- Boost-users - lists.boost.org

problem with boost::phoenix::lambda
by Kim Kuen Tang 25 Jul '09

25 Jul '09

Hi all, the following code double abc=lambda(_a=*ref(it)++)[_a*2.0]()(); // here 'it' is an //iterator produces the error C2440: 'initializing' : cannot convert from 'boost::phoenix::detail::error_expecting_arguments' to 'double' which should not be. The two lines of code let(_a=*ref(it)++)[_a*2.0](); //or lambda(_a=*ref(it)++)[_a*2.0*arg1]()( val); compile fine. Perhaps someone has an answer to this error? ( I use boost trunk version and msvc 2008) To reproduce the errors just compile the code below. Best regards Kim Tang # include <algorithm> # include <vector> # include <boost/spirit/include/phoenix.hpp> using namespace boost::phoenix; using namespace boost::phoenix::arg_names; using namespace boost::phoenix::local_names; int main() { std::vector<double> u(11,1.0); std::vector<double> w(11,2.0); std::vector<double>::const_iterator it=w.begin(); //boost::phoenix::generate(ref(u) // ,lambda(_a=*ref(it)++)[_a*2.0 ] //)(); double abc=lambda(_a=*ref(it)++)[_a*2.0]()(); return 0; }

2 3

Problem in running blocking_udp_echo_client on MacOSX
by n179911 25 Jul '09

25 Jul '09

I am trying to run blocking_udp_echo_client on MacOS X http://www.boost.org/doc/libs/1_35_0/doc/html/boost_asio/example/echo/block… I run it with argument 'localhost 9000' But the program crashes and this is the line in the source which crashes: udp::socket s(io_service, udp::endpoint(udp::v4(), 0)); this is the stack trace: #0 0x918c3e42 in __kill #1 0x918c3e34 in kill$UNIX2003 #2 0x9193623a in raise #3 0x91942679 in abort #4 0x940d96f9 in __gnu_debug::_Error_formatter::_M_error #5 0x0000e76e in __gnu_debug::_Safe_iterator<__gnu_norm::_List_iterator<std::pair<int, boost::asio::detail::reactor_op_queue<int>::op_base*> >, __gnu_debug_def::list<std::pair<int, boost::asio::detail::reactor_op_queue<int>::op_base*>, std::allocator<std::pair<int, boost::asio::detail::reactor_op_queue<int>::op_base*> > > >::_Safe_iterator at safe_iterator.h:124 #6 0x00014729 in boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type::bucket_type at hash_map.hpp:277 #7 0x00019e97 in std::_Construct<boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type, boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type> at stl_construct.h:81 #8 0x0001a457 in std::__uninitialized_fill_n_aux<__gnu_cxx::__normal_iterator<boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type*, __gnu_norm::vector<boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type, std::allocator<boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type> > >, unsigned long, boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type> at stl_uninitialized.h:194 #9 0x0001a4e1 in std::uninitialized_fill_n<__gnu_cxx::__normal_iterator<boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type*, __gnu_norm::vector<boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type, std::allocator<boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type> > >, unsigned long, boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type> at stl_uninitialized.h:218 #10 0x0001a509 in std::__uninitialized_fill_n_a<__gnu_cxx::__normal_iterator<boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type*, __gnu_norm::vector<boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type, std::allocator<boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type> > >, unsigned long, boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type, boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type> at stl_uninitialized.h:310 #11 0x0001aa34 in __gnu_norm::vector<boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type, std::allocator<boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type> >::_M_fill_insert at vector.tcc:365 #12 0x0001acda in __gnu_norm::vector<boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type, std::allocator<boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type> >::insert at stl_vector.h:658 #13 0x0001ad81 in __gnu_norm::vector<boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type, std::allocator<boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type> >::resize at stl_vector.h:427 #14 0x0001ae3a in __gnu_debug_def::vector<boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type, std::allocator<boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::bucket_type> >::resize at vector:169 #15 0x0001b7be in boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::rehash at hash_map.hpp:221 #16 0x0001bbeb in boost::asio::detail::hash_map<int, boost::asio::detail::reactor_op_queue<int>::op_base*>::hash_map at hash_map.hpp:67 #17 0x0001bc74 in boost::asio::detail::reactor_op_queue<int>::reactor_op_queue at reactor_op_queue.hpp:42 #18 0x0001bd24 in boost::asio::detail::kqueue_reactor<false>::kqueue_reactor at kqueue_reactor.hpp:86 #19 0x0001c000 in boost::asio::detail::service_registry::use_service<boost::asio::detail::kqueue_reactor<false> > at service_registry.hpp:109 #20 0x0001c14d in boost::asio::use_service<boost::asio::detail::kqueue_reactor<false> > at io_service.ipp:195 #21 0x0001c26d in boost::asio::detail::reactive_socket_service<boost::asio::ip::udp, boost::asio::detail::kqueue_reactor<false> >::reactive_socket_service at reactive_socket_service.hpp:111 #22 0x0001c344 in boost::asio::detail::service_registry::use_service<boost::asio::detail::reactive_socket_service<boost::asio::ip::udp, boost::asio::detail::kqueue_reactor<false> > > at service_registry.hpp:109 #23 0x0001c491 in boost::asio::use_service<boost::asio::detail::reactive_socket_service<boost::asio::ip::udp, boost::asio::detail::kqueue_reactor<false> > > at io_service.ipp:195 #24 0x0001c4d5 in boost::asio::datagram_socket_service<boost::asio::ip::udp>::datagram_socket_service at datagram_socket_service.hpp:95 #25 0x0001c59e in boost::asio::detail::service_registry::use_service<boost::asio::datagram_socket_service<boost::asio::ip::udp> > at service_registry.hpp:109 #26 0x0001c6eb in boost::asio::use_service<boost::asio::datagram_socket_service<boost::asio::ip::udp> > at io_service.ipp:195 #27 0x0001c711 in boost::asio::basic_io_object<boost::asio::datagram_socket_service<boost::asio::ip::udp> >::basic_io_object at basic_io_object.hpp:72 #28 0x0001c783 in boost::asio::basic_socket<boost::asio::ip::udp, boost::asio::datagram_socket_service<boost::asio::ip::udp> >::basic_socket at basic_socket.hpp:108 #29 0x0001c865 in boost::asio::basic_datagram_socket<boost::asio::ip::udp, boost::asio::datagram_socket_service<boost::asio::ip::udp> >::basic_datagram_socket at basic_datagram_socket.hpp:107 #30 0x000027bc in main at main.cpp:32 This is the gdb output: (gdb) continue /Developer/SDKs/MacOSX10.5.sdk/usr/include/c++/4.0.0/debug/safe_iterator.h:127: error: attempt to copy-construct an iterator from a singular iterator. Objects involved in the operation: iterator "this" @ 0x0x100420 { type = N11__gnu_debug14_Safe_iteratorIN10__gnu_norm14_List_iteratorISt4pairIiPN5boost4asio6detail16reactor_op_queueIiE7op_baseEEEEN15__gnu_debug_def4listISB_SaISB_EEEEE (mutable iterator); state = singular; } iterator "other" @ 0x0xbfffe8a4 { type = N11__gnu_debug14_Safe_iteratorIN10__gnu_norm14_List_iteratorISt4pairIiPN5boost4asio6detail16reactor_op_queueIiE7op_baseEEEEN15__gnu_debug_def4listISB_SaISB_EEEEE (mutable iterator); state = singular; } Program received signal: “SIGABRT”. (gdb) continue Program received signal: “?”. Does someone has any idea why this example does not work on mac osx? Thank you.

1 0

Using boost library on MacOSx
by n179911 25 Jul '09

25 Jul '09

Hi, I have install boost library using this: $ sudo port install boost It seems download and compile fine on my local machine. But then i tried to compile a simple echo client example from http://www.boost.org/doc/libs/1_35_0/doc/html/boost_asio/examples.html I get a bunch of compiler errors. I am using "g++ -o block_client blocking_udp_echo_client.cpp " Here are some of the errors: $ g++ -o block_client blocking_udp_echo_client.cpp blocking_udp_echo_client.cpp:68:10: error: #include expects "FILENAME" or <FILENAME> blocking_udp_echo_client.cpp:69:10: error: #include expects "FILENAME" or <FILENAME> blocking_udp_echo_client.cpp:70:10: error: #include expects "FILENAME" or <FILENAME> blocking_udp_echo_client.cpp:71:10: error: #include expects "FILENAME" or <FILENAME> blocking_udp_echo_client.cpp:83: error: stray ‘\’ in program blocking_udp_echo_client.cpp:108: error: stray ‘\’ in program blocking_udp_echo_client.cpp:112: error: stray ‘\’ in program Thank you for any help.

7 11

A lambda and boost function problem. Can any one with kindness help me?
by fmingu 25 Jul '09

25 Jul '09

I am using Dev-C++ 4.9.8.0 and lambda expression. I builded a class and put it into a dll made by myself. The dll will be used by else's programs which contain the functions that I do not know. All I know is just the function type.So I used the boost function library. ............ class classA{ ................. public: boost::function<double (const int& )> theunknownfunc; ........................ and a member function in classA used such function: double classA::function1( int& q, const int& n){ double result=0.0; int loopvalue=1, totaltime=thenumbern; int innern=1; ( for_loop(var(loopvalue)=1,var(loopvalue)<=var(totaltime),++var(loopvalue), (var(result)+= ( bind(&classA::theunknownfunc,this,_2)*bind(&classA::function2,this,_1,_2)), ++_2,_2%=_1))) (q,innern); return result; } ................. but the complier told me that: instantiated from `RET boost::lambda::lambda_functor_base<boost::lambda::forloop_action, Args>::call(A&, B&, C&, Env&) const [with RET = void, A = int, B = int, C = const boost::tuples::null_type,<............. instantiated from `T::sig<boost::tuples::tuple<A&, B&, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, .............. instantiated from here The user do not want to read the source code of mine since it is built with many lambda expressions. He just want to use the dll. And I do not know how to solve it by using boost function library. Can anyone with kindness help me?

2 1

[filesystem] Strange seg.faults of boost::filesystem under ElectricFence
by Pavel Shevaev 25 Jul '09

25 Jul '09

Folks, I'm trying to spot a memory corruption error in my application using ElectricFence[1] and I'm facing really weird segfaults in boost::filesystem. I don't really believe it is boost::filesystem which causes a seg.fault but rather my improper usage of ElectricFence. Here is the most interesting part of the core dump: #0 0x00007f2b4aa1c517 in kill () from /lib/libc.so.6 #1 0x000000000048f46b in on_signal (s=4) at main.cpp:180 #2 <signal handler called> #3 0x00007f2b4aa1c517 in kill () from /lib/libc.so.6 #4 0x00007f2b4b4e746f in ?? () from /usr/lib/libefence.so.0 #5 0x00007f2b4b4e8290 in _eff_deallocate () from /usr/lib/libefence.so.0 #6 0x00007f2b4b4e884e in _eff_allocate () from /usr/lib/libefence.so.0 #7 0x00007f2b4b4e7288 in operator new () from /usr/lib/libefence.so.0 #8 0x00007f2b4b27d711 in std::string::_Rep::_S_create () from /usr/lib/gcc/x86_64-pc-linux-gnu/4.3.3/libstdc++.so.6 #9 0x00007f2b4b27e0d5 in ?? () from /usr/lib/gcc/x86_64-pc-linux-gnu/4.3.3/libstdc++.so.6 #10 0x00007f2b4b27e213 in std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string () from /usr/lib/gcc/x86_64-pc-linux-gnu/4.3.3/libstdc++.so.6 #11 0x00007f2b4cbaa81e in boost::filesystem::detail::dir_itr_first () from /home/game/hg/master_49100/shared/scripts/../lib/boost/build/lib/libboost_filesystem-mt.so Basically the following line in my app cases the seg.fault: boost::filesystem::directory_iterator dir_iter(path); Inspecting path variable under gdb shows it's ok and actuall directory exists. Here is some information about my application: * built with gcc-4.3.3 * runs under linux-2.6.29-gentoo * uses boost-1.35 * boost is built with options: ./bjam link=shared --build-type=minimal --layout=system --toolset=gcc * ElectricFence built from gentoo package efence-2.4.13-r1 The question is whether there are any special boost build options which should be used with ElectricFence. Thanks in advance. [1]http://www.pf-lug.de/projekte/haya/efence.php -- Best regards, Pavel

2 2

Help with updating PowerDNS to boost for easier windows compilation
by Todd Nine 25 Jul '09

25 Jul '09

Hi all, I'm in the process of updating the 2.9.22 source of PowerDNS to be a bit more "Windows Friendly" and building it with Visual C++ 8 (2008). However, I'm having some issues I could use a hand with. Specifically, the authors of powerdns define their own following types #ifdef NEED_POSIX_TYPEDEF typedef unsigned char uint8_t; typedef unsigned short int uint16_t; typedef unsigned int uint32_t; typedef unsigned long long uint64_t; #endif These types are used extensively in the code. Rather than prefix each reference with the boost:: namspace, I would like to make boot the standard namespace for these data types. Everything includes the header file with the definition above, is there a way for me to do this? I haven't done C and C++ in 9 years, and even then only on very small projects and small patches, so your help is greatly appreciated. Thanks, todd SENIOR SOFTWARE ENGINEER todd nine | spidertracks ltd | 117a the square po box 5203 | palmerston north 4441 | new zealand P: +64 6 353 3395 | M: +64 210 255 8576 E: todd(a)spidertracks.co.nz W: www.spidertracks.com

2 1

FREE debugger
by Caligula 24 Jul '09

24 Jul '09

Can anyone recommend a FREE debugger to use for boost, under linux. I want to see if I can fix copy_graph to my liking. I'm used to using the gdb debugger, but I think there must be something better. Thanks -Caligula

3 2

UTF-16
by Robert Dailey 24 Jul '09

24 Jul '09

Hi everyone, I did a bit of googling to see if Boost 1.39 as any portable support for UTF-16 encoded strings, but I did not find any. I'm currently using wxWidgets in my application, and I need a decent string object to use. I know that wxWidgets has UTF-16 string support through wxString, however I do not want to expose this object in my interfaces. I want to remain as abstracted away from wxWidgets as possible. Having said that, if someone could tell me if there is any existing UTF-16 string support in Boost, I'd appreciate it. I did not find anything in the vault, sandbox, or trunk in Boost. If boost has no such string object, could someone give me a head start on where to look? Thanks.

9 15

[Signals] Another performance discussion
by Sajjan Kalle 24 Jul '09

24 Jul '09

Hi, I see that there's already been some discussion concerning the performance of the signals library, it's fairly old though so I hope nobody minds me brining it up in a new thread. We use signals fairly extensively and have seen it coming in fairly high in our profiling sessions. I did a search on the mailing list and found a discussion from 2005 on the performance of the library, results at that time showed a vector with boost::function being about 100 times faster than boost::signals. Our tests shows that this still very much holds true. I suspect there difference is considerably worse on in order RISC processors. I think it would be nice if either the manual states that performance isn't one of the design goals of boost::signals, or that the interface allows the application programmer greater controll over implementation details which affects performance. I saw in one discussion going ( although once again, an old one ) that boost::signals use list as the container of slots instead of for example vector. This is understandable for the general case since otherwise connecting / disconnecting slots would be very expensive on large collections. However one use case which I'd think is very very frequent ( which resembles ours ), is to have fairly few slots connected and a somewhat constant collection, in this case one would rather have the expensive connection management and instead have the better cache locality and invocation performance. Blocking / unblocking slots is another feature which while useful for a lot of people perhaps should be optional. I don't know exactly how blocking / unblocking slots are implemented, but perhaps simply an added iterator which doesn't respect the blocked status could be easily added and a matching slot invocation function.

4 15

Intel Compiler 11 and Boost 1.39 Bessel functions
by Matthieu Brucher 24 Jul '09

24 Jul '09

Hi, I've tried this code with Boost 1.39 (1.37 has the same behavior) and icpc 11.0.083: #include <iostream> #include <boost/math/special_functions/bessel.hpp> int main(int argv, char** argc) { std::cout << boost::math::cyl_bessel_i(0, 0) << std::endl; } With -g -03, this crashes with an internal error. The issue was reported to Intel (but if you have a solution, I'm all ears). Matthieu -- Information System Engineer, Ph.D. Website: http://matthieu-brucher.developpez.com/ Blogs: http://matt.eifelle.com and http://blog.developpez.com/?blog=92 LinkedIn: http://www.linkedin.com/in/matthieubrucher

3 10