July 2006 - Boost-users - lists.boost.org

(de)serializing map<const A*>
by Cheok Yan Cheng 28 Jul '06

28 Jul '06

By refering to message http://groups.google.com/group/boost-list/browse_frm/thread/79dba906901d039… I am also facing similar problem. I need to iterate through the content of map, and remove the constantness before deserialization. Due to this, I need to save the map size into disk as well. I know that there is no obvious fix for this. However, I was wondering whether is there any much better workaround? Thank you very much! yccheok

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Re: [Boost-users] XML Serialization Traits Question
by William Bardon 28 Jul '06

28 Jul '06

Robert, I forced a crude solution by defining a custom XML output archive and defining My_Archive::save_override(const nvp<T>&, int) as below. This would double the class information in some objects, so I also set the BOOST_CLASS_IMPLEMENTATION to object_serializable for my serialized classes. It is crude, but seems to give me the results I need. class My_Archive : public boost::archive::xml_oarchive_impl<OArchive_Versioned> { ... template<class T> void save_override( #ifndef BOOST_NO_FUNCTION_TEMPLATE_ORDERING const #endif ::boost::serialization::nvp<T> & t, int) { save_start(t.name()); if (boost::serialization::implementation_level<T>::value >= boost::serialization::object_serializable) { write_attribute("version", boost::serialization::version<T>::value, "=\""); } boost::archive::save(* this->This(), t.const_value()); save_end(t.name()); } // redeclared fall thru versions of all specialized versions of save_override omitted for space }; By examining the library's source code, I have determined that the tracking of class traits in serialization occurs in basic_oarchive_impl::save_object, defined in basic_oarchive.cpp. It uses the class cobject_type to track classes it has seen. Because basic_archive_impl and cobject_type are completely defined within basic_archive.cpp, the ability to customize XML attributes is limited. Perhaps future versions of Serialization could look into making the XML optionally generate an XML schema for interoperation with other XML-based applications. Thanks, Bill -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Robert Ramey Sent: Wednesday, July 26, 2006 5:57 PM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] XML Serialization Traits Question I would have to go back and study the code again to give a good answer and I'm not up to this right now. But I can offer a suggestion in the short term. I use VC 7.1 debugger. Set a trap at save_override(const version ... When the program traps in the debugger. examine the stack trace to see the chain of overrides and specializations whch got you there. Robert Ramey William Bardon wrote: > Robert, > > Thanks for the example; it helped clear up some uncertainty about the > template arguments in the derived class. > > Regarding save_override, I see where specialized versions for the > different trait types are defined in basic_xml_oarchive.ipp. I also > see that save_override is called from the operator<< redefinition in > interface_oarchive.hpp. What I'm missing is the link between > serializing a user-defined class object and the traits of that object. > > template<class Archive> > BOOST_ARCHIVE_OR_WARCHIVE_DECL(void) > basic_xml_oarchive<Archive>::save_override(const version_type & t, > int) { > int i = t.t; // extra .t is for borland > write_attribute(VERSION(), i); > } > > This function already displays a version attribute in the XML. How do > I make sure this is called for every element? I'm sorry, but I can't > figure out how to modify chain of control to force output of class > traits. > > Starting in oserializer.hpp, boost::archive::save<Archive,T> calls > static save_non_pointer_type<Archive, T>::invoke calls serialize_adl > calls boost::serialization::serialize<Archive, T> calls > access::serialize calls myClass::serialize<Archive> (Archive& ar, > unsigned int version) > > There is also a function oserializer<Archive,T>::save_object_data that > calls serialize_adl, but I can't find anything that calls it. > > The struct save_non_pointer_type<Archive, T> in oserializer.hpp may be > the key, but I'm not sure how it works. > > In oserializer.hpp, struct > save_non_pointer_type<Archive,T>::save_standard::invoke calls > Archive::save_object, but I do not see an implementation of the > function anywhere: > > $ find /usr/include/boost -type f -exec grep -H save_object {} \;| > grep -v save_object_ | more > /usr/include/boost/archive/polymorphic_oarchive.hpp: virtual void > save_object( > /usr/include/boost/archive/detail/oserializer.hpp: > ar.save_object(& t, oserializer<Archive, T>::instantiate()); > /usr/include/boost/archive/detail/basic_oarchive.hpp: void > save_object( > /usr/include/boost/archive/detail/polymorphic_oarchive_impl.hpp: > virtual void save_object( > /usr/include/boost/archive/detail/polymorphic_oarchive_impl.hpp: > ArchiveImplementation::save_object(x, bos); > > I'd appreciate any suggestions. Am I even looking in the right place? > > Thanks in advance, > Bill > > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Robert Ramey > Sent: Wednesday, July 26, 2006 12:14 PM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] XML Serialization Traits Question > > > "William Bardon" <wbardon(a)cabcds.org> wrote in message > news:C73E689C9FCF884B9A550ECFADA0721C087D3E@exchange.cab-cds.org... > I have read both the Boost Serialization online documentation and the > archives of the Boost-Users mailing list looking for guidance, but I > haven't found anything relevant. I see how to use > BOOST_CLASS_TRACKING and BOOST_CLASS_IMPLEMENTATION to remove version > tracking attributes from the XML tags. > > Usage of these macros does a lot more than remove attributes from the > tags. > > I want to go in the opposite direction. I notice that the class_id > and version attributes only appear the first time an object of a > particular class is serialized. I want to force the version attribute > to appear in every object's attribute list. > > Do I need to derive a custom archive to do this? > > yes > > I have looked at the source code for serialization, but I have trouble > plowing through all of the macros, template expansions, and overloaded > functions to locate the specific part that controls whether class > traits are stored as attributes in a particular XML tag. > > I sympathize - its hard to follow. And I wrote it. Here are some > hints: > > a) look at demo_fast_archive.cpp to see a model of how one can derive > from an existing archive. > b) You'll want to derive from xml_oarchive_impl<...> to create > my_xml_oarchive > c) add a "save_override" function to my_xml_oarchive which replaces > the "save_override" function in > basic_xml_oarchive.ipp. Implement this using functions defined > basic_xml_oarchive.ipp > > Good luck - > > Robert Ramey > > > Thanks in advance, > Bill > > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users > > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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regex problem in multithreading...
by yogendra karki 28 Jul '06

28 Jul '06

Hello all, i am using boost regex to check the syntax of a URL. the regex is as :- static const char *URLSYNTAXREGEX = "^((file|https?|ftp)://)?(([-a-zA-Z0-9_]+[.]{1})+(([-a-zA-Z0-9]+))([:]{1}([0-9]+)){0,1})([?/][^[:space:]]*)?" the function for evaluation is:- bool URLHandler::EvaluateRegex(const char *regularexp,std::string url){ boost::smatch what; boost::regex exp(regularexp,boost::regex::extended); boost::regex_search(url,what,exp); std::string search=(std::string)what[0]; if(search.length() == url.length()) { return true; } else { return false; } } when i am running this code with single thread it is running fine. But when i am integrating this code with a multithreaded application it is giving this error:- terminate called after throwing an instance of 'boost::regex_error' what(): Invalid content of repeat range Aborted Can you please help me in this. Its very urgent for me. Thanks. Yogendra --------------------------------- Do you Yahoo!? Everyone is raving about the all-new Yahoo! Mail Beta.

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regular expression for random word wrap to multiple line
by Winson Yung 28 Jul '06

28 Jul '06

Hi all, I am not sure this is an old topic or not, but I cannot seem to find an answer for this. I have a table, because of the table column width restriction, some of the line in a table row/field gets wrapped around to second/third lines. Here is a simple illustrated the issue: sales and marketing (excludes stock-based compensation of $817, $369 and $113 for 2005, 2004 AND 2003, RESPECTIVELY) 74,823 36,000 21,162 As you can see the description txt gets break down into three lines. If I write something like this "^sales and marketing (excludes stock-based compensation of", it's not gonna capture the entire line that ended with numbers. The exact location where the line gets wrapped around is not known, so it's impossible to craft the regular expression like this beforehand. Is there a way to write *ONE* regular expression to handle this? /Winson.

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Re: [Boost-users] default copy constructors
by Andrew McDonald 28 Jul '06

28 Jul '06

> I have a specific c++ question, and was wondering whether someone > could offer some advice. It is probably better to post such questions to comp.lang.c++ or comp.lang.c++.moderated > ie is it safe to assume that Test's copy constructor will call the > copy constructor of all the above attributes. >From the C++ standard ISO/IEC 14882:1998(E) Section 12.8.8; The implicitly defined copy constructor for class X performs a memberwise copy of its subobjects. The order of copying is the same as the order of initialization of bases and members in a user defined constructor (see 12.6.2). Each subobject is copied in the manner appropriate to its type: - if the subobject is of class type, the copy constructor for the class is used; - if the subobject is an array, each element is copied, in the manner appropriate to the element type; - if the subobject is of scalar type, the builtin assignment operator is used. Virtual base class subobjects shall be copied only once by the implicitly defined copy constructor (see 12.6.2). regards, Andrew McDonald System Architect Norwood Systems Australia Pty Ltd Level 1, 71 Troy Terrace PO Box 1281 Subiaco, WA 6904 Tel +61 8 9380 7766 Fax +61 8 9380 7733 The information in this email, and any attachments, may contain confidential information and is intended solely for the attention and use of the named addressee (s). It must not be disclosed to any person(s) without authorization. If you are not the intended recipient, or a person responsible for delivering it to the intended recipient, you are not authorized to, and must not, disclose, copy, distribute, or retain this message or any part of it. If you have received this communication in error, please notify the sender immediately.

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regular expression help
by llwaeva＠21cn.com 28 Jul '06

28 Jul '06

Hi there, I am going to retrieve the following pattern %K{xxx} where xxx can be anything except line break. I find and modify the following code from document, is that right for my case? boost::regex expK("[^%]*%K{([^\r\n])}"); std::string::const_iterator start, end; start = sourcesrc.begin(); end = sourcesrc.end(); boost::match_results<std::string::const_iterator> what; boost::match_flag_type flags = boost::match_default; while ( regex_search(start, end, what, expK, flags) ) { // handle the match string, i.e. xxx my_fun( std::string( what[1].first, what[1].second ) ); start = what[1].second; flags |= boost::match_prev_avail; flags |= boost::match_not_bob; } Here, expK found all the substring matching %K{xxx} (not including double % case). But the program didn't give me what I want, I guess the problem is from the expression where { and } is not expressed correctly. However, I didn't found how to express { and } in the document. Here is my guess of the correct form, tell me if it is correct or not 1) boost::regex expK("[^%]*%K\{([^\r\n])\}"); // here \{ represents { and \} represents } 2) boost::regex expK("[^%]*%K[{]{1}([^\r\n])[}]{1}"); // use [{]{1} and [}]{1} to limit the { and } occur once exactly 3) boost::regex expK("[^%]*%K\\{([^\r\n])\\}"); // here \\{ represents { and \\} represents } which one is correct? or all is wrong? Please help! Thanks in advance.

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error in regex_replace!?
by llwaeva＠21cn.com 28 Jul '06

28 Jul '06

Hi there, I am using regex_replace to find_replace a pattern. The code is shown below string src = "xxx%R__xy\r\n%\r\nRyyyy% A__%%A\r\n%Rzzz%C%Appp_%C0123\r\n%Rooo"; re = "(%R)|(%A)|(%C)"; format = "(?1#R)(?2#A)(?3#C)"; cout << "SOURCE:" << endl << src << endl << endl; regex_replace( src.begin(), src.begin(), src.end(), re, format, format_all ); cout << "OUTPUT:" << endl << src << endl << endl; 1) For replacing %R with #R, %A with #A and %C with #C, and the output string save back to the source string, the above code do a good job. And the output is xxx#R__xy % Ryyyy% A__%#A #Rzzz#C#Appp_#C0123 #Rooo NOTE that %%A is replaced with %#A 2) If I change the format so that the length of format longer than that of subsitute string, e.g. re = "(%R)|(%A)|(%C)"; format = "(?1#RRR)(?2#AAA)(?3#CCC)"; regex_replace raise an error. I think the error is come from the original string is not long enough to store the output string. The problem can be solved by the following code string src = "xxx%R__xy\r\n%\r\nRyyyy% A__%%A\r\n%Rzzz%C%Appp_%C0123\r\n%Rooo"; string output=src; re = "(%R)|(%A)|(%C)"; format = "(?1#RRR)(?2#AAA)(?3#CCC)"; cout << "SOURCE:" << endl << src << endl << endl; regex_replace( output.begin(), src.begin(), src.end(), re, format, format_all); cout << "OUTPUT:" << endl << output << endl << endl; But I do want the output store in the original string. Reassigning the source string slove the problem, i.e. src = output, but for a large input string (for my case , >5M), this way is not that good. I am looking for a better approach. BTW, if the length of the output string shorter than the original string, the output carry some other extra characerts. e.g. string src = "xxx%Ry%Az%Ce"; string output=src; re = "(%R)|(%A)|(%C)"; format = "(?1R)(?2A)(?3C)"; The output is "xxxRyAzCe%Ce" where the last %Ce are extra characters from source string. How can I kill the extra characters? 3) Finally, I will modify the search condition to make sure that only %X rather than %%X (X can be R, A or C) is replaced. I try the following regular expression re = "([^%]%R)|([^%]%A)|([^%]%C)"; but it doesn't work properly for my problem. e.g. for src = "xxx%R %%R", for the format "(?1#R)(?2#A)(?3#C)"; the regular expression will kill the 'x' before %R, i..e. the output is "xx#R %%R" rather than "xxx#R %%R" Please help! Thanks in advance.

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Labeling patched Boost versions
by Daniel Krügler 28 Jul '06

28 Jul '06

Hello, Recently I had a discussion with a colleague concerning the possibility to influence the resulting file names of the default boost output. This discussion was actually inspired by the outcome of thread "[thread] Keeping leak detectors still..." on 2006-07-11 where we had the situation of an inofficial patch which we would like to use. The problem is: How can/should I signal a patched boost version? According to the naming scheme described in http://boost.org/more/getting_started.html one could change the boost subminor version. Regrettably we found out that most programmers actually expect that such a number belongs to one of the *official* boost versions provided by http://boost.org/, (most probably because the naming scheme smoothly integrates). Now I had the idea of an optional "build id", which is a well-known tool in many projects to signal a given state or "snap shot". The very advantage of a build id - which's format is usually not fixed, but typically is a string of numbers, letters and some file-name compatible characters like '-', normally without any white spaces and of arbitrary length - is, that it accentuates and differs very strongly from the regular pattern of the subdivided version number. Ideally it should be possible to define a kind of bjam constant, e.g -sBUILD_ID=string (I'm not a bjam expert and I hope that the above proposed name does not violate any naming policies of such configuration parameters), which would allow to explicitly set build id for a bjam build. I have no strong opinion concerning the exact position of that build id in a lib name, but probably the most resonable one would be just after the version number, e.g. libboost_date_time-gcc-mt-d-1_31_M20060721.a for -sBUILD_ID=M20060721 Does there already exist such a possibility to do that and if not: I would really appreciate such a general available "callback" for injecting a build id (a sequence of characters) into the final output. Standard behaviour would of course be, *not* to attach such id, but the possibility to do that via a userdefined program parameter of bjam would be fantastic! The problem is: If I would manually hack the boost bjam files to do just this, I could never update to the next boost version without fears, because I always would need to manipulate the new version also. Since I assume that this request is of general interest for the community I would like to humbly ask for support of it. What do you think? Any chances for that idea? Or better ones? Greetings from Bremen, Daniel Krügler

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DateTime: Seconds until next month
by Olaf van der Spek 28 Jul '06

28 Jul '06

Hi, I'm currently using the following code to calculate the number of seconds until the next month. I'm wondering whether there's an easier way. date d(day_clock::universal_day()); d += months(1); cout << duration2a((ptime(date(d.year(), d.month(), 1)) - second_clock::universal_time()).total_seconds()) + " until ladders reset" << endl; return 0;

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regex_replace help
by llwaeva＠21cn.com 28 Jul '06

28 Jul '06

Hi there, I am using regex_replace for string replacing. I am working with a very large string (about 3M) and need to do the following replacment %R% --> #R# %A% --> #R1# %C% --> #R2# and so on. I am new to regular express and regex. After having read the document, I know how regex works, but still not sure if regex_replace meet my demand 1) I invoke regex_replace several times to replace difference patterns. For a large input string, the operation is very slow. Can I call regex_replace once to do the several replacments. i.e. calling regex_replace( output, begin, end, "%R ,%A ,%C", "#R#, #R1#, #R2#", match_default); for replacing %R% with #R# %A% with #R1# %C% with #R2# 2) According to the document, the output fashion depends on the match_flag_type, for my case, I hope the output string, including both matched and nonmatched part, replace the whole input string. e.g. SourceStr = "xxxx%R%yyy%A%zzz%C%" Apply regex_replace( output_string, SourceStr.begin, SourceStr.end, ... ) We have , output_string = "xxxx#R#yyy#R1#zzz#R2#" rather than #R#, #R1# and #R2# Any reply will be highly appreciated.

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