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Re: [Boost-users] [boost:regex]an compiler error when use boost1_36 inapplication
by gmail 09 Sep '08

09 Sep '08

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Is there a function to compute the determinant of a square matrix?
by Peng Yu 09 Sep '08

09 Sep '08

Hi, boost has ublas. I'm wondering if there is a function to compute the determinant of a square matrix in boost? Thanks, Peng

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mpl::transform<...> --- compile error: is not derived from type
by e r 09 Sep '08

09 Sep '08

hi, here's the problem i have: struct my{ template<typename UInt> struct apply{ typedef mpl::int_<UInt::value> type; }; }; template<int First,int Last> struct id_range{ typedef mpl::transform< mpl::range_c<int,First,Last> , my , mpl::back_inserter< mpl::vector<> > >::type type; /home/er/cpp/boost/random/mcmc/id_range.hpp|32|error: type ‘boost::mpl::transform<boost::mpl::range_c<int, First, Last>, boost::random::mcmc::<unnamed>::my, boost::mpl::back_inserter<boost::mpl::vector<mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na> >, mpl_::na>’ is not derived from type ‘boost::random::mcmc::id_range<First, Last>’| however, for example, this --instead-- compiles fine: struct id_range{ typedef mpl::transform< mpl::range_c<int,1,3> , my , mpl::back_inserter< mpl::vector<> > >::type type; }; any suggestion appreciated. thanks!

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[dataflow][review] loading Dataflow.Signals components from shared libraries
by Stjepan Rajko 09 Sep '08

09 Sep '08

In the Dataflow library / Dataflow.Signals layer review discussions, a few people have mentioned the potential usefulness of loading components at runtime (e.g., from a shared library). I put together a small example of how this could be done for Dataflow.Signals components using the (prototype) Dataflow.Blueprint layer and the Extension library: http://svn.boost.org/svn/boost/sandbox/SOC/2007/signals/libs/dataflow/examp… The component_add.cpp file contains the implementation of a component (that adds two numbers and outputs the result), and the code required to access it through an Extension factory_map. The extension_example.cpp file loads the shared library created from component_add.cpp, instantiates the provided component, and uses it to complete a network. The Blueprint layer is still under development (and has somewhat ugly syntax), but I hope this example can still demonstrate some future possibilities of the Dataflow library with regards to loading components at run-time. It has been tested to work with MSVC 2005. Regards, Stjepan

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[boost-users][DateTime] crash with time_duration
by Igor R 08 Sep '08

08 Sep '08

Hi, The following code crashes (MSVC2005, boost1.36): //.... time_duration td = hours(25); cout << td; It seems that operator <<() uses to_tm() function, and the latter sets tm_hour = 25, which causes an assertion in CRT _expandtime() and program termination. Is this desired behavior / known issue / unknown bug? Thanks, Igor'.

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[variant] variant member function apply_visitor( visitor ) thread-safe?
by Hicham Mouline 08 Sep '08

08 Sep '08

Hello, Is the apply_visitor() method per se thread-safe, meaning, if i have variant object, and i visit it from different threads at same time, and if i assume the visitor i write is thread-safe, my question is about the machinery of apply_visitor() itself, is it thread-safe? regards,

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asio::serial_port how to know how many bytes are available for read
by Jean-Sebastien Stoezel 08 Sep '08

08 Sep '08

Hi, Is there a way to know how many bytes are available for read from a serial port, using asio::serial_port::read_some? The sockets have bytes_readable or something similar... Any equivalent for the serial ports? Thanks! Jean

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Borland c++ 5.8.2 and Boost 1.3.6 - Thread problem???
by Stephen Kierzewski 08 Sep '08

08 Sep '08

Hello, Has anyone successfully compiled the Boost libraries with the Borland / Codegear Turbo C++ Pro, compiler version 5.8.2? I was able to build the libraries but I got a lot of errors and a simple Hello World program using boost::thread will not work. Any help on switches or tweaks I can do to get Boost to work would be appreciated. Here is the program I am compiling and the error I get when running it. I am linking to the debug version of the multi-threaded DLL (boost_thread-bcb-mt-d-1_36.dll) The sample program compiles fine but when I run it I get an assertion error and the program terminates. Any feedback is welcome. Thank you, Stephen ________________________________ Assertion failed: p_ != 0, file .\boost/intrusive_ptr.hpp, line 149 Abnormal program termination ________________________________ #include <boost/thread/thread.hpp> #include <iostream> using namespace std; void hello_world() { cout << "Hello world, I'm a thread!" << endl; } int main(int argc, char* argv[]) { // start a new thread that calls the "hello_world" function boost::thread my_thread(&hello_world); // wait for the thread to finish my_thread.join(); return 0; }

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Boost Graph Library and Boehm Garbage Collector
by FBSL 08 Sep '08

08 Sep '08

Hello I am having trouble to garbage-collect adjacency_list<>. I have instanciated it with correctly garbage-collected vectors and lists (I have copied vecS and listS definitions, and added Boehm GC's default allocator so that they are garbage-collected). In my application I need to dynamically allocate many graphs, but it does not work, there is a (big) memory leak. Unfortunately, there is no template argument in adjacency_list<> to specify Boehm GC's allocator. Does anyone have a hint ? Snippet code "main.cpp" follows, compiled with Boost Graph Library 1.32, Boehm GC 6.4 and G++ 3.3.5, with command line : $ g++ -o main main.cpp -lgc -lgccpp -- #include <boost/graph/adjacency_list.hpp> #include <gc/gc_allocator.h> #include <gc/gc_cpp.h> #include <iostream> #include <vector> #include <list> using namespace std; using namespace boost; namespace boost { struct collected_vecS {}; struct collected_listS {}; template <class ValueType> struct container_gen<collected_vecS, ValueType> { typedef vector<ValueType,gc_allocator<ValueType> > type; }; template <class ValueType> struct container_gen<collected_listS, ValueType> { typedef list<ValueType,gc_allocator<ValueType> > type; }; template <> struct parallel_edge_traits<collected_vecS> { typedef allow_parallel_edge_tag type; }; template <> struct parallel_edge_traits<collected_listS> { typedef allow_parallel_edge_tag type; }; namespace detail { template <> struct is_random_access<collected_vecS> { enum { value = true }; typedef true_type type; }; } } typedef adjacency_list<collected_vecS, collected_vecS, directedS, no_property, no_property, no_property, collected_listS> graph; int main() { // leaks... while(true){ graph * g=new (UseGC) graph; for(unsigned int i=0; i<100; ++i){ add_vertex(*g); } for(unsigned int i=0; i<100; ++i){ for(unsigned int j=0; j<100; ++j){ add_edge(i,j,*g); } } } }

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throw exception in boost
by gj_uestc 08 Sep '08

08 Sep '08

Hi, all When I use boost_1_36 in intel compiler, I got such error "runtime support for RTTI is disabled".It seems like RTTI is used in exception.hpp. Is there a way to let me choose not use the exception.hpp? I remembered in boose_1_35 you have to defined Macro "BOOST_NO_EXCEPTIONS" then "exception.hpp" would be included, otherwise this file is not necessary. Thanks Juan

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