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How to pass additional arguments to a boost test case?
by Marc Magrans de Abril 07 Dec '11

07 Dec '11

Dear colleagues, I would like to pass additional command line arguments to a given boost test. For example, if I execute the following from the command line: mytest.exe --log_level=all --param1=value1 --param2=value2 then I would like to be able to get param1 and param2 parameters inside the test cases doing: BOOST_AUTO_TEST_CASE(read_ param_from_command_line) { std::cout << "Param1=" << some_function("param1") << std::endl; std::cout << "Param2=" << some_function("param2") << std::endl; } What s the recommended approach in this case? Thanks, marc

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signature discrepancy between equal_range and upper_bound
by giecrilj＠stegny.2a.pl 06 Dec '11

06 Dec '11

The algorithm equal_range takes the Value by constant reference while the algorithm upper_bound takes Value by value. Why is that? (Note that standard algorithms take a constant reference.)

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[Units] How do you declare a plane angle to be dimensionless?
by Stephen Torri 06 Dec '11

06 Dec '11

Boost ver: 1.45 Compiler: Visual Studio 2008 I am trying to figure out how to declare a plane angle to be dimensionless. In the code I have so far I am using: typedef boost::units::make_system<radii_base_unit, minute_base_unit, boost::units::angle::radian_base_unit >::type myproject_system_t; I have one velocity in radii^1.5/min and a second velocity in radian/min. When I divide the radii^1.5/min by radian/min I am expecting to see radii to be the final dimension. What I am seeing is the denominator has radians in it. Here is my equation ke = radii^1.5/min n = radian/min a1 = ( ke / n ) ^ (2/3) The 'min' dimension cancel out so I am left with radii^1.5/radian before applying the power of 2/3. Applying the power of 2 I see the units are radii^3/radian^2 and then the 1/3 to get a final of radii/radian^(2/3). According to the almighty Wikipedia the radian angle is a dimensionless term. I am wondering what is the recommended course of action I should be taking here? Stephen

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[function] How to use function with templated member functions
by Christian Henning 06 Dec '11

06 Dec '11

Hi there, I would like to boost::function with a templated member function. Please consider the following code: struct my_reader { my_reader(bool full) { if( full ) { _read_function = &my_reader::read_full<int>; } else { _read_function = &my_reader::read_partial<int>; } } void read() { _read_function(this); } private: template< typename T > void read_full() { std::cout << "reading full image" << std::endl; } template< typename T > void read_partial() { std::cout << "reading partial image" << std::endl; } boost::function<void (my_reader*)> _read_function; }; int main(int argc, char* argv[]) { my_reader r(false); r.read(); return 0; } This doesn't compile with Visual Studio 2010 since the compiler cannot: "cannot convert from 'overloaded-function' to 'boost::function<Signature>'" Is there is way to make this happen? Regards, Christian

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Using boost::asio::io_service with boost::packaged_task
by Kelvin Chung 06 Dec '11

06 Dec '11

I'm trying to create a thread pool / task queue like system via boost::asio::io_service and boost::packaged_task rather than attempt to make 800+ threads for 800+ tasks that I have to make. (I'm not sure of the various concurrency issues that I might have, so reducing thread creation overhead is probably one of my big refactorings in my project.) A cursory glance from various sources reveals that I could do something like the following: template <class Ret> class TaskWrapper { // Wrapper around a boost::shared_ptr<boost::packaged_task<Ret>>, as boost::asio::io_service::post() // requires copyable input boost::shared_ptr<boost::packaged_task<Ret>> task; boost::unique_future<Ret> future; public: TaskWrapper(boost::shared_ptr<boost::packaged_task<Ret>>& task_) : task_(task) {} void operator()() { (*task)(); } boost::unique_future<Ret> get_future() { return future; } }; class TaskQueue { boost::asio::io_service io_service; boost::asio::io_service work; boost::thread_group threads; void run() { io_service.run(); } public: TaskQueue(std::size_t size = boost::thread::hardware_concurrency()) : work(io_service) { for (std::size_t i = 0; i < size; ++i) { // Create threads in pool threads.create_thread(boost::bind(&TaskQueue::run, this)); } } ~TaskQueue() { io_service.stop(); threads.join_all(); } template<class Ret> boost::unique_future<Ret> schedule(TaskWrapper<Ret>& task) { io_service.post(boost::bind(&TaskWrapper<Ret>::operator(), boost::ref(task))); return task.get_future(); } }; There are a few questions that I'd like to ask with this: * Would you recommend this? * To retrieve the results, I'd still have to extract all the futures (from TaskQueue::schedule() returns) into a list of boost::shared_futures, and then call boost::wait_for_all() on the list, right? * If a TaskWrapper itself posts other tasks, would a priority inversion or resource starvation issue occur (I keep thinking that it will, for some reason). How should I address this?

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[BGL] clear_vertex in subgraph
by Avishay Ben Shabtai 05 Dec '11

05 Dec '11

> > > According to Ticket #4753 <https://svn.boost.org/trac/boost/ticket/4753> clear > vertex should work on subgraph BUT according to documentation clear_vertex > should remove all edges of specified vertex but in the boost 1.47 > implementation of clear_vertex of subgarph it removes only the out_edges() > is there a prbolem with documentation or the issue was not fixed? > > The code of subgraph is: > > template <typename G>void > clear_vertex(typename subgraph<G>::vertex_descriptor v, subgraph<G>& g) { > while (true) { > typedef typename subgraph<G>::out_edge_iterator oei_type; > std::pair<oei_type, oei_type> p = out_edges(v, g); > if (p.first == p.second) break; > remove_edge(*p.first, g); > } > } > > Thanks > > Avishay > >

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lexical_cast<uint_value_t<10>::least>("7") = 55
by Nathan Ridge 05 Dec '11

05 Dec '11

Whoops! uint_value_t<10>::least is unsigned char... Can something be done about this, like having uint_value_t<10>::least be something that looks and acts like an unsigned char but is recognized by lexical_cast to be an integer type, not a character type?

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Container with insertion order
by Claude 05 Dec '11

05 Dec '11

Is available in BOOST some container (set or map) that can keep the insertion order of elements? -- View this message in context: http://boost.2283326.n4.nabble.com/Container-with-insertion-order-tp4097717… Sent from the Boost - Users mailing list archive at Nabble.com.

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[Bimap][Function] Create a Boost.bimap of SDLKeys and Boost.functions
by John M 05 Dec '11

05 Dec '11

What is the correct syntax for creating a boost::bimap<SDLKey, boost::function<void(boost::shared_ptr<Player>, bool)> >? (SDLKey is part of the SDL library. It is an enumeration. See here http://www.libsdl.org/cgi/docwiki.cgi/SDLKey) The code above does not compile, generating long cryptic template-related errors. Using an std::map<SDLKey, boost::function<void(boost::shared_ptr<Player>, bool)> > works, however. I could use some help overcoming this obstacle.

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[Units] Unable to raise constant to power of two
by Stephen Torri 05 Dec '11

05 Dec '11

In the attached code I am trying to take a constant physical unit and raise it to a power of two. The compiler is complaining that it cannot find a template to satisfy multiply_typeof_helper. It says that there are more than one partial specialization that matches the template argument list. I read something on the web about there was no pow operation for constants. The solution to that problem was to upgrade to Boost 1.48. Unforunately I am constrained to using Boost 1.45. What is an work around for this problem? Here is the compiler output with the file attached: 1>------ Build started: Project: boost_units, Configuration: Debug Win32 ------ 1>Compiling... 1>boost_units.cpp 1>C:\boost\boost/units/detail/static_rational_power.hpp(126) : error C2752: 'boost::units::multiply_typeof_helper<X,Y>' : more than one partial specialization matches the template argument list 1> with 1> [ 1> X=boost::units::quantity<myproject::second_types::squared_radii_unit>, 1> Y=boost::units::one 1> ] 1> C:\boost\boost/units/quantity.hpp(689): could be 'boost::units::multiply_typeof_helper<boost::units::quantity<Unit1,T1>,Y>' 1> C:\boost\boost/units/detail/one.hpp(36): or 'boost::units::multiply_typeof_helper<T,boost::units::one>' 1> C:\boost\boost/units/detail/static_rational_power.hpp(93) : see reference to class template instantiation 'boost::units::detail::static_int_power_impl<1,false>::apply<Y,R>' being compiled 1> with 1> [ 1> Y=boost::units::quantity<myproject::second_types::squared_radii_unit>, 1> R=boost::units::one 1> ] 1> C:\boost\boost/units/detail/static_rational_power.hpp(158) : see reference to class template instantiation 'boost::units::detail::static_int_power_impl<N>::apply<Y,R>' being compiled 1> with 1> [ 1> N=2, 1> Y=boost::units::constant<boost::units::physical_constant<myproject::second_types::equatorial_radius_of_earth_t>>, 1> R=boost::units::one 1> ] 1> C:\boost\boost/units/detail/static_rational_power.hpp(187) : see reference to class template instantiation 'boost::units::detail::static_int_power_sign_impl<N>::apply<Y>' being compiled 1> with 1> [ 1> N=2, 1> Y=boost::units::constant<boost::units::physical_constant<myproject::second_types::equatorial_radius_of_earth_t>> 1> ] 1> C:\boost\boost/units/pow.hpp(52) : see reference to class template instantiation 'boost::units::detail::static_rational_power_impl<R,Y>' being compiled 1> with 1> [ 1> R=boost::units::static_rational<2>, 1> Y=boost::units::constant<boost::units::physical_constant<myproject::second_types::equatorial_radius_of_earth_t>> 1> ] 1> ..\..\..\apps\boost_units\boost_units.cpp(104) : see reference to class template instantiation 'boost::units::power_typeof_helper<X,Y>' being compiled 1> with 1> [ 1> X=boost::units::constant<boost::units::physical_constant<myproject::second_types::equatorial_radius_of_earth_t>>, 1> Y=boost::units::static_rational<2> 1> ] 1>Build log was saved at "file://c:\documents and settings\stephen.torri\my documents\visual studio 2008\projects\satsim_boost_units\vs2008\apps\boost_units\boost_units.dir\Debug\BuildLog.htm" 1>boost_units - 1 error(s), 0 warning(s) ========== Build: 0 succeeded, 1 failed, 1 up-to-date, 0 skipped ========== Regards, Stephen

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