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[mpl] bind help sought
by Manfred Doudar 23 Feb '10

23 Feb '10

Hi, I need to be explicit about a function call, but unsure quite how to make it work, cut down example follows: struct M { static void foo() { ... } }; struct R { static void foo() { ... } }; struct Func { typedef void result_type; template <typename T, typename U> result_type operator()(U& u) const { T::foo(); // call on either M or R // do something with 'u' } }; int main(int argc, char** argv) { using namespace boost::mpl; typedef vector<M, R> vec; Func f; Object instance; for_each<vec>(boost::bind(&Func::operator()<XXX, Object>, boost::ref(f), instance) ); return 0; } Question is, what goes in at XXX above? I was thinking something along the lines of: boost::mpl::bind<boost::mpl::_1> ..but well, that doesn't work. All help appreciated. Cheers, -- Manfred

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[proto] Problem using BOOST_PROTO_AUTO
by Manjunath Kudlur 23 Feb '10

23 Feb '10

I have the following program to print out the arguments of a function call expression. It works fine when I directly call the grammar on the expression like so : foo_tostr()(f(a,b,c)). However, if I assign the expression to a variable pr using BOOST_PROTO_AUTO and call foo_tostr()(pr), I get error of the form "conversion from ‘boost::fusion::... to non-scalar type .... requested". Can someone let me know what I am doing wrong? #include <iostream> #include <boost/proto/proto.hpp> #include <boost/proto/proto_typeof.hpp> #include <sstream> #include <string> using namespace std; namespace proto = boost::proto; unsigned ids; struct var { unsigned id; var() { id = ++ids; } }; struct foo {}; typedef proto::terminal<var>::type Var; typedef proto::terminal<foo>::type Foo; struct _var_tostr : proto::callable { typedef string result_type; result_type operator()(var const &v) const { stringstream sout; sout << "v" << v.id << " "; return sout.str(); } result_type operator()(foo const &v) const { stringstream sout; sout << "foo("; return sout.str(); } }; struct var_tostr : proto::or_< proto::when<proto::terminal<var>, _var_tostr(proto::_value)> > {}; struct str_plus : std::plus<std::string>, proto::callable {}; struct foo_tostr : proto::or_ < proto::when<proto::function<proto::terminal<foo>, proto::vararg<proto::terminal<var> > >, proto::fold<proto::functional::pop_front(proto::_expr), string(), str_plus(proto::_state, var_tostr)> > > {}; int main() { Var a, b, c; Foo f; #define COPY_AND_PRINT #ifdef COPY_AND_PRINT BOOST_PROTO_AUTO(pr, (f(a,b,c))); cout << foo_tostr()(pr) << endl; #else cout << foo_tostr()(f(a,b,c)) << endl; #endif } -- Manjunath

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[proto] vararg expressions to string
by Manjunath Kudlur 23 Feb '10

23 Feb '10

I am trying understand the use of proto::fold to handle vararg expressions. As an experiment, I am trying to convert expressions of the form foo(a,b,c) to a string of the form "foo(a,b,c)". I currently have the following code where I treat the vararg expression as a fusion sequence and convert each parameter to a string using appropriate grammar. In the operator() of _foo_tostr, I have a case for each length of the vararg expression. Please let me know if there are better ways of doing this. #include <iostream> #include <boost/proto/proto.hpp> #include <boost/fusion/container/list/cons.hpp> #include <boost/fusion/include/cons.hpp> #include <boost/fusion/include/transform.hpp> #include <sstream> #include <string> using namespace std; namespace proto = boost::proto; namespace fusion = boost::fusion; unsigned ids; struct var { unsigned id; var() { id = ++ids; } }; struct foo {}; typedef proto::terminal<var>::type Var; typedef proto::terminal<foo>::type Foo; struct _var_tostr : proto::callable { typedef string result_type; result_type operator()(var const &v) const { stringstream sout; sout << "v" << v.id; return sout.str(); } }; struct var_tostr : proto::or_< proto::when<proto::terminal<var>, _var_tostr(proto::_value)> > {}; struct _foo_tostr : proto::callable { typedef string result_type; template<typename T> result_type operator()(T const &e) const { stringstream sout; sout << "foo("; if(fusion::size(e) == 1) { sout << ")"; } else if(fusion::size(e) == 2) { sout << var_tostr()(fusion::at_c<1>(e)) << ")"; } else if(fusion::size(e) == 3) { sout << var_tostr()(fusion::at_c<1>(e)) << ", " << var_tostr()(fusion::at_c<2>(e)) << ")"; } else if(fusion::size(e) == 4) { sout << var_tostr()(fusion::at_c<1>(e)) << ", " << var_tostr()(fusion::at_c<2>(e)) << ", " << var_tostr()(fusion::at_c<3>(e)) << ")"; } return sout.str(); } }; struct foo_tostr : proto::or_ < proto::when<proto::function<proto::terminal<foo>, proto::vararg<proto::terminal<var> > >, _foo_tostr(proto::_expr)> > {}; int main() { Var a, b, c; Foo f; cout << foo_tostr()(f(a,b,c)) << endl; }

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Re: [Boost-users] [serialization] Polymorphic serialization with polymorphic archives problem...
by Bogdan 23 Feb '10

23 Feb '10

> Hi, > I have the same scenario, and it's not a problem. > If i understand (my english is poor, sorry) well. > But there is differences: > - I use GCC compilers (but boost is portable). > - I use static linking. > Probably this differences should not have consequences on the result. > I didn't read your code... Had you follow this rules ? > - Register child class (a simple way is using the > BOOST_CLASS_EXPORT macro). > - In the serialize method of your child class, call the > serialization of parent's class (optional). I use > BOOST_SERIALIZATION_BASE_OBJECT's macro. > > If you register child class it should be ok... > Regards, > Damien. > > Hi Damien, My reply has not been posted in gmane so I try again: Thank you for your quick reply. I believe I followed the rules: 1. polymorphic_derived1 and polymorphic_derived2 do include the serialization of the base class via "ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(polymorphic_base); " 2. there is no usage of BOOST_CLASS_EXPORT ( and there shouldn't be any: according to the documentation, in a dll setup one must declare BOOST_CLASS_EXPORT_KEY in the headers containing the classes to be serialized and BOOST_CLASS_EXPORT_IMPLEMENT in the .cpp files). In my example, there are exactly three declarations of BOOST_CLASS_EXPORT_KEY: one in polymorphic_base.hpp, and two in polymorphic_derived2.hpp one for polymorphic_derived1 and another for polymorphic_derived2. Similarly, there are only three usages of BOOST_CLASS_EXPORT_IMPLEMENT. 3. for deeper hierarchies where every class can be potentially serialized, one should probably register all the classes and not just the most derived children. I have the feeling that the type of deployment (dll vs exe) is the crux of the problem. For that, I created four different scenarios with the same source files and I got the following results: 1. all files in one exe with the serialization library linked statically - WORKS AS EXPECTED. 2. all files in one exe with the serialization library linked as a dll - WORKS AS EXPECTED. 3. serialization files in a separate dll. Both the main executable and my dll link with the dll version of the serialization library: main.exe my_serialization.dll boost_serialization.dll my_serialization.dll boost_serialization.dll Builds OK but FAILS at runtime , at run time I get a C++ exception BEFORE main() in basic_serializer_map.cpp around the line 48: 'archive_exception::multiple_code_instantiation with the message "code instantiated in more than one module - polymorphic_base"' 4. serialization files in a separate dll. Both the main executable and my dll link with the static version of the serialization library: main.exe my_serialization.dll boost_serialization.lib my_serialization.dll boost_serialization.lib Builds OK but FAILS at runtime while trying to serialize with the following exception thrown in oserializer.hpp(line 424):struct polymorphic::save(): 'unregistered void cast class polymorphic_derived1<-polymorphic_base in function 'int __cdecl main(int,char *[])'' The source code in the scenarios above is identical with the exception of dllexport/dllimport declaration needed for dlls. Whenever the serialization code is relegated to a different library it seems there are problems with boost serialization: - if boost is linked as a static lib into a user dll, the class serializers do not get registered at all with their associated map singleton. - if boost is linked as a dynamic lib into a user dll, the class serializers register twice with the map singleton of the polymorphic base archive. I don't want to add them here but I can provide any of the projects above to those interested. Thank you all, Bogdan

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Re: [Boost-users] Foreach For iterating two containers
by Rusty Jones 23 Feb '10

23 Feb '10

I agree that a built-in solution to FOREACH would be best, but a secondary choice would be to use a zip iterator. http://www.boost.org/doc/libs/1_42_0/libs/iterator/doc/zip_iterator.html Cheers, Rusty

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Re: [Boost-users] MPL. Nested Lambdas
by dilas dilas 22 Feb '10

22 Feb '10

Steven Watanabe wrote: >dilas dilas wrote: >> Please, tell me if one can write nested lambda expressions like >> >> " >> template<class Result, class Seq, class Elem> struct pairs: bm::fold<Seq, >>Result, bm::push_back<_1,bm::pair<Elem, _2 > > >{}; >> template<class Seq1, class Seq2> >> struct AllPairs: bm::fold<Seq1, bm::vector<>, pairs<_1,Seq2,_2> >{}; >> " >> >> without using intermediate metafunctions. >This ought to work, since the placeholders in AllPairs will be expanded >before >pairs is ever invoked. Here I've presented the example of "intermediate metafunction" i.e pairs. And I'm speaking about writing just one metafunction using nested construction. Is it possible? Yours respectfully, Dilas

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Re: [Boost-users] [fusion] runtime unsigned to a template argument compile-time unsigned
by Hicham Mouline 22 Feb '10

22 Feb '10

-----Original Message----- From: "Larry Evans" [cppljevans(a)suddenlink.net] Date: 22/02/2010 07:23 PM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] [fusion] runtime unsigned to a template argument compile-time unsigned On 02/22/10 10:02, Larry Evans wrote: > On 02/21/10 05:27, Hicham Mouline wrote: > [snip] >>> >> 3. Can I generate an array of function pointers to the various >> at<>() functions and call the right one at runtime? > > The 2 attached files show how this can be done. > > Obviously, instead of: > > typedef > void(* > method_type > )(void) > ; > > you'd have: > > typedef > double(* > method_type > )(void) > ; > This could even be done for heterogeneous return types; however, in that case, a tagged variant. The tag for this variant would be the field index. In the attached code, this would be something like the super_numerals. ------------------------ This looks like it should go, already is in some library? I have many places where I read the index, and I would like to use the index as the template argument, thanks very much, will do,

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[fusion] runtime unsigned to a template argument compile-time unsigned
by Hicham Mouline 22 Feb '10

22 Feb '10

Hi, I have a struct adapted as a fusion sequence. My user inputs at runtime the index of the member she is interested in. Assuming all members are convertible to double, the only solution I found so far is: double f(unsigned index) { switch(index) { case 0: return boost::fusion::at_c<0>( sequence ); case 1: return boost::fusion::at_c<1>( sequence ); . case 6: return boost::fusion::at_c<6>( sequence ); } } To generate this: 1. 0 to fusion::result_of::size<Seq>::type::value - 1 is the range I want. 2. I can't use PP to generate the cases inside the switch 3. Can I generate an array of function pointers to the various at<>() functions and call the right one at runtime? I am basically looking for the runtime version of at_c. Regards,

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Accessing an element of multi_index_container using iterator_to
by Andrew Kokkalis 22 Feb '10

22 Feb '10

First of all, i'm a programmer with no much experience using Boost Libraries. I'm using Boost for academic purposes and here's my problem. I simply want to access an element of a multi_index_container, by using the iterator_to iterator. the container has entries that are <word(string), word_id(int), tf_idf(float)> and is indexed by unique order for the first two values :word and word_id. *Declaration of my container is below:* *struct counterpart { string word; int id; float tf_idf; counterpart(string word_, int id_) { word = word_; id = id_; tf_idf = 0.0; } }; struct word_name{}; //or word char struct word_id{}; struct word_tf_idf{}; typedef multi_index_container< counterpart, indexed_by< ordered_unique< tag<word_name>, BOOST_MULTI_INDEX_MEMBER(counterpart, string, word)>, ordered_unique< tag<word_id>, BOOST_MULTI_INDEX_MEMBER(counterpart, int, id)>, ordered_non_unique< tag<word_tf_idf>, BOOST_MULTI_INDEX_MEMBER(counterpart, float, tf_idf)> > > word_index;* word_index word_set; int word_count_id = 1; >From main, I insert some "entries" like below. *This a test main* *int main(void){ //insert to word_set pair<word_index::iterator, bool> word_pair; if((word_pair = word_set.insert(counterpart("apple", word_count_id))).second) //word does not exist word_count_id++; }* I want to access the entry inserted, as i could do with a map. ex map["apple"] The reason i do this, is because i want to get the value of a unique word_id, by accessing the name of the word and a unique word name by accessing a word_id. This of course is not possible, so i have to use iterator_to. But i cannot think how to do this. Should i prepeare a pair as donne when inserting? Also how a value or an entire entry is returned? In which form? Thank you all and I hope you can help me! Andrew Kokkalis undergraduate student of Informatics and Telecomunications University of Athens, Greece

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Re: [Boost-users] Foreach For iterating two containers
by Pete Bartlett 21 Feb '10

21 Feb '10

Gokulakannan Somasundaram wrote: >Meanwhile, a gentleman helped me by providing this code. Posting it here for any comments >#include <boost/typeof/typeof.hpp> > >#define FOREACH_2(def1, def2, r1, r2) \ > > for(std::pair<BOOST_TYPEOF((r1).begin()), \ > BOOST_TYPEOF((r2).begin())> _it12_((r1).begin(),(r2).begin()),\ > > _e12_((r1).end(), (r2).end()); \ [...] If you don't mind the "weight" of BOOST_TYPEOF just for a for loop, it's not bad as some of the complexity is hidden in that inner macro. However bear in mind in falls short of the original FOREACH because it uses its arguments r1 and r2 repeatedly which may be inefficient, or even flat out wrong, if r1 and/or r2 are temporaries. Also, there is an open ticket against some extra functionality in Boost.Foreach - BOOST_FOREACH_FIELD I think it is called. If that macro came to pass, I think you could solve your use case with a make_zip_range. Pete

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[graph] linking error read_graphviz
by Tillmann Vogt 21 Feb '10

21 Feb '10

Hello, My aim is to parse the graphviz-dot format with boost. The two examples from the getting-started web page build fine (in Ubuntu 9.10 and also Windows 7) Building graph-thingie.cpp in VC9.0 with boost 1.42 gives this error: example.obj : error LNK2001: unresolved external symbol "bool __cdecl boost::detail::graph::read_graphviz(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,class boost::detail::graph::mutate_graph *)" (?read_graphviz@graph@detail@boost@@YA_NABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@PAVmutate_graph@123@@Z) 1>C:\Users\till\Documents\Visual Studio 2008\Projects\example\Release\example.exe : fatal error LNK1120: 1 unresolved externals The next thing I tried was building the "boost_graph" library separately by executing bjam in libs/graph/build which generated C:\Program Files (x86)\boost\boost_1_42\bin.v2\libs\graph\build\msvc-9.0\debug\libboost_graph-vc90-mt-1_42.lib and also a .lib in the release folder. The two new libs seem to be same as in boost/lib/ because they have the same size. So the question is: Do I really have to build "boost_graph" library separately to use the GraphViz readers, like it says on http://www.boost.org/doc/libs/1_42_0/libs/graph/doc/read_graphviz.html? I tried several compiler options and have all 8 variations of libboost_graph-vc90 ... .lib in /boost/lib, but no idea how the compiler magically choses the right one. I don't know what to try next, since I get similar errors on Ubuntu 9.10 (on Ubuntu boost 1.38 is preinstalled).

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Foreach For iterating two containers
by Gokulakannan Somasundaram 21 Feb '10

21 Feb '10

Hi, Is it possible to use Boost Foreach to iterate over two containers simultaneously? I have done my preliminary search in the lists and i couldn't find a solution. I am asking for a solution to iteration like this std::vector<int>::iterator iter1; std::vector<std::string>::iterator iter2; for( iter1 = cont1->begin(), iter2 = cont2->begin(); iter1 != cont1->end() || iter2 != cont2->end(); ++iter1, ++iter2 ) { int x = *iter1; std::string y = *iter2; ..... } If this is not present, please consider this as a feature request. The syntax below can also be considered forboth( int x, std::string y, cont1, cont2 ) { } Thanks, Gokul.

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[Filesystem V3] Filesystem Version 3 beta 1 available for download and comment
by Beman Dawes 21 Feb '10

21 Feb '10

The first beta release of Boost.Filesystem Version 3 is now available. The documentation can be viewed at http://mysite.verizon.net/beman/v3/index.htm Important differences from the prior version: http://mysite.verizon.net/beman/v3/v3.html The beta can be downloaded from the Boost vault. See http://www.boostpro.com/vault/index.php?&direction=0&order=&directory=Files… Installing the beta is described at http://mysite.verizon.net/beman/v3/install_distro.html I'm concerned about breaking existing code. While some workarounds have been provided already, I'd open to further suggestions as to how to mitigate code breakage. The tentative plan for integrating V3 into the boost release cycle involves several steps: * For the first boost release cycle, ship V2 as the default, but V3 is present and can be activated by users. * For an additional boost release cycle, ship V3 as the default, but V2 is present (but deprecated) and can be activated by users. * For the following boost release cycle, V2 is removed and no longer supported. The plan is to go through as many beta cycles as needed to reach stability. Although quite a bit of testing has already been done, this is definitely beta software that isn't ready yet for production use. Any comments appreciated. --Beman

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FW: [serialization] Polymorphic serialization with polymorphic archives problem...
by Bogdan 21 Feb '10

21 Feb '10

Hi Damien, Thank you for your quick reply. I believe I followed the rules: 1. polymorphic_derived1 and polymorphic_derived2 do include the serialization of the base class via "ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(polymorphic_base); " 2. there is no usage of BOOST_CLASS_EXPORT ( and there shouldn't be any: according to the documentation, in a dll setup one must declare BOOST_CLASS_EXPORT_KEY in the headers containing the classes to be serialized and BOOST_CLASS_EXPORT_IMPLEMENT in the .cpp files). In my example, there are exactly three declarations of BOOST_CLASS_EXPORT_KEY: one in polymorphic_base.hpp, and two in polymorphic_derived2.hpp one for polymorphic_derived1 and another for polymorphic_derived2. Similarly, there are only three usages of BOOST_CLASS_EXPORT_IMPLEMENT. 3. for deeper hierarchies where every class can be potentially serialized, one should probably register all the classes and not just the most derived children. I have the feeling that the type of deployment (dll vs exe) is the crux of the problem. For that, I created four different scenarios with the same source files and I got the following results: 1. all files in one exe with the serialization library linked statically - WORKS AS EXPECTED. 2. all files in one exe with the serialization library linked as a dll - WORKS AS EXPECTED. 3. serialization files in a separate dll. Both the main executable and my dll link with the dll version of the serialization library: main.exe my_serialization.dll boost_serialization.dll my_serialization.dll boost_serialization.dll Builds OK but FAILS at runtime , at run time I get a C++ exception BEFORE main() in basic_serializer_map.cpp around the line 48: 'archive_exception::multiple_code_instantiation with the message "code instantiated in more than one module - polymorphic_base"' 4. serialization files in a separate dll. Both the main executable and my dll link with the static version of the serialization library: main.exe my_serialization.dll boost_serialization.lib my_serialization.dll boost_serialization.lib Builds OK but FAILS at runtime while trying to serialize with the following exception thrown in oserializer.hpp(line 424):struct polymorphic::save(): 'unregistered void cast class polymorphic_derived1<-polymorphic_base in function 'int __cdecl main(int,char *[])'' The source code in the scenarios above is identical with the exception of dllexport/dllimport declaration needed for dlls. Whenever the serialization code is relegated to a different library it seems there are problems with boost serialization: - if boost is linked as a static lib into a user dll, the class serializers do not get registered at all with their associated map singleton. - if boost is linked as a dynamic lib into a user dll, the class serializers register twice with the map singleton of the polymorphic base archive. I don't want to add them here but I can provide any of the projects above to those interested. Thank you all, Bogdan ============================================================================ ============== > Hi, > I have the same scenario, and it's not a problem. > If i understand (my english is poor, sorry) well. > But there is differences: > - I use GCC compilers (but boost is portable). > - I use static linking. > Probably this differences should not have consequences on the result. > I didn't read your code... Had you follow this rules ? > - Register child class (a simple way is using the BOOST_CLASS_EXPORT > macro). > - In the serialize method of your child class, call the > serialization of parent's class (optional). I use > BOOST_SERIALIZATION_BASE_OBJECT's macro. > > If you register child class it should be ok... > Regards, > Damien. > >

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non-blocking read
by David Kaplan 21 Feb '10

21 Feb '10

I'm trying to implement a non_blocking read as follows (based on some code on the net): void util::net::set_result(optional<boost::system::error_code>* a, boost::system::error_code b) { a->reset(b); } template <typename MutableBufferSequence> optional<boost::system::error_code> util::net::read_non_blocking(ip::tcp::socket *sock, const MutableBufferSequence& buffers, int timeoutSec) { optional<boost::system::error_code> timer_result; deadline_timer timer(sock->io_service()); timer.expires_from_now(boost::posix_time::seconds(timeoutSec)); timer.async_wait(boost::bind(set_result, &timer_result, _1)); optional<boost::system::error_code> read_result; async_read(*sock, buffers, boost::bind(set_result, &read_result, _1)); sock->io_service().reset(); while (sock->io_service().run_one()) { if (read_result) timer.cancel(); else if (timer_result) { sock->cancel(); throw system_error(boost::system::error_code(errc::timed_out, get_generic_category())); } } return read_result; } I call the code as follows: util::net::read_non_blocking(Module::_socket, buffer(buf, 4), 1); (_socket is a ptr of type tcp::socket) However I'm having problems linking: undefined reference to `boost::optional<boost::system::error_code> util::net::read_non_blocking<boost::asio::mutable_buffers_1>(boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> >*, boost::asio::mutable_buffers_1 const&, int) Also, what will this code return exacty?

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Memory tools
by Bo Jensen 21 Feb '10

21 Feb '10

For a multi threaded project I need to be able to closely monitor memory stats such as memory usage, number of allocations etc. Of course I could overload new/delete, but do boost have such memory tools or do you know of other libraries that has this feature ? Any suggestions ? Sorry if this is slightly off-topic.

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Can't asio::write when len > 14
by David Kaplan 21 Feb '10

21 Feb '10

I can't seem to write to my tcp socket with boost::asio any buffer with len > 14: uint8_t tmp[20]; int len = 20; asio::write(_socket, buffer(tmp, len)); if len > 14, it will always only return 14 bytes written! If len < 14, it writes correctly. What's going on?

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[program_options] allow_guessing issue
by Filip Konvička 21 Feb '10

21 Feb '10

Hi, I've just upgraded to boost 1.42 from 1.40, and it seems that the new feature 'allow_guessing', a default setting, breaks my existing code. I have two options: "lang" and "lang-dir", the first obviously a prefix of the other, and when my program is run with "--lang=en_US --lang-dir=.", the first argument is interpreted as "lang-dir". Even though the documentation says somewhere that one argument should not be a prefix of another with 'allow_guessing' on, this is a breaking change and should be put in a big red box somewhere on the front page :-) If the change is intended to be kept for the future, it would be wise to detect the problem by examining the options, rather than wait until another problem occurs (in my case, the runtime exception is 'multiple_options' when the user uses both options, and - much worse! - the option gets misinterpreted without a warning if he only uses the shorter option). Cheers, Filip

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[program_options] allow_guessing compatibility issue
by Filip Konvička 21 Feb '10

21 Feb '10

Hi, I've just upgraded to boost 1.42 from 1.40, and it seems that the new feature 'allow_guessing', a default setting, breaks my existing code. I have two options: "lang" and "lang-dir", the first obviously a prefix of the other, and when my program is run with "--lang=en_US --lang-dir=.", the first argument is interpreted as "lang-dir". Even though the documentation says somewhere that one argument should not be a prefix of another with 'allow_guessing' on, this is a breaking change and should be put in a big red box somewhere on the front page :-) If the change is intended to be kept for the future, it would be wise to detect the problem by examining the options, rather than wait until another problem occurs (in my case, the runtime exception is 'multiple_options' when the user uses both options, and - much worse! - the option gets misinterpreted without a warning if he only uses the shorter option). Cheers, Filip

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[multi_array] std::swap and subarray
by Sergey Mitsyn 21 Feb '10

21 Feb '10

Hello! I've got somehow unexpected behaviour of std::swap with multi_array's subarray. For example, given a 2x2 multi_array: boost::multi_array<double, 2> a; a.resize( boost::extents[2][2] ); for (int i = 0; i < 2; ++i) for (int j = 0; j < 2; ++j) a[i][j] = (i+1)*10 + j+1; std::swap( a[0], a[1] ); for (int i = 0; i < 2; ++i) { for (int j = 0; j < 2; ++j) std::cout << a[i][j] << " "; std::cout << std::endl; } With msvc 2008 + boost 1.42, one of the rows overwrites the other and the output is: 21 22 21 22 The fastest hacky solution i've came is this: namespace std { template <typename TValue, int K> void swap( boost::detail::multi_array::sub_array<TValue, K> &lhs, boost::detail::multi_array::sub_array<TValue, K> &rhs) { boost::multi_array<TValue, K> tmp = lhs; lhs = rhs; rhs = tmp; } } // namespace std Now, the rows are properly swapped and the output is: 21 22 11 12 Well, probably that's not a problem for now, but I dunno if it's a bug or std::swap is not supported - coundn't find anything about this. ---------------- Sergey Mitsyn.

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[serialization] Polymorphic serialization with polymorphic archives problem...
by Bogdan 21 Feb '10

21 Feb '10

Hi all, I am unable to use the following functionality in boost 1.42 built with Visual Studio 2008: - serialize/deserialize a derived class via a base class pointer using polymorphic archives. - the class serialization is implemented in a DLL using a base polymorphic archive. - the actual serialization is performed in a separate executable (linked with the DLL above); in that executable I use a polymorphic text archive. The documentation states this scenario is legitimate; however none of the tests shipped with boost demonstrates it (there are examples either about polymorphic classes or polymorphic archives but no test combining both). The example proving my point is a variation of the test using test_dll_exported.cpp and polymorphic_derived2.cpp where I removed the template-based archives defeating the purpose of polymorphic archives. My example throws an exception before main(), complaining the serializers try to register twice with the archive map singleton of the polymorphic base class. I described the same issue in the thread "[serialization] Can one deserialize a derived classes via pointers to the base class using polymorphic archives in a DLL context?" I posted in gmane.comp.lib.boost.devel where I provided more implementation details. Robert Ramey has graciously replied with a series of suggestions; unfortunately my example seems to have fulfilled all the conditions he mentioned. So, my question is: has anyone been able to run successfully a scenario similar to the one I described? Thank you, Bogdan ============================================================================ ====== I am enclosing a bare-bone example containing 8 files in two project files plus one solution file. My environment setup contains: _CL_=/D_HAS_ITERATOR_DEBUGGING#0 /D_SECURE_SCL#0 /wd4996 /wd4503 /DBOOST_ALL_NO_LIB BOOST_HOME=C:\_APP_\boost_1_42_0 Boost header files are installed under %BOOST_HOME%\include while the libraries are installed under %BOOST_HOME%\lib. I used Boost libraries (multi-threaded DLL versions) built with no automatic dependencies (note /DBOOST_ALL_NO_LIB above). Their names are boost_serialization-mt.lib and boost_serialization-mt-gd.lib for Release/Debug configurations, respectively. The PropertyPages/ConfigurationProperties/Debugging/Environment contains: PATH=$(BOOST_HOME)\lib;$(PATH) used while debugging.

2 1

[Fusion] documentation - bad link [Phoenix] Related question
by OvermindDL1 21 Feb '10

21 Feb '10

On the documentation page: http://www.boost.org/doc/libs/1_42_0/libs/fusion/doc/html/fusion/functional… Search for the sentence near the bottom of: The library provides both a strictly typed and a generic variant for this transformation. The latter should be used in combination with Boost.Functional/Forward to attack The Forwarding Problem. The words "Boost.Functional/Forward" are a link pointing to: http://www.boost.org/libs/functional/forward/doc/html/index.html However, that link does not exist, and I tried searching through: http://www.boost.org/libs/functional/ But I could not find anything that even had the word "forward" in it through any sub-link (courtesy of google, also searched in 1_41_0). Where is this documentation that Fusion is pointing to? Also, why does Phoenix2 not use the Fusion fused/unfused/etc... to support passing constants like the integer 42 directly to an actor? Is there some limitation that would not make it work, or...?

1 1

MPL. Nested Lambdas
by dilas dilas 21 Feb '10

21 Feb '10

Please, tell me if one can write nested lambda expressions like " template<class Result, class Seq, class Elem> struct pairs: bm::fold<Seq, Result, bm::push_back<_1,bm::pair<Elem, _2 > > >{}; template<class Seq1, class Seq2> struct AllPairs: bm::fold<Seq1, bm::vector<>, pairs<_1,Seq2,_2> >{}; " without using intermediate metafunctions.

3 4

XML Serialization: Putting Stylesheet tag inside XML file
by girish hilage 20 Feb '10

20 Feb '10

Hi, Using XML serialization I have created an XML file which I want to see through a browser using a stylesheet. So I want to put a statement : <?xml-stylesheet type="text/xsl" href="XSLTFile.xsl"?> in between below 2 statements : <?xml version="1.0" encoding="UTF-8" standalone="yes" ?> <!DOCTYPE boost_serialization> like this : <?xml version="1.0" encoding="UTF-8" standalone="yes" ?> <?xml-stylesheet type="text/xsl" href="XSLTFile.xsl"?> <!DOCTYPE boost_serialization> <boost_serialization signature="serialization::archive" version="5"> But the code for a init() function inside file boost/archive/impl/basic_xml_oarchive.ipp is as follows : basic_xml_oarchive<Archive>::init(){ // xml header this->This()->put("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\" ?>\n"); this->This()->put("<!DOCTYPE boost_serialization>\n"); // xml document wrapper - outer root this->This()->put("<boost_serialization"); write_attribute("signature", BOOST_ARCHIVE_SIGNATURE()); write_attribute("version", BOOST_ARCHIVE_VERSION()); this->This()->put(">\n"); } File XSLTFile.xml contain stylesheet info. * So, how is it possible to put a stylesheet related statement just after the 1st statement? * Another query is, how to change the the tag name "boost_serialization" to something else? Regards, Girish

3 5

Re: [Boost-users] boost::asio::read_until w/ boost::function
by marty 20 Feb '10

20 Feb '10

I'm following up my original post with some actual code an interested person might try to compile, as well as the specific errors I'm getting. boost 1.41.0, gcc 3.4.6 both here: http://www.pastebin.ca/1803396 any insight would be welcome, ...m > > ------------------------------------------------------------------------ > > Subject: > boost::asio::read_until w/ boost::function > From: > marty <marty(a)ice.org> > Date: > Fri, 19 Feb 2010 13:47:22 -0500 > To: > boost-users(a)lists.boost.org > > To: > boost-users(a)lists.boost.org > > > I'm having some trouble resolving the call to read_until > (see snippet below) > > Is there some reason I am not be able to use a boost::function > as the MatchCondition object? > > > Thanks, > ...m

1 0

Re: [Boost-users] [boost] [Filesystem V3] Filesystem Version 3 beta 1 available for download and comment
by Beman Dawes 20 Feb '10

20 Feb '10

On Thu, Feb 18, 2010 at 11:30 AM, Zach Laine <whatwasthataddress(a)gmail.com> wrote: > On Thu, Feb 18, 2010 at 8:43 AM, Beman Dawes <bdawes(a)acm.org> wrote: >> The first beta release of Boost.Filesystem Version 3 is now available. >> >> The documentation can be viewed at http://mysite.verizon.net/beman/v3/index.htm > > The descriptions for portable_name() and portable_directory_name() > appear to be at odds. > > portable_name() : ... && (name is "." or "..", and the first character > not a period or hyphen) > > portable_directory_name(): ... && (name is "." or ".." or contains no periods) > > Should portable_name() be "... && (name is "." or "..", or contains no > periods) && (first character not a hyphen)"? Maybe I'm missing > something? I haven't looked at these in years. They need to be brought up to date. Added to do list. > > Also, in the tut3.cpp tutorial code, there's no mention of the dangers > of using "*it" inside the directory_iterator loop. IIRC, in previous > Filesystem revisions, this would throw if you did not have adequate > permissions to see the file to which "it" refers. Has this changed? Nice catch! No, nothing is changed. The code is not robust. > If not, I think that you should either wrap the body of the loop in a > try-catch block, or use one of the non-throwing function overloads, > and indicate to the user what the exception safety concerns are. Yes, this would be a great place to introduce the non-throwing function overloads. Added to do list. I > think the tutorial code should exhibit enough robustness that the user > can just cut-and-paste to get the basic code needed to use the > library. Definitely. If anyone spots other robustness issues, be sure to let me know. Thanks, --Beman

1 0

mpl Generate integral sequence wrapper from 0 to N
by Hicham Mouline 20 Feb '10

20 Feb '10

Hi, Given a size_t N known at compile, what's the cleanest way to generate mpl::vector_c<size_t, 0, 1, .., N> what is the fastest way compile-time wise? what is the most mpl algos reusing way? Regards,

2 1

Inconsistent unicode encoding between boost and wx on mac osx
by Sachin Garg 19 Feb '10

19 Feb '10

My project uses both boost and wxwidgets and unicode encoding by both is different on Mac OSX. Everything works fine on windows. Problem: Boost and WX do end up encoding the strings differently when converting to unicode on OSX. I am detailing an example: WX's encoding is same on both windows and osx but Boost's encoding is different on both platforms. It is probably not a bug but I am unable to figure out the reason and how to make them both work together. The string: 国際的な一流のホールダー (I don't know if this foreign language string will show up fine in your email client). Hex dumps of Unicode encodings of this string >From Boost on Mac (32-bit): e5 0 0 0 9b 0 0 0 bd 0 0 0 e9 0 0 0 9a 0 0 0 9b 0 0 0 e7 0 0 0... >From WX on Mac (32-bit): fd 56 0 0 9b 96 0 0 84 76 0 0 6a 30 0 0 0 4e 0 0.... >From WX and Boost on Windows (16-bit): fd 56 9b 96 84 76 6a 30 0 4e 41 6d 6e 30... (To be more exact, this is how boost::filesystem encodes a directory name it read from disk, and its the wxChar** argv value from wxApp for a Unicode build of wx). So wx does same thing on windows and mac, and boost does that same thing on windows. But boost encodes it differently on mac and I have no idea why. My wild guess is its due to locale etc settings but I don't know how check for this or fix it. SG

6 15

[graph] boost::adj_list_edge_property_map
by Christine SINOQUET 19 Feb '10

19 Feb '10

Hello, I encounter some problems when porting an application using boost from Windows to Linux. I work with Ubuntu, I use codeblocks as a compiling environment. The boost library I use is boost_1_38 containing boost_1_38/boost/property_map.hpp boost_1_38/boost/config.hpp boost_1_38/boost/graph/adjacency_list.hpp boost_1_38/boost/graph/graph_utility.hpp. I believe the boost library is compatible with Windows and Linux. The compiler reports the following errror: .../structure_learning/src/graph_tools/GraphPDAG.cpp:295 erreur: conversion from "boost::adj_list_edge_property_map<boost::bidirectional::tag, boost::detail::error_property_not_found, boost::detail::error_property_not_found&, void*, boost::property<boost::edge_weight_t, long double, boost::no_property>, boost::edge_bundle_t" to non-scalar type "boost::no_edge_bundle" requested. Then, it finds a second error: .../structure_learning/src/graph_tools/GraphPDAG.cpp:296 erreur: "struct boost::no_edge_bundle" has no member named "ambiguous". Finally, the third error is (after verbose comments which I can not copy here): GraphPDAG.cpp:296: instantiated from here: boost_1_38/boost/graph/adjacency_list.hpp:463:erreur:invalid initialisation of reference of type "boost::no_edge_bundle&" from expression of type "boost::detail::error_property_not_found". Do you have any idea why this code is correct with Windows but not with Linux ? I would have thought that the boost C++ library is compatible with any system. Thank you in advance for considering my questions. Best regards, C.S. //============================================================================== void PDAG::putWeightPDAG(slBayesianNetwork* bn, slEdge e, int w) { unsigned int a, b; this->pBN = bn; this->getEdgeNodesIndex(e, a, b); this->putWeightPDAG(a, b, w); slGraph& graph = bn->get_graph(); property_map<slGraph, edge_weight_t>::type weightMap = get(edge_weight, graph); line 295 >>>>> edge_bundle_type<slGraph>::type ambiguousTypeMap = get(edge_bundle, graph); line 296 >>>>> graph[e].ambiguous = true; }

2 1

MPL. Difference between variadic and numbered forms of sequences
by dilas dilas 19 Feb '10

19 Feb '10

When I write expressions like: template<class Seq, class Elem> struct pairs: fold<Seq, vector<>, push_back<_1,vector2<Elem, _2 > > >{}; Everything works just fine, but when I use variadic form: template<class Seq, class Elem> struct pairs: fold<Seq, vector<>, push_back<_1,vector<Elem, _2 > > >{}; I have a lot of errors. Can someone explain me what's the difference?

2 1

Cost of constructing models of RandomDistribution
by Robert Patterson 19 Feb '10

19 Feb '10

I have a fairly large simulation code, that I need to get into a state in which I can multi-thread it. One of my problems is a global random number generator state. I am thinking that I should replace this global object with a collection of generator engines, one for each thread, which would be passed down by non-const reference from the top level of each thread to the places where random numbers are needed. In this case it seems best to pass around engines that model PseudoRandomNumberGenerator. In each place that I want a random number (I rarely need more than 1 or 2 at once or with the same parameters) I would then have to construct and use a RandomDistribution, such as uniform_int, exponential_distribution (or poisson, but that is a question for another day). This approach relies on these models of RandomDistribution being fairly cheap to construct. I cannot see any reason why this should not be the case, but equally I cannot see any promise in the docs that they will be cheap to construct. Am I proposing to use the library in a sensible way? Thanks Robert Patterson

3 2

doubt on boost::bind and boost::function
by Conoscenza Silente 19 Feb '10

19 Feb '10

Hi all I am trying to use boost::function combined with boost::bind in order to be able to pass a callback to another function. The callback I want to pass is a member function of the class. The code is below class CA{ bool IsMemberFunction( const std::string& aLine ){ return true; } void testUseFooPtr( boost::function< bool(const std::string& ) > aFooPtr ){ std::string aLine; // read from somewhere if( aFooPtr( aLine ) ){ std::cout << "is fine" << std::endl; } } void testFooPtr(){ std::string ciao("aa"); boost::function< bool(const std::string& ) > fooPtr( boost::bind( &CA::IsMemberFunction, this ) ); // create // a boost function using the class memebr testUseFooPtr( fooPtr ); // pass it as callback to another // function } }; I have the following compilation error. /usr/local/include/boost/bind/mem_fn.hpp:342: error: invalid use of non-static member function Do you know what I am doing wrong? Is the signature fine? Thanks

4 6

error: no matching function for call to ‘boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> >::basic_stream_socket()’
by David Kaplan 19 Feb '10

19 Feb '10

Hi Why doesn't this work: _socket = tcp::socket(ioService); _socket is a private member of type tcp::socket. How can I store the socket as a class member (so I can access it when using read/write from other class methods)? Also, is there any way to define a timeout on a synchronous connect()? If not, what's the workaround? Can I do an async connect and then somehow return to synchronous mode of operation? Thanks, David

3 9

[Random] random_device not available for linking?
by Roland Bock 19 Feb '10

19 Feb '10

Hi, I tried to experiment with boost::random_device (e.g. http://www.boost.org/doc/libs/1_42_0/libs/random/nondet_random_speed.cpp) but failed to link it: randomTest.cpp:36: undefined reference to `boost::random_device::operator()()' randomTest.o: In function `main': randomTest.cpp:57: undefined reference to `boost::random_device::default_token' randomTest.cpp:57: undefined reference to `boost::random_device::random_device(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)' randomTest.cpp:63: undefined reference to `boost::random_device::~random_device()' There seems to be a boost_random library missing. I am using Ubuntu-8.04, 64bit with gcc-4.2.4. Thanks and regards, Roland

2 1

转发: How to detatch native socket from boost asio basic_socket?
by BlueStone 19 Feb '10

19 Feb '10

Hey! In my scenario, first, I use ip::tcp::acceptor to accept an incoming connection request, and got the basic_socket instance, then I read some data from it, and after checking validity of the data received, I need to create another class to manage i/o operation with this basic_socket instance. And at this point, in my opinion, I must detach native socket from the previous instance of basic_socket, and assign it to the new one, but I cannot find that asio provide the method to detach native socket from the basic_socket. How can I do ? Any advice will be appreciated.

1 0

Boost Threading Multiple Reader / Single Writer Usage Questions
by Brian Nantz 19 Feb '10

19 Feb '10

I am working in legacy code and I have a list collection of pointers that is accessed by multiple threads. I am having some thread locking issues with it. Mostly the list is read and very few changes (adds or deletes) are made to the list. I thought this would be a great opportunity to use a Reader Writer Lock (RWL). It seems that the shared_mutex is the Boost RWL. There are a few requirements that I am not sure shared_mutex will do for me: 1. There could be nested locks and the RWL should handle unwinding them correctly. I see that recursive_mutex seems to handle that. Does shared_mutex handle that as well? 2. Is there a way to give a higher priority to writes? I am worried about the readers starving the writers, so I would like any pending writers to be given preference over pending readers. How can I get this functionality from the Boost thread library? If I need to build my own, what class do you recommend using as a base to build from?

2 1

Re: [Boost-users] Object pools?
by michele.caini＠gmail.com 19 Feb '10

19 Feb '10

Hi, of course, in my opinion pool has to manage objects life time. However sharing objects with pool owner by shared ptr seems to be a good idea, because pool still manages objects life time. Using shared pointer also inside pool solves the problem, maybe. It is correct? ----- Reply message ----- Da: "Ryan McConnehey" <mccorywork(a)gmail.com> Data: gio, feb 18, 2010 02:50 Oggetto: [Boost-users] Object pools? A: <boost-users(a)lists.boost.org> Michele Caini wrote: > Pool will create objects, pool will release and reclaim objects, and pool will delete > objects. > If the pool manages the life time of the object then the pool can't release the object, correct. The pool will at most loan the object to the user. > You are looking for something that create objects and forbid about them, > until you return that objects to the home. Is correct? > Did you mean forget instead of forbid. The kind of pool I'm talking about would only forget about those objects that it released. It still needs to manage the life time of the objects it didn't release. > Really, it's possible but it is not as a pool works, simply. > Are you stating that Boost.Pool doesn't work this way or all pools? Is there a definition for a pool that I'm missing. I thought a pool was a collection of objects and an object could be provided to the user. The implementation and life time of the object were left up to the pool. > Your idea breaks also raii pattern and you risk to have memory leaks, > because not reclaimed objects maybe be lost during their life time. > In my requirements, to avoid memory leaks, the objects were passed to the user with a boost::shared_ptr. > What about a monostate pattern that globally manages objects as a pool > and will be destroyed only when program terminates? That's can be a > valid alternative, or not? > I believe the monostate pattern shares its (static) data. Wouldn't this mean the amount of data can't be increased? If the data can't be increased it not as useful to the user when all the objects have been used but more are still needed. Ryan _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

4 6

[1.41.0] Intel 11.1 Linux vs. cmath header
by Richard Hadsell 19 Feb '10

19 Feb '10

I am trying to build the Boost 1.41.0 libraries with an evaluation copy of Intel C++ 11.1 for 64-bit Linux. My system is Fedora 12 with G++ 4.4.3 installed as the default compiler. This fatal error is preventing most of the libraries from building: /usr/include/c++/4.4.3/cmath(500): error: identifier "__builtin_fpclassify" is undefined return __builtin_fpclassify(FP_NAN, FP_INFINITE, FP_NORMAL, ^ detected during: instantiation of "__gnu_cxx::__enable_if<std::__is_arithmetic<_Tp>::__value, int>::__type std::fpclassify(_Tp) [with _Tp=float]" at line 65 of "./boost/functional/hash/detail/hash_float.hpp" instantiation of "size_t={unsigned long} boost::hash_detail::float_hash_value(T) [with T=float]" at line 282 of "./boost/functional/hash/hash.hpp" I am building the libraries with this command: bjam toolset=intel-linux threading=multi variant=release link=static,shared --stagedir=stageIF12 stage Release notes seem to indicate that someone has successfully built Boost libraries with Intel 11.1 and G++ 4.4.1 (whose cmath header looks the same as for 4.4.3). I have not used the Intel compiler for several years, so I may be missing something that is familiar to other users. Help? -- Dick Hadsell 203-992-6320 Fax: 203-992-6001 Reply-to: hadsell(a)blueskystudios.com Blue Sky Studios http://www.blueskystudios.com 1 American Lane, Greenwich, CT 06831-2560

2 2

[spirit] first steps
by Igor R 18 Feb '10

18 Feb '10

Hello, How to use the string parser? I tried this way: std::string s1; bool r = qi::phrase_parse(first, last, ( string[ref(s1) = _1] ) , space); But it doesn't compile. Thanks.

4 15

mpl for_each: stop applying functor when runtime predicate is true
by Hicham Mouline 18 Feb '10

18 Feb '10

With a mpl sequence, applying a functor f with for_each on that sequence applies f at runtime on every element of the sequence. If I wish to stop applying f once I've found the element in the sequence which satisfies some runtime predicate, how can I do that? I'm thinking of putting a bool state in f, and turn it to false once I decide not to apply anymore, and on invocations of, just do nothing when the state is false. Any better way of doing this? Regards,

1 0

[Iostreams] unresolved problem
by Michał Nowotka 18 Feb '10

18 Feb '10

Hello, I have the same problem as described here: http://thread.gmane.org/gmane.comp.lib.boost.user/34531 . There wasn't any answer to this post and it was asked over a year ago. I think this is quite important. Can anyone can help? -- Regards Michał Nowotka

1 0

tokenize string delimiter
by Lloyd 18 Feb '10

18 Feb '10

Hi, Is it possibleto tokenize a string based on a string delimiter? Thanks, Lloyd ______________________________________ Scanned and protected by Email scanner

11 19

fusion: work of 4 sequences at the same time
by Hicham Mouline 18 Feb '10

18 Feb '10

Hi, I am trying to apply fusion::for_each on a sequence, but inside the unary functor applied to each element, I need to know the index of the element in question, because I need to extract elements with the same index from other sequences. fusion::vector<...> fseq1; fusion::vector<...> fseq2; fusion::vector<...> fseq3; fusion::vector<...> fseq4; fusion::for_each( fseq1, functor<...>(fseq2, fseq3, fseq4) ); template <typename Seq2, typename Seq3, typename Seq4) struct functor { /// ctor template <typename T> void operator()( const T& t) const { /// find out index of t in fseq1, /// use elements from fseq2,3,4 at the same index } }; I could use boost::fusion::find to get an iterator and then get its index, but this doesn not look clean, Any ideas, Rds,

2 2

Re: [Boost-users] fusion: work of 4 sequences at the same time
by Hicham Mouline 18 Feb '10

18 Feb '10

> -----Original Message----- > From: Hicham Mouline [mailto:hicham@mouline.org] > Sent: 18 February 2010 17:38 > To: 'boost-users(a)lists.boost.org' > Subject: fusion: work of 4 sequences at the same time > > Hi, > > I am trying to apply fusion::for_each on a sequence, but inside the unary > functor applied to each element, I need to know the index of the element in > question, because I need to extract elements with the same index from other > sequences. > > fusion::vector<...> fseq1; > fusion::vector<...> fseq2; > fusion::vector<...> fseq3; > fusion::vector<...> fseq4; > > fusion::for_each( fseq1, functor<...>(fseq2, fseq3, fseq4) ); > > template <typename Seq2, typename Seq3, typename Seq4) > struct functor { > /// ctor > > template <typename T> > void operator()( const T& t) const > { > /// find out index of t in fseq1, > /// use elements from fseq2,3,4 at the same index > } > }; > > I could use boost::fusion::find to get an iterator and then get its index, but > this doesn not look clean, > > Any ideas, > > Rds, > Ah! fusion::zip is my friend. fusion::for_each( fusion::zip(fseq1, fseq2, fseq3, fseq4), functor() ); Could u confirm though that I will be able to modify fseq1, even through the zipping? Rds,

1 0

Transfering the process state to another process
by Lloyd 18 Feb '10

18 Feb '10

Hi, We want to have a program which cannot be terminated by the user (even admin). I think the only way to do this is to write a watchdog process. So there will be a master and a slave process, the master will be the active process, and the slave keep on watching the master. I case if the master is terminated, the slave become master and initiates a new slave process. But we need to transfer (or share) the process state of "old master" with the "new master" (So that the new master can continue form where the old master has stopped). Is this possible with shared memory? Or is there is a better way? Thanks, Lloyd ______________________________________ Scanned and protected by Email scanner

8 11

multichar_input_filter, what I'm doing wrong?
by eial＠cs.bgu.ac.il 18 Feb '10

18 Feb '10

I'm implementing a base64 decoder using multichar_input_filter, it works well but it doesn't seems to stop, after the last char of the testcase string (which is reads from file), it continues to read, I must be missing something, here is the code: http://codepad.org/YvKREpKS the convert funcion does the actual convert and I don't think it is relevant to the code but if someone thinks it is, I'll include it. I'm banging my head against the wall for a couple of days in this issue... thanks.

2 1

fusion: mpl vector as a fusion vector
by Hicham Mouline 18 Feb '10

18 Feb '10

Hello by include <fusion/include/mpl.hpp> if I have a mpl::vector<> and I want to use it as a member of a struct. This member will actually hold runtime data. typedef mpl::vector<......> mplvector_t; can I just define it as struct S { mplvector_t m; }; or do I need to do this: struct S { fusion::result_of::as_vector<mplvector_t>::type m; }; and then I can store data in m? Regards,

2 1

boost::asio - Can't get timeout on accept to work
by Jean-Sebastien Stoezel 18 Feb '10

18 Feb '10

Hello, I would like to implement a timeout while accepting a connection on a TCP socket. I have reviewed the following example: http://www.boost.org/doc/libs/1_42_0/doc/html/boost_asio/example/timeouts/a… And here is my implementation of it, though it does not seem to wait for the given timeout... And I don't seem to see CProtobufSocket::HandleAccept being called. Could anybody tell me what I am missing with this code? Thanks! Jean-Sebastien int CProtobufSocket::Receive( string port, google::protobuf::Message & message, const boost::posix_time::milliseconds timeout ) { int result = -1; boost::asio::io_service ioService; boost::asio::ip::tcp::acceptor acceptor(ioService, boost::asio::ip::tcp::endpoint(boost::asio::ip::tcp::v4(), atoi(port.data()))); boost::asio::ip::tcp::socket socket(ioService); try { boost::asio::deadline_timer mytimer(ioService); acceptor.async_accept(socket, boost::bind(CProtobufSocket::HandleAccept, boost::asio::placeholders::error, result)); mytimer.expires_from_now(timeout); mytimer.async_wait(boost::bind(CProtobufSocket::Close, &acceptor)); if(0 == result) { // receive on the socket. result = Receive(socket, message, timeout); } else {} } catch (std::exception& e) { // jstoezel 2910208: removes warning C4101: 'e' : unreferenced local variable e; } try { socket.shutdown(socket.shutdown_both); socket.close(); } catch (std::exception& e) { // jstoezel 2910208: removes warning C4101: 'e' : unreferenced local variable e; } return result; } void CProtobufSocket::Close( boost::asio::ip::tcp::acceptor * acceptor ) { acceptor->close(); } void CProtobufSocket::HandleAccept(const boost::system::error_code &err, int & result) { err; if(err) {} else { result = 0; } }

2 4

Re: [Boost-users] Object pools?
by Michele Caini 18 Feb '10

18 Feb '10

Il 17/02/2010 17:18, Ryan McConnehey ha scritto: > michele.caini(a)gmail.com wrote: >> Simply, That's not as a pool have to work. You are looking for >> something that is a pool but working not as a pool does. > Then what is the definition of a pool? Do you mean that I'm looking for > something that is a pool but doesn't work like a Boost.pool? > > Ryan No, sorry. I mean that pool has responsability for manage offered objects, and so it manages them along their life time. Pool will create objects, pool will release and reclaim objects, and pool will delete objects. That's all. You are looking for something that create objects and forbid about them, until you return that objects to the home. Is correct? Really, it's possible but it is not as a pool works, simply. Your idea breaks also raii pattern and you risk to have memory leaks, because not reclaimed objects maybe be lost during their life time. So, in my opinion, it is not a good idea. I think that is better to create a pool of object during pool construction, so delete them during destruction, eventually resizing pool during use. What about a monostate pattern that globally manages objects as a pool and will be destroyed only when program terminates? That's can be a valid alternative, or not?

3 3

[parameter][mpl] How to do a union of ArgumentPacks?
by Jesse Perla 17 Feb '10

17 Feb '10

I would like to call a function using named parameters where I construct the values from two different argument packs. How do I write a function that will generically take the union of all of the named parameters? I am using Intel C++ 11.1 with C++0X features turned on, so 'decltype' and 'auto' are kosher, but not alternative function syntax. Also, the types I might have in the args could be by value or reference or constant reference, so I can't just copy them all by value. Here is a simple example to see what I mean: BOOST_PARAMETER_NAME(name1) BOOST_PARAMETER_NAME(name2) BOOST_PARAMETER_NAME(name3) template<typename ArgPack> double f(const ArgPack& args) { return args[_name1] + args[_name2] + args[_name3]; } //Test using the argpack directly... this works fine. std::cout << f( (_name1 = 1.0, _name2 = 1.0, _name3 = 1.0) ); //Now try to combine them: template<typename ArgPack1, typename ArgPack2> double g(const ArgPack1& args1, const ArgPack2& args2) { return f( parameter_union(args1, args2) ); //HOW DO I WRITE THE parameter_union FUNCTION? } //usage std::cout << g( (_name1 = 1.0, _name2 = 1.0), (_name3 = 1.0) ); Thanks for your help, Jesse

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Re: [Boost-users] [Serialization] unable to fix UNREGISTERED CLASSexception
by David Graf 17 Feb '10

17 Feb '10

Hello Robert Sorry to bother you again, but I am unable to use force_include correctly. I guest the makro BOOST_USED must be used, correct? I wrote BOOST_USED into each function header in the example. But it doesn't change anything. David On Feb 17, 2010, at 5:25 PM, Robert Ramey wrote: > This is likely due to the fact that a static linker will only include > modules which have have been explicitly referred to. The library uses > "force_include" to implement this when it can. You'll just have to figure > out what the linker is excluding and make sure it's included. > > > Robert Ramey > 830 Cathedral Vista Lane > Santa Barbara, CA 93110 > (805)569-3793 > www.rrsd.com > -----Original Message----- > From: David Graf [mailto:davidagraf@gmail.com] On Behalf Of David Graf > Sent: Wednesday, February 17, 2010 8:08 AM > To: boost-users(a)lists.boost.org; Robert Ramey > Subject: Re: [Boost-users] [Serialization] unable to fix UNREGISTERED > CLASSexception > > Hello Robert > > I fixed the example. I had to add somewhere a virtual function. Otherwise, > the polymorphism doesn't work. > > Unfortunately, I have a new problem. If I put the code into a static > library, the serialization from the outside doesn't work anymore. Then, I > get a unregistered class exception. It only works when I put the code to > execute the serialization into the cpp file where the classes are registered > with BOOST_CLASS_EXPORT_GUID. > > Again, I attached the example source code. The library is created with > cmake. Therefore, you need to have cmake installed on your machine to test > the example. The commands to build the example are cd > /path/to/unpacked/testfolder mkdir build cd build cmake .. > make > > Funnily enough, the serialization from the outside (from the main function) > works if the serialization in the cpp file is executed in advance. > > The example works if the library is a dynamic library. If you wanna see > this, you need to replace STATIC in CMakeLists.txt with SHARED. > > David > > >

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[exception] Conditional error_info addition
by Adam Badura 17 Feb '10

17 Feb '10

Is there a way to add error_info to an exception object conditionally? In my use case I throw upon error during Windows Registry manipulation. One of the data attached to the exception object is the path to the registry key on which operation failed. The problem however is that sometimes (while the library is still developed...) the failure is due to internal code error: the handle to the key is no longer valid because it was closed (erroneously) previously. In such case obtaining path to the key will yield an empty string. I don't want to attach an empty string. I would prefer not to attach anything. (Now actually in this particular case it might be even useful to attach an empty string which is then a clear indication that the key handle was invalid. However I hope that my point is clear here.) Currently I would have to do something like: ExceptionType e; std::wstring path = getPath( hKey ); if ( !path.empty() ) e << PathInfo( path ); BOOST_THROW_EXCEPTION( e ); This code however involves more copying with little hopes for optimization. And it is obviously long. If this was to be done for two or three data items the throwing code would become quite long... Can anything be done about it? Can we have some form of conditional error_info insertion? Adam Badura

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[Serialization] unable to fix UNREGISTERED CLASS exception
by David Graf 17 Feb '10

17 Feb '10

Hello Everybody I am using boost serialization heavily in my project to serialize C++ objects. Unfortunately, I have a big problem when I when polymorphic pointers and non intrusive serialize functions are involved in the serialization. Therefore, I made a little project which demonstrates my usage of boost functionality (see attachment). Basically, I have four classes which are derived in the following way: Item <- AtomicItem <- BooleanItem <- SpecialItem. SpecialItem contains an intrusive serialized functions. The other three contain non intrusive serialize functions. In the main function (testing.cpp), I create a SpecialItem and the stack and assign it to a pointer to an Item. Then, I serialize that Item. Unfortunately, it doesn't work. Only the serialize function of the class Item is invoked. Can you please tell me what I did wrong in my example? Note: The example can be compiled with the command: g++ atomic_items_serialization.cpp testing.cpp -o testing -lboost_serialization-mt And the expected result is: serializing Item serializing AtomicItem serializing BooleanItem serializing SpecialItem Thanks in advance David

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Property tree custom_data_type.cpp fails to compile in boost 1.42.
by Mauricio Gomes 17 Feb '10

17 Feb '10

The example C:\boost_1_42_0\libs\property_tree\examples\custom_data_type.cpp fails to compile for me. I am using Code::Blocks 8.02 with mingw gcc 4.4.0. I am getting the following error message: ||=== test, Debug ===| C:\projects\test\main2.cpp||In function 'int main()':| C:\projects\test\main2.cpp|59|error: wrong number of template arguments (5, should be 3)| C:\boost_1_42_0\boost\property_tree\ptree_fwd.hpp|29|error: provided for 'template<class Key, class Data, class KeyCompare> class boost::property_tree::basic_ptree'| C:\projects\test\main2.cpp|59|error: invalid type in declaration before ';' token| C:\projects\test\main2.cpp|63|error: request for member 'put' in 'pt', which is of non-class type 'my_ptree'| C:\projects\test\main2.cpp|64|error: request for member 'get' in 'pt', which is of non-class type 'my_ptree'| C:\projects\test\main2.cpp|64|error: expected primary-expression before 'int'| C:\projects\test\main2.cpp|64|error: expected ',' or ';' before 'int'| C:\projects\test\main2.cpp|68|error: request for member 'put' in 'pt', which is of non-class type 'my_ptree'| C:\projects\test\main2.cpp|68|error: expected primary-expression before '>' token| C:\projects\test\main2.cpp|68|warning: left-hand operand of comma has no effect| C:\projects\test\main2.cpp|69|error: request for member 'get' in 'pt', which is of non-class type 'my_ptree'| C:\projects\test\main2.cpp|69|error: expected primary-expression before '>' token| C:\projects\test\main2.cpp|74|error: request for member 'put' in 'pt', which is of non-class type 'my_ptree'| C:\projects\test\main2.cpp|74|error: expected primary-expression before '>' token| C:\projects\test\main2.cpp|74|warning: left-hand operand of comma has no effect| C:\projects\test\main2.cpp|75|error: request for member 'get' in 'pt', which is of non-class type 'my_ptree'| C:\projects\test\main2.cpp|75|error: expected primary-expression before '>' token| ||=== Build finished: 15 errors, 2 warnings ===| The problem seems to be the number of template parameters in line 59: // Property_tree with boost::any as data type // Key comparison: std::less<std::string> // Key type: std::string // Path type: path // Data type: boost::any // Translator type: my_translator typedef basic_ptree<std::less<std::string>, std::string, path, boost::any, my_translator> my_ptree; my_ptree pt; Am I missing something ? Thanks for your attention, -- Mauricio Gomes Pensar Digital 55-11-9698-1683 (Brazil - mobile)

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[Boost.Build]: Suppress compiler version in build path
by Roland Bock 17 Feb '10

17 Feb '10

Hi, using the current version of boost.build, compilation results are generated in paths like this: /example/gcc-4.2.4/debug/threading-multi Earlier versions (e.g. at a customer's site) ignore the compiler version, thus /example/gcc/debug/threading-multi Can I tell the current bjam to omit the compiler version in the path? Thanks and regards, Roland

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info about connect method of boost::asio::ip::tcp::iostream
by Conoscenza Silente 17 Feb '10

17 Feb '10

Hi All Right now I started using boost::asio::ip::tcp::iostream class. If I use the constructor of this class with 2 strings stating IP and PORT everything is fine and I can connect to my server. boost::asio::ip::tcp::iostream sockStream("1.2.3.4","5000"); Instead if I use the connect method using the port as int, connection doesn't happen. boost::asio::ip::tcp::iostream sockStream; sockStream.connect ("1.2.3.4", 5000 ); if( sockStream.fail() ){ std::cout << "I am not connected" << std::endl; } What am I doing wrong? It is something allowed to do or should I use other classes like resolver::query + resolver::iterator? Thanks CS

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Re: [Boost-users] [program_options][1.35] validating string value
by michele.caini＠gmail.com 17 Feb '10

17 Feb '10

If you have problem using boost.regex or another regex framework, don't worry about ask for help, please. :) ----- Reply message ----- Da: "Soumen" <soumen78(a)gmail.com> Data: mer, feb 17, 2010 12:21 Oggetto: [Boost-users] [program_options][1.35] validating string value A: <boost-users(a)lists.boost.org> Thanks Andre and Michele - got the way to accomplish it. -- View this message in context: http://old.nabble.com/-program_options--1.35--validating-string-value-tp276… Sent from the Boost - Users mailing list archive at Nabble.com. _______________________________________________ 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] [program_options][1.35] validating string value
by michele.caini＠gmail.com 17 Feb '10

17 Feb '10

Using regex can help you, maybe? ----- Reply message ----- Da: "Soumen" <soumen78(a)gmail.com> Data: mer, feb 17, 2010 11:40 Oggetto: [Boost-users] [program_options][1.35] validating string value A: <boost-users(a)lists.boost.org> Hi, My option (say, "opt1") can take any of only few possible string type values (say, "value1", "value2", "value3" and "value4"). Is there anyway to specify this such that if any other value, say - "valueXX", is passed to "opt1", it throws an error? If yes, can someone point me to documentation or sample code snippet to show how to do this? Or, explicitly, checking against these possible values is my only option? Regards, ~ Soumen -- View this message in context: http://old.nabble.com/-program_options--1.35--validating-string-value-tp276… Sent from the Boost - Users mailing list archive at Nabble.com. _______________________________________________ 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] [program_options][1.35] validating string value
by michele.caini＠gmail.com 17 Feb '10

17 Feb '10

Something like [on¦off¦error] is enough, for that simple case. ;) ----- Reply message ----- Da: "Soumen" <soumen78(a)gmail.com> Data: mer, feb 17, 2010 11:58 Oggetto: [Boost-users] [program_options][1.35] validating string value A: <boost-users(a)lists.boost.org> Using regex can help you, maybe? Say, my switch name is "semantic_check" and possible values are "on" (turns on the checker, issues warning when something fails), "off" and "error" (changes severity of warning to error). Could you cite an example code snippet me how regex may help? Regards, ~ Soumen -- View this message in context: http://old.nabble.com/-program_options--1.35--validating-string-value-tp276… Sent from the Boost - Users mailing list archive at Nabble.com. _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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[1.35.0][OSX][iostreams] Exception thrown with utf8 filename
by Christophe Radondy 17 Feb '10

17 Feb '10

Hi, I try to do a cross-platform source code and I have this code. I compiled boost 1.35 in universal binaries on Mac OS 10.5.4 with intel platform (IMAC core 2 duo 3Ghz) The same code works on linux (Ubuntu 8.0.4 and debian) and windows platforms but on Mac OS 10.5 I have an exception in boost's libraries. We compile on universal binaries with -fexceptions options of g++ 4.0.1 (Apple). This is my code: <code> boost::filesystem::wpath unicode(L"abcdef\u0110"); boost::filesystem::ofstream file(unicode.string()); // throws Invalid Argument on Mac file << "abcdef" << endl; file.close(); <endcode/> If I do this, it works: <code> boost::filesystem::path utf8("abcdef\xC4\x90"); // \xC4\x90 == \u0110 boost::filesystem::ofstream file(utf8.string()); // works ok file << "abcdef" << endl; file.close(); <endcode/> When the ofstream is created, this function is executed and crashes when I use Unicode parameters : <code> unicode.external_file_string(); // throws uncaught exception of type boost::filesystem::basic_filesystem_error<boost::filesystem::basic_path<std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >, boost::filesystem::wpath_traits> > - boost::filesystem::wpath::to_external conversion error: Invalid argument <endcode/> Do you have any idea? Is this a known bug? Did I miss a setting? Thanks for your help. Regards, Christophe.

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error importing hello_ext
by hitesh dhiman 17 Feb '10

17 Feb '10

Hi all, I'm trying to get the boost.python tutorial working. The hello.py example builds successfully. The problem is, when i run my python file, there is an error: Evaluating hello.py Traceback (most recent call last): File "<string>", line 6, in <fragment> ImportError: No module named hello_ext Now, the tutorial directory has the python and c++ file, and a bin directory. the bin directory is as follows : tutorial\bin\msvc-9.0\debug\threading-multi the hello_ext.pyd file is located inside here. Can anyone help? Its a path problem i believe, but i'm not able to pin point whats wrong. -- Regards, Hitesh Dhiman Electrical Engineering National University of Singapore

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Object pools?
by Ryan McConnehey 17 Feb '10

17 Feb '10

I recently had to create a class that managed a pool of objects for the user. Instead of the user creating the object themselves they would ask the class for an object. The class would hand the user a boost::shared_ptr of the object. When the boost::shared_ptr needed to destroy the object it handed it back to the class to reuse. The class is designed for those areas that need a lot of the same object but not all at the same time. This class has been useful for the boost::asio library where the async_receive and async_write need the buffer to be valid until the callback occurs. Other people at my work have shown interest and I'm looking at needing to improve the class to make it more general. Instead of spending time doing the improvements I would like to know if the boost libraries have anything like what I described. I'll looked through the descriptions but haven't seen anything that comes close. Ryan

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Embedding boost in a given project
by joel falcou 17 Feb '10

17 Feb '10

In order to satisfy various users request and to limit potential whining about implicit dependencies on boost, I've started lookign at how to embed boost components into my own tools. What are the usual way to do that ? I pondered working with a given version (say 1.42) in which I could add w/e patches and fixed from the trunk along with my own custom patches. I then use BCP to extract sub boost compoennt to my release package. Now, the final funny thing is that, for various reason, we don't use bjam atm for our own product build. I guess adding a makefile fuel like dependency: bjam --with-xxxx is enough for example ? Any experience to be shared on that topic ? -- ___________________________________________ Joel Falcou - Assistant Professor PARALL Team - LRI - Universite Paris Sud XI Tel : (+33)1 69 15 66 35

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Plugin library boost
by Lloyd 17 Feb '10

17 Feb '10

Hi, Does boost have a plug-in framework to develop a plug-in in applications. If not, does anybody know a good plug-in framework. Thank you very much, Lloyd ______________________________________ Scanned and protected by Email scanner

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random: uniform_01 usage and mixing boost::random with boost::math::normal
by Hicham Mouline 16 Feb '10

16 Feb '10

Hello, I have this code: boost::mt19937 mers; boost::uniform_01<boost::mt19937> uf01(mers); boost::exponential_distribution<> ed(0.1); I call the operator() on uf01 3 million times, as uf01() I don't quite understand the warning in the documentation about the constructor taking the generator by value. This means that my mers doesn't change between calls to uf01(). Is this bad? Will it affect the quality of the randomness of the uniform numbers generated? I also have boost::math::normal nrm; and I use boost::math::cdf(nrm, …) and boost::math::quantile( nrm, … ); Are there any issues with using both boost∷math∷normal and other distributions from the boost∷random library? Regards,

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[ASIO] When the work object is destroyed?
by Daniele Barzotti 16 Feb '10

16 Feb '10

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, in my library I create a work object on the heap to maintain the io_service running and I assign it to a object member shared_ptr so, when the last object is destroyed, the work ends and the io_service.run() returns. All works but, if when I create an object after the thread is ended, the io_service returns immediately.. ..and I don't know why, any suggestions? Thanks! Daniele. - ------------------------------------------------------------------- // Main io_service static boost::asio::io_service io_service; static boost::scoped_ptr<boost::thread> io_service_thread; static boost::asio::io_service::work* p_work; static BOOL thread_started; void io_worker_thread(void) { #if(WIN32 && _WIN32_DCOM) struct com_init { com_init() { CoInitializeEx(NULL, COINIT_APARTMENTTHREADED); } ~com_init() { CoUninitialize(); } } initializer_object; #endif io_service.run(); thread_started = false; }; EXTERN_C EUROATLIB_API Hndl CALL GetTETRAMotoObj() { if (!thread_started) { try { // create the work object on the heap p_work = new boost::asio::io_service::work(io_service); // run the IO service as a separate thread: // Instead of start the worker thread directly by passing the // io_service object, // I call the io_worker_thread function where I can do some // initialization tasks like calling CoInitializeEx for COM io_service_thread.reset(new boost::thread(io_worker_thread)); thread_started = !thread_started; } catch (boost::thread_resource_error e) { // Failed to create the new thread return 0; } } // create the new object TETRAMoto* pTETRAMoto = new TETRAMoto(io_service); // Assign a reference to io_service work object: // This reference is used to counting the objects created. // When the last TETRAMoto object is deleted the main work object // is destroyed and the io_service thread ends. pTETRAMoto->_io_work_ptr.reset(p_work); // return the object return pTETRAMoto; }; - ------------------------------------------------------------------- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (MingW32) iEYEARECAAYFAkt6f04ACgkQ/l+kMioSZwjYiwCgleSrLLiKKQlmZjN7HQBSEs75 olUAoKhMEV7/SK6tiI4hIxUoRjQv9qEE =KGSy -----END PGP SIGNATURE-----

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[Iostreams] stream<file_sink> does not throw an exception and not set fail/bad bits when file is wrong
by Mariusz Wojtysiak 16 Feb '10

16 Feb '10

Hello! I'm trying to write some content to a new file using boost::stream<file_sink> class. Unfortunately errors/failures during opening the file are ignored by boost library. Here is a snippet: using namespace boost::iostreams; stream<file_sink> stream( "/wrong.txt" ); std::cout << stream.fail() << ' ' << stream.bad() << std::endl; stream.exceptions( std::ios::badbit | std::ios::failbit ); stream << "test" << std::endl; stream.close(); Program is started as not root user and have not access for file / wrong.txt. It should throw an exception, but instead of this: - console prints: 0 0 - none exception is thrown - file /wrong.txt is not created Similar piece of code using std::ofstream works as I expect: using namespace std; ofstream stream( "/wrong.txt" ); std::cout << stream.fail() << ' ' << stream.bad() << std::endl; stream.exceptions( std::ios::badbit | std::ios::failbit ); stream << "test" << std::endl; stream.close(); - console prints: 1 0 - exception is thrown I cannot believe that boost::iostreams has such obvious bug and just ignore failures! I have to do something wrong. But what? Regards, Mariusz Wojtysiak

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how to realize that a connection is closed by a client
by Conoscenza Silente 16 Feb '10

16 Feb '10

Hi All I am doing first steps with boost::asio and I want to use ip::tcp::stream to send data from a server to a client. Reading the sample in boost docs I did a first sample of server code. Is there any way for the server to check if a client connection is closed or gone at some point? for( ;; ){ boost::asio::ip::tcp::iostream stream; acceptor.accept( *stream.rdbuf() ); for( int i = 0; i < 10; i++ ){ stream << "message" << i << std::endl; // how to realize that the client has gone here? boost::this_thread::sleep( boost::posix_time::milliseconds(1000) ); }

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Problems with boost build 1.42
by Avi Bahra 16 Feb '10

16 Feb '10

I am using bjam to build my application on suse linux. I have defined a environment variable BOOST_ROOT, which allows me to switch between boost builds. I have used this approach for 1.38, 1.39,1.40. I always build the boost libraries I need myself using bjam. bjam --build-dir=./tmpBuildDir toolset=gcc stage link=static --with-system i.e I don't bother with build scripts in $BOOST_ROOT With 1.42 when I build my application I get an error of the form: error: Unable to find file or target named error: '/var/tmp/ma0/boost/boost_1_42_0/stage/lib/libboost_system.a' error: referred from project at error: '' The error is very misleading because the file exists? When I switch back, to 1.39/1.40 there are no problems. This is what my boost-build.jam look like: -------------------------------------------------------------------------------- BOOST_BUILD = [ MATCH --boost-build=(.*) : $(ARGV) ] ; BOOST_BUILD ?= $(BOOST_ROOT)/tools/build/v2 ; boost-build $(BOOST_BUILD) ; Here is jam file for my leaf project: ---------------------------------------------------------------------------- use-project theCore : ../ACore ; exe test : [ glob src/*.cpp ] /site-config//boost_system /site-config//boost_serialization : <include>../SCRATCH/src <variant>debug:<define>DEBUG ; -------------------------------------------------------------------------- Notice that I reference /site-config// to reference the boost libs. for some reason in 1.42 this fails ! My site-config.file which is located in $BOOST_ROOT/tools/build/v2 is of the form: ------------------------------------------------------------------------ import os ; local BOOST_ROOT = [ os.environ BOOST_ROOT ] ; lib boost_serialization : : <file>$(BOOST_ROOT)/stage/lib/libboost_serialization.a ; lib boost_system : : <file>$(BOOST_ROOT)/stage/lib/libboost_system.a ; project site-config : requirements <include>$(BOOST_ROOT) ; using gcc ; using testing ; -------------------------------------------------------------------- My site-config.jam is the same between 1.40 and 1.42. There is probably a silly mistake on my part somewhere, but its preventing me from moving to 1.42. Any help appreciated. Best regards, Ta, Avi

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Server / client Boost.Test
by Christian Auby 16 Feb '10

16 Feb '10

How would I go about writing a unit test that runs first a network server, then connects to it and does some operations with it? I can see issues with the run order, and if there's a problem in the server it might never respond and the test would run forever. regards, Christian

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boost.asio Bus error on g++ 4.5 / Mac OS X 10.5.6
by Orca X 16 Feb '10

16 Feb '10

Hi! For some reason very simple program crashes with Bus error. code is --------------------------- #include <iostream> #include <boost/asio.hpp> int main(int argc, char **argv) { std::cout << "xxx" << std::endl; return 0; } --------------------------- Crash happens before any output is made. I'm using boost.build to build executables. The bug dissapears when building variant=debug. Gdb output: --------------------------- Program received signal EXC_BAD_ACCESS, Could not access memory. Reason: KERN_PROTECTION_FAILURE at address: 0x00000000 0x000019a8 in ?? () (gdb) bt #0 0x000019a8 in ?? () #1 0x00001e90 in boost::asio::detail::service_id<boost::asio::detail::reactive_descriptor_service<boost::asio::detail::kqueue_reactor<false> > >::~service_id () Previous frame inner to this frame (gdb could not unwind past this frame) --------------------------- Situation is that I'm building with g++4.5 installed from macports, with --std=c++0x, but boost itself was built with regular gcc 4.0.1. 4.5 version located at /opt/local/* , boost located at /usr/local/*. How could it happen that asio library destroys something even before my code is reached? No library initialization involved. Thanks in advance!

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Boost asio serial and rs-485
by Christian Auby 15 Feb '10

15 Feb '10

Is it possible to use Boost asio serial with rs485? If yes, is there anything special you need to be aware of? regards, Christian

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Trouble using bjam
by Roland Bock 15 Feb '10

15 Feb '10

Hi, I have a little trouble using bjam: I'd like to tell it to add /my/path to the include paths, by using this command-line: bjam include=/my/path I took this syntax from here: http://www.boost.org/boost-build2/doc/html/bbv2/overview/invocation.html#bb… But bjam answers with /usr/share/boost-build/build/property.jam:258: in validate1 from module property error: Invalid property '<include>': No value specified for feature 'include'. /usr/share/boost-build/build/property.jam:266: in property.validate from module property /usr/share/boost-build/build/build-request.jam:185: in convert-command-line-element from module build-request /usr/share/boost-build/build/build-request.jam:143: in build-request.from-command-line from module build-request /usr/share/boost-build/build-system.jam:164: in load from module build-system /usr/share/boost-build/kernel/modules.jam:261: in import from module modules /usr/share/boost-build/kernel/bootstrap.jam:132: in boost-build from module /usr/share/boost-build/boost-build.jam:1: in module scope from module Any idea? I am using bjam installed by Ubuntu-8.04: Boost.Build V2 (Milestone 11) Boost.Jam 03.1.14 Regards, Roland

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[Boost.Asio] Compiling Boost.Asio with OpenMPI
by vibhor aggarwal 15 Feb '10

15 Feb '10

Hello, I am trying to write a program which runs using OpenMPI on our cluster and communicates the results using TCP/IP to another machine which has a network connection to the cluster. I am using Boost.Asio for the TCP/IP connection. If I remove the MPI code from the executable and compile it with g++, it connects to the remote machine without a problem. But when I add a simple MPI code to it and compile with mpicxx and execute using mpirun, it generates a connection time out in the call to socket.connect(). Any idea what might be going wrong ? Thanks. Your Mail works best with the New Yahoo Optimized IE8. Get it NOW! http://downloads.yahoo.com/in/internetexplorer/

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[Serialization] crash in boost::serialization::extended_type_info::key_unregister ()
by Avi Bahra 15 Feb '10

15 Feb '10

> Hi, > I had the same problem... > > This problem was fixed in the next release (1.40) > Regards, > Damien. Ok I tried this and found: a/ whereas 1.39 serialisation compiles with out _any_ warnings. 1.40 has a _blizzard_ sorry I meant avalanche of warnings on building boost and on my application of the kind: /var/tmp/ma0/boost/boost_1_40_0/boost/archive/basic_binary_oarchive.hpp:88: warning: comparison between signed and unsigned integer expressions This makes it extremely difficult to see my own warnings. Is 1.40 really production quality ? We have a policy of no warnings, so the obvious question now, is what release are these warning's fixed ? b/ Still get the same crash on program exit. Program received signal SIGSEGV, Segmentation fault. 0xb7ce3a08 in strcmp () from /lib/libc.so.6 (gdb) bt #0 0xb7ce3a08 in strcmp () from /lib/libc.so.6 #1 0x083c814d in boost::serialization::extended_type_info::key_unregister () #2 0x083c8407 in boost::serialization::extended_type_info::~extended_type_info () #3 0x081bf8cc in ~extended_type_info_typeid (this=0x8789604) at /var/tmp/ma0/boost/boost_1_40_0/boost/serialization/extended_type_info_typeid.hpp:80 #4 0x081bf98e in ~singleton_wrapper (this=0x8789604) at /var/tmp/ma0/boost/boost_1_40_0/boost/serialization/singleton.hpp:104 #5 0x0819f508 in __tcf_25 () at /var/tmp/ma0/boost/boost_1_40_0/boost/serialization/singleton.hpp:121 #6 0xb7ca3599 in exit () from /lib/libc.so.6 #7 0xb7c8cfe8 in __libc_start_main () from /lib/libc.so.6 #8 0x08053921 in _start () Oh well! I will have to go back placing all the serialisation in one translation unit and stick with 1.39. Best regards, Ta, Avi

2 1

[Serialization] crash in boost::serialization::extended_type_info::key_unregister ()
by Avi Bahra 15 Feb '10

15 Feb '10

I am using boost 1.39 on suse linux with gcc 4.2.1 and using a debug build. In order to rationalize the long compile times, I was attempting to split a file into multiple translation units. When I ran my tests, they all passed, but then crashed with a memory fault. Program received signal SIGSEGV, Segmentation fault. [Switching to Thread 0xb7cd26d0 (LWP 21897)] 0xb7d40a08 in strcmp () from /lib/libc.so.6 (gdb) bt #0 0xb7d40a08 in strcmp () from /lib/libc.so.6 #1 0x08e19924 in boost::serialization::extended_type_info::key_unregister () #2 0x08e19ace in boost::serialization::extended_type_info::~extended_type_info () #3 0x08c41afc in ~extended_type_info_typeid (this=0x92179cc) at /var/tmp/ma0/boost/boost_1_39_0/boost/serialization/extended_type_info_typeid.hpp:80 #4 0x08c41bbe in ~singleton_wrapper (this=0x92179cc) at /var/tmp/ma0/boost/boost_1_39_0/boost/serialization/singleton.hpp:104 #5 0x08c209e0 in __tcf_25 () at /var/tmp/ma0/boost/boost_1_39_0/boost/serialization/singleton.hpp:121 #6 0xb7d00599 in exit () from /lib/libc.so.6 #7 0xb7ce9fe8 in __libc_start_main () from /lib/libc.so.6 #8 0x08a833f1 in _start () It appears that boost serialisation type registration has problems when it is split into multiple files. Also it appears that most of serialisation test all appear in a single file, hence these kinds of issues can easily be missed. Is there any work around to this problem ? Best regards, Ta, Avi

2 1

[Boost Graph] Two-graphs common spanning tree problem: generic algorithm (with concept checking, of course)
by Michele Caini 15 Feb '10

15 Feb '10

Hi all, my name is Michele Caini, I write from Italy, Florence, and this is my first mail on this list. I'd like to propose a new generic implementation of the two-graphs common three algorithm, proposed first by Grimbleby and then modified by Schach, that made a revolution on the first idea basing his algorithm on the solution for the single spanning three problem proposed and developed by Mint, Read and Tarjan. This algorithm is mainly used in symbolic circuit analysis, and I develop a generic solution for my symbolic solutor: QSapecNG, Qt-based frontend for symbolic circuit solution. If Boost Graph library mantainers are interested on publishing this algorithm with the next release of library, I'm happy to submit it, and to work on to optimize the code. Thanks to all, Michele ps: sorry for my English. :-)

2 2

Re: [Boost-users] [Serialization] crash in boost::serialization::extended_type_info::key_unregister ()
by dada＠lamef.bordeaux.ensam.fr 15 Feb '10

15 Feb '10

Hi, I had the same problem... This problem was fixed in the next release (1.40) Regards, Damien. Le lundi 15 février 2010 à 10:30 +0000, Avi Bahra a écrit : > I am using boost 1.39 on suse linux with gcc 4.2.1 and using a debug > build. > In order to rationalize the long compile times, I was attempting to > split a file > into multiple translation units. When I ran my tests, they all passed, > but then > crashed with a memory fault. > > Program received signal SIGSEGV, Segmentation fault. > [Switching to Thread 0xb7cd26d0 (LWP 21897)] > 0xb7d40a08 in strcmp () from /lib/libc.so.6 > (gdb) bt > #0 0xb7d40a08 in strcmp () from /lib/libc.so.6 > #1 0x08e19924 in > boost::serialization::extended_type_info::key_unregister () > #2 0x08e19ace in > boost::serialization::extended_type_info::~extended_type_info () > #3 0x08c41afc in ~extended_type_info_typeid (this=0x92179cc) > at /var/tmp/ma0/boost/boost_1_39_0/boost/serialization/extended_type_info_typeid.hpp:80 > #4 0x08c41bbe in ~singleton_wrapper (this=0x92179cc) > at /var/tmp/ma0/boost/boost_1_39_0/boost/serialization/singleton.hpp:104 > #5 0x08c209e0 in __tcf_25 () > at /var/tmp/ma0/boost/boost_1_39_0/boost/serialization/singleton.hpp:121 > #6 0xb7d00599 in exit () from /lib/libc.so.6 > #7 0xb7ce9fe8 in __libc_start_main () from /lib/libc.so.6 > #8 0x08a833f1 in _start () > > It appears that boost serialisation type registration has problems > when it is split into multiple files. Also it appears > that most of serialisation test all appear in a single file, hence > these kinds of issues can easily be missed. > Is there any work around to this problem ? > > Best regards, > Ta, > Avi > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users

1 0

[Python]
by Oliver Rudolph 15 Feb '10

15 Feb '10

Hi folks! When trying to run Python-wrapped C++ code, I receive the following message (this was a simple call to one of the c'tors of class TextFile): Traceback (most recent call last): File "./FileTest.py", line 5, in <module> t_out = TextFile("sample.txt", "This is some sample text. It says:\n\nHello world!") Boost.Python.ArgumentError: Python argument types in TextFile.__init__(TextFile, str, str) did not match C++ signature: __init__(_object*, std::string filename, dretchy::io::DeviceDataType type, std::string content, dretchy::io::CompressionType zipper) __init__(_object*, std::string filename, dretchy::io::DeviceDataType type, dretchy::io::CompressionType zipper) __init__(_object*, std::string filename, dretchy::io::DeviceDataType type, std::string content) __init__(_object*, std::string filename, dretchy::io::DeviceDataType type) __init__(_object*, std::string filename, std::string content, dretchy::io::CompressionType zipper) __init__(_object*, std::string filename, dretchy::io::CompressionType zipper) __init__(_object*, std::string filename, std::string content) __init__(_object*, std::string filename) Strangely enough, this only happens when doing so on my openSuSE 11.0 machine. If I try the same thing on my Ubuntu 9.10 notebook, it works perfectly. What could be the source of this problem? The code is a bit lengthy, so I attached the non-compilable headers only. Personally, I presume the error is rooted in the C-string / C++ std::string conversion. The Python wrapping itself was done via Py++, the boost libs in use are of version 1.41.0. Thanks a lot and best regards, Oliver

1 0

[accumulators] question
by Neal Becker 15 Feb '10

15 Feb '10

If I have: typedef accumulator_set<el_t,stats<tag::mean> > accum_t; Is there a way to get the count of the number of samples?

2 3

installing boost 1.34.0 in snow leopard
by Murali Krishna Pusala 15 Feb '10

15 Feb '10

Hi every one, I am trying to install boost 1.34.0 on snow leopard, it is able to build .a files but it is not building .dylib libraries. It giving an error ld: unknown option: -h krishna

5 6

Asio exception handling
by Matthias Vallentin 15 Feb '10

15 Feb '10

Hi, Consider the example where an io_service objects is used as scheduler, with tasks handed to io_service::post(). According to the manual [1], exceptions should propagate to the caller of io_service::run. However, this does not seem to be the case with the attached example. Essentially, I am doing the following: while (true) { try { io_service.post(task(&work)); io_service.post(task(&work)); io_service.post(task(&work)); io_service.run(); break; } catch (...) { // Never reached! std::cout << "catching exception" << std::endl; } } I attached a minimal example that demonstrates this issue. Any help would be appreciated. Matthias [1] http://www.boost.org/doc/libs/1_42_0/doc/html/boost_asio/reference/io_servi… -- Matthias Vallentin vallentin(a)icsi.berkeley.edu http://www.icir.org/matthias

2 2

[filesystem] Mac OS default codecvt facet
by Beman Dawes 14 Feb '10

14 Feb '10

On Mac OS, Boost.Filesystem currently uses std::locale() as the default, since Apple doesn't see fit to support std::locale(""). There has been a request (ticket #3928) to change the codecvt facet to UTF-8 for the Boost.Filesystem default on Mac OS. This would at least potentially be a breaking change, so I wanted to ask other's opinions before making it. Questions: * Is UTF-8 OK with Mac OS users as the Boost.Filesystem default? * Would Linux users also prefer UTF-8 as the Boost.Filesystem default? Thanks, --Beman

1 0

generate structs with all combinations of members from a given struct
by Hicham Mouline 14 Feb '10

14 Feb '10

Hello, struct params { double field1; double field2; double field3; double fiedl4; }; I would like to generate all the types that hold any combination of the members of params. struct params_field1 { double field1; }; struct params_field2 { double field2; }; struct params_field3 { double field3; }; struct params_field4 { double field4; }; struct params_field1_field2 { double field1; double field2; }; struct params_field1_field3 { double field1; double field3; }; struct params_field1_field4 { double field1; double field4; }; struct params_field2_field3 { double field2; double field3; }; struct params_field2_field4 { double field2; double field4; }; struct params_field3_field4 { double field3; double field4; }; struct params_field1_field2_field3 { double field1; double field2; double field3; }; struct params_field1_field2_field4 { double field1; double field2; double field4; }; struct params_field1_field3_field4 { double field1; double field3; double field4; }; struct params_field2_field3_field4 { double field2; double field3; double field4; }; struct params_field1_field2_field3_field4 { double field1; double field2; double field3; double field4; }; There are 15 of these, which is 2^4 -1, where 4 is the number of members in params. Assuming params is adapted as a fusion sequence, this looks doable with PP? Should I be looking at BOOST_PP_LIST_FOLD_xxx macros? regards,

5 28

[Function] Takes functor by value not reference?
by Alexander Lamaison 14 Feb '10

14 Feb '10

I may be misunderstanding as the boost::function code is tricky to follow but it seems to me that the function contructor takes the functor it is passed by value rather than by reference. This requires the functor to be copyable. In my case I'm trying to pass a functor as its abstract supertype which prevents copying. Is it not possible to take the functor my reference, thereby removing the need for copying? The constructor in question appears in function_template.hpp at line 1056 in version 1.40.0: Summarised: template<typename R BOOST_FUNCTION_COMMA BOOST_FUNCTION_TEMPLATE_PARMS> class function<BOOST_FUNCTION_PARTIAL_SPEC> : public BOOST_FUNCTION_FUNCTION<R BOOST_FUNCTION_COMMA BOOST_FUNCTION_TEMPLATE_ARGS> { typedef BOOST_FUNCTION_FUNCTION<R BOOST_FUNCTION_COMMA BOOST_FUNCTION_TEMPLATE_ARGS> base_type; template<typename Functor> function(Functor f) : base_type(f) { } } Many thanks. Alex Lamaison -- http://swish.sourceforge.net

2 2

Re: [Boost-users] [random] number generator as static class member
by Moritz Beber 14 Feb '10

14 Feb '10

(I'm sorry for creating a new message in reply but I don't get my own messages.) The problem was of course the uniform_01 distribution which uses the underlying generator by value rather than reference. I now tie in a uniform_real in the same interval and it works just fine. Enjoy the rest of the weekend, Moritz

1 0

[Function] Overloaded functor as a boost::function
by Alexander Lamaison 14 Feb '10

14 Feb '10

I'm trying to pass a function with an overloaded operator() to a function expecting a boost::function parameter. This fails to compile as it appears to pick the wrong overload. Here is the functor interface with the two ways it can be called: class Command { public: virtual void operator()( const com_ptr<IShellItemArray>& items, const com_ptr<IBindCtx>& bind_ctx); virtual void operator()( const com_ptr<IDataObject>& data_object, const com_ptr<IBindCtx>& bind_ctx); }; When I try to pass an instance of this functor to a method expecting a boost::function of this type: boost::function<void( const com_ptr<IShellItemArray>& items, const com_ptr<IBindCtx>& bind_ctx)> I get a compiler error C2440: '=' : cannot convert from 'IShellItemArray *' to 'IDataObject *'. This seems to indicate that the boost::function is trying to pass its parameters to the second overload rather than the first. Any ideas how I can make boost::function pick the correct overload? I'm using Boost 1.40.0. Many thanks. Alex Lamaison -- http://swish.sourceforge.net

1 1

[random] number generator as static class member
by Moritz Beber 14 Feb '10

14 Feb '10

Dear list users, I have attached a reduced case of what I want to do. Basically, I thought it would be a good idea to have one general number generator that I attach to specific distributions in my member functions according to my needs (uniform_01 in this example, but I also want to use others). So for example I do the following in my real code, where 'rng' is my static member object: typedef boost::lagged_fibonacci607 rand_gen; boost::bernoulli_distribution<double> b_dist(p); boost::variate_generator<rand_gen&, boost::bernoulli_distribution<double> > bool_gen(MyClass::rng, b_dist); boost::uniform_smallint<short unsigned> in_dist(0, this->nodes_in - 1); boost::variate_generator<rand_gen&, boost::uniform_smallint<short unsigned> > in_gen(MyClass::rng, in_dist); Unfortunately, as the code I attached demonstrates, every time I do that the original state of the 'rng' seems to be used. Do you have suggestions for fixing this? Thank you in advance, Moritz

1 0

[boost.asio] Getting/setting RTS and CTS/DSR/DCD with serial_port
by David Faure 13 Feb '10

13 Feb '10

Hello, I'm porting old platform-specific serial port code to use asio::serial_port, and it's working nicely overall, but I'm missing some functionality. How can I get/set the status of the DTR, RTS and DCD pins? This seems to be needed for some devices. I'm no expert, but the current documentation says: // RTS on if Data in Transmit queue or while BREAK transmitted // RTS off iff no data in transmit queue and // Output Handshaking via CTS/DSR/DCD // data is transmitted only when all lines which are enabled for // output handshake are up. (BREAKs can be transmitted) There is also this one, can this be implemented in asio? // setErrorChar ... enable/disable Error handling and lets you define // the error replacement char. // Specifies whether bytes received with parity errors are replaced // with the character specified by the ErrorChar member. void setErrorChar(bool on, char errorChar); If it helps, the Windows implementation was: dcbI.fbFlowReplace |= MODE_ERROR_CHAR; dcbI.bErrorReplacementChar = cError; but I suppose I don't have access to the DCBINFO used inside boost, and anyway the whole purpose is to make this cross-platform :) -- David Faure | dfaure(a)kdab.com | KDE/Qt Senior Software Engineer Klarälvdalens Datakonsult AB, a KDAB Group company Tel. Sweden (HQ) +46-563-540090, USA +1-866-777-KDAB(5322) KDAB - Qt Experts - Platform-independent software solutions

2 2

metaprogramming -- does a specialization exist?
by Peter Foelsche 13 Feb '10

13 Feb '10

Is there some way to check at compile time whether a particular specialization exists? E.g. I have a template class with two template arguments which are commutative -- means they can be exchanged and the result is the same. Can I check whether type<A, B> exists and if not select type<B, A>? Peter

3 2

Sun C++ 5.10 and BGL adjacency_list
by Nicholas Brealey 13 Feb '10

13 Feb '10

I am trying to use the Boost Graph Library from Boost 1.42.0 with Sun Studio 12 update 1 but the adjacency_list.cpp example from the libs/graph/example directory does not compile. Does anyoone have a workaround? > $ CC -V > CC: Sun C++ 5.10 SunOS_i386 128229-04 2009/11/25 > Usage: CC [ options ] files. Use 'CC -flags' for details > $ CC -library=stlport4 -features=tmplife -features=tmplrefstatic -I/home/nick/boost_1_42_0 -o adjacency_list adjacency_list.cpp > "/home/nick/boost_1_42_0/boost/graph/detail/adjacency_list.hpp", line 1722: Error: Could not find a match for boost::detail::get_dispatch<boost::detail::Config, boost::detail::Base, boost::detail::Property>(boost::adj_list_helper<boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS, boost::listS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>, boost::listS, boost::vecS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>::config, boost::undirected_graph_helper<boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS, boost::listS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>, boost::listS, boost::vecS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>::config>>, unsigned VertexProperties::*, int) needed in boost::get<boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS, boost::listS, boost::undir ectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>, boost::listS, boost::vecS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>::config, boost::undirected_graph_helper<boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS, boost::listS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>, boost::listS, boost::vecS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>::config>, unsigned VertexProperties::*>(unsigned VertexProperties::*, boost::adj_list_helper<boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS, boost::listS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>, boost::listS, boost::vecS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>::config, boost::undirected_graph_helper<boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS, boost::listS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>, boost::listS, boost::vecS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>::config>>&). > "adjacency_list.cpp", line 63: Where: While instantiating "boost::get<boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS, boost::listS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>, boost::listS, boost::vecS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>::config, boost::undirected_graph_helper<boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS, boost::listS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>, boost::listS, boost::vecS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>::config>, unsigned VertexProperties::*>(unsigned VertexProperties::*, boost::adj_list_helper<boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS, boost::listS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>, boost::listS, boost::vecS, boost::undirectedS, Vertex Properties, EdgeProperties, boost::no_property, boost::listS>::config, boost::undirected_graph_helper<boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS, boost::listS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>, boost::listS, boost::vecS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>::config>>&)". > "adjacency_list.cpp", line 63: Where: Instantiated from non-template code. > "adjacency_list.cpp", line 71: Warning (Anachronism): Assigning int to boost::detail::error_property_not_found. > "adjacency_list.cpp", line 71: Error: Cannot cast from int to boost::detail::error_property_not_found. > "adjacency_list.cpp", line 82: Error: The operation "std::ostream<<boost::detail::error_property_not_found" is illegal. > "adjacency_list.cpp", line 84: Error: The operation "boost::adj_list_vertex_property_map<boost::adjacency_list<boost::vecS, boost::listS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>, boost::detail::error_property_not_found, boost::detail::error_property_not_found&, std::string EdgeProperties::*>[boost::detail::edge_desc_impl<boost::undirected_tag, void*>]" is illegal. > "adjacency_list.cpp", line 93: Error: The operation "std::ostream<<boost::detail::error_property_not_found" is illegal. > "adjacency_list.cpp", line 98: Error: The operation "std::ostream<<boost::detail::error_property_not_found" is illegal. > "adjacency_list.cpp", line 100: Error: The operation "boost::adj_list_vertex_property_map<boost::adjacency_list<boost::vecS, boost::listS, boost::undirectedS, VertexProperties, EdgeProperties, boost::no_property, boost::listS>, boost::detail::error_property_not_found, boost::detail::error_property_not_found&, std::string EdgeProperties::*>[boost::detail::edge_desc_impl<boost::undirected_tag, void*>]" is illegal. > 7 Error(s) and 1 Warning(s) detected. I posted a similar question on the Sun C++ forum last year but no one had a solution: http://forums.sun.com/thread.jspa?threadID=5419942 g++ works fine: > $ g++ -I/home/nick/boost_1_42_0 -o adjacency_list adjacency_list.cpp > $ g++ --version > g++ (GCC) 3.4.3 (csl-sol210-3_4-branch+sol_rpath) > Copyright (C) 2004 Free Software Foundation, Inc. > This is free software; see the source for copying conditions. There is NO > warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. > Thanks Nick

2 3

Complete vs incomplete (fwd decl'd) types
by Dominique Devienne 12 Feb '10

12 Feb '10

In client code including the header for MyDerived, I'm using a MyPtr<MyDerived>, but the static assert below was failing. It took me a little while to figure out that in myderived.h, the MyDerived::nested_type typedef is using a forward-declared MyNestedDerived type declared in my_nested_derived.h, that the client code was not including, which was the reason is_base_of was failing with the error below (Boost 1.41, VC9). Adding a #include <my_nested_derived.h> fixed it. boost\type_traits\is_base_and_derived.hpp(228) : error C2139: 'MyNestedDerived' : an undefined class is not allowed as an argument to compiler intrinsic type trait '__is_base_of' But is there a way to get a more obvious error message stating that MyNestedDerived is an incomplete type or something? In retrospect the message is not that bad, but I'm hoping there's a better way. Thanks, --DD PS: Of course there's a reason the nested type is in a separate header, and it's an idiom repeated often in our code base. template <class E> class MyPtr { public: ... typedef typename E::nested_type nested_type; explicit MyPtr(const shared_ptr<nested_type>& n) : ... { BOOST_STATIC_ASSERT((is_base_of<MyNestedBase, nested_type>::value)); } ... };

2 1

PP: LOCAL_ITERATE: how to get rid of extra empty lines
by Hicham Mouline 12 Feb '10

12 Feb '10

Hello I get the following preprocessed output # 34 "my_header.hpp" # 1 "/usr/include/boost/preprocessor/iteration/detail/local.hpp" 1 3 4 # 34 "/usr/include/boost/preprocessor/iteration/detail/local.hpp" 3 4 //result of LOCAL_macro expansion //result of macro expansion //result of macro expansion //result of macro expansion How do I get rid of the blank lines in the middle? Regards,

2 1

Boost File Locks Do not work as advertised?
by Michael Dehmlow 12 Feb '10

12 Feb '10

I'm following the example at: http://www.boost.org/doc/libs/1_35_0/doc/html/interprocess/synchronization_… for locking and writing to a file, but when a flush is called either implicitly due to a full buffer, or an explicit flush no data is written and the fstream bad() call returns true. If I write a small enough amount of data and don't explicitly flush it works because I unlock the file then call close (where an implicit flush occurs). However, if a flush occurs at any time the file lock is locked no data is written and bad() return true. [START OF CODE] #include <fstream> #include <iostream> #include <boost/interprocess/sync/file_lock.hpp> #include <boost/interprocess/sync/scoped_lock.hpp> int main() { std::string tocFile("C:\\temp\\myfile.bin"); std::fstream file; file.open(tocFile.c_str(), std::ios::out | std::ios::binary | std::ios::trunc); if (!file.is_open() || file.bad()) { std::cout << "Open failed" << std::endl; exit(-1); } boost::interprocess::file_lock f_lock(tocFile.c_str()); { boost::interprocess::scoped_lock<boost::interprocess::file_lock> e_lock(f_lock); file.write(tocFile.c_str(),tocFile.length()); if (!file.is_open() || file.bad()) { std::cout << "Write failed" << std::endl; exit(-1); } file.flush(); if (!file.is_open() || file.bad()) { std::cout << "Flush failed" << std::endl; exit(-1); } } file.close(); return 0; } [END OF CODE] -- View this message in context: http://old.nabble.com/Boost-File-Locks-Do-not-work-as-advertised--tp2757007… Sent from the Boost - Users mailing list archive at Nabble.com.

1 0

PP: is macro expansion cached?
by Hicham Mouline 12 Feb '10

12 Feb '10

Hello, Say I define a macro #define MYMACRO(x,y) .. MYMACRO because of various reasons takes very long to expand (1mn) (uses PP_FOR, PP_WHILE, PP_SEQ_FOR_EACH .). If later in the translation unit, I have a "call" to MYMACRO MYMACRO(a,b) and then a couple of lines later MYMACRO(a,b) Will it be faster to define line 15: #define MYMACRO_ab MYMACRO(a,b) and then use line 25: MYMACRO_ab . line 35: MYMACRO_ab When does MYMACRO expansion happen? Is it at line 15 once, or at lines 25 and 35? Is the answer compiler-dependent? Regards,

1 0

PP: are there known incompatibilities with vs2008?
by Hicham Mouline 12 Feb '10

12 Feb '10

Hi, I have some PP macros that expand correctly under g++4.4 but when I came to try them on vs2008sp1, it generated errors. I will dig inside the code now, but if anyone is aware of msvc-specific problems... Regards,

1 0

abandoned named_mutex
by Carla Strembicke 12 Feb '10

12 Feb '10

Hello, My question is with regard to named_mutexes that are abandoned by a process that dies abnormally. Essentially I have shared memory( utilizing boost shared memory libraries ) and am incorporating boost named mutexes to limit access to one process at a time. There is no concept of a server/client or parent/child process....the process have equal opportunity. This is Microsoft centric code that I am required to support cross-platforms( Unix-like). Microsoft's mutexes have the concept of a mutex object being abandoned if the thread terminates without releasing. Is there any support in the boost mutex to determine if the mutex has been abandoned? Option: What I am considering is perhaps before the mutex is locked, it check a file that has been created with the mutex name and the pid of the process that has it locked. If the process does not exisit the file the mutex is unlocked and the file entry is removed and the new process id is entered. I am not sure if there is a chance of a race condition I would have to scope it out. FYI - I am using 1.41. is there any changes in 1.42 ( i will be checking ). Any other suggestions? Carla Strembicke Software Developer [cid:imagea03ff0.jpg@eeae924c.570740bf] SUBNET Solutions Inc. www.SUBNET.com<http://www.subnet.com/> Making Substations More Intelligent T: 403.270.8885 F: 403.270.9631 #100, 4639 Manhattan Road SE, Calgary, Alberta, Canada; T2G 4B3 Follow SUBNET: Twitter<http://twitter.com/subnetsolutions> | Facebook<http://www.facebook.com/subnetsolutions> | Linkedln<http://www.linkedin.com/groups?gid=2733031&trk=hb_side_g> Visit the all new SUBNET website at http://www.SUBNET.com<http://www.subnet.com/> CONFIDENTIAL INFORMATION NOTICE: The information contained in this e-mail is privileged, confidential and intended solely for the use of the addressee named above. If the reader of this e-mail is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this e-mail is strictly prohibited. If you received this in error, please contact the sender and destroy all copies of this e-mail. Thank you.

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Asio sharedptr heap corruption
by Lloyd 12 Feb '10

12 Feb '10

Hi, My program uses Asio to connect to a remote server. The connection class make use of sharedptr() as shown below... class Connect:public boost::enable_shared_from_this<Connect> { .... } All the async calls use sharedptr() And the object is created like this... boost::shared_ptr<Connect> Conn=boost::shared_ptr<Connect>(new Connect(IoService)); When the destructor of Conn is called the program crashes with the error... First-chance exception at 0x7c81eb33 in MYPROGRAM.exe: 0x000006D9: There are no more endpoints available from the endpoint mapper. HEAP[MYPROGRAM.exe]: Heap block at 00369710 modified at 00369918 past requested size of 200 Windows has triggered a breakpoint in MYPROGRAM.exe. What could be the reason? (If I avoid using sharedptr() and let it leak the memory, the program does not crash) Please give some hints to come out of this problem... Thanks a lot, Lloyd ______________________________________ Scanned and protected by Email scanner

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[type_traits] remove_pointer from member function types?
by Rutger ter Borg 12 Feb '10

12 Feb '10

Hello, although mentioned as a tip on the function_traits documentation page, it seems that remove_pointer doesn't work for member functions. It does work for normal function pointers. See attached an example. Is this the described/correct behaviour? If so, how do I easily transform a member function pointer type to a function type? Thanks, Rutger

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[proto] using proto with nvcc
by Eric Jourdanneau 12 Feb '10

12 Feb '10

Hi everybody, Nice to meet you :) I would like to test proto with nvcc, and when I compile the simple Hello world example of 1.42, I get the following error message: /usr/include/boost/proto/detail/decltype.hpp:314: error: invalid use of template-name ‘boost::type’ without an argument list. Of course it works with g++ I just don't know what to do, can somebody help me on that point? Thanks Eric

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