August 2010 - Boost-users - lists.boost.org

function_traits for constructors?
by Kenny Riddile 16 Aug '10

16 Aug '10

I would like to detect the arity and argument types of a class's constructor. Is this possible? The documentation for function_traits says: "function_traits is intended to introspect only C++ functions of the form R (), R( A1 ), R ( A1, ... etc. ) and not function pointers or class member functions."

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Multi index assistance
by Etienne Philip Pretorius 16 Aug '10

16 Aug '10

Hello List, I have defined a multi_index container, but I am not able to populate the container. Is there something that I have missed? struct element { element( std::uint8_t x, std::uint8_t y, std::uint8_t z ) : x(x),y(y),z(z) {}; std::uint8_t x,y,z; }; typedef boost::multi_index_container< element, boost::multi_index::indexed_by< boost::multi_index::ordered_non_unique< boost::multi_index::member< element, std::uint8_t, &element::x > >, boost::multi_index::ordered_non_unique< boost::multi_index::member< element, std::uint8_t, &element::y > >, boost::multi_index::ordered_unique< boost::multi_index::member< element, std::uint8_t, &element::z > > > > matrix_t; Then I define: matrix_t m; element e(1,2,3); m.insert <-- not valid So what is the correct way to populate the container? Kind Regards, Etienne

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[Boost::mpl] transforming expression both at compile time and runtime
by Noman Javed 16 Aug '10

16 Aug '10

Can someone guide me how to transform an expression both at compile time and at runtime? I explain by an example Suppose I want to transform the following expression like that foo(f,other(g,bar)) --> other(g,foo(f,bar)) where bar is an Array and the "foo" and "other" are the higher order functions. I can write the metafunction for transforming the type of the expression i.e from Foo<F, Other<G, Array> > --> Other<G, Foo<F, Array> > I want to execute this expression in the following way Array result = foo(f, other(g, bar)) where within the body of the operator= overload of the Array class I have the function transform to transform this expression as said above. The problem is that how can I write the runtime equivalent of the metafunction transform or is there some other way possible? Thanking in anticipation Noman

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compilation gcc version??
by pedro chaparro 16 Aug '10

16 Aug '10

hi, there is some way to know what version of gcc i used to compile my boos libraries?? thanks -- Pedro Alonso Chaparro Valero R&D Engineer Ciudad Politecnica de la Innovación iTEAM - Mobile Communications Group Polytechnic University of Valencia C\ Camino de Vera S/N, Edificio 8G 46022 Valencia, Spain

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GCC errror?
by pedro chaparro 16 Aug '10

16 Aug '10

Hi, i'm using boos libraries to add some extra functions in network simulator 2, ns-2, a network and protocols simulator, i have the version 2.34 working good with boost, but now i need to work with other version of ns2 the 2.27 version, i modified the Makefile as in the version i have already working, but i get the error below, but i really dont know what could be the reason of it. i'll aprecciate some help, or directions for fix it. Could be something related to the boost libraries were complied using gcc-4.3 and to compile this version of ns2 i need gcc-3.2.3???do i recompile boost libraries with gcc-3.2.3 version?? thanks /usr/bin/ld: warning: libstdc++.so.6, needed by /usr/local/lib/libboost_serialization.so, may conflict with libstdc++.so.5 /usr/lib/libstdc++.so.6: undefined reference to `_Unwind_Resume_or_Rethrow(a)GCC_3.3' /usr/lib/libstdc++.so.6: undefined reference to `_Unwind_GetIPInfo(a)GCC_4.2.0 ' collect2: ld returned 1 exit status make: *** [ns] Error 1 -- Pedro Alonso Chaparro Valero R&D Engineer Ciudad Politecnica de la Innovación iTEAM - Mobile Communications Group Polytechnic University of Valencia C\ Camino de Vera S/N, Edificio 8G 46022 Valencia, Spain

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QuickBook
by OvermindDL1 16 Aug '10

16 Aug '10

Attempting to use QuickBook to create both HTML and PDF documentation. First of all, compiled just about everything I can compile in boost, including about all the tools, on Ubuntu. I created a directory named qb_test. I created a file called test.qbk and filled it with: """ [article TestingArticle [quickbook 1.5] [version 0.1] [authors [, OvermindDL1]] [copyright 2010 OvermindDL1] [/ [purpose /WikiWiki/ style documentation tool]] [id test] ] [section:intro Introduction] This is just a simple testing thing, we shall see how it works overall... [endsect] [section:change_log Change Log] [h3 Version 0.1] * Initial creation... * Two pages setup, intro and change_log [endsect] """ I ran: """ quickbook test.qbk """ It created a test.xml file, not quite what I was looking for, I take it that it does not call boostbook directly... So then I started looking for how to call boostbook and became pretty lost, for some reason I recall this being easier on Windows... Decided to try to use bjam (although the project this is eventually going into uses CMake, so no bjam eventually...), made a Jamfile containing: """ project test import boostbook : boostbook ; boostbook test : test.qbk : <include>. ; """ And running bjam complains about not having found boost, which makes sense since boost was build as a different user so its building directory is inaccessible. Basically I want to build a quickbook documentation for another very large C++ project that itself uses CMake, how would I go about doing this? The quickbook documentation is lacking in how to get a finished html/pdf/etc...

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About naming of integer log in base 2
by Murilo Adriano Vasconcelos 16 Aug '10

16 Aug '10

Hi all, I implemented a function [0] wich computes the logarithm in base two of integers and want to know what naming is most appropriated: ilog2 or simply log2 [0] - http://svn.boost.org/svn/boost/sandbox/SOC/2010/bits_and_ints/boost/integer… Best, -- Murilo Adriano Vasconcelos http://murilo.wordpress.com

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How to access a GRAPH property? - simple
by Mike Douglass 16 Aug '10

16 Aug '10

I have struct vertex_properties { blah blah } struct edge_properties { blah blah } struct graph_properties { int bobo; } typedef adjacency_list < vecS, vecS, bidirectionalS, property< vertex_predecessor_t, vertex_t, vertex_properties >, property< edge_reverse_t, edge_t, edge_properties >, graph_properties > graph_t; graph_t g; But how can I access bobo? g.bobo; does not compile (otherwise compiles OK). thanks

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boost::bind with template
by Kraus Philipp 15 Aug '10

15 Aug '10

Hi, I would like to create a thread group for my "worker objects" like: std::vector< worker<T,D> > l_worker; boost::thread_group l_threads; for(std::size_t i=0; i < p_threads; ++i) { l_worker.push_back( worker<T,D>(p_iteration, p_stepsize, m_derivation, m_optimize, m_static, p_batch) ); l_threads.create_thread( boost::bind( &worker<T,D>::optimize ), l_worker[i] ); (*) } I get a compiler error at (*) on boost/bind/bind.hpp: In instantiation of 'boost::_bi::result_traits<boost::_bi::unspecified, void (worker<double, 2ul>::*)()>': error: 'void (worker<double, 2ul>::*)()' is not a class, struct, or union type boost/bind/bind_template.hpp:15: instantiated from 'boost::_bi::bind_t<boost::_bi::unspecified, void (worker<double, 2ul>::*)(), boost::_bi::list0>' The variables T is a typename and D is std::size_t > 0 How can I bind my template object (<doube, 2>) to the create_thread methode? Thanks Phil

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[asio] Crash in io_service::run()
by Germán Diago 15 Aug '10

15 Aug '10

Hello. I have a client application that accesses a server, both coded with Boost.Asio. The code in the client is like this: Client::Client() : socket_(service_), work_(service_) { } void Client::connectWith(const std::string & hostname, int puerto, const std::string & nombre, int equipo) { using namespace boost::asio::ip; tcp::resolver resolver(service_); tcp::resolver::query query(tcp::v4(), hostname, std::to_string(puerto)); tcp::resolver::iterator endpoint_iterator = resolver.resolve(query), endpoint_end; tcp::endpoint endpoint = *endpoint_iterator; socket_.async_connect(endpoint, boost::bind(&Cliente::handleConnect, this, boost::asio::placeholders::error, ++endpoint_iterator)); std::thread([&] {service_.run(); }); } void Client::handleConnect(const boost::system::error_code & e, boost::asio::ip::tcp::resolver::iterator endpoint_iterator) { if (!e) { } else if (endpoint_iterator != boost::asio::ip::tcp::resolver::iterator()) { socket_.close(); boost::asio::ip::tcp::endpoint endpoint = *endpoint_iterator; socket_.async_connect(endpoint, boost::bind(&Cliente::handleConnect, this, boost::asio::placeholders::error, ++endpoint_iterator)); } else { std::cerr << e.message() << std::endl; } } My application crashes when calling Client::connectWith when I run the io_service::run() function in another thread, which is what I exactly want to do. If I run io_service::run() in the same thread, everything is ok. Anyone knows why? This is a GUI application, maybe it's a problem with gtkmm interaction and threads? Anyway, I would like how to handle to run io_service's run() in another thread. Thanks in advance.

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