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[iostreams] container_device example does not compile?
by Robert Dailey 26 Aug '09

26 Aug '09

Hello, I'm using the container_device example listed here (The full example near the bottom): http://www.boost.org/doc/libs/1_39_0/libs/iostreams/doc/tutorial/container_… I modified this class to exist in the global namespace (i.e. not in boost::iostreams::example). It does not compile under MSVC9. I get the following errors. I have NO idea what the compiler is trying to tell me. 1>c:\it\work\vfdtester\ContainerDevice.hpp(50) : error C2061: syntax error : identifier 'stream_offset' 1> c:\it\work\vfdtester\ContainerDevice.hpp(79) : see reference to class template instantiation 'container_device<Container>' being compiled 1>c:\it\work\vfdtester\ContainerDevice.hpp(50) : error C2061: syntax error : identifier 'stream_offset' 1> C:\IT\third_party\boost_1_40_0_beta1\boost/iostreams/traits.hpp(176) : see reference to class template instantiation 'container_device<Container>' being compiled 1> with 1> [ 1> Container=std::vector<boost::uint8_t> 1> ] 1> C:\IT\third_party\boost_1_40_0_beta1\boost/iostreams/traits.hpp(188) : see reference to class template instantiation 'boost::iostreams::detail::member_char_type<T>' being compiled 1> with 1> [ 1> T=container_device<std::vector<boost::uint8_t>> 1> ] 1> C:\IT\third_party\boost_1_40_0_beta1\boost/iostreams/stream.hpp(104) : see reference to class template instantiation 'boost::iostreams::char_type_of<T>' being compiled 1> with 1> [ 1> T=container_device<std::vector<boost::uint8_t>> 1> ] --------- Robert Dailey

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[serialization] Binary archive headers?
by Robert Dailey 26 Aug '09

26 Aug '09

Hi, I'm looking at the streambuf filled with data after I do this: boost::asio::streambuf buf; std::ostream stream( &buf ); boost::archive::binary_oarchive archive( stream ); archive << "Hello World"; And I see that there's a lot of binary data that preceeds the "Hello World" data. Looks like custom header information that boost::serialization inserts into the stream. Is there a way to prevent any automatic header information from being inserted into the archive's stream? I'm using this serialized buffer to communicate with a device over a COM port and I can't have this extra information in my buffer. Thanks. --------- Robert Dailey

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Transmitting serialized data of multiple types and variable length over a socket
by A.Agrawal＠patrick.com.au 26 Aug '09

26 Aug '09

Hello, I am new to boost (few months). I have a client - server situation where there can be multiple clients (Linux or Window) connected to one server (Linux). Clients send requests and Server sends response to the clients. Server also sends new updates which the clients will keep receiving. The request /response has following structure: struct Message { uint8_t data_name; uint16_t count_of_data_records; // uint16_t data_len; //length of serialized_data string serialized_data; //serialized_data is binary serialized data using boost serialization. }; We have 6 types of structs (identified by data_name) that are serialized into serialized_data. I understand that I have to send two buffers one (ASCII buffer) with data_name, count_of_data_records and data_len and other binary buffer. I have seen example: http://www.boost.org/doc/libs/1_39_0/doc/html/boost_asio/example/serializat… Questions: 1. I am not sure if I should use synchronous or asynchronous communication, I am inclined towards synchronous. 2. What is the best way to send this data across from a server to multiple clients and from one client to one server.I don't know the best way to implement it. Please advise what is the best way or if you know of an example. Regards, Anil Agrawal

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[asio] Passing streams into async_write()?
by Robert Dailey 25 Aug '09

25 Aug '09

Hello, I have a std::istream that I pass into a function that calls async_write. Currently here is what I have: void SerialClient::DoWrite( std::istream const& data ) { boost::asio::async_write( m_port, boost::asio::buffer( data.rdbuf() ), boost::bind( &SerialClient::WriteCompleted, this, boost::asio::placeholders::error ) ); } Obviously this does not compile. There is no overload of buffer() that takes a streambuf. How can I get asio to write out my stream? --------- Robert Dailey

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[serialization] Stop tracking a specific item
by Chard 25 Aug '09

25 Aug '09

I have no access to the default constructor of a type I want to serialize (and no knowledge of any other constructors). However, the type is a friend to boost::serialization::access. Rather than duplicating a chunk of the serialization code, I thought I could just reuse the guts of it by serializing the object through a pointer. However, this would require me to construct the pointer during the serialization process, which would mess up the object tracking. Is it possible to turn the tracking off for a specific serialized object, but not the whole type ? E.g. a contrived example: template ... void serialize(Archive &ar, const unsigned) { Type *p = 0; if (Archive::is_saving::value) { p = FuncThatCanGiveMeAPointerToType(); } // Want to turn off object tracking on p here ar & p; // or remove it here if (Archive::is_loading::value) { FuncThatCanAssignTypeByValue(*p); delete p; } } It's like I require a remove_object_address, as opposed to reset_object_address. Or is there an alternative approach?

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[serialization] [archive] Bug serializing vectors consecutively
by Paul Eipper 25 Aug '09

25 Aug '09

Hi, I've hit what I believe is a bug in boost serialization, at least on binary and text archive modes. If I have two member vectors (of int, for example), and the serialize code is like this: ar & vector1; ar & vector2; I cannot deserialize it back, since boost throws "stream error" if it's a text archive, or "std::length_error" on vector::reserve if it's a binary archive. Attached is an example code. att, -- Paul Eipper

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[asio] It pollutes my O-Zone!
by Robert Dailey 25 Aug '09

25 Aug '09

I noticed that <boost/asio.hpp> and <boost/asio/io_service.hpp> both include windows specific header files through some level of indirection. I know this because it is causing problems with wxWidgets depending on the order of my include directives. I was considering using a mediator/pimpl of some sort to keep the asio includes limited to a very confined translation unit, but this would complicate the usage of ASIO in general. I have a class that owns an io_service object by-value in its header. Anyone have any suggestions to reduce the amount of namespace polluting ASIO does? I really blame this on the Windows API, since ASIO is just as limited by it as I am. Thanks in advance. --------- Robert Dailey

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[proto] another const issue
by Maurizio Vitale 25 Aug '09

25 Aug '09

Eric, this may or may not be related to the other problem w/ the assignment operator. In my application eventually I'll want to allow literals of builtin constants on the right hand side of the assignment, but not on the left hand side. So given: my_int my_i; // a proto terminal int i; The following should happen: my_i = 5; // OK (i,my_i) = my_i; // OK (5,my_i) = my_i; // NOT OK For that I have a grammar for the left hand side and one for the right hand side. In the attached file, the grammar for the left hand side doesn't match and I'm not sure why. What I'm doing wrong? TIA, Maurizio

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Problem with compiler options ?
by Victor Perron 25 Aug '09

25 Aug '09

Hello, I, trying to use some phoenix functions inside of a big project. The problem is that, although everything runs well in my test cases, when I integrate the very same code inside of the huge project, it always fails in a segfault. Let's explain it further : I have a code in main(), directly, both for test case and program, which is the same : int main(int argc, char *argv[]) { State my_state; my_state.setPosition(new Point(1250,8907)); my_state.setName(new string("myname")); setRobotState(&my_state); if(areamanager(localhost, 888) == false) cerr << "Could not Connect to server." << endl; while(true) {}; return 0; } ... quite simple. It is not interesting, but at some point inside of the parsing, I call (within a grammar) the following line : [...] confix_p( str_p(Message::nameMark.c_str()) >> ch_p('='), strval[phoenix::bind(&Message::setName)(self.variable1,phoenix::new_<std::string>(arg1, arg2))], ch_p(';')) [...] Where str_p is a very simple parser for strings, nameMark is a string marker for the parsing, and I'm supposed to call the member function variable1::setName(new string(arg1,arg2)) ... this is basically what phoenix does. And it works, my function is called. But in only one case... First one : (on the same computer, Linux mpc182 2.6.23.1-42.fc8 #1 SMP Tue Oct 30 13:55:12 EDT 2007 i686 i686 i386 GNU/Linux ) g++ main.o -L./ -lboost_system-mt -lboost_thread-mt -lareacommunication -o demo : This works well, no segfault during parsing, member function is called. Second one: gcc -g -O3 main.o -odemo_main -lfacetracker `xml2-config --libs` `Magick-config --ldflags` `Magick-config --libs` -lmpisearch -L/usr/lib/mysql/ -lboost_system-mt -lboost_thread-mt -lareacommunication -lpthread -lstdc++ What should make it segfault ? I tried changing back gcc to g++, then remove the -O3 flag, the -g flag, the -lstdc++... I really don't know where is the problem. Any idea ? -- Victor

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Problem with casting numeric array to/from PyArrayObject
by Lionel LE ROUX 25 Aug '09

25 Aug '09

Hi, To start with Boost, I wrote a (very simple) test_that_() function in C/Boost with a numeric::array& as argument. I compiled a .so file and I'm then able to seamlessly use this function from Python : that's for the successful part... Now I want to trace memory usage (and possible leaks) using Valgrind : then I don't use Python anymore and decide to stay in the C world : so I wrote a short test program in C which only includes a call to the function in the .so : /int main(void) { Py_Initialize(); import_array(); npy_intp dim[]={1000}; PyArrayObject* X = (PyArrayObject*)PyArray_SimpleNew(1, dim, PyArray_FLOAT); test_that_((numeric::array&)X); Py_DECREF(X); Py_Finalize(); return 0; }/ I can compile and build the executable file with no error but when I run it : segmentation fault when I try to use PyArray_Size within the test_that() function, which only "link" a PyArrayObject to the numeric::array argument. The manipulation of the data seems to be OK but problem arises with PyArray_Size. Well, looks like the double cast (PyArrayObject -> numeric::array -> PyArrayObject) is not valid. Could someone confirm (or not) my (very) bad coding ? Thanks.

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Re: [Boost-users] [proto] a question on assignment operators
by Eric Niebler 25 Aug '09

25 Aug '09

(Public response to Maurizio's private follow-up. Hope Maurizio doesn't mind.) Maurizio Vitale wrote: >>>>>> "Eric" == Eric Niebler <eric(a)boostpro.com> writes: > > Eric> Maurizio Vitale wrote: > >> Hi Eric, while you were on vacation I posted the following on the > >> boost.users > Eric> <snip> > > Eric> Sorry for the delay; I missed your original message. I've > Eric> followed up on the boost-users list. In short: I don't > Eric> understand enough of what you're trying to do to help. Please > Eric> clarify and I'll help as best I can. > > Let me try to rephrase what I was trying to ask and see if I'm more > successful. > > The gist of the question is what happens when you have to add an > operator= to a proto extended expression. You normally wouldn't because > in general it doesn't make much sense to do things like: > > a+b = c-d; > > (although it could make sense in a DSL for linear algebra) > In my case something like: > > (a,b,c) = expression; > > would require to do (inside my_expr::operator=): > a = f (expression); > b = g (expression); > c = h (expression); > > where f,g,h depend on the semantics. In my case they would carve a > certain number of bits from expression. In a DSL dealing with tuples > they would select the appropriate component from expression. OK sure, that makes sense. > The problem I'm having is that expressions built by proto seem to be > const, forcing operator= to be const (or at least that's what happens in > my example). It's true, Proto's objects have a top-level const qualification. They are, after all, rvalues (temporaries) so they should not be modified. HOWEVER, the const-ness only applies at the top-level. The const-ness of child nodes is preserved. In particular, non-const lvalue terminals are held by reference and remain non-const. Consider: typedef proto::terminal<int>::type I; I i = {42}; I & refi = proto::left(i+i); The temporary object created by i+i is const, but each i is held by non-const reference, which is what is returned by proto::left. > If that's true, then my followup question was whether it is > ok to perform the assignment the way I was doing it, casting away const. In short, it shouldn't be necessary. You're using proto::flatten and fusion::fold. Somewhere in there the constness is getting messed up. You should file a bug. Proto's fold_tree transform gets the constness correct. See the attached code which is equivalent to yours, but doesn't require any ugly const_cast's. > The other question I had was on what was the reason for explicitely > disable assignment operators in grammars. This is something you do in > many of your examples I do? Which examples? I don't see it. > , but doesn't seem to make a difference in my code > (e.g. having an operator= in my expression seems to stop proto from > building a larger tree including the '=' anyhow, without needing to > disable it explicitly) I'm afraid you've lost me again. > The last question, which was the first, it is not very important. What > I'm really interesting in is how to use proto when you need to assign to > a proto expression, rather than a proto terminal. And I hope at least that much has been cleared up. HTH, -- Eric Niebler BoostPro Computing http://www.boostpro.com #include <iostream> #include <boost/mpl/plus.hpp> #include <boost/mpl/sizeof.hpp> #include <boost/proto/core.hpp> #include <boost/proto/transform.hpp> namespace mpl = boost::mpl; namespace proto = boost::proto; namespace fusion = boost::fusion; using proto::_; struct my_grammar : proto::or_< proto::terminal< int >, proto::binary_expr<_, my_grammar, my_grammar> > {}; template<typename Expr> struct my_expr; struct my_domain : proto::domain<proto::generator<my_expr>, my_grammar> {}; struct AssignTerminal : proto::callable { template<typename Sig> struct result; template<typename This, typename Terminal, typename Offset> struct result<This(Terminal &, Offset)> { typedef mpl::plus<mpl::sizeof_<Terminal>, Offset> type; }; template<typename Terminal, typename Offset> mpl::plus<mpl::sizeof_<Terminal>, Offset> operator()(Terminal & t, Offset) const { proto::value(t) = Offset::value; return mpl::plus<mpl::sizeof_<Terminal>, Offset>(); } }; struct AssignGroup : proto::fold_tree< proto::_, mpl::size_t<0>(), AssignTerminal(proto::_, proto::_state) > {}; template<typename Expr> struct my_expr : proto::extends<Expr, my_expr<Expr>, my_domain> { typedef proto::extends<Expr, my_expr<Expr>, my_domain> base_type; my_expr( Expr const & expr = Expr() ) : base_type( expr ) {} template<typename E> const my_expr& operator=(const E&) const { AssignGroup()(*this); return *this; } }; struct my_int : my_expr< proto::terminal< int >::type > { typedef my_expr< proto::terminal< int >::type > base_type; explicit my_int (int i = 0) : base_type (base_type::proto_base_expr::make (i)) {} operator int () { return proto::value (*this); } }; int main() { my_int i (1); my_int j (2); my_int k (3); (k,j) = (j,k); std::cout << j << std::endl << k << std::endl; } /// Local Variables: /// mode:c++ /// comment-column:60 /// fill-column:150 /// compile-command:"g++ -I. -I./boost -o testcase testcase.cpp" /// c-macro-cppflags:"-C -I. -I./boost" /// c-backslash-column:120 /// c-backslash-max-column:149 /// End:

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Re: [Boost-users] Boost program_options
by Steve Nolen 25 Aug '09

25 Aug '09

Date: Sat, 22 Aug 2009 10:22:40 +0400 From: Vladimir Prus <vladimir(a)codesourcery.com> To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] Boost program_options Message-ID: <h6o2r1$j2f$1(a)ger.gmane.org> Content-Type: text/plain; charset=us-ascii Steve Nolen wrote: > > in program_options::parse_command_line - why can't the the argument > > "argv" be of type 'const charT*' rather than 'charT*'? > > > > i ask because our unit tests were giving a bunch of errors because they > > were written like this.. > > > > vector< char* > cmdLine; > > cmdLine.push_back( "someExec" ); > > cmdLine.push_back( "--optflag1" ); > > cmdLine.push_back( "value1" ); > > etc. > > > > then... > > char ** argv = &cmdLine[ 0 ]; > > > > then passing this to parse_command_line. when we compile under g++ 4.x > > we get warnings that assigning string literals to char* is a deprecated > > conversion. Actually I agree with the rationale, but this leaves me > > with a problem calling parse_command_line. Is it going to change any of > > these values? > No, it's not actually changing anything. > > I know the c standard calls for the argv in main's prototype to be > > non-const, but why can't parse_command_line be more restrictive? > Because it that case, you won't be able to pass main's argv to parse_command_line. - Volodya --------------------- ok why not? you would be passing a non-const (main::argv) to a const qualified parameter. this would just guarantee that the function couldn't modify it (which is what you're telling me is the case here). i thought this was allowed. -steve

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Linking fails to Boost_system (cannot open shared object file: No such file or directory)
by stationx 25 Aug '09

25 Aug '09

Hi all, I have linked my simple program that uses boost.filesystem as follows: accesstimer: acctime.o bentimer.o g++ -L/usr/local/boost/boost_1_39_0/stage/lib -lboost_system-gcc41-mt -lboost_filesystem-gcc41-mt acctime.o bentimer.o -o accesstimer acctime.o: acctime.cpp bentimer.h g++ -I /usr/local/boost/boost_1_39_0 -c acctime.cpp bentimer.o: bentimer.cpp bentimer.h g++ -c bentimer.cpp This compiles fine, but when I execute I get the following error: ./accesstimer: error while loading shared libraries: libboost_system-gcc41-mt-1_39.so.1.39.0: cannot open shared object file: No such file or directory I have looked in the .../stage/lib directory and the file does exist there. Can anyone see what I've done wrong? thanks -- View this message in context: http://www.nabble.com/Linking-fails-to-Boost_system-%28cannot-open-shared-o… Sent from the Boost - Users mailing list archive at Nabble.com.

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copy constructor for derived boost::multi_array
by HweeKuan Lee 25 Aug '09

25 Aug '09

i am having problems compiling class derived from boost::multi_array. the copy constructor does not compile. as i understand, the usual copy constructor for derived class can be implemented as in line 12 in the code below. however, can't do the same for boost::multi_array at line 21. lots of compile error, i extracted a small part of it below 1 #include <boost/multi_array.hpp> 2 3 // ------------------------------------------ 4 template<class V> struct base { 5 base(int y) : u(y ) { } 6 base(const base<V>& b) : u(b.u) { } 7 int u; 8 }; 9 10 template<class V> struct derived : public base<V> { 11 derived(int y) : base<V>(y) { } 12 derived(const derived<V>& d) : base<V>(d) { } 13 }; 14 // ------------------------------------------ 15 template<class V, unsigned int D> 16 struct my_multi : public boost::multi_array<V,D> { 17 18 template<class extent_type> 19 my_multi(const extent_type& e) : boost::multi_array<V,D>(e) { } 20 21 my_multi(const my_multi<V,D>& t) : boost::multi_array<V,D>(t) { } 22 }; 23 // ------------------------------------------ 24 int main () { 25 derived<int> d(1.0); 26 derived<int> e(d); // ok 27 28 my_multi<int,2> mm0(boost::extents[3][4]); 29 mm0[0][0] = 6; // ok 30 my_multi<int,2> mm1(mm0); 31 } -------------- extracted compile error: bmulti.C:21: instantiated from 'my_multi<V, D>::my_multi(const my_multi<V, D>&) [with V = int, unsigned int D = 2u]' bmulti.C:30: instantiated from here /opt/local/include/boost/multi_array/collection_concept.hpp:44: error: 'struct my_multi<int, 2u>' has no member named 'swap' bmulti.C:21: instantiated from 'my_multi<V, D>::my_multi(const my_multi<V, D>&) [with V = int, unsigned int D = 2u]' bmulti.C:30: instantiated from here /opt/local/include/boost/multi_array/algorithm.hpp:56: error: cannot convert 'boost::detail::multi_array::const_sub_array<int, 1ul, const int*>' to 'long unsigned int' in assignment

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Boost program_options
by Steve Nolen 24 Aug '09

24 Aug '09

in program_options::parse_command_line - why can't the the argument "argv" be of type 'const charT*' rather than 'charT*'? i ask because our unit tests were giving a bunch of errors because they were written like this.. vector< char* > cmdLine; cmdLine.push_back( "someExec" ); cmdLine.push_back( "--optflag1" ); cmdLine.push_back( "value1" ); etc. then... char ** argv = &cmdLine[ 0 ]; then passing this to parse_command_line. when we compile under g++ 4.x we get warnings that assigning string literals to char* is a deprecated conversion. Actually I agree with the rationale, but this leaves me with a problem calling parse_command_line. Is it going to change any of these values? I know the c standard calls for the argv in main's prototype to be non-const, but why can't parse_command_line be more restrictive?

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[tuple] [serialization] serialize a tuple
by Dmitry Vinogradov 24 Aug '09

24 Aug '09

How to serialize a tuple? Where are no boost/serialization/tuple.hpp, nor boost/tuple/tuple_serialization.hpp...

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[boost] Formal Review: Boost.Polygon starts today August 24, 2009
by Fernando Cacciola 24 Aug '09

24 Aug '09

Dear Developers, The formal review of the Boost.Polygon library by Lucanus Simonson starts today, August 24, 2009 and will finish September 2, 2009. I really hope to see your vote and your participation in the discussions on the Boost mailing lists! --------------------------------------------------- About the library: The boost polygon library provides algorithms focused on manipulating planar polygon geometry data. Specific algorithms provided are the polygon set operations (intersection, union, difference, disjoint-union) and related algorithms such as polygon connectivity graph extraction, offsetting and map-overlay. These so-called Boolean algorithms are of significant interest in GIS (Geospatial Information Systems), VLSI CAD as well al other fields of CAD, and many more application areas, and providing them is the primary focus of this library. The polygon library is not intended to cover all of computational geometry in its scope, and provides a set of capabilities for working with coordinates, points, intervals and rectangles that are needed to support implementing and interacting with polygon data structures and algorithms. Specifically, 3d and non-Cartesian/non-planar geometry is outside of the scope of the polygon library The design philosophy behind the polygon library was to create an API for invoking the library algorithms it provides on user geometry data types that is maximally intuitive, minimally error-prone and easy to integrate into pre-existing applications. C++-concepts based template meta-programming combined with generic operator overloading meets these design goals without sacrificing the runtime or memory efficiency of the underlying algorithms. This API makes the following code snippet that operates on non-library geometry types possible: void foo(list<CPolygon>& result, const list<CPolygon>& a, const list<CPolygon>& b, int deflateValue) { CBoundingBox domainExtent; using namespace boost::polygon::operators; boost::polygon::extents(domainExtent, a); result += (b & domainExtent) ^ (a - deflateValue); } The source is available at http://svn.boost.org/svn/boost/sandbox/gtl/boost/polygon/ And the documentation is at http://svn.boost.org/svn/boost/sandbox/gtl/doc/index.htm --------------------------------------------------- Please always state in your review, whether you think the library should be accepted as a Boost library! Additionally please consider giving feedback on the following general topics: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Best Regards Fernando Cacciola Review Manager _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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[proto] extended expressions and assignment operator
by Maurizio Vitale 24 Aug '09

24 Aug '09

Hi Eric, I'm trying to have proto allow me to do things like: (a,b,c) = expr; where a, b, c are integers of different width and they should be assigned the appropriate slice of expr. For instance: | variable | width | value | |----------+-------+-----------| | a | 2 | expr[6:7] | | b | 4 | expr[2:5] | | c | 2 | expr[0:1] | width are compile-time constants and I need to keep them so (they'll be used to compute masks and shifts at compile time). First problem is that I do not know of a good way for doing this. As you'll see in the code attached, right now I'm using fusion::fold and proto::flatten, but this does the width part at run-time (in the example I'm using sizeof () instead of real widths to keep things simple). The second problem is that operator= needs to be const. I think I've an idea of why, but I'd appreciate if you could tell me. Assuming this is what it should be, is it safe to cast away the constness in struct assign? Last question, I've seen in some of your examples that you explicitly disable all assignment operators. It doesn't seem to make a difference here. What is the story? Thanks a lot in advance, Maurizio --

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commandline args
by Shaolin 24 Aug '09

24 Aug '09

Hi Guys Below is my current code used to retrieve commandline arguments: int i = 1; while (i < argc) { if (strcmp(argv[i], "-f") == 0) { for (++i; i < argc && strcmp(argv[i], "-s") != 0; ++i) { filearr.push_back(argv[i]); } } else if (strcmp(argv[i], "-s") == 0) { for (++i; i < argc && strcmp(argv[i], "-f") != 0; ++i) { searchtext = argv[i]; } } else { ++i; } } As you can see, its not very scalable. I am thinking of adding another feature args but it'll become difficult to manage. Is there anything on boost which does the same thing albeit with alot less code ?

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boost.m4 checks correct header but detects wrong header version
by Peter Schueller 24 Aug '09

24 Aug '09

(posting to the boost-users list and to the boost.m4 maintainer) I'm using autotools with the newest boost.m4 from http://repo.or.cz/w/boost.m4.git and have the following problem: I have several boost installations, among others a 1.34.1 in /usr/include and several in my homedir in /home/staff/ps/include/boost-1_36/ /home/staff/ps/include/boost-1_37/ /home/staff/ps/include/boost-1_39/ Calling configure with --with-boost=/home/staff/ps/include/boost-1_37/ I get the following information: checking for Boost headers version >= 103300... /home/staff/ps/include/boost-1_37/include checking for Boost's header version... 1_34_1 The first check finds the correct headers, the second one uses the wrong ones. configure.log says: ==== configure:20676: checking for a sed that does not truncate output configure:20755: result: /usr/bin/sed configure:20787: checking for Boost headers version >= 103300 configure:20841: g++ -c -g -O2 -I/home/staff/ps/include/boost-1_37/include conftest.cpp >&5 configure:20847: $? = 0 configure:20876: result: /home/staff/ps/include/boost-1_37/include configure:20886: checking for Boost's header version configure:20907: result: 1_34_1 configure:20938: checking boost/scoped_ptr.hpp usability configure:20955: g++ -c -g -O2 -I/home/staff/ps/include/boost-1_37/include conftest.cpp >&5 configure:20961: $? = 0 configure:20975: result: yes configure:20979: checking boost/scoped_ptr.hpp presence configure:20994: g++ -E -I/home/staff/ps/include/boost-1_37/include conftest.cpp configure:21000: $? = 0 configure:21014: result: yes ==== So only the one check does not use the newly found CPPFLAGS. I also saw that the header check is done WITHOUT using _AC_DO_STDERR so the actual g++ call for the header check is not shown. Unfortunately I did not succeed in changing the check to use _AC_DO_STDERR so I'm writing this mail instead of sending a patch suggestion. Regards, Peter Schüller -- Peter Schüller Institute of Information Systems, Vienna University of Technology Favoritenstrasse 9-11/1843, A-1040 Vienna, Austria T: +43 (1) 58801-18470 E: ps AT kr DOT tuwien DOT ac DOT at Homepage: http://www.kr.tuwien.ac.at/staff/ps/ TU Wien DVR: 0005886

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[Boost.function_types] Function synthesis and property tags
by Yury Korobkin 24 Aug '09

24 Aug '09

Hi, everybody. I'm trying to synthesize a function type G from another function type F with some changes on return and arg types. What I need to leave constant, are all these additional properties that are returned by components<F>::tag. I want them all as a bunch, don't really fancy querying them one by one, they sorta look contradictive or at least redundant. The naive approach of passing the same tag to the function_type<Seq, Tag> does not make a change - it leads to the same result as if default null_tag were passed. How do you generate a function type with the same additional properties as the given one? Sample code: //---------------------------------------------------------------------- ---------------------------- typedef int (__stdcall * pF)(char); typedef int ( * pG)(char); typedef remove_pointer<pF>::type F; typedef components<F> compsF; // generate type hopefully like pF typedef function_pointer<compsF, //create tag from mask and bits detail::property_tag<compsF::bits::value, compsF::mask::value> >::type pfn_gen; BOOST_MPL_ASSERT((is_same<pfn_gen, pG>)); // this one passes, should fail, though BOOST_MPL_ASSERT((is_same<pfn_gen, pF>)); // I wish, but fails //---------------------------------------------------------------------- ---------------------------- Thanks, YuryK This mail was received via Mail-SeCure System. STATEMENT OF CONFIDENTIALITY The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain confidential or privileged information. If you are not the intended recipient, please notify Exent Technologies Ltd. immediately at +972-3-9243828 or by reply e-mail and destroy all copies of this message and any attachments

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functor for boost::thread_group threads: which one is correct?
by Boost lzw 24 Aug '09

24 Aug '09

Hi there, I have two versions (VERSION1 and VERSION2) of a group_helper functor to be called from boost::thread_group, which one of them is correct? class FileThread { public: void print() {...} void find() {...} }; class group_helper { private: boost::shared_ptr<FileThread> m_object; public: //VISION1 group_helper(boost::shared_ptr<FileThread>& object) : m_object(object) { } //VISION2 group_helper() : m_object(boost::shared_ptr<FileThread>(new FileThread)) { } void operator()() { m_object->find(); m_object->print(); } }; On another matter, why the following code results in a runtime exception from the group_helper's dtor? #include <iostream> #include "boost/thread/thread.hpp" class FileThread { public: void find() { } void print() { } }; class group_helper { private: FileThread* m_object; public: group_helper() : m_object(new FileThread) {} void operator()() { m_object->find(); m_object->print(); } ~group_helper() { if (m_object) delete m_object; }// EXCEPTION from dtor }; int main() { group_helper gh; boost::thread thrd(gh); thrd.join(); }

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errors in function_equal.hpp?
by worldeb＠ukr.net 23 Aug '09

23 Aug '09

Hi folks. I use some library which use boost in my project. I am not familiar with c++ and boost. Compilation of my project shows me the next: function_equal.hpp:15: error: expected nested-name-specifier before numeric constant function_equal.hpp:15: error: expected `>' before numeric constant function_equal.hpp:16: error: expected ‘,’ or ‘...’ before numeric constant function_equal.hpp:16: error: ISO C++ forbids declaration of ‘parameter’ with no type function_equal.hpp: In function ‘bool boost::function_equal_impl(const F&, int)’: function_equal.hpp:17: error: ‘g’ was not declared in this scope function_equal.hpp: At global scope: function_equal.hpp:22: error: expected nested-name-specifier before numeric constant function_equal.hpp:22: error: expected `>' before numeric constant function_equal.hpp:23: error: expected ‘,’ or ‘...’ before numeric constant function_equal.hpp:23: error: ISO C++ forbids declaration of ‘parameter’ with no type function_equal.hpp: In function ‘bool boost::function_equal(const F&, int)’: function_equal.hpp:24: error: ‘g’ was not declared in this scope I cannot identify really if it is a problem of the boost, or the libraries which I use or... Who can comment these errors? Thanx a lot.

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Re: [Boost-users] [iostreams] [archive] [serialization] lexical_cast<string> with binary_archive vs. text_archive
by Johann Goetz 23 Aug '09

23 Aug '09

This is not portable across platforms (32/64 for example). I wish to use the portability of ascii when needed. But I want to option to be non-portable (without the stringstream/lexical_cast<string> or gzip) in order to speed up the serialization process. > I don't see what lexical cast is doing in there. > What's the matter with: > numerics -> binary_archive -> gzip -> out_file > Robert Ramey Johann Goetz wrote: > Consider the following serialization archive. I can serialize a > collection of variables (floats, ints, etc) through the series: > numerics --> text_oarchive --> gzip --> output_file > The text_archive step is essentially a stringstream filter. This > filter gives the serialization the portability I (sometimes) need. > > namespace io = boost::iostreams; > namespace ar = boost::archive; > > io::filtering_ostream fos; > fis.push(io::gzip_compressor()); > fis.push(io::file_sink("output.txt.gz")); > ar::text_oarchive oa(fos); > > OK. Now what I wish to do is to create a binary_archive and to push > the stringstream filter to the filtering_ostream: > numerics -> binary_archive -> lexical_cast<string> -> gzip -> out_file > This way I could turn this part (and the gzip) on or off at will (the > ol' speed vs portability thing): > > io::filtering_ostream fos; > fis.push(/*stringstream_filter*/); > fis.push(io::gzip_compressor()); > fis.push(io::file_sink("output.txt.gz")); > ar::binary_oarchive oa(fos); > > I am not sure how to create such a filter, but I'm guessing such a > filter already exists. Perhaps the answer lies in > lexical_cast<string>? any help with this would be greatly > appreciated, thanks! > Johann.

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Invoke several functions with the same thread
by Shaolin 23 Aug '09

23 Aug '09

Hi Guys I am trying to convert my application to a multithreaded app. Please see code below: boost::thread_group threads; FileThread *fThreads[filearr.size()]; for(int i=0; i < filearr.size(); i++) { fThreads[i] = new FileThread(filearr[i]); threads.create_thread(fThreads[i]->find()); } threads.join_all(); As you can see from the code above, I have an array of FileThread objects, which have several functions. What I want to do, is to first off invoke the find() function which will go through some algorthms (this is already done) and then the print() function which will print the results. How can I invoke the print() function with the same thread ?

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