- Boost-users - lists.preview.boost.org

RE: [Boost-users] Re: detect unneded includes
by Ben Hutchings 05 Jul '04

05 Jul '04

Adrian Stoica <adrian_stoica(a)btinternet.com> wrote: > I'm not aware of any such tools, but it could be done with a Perl > script that removes the includes one at a time, and then invokes the > compiler. If the file compiles ok, it's probably safe to remove that > include. No, unfortunately not. A header might appear to be redundant because it is included by another, yet this may be a mere implementation detail which is subject to change and should not be relied upon. In the absence of a true module system this is impossible to determine. Also it could be that the header defines template specialisations, or macros with the same names as functions/objects. Removing such a header might not make the program ill-formed but could still break it subtly. Instantiating a template in one translation unit for the same template arguments for which there is an explicit specialisation in another translation unit results in undefined behaviour. With sufficient testing you can *probably* avoid such mishaps but I would be very wary of trying to automate this.

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newbie: need example (call python from c++)
by Peter Piehler 04 Jul '04

04 Jul '04

Hello, I use call<void>(pyFunc,arg1,..) to call a python function with standard double, int etc. What must I do to call a function with a c++ object as argument? psydocode: class MyAnimal { /*...*/ std::string __strName; public: MyAnimal() : __strName("Tux") {} /*...*/ std::string getName() { return __strName;} void setName(const std::string &strName) { __strName = strName; } }; int main() { /*...*/ MyAnimal* pTux = new Animal; /*do something with pTux*/ /*use a python function with pTux*/ call<void>(pyFunc1, ?pTux? ); /*change attributes pTux in pyFunc2*/ dog = call<MyAnimal>(pyFunc2, ?pTux?); /*if it possible to call by reference?*/ call<void>(pyFunc3, ?pTux?); pTux->getName();// return Cat } python module: def py_func1(a): print a.getName() def py_func2(a): a.setName('Dog') return a def py_funnc3(a): a.setName('Cat') ___________________________________________________________ Gesendet von Yahoo! Mail - Jetzt mit 100MB Speicher kostenlos - Hier anmelden: http://mail.yahoo.de

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Problem with boost random library.
by Joshua Little 04 Jul '04

04 Jul '04

Hi all, I'm trying to use the randome number generators but I am having some problems. I'm using boost 1.31.0 and gcc 3.2 on Windows 2000. Here is my code : printf(" Die \n "); //std::cout << "Die Rolls" << std::endl; try { boost::mt19937 rng; // produces randomness out of thin air // see pseudo-random number generators boost::uniform_int<> six(1,6); // distribution that maps to 1..6 // see random number distributions boost::variate_generator<boost::mt19937, boost::uniform_int<> > die(rng, six); // glues randomness with mapping int x = die(); printf(" Die %d\n ",x); } catch(...) { std::cout << "exception" << std::endl; printf(" Die exception \n "); } I basically copied the example code off the web site to see if I could get it to work but I'm not having any luck. If I have the variate_generator defined as above I do not not get any output to the console after the declaration of die. I tried printf's and stream output but neither works, I never see the "Die %d" printed out and I do not see either of the outputs in the catch(...) section. printed either. I even had a throw in the try block at one time to see if it could get to the catch section and did not see output. When I remove the die declaration (and comment out the code that uses it) but leave the generator and the distribution then I can see output again and if I throw after the distribution declaration then I see both output statements in the catch block. So it seems like if I have the variate generator declared then I can't see any output after that, but when I comment it out I can see output again. I'm not sure what I'm doing wrong since I am basically copying a pretty simple example from the book I just can't get it to work. Ah and just incase this makes a difference I'm running this code as a test case in a boost test suite. I wanted to try to get it to work there before putting it into my main app. Thanks, Joshua.

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building boost program options
by Christopher Baus 03 Jul '04

03 Jul '04

I'm trying to build the boost sandbox project program_options and am failing. Anyone know what version of boost is compiles cleanly with? -- Christopher Baus http://www.baus.net/

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RE: [Boost-users] Re: boost test doesn't track validation outside autofunctions
by Rozental, Gennadiy 02 Jul '04

02 Jul '04

> > > void validate(X args) { > > > if (some tests) > > > BOOST_ERROR("message"); > > > } > > > BOOST_AUTO_UNIT_TEST(testfunction) { > > > // set up arguments > > > validate(args) > > > } [...] > I think the problem is a think-o on my part. > In the pseudo-code above, BOOST_ERROR is not executed unless > "some tests" is true. So if the tests are OK, BOOST_ERROR is > never hit. > > I think the report of 0 (boost) tests being run is therefore > accurate, though confusing. It should actually say that 1 test cases being run, but no assertions executed. > Does that sound right? > > Is there a way to signal to boost that you are doing a test, > without the error? You have 2 choices. 1. Rewrite your test, so that it looks like: ... BOOST_CHECK_MESSAGE( some_test, "message" ); 2. Or you could write it like this: .... If(some_test) BOOST_ERROR("message") else BOOST_MESSAGE( "no error" ); I prefer first solution usually. HTH, Gennadiy

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boost test doesn't track validation outside auto functions
by Ross Boylan 02 Jul '04

02 Jul '04

I have a test program that looks like this, in stylized form: -------------------------- #include <boost/test/auto_unit_test.hpp> using namespace boost::unit_test_framework; void validate(X args) { if (some tests) BOOST_ERROR("message"); } BOOST_AUTO_UNIT_TEST(testfunction) { // set up arguments validate(args) } ---------------------------------- When I run this with report-level detailed, it reports that there are 0 assertions in testfunction. Furthermore, the assertions done in validate are not even added to the overall number of assertions reported for the run. I know the checks are being run, because I have seen errors from them. Also, the error messages include the name "testfunction", so it is available at run time. It would be nice if the error reporting and logging functions got their info at run-time; apparently they are grabbing it from some pre-processor magic at the moment (I haven't examined the code in detail; that's just an inference from the behavior). Since the tests do seem to be run, this is basically a cosmetic problem, but it would be nice to fix. If any easy fixes occur to anyone, I'd love to know. Boost 1.31.0 on Debian. P.S. The module's author is listed as rogeeff(a)fusemail.com in the documentation, but that address doesn't work. -- Ross Boylan wk: (415) 502-4031 530 Parnassus Avenue (Library) rm 115-4 ross(a)biostat.ucsf.edu Dept of Epidemiology and Biostatistics fax: (415) 476-9856 University of California, San Francisco San Francisco, CA 94143-0840 hm: (415) 550-1062

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Sun Solaris Forte 8 and boost_1_31_0
by Tom Aratari 02 Jul '04

02 Jul '04

Hello, Has anyone gotten boost_1_31 to compile with Forte 8.0 (__SUNPRO_CC = x550) ? I get errors for the boost::iterator. Also, does anyone know if the next release of boost will be compatible with forte 8.0? Thanks Tom

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Boost Test Tutorial
by Sebastian Stein 02 Jul '04

02 Jul '04

I have written a small tutorial how to use boost test within the KDE project. If you are interested, you will find it under: http://www.hpfsc.de/boosttest/ Sebastian -- http://www.hpfsc.de/ - die Seite rund um: Assembler, Bundeswehr, TFT LCDs, Halle/Saale, Fahrradtouren, Neuseeland, Wanderstaat Mauma, Raumschiff USS Nathan, Enemy Room, MLCAD Tutorial

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standard way to specify undefined values
by Erik Thiele 02 Jul '04

02 Jul '04

hi, i have a userdefined type "foobar". it has a special value that means "undefined". is there a standard way to specify which value is undefined? i do not want to use boost::optional here, as foobar itself can be "undefined". you know: class foobar { static const foobar undefined(blablabla); int a,b,c; } but is this "standard"? cya erik -- Erik Thiele

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RE: [Boost-users] Re: [mpl] Alexandrescu's hierarchy generators
by Klaus Nowikow 02 Jul '04

02 Jul '04

David Abrahams wrote: > [..] > template<class T, class Base> > struct node; > > typedef mpl::vector<int, char, long> types; > > // node<int, node<char, node<long, mpl::empty_base> > > > typedef mpl::inherit_linearly< > types > , node<_2,_1> > >::type lin; > [...] > HTH. That helps a lot. Thank you! -- Klaus Nowikow

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iterator_adaptor problem (mpl?)
by Angus Leeming 01 Jul '04

01 Jul '04

Consider a container such as std::vector<std::pair<int, std::string> > my_container; I want to be able to iterate over the ints of this container so, following the tutorial to the iterator_adaptor docs, came up with template <typename BaseIterator> class first_iter : public boost::iterator_adaptor< first_iter<BaseIterator>, BaseIterator, boost::use_default, boost::use_default, typename BaseIterator::value_type::first_type & > { // snip body }; This works fine so long as BaseIterator::value_type is not const, but falls over when it is because I've defined the 'super_t::reference' type to be mutable. I guess that I need a piece of metafunction magic, but my naive implementation fails typename boost::mpl::apply_if< boost::is_const<typename BaseIterator::value_type> , typename BaseIterator::value_type::first_type const & , typename BaseIterator::value_type::first_type & >::type trial.C:38: error: no type named `type' in `struct boost::mpl::apply_if< boost::is_const<std::pair<int, std::string> >, const int&, int&>' I must admit I'm a bit baffled. There plainly is a 'type' in the apply_if class template. Any pointers? I attach the code as I have it. While I'm at it, is there not something in the MPL that will return the appropriate const-qualified reference for me? None of the header file names in boost/mpl jump out and grab me, but I may well be looking in the wrong place. Regards, Angus

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RE: [Boost-users] [pool] Speed of pool_allocator<>
by Klaus Nowikow 01 Jul '04

01 Jul '04

Peter Dimov wrote: > Klaus Nowikow wrote: > > > > I changed the test program (see below). Now I use object_pool<> > > to create and destroy a number of elements (I use a vector<C*> to > > store them in the meantime). The results are even worse than before: > > > > new/delete: 0.08s > > object_pool: 25.20s > > [...] > > > template <template <class, class> class Pool> > > double Test() > > { > > Pool<C> P(CHUNK_SIZE); > > boost::timer Timer; > > > > std::vector<C*> V; > > for(int i = 0; i < NUM_ELEMENTS; ++i) > > { > > V.push_back(P.construct()); > > } > > for(std::vector<C*>::iterator pos = V.begin(), end = V.end(); pos != > > end; ++pos) { > > P.destroy(*pos); > > } > > > > return Timer.elapsed(); > > } > > Your test is still very unrealistic. You create a large > number of objects in > one batch, then destroy them afterwards. A more realistic > scenario would > have creation and destruction interleaved. > > The most accurate test would be to try Boost.Pool with your actual > application and see how it affects its real-world > performance. It's still > possible for it to be slower, of course, but at least you'd > measure the real > thing. Of course you're right. Obviously I broke the "don't optimize what does not have to be optimized" rule ;-). When creating and deleting 100000 Objects with new/delete takes only 0.1 seconds I won't have to look for something more efficient. I will do what you suggest: write my code and see if it needs optimization. Regards, Klaus

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[mpl] Alexandrescu's hierarchy generators
by Klaus Nowikow 01 Jul '04

01 Jul '04

Greetings! Does boost.mpl provide type hierarchy generators like GenScatterHierarchy and GenLinearHierarchy as described in "Modern C++ Design"? I must confess I do not understand the mpl completely yet ;-) Best regards, Klaus

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RE: [Boost-users] [pool] Speed of pool_allocator<>
by Klaus Nowikow 01 Jul '04

01 Jul '04

Peter Dimov wrote: > Klaus Nowikow wrote: > > I am in the process of writing a program which has to > > handle large numbers (~200000 - 400000) objects of the same class. > > These objects will be created and deleted frequently, so I thought > > some kind of specialized memory management would be handy. > > > > I wrote a test program (see below) to check what boost.pool > would gain > > me. The results make me think that I have done something wrong: > > > > [...] > > > > i.e., std::allocator was more than 3 times faster than > > boost::pool_allocator (Win2k, 256MB). Any ideas what i have done > > wrong? > > [...] > > > template <class Allocator> > > double Test() > > { > > std::vector<Allocator::value_type, Allocator> Vector; > > boost::timer Timer; > > > > for(int i = 0; i < NUM_ELEMENTS; ++i) > > { > > Vector.push_back(i); > > } > > > > return Timer.elapsed(); > > } > > If I read the code correctly, you don't create or delete > objects. You create > and delete (large) arrays of objects. Hmm. I'll have to think about this. Maybe the test was a bit over-simplified. The real program would have a vector<C*> where C is my class. I'll change the example (using object_pool) and post the results.

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[pool] Speed of pool_allocator<>
by Klaus Nowikow 01 Jul '04

01 Jul '04

Hi! I am in the process of writing a program which has to handle large numbers (~200000 - 400000) objects of the same class. These objects will be created and deleted frequently, so I thought some kind of specialized memory management would be handy. I wrote a test program (see below) to check what boost.pool would gain me. The results make me think that I have done something wrong: debug mode: std::allocator 2.17s boost::pool_allocator 7.18s release mode: std::allocator 0.11s boost::pool_allocator 0.36s i.e., std::allocator was more than 3 times faster than boost::pool_allocator (Win2k, 256MB). Any ideas what i have done wrong? See the test program below. // MemoryPoolTest.cpp // Boost includes ------------------------------------------------------------- #include <boost/timer.hpp> #include <boost/pool/pool_alloc.hpp> // Std includes --------------------------------------------------------------- #include <vector> #include <iostream> enum { NUM_ELEMENTS = 3000000 }; template <class Allocator> double Test() { std::vector<Allocator::value_type, Allocator> Vector; boost::timer Timer; for(int i = 0; i < NUM_ELEMENTS; ++i) { Vector.push_back(i); } return Timer.elapsed(); } int main(int argc, char* argv[]) { std::cout << "Starting memory pool test" << std::endl; double Time; std::cout << "Allocating with boost::pool_allocator<>: "; Time = Test<boost::pool_allocator<int> >(); std::cout << Time << "s" << std::endl; std::cout << "Allocating with std::allocator<> : "; Time = Test<std::allocator<int> >(); std::cout << Time << "s" << std::endl; return 0; }

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Newbie question... (sorry)
by Chris 30 Jun '04

30 Jun '04

Hi all, sorry for the newbie question... I have been trying to use the boost libraries with no luck I will briefly as possible list the steps I took, so that you can let me know where I went wrong. (please bear with me) 1) I downloaded the latest version and decompressed it so that i have a "C:\boost_1_31_0 directory". 2) I built Boost.Jam by starting the Visual Studio.Net command prompt, cd'ed to the "C:\boost_1_31_0\tools\build\jam_src" directory and invoked the build.bat .... The build was succesfull. 3) Copied the bjam.exe from the "C:\boost_1_31_0\tools\build\jam_src\bin.ntx86" directory to the Vc7/bin directory. 4)Added the VC71_ROOT environment variable to windows with the "C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7" path as the value. 5) Made sure that the PATH environment variable had the Vc7\bin path in it. 6) reset. 7) Started the Visual Studio.Net command prompt, cd'ed to the "C:\boost_1_31_0" directory and invoked bjam "-sTOOLS=vc7.1" install ... the whole process started.. building was succesfull (I believe) and I had a new directory c:\Boost with the \include and \lib sub dirs as mentioned in the "Getting Started" page. 8) Started visual studio.NET, went into the menu "Tools->Options->Projects->VC++ Directories" where I set "C:\boost_1_31_0" in the list of INCLUDE directories. 9) Copied a simple example from the boost website to test the libraries, compiled and VC doesn't find one of the header files.. 10) After many, many attempts I lost it and added the "C:\boost_1_31_0\lib" and "C:\boost_1_31_0\bin" to the other list of directories in the LIBRARY and EXECUTABLE list of directories in VC. After loosing it some more (after more attempts) I added even "C:\boost" in the same places as I had done in the previous steps (just in case). Now I get this fatal error "fatal error LNK1104: cannot open file 'libboost_filesystem-vc71-sgd-1_31.lib' " It doesn't seem to find the .lib but I have checked in the boost directories and that .lib is there!!! Any suggestions.... please... I also feel really bad, 'cause it seems I am the only idiot who hasn't been able to do this :(((( If someone can help me I will gladly return the favor (if I can) Thank you very very much in advance, Chris ------------------------ "Programming is Understanding" - Kristen Nygaard (I just wish I could understand more)

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[admin] Wiki Spam -- IP's are being banned
by Jeff Garland 28 Jun '04

28 Jun '04

All - I'm cross-posting this to boost-users and the developer list since it pertains to both. Over the last couple months there has been a rise in 'spam attacks' on the Wiki. Basically people are inserting links to commercial sites on wiki pages. These sites are totally unrelated to boost, c++, etc. I thank the many boosters that have spent their precious time removing the defacements. But the time has come to crack down. The following IP ranges have been banned from the Wiki. 61.55.32.* 61.55.33.* 69.63.103.* 210.82.76.* 210.82.106.* 219.233.195.* 218.5.65.* I will be monitoring and banning additional IP addresses as needed. If I have accidentally banned someone incorrectly, please let me know offlist: jeff at crystalclearsoftware.com Thanks, Jeff

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singleton_pool
by . . 28 Jun '04

28 Jun '04

hi all, i want to use singleton_pool, but on vc6.0 i get the following error (i have vc6.0 sp5): boost\pool\simple_segregated_storage.hpp(51) : error C2248: 'object_creator' : cannot access private struct declared in class 'boost::details::pool::singleton_default<struct boost::singleton_pool<class CMate rialProxy,4,struct boost::default_user_allocator_new_delete,class boost::details::pool::win32_mutex,32>::pool_type>' e:\documents\develop\include\boost-1.30.2\boost\pool\detail\singleton.hpp(63) : see declaration of 'object_creator' e:\documents\develop\include\boost-1.30.2\boost\pool\simple_segregated_storage.hpp(51) : while compiling class-template static data member 'struct boost::details::pool::singleton_default<struct boost::singleton_pool<class CMaterialProxy,4,st ruct boost::default_user_allocator_new_delete,class boost::details::pool::win32_mutex,32>::pool_type>::object_creator boost::details::pool::singleton_default<boost::singleton_pool<CMaterialProxy,4,boost::default_user_allocator_new_delete,boost::deta ils::pool::win32_mutex,32>::pool_type>::create_object' thanks in advance Fabio --------------------------------- Do you Yahoo!? New and Improved Yahoo! Mail - Send 10MB messages!

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ternary search trie
by Sybrand Badenhorst 28 Jun '04

28 Jun '04

Hi, Does the BOOST library (somewhere) contain a ternary search trie container type (as described by Robert Sedgewick in his "Algorithms - 3ed edition" or here: http://www.cs.princeton.edu/~rs/strings/) that can by used as a standalone container (such as for example STL's map) ? I don't find something like this listed on the Boost library page (http://www.boost.org/libs/libraries.htm) Any help will be greatly appreciated, Thanks Sybrand

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Spirit problem
by Michael Orlov 28 Jun '04

28 Jun '04

Hi, I am new to Spirit, and I am writing a reader for s-expressions, and so far has encountered the following problems, which seem to me to be contrarry to the documentation (Spirit 1.8.0 in Boost 1.31.0). Consider the following (small) C++ program: --------------------------------------------- #include <iostream> #include <iterator> #include <string> #include <boost/spirit/core.hpp> #include <boost/spirit/iterator/multi_pass.hpp> using namespace std; using namespace boost::spirit; struct Sexp : public boost::spirit::grammar<Sexp> { template <typename ScannerT> struct definition { typedef rule<ScannerT> rule; definition(const Sexp &self) { first = ( sexp = '(' >> *sexp >> ')' ); } subrule<0> sexp; rule first; const rule& start() const { return first; } }; }; int main() { typedef std::istream_iterator<char> iterator_t; typedef boost::spirit::multi_pass< iterator_t, boost::spirit::multi_pass_policies::input_iterator, boost::spirit::multi_pass_policies::first_owner > iterator_wrapper_t; Sexp sexper; iterator_t under_first(cin); iterator_t under_last; iterator_wrapper_t first(under_first); iterator_wrapper_t last(under_last); while (true) { parse_info<iterator_wrapper_t> info = parse(first, last, sexper); first.clear_queue(); if (info.hit) std::cout << "Hit: " << info.length << std::endl; else break; }; } --------------------------------------------- The purpose is to read s-expression from input, delivering them to the user the moment they are ready. Since whitespace skipper tries to consume as much space as it can, it is not suitable here, so I don't want to use it. Here comes the first problem: even when I don't pass space_p to parse(), the skipper is still present: --- ( ) ^D Hit: 2 --- --- (())( Hit: 4 ) ^D Hit: 2 --- Another problem is when I try to use istreambuf_iterator instead of istream_iterator (this is done in Spirit examples, too). When substituting istreambuf_iterator in the first typedef in main(), the program no longer compiles - neither with Intel Compiler 8.0.055, nor with GCC 3.3.2. Intel complains about /usr/local/include/boost/spirit/iterator/multi_pass.hpp(537): error: initial value of reference to non-const must be an lvalue return **input; and GCC's messages are too long to parse. :) Any help? Thanks, Michael

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Using Regex
by kinshuk srivastava 27 Jun '04

27 Jun '04

Hi I have installed the boost 1.31.0 and have been trying to compile the test examples that were there in the regular expression library.But the compiler isnt able to identify the header files.So I did include the path during my compilation by using the -I and the path name..However it is still inable to compile as it is unable to include or search the indented header files... This is my first time I have been using this kind of library.Can someone suggest a way so that I can start using the library.Is there a way in which I can directly compile nad run the files without having to go through the ordeal of specifying the path at compile time everytime I wanna use the file Any help will be highly appreciated. Sincerely -Kinshuk ________________________________________________________________________ Yahoo! India Matrimony: Find your partner online. http://yahoo.shaadi.com/india-matrimony/

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Automake/Autoconf rules for boost libs
by Sebastian Stein 27 Jun '04

27 Jun '04

Hi folks, is somewhere documented how to add automake/autoconf stuff for boost to a project? I have a set of small testcases and the need boost_unit_test_framework-gcc library to compile. At the moment I add the lib directly to linker options with project_test_LDADD = -lboost_unit_test_framework-gcc But this is not platform independent, because someone might have not gcc installed. So how can I do it in a better way? Sebastian

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[Fwd: [subgraph] unable to set graph properties using set_property() method]
by LOU Wenwu 27 Jun '04

27 Jun '04

Hi, I was trying to set graph properties, such as a meaningful name, to individual subgraphs, but the following test code failed. ====================================== typedef adjacency_list<v ecS, vecS, directedS, no_property, no_property no_property, property<graph_name_t, std::string> > graph_t; typedef subgraph<graph_t> subgraph_t; graph_t g; boost::set_property(g, graph_name, "a graph"); // **this worked, of course subgraph_t sg; boost::set_property(g, graph_name, "subgraphs"); // ** Error C2784 Error C2784: could not deduce template argument... ======================================= I used the BGL came with Boost 1.30.0 in .NET 2003. Any idea of how to make it work? Thanks, Daniel

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Newbie question: add_edge()
by Tim Rowe 27 Jun '04

27 Jun '04

Thanks for all the help so far. I'm not there yet, though! The documentation for add_edge() says that the first two parameters are of type boost::graph_traits<G>::vertex_descriptor. In the example in quick_tour.html it is called with integers (from an enum) as its first two parameters. Is that because: i. add_edge is overloaded to take integers as the first two parameters; ii. boost::graph_traits<G>::vertex_descriptor just happens to be an integer type in this case; iii. boost::graph_traits<G>::vertex_descriptor is /always/ an integer type; or iv. some other reason I haven't thought of. Thanks in advance.

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Problem
by przemyslaw.sliwa＠gazeta.pl 26 Jun '04

26 Jun '04

Dear All, I am a beginner with Boost and hae compiled the library on my suse 9.0 Athlon-m machine. I can compile the programs and link them (using Kdevelop) but if I invoke the programm I am getting a strange error which shows me that the shared library libboost_date_time-gcc-1_31.so.1. 31.0 cannot be loaded. This is somehow strange since I have linked against the static library using the argument -lboost_date_time-gcc. The boost install process compile a big rane of libraries and I am ot familar ith them. Can you help me with this issue??? Thank you very much for any kind of help, Przemyslaw

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