February 2006 - Boost-users

[program_options] Notifiers
by David Greene 15 Feb '06

15 Feb '06

How does one install a notifier for an option that does not have a value? For example, if I have an option --foo and I want to call foo_handler() when it is parsed, how do I do that? As far as I can tell from the documentation the only way to install a notifier is through a value_semantic, which doesn't apply here. -Dave

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Newbie question : enable_if equivalent ?
by khasimo 15 Feb '06

15 Feb '06

Hi there, I'm trying to port the xmlbeansxx library (sourceforge.net/projects/xmlbeansxx) under windows using "Borland C++ 5.6.4". The thing is I am having trouble with the "enable_if" construction. From the "config\compiler\borland.hpp", I know that the bcc compiler do not support SFINAE trick and so the "enable_if" and like constructions. In order to continue the port I have to modify the "enable_if" implementation with something equivalent. Here is the code : template<typename TO, typename FROM, typename Enable = void> class cast_traits { public: TO operator ()(const FROM &from) const { return (TO)(from); } }; class Ptr { public: template <typename TYPE, typename TYPE_I> static inline TYPE ptrFromThis(const boost::shared_ptr<TYPE_I> &from) { TYPE n; n.ptr = from; return n; } }; /* (2) begin */ template<typename TO, typename FROM> class cast_traits<TO, FROM, typename boost::enable_if< boost::mpl::and_< boost::is_base_and_derived<Ptr, FROM>, boost::is_base_and_derived<Ptr, TO> > >::type > { public: TO operator ()(const FROM &from) const { TO r; r.ptr = ptr_cast<typename TO::value_type>(from.ptr); return r; } }; /* (2) end */ template<typename TO, typename FROM> inline TO cast(const FROM &from) { return cast_traits<TO, FROM>()(from); } My problem is with the "/*(2)*/" part of the code. In the library code there is other constructions based on "enable_if" but they are the same as the "/*(2)*/" example. Thanks folks in advance. I'am really a newbie to boost (and templates) and have no idea about a workaround. PS: It is obvious that I will contribute the port to the xmlbeansxx project.

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Building Boost 1.31.1 on OpenBSD
by Quantum Skyline 15 Feb '06

15 Feb '06

Hi, I've been trying to compile Boost on OpenBSD 3.8 with no success, but I would like to have the threading library available. I've gone through the list a few times, and the only thing related to OpenBSD was posted back in '02 or '03. I compiled GCC 3.4.4 with threads because the default compiler is not threaded and run ./configure as the docs say, but I still can't get it to work. Is there anything else I need to know to get Boost::Threads to compile properly? Thanks

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Re: [Boost-users] [program_options] multitoken
by Sohail Somani 15 Feb '06

15 Feb '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of > Alexander Kondratyuk > Sent: Tuesday, February 14, 2006 2:57 AM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] [program_options] multitoken > > Thanks to all for the comments. > I want to allow "--first=11,12" and ""--first=11 --first=12" > both, so its seems I need to do it manually. This should be simple enough using push() and a tokenizer so that the rest of your program doesn't have to care.

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[serialization] linking issues with 1.33
by rwm33＠drexel.edu 15 Feb '06

15 Feb '06

Hello When updating libraries from boost 1.32 to 1.33 our previous code that had no previous linking problems developed linking errors. I then attempted to compile the demo.cpp serialization code included in the boost documentation tutorial and received the same errors. I attach below the code and the error message I got. I am working on a Linux Gentoo machine with Boost installed by e-portage. I believe boost is properly installed as it works with other libraries. Any suggestion? Thanks Ryan McKeown Drexel University Physics Dept. ========================================== CODE #include <fstream> // include headers that implement a archive in simple text format #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> ///////////////////////////////////////////////////////////// // gps coordinate // // illustrates serialization for a simple type // class gps_position { private: friend class boost::serialization::access; // When the class Archive corresponds to an output archive, the // & operator is defined similar to <<. Likewise, when the class Archive // is a type of input archive the & operator is defined similar to >>. template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & degrees; ar & minutes; ar & seconds; } int degrees; int minutes; float seconds; public: gps_position(){}; gps_position(int d, int m, float s) : degrees(d), minutes(m), seconds(s) {} }; int main() { // create and open a character archive for output std::ofstream ofs("filename"); // create class instance const gps_position g(35, 59, 24.567f); // save data to archive { boost::archive::text_oarchive oa(ofs); // write class instance to archive oa << g; // archive and stream closed when destructors are called } // ... some time later restore the class instance to its orginal state gps_position newg; { // create and open an archive for input std::ifstream ifs("filename", std::ios::binary); boost::archive::text_iarchive ia(ifs); // read class state from archive ia >> newg; // archive and stream closed when destructors are called } return 0; } ====================================== ERROR /tmp/cchtRupV.o(.gnu.linkonce.t._ZN5boost7archive6detail15common_oarchiveINS0_13text_oarchiveEE4initEv+0x1a): In function `boost::archive::detail::common_oarchive<boost::archive::text_oarchive>::init()': : undefined reference to `boost::archive::ARCHIVE_SIGNATURE' /tmp/cchtRupV.o(.gnu.linkonce.t._ZN5boost7archive6detail15common_oarchiveINS0_13text_oarchiveEE4initEv+0x84): In function `boost::archive::detail::common_oarchive<boost::archive::text_oarchive>::init()': : undefined reference to `boost::archive::ARCHIVE_VERSION' /tmp/cchtRupV.o(.gnu.linkonce.t._ZN5boost7archive6detail15common_iarchiveINS0_13text_iarchiveEE4initEv+0x2f): In function `boost::archive::detail::common_iarchive<boost::archive::text_iarchive>::init()': : undefined reference to `boost::archive::ARCHIVE_SIGNATURE' /tmp/cchtRupV.o(.gnu.linkonce.t._ZN5boost7archive6detail15common_iarchiveINS0_13text_iarchiveEE4initEv+0xd0): In function `boost::archive::detail::common_iarchive<boost::archive::text_iarchive>::init()': : undefined reference to `boost::archive::ARCHIVE_VERSION' /tmp/cchtRupV.o(.gnu.linkonce.t._ZN5boost7archive6detail15common_oarchiveINS0_13text_oarchiveEEC2Ev+0xe): In function `boost::archive::detail::common_oarchive<boost::archive::text_oarchive>::common_oarchive()': : undefined reference to `boost::archive::detail::basic_oarchive::basic_oarchive()' /tmp/cchtRupV.o(.gnu.linkonce.t._ZN5boost7archive6detail15common_iarchiveINS0_13text_iarchiveEEC2Ev+0xe): In function `boost::archive::detail::common_iarchive<boost::archive::text_iarchive>::common_iarchive()': : undefined reference to `boost::archive::detail::basic_iarchive::basic_iarchive()' /tmp/cchtRupV.o(.gnu.linkonce.t._ZN5boost13serialization6detail27extended_type_info_typeid_0C2Ev+0x7): In function `boost::serialization::detail::extended_type_info_typeid_0::extended_type_info_typeid_0()': : undefined reference to `boost::serialization::detail::extended_type_info_typeid_0::type_info_key' collect2: ld returned 1 exit status

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AIX/g++
by Sohail Somani 15 Feb '06

15 Feb '06

Hi, I don't see any AIX regressions so I'm assuming no one officially tests this. Does anyone have any notes about this platform/compiler combination? Does it work? :) Thanks in advance, Sohail

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bind()ing only some arguments of a member function
by Sean Rhea 14 Feb '06

14 Feb '06

Hello, Can someone please tell me why this doesn't work? #include <boost/bind.hpp> #include <boost/function.hpp> #include <boost/shared_ptr.hpp> using namespace std; using namespace boost; struct MyClass { int i; void foo(int j){ printf("%d, %d\n", i, j); } function<void(int)> bar() { return bind<void>(&MyClass::foo, this); } }; $ g++ -c -g -I/usr/local/include/boost-1_33_1 -I.. foo.cpp /usr/local/include/boost-1_33_1/boost/mem_fn.hpp: In member function 'R& boost::_mfi::dm<R, T>::operator()(T*) const [with R = void () (int), T = MyClass]': /usr/local/include/boost-1_33_1/boost/bind.hpp:229: instantiated from 'void boost::_bi::list1<A1>::operator()(boost::_bi::type<void>, F&, A&, int) [with F = void (MyClass::*)(int), A = boost::_bi::list1<int&>, A1 = boost::_bi::value<MyClass*>]' /usr/local/include/boost-1_33_1/boost/bind/bind_template.hpp:32: instantiated from 'typename boost::_bi::result_traits<R, F>::type boost::_bi::bind_t<R, F, L>::operator()(A1&) [with A1 = int, R = void, F = void (MyClass::*)(int), L = boost::_bi::list1<boost::_bi::value<MyClass*> >]' /usr/local/include/boost-1_33_1/boost/function/function_template.hpp: 136: instantiated from 'static void boost::detail::function::void_function_obj_invoker1<FunctionObj, R, T0>::invoke(boost::detail::function::any_pointer, T0) [with FunctionObj = boost::_bi::bind_t<void, void (MyClass::*)(int), boost::_bi::list1<boost::_bi::value<MyClass*> > >, R = void, T0 = int]' /usr/local/include/boost-1_33_1/boost/function/function_template.hpp: 479: instantiated from 'void boost::function1<R, T0, Allocator>::assign_to(FunctionObj, boost::detail::function::function_obj_tag) [with FunctionObj = boost::_bi::bind_t<void, void (MyClass::*)(int), boost::_bi::list1<boost::_bi::value<MyClass*> > >, R = void, T0 = int, Allocator = std::allocator<void>]' /usr/local/include/boost-1_33_1/boost/function/function_template.hpp: 430: instantiated from 'void boost::function1<R, T0, Allocator>::assign_to(Functor) [with Functor = boost::_bi::bind_t<void, void (MyClass::*)(int), boost::_bi::list1<boost::_bi::value<MyClass*> > >, R = void, T0 = int, Allocator = std::allocator<void>]' /usr/local/include/boost-1_33_1/boost/function/function_template.hpp: 294: instantiated from 'boost::function1<R, T0, Allocator>::function1(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functo r>::value>::value, int>::type) [with Functor = boost::_bi::bind_t<void, void (MyClass::*)(int), boost::_bi::list1<boost::_bi::value<MyClass*> > >, R = void, T0 = int, Allocator = std::allocator<void>]' /usr/local/include/boost-1_33_1/boost/function/function_template.hpp: 637: instantiated from 'boost::function<R ()(T0), Allocator>::function(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functo r>::value>::value, int>::type) [with Functor = boost::_bi::bind_t<void, void (MyClass::*)(int), boost::_bi::list1<boost::_bi::value<MyClass*> > >, R = void, T0 = int, Allocator = std::allocator<void>]' foo.cpp:15: instantiated from here /usr/local/include/boost-1_33_1/boost/mem_fn.hpp:347: error: invalid use of non-static member function Thanks, Sean -- Compassion, tolerance, consideration of others, the responsible use of knowledge and power. These principles transcend the barriers between religious believers and non-believers; they belong not to one faith, but to all faiths. -- The 14th Dalai Lama

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Tricky RPC code using bind()
by Sean Rhea 14 Feb '06

14 Feb '06

All, I've written what I thought was a pretty clever RPC server using bind and templated functions to make server callbacks typesafe. It all resolves around this one function: class rpc_server { ... template <class A, class R> void set_handler(int prog, int vers, int proc, bool_t (*arg_fn)(XDR *, A*), bool_t (*res_fn)(XDR *, R*), function<void(A*,function<void(R*)>)> req_cb) { ... } } The idea being that you pass it the program, version, and procedure numbers, pointers to the xdr_ functions that encode/decode the argument and response types, and a function object that takes a pointer to the argument type and a callback to call with the result. It should be really nice to use, as it makes sure your callback handles the same types as the relevant encoding/decoding functions. Currently, however, I can't get it to compile. The error from gcc 4.0.1 on OS X Tiger is: g++ -c -g -I/usr/local/include/boost-1_33_1 -I.. rpc_server.cpp rpc_server.cpp: In member function 'void rpc_server::set_handler(int, int, int, int (*)(XDR*, A*), int (*)(XDR*, R*), boost::function<void ()(A*, boost::function<void ()(R*), std::allocator<void> >), std::allocator<void> >) [with A = example_args, R = example_res]': rpc_server.cpp:277: instantiated from here rpc_server.cpp:171: error: cannot resolve overloaded function 'call_req' based on conversion to type 'int' make: *** [rpc_server.o] Error 1 I've attached rpc_server.cpp. Can anyone tell me why the compiler doesn't have the information it needs? It seems to have figured out what types A and R are. What else does it need to resolve call_req? Thanks for your time, Sean -- When I see the price that you pay / I don't wanna grow up -- Tom Waits

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iostreams library and zlib/bzip2 support
by Robert Vinluan 14 Feb '06

14 Feb '06

Hi All, Right now, in order to compile and link to the iostreams library with zlib/bzip2 support, I have to include the .cpp files in my project (as mentioned in the boost docs). I'm not too fond of this idea as I want to keep 3rd-party code outside of my project build. Perhaps I have missed something in the docs, but is there another way to link with the iostreams library without including the .cpp files? Also along these lines ... is there any reason why zlib.cpp and bzip2.cpp are not compiled into libboost_iostreams-*.lib? Many Thanks, Rob

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Re: [Boost-users] Tree data structure
by Gottlob Frege 14 Feb '06

14 Feb '06

On 2/14/06, boost-users-request(a)lists.boost.org < boost-users-request(a)lists.boost.org> wrote: > > ---------------------------------------------------------------------- > > Message: 1 > Date: Tue, 14 Feb 2006 11:47:42 +0100 > From: Jeroen Vanattenhoven <jeroen.vanattenhoven(a)esat.kuleuven.be> > Subject: [Boost-users] Tree data structure > To: boost-users(a)lists.boost.org > Message-ID: <43F1B54E.1080805(a)esat.kuleuven.be> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Which of the boost libraries do I need for creating a tree data > structure? Purpose is to hold data for a legend for a map. The legend > has different layers and each layer may have sublayers. > > Thanks, > > Jeroen > > Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm > > > Not part of boost, but you can try the 'forest' type in Adobe's open source library. opensource.adobe.com.

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