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

[phoenix] Staus of phoenix
by Edward Diener 18 Dec '09

18 Dec '09

Is phoenix an official Boost library ? I do not see it listed among the Boost libraries for 1.40 or 1.41 although I do see it in the pdf documentation for Boost libraries put together by John Maddock.

6 11

Template type questions
by Glenn Macgregor 18 Dec '09

18 Dec '09

Hi All, I am using the boost::variant with the binary visitor algorithm, apply_visitor. struct UnknownValue {}; typedef boost::variant<UnknownValue, long, unsigned long, double, string, char> ValueType; I am using apply_visitor for binary visitation as below: class AddVisitor : public boost::static_visitor<> { public: template <typename T> void operator()(const T &lhs, const T &rhs) { T val = lhs + rhs; } template <typename T, typename R> void operator()(const T &lhs, const R &rhs) { // do nothing...different types } template <typename T> void operator()(const T &lhs, const UnknownValue &rhs) { // do nothing...we have an unknown value } template <typename T> void operator()(const UnknownValue &lhs, const T &rhs) { // do nothing...we have an unknown value } void operator()(const UnknownValue &lhs, const UnknownValue &rhs) { // do nothing...we have an unknown value } }; The above is not complete because I can do addition if the types are long and unsigned long or long and double or long and char...etc. What is the preferred method for doing this? Do I need to create an overridden operator() for every argument combination that is valid or can I get the argument types in the function? Thanks Glenn

2 1

[spirit] help parsing data file into a struct
by Kenny Riddile 18 Dec '09

18 Dec '09

This is my first time using Spirit and I haven't messed with writing EBNF grammars since college, so I'm sorry if this is a simple question. Lets say I have a structure that looks like this: struct Foo { std::string someString; std::string someOtherString; std::vector<std::string> stringList; }; BOOST_FUSION_ADAPT_STRUCT( Foo, (std::string, someString) (std::string, someOtherString) (std::vector<std::string>, stringList) ) and I have a data file that looks like this: SOMESTRING hello SOMEOTHERSTRING goodbye STRINGLIST { string1 string2 string3 } I have written the following grammar to parse such a file into the struct above: template< typename Iterator > struct FooDefinition : spirit::qi::grammar< Iterator, Foo() > { FooDefinition() : FooDefinition::base_type( start ) { using namespace spirit::qi; start = someString >> +space >> someOtherString >> +space >> stringList; someString = lit("SOMESTRING") >> +space >> value; someOtherString = lit("SOMEOTHERSTRING") >> +space >> value; stringList = lit("STRINGLIST") >> *space >> lit('{') >> *space >> (value % +space) >> *space >> lit('}'); value = +char_("a-zA-Z_0-9"); space = lit(' ') | lit('\n') | lit('\t'); } spirit::qi::rule< Iterator, Foo() > start; spirit::qi::rule< Iterator, std::string() > someString; spirit::qi::rule< Iterator, std::string() > someOtherString; spirit::qi::rule< Iterator, std::vector<std::string>() > stringList; spirit::qi::rule< Iterator, std::string() > value; spirit::qi::rule< Iterator > space; }; However, I would like the order of the three statements in the data file (SOMESTRING, SOMEOTHERSTRING, and STRINGLIST) to be irrelevant. Right now, they must be in the order shown above for parsing to succeed. How would I go about accomplishing this with Spirit?

2 2

inheritance, input streams, parsing and arithmetic range of values
by Hicham Mouline 18 Dec '09

18 Dec '09

Hello I would like your opinions about design/implementation choices for an application I am writing. I have a list of models. Each model is a kind of black box that takes inputs and produces outputs. All the inputs are either of boolean or arithmetic type. (bool, int, double) A subset of inputs is valid for all models. Then different models have different number of other inputs. For a fixed set of inputs, the model produces 1 fixed set of outputs. It is desired to vary the values of some/all (at least 1) of the inputs and get different outputs sets, and then plot that. The inputs are specified in files (considered as std::istream in the code), the syntax is trivial: input1 = value1 ... inputn = valuen When it is desired to vary the input values, the syntax changes a little: input1 = value1 input2 = value21..value22 ... inputn = valuen in this example only input2 changes, and the idea is to plot one of the outputs over the differnt values of input2. Each derived model has a concrete struct input_i_s { ... } that holds its inputs. class model { public: virtual fixed_inputs get_fixed_inputs( std::istream& ) const =0; /// throws if syntax error, or not all inputs are specified, or some values are not valid virtual variable_inputs get_variable_inputs( std::istream& ) const =0; /// the same, allows the '..' notation though for ranges, at least of the inputs need to be a range }; // fixed_inputs is a pointer to a base class of all inputs for all models 1 implementation pseud-code looks like: fixed_inputs model_i::get_fixed_inputs( std::istream& input) const { size_t inputs = 7; std::string buffer; while (inputs>0 && input.good()) { input >> buffer; if ( buffer.substr(0, sizeof("input1")) == "input1=") { std::istringstream is(buffer.substr(0, sizeof("input1"))); is >> .... ; /// pseudo-code : stores the value into a field in fixed_input1s // if wrong value, throws an exception } else if ... ... } return fixed_inputs( new input_i_s() ); // pseudo-code, say for model number i } I would like then to write the implementation for the syntax which accepts ranges as well. (the get_variable_inputs function) I hope to be able to factorize code between the 2 implementations. 1. boost::program_options can read options from input streams. Given that I am interested in ranges as well, is it adviced to go down that road? 2. Is there a library that helps to generate the expected format of the input stream from the struct of inputs for each model, and reads the stream automatically. Can it do range values as well? 3. is it possible then to factorize code between the get_fixed_inputs and get_variable_inputs? Regards,

1 0

(no subject)
by Michael Fowler 18 Dec '09

18 Dec '09

Hello. I tried using the code provided here: http://www.boost.org/doc/libs/1_41_0/doc/html/boost_asio/example/echo/block… to echo text back to a client but i haven't been successful. It seems to hang at size_t length = sock->read_some(boost::asio::buffer(data), error); what is wrong? Thanks

1 0

Function template specialization
by Surya Kiran Gullapalli 18 Dec '09

18 Dec '09

Hello all, The following question may not be related to boost, but if a solution can be found with boost or otherwise would be great. I've a base class with a function template. I derive from base class and try to have a specialization for the function template in derived class I did something like this. ////////////////////////// Header file begin ////////////////////////// class Base { .. template <typename T> fun (T arg) { ... } }; class Derived : public Base { ... } ; template <> Derived::fun(int arg); ///////////////////////// Header file end //////////////////////////// and in .cpp file I've provided implementation for the template specialization. This works fine with MSVC 8.0 and g++ complains about lack of function declaration fun in Derived class. I do not know which compiler is behaving correctly. Any help in this is greatly appreciated. Thanks in advance, Surya

2 1

boost lambda and bind
by Conoscenza Silente 18 Dec '09

18 Dec '09

Hi All I am trying to use boost lambda for looping over a std::map to get each element and pass those to a class function using lambda functions. I don't know why but the binding inside my std::for_each is not compiling and I have 2 errors pointing to the line where boost::assign is used. 'invalid initialization of reference of type int&' 'invalid initialization of reference of type std::basic_string<>&' Do you know how to fix this and why it is happening Thank you very much Regards CS //Boost //#include<boost/assign/std/map.hpp> #include<boost/assign/list_of.hpp> #include<boost/lambda/lambda.hpp> #include<boost/lambda/core.hpp> #include<boost/lambda/bind.hpp> #include<boost/lambda/construct.hpp> class CInnerClassHandler{ public: void DoSomething( int aIntValue, const std::string& aStringValue ){ std::cout << "INT:" << aIntValue << "STRING:" << aStringValue << std::endl; // here we just trace } }; void map_lambda_test(){ typedef std::pair< int, std::string > this_pair; std::map< int, std::string > dictionary = boost::assign::map_list_of(3,"A")(4,"B")(5,"C"); // Errors points to // this line of code CInnerClassHandler obj; std::for_each( dictionary.begin(), dictionary.end(), boost::lambda::bind( &CInnerClassHandler::DoSomething, &obj, boost::lambda::bind(&this_pair::first, boost::lambda::_1), boost::lambda::bind(&this_pair::second,boost::lambda::_1)) ); }

2 2

Build boost for i686 (instead of i386)
by Christoph Duelli 18 Dec '09

18 Dec '09

What do I have to pass to bjam to build Boost with i686 instead of the default i386 as cpu? (I am using Linux, with gcc 4.3.2) So far I am calling ./bjam architecture=x86 address-model=32 Best regards Christoph

2 1

Re: [Boost-users] [Boost.Test] valgrind complains about invalid reads
by Scott Banachowski 18 Dec '09

18 Dec '09

Thanks for the reply Gennadiy, see inline for comments: --- On Wed, 12/16/09, Gennadiy Rozental <rogeeff(a)gmail.com> wrote: > From: Gennadiy Rozental <rogeeff(a)gmail.com> > Subject: Re: [Boost-users] [Boost.Test] valgrind complains about invalid reads > To: boost-users(a)lists.boost.org > Date: Wednesday, December 16, 2009, 9:32 PM > Scott Banachowski <sbanacho > <at> yahoo.com> writes: > > > > > > > I agree with Peter here, the destructor for test_unit > should be virtual. > > 'Should' is a strong statement. Do you have anything to > based it on? > Ok, should is too strong. Change that to "it would be nice to", because the possibility that the base class destructor may be called (even if not by your code, possibly by others). > > I find that it is being deleted when > > test_unit* is a stored in reference counted pointer, > > Where? My mistake, it's held in a map. See the next comment: > > > and at program exit it is being deleted by calling > ~test_unit(). > > Where do I call destructor explicitly? You don't. It's being called implicitly at program exit, by valgrind. I think what is happening is that valgrind replaces the delete operator with its own, which is "operator delete(void*)" The typeinfo is likely lost by this replacement of delete. Just because you don't call the destructor, it doesn't mean others won't. If a base class is derived from, best practice is to declare its destructor virtual. It is relatively common to replace allocators (e.g. tcmalloc). > > > If you use a derived class (test_suite), this is > leading to an error. > > Where? As already mentioned, reported by valgrind. > > > Also, in the code I'm looking at (1.40.0), the > test_suite class has a > > virtual destructor, but its base class test_unit > does not. > > Not making the base class virtual seems to be > defeating the purpose. > > What purpose? The only reason that test_suite destructor is > virtual is because > this class in fact is being polymorphically. It has > subclass master_test_suite. > By defeating the purpose, I mean it forces code like the following: if( ut_detail::test_id_2_unit_type( tu.second->p_id ) == tut_suite ) delete static_cast<test_suite const*>(tu.second); else delete static_cast<test_case const*>(tu.second); A virtual base case simplifies this code (especially if in the future other classes are added, or in the case of replacement allocator it does the right thing). thanks, Scott > Gennadiy > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

4 3

[serialization] object tracking for shared strings
by Nils Krumnack 17 Dec '09

17 Dec '09

Hi all, I hope one of you will be able to help me with this: I am working with a data structure that contains a large number of (mostly identical) strings. To save memory I put together a shared memory string implementation, which ensures that each string is kept in memory only once (implemented through a global map with all strings). However, once I write them to disk, I again have n copies of each string. I would really prefer, if I could avoid the space overhead. At first glance, object tracking seems to be the way to go. If my strings were tracked, there would automatically be only one copy of each string. However I can't quite figure out how. I don't really want to change the global tracking behavior for std::string, since that might end up affecting code all over the place. Serializing pointers would be an option, but then I would have to deal with the issue of when to deallocate that object. I suppose I could serialize shared pointers, but then I would have to change my implementation to use shared pointers internally. Alternatively I could also wrap a struct around the strings internally and turn on tracking for that struct, but again I would have to complicate my implementation for the sake of serialization. What I was hoping to find was some way of telling the archive at the point where I am serializing the object, that it should track this one object. I am thinking of something like ar & BOOST_SERIALIZATION_TRACK_THIS (mystring); I was looking for something like that in the documentation, but wasn't very successful. Any ideas? Thanks in advance for any help, Nils

3 7

are boost::interprocess containers thread-safe?
by blp330 17 Dec '09

17 Dec '09

Hi, I must implement a multiple producer-consumer IPC application in win32 (but will port to linux in near future). I am wondering whether the boost::interprocess container like list, vector or map is thread-safe (actually, interprocess-safe?) or I need to use lock in my producer-consumer application? I mean, can Producer just simply put shared memory string to container and take it from Consumer without any lock? Or is there any multiple producer-consumer example that uses boost::interprocess? Thanks a lot. -- View this message in context: http://old.nabble.com/are-boost%3A%3Ainterprocess-containers-thread-safe--t… Sent from the Boost - Users mailing list archive at Nabble.com.

2 3

[proto] extends example not compiling
by alfC 17 Dec '09

17 Dec '09

Is this example, contained in the boost.Proto manual supposed to compile? #include<complex> #include <boost/proto/core.hpp> #include <boost/proto/context.hpp> #include <boost/proto/debug.hpp> #include<boost/proto/extends.hpp> template<class T, class Dummy = boost::proto::is_proto_expr> struct my_complex { BOOST_PROTO_EXTENDS( typename boost::proto::terminal<std::complex<T> >::type , my_complex<T> , boost::proto::default_domain ) }; int main() { my_complex<int> c0, c1; c0 + c1; // OK, operator+ found now! } I get this error (with gcc 4.3 and gcc 4.4): proto_complex.cpp:10: error: expected nested-name-specifier before ‘typename’ proto_complex.cpp:10: error: two or more data types in declaration of ‘proto_base_expr’ proto_complex.cpp:10: error: ‘proto_base_expr’ has not been declared proto_complex.cpp:10: error: ‘proto_base_expr’ has not been declared The strangest thing is that when I replace the macro by its explicit code the code seems to compile. Thank you, Alfredo

2 5

[Re: ] boost.plot: integrating plotting in a C++ native application: general questions about which tools to use
by Richard Ulrich 17 Dec '09

17 Dec '09

Hi Hicham, another possibility is to use a webapp like Wt from http://webtoolkit.eu It's great to work with and has good support for 2D plots. As for the 3D: I've been thinking about that as well for a whild especially embedded in an interactive webpage. I came across openVRML which looks promising, but is a hell of a beast to build (the supporting libraries). So no experiences yet. Rgds Richard

3 2

newbie - graph library - vertex properties
by List User 17 Dec '09

17 Dec '09

Hi 1. In the creation of adjacency list, vertex properties and edge properties could be vecS, listS etc.But how will one access this vertex_properties vector, for example? 2. In the kevin-bacon2.cpp example file available with boost distribution, a struct is used to store vertex properties. But that example does not seem to have used boost_install_property or property_map etc. I thought one would need to use them for having new properties for the vertex. 3. In the kevin-bacon2.cpp approach for adding new properties to the graph, the vertex_properties are read as adjacency_list[vertex_descriptior]. How will have a read only access in such a case? When I use this in a function which is defined as const in c++, the compiler cribs :)Thanks suresh

5 15

[asio] Socket closed notification?
by Nicola Michael Gutberlet 17 Dec '09

17 Dec '09

Hello everybody, I'm using TCP sockets and wonder, if there's a possibility to get an automatic notification when one side of a socket is closed (even if the other side is crashed / not closed properly). Thanks in advance for any help. Regards, Nicola

4 14

Re: [Boost-users] [Boost.Test] valgrind complains about invalid reads
by Scott Banachowski 17 Dec '09

17 Dec '09

I agree with Peter here, the destructor for test_unit should be virtual. I find that it is being deleted when test_unit* is a stored in reference counted pointer, and at program exit it is being deleted by calling ~test_unit(). If you use a derived class (test_suite), this is leading to an error. Also, in the code I'm looking at (1.40.0), the test_suite class has a virtual destructor, but its base class test_unit does not. Not making the base class virtual seems to be defeating the purpose. Scott

2 1

Interfaces in C++
by Jerry Jeremiah 16 Dec '09

16 Dec '09

Hello, I am really interested in interfaces ever since Google's new Go language brought them to my attention. Who would have guessed they are a really old thing? Joel posted some code based on fusion that does interfaces at http://lists.boost.org/Archives/boost/2005/06/89418.php but it is based on a version of fusion before it became a separate library. I have fiddled with it trying to get it to compile against the trunk but I guess I just don't understand enough about fusion to get it going. :-( If Joel or some other fusion guru could tell me how to change it to get it to compile with the current version of fusion I would really appreciate it. Besides getting the ability to play with interfaces hopefully I will gain more in depth knowledge of how to use fusion... Jerry

1 0

boost graph library, default_dfs_visitor, dfs
by List User 16 Dec '09

16 Dec '09

Hi Please see the code below. class my_visitor: public default_dfs_visitor { public: my_visitor(){} void finish_vertex(Vertex u, const Graph & g); vector<Vertex> getFinishingOrder(void){return finishingOrder;} //private: vector<Vertex> finishingOrder;//stores the vertices in the finishing order }; template<typename Vertex, typename Graph> void my_visitor::finish_vertex(Vertex u, const Graph & g){ finishingOrder.push_back(u); } main.cpp has the following: my_visitor vis; depth_first_search(g, visitor(vis));//to get the finishing order on vertices cout << "size of fin vector = " << vis.finishingOrder.size() << endl; My problem: size of the finishingOrder vector is zero outside the my_visitor::finish_vertex method. I checked its size inside the my_visitor::finish_vertex method and its value is increasing... Does I miss something in the understanding of the visitor concept? Thanks suresh

4 3

[GIL] Change layout type of a pixel...
by Eloi Du Bois 16 Dec '09

16 Dec '09

Hi all, I would like to know how to change the layout of a given pixel type. For example, I would like to do something like: // Pixel = rgb16_pixel_t for example. template<class Pixel> void foo(Pixel & A) { typedef typename pixel<hsl_t, Pixel::bits>::type hsl_pixel_t; hsl_pixel_t a; color_convert(A, a); } Thank you by advance, Eloi.

2 4

[GIL]
by Eloi Du Bois 16 Dec '09

16 Dec '09

Hi all, Sorry to bother you with my problems but I am experiencing a new probable bug: I am trying to manage with data that are set as follow: P;P;P;P;...... Where P is a rgb pixel (10 bits per components) packed on an uint32 as follow: 00RGB;00RGB;00RGB;00RGB........ I mean there is two bits unused on each 32 bits pixel. So I tried to set up a view using packed_pixel and a bug occurs when using copy_and_convert_pixels... The very strange thing is that it is working when using color_convert on two pixels... I think there may exist something I didn't understood... Anyway, I give you the buggy code: /// 10 bits rgb packed to uint32_t starting at the 2nd bit typedef const packed_channel_reference<uint32_t, 22, 10, true> rgb10_packed_channel0_t; typedef const packed_channel_reference<uint32_t, 12, 10, true> rgb10_packed_channel1_t; typedef const packed_channel_reference<uint32_t, 02, 10, true> rgb10_packed_channel2_t; typedef mpl::vector3<rgb10_packed_channel0_t, rgb10_packed_channel1_t, rgb10_packed_channel2_t> rgb10_packed_channels_t; typedef packed_pixel<uint32_t, rgb10_packed_channels_t, rgb_layout_t> rgb10_packed_pixel_t; typedef view_type_from_pixel<rgb10_packed_pixel_t>::type rgb10_packed_view_t; // image data of dimension: {w,h} = {1,0} uint32_t *data=new uint32_t[1]; data[0] = 0xFFFFF00C; rgb10_packed_view_t vw10 = interleaved_view( 1, 0, (rgb10_packed_pixel_t*)( data ), sizeof( uint32_t ) ); rgb10_packed_pixel_t pix10 = *vw10.row_begin(0); rgb16_pixel_t pix16; // This is working color_convert(pix10, pix16); std::cout << "Right {R,G,B}={" << get_color(pix16, red_t()) << "," << get_color(pix16, green_t()) << "," << get_color(pix16, blue_t()) << "}" << std::endl; // Assert that are ok assert( get_color( pix16, red_t() ) == 0xFFFF ); assert( get_color( pix16, green_t() ) == 0xFFFF ); assert( get_color( pix16, blue_t() ) == 0x00C0 ); rgb16_image_t img16(vw10.width(), vw10.height()); rgb16_view_t vw16(view(img16)); // This isn't working with packed_view copy_and_convert_pixels(vw10, vw16); pix16 = *vw16.row_begin(0); std::cout << "Wrong {R,G,B}={" << get_color(pix16, red_t()) << "," << get_color(pix16, green_t()) << "," << get_color(pix16, blue_t()) << "}" << std::endl; // Assert that doesn't pass assert( get_color( pix16, red_t() ) == 0xFFFF ); assert( get_color( pix16, green_t() ) == 0xFFFF ); assert( get_color( pix16, blue_t() ) == 0x00C0 ); Hope this will help, Eloi.

3 5

boost.plot: integrating plotting in a C++ native application: general questions about which tools to use
by Hicham Mouline 16 Dec '09

16 Dec '09

Hello, I am writing an application with a native C++ computation engine (library) that generates plotable data 2d and 3d, and a plotting engine. I am trying to determine what tools/libraries to use for the plotting engine. My graphs are all time series in the x axis (typically dates but maybe day numbers). I have a y axis and sometimes a z axis as well. Data is available in std::vector/list< pair<> > or std::vector/list< boost::tuple<> >, sometimes std::map<k,v>, perhaps later boost::multi_array<2> or <3> as well, or in fact just native arrays of pairs or boost::tuples. Decisions are made by the users, tweaking parameters and seeing how the plots change. The application user interface will be as: 1. win command line and just the plotting being graphical 2. Linux command line and just the plotting being graphical 3. win .net interface - input of parameters to the computing engine, and the plotting being graphical 4. Linux with X (maybe gtk/qt) - input of parameters to the computing engine, and the plotting being graphical And the results of the computation will then need to be plotted. So far, I have seen these solutions: ***1 - With 1,2,3 and 4, I can see a write the numbers to a file, call the external process on windows that runs gnuplot that runs a script file to plot the file. Both 2D (y(x)) and 3D(z(x,y)) visualizations are pretty flexible, in particular 3D visualizations allow to rotate the graph and view from different angles. But this process seems tortuous, gnuplot accepts piped data on linux but not on windows without mingw/cigwin. It would be preferable to not generate intermediary files, especially if that is very large. There is also a gnuplot c++ interface, but that doesn't avoid running the gnuplot external process. ***2 - I've come across boost.plot and it generates svg files which have only 2D if I understood correctly, SVG doesn't express 3D, and then use a browser (chrome) or that tool that uses SVG as its native format, or use ImageDisplay for e.g.( this comes with c++ dev library, perhaps that helps to plot directly the svg without running the process externally ) Cons: no 3d (rotating and different angles) and still require external programs. ***3 - I don't know .net but it seems c# is more convenient for the GUI part (inputting parameters, selecting options), running the c++ computation engine, and .net probably has some plotting part (don't know about 3D plots and rotating though) Cons: non portable solution - how would c# plotting interact with native c++ stl? ***4 - gtk/qt : does it have plotting features? It is ported to linux and win, does the windows port requires cygwin/mingw? How does it interact with STL containers? The solution is ideally the quickest-to-deploy and most portable, with windows not requiring cygwin/mingw, and not needing to run an external process. The need for portability comes from hardware requirements machines with a large number of processor cores run linux, while smaller boxes run win. I appreciate there are a lot of questions here, that deal with many topics and I thank everyone for answers or suggestions, Regards,

5 6

[boost-users][asio] async operations order.
by Germán Diago 16 Dec '09

16 Dec '09

Hello. I'm implementing a fully asynchronous server and I would like to know the order of async operations. The server receives, first of all, a size, and later the data. The onSizeRead handler allocates the memory required to store the data that is coming after the async_read. So I would like to know if this buffer will be available when onDataRead is called. so I get the size and data with two async_read operations. I would like to know if the relative order of the async calls is respected, since I'm reading from the same socket for both operations and I need the resources dictated by the first read before using the second one.

2 1

Compiler crash with Phoenix and PropertyTree.
by Surya Kiran Gullapalli 16 Dec '09

16 Dec '09

Hello all, I'm seeing a compiler crash (MSVC 8.0) with the following piece of code. I'm using Boost.Phoenix along with Boost.PropertyTree namespace pt = boost::property_tree ; pt::ptree tree ; boost::phoenix::bind (&pt::ptree::put<string, bool>, tree, string("Temp.Flag"), true) ; Attached is the build log. Actually, this is a test program, I wrote to reproduce a C4180 warning, but I see a crash here (actually I see C4180 also) Let me know if I'm doing something wrong. Thanks, Surya

4 7

is visitor object destroyed immediately after the execution of depth_first_search?
by Suresh Kumar 16 Dec '09

16 Dec '09

Hi, my idea is to get the finishing order of vertices in dfs by pushing the vertices in a vector and return it later through a function return value from my visitor class object. //code snippet int main() { my_visitor vis; depth_first_search(g, visitor(vis)); cout << "size of fin vector = " << vis.finishingOrder.size() << endl; //i get zero here!!! } class my_visitor: public default_dfs_visitor { public: my_visitor(){} void finish_vertex(Vertex u, const Graph & g){finishingOrder.push_back(u);}; vector<Vertex> getFinishingOrder(void){return finishingOrder;} private: vector<Vertex> finishingOrder; }; My problem: size of the finishingOrder vector is zero outside the my_visitor::finish_vertex method. I checked its size inside the my_visitor::finish_vertex method and its value is increasing every time a vertex is finished. Does I miss something in the understanding of the visitor concept? Thanks suresh -- R. Suresh Kumar PhD Student, Vislab #216, Engineering II Bldg University of California, Riverside, CA 92521

2 2

[phoenix] A simple lambda func as boost::function
by Richard Vock 16 Dec '09

16 Dec '09

Hi boost gurus, after some time and a lot of pain I somehow managed to work with boost.lambda in a way that actually outweighs the costs (code elegance versus time spent compiling it), but I miss some features (like local variables) I see in that cute phoenix documentation and a lot of mailing list threads which all seem to propose using phoenix rather than lambda (and it indeed looks a lot better). But whenever I try to use it, I somehow fail at the most simple tasks. Take for example this minimalistic code example here (note the use of #define USE_LAMBDA): http://pastebin.com/m3f590a01 Both versions (with and without USE_LAMBDA defined) compile well on the most recent stable g++ compiler, but the phoenix version does not output anything. Not at all. Also note, that this exact lambda expression is mentioned here: http://tinyurl.com/ybmp2lw (well, without the << "\n" but that doesn't change the problem) Could someone please enlighten me by telling me what I have to do here? I should mention I am bound to boost::function, not some funky phoenix::actor derivations... Greets, Richard Vock

4 9

Boost version of Loki StaticDispatcher
by Glenn Macgregor 16 Dec '09

16 Dec '09

Hi All, I am looking to replace Loki with Boost since we use Boost for other parts of projects. Example of current situation: template<typename T> struct param_traits {}; template<> struct param_traits<long> { typedef long param_type; static param_type init() { return 0; } static bool fromString(const string &str, param_type &value, int base) { // Do conversion } static string toString(param_type &value, const string &fmt) { // Do conversion } }; template<> struct param_traits<double> { typedef double param_type; static param_type init() { return 0.0; } static bool fromString(const string &str, param_type &value, int base) { // Do conversion } static string toString(param_type &value, const string &fmt) { // Do conversion } }; Class BaseParamValue { public: virtual ~BaseParamValue() {}; virtual bool fromString(const string &str, int base = 0) = 0; virtual string toString(const string &ftm = "") = 0; static BaseParamValue *create(const string &type) { if (type == string("LONG")) { return new ParamValue<long>(); } else if (type == string("DOUBLE")) { return new ParamValue<double>(); } return 0; } }; template<typename T> class ParamValue : public BaseParamValue { public: typedef param_traits<T> traits_type; typedef typename traits_type::param_type ParamType; ParamValue() : mValue() { } ~ParamValue() {}; bool fromString(const string &str, int base) { return traits_type::fromString(str, mValue, base); } string toString(const string &fmt) { return traits_type::toString(mValue, fmt); } private: ParamType mValue; }; class Param { public: Param() : mParamValue(0) { } Param(const string &type) : mParamValue(BaseParamValue::create(type)) { } ~Param() { delete mParamValue; } private: BaseParamValue *mParamValue; }; So as you can see I store a BaseParamValue in the param class instead of making the Param class itself a template, which is not an option at the moment. I am currently using loki StaticDispatcher to up cast (I guess) to the correct templatized instance in the operations. What I am trying to get done is the following: class TestVisit { public: TestVisit(); ~TestVisit(); void visit(const ParamValue<long> &value); void visit(const ParamValue<double> &value); }; Is there a way in Boost to go from a BaseParamValue * to the actual templatized ParamValue and call the correct visit using: testVisit.visit(*mParamValue). Currently I get a compiler error saying: cannot conver parameter 1 from 'BaseParamValue' to 'const ParamValue<T> &' Sorry for the long post, thanks in advance. Glenn

2 1

BOOST_FOREACH with Index
by The Dude 15 Dec '09

15 Dec '09

Hello, Boost::foreach is very useful for iterating over a sequence and doing something that depends only on the iterated element, e.g., <code> BOOST_FOREACH(const Foo &f, foos) cout << f.bar() << endl; </code> However, I often need to iterate over a sequence and do some operation that depends on both the iterated element and the iteration index. E.g., I would like something like <code> BOOST_FOREACH(size_t i, const Foo &f, foos) cout << "The bar of element " << i << " is " << f.bar() << endl; </code> Is there an easy way to do so? Thanks & Bye, TD

7 11

[program-options] c++/clr problem with variables_map
by Freeman, Ian J. 15 Dec '09

15 Dec '09

Greetings. This is my first use of Boost, despite knowing of its existence for quite some time. I've compiled Boost 1.41 with msvc and am using basically the tutorial code for program_options. When I compile it as native c++ with the msvc compiler, it works fine, however when I wrap the same code into a c++ dll to be called via .NET C# code, the variables_map always fails to locate the program options via .count("option_name"). I've stepped through the debugger and that doesn't really help because the debugger is unable to list the contents of variables that are outside of the current stack frame (according to Microsoft), even though when I try to access the contents of the variables the stack pointer is in their respective single-threaded assemblies. I'm hoping someone here has experience integrating Boost with .net via a c++/clr dll and can help point me to what the problem might be. Somewhere in the parse_command_line() call is where I lose track of the variable data. Before the call to po::store(po::parse_command_line(argc, cstr, desc), vm); the argc, argv, and desc variables contain the correct contents. The result of the below code is that "Compression level was not set." is always output. The non-working dll code: // mtest1.cpp : Defines the exported functions for the DLL application. // #include "stdafx.h" #include <tchar.h> #define WIN32_LEAN_AND_MEAN // Exclude rarely-used stuff from Windows headers #include <windows.h> #include <iostream> #include <msclr/marshal.h> #include <boost/program_options.hpp> #using<mscorlib.dll> using namespace System; using namespace std; using namespace msclr::interop; namespace po = boost::program_options; namespace boost_TestDLL { public ref class Boost_Test { public: static void Test(int argc, array<String^>^ argv) { //convert String array to char* array marshal_context ^ context = gcnew marshal_context(); char** cstr = new char*[argc]; for(int i = 0; i < argc; i++) { cstr[i] = (char*)context->marshal_as<const char*>(argv[i]); } po::options_description desc("Allowed options"); desc.add_options() ("help", "produce help message") ("compression", po::value<int>(), "set compression level") ; po::variables_map vm; po::store(po::parse_command_line(argc, cstr, desc), vm); po::notify(vm); if (vm.count("help")) { cout << desc << "\n"; } else if (vm.count("compression")) { cout << "Compression level was set to " << vm["compression"].as<int>() << ".\n"; } else { cout << "Compression level was not set.\n"; } delete context; } }; }

1 0

[asio] Error in async_accept
by Germán Diago 15 Dec '09

15 Dec '09

Hello. I have this code (the variables that end with _ are instance variables). The code works well as is, in a synchronous way. void tcpServer::startAccept() { tcpConnection::pointer new_connection = tcpConnection::create(acceptor_.io_service()); boost::system::error_code error; acceptor_.accept(new_connection->socket()); onAccept(new_connection, boost::system::error_code()); } void tcpServer::onAccept(tcpConnection::pointer new_connection, const boost::system::error_code & error) { if (!error) { if (currentconnections_ < maxconnections_) { boost::lock_guard<boost::mutex> l(mutexcurrconnections_); /*connectionsinfo_.push_back(ServerConnectionInfoPtr(new ServerConnectionInfo( new_connection->socket().remote_endpoint().address().to_string(), new_connection->socket().remote_endpoint().port(), new_connection))); */ currentconnections_++; } else throw std::runtime_error("The server is full. No more connections accepted"); /*boost::asio::async_read(new_connection->socket(), boost::asio::buffer(bufferread_), boost::bind(&tcpServer::onRead, this, _1, _2)); */ vector<char> vecrecv(12); std::size_t readsize = boost::asio::read(new_connection->socket(), boost::asio::buffer(vecrecv)); cout << "Server received " << readsize << " bytes: " << endl; copy(vecrecv.begin(), vecrecv.end(), ostream_iterator<char>(cout)); cout << endl; std::string helloclient = "hello client"; std::vector<char> sendvec(helloclient.begin(), helloclient.end()); //TODO:Cambiar por receiveAllData() //std::size_t writesize = new_connection->socket().send(boost::asio::buffer(sendvec, sendvec.size())); std::size_t writesize = boost::asio::write(new_connection->socket(), boost::asio::buffer(sendvec)); std::cout << "Written " << writesize << " bytes" << std::endl; } startAccept(); } But if I change the function startAccept so that instead of doing what it used to do, it does an asynchronous_accept: void tcpServer::startAccept() { tcpConnection::pointer new_connection = tcpConnection::create(acceptor_.io_service()); boost::system::error_code error; acceptor_.async_accept(new_connection->socket(), boost::bind(&tcpServer::onAccept, this, boost::ref(new_connection), boost::asio::placeholders::error)); } I get the following errors: terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::system::system_error> >' what(): Socket operation on non-socket terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::system::system_error> >' what(): Connection reset by peer Anyone can help? I have no clue of what's happening. The socket is a shared_ptr, so it should be there when I use onAccept. Don't know what happens. Thanks for your time.

1 1

Re: [Boost-users] [asio] Sending large packages
by Nicola Michael Gutberlet 15 Dec '09

15 Dec '09

Some testing showed that the maximum package (load) size of boost::asio::write/read() for a TCP socket seems to be 1007 kB _____ From: Nicola Michael Gutberlet [mailto:nicola.gutberlet@hhi.fraunhofer.de] Sent: 15 December 2009 17:11 To: 'boost-users(a)lists.boost.org' Subject: [asio] Sending large packages Dear all, Is there a well-defined way of sending large packages over TCP? Or do I have to split the packages on my own? For explanation: I want to send images (size around 6MB). Best regards, Nicola ***** Nicola Michael Gutberlet (Dipl.-Inf.) Image Processing Dept. Fraunhofer-Institut für Nachrichtentechnik Heinrich-Hertz-Institut Einsteinufer 37 10587 Berlin Phone: +49 (0) 30 / 31002-564 Room: AM 601

1 0

Re. [Boost Graph] newbie - dijkstra & external weightmap
by Fergal Dalton 15 Dec '09

15 Dec '09

Thanks again, > > > > But I'm talking about edge weights - why would you put in > > "get(vertex_index,g)" and not "get(edge_index,g)" or similar (I've tried this > > simple substitution and it doesn't work; so it's obviously more complex than > > that)? > OK. I misread that -- you do want edge_index. You will need to provide > them yourself, though. You must have some mapping from edges to numbers > already to index the vector; that needs to be turned into a property map. Exactly, that's the bit I can't understand. How do I do that? It's not a stupid question, I've been banging my head against it for 2 weeks but the documentation is full of examples far more complex than I need and I lose myself in the syntax (I'm a half-newbie to C++, which is not helping). > I do not know the exact cause of the operator[] error; you > removed too much of the error message to tell. So it's probably due to using "vertex_index" to get edge weights right? In any case, let's see if it still occurs when we figure out the right property_map. If so, then I can paste the entire error (it's very long and, to me, indecipherable). Fergal.

2 1

[asio] Sending large packages
by Nicola Michael Gutberlet 15 Dec '09

15 Dec '09

Dear all, Is there a well-defined way of sending large packages over TCP? Or do I have to split the packages on my own? For explanation: I want to send images (size around 6MB). Best regards, Nicola ***** Nicola Michael Gutberlet (Dipl.-Inf.) Image Processing Dept. Fraunhofer-Institut für Nachrichtentechnik Heinrich-Hertz-Institut Einsteinufer 37 10587 Berlin Phone: +49 (0) 30 / 31002-564 Room: AM 601

1 0

Re: [Boost-users] [Boost Graph] newbie - dijkstra & external weightmap
by Fergal Dalton 15 Dec '09

15 Dec '09

> Use iterator_property_map > (http://www.boost.org/doc/libs/1_41_0/libs/property_map/doc/iterator_propert…) > using syntax such as the following (replacing > "weight_map(agent_weightmap)" in the code just above): > > weight_map( > make_iterator_property_map( > agent_weightmap.begin(), > get(vertex_index, g))) > > You will need to include <boost/property_map/property_map.hpp> to get > iterator_property_map. > > -- Jeremiah Willcock > Thanks Jeremiah, But I'm talking about edge weights - why would you put in "get(vertex_index,g)" and not "get(edge_index,g)" or similar (I've tried this simple substitution and it doesn't work; so it's obviously more complex than that)? In any case I've tried more or less exactly what you suggested as follows but the compiler spits out a long error, reported below (libboost1.40): -------- #include <boost/property_map/property_map.hpp> class road; typedef adjacency_list<setS,vecS,undirectedS,no_property,road> Graph; typedef boost::vertex_descriptor vdest; vdest shortest_path(Graph& g, vdest src, vdest dst) { vector<vdest> parent(num_vertices(g)); vector<double> agent_weightmap(num_edges(g)); dijkstra_shortest_paths(g,src, //weight_map(get(&road::transit_time,g)) // ---> this weight_map works weight_map(make_iterator_property_map(agent_weightmap.begin(), get(vertex_index, g))) .predecessor_map(make_iterator_property_map(parent.begin(), get(vertex_index, g)))); vdest vd; for (vd=dst ; parent[vd]!=src ; vd=parent[vd]); return(vd); } -------- Compiler error: ------- /usr/include/boost/property_map/property_map.hpp: In function ‘Reference boost::get(... [lots of instantiated froms] ... instantiated from [dijkstra_shortest_paths(...)] /usr/include/boost/property_map/property_map.hpp:317: error: no match for ‘operator[]’ in ‘(const boost::iterator_property_map<__gnu_cxx::__normal_iterator<double*, .... /usr/include/boost/property_map/property_map.hpp:354: note: candidates are: R boost::iterator_property_map<RandomAccessIterator, IndexMap, ....... ------- I'm getting a backward warning on hash_set included from boost/graph/adjacency_list.hpp - could this be an issue? Thanks again, Fergal.

2 1

[type_traits] data pointers and function pointers
by Edward Diener 15 Dec '09

15 Dec '09

It is difficult in some places in the type_traits documentation to tell when the documentation mentions "pointer" whether this refers to data pointers, function pointers, member data pointers, and/or member function pointers. I assume that if the documentation just refers to "pointer" that it should mean all of the above. But here goes: 1) Does the 'remove_pointer' refer to all of the above ? The examples are only for a single one of the above, a data pointer. 2) The 'is_pointer' doc does say it excludes pointer to members by which I assume this means both member data and member functions. Is there any way to tell whether a pointer is a function pointer or a data pointer by using type_traits since 'is_pointer' includes both ?

3 3

[ANN] CLI 1.1.0 released
by Boris Kolpackov 15 Dec '09

15 Dec '09

Hi, Seeing that I've got a lot of useful feedback for the initial release, I am pleased to announce the availability of CLI 1.1.0. CLI is an open-source (MIT license), cross-platform command line interface compiler for C++. It allows you to specify the options that your program supports, their types, default values, and documentation. This specification can then be automatically translated to C++ classes that implement parsing of the command line arguments and provide a convenient and type-safe interface for accessing the extracted data. The automatic usage and documentation generation is by far the biggest new feature in this release. The usage information is formatted during compilation and the documentation can be generated in the HTML and man page formats. For an example of the HTML output, see the documentation for the CLI compiler itself (you may also want to check the cli.1 man page and the usage information printed by the compiler): http://www.codesynthesis.com/projects/cli/doc/cli.xhtml Other new features in this release: * Optional generation of modifiers in addition to accessors. * Support for erasing the parsed elements from the argv array. * Support for custom argument sources via an abstract scanner interface. * Support for reading command line arguments from the argv array as well as files specified with command line options. For a more detailed list of new features in this release see: http://www.codesynthesis.com/pipermail/cli-users/2009-December/000001.html More information, documentation, and source code distributions are available from the project's web page: http://www.codesynthesis.com/projects/cli/ Enjoy, Boris -- Boris Kolpackov, Code Synthesis http://codesynthesis.com/~boris/blog Open-source XML data binding for C++ http://codesynthesis.com/products/xsd XML data binding for embedded systems http://codesynthesis.com/products/xsde Command line interface to C++ compiler http://codesynthesis.com/projects/cli

1 0

Template metaprogramming technique for operator overloading
by Edward Diener 15 Dec '09

15 Dec '09

I could not find this in type_traits, or any other Boost TMP library, but I am wondering if there is any TMP technique which can determine if a user-defined type supports a particular operator overload for that type ?

3 2

[1.41][serialization] deserialization of weak_ptr fails
by Alexander Gutenev 15 Dec '09

15 Dec '09

The example below works in 1.40 and fails in 1.41 #include <string> #include <sstream> #include <vector> #include <boost/smart_ptr.hpp> #include <boost/serialization/serialization.hpp> #include <boost/serialization/shared_ptr.hpp> #include <boost/serialization/vector.hpp> #include <boost/archive/xml_oarchive.hpp> #include <boost/archive/xml_iarchive.hpp> struct X : boost::enable_shared_from_this<X> { X(){} virtual ~X() {} explicit X(int i) : i(i) {} template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & boost::serialization::make_nvp("i", i); (void) version; } int i; }; typedef boost::shared_ptr<X> PX; typedef std::vector<PX> VPX; int main() { std::ostringstream oss; VPX vpx; vpx.push_back(PX(new X(2))); vpx.push_back(PX(new X(5))); vpx.push_back(PX(new X(7))); boost::archive::xml_oarchive oa(oss); oa << boost::serialization::make_nvp("v", vpx); vpx.clear(); std::string s = oss.str(); std::istringstream iss(s); boost::archive::xml_iarchive ia(iss); ia >> boost::serialization::make_nvp("v", vpx); PX px = vpx[1].get()->shared_from_this(); return 0; }

2 3

[Boost Graph] newbie - dijkstra & external weightmap
by Fergal Dalton 14 Dec '09

14 Dec '09

Hi, I'm trying to write a program which considers some "agents" traversing a graph following dijkstra, from some source vertex to some destination. Each agent will have a different weightmap for the network. Therefore, I need a routine to which I pass the source & destination vertices, and a pointer or reference to the calling agents weightmap. This routine should return the next step for that agent. Alternatively, I could write a visitor which, everytime any agent calls dijkstra, overwrites the weight in the bundled edge structure, with that agent's weights array. Here below is the nuts of what I have, which works but only with the bundled edge_weight (called "transit_time"). Below that, is what I'd like to do. Anyway, the long & short of it is, I couldn't wrap my head around the syntax for either. I've looked in the books, in the lists, on the site, and I can't find any help on how to incorporate external weightmaps with dijkstra. Can anyone tell me how to proceed? Thanks, Fergal. --------------- This works, but only with the bundled weight property, identical for all agents: class road; typedef adjacency_list<setS,vecS,undirectedS,no_property,road> Graph; typedef Graph::vertex_descriptor vdest; vdest shortest_path(Graph& g, vdest src, vdest dst) { vector<vdest> parent(num_vertices(g)); dijkstra_shortest_paths(g,src,weight_map(get(&road::transit_time,g)) .predecessor_map(make_iterator_property_map(parent.begin(), get(vertex_index, g)))); vdest vd; for (vd=dst ; parent[vd]!=src ; vd=parent[vd]); // ATTN: isolated vertices return(vd); } ----------------- What I would like, where agent_weightmap is (a pointer to) the agent's weightmap: class road; typedef adjacency_list<setS,vecS,undirectedS,no_property,road> Graph; typedef Graph::vertex_descriptor vdest; vdest shortest_path(Graph& g, vdest src, vdest dst, vector<double> agent_weightmap) { vector<vdest> parent(num_vertices(g)); dijkstra_shortest_paths(g,src,weight_map(agent_weightmap)) .predecessor_map(make_iterator_property_map(parent.begin(), get(vertex_index, g)))); vdest vd; for (vd=dst ; parent[vd]!=src ; vd=parent[vd]); // ATTN: isolated vertices return(vd); }

2 1

Linker error with boost::filesystem
by seandr＠millisecond.com 14 Dec '09

14 Dec '09

Hi, I'm trying to use the boost::filesystem library, and I'm getting two linker errors that I can't figure out. Does anyone have any ideas why I'm seeing these and how I can fix them? 1. error LNK2001: unresolved external symbol "class boost::filesystem::file_status __cdecl boost::filesystem::detail::status_api(class std::basic_string<unsigned short,struct std::char_traits<unsigned short>,class std::allocator<unsigned short> > const &,class boost::system::error_code &)" 2. error LNK2001: unresolved external symbol "class boost::system::error_code __cdecl boost::filesystem::detail::set_current_path_api(class std::basic_string<unsigned short,struct std::char_traits<unsigned short>,class std::allocator<unsigned short> > const &)" I'm using the msvc8 toolset. Thanks, Sean

1 0

documentation build problem
by Stefan Strasser 14 Dec '09

14 Dec '09

I get the following error when I try to build any documentation with boost 1.41: cat "/tmp/jam112c3106.000" > "/bin/boostbook_catalog.xml" obviously it can't copy to /bin/, but BOOST_ROOT is set. not only is the root missing from the directory, but the bin directory is called "bin.v2", not "bin". I can't figure out where this "cat" is coming from or how to set the path correctly. can anyone help me with this?

2 1

io_service object pool X io_service::run thread pool
by Matheus Araújo Aguiar 14 Dec '09

14 Dec '09

Hello dear list, I am using boost for some months now and i have implemented a server which creates several threads of io_service::run in order to respond to async writes and reads. I am looking for some performance improvements and just read the http server 2 example and saw that it uses a pool of io_service objects. So my question is, what would be the pros and cons of using such a pool instead of a thread pool of io_service::run ? Thanks in avance and best regards, -- Matheus Araújo Aguiar Computer Scientist matheus.pit(a)gmail.com

1 0

[thread] 1 blocks are still reachable in loss record
by Sakharuk, Vladimir 14 Dec '09

14 Dec '09

Hi all, Valgrind reports follows memory leak. ==24567== at 0x4A1FE1B: malloc (vg_replace_malloc.c:207) ==24567== by 0x6AC7FDD: boost::detail::get_once_per_thread_epoch() (in /app/local/pkgs/boost/lib/libboost_thread-gcc41-mt-1_39.so.1.39.0) ==24567== by 0x6AC4A17: void boost::call_once<void (*)()>(boost::once_flag&, void (*)()) (in /app/local/pkgs/boost/lib/libboost_thread-gcc41-mt-1_39.so.1.39.0) ==24567== by 0x6AC1D96: boost::detail::get_current_thread_data() (in /app/local/pkgs/boost/lib/libboost_thread-gcc41-mt-1_39.so.1.39.0) ==24567== by 0x6AC36B4: boost::thread::join() (in /app/local/pkgs/boost/lib/libboost_thread-gcc41-mt-1_39.so.1.39.0) Code is looks like: thread_->join(); delete thread_; Is there a way to fix it? Regards \/lad. =============================================================================== Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html ===============================================================================

2 1

[date_time] Is there a more direct way to format time strings?
by Sajjan Kalle 14 Dec '09

14 Dec '09

In the examples all formatting of strings seems to use date_facet, which requires ( ? ) the use of streams and locales. Is there a more direct way to format a time?

1 0

[program-options] Modifying the variable_value of a variables_map...
by W Eryk Wolski 14 Dec '09

14 Dec '09

Hi, I am using program options to parse cmdline parameters. I would like to use the variable_map to pass parameters in my application and I would like to modify the values of the boost::program_options::variable_map. while variable_value provides a method value() allowing me to modify the content... the variable_map "overrides" the operator[] of the std::map const variable_value& operator[](const std::string& name) const; so something like this (where mmap is a variable_map) mmap["x"].value() = 2.; does not compile..... I tried this because the doc reads : The variables_map class can be used just like std::map, except that values stored there must be retrieved with the as method shown above. (If the type specified in the call to the asmethod is different from the actually stored type, an exception is thrown.) Using the iterator it is map_t::iterator it(mmap.find("x")); boost::program_options::variable_value & vx(it->second); vx.value() = 2.; still easily possible to modify the variable_value . I would like to better understand why the operator[] returns a const variable_value? regards Eryk Here is some sample code I wrote to test how to modify a variable_map. boost::any a(1.); boost::program_options::variable_value vv(a,false); //variable_value provides the method value() returning a reference via which I am able to modify the content. // i.e. vv.value() = 2.1; //I store the variable_value in a variables_map typedef boost::program_options::variables_map map_t; map_t mmap; mmap.insert( std::make_pair(std::string("x"), vv ) ); std::cout << mmap["x"].as<double>() << std::endl; //now I would like to modify the value.. mmap["x"].value() = 2.; //does not compile..... ///error C2678: binary '=' : no operator found which takes a left-hand operand of type 'const boost::any' (or there is no acceptable conversion) // thats because abstract_variables_map defines the operator[] as follows // const variable_value& operator[](const std::string& name) const; //my workaround... map_t::iterator it(mmap.find("x")); boost::program_options::variable_value & vx(it->second); vx.value() = 2.; std::cout << mmap["x"].as<double>() << std::endl; -- Witold Eryk Wolski Heidmark str 5 D-28329 Bremen tel.: 04215261837

1 0

[Interprocess] How to prevent collision of mapping addresses with DLL Loading on Windows?
by pheres 14 Dec '09

14 Dec '09

Hi, I do something like fixed_managed_shared_memory segment (open_only, "MyFixedAddressSharedMemory" //Shared memory object name ,(void*)0x30000000 //Mapping address to establish an shared memory segment which gets faded into the virtual address space of every process taking part on the IPC at the same offset (this is important for me). This works quite well for most processes. But problems arise with IPC-clients using a lot of delay loaded DLL's. This seems to be especially to be true for MFC windows programs. While normal loaded DLL's goes to 0x10000000, or their fixed address or are relocated to some there like 0x0..., some windows delay loaded DLL's seem to can be placed nearly anywhere inside the virtual address space, This makes the success of establishing the IPC into a lottery game. For example I used 0x40000000 for a shared memory range in the IPC clients. One client used windows MFC. Taking part on the IPC inside this client should happen after some pushbutton was pressed but it failed sometimes. I found out that in the moment of the button press windows delay loaded two additional DLL's which unfortunately faded in at the memory range I configured for the IPC (around 0x40000000). I was not able to find a 100% satisfying solution. The best thing I came up with was: -link everything you can static -Link the self produced DLL's with fixed base address -Allocate the memory range as the first call in main() using OS-specific functions like VirtualAlloc() -Free the allocated memory just before initializing the IPC (so it's sure that no delay loaded DLL can be faded in in the mean time) -for the rest (mainly windows or other 3rd party DLLs) hope the best This seem to work at least for now but I guess there must be a more elegant solution. I did google a lot about the MS loader/run time linker, but there seems to be no option to prevent it from selecting a certain address range. Could anybody help me out? Thank you in advance! Best Regards Joerg

3 8

[preprocessor]
by Christian Henning 14 Dec '09

14 Dec '09

Hi there, let's assume I have a structure which takes 5 ints as template parameters. template< int NumChannel , int FirstChannelBits = 0 , int SecondChannelBits = 0 , int ThirdChannelBits = 0 , int FourthChannelBits = 0 , int FifthChannelBits = 0 > struct pixel_type_generator { /* omitted*/ } The first parameter is different as it defines how many of the other parameters are actually used. How can I use boost::preprocessor to get this kind of code repetition: // one channel test pixel_pixel_test< pixel_type_generator< 1, 1 >::type >(); pixel_pixel_test< pixel_type_generator< 1, 2 >::type >(); pixel_pixel_test< pixel_type_generator< 1, 3 >::type >(); pixel_pixel_test< pixel_type_generator< 1, 4 >::type >(); pixel_pixel_test< pixel_type_generator< 1, 5 >::type >(); pixel_pixel_test< pixel_type_generator< 1, 6 >::type >(); // up to 64 // two channels test pixel_pixel_test< pixel_type_generator< 2, 1, 1 >::type >(); pixel_pixel_test< pixel_type_generator< 2, 1, 2 >::type >(); pixel_pixel_test< pixel_type_generator< 2, 1, 3 >::type >(); // ... pixel_pixel_test< pixel_type_generator< 2, 1, 32 >::type >(); pixel_pixel_test< pixel_type_generator< 2, 2, 1 >::type >(); pixel_pixel_test< pixel_type_generator< 2, 2, 2 >::type >(); pixel_pixel_test< pixel_type_generator< 2, 2, 3 >::type >(); // ... // ... pixel_pixel_test< pixel_type_generator< 2, 32, 32 >::type >(); // last two parameters up to 32 - which means there are 32 x 32 calls // three channels test pixel_pixel_test< pixel_type_generator< 3, 1, 1, 1 >::type >(); pixel_pixel_test< pixel_type_generator< 3, 1, 1, 2 >::type >(); // ... // last three parameters up to 21 - which means there are 21 x 21 x 21 calls // four channels test pixel_pixel_test< pixel_type_generator< 4, 1, 1, 1, 1 >::type >(); pixel_pixel_test< pixel_type_generator< 4, 1, 1, 1, 2 >::type >(); // ... // last four parameters up to 16 - which means there are 16 x 16 x 16 x 16 calls // five channels test pixel_pixel_test< pixel_type_generator< 5, 1, 1, 1, 1, 1 >::type >(); pixel_pixel_test< pixel_type_generator< 5, 1, 1, 1, 1, 2 >::type >(); // ... // last four parameters up to 12 - which means there are 12 x 12 x 12 x 12 x 12 calls As you might realize, I try to test every combination until the sum of all channels hits 64. Thanks, Christian

4 11

regex
by Dejan 14 Dec '09

14 Dec '09

Hi all, I have a question regarding boost::regex. I have one regex which should identify my string AND cut it into pieces. I've tried with regex_token_iterator and cmatch and failed. code: #include <string> #include <iostream> #include <boost/regex.hpp> int main() { std::string s("s0,s1,s2"); boost::regex re("^(s[0-9])(,s[0-9])*$"); // 1. attempt boost::sregex_token_iterator i(s.begin(), s.end(), re), j; while(i!=j) { std::cout << *i++ << std::endl; } // 2. attempt boost::cmatch matches; if(boost::regex_search(s.c_str(), matches, re)) { for(int p=0, q=matches.size(); p<q; p++) { std::string match(matches[p].first, matches[p].second); std::cout << match << std::endl; } } } output: s0,s1,s2 s0,s1,s2 s0 ,s2 desired output: s0,s1,s2 s0 ,s1 ,s2 Any hints how to do this in one step? Thanks!

2 2

Re: [Boost-users] BOOST_FOREACH with Index
by pete＠pcbartlett.com 14 Dec '09

14 Dec '09

> Nat Goodspeed wrote: > > Maybe this shouldn't be a BOOST_FOREACH feature at all. As with > Python's > > builtin enumerate() function, maybe what we want here is an > iterator > > adapter that dereferences to a std::pair > original_iterator_value_type>? > Couldn't you just do a BOOST_FOREACH over combine(count_range(), > foos) > for that? > (uses zip_iterator) Yup, Nat's idea is a nice one and easy to implement. As Eric alluded to with his reference to the ticket on FOREACH_FIELD, the heart of the matter really though is getting a syntactically convenient version. We've seen this situation - where we have the neat iterators/ranges but not the syntactic convenience - a few times (REVERSE_FOREACH, FOREACH_FIELD, this "FOREACH_WITHINDEX" spring to mind) - I wonder if there is an opportunity to expose a lower level API in the FOREACH mini-library that would enable advanced users to build such macros themselves.

1 0

Hello Everyone
by Rick Eyre 14 Dec '09

14 Dec '09

I have a problem with installing boost. I downloaded the installer 1.40 for VC 2008 and followed all the instructions in the manual but I'm getting the error 1>LINK : fatal error LNK1104: cannot open file 'libboost_thread-vc90-mt-gd-1_40.lib'. This is from the header #include <boost/thread/thread.hpp> in my code. Does anyone know what I can possible do to resolve this? Thanks

4 10

Compilation error Boost lambda function (Boost 1.40)
by Joost Kraaijeveld 13 Dec '09

13 Dec '09

Hi, What is wrong in my syntax in the std::for_each call (the BOOST_FOREACH works fine): ... class Session { virtual void stopSession(); } class ServerSession : public Sessoon { } typedef std::map<unsigned long, ServerSession*> ServerSessions; ServerSessions serverSessions; ... ... typedef std::pair<unsigned long, ServerSession*> ServerSessionsIterator; BOOST_FOREACH(ServerSessionsIterator session,serverSessions) { session.second->stopSession(); } std::for_each( serverSessions.begin(), serverSessions.end(), boost::lambda::bind( &ServerSession::stopSession, // function boost::bind(&ServerSessions::value_type::second, boost::lambda::_1))); // object The actual error is: make -k -j6 all /bin/bash ../libtool --tag=CXX --mode=compile g++ -DHAVE_CONFIG_H -I. -I/home/jkr/Programming/C++/Dagda/library/DagdaCom -I../../include/Dagda/DagdaConfig -DDEVELOPMENT -DDANUEXE=1 -I/home/jkr/Programming/C++/Danu/include/Danu -DDAGDADLL=1 -I /home/jkr/Programming/C++/Dagda/library/../include/Dagda -pipe -Wall -Wextra -Wundef -Wshadow -Wconversion -I/usr/include -I/usr/lib/wx/include/gtk2-unicode-release-2.8 -I/usr/include/wx-2.8 -D_FILE_OFFSET_BITS=64 -D_LARGE_FILES -D__WXGTK__ -pthread -g -O2 -MT libdagdacom_la-Server.lo -MD -MP -MF .deps/libdagdacom_la-Server.Tpo -c -o libdagdacom_la-Server.lo `test -f 'Server.cpp' || echo '/home/jkr/Programming/C++/Dagda/library/DagdaCom/'`Server.cpp libtool: compile: g++ -DHAVE_CONFIG_H -I. -I/home/jkr/Programming/C++/Dagda/library/DagdaCom -I../../include/Dagda/DagdaConfig -DDEVELOPMENT -DDANUEXE=1 -I/home/jkr/Programming/C++/Danu/include/Danu -DDAGDADLL=1 -I /home/jkr/Programming/C++/Dagda/library/../include/Dagda -pipe -Wall -Wextra -Wundef -Wshadow -Wconversion -I/usr/include -I/usr/lib/wx/include/gtk2-unicode-release-2.8 -I/usr/include/wx-2.8 -D_FILE_OFFSET_BITS=64 -D_LARGE_FILES -D__WXGTK__ -pthread -g -O2 -MT libdagdacom_la-Server.lo -MD -MP -MF .deps/libdagdacom_la-Server.Tpo -c /home/jkr/Programming/C++/Dagda/library/DagdaCom/Server.cpp -fPIC -DPIC -o .libs/libdagdacom_la-Server.o /usr/include/boost/lambda/detail/actions.hpp: In static member function ‘static RET boost::lambda::function_action<2, T>::apply(A1&, A2&) [with RET = void, A1 = void (DagdaCom::Session::* const)(), A2 = const boost::_bi::bind_t<DagdaCom::ServerSession* const&, boost::_mfi::dm<DagdaCom::ServerSession*, std::pair<const long unsigned int, DagdaCom::ServerSession*> >, boost::_bi::list1<boost::arg<1> > >, T = boost::lambda::detail::unspecified]’: /usr/include/boost/lambda/detail/lambda_functor_base.hpp:418: instantiated from ‘RET boost::lambda::lambda_functor_base<boost::lambda::action<2, Act>, Args>::call(A&, B&, C&, Env&) const [with RET = void, A = std::pair<const long unsigned int, DagdaCom::ServerSession*>, B = const boost::tuples::null_type, C = const boost::tuples::null_type, Env = const boost::tuples::null_type, Act = boost::lambda::function_action<2, boost::lambda::detail::unspecified>, Args = boost::tuples::tuple<void (DagdaCom::Session::* const)(), const boost::_bi::bind_t<DagdaCom::ServerSession* const&, boost::_mfi::dm<DagdaCom::ServerSession*, std::pair<const long unsigned int, DagdaCom::ServerSession*> >, boost::_bi::list1<boost::arg<1> > >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>]’ /usr/include/boost/lambda/detail/lambda_functors.hpp:175: instantiated from ‘typename T::sig<boost::tuples::tuple<A&, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >::type boost::lambda::lambda_functor<Base>::operator()(A&) const [with A = std::pair<const long unsigned int, DagdaCom::ServerSession*>, T = boost::lambda::lambda_functor_base<boost::lambda::action<2, boost::lambda::function_action<2, boost::lambda::detail::unspecified> >, boost::tuples::tuple<void (DagdaCom::Session::* const)(), const boost::_bi::bind_t<DagdaCom::ServerSession* const&, boost::_mfi::dm<DagdaCom::ServerSession*, std::pair<const long unsigned int, DagdaCom::ServerSession*> >, boost::_bi::list1<boost::arg<1> > >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >]’ /usr/include/c++/4.3/bits/stl_algo.h:3791: instantiated from ‘_Funct std::for_each(_IIter, _IIter, _Funct) [with _IIter = std::_Rb_tree_iterator<std::pair<const long unsigned int, DagdaCom::ServerSession*> >, _Funct = boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::action<2, boost::lambda::function_action<2, boost::lambda::detail::unspecified> >, boost::tuples::tuple<void (DagdaCom::Session::* const)(), const boost::_bi::bind_t<DagdaCom::ServerSession* const&, boost::_mfi::dm<DagdaCom::ServerSession*, std::pair<const long unsigned int, DagdaCom::ServerSession*> >, boost::_bi::list1<boost::arg<1> > >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > >]’ /home/jkr/Programming/C++/Dagda/library/DagdaCom/Server.cpp:204: instantiated from here /usr/include/boost/lambda/detail/actions.hpp:87: error: no matching function for call to ‘boost::lambda::function_adaptor<void (DagdaCom::Session::*)()>::apply(void (DagdaCom::Session::* const&)(), const boost::_bi::bind_t<DagdaCom::ServerSession* const&, boost::_mfi::dm<DagdaCom::ServerSession*, std::pair<const long unsigned int, DagdaCom::ServerSession*> >, boost::_bi::list1<boost::arg<1> > >&)’ /usr/include/boost/lambda/detail/actions.hpp:87: error: return-statement with a value, in function returning 'void' make: *** [libdagdacom_la-Server.lo] Error 1 make: Target `all' not remade because of errors. TIA -- Groeten, Joost Kraaijeveld Askesis B.V. Molukkenstraat 14 6524NB Nijmegen tel: 024-3888063 / 06-51855277 fax: 024-3608416 web: www.askesis.nl

2 1

Bundled properties with boyer_myrvold_planarity_test
by Nick Wiggill 13 Dec '09

13 Dec '09

Can't seem to get this working. I'm not sure if there was something I missed in the docs, but as soon as I use bundled properties boyer_myrvold_planarity_test falls over. void SomeClass::create() { typedef adjacency_list<listS, listS, undirectedS, property <vertex_index_t, int>, property <edge_index_t, int> > Graph; typedef graph_traits<Graph>::vertex_descriptor Vertex; typedef graph_traits<Graph>::edge_descriptor Edge; typedef graph_traits<Graph>::vertex_iterator VertexIterator; BOOST_CONCEPT_ASSERT ((boost::concepts::VertexAndEdgeListGraph<Graph>)); BOOST_CONCEPT_ASSERT ((boost::concepts::IncidenceGraph<Graph>)); //Create graph const int NUM_VERTICES = 5; Graph graph(NUM_VERTICES); //Create vertices and edges Vertex u, v; u = vertex(0, graph); v = vertex(4, graph); //add_edge(u, v, graph); //BAD line! //Other attempted/failed way of adding edges //Edge e; //e = edge(u, v, graph); //Another attempt, doesn't seem to work with //bundled props, unsurprisingly. //add_edge(0, 4, graph); cout << "Vertex and edge additions complete." << endl; //iterate through vertices VertexIterator vItr, vItrEnd; for (tie(vItr, vItrEnd) = vertices(graph); vItr != vItrEnd; ++vItr) { cout << "#"<< endl; //<< graph[*vItr] << endl; } cout << "Vertex iteration complete." << endl; if (boyer_myrvold_planarity_test(graph)) cout << "Test claims graph is planar" << endl; else cout << "Test claims graph is non-planar" << endl; cout << "Planarity testing complete." << endl; } The line commented "BAD line!" causes an exit on calling boyer_myrvold_planarity_test. With the test commented out, the program will run to its normal completion. What am I failing to grasp? TIA -Nick

2 2

Unable to access graph concepts
by Nick Wiggill 13 Dec '09

13 Dec '09

Hi I'm new to Boost (using 1.41.0) and specifcally the BGL and am having a small problem with accessing graph concepts. My IDE (Eclipse/CDT) and compiler (GCC 3.4.5) are having trouble seeing definitions of graph concepts, although I have included boost/graph/graph_concepts.hpp. When I type the boost namespace specifier, autocomplete can find e.g. EqualityComparable, but it cannot find VertexAndEdgeListGraph (among others... but this the one I need). I can see the basic BCCL concepts from boost/concept_check.hpp just fine, making this all the more confusing. My paths are correct, as for example adjacency_list (residing in the same path) works fine. PS. Try to have mercy on me, I'm not only returning to C++ after a number of years but I'm also in the process of reacquainting myself fully with generic programming (and the STL), something I was never too great at... so a lot of things still meet with a blank stare from me. I've just been learning these things slowly by example and by trial-and-error so far. TIA, -- Nick Wiggill skype: nickwiggill nick.wiggill(a)gmail.com www.handcraftedgames.net -- "He uses statistics as a drunken man uses lamp-posts... for support rather than illumination." -Andrew Lang (1844-1912)

2 4

Asio io_service::work destructor throwing mutex exception
by Florian Turck 13 Dec '09

13 Dec '09

Hi, I am using asio´s io_service::work class to prevent io_service.run() from returning. Unfortunatly on deletion of my object the destructor of io_service::work throws an exception: terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::system::system_error> >' what(): mutex: Invalid argument Thread 0 Crashed: Dispatch queue: com.apple.main-thread 0 libSystem.B.dylib 0x9578c732 __kill + 10 1 libSystem.B.dylib 0x9578c724 kill$UNIX2003 + 32 2 libSystem.B.dylib 0x9581f98d raise + 26 3 libSystem.B.dylib 0x95835a44 abort + 93 4 libstdc++.6.dylib 0x9122afda __gnu_cxx::__verbose_terminate_handler() + 433 5 libstdc++.6.dylib 0x9122917a __cxxabiv1::__terminate(void (*)()) + 10 6 libstdc++.6.dylib 0x9122851d __cxa_call_terminate + 53 7 libstdc++.6.dylib 0x9122909d __gxx_personality_v0 + 911 8 libSystem.B.dylib 0x9579aa9d unwind_phase2 + 205 9 libSystem.B.dylib 0x957b1fd9 _Unwind_Resume + 73 10 com.yourcompany.ReclaimR 0x00026ed3 boost::asio::detail::scoped_lock<boost::asio::detail::posix_mutex>::scoped_lock(boost::asio::detail::posix_mutex&) + 79 (scoped_lock.hpp:37) 11 com.yourcompany.ReclaimR 0x00027dfa boost::asio::detail::task_io_service<boost::asio::detail::kqueue_reactor<false> >::work_finished() + 28 (task_io_service.hpp:171) 12 com.yourcompany.ReclaimR 0x00027e72 boost::asio::io_service::work::~work() + 22 (io_service.ipp:155) The asio related objects are all members of my class: [...] private: io_service ioService; io_service::work ioWork; thread ioThread; tcp::socket controlSocket; tcp::acceptor acceptor; [...] This is how I initialize everything: [...] MyClass() : ioService(), ioWork(ioService), ioThread(bind(&io_service::run, &ioService)), controlSocket(ioService), acceptor(ioService), [...] Finally this is what happens in the destructor: [...] if (connected) disconnect(); ioService.stop(); ioThread.join(); [...] Anyone knows how to deal with this? Regards, Florian

2 1

can't build an official example on eclipse
by loveley 13 Dec '09

13 Dec '09

hello, I have an issue while trying to run boost for the first time. I downloaded boost on my mac snow leopard, with eclipse. I compiled the sources(with bjam, without options), and I added the "include" directory (ie boost_1_41_0/boost)and the "libs" one (ie boost_1_41_0/libs) in eclipse. the example I used is the one provided by the official tutorial : ****************************************************** #define BOOST_TEST_MODULE MyTest #include <boost/test/unit_test.hpp> int add( int i, int j ) { return i+j; } BOOST_AUTO_TEST_CASE( my_test ) { // seven ways to detect and report the same error: BOOST_CHECK( add( 2,2 ) == 4 ); // #1 continues on error BOOST_REQUIRE( add( 2,2 ) == 4 ); // #2 throws on error if( add( 2,2 ) != 4 ) BOOST_ERROR( "Ouch..." ); // #3 continues on error if( add( 2,2 ) != 4 ) BOOST_FAIL( "Ouch..." ); // #4 throws on error if( add( 2,2 ) != 4 ) throw "Ouch..."; // #5 throws on error BOOST_CHECK_MESSAGE( add( 2,2 ) == 4, // #6 continues on error "add(..) result: " << add( 2,2 ) ); BOOST_CHECK_EQUAL( add( 2,2 ), 4 ); // #7 continues on error } ****************************************************** and the error is: http://pastebin.com/m4c85af13 . can you help me? thank you, olivier. ****************************************************** ___________________________________________________________________________ Yahoo! Mail réinvente le mail ! Découvrez le nouveau Yahoo! Mail et son interface révolutionnaire. http://fr.mail.yahoo.com

4 11

[Serialization] Saving non-const values
by Patrick Moran 12 Dec '09

12 Dec '09

Hello all, I noticed in the documentation of Boost.Serialization in 1.41.0 that under the "Rationale" section the link for "Compile time trap when saving a non-const value" still appears at the top of the page, but the section it points to is now missing. Is this just an error in the documentation, or has this restriction been removed in 1.41.0. No such change is mentioned in the release notes, but I read somewhere a while ago that they were considering removing the saving-const restriction. In case it helps, the context I'm using this in is using Boost.Serialization to serialize polymorphic classes and polymorphic containers from Boost.PointerContainer. Thanks, Patrick Moran

2 1

boost port for S60 (Symbian)
by Yuriy Krasnoschek 12 Dec '09

12 Dec '09

Hello. I spent some efforts to make several libraries from boost compile and run on Symbian Series 60 with winscw (Code warrior by Nokia). I can share my work with community and continue porting, just need to know where to start. The problem is I was forced to modify original boost sources (like select_platform.hpp) and libraries files due to compiler / platfom limitations. Libraries that ran on S60 3rd Edition Feature Pack 2 + are: thread, date_time, system, regex, asio (partially) and of cource libraries that don't depend on platfom so much smart_pointers / type_traits / integer / etc. -- Best regards, Yuriy A. Krasnoschek aka D.Rider

3 4

Getting metadata of class
by Alex Vinokur 12 Dec '09

12 Dec '09

Hi, Does Boost contain any features to get metadata of classes? For instance, Let Foo be some class class Foo { int m_var1; long* m_var2] char m_var3[100]; dooble m_var4; }; I would like to get the following info (as vector, file, etc) of its members: {" m_var1", "int", sizeof (m_var1), offset of (m_var1) }, {" m_var2", "long", "Pointer", sizeof (m_var2), sizeof (base-variable, i.e., long), offset of (m_var2 }, {" m_var3, "char", "array", sizeof (m_var3), sizeof (base-variable, i.e., char), offset of (m_var3 }, {" m_var4", "double", sizeof (m_var4), offset of (m_var4) }, That info I would like to get as a result of some feature (function, ...) applied to class Foo, not to each member of Foo. Alex.

3 5

Re: [Boost-users] default mpi implementation
by Vladimir Prus 12 Dec '09

12 Dec '09

Sean Farrow wrote: > Hi: > > Could someone give me a url for the default mpi compiler used with > boost.mpi, I believe this is mpi++ but could be wrong. There's no default compiler -- a few will be probed. Specifically, this is what is probed on Unix: binaries named * mpic++ * mpiCC (supposedly used by MPICH) * mpicxx (supposedly used by OpenMPI and MPICH2) Does this help? - Volodya

2 1

My First Boost Program At Work With Visual Studio
by Dave Schwartz 12 Dec '09

12 Dec '09

Hello Gurus, First, my 2 lines of appreciation to the community. I am new to boost library and I must tell, I have been enjoying myself going through various boost libraries and running sample programs provided. Must say all this has been quite straightforward and given me a headstart and confidence in learning the libraries. I have been trying the samples on my home PC with Visual Studio 2008 with the libraries provided by boostpro 1.4 installation. No issues. Yesterday I tried using the serialization library at work and wanted to serialize a simple class to an XML file and de-serialize it. This example worked on my home PC (visual studio 2008). On my work PC that has visual studio 2005, the compilation went fine but the program ended up generating a library as in InventoryConfig.lib, instead of the regular InventoryConfig.exe. Apparently it looks like the output type of the program changed from .exe to .lib on visual studio 2005 on my work computer. When I remove the serialization code, the output type goes back to .exe I copied the same code back to my home pc and with visual studio 2008 I get the correct result and the output type remains an executable as set initially while creating the project. Can't seem to figure out what project properties are getting changed on VS2005 when I use the library. I am not sure where to look or how to go about fixing this issue. Appreciate your help. Thanks a lot Dece

2 1

condition_variable
by Alessandro Bellina 11 Dec '09

11 Dec '09

Hello, I am using boost condition_variables to block while waiting for an asynchronous response. I am seeing an error that happens at random whenever I am releasing the lock just before calling notify_one. The error goes away if I keep the lock and release after notify_one. Here is the code: class BlockingRequest{ public: // predicate class class ResponseStatus { public: ResponseStatus( bool& received ) : m_received( received ) { } bool operator()() const { return m_received; } private: bool& m_received; }; //blocking request std::string Request( const std::string& request ) { boost::mutex::scoped_lock lock( mutex ); //perform asynchronous request through network or something else, pass RequestHandler as a handler boost::posix_time::milliseconds timeoutDuration( 10000 ); //wait for 10 seconds if( !condition.timed_wait( lock, timeoutDuration, ResponseStatus( received ) ) ) { throw std::exception( "Request timed out" ); } return receivedMessage; } //some other thread calls this function void RequestHandler( const std::string& message, void* caller ) { BlockingRequest* myRequest = reinterpret_cast< BlockingRequest* >( caller ); boost::mutex::scoped_lock lock( myRequest->mutex ); myRequest->receivedMessage = message; myRequest->received = true; /* if this next line in bold is commented out, code works fine... contrary to Boost documentation. http://www.boost.org/doc/libs/1_41_0/doc/html/thread/synchronization.html#t… */ *lock.unlock();* myRequest->condition.notify_one(); } };

4 8

privately inherit enable_shared_from_this?
by Eric J. Holtman 11 Dec '09

11 Dec '09

I have some code that uses enable_shared_from_this. I was publicly deriving, i.e. (and this works) class Request : public boost::enable_shared_from_this<Request> { }; I wanted to change my code around so that I wrapped the shared_from_this function inside the class, so that I could check at runtime whether certain conditions hold, i.e. class Request : private boost::enable_shared_from_this<Request> { public: boost::shared_ptr<Request> get_ptr () { if (conditions_are_good) return shared_from this (); else throw std::logic_error ("Bad get"); }; }; This won't compile (visual studio 2008). 1>Compiling... 1>Request.cpp 1>c:\boost\boost_1_40_0\boost\smart_ptr\enable_shared_from_this.hpp(50) : error C2243: 'type cast' : conversion from 'Request *' to 'boost::enable_shared_from_this<T> *const ' exists, but is inaccessible 1> with 1> [ 1> T=Request 1> ] 1> c:\boost\boost_1_40_0\boost\smart_ptr\enable_shared_from_this.hpp(48) : while compiling class template member function 'boost::shared_ptr<T> boost::enable_shared_from_this<T>::shared_from_this(void)' 1> with 1> [ 1> T=Request 1> ] 1> c:\src\cpp\trunk\request_lib\request.h(48) : see reference to class template instantiation 'boost::enable_shared_from_this<T>' being compiled 1> with 1> [ 1> T=Request 1> ] Can I get this to work?

3 3

[integer]/cstdint.hpp How to use portable literals?
by vicente.botet 11 Dec '09

11 Dec '09

Hi, I need to use boost::intmax_t literals in a portable way. I remember some discussion related to this subject, but I've not found the thread. Could someone point me to these threads, or tell me how I can achieve this. I'm currently using the macro INTMAX_C, but it seems that this macro is not always defined. Thanks, _____________________ Vicente Juan Botet Escribá

9 17

Recognition simple variables, pointers and arrays
by Alex Vinokur 11 Dec '09

11 Dec '09

Hi, Is there any Boost method/class that enables to recognize simple variables, pointers, arrays in C++? Something like: http://groups.google.com/group/alt.sources/browse_thread/thread/8b059c1df87… Alex

2 2

[chrono] New Features + Bug fixes + Updated documentation
by vicente.botet 11 Dec '09

11 Dec '09

Hi, I'm pleased to annonce the new version of the Boost.Chrono library. Even if the library is not yet ready for review I wanted to share it with you. The library can be downloaded from the vault http://www.boostpro.com/vault/index.php?action=downloadfile&filename=chrono… and the documentation is online on the sandbox http://svn.boost.org/svn/boost/sandbox/chrono/libs/chrono/doc/html. For the moment I'm not able to test it on Windows and Mac platforms. Could you check if there are some regressions on Windows or on Mac platforms? Of course, any comments or suggestions are welcome. If there is a volontary review manager that can start inspecting the library s/he is also welcome :). This library is based on the Beman's boostified version of the probe of concept of Howard. Many thanks to Howard the originator of the library and to Beman to start the boostification. Next follows the contents of the library and the updates of the new version Version 0.1.0, April 29, 2009 Beman's boostified version Features: * The C++0x Standard Library's class common_type. * The C++0x Standard Library's compile-time rational arithmetic. * The C++0x Standard Library's time utilities, including: * Class template duration * Class template time_point * Clocks: * system_clock * monotonic_clock * high_resolution_clock * Class template timer, with typedefs: * system_timer * monotonic_timer * high_resolution_timer * Process clocks and timers: * process_clock, capturing real, user-CPU, and system-CPU times. * process_timer, capturing elapsed real, user-CPU, and system-CPU times. * run_timer, convenient reporting of process_timer results. Version 0.2.0, December 8, 2009 + New Features + Bug fixes + Updated documentation Features: * Added ratio construction and assignment from an equivalent ratio (LWG 1281. CopyConstruction and Assignment between ratios having the same normalized form) * Added nested ratio typedef type (LWG 1281. CopyConstruction and Assignment between ratios having the same normalized form) * Added BOOST_CHRONO_HAS_CLOCK_MONOTONIC macro to state if monotonic_clock is provided on a platform. * Added duration operator% (LWG 934. duration is missing operator%) * Complete duration operator* and operator/ Implementation: * Use INTMAC_C to name intmax_t constants instead of LL. * Separate chrono.cpp on # files win/chrono.cpp, mac/chrono.cpp and posix/chrono.cpp to make easier the maintenance on different platforms. * Separate process_clock.cpp on # files win/process_clock.cpp, mac/process_clock.cpp and posix/process_clock.cpp to make easir the maintenace on different platforms. * Added the error_code prototype for monotonic_clock::now for mac/chono.cpp * Fully implement mac/chrono.cpp with error handling. * Take care on POSIX systems when CLOCK_MONOTONIC is not defined. Documentation: * The documentation is written now using quick-book using as base "N2661 - A Foundation to Sleep On". Fixed Bugs * operator/ was ambiguous: Disambiguate duration operator/ * CLOCK_MONOTONIC is not defined with cygwin/gcc 3.4: Disable code when BOOST_CHRONO_HAS_CLOCK_MONOTONIC is not defined. * result of metafunctions ratio_multiply and ratio_divide were not normalized ratios: Use of the nested ratio typedef type on ratio arithmetic operations. * Copy constructor from similar duration masked the defaulted operations: Added duration defaulted implementations Note that the comon_type class should be integrated by Boost.TypeTraits, class ratio will be proposed as a standalone library Boost.Ratio, and the Timer and Process clock part could be proposed as an update of Boost.Timer. Best regards, _____________________ Vicente Juan Botet Escribá

2 2

multi-index/interprocess find key must be allocated in shared memory?
by Jerry Hicks 11 Dec '09

11 Dec '09

Hi, I have a multi_index set working nicely in shared memory but I'm trying to figure out how to search one of my indices without allocating the search key in shared memory. Assuming my index is based on a char_string (basic_string with a segment manager allocator), is there an easy way to perform a find() operation that can use a const char *key? Trying to avoid the rather substantial overhead of instantiating my const char *key as a char_string in shared memory. Any other suggestions how I might organize things to avoid the situation would be welcomed.. Cheers, Jerry Hicks

2 2

[BoostCon 2010] Submission deadline extended
by Hartmut Kaiser 11 Dec '09

11 Dec '09

In 2010 BoostCon celebrates its 4th anniversary in Aspen. You are invited to submit a paper or a session (see the original call for participation here: http://www.boostcon.com/community/wiki/show/Start/) for BoostCon 2010, Aspen on May 10 - May 14th, 2010. Please, see http://www.boostcon.com for more information. Important dates: Proposal submissions Extended to January 3, 2010 Proposals decisions sent January 25, 2010 (tentative program available) Fully scheduled program available February 10, 2010 Session materials due April 15, 2010 Hartmut Kaiser, email: hartmut.kaiser(a)gmail.com (Program Committee Chair) David Abrahams, email: dave(a)boostpro.com (Conference Chair) On behalf of the conference organizers

1 0

Re: [Boost-users] Simple serial port demonstration with boost asio asynchronous I/O
by philipp_muenzel＠web.de 11 Dec '09

11 Dec '09

Hello, in reply to this old posting: http://lists.boost.org/boost-users/2008/10/41140.php I would like to kindly ask the author Jeff Gray if he tested his example on a Mac. On Linux, the example works flawlessly and lets me communicate with both "native" serial port hardware and USB-to-serial converted hardware with FTDI chips, which can be adressed via /dev/ttyUSB. On a Power Mac with OS Tiger, using boost 1.40 and the gcc 4.0 compiler, everytime I start the example I get the following errors: $ ./minicom.app/Contents/MacOS/minicom 57600 /dev/cu.usbserial-4B11 Error: Operation not supported Press Enter to exit Error: Bad file descriptor Press Enter to exit However, I can talk to the serial-via-usb hardware using some native socket functions, so the file descriptor itself can't be the problem. How can I get the minicom example to work on Mac also? Regards, Philipp ___________________________________________________________ Preisknaller: WEB.DE DSL Flatrate für nur 16,99 Euro/mtl.! http://produkte.web.de/go/02/

1 0

Workaround for g++ problem compiling Boost.Asio examples on Ubuntu 8.04.3
by David Featherstone 11 Dec '09

11 Dec '09

I'm running Ubuntu 8.04.3 as a VMware virtual machine hosted by Windows XP on a Lenovo T61 laptop. Synaptic Package Manager [or apt-get] on Ubuntu 8.04.3 offers both the libboost-dev v1.34.1 and the libasio-dev v0.3.8 packages with pre-built libraries. Version 1.34 of Boost does not have an integrated asio library; asio integration appears in v1.35 and later versions of Boost. Source code for the problematic example program can be found here: http://www.boost.org/doc/libs/1_41_0/doc/html/boost_asio/tutorial/tuttimer4… Source listing for Timer.4 The first compile problem occurs at the second #include: #include <boost/asio.hpp> The compiler cannot find this header because asio.hpp was installed under /usr/include rather than under /usr/include/boost. I fixed this issue by creating a soft link to /usr/include/asio.hpp in /usr/include/boost: $ sudo ln -s ../asio.hpp /usr/include/boost/asio.hpp Solving the second compile problem proved more difficult. The second compile problem occurred at the first use of the boost::asio namespace: printer(boost::asio::io_service& io) Changing all occurrences of 'boost::asio' to simply 'asio' solves this problem, but makes tedium of playing with the examples and developing new code that will be compatible with v1.35+ of Boost. Instead, I employed namespace declarations to (artificially) nest the asio namespace within the boost namespace. This artificial nesting is straight-forward - a single line of code: #include <iostream> #include <boost/asio.hpp> #include <boost/bind.hpp> #include <boost/date_time/posix_time/posix_time.hpp> namespace boost { namespace asio { using namespace ::asio; } } class printer { public: printer(boost::asio::io_service& io) o o o Caution: I have not made exhaustive tests of this workaround, but it does compile [g++ 4.2.4] , link, and run on my platform: $ g++ -o timer timer.cpp -lboost_thread $ ./timer 0 1 2 3 4 Final count is 5 You may find more helpful information here, from the developer of the asio library: http://blog.think-async.com/ http://blog.think-async.com -- View this message in context: http://old.nabble.com/Workaround-for-g%2B%2B-problem-compiling-Boost.Asio-e… Sent from the Boost - Users mailing list archive at Nabble.com.

2 2

default mpi implementation
by Sean Farrow 11 Dec '09

11 Dec '09

Hi: Could someone give me a url for the default mpi compiler used with boost.mpi, I believe this is mpi++ but could be wrong. Any help appreciated. Sean.

1 0

Including only the needed boost headers.
by Al Gambardella 11 Dec '09

11 Dec '09

I am currently using the tokenizer library to do some simple log file processing. I am the only person on my team currently using the boost libraries. This code I wrote was originally just a utility for myself so I was able to get away with installing boost "only" on my PC. Now others on the team want to use my utility. Is there a way I can share this code with them without forcing them to install boost on there PCs? I am only using a very very small portion of the boost library so I think it would be overkill to make everyone install boost. Can I create a DLL or library to solve this? If this helps... I am running visual studio 2005. My project is not GUI based. Thanks

4 3

Re: [Boost-users] [ASIO] Wrong usage of streambuf ?
by Imran Fanaswala 11 Dec '09

11 Dec '09

> Date: Tue, 08 Dec 2009 15:03:46 +0100 > From: Axel <axel.boost(a)laposte.net> > To: boost-users(a)lists.boost.org > Subject: [Boost-users] [ASIO] Wrong usage of streambuf ? > Message-ID: <4B1E5CC2.6040103(a)laposte.net> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Hello > > I m writing a simple client/server program. On a request the server > answers "ok\r\n". It works well. I have a problem with the client. > Using async functions, I don't manage to handle the response from the > server. Once the server sent the response, I want to read the data, > close the socket, and open a new connection to the server. > > When I don't read the data sent by the server, I manage to close the > socket and repeat the operation (close the socket, and reconnect to the > server). > When I read the data, the program seems to block. > > /* Callback to the async_write function. On any request, the server > sends "ok\r_n" */ > void Client::handle_write(boost::asio::ip::tcp::socket* socket, const > boost::system::error_code& err) > { > if(!err) > { > cout << "Read..." << endl ; > // response_ is a boost::asio::streambuf variable > boost::asio::async_read_until(*socket, response_, "\r\n", > boost::bind(&Client::handle_read, this, socket, > boost::asio::placeholders::error, > boost::asio::placeholders::bytes_transferred)) ; > } > else > { > cout << "Error when writing to host: " << err.message() << "\n" ; > } > } > > void Client::handle_read(boost::asio::ip::tcp::socket* socket, const > boost::system::error_code& err, size_t bytes_transferred) > { > cout << bytes_transferred << " bytes received. " << endl ; > > /* Dont count the 2 bytes long "\r\n" string */ > int message_size = bytes_transferred - 2 ; > > > char * response_char = new char[message_size + 1] ; > response_char[message_size] = '\0' ; > response_stream.read(response_char, message_size) ; > string result(response_char) ; > delete response_char ; > response_.consume(2) ; > > socket->close() ; > delete socket ; > connect() ; > return ; > } > > If I skip the block where I read the response_ into a string, the > program works flawlessly. If I try to read the response from the > streambuf variable, the program is blocked at the next call to > async_read_until() */ > So I guess that I m doing something wrong with the streambuf variable > named "response_", but I dont understand what. Can someone explain me > what is wrong ? > > Thanks in advance. > I am not really sure what response_stream is, but I see what you are trying to do. Consider doing the following instead: void Client::handle_read(boost::asio::ip::tcp::socket* socket, const boost::system::error_code& err, size_t bytes_transferred) { ... //Note: data, will contain the "ok\r\n".. so just do some string manip to get rid of it const char* data=boost::asio::buffer_cast<const char*>(response_.data()); response_.consume(bytes_transferred); //This is the key... ... }

1 0

sending a serialized object using message_queue
by Luciano Afranllie 11 Dec '09

11 Dec '09

Hi, I am trying to send a serialized object using message_queue but I am getting a boost::interprocess_exception::library_error in the sender side. I think the problem is me but after a lot of google I could not find a way to make it work This is the method where I am trying to send the message: int RemoteMgr::sendMsgToPeers(const IPCMsg &msg) { std::cout << "RemoteMgr::sendMsgToPeers()\n"; std::ostringstream archive_stream; boost::archive::text_oarchive archive(archive_stream); archive << msg; std::string outbound_data = archive_stream.str(); std::vector<char> outbound(outbound_data.begin(), outbound_data.end()); std::cout << "outbound_data = [" << outbound_data << "]\n"; std::cout << "size = " << outbound.size() << "\n"; // TODO: Not working yet. How to send a string with serialized data? message_queue mq_master(open_only, "master_queue"); mq_master.send(&outbound, outbound.size(), 0); } Where IPCMsg is class IPCMsg { public: IPCMsg() {} IPCMsg(const std::string &type, const std::string &payload); ~IPCMsg(); std::string getSender() { return m_sender; } std::string getType() { return m_type; } std::string getPayload() { return m_payload; } template<class Archive> void serialize(Archive & ar, const unsigned int /* file_version */) { ar & BOOST_SERIALIZATION_NVP(m_sender) & BOOST_SERIALIZATION_NVP(m_type) & BOOST_SERIALIZATION_NVP(m_payload); } private: std::string m_sender; std::string m_type; std::string m_payload; }; Receiver code is like this: unsigned int priority; std::size_t recvd_size; IPCMsg msg; std::vector<char> inbound_data(100); std::cout << "Waiting for peers" << std::endl; while (!terminate) { if (mq.try_receive(&inbound_data, inbound_data.size(), recvd_size, priority)) { std::cout << "New message received.\n"; std::string archive_data(&inbound_data[0], inbound_data.size()); std::istringstream archive_stream(archive_data); boost::archive::text_iarchive archive(archive_stream); archive >> msg; std::cout << "msg type = " << msg.getType() << "\n"; } } Hope you can help. Thanks! Luciano

1 0

[ASIO] Wrong usage of streambuf ?
by Axel 11 Dec '09

11 Dec '09

Hello I m writing a simple client/server program. On a request the server answers "ok\r\n". It works well. I have a problem with the client. Using async functions, I don't manage to handle the response from the server. Once the server sent the response, I want to read the data, close the socket, and open a new connection to the server. When I don't read the data sent by the server, I manage to close the socket and repeat the operation (close the socket, and reconnect to the server). When I read the data, the program seems to block. /* Callback to the async_write function. On any request, the server sends "ok\r_n" */ void Client::handle_write(boost::asio::ip::tcp::socket* socket, const boost::system::error_code& err) { if(!err) { cout << "Read..." << endl ; // response_ is a boost::asio::streambuf variable boost::asio::async_read_until(*socket, response_, "\r\n", boost::bind(&Client::handle_read, this, socket, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)) ; } else { cout << "Error when writing to host: " << err.message() << "\n" ; } } void Client::handle_read(boost::asio::ip::tcp::socket* socket, const boost::system::error_code& err, size_t bytes_transferred) { cout << bytes_transferred << " bytes received. " << endl ; /* Dont count the 2 bytes long "\r\n" string */ int message_size = bytes_transferred - 2 ; char * response_char = new char[message_size + 1] ; response_char[message_size] = '\0' ; response_stream.read(response_char, message_size) ; string result(response_char) ; delete response_char ; response_.consume(2) ; socket->close() ; delete socket ; connect() ; return ; } If I skip the block where I read the response_ into a string, the program works flawlessly. If I try to read the response from the streambuf variable, the program is blocked at the next call to async_read_until() */ So I guess that I m doing something wrong with the streambuf variable named "response_", but I dont understand what. Can someone explain me what is wrong ? Thanks in advance.

5 8

[LibrariesUnderConstruction] Please update Boost.Coroutines entry
by Nat Goodspeed 11 Dec '09

11 Dec '09

Links: Boost Vault: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=boost-… Last upload: 2009 Dec 01 Thank you!

2 2

ASIO: udp datagrams question
by Jay Sprenkle 10 Dec '09

10 Dec '09

When using asio with an async udp connection can I assume I will always receive a complete datagram or nothing at all? If packets are lost I will get nothing. If I get a data read callback I can assume the entire datagram has been received and assembled (even if it consisted of multiple packets)? Some of the underlying assumptions aren't clear from the documentation. Thanks! -- Cause united breaks guitars http://www.youtube.com/watch?v=5YGc4zOqozo

1 0

program_options: main and other translation units
by Hicham Mouline 10 Dec '09

10 Dec '09

Hello, I have a main.cpp translation unit with the main(int argc, char* argv[]) function. My application runs in 1 of 4 modes. The mode is selected by the command line options, something like --mode1 --mode2 --mode3 --mode4 In main(), I have defined a mode_options instance of options_description, added these modes to it and defined the variables_map 'vm' that will be passed around to functions (1 for each mode) that reside in other translation units. I then get to a try/catch block, where: I store( command_line_parser(argc, argv).options(mode_options).run(), vm ); notify(vm); I have a sanity check that only 1 and at least 1 of the 4 modes is selected. I then call the function relevant to the mode selected, and pass to it 'vm'. In each of these other functions, I have other instances of options_description, reuse the same 'vm' and store again in vm the parsing ran on the appropriate options_description instance. Each mode option has specific suboptions. Question 1: I want the help option to print usage for all modes and all suboptions if no mode is selected. I want the help option to print usage for just 1 mode if a mode is selected. Question 2: I still want to program_options to throw if an unrecognized option is input, however, I throw my own exceptions if an option for mode_i is set with --mode_j for e.g. Question 3: I may eventually move to a GUI (probably c#-based) for passing options. Is there any particular advice to isolate the machinery of program_options from the functional part of my application. A big thanks to the library developer(s) and to the mailing list contributors for all the useful answers. Best regards, H

2 1

mpl: POD decoration with constructors and getters/setters
by Hicham Mouline 10 Dec '09

10 Dec '09

Hello, I posted a question to comp.lang.c++ first and now realize this maybe a mpl or PP question as well. Here is the original question: > Hicham Mouline wrote: >> I have functions that each take 1 parameter. This parameter is of type >> >> struct S { >> <arithmetic_or_bool_type_1> member_name_1; >> <arithmetic_or_bool_type_n> member_name_n; >> }; // n can be of order 10 or so >> >> class C { >> public: >> return_type apply( const S& ) const; >> }; >> >> Now I want to optimize the returned value. > > "Optimize"? > >> I would optimize by fixing any subset of the n members fixed, ie none at >> all, or just member 5, or members 4 and 8, or members 7,3 and n, or n-1 >> members of the {1....n} set. >> >> How can I do this? >> >> maybe >> >> class C{ >> public: >> pair<return_type, S> optimize(...) const; // returns the optimum S >> that gives the best return value > > What's "return_type" here? What does it mean for the return value to be > "the best"? > >> }; >> >> Some interface like this looks nice to me (as a user). >> >> The question is how to pass the fixed members to optimize. A response came as: > If your 'return_type' has to be the same *type*, there is no better > solution than to return an 'S', if the members that you don't want to > "return" are set to some "invalid" value. As an alternative you could > consider supplying another member to 'S', which would indicate the "valid" > or "active" members. You can have another (nested) struct in 'S' with bit > fields: > > struct S { > ... // as you have now > struct { > unsigned use_1:1; > unsigned use_2:1; > ... > unsigned use_n:1; > } which_members_to_use; > }; > My intial email not being clear, further clarifications are here: return_type is just double. C c; S s1; c.apply( s1 ); //// returns double , say 15.0 By optimize, I mean in most cases maximize, but sometimes minimize. So I'm trying to get the largest double by changing parts or all of s1. I was thinking of some metaprogramming magic that would generate automatically S constructors with arguments all the possible subsets of the member fields, and depending on the ctor selected by the user, would set those bits in the nested struct appropriately. This could generate also getters/setters that the optimize function could use. This could be a metafunction that returns a type SS based on the type S. I realize this is definitely a question for boost as well. The C::optimize function would then return the "optimal" S, along with the maximum/minimum double found. The details and meaning of the optimization would be specific to C::optimize. Best regards,

1 0

Boost Unit Testing Macros on Visual Studio 2005/Visual C++ 8.0
by Andrew Leer 10 Dec '09

10 Dec '09

I'm reading this article (http://www.ibm.com/developerworks/aix/library/au-ctools1_boost/?S_TACT=105A…) on the Boost Unit Testing Framework. However I'm having a bit of trouble with the first example, my guess is that they left something out (something that would be obvious to hardcore C++ coders) as IBM often does in their articles. Another possibility is that my Visual Studio 2005 C++ compiler is just too old for the example. #define _MYSTRING #define BOOST_TEST_MODULE stringtest #include <boost/test/unit_test.hpp> #include "stdafx.h" //#include "mystring.h" BOOST_AUTO_TEST_SUITE (stringtest) // name of the test suite is stringtest BOOST_AUTO_TEST_CASE (test1) { /* mystring s; BOOST_CHECK(s.size() == 0); */ BOOST_CHECK(0 == 0); } BOOST_AUTO_TEST_CASE(test2) { /* mystring s; s.setbuffer("hello world"); BOOST_REQUIRE_EQUAL('h', s[0]); // basic test */ BOOST_CHECK(0 == 0); } BOOST_AUTO_TEST_SUITE_END( ) To me the BOOST_AUTO_TEST_SUITE and BOOST_AUTO_TEST_CASE lines look a little suspect (especially since they don't have quotes around the arguments, and they are undeclared identifiers...but this probably means they are macros and I'm not certain I understand the concept or if that is available in VC++ 8.0)... Is there any reason why this code won't work? Bellow are the errors I'm receiving: 1>c:\users\andy\documents\visual studio 2005\projects\unittesttests\unittesttests\unittesttests.cpp(7) : error C2065: 'stringtest' : undeclared identifier 1>c:\users\andy\documents\visual studio 2005\projects\unittesttests\unittesttests\unittesttests.cpp(9) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int 1>c:\users\andy\documents\visual studio 2005\projects\unittesttests\unittesttests\unittesttests.cpp(9) : error C2146: syntax error : missing ';' before identifier 'BOOST_AUTO_TEST_CASE' 1>c:\users\andy\documents\visual studio 2005\projects\unittesttests\unittesttests\unittesttests.cpp(9) : error C2065: 'test1' : undeclared identifier 1>c:\users\andy\documents\visual studio 2005\projects\unittesttests\unittesttests\unittesttests.cpp(10) : error C2448: 'BOOST_AUTO_TEST_CASE' : function-style initializer appears to be a function definition 1>c:\users\andy\documents\visual studio 2005\projects\unittesttests\unittesttests\unittesttests.cpp(18) : error C2065: 'test2' : undeclared identifier 1>c:\users\andy\documents\visual studio 2005\projects\unittesttests\unittesttests\unittesttests.cpp(19) : error C2448: 'BOOST_AUTO_TEST_CASE' : function-style initializer appears to be a function definition 1>c:\users\andy\documents\visual studio 2005\projects\unittesttests\unittesttests\unittesttests.cpp(29) : fatal error C1004: unexpected end-of-file found

5 13

socket type?
by pedro chaparro 10 Dec '09

10 Dec '09

hi, i wanna to pass the same socket decriptor among differents functions, that way all work over the same socket, but i'm no sure what kinf o data is a socket descriptor? what kind o data must retunr my function? thanks ? getsocket() { } -- Ing Pedro Alonso Chaparro Valero Ciudad Politecnica de la Innovación iTEAM - Mobile Communications Group Polytechnic University of Valencia C\ Camino de Vera S/N, Edificio 8G 46022 Valencia, Spain

2 1

[interprocess] mapped_region::flush()
by Stefan Strasser 10 Dec '09

10 Dec '09

Hi, I have a few questions regarding mapped_region. 1. first of all, is mapped_region::flush() safe to use? on linux it is implemented as msync(MS_SYNC) which seems fine, but on windows it uses FlushViewOfFile alone, which IIUC does not flush the changes to disk. MSDN: "The FlushViewOfFile function [...] does not wait to return until the changes are flushed from the underlying hardware disk cache and physically written to disk. To flush all the dirty pages plus the metadata for the file and ensure that they are physically written to disk, call FlushViewOfFile and then call the FlushFileBuffers function." I'm not sure if they really mean "hardware disk cache", since no sync or flush function can entirely make sure of that. but FlushFileBuffers is documented to flush operating system buffers. and the quote above says a call to FlushFileBuffers is necessary. 2. can the mapped memory be accessed while another thread is calling flush()? does that affect the flushing? it is still required that all data that was written to the mapped region at the point of the flush() call is written to disk when it returns. Interprocess' documentation doesn't say anything about that and I can't seem to find any information about that on the underlying functions mmap/FlushViewOfFile either. and 3, not entirely boost related: I get some strange performance results using mapped_region::flush() on linux (not tested on windows so far). I already reduced the flush() calls to a minimum but I still get better performance in many cases using my own filebuf implementation that performs paging without hardware support, using a std::filebuf. using std::filebuf shouldn't be faster than hardware file mapping. when I call flush() relatively frequently that in itself drives performance down, but when I call it less frequently it blocks for noticeable amounts of time. (thus, question 2) do the offset/size arguments to mapped_region::flush() affect performance? I could track what pages are changed, but I was under the assumption the OS already does that. Thanks

2 2

Runtime error with Boost's unit test framework
by Joey Mink 10 Dec '09

10 Dec '09

Hi all, I'm a newbie using the boost unit test framework. I'm getting a run-time exception that presents itself with the following message: Unhandled exception at 0x61c3b130 (msvcr80d.dll) in test.exe: 0xC0000005: Access violation reading location 0xcccccccc. If I step through the code, the exception is thrown the 3rd time this line from Boost is invoked: unit_test_suite_impl.hpp:111 callback0<> const& test_func() const { return m_test_func; } I can't seem to uncover what the problem is - has anyone else had this problem? Might anyone have any insight to my possible misuse of it? I'm linking with libboost_program_options-vc80-mt-gd-1_41.lib. Running Visual Studio 2005 (VC8) Thanks! Joey

4 3

boost::lambda questions
by Peter Foelsche 09 Dec '09

09 Dec '09

I would like to be able to: * return multiple results from a lambda function * use temporary variables inside a lambda function, declared using BOOST_AUTO * I would need the ability to deduce the type of the returned values via BOOST_AUTO to declare the matching variables. I think I could use boost::tuple for this: const BOOST_AUTO(sTupleVar, someThing); const BOOST_AUTO(sFirstResult, get<0>(sTupleVar)); const BOOST_AUTO(sSecond, get<1>(sTupleVar)); But how to declare a local variable inside a lambda function? Peter

2 1

Re: [Boost-users] Problem using Boost regex
by John Emmas 09 Dec '09

09 Dec '09

[Addendum...] Following my original post, firstly, apologies - I should have mentioned that I'm trying to build the regex example using Visual Studio 8 Express Edition (i.e. VC++2005). Also, I've got some more information.... Apart from those libs that I mentioned in my original post, I've found a whole bunch of libs beginning with "libboost-regex-vc80-" and ending with these suffixes:- mt-1_40.lib mt-gd-1_40.lib mt-s-1_40.lib mt-sgd-1_40.lib s-1_40.lib I guess these must be the static link libs. Anyway, I've discovered that if I link to any lib that ends in "mt-1_40.lib" I can build my app and launch it successfully as long as I build in Release mode. But in Debug mode, the app either doesn't launch - or if it does launch, it gives the unhandled exception that I described earlier. Hope that helps, John

4 19

ASIO async I/O with iostream?
by Jay Sprenkle 09 Dec '09

09 Dec '09

Good afternoon all, I'm interested in writing a program using asio. I'm new to both boost and asio. Is it possible to use async I/O with streams? A stream is a good method for what I'm interested in doing but I don't see how to make it work. What I've got so far: A class using event driven async I/O. The class parses the data into variable arbitrary sized messages. I read from the tcp socket into a buffer, then create a stream from the buffer, then deserialize the data from the stream. unsigned char buffer[1024]; // connect receive event socket->async_read_some( boost::asio::buffer(buffer), boost::bind( &TcpConnection::receive, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred ) ); I'd like to be able to skip the buffer and just read directly to the stream with an event to notify me of the arrival of data. Thanks! -- Cause united breaks guitars http://www.youtube.com/watch?v=5YGc4zOqozo

2 3

Bug in mingw with gcc 4.3.0: boost_concept_check.h
by Eloi Du Bois 09 Dec '09

09 Dec '09

Hi all, I found a probable bug in mingw. Here is the minimal code that can not compile: #include <boost/ptr_container/ptr_list.hpp> > > #include <iostream> > > class A > { > public: > A(const int id):_id(id){} > virtual ~A()=0; > bool operator==(const A& other) const { return _id == other._id; } > int _id; > }; > > A::~A(){} > > class B : public A > { > public: > B(const int id):A(id){} > virtual ~B() {} > }; > > class C : public A > { > public: > C(const int id):A(id){} > virtual ~C() {} > }; > > int main() { > typedef boost::ptr_list<A> AList; > AList a,b; > a.push_back( new B(0) ); > a.push_back( new C(1) ); > b.push_back( new B(0) ); > b.push_back( new C(1) ); > > return a == b; > } > And the compilation error: gcc.compile.c++ > T:\Analyse1\dist\lib\bin\gcc-mingw-4.3.0\debug\threading-multi\src\main.o > c:\qt\mingw\bin\../lib/gcc/mingw32/4.3.0/include/c++/bits/boost_concept_check.h: > In instantiation of '__gnu_cxx::_EqualOpConcept<A, A>': > c:\qt\mingw\bin\../lib/gcc/mingw32/4.3.0/include/c++/bits/boost_concept_check.h:62: > instantiated from 'void __gnu_cxx::__function_requires() [with _Concept = > __gnu_cxx::_EqualOpCon > cept<A, A>]' > c:\qt\mingw\bin\../lib/gcc/mingw32/4.3.0/include/c++/bits/stl_algobase.h:943: > instantiated from 'bool std::equal(_II1, _II1, _II2) [with _II1 = > boost::void_ptr_iterator<std::_List_ > const_iterator<void*>, const A>, _II2 = > boost::void_ptr_iterator<std::_List_const_iterator<void*>, const A>]' > T:\Analyse1\3rdParty\boost/boost/ptr_container/detail/reversible_ptr_container.hpp:531: > instantiated from 'bool > boost::ptr_container_detail::reversible_ptr_container<Config, CloneA > llocator>::operator==(const > boost::ptr_container_detail::reversible_ptr_container<Config, > CloneAllocator>&) const [with Config = > boost::ptr_container_detail::sequence_config<A, std:: > list<void*, std::allocator<void*> > >, CloneAllocator = > boost::heap_clone_allocator]' > tests\src\main.cpp:38: instantiated from here > c:\qt\mingw\bin\../lib/gcc/mingw32/4.3.0/include/c++/bits/boost_concept_check.h:296: > error: cannot declare field '__gnu_cxx::_EqualOpConcept<A, A>::__a' to be of > abstract type 'A' > tests\src\main.cpp:6: note: because the following virtual functions are > pure within 'A': > tests\src\main.cpp:14: note: virtual A::~A() > c:\qt\mingw\bin\../lib/gcc/mingw32/4.3.0/include/c++/bits/boost_concept_check.h:296: > error: cannot declare field '__gnu_cxx::_EqualOpConcept<A, A>::__b' to be of > abstract type 'A' > tests\src\main.cpp:6: note: since type 'A' has pure virtual functions > > "g++" -ftemplate-depth-128 -O0 -fno-inline -Wall -g -mthreads > -DBOOST_SYSTEM_DYN_LINK=1 -I"T:\Analyse1\3rdParty\boost" -I"tests\src" -c > -o "T:\Analyse1\dist\lib\bin\gcc-mingw- > 4.3.0\debug\threading-multi\src\main.o" "tests\src\main.cpp" > The problem might come from this: #define _GLIBCXX_DEFINE_BINARY_OPERATOR_CONSTRAINT(_OP,_NAME) \ template <class _Ret, class _First, class _Second> \ struct _NAME { \ void __constraints() { (void)__constraints_(); } \ _Ret __constraints_() { \ return __a _OP __b; \ } \ _First __a; \ _Second __b; \ } I hope it comes from me and not from boost... If anyone have an idea of what I can do to solve this, It would be great :) Regards, Eloi.

1 0

Problem building boost on Windows
by Nathan Ridge 09 Dec '09

09 Dec '09

Hello, I'm having some trouble building the Boost libraries on Windows. - My OS is Windows Vista SP2 - My compiler in MinGW g++ 4.4. The folder containing the g++ executable is in my PATH environment variable. This is what I've done: - Downloaded the latest version (1.41) of the Boost libraries from www.boost.org and extracted it to C:\Dev\Libraries\boost (so e.g. C:\Dev\Libraries\boost\libs is a subfolder) - Downloaded the latest version (3.1.17) of Boost Jam from http://sourceforge.net/projects/boost/files/boost-jam and extracted bjam.exe into C:\Dev\Libraries\boost - Opened up a command prompt, cd'd into C:\Dev\Libraries\boost - Ran the command "bjam --with-filesystem variant=release link=static threading=single toolset=gcc" The output, up to the first error, is the following: == START BJAM OUTPUT == WARNING: No python installation configured and autoconfiguration failed. See http://www.boost.org/libs/python/doc/building.html for configuration instructions or pass --without-python to suppress this message and silently skip all Boost.Python targets Building the Boost C++ Libraries. After the build, the headers will be located at C:\Dev\Libraries\boost The libraries will be located at C:\Dev\Libraries\boost\stage\lib Use 'bjam install --prefix=<path>' if you wish to install headers and libraries to a different location and remove the source tree. ...patience... ...found 441 targets... ...updating 27 targets... common.mkdir stage common.mkdir stage\lib common.mkdir bin.v2 common.mkdir bin.v2\libs common.mkdir bin.v2\libs\system common.mkdir bin.v2\libs\system\build common.mkdir bin.v2\libs\system\build\gcc-mingw-4.4.0 common.mkdir bin.v2\libs\system\build\gcc-mingw-4.4.0\release common.mkdir bin.v2\libs\system\build\gcc-mingw-4.4.0\release\link-static gcc.compile.c++ bin.v2\libs\system\build\gcc-mingw-4.4.0\release\link-static\error_code.o g++: libs\system\src\error_code.cpp: No such file or directory g++: no input files "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -DBOOST_ALL_NO_LIB=1 -DBOO ST_SYSTEM_STATIC_LINK=1 -DNDEBUG -I"." -c -o "bin.v2\libs\system\build\gcc-mingw-4.4.0\release\link -static\error_code.o" "libs\system\src\error_code.cpp" ...failed gcc.compile.c++ bin.v2\libs\system\build\gcc-mingw-4.4.0\release\link-static\error_code.o. .. ...skipped <pbin.v2\libs\system\build\gcc-mingw-4.4.0\release\link-static>libboost_system-mgw44-1_41 .lib(clean) for lack of <pbin.v2\libs\system\build\gcc-mingw-4.4.0\release\link-static>error_code.o. .. ...skipped <pbin.v2\libs\system\build\gcc-mingw-4.4.0\release\link-static>libboost_system-mgw44-1_41 .lib for lack of <pbin.v2\libs\system\build\gcc-mingw-4.4.0\release\link-static>error_code.o... ...skipped <pstage\lib>libboost_system-mgw44-1_41.lib for lack of <pbin.v2\libs\system\build\gcc-min gw-4.4.0\release\link-static>libboost_system-mgw44-1_41.lib... [more similar errors] == END BJAM OUTPUT == So for some reason, it cannot find libs\system\src\error_code.cpp, which is actually located at C:\Dev\Libraries\boost\libs\system\src\error_code.cpp. Am I supposed to somehow specify the exact path where it should be looking? I tried adding the option --build-dir=C:\Dev\Libraries\boost, but I still get the same error. One suspicious thing that I noticed is that without the --build-dir option, the bin.v2 folder that is created is C:\Dev\bin.v2, as opposed to C:\Dev\Libraries\boost\bin.v2 or something like that. Not sure if this is related to my problem or not. What am I doing wrong? Thanks, Nate. _________________________________________________________________ Windows Live: Keep your friends up to date with what you do online. http://go.microsoft.com/?linkid=9691815

3 5

how to delete references to objects from a container...
by rv_nath 09 Dec '09

09 Dec '09

Hi forum members, I want to use boost's shared_ptr class for the connection pool class that i am writing. However, i have a requirement to delete the connection object (which is going to be the shared-ptr) explicitly based on certain checks like validity and expiry etc. If I store the shared_ptr, I want to know how to delete this explicitly from the stl container. According to my understanding shared_ptrs cannot be 'delete'd. So, how to achieve this...? Thanx in advance and regards, RV -- View this message in context: http://old.nabble.com/how-to-delete-references-to-objects-from-a-container.… Sent from the Boost - Users mailing list archive at Nabble.com.

4 6

How do I copy files and folders using boost and Visual Studio 2005?
by leeand00 09 Dec '09

09 Dec '09

I'm trying to use boost::filesystem to copy files and folders (just like a standard copy a folder and paste it in windows explorer). Although I've been to the boost::filesystem documentation, I still don't really know how to go about doing this. Do you have to recursively go though each directory (creating it) and find each file copying it? Additionally, how do you copy the file in C++/Boost? P.S. I'm using Boost 1.40.0 Update I think I may have ended up creating an answer to this one, only concern being that I don't do any try-catch errors to check for locked files and folders. The following code makes a copy of a directory in the relative path "../example/ecomm" and duplicates it to a non-existing path "../example/dup_ecomm": #include <boost/test/unit_test.hpp> #include <boost/algorithm/string.hpp> #include <boost/filesystem/operations.hpp> #include <boost/regex.hpp> #include <iostream> #include <fstream> #include<string> bool copy_dir( const boost::filesystem::path & ext_dir_path, // the existing directory const boost::filesystem::path & duplicate_dir_path // the duplicate directory ) { std::cout << "BEGIN: copy_dir " << endl; std::cout << "- ext_dir_path: " << ext_dir_path << endl; std::cout << "- duplicate_dir_path: " << duplicate_dir_path << endl; // 1. Ensure that the directory we are trying to copy exists. if (!boost::filesystem::exists( ext_dir_path ) ) return false; bool createdDir = boost::filesystem::create_directory( duplicate_dir_path ); // cout << "createdDir: " << createdDir << endl; copy_dir(ext_dir_path, // the existing directory duplicate_dir_path, // the duplicate directory, ext_dir_path, // the base path for the existing directory duplicate_dir_path, true); std::cout << "END: copy_dir " << endl; } bool copy_dir( const boost::filesystem::path & ext_dir_path, // the existing directory const boost::filesystem::path & duplicate_dir_path, // the duplicate directory, const boost::filesystem::path & base_ext_dir_path, // the base path for the existing directory const boost::filesystem::path & base_duplicate_dir_path, // the base path for the duplicate of the exisiting directory bool isRootPath) { // Debug input arguments std::cout << "BEGIN: copy_dir " << endl; std::cout << "- ext_dir_path: " << ext_dir_path << endl; std::cout << "- duplicate_dir_path: " << duplicate_dir_path << endl; std::cout << "- base_ext_dir_path: " << base_ext_dir_path << endl; std::cout << "- base_duplicate_dir_path: " << base_duplicate_dir_path << endl; std::cout << "- isRootPath: " << isRootPath << endl; boost::filesystem::directory_iterator end_itr; // default construction yields past-the-end cout << "--Beginning itr loop" << endl; for ( boost::filesystem::directory_iterator itr( ext_dir_path ); itr != end_itr; ++itr ) { if ( boost::filesystem::is_directory(itr->status()) ) { cout << "---itr->path(): " << itr->path() << endl; boost::filesystem::path newExtDir(itr->path()); string dup_path = itr->path().string(); boost::algorithm::replace_first(dup_path, base_ext_dir_path.string(), base_duplicate_dir_path.string()); cout << "dup_path: " << dup_path << endl; boost::filesystem::path new_dup_dir(dup_path); bool createdDir = boost::filesystem::create_directory( new_dup_dir ); cout << "creating directory " << dup_path << " created: " << createdDir << endl; boost::filesystem::path newDuplicateDir(duplicate_dir_path); copy_dir(newExtDir, // the existing directory newDuplicateDir, // the duplicate directory, base_ext_dir_path, base_duplicate_dir_path, false); } else { cout << "---isLeaf: " << itr->path() << endl; string dup_path = itr->path().string(); boost::algorithm::replace_first(dup_path, base_ext_dir_path.string(), base_duplicate_dir_path.string()); string src_path = itr->path().string(); cout << "src_path: " << src_path << endl; cout << "dup_path: " << dup_path << endl; boost::filesystem::path s_path(src_path); boost::filesystem::path d_path(dup_path); boost::filesystem::copy_file(s_path, d_path); } } std::cout << "--Ending itr loop" << endl; std::cout << "END: copy_dir " << endl; return false; } test_suite* init_unit_test_suite( int, char* [] ) { boost::filesystem::path ext_dir("..\\example\\ecomm"); boost::filesystem::path dir_dup("..\\example\\dup_ecomm"); copy_dir(ext_dir, dir_dup); // the duplicate directory, // ... unit tests...etc... } My question now is what I'm I forgetting to do in regards to locked files and directories? Additionally this same question has been posted over at http://stackoverflow.com/questions/1853812/how-do-i-copy-files-and-folders-… so that the rest of the programmer community may learn about boost. (You're welcome to answer there if you like). Thank you, Andrew J. Leer ----- Thank you,    Andrew J. Leer - http://leeand00.tiddlyspot.com/ My Blog -- View this message in context: http://old.nabble.com/How-do-I-copy-files-and-folders-using-boost-and-Visua… Sent from the Boost - Users mailing list archive at Nabble.com.

1 0

[Bind] How to create a functor which returns one of its arguments?
by Vadim Guchenko 09 Dec '09

09 Dec '09

Hello, All! Is there a simple way to create a functor that returns one of its arguments _1, _2, ...? Does standard unary functor exist, which simply returns its argument unchanged? I.e.: template<typename T> struct arg: public std::unary_function<T, T> { T operator()(const T &x) const { return x; } }; Then I could write: boost::bind(arg<int>(), _2) to create a functor which returns the value of its second argument, or boost::bind(arg<bool>(), true) to create a functor which always returns true. -- Best regards, Vadim Guchenko [yhw at relost dot net].

5 5

[Regex] Compile error in char_regex_traits.hpp with gcc 3.3.1
by Olexandr Marchenko 09 Dec '09

09 Dec '09

Hi, All I've got a compile error(please see below) while trying to compile my simple program with gcc 3.3.1 and boost 1.41.0. The strange thing is that I was able to compile the program before, but got the error after I had moved the line "include <boost/regex.hpp>" from .cpp file to .h file. At least that's what I think, maybe I've changed something I don't remember about. Anyway, it looks like I have the error even before my code starts compiling. I don't understand the error message at all. Where is this "__attribute__"? I tried to google it but found nothing. I would appreciate any help The error: In file included from d:/pnw/06072009/build/incsys/boost/regex/v4/regex.hpp:55, from d:/pnw/06072009/build/incsys/boost/regex.hpp:31, from d:/pnw/06072009/be/csvrdeng/csvcursor.h:1, from csvcursor.cpp:2: d:/pnw/06072009/build/incsys/boost/regex/v4/char_regex_traits.hpp:36: error: syntax error before `__attribute__' d:/pnw/06072009/build/incsys/boost/regex/v4/char_regex_traits.hpp:44: error: `char_regex_traits_i' is not a template d:/pnw/06072009/build/incsys/boost/regex/v4/char_regex_traits.hpp:47: confused by earlier errors, bailing out char_regex_traits.hpp(with unnecessary defines and comments omitted): namespace boost{ namespace deprecated{ //line 36 template <class charT> class char_regex_traits_i : public regex_traits<charT> {}; template<> class char_regex_traits_i<char> : public regex_traits<char> // line 44 { public: typedef char char_type; //line 47 typedef unsigned char uchar_type; typedef unsigned int size_type; typedef regex_traits<char> base_type; }; } // namespace deprecated } // namespace boost -- Regards, Alexandr

2 1

[Serialization] How to serialize third party library function
by elizabeta petreska 09 Dec '09

09 Dec '09

Hello First all, sorry for my long post, and I hope I will be clear with the question. In my project I have a lot of classes, which I plan to serialize with boost serialization library. Most of my classes have as members third party library classes. The thing is that the third party library classes are very complex and I can't serialize them directly in the standard way i.e I can't say this : template<class Arhive,class MyThirdPartyClass> void serialize(Archive& ar, MyThirdPartyClass& t, const unsigned int version) { ar & t.meber1; ar & t.member2; .... } MyThirdparty library classes all provide their own method for serialization ( storing in custom archive and reading from the archive), so I was thinking to do this : namespace boost { namespace serialization { template<class Archive> inline void save(Archive & ar, const CustomClass& t, const unsigned int version) { /// save t to the custom archive here . } template<class Archive> inline void load(Archive & ar, CustomClass& t, const unsigned int version) { ////// read data from archive and assign to t } } } Now when I do the following : // save data CustomClass* cc=new CustomClass(.....); outarchive & cc; /// later on read CustomClass * rcc=0; inarchive & rcc; delete rcc; /// (*) crash here. delete is operator implemented in my CustomClass I notice that the crash maybe has to do something with that, that my CustomClass implements its own new and delete operators. I know that the default implementation of load_construct data uses operator placement ::new ( global new operator ) to allocate object when loading through pointer, and I am deleting the object above ( * ) with its specific class delete operator. To avoid the mismatch I did this : template<class Archive> inline void load_construct_data(Archive & ar, CustomClass * t, const unsigned int file_version) { new (t) CustomClass; // notice that this is the custom class operator , not :: new } In my suprise (*) is still crashing. Why ? Also I notice that if in load_construct data I am using the global new operator, and when deleting the global ::delete ( i.e :: delete rcc) operator there is no problem at all. But this is not solution, cause I want my CustomClass to use their own specific operators new and delete.

5 10

[multi_index and flyweight]
by Samuel Charron 09 Dec '09

09 Dec '09

Hi, I'm currently facing some limitations from flyweight and multi_index. Let's begin with multi_index: I'd want to have a multi_index storing containers, and have one index based on all the contained elements. For example: two vectors [1 2 3] and [3 4] would be indexed as 1 -> [1 2 3] 2 -> [1 2 3] 3 -> [1 2 3] [3 4] 4 -> [3 4] How would you do that ? Flyweight: I'd like to have a scoped flyweight, without tracking, i.e.: { ... // create some elements } // All elements are deleted when leaving the scope. However, currently I didn't see a method to clear the internal container. One way I could do that would be copying - pasting the hashed_factory and adding a clear method. It would be easier to extend the class, just having the private container be protected. Would that be possible to do one a future release ? Or is there another easy way to do so ? Regards, Samuel

4 5

Re: [Boost-users] [chrono] New Features + Bug fixes + Updated + documentation
by Tan, Tom (Shanghai) 09 Dec '09

09 Dec '09

I have some more results regarding Windows platform to report. I tried with GCC-4.4.0 that's shipped with QT4.6 SDK on the same Win XP sp3 and received some different errors/warnings as pasted below: gcc.compile.c++ bin.v2\libs\chrono\build\gcc-mingw-4.4.0\debug\link-static\runtime-link- static\threading-multi\chrono.o In file included from ./boost/chrono/chrono.hpp:73, from libs\chrono\src\chrono.cpp:13: ./boost/ratio.hpp:66: warning: integer constant is too large for 'long' type ./boost/ratio.hpp:67: warning: integer constant is too large for 'long' type ./boost/ratio.hpp:68: warning: integer constant is too large for 'long' type ./boost/ratio.hpp:79: warning: integer constant is too large for 'long' type ./boost/ratio.hpp:80: warning: integer constant is too large for 'long' type ./boost/ratio.hpp:81: warning: integer constant is too large for 'long' type ./boost/ratio.hpp:66: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:66: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:66: error: template argument 1 is invalid ./boost/ratio.hpp:66: error: template argument 2 is invalid ./boost/ratio.hpp:66: error: invalid type in declaration before ';' token ./boost/ratio.hpp:67: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:67: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:67: error: template argument 1 is invalid ./boost/ratio.hpp:67: error: template argument 2 is invalid ./boost/ratio.hpp:67: error: invalid type in declaration before ';' token ./boost/ratio.hpp:68: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:68: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:68: error: template argument 1 is invalid ./boost/ratio.hpp:68: error: template argument 2 is invalid ./boost/ratio.hpp:68: error: invalid type in declaration before ';' token ./boost/ratio.hpp:69: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:69: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:69: error: template argument 1 is invalid ./boost/ratio.hpp:69: error: template argument 2 is invalid ./boost/ratio.hpp:69: error: invalid type in declaration before ';' token ./boost/ratio.hpp:70: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:70: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:70: error: template argument 1 is invalid ./boost/ratio.hpp:70: error: template argument 2 is invalid ./boost/ratio.hpp:70: error: invalid type in declaration before ';' token ./boost/ratio.hpp:71: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:71: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:71: error: template argument 1 is invalid ./boost/ratio.hpp:71: error: template argument 2 is invalid ./boost/ratio.hpp:71: error: invalid type in declaration before ';' token ./boost/ratio.hpp:72: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:72: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:72: error: template argument 1 is invalid ./boost/ratio.hpp:72: error: template argument 2 is invalid ./boost/ratio.hpp:72: error: invalid type in declaration before ';' token ./boost/ratio.hpp:73: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:73: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:73: error: template argument 1 is invalid ./boost/ratio.hpp:73: error: template argument 2 is invalid ./boost/ratio.hpp:73: error: invalid type in declaration before ';' token ./boost/ratio.hpp:74: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:74: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:74: error: template argument 1 is invalid ./boost/ratio.hpp:74: error: template argument 2 is invalid ./boost/ratio.hpp:74: error: invalid type in declaration before ';' token ./boost/ratio.hpp:75: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:75: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:75: error: template argument 1 is invalid ./boost/ratio.hpp:75: error: template argument 2 is invalid ./boost/ratio.hpp:75: error: invalid type in declaration before ';' token ./boost/ratio.hpp:76: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:76: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:76: error: template argument 1 is invalid ./boost/ratio.hpp:76: error: template argument 2 is invalid ./boost/ratio.hpp:76: error: invalid type in declaration before ';' token ./boost/ratio.hpp:77: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:77: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:77: error: template argument 1 is invalid ./boost/ratio.hpp:77: error: template argument 2 is invalid ./boost/ratio.hpp:77: error: invalid type in declaration before ';' token ./boost/ratio.hpp:78: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:78: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:78: error: template argument 1 is invalid ./boost/ratio.hpp:78: error: template argument 2 is invalid ./boost/ratio.hpp:78: error: invalid type in declaration before ';' token ./boost/ratio.hpp:79: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:79: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:79: error: template argument 1 is invalid ./boost/ratio.hpp:79: error: template argument 2 is invalid ./boost/ratio.hpp:79: error: invalid type in declaration before ';' token ./boost/ratio.hpp:80: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:80: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:80: error: template argument 1 is invalid ./boost/ratio.hpp:80: error: template argument 2 is invalid ./boost/ratio.hpp:80: error: invalid type in declaration before ';' token ./boost/ratio.hpp:81: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:81: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:81: error: template argument 1 is invalid ./boost/ratio.hpp:81: error: template argument 2 is invalid ./boost/ratio.hpp:81: error: invalid type in declaration before ';' token ./boost/ratio.hpp:131: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:132: error: 'boost::detail::ll_add<X, Y, 1ll>::max' cannot be initialized by a non-constant expression when being declared ./boost/ratio.hpp:151: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:152: error: 'boost::detail::ll_add<X, Y, -0x000000001ll>::max' cannot be initialized by a non-constant expression when being declared ./boost/ratio.hpp:167: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:168: error: 'boost::detail::ll_sub<X, Y, 1ll>::max' cannot be initialized by a non-constant expression when being declared ./boost/ratio.hpp:187: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:188: error: 'boost::detail::ll_sub<X, Y, -0x000000001ll>::max' cannot be initialized by a non-constant expression when being declared ./boost/ratio.hpp:200: error: a function call cannot appear in a constant-expression ./boost/ratio.hpp:201: error: 'boost::detail::ll_mul<X, Y>::min' cannot be initialized by a non-constant expression when being declared ./boost/ratio.hpp:202: error: 'boost::detail::ll_mul<X, Y>::max' cannot be initialized by a non-constant expression when being declared In file included from libs\chrono\src\chrono.cpp:13: ./boost/chrono/chrono.hpp:945: error: a function call cannot appear in a constant-expression ./boost/chrono/chrono.hpp:945: error: a function call cannot appear in a constant-expression ./boost/chrono/chrono.hpp:945: error: template argument 1 is invalid ./boost/chrono/chrono.hpp:945: error: template argument 2 is invalid ./boost/chrono/chrono.hpp:945: error: template argument 2 is invalid ./boost/chrono/chrono.hpp:946: error: typedef name may not be a nested-name-specifier ./boost/chrono/chrono.hpp:946: error: expected ';' before 'rep' ./boost/chrono/chrono.hpp:947: error: typedef name may not be a nested-name-specifier ./boost/chrono/chrono.hpp:947: error: expected ';' before 'period' In file included from libs\chrono\src\chrono.cpp:27: libs\chrono\src\/win/chrono.cpp:34: error: 'monotonic_clock' has not been declared libs\chrono\src\/win/chrono.cpp:34: error: expected constructor, destructor, or type conversion before 'monotonic_clock' libs\chrono\src\/win/chrono.cpp:112: error: expected '}' at end of input libs\chrono\src\/win/chrono.cpp:112: error: expected '}' at end of input libs\chrono\src\/win/chrono.cpp:26: warning: '<unnamed>::nanosecs_per_tic' defined but not used ./boost/system/error_code.hpp:208: warning: 'boost::system::system_category' defined but not used ./boost/system/error_code.hpp:209: warning: 'boost::system::generic_category' defined but not used ./boost/system/error_code.hpp:214: warning: 'boost::system::posix_category' defined but not used ./boost/system/error_code.hpp:215: warning: 'boost::system::errno_ecat' defined but not used ./boost/system/error_code.hpp:216: warning: 'boost::system::native_ecat' defined but not used -----Original Message----- From: Tan, Tom (Shanghai) Sent: 2009-12-09 13:41 To: 'boost-users(a)lists.boost.org' Cc: 'vicente.botet(a)wanadoo.fr' Subject: RE: [chrono] New Features + Bug fixes + Updated + documentation >Date: Tue, 8 Dec 2009 23:46:18 +0100 >From: "vicente.botet" <vicente.botet(a)wanadoo.fr> Hi, > >I'm pleased to annonce the new version of the Boost.Chrono library. Even if the library is not yet ready for review I wanted to share it with you. >For the moment I'm not able to test it on Windows and Mac platforms. >Could you check if there are some regressions on Windows or on Mac platforms? Thanks for continuing this library, I've using Beman's version from the sandbox mainly for the process_timer class for benchmarking code efficiency. I just copied your code from the sandbox and compiled it against the latest boost trunk version with VC++10 on WinXP sp3, and received several occurrences of " error C3861: 'INTMAX_C': identifier not found " among others as attached. There seems to be missing some macro guards that could guarantee a correct import of 'INTMAX_C' from boost/cstdint.hpp.

1 0

Re: [Boost-users] [chrono] New Features + Bug fixes + Updated + documentation
by Tan, Tom (Shanghai) 09 Dec '09

09 Dec '09

>Date: Tue, 8 Dec 2009 23:46:18 +0100 >From: "vicente.botet" <vicente.botet(a)wanadoo.fr> >Hi, > >I'm pleased to annonce the new version of the Boost.Chrono library. Even if the library is not yet ready for review I wanted to share it with you. >For the moment I'm not able to test it on Windows and Mac platforms. >Could you check if there are some regressions on Windows or on Mac platforms? Thanks for continuing this library, I've using Beman's version from the sandbox mainly for the process_timer class for benchmarking code efficiency. I just copied your code from the sandbox and compiled it against the latest boost trunk version with VC++10 on WinXP sp3, and received several occurrences of " error C3861: 'INTMAX_C': identifier not found " among others as attached. There seems to be missing some macro guards that could guarantee a correct import of 'INTMAX_C' from boost/cstdint.hpp.

1 0

[thread] variables in thread examples require 'volatile'?
by Gabriel Redner 09 Dec '09

09 Dec '09

Dear Boosters, I'm involved in a bit of a dispute in which a colleague is claiming that 'volatile' is necessary to make certain synchronization patterns correct. As part of my response I pointed out that the boost.thread examples don't use it, but he maintains his position - saying that the examples are flawed. I'm frankly somewhat out of my element here, and I'd like to get input from people who have presumably thought about this stuff a good deal. The example in question is here, under "synopsis": http://www.boost.org/doc/libs/1_41_0/doc/html/thread/synchronization.html#t… The claim is that 'volatile' is needed on the boolean, otherwise the compiler might cache the boolean in a register, and the loop would never exit. He cites for support two articles: http://www.ddj.com/cpp/184403766 https://www.securecoding.cert.org/confluence/display/seccode/DCL17-C.+Bewar… Who's right? Thanks, -Gabe

7 8

Boost.Interfaces
by Jerry Jeremiah 08 Dec '09

08 Dec '09

Hello, I was looking at the Go language that Google just announced and I was thinking that these "interfaces" were cool. So I found these emails from the Boost users group from 2008: http://archives.free.net.ph/message/20080120.235150.027a4293.en.html http://archives.free.net.ph/message/20080201.165555.eb39994f.en.html It sounds like Jonathon intended to submit a proposal for his library in 2008 but I can't find anything about what happened after that. All I have is http://www.coderage.com/interfaces/ which was last updated 2005. I tried emailing him directly via the email address on that page but there was no answer. Does anyone know if there is a newer version than the 2005 zip file on that page? His Boost user list emails imply that there is one with changes in 2008 and that it was going to be submitted for review so if someone could point me in the right direction I would appreciate it. Jerry

1 0

usage of bcp
by Geoff Hilton 08 Dec '09

08 Dec '09

Hello, I've been reconsidering the use of bcp to import boost code into a public-facing portion of our api for intrusive_ptr, I've read the documentation somewhat, and tried using the command as follows: C:\Program Files\boost\boost_1_41_0\>bcp intrusive_ptr ../../intrusive_ptr This seems to fail as it brings up the usage screen instead of producing anything useful, how can I get it to work correctly? even going into the boost subdirectory and pointing to a destination of /int_ptr gave the same result. Also, I read about a way to rename the namespaces/defines in boost to limit/prevent clashing with client code, how do I go about triggering this? Thanks very much, Geoff

3 6

Newbie question
by Vadim Ryvchin 08 Dec '09

08 Dec '09

Hello, I have a problem with interruption of threads. I have one function that I want to run in two different threads with different parameters. When one of the function's instances finishes it stops the other instance. I can't change the function's code, but I can write wrapper to it. My problem is in stopping the other thread. Using timed_join I find which thread is finished, but I can't find a good solution for stopping the second one. How should I use interrupt method correctly or suggest me for correct thread stopping function. BTW, I can't just leave the other thread to run, it's very high CPU consumer. Thank you all.

4 10

Re: [Boost-users] thread_group::interrupt_all is not reliable
by Stonewall Ballard 08 Dec '09

08 Dec '09

I think I found the cause of this problem. It seems that the caller of interrupt_all should be holding the mutex associated with the condition on which the threads are waiting. This gave me the clue to try that: <http://www.opengroup.org/onlinepubs/009695399/functions/pthread_cond_broadc…> > The pthread_cond_broadcast() or pthread_cond_signal() functions may be called by a thread whether or not it currently owns the mutex that threads calling pthread_cond_wait() or pthread_cond_timedwait() have associated with the condition variable during their waits; however, if predictable scheduling behavior is required, then that mutex shall be locked by the thread calling pthread_cond_broadcast() or pthread_cond_signal(). thread::interrupt() calls pthread_cond_broadcast in pthread/thread.cpp. Although "predictable scheduling" doesn't seem like it should include a failure to wake up, taking the mutex around the call to thread_pool::interrupt_all() appears to be 100% reliable. I can patch my app to do that, but I don't think there's a general solution. The documentation should include a note that thread::interrupt() isn't reliable unless the caller is holding the mutex associated with the condition variable on which the interrupted thread is waiting. Of course, this could be a bug in the OS X pthreads implementation as well. - Stoney > I've discovered that under circumstances apparently related to timing > and load, sending interrupt_all to a thread_group when all the threads > are waiting on a boost::condition_variable leaves one thread waiting > about 1/3 of the time. This is with boost 1_40_0 running on Mac OS X > 10.6.2, with 32-bit boost libraries. Boost uses the posix thread > system here. > I boiled my app down to some test code that runs as a command-line > app. It's a bit longer than I'd like, but this configuration seems to > be necessary to invoke the problem. The test uses a queue to pass > "tasks" from the main thread to worker threads, and another queue to > pass "results" back to the main thread. The problem is most apparent > when all the tasks are finished and the queue empties, so that all the > worker threads are waiting on the input queue when the main thread > sends interrupt_all. > > I've looked at the waiting thread in a debugger when this happens, and > found that it has been interrupted, but is still waiting on the > condition. It looks like it just got missed by the interrupt_all. This > is more likely to happen when there are a lot of worker threads (16, > or one per core in my testing). > > The test code is parked at <http://sb.org/ThreadTest.zip>, 20KB. It's > an XCode 3.2 project, but the five source files could be readily > compiled and run in any Unix environment. > > I don't see any errors in the code that could cause these failures. > There is a work-around, which is to interrupt the waiting thread > again. This required a modified version of thread_group so I could do > a timed_join_all on it. > > I welcome any suggestions about what could be wrong here, or ways to > simplify the test to make it more suitable for a bug report. > > - Stoney -- Stonewall Ballard stoney(a)sb.org http://stoney.sb.org/

3 8

feature request: program_options: generate OS dependent options
by Hicham Mouline 08 Dec '09

08 Dec '09

Hello, Following the discussion in http://lists.boost.org/boost-users/2009/12/54327.php, let me then request that the feature be implemented in program_options. The 2 systems that I know a little about are POSIX(thanks Ovanes) and Windows: .POSIX: Typically, the command line would options with the '-' being the delimiter, like for the 'ls' program on a linux system: ls --help .... -a, --all do not ignore entries starting with . -A, --almost-all do not list implied . and .. --author with -l, print the author of each file -b, --escape print octal escapes for nongraphic characters --block-size=SIZE use SIZE-byte blocks --help print this .... .Windows dir /?: Typically, the '/' is the delimiter. ... /B Uses bare format (no heading information or summary). ... So in fact, I have 2 feature requests :-) : 1. Detect automatically the OS platform and the appropriate delimiter ( / or - or -- ) for win or POSIX 2. Detect the special option (help) that dislays the usage, which is /? on windows and --help on POSIX, and treat it symbolically in the user code calling program_options, ie not having to test for the "help" string as shown in the tutorial. I can create the trac tickets if preferred, Regards,

2 2