save, shut down the application, then load the data. I have verified that the loaded data is a bit by bit equivalent in both cases. The best that I can come up with is that I am loading the serialization library as a side effect of calling LoadLibrary at runtime. So I am linking in the serialization library after everything else has been loaded and is running. But again, none of the libraries are ever unloaded, and the load sequence should always be the same. The actual situation is that I have a library . call it Library A, which is linked to libraries B, and C. The library A is being linked using the LoadLibrary call, each of libraries B are C are linked to the boost serialization library. In each of libraries B, and C, I have used the macro: BOOST_CLASS_EXPORT_GUID( class, "ClassNameText" ) To define all of my classes I am serializing, including all classes that I am serializing using shared_ptr's. I was thinking originally that the problems were all shared_ptr's of classes that are derived from enable_shared_from_this<T>, but I am no longer confident that has anything to do with it. In fact, truth be told, I have no idea if any of the above has anything to do with the problem. When I commented out the assertion, everything seems to work just fine, except now I am getting a stack overflow on very complex hierarchies in the spirit parser (again, load only), but the simpler ones seem to work repeatedly without any problems. I have no doubt that the assertion was added there for a reason, so I hate to comment it out without finding out what else I might have broken. Edward Reusser Principal Engineer Actel Corporation (650) 318-4972 The information contained in or attached to this email may be subject to the Export Administration Regulations (EAR), administered by the U.S. Department of Commerce, or the International Traffic in Arms Regulations (ITAR), administered by the U.S. Department of State, and may require an export license from the Commerce or State Department prior to its export. An export can include a release or disclosure to a foreign national inside or outside the United States. Include this notice with any reproduced portion of this information. _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

2 1

[Serialization] a coupla crashes from hiearchy complexity
by Reusser, Edward 13 Nov '06

13 Nov '06

I am using the serialization library in boost 1.33.1. I am compiling on windows using the VC 7.1 compiler. The problem I am having is that when I use xml_iarchive and xml_oarchive, everything works just fine for simple cases, but if the xml gets very deep ( same exact class hierarchy, just more data organized a little more complexly) I am getting runtime stack overflow crashes in the spirit parser. I figured I could solve that by simply substituting text_iarchive and text_oarchive. Please note that I am simply substituting in these archive types instead of using the xml archive headers, which work. There are no other code changes anywhere. Now I am getting the following compiler error: \boost\mpl\eval_if.hpp(40) : fatal error C1204: compiler limit : internal structure overflow Any suggestions? I can try increasing the stack size of my current application to eliminate the xml runtime stack overflow problem, but I am uneasy doing this until I understand how to calculate the stack sizes required, and why it is happening. Furthermore, I would prefer using the text archives, since the data is more compact than the xml ones. Ed Reusser Principal Software Engineer Actel Corporation (408) 318-4972 The information contained in or attached to this email may be subject to the Export Administration Regulations (EAR), administered by the U.S. Department of Commerce, or the International Traffic in Arms Regulations (ITAR), administered by the U.S. Department of State, and may require an export license from the Commerce or State Department prior to its export. An export can include a release or disclosure to a foreign national inside or outside the United States. Include this notice with any reproduced portion of this information.

2 1

[Serialization] unexpected assert registering classes
by Reusser, Edward 13 Nov '06

13 Nov '06

I am using the boost 1.33.1 distribution, and the xml_iarchive and xml_oachive to serialize a rather deep and complex data structure to xml. I am using make_nvp directly in all cases (not the macro). I am sometimes getting the following assert (line 71 in extended_type_info.cpp) when I load previously serialized data: assert( lookup(eti) == m_self->m_map.end() ); It seems obvious that what is happening is that somehow I am calling self_register more than once for a specific class. Tracing through the code however I am puzzled exactly how this could happen, since the registration should only happen once when the libraries are loaded. This never happens on save by the way, only on load. It also never happens if I do the save, followed by a load immediately. It only happens if I do the save, shut down the application, then load the data. I have verified that the loaded data is a bit by bit equivalent in both cases. The best that I can come up with is that I am loading the serialization library as a side effect of calling LoadLibrary at runtime. So I am linking in the serialization library after everything else has been loaded and is running. But again, none of the libraries are ever unloaded, and the load sequence should always be the same. The actual situation is that I have a library ... call it Library A, which is linked to libraries B, and C. The library A is being linked using the LoadLibrary call, each of libraries B are C are linked to the boost serialization library. In each of libraries B, and C, I have used the macro: BOOST_CLASS_EXPORT_GUID( class, "ClassNameText" ) To define all of my classes I am serializing, including all classes that I am serializing using shared_ptr's. I was thinking originally that the problems were all shared_ptr's of classes that are derived from enable_shared_from_this<T>, but I am no longer confident that has anything to do with it. In fact, truth be told, I have no idea if any of the above has anything to do with the problem. When I commented out the assertion, everything seems to work just fine, except now I am getting a stack overflow on very complex hierarchies in the spirit parser (again, load only), but the simpler ones seem to work repeatedly without any problems. I have no doubt that the assertion was added there for a reason, so I hate to comment it out without finding out what else I might have broken... Edward Reusser Principal Engineer Actel Corporation (650) 318-4972 The information contained in or attached to this email may be subject to the Export Administration Regulations (EAR), administered by the U.S. Department of Commerce, or the International Traffic in Arms Regulations (ITAR), administered by the U.S. Department of State, and may require an export license from the Commerce or State Department prior to its export. An export can include a release or disclosure to a foreign national inside or outside the United States. Include this notice with any reproduced portion of this information.

2 1

Iterater for subset extraction?
by Thom DeCarlo 12 Nov '06

12 Nov '06

I have a couple of n00b questions. I have constructed a BGL graph that uses the edge_name_t property to road names. I want to change the weights of some of the roads based on input from the user. Is there a way to set up an iterator to step through edges that have names which match elements of a set? (e.g., "A,B,B1,L,M") In a related question, I need to extract a vertex whose vertex_index_t value matches a specific value. The vertices were not entered in any specific order, so the "vertex(1, g)" function returns the first vertex to have been entered into the graph, but not necessarily the one whose index value is "1". Thanks, Thom -- this sig intentionally left blank

2 3

format un-debuggability
by Drumheller, Michael 12 Nov '06

12 Nov '06

If you don't pass enough arguments to a boost::format you get this: "boost::too_few_args: format-string refered to more arguments than were passed" Unfortunately there is, as far as I can tell, no way to figure out where the error happened, other than building a debug version of your app and breaking into the debugger on that error. Needless to say that can be very inconvenient. Would it be possible to fix boost::format (which, by the way, is IMHO one of the most wonderful of all the Boost libraries!!) so that its exceptions carry a little more information about their origins (e.g., embedding the format-string itself in the message)? Thank you. Michael Drumheller Boeing Phantom Works Mathematics and Engineering Analysis 425.373.2703 michael.drumheller(a)boeing.com This email may contain proprietary information. If you are not the intended recipient please delete it and notify the sender that you received it in error.

1 0

Boost crosscompilation
by Vinh 12 Nov '06

12 Nov '06

Hi everyone, I'm new to boost and have successfully installed it on my debian sarge system. For a particle Filter using the Bayes++ Library, I would need to crosscompile the boost library for an ARM processor. Does anyone know whether that is possible? (I already have a crosscompiler installed, but don't know whether boost supports crosscompilation?) Vinh

2 2

iterating over arbitrary python object in c++
by Augusto Callejas 12 Nov '06

12 Nov '06

hi- i'm writing a C++ class that i want to expose as a python class. one method in my class has an argument that takes in a python object that "implements" the iterator interface (that is the python object has defined "__iter__" and "__next__" and can be used in a "for x in y" loop). how do i go about iterating over that python object in my C++ code? for example: void my_class::method(object my_iterable_obj) { // iterate over "my_iterable_obj" } one method i tried was calling the "__next__" method explicity: my_iterable_obj.attr("__next__")() however, "__next__" raises a StopIteration exception when there are no more objects in the iterator. i could not find any examples in the boost python tutorials for handling python exceptions from c++. is there another way i can go about this? thanks, augusto.

3 2

[Boost.Signals] in Multithreaded Environment
by Terry G 11 Nov '06

11 Nov '06

Hello again everyone! Boo ST == (Scarey signals & threads) Signals/slots are just too good not to use in a multi-threaded environment. Someday, this will be fixed, I know. But for now... I'm trying to serialize access to boost.signals using Bjarne Stroustrups "wrapper" concept. Here's what I'm doing. Is this likely to cause problems? Sorry about the length. If this is too dangerous, what's a better alternative? I typed this from memory and didn't try to compile. Please disregard any typos or syntactic blunders. // Implements Bjarne Stroustrup's "wrapper" concept using boost::shared_ptr. template <typename T> class Wrapper { T* p; public: explicit Wrapper(T& obj) : p(&obj) { } boost::shared_ptr<T> get() const { p->prefix(); return boost::shared_ptr<T>(p, boost::mem_fn(&T::suffix)); } // get boost::shared_ptr<T> operator->() const { return get(); } }; //Wrapper // Provides signals through "safe" wrapper. (?) class TiePoint { public: class Events { Mutex lock; // Provided elsewhere. void prefix() { lock.acquire(); } void suffix() { lock.release(); } friend class Wrapper<Events>; public: boost::signal<void (Signal1Args)> signal1; boost::signal<void (Signal2Args)> signal2; // etc... template <class Iter> void disconnect(Iter begin_, Iter end_) { std::for_each(begin_, end_, boost::mem_fn(&boost::signals::connection::disconnect); } // disconnect }; // Events private: Events _events; public: Wrapper<Events> events; TiePoint() : _events(), event(_events) { } }; // TiePoint // Demonstrates use of TiePoint class. class UsesSignals { private: void handle1(Signal1Args) { ... } void handle2(Signal2Args) { ... } std::vector<boost::signals::connection> conns; // Be very careful with these. public: void connect(TiePoint& tiePt) { boost::shared_ptr<TiePoint::Events> events = tiePt.events.get(); conns.push_back(events->signal1.connect(Handle1)); conns.push_back(events->signal2.connect(Handle2)); } // connect void disconnect(TiePoint& tiePt) { tiePt.events->disconnect(conns.begin(), conns.end()); conns.clear(); } // disconnect void signalJustOne(TiePoint& tiePt) { tiePt.events->signal1(signal1args); } // signalJustOne void signalMany(TiePt& tiePt) { boost::shared_ptr<MyClass::Events> events = tiePt.events.get(); events->signal1(signal1args); events->signal2(signal2args); ... } // signalMany }; // UsesSignals

1 0

Serialization of an std::list into XML without a NVP
by Devin Fallak 10 Nov '06

10 Nov '06

Hi all, I'm working with the Serialization library and trying to output a list of objects into an XML file. The problem I'm having is that in serializing a std::list, the Serialization library requires that the list itself is given a NVP. The specification I'm working with requires a list of undefined length WITHOUT its own NVP. Is there any way to serialize a std::list into/out of an xml_oarchive/xml_iarchive? Any help would be much appreciated. Thanks, Devin Fallak

2 3

Problem with counting iterator and bind
by Maitre Bart 10 Nov '06

10 Nov '06

I have this: typedef LegacySequentialContainer<string> LegacyStringVector; LegacyStringVector lsv; // ... filling lsv with strings ... I realized this: boost::counting_iterator<int> it(0); boost::counting_iterator<int> end(lsv.length()); while (it < end) cout << boost::bind(&LegacyStringVector::operator[], v3, _1)(*it++) << " "; cout << "\n"; and it works. However, I wish to do the same but using std::copy or std::for_each instead. I tried the following but none is able to compile: copy(boost::counting_iterator<int>(0), boost::counting_iterator<int>(v3.size()), boost::bind(ostream_iterator<string>(cout, " "), &vector<string>::operator[], v3, _1)); copy(boost::counting_iterator<int>(0), boost::counting_iterator<int>(v3.size()), boost::bind(ostream_iterator<string>(cout, " "), boost::bind<string,int>(&vector<string>::operator[], v3, _1))); copy(boost::counting_iterator<int>(0), boost::counting_iterator<int>(v3.size()), boost::bind(ostream_iterator<string>(cout, " "), boost::bind<string,int>(&vector<string>::operator[], v3), _1)); I must be close to the solution but error messages do not help guiding me in the right direction. Anyone has any suggestion?

2 4

reference to void in shared_ptr_nmt
by Oliver Kania 10 Nov '06

10 Nov '06

Hello, I am encountering the following problem when using boost with shared pointers (Ubuntu Edgy, G++4.1/4.0/3.4): ======================= /usr/include/boost/detail/shared_ptr_nmt.hpp:115: error: forming reference to void shared_ptr_nmt.hpp:114: error: forming reference to void ========================== the source code reads : ========================= T & operator*() const // never throws { BOOST_ASSERT(px != 0); return *px; } ========================= To me, this seems like a g++ (GNU GCC) problem, (It seems that G++ checks if void would be a viable substitutiion for T) however, I have tried three different versions of g++ and get the same result every time. There once was such a bug in GCC but it has been resolved ages ago. Regards, Oliver Kania

2 2

Building Boost on Solaris 10/Sparc: No release version of libraries?
by Boris 10 Nov '06

10 Nov '06

I built Boost 1.33.1 on a Solaris 10/Sparc machine. Problem is that no release version of the various libraries are built. There is for example libboost_date_time-gcc-d-1_33_1.so but no libboost_date_time-gcc-mt-s-1_33_1.so. Is this a known problem on Solaris? The Solaris machine has GCC 3.4.6 installed. I built bjam myself (with tools/build/jam_src/buid.sh) and then entered: ./bjam "-sTOOLS=gcc" "-sBUILD=<define>NO_BZIP2" --without-python stage When I look then into stage/lib there are only debug versions of the libraries? Boris

1 0

[WAVE] position of tokens
by Andreas Sæbjørnsen 10 Nov '06

10 Nov '06

Hi, I need some advice regarding Wave. What I want to do is to operate with Wave on a token stream and extract the token stream representing macro calls after expansion. The twist is that I want the token stream after expansion to have the positions that another preprocessor would see on the already expanded output from Wave. E.g: #define MACRO_CALL int x; int main(){ MACRO }; Exands into #line 2 int main(){ int x; }; Where 'int x' should have a position of line 3 instead of line 1 after expansion. I also want the column number to represent what we see on line 3 instead of what we see on line 1. Is this possible ? Thanks Andreas

3 12

Boost:ASIO mailing list/group
by Stas 10 Nov '06

10 Nov '06

What is a right group/ mailing list ot ask ASIO related questions? Regards Stas

3 6

locale for lexical_cast?
by Amin Kharchi 10 Nov '06

10 Nov '06

Hello! Is it possible to set a locale for the lexical_cast? It looks like that it is only possible to convert english/us numbers to a string? Example: float a = boost::lexical_cast<float>("12,3"); This would be in english 12.3. But I get a bad_cast exception for german numbers. A locale would be very helpful. Best regards Amin Kharchi

2 1

Lambda, how difficult should it be?
by Martin Young 10 Nov '06

10 Nov '06

Hi, I've just started trying to use the Boost lambda library and I'm finding that I can't get anything much to work how I'd expect. I've read the docs and I'm none the wiser. I'm running on Cygwin using GCC 3.4.4 if that makes any difference. My problem is pretty nebulous - I can't get the non-workingness nailed down a specific issue - whenever I try something different I get several screenfulls of different error messages. So, previously I had a alot of code in the form below which performs linear searches of a vector. Clearly this is not the Right Thing, especially as I will want to change the vectors to different containers at a later point. typedef struct { int a; void* b; } foo; vector<foo*>* v = buildAndPopulateVector(); for( int i=0, iL=v->size(); i<iL; i++ ) { foo* thisFoo = (*v)[i]; if( thisFoo->a == 0 ) { thisFoo->a = 1; *(int*)(thisFoo->b) = 42; } } Instead, I'd like to use the for_each algorithm to iterate over the contents of the vector like this: foreach( v->begin(), b->end(), ### ) Where the ### would normally be a function pointer (or relative thereof). I'd like to use lambda so I can put my code inline. At first I thought I could do something like: foreach( v->being(), b->end(), if_then( _1->a == 0, ( _1->a = 1, *(int*)(_1->b) = 42 ) ) I quickly discovered that the placeholders don't work like that and a pile of bind and/or ->* operators are required to extract any interesting information. I think I've got this bit sorted now though. What I'm getting stuck on now is constructing a working version of the if/then construct. The condition expression seems okay... if_then( bind(&foo::a,_1)==0, but I just can't get the "body" part to compile. I have to enclose it in round brackets so it appears as one expression to the compiler, but then it's not a lambda expression so I need to wrap it in something to make it a lambda. I should then pass _1 in as the single parameter of my new nested lambda because the previous _1 won't be in scope anymore - is this right? Is there another (better) way to include multiple expressions in an if_then construct without making a nested lambda and thus losing the bindings from the original lambda? What should I wrap my expression in to make it a unary lambda into which I can pass _1 from the main lambda? It's not getting automatically picked up as a lambda expression because the use of _1 is in the middle of one of the comma separated sub exprssions. Can I even pass _1 into a nested lambda like that or does it need massaging first? I've found dealing with the placeholders to be very painful so far... Are there any examples of this kind of thing anywhere? All the examples I've found are incomplete or for very trivial cases, or have not been answered. Even the "Beyond the std lib/boost" book has only very simple examples and esoteric gotchas. It seems to me this ought to be a very simple thing - am I going about it in the wrong way? I've had a good Google and a read through this list's archives and there seems to be very little discussion about the lambda library. Is it moribund or am I the only person who can't make it work? Sorry for all the rather vague questions and thanks for any pointers. -Martin.

2 1

binary_to_base64 example
by Kervin L. Pierre 10 Nov '06

10 Nov '06

Hello, Does someone have an example of how to use the base64_from_binary class to convert a 'char *' buffer to base64 text in a local buffer? I believe this is probably one of the simplest uses of the function but I can't make sense of the documentation. Best regards, Kervin

2 1

no output from BOOST_MESSAGE
by Kervin L. Pierre 09 Nov '06

09 Nov '06

Hello, I wrote a few simple test cases using Boost test, and things seem to work ok except done of my BOOST_MESSAGE() calls output anything. If the predicate fails for BOOST_REQUIRE_MESSAGE() I do get the message outputed to the screen, but not for regular BOOST_MESSAGE() Is there a setting that I should tune to output BOOST_MESSAGE, or may suppress BOOST_MESSAGE? Also I saw in a message somewhere that these functions can output to other targets than the screen. If that is the case, how do I go about doing this? Best regards, Kervin

2 6

[program_options] define precedent options?
by Rui Maciel 09 Nov '06

09 Nov '06

I've just discovered boost's program_options and at first glance it looked exactly what I was searching for, which was a easy to use library which was capable of handling the command line arguments parsing in a fast and efficient way. Unfortunately one of the things which I had my mind set to was the possibility of defining precedent options. To put it in other words, enable the parser to accept some options only if they were casted in a particular order and complain if that order wasn't respected. For example, accepting something like: app --add --file but complain if the arguments are like: app --file --add or app --add One other thing that I was hoping that boost's program_options was capable of handling was some sort of semantic interpretation according to the option's orders. Take this case for example: app --add --file --remove --file What I was hoping for was that program_options was capable of interpreting the first invocation of --file as relating to --add and the second invocation relating to --remove, instead of intepreting as two distinct invocations of --file. So, is it possible to accomplish that with boost's program_options? If so, could anyone be so kind to provide a simple example? Thanks in advance Rui Maciel -- Running Kubuntu 6.10 with KDE 3.5.5 and proud of it. jabber:rui_maciel@jabber.org

1 0

efficient string to numeric conversion (and vice-versa)
by Maitre Bart 09 Nov '06

09 Nov '06

Is there a Boost lib that offers efficient string to numeric type conversion ? What about numeric to string conversion ?

3 2

Ann: Alpha release of Boost.TR1-1.34
by John Maddock 09 Nov '06

09 Nov '06

I've placed an alpha release of the TR1 subset of Boost on the sourceforge download page: https://sourceforge.net/project/showfiles.php?group_id=7586&package_id=1893… Eventually, this package will track Boost-1.34 releases, but until that happens, I wanted to test the water and see how a subset like this would be received, and how best to organise it's packaging etc. So any feedback you have would be most welcome! The subset includes: TR1 Reference Wrappers Shared_ptr result_of mem_fn Function Object Binders Polymorphic Function Wrappers Type Traits Random Numbers Tuples Array Hash Functions Regular Expressions Complex Number Algorithms Enjoy! Regards, John Maddock.

1 0

Add library to link against in Jamfile (building a Boost.python extension)
by Alexander Eisenhuth 09 Nov '06

09 Nov '06

Hello, I'm writing a Boost.python extension, that needs the Boost.thread library. I use the Jamfiles from Boost.python example (works, except of linking), and need to add the thread library. How can I do that? Jamfiele: ---------------------------------------------- # This is the top of our own project tree project-root ; # Include definitions needed for Python modules import python ; # ----- getting_started1 ------- # Declare a Python extension called getting_started1 extension getting_started1 : # sources getting_started1.cpp # requirements and dependencies for Boost.Python extensions <template>@boost/libs/python/build/extension ; ------------------------------------------------- Thanks a lot Regards Alexander

2 1

undefined reference to `boost::read_graphviz
by Teodora Miteva 09 Nov '06

09 Nov '06

Hi, i got this problem when i tried to compile the graphviz.cpp: ------------------------- undefined reference to `boost::read_graphviz(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, boost::subgraph<boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, boost::property<boost::vertex_attribute_t, std::map<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, boost::no_property>, boost::property<boost::edge_attribute_t, std::map<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, boost::property<boost::edge_index_t, int, boost::no_property> >, boost::property<boost::graph_graph_attribute_t, std::map<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, boost::property<boost::graph_vertex_attribute_t, std::map<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, boost::property<boost::graph_edge_attribute_t, std::map<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, boost::property<boost::graph_name_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::no_property> > > >, boost::listS> >&)' --------------------------------- i saw the explanation and some previous mails but still i have the problem... i built the lib libbgl-viz.a following the instructions ( http://www.cs.brown.edu/~jwicks/boost/libs/graph/doc/read-graphviz.html<http://www.cs.brown.edu/%7Ejwicks/boost/libs/graph/doc/read-graphviz.html>) , but still doesnt work ......... could you tell me what i could i do to salve it? thanks best teodora

1 0

converting a string to a function name
by Fred J. 09 Nov '06

09 Nov '06

Hi is there a way to convert a string to a function name and fire it. like void his_fun(){ cout << "his is here" << endl; } vector<string> vec; vec.push_back("his"); vec.push_back("me"); for(i=0; i<vec.size(); i++) string var = vec[i] + _fun; fire(var); and it will fire the routine "his_fun? is so, how? what whole idea is to avoid typing vector<func_ptr> vec; vec.push_back( &func_1 ); vec.push_back( &func_n ); ... thanks --------------------------------- Everyone is raving about the all-new Yahoo! Mail.

2 1

got a bad_any_cast exception
by ClassyK_Danad 09 Nov '06

09 Nov '06

#include <iostream> #include <boost/any.hpp> template<typename A, typename B> boost::any min(const A& a,const B& b) { return a < b ? a : b; } void main() { //got a bad_any_cast exception ! std::cout << boost::any_cast<int>( min( 1, 1.1)) << std::endl; } how could this happen?

3 3

Re: [Boost-users] Socket and iostream
by Nat Goodspeed 09 Nov '06

09 Nov '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > bounces(a)lists.boost.org] On Behalf Of Jakub Stachowski > Sent: Wednesday, November 08, 2006 2:22 AM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Socket and iostream > > > nothing seems to be written nor readen to/from the socket except for > > the first getline. What am I doing wrong here ? > > Try flushing the stream after each write. [Nat] I wondered about that -- but doesn't std::endl implicitly flush?

3 2

Re: [Boost-users] Sequence of Types, What For?
by james.jones＠firstinvestors.com 09 Nov '06

09 Nov '06

From: "Andrew Holden" <aholden(a)charteroaksystems.com> > 3: Look up the value in the first array, and then look up the code block > number in the second array. > > 4: Go to the pointer you just got. > > The actual blocks of code are laid out in order right after the goto in > step 4, in the same order as the source code. Breaks become goto end of > switch. If you leave out a break, the processor really does JUST fall > through to the next case. > > All in all, if you have a monster switch statement, the > compiler-generated code probably is just about as fast as you can get. > It takes less than a dozen machine instructions to implement it, and it > has constant complexity. Actually this is not particularly good. For one thing, it's O(n), not constant time, because doing an array lookup is O(n). For many switch use-cases this is no big deal, but it certainly isn't unheard of to have a switch with dozens (or more) of cases, each of which does almost nothing (like return a value). In this case, the lookup can actually dominate your runtime. There's a theorem in hash theory (proved by Komlos, one of my old profs) that says that you can always generate a perfect hash function if you know the values you need to hash. That is, you can generate a hash function that requires exactly one lookup in every case. But I don't know any compiler that actually does this. Since all cases are known at compile time, doing this should be a beneficial runtime optimization for large switches (if the generated hash function is sufficiently cheap). Maybe this could be done using the MPL? I don't know TMP well enough to know where to begin on something like this. See http://en.wikipedia.org/wiki/Perfect_hash_function for more detail. - James Jones Administrative Data Mgmt. Webmaster 375 Raritan Center Pkwy, Suite A Data Architect Edison, NJ 08837

5 5

BOOST_FOREACH VC8 warning: change in behavior
by Nico Galoppo 08 Nov '06

08 Nov '06

Hi, I'm getting the following warning in VC8, using BOOST_FOREACH on a container of shared_ptr<>s. The container itself is also a shared_ptr. warning C4686: 'boost::foreach_detail_::make_probe' : possible change in behavior, change in UDT return calling convention The warning happens at the following line shared_ptr<Scene> scene(new Scene()); typedef shared_ptr<Character> character_ptr; BOOST_FOREACH(character_ptr & actor, *scene) { ... } Unfortunately, I can't reproduce it in a simple program, it doesn't give me the warning there. --nico

2 2

Re: [Boost-users] [Boost.Filesystem] problem to link an executabl e to boost_filesys tem static library on Windows XP
by Johan.GUIHENEUF＠external.thalesgroup.com 08 Nov '06

08 Nov '06

Hello Rush and everybody, Thank you for your answer. Unfortunately, it does NOT match the name. The name computed "by auto_link.hpp" is boost_filesystem-vc71-mt-s-1_33.lib and the name of the static library on my computer is boost_filesystem-vc71-mt-1_33.lib (without the '-s'). So my problem is a problem of name mismatch, not a problem of project configuration for linking. Thank you. Johan GUIHENEUF -----Message d'origine----- De : boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] De la part de Rush Manbert Envoyé : mardi 7 novembre 2006 20:40 À : boost-users(a)lists.boost.org Objet : Re: [Boost-users] [Boost.Filesystem] problem to link an executable to boost_filesys tem static library on Windows XP Johan.GUIHENEUF(a)external.thalesgroup.com wrote: > Hello, > > I try to build an console executable that uses boost_fileystem library. > I have got the file boost_filesystem-vc71-mt-1_33.lib. My IDE is Visual C++ 7.1. > I set the preprocessor definition _MT. > At build step, I have this error: "could not find boost_filesystem-vc71-mt-s-1_33.lib". > I had a look to boost/config/auto_link.hpp to see what "#define" I forgot but I do not understand why it chooses "#define BOOST_LIB_RT_OPT -s". > > hat preprocessor macro should I define to make it choose "#define BOOST_LIB_RT_OPT" (i.e. empty) ? Is there a blocking problem with Visual C++ 7.1 on Windows XP ? > Hi Johan, If you have verified that the library name generated by the auto link (boost_filesystem-vc71-mt-s-1_33.lib) matches what was installed by the boost build, then it looks like you didn't define the path to the library for the linker. This should be settable via the linker preferences, but I use VS 2005, so don't know how you would do it. - Rush _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

3 2

unit_test_result: is it deprecated?
by Stephen Torri 08 Nov '06

08 Nov '06

Is the class unit_test_result deprecated? I have boost 1.33.1 installed and it is not a part of the installation. Is there something else I am suppose to be using? Stephen

2 5

[regex] boost, problem compiling doc example of boost::match_extra
by Rick Weiss 08 Nov '06

08 Nov '06

I am trying to use the repeat capture mechanism in regex i thought i would start with the documentation example, but im having problems compiling it. Any help is appreciated. (There is likely a problem between my seat and the keyboard) Here is my compile output: and below that is the actual example. /usr/bin/g++ -Wno-ctor-dtor-privacy -O -o file2AssocTable.o -I/afs/apd.pok.ibm.com/func/vlsi/eclipz/common/integration/OA_migration/OpenAccess/2.2.4/include/oa \ -I/afs/apd.pok.ibm.com/func/vlsi/eclipz/common/integration/OA_migration/OpenAccess/2.2.4/include -I/afs/apd.pok.ibm.com/func/vlsi/eclipz/common/integration/GNU/boost/boost_1_33_1/include/boost-1_33_1 \ -c file2AssocTable.cpp file2AssocTable.cpp: In function `void print_captures(const std::string&, const std::string&)': file2AssocTable.cpp:171: no matching function for call to ` boost::match_results<__gnu_cxx::__normal_iterator<const char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<const char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > >::captures(unsigned int&)' file2AssocTable.cpp:177: no matching function for call to ` boost::match_results<__gnu_cxx::__normal_iterator<const char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<const char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > >::captures(unsigned int&)' make: *** [file2AssocTable.o] Error 1 void print_captures(const std::string& regx, const std::string& text) { boost::regex e(regx); boost::smatch what; std::cout << "Expression: \"" << regx << "\"\n"; std::cout << "Text: \"" << text << "\"\n"; if(boost::regex_match(text, what, e, boost::match_extra)) { unsigned i, j; std::cout << "** Match found **\n Sub-Expressions:\n"; for(i = 0; i < what.size(); ++i) std::cout << " $" << i << " = \"" << what[i] << "\"\n"; std::cout << " Captures:\n"; for(i = 0; i < what.size(); ++i) { std::cout << " $" << i << " = {"; for(j = 0; j < what.captures(i).size(); ++j) { if(j) std::cout << ", "; else std::cout << " "; std::cout << "\"" << what.captures(i)[j] << "\""; } std::cout << " }\n"; } } else { std::cout << "** No Match found **\n"; } }

2 3

[lambda] if-then-else construct gets broken by lambda-lib
by Sebastian Weber 08 Nov '06

08 Nov '06

Hello everybody! I'm trying to store a reference to a function depending upon a condition within a function object like this: boost::function< double (std::size_t) > wf = (sIndex < m_maxIndex+1) ? ( boost::lambda::bind(boost::ref(m_cf), sDeg, boost::lambda::_1) ) : ( boost::ref(*m_wf) ); However, this does not compile. The error message is: error: no match for ternary 'operator?:' in '(sIndex < (((boost::cor_cm_iterator4<RandomGenerator, Graph>*)this)->boost::cor_cm_iterator4<RandomGenerator, Graph>::m_maxIndex + 1)) ? boost::lambda::bind(boost::ref(((boost::cor_cm_iterator4<RandomGenerator, Graph>*)this)->boost::cor_cm_iterator4<RandomGenerator, Graph>::m_cf), sDeg, boost::lambda::<unnamed>::_1) : boost::ref((*((boost::cor_cm_iterator4<RandomGenerator, Graph>*)this)->boost::cor_cm_iterator4<RandomGenerator, Graph>::m_wf))' But the lengthy code boost::function< double (std::size_t) > wf; if(sIndex < m_maxIndex+1) wf = boost::lambda::bind(boost::ref(m_cf), sDeg, boost::lambda::_1); else wf = boost::ref(*m_wf); compiles fine. Any idea? How can lambda eat up the ? : construct? How do I prevent that? My system is a ubunut edgy which means, I have g++ 4.1 and use boost 1.33.1. Greetings, Sebastian Weber

3 3

Dependencies between boost libraries
by Loïc Joly 08 Nov '06

08 Nov '06

Hello, I was curious to know wether there was somewhere available a graph of dependencies between boost libraries ? Best regards, -- Loïc

3 4

Socket and iostream
by Ivan LAURETTE 08 Nov '06

08 Nov '06

Darwin 8.8.0 Boost 1.33.1 gcc 4.0.1 Hello, I want to establish a SMTP connection through a socket, then dialog with the server using a stream. I thought I could to it like this: //-------------------------------------------- #include <boost/iostreams/stream.hpp> #include <boost/iostreams/device/file_descriptor.hpp> using namespace std; using namespace boost::iostreams; ... int theSocket = socket(AF_INET,SOCK_STREAM,0); connect(theSocket, ...); file_descriptor fdDevice(theSocket); stream_buffer<file_descriptor> fdstream(fdDevice); iostream os(&fdstream); string answer; getline(os, answer); cout << answer << endl; os << "HELO xxxxx" << endl; getline(os, answer); cout << answer << endl; os << "MAIL FROM: <xxx.xxx(a)xxx.xxx>" << endl; getline(os, answer); cout << answer << endl; ... //-------------------------------------------- But nothing seems to be written nor readen to/from the socket except for the first getline. What am I doing wrong here ? Thanks in advance for any help.

2 1

[asio] Breaking changes committed to cvs HEAD
by Christopher Kohlhoff 08 Nov '06

08 Nov '06

I have just committed some asio changes to cvs HEAD that will break application code. These changes are part of what's needed to bring the interface into sync with the TR2 proposal. The big change is to the error handling classes, as described below. An async handler of the form: void my_handler(const boost::asio::error& e); becomes: void my_handler(const boost::system::error_code& e); Synchronous error handling like this: boost::asio::error e; sock.connect(ep, boost::asio::assign_error(e)); becomes: boost::system::error_code e; sock.connect(ep, e); And where previously a boost::asio::error exception was thrown, the new exception thrown is boost::system::system_error. Error constants like boost::asio::error::eof stay as they are, i.e.: void my_handler(const boost::system::error_code& e) { if (e == boost::asio::error::eof) { ... } } Programs will now need to link against the boost.system library (which is where boost::system::error_code and boost::system::system_error reside). Once I do a few more TR2-related changes I will post regenerated doxygen documentation to the vault. Stay tuned. Cheers, Chris

1 0

[Threads]Exception-safety of thread_group::add_thread
by Ai Azuma 08 Nov '06

08 Nov '06

Hi, I have questions about `boost::thread_group::add_thread' member function. The documents don't seem to say anything about exception-safety of this function. Therefore, I have questions; 1. Is this no-throw? 2. If the answer to 1. is "no", then how does it treat the ownership of its argument when an exception is thrown? Could anyone help me? Thanks in advance. -- Ai Azuma <ai.azuma(a)gmail.com>

1 0

progress_display+CProgressBar MFC
by Gennady Khokhorin 07 Nov '06

07 Nov '06

I'm wonder what could be a schema to connect boost::progress_timer to MFC CProgressBar (msvc) gui? Thanks in advance. gok

2 1

[Boost.Filesystem] problem to link an executable to boost_filesys tem static library on Windows XP
by Johan.GUIHENEUF＠external.thalesgroup.com 07 Nov '06

07 Nov '06

Hello, I try to build an console executable that uses boost_fileystem library. I have got the file boost_filesystem-vc71-mt-1_33.lib. My IDE is Visual C++ 7.1. I set the preprocessor definition _MT. At build step, I have this error: "could not find boost_filesystem-vc71-mt-s-1_33.lib". I had a look to boost/config/auto_link.hpp to see what "#define" I forgot but I do not understand why it chooses "#define BOOST_LIB_RT_OPT -s". hat preprocessor macro should I define to make it choose "#define BOOST_LIB_RT_OPT" (i.e. empty) ? Is there a blocking problem with Visual C++ 7.1 on Windows XP ? Thank you. Johan GUIHENEUF

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Re: [Boost-users] [lambda] if-then-else construct gets broken bylambda-lib
by Nat Goodspeed 07 Nov '06

07 Nov '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > bounces(a)lists.boost.org] On Behalf Of Sebastian Weber > Sent: Tuesday, November 07, 2006 12:41 PM > To: boost-users(a)lists.boost.org > Subject: [Boost-users] [lambda] if-then-else construct gets broken > bylambda-lib > > I'm trying to store a reference to a function depending upon a condition > within a function object like this: > > boost::function< double (std::size_t) > wf = (sIndex < m_maxIndex+1) ? > ( boost::lambda::bind(boost::ref(m_cf), sDeg, boost::lambda::_1) ) : > ( boost::ref(*m_wf) ); [Nat] Does it work better if the 'else' clause is something more like: ( boost::lambda::bind(boost::ref(*m_wf)) ) ? This is a wild guess, but boost::ref() isn't by itself a lambda bind expression -- is it? Both halves of the ternary operator are convertible to boost::function -- but they're not the same type. I don't know whether two different boost::lambda::bind expressions are going to be compatible either. You may have to explicitly instantiate boost::function objects on both sides of the : -- which would end up being less terse than writing the if/else statement. But it seems worth a try.

2 1

Serialization with polymorphic_*_archive and BOOST_CLASS_EXPORT
by Anders Wang Kristensen 07 Nov '06

07 Nov '06

Hi, I'm having trouble serializing through the a pointer to the base as shown below. If I manually register class B with template register_type<B>() it works, but I would rather use the BOOST_CLASS_EXPORT macros since that is more convenient. Unfortunately BOOST_CLASS_EXPORT assumes you are using the templated version of serialize, and not polymorphic_iarchive/oarchive, that I'm using. Anyone know how to get around that problem? Thanks! -- wang Example: #include <boost/archive/polymorphic_text_iarchive.hpp> #include <boost/archive/polymorphic_text_oarchive.hpp> #include <boost/archive/polymorphic_xml_iarchive.hpp> #include <boost/archive/polymorphic_xml_oarchive.hpp> #include <boost/serialization/shared_ptr.hpp> #include <boost/serialization/export.hpp> struct A { void serialize(boost::archive::polymorphic_iarchive & ar, const unsigned int file_version); void serialize(boost::archive::polymorphic_oarchive & ar, const unsigned int file_version); int data; bool operator==(const A & rhs) const { return data == rhs.data; } A() : data(0) {} virtual ~A() = 0 {} }; void A::serialize( boost::archive::polymorphic_iarchive & ar, const unsigned int file_version ){ ar & BOOST_SERIALIZATION_NVP(data); } void A::serialize( boost::archive::polymorphic_oarchive & ar, const unsigned int file_version ){ ar & BOOST_SERIALIZATION_NVP(data); } struct B : public A { void serialize(boost::archive::polymorphic_iarchive & ar, const unsigned int file_version); void serialize(boost::archive::polymorphic_oarchive & ar, const unsigned int file_version); int foo; bool operator==(const B & rhs) const { return data==rhs.data && foo==rhs.foo; } B() : foo(2) {} }; void B::serialize( boost::archive::polymorphic_iarchive & ar, const unsigned int file_version ){ ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(A); ar & BOOST_SERIALIZATION_NVP(foo); } void B::serialize( boost::archive::polymorphic_oarchive & ar, const unsigned int file_version ){ ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(A); ar & BOOST_SERIALIZATION_NVP(foo); } BOOST_CLASS_EXPORT(B) int main(int argc, const char* argv[]) { boost::shared_ptr<A> a(new B); boost::shared_ptr<A> b; { std::stringstream ss; { boost::archive::polymorphic_text_oarchive oa(ss); //oa.template register_type<B>(); oa << BOOST_SERIALIZATION_NVP(a); } { boost::archive::polymorphic_text_iarchive ia(ss); //ia.template register_type<B>(); ia >> BOOST_SERIALIZATION_NVP(b); } } B* x = dynamic_cast<B*>(a.get()); B* y = dynamic_cast<B*>(b.get()); assert(*x == *y); return 0; }

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Re: [Boost-users] Serialization problem on 64-bit Windows release
by Сергей Филиппов 07 Nov '06

07 Nov '06

Robert Ramey <ramey <at> rrsd.com> writes: > > Is it possible that this might be related to the recently discovered fact > (at least by me) versions of the serialization library are, contrary to > intention, not thread safe? That is, conflict occurs when multiple threads > are using serilization even with different archive instances due to the fact > that they share the same gobal extended_type_info table. This has been > addressed - and hopefully remedied in 1.35. > > Robert Ramey What does it mean that the serialization library is "not thread safe"? Does it mean that the serialization must be used in one thread only or the serialization can be used in different, non-concurrent threads? I'm not familiar with the serialization library internals so it's hard to me to make a guess where it is related to my case. My application is an RPC server that supports only one client connection. The client establishes connection, makes some calls to the server and exits. Each call can generate "events" that are stored on the server in a vector. After a call the client may call the server's function SerializeEvents which serializes the vector into buffer and transmits the buffer to the client. Actual serialization code is straightforward. void CEventLogger::Serialize(std::vector<BYTE>* pBuffer) { std::stringstream stream; boost::archive::text_oarchive ar(stream); ar & m_Events; std::string str(stream.rdbuf()->str()); if(str.length()) { BYTE *pBuf = reinterpret_cast<BYTE*>(const_cast<char*>(str.c_str())); pBuffer->assign(pBuf, pBuf + str.length()); } else pBuffer->clear(); } The client communicates with the server in one thread only. So the functions that are populating m_Events and CEventLogger::Serialize are called in different threads, but these calls are serialized. What you think? Can "not thread safety" be a reason in my case? Thanks, Sergey (Sorry, I forget to mention I'm using boost 1.33.0.)

2 1

fpclassify
by Johan Råde 07 Nov '06

07 Nov '06

Ignore my last message. It was sent by mistake. --Johan

1 0

fpclassify
by Johan Råde 07 Nov '06

07 Nov '06

Olivier, Håkan, Kan ni testa den här? Fungerar den här, så får den bli den slutgiltiga versionen. --Johan

1 0

Re: [Boost-users] [Threads] Problem with starting a sub thread
by Goroll, Torsten 07 Nov '06

07 Nov '06

Hi, thank you all for your help. It was a basically missunderstanding of join() on my side. The message of Nat Goodspeed helped me to discover that. So, lets close this thread. Torsten -----Ursprüngliche Nachricht----- Von: Ovanes Markarian [mailto:om_boost@keywallet.com] Gesendet: Dienstag, 7. November 2006 00:29 An: boost-users(a)lists.boost.org Betreff: Re: [Boost-users] [Threads] Problem with starting a sub thread An additional approach could be a thread group, which can create a bunch of threads. Than you can call join on entire group, where the caller thread blocks until all threads are finished. -----Original Message----- From: Nat Goodspeed [mailto:ngoodspeed@solidworks.com] Sent: Monday, November 06, 2006 5:57 PM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] [Threads] Problem with starting a sub thread > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > bounces(a)lists.boost.org] On Behalf Of Goroll, Torsten > Sent: Monday, November 06, 2006 11:46 AM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] [Threads] Problem with starting a sub thread > > I understood and experienced that the main thread blocks. But how can it > join > other threads, if it is blocked? That doesn't seem consistent to me. [Nat] Usually one wouldn't create a thread and then immediately join() it. The net effect of that would seem to be an expensive function call. Usually if you want a new thread to run in parallel with the thread that created it, you let both threads run for a while before one thread attempts to join() the other. _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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[Serialization] Need help resolving problem putting serialization code into static library
by Mark Melton 07 Nov '06

07 Nov '06

All, I am hoping someone can help me resolve a problem I am having putting serialization code into a static library. If I am lucky, it will be simple user error. Here is a quick synopsis of the code: a.hpp class A { virtual ~A() { } ...} b.hpp class B : public A { virtual ~B() { } ... } with classes A and B both having the standard serialization functions defined in a.cpp and b.cpp respectively along with the necessary BOOST_CLASS_EXPORT statements. Now, compiling a single program like this works fine and the program is able to serialize objects of types A and B through pointers of type A without any problems. Life is good. g++ -o my_prog my_prog.cpp a.cpp b.cpp -lboost_serialization However, compiling a static library and then linking the same program like this produces a my_prog that gets an unregistered_class exception when trying to serialize an object of type B through a pointer of type A. Not what I expected because the only difference is in the linking phase where code is now coming from the library instead of the object files. g++ -o a.o -c a.cpp g++ -o b.o -c b.cpp ar cru a.o b.o libmine.a ranlib libmine.a g++ -o my_prog my_prog.cpp libmine.a -lboost_serialization Now, combining a.cpp and b.cpp and building the library produces a working program. Confusion reigns. g++ -o ab.o -c a.cpp b.cpp ar cru ab.o libmine.a ranlib libmine.a g++ -o my_prog my_prog.cpp libmine.a -lboost_serialization Any ideas would be greatly appreciated. I have tried several incantations, but I cannot make any headway. I am working under the assumptions that it has something do to with the initialization code difference between using the object files and the library. I am using boost 1.33.1 on intel OS X 10.4.8 with g++ in 64 bit mode. If it would be useful, I can run experiments in 32 bit mode or on Ubuntu, but I have yet to find any differences with this issue. Thanks, mark

2 1

Global Mutex
by Daher 07 Nov '06

07 Nov '06

Hi, How do I create a global mutex in boost.threads ? Dee

3 3

Re: [Boost-users] [Threads] Problem with starting a sub thread
by Ovanes Markarian 06 Nov '06

06 Nov '06

An additional approach could be a thread group, which can create a bunch of threads. Than you can call join on entire group, where the caller thread blocks until all threads are finished. -----Original Message----- From: Nat Goodspeed [mailto:ngoodspeed@solidworks.com] Sent: Monday, November 06, 2006 5:57 PM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] [Threads] Problem with starting a sub thread > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > bounces(a)lists.boost.org] On Behalf Of Goroll, Torsten > Sent: Monday, November 06, 2006 11:46 AM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] [Threads] Problem with starting a sub thread > > I understood and experienced that the main thread blocks. But how can it > join > other threads, if it is blocked? That doesn't seem consistent to me. [Nat] Usually one wouldn't create a thread and then immediately join() it. The net effect of that would seem to be an expensive function call. Usually if you want a new thread to run in parallel with the thread that created it, you let both threads run for a while before one thread attempts to join() the other. _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

1 0

Re: [Boost-users] [Threads] Problem with starting a sub thread
by Goroll, Torsten 06 Nov '06

06 Nov '06

Thanks for the quick answers. I understood and experienced that the main thread blocks. But how can it join other threads, if it is blocked? That doesn't seem consistent to me. Torsten > > > Hi! > > join cause a calling thread to block until the second one is finished. This is also stated in the > docs: > 1.void join(); > Requires: *this is joinable. > !!!!!Effects: The current thread of execution blocks until the initial function of the thread of > execution represented by *this finishes and all resources are reclaimed. > Notes: If *this == thread() the result is implementation-defined. If the implementation > doesn't detect this the result will be deadlock.

2 1

Re: [Boost-users] [Threads] Problem with starting a sub thread
by Nat Goodspeed 06 Nov '06

06 Nov '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > bounces(a)lists.boost.org] On Behalf Of Goroll, Torsten > Sent: Monday, November 06, 2006 11:46 AM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] [Threads] Problem with starting a sub thread > > I understood and experienced that the main thread blocks. But how can it > join > other threads, if it is blocked? That doesn't seem consistent to me. [Nat] Usually one wouldn't create a thread and then immediately join() it. The net effect of that would seem to be an expensive function call. Usually if you want a new thread to run in parallel with the thread that created it, you let both threads run for a while before one thread attempts to join() the other.

1 0

Compiling error in windows VC8: unrecognized posix_time:: microsec_clock
by Cheng, Victor S 06 Nov '06

06 Nov '06

I'm testing the boost 1_33_1 date_time library, but run into a strange compilation problem. In the following code, second_clock::local_time() is fine, but microsec_clock::local_time() will not compile. I'm using XP and visual studio 2005 and VC8. Am I missing anything in my build? compiler messages: 1>.\t2.cpp(18) : error C2653: 'microsec_clock' : is not a class or namespace name 1>.\t2.cpp(18) : error C3861: 'local_time': identifier not found the code: #include "boost/date_time/posix_time/posix_time.hpp" #include <iostream> int main() { using namespace boost::posix_time; ptime now = microsec_clock::local_time(); std::cout << now << std::endl; return 0; } ------------------------------------------------------------------------------ This message is intended only for the personal and confidential use of the designated recipient(s) named above. If you are not the intended recipient of this message you are hereby notified that any review, dissemination, distribution or copying of this message is strictly prohibited. This communication is for information purposes only and should not be regarded as an offer to sell or as a solicitation of an offer to buy any financial product, an official confirmation of any transaction, or as an official statement of Lehman Brothers. Email transmission cannot be guaranteed to be secure or error-free. Therefore, we do not represent that this information is complete or accurate and it should not be relied upon as such. All information is subject to change without notice. -------- IRS Circular 230 Disclosure: Please be advised that any discussion of U.S. tax matters contained within this communication (including any attachments) is not intended or written to be used and cannot be used for the purpose of (i) avoiding U.S. tax related penalties or (ii) promoting, marketing or recommending to another party any transaction or matter addressed herein.

3 2

Re: [Boost-users] [Threads] Problem with starting a sub thread
by Ovanes Markarian 06 Nov '06

06 Nov '06

Hi! join cause a calling thread to block until the second one is finished. This is also stated in the docs: 1.void join(); Requires: *this is joinable. !!!!!Effects: The current thread of execution blocks until the initial function of the thread of execution represented by *this finishes and all resources are reclaimed. Notes: If *this == thread() the result is implementation-defined. If the implementation doesn't detect this the result will be deadlock. There is a good article on boost threads at Dr.Dobbs site: http://www.ddj.com/dept/cpp/184401518 With Kind Regards, Ovanes Markarian On Mon, November 6, 2006 14:17, Torsten wrote: > Hi, > > im trying to initiate a sub thread for checking some variables during the main program is running: > > ...do sth... > > boost::thread checkT(&check); > checkT.join(); > > ...do sth... > > As I understand boost::threads the second "do sth" should be performed during the thread is running. Well, it doesn't seem so. After experimenting some time it came up that starting two threads like that: > > boost::thread checkT(&check); > boost::thread stopCheckT(&stopCheck); > checkT.join(); > scheckT.join(); > > does work, but that: > > boost::thread checkT(&check); > checkT.join(); > boost::thread stopCheckT(&stopCheck); > scheckT.join(); > > does not. I really don't understand why. Either .join() stops executing the code (so the scheckT.join() in the first example shouldn't be called) or it doesn't (than the second scheckT should be called too). > > Where am I wrong? Has anybody an idea? > > Torsten > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users > With Kind Regards, Ovanes Markarian

1 0

[Threads] Problem with starting a sub thread
by Torsten 06 Nov '06

06 Nov '06

Hi, im trying to initiate a sub thread for checking some variables during the main program is running: ...do sth... boost::thread checkT(&check); checkT.join(); ...do sth... As I understand boost::threads the second "do sth" should be performed during the thread is running. Well, it doesn't seem so. After experimenting some time it came up that starting two threads like that: boost::thread checkT(&check); boost::thread stopCheckT(&stopCheck); checkT.join(); scheckT.join(); does work, but that: boost::thread checkT(&check); checkT.join(); boost::thread stopCheckT(&stopCheck); scheckT.join(); does not. I really don't understand why. Either .join() stops executing the code (so the scheckT.join() in the first example shouldn't be called) or it doesn't (than the second scheckT should be called too). Where am I wrong? Has anybody an idea? Torsten

2 1

dynamic-bitset: reversing bits.
by chun ping wang 06 Nov '06

06 Nov '06

Hey i have a quick question regarding dynamic bits. Is there a quick and effective way to reverse bits. (if so how)... i try swapping.. but i get compile time error. so that i can calculate iterative-fft since it requires bit-reverse-copy for (i = 0; i<num_bits/2; ++i) swap(b[i], b[i+numbits/2]);

3 2

Re: [Boost-users] [filesystem] unable to parse file path
by Nat Goodspeed 06 Nov '06

06 Nov '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > bounces(a)lists.boost.org] On Behalf Of Küppers, Ben > Sent: Monday, November 06, 2006 2:59 AM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] [filesystem] unable to parse file path > > Ongoing development now warrants that we interact with the Windows > apps from Linux and vice versa. In the midst of all this it becomes > inevitable to run into the occasional Windows file path on Linux (or Linux > path on Windows)(usually through file IO). I use portable paths wherever I > can but I don't have control over all the input. [Nat] I see. But it should work to convert to forward-slashes everywhere. Sorry for being terse earlier. When I said a character-substitution pass is "cheaper" than reimplementing any significant part of boost::filesystem, I was really thinking of coding/maintenance time. > I am disappointed that the library eliminates the code to treat > backslashes as directory separators at compile-time on non-Windows systems > and doesn't provide me with an option to explicitly enable this code for > the few file paths that I know will have a Windows syntax. [Nat] That could be a useful enhancement. If you're interested enough, you might submit a code and documentation patch. Until then, maybe you could introduce a path subclass for your own use that replaces all '\' with '/' before passing the input path string to the base class.

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[mpl::map] generating map for 150 types
by Ovanes Markarian 06 Nov '06

06 Nov '06

Hi! I need to define a map with int_<1...150>->Type1...150 pairs. Im source file I define: #define BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS #define BOOST_MPL_LIMIT_MAP_SIZE 150 #include <boost/mpl/map.hpp> When compiling I get an error in the file: ...\boost\include\boost-1_33_1\boost\mpl\map.hpp on line: 36 fatal error C1083: Cannot open include file: 'boost/mpl/map/map150.hpp': No such file or directory Development environment is Visual C++ 8 Express Edition The help states: BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS is an boolean configuration macro regulating library's internal use of preprocessed headers. When defined, it instructs the MPL to discard the pre-generated headers found in boost/mpl/aux_/preprocessed directory and use preprocessor metaprogramming techniques to generate the necessary versions of the library components on the fly. In this implementation of the library, the macro is not defined by default. To change the default configuration, define BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS before including any library header. I did what is written here and get this compiler error. Can someone suggest smth? With Kind Regards, Ovanes Markarian

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Re: [Boost-users] [filesystem] unable to parse file path
by Küppers, Ben 06 Nov '06

06 Nov '06

> [Nat] I guess I have a couple of comments. > > One is that a character substitution pass is still cheaper than the > directory parsing and other goodies that boost::filesystem gets you. Speed is not a concern. > The other is to ask why your *nix requirements include backslashes as > directory separators? Backslashes have other significance everywhere but > Windows, which is presumably why boost::filesystem::path wasn't written to > treat '\' and '/' interchangeably on all platforms. Backslashes (and > forward slashes) work on Windows, forward slashes work elsewhere, all per > convention. I work on a large application that runs on Windows and Linux and interacts with various 3rd party applications on either platform, all of them designed with only the dedicated platform in mind and thus using native syntax. Ongoing development now warrants that we interact with the Windows apps from Linux and vice versa. In the midst of all this it becomes inevitable to run into the occasional Windows file path on Linux (or Linux path on Windows)(usually through file IO). I use portable paths wherever I can but I don't have control over all the input. > You seem disappointed that boost::filesystem::path doesn't treat > backslashes as directory separators on non-Windows systems. Not quite, I am disappointed that the library eliminates the code to treat backslashes as directory separators at compile-time on non-Windows systems and doesn't provide me with an option to explicitly enable this code for the few file paths that I know will have a Windows syntax. Note that because Windows supports either directory separator it is possible to parse a Linux relative file path on Windows (with minimal limitations). This e-mail and any attachment is for authorised use by the intended recipient(s) only. It may contain proprietary material, confidential information and/or be subject to legal privilege. It should not be copied, disclosed to, retained or used by, any other party. If you are not an intended recipient then please promptly delete this e-mail and any attachment and all copies and inform the sender. Thank you.

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[variant] trouble using recursive_variant with MSVC ...
by Andy Wu 06 Nov '06

06 Nov '06

Hi all, I'm trying to use the recursive variant as following: typedef boost::make_recursive_variant< int, std::vector<boost::recursive_variant_>, std::map<std::string, boost::recursive_variant_> >::type var_t; ... var_t var(34); ... VC 8.0 can not compile with error C2079: 'std::pair<_Ty1,_Ty2>::second' uses undefined struct 'boost::recursive_variant_' Struct recursive_variant_ is declared but not implement at all. But GCC works well. I'm confused how to solve the problem. Here is the whole program: #include "boost/variant.hpp" #include <iostream> #include <sstream> #include <vector> #include <map> struct vector_printer : boost::static_visitor<std::string> { template <typename T> std::string *operator*()(const std::vector<T>& vec) const { std::ostringstream ost; ost << "( "; typename std::vector<T>::const_iterator it = vec.begin(); *for* (; it != vec.end(); ++it) ost << boost::apply_visitor( vector_printer(), *it ); ost << ") "; *return* ost.str(); } template <typename T> std::string *operator*()(const std::map<std::string, T>& m) const { std::ostringstream ost; ost << "( "; typename std::map<std::string, T>::const_iterator it = m.begin(); *for* (; it != m.end(); ++it) ost << it->first << '\t' << boost::apply_visitor( vector_printer(), it->second ); ost << ") "; *return* ost.str(); } template <typename T> std::string *operator*()(const T& operand) const { std::ostringstream ost; ost << operand << ' '; *return* ost.str(); } }; int main(int , char* []) { typedef boost::make_recursive_variant< int, std::vector<boost::recursive_variant_>, std::map<std::string, boost::recursive_variant_> >::type var_t; std::vector<var_t> vec; vec.push_back(3); vec.push_back(5); vec.push_back(vec); vec.push_back(7); var_t var(vec); std::string result( boost::apply_visitor( vector_printer(), var ) ); std::cout << "result: " << result << '\n'; *return* 0; } And the compile error from VC8 is : test_map_variant.cpp D:\Program\boost\boost_1_33_1\boost/type_traits/is_base_and_derived.hpp : warning C4819: The file contains a character that cannot be represented in the current code page (936). Save the file in Unicode format to prevent data loss D:\Program\boost\boost_1_33_1\boost/utility/enable_if.hpp : warning C4819: The file contains a character that cannot be represented in the current code page (936). Save the file in Unicode format to prevent data loss D:\Program\boost\boost_1_33_1\boost/type_traits/is_base_and_derived.hpp : warning C4819: The file contains a character that cannot be represented in the current code page (936). Save the file in Unicode format to prevent data loss D:\Program\boost\boost_1_33_1\boost/utility/enable_if.hpp : warning C4819: The file contains a character that cannot be represented in the current code page (936). Save the file in Unicode format to prevent data loss D:\Program\boost\boost_1_33_1\boost/utility/enable_if.hpp : warning C4819: The file contains a character that cannot be represented in the current code page (936). Save the file in Unicode format to prevent data loss D:\Program\vs8\VC\INCLUDE\utility(54) : error C2079: 'std::pair<_Ty1,_Ty2>::second' uses undefined struct 'boost::recursive_variant_' with [ _Ty1=const std::string, _Ty2=boost::recursive_variant_ ] D:\Program\vs8\VC\INCLUDE\vector(1083) : see reference to class template instantiation 'std::pair<_Ty1,_Ty2>' being compiled with [ _Ty1=const std::string, _Ty2=boost::recursive_variant_ ] D:\Program\vs8\VC\INCLUDE\vector(1082) : while compiling class template member function 'void std::vector<_Ty>::_Destroy(boost::variant<T0_,T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12,T13,T14,T15,T16,T17,T18,T19> *,boost::variant<T0_,T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12,T13,T14,T15,T16,T17,T18,T19> *)' with [ _Ty=var_t, T0_=boost::detail::variant::recursive_flag<int>, T1=std::vector<boost::recursive_variant_>, T2=std::map<std::string,boost::recursive_variant_>, T3=boost::detail::variant::void_, T4=boost::detail::variant::void_, T5=boost::detail::variant::void_, T6=boost::detail::variant::void_, T7=boost::detail::variant::void_, T8=boost::detail::variant::void_, T9=boost::detail::variant::void_, T10=boost::detail::variant::void_, T11=boost::detail::variant::void_, T12=boost::detail::variant::void_, T13=boost::detail::variant::void_, T14=boost::detail::variant::void_, T15=boost::detail::variant::void_, T16=boost::detail::variant::void_, T17=boost::detail::variant::void_, T18=boost::detail::variant::void_, T19=boost::detail::variant::void_ ] test_map_variant.cpp(63) : see reference to class template instantiation 'std::vector<_Ty>' being compiled with [ _Ty=var_t ] -- B. R. Andy

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[asio] doc directory not present in cvs?
by Andrew Schweitzer 05 Nov '06

05 Nov '06

I assume this is on purpose? Because doc isn't updated to latest changes? Doc is included if I download 0.3.7

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Any interest in a separate Boost.TR1 release/download?
by John Maddock 05 Nov '06

05 Nov '06

I wonder if people would find a separate download for the Boost TR1 components useful ? At present this is vapourware: I'm not sure how easy it will be to sort out documentation and build issues when extracting the TR1 subset, but I'm prepared to put together a preliminary (alpha) release of such a beast if there's demand, and from there we can at least see how viable releasing such a Boost subset would be. Thought? Thanks, John.

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Re: [Boost-users] [mpl::map] generating map for 150 types
by Ovanes Markarian 05 Nov '06

05 Nov '06

Dave, Sorry for my misleading words, the meaning was: As more as I can pre-calculate code at compile time (means slower compilation times) and substitute runtime calculation the more speed I get at runtime. Hope that was what you were meaning in the MPL book. I also understand, that I can bloat compiler with unnecessary calculations without any gain in speed, but my initial sentence was a thank to you an Aleksey for such a nice lib, which can boost the runtime speed if used properly ;) Thanks, Ovanes. -----Original Message----- From: David Abrahams [mailto:dave@boost-consulting.com] Sent: Saturday, November 04, 2006 7:18 PM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] [mpl::map] generating map for 150 types "Ovanes Markarian" <om_boost(a)keywallet.com> writes: > Aleksey, > > Many thanks for your detailed reply. I think the second scenario with > pre-generated headers convinces me more, since our compilation times > are not optimal at all :(. But as you stated in the book: more work > for compiler means less work at runtime. In this case you won't get any runtime speedups by using the method that's slower at compile time. > These were not exactly the words, but I can remember the meaning. I'm not sure you got the meaning exactly right either ;-) -- Dave Abrahams Boost Consulting 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.python] Converting python file object to std::istream.
by Dan 04 Nov '06

04 Nov '06

I am exposing a C++ class to python that takes a reference to a std::istream object and operates on it. It looks something like this: class StreamReader { public: StreamReader(std::istream& strm); private: std::istream& strm_; } I would like to expose this class to python allowing a python client to pass in any python file type object (regular file object, StringIO object, stdin, etc.), as a C++ client would be able to pass any std::istream derived object. Now it seems to me that someone must have encountered this problem before, but I haven't seen any references as to how to make this work. Any ideas on the best way to proceed would be appreciated. thanks, Dan

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[mpl::map & mpl::transform] Problems using mpl::map in mpl::for_each
by Ovanes Markarian 04 Nov '06

04 Nov '06

Hello, I have some slightly different code, which is presented in C++ Template Metaprogramming book to use the mpl::for_each function: mpl::for_each< mpl::transform<seq, wrap<_1> >::type >(dispatcher_type()); The deviation from the book is that my seq it not mpl::vector<...>, but mpl::map<...> In the docs is written, that mpl::transform operates on Forward Sequence. In the doc of forward sequence is stated that mpl::map is a model of it. Unfortunately this code does not compile. I could transform the map to vector, but I would not like doing it, since that would cost compile time and slow down the compilation. Is it a known issue or should not I expect map to work with transform? I also tried using itertors on seq, but that did not help. With Kind Regards, Ovanes Markarian

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Re: [Boost-users] Building boost with icl 9
by Sohail Somani 03 Nov '06

03 Nov '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of John Maddock > Actually you can ignore that message as it happens: it's a > compiler message > and the lib's should still build OK. It was inserted in > because we hadn't > tested the last release with Intel 9 (it didn't exist then), > however there > are no configuration changes required compared to previous > Intel versions, > so you can just ignor the message if you want. If it's > annoying, then > comment out the line in boost/config/compiler/intel.hpp that > generates it. Ok, I did ignore it and it seemed to work fine. Thanks.

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[Boost.Format] Erroneous Behaviour with %d Formatter
by Wu Yinghui, Freddie 03 Nov '06

03 Nov '06

Hi all, I'm using Boost CVS version in the release branch. But according to the change log, it seems that this problem shall exist in Boost 1.33 too. I have the following code snippet, which doesn't produce the desired output: typedef unsigned char qquint8; qquint8 port = 1; boost::format fmt("Trying to probe COM%1$d:..."); std::cout << (fmt % port) << std::endl; The output will was: Trying to probe COM^A:... but what I want should be: Trying to probe COM1:... I understand that the underlying stream might have treated port as a character, thus output it as a character. But from Boost.Format's documentation, this doesn't seem obvious to me, since it always refers this as "printf-like" format string. So my question is: Is this considered a bug (thus, shall be fixed), or is it just considered a special case (thus, shall be explicitly documented under the "Differences of behaviour vs printf" section)? Cheers, Freddie -- Wu Yinghui, Freddie Research & Development Senior Software Engineer Volume Interactions Pte Ltd 1 Kim Seng Promenade, #12-01 Great World City East Tower Singapore 237994 Tel: +65 62226962 (Ext 216) Fax: +65 62226215 Email: yhwu(a)volumeinteractions.com URL: http://www.volumeinteractions.com Important: This message is intended for the recipient(s) addressed above. It contains privileged and confidential information. If you are not the intended recipient, please notify the sender immediately by replying to this message and then delete it from your system. You must not read, copy, use, or disseminate this communication in any form. Thank you.

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Re: [Boost-users] Boost ROCKS !!!!!
by Nindi Singh 03 Nov '06

03 Nov '06

Ok .... as good a time as any other to look at the Preprocessor library. So now my factories look like this. There still needs to be alot of polishing, error handling etc, but I think I have mad a fair application of Boost. So I'll post the code taking on board your suggestion for completeness. ( Hopefully NOT in HTML 8-) ) --------------------------------------------------------------------------- <Singleton.h> #ifndef SINGLETON_HEADER_GUARD #define SINGLETON_HEADER_GUARD #include <boost/utility.hpp> template<class Object> struct Singleton :boost::noncopyable{ public: static Object & instance(){static Object theObject;return theObject;} virtual ~Singleton(){} }; #endif -------------------------------------------------------------------------------------- <Factory.h> #ifndef FACTORY_HEADER_GUARD #define FACTORY_HEADER_GUARD #include<string> #include<map> #include"Singleton.h" #include<boost/shared_ptr.hpp> #include<boost/mpl/size.hpp> #include<boost/mpl/list.hpp> #include<boost/mpl/at.hpp> #include<boost/preprocessor/repetition.hpp> #include<boost/preprocessor/arithmetic/sub.hpp> #ifndef MAX_FACTORIES #define MAX_FACTORIES 10 #endif // One Registration object per class in a hireachy, this is the template blue print for the base classes of // the registration objects template < class BaseClass, typename Key = std::string, unsigned long = boost::mpl::size<typename BaseClass::Constructor_TypeList>::value > struct RegistraBase {}; // This is the template blue print for the concrete classes of // the registration objects template < class BaseClass, class Derived, typename Key = std::string, unsigned long n = boost::mpl::size<typename BaseClass::Constructor_TypeList>::value > struct Registra :public RegistraBase<BaseClass,Key,n>{}; // This is the factory template blue print of the Factory class template < class BaseClass, typename Key = std::string , unsigned long n = boost::mpl::size<typename BaseClass::Constructor_TypeList>::value > class Factory {}; //Helper Macros #define PARAM(z,Nb,data) typename boost::mpl::at_c<typename BaseClass::Constructor_TypeList,Nb>::type P##Nb #define REGISTRABASE(z,Nb,data) \ template<class BaseClass,typename Key> struct RegistraBase<BaseClass,Key,Nb> { \ virtual boost::shared_ptr<BaseClass> RetrieveObject(BOOST_PP_ENUM(Nb,PARAM,~))const=0; \ }; BOOST_PP_REPEAT(MAX_FACTORIES,REGISTRABASE,~) #define FACTORY(z,Nb,data) \ template \ < \ class BaseClass, \ typename Key \ > \ class Factory<BaseClass,Key,Nb> { \ public: \ bool Register(const Key & theKey,RegistraBase<BaseClass,Key,Nb> *theRegistra){ \ return theInnerMap.insert(InnerMap::value_type(theKey,theRegistra)).second; \ } \ \ boost::shared_ptr<BaseClass> RetrieveObject(const Key &id BOOST_PP_COMMA_IF(Nb) BOOST_PP_ENUM(Nb,PARAM,~))const { \ InnerMapIterator theIterator (theInnerMap.find(id)); \ if(theIterator==theInnerMap.end())return boost::shared_ptr<BaseClass>(static_cast<BaseClass *>(0)); \ return theIterator->second->RetrieveObject( BOOST_PP_ENUM_PARAMS(Nb,P)); \ } \ private: \ typedef typename std::map<Key,RegistraBase<BaseClass,Key,Nb> *> InnerMap; \ typedef typename std::map<Key,RegistraBase<BaseClass,Key,Nb> *>::const_iterator InnerMapIterator; \ std::map<Key,RegistraBase<BaseClass,Key,Nb> *> theInnerMap; \ }; BOOST_PP_REPEAT(MAX_FACTORIES,FACTORY,~) // The macro defintions of the Registration Objects #define REGISTRA(z,Nb,data) \ template<class BaseClass,class Derived,typename Key> \ struct Registra<BaseClass,Derived,Key,Nb>:public RegistraBase<BaseClass,Key,Nb> { \ Registra(const Key & theKey){Singleton<Factory<BaseClass,Key,Nb> >::instance().Register(theKey,this);} \ boost::shared_ptr<BaseClass> RetrieveObject(BOOST_PP_ENUM(Nb,PARAM,~))const \ {return boost::shared_ptr<BaseClass>(new Derived( BOOST_PP_ENUM_PARAMS(Nb,P)));} \ virtual ~Registra(){} \ }; BOOST_PP_REPEAT(MAX_FACTORIES,REGISTRA,~) #undef MAX_FACTORIES #undef PARAM #undef REGISTRA #undef REGISTRABASE #undef FACTORY #include"StaticFactory.h" #endif ----------------------------------------------------------------------------------------------------------------------------- <StaticFactory.h> #ifndef STATIC_FACTORY_HEADER_GUARD #define STATIC_FACTORY_HEADER_GUARD #include<string> #include<map> #include"Singleton.h" #include<boost/shared_ptr.hpp> #include<boost/mpl/size.hpp> #include<boost/mpl/list.hpp> #include<boost/mpl/at.hpp> #include<boost/preprocessor/repetition.hpp> #include<boost/preprocessor/arithmetic/sub.hpp> #ifndef MAX_STATIC_FACTORIES #define MAX_STATIC_FACTORIES 10 #endif template < class BaseClass, typename Key = std::string > struct StaticRegistraBase { virtual boost::shared_ptr<BaseClass> RetrieveObject()const=0; }; template < class BaseClass, class Derived, typename Key = std::string, unsigned long n = boost::mpl::size<typename BaseClass::Constructor_TypeList>::value > struct StaticRegistra :public StaticRegistraBase<BaseClass,Key>{}; template < class BaseClass, typename Key=std::string > class StaticFactory { public: bool Register(const Key & theKey,StaticRegistraBase<BaseClass,Key> *theRegistra){ return theInnerMap.insert(InnerMap::value_type(theKey,theRegistra)).second; } boost::shared_ptr<BaseClass> RetrieveObject(const Key &id )const { InnerMapIterator theIterator (theInnerMap.find(id)); if(theIterator==theInnerMap.end())return boost::shared_ptr<BaseClass>(static_cast<BaseClass *>(0)); return theIterator->second->RetrieveObject(); } private: typedef typename std::map<Key,StaticRegistraBase<BaseClass,Key> *> InnerMap; typedef typename std::map<Key,StaticRegistraBase<BaseClass,Key> *>::const_iterator InnerMapIterator; std::map<Key,StaticRegistraBase<BaseClass,Key> *> theInnerMap; }; //Helper Macros #define PARAM(z,Nb,data) typename boost::mpl::at_c<typename BaseClass::Constructor_TypeList,Nb>::type P##Nb #define STATICREGISTRA(z,Nb,data) template<class BaseClass,class Derived,typename Key> \ struct StaticRegistra<BaseClass,Derived,Key, Nb >:public StaticRegistraBase<BaseClass,Key> \ { \ StaticRegistra(const Key & theKey BOOST_PP_COMMA_IF(Nb) BOOST_PP_ENUM(Nb,PARAM,~)): \ theObjectPtr(new Derived(BOOST_PP_ENUM_PARAMS(Nb,P))) \ { \ Singleton<StaticFactory<BaseClass,Key> >::instance().Register(theKey,this); \ } \ boost::shared_ptr<BaseClass> RetrieveObject()const{return theObjectPtr;} \ virtual ~StaticRegistra(){} \ private: \ boost::shared_ptr<BaseClass> theObjectPtr; \ }; BOOST_PP_REPEAT(MAX_STATIC_FACTORIES,STATICREGISTRA,~) #undef MAX_STATIC_FACTORIES #undef PARAM #undef STATICREGISTRA #endif -------------------------------------------------------------------------------------------------------------- <Phactory.h> #ifndef PHACTORY_HEADER_GUARD #define PHACTORY_HEADER_GUARD #include<string> #include<map> #include<cassert> #include<boost/shared_ptr.hpp> #include<boost/variant.hpp> #include<boost/utility.hpp> #include<boost/static_assert.hpp> #include<boost/mpl/size.hpp> #include<boost/mpl/list.hpp> #include<boost/mpl/at.hpp> #include<boost/preprocessor/repetition.hpp> #ifndef MAX_PHACTORIES #define MAX_PHACTORIES 10 #endif template<unsigned long i> struct unsigned_long {enum {value=i};}; template<class BaseClass> struct PhRegistraBase { typedef typename boost::make_variant_over<typename BaseClass::variant_type_list::type>::type variant; typedef std::map<std::string,variant> ParameterMap; virtual boost::shared_ptr<BaseClass> RetrieveObject(const std::string &theKey,const ParameterMap& theMap )const=0; }; template<class BaseClass> class Phactory { public: typedef typename boost::make_variant_over<typename BaseClass::variant_type_list::type>::type variant; typedef std::map<std::string,variant> ParameterMap; bool Register(const std::string &theKey, const PhRegistraBase<BaseClass>* theRegistra){ return theInnerMap.insert(InnerMap::value_type(theKey,theRegistra)).second; } boost::shared_ptr<BaseClass> RetrieveObject(const std::string &id, const ParameterMap & theMap)const { InnerMapIterator theIterator (theInnerMap.find(id)); if(theIterator==theInnerMap.end())return boost::shared_ptr<BaseClass>(static_cast<BaseClass *>(0)); return theIterator->second->RetrieveObject(id,theMap); } private: typedef typename std::map<std::string,const PhRegistraBase<BaseClass> *> InnerMap; typedef typename std::map<std::string,const PhRegistraBase<BaseClass> *>::const_iterator InnerMapIterator; std::map<std::string,const PhRegistraBase<BaseClass> *> theInnerMap; }; #define PARAM(z,Nb,data) boost::get<const boost::mpl::at_c<signature, Nb >::type &>(theMap.find(theVarNames[Nb])->second) #define INNER_RETRIVE_OBJECT(z,Nb,data) \ template<> boost::shared_ptr<BaseClass> InnerRetrieveObject< Nb >(const std::string &theKey,const ParameterMap& theMap) \ const{ \ CheckMap(theMap); \ return boost::shared_ptr<BaseClass>(new DerivedClass( BOOST_PP_ENUM(Nb,PARAM,~) ) \ ); \ } template < class BaseClass, class DerivedClass > class PhRegistra:public PhRegistraBase<BaseClass>{ public: typedef typename DerivedClass::constructor_signature_typelist signature; typedef typename boost::make_variant_over<typename BaseClass::variant_type_list::type>::type variant; typedef std::map<std::string,variant> ParameterMap; enum {ssize = boost::mpl::size<signature>::value}; template<unsigned long i> PhRegistra(const std::string &theKey, const char *theVariableNames[],const unsigned_long<i> *p=0) { BOOST_STATIC_ASSERT(i==ssize); // Must have ONE variable name for each paramter of the constructor for(unsigned long i(0);i<ssize;++i) theVarNames[i]=std::string(theVariableNames[i]); Singleton<Phactory<BaseClass> >::instance().Register(theKey,this); } boost::shared_ptr<BaseClass> RetrieveObject(const std::string &theKey,const ParameterMap& theMap)const{ return InnerRetrieveObject<ssize>(theKey,theMap); } template<int i> boost::shared_ptr<BaseClass> InnerRetrieveObject(const std::string &theKey,const ParameterMap&)const; BOOST_PP_REPEAT(MAX_PHACTORIES,INNER_RETRIVE_OBJECT,~) private: void CheckMap(const ParameterMap& theMap)const { assert(theMap.size()==ssize); for(unsigned long i(0);i<ssize;++i)assert(theMap.find(theVarNames[i])!=theMap.end()); } std::string theVarNames[ssize]; }; #define PARAM_NAMES(n) n , static_cast<unsigned_long<sizeof(n)/sizeof(char*)> *>(0) #undef MAX_PHACTORIES #undef PARAM #undef INNER_RETRIVE_OBJECT #endif ----------------------------------------------------------------------------------------------------------------------------------- <main.cpp> #include<vector> #include<iostream> #include"Factory.h" #include"Phactory.h" using namespace std; struct MyClassVoid { typedef boost::mpl::list<> Constructor_TypeList; MyClassVoid(){} virtual void f()const=0; virtual ~MyClassVoid(){}; }; struct MyClassVoidDerived :public MyClassVoid { MyClassVoidDerived(){} virtual void f()const{cout << " I am in MyClassVoidDerived \n";} virtual ~MyClassVoidDerived(){}; }; namespace { Registra<MyClassVoid,MyClassVoidDerived> theRegistraVoid(std::string("MyClassVoidDerived")); } struct MyClassDouble { typedef boost::mpl::list<double> Constructor_TypeList; typedef boost::mpl::list<double> variant_type_list; MyClassDouble(double){} virtual void f(){cout << " I am in MyClassDouble \n";} virtual ~MyClassDouble(){}; }; struct MyClassDoubleDerived :public MyClassDouble { typedef boost::mpl::list<double> constructor_signature_typelist; MyClassDoubleDerived(double x):MyClassDouble(x){} virtual void f(){cout << " I am in MyClassDoubleDerived \n";} virtual ~MyClassDoubleDerived(){}; }; namespace { Registra<MyClassDouble,MyClassDouble> theRegistra(std::string("MyClassDouble")); Registra<MyClassDouble,MyClassDoubleDerived> theRegistraD(std::string("MyClassDoubleDerived")); } struct MyClassMultiple { typedef boost::mpl::list<std::string,std::vector<double>,double,MyClassDoubleDerived > Constructor_TypeList; MyClassMultiple(std::string,std::vector<double>,double,MyClassDoubleDerived){} virtual void f(){cout << " I am in MyClassMultiple \n";} virtual ~MyClassMultiple(){}; }; namespace { Registra<MyClassMultiple,MyClassMultiple> theRegistraM(std::string("MyClassMultiple")); StaticRegistra<MyClassMultiple,MyClassMultiple> theStaticRegistraM(std::string("MyClassMultiple"),std::string("String"),std::vector<double>(2),1.0,MyClassDoubleDerived(1.0)); } struct Dummy{}; struct Base { typedef boost::mpl::list<double,int,unsigned long,std::string,std::vector<double>,float,Dummy> variant_type_list; Base(){} virtual void f()const=0; virtual ~Base(){}; }; struct Derived :public Base { typedef boost::mpl::list<double,int,std::string,std::vector<double> > constructor_signature_typelist; Derived(double x_,int n_,const std::string &s_,const std::vector<double>&v_): x(x_),n(n_),s(s_),v(v_){} virtual void f()const{ cout << "My Double is " << x << "\n" << "My int is " << n << "\n" << "My String is " << s << "\n" << "My Vector Size is " << v.size() << "\n"; } private: double x; int n; std::string s; std::vector<double> v; }; namespace { const char * theVarNames[]={"Double","Int","String","Vector"}; PhRegistra<Base,Derived> thePhRegistra(std::string("DerivedObject"),PARAM_NAMES(theVarNames)); } int main() { char ch; boost::shared_ptr<MyClassVoid> thePtrVoid(Singleton<Factory<MyClassVoid> >::instance().RetrieveObject("MyClassVoidDerived")); thePtrVoid->f(); boost::shared_ptr<MyClassDouble> thePtrDoubleDerived(Singleton<Factory<MyClassDouble> >::instance().RetrieveObject("MyClassDoubleDerived",1.0)); thePtrDoubleDerived->f(); boost::shared_ptr<MyClassDouble> thePtrDouble(Singleton<Factory<MyClassDouble> >::instance().RetrieveObject("MyClassDouble",1.0)); thePtrDouble->f(); boost::shared_ptr<MyClassMultiple> thePtrM(Singleton<Factory<MyClassMultiple> >::instance().RetrieveObject("MyClassMultiple",std::string("String"),std::vector<double>(2),1.0,MyClassDoubleDerived(1.0))); thePtrM->f(); boost::shared_ptr<MyClassMultiple> thePtrSM(Singleton<StaticFactory<MyClassMultiple> >::instance().RetrieveObject("MyClassMultiple")); thePtrSM->f(); std::map<std::string,typename boost::make_variant_over<typename Base::variant_type_list::type>::type> theMap; theMap["Double"]=1.0; theMap["Int"]=1; theMap["String"]="hello"; theMap["Vector"]=std::vector<double>(10); boost::shared_ptr<Base> thePtrPhM(Singleton<Phactory<Base> >::instance().RetrieveObject("DerivedObject",theMap)); thePtrPhM->f(); cin >>ch; } -------------------------------------------------------------------------------------------------------------------------------------- ----- Original Message ---- From: David Abrahams <dave(a)boost-consulting.com> To: boost-users(a)lists.boost.org Sent: Thursday, 2 November, 2006 5:33:36 PM Subject: Re: [Boost-users] Boost ROCKS !!!!! Nindi Singh <nindi73(a)yahoo.co.uk> writes: > Any comments on my use ( or indeed abuse !) of Boost would be more > than apprieciated. You might consider using the preprocessor library to eliminate some of that repetitive macro code. -- Dave Abrahams Boost Consulting www.boost-consulting.com _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users ___________________________________________________________ The all-new Yahoo! Mail goes wherever you go - free your email address from your Internet provider. http://uk.docs.yahoo.com/nowyoucan.html

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Re: [Boost-users] [filesystem] unable to parse file path
by Nat Goodspeed 03 Nov '06

03 Nov '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > bounces(a)lists.boost.org] On Behalf Of Küppers, Ben > Sent: Friday, November 03, 2006 1:56 AM > To: boost-users(a)lists.boost.org > Subject: RE: [Boost-users] [filesystem] unable to parse file path > > > [Nat] I'd suggest a string pass -- on every platform -- to change every > > '\' to '/' before passing it to boost::filesystem::path. I believe > > forward slash should work everywhere. I find it plausible that backslash > > would only work on Windows. > > That is what I am doing right now but I started using > boost::filesystem::path to get out of that business. [Nat] I guess I have a couple of comments. One is that a character substitution pass is still cheaper than the directory parsing and other goodies that boost::filesystem gets you. The other is to ask why your *nix requirements include backslashes as directory separators? Backslashes have other significance everywhere but Windows, which is presumably why boost::filesystem::path wasn't written to treat '\' and '/' interchangeably on all platforms. Backslashes (and forward slashes) work on Windows, forward slashes work elsewhere, all per convention. You seem disappointed that boost::filesystem::path doesn't treat backslashes as directory separators on non-Windows systems.

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Building boost with icl 9
by Sohail Somani 03 Nov '06

03 Nov '06

Hi, I'm trying to build bjam using the Intel compiler, version 9. I use the v1 command line of: bjam "-sTOOLS=intel-win32" "-sBUILD=release <runtime-link>dynamic <threading>multi" ... to build the thread library (although the <threading>multi is probably redundant!). I get the following output: Unknown compiler version - please run the configure tests and report the results Which configure tests should I run? Thanks, Sohail

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Re: [Boost-users] [filesystem] unable to parse file path
by Nat Goodspeed 03 Nov '06

03 Nov '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > bounces(a)lists.boost.org] On Behalf Of Küppers, Ben > Sent: Thursday, November 02, 2006 4:37 AM > To: boost-users(a)lists.boost.org > Subject: [Boost-users] [filesystem] unable to parse file path > > At the moment, I don't see any other option > than to process the path string manually before passing it to the path > constructor (kind-a defeats the whole purpose of using this class). [Nat] I'd suggest a string pass -- on every platform -- to change every '\' to '/' before passing it to boost::filesystem::path. I believe forward slash should work everywhere. I find it plausible that backslash would only work on Windows.

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Unable to check exception with BOOST_CHECK_THROW
by Stephen Torri 03 Nov '06

03 Nov '06

I am finding that the BOOST_CHECK_THROW is not catching an exception class I made. Below is how I am calling it: void test_read_FAIL_EMPTY_READ () { boost::uint32_t size = 0; boost::uint8_t* data = 0; boost::uint32_t length = 5; Memory_Map a_ref ( size ); BOOST_CHECK_THROW ( a_ref.read ( data, length ), errors::IO_Exception ); } The read function is suppose to throw an errors::IO_Exception(int) when it finds out that the length of the read exceeds the length of the Memory_Map. What I am finding out is that the exception is being thrown but no message from Boost telling me that exception errors::IO_Exception has occurred and calling this test a success. Have I used the wrong macro? Stephen

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[Serialization] Need help resolving problem putting serialization code into static library
by Mark Melton 02 Nov '06

02 Nov '06

All, I am hoping someone can help me resolve a problem I am having putting serialization code into a static library. If I am lucky, it will be simple user error. Here is a quick synopsis of the code: a.hpp class A { virtual ~A() { } ...} b.hpp class B : public A { virtual ~B() { } ... } with classes A and B both having the standard serialization functions defined in a.cpp and b.cpp respectively along with the necessary BOOST_CLASS_EXPORT statements. Now, compiling a single program like this works fine and the program is able to serialize objects of types A and B through pointers of type A without any problems. Life is good. g++ -o my_prog my_prog.cpp a.cpp b.cpp -lboost_serialization However, compiling a static library and then linking the same program like this produces a my_prog that gets an unregistered_class exception when trying to serialize an object of type B through a pointer of type A. Not what I expected because the only difference is in the linking phase where code is now coming from the library instead of the object files. g++ -o a.o -c a.cpp g++ -o b.o -c b.cpp ar cru a.o b.o libmine.a ranlib libmine.a g++ -o my_prog my_prog.cpp libmine.a -lboost_serialization Now, combining a.cpp and b.cpp and building the library produces a working program. Confusion reigns. g++ -o ab.o -c a.cpp b.cpp ar cru ab.o libmine.a ranlib libmine.a g++ -o my_prog my_prog.cpp libmine.a -lboost_serialization Any ideas would be greatly appreciated. I have tried several incantations, but I cannot make any headway. I am working under the assumptions that it has something do to with the initialization code difference between using the object files and the library. I am using boost 1.33.1 on intel OS X 10.4.8 with g++ in 64 bit mode. If it would be useful, I can run experiments in 32 bit mode or on Ubuntu, but I have yet to find any differences with this issue. Thanks, mark

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[property_tree] Why I get such a big Lib?
by Andrea Carbone 02 Nov '06

02 Nov '06

Hello, I am working on a little class using the property_tree lib. MSVC 7.1, boost 1.33.1 and latest property_tree cvs from sandbox. I have simply Pimpled the boost::property_tree::ptree class and implemented a templated get<> to extract values from a conf file ... I don't know if it is fair to attach files to the mail so I just paste the header... Here the interface: #ifndef xml_config_t_H_INCLUDED #define xml_config_t_H_INCLUDED //--------------------------------------------------------------------- #include <string> #include <memory> //--------------------------------------------------------------------- //just tags ... namespace all { namespace core{ namespace detail { struct xml_t{}; struct ini_t{}; } static const core::detail::xml_t xml = core::detail::xml_t(); static const core::detail::ini_t ini = core::detail::ini_t(); }} //--------------------------------------------------------------------- namespace all { namespace core{ //the implementation namespace detail{class xml_config_impl;} class xml_config_t; }} //--------------------------------------------------------------------- class all::core::xml_config_t { public: ///Constructor xml_config_t(); ~xml_config_t(); ///this one calls read_xml void load(core::detail::xml_t, const std::string&); ///this one calls read_ini void load(core::detail::ini_t, const std::string&); public: ///the template get method .. calls ptree::get<T> .... template <typename T> T get(const std::string&, const T& defval = T()) const; private: //pimpl idiom std::auto_ptr<core::detail::xml_config_impl> impl; }; //--------------------------------------------------------------------------- #endif //xml_config_t_H_INCLUDED //--------------------------------------------------------------------------- The code compiles and it actually works ... that is fine. But the problem is that Compiling the class as a static lib, produces an huge library (~14 MB !!). I am compiling wiht /MT flag .. RTTI is off and there are just default settings ... Why such a huge library file? The templated method is defined for some builtin data types such as int, float, long ...etc ... Thanks for your attention ....

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Thread pool
by Sohail Somani 02 Nov '06

02 Nov '06

Hi, Does Boost have any thread-pooling classes? I'm thinking something that allows you to weight tasks perhaps by expected computational time or other random things. If not, can someone generously point me to some? Preferably some that work with boost threads. I've found http://threadpool.sf.net and I am currently looking at it. Thanks, Sohail

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Re: [Boost-users] Compiling with VC8 gives libraries and DLLs withvc71
by Javier Estrada 02 Nov '06

02 Nov '06

Thx. Apparently I messed up by using "bjam -sTOOLS=vc-8_0_tool install" instead. A related question: The reason I found this is because I ported a project to VC8 and the linker barfs, asking for the vc8 infix in the libraries. I assume a macro is defining the infix, am I correct.? -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of John Maddock Sent: Thursday, November 02, 2006 9:37 AM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] Compiling with VC8 gives libraries and DLLs withvc71 Javier Estrada wrote: > I'm running into a problem when compiling with VC8 regarding the > library names that are produced. > > The names come out with an infix of 'vc71' (e.g., > libboost_thread-vc71-mt-1_33_1.lib). > > I gathered that this infix comes from some of the macros that are > defined, but have been unable to uncover why the name is not picked up > correctly, given that the compiler version is correct. > > I'm quite sure I've followed the installation instructions correctly, > open the right command prompt and the vcvars batch file, etc. The library names come from the toolset you select to build with, you need to use: bjam -sTOOLS=vc-8_0 install to get names with "vc80" in them. John. _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Solving boost version issues
by Daniel Krügler 02 Nov '06

02 Nov '06

Hello, I apologize in advance, if this contribution is slightly off-topic, but I assume that the discussed problem is of general interest for most boost users. Not rarely one stumbles across the problem that even your most favourite 3rd party library has an implementation error, and you need a fix for that. And the good thing: Those highly motivated guys have already found the error and fixed it - in cvs. Well, that is actually all very fine, especially if you are able to handle with cvs (who of the programmers can not?) and you could use this fixed version, but there remains one big problem: The 3rd party library has not been released and you want to prevent nasty effects, if your fixed version meets the older version - the have all the same lib names. OK, end of the scenario, I assume that I describe here a well-known and well-feared problem ;-) Actually everything is fine, besides...: I would like to modify the lib names and which place would be more reasonable than the bjam configuration? First, because the described problem just hits me in the moment concerning a boost fix and I would like to influence the current bjam, such that all libraries are build as usual, but with an additional user-defined (or even hard-coded(!) string constant (aka "build id") at the end of each name. I have to confess that I have little experience with bjam and I don't understand the way how I can modify the related file(s) to reach the wanted effect: I can only assume that one has to change the file Jamfile.v2, probably the "function" rule tag beginning with line 95. Please, is someone willing to help me in that situation? Second I would like to propose that the current bjam script is generally modified to allow the addition of such a user-defined build-id simply attached after the normal naming scheme described on http://boost.org/more/getting_started.html#Results libboost_date_time-gcc-mt-d-1_31-your_build_id.a with a new, to be defined bejam option, which allows such an addition. Sorry for the noise and thank you for your patience! With Greetings from Bremen, Daniel Krügler

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[Boost.Parameter] How to Use Named Parameters in a Class Hierarchy?
by Wu Yinghui, Freddie 02 Nov '06

02 Nov '06

Dear all, I'm implementing a hierarchy of classes to handle different types of objects. The characteristics of these objects are mostly similar (so I can put them into a container that knows only about the pure abstract base interface type), but some properties are specific to each object types. I plan to use Boost.Parameter for its capability of providing named parameter to these object types. However, I have one problem in this approach: Since Boost.Parameter requires that the function processing the ArgumentPack to be a template, I cannot make it virtual (a member function template cannot be virtual) in my pure abstract base interface. Furthermore, due to the lack of "virtual" member function, I cannot use the base class pointer to provide these named parameters to some subclasses. So my question is: Is there a way to tackle this problem? (Use Boost.Parameter with virtual member functions? Or avoid using Boost.Parameter, but provide a way to access subclass properties that are not know directly via the base class?) Any suggestion is welcomed! Cheers, Freddie -- Wu Yinghui, Freddie Research & Development Senior Software Engineer Volume Interactions Pte Ltd 1 Kim Seng Promenade, #12-01 Great World City East Tower Singapore 237994 Tel: +65 62226962 (Ext 216) Fax: +65 62226215 Email: yhwu(a)volumeinteractions.com URL: http://www.volumeinteractions.com Important: This message is intended for the recipient(s) addressed above. It contains privileged and confidential information. If you are not the intended recipient, please notify the sender immediately by replying to this message and then delete it from your system. You must not read, copy, use, or disseminate this communication in any form. Thank you.

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