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list of optional dependencies for building boost?
by Benjamin Rutt 21 Sep '05

21 Sep '05

I am new to boost and have a question on building it from source. I built it once using the command: bjam --with-python-root=/home/rutt/python-2.4 -sPYTHON_VERSION=2.4 --prefix=/home/rutt/boost install So you can see that I at least resolved the optional dependency on Python. I also noticed that it warned me that it could not find the bzip2 or gzip packages (I can't remember which). At the end of the build, it mentioned something about a number of errors it had in building, yet it did install the boost libraries. So it seems that the build process continues on past failures (something like 'make -k'). I guess those "failures" must have been unmet optional dependencies? My intention is to build a fully capable boost library and have zero errors and zero unmet dependencies. Is there some documentation or method to obtain information about all optional dependencies boost can pick up at build time? I would like to install them all, to ensure a clean, zero-error build and know that I have a fully functional boost. Thank you, -- Benjamin Rutt

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Re: [Boost-users] inheriting from boost::thread
by Simmons, Aaron 21 Sep '05

21 Sep '05

I write a lot of cross-platform code that's used from JNI. In JNI, you should tell the JVM about native threads that are running. Because Java threads are named, when you attach a native thread to the JVM you have to specify a name. It occurred to me that I could write a "jnithread" class that inherits from boost::thread. It would take a thread-name argument. Before the threadfunc runs it would attach the new thread to the JVM, and when the threadfunc ends it would detach from the JVM. It's relatively easy to write such a class, and would make life easier for thread creation within JNI. However, I hesitate because of the lack of a virtual destructor... -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of me22 Sent: Wednesday, September 21, 2005 1:27 PM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] inheriting from boost::thread On 21/09/05, Simmons, Aaron <a-simmons1(a)ti.com> wrote: > > I've been thinking about writing a class that inherits from boost::thread. > However, I noticed that the destructor isn't virtual. Shouldn't it be? > boost::thread is designed neither as a base class nor to be used polymorphically. Why do you want to inherit from a thread? You still couldn't get at the private thread handles and there are no virtual functions to modify behavior. - Scott _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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boost::test 1.33 compile problem on VC7.0+STLport (1.32 fine)
by Steve Streeting 21 Sep '05

21 Sep '05

Hi, I just upgraded to Boost 1.33 and a set of my unit test routines written against boost::test 1.32 have suddenly started reporting compile errors. I can trigger the issue very simply: --- #include <boost/test/included/unit_test_framework.hpp> #include <boost/test/unit_test.hpp> using namespace boost::unit_test; test_suite* init_unit_test_suite( int argc, char* argv[] ) { test_suite* test = BOOST_TEST_SUITE( "tests" ); } --- In Boost 1.32 this works fine, in Boost 1.33 it reports: --- c:\temp\boost_1_33_0\boost\test\impl\framework.ipp(305) : error C2440: 'initializing' : cannot convert from 'long' to 'boost::unit_test::for _each::static_any_t' Reason: cannot convert from 'long' to 'const boost::unit_test::for_each::static_any_base' No constructor could take the source type, or constructor overload resolution was ambiguous c:\temp\boost_1_33_0\boost\test\impl\framework.ipp(305) : error C2143: syntax error : missing ')' before '=' c:\temp\boost_1_33_0\boost\test\impl\framework.ipp(305) : error C2143: syntax error : missing ';' before '=' c:\temp\boost_1_33_0\boost\test\impl\framework.ipp(305) : error C2059: syntax error : ')' c:\temp\boost_1_33_0\boost\test\impl\framework.ipp(305) : error C2143: syntax error : missing ';' before '{' c:\temp\boost_1_33_0\boost\test\impl\framework.ipp(305) : error C2181: illegal else without matching if c:\temp\boost_1_33_0\boost\test\impl\framework.ipp(305) : error C2440: 'initializing' : cannot convert from 'long' to 'boost::unit_test::for_each::static_any_t' Reason: cannot convert from 'long' to 'const boost::unit_test::for_each::static_any_base' No constructor could take the source type, or constructor overload resolution was ambiguous --- .. and so on (hits upper error limit). I've just reverted back to 1.32 for now, but can you tell me why this happens? Many thanks Steveboost::test 1.33 compile problem on VC7.0+STLport

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Re: [Boost-users] inheriting from boost::thread
by Sohail Somani 21 Sep '05

21 Sep '05

-----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Simmons, Aaron Sent: Wednesday, September 21, 2005 10:29 AM To: boost-users(a)lists.boost.org Subject: [Boost-users] inheriting from boost::thread I've been thinking about writing a class that inherits from boost::thread. However, I noticed that the destructor isn't virtual. Shouldn't it be? Your problem might be better solved using containment

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inheriting from boost::thread
by Simmons, Aaron 21 Sep '05

21 Sep '05

I've been thinking about writing a class that inherits from boost::thread. However, I noticed that the destructor isn't virtual. Shouldn't it be? Thanks, aaron

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Re: [Boost-users] static maps (was trouble with boost::assign)
by Gottlob Frege 21 Sep '05

21 Sep '05

On 9/20/05, boost-users-request(a)lists.boost.org < boost-users-request(a)lists.boost.org> wrote: > > Message: 2 > Date: Mon, 19 Sep 2005 12:35:08 -0500 > From: "Lee Crabtree" <lcrabtree(a)goisi.com> > Subject: [Boost-users] trouble with boost::assign > To: boost-users(a)lists.boost.org > Message-ID: <dgmsos$amg$1(a)sea.gmane.org> > > Hi, I'm trying initialize a static map with map_list_of. Something along > the > lines of: > > map<int,int> blarg = map_list_of(1, 2); > > However, when I go to compile, I receive the following error: ... Lee Crabtree > > > Can't help you with the error, unfortunately, but just wondering - does this map *remain* static after initialization? ie Do you do any inserts or deletes after init? I wrote a static_map<K, T> that is constructed from a static array, which I use for those cases where the map doesn't change, and I was just wondering how useful people thought it might be - ie how often do you have maps that never change after initialization from static data?

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Re: [Boost-users] algorithms and member functions
by Foster Gareth 21 Sep '05

21 Sep '05

> " > class A { > void wee(); > } > > container<A> as; > for_each(in as, a::wee()); > " > So as as not to miss the point, I think I'd better expand the pseudo code example just a tad ... " class A { int wee() { return m_wee } // returns bit flag style int int m_wee; }; container<A> as; find_if ( in as, // somehow need to say here "current->wee() & SOME_FLAG" ); " Hope that is a little more clear. Thanks again, Gaz

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algorithms and member functions
by Foster Gareth 21 Sep '05

21 Sep '05

Hello all, Take for example, a situation where, in psuedo code of course, I want to do this sort of thing ... " class A { void wee(); } container<A> as; for_each(in as, a::wee()); " I did a little google work on this and found this amazing flame war between a Java user and a Boost/C++ user: [ http://episteme.arstechnica.com/groupee/forums/a/tpc/f/6330927813/m/26500301 5731 ] It seems from this that we, as c++ users, have as options: * writing a new functor to call methods * using std::mem_fn * using the boost enhancements to the above I get the impression that boost bind and lambda are relevent here, although I've only glanced at examples. What interests me is the anonymous methods / class style syntax that Java offers. I've played with it myself, and it seems nice, and one of the proponents in the afore mentioned flame war advocates it. What is the thinking behind not introducing such syntax into C++? I am sort of working from the assumption that the template solutions (as opposed to language modification solutions) in boost at the moment, will be moved into std:: and offered as a solution rather than an update to the language. It may be that I have the wrong end of the stick there, and that the boost solutions are a temporary solution. It may also be there are good reasons to prefer the template style solution. It may also be I am talking tripe :) Anyway, I hope this doesn't make a mountain out of a mole hill. I'm just wondering about the decisions that have been / are likely to be made, in this area. I don't claim to hold any opionion on the matter, other than "I think it is an interesting matter" :) Thanks all, Gaz ********************************************** * http://www.mozilla.org/products/firefox/ * **********************************************

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BGL - edge descriptor and map
by Giulio Veronesi 21 Sep '05

21 Sep '05

I'd like to specify better my problem. I'd like to use an edge_descriptor (graph_traits<G>::edge_descriptor) as key in a map. The graph type is something like this: typedef adjacency_list<vecS, vecS, bidirectionalS, no_property, MyStuff> G; I think that I've to overload the < operator for graph_traits<G>::edge_descriptor. Is this correct? If so, given two edge_descriptors I need to access the source and the target of the edge in such a way to define a sort ordering. Thanks, Giulio

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enable_if missing from status summary
by Steven Solie 21 Sep '05

21 Sep '05

I'm finding the utility/enable_if tests are missing from the status summary for my AmigaOS port. I think the process_jam_log tool is unable to handle it for some reason because the xml output files are incorrect. I see from a Google search this has been discussed before. Has there been any resolution to this problem? --Steven

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[BGL] detecting cycles path in a graph
by Giulio Veronesi 21 Sep '05

21 Sep '05

Hi, I'd like to obtain the path of a cycle in a graph. The file dependency example in the user guide only allow to discover cycles and not the path that forms the cycle. Please, could you help me to address this problem? Thanks a lot, Giulio

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Re: [Boost-users] list of optional dependencies for building boost?
by Andrew Holden 21 Sep '05

21 Sep '05

One other I know of: the Regex library can depend on the ICU Unicode libraries (http://www-306.ibm.com/software/globalization/icu/index.jsp) Andrew Holden -----Original Message----- From: Benjamin Rutt [mailto:rutt@bmi.osu.edu] Sent: Tuesday, September 20, 2005 9:38 AM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] list of optional dependencies for building boost? OK, from what I've gathered, boost can optionally depend on python and gzip+bzip2 libraries. If anyone can think of something I have missed, let me know. Thanks, -- Benjamin Rutt _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Re: [Boost-users] Scons users?
by David Abrahams 21 Sep '05

21 Sep '05

Andy Moreton <andy.moreton(a)artimi.com> writes: > I think that the effort expended on BBv1/BBv2 would have been far better > spent on fixing the performance issues in scons. Just for the record, BBv1 predates Scons by some considerable time. When I began that project I tried to get Steven Knight to start on Scons with me and at the time he wasn't ready yet. -- Dave Abrahams Boost Consulting www.boost-consulting.com

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BGL - edge descriptor
by Giulio Veronesi 21 Sep '05

21 Sep '05

Hi, I'd like to extract the source and target vertex id from an edge_descriptor without using the graph that contains the edge. More specifically, consider the following code: typedef graph_traits<MyGraph>::edge_descriptor MyLink; void MyFunction(MyLink& link) { cout << "source vertex id: " << ??? << ", target vertex id: " << ??? << endl; } What I've to put at place of ??? to print the source and target vertex id? Is it a dirty solution to use the m_source and m_target field of the edge_descriptor structure? Thanks, Giulio

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Date_time library question
by Michal Lijowski 20 Sep '05

20 Sep '05

I just started with date_time library using boost-1.33.0-3 on FC4 and gcc 4.0.1 20050727. It is rpm version downloaded from http://download.fedora.redhat.com/pub/fedora/linux/core/development/i386/Fe…. I copied some lines of code from boost_date_time.pdf to get familiar with capabilities of this library and I encountered some problems. Here is a modified code taken from page 3 of the manual /* The following is a simple example that shows conversion of dates * to and from a std::string. ** Expected output: * 2001-Oct-09 * 2001-10-09 * Tuesday October 9, 2001 * An expected exception is next: * Exception: Month number is out of range 1..12 */ #include "boost/date_time/gregorian/gregorian.hpp" #include "boost/date_time/posix_time/posix_time.hpp" #include "boost/date_time/posix_time/posix_time_duration.hpp" #include "boost/date_time/local_time/local_time.hpp" #include <iostream> #include <string> #include <sstream> using namespace boost::gregorian; using namespace boost::local_time; using namespace boost::posix_time; using namespace std; int main() { try { //input streaming stringstream ss("2004-Jan-1"); date d; ss >> d; cout << " d " << d << endl; ptime t0; ss >> t0; cout << " t0 " << t0 << endl; date d1(1999, Jan, 1); ss >> d1; cout << " d1 " << d1 << endl; ptime t2(d1, minutes(0)); cout << " t2 " << t2 << endl; ss >> t2; cout << " t2 " << t2 << endl; date d3(2002,Feb,1); //an arbitrary date // the line below compiles with error: ‘nanosec’ was not declared in this scope // ptime t1(d3, hours(5)+nanosec(100)); //date + time of day offset ptime t1(d3, hours(5)); cout << " d3 " << d3 << endl; ptime t3 = t1 - minutes(4)+seconds(2); ptime now = second_clock::local_time(); //use the clock date today = now.date(); //Get the date part out of the time date tomorrow = today + date_duration(1); ptime tomorrow_start(tomorrow); //midnight // std::stringstream ss1("2004-Jan-1 05:21:33.20"); stringstream ss1("2004-Jan-1"); ss1 >> t2; cout << " t2 " << t2 << endl; //starting at current time iterator adds by one hour time_iterator titr(now,hours(1)); for (; titr < tomorrow_start; ++titr) { cout << (*titr) << std::endl; } } catch(std::exception& e) { std::cout << " Exception: " << e.what() << std::endl; } return 0; } And output from this program is d not-a-date-time t0 not-a-date-time d1 1999-Jan-01 t2 1999-Jan-01 00:00:00 t2 1999-Jan-01 00:00:00 d3 2002-Feb-01 t2 2004-Jan-01 00:00:00 2005-Sep-16 08:58:09 2005-Sep-16 09:58:09 2005-Sep-16 10:58:09 2005-Sep-16 11:58:09 2005-Sep-16 12:58:09 2005-Sep-16 13:58:09 2005-Sep-16 14:58:09 2005-Sep-16 15:58:09 2005-Sep-16 16:58:09 2005-Sep-16 17:58:09 2005-Sep-16 18:58:09 2005-Sep-16 19:58:09 2005-Sep-16 20:58:09 2005-Sep-16 21:58:09 2005-Sep-16 22:58:09 2005-Sep-16 23:58:09 My question is why d and t0 are not-a-date-time? Is this expected? Also the line ptime t1(d3, hours(5)+nanosec(100)); //date + time of day offset compiles with error: ‘nanosec’ was not declared in this scope Thanks, Michal

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Re: [Boost-users] Scons users?
by David Abrahams 20 Sep '05

20 Sep '05

"Reece Dunn" <msclrhd(a)hotmail.com> writes: > David Abrahams wrote: >>Kevin Wheatley <hxpro(a)cinesite.co.uk> writes: >> > David Abrahams wrote: >> >> On the Boost.Build list we were just discussing the fact that some >> >> people otherwise inclined towards Boost have chosen Scons over >> >> Boost.Build. It would be useful for us to understand some of the >> >> reasons why, if some of you wouldn't mind letting us know. No flames, >> >> please! >> > >> > not a flame, but some test results (Noel Llopis' Blog) shows a few >> > interesting results: >> > >> > http://tinyurl.com/7fdns (www.gamesfromwithin.com) >> > >> > These are updated from previously. >> >>Wow, harsh. The numbers aside, I think his commentary is rather >>flame-ish. > > I thought it was harsh as well. Here are a few comments: > > Ant/Rant outperform Jam on full builds even though he claims Jam is the > fastest performing build system. > > BBv2 and SCons are aimed at being truely platform independant, i.e. one > script will work for everything, whereas the others need work on your part > to get that or only support one target. I didn't think Scons was trying to achieve that. IIUC you still deal with many platform specifics when writing Sconscripts... no? > I agree with him that there is a learning curve when learning Jam/BBv2, but > you get this with learning any new language. Yes, but we ought to be doing more to make it shallow. I am about to start posting editorial review commentary on our documentation. I hope that many on this list will participate, so we can make BBv2 much more usable. > He says to avoid BBv2/SCons because of performance, but performance > is only one factor. Well, yes. The other factor for most people is "how easy is it for me to get it to do what I want?" If the system is complex and hard-to-understand, it won't be easy to use, so we may be failing on both counts. > [As a note, how much of a performance penalty is there from BBv2 and > SCons being built on top of and run from a scripting engine?] Some, but I think for BBv2 that only hurts to the extent that we're trying to do something smarter and more abstract than what people do with the other systems. Gnu Make, too, has a kind of scripting engine in it. However, some of its primitives are more closely directed at the problem domain. > What I like about BBv2 is that I can create a hello world > application in 1 minute! The jam file: > > exe hello : hello.cpp ; > install . : hello ; # copy hello.exe to this directory > > hello.cpp: > > #include <iostream> > int main() > { > std::cout << "Hello World!" << std::endl; > return 0; > } > > and most of that is writing hello.cpp! Heh, with make I think you might not even need a makefile for this one ;-) $ cat > foo.cpp #include <iostream> int main() { std::cout << "hello, world!" << std::endl; return 0; } dave@i9300 /tmp $ make foo g++ foo.cpp -o foo dave@i9300 /tmp $ ls *ake* ls: *ake*: No such file or directory See? > With this, I can now build debug and release versions - and build on > any supported C++ compiler/platform - as easily as changing the > command line, BBv2 takes care of the rest. Make and Jam don't give > you this out of the box. Now you're talking... but: "changing the command line" isn't easy unless you can come to grips with the system, and we've made that a bit too difficult. > I have lost count of the number of times I have run into problems with > incorrect project settings for MSVC projects, most of which are due to the > IDE defaulting to the current configuration (debug or release) instead of > editing all configurations. > > BBv2 (and I assume SCons has this as well) allows you to set project wide > settings (e.g. include paths) that are inherited by all targets in this > directory and below. You can't do this with the other build tools as far as > I am aware, or doing so is complex and unmaintainable. That's also true. > Also, BBv2 (and SCons?) works out the build dependancies for you based on > how targets are associated, so if you add another dependancy on one of the > targets, you don't need to change the build order as you would in *Ant. > (MSVC does dependancy analysis, but only for the current solution and you > can't nest solution files). > > It would be interesting to have more data from large build projects and > timing/profile data for these. Q: Is it possible to get profiling data for > bjam and BBv2 to see what parts of bjam and BBv2 are taking the most time. Yes, pass -d+10 on the command line. > Also, I don't believe that BBv2 has incremental build support. I > wonder what this and pre-compiled header support would do to the > timing data. What do you mean by "incremental build support?" -- Dave Abrahams Boost Consulting www.boost-consulting.com

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Scons users?
by David Abrahams 20 Sep '05

20 Sep '05

Hi, On the Boost.Build list we were just discussing the fact that some people otherwise inclined towards Boost have chosen Scons over Boost.Build. It would be useful for us to understand some of the reasons why, if some of you wouldn't mind letting us know. No flames, please! -- Dave Abrahams Boost Consulting www.boost-consulting.com

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Re: [Boost-users] Scons users?
by Vladimir Prus 20 Sep '05

20 Sep '05

Arkadiy Vertleyb wrote: > "Reece Dunn" <msclrhd(a)hotmail.com> wrote > >> Also, I don't believe that BBv2 has incremental build support. > > Do you mean it always rebuilds everything?! Any reason why it is > acceptable? Ehm... do you really think that Boost.Build rebuilds every target on every invocation? Reece most likely meant various "incremental rebuild" options in windows compilers. - Volodya

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Re: [Boost-users] [boost] Scons users?
by Martin Bonner 20 Sep '05

20 Sep '05

----Original Message---- From: David Abrahams [mailto:dave@boost-consulting.com] Sent: 20 September 2005 12:59 To: boost(a)lists.boost.org Cc: jamboost(a)yahoogroups.com; boost-users(a)lists.boost.org Subject: Re: [boost] Scons users? > Kevin Wheatley <hxpro(a)cinesite.co.uk> writes: > >> David Abrahams wrote: >>> On the Boost.Build list we were just discussing the fact that some >>> people otherwise inclined towards Boost have chosen Scons over >>> Boost.Build. It would be useful for us to understand some of the >>> reasons why, if some of you wouldn't mind letting us know. No >>> flames, please! >> >> not a flame, but some test results (Noel Llopis' Blog) shows a few >> interesting results: >> >> http://tinyurl.com/7fdns (www.gamesfromwithin.com) >> >> These are updated from previously. > > Wow, harsh. The numbers aside, I think his commentary is rather > flame-ish. Well, without the numbers, I agree. But the numbers do rather back him up (except that BoostBuild does seem to be marginally quicker than Scons on three out of four tests, whereas he describes it as "Slower even than Scons!"). Are there any known optimization oportunities in BoostBuild? Are the results an artifact of his test set up? -- Martin Bonner Martin.Bonner(a)Pitechnology.com Pi Technology, Milton Hall, Ely Road, Milton, Cambridge, CB4 6WZ, ENGLAND Tel: +44 (0)1223 441434

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[iostreams] experience with automatically decompressing with gzip or bzip2
by Marcus Alanen 19 Sep '05

19 Sep '05

Hello, I've recently used iostreams for easier gziping and bzip2ing of output streams. However, I'd also like to be able to read any file compressed with either gzip or bzip2, by analyzing the input stream and deducing which decompressor to use. I don't want to open the file twice or to seek in the stream, as this might not be possible due to e.g. reading from the network. My solution is to create a custom streambuf, which is told to read and retain the first few bytes to determine which decompressor to push onto the boost::iostreams::filtering_streambuf. Then the actual reading can take place, and the custom streambuf first returns the retained bytes, then just streams the rest of the actual input streambuf. As far as I can tell, this works nicely. I wonder if anybody else has better solutions for this? Perhaps there is come capability of iostreams that I've overlooked? Below is the code, feel free to use as you wish. I don't know if I need to override xsgetc(), underflow() and uflow(), so they are currently just non-working stubs. So far nothing seems to have triggered any of them: only xsgetn seems to be used. I haven't found any actual errors, though. Both gzip and bzip2 files seem to decompress. Otherwise the code can be improved a lot, e.g. by registering separate compression detectors instead of hard-coding them in the streambuf. I think I'm also lost a bit where and when to use streambufs instead of streams, e.g. m_input. Apologies if the code is too long for your mailing-list, I didn't find any guidelines for this. Regards, Marcus #include <boost/iostreams/filtering_streambuf.hpp> #include <boost/iostreams/copy.hpp> #include <boost/iostreams/filter/bzip2.hpp> #include <boost/iostreams/filter/gzip.hpp> #include <iostream> #include <boost/noncopyable.hpp> class general_decompressor_streambuf : public std::basic_streambuf<char, std::char_traits<char> >, public boost::noncopyable { private: std::streambuf& m_input; static const int BUFFER_SIZE = 5; unsigned char m_read[BUFFER_SIZE]; std::streamsize m_readpos; std::string m_compression_type; public: general_decompressor_streambuf(std::streambuf& i) : m_input(i), m_readpos(0) { ; } ~general_decompressor_streambuf() throw () { ; } std::string get_compression_type() const { return m_compression_type; } void resolve_compressor (boost::iostreams::filtering_streambuf<boost::iostreams::input>& sb) { int pos = 0; while (pos < BUFFER_SIZE) { int c = m_input.sbumpc(); if (c == EOF) return; m_read[pos++] = c; } if (m_read[0] == 037 && m_read[1] == 0213) { m_compression_type = "GZIP"; sb.push( boost::iostreams::gzip_decompressor() ); } else if (m_read[0] == 'B' && m_read[1] == 'Z' && m_read[2] == 'h') { m_compression_type = "BZIP2"; sb.push( boost::iostreams::bzip2_decompressor() ); } else { ; } } std::streamsize xsgetn(char* s, std::streamsize n) { std::streamsize cnt = 0; if (m_readpos < BUFFER_SIZE) { while (m_readpos < BUFFER_SIZE && n > 0) { unsigned char ch = m_read[m_readpos++]; *s++ = ch; ++cnt; } if (cnt == n) return cnt; } std::streamsize ss = m_input.sgetn(s, n - cnt); ss += cnt; return ss; } int xsgetc() { std::cerr << "xsgetc" << std::endl; return m_input.sgetc(); } int underflow ( ) { std::cerr << "underflow" << std::endl; return m_input.sgetc(); } int uflow ( ) { std::cerr << "uflow" << std::endl; return m_input.sgetc(); } }; int main() { general_decompressor_streambuf buffering_in_streambuf(*std::cin.rdbuf()); boost::iostreams::filtering_streambuf<boost::iostreams::input> cmpr; buffering_in_streambuf.resolve_compressor(cmpr); cmpr.push(buffering_in_streambuf); std::istream i(&cmpr); boost::iostreams::copy(i, std::cout); return 0; }

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trouble with boost::assign
by Lee Crabtree 19 Sep '05

19 Sep '05

Hi, I'm trying initialize a static map with map_list_of. Something along the lines of: map<int,int> blarg = map_list_of(1, 2); However, when I go to compile, I receive the following error: error C2440: 'initializing' : cannot convert from 'boost::assign_detail::generic_list<T>' to 'std::map<_Kty,_Ty,_Pr,_Alloc>' with [ T=std::pair<boost::assign_detail::assign_decay<int>::type,boost::assign_detail::assign_decay<int>::type> ] and [ _Kty=int, _Ty=int, _Pr=std::less<int>, _Alloc=std::allocator<std::pair<const int,int>> ] I have absolutely no idea what this means. Am I missing something obvious, or is there a more sinister problem afoot? Lee Crabtree

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Re: [Boost-users] [RMI-like-lib] is there any interest in such?
by Foster Gareth 19 Sep '05

19 Sep '05

> Jarl Lindrud has done a lot of work on this already - see > > http://www.codeproject.com/threads/RMI_For_Cpp.asp > > While it uses boost and mpl techniques extensively it's not > quite boost style. > I'd be using it extensively but for the fact that it doesn't > integrate well with > our own code framework. > Looks interesting. Just out of interest, could you site any examples, or point me toward previous discussion that does so? Cheers, Gaz

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Find all the shortest path from a graph
by Giulio Veronesi 19 Sep '05

19 Sep '05

Hi all, I'd like to extract all possible shortest path from a source to a destination... not only one path. Please, could you help me to resolve this problem? Thanks a lot in advance, Giulio

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locate vertex
by Giulio Veronesi 19 Sep '05

19 Sep '05

Hi, I would like to locate an edge of a graph starting from the source and target vertex. For instance vertex(n, g) return the nth vertex of graph g. I would access the edge from vertex x to vertex y... something like this edge(x, y, g) Is there a fast way to do this? Thanks, Giulio

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[RMI-like-lib] is there any interest in such?
by Slawomir Lisznianski 19 Sep '05

19 Sep '05

I've been thinking of a library that would bring RMI-like capabilities to C++ (RMI stands for Remote Method Invocation). Primary goal, and differentiating feature, of this library is not to rely on IDL-like compiler, hence no cross-language support either -- if you need that, check out CORBA (www.omg.org) or ICE (http://www.zeroc.com) As an example, I'm going to "implement" client and server sides of a trivial calculator using proposed library. Step 1. Define calculator interface ----------------------------------- // // Operations: add, subtract, multiply and divide // struct add { typedef function2<double, double, double> function_type; }; struct subtract { typedef function2<double, double, double> function_type; }; struct multiply { typedef function2<double, double, double> function_type; }; struct divide { typedef function2<double, double, double> function_type; }; // Calculator interface // typedef interface< operation<sum>, operation<subtract>, operation<multiply>, operation<divide> > calculator_i; Step 2. Client invocation ------------------------- // Construct a proxy to the remote calculator // instance. Arguments to the constructor // describe remote object's location (not shown). // proxy<calculator_i> calculator(...); // Call `subtract' on remote object (call // doesn't block). Returned object implements // Asynchronous Completion Token (or Future) // concept. // act<double> res = call<subtract>(calculator, 12, 43); // Retrieve actual result, or get an exception... // double result = res(); Step 3. Server implementation ----------------------------- // Implement actual calculator. // struct calculator_servant { double sum(double a, double b) { return a + b; } ... // other operations here }; // Instantiate calculator servant // calculator_servant servant; // Create a TCP listener. // tcp_listener listener(...) // Create a stub object that acts as an // adapter between transport and a servant. // stub<calculator_i> calculator(listener); // Install operation handlers. // calculator.register_function<add>(bind(&calculator_servant::sum, ref(servant), _1, _2)); ... // register remaining handlers // Start accepting calls. // calculator.activate(); // Block until exiting. // calculator.wait_for_shutdown(); ... -- end of example] I'm fairly satisfied with the client side, but I'm not so enthusiastic about the server side though. For one, it feels less safe. For example, what if a user forgets to register a "handler" for a particular operation? Any way to enforce this at compile time? Typically, say with CORBA, IDL compiler generates operations as pure virtual functions, so at compile time, the user knows what's left out in her servant. On the other side, it's quite powerful too (being able to "bind" functors to operations, that is). Would that be a problem for you or you'd see it as a good feature? Let me know what you think. Cheers, Slawomir Lisznianski

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Re: [Boost-users] [Graph] Help on custom VertexList
by Nicola Vitacolonna 19 Sep '05

19 Sep '05

>> Why isn't there any "dequeS" tag in BGL? > > Historical accident. If you'd like we could add your implementation > for deque. Below you find my implementation for deque. Regards Nicola PS: sorry for forgetting the subject in my previous post, causing a mess with message threading... #include <boost/graph/graph_traits.hpp> #include <boost/graph/adjacency_list.hpp> #include <deque> namespace boost { namespace graph_detail { struct deque_tag : virtual public random_access_container_tag, virtual public back_insertion_sequence_tag { }; // No front_insertion_sequence_tag? template <class T, class Alloc> deque_tag container_category(const std::deque<T, Alloc>&){ return deque_tag(); } template <class T, class Alloc> unstable_tag iterator_stability(const std::deque<T, Alloc>&) { return unstable_tag(); } #if !defined BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION template <class T, class Alloc> struct container_traits< std::deque<T, Alloc> > { typedef deque_tag category; typedef unstable_tag iterator_stability; }; #endif } // namespace graph_detail struct dequeS { }; template <typename ValueType> struct container_gen<dequeS, ValueType> { typedef typename std::deque<ValueType> type; }; } // namespace boost // Test int main(int, char*[]) { typedef boost::adjacency_list<boost::vecS, boost::dequeS, boost::bidirectionalS> Graph; Graph g; Graph::vertex_descriptor v1, v2; v1 = boost::add_vertex(g); v2 = boost::add_vertex(g); boost::add_edge(v1, v2, g); }

1 0

Re: [Boost-users] [boost] Beyond the C++ Standard Library: An Introduction to B oost
by Bjorn.Karlsson＠readsoft.com 19 Sep '05

19 Sep '05

Hello Beman, > From: Beman Dawes [mailto:bdawes@acm.org] > > What kind of animal is that on the cover? Some kind of Lemur? Yes, they are lemurs. In case some of you are wondering what lemurs and Boost have in common, I must confess that I have absolutely no idea. My editor, Peter Gordon, came up with the unbelievably far-fetched connection that "Boost is giving a lift to the C++ Standard Library". I think that he, just as you and I did, simply thought that they were just about the cutest things you ever saw. (When deciding which cover picture to go with, I also consulted my six-year-old son, who made it quite clear that the other options were, ahem, less perfect than the one with the lemurs.) > It is about the cutest thing I've seen in a long time. (Don't > tell my office cat I said that.) My lips are sealed. Björn

1 0

[bind] Pointer to functions as template parameters
by Bruno Martínez 19 Sep '05

19 Sep '05

Hi. When using pointers to functions with bind, the particular function doesn't play a part in the return value's type of bind. That is void func1(); void func2(); typeid(boost::bind(&func1)) == typeid(boost::bind(&func1)) // this is true I need the types to be different to store bind objects with the serialization library. The C++ Templates book proposes an adaptor that takes the pointer to function as a template parameter. However, this adaptor is particular to a given signature, and I don't know how to rewrite it more generally. Is this possible? Can I more easily make boost::bind do what I want? Bruno

4 7

Parsing RFC 822 date/time
by Tobias Grimm 19 Sep '05

19 Sep '05

Hi! I'm trying to parse a rfc822 date as used in RSS feeds. It looks like this: Sat, 07 Sep 2002 00:00:01 GMT Is this possible with time_facet somehow? I think at least the time zone can't be parsed, because the corresponding format specifiers are for output only. Any idea how this kind of date format should be parsed? bye, Tobias

2 3

(no subject)
by Nicola Vitacolonna 18 Sep '05

18 Sep '05

Thank you! Actually, boost::array is an unfortunate choice, as it does not model a Sequence. But I have successfully built a vertex list out of std::deque. Which has suggested me a couple of more questions: 1) I should also overload iterator_stability() for my container, shouldn't I? 2) I did a quick test: adding vertices to a graph (adjacency_list) whose vertex list is implemented as a deque turns out to be faster than adding vertices to a vector-based (or even a list-based) graph. Why isn't there any "dequeS" tag in BGL? Regards Nicola > > Hi everybody, > > I want to use my custom container as a vertex list in a graph. I > have > > followed the documentation, but I don't know exactly how I should > > overload the push() and erase() functions. > > Sorry, looks like the documentation is incomplete in that regard. > I'll fix that. > > You can find examples of push() and erase() in: > > boost/pending/container_traits.hpp > > > The following example code, using boost::array, gives an error: "no > > matching function for call to 'container_category > (boost::array<void*, > > 10ul>&)". Can someone help me? > > You'll need to define a container_category function for boost::array. > There are examples of this also in container_traits.hpp. > > Cheers, > Jeremy

2 1

Question about network flow examples
by Sumanth J.V 18 Sep '05

18 Sep '05

Greetings, On the edmunds-karp-eg.cpp and the push-relabel-eg.cpp, the output is is as shown below. But I dont understand how in the first flow describing line "f 0 6 3" is listed since there is not vertex with id 0. The vertices are labeled from 1 to N as I understand. Even the input file max_flow.dat in the examples folder labels the vertices from 1..N. thanx // Sample output: // c The total flow: // s 13 // // c flow values: // f 0 6 3 // f 0 1 0 // f 0 2 10 // f 1 5 1 // f 1 0 0 // f 1 3 0 // f 2 4 4 // f 2 3 6 // f 2 0 0 // f 3 7 5 // f 3 2 0 // f 3 1 1 // f 4 5 4 // f 4 6 0 // f 5 4 0 // f 5 7 5 // f 6 7 3 // f 6 4 0 // f 7 6 0 // f 7 5 0

1 0

multi-index container: a more general basic usage example 1
by Alexander Schuh 18 Sep '05

18 Sep '05

Hi, in Example 1 there is a structure: struct employee { int id; std::string name; int age; … }; Is it possible to create automatically A) container with id as an index B) a view with name as index C) a view with age as index ? For this example it is easy to create the containers and views by hand but I plan to use at least 10 structures with many dimensions. For some containers I also need hash_indices - so there is really a lot of similar code, which I don’t want to have. Also I want to provide iterators or one general (template) iterator for all dimensions. How would you write such a general iterator? There should be a function that takes for example “employee_name” or “employee_id” as a parameter to query the employee container. It would also be interesting to have a function that creates an iterator based only on the Information, for example, multi_index::container(1)_index(2). Is there a function that calculates the max. index number of a certain container? Thank you very much, Alex Schuh -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.344 / Virus Database: 267.11.1/104 - Release Date: 16.09.2005

2 1

[Graph] Help on custom VertexList
by Nicola Vitacolonna 18 Sep '05

18 Sep '05

Hi everybody, I want to use my custom container as a vertex list in a graph. I have followed the documentation, but I don't know exactly how I should overload the push() and erase() functions. The following example code, using boost::array, gives an error: "no matching function for call to 'container_category(boost::array<void*, 10ul>&)". Can someone help me? One more question: is it possible to get a reference to the vertex container, given an adjacency_list<...> object? Nicola #include <boost/graph/adjacency_list.hpp> #include <boost/array.hpp> struct arrayS { }; namespace boost { template <class ValueType> struct container_gen<arrayS, ValueType> { typedef array<ValueType, 10> type; }; } int main(int,char*[]) { typedef boost::adjacency_list<boost::vecS, arrayS, boost::bidirectionalS> Graph; Graph g(10); boost::add_vertex(g); boost::add_vertex(g); boost::add_edge(vertex(0, g), vertex(1, g), g); return 0; }

2 1

[MPL] vector_c which contains string literals
by Hossein Haeri 18 Sep '05

18 Sep '05

Dear MPL maniacs, AFAIK, there is no mpl::vetor_c which can hold string literals. Or is it? If not, isn't there any way to implement one? Any voluteers please? Thanks in Advance, --Hossein ___________________________________________________________ Yahoo! Messenger - NEW crystal clear PC to PC calling worldwide with voicemail http://uk.messenger.yahoo.com

2 2

Question about proper container/algorithm to use for fast dictionary lookup
by Elisha Berns 18 Sep '05

18 Sep '05

Hi, This question is whether Boost already has, or perhaps needs to have a container type that is specifically designed for fast word lookup in a UNICODE dictionary. It has occurred to me that an associative container that is specifically designed for word lookup may be much faster than the standard containers such as map, hash_map, associative_vector as they are general purpose containers. So the more detailed questions are: 1) What type of algorithm/container should be used here? 2) Would its performance be much better than a general purpose associative container? Thanks, Elisha Berns e.berns(a)computer.org tel. (310) 556 - 8332 fax (310) 556 - 2839

3 3

BGL - randomize_property & bundled properties
by Giulio Veronesi 17 Sep '05

17 Sep '05

Hi all, Is it possible to use the randomize_property routines with boundled properties? If so, could you please explain me how? For istance let us consider the following example: struct MyVertexAttr { int attr; }; typedef adjacency_list<vecS, vecS, bidirectionalS, MyvertexAttr, MyEdgeAttr> MyGraph; MyGraph g(...); Now I would like to randomly assign a number in [1,10] to the 'attr' property of each vertex. randomize_property<????????>(g, MyRandGenerator); What is the correct invocation of the randomize_property function? Thanks in advance, Giulio

1 0

regex and ICU
by louis 17 Sep '05

17 Sep '05

Hi, I am trying to build the regex library with ICU (MSVC 6.0). I get the following error: Z:\dev\3rd\boost_1_33_0\boost/regex/icu.hpp(42) : error C2039: 'Locale' : is not a member of '`global namespace'' Any help would be greatly appreciated. Thanks Louis

3 3

[Pre-processing] String Litereal Comparison for Equality
by Hossein Haeri 17 Sep '05

17 Sep '05

Dear all, Is there anyway (say using a utility in BOOST_PP) at pre-processing phase to compare string literals for equality? TIA, --Hossein ___________________________________________________________ Yahoo! Messenger - NEW crystal clear PC to PC calling worldwide with voicemail http://uk.messenger.yahoo.com

2 2

Build errors and crash with 1.33.0 under Mac OS X CodeWarrior
by Allen Cronce 17 Sep '05

17 Sep '05

Hi all, I just updated from boost 1.32.0 to 1.33.0 for a CodeWarrior MSL/carbon project under Mac OS X. There were several build errors stemming from the fact that "check" is already defined in /usr/include/AssertMacros.h. For now I dealt with this my modifying my copy of the boost libraries to substitute _check for check. This is of course an ugly solution, but I wanted to move forward. Unfortunately now I'm seeing crashes with code that worked fine with 1.32.0. Here's some test code that demonstrates the crash: _tprintf(_T("\nTest a vector of boost shared_ptr's:\n")); typedef boost::shared_ptr<std::string> SharedPtrString; typedef vector<SharedPtrString> StringContainer; typedef vector<SharedPtrString>::iterator StringContainerIterator; { SharedPtrString sharedPtrString1(new std::string("Hi there!")); SharedPtrString sharedPtrString2(new std::string("Hi there!")); _tprintf( _T(" sharedPtrString1->c_str() = \"%s\"\n"), sharedPtrString1->c_str() ); _tprintf( _T(" sharedPtrString2->c_str() = \"%s\"\n"), sharedPtrString2->c_str() ); } // We never get here because of an access error Basically when the SharedPtrString goes out of scope, I get an access error deep in the allocation code. Does anyone have suggestions for resolving these issues? Note that I could go back to 1.32.0, but I want to use the new Pointer Container Library. Best regards, -- Allen Cronce

3 6

[iostream]: Simple sinks result in runtime error
by Marius Renn 17 Sep '05

17 Sep '05

Hi all, This is my first post, so please let me know if I am doing anything wrong. I am having trouble using the new iostream headers in Boost 3.3. I cannot get simple Sinks to function correctly. Take the following code for example: namespace bio = boost::iostreams; int main() { typedef bio::stream<bio::null_sink> nullsink; nullsink out; out << "Ignore me"; } This code always results in a runtime assertion failure: /usr/local/include/boost/iostreams/detail/optional.hpp:54: failed assertion `initialized_' What am I doing wrong? Any help would be greatly appreciated. Cheers, Marius

2 1

compiling boost.signals without exception
by Martin Sarrazac 17 Sep '05

17 Sep '05

Hi, compiler: mingw gcc 3.4.4 I would like to compile boost.signals without exception handling, I read somewhere about the <exception-handling> feature so I tried: bjam --builddir=c:\temp -sTOOLS=mingw "-sBUILD=debug <exception-handling>off <runtime-link>dynamic <threading>single" --libdir=C:\boost\lib\noe --with-signals -d2 install without success, it compiles fine but not without exception handling. specifically the -fno-exception command line option should be passed to gcc and it's not. I had a look at tools/build/v1/gcc-tools.jam and I found this line for rtti support for instance: flags gcc C++FLAGS <rtti>off : -fno-rtti ; However there is nothing equivalent for exceptions... On a side note I don't know how to give a new tag to the 'no exception' version of the library, so I compiled it in an other directory (--libdir=C:\boost\lib\noe). However I would much prefer to give it a specific name. Is there somewhere information about all the -sBUILD flags can be found? Can't seem to locate it. Thanks for your help

2 1

Problems going from Serialization 1.32 to 1.33
by Stefan Arentz 17 Sep '05

17 Sep '05

Hello fellow Boost users, Consider the following program: #include <sstream> #include <string> #include <vector> #include <boost/archive/text_oarchive.hpp> #include <boost/serialization/base_object.hpp> #include <boost/serialization/string.hpp> #include <boost/serialization/vector.hpp> template <typename T> std::string archive(T thing) { std::ostringstream oss; boost::archive::text_oarchive oa(oss); oa << thing; return oss.str(); } typedef std::vector< std::string > parameters_t; int main() { parameters_t parameters; parameters.push_back("a"); parameters.push_back("b"); std::string s = archive<parameters_t>(parameters); return 0; } When I compile this with Boost 1.32 it compiles and works fine. However, with Boost.1.33 it fails with: /usr/local/include/boost/archive/detail/oserializer.hpp: In function `void boost::archive::save(Archive&, T&) [with Archive = boost::archive::text_oarchive, T = std::vector<std::string, std::allocator<std::string> >]': /usr/local/include/boost/archive/basic_text_oarchive.hpp:78: instantiated from `void boost::archive::basic_text_oarchive<Archive>::save_override(T&, int) [with T = std::vector<std::string, std::allocator<std::string> >, Archive = boost::archive::text_oarchive]' /usr/local/include/boost/archive/detail/interface_oarchive.hpp:85: instantiated from `Archive& boost::archive::detail::interface_oarchive<Archive>::operator<<(T&) [with T = parameters_t, Archive = boost::archive::text_oarchive]' test.cpp:16: instantiated from `std::string archive(T) [with T = parameters_t]' test.cpp:28: instantiated from here /usr/local/include/boost/archive/detail/oserializer.hpp:566: error: incomplete type `boost::STATIC_ASSERTION_FAILURE<false>' does not have member `value' I'm not sure what to change. Is this correct behaviour? S.

2 1

Re: [Boost-users] Help on Boost.MultiArray
by Adewole, Mike 16 Sep '05

16 Sep '05

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of > Sohail Somani > Sent: Friday, September 16, 2005 2:44 PM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Help on Boost.MultiArray > > > > -----Original Message----- > > From: boost-users-bounces(a)lists.boost.org > > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of > > Adewole, Mike > > Sent: Friday, September 16, 2005 10:46 AM > > To: boost-users(a)lists.boost.org > > Subject: [Boost-users] Help on Boost.MultiArray > > > > > > Hi all, > > > > Does anyone know how to insert and delete a range of rows > > and/or columns in the multiarray class documented at > > http://www.boost.org/libs/multi_array/doc/ ? What > > performance guarantees can I expect for these operations ? > > > > I'm a little pressed for time and haven't been able to figure > > out how to do this on my own. The statement that "The number > > of elements will remain fixed for the duration of a > > multi_array's lifetime" on the documentation page suggests > > that these operations may not even be supported, but I'm not > > sure if I'm misunderstanding the statement or not. > > I don't think you can insert/delete stuff like in a vector. > Seemed to me too that the library doesn't support insertions/deletions but I had to be sure before doing this thing the hard way. Thanks a million. Mike

1 0

[filesystem] function to determine available space
by Beman Dawes 16 Sep '05

16 Sep '05

I'm planning to add a filesystem function to determine available disk space. Perhaps something like: struct space_status { boost::uintmax_t available; // free space available to user boost::uintmax_t total; // total space on volume }; space_status filesystem_space( const path & p ); Comments? Better suggestions for the names? --Beman

6 11

Re: [Boost-users] Help on Boost.MultiArray
by Sohail Somani 16 Sep '05

16 Sep '05

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of > Adewole, Mike > Sent: Friday, September 16, 2005 10:46 AM > To: boost-users(a)lists.boost.org > Subject: [Boost-users] Help on Boost.MultiArray > > > Hi all, > > Does anyone know how to insert and delete a range of rows > and/or columns in the multiarray class documented at > http://www.boost.org/libs/multi_array/doc/ ? What > performance guarantees can I expect for these operations ? > > I'm a little pressed for time and haven't been able to figure > out how to do this on my own. The statement that "The number > of elements will remain fixed for the duration of a > multi_array's lifetime" on the documentation page suggests > that these operations may not even be supported, but I'm not > sure if I'm misunderstanding the statement or not. I don't think you can insert/delete stuff like in a vector.

1 0

Help on Boost.MultiArray
by Adewole, Mike 16 Sep '05

16 Sep '05

Hi all, Does anyone know how to insert and delete a range of rows and/or columns in the multiarray class documented at http://www.boost.org/libs/multi_array/doc/ ? What performance guarantees can I expect for these operations ? I'm a little pressed for time and haven't been able to figure out how to do this on my own. The statement that "The number of elements will remain fixed for the duration of a multi_array's lifetime" on the documentation page suggests that these operations may not even be supported, but I'm not sure if I'm misunderstanding the statement or not. Thanks a lot. -------------------------------------------------------- Mike Adewole ACNielsen, Global Decision Support Services ph: 905-475-3344x2411 fx: 905-475-8357 mike.adewole(a)acnielsen.ca --------------------------------------------------------

1 0

Could the BGL graph algorithms be improved to automatically work with VertexList = listS graphs?
by Tony Cook 16 Sep '05

16 Sep '05

Hi, If I define a BGL graph of the type typedef boost::adjacency_list <boost::vecS, boost::listS, boost::undirectedS, boost::no_property, boost::no_property, boost::no_property> BadGraphType ; Then many of the standard BGL graph algorithms such as boost::graph_copy will not compile (e.g you get "binary '+' : no operator found which takes a left-hand operand of type <type>" with VC7.1 - this did not help me understand what the problem really was - i.e. a missing vertex_index property!) This "no-compiler" problem is only fixed if either a vertex_index property map is made explicitly present on this graph type via VertexProperties template argument (See #5 on the BGL FAQ page (http://www.boost.org/libs/graphd/oc/faq.html .)) OR the particular graph algorithm is passed an external (or internal - if not of the vertex_index_t type) property map as a named parameter as in: boost::graph_copy (graph_in, graph_out, boost::vertex_index_map (i_map)) ; In either case prior to copying (or whatever) you need to ensure this property map is numbered contiguously from 0 to n - 1, where n is the number of graph vertices. My graph does not support an implicit vertex_index property, nor do I *want* to add an explicit vertex_index compatible property *just* to make these algorithms work. Especially as my graphs are dynamic and I would have to remember to renumber the property values to eliminate gaps after vertices are deleted. The BGL algorithms in this situation are particularly weak as first the "no-compile" messages are remote from the real problem, and when you have solved that then you have to prepare the graph properly prior using the algorithm! (if not you get memory scribbles if the indices are not contiguous and confined to 0 to n-1) These lead me to wonder if this problem can be eliminated and be automated as part of the algorithm itself, i.e. if no vertex_index property was supplied by any means, then the algorithm creates a temporary vertex index map, loads it with vertices mapped to indices 0 to n-1 and runs the algoritm out-of-the-box. It should be possible for the compiler to detect that the internal property map is missing AND the named parameter alternative is missing (in fact the implementations of these BGL algorithms *do* set out to discover that this is the case, but unfortunately a final vertex "descriptor-is-the-index" map (which is only true when VertexList=vecS) is assumed and hence the compilation failure and a lot grief and a steep learning curve is experienced :( ) Now to the point I wanted to make :). There IS a solution that can do this. However I'm not expert enough to merge this into the heart of each BGL graph algorithm algorithm that requires a vertex_index property. I have however developed crude wrappers that do this. Here is an example solution for boost::copy_graph that handles any graph type out of the box /** copy_graph_ex. A wrapper for boost::copy_graph that sets up the required vertex to 0 -> n - 1 index translation map @param g_in the graph to copy @param g_out the graph copy */ template <class G1, class G2> void copy_graph_ex (const G1& g_in, G2& g_out) { // Create a temporary external property map that maps vertex // descriptors to indices that will run 0 to n-1 typedef std::map<typename G1::vertex_descriptor, typename G1::vertices_size_type> i_type ; typedef boost::associative_property_map<i_type> i_map_type ; i_type i ; i_map_type i_map (i) ; // Load the external property map with values 0 to n-1 G1::vertices_size_type n = 0 ; G1::vertex_iterator vi ; G1::vertex_iterator vi_end ; for (boost::tie (vi, vi_end) = boost::vertices (g_in) ; vi != vi_end ; ++vi) { boost::put (i_map, *vi, n++) ; } // Get the BGL graph algorithm to use the constructed index map boost::copy_graph (g_in, g_out, boost::vertex_index_map (i_map)) ; } It would be much nicer if this external setup code was made part of the default handling of BGL graph algorithms that require it. What do to BGL experts/implementers say? Would it not be **saner** to get these algorithms to work automatically no matter what graph type was chosen? TIA Tony Cook (who went insane with this problem for two days)

7 14

[Graph] how to obtain the complement of a graph?
by Tzu-Chien Chiu 16 Sep '05

16 Sep '05

Given a graph G=(V,E) and its complete graph G'=(V,E'), what is the shortest code lines to obtain the complement of G_c=(V,E'-E) ?

2 1

[signal/bind/mem_fn] std::vector< boost::signal<> >
by kartoffelsack 16 Sep '05

16 Sep '05

Hi! I'd like to save any kind of functions/functors with void as parameter and as return-value in a container. I thought to use boost::bind: Let me show you some code: void bar( ) { } struct Foo { void operator(); }foo; typedef boost::signal<void ()> voidFunctionSig; std::vector< voidFunctionSig> voidFunctions; voidFunctionSig signal1; voidFunctionSig signal2; signal1.connect( &bar); signal2.connect( &foo); voidFunctions.push_back( signal1); //error voidFunctions.push_back( signal2); //same error I'm getting a Compiler-errors in the push_back-Lines: 'boost::signal<Signature>::__ctor': no nonexplicit constructor for implicit conversion: with [ Signature=void (void) ] and [ Signature=void (void) ] well, i'm not shure if boost::bind is the right choice at all, because I do not need multiple slots. Perhaps boost::bind/boost::mem_fn was enough but i cannot think how to use it. Can anybody help me to save my void (*)(void)-functions/functors and in a container? I could do it writing a superclass and a virtual op() but I would prefer to use ready-to-use boost-classes for this task. PS: using VC 7.1

2 2

Exception occurred in "boost::thread" cannot be caught by vs.net.
by 蹬三轮的 16 Sep '05

16 Sep '05

When an "access violation" exception occurred and didn't be caught by the program, it would be caught by debugger such like vs.net. 1: int main() 2: { 3: int *i = 0; 4: *i = 1; 5: } If I debug this program in vs.net, program will be broken at line 4 and an exception dialog box will be displayed. So I can know the origin of the exception. The problem is when the exception occurred in the thread started by boost::thread, program cannot be broken at the line from which exception been thrown. 01: void func() 02: { 03: int *i = NULL; 04: *i = 1; 05: } 06: int _tmain(int argc, _TCHAR* argv[]) 07: { 08: thread *t = new thread(func); 10: t->join(); 11: delete t; 12: return 0; 13: } The program should be broken at line 4, but it didn't. This makes the debugging boost::thread more difficult. How can I resolve the problem? thanks.

4 4

[Boost.Python] Infinite recursion attempting to_python conversion
by Nat Goodspeed 16 Sep '05

16 Sep '05

For some purposes we have a special string class derived from std::wstring. Simplified declaration: class cbstring: public std::wstring { public: cbstring(const wchar_t* that): std::wstring(that) {} cbstring(const std::wstring& that): std::wstring(that) {} ... }; I want to return such objects from C++ as Python Unicode strings, e.g.: cbstring produceWString() { return L"This is a test Unicode string"; } If produceWString() returns std::wstring, the conversion happens by magic. But with the cbstring return type, I get: TypeError: No to_python (by-value) converter found for C++ type: class cbstring The corresponding conversion problem (passing u"Foo" from Python to a function accepting const cbstring&) can be handled with the following call in the extension module: implicitly_convertible<std::wstring, cbstring>(); However, implicitly_convertible<cbstring, std::wstring>(); does NOT allow the produceWString() function to succeed: I still get the aforementioned TypeError. So I declared a type converter: struct cbstring_to_python { static PyObject* convert(const cbstring& cbs) { return PyUnicode_FromUnicode(cbs.c_str(), cbs.length()); } }; and registered it with: to_python_converter<cbstring, cbstring_to_python>(); The result is a stack overflow. I'm not clear on exactly why it happens, but something inside the cbstring_to_python converter is apparently recursively invoking cbstring_to_python::convert(). How *should* I go about returning our specialized string type as a Python Unicode string? OS: Microsoft Windows XP Pro, SP1 Compiler: Microsoft VC++ 7.1 with STLport 4.6 Boost version: 1.31

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Re: [Boost-users] [serialization, 1_33_0] Correct usage and implementation for serializable objects without default constructors
by Martin Proulx 16 Sep '05

16 Sep '05

> In this example, we have a class A that doesn't have a default > constructor. > An int is needed by the constructor, which is stored in the i member > variable. load/save_construct_data are used to un/serialize the i member, > while the serialize member is used for all other members. > > Looking at this test, I see a couple of behaviors that puzzle me. > > -) Saving the 'a' instance in the save() function doesn't end up calling > save_construct_data. This leaves a serialized version of A which lacks > the > 'i' member. This makes it impossible to fully restore the 'a' > instance. It > seems problematic to me that save_construct_data isn't called in this > case. > >> I just re-ran test_non_default_ctor. I ran under the VC 7.1 debugger and >> inserted traps inside both save_construct_data and >> load_construct_data. II >> verified that save_construct_data and load_construct_data are being >> invoked >> exactly as they are intended. I see no problem here. > > > In my planned usage, I'd like to fully serialize all members, > regardless if > the objects are serialized directly or through pointers. I cannot see how > to do this without serializing the members needed to reconstruct the > object > in both serialize and save_construct_data, even if some members will > end up > serialized twice when an object is stored through a pointer. > >> If the members are not pointers, the constructor is never called. so the >> parameters set by the constructor are not needed. >> save_load_contruct_data >> is only called when its necessary to create a new object. > > > What's the proper way to serialize all members of a class without a > default > constructor so that it gets fully serialized regardless how the > objects are > managed? > >> Exactly as described in the manual and illustrated by the example >> test_non_default_ctor. > > > -) When restoring the 'a' instance within load(), in order to restore > it, we > first create another 'a' instance (with a different constructor > argument), > then restore the other members within, leaving untouched the 'i' member. > Assuming I'd like to be able to serialize and unserialize completely > objects > that do not have a default constructor, I'm wondering how I can fully > restore an object that doesn't have a default constructor. > >> All you have to do is define save_construct_data and >> load_construct_data for >> all types which don't have a default constructor. The library takes >> care of >> everything else. > > > I've looked for some other mechanism relying on a copy constructor and > something along the lines of load_construct_data, but I haven't found > any. > >> Somehow I'm thinking you're looking for the wrong thing. I wonder if >> you're >> not underestimating what the library does for you. As I said, you, only >> need to define save/load_construct_data for those types which don't >> have a >> default constructor - there is nothing else required to do. >> >> Robert Ramey > > Hello, As this discussion is going, it seems clear that either I'm missing something somewhere or that I'm not being clear enough in exposing my problems... I'll directly include a sample of something similar to what I'd like to achieve that doesn't work. Please take a look at the example, and let me know how you would modify this to make both assert succeed. If you notice that I've missed some concept in the way the library should be used, please enlighten me! Thanks, Martin ------------------------------------------------------------------------ #include <cstdlib> #include <cassert> #include <sstream> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/serialization/string.hpp> using namespace std; class Person { public: Person(const string& name) : _name(name), _favoriteFood("none") {} const string& getName() const {return _name;} const string& getFavoriteFood() const {return _favoriteFood;} void setFavoriteFood(const string& favoriteFood) {_favoriteFood = favoriteFood;} private: const string _name; string _favoriteFood; friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int /* file_version */){ ar & _favoriteFood; } }; namespace boost { namespace serialization { template<class Archive> inline void save_construct_data(Archive & ar, const Person * person, const unsigned int /* file_version */) { ar << person->getName(); } template<class Archive> inline void load_construct_data(Archive & ar, Person * person, const unsigned int /* file_version */) { string name; ar >> name; ::new(person)Person(name); } } // serialization } // namespace boost template<class Archive> void serializePerson(Archive& oa, const Person& someone) { // save_construct_data isn't called when serializing a Person in this fashion. // The person's name will not appear in the archive. oa << someone; } template<class Archive> Person UnserializePerson(Archive& ia) { // I'm constructing a temporary person, with a bogus name, as it's the only workaround I've come up with. // There is no way that unserializing returns an actual object, like I'm needing here. Person someone("bogus name"); // When unserializing in this fashion, load_construct_data isn't called either. ia >> someone; // The initial person's name is then lost. return someone; } void main(void) { Person *const Joe = new Person("Joe"); Person John("John"); stringstream stringStream; boost::archive::text_oarchive oa(stringStream); oa << Joe; serializePerson(oa, John); boost::archive::text_iarchive ia(stringStream); Person* restoredPersonPointer; ia >> restoredPersonPointer; Person restoredPerson(UnserializePerson(ia)); assert(restoredPersonPointer->getName() == Joe->getName()); // works fine. assert(restoredPerson.getName() == John.getName()); // fails. } -- Tel: (450) 681-1681, #271 ------------------------------------------------------------------------ OKIOK Enterprise and e-business security solutions Solutions de sécurité d'entreprise et d'affaires électronique Tel. : (450) 681.1681 http://www.okiok.com This e-mail message (including attachments, if any) is intended for the use of the individual or entity to which it is addressed and may contain information that is privileged, proprietary, confidential and exempt from disclosure. If you are not the intended recipient, you are notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify the sender and erase this e-mail message immediately. Le présent message électronique (y compris les pièces qui y sont annexées, le cas échéant) s'adresse au destinataire indiqué et peut contenir des renseignements de caractère privé ou confidentiel. Si vous n'êtes pas le destinataire de ce document, nous vous signalons qu'il est strictement interdit de le diffuser, de le distribuer ou de le reproduire. Si ce message vous a été transmis par erreur, veuillez en informer l'expéditeur et le supprimer immédiatement.

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Re: [Boost-users] Could the BGL graph algorithms be improvedto automatically work with VertexList = listS graphs?
by Tony Cook 16 Sep '05

16 Sep '05

I retracted this in a subsequent post - it was my problem with a custom vertex property (blush) >From: Daryle Walker <darylew(a)hotmail.com> >Reply-To: boost-users(a)lists.boost.org >To: Boost Users mailing list <boost-users(a)lists.boost.org> >Subject: Re: [Boost-users] Could the BGL graph algorithms be >improvedto automatically work with VertexList = listS graphs? >Date: Thu, 15 Sep 2005 18:05:46 -0400 > >On 9/15/05 7:05 AM, "Tony Cook" <tony__cook(a)hotmail.com> wrote: > > > Can I add that misuse of graph assignment and a graph copy constructor >is > > possible - corruptible shallow copies are the result. These methods >should > > be given private scope to prevent (mis)use or be correctly implemented > > > > G2 = G1 ; // Compiles but NO you must use boost::graph_copy (G1, G2) >instead > >If this is accurate, then it should be fixed. Types with abnormal copying >semantics can't be used in STL containers or similar contexts. > >-- >Daryle Walker >Mac, Internet, and Video Game Junkie >darylew AT hotmail DOT com > >_______________________________________________ >Boost-users mailing list >Boost-users(a)lists.boost.org >http://lists.boost.org/mailman/listinfo.cgi/boost-users

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How can I find all the shortest path in a graph?
by Giulio Veronesi 16 Sep '05

16 Sep '05

Hi all, Please excuse me if I post my question again, but I've spent all the night and the day before looking for a solution of the following problem: How to find *all* the possible shortest paths from a source vertex to a target vertex in a directed graph? I tried using depth_first_search and acting on visitors without any success. Please, could you help me? Thanks a lot in advance, Giulio

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How to extending algorithms with visitors
by Giulio Veronesi 15 Sep '05

15 Sep '05

Hi all, I'm enjoying learning the boost graph library. I'm trying to use the Dijkstra algorithm and try to store the shortest path as explained in the subsection "Extending Algorithms with Visitors" of the section "Quick Tour" of the BGL user guide. When I try to compile my code, I get the following error message: mesh.cpp:38: error: expected constructor, destructor, or type conversion before '<' token mesh.cpp:38: error: expected `;' before '<' token where line 38 is highlighted in the following portion of code. Could you help me to resolve this problem? Thanks in advance, Giulio template <class PredecessorMap> class record_predecessors : public dijkstra_visitor<> { public: record_predecessors(PredecessorMap p) : m_predecessor(p) { } template <class Edge, class Graph> void edge_relaxed(Edge e, Graph& g) { // set the parent of the target(e) to source(e) put(m_predecessor, target(e, g), source(e, g)); } protected: PredecessorMap m_predecessor; }; template <class PredecessorMap> line 38: record_predecessors<PredecessorMap> make_predecessor_recorder(PredecessorMap p) { return record_predecessors<PredecessorMap>(p); } ___________________________________ Yahoo! Mail: gratis 1GB per i messaggi e allegati da 10MB http://mail.yahoo.it

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Matrix of submatricies...
by Edward Grace 15 Sep '05

15 Sep '05

Dear all, [you may need a fixed with font] Consider the following 4x4 matrix which is a 2x2 matrix of submatricies. A B | 0 0 C D | 0 0 ----+---- 0 0 | a b 0 0 | c d Clearly matrix operations such as products do not need to involve the off diagonal (zero) sub matricies. Is there a matrix type that "knows" about this type of matrix so that when prod() is carried out it does not do unnecessary operations with the zero elements? -ed

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[Regex] Empty regular expression
by Marco Craveiro 15 Sep '05

15 Sep '05

Hello boosters, First, apologies if this has been discussed before - I did some googling and could not find it. I've bumped into an interesting issue while using Boost.Regex. The documentation states: http://www.boost.org/libs/regex/doc/basic_regex.html Effects: Constructs an object of class basic_regex. The postconditions of this function are indicated in the table: Element Value empty() true size() 0 str() basic_string<charT>() Using 1.33, I get empty() set to false with the default constructor. In addition, if you attempt to search using an empty regex, the program segfaults. The following example demonstrates the problem: code: ------ #include <iostream> #include <string> #include <boost/regex.hpp> int main() { std::string line("this is an example line"); boost::smatch what; boost::regex re; std::cout << "re.empty(): " << re.empty() << std::endl; bool result = boost::regex_search(line, what, re); } output: ------ re.empty(): 0 Segmentation fault This does not happen if I initialize the regex using an empty string (it throws empty expression). Which leads to the main question (and the reason why I discovered all of this): is it possible to make a regular expression that matches anything? For instance, when using AWK, if you define a rule without a pattern, i.e.: { print $0; } I thought an empty regex would do the trick. Regards, Marco -- in software development, the design document is a source code listing. -- jack reeves

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Error compiling boost/tuple/tuple.hpp with boost 1.33 on VC 7.1
by Rob Caldecott 15 Sep '05

15 Sep '05

I have just upgraded to boost 1.33 from 1.32 and boost/tuple/tuple.hpp no longer compiles. I am using MS Visual Studio 2003 (7.1). Errors include: "boost-1_33\boost\tuple\detail\tuple_basic.hpp(66) : error C2332: 'class' : missing tag name" when compiling: template <class HT, class TT> struct cons; As I am new to boost, I have no idea how to continue. I am not even using tuple directly - it is included by iterator/indirect_iterator.hpp. Anyone else come across this? Looks like I'll have to switch back to 1.32. Thanks in advance.

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boost libraries under VxWorks
by swoh 15 Sep '05

15 Sep '05

Hello all. I am failing to compile the serialization library (from version 1.0.32) for use with VxWorks 5.4.2 (Tornado 2.2.1). I am restricted to their version of the g++2.96 compiler and matching libraries. I will probably be interested in using other boost libraries in the future (shared pointer at the least). The errors I am getting all have to do with default template parameters, although there may be other problems lurking ahead. Has anyone succeeded in using boost with this combination? Any tips? Thank you ori

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Boost.Iostreams + error handling
by Martin Slater 14 Sep '05

14 Sep '05

Hi there, Are exceptions the only way to propogate an error out of and IOStreams.Device policy? We have a lot of code using this style std::istream is(file); if(is) { .... } and would like not to have to change it all over to use ios exceptions but I can't see a way to avoid it. Is it possible? thanks Martin

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Re: [Boost-users] [filesystem] function to determine available space
by Sohail Somani 14 Sep '05

14 Sep '05

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Delfin Rojas > Sent: Wednesday, September 14, 2005 11:55 AM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] [filesystem] function to determine > available space > > > > > I think the word "status" in space_status is misleading since > > > available/total space is not really a status. > > > > What makes you say that? > > > > Ben. > > > > It is just my interpretation of the word "status": the status > of a patient (stable, critical, etc.), the status of an > electronic device (powered, running, connected, disconnected, etc.). > > If I see a function or structure that is called > filesystem_status I would think it represents one or more > states in which the files system can be, like empty/full or > online/offline. I guess each possible total_size / used_size > combination is a possible filesystem status but still it > doesn't sound good to me. > > At the end of the day it is up to whoever implements the > function to decide, I was just giving my suggestion because I > think it is important programming constructs have a name from > which their usage/meaning can be easily guessed or deduced. Design by committee rocks.

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Re: [Boost-users] [statechart] Can events carry data?
by BRIDGES Dick 14 Sep '05

14 Sep '05

Sorry about the delay - got sidetracked by work. ;) Your clarifications were a great help. Many thanks for the library *AND* the help! Regards, Dick > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of > Andreas Huber > Sent: Wednesday, August 31, 2005 2:57 PM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] [statechart] Can events carry data? > > > BRIDGES Dick wrote: > > I'm still not clear on the requirements surrounding such an > > instance. For example, the reference requires that > > <code>new E(*pCE)</code> be well-formed and make "a copy of > > pE". > > Maybe I should have described that differently. That row in the table > translates as follows: > 1. event<> subtypes must have a publicly accessible copy constructor > (compiler-generated or not) > 2. If overloaded, operator new must be publicly accessible > > Since the library only requires the quoted expressions be > well-formed, > it is up to you to define the semantics of the copying. What the > copy-ctor actually does is of no concern to the library. > > > Does the current implementation work ok with > > boost::shared_ptr? > > I assume you mean shared_ptr<> instances as members of > events? I don't > see any problems here. > > > How about auto_ptr? > > That should work if you define a copy-ctor that transfers > ownership to > the copy. > > > If a data member > > would normally require a deep copy, would I be better off > > managing it external to the event object > > I'm not sure I understand the question. I don't see how you > would manage > that data-member externally; you don't mean a global > variable, do you? > Also, are we talking about a single-threaded or an MT system? > > > - or avoiding that > > type of data altogether? How many copies are we talking > > about here? > > Events that the user allocates with new are never copied. > Stack-allocated events are copied exactly once only if they are > deferred. See Step 8 here: > > http://boost-sandbox.sourceforge.net/libs/statechart/doc/refer ence.html#process_event > Any cautions and/or advise regarding the use of data members > in events would be appreciated. The library does not introduce problems that wouldn't exist otherwise. In an ST system everything should "just work" without you spending any thought on copying, other than that a reaction might be working with the original *or* the copy of the event. In an MT system the usual precautions against race-conditions, deadlocks, etc. apply. If it is too costly to deep-copy everything in the event, you must ensure that multiple threads accessing the shared part are appropriately locking mutexes, etc. HTH, -- Andreas Huber When replying by private email, please remove the words spam and trap from the address shown in the header. _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Re: [Boost-users] Scons users?
by Thore Karlsen 14 Sep '05

14 Sep '05

On Tue, 13 Sep 2005 18:46:08 +0500, Alex Besogonov <cyberax(a)elewise.com> wrote: > >> On the Boost.Build list we were just discussing the fact that some > >> people otherwise inclined towards Boost have chosen Scons over > >> Boost.Build. It would be useful for us to understand some of the > >> reasons why, if some of you wouldn't mind letting us know. No flames, > >> please! >Well, SCons supports distributed building and binary repositories - >that's a MAJOR selling point. And Python is much nicer than jamfiles. > >PS: there's also mxx_ru (http://eao197.narod.ru/mxx_ru/) it's a build >system based on Ruby - it has some interesting features worth attention. >Unfortunately, its documentation is only in Russian, but this should not >be a problem for Vladimir Prus :) Another Python-based build system I like a lot is A-A-P (http://www.a-a-p.org) I haven't played much with SCons, but judging from the SCons documentation, A-A-P is a lot more powerful. I've found A-A-P to be indispensable for my builds, as well as other things like web page publishing. -- Be seeing you.

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locate a vertex by the index
by Giulio Veronesi 14 Sep '05

14 Sep '05

Hi, Excuse me for the very trivial question, but I'm new with boost and I'm looking for help. How I can locate a vertex of a graph by the index of the vertex? Thanks a lot in advance, Giulio

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boost libs dlls
by ned stoyanov 14 Sep '05

14 Sep '05

I am trying to introduce boost to my current company. I was wandering whether using boost requires linking against any libraries or is it all used like the STL simply by including header files. I've used some parts of boost before, which didn't require to link against anything but I want to make sure so I can package it up properly for other ppl to use. Cheers, Ned

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Re: [Boost-users] Scons users?
by Merrill Cornish 14 Sep '05

14 Sep '05

Parveen, Thank you. That's an excellent factual reference. Merrill

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Beyond the C++ Standard Library: An Introduction to Boost
by Bjorn.Karlsson＠readsoft.com 14 Sep '05

14 Sep '05

Dear All, A long time ago, I came here--to the Boost developers and Boost users mailing lists--asking for help with reviewing a book about the Boost libraries. Your response was fantastic. Back then, I concluded my email with saying thanks to all Boosters; for the libraries, the ideas, the research, the discussions, and the enthusiasm. Today, when the book is finally shipping, I'd like to extend that thank you to the Boosters who helped make "Beyond the C++ Standard Library" reality. Beman Dawes, Rob Stewart, David Abrahams, Aleksey Gurtovoy, David Brownell, Douglas Gregor, Duane Murphy, Eric Friedman, Eric Niebler, Fernando Cacciola, Frank Griswold, Jaakko Järvi, James Curran, Jeremy Siek, John Maddock, Kevlin Henney, Michiel Salters, Paul Grenyer, Peter Dimov, Phil Boyd, Ronald Garcia, Thorsten Ottosen, Tommy Svensson, and Vladimir Prus; thank you all so much! I sincerely hope that I am giving something back to the amazing Boost community through this book. Best regards, Björn Karlsson

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Re: [Boost-users] Scons users?
by Sohail Somani 13 Sep '05

13 Sep '05

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of > Foster Gareth > Sent: Tuesday, September 13, 2005 10:47 AM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Scons users? > > > I suppose in terms of scons and boost, then next question is > how easy is it > to build rpm/deb packages etc when using these build systems? > Its very easy > with autotooled projects. I think this is an area where scons is lacking. Its great in building, but not so good at deployment.

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Putting together boost::any, mpl::vector, iterator::filter_iterator
by Stephen Gross 13 Sep '05

13 Sep '05

I've put together a class called 'AnyVector' for doing type-based iteration on a vector. The basic idea is that AnyVector wraps a std::vector<boost::any>. The AnyVector lets you iterate across a subset of the underlying vector by using filter_iterators. The filter iterators, in turn, dereference to the requested type for ease of use. For instance, you can do the following: === CODE === AnyVector<> a; a.push_back(1); a.push_back(std::string("hello")); a.push_back(2); a.push_back(std::string("goodbye")); for(AnyVector<>::Iterator<int> i = a.begin<int>(); i != a.end<int>(); ++i) std::cout << (*i + 5); for(AnyVector<>::Iterator<std::string> i = a.begin<std::string>(); i != a.end<std::string>(); ++i) std::cout << i->length(); ============ Furthermore, you can restrict (at compile-time) which objects are allowed to be inserted into the AnyVector. This is done by listing those types when you create your AnyVector: === CODE ==== AnyVector<int, std::string> a; // Only allows int's and string's a.push_back(3.5); // Fails at compile time - double's not allowed! ============= Would this be a useful addition to boost, or does it already exist somewhere in boost and I just missed it? --Steve Stephen Gross Case Western School of Medicine Cleveland, OH "By Grabthar's hammer, by the sons of Worvan, you shall be avenged." - Dr. Lazarus

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Filter_iterator and boost::any follow-up
by Stephen Gross 13 Sep '05

13 Sep '05

>I think you'll need to use something like: >for(filter_itr f(i.begin(), i.end()); f != filter_itr(i.end()); ++f) Ok, cool, I've got it working on a vector of ints. My next question is this: I've got a vector of boost::any's, and I want to iterate across only the boost::any's representing int's. For example: === CODE === template<typename T> struct isT { bool operator() (const boost::any & a) const { return a.type() == typeid(T); } }; int main() { std::vector<boost::any> av; av.push_back(1); av.push_back(std::string("hello")); av.push_back(2); typedef boost::filter_iterator<isT<int>, std::vector<boost::any>::iterator > int_itr; for(int_itr itr(av.begin()); itr != int_itr(av.end()); ++itr) ; } ========= Unfortunately, the above code seg faults when executed. I imagine I've probably constructed my filter_iterator incorrectly somehow. Any ideas? Thanks, --Steve Stephen Gross Case Western School of Medicine Cleveland, OH "By Grabthar's hammer, by the sons of Worvan, you shall be avenged." - Dr. Lazarus

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Newbie question on filter_iterators
by Stephen Gross 13 Sep '05

13 Sep '05

Ok, I'm trying to learn the basics of filter_iterators. I've got a vector of ints. I want to iterate across the vector and print out every positive value in the vector. Currently, my code doesn't work because g++ doesn't like me assigning a vector::iterator to a filtered_iterator. Obviously, I've missed some crucial point on how the filtered_iterator is supposed to work. The example code in the boost library doesn't really address this specific use. Can someone show me how to make the code below work as intended? Thanks in advance, --Steve ==== CODE FOLLOWS ==== struct is_positive { bool operator() (int i) { return i >= 0; } }; int main() { std::vector<int> i; i.push_back(-5); i.push_back( 5); i.push_back(-4); i.push_back( 4); i.push_back(-3); i.push_back( 3); i.push_back(-2); i.push_back( 1); typedef boost::filter_iterator<is_positive, std::vector<int>::iterator> filter_itr; for(filter_itr f = i.begin(); f != i.end(); ++f) { std::cout << *f << std::endl; } return 0; }

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Re: [Boost-users] Scons users?
by Foster Gareth 13 Sep '05

13 Sep '05

I suppose in terms of scons and boost, then next question is how easy is it to build rpm/deb packages etc when using these build systems? Its very easy with autotooled projects. Don't get me wrong, I hate autotools, hence my interest in alternatives. Hopefully these comments aren't dragging us off topic here - these could be reasons to use Scons over Boost Build I suppose - depends on the answers really. Cheers, Gaz > -----Original Message----- > From: Sohail Somani [mailto:s.somani@fincad.com] > Sent: 13 September 2005 18:19 > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Scons users? > > > -----Original Message----- > > From: boost-users-bounces(a)lists.boost.org > > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of > > Foster Gareth > > Sent: Tuesday, September 13, 2005 9:37 AM > > To: boost-users(a)lists.boost.org > > Subject: Re: [Boost-users] Scons users? > > > > > > How does scons fair in terms of pulling in other libraries? I > > have used Autotools and using anything from there that > > doesn't have pkg-config support (like boost, opengl etc) is a > > nightmare. > > I believe scons can parse pkg-config output out of the box and set up > your CFLAGs etc appropriately but my mileage with this has varied > immensly. Anyway, its very simple to do it yourself as you have a real > programming language available. > > I think scons could learn a bit from autotools though I guess > autotools > is only useful because its popular. > > Sohail > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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Re: [Boost-users] Scons users?
by Sohail Somani 13 Sep '05

13 Sep '05

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of > Foster Gareth > Sent: Tuesday, September 13, 2005 9:37 AM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Scons users? > > > How does scons fair in terms of pulling in other libraries? I > have used Autotools and using anything from there that > doesn't have pkg-config support (like boost, opengl etc) is a > nightmare. I believe scons can parse pkg-config output out of the box and set up your CFLAGs etc appropriately but my mileage with this has varied immensly. Anyway, its very simple to do it yourself as you have a real programming language available. I think scons could learn a bit from autotools though I guess autotools is only useful because its popular. Sohail

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Re: [Boost-users] [BULK] Re: [BULK] [filesystem] function todetermineavailable space
by Sohail Somani 13 Sep '05

13 Sep '05

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of me22 > Sent: Monday, September 12, 2005 4:36 PM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] [BULK] Re: [BULK] [filesystem] > function todetermineavailable space > > > On 12/09/05, Sohail Somani <s.somani(a)fincad.com> wrote: > > What about using a type that guarantees a certain amount instead of > > just "max" (which may vary)? Or equivalently, are we > guaranteed that > > uintmax_t can hold, say one TB, on any platform that boost supports? > > > > Even 1 TB isn't really safe. I know a number of people with > more total storage than that. > > How about a double? The imprecision shouldn't be a worry -- > if you're beyond the range of a double's precision for free > space then being off by even a few MB it doesn't matter and > doubles are perfectly precise for small integral numbers. ( > on x86 linux it seems my 64-bit doubles have 53 bits of > mantissa meaning they're perfectly precise for anything less > than 8192 TeraBytes. I don't know what the standard specifes > though, and my 32-bit floats are only perfectly precise for > under 16 MB. That being said, even the 32-bit float has a > max of over 3e26 TB, so just saying the precision of the > number returned is dependant on the precision of your > platform's double would get around that, assuming of course > we can assure that any rounding is done on the safe side. ) > > Also, the implementation could work internally in whatever it > wants to keep perfect precision and just feed out a double at the end. Great idea. I'm ok with this. What about platforms like linux or windows? What types do they use to report these stats?

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Re: [Boost-users] Scons users?
by Foster Gareth 13 Sep '05

13 Sep '05

How does scons fair in terms of pulling in other libraries? I have used Autotools and using anything from there that doesn't have pkg-config support (like boost, opengl etc) is a nightmare. > -----Original Message----- > From: Jon Stewart [mailto:stew1@ellipsis.cx] > Sent: 13 September 2005 17:30 > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Scons users? > > > On the Boost.Build list we were just discussing the fact that some > > people otherwise inclined towards Boost have chosen Scons over > > Boost.Build. It would be useful for us to understand some of the > > reasons why, if some of you wouldn't mind letting us know. > No flames, > > please! > > > I have been using Scons more for tiny projects* than for > large ones, and I > am still somewhat ignorant about Boost.Build, so I can't give a fair > comparison. But people aren't fair, so I think the data > points are still > valid: > > 1. Scons is a nice framework embedded in a general purpose > programming language. So, you get the benefit of a DSL that > does 80% of > the job very nicely, but you've got all that is Python for > the 20% that > doesn't fit -- and the two parts integrate naturally. I moved > from Ant to > Scons and liked that Scons provided lots of high-level > functionality but > didn't straightjacket me into abstractions that didn't fit my > situation. > > 2. My standard SConstruct file is 4 lines (2 imports, 2 > statements). I get > a full dependency analysis, can make full use of ccache and > distcc, and > run my unit tests after the build. I can't imagine life being > better. :-) > > 3. Boost.Build started out life as a fork (right?), and I > haven't noticed > many other projects outside of Boost using it. Scons seems to > have more > "momentum". > > 4. Boost.Build docs don't/didn't offer the trivial example of how > to get "Hello, World" to build. Compare: > > http://www.boost.org/tools/build/v1/build_system.htm#getting_started > > with: > > http://www.scons.org/doc/HTML/scons-user.html#AEN239 > > 5. A fair amount of traffic on this list seems to be from > people who have > trouble with Boost.Build. Of course, I'm not subscribed to > the scons users > list so this isn't fair, but my perception was that > Boost.Build would have > a steeper learning curve. > > I'm sure Boost.Build is a powerful system and can do the > job... it just > seemed to require more thought to get running the first time, > and I wanted > to devote my thought to writing code. > > Hope this helps, > > > Jon > > * The majority of my tiny projects are stub programs to play > around with > all the other Boost libraries! :-) > -- > Jon Stewart > stew1(a)ellipsis.cx > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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[Boost.Program_options] some trouble w/ multitoken()?
by Marc VIALA 13 Sep '05

13 Sep '05

I'm just trying to use Boost.Program_options in an application and during my implementation, it appears a couple of questions: - Is it possible to introduce more than one "multitoken" options in command line? I didn't see any limitation in the documentation but my sample hereafter seems to prove that yes. - If the answer to the first question is yes, then how I can handle this feature? I seemed that with the older version, 1.32, this feature was supported? Thanks in advance. Best regards, Marc VIALA -------------------------------------------------------------- Test Configuration: -------------------------------------------------------------- PC / WinXP SP2 Visual C++ 7.1 Boost 1.33 -------------------------------------------------------------- Code Example: -------------------------------------------------------------- // How to use multitoken options in command line? #include <vector> #include <iostream> #include <iterator> #include <boost/program_options.hpp> #include <boost/lambda/lambda.hpp> using namespace boost ; using namespace boost::lambda ; namespace po = boost::program_options ; using namespace std ; int main(int argc, char* argv[] ) { string rootDir ; vector<string> inputList, outputList ; // Options declaration po::options_description generic("Generic options") ; generic.add_options() ("help" , "produce a help message" ) ("version" , "output the version number") ; po::options_description mandatory("Mandatory options"); mandatory.add_options() ("root,r" , po::value<string>(&rootDir) , "set project root catalog" ) ("acq,a" , po::value<vector<string> >(&inputList)->multitoken() , "set list of acquisition catalog#") ("measure,m", po::value<vector<string> >(&outputList)->multitoken() , "set list of measurement catalog#") ; // Group mandatory & generic options po::options_description cmdLineOpt("Allowed options") ; cmdLineOpt.add(generic).add(mandatory) ; // Simulate command line sample vector<string> args = po::split_winmain("-r Test --acq 11 tt 13 --measure 20 21 23"); // Parse command line po::variables_map vm ; po::store(po::command_line_parser(args).options(cmdLineOpt).run(), vm); po::notify(vm) ; // Display options & args in command lines cout << "root args : \n" ; if( vm.count("root") ) cout << '\t' << vm["root"].as<string>() << '\n' ; cout << "acq args : \n" ; if( vm.count("acq") ) { const vector<string>& vs = vm["acq"].as<vector<string> >() ; for_each(vs.begin(), vs.end(), cout << constant('\t') << _1 << constant('\n')) ; } cout << "measure args: \n" ; if( vm.count("measure") ) { const vector<string>& vs = vm["measure"].as<vector<string> >() ; for_each(vs.begin(), vs.end(), cout << constant('\t') << _1 << constant('\n')) ; } return 0 ; } -------------------------------------------------------------- -------------------------------------------------------------- Output results: -------------------------------------------------------------- root args : Test acq args : 11 tt 13 --measure (it seems to insert also option item w/ its args?) 20 21 23 measure args:

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random numbers
by Anakreon 13 Sep '05

13 Sep '05

I am considering to use boost.random library but have a problem with efficiency. I have a class which provides two public methods: double exponential(double mean) and double getUniform(double min, double max) The implementation I have using boost.random is inefficient and I need some advice in order to improve it. In both the above methods I create a variate_generator object with a mersenne_twister generator and the appropriate distribution. The problem is that the methods are called often which leads to creation and destruction of the variate_generator and the distribution object. I can not store those objects as member variables because the parameters mean in exponential and (min, max) in getUniform varies Thanks in advanced Anakreon

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Re: [Boost-users] [BULK] Re: [BULK] [filesystem] function to determineavailable space
by Sohail Somani 12 Sep '05

12 Sep '05

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Beman Dawes > Sent: Monday, September 12, 2005 2:20 PM > To: boost-users(a)lists.boost.org > Subject: [BULK] Re: [Boost-users] [BULK] [filesystem] > function to determineavailable space > Importance: Low > > "Sohail Somani" <s.somani(a)fincad.com> wrote in message > news:1C1EBEF8DBACDC439D038EA051674EC709C5D4@xbox.financialcad.com... > >> -----Original Message----- > >> From: boost-users-bounces(a)lists.boost.org > >> [mailto:boost-users-bounces@lists.boost.org] On Behalf Of > Beman Dawes > >> Sent: Monday, September 12, 2005 10:23 AM > >> To: boost-users(a)lists.boost.org > >> Subject: [BULK] [Boost-users] [filesystem] function to determine > >> available space > >> Importance: Low > >> > >> > >> I'm planning to add a filesystem function to determine > available disk > >> space. Perhaps something like: > >> > >> struct space_status > >> { > >> boost::uintmax_t available; // free space available to user > >> boost::uintmax_t total; // total space on volume > >> }; > >> > >> space_status filesystem_space( const path & p ); > >> > >> Comments? > > > > Standard unit of measure? Bytes? Megabytes? Gigabytes? > > Bytes. Individual bytes still matter in some applications. What about using a type that guarantees a certain amount instead of just "max" (which may vary)? Or equivalently, are we guaranteed that uintmax_t can hold, say one TB, on any platform that boost supports?

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Re: [Boost-users] [BULK] [filesystem] function to determine available space
by Sohail Somani 12 Sep '05

12 Sep '05

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Beman Dawes > Sent: Monday, September 12, 2005 10:23 AM > To: boost-users(a)lists.boost.org > Subject: [BULK] [Boost-users] [filesystem] function to > determine available space > Importance: Low > > > I'm planning to add a filesystem function to determine > available disk space. > Perhaps something like: > > struct space_status > { > boost::uintmax_t available; // free space available to user > boost::uintmax_t total; // total space on volume > }; > > space_status filesystem_space( const path & p ); > > Comments? Standard unit of measure? Bytes? Megabytes? Gigabytes?

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[wave] Some bugs (posted here, 'coz SF bug-tracking is currently down)
by Mihalicza, Jozsef 12 Sep '05

12 Sep '05

Hello, I've built a spirit grammer to process the token sequence of wave. 1. Scope missing in macros. The first problem arose when I tried to write the wave token equivalent of chlit: struct token_lit : public boost::spirit::char_parser<token_lit> { token_lit(boost::wave::token_id id_) : id(id_) {} template <typename T> bool test(T id_) const { return BASE_TOKEN(id_) == BASE_TOKEN(id); } boost::wave::token_id id; }; The code above doesn't compile, because BASE_TOKEN uses constants from boost::wave without explicit scope. Lines to fix: token_ids.hpp(37-40,305,309). 2. Newline token reports bad position. For debug purposes I reported the match positions in the grammer actions using the file_position interface of the wave token type. The results were quite strange, sometimes pointing into the middle of a keyword, so I decided to take a smaller step and modified the wave example (the one in the documentation) just to see what happens, as follows: while (first != last) { std::cout << "value: \"" << (*first).get_value() << "\" pos: " << (*first).get_position ().get_file () << "(" << (*first).get_position ().get_line () << ") @" << (*first).get_position ().get_column () << std::endl; ++first; } Attached you can find some very small inputs and their corresponding outputs. 2.1. A file containing only whites and comments produced no tokens at all 2.2. Position of the enter token reports the new line number but the old column 2.3. The #line directive affects the position in a very strange way Please clarify if some of these are not errors. Oops, I almost forgot, I am using a fresh verison from the CVS repository already containing the fix for the SF bug #1274584. Best regards, József Mihalicza

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Re: [Boost-users] Some thoughts on Unary / BinaryFunctionConcept limitations
by Stephen Gross 12 Sep '05

12 Sep '05

> (1) The implementation of Unary and Binary (FunctionConcepts) > assume that > the return type is assignable ("r = f(arg)" tries to assign a value > to r). > But what if the return type is a reference? Won't the function > concept fail > to compile? Is this a bug? >That looks like a bug. >Here's a challenge for you: how would you fix this bug? In my own functor concept implementation, I used the function-pointer trick to make it work: ==== CODE ==== template<typename Func, typename Ret, typename Arg> struct special_UnaryFunctionConcept { void constraints() { Ret (Func::*x) (Arg) = Func::operator(); } }; ============== > (2) I'm implementing an NaryFunctionConcept for functors taking > more than 2 > arguments. The BOOST_CLASS_REQUIREx macro, however, appears to be > limited to > 4 types. This limits the NaryFunctionConcept to functors with up to > two > arguments. Is there a way to expand the BOOST_CLASS_REQUIREx macro > to handle > more than 4 types? >I'm sure there is a way. Can you think of a way to do it? Perhaps the >boost preprocessor library would help. Well, I was thinking that it BOOST_CLASS_REQUIREx for x > 4 could be added to the concept_check library in the same way that it is for x <= 4. Is this possible? > (3) I ran into a compiler problem when using BOOST_CLASS_REQUIREx; > when any > of the type macros have spaces or non-alphanumeric characters in > them, the > compiler reports an error. In the following example, I try to use > the macro > to require a UnaryFunctor taking a const std::string & and > returning an int. >Yes, you need to create a typedef for such types. This restriction >should be documented. I've checked in a fix to the docs. Ok, gotcha. Interesting... Thanks, --Steve

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Some thoughts on Unary / BinaryFunctionConcept limitations
by Stephen Gross 12 Sep '05

12 Sep '05

I'm just now learning about the concept_check library and how Unary and BinaryFunctionConcepts work in it. I have a few questions: (1) The implementation of Unary and Binary (FunctionConcepts) assume that the return type is assignable ("r = f(arg)" tries to assign a value to r). But what if the return type is a reference? Won't the function concept fail to compile? Is this a bug? (2) I'm implementing an NaryFunctionConcept for functors taking more than 2 arguments. The BOOST_CLASS_REQUIREx macro, however, appears to be limited to 4 types. This limits the NaryFunctionConcept to functors with up to two arguments. Is there a way to expand the BOOST_CLASS_REQUIREx macro to handle more than 4 types? (3) I ran into a compiler problem when using BOOST_CLASS_REQUIREx; when any of the type macros have spaces or non-alphanumeric characters in them, the compiler reports an error. In the following example, I try to use the macro to require a UnaryFunctor taking a const std::string & and returning an int. The code, however, fails to compile. Here's the code and error log: === CODE === template<typename T> class foo { BOOST_CLASS_REQUIRE3(T, int, const std::string &, boost, UnaryFunctionConcept); }; ============ Produces the following error (from g++): ==== ERROR LOG ==== test.cpp:42: error: parse error before `::' token test.cpp:42:80: pasting "&" and "UnaryFunctionConcept" does not give a valid preprocessing token test.cpp:42: error: parse error before `std' test.cpp:42:80: pasting "&" and "UnaryFunctionConcept" does not give a valid preprocessing token test.cpp:42:80: pasting "&" and "UnaryFunctionConcept" does not give a valid preprocessing token test.cpp:42: error: missing ';' before right brace test.cpp:42: confused by earlier errors, bailing out =================== Is this a bug? Thanks in advance for your thoughts, --Steve Stephen Gross Case Western School of Medicine Cleveland, OH "By Grabthar's hammer, by the sons of Worvan, you shall be avenged." - Dr. Lazarus

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Looking for example of BOOST_CLASS_REQUIREx
by Stephen Gross 12 Sep '05

12 Sep '05

I'm trying to find an example of how to invoke the BOOST_CLASS_REQUIREx macro (from the concept_check library). Can anyone point me in the right direction? Thanks, --Steve Stephen Gross Case Western School of Medicine Cleveland, OH "By Grabthar's hammer, by the sons of Worvan, you shall be avenged." - Dr. Lazarus

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Inheriting matrix_array
by Edward Grace 12 Sep '05

12 Sep '05

Dear all, I am evaluating aspects of the boost library. I wish to generate a simple implementation of ray transfer (ABCD) matricies, http://en.wikipedia.org/wiki/ABCD_matrix Since these matricies are 2x2 and will need multiplication, trace and other similar matrix like operations it makes sense to use: matrix_array<double,2> or boost::numeric::ublas::matrix_scalar<double> I wish to generate a ray transfer matrix class by overloading (say) matrix_array<double,2> and adding member functions such as: class rtm : boost::multi_array<double,2> { public: void setA(double val) { boost::multi_array<double,2>::operator()(0,0) = val; } }; Now, this is wrong... Essentially I just want to know something very simple.... When I inherit multi_array or any other class that I want to use the [] or (x,x) notation to access elements (subscript operators) how on earth do I do it? Your help will be greatly appreciated, this is driving me crazy! -ed

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scalar_matrix or containers and different contained types...
by Edward Grace 12 Sep '05

12 Sep '05

Dear All, Is there specifically a way I can do the following? boost::numeric::ublas::scalar_matrix<double> mD(3,3); boost::numeric::ublas::scalar_matrix<complex<double> > mC(3,3); mC = mD; Since I can do, complex<double> a; double b; a = b; without any problem why can the same thing be done with the container? Perhaps this is a more general point with C++ containers. If I can carry out a type conversion on the contained object (e.g. double -> complex<double> assuming the double is real) is there a way I can make sure the same carries through for casting of the contained objects? -ed -- Dr. Edward Grace Photonics Group, Physics Department Blackett Laboratory Imperial College SW7 2BW t: 020 759 47719 e: ej.grace(a)imperial.ac.uk w: http://ptweb.op.ph.ic.ac.uk/~graceej

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Serialization of template classes via base
by Bruno Martínez 12 Sep '05

12 Sep '05

Hi. This has been asked before here http://lists.boost.org/boost-users/2005/05/11706.php but I didn't understand the workaround. What I want is to serialize class B where class A { ... }; template<...> class B : public A { ... }; when I have an A*. The workarounds proposed were using RTTI non portably, or registering the classes each time. How would such solution look like? Regards, Bruno

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Boost post on codetools
by gast128 11 Sep '05

11 Sep '05

I have posted two articles ('File rename using boost regex and boost file system' and 'Building boost libraries for Visual Studio')on www.codetools.com on Boost issues. In this way I hope to promote Boost use in a community which is more geared towards MFC use. Wkr, me

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boost-1.33, [date_time]: missing std::localtime_r/gmtime_r
by Michael Haubenwallner 11 Sep '05

11 Sep '05

Hi, There's a problem on HP-UX (especially hppa2.0w-hp-hpux11.11) with gcc-3.3.6, where localtime_r and gmtime_r are not in namespace std. boost-1.33 itself is built with "<cxxflags>-pthread/<linkflags>-pthread" $ cat xx.cc #include <boost/date_time/posix_time/posix_time_system.hpp> $ g++ -pthread xx.cc In file included from /tools/snapshot/toolsbox-3.5.0.16rc.20050904/HP-UX/boost/include/boost/date_time/date_clock_device.hpp:12, from /tools/snapshot/toolsbox-3.5.0.16rc.20050904/HP-UX/boost/include/boost/date_time/gregorian/gregorian_types.hpp:26, from /tools/snapshot/toolsbox-3.5.0.16rc.20050904/HP-UX/boost/include/boost/date_time/posix_time/posix_time_config.hpp:14, from /tools/snapshot/toolsbox-3.5.0.16rc.20050904/HP-UX/boost/include/boost/date_time/posix_time/posix_time_system.hpp:13, from xx.cc:1: /tools/snapshot/toolsbox-3.5.0.16rc.20050904/HP-UX/boost/include/boost/date_time/c_time.hpp: In static member function `static tm* boost::date_time::c_time::localtime(const time_t*, tm*)': /tools/snapshot/toolsbox-3.5.0.16rc.20050904/HP-UX/boost/include/boost/date_time/c_time.hpp:56: error: ` localtime_r' undeclared in namespace `std' /tools/snapshot/toolsbox-3.5.0.16rc.20050904/HP-UX/boost/include/boost/date_time/c_time.hpp: In static member function `static tm* boost::date_time::c_time::gmtime(const time_t*, tm*)': /tools/snapshot/toolsbox-3.5.0.16rc.20050904/HP-UX/boost/include/boost/date_time/c_time.hpp:64: error: ` gmtime_r' undeclared in namespace `std' $ $ gcc -v Reading specs from /mnt/toolsjunk/snapshot/toolsbox-3.5.0.16rc.20050904/HP-UX/lib/gcc-lib/hppa2.0w-hp-hpux11.11/3.3.6/specs Configured with: /mnt/toolsjunk/snapshot/src/sasrvb/toolsbox-3.5.0.16rc.20050904/buildroot/gcc/gcc-3.3.6/configure --with-gnu-as --with-as=/tools/snapshot/toolsbox-3.5.0.16rc.20050904/HP-UX/hppa2.0w-hp-hpux11.11/bin/as --without-gnu-ld --with-ld=/usr/ccs/bin/ld --enable-threads=posix --with-local-prefix=/tools/snapshot/toolsbox-3.5.0.16rc.20050904/HP-UX --disable-nls --prefix=/tools/snapshot/toolsbox-3.5.0.16rc.20050904/HP-UX Thread model: posix gcc version 3.3.6 Two maybe interesting notes: 1) /usr/include/time.h only declares localtime_r/gmtime_r if '-pthread' compiler-flag is used (and therefore _REENTRANT is defined). 2) gcc-shipped <ctime> does not pull localtime_r/gmtime_r into namespace std Thanks! ~haubi -- Michael Haubenwallner SALOMON Automation GmbH Forschung & Entwicklung A-8114 Friesach bei Graz mailto:michael.haubenwallner@salomon.at http://www.salomon.at No HTML/MIME please, see http://expita.com/nomime.html

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Re: [Boost-users] [preprocessor] break "names"
by Mihalicza, Jozsef 10 Sep '05

10 Sep '05

Hi, Not a naive question, check this: http://lists.boost.org/Archives/boost/2005/03/83253.php Regards, József Mihalicza ________________________________ Feladó: boost-users-bounces(a)lists.boost.org meghatalmazó: Felipe Magno de Almeida Hi, Maybe it is a naive question, but I've been researching a little and couldnt find an answer to this(not an affirmative and nor negative): Is it possible to have such usages: SOME_MACRO(hello world) or SOME_MACRO("hello world") (or something that doesnt have much "characters overhead", like using space for every character) and have the expansion result in this: h e l l o w o r l d or even better: 'h','e','l','l','o', ' ', 'w', 'o', 'r', 'l', 'd' Well, what I'm trying to find is if it is possible to give something to a macro and the macro create an vector_c with all the characters inside it. Like: SOME_MACRO(Hello World) and expand to: boost::mpl::vector<char, 'H','e','l','l','o',' ','W','o','r','l','d'> Thanks in advance, -- Felipe Magno de Almeida Developer from synergy and Computer Science student from State University of Campinas(UNICAMP). Unicamp: http://www.ic.unicamp.br Synergy: http://www.synergy.com.br "There is no dark side of the moon really. Matter of fact it's all dark." _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Serialization segfaulting
by Dmitriy Morozov 10 Sep '05

10 Sep '05

Hi, I'm having problems with boost serialization library. There are two cases in which it is segfaulting on me. One is during a register_type() call, but we can discuss that one later. Another one which I am trying to debug right now is when I am trying to serialize a large binary tree (lots of pointers all over the place, sometimes pointing at themselves, sometimes at 0, sometimes jumping all over the tree). I am not quite sure how to approach the debugging of this issue since for some reason I am not able to step into the boost serialization routines themselves (but I'm not so good with the debugger). The actual segfault as given by DDD is: Program received signal SIGSEGV, Segmentation fault. 0x40075b75 in std::_Rb_tree<boost::archive::detail::basic_oarchive_impl::cobject_type, boost::archive::detail::basic_oarchive_impl::cobject_type, std::_Identity<boost::archive::detail::basic_oarchive_impl::cobject_type>, std::less<boost::archive::detail::basic_oarchive_impl::cobject_type>, std::allocator<boost::archive::detail::basic_oarchive_impl::cobject_type> >::insert_unique(boost::archive::detail::basic_oarchive_impl::cobject_type const&) () from /usr/lib/libboost_serialization.so.1.33.0 Any advice is appreciated. Best, Dmitriy P.S. On a completely unrelated note, when the abstract base class is a template, the BOOST_IS_ABSTRACT macro is not applicable. It would be helpful if the documentation listed the chunk of code that needs to be added in that case. It's pretty easy to find it in the header files (is_abstract.hpp), but it may be helpful to just list it.

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[preprocessor] break "names"
by Felipe Magno de Almeida 10 Sep '05

10 Sep '05

Hi, Maybe it is a naive question, but I've been researching a little and couldnt find an answer to this(not an affirmative and nor negative): Is it possible to have such usages: SOME_MACRO(hello world) or SOME_MACRO("hello world") (or something that doesnt have much "characters overhead", like using space for every character) and have the expansion result in this: h e l l o w o r l d or even better: 'h','e','l','l','o', ' ', 'w', 'o', 'r', 'l', 'd' Well, what I'm trying to find is if it is possible to give something to a macro and the macro create an vector_c with all the characters inside it. Like: SOME_MACRO(Hello World) and expand to: boost::mpl::vector<char, 'H','e','l','l','o',' ','W','o','r','l','d'> Thanks in advance, -- Felipe Magno de Almeida Developer from synergy and Computer Science student from State University of Campinas(UNICAMP). Unicamp: http://www.ic.unicamp.br Synergy: http://www.synergy.com.br "There is no dark side of the moon really. Matter of fact it's all dark."

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boost-1.33 [date_time] simple_format template: missing default for <charT>
by Michael Haubenwallner 10 Sep '05

10 Sep '05

Hi, is there any reason besides being a bug why the formatters found in boost/date_time/date_formatting.hpp have a default value 'char' for template argument 'charT', but boost::date_time::simple_format does not ? Thanks, haubi -- Michael Haubenwallner SALOMON Automation GmbH Forschung & Entwicklung A-8114 Friesach bei Graz mailto:michael.haubenwallner@salomon.at http://www.salomon.at No HTML/MIME please, see http://expita.com/nomime.html

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Re: [Boost-users] Thread events
by Christopher Hunt 10 Sep '05

10 Sep '05

On 10/09/2005, at 2:12 AM, boost-users-request(a)lists.boost.org wrote: >> Thanks for your replies. >> >> To me boost::condition looks very much like the old event >> variable, except >> that it works together with a mutex. I am now wondering why you >> should >> lock >> a mutex before waiting for the condition? Is there a rationale >> about this? > Also note that the wait() on the condition unlocks the mutex until you > return from the wait call. That's not always obvious from the > examples. Someone else mentioned the Butenhof book so I won't go down that path; suffice to state that anyone that wants to do any thread programming absolutely must read that book. In fact, the book really is more about thread paradigms than pthreads. IMHO pthreads are more of a case study in the book. A quick example to fill in the time between you ordering the book and receiving it might help. Suppose you have a mutex for the purpose of protecting a variable. Suppose you must also wait on a condition because that variable isn't in a state that you need to progress. If you keep the mutex locked while waiting on a condition then no other thread will get the opportunity to modify the variable's value. To solve this many programmers will just unlock the mutex prior to waiting on the condition. However, the problem with this approach is that in the time between the mutex being unlocked, and the condition is waited on, another thread can come along, lock the mutex and change the variable. Thus you might be waiting on a condition that never occurs. Remember that conditions are generally signaled only to threads currently waiting on them or to the 1st thread that comes along and waits on a condition. Thus, if you're not waiting on a condition, you may never receive its signal. You may think that the chances of another thread coming along and upsetting your world are slim, but one day, it will happen and you'll be wanting to ignore that bug in your app 'cause it'll be hard to reproduce. pthread conditions are associated with mutexes so that they guarantee to unlock a mutex and wait on a condition without the chance of another thread coming along and doing what is described above. From an implementation perspective, I imagine pthread conditions enter into a critical section while they unlock a mutex and move to a wait state. As stated before, when you return from the condition, the mutex will be locked again, and you should re-test for your condition. Something like the following logic may help: ***** lock mutex while var not in state you need to proceed { wait on condition associated with mutex } unlock mutex do your stuff. ***** Note that it is also healthy to unlock your mutexes asap so as to reduce contention. 'hope that this helps. Cheers, -C

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Problem with BGL copy_graph algorithm - HELP
by Tony Cook 09 Sep '05

09 Sep '05

Hello, Can anyone tell me if I've exposed a bug in the Boost Graph Library or if the following behaviour is expected and I need to code the solution in a different way, and if so HOW? In summary the boost::copy_graph algorithm fails to compile when defining the graph using std::vector for the edge container and std::list for the vertex container (Visual Studio 7.1, Boost 1.32.0). Other graph type definitions work. (NB I can't use the "working" graph types in my main application as VC 7.1 bombs with an Internal Compiler Error. I'm forced to use a vecS,lists graph just to work round the ICE problem!!). I've distilled the problem down to the minimum code possible. ------------------------------------------------- // A vecS, vecS based graph works typedef boost::adjacency_list <boost::vecS, boost::vecS, boost::undirectedS, boost::no_property, boost::no_property, boost::no_property> GoodGraphType ; GoodGraphType good_graph_1 ; GoodGraphType good_graph_2 ; boost::copy_graph (good_graph_1, good_graph_2) ; // Compiles OK ------------------------------------------------- // A listS, vecS based graph also works typedef boost::adjacency_list <boost::listS, boost::vecS, boost::undirectedS, boost::no_property, boost::no_property, boost::no_property> AnotherGoodGraphType ; AnotherGoodGraphType another_good_graph_1 ; AnotherGoodGraphType another_good_graph_2 ; boost::copy_graph (another_good_graph_1, another_good_graph_2) ; // Compiles OK ------------------------------------------------- // A vecS, lists based graph fails to compile - BGL error or expected?? typedef boost::adjacency_list <boost::vecS, boost::listS, // root cause of compilation failure boost::undirectedS, boost::no_property, boost::no_property, boost::no_property> BadGraphType ; BadGraphType bad_graph_1 ; BadGraphType bad_graph_2 ; boost::copy_graph (bad_graph_1, bad_graph_2) ; // ***** Does not compile ****** ------------------------------------------------------- Here is the exact wording of the VC7.1 compiler output. ------------------------------------------------------- ..\boost_1_32_0\boost\property_map.hpp(349) : error C2678: binary '+' : no operator found which takes a left-hand operand of type 'const std::vector<_Ty>::iterator' (or there is no acceptable conversion) with [ _Ty=boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS,boost::vec S,boost::undirectedS,boost::no_property,boost::no_property,boost::no_propert y>,boost::vecS,boost::vecS,boost::undirectedS,boost::detail::retag_property_ list<boost::vertex_bundle_t,boost::no_property>::type,boost::detail::retag_p roperty_list<boost::edge_bundle_t,boost::no_property>::type,boost::no_proper ty,boost::listS>::config::vertex_ptr ] ...\boost_1_32_0\boost\property_map.hpp(349) : while compiling class-template member function 'void boost::iterator_property_map<RandomAccessIterator,IndexMap,T,R>::operator [](boost::iterator_property_map<RandomAccessIterator,IndexMap,T,R>::key_type ) const' with [ RandomAccessIterator=std::vector<boost::detail::adj_list_gen<boost::adjacenc y_list<boost::vecS,boost::vecS,boost::undirectedS,boost::no_property,boost:: no_property,boost::no_property>,boost::vecS,boost::vecS,boost::undirectedS,b oost::detail::retag_property_list<boost::vertex_bundle_t,boost::no_property> ::type,boost::detail::retag_property_list<boost::edge_bundle_t,boost::no_pro perty>::type,boost::no_property,boost::listS>::config::vertex_ptr >::iterator, IndexMap=boost::property_map<boost::adjacency_list<boost::vecS,boost::listS, boost::undirectedS,boost::no_property,boost::no_property,boost::no_property> ,boost::vertex_index_t>::const_type, T=std::allocator<boost::detail::adj_list_gen<boost::adjacency_list<boost::ve cS,boost::vecS,boost::undirectedS,boost::no_property,boost::no_property,boos t::no_property>,boost::vecS,boost::vecS,boost::undirectedS,boost::detail::re tag_property_list<boost::vertex_bundle_t,boost::no_property>::type,boost::de tail::retag_property_list<boost::edge_bundle_t,boost::no_property>::type,boo st::no_property,boost::listS>::config::vertex_ptr >::value_type, R=std::allocator<boost::detail::adj_list_gen<boost::adjacency_list<boost::ve cS,boost::vecS,boost::undirectedS,boost::no_property,boost::no_property,boos t::no_property>,boost::vecS,boost::vecS,boost::undirectedS,boost::detail::re tag_property_list<boost::vertex_bundle_t,boost::no_property>::type,boost::de tail::retag_property_list<boost::edge_bundle_t,boost::no_property>::type,boo st::no_property,boost::listS>::config::vertex_ptr >::value_type & ] ...\boost_1_32_0\boost\graph\copy.hpp(323) : see reference to class template instantiation 'boost::iterator_property_map<RandomAccessIterator,IndexMap,T,R>' being compiled with [ RandomAccessIterator=std::vector<boost::detail::adj_list_gen<boost::adjacenc y_list<boost::vecS,boost::vecS,boost::undirectedS,boost::no_property,boost:: no_property,boost::no_property>,boost::vecS,boost::vecS,boost::undirectedS,b oost::detail::retag_property_list<boost::vertex_bundle_t,boost::no_property> ::type,boost::detail::retag_property_list<boost::edge_bundle_t,boost::no_pro perty>::type,boost::no_property,boost::listS>::config::vertex_ptr >::iterator, IndexMap=boost::property_map<boost::adjacency_list<boost::vecS,boost::listS, boost::undirectedS,boost::no_property,boost::no_property,boost::no_property> ,boost::vertex_index_t>::const_type, T=std::allocator<boost::detail::adj_list_gen<boost::adjacency_list<boost::ve cS,boost::vecS,boost::undirectedS,boost::no_property,boost::no_property,boos t::no_property>,boost::vecS,boost::vecS,boost::undirectedS,boost::detail::re tag_property_list<boost::vertex_bundle_t,boost::no_property>::type,boost::de tail::retag_property_list<boost::edge_bundle_t,boost::no_property>::type,boo st::no_property,boost::listS>::config::vertex_ptr >::value_type, R=std::allocator<boost::detail::adj_list_gen<boost::adjacency_list<boost::ve cS,boost::vecS,boost::undirectedS,boost::no_property,boost::no_property,boos t::no_property>,boost::vecS,boost::vecS,boost::undirectedS,boost::detail::re tag_property_list<boost::vertex_bundle_t,boost::no_property>::type,boost::de tail::retag_property_list<boost::edge_bundle_t,boost::no_property>::type,boo st::no_property,boost::listS>::config::vertex_ptr >::value_type & ] ...\CopyGraphTest.cpp(50) : see reference to function template instantiation 'void boost::copy_graph<BadGraphType,BadGraphType>(const VertexListGraph &,MutableGraph &)' being compiled with [ VertexListGraph=BadGraphType, MutableGraph=BadGraphType ] ------------------------------------------------------- Here is the code from property_map.hpp the generates the error - error line marked with //<----- HERE //========================================================================= // Adapter to turn a RandomAccessIterator into a property map template <class RandomAccessIterator, class IndexMap #ifdef BOOST_NO_STD_ITERATOR_TRAITS , class T, class R #else , class T = typename std::iterator_traits<RandomAccessIterator>::value_type , class R = typename std::iterator_traits<RandomAccessIterator>::reference #endif > class iterator_property_map : public boost::put_get_helper< R, iterator_property_map<RandomAccessIterator, IndexMap, T, R> > { public: typedef typename property_traits<IndexMap>::key_type key_type; typedef T value_type; typedef R reference; typedef boost::lvalue_property_map_tag category; inline iterator_property_map( RandomAccessIterator cc = RandomAccessIterator(), const IndexMap& _id = IndexMap() ) : iter(cc), index(_id) { } inline R operator[](key_type v) const { return *(iter + get(index, v)) ; } //<----- HERE protected: RandomAccessIterator iter; IndexMap index; }; -------------------------------------------------------- TIA for any help in this matter Tony Cook

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[BGL] Help with Brandes' Betweenness
by Rui Carvalho 09 Sep '05

09 Sep '05

Hi, I'm trying to write code to compute Brandes' Betweenness Centrality for a very simple graph: a star. I'm doing this, as I haven't been able to find simple examples in the documentation [hint :)] for vecS,vecS graphs and still haven't grasped how edge property maps work. I've got it running if all I want is to compute vertex BC (see below, also attached), but can't get it to compute both vertex and edge BC. I'd appreciate any suggestions -perhaps my example (or something similar) could be corrected and included in the BGL? Thanks, Rui #include <iostream> // for std::dataout #include <utility> // for std::pair #include <boost/utility.hpp> // for boost::tie #include <boost/graph/graph_traits.hpp> // for boost::graph_traits #include <boost/graph/graph_utility.hpp> #include <boost/graph/betweenness_centrality.hpp>//for boost::brandes_betweenness_centrality #include <boost/graph/adjacency_list.hpp> using namespace boost; using namespace std; typedef adjacency_list < vecS, //Store out-edges vecS, //Store vertex set undirectedS, //the graph is undirected property<edge_index_t, int> > Graph; typedef graph_traits<Graph>::vertex_descriptor Vertex; typedef graph_traits<Graph>::vertex_iterator Vertex_Iter; typedef graph_traits<Graph>::edge_descriptor Edge; typedef graph_traits<Graph>::edge_iterator Edge_Iter; typedef property_map<Graph, vertex_name_t>::type Name_Map_t; typedef property_map<Graph, edge_index_t>::type Edge_Map_t; int main(int,char*[]) { int n_vrtx = 5; //Builds graph with vertices, but no edges Graph g_star(n_vrtx); //Add edges. Graph g_star is a star add_edge(vertex(0, g_star), vertex(4, g_star), g_star); add_edge(vertex(1, g_star), vertex(4, g_star), g_star); add_edge(vertex(2, g_star), vertex(4, g_star), g_star); add_edge(vertex(3, g_star), vertex(4, g_star), g_star); Vertex_Iter vertex_iterator_begin, vertex_iterator_end; std::vector<double> centrality(n_vrtx); brandes_betweenness_centrality(g_star, centrality_map(make_iterator_property_map(centrality.begin(), get(vertex_index, g_star),double())).vertex_index_map(get(vertex_index, g_star))); for ( tie(vertex_iterator_begin, vertex_iterator_end) = vertices(g_star); vertex_iterator_begin != vertex_iterator_end; ++vertex_iterator_begin) { cout << "Vertex: " << *vertex_iterator_begin <<"\tBC: "<< centrality[*vertex_iterator_begin] << endl; } }

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[Logging] Issues with dlls
by Paolo Coletta 09 Sep '05

09 Sep '05

Hi, I'm using Torjo's logging library in both an exe and a dll loaded from that exe (OS: Windows Xp, Compiler VC71 - /MD compile flag - multithreaded dll). I need the exe and the dll to have independent logs, as the dll are plugins implemented by third parties which may or not use boost log. The approach I was trying to follow was: - The exe declares/defines the log it needs. In its main function it initializes the logging system (appenders/modifiers/flush_log_cache). - Some of the dlls (at least the ones developed by me), declare/defines their own logs. In the DllMain they initialize theri logging system (appenders/modifiers/flush_log_cache). Is this expected to work? I made some tests and I got an access violation when exiting the main app, in the destructor of default_log_manager_impl(). (I can send a simple test case if needed). I also tried to compile the exe with BOOST_LOG_DYN_LINK but I always get the access violation (don't know if this could help - I remember to have seen this suggested in a similar case). What am i doing wrong? Paolo Coletta

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Thread events
by Johan 't Hart 09 Sep '05

09 Sep '05

(I'm not that familiair with news servers, so this post might appear for the second time. I hope to get an answer though) Hello, I'm quite a newbie in the boost world, and I read the documentation about boost::threads. Inthere I read that events were not included in boost because they were too error-phrone. That made me wonder how to do multithreading without events, for example, how do you make a thread wait for something to do without events? I don't know how to implement that with just mutexes. Can someone help me? Thanks in advance. Johan 't Hart -- -- Mijn Postvak In wordt beschermd door SPAMfighter 11622 spam-mails zijn er tot op heden geblokkeerd. Download de gratis www.SPAMfighter.com vandaag nog!

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bbv2 filesystem link issue?
by Daniel Schlyder 09 Sep '05

09 Sep '05

Hi, I'm in the process of upgrading to Boost.Build v2 and have run into a problem with Boost.Filesystem (or my use of it). Executables using this library crash when built with my BBv2 files, but work fine with my old BBv1 files. I'm using Boost CVS HEAD, MinGW GCC 3.4.4 and Boost.Jam 03.01.11. The crash is a SIGSEGV in std::string::find_first_of() when called from boost::filesystem::windows_name(). It doesn't matter whether I use a shared or static variant of the library. Moving the definition of windows_invalid_chars into windows_name() fixes it as long as I use a static variant. I guess this should give some clue as to what is going wrong, but I don't get it. I tried comparing the build commands of BB v1 and v2 but if there is anything wrong I don't have the knowledge to see it. I tried duplicating the crash using a simple BBv2 Jamroot and a "hello world"-ish Boost.Filesystem program, but that works fine. I'm completely stuck here and any help would be much appreciated. Thanks, -- Daniel Schlyder http://bitblaze.com/

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Re: [Boost-users] Thread events
by Gottlob Frege 09 Sep '05

09 Sep '05

> > Date: Thu, 8 Sep 2005 21:06:12 +0200 > From: "Johan 't Hart" <jopie64(a)hotmail.com> > Subject: Re: [Boost-users] Thread events > To: <boost-users(a)lists.boost.org> > Message-ID: <BAY109-DAV27468EBFC3012D63D9A99B4990(a)phx.gbl> > Content-Type: text/plain; format=flowed; charset="iso-8859-1"; > reply-type=original > > Thanks for your replies. > > To me boost::condition looks very much like the old event variable, except > that it works together with a mutex. I am now wondering why you should > lock > a mutex before waiting for the condition? Is there a rationale about this? > > Johan Also note that the wait() on the condition unlocks the mutex until you return from the wait call. That's not always obvious from the examples.

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request: make atomic operations (boost/detail/atomic_count*) available for library users
by Paul Pogonyshev 08 Sep '05

08 Sep '05

Hi, Is it possible that atomic operations in Boost are made available for library users? `shared_ptr' is good, but sometimes one might need the low-level operations too. Paul

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