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VS 2008 Link1104 Error
by Mantas Matelis 04 Mar '09

04 Mar '09

Hello everyone, I've just built the boost libraries and I'm trying to get visual studio 2008 to properly recognize the libraries. The library that the linker is looking for is in C:\development\boost\build\boost\bin.v2\libs\filesystem\build\msvc-9.0\debug\link-static\threading-multi\libboost_filesystem-vc90-mt-gd-1_38.lib Even though I've added C:\development\boost\build\boost\bin.v2\libs to the extra libraries vc++ global setting. Error Message: 1>LINK : fatal error LNK1104: cannot open file 'libboost_filesystem-vc90-mt-gd-1_38.lib' If I add C:\development\boost\build\boost\bin.v2\libs\filesystem\build\msvc-9.0\debug\link-static\threading-multi to the project extra library setting though, the program compiles and links properly. On MSDN, http://msdn.microsoft.com/en-us/library/ts7eyw4s.aspx I've seen nothing that I think applies to me. So, what do I do?

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Re: [Boost-users] re alization of Last Recently Used cache with boost::multi_index
by Joaquin M Lopez Munoz 04 Mar '09

04 Mar '09

Hi Pavel, pavel5 wrote: > > I am trying to realize class for strings caching using boost::multi_index. > [...] > My class works without any problem, but i want to have template class, for > easily type of key and value selection. I modified my source: > [...] > After modification, gcc compiler prints for line: > > LRUCacheItems::nth_index<0>::type& hash_index=cache.get<0>(); > > many errors:[...] > Replace the offending line with typename LRUCacheItems::nth_index<0>::type& hash_index=cache.template get<0>(); Note the extra "typename" and also the "template" keyword between "cache." and "get<0>()". After templatizing your LRUCache, the expression happens to be in a so-called dependent context, and turns out you've got to help the compiler figure it out right (i.e. disambiguate from some other interpretations theoretically possible in the given context). Learn more about this issue at http://www.informit.com/guides/content.aspx?g=cplusplus&seqNum=388 Hope this helps, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo -- View this message in context: http://www.nabble.com/realization-of-Last-Recently-Used-cache-with-boost%3A… Sent from the Boost - Users mailing list archive at Nabble.com.

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boost::bind used with boost shared_ptr
by Kevin Ludwig 04 Mar '09

04 Mar '09

Hi, I've recently been making more use of boost::bind, and I coded the following, which I thought would work: class A { public: void reset () {} }; typedef std::map<int, boost::shared_ptr<A> > map_type; map_type m; std::for_each (m.begin(), m.end(), boost::bind(&A::reset, boost::bind(&map_type::value_type::second, _1))); but fails to compile. Next I tried this: std::for_each (m.begin(), m.end(), boost::bind(&A::reset, boost::bind(&boost::shared_ptr<A>::get, boost::bind(&map_type::value_type::second, _1)))); Which works and is fine (I guess). I just wonder why the first syntax is not supported? boost::shared_ptr is supposed to behave like a pointer (and here it seems that it does not). -- Kevin

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[enable_shared_from_this] My derivation of enable_shared_from_this wants to be templated
by Rob Currey 04 Mar '09

04 Mar '09

Here's some code based upon the example at : http://www.boost.org/doc/libs/1_38_0/libs/smart_ptr/enable_shared_from_this… class X { public: X() { }; }; template<class X> class Y: public enable_shared_from_this< Y<X> > { public: shared_ptr< Y<X> > f() { return shared_from_this(); } }; typedef Y<X> templatedY; int main() { shared_ptr<templatedY> p(new Y<X>); shared_ptr<templatedY> q = p->f(); assert(p == q); assert(!(p < q || q < p)); // p and q must share ownership } compiles with: $ gcc -o test -I/usr/local/include/boost-1_38 -lstdc++ -L/usr/local/lib -lboost_system-gcc41-mt test.cpp test.cpp: In member function âboost::shared_ptr<Y<X> > Y<X>::f()â: test.cpp:13: error: there are no arguments to âshared_from_thisâ that depend on a template parameter, so a declaration of âshared_from_thisâ must be available test.cpp:13: error: (if you use â-fpermissiveâ, G++ will accept your code, but allowing the use of an undeclared name is deprecated) Any resolution (other than the -fpermissive hack) TIA (my skilz with shared_ptr<> are somewhat lacking ...)

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[iterators ]bug?
by bismuth＠list.ru 04 Mar '09

04 Mar '09

There is probably a bug in boost::iterators library. boost::transform_iteartor degrade stl iterator_category. There is a code below, illustrating a problem(using VS2008 c++ compiler): --------------------- #include <stdio.h> #include <tchar.h> #include <vector> #include <boost/iterator/transform_iterator.hpp> #include <boost/static_assert.hpp> struct Tr1: std::unary_function<unsigned, unsigned> { unsigned operator()(unsigned a)const { return a; } }; int _tmain(int argc, _TCHAR* argv[]) { typedef std::vector<unsigned>::iterator some_ra_iterator_t; typedef boost::transform_iterator<Tr1, some_ra_iterator_t> tr_iter_t; BOOST_STATIC_ASSERT (( boost::is_convertible < std::iterator_traits<some_ra_iterator_t>::iterator_category, std::random_access_iterator_tag >::value )); BOOST_STATIC_ASSERT (( ! boost::is_convertible < std::iterator_traits<tr_iter_t>::iterator_category, std::random_access_iterator_tag >::value )); BOOST_STATIC_ASSERT (( boost::is_same < std::iterator_traits<tr_iter_t>::iterator_category, boost::detail::iterator_category_with_traversal < std::input_iterator_tag, //?! boost::random_access_traversal_tag > >::value )); return 0; } ---------------------

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[Graph] edge_range() with hash_setS as OutEdgeList in adjacency_list
by Ignacy Gawedzki 04 Mar '09

04 Mar '09

Hi, The following issue seems to have been discussed on this list a while ago, but nothing seems to have changed since and I was usable to find a proper answer so far. The edge_range() function uses std::equal_range() to extract a pair of iterators to the edges of interest. The problem lies in the fact that according to the SGI STL documentation, std::equal_range() requires the entries to be sorted (although I found no explicit mention of that in the standard). With hash_setS as OutEdgeList in adjacency_list, the entries are obviously not sorted, and std::equal_range() must not be used. While it's easy to write an edge_range_custom() function that would call the equal_range() method instead of the global function, nothing can be done to prevent the use of the original edge_range() by other library code like bidirectional_graph_helper_with_property::get_parallel_edge_sublist(). These overloaded methods are called from within remove_edge() which apparently causes trouble with hash_setS. I tried myself to overload the original edge_range(), for the case where hash_setS is used, but the solution is far from elegant and it feels like something be better done upstream. What do you think about that? Shouldn't the equal_range() method be used directly instead of std::equal_range() in any case? Thanks for your help. Ignacy -- /* This is not a comment */

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workaround ideas?
by Noah Roberts 04 Mar '09

04 Mar '09

This may be a little OT but as it applies to metaprogramming and ideas from the book I thought it the best place to ask. On pgs 191/2 of the MPL book (section 9.5) is a set of ideas meant to introduce the inherit_linearly metafunction. There are some things I want to do that suggested this was actually the better way to go for me. So I implemented something like the following: struct empty {}; template < typename FIELD, typename CDR > struct rec : CDR { typename FIELD::type value; rec() : value() {} }; template < typename VEC > struct generate_record //: boost::mpl::inherit_linearly< VEC, boost::mpl::inherit< rec<pl::_2>, pl::_1> >::type : boost::mpl::fold< VEC, empty, rec< pl::_2, pl::_1> > {}; I implemented a getter function like so: template < typename FIELD, typename CDR > typename FIELD::type & get(rec< FIELD, CDR > & r) { return r.value; } Now, minus the "field" concept this seems to be exactly the same basic thing. The field concept is something I need for what I'm working on that currently, for this test, just has a type in it. I create a "record" like so: typedef generate_record< boost::mpl::vector<field1, field2, field3> >::type test_record; When I print the type I end up with: "rec<field3,rec<field2,rec<field1,empty> > >" and in main attempt to access it: test_record tr; get<field1>(tr) = 3; This works fine in comeau and I'd expect it to work anywhere but MSVC++ 8 doesn't like it. It says that the FIELD param is ambiguous and could be field1 (what I specified in the call) or field3 (the first field on the inheritance tree). The error text is exactly: 1>e:\dev_workspace\experimental\record_generation\record_generation\main.cpp(78) : error C2782: 'FIELD::type &get(rec<FIELD,CDR> &)' : template parameter 'FIELD' is ambiguous 1> e:\dev_workspace\experimental\record_generation\record_generation\main.cpp(58) : see declaration of 'get' 1> could be 'field3' 1> or 'field1' I'm calling this a compiler bug at this point. I suspect many here have had to deal with this, since it's basic template usage, and might know a workaround. Or maybe you see something I've done incorrectly.

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boost logging or tracing library?
by Archie14 04 Mar '09

04 Mar '09

I was wandering - is there any support in boost for logging or tracing? If not, may be you can offer suggestions for the library that had been successfully used in production?

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uploaded Channel - a lib for (distributed) message passing and event dispatching to boost vault
by Yigong Liu 04 Mar '09

04 Mar '09

Hello there, I just upload a updated version of my Channel library to Vault under Main/"Distributed Computing". This version contains some update for Channel to work with the latest boost distributions and change to boost license, since there are several requests for me to update and upload to Vault. A brief description: Channel procides name space for distributed message passing and event dispatching. Its major components (message IDs, routing algorithms...) are configurable as template parameters. As a namespace shared by peer threads, channels support publish/subscribe scope control, message filtering, and translation.. Thanks Yigong

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[asio] sync receive_from with timeout
by Stephan Menzel 04 Mar '09

04 Mar '09

Is the subject Jehova enough for you? ;-) Great. Well, I haven't raised the subject so far but I'd certainly like to do so now. For years now I am not only a user but also an admirer of boost asio. Something that has always puzzled me however is, why a timeout functionality which is something very common and essential for sync IO just doesn't seem to be there. I think there are cases where syncronous IO is a better way to go and no async approach is sensible. In my case this is a collection of static functions that do UDP communication and therefore have to be sync because I just want them to be able to return and throw exceptions and be able to be called from anyone at any time. As always when I stumble across the asio/timeout problem I start googling around. When people raise the topic here they are usually pointed to an answer Chris Kohlhoff gave to someone asking that: http://lists.boost.org/Archives/boost/2007/04/120339.php ... which is good for tcp and works alright even though in my opinion it leaves the question why it has to be so compilicated to do something so basic. IMHO sync IO is all but pointless without a timeout. Anyway, I started to turn this into a UDP version and ended up with something very similar: inline void set_result(boost::optional<boost::system::error_code>* a, boost::system::error_code b) { a->reset(b); }; template <typename MutableBufferSequence> void udp_read_with_timeout(boost::asio::ip::udp::socket& sock, int tmo, boost::asio::ip::udp::endpoint &endpoint, const MutableBufferSequence& buffers) { boost::optional<boost::system::error_code> timer_result; boost::asio::deadline_timer timer(sock.io_service()); timer.expires_from_now(boost::posix_time::seconds(tmo)); timer.async_wait(boost::bind(set_result, &timer_result, _1)); boost::optional<boost::system::error_code> read_result; sock.async_receive_from(buffers, endpoint, 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(); } if (*read_result) throw boost::system::system_error(*read_result); }; So now I started to go ahead with that but I had to notice two things. First, the performance impact is massive to a point that forces me to reconsider. Second, when I use that in a multithreaded environment the whole thing seems to block in some threads randomly. I have made test program where I have multiple threads using that method, just sending an UDP request to a server and waiting for an answer using this function. In one thread everything is slow but continously running. In more than one thread it blocks for up to 5 or 6 seconds every few (10-20) runs for no visible reason. In my scenario all those threads share a socket protected by a mutex so if one of them blocks all will be halted. So I come to think this is not a good way to handle the problem. Does anyone have some thoughts on that? May this be a bug in asio (1.38) or perhaps in my function? Or is there a better way to do sync UDP IO with a timeout functionality? Cheers... Stephan

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BGL: is it safe to store vertex_descriptors?
by Cory Riddell 04 Mar '09

04 Mar '09

Is it safe to store vertex descriptors? Does adding a new vertex / edge ever renumber existing vertices? (I know removing does this) Say I have a class to represent a state from the USA. class State { ... }; and I have a bunch of instances: State california, oregon, nevada, hawaii, ...; I want a graph with a vertex for each state and an edge for each border: typedef adjacency_list<vecS, vecS, bidirectionalS> Graph; Graph graph; I build my graph like this: Graph::vertex_descriptor v_california = add_vertex(graph); Graph::vertex_descriptor v_oregon = add_vertex(graph); Graph::vertex_descriptor v_nevada = add_vertex(graph); Graph::vertex_descriptor v_hawaii = add_vertex(graph); ... add_edge(v_california, v_oregon, graph); add_edge(v_california, v_nevada, graph); add_edge(v_nevada, v_oregon, graph); ... To associate each State instance with a vertex, I make a map: map<State, Graph::vertex_descriptor> state_to_vtx_map; state_to_vtx_map[california] = v_california; state_to_vtx_map[oregon ] = v_oregon ; state_to_vtx_map[nevada ] = v_nevada ; state_to_vtx_map[hawaii ] = v_hawaii ; Now I can find all the states Nevada has a border with by doing this: Graph::vertex_descriptor v = state_to_vtx_map[nevada]; tie(begin, end) = out_edges(v, g); (please assume that I didn't store v_nevada from above) Is my state_to_vtx_map safe? Since a delete can totally renumber everything, I don't think it is safe. What's the correct way of associating a vertex with a State instance? Thanks, Cory

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Compile error with QNX compiler
by Kito Berg-Taylor 04 Mar '09

04 Mar '09

I am using the QNX 6.4.0 development environment (based on gcc 4.2.4) to compile boost_thread-static-mt from boost 1.38, and I am getting the following errors. I was wondering if someone could tell me whether this is a compiler problem or a problem with boost. I should mention that I don't get the same error with gcc4 or mingw-gcc4. I have the latest boost from svn, but I'm unable to test that on this compiler because I'm still sorting through other build problems there. cd /path_to_build/build.qnx/Core/LIB_MISSIONPLANNER && /path_to_qnx/qnx640/host/linux/x86/usr/bin/qcc -Vgcc_ntox86 -lang-c++ -w1 -I/path_to_build/Externals/boost_1_38_0 -o CMakeFiles/MISSIONPLANNER.dir/CommTCP.cpp.obj -c /path_to_build/Core/LIB_MISSIONPLANNER/CommTCP.cpp In file included from /path_to_build/Externals/boost_1_38_0/boost/serialization/extended_type_info_typeid.hpp:33, from /path_to_build/Externals/boost_1_38_0/boost/archive/detail/iserializer.hpp:64, from /path_to_build/Externals/boost_1_38_0/boost/archive/detail/interface_iarchive.hpp:23, from /path_to_build/Externals/boost_1_38_0/boost/archive/detail/common_iarchive.hpp:20, from /path_to_build/Externals/boost_1_38_0/boost/archive/basic_text_iarchive.hpp:31, from /path_to_build/Externals/boost_1_38_0/boost/archive/text_iarchive.hpp:23, from /path_to_build/Core/LIB_MISSIONPLANNER/Connection.hpp:19, from /path_to_build/Core/LIB_MISSIONPLANNER/CommTCP.hpp:6, from /path_to_build/Core/LIB_MISSIONPLANNER/CommTCP.cpp:1: /path_to_build/Externals/boost_1_38_0/boost/serialization/factory.hpp:37: error: template declaration of 'T* boost::serialization::factory' /path_to_build/Externals/boost_1_38_0/boost/serialization/factory.hpp:37: error: 'va_list' is not a member of 'std' In file included from /path_to_build/Externals/boost_1_38_0/boost/archive/detail/iserializer.hpp:64, from /path_to_build/Externals/boost_1_38_0/boost/archive/detail/interface_iarchive.hpp:23, from /path_to_build/Externals/boost_1_38_0/boost/archive/detail/common_iarchive.hpp:20, from /path_to_build/Externals/boost_1_38_0/boost/archive/basic_text_iarchive.hpp:31, from /path_to_build/Externals/boost_1_38_0/boost/archive/text_iarchive.hpp:23, from /path_to_build/Core/LIB_MISSIONPLANNER/Connection.hpp:19, from /path_to_build/Core/LIB_MISSIONPLANNER/CommTCP.hpp:6, from /path_to_build/Core/LIB_MISSIONPLANNER/CommTCP.cpp:1: /path_to_build/Externals/boost_1_38_0/boost/serialization/extended_type_info_typeid.hpp: In member function 'void* boost::serialization::extended_type_info_typeid<T>::construct(unsigned int, ...) const': /path_to_build/Externals/boost_1_38_0/boost/serialization/extended_type_info_typeid.hpp:96: error: 'va_list' is not a member of 'std' /path_to_build/Externals/boost_1_38_0/boost/serialization/extended_type_info_typeid.hpp:96: error: expected `;' before 'ap' /path_to_build/Externals/boost_1_38_0/boost/serialization/extended_type_info_typeid.hpp:97: error: 'ap' was not declared in this scope /path_to_build/Externals/boost_1_38_0/boost/serialization/extended_type_info_typeid.hpp:100: error: 'factory' was not declared in this scope /path_to_build/Externals/boost_1_38_0/boost/serialization/extended_type_info_typeid.hpp:100: error: expected primary-expression before ',' token /path_to_build/Externals/boost_1_38_0/boost/serialization/extended_type_info_typeid.hpp:102: error: expected primary-expression before ',' token /path_to_build/Externals/boost_1_38_0/boost/serialization/extended_type_info_typeid.hpp:104: error: expected primary-expression before ',' token /path_to_build/Externals/boost_1_38_0/boost/serialization/extended_type_info_typeid.hpp:106: error: expected primary-expression before ',' token /path_to_build/Externals/boost_1_38_0/boost/serialization/extended_type_info_typeid.hpp:108: error: expected primary-expression before ',' token cc: /path_to_qnx/qnx640/host/linux/x86/usr/lib/gcc/i386-pc-nto-qnx6.4.0/4.2.4/cc1plus error 1 compiler identifies itself as gcc 4.2.4: kito@Vostok:~$ ntox86-g++ --version ntox86-g++ (GCC) 4.2.4

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I Can't Compile The QuickStart Example
by Fagner Patricio 04 Mar '09

04 Mar '09

Hello!! I'm new in the list, I from Brazil, so, sorry about my english :) I have a problem, I am try to compile the QuickStart Python Example on ubuntu 8.04 using the 1.34 library version, this is the result: fagner@fagner-desktop:/usr/share/doc/libboost-doc/examples/libs/python/example/quickstart$ sudo bjam toolset=gcc --verbose-teste test --debug-configuration notice: found boost-build.jam at /usr/share/doc/libboost-doc/examples/libs/python/example/quickstart/boost-build.jam notice: loading Boost.Build from /usr/share/boost-build notice: loading site-config.jam from /etc/site-config.jam notice: loading user-config.jam from /usr/share/boost-build/user-config.jam notice: using gcc libraries :: <toolset>gcc-4.2 :: /usr/bin /usr/lib /usr/lib32 /usr/lib64 notice: using gcc archiver :: <toolset>gcc-4.2 :: /usr/bin/ar warning: toolset gcc initialization: can't find tool windres warning: initialized from notice: using rc compiler :: <toolset>gcc-4.2 :: /usr/bin/as error: Unable to find file or target named error: '/boost/python//boost_python' error: referred from project at error: '.' fagner@fagner-desktop:/usr/share/doc/libboost-doc/examples/libs/python/example/quickstart$ What's my mistake? -- Fagner Patrício João Pessoa - PB Brasil

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Re: [Boost-users] Tag dispatching
by Hicham Mouline 04 Mar '09

04 Mar '09

> ----- Original Message ----- > From: "Ovanes Markarian" <om_boost(a)keywallet.com> > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Tag dispatching > Date: Wed, 4 Mar 2009 14:12:09 +0100 > > Hicham, > > please see my comments below: > > On Wed, Mar 4, 2009 at 1:54 PM, Hicham Mouline <hicham(a)mouline.org> wrote: > > > Hello, > > > > I have a question about tag dispatching (for e.g. the std::advance() > > function in the std lib, as described for instance in > > http://www.boost.org/community/generic_programming.html#tag_dispatching) > > > > 1. The call to > > detail::advance_dispatch(i, n, category); > > I don't understand. category is a type not an object, it should be > > category(), right? > > > typename *iterator_traits<InputIterator>::iterator_category* category; > detail::advance_dispatch(i, n, *category*); > > here is no typedef used, so category is an instance of iterator_category. In > the template context you have to prefix it with typename keyword. Using: > > typename *iterator_traits<InputIterator>::iterator_category* category(); > > declares a function, which returns iterator_category, but does not create a > class instance. ah yes of course. I misread the typename as typedef, thanks. category is an auto instance. Can it be also written also as a temporary etail::advance_dispatch(i, n, iterator_traits<InputIterator>::iterator_category() ); > > 2. If I am correct, > > the tags are empty structs which I assume allows modern compilers > > (g++4, msvc8/9, intel) to optimize away the creation of that category > > object ? > > This is compiler dependent. ISO C++ 03 standard requires an instance of an > empty type to be at least 1 byte big. To check if that happens read the > documentation to the corresponding compiler. > > 3. If i am still correct, I have a tag which has no members except 1 static > > function that returns void. > > Would that optimization still apply? > > Applies the same as in 2. Whether the compiler prints sizeof(myType) as 1byte or something else has no bearing on whether it doesn't create an instance at runtime, right? need to read their docs (though it's quite hard to see where for g++ for e.g.) thanks very much, regards,

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[BGL] Structure for BFSvisitor is in header file (visitor & property confusion)??
by Trevor Bain 04 Mar '09

04 Mar '09

I have my graph working with BFS, and a BFSvisitor. But, I don't want the BFSvisitor to be in the header file. Since, it is, I have to declare properties I want to use in the visitor, but then I have to pass them in in the constructor for the class that contains the graph and the visitor structure ... Here is my visitor (in .hpp): /* ... other code */ /*! Structure for creating BFSvisitor * * The property maps are being assigned in the constructor for the * Ann object - I don't know how inneficient of a method that is. * i.e. if I should be using references. */ struct propagate_node : public boost::base_visitor<propagate_node> { // getting the dynamically created VoltageMap boost::property_map<Digraph, vertex_voltage_t>::type voltmap; boost::property_map<Digraph, vertex_input_t>::type inputmap; boost::property_map<Digraph, vertex_output_t>::type outputmap; typedef boost::on_discover_vertex event_filter; /* * This is a functor For Breadth First Visit. */ template <class Vertex, class Digraph> void operator()(Vertex v, Digraph& G) { boost::graph_traits<Digraph>::out_edge_iterator ed; // getting the dynamically created VoltageMap && InputMap double volt = boost::get(voltmap, v); bool in = boost::get(inputmap, v); bool out = boost::get(outputmap, v); // mapping sigmoid (don't apply sigmoid to input/output layers) if (in == false && out == false) { // justify this sigmoid ??? volt = 1/(1+pow(MYEXP,-volt)); boost::put(voltmap, v, volt); } if (v != *vertices(G).first) { for ( ed = boost::out_edges(v, G).first; ed != boost::out_edges(v, G).second; ed++) { boost::put( voltmap, target(*ed, G), get(voltmap,target(*ed,G))+get(boost::edge_weight,G,*ed)* volt); } } } } prop; /* ... other code */ So in the c'tor I have to do (in .cpp): /* ... in initializer list */ VoltageMap(get(vertex_voltage_t(), net)), InputMap(get(vertex_input_t(), net)), OutputMap(get(vertex_output_t(), net)), /* ... other code */ prop.voltmap = VoltageMap; prop.inputmap = InputMap; prop.outputmap = OutputMap; to pass my properties from the graph to the visitor ... there has to be a better way to do this. How can I put the visitor definition into the .cpp, and only declare it in the .hpp?

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Tag dispatching
by Hicham Mouline 04 Mar '09

04 Mar '09

Hello, I have a question about tag dispatching (for e.g. the std::advance() function in the std lib, as described for instance in http://www.boost.org/community/generic_programming.html#tag_dispatching) 1. The call to detail::advance_dispatch(i, n, category); I don't understand. category is a type not an object, it should be category(), right? 2. If I am correct, the tags are empty structs which I assume allows modern compilers (g++4, msvc8/9, intel) to optimize away the creation of that category object ? 3. If i am still correct, I have a tag which has no members except 1 static function that returns void. Would that optimization still apply? regards,

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Unhandled exception at 0x781451eb in ********.exe: 0xC0000005: Access violation reading location 0x0129ffff.
by ddribes 04 Mar '09

04 Mar '09

Dear Boost Users, I am new with Boost and I am facing a Unhandled exception. The program I am triying to use is working fine in release mode but crashing in debug mode. Maybe compiler options are not set correctly. Is there something specific for release and/or debug version ? Something to diseable exceptions ? I am working with VStudio 8. I've set the same compiler options for both but I still have the same error. Any ideas ? Thanks, -- View this message in context: http://www.nabble.com/Unhandled-exception-at-0x781451eb-in-********.exe%3A-… Sent from the Boost - Users mailing list archive at Nabble.com.

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[boost-users][bind] binding std::for_each
by Igor R 04 Mar '09

04 Mar '09

Hello, I'd like to bind std::for_each with some other functor created on the fly, like this: struct A { void f(int, int); }; vector<shared_ptr<A> > vec; void f(function<void(void)>); // I want to call f() with a functor that would call A::f for every element in vec f(bind(&for_each, vec.begin(), vec.end(), bind(&A::f, _1, 1))); // doesn't compile f(bind(&for_each, vec.begin(), vec.end(), protect(bind(&A::f, _1, 1)))); // also doesn't compile Thank you.

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1.38 build cmake error
by Randy Heiland 04 Mar '09

04 Mar '09

Hello, Just downloaded 1.38 and trying to use the cmake build. I get my CMakeCache.txt setup the way I want, then: cmake . make sudo make install ... -- Installing: /usr/local/include//boost/xpressive/xpressive_static.hpp -- Installing: /usr/local/include//boost/xpressive/xpressive_typeof.hpp CMake Error at libs/preprocessor/cmake_install.cmake:31 (FILE): file INSTALL cannot find file "/Users/heiland/dev/boost_1_38_0/libs/preprocessor/include/boost" to install. Call Stack (most recent call first): libs/cmake_install.cmake:32 (INCLUDE) cmake_install.cmake:37 (INCLUDE) and sure enough, there's no .../preprocessor/include... heiland@Macintosh:~/dev/boost-build$ ls /Users/heiland/dev/ boost_1_38_0/libs/preprocessor CMakeLists.txt doc/ index.html module.cmake test/ Suggestions? OSX 10.5.6 cmake version 2.6-patch 2 thanks, Randy

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Including a source library with Boost.Build
by Z. S. O. 04 Mar '09

04 Mar '09

I have a source library I'd like to include in my Boost.Build project. The library consists of an assortment of header and cpp files in a folder next to the main cpp file and jamfile. It doesn't require any elaborate precompilation, so it should work just by #including the appropriate header files in the main cpp file (i.e., #include "FolderName/FileName.h"). My question is, do I need to do anything other than that to make this work? I'm getting an "undefined symbols" error, so clearly Boost.Build not finding something correctly.

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boost.serialization, asio and iostreams...
by Hajo Kirchhoff 04 Mar '09

04 Mar '09

(forwarded from asio.user as serialization questions might be more appropriate here) Hi all, I plan to use serialization and asio together to exchange 'command objects' between two applications. Basically marshalling an object and sending it to a remote application. There is a simple asio example using serialization, but there are two issues I'd like to improve. [1] I am concerned about performance. The example constructs and destructs an archive for every single object and uses stringstream, which creates and copies a string object. Wouldn't using asio::tcp::iostreams give better performance? and [2]: I would like to utilize the boost.serialize class registration system to allow peer programmers to create new objects. In the example I would need to send a 'type' and the size manually in a 'header' before I serialize and send the actual object. That would require a system wide enumeration or other 'type' mechanism. My idea is to require all objects be derived from a common polymorphic base and then serialize a pointer to the object. The archive would serialize the entire object and also send type information with it, so the receiver could reconstruct the object simply by receiving a pointer. class basic_command; class my_command:public basic_command; On the senders side: my_command dosomething; archive << &dosomething; On the receiver side: basic_command *next_command; archive >> next_command; next_command->execute(); This would have the benefit that new commands could simply be created by deriving from basic_command. It might also have performance consequences and I have one specific question: For this in order to work I would need to disable tracking for 'my_command'. Otherwise only the very first instance of archive << &dosomething would actually send something. Question: Can I 'reset' the binary archive such that the tracking information is reset, but not the type information? Or can I temporarily disable tracking for a class or for the next save/load operation? I don't want to globally disable tracking for my_command, because I cannot rule out that someone might actually want tracking for their object in a different archive (such as saving settings to disk). I'd love to hear from you and any comments are welcome. Has anyone already done this? What are your experiences? Regards Hajo

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[Units] implicit conversion of quantities
by Christopher Bruns 03 Mar '09

03 Mar '09

Kudos on the excellent implementation of the Boost.Units library. I am also very grateful for the extremely timely help I have got in the past from the principal authors Matthias Schabel and Steven Watanabe. Is there any way to force implicit conversion of Angstrom quantities to nanometer quantities in assignment and method calls using Boost.Units? I would appreciate any suggestions on how to get the final three method calls in the attached program to compile. I suppose I could overload the showBondLength() method in this example to take both types. I think I would prefer implicit conversion, if that is possible. I am using boost from subversion revision 51579, from March 3, 2009. --Chris Bruns /* =========== begin test program ========== */ #include <boost/units/systems/si.hpp> #include <boost/units/base_units/metric/angstrom.hpp> #include <iostream> namespace boost { namespace units { typedef metric::angstrom_base_unit::unit_type angstrom_unit; BOOST_UNITS_STATIC_CONSTANT(angstrom, angstrom_unit); typedef scaled_base_unit< si::meter_base_unit, scale<10, static_rational<-9> > > nanometer_base_unit; typedef nanometer_base_unit::unit_type nanometer_unit; BOOST_UNITS_STATIC_CONSTANT(nanometer, nanometer_unit); } } // namespace boost::units // No permutation of BOOST_UNITS_DEFAULT_CONVERSION macro has // *ever* had a measurable effect in my hands BOOST_UNITS_DEFAULT_CONVERSION( boost::units::angstrom_unit, boost::units::nanometer_unit ); using namespace boost::units; using namespace std; ostream& showBondLength( quantity<nanometer_unit> len, std::ostream& os) { os << len << endl; return os; } int main() { // These constructors all work; conversions are automatic quantity<nanometer_unit> len1( 0.152 * nanometer ); quantity<angstrom_unit> len2( 1.52 * angstrom ); quantity<nanometer_unit> len3( 1.52 * angstrom ); quantity<angstrom_unit> len4( 0.152 * nanometer ); // These three calls are OK, nanometer quantity is passed showBondLength(0.152 * nanometer, cout); showBondLength(len1, cout); showBondLength(len3, cout); // Explicit casts to nanometer are OK for angstrom quantities... // but yuck showBondLength( (quantity<nanometer_unit>) (1.52 * angstrom), cout ); showBondLength( (quantity<nanometer_unit>) len2, cout ); showBondLength( (quantity<nanometer_unit>) len4, cout ); // These all fail to compile. Users want implicit conversion here showBondLength(1.52 * angstrom, cout); showBondLength(len2, cout); showBondLength(len4, cout); } /* =========== end test program =========== */

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[regex] Context-sensitive replacement of text using regex_replace
by KEN RODE 03 Mar '09

03 Mar '09

I've been struggling with a problem with using regex_replace this afternoon, and I would appreciate some pointers on properly using the regex package. I've got a file that is similar to a CSS style sheet (it's actually a Qt style sheet) that contains color entries that similar to: rgb( 200, 255, 200 ). I've already successfully written some code that finds these patterns and replaced them with statically determined text, just to verify that I was able to locate them all properly. I have an application in which the color scheme of the user interface (specified in the style sheet) has to change between a daytime and nighttime color scheme. The nighttime color scheme is derived from the daytime color scheme by reducing the luminance of the colors. I'd like to generate the nighttime color scheme from the daytime scheme by extracting the components of the color and applying a calculation to them, then replacing the original text with the new text. The examples on the Boost site for regex_replace all demonstrate replacement with static text. I suspect that I have to do some sort of combination using regex_replace, regex_iterator, and match_results, but I can't quite wrap my head around the documentation for these classes to see how they interoperate. I would appreciate some pointers as to how to proceed.

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Re: [Boost-users] New and updated serialization performance results
by Brian Wood 03 Mar '09

03 Mar '09

Robert Ramey writes: >Given your interest in this topic, you might want to take a look at > >boost/libs/serialization/performance. > >included with the boost 1.38 package. > >There is a Jamfile.v2 in that directory and everything is set >up just the way boost testing is. The only difference is >that, using the GCC compiler, a function by function >time table is generated which pinpoints where time >is being consumed. This would help answer such questions >as "what if I replaced std::string with something else". > >I only included a couple of performance tests to >demonstrate the system. I havn't had time to make >a more complete set of tests. Ideally, I would like >to see your tests included for comparison. The source code on webEbenezer.net is not copyright protected, so anyone interested in doing what you suggest is welcome to do so. I doubt I'm going to be able to do that anytime soon. > >My question has always been that since serialization >(in at least the simpler cases) just boils down >to writing out the data, whether the code is >generated by one template or another shouldn't >make a big difference. That is, at the end of the >day, the sequence of operations should be pretty >much the same whether one is hand rolling the code >or whether it is generated by templates. > It may have something to do with your use of iostreams. I don't think that accounts for all of the difference, but my guess is it's a big part of it. In my opinion using insert with a hint is an easy way to improve the performance of the Boost Serialization library when loading instances of (multi)set, multi(map) and rb_tree. To my knowledge the only draw back with that is if someone is serializing from say a list<int> to a set<int> and the data in the list is not ordered. In that case using a hint would impede performance. Since that situation does not come up a lot, I think using hinted inserts as a default makes sense. We plan to change (this month) from a default of "regular" insert functions to hinted inserts for the types mentioned here. Currently we have a @hi option to turn on hinted inserts. That will change to @nohi to turn them off and could be used if data from a non-ordered list<int> is being sent to a set<int>. Brian Wood Ebenezer Enterprises www.webEbenezer.net "Then Samuel took a rock and set it up between Mizpah and Shen. He named it Ebenezer [Rock of Help] and said, 'Until now the LORD has helped us.'"

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[Review] RangeEx review extended to the 10th of March
by Thorsten Ottosen 03 Mar '09

03 Mar '09

Dear Developers and Users, The review period is extended one week. If you find this library interesting, please submit a review. The discussion so far may be found here: http://archives.free.net.ph/message/20090220.122836.73bdbd04.en.html Below you will find a description of the library and information on how to write a review. best regards Thorsten, review manager What is it? +++++++++++ The library provide two very useful extensions to the range library 1. Range-based algorithms. E.g. boost::sort( rng ); which is a convenient wrapper of instead of std::sort( boost::begin(rng), boost::end(rng) ); But the new interface also allows for more expressive code because (on the fly) composition of algorithms suddenly is possible. 2. Range adaptors. E.g. std::vector<int> vec = ...; boost::copy( vec | boost::adaptors::reversed, std::ostream_iterator<int>( std::cout ) ); where the expression "vec | boost::adaptors::reversed" wraps the iterators of the range on the left in reverse iterators. The library provides a wide range (no pun intended) of Range adaptors, and they are a powerful way to create ranges on the fly and pass them to algorithms. Getting the library +++++++++++++++++++ The library may be downloaded from http://www.cs.aau.dk/~nesotto/boost/range_ex.zip or from the Boost vault under "Algorithms". The docs may be browsed online here http://www.cs.aau.dk/~nesotto/boost/libs/range/ Please note that the documentation is integrated with the current Range ilbrary. Therefore the relevant sections for the review is http://www.cs.aau.dk/~nesotto/boost/libs/range/doc/adaptors.html and http://www.cs.aau.dk/~nesotto/boost/libs/range/doc/algorithms.html The code may be browsed here: http://www.cs.aau.dk/~nesotto/boost/boost/range/ Notice the library is header only (exception: the adaptor tokenized() depends on Boost.Regex). Writing a review ++++++++++++++++ If you feel this is an interesting library, then please submit your review to the developer list (preferably), or to the review manager. Here are some questions you might want to answer in your review: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick - reading? In-depth study? - Are you knowledgeable about the problem domain? And finally, every review should answer this question: - Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. Special considerations ++++++++++++++++++++++ Various RangeEx like libraries have been implemented in the past. You might want to compare with those libraries when you form your oppinion: 1. John Torjo's range lib http://rangelib.synesis.com.au/libs/boost-rangelib-20040913.zip http://torjo.com/rangelib/index.html 2. Adobe's ASL libraries include range-based algorithms: http://stlab.adobe.com/group__algorithm.html I'm looking forward to your review. best regards Thorsten, Review Manager

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