- Boost-users - lists.preview.boost.org

Boost.Pool - Are you using this library, please can we have your input?
by Paul A. Bristow 19 Jan '11

19 Jan '11

Boost.Pool is the subject of a 'make-over' by Boost.Guild. (This is some of a test-bed for a process of revision of older, perhaps orphaned, libraries using the relative safety of the sandbox). In order to permit any modification, the original (hand-written?) html documentation has been converted to Quickbook (and somewhat revised) at http://svn.boost.org/svn/boost/sandbox/guild/pool/libs/pool/doc/ You can build the html docs using the jamfile.v2 in the normal way, but you will probably find it more convenient to go direct to the pdf version http://svn.boost.org/svn/boost/sandbox/guild/pool/libs/pool/doc/pool.pdf This is fairly fully hyperlinked, and includes a reference section using Doxygen. Doxygen comments have been added to the header files (from the original html docs). (If you are a Doxygen fan, there is also a Doxyfile for generating Doxygen-style docs in the /doc/Doxygen/ folder). We are now considering some better tests, and perhaps some enhancements to the code. We'd like input from users about: 1 Things missing or wrong from the docs. More up to date references? 2 Things missing (or don't work well) from Pool. 3 New things that you would like (this is not a promise!). 4 Examples of your use. Perhaps you built some during your development that could be used? 5 Better tests. Thanks. Paul PS Don't panic - the release version will not be changed without a mini-review. --- Paul A. Bristow, Prizet Farmhouse, Kendal LA8 8AB UK +44 1539 561830 07714330204 pbristow(a)hetp.u-net.com

7 8

Time Series lib
by Peter Godino 19 Jan '11

19 Jan '11

I've found there is a boost lib called Time Series. It is not yet in SVN. Is it possible access this library? Thanks, Peter

2 2

Having program_options generate a round-trippable config file?
by Rhys Ulerich 19 Jan '11

19 Jan '11

Hi all, I'm using program_options to combine arguments from the command line, the environment, and one or more input files. As you'd expect, it works very well. However, I have an additional requirement that I'm unsure how to implement cleanly atop the library: Given instances of program_options::options_description and program_options::variables_map, I'd like to save a program_options::parse_config_file-friendly file containing the final values obtained. Such a config file could be given back to the program and would identically reproduce the options used. The need is for some scientific software where I want a precise record of what a user has chosen for reasons of scientific repeatability. I see several ways to go about achieving this need, but all of them are ugly, brittle hacks: 1) Accessing the information directly from variables_map seems difficult due to variables_map's use of type erasure and the fact that it does not save the tokens from which values are derived. 2) Obtaining the tokens from the intermediate program_options::parsed_options instances is a possibility but requires me to effectively reimplement the logic contained within program_options::store. It also fails to account for defaulted values. 3) Looping over each program_options::value_semantic found in the options_description instance and adding a notify() callback again runs into type erasure troubles. 4) Adding a notify() to each option_description at its point of declaration avoids type erasure but makes the code impact O(n) where n is the number of options. Has anyone built such a feature atop program_options? Can anyone lend some wisdom? Thanks, Rhys

2 1

boost.type_traits - is_convertible issue with aligned types
by Christoph Heindl 19 Jan '11

19 Jan '11

Hi, consider the following simple example struct aligned_type { __declspec(align(16)) float vals[4]; }; BOOST_STATIC_ASSERT((boost::is_convertible<aligned_type , aligned_type >::value)); It fails on MSVC 9.0 with boost 1.43 with the following error type_traits/is_convertible.hpp(254) : error C2719: 'unnamed-parameter': formal parameter with __declspec(align('16')) won't be aligned References won't help either BOOST_STATIC_ASSERT((boost::is_convertible<aligned_type &, aligned_type &>::value)); as it breaks with a similar error type_traits/is_convertible.hpp(263) : error C2718: 'const vec_aligned': actual parameter with __declspec(align('16')) won't be aligned A bug database search did not bring up any relevant matches, so I wonder if that is a new issue or just by design? Best regards, Christoph

2 7

[Proto] Returns double
by Hossein Haeri 18 Jan '11

18 Jan '11

Dear all, I am working in an application where I use Proto to evaluate an expression template like _1 >> f >> g to g(f(x)) once x is assigned to _1. (Please note that f and g are not necessarily functions -- they might be function objects too.) I am interested in putting a compile-time sanity check to ensure that the functions/function objects f and g do indeed return a double (or something convertible to it). For that, I wrote the following grammar which GCC 4.5.1 (Boost 1.42, MinGW32, WinXP, SP3) doesn't like, with the error messages being at the P.S. section: struct EmtnRet2DblChk: or_ < terminal<_>, and_ < shift_right<EmtnRet2DblChk, terminal<_> >, if_ < typename boost::is_convertible < typename boost::result_of<(_value(_right))(double)>::type, double >::type > > > {}; (The above code starts in my line 81 and ends in my line 98.) Any idea please? TIA,--Hossein P.S. Compiling: main.cpp main.cpp:98:2: error: a cast to a type other than an integral or enumeration type cannot appear in a constant-expression main.cpp:98:2: error: template argument 1 is invalid main.cpp:92:22: error: wrong number of template arguments (1, should be 2) /boost/type_traits/is_convertible.hpp:418:1: error: provided for 'template<class From, class To> struct boost::is_convertible' main.cpp:90:21: error: template argument 1 is invalid main.cpp:88:4: error: template argument 2 is invalid 85:3: error: template argument 2 is invalid main.cpp:98:3: error: expected '{' before ';' token

1 0

[asio] io_service hang on stop
by Daniele Barzotti 18 Jan '11

18 Jan '11

Hi, I designed a library to start a io_service background thread when the first object is created (these objects use serial_port) and to terminate it when the last object is destroyed. This is the io_worker_thread: void io_worker_thread(void) { io_service.reset(); io_service.run(); p_work.reset(); io_service.stop(); thread_started = false; }; All seems to work, when the last object is destroyed the io_service.run() returns...but the calling application hang! I noted that the win_thread::join() (in win_thread.ipp) is still running and waiting on "::WaitForSingleObject(thread_, INFINITE);" Follow I post the threads and the call stack when the application is ended: ----------------------------------------------- Main Thread Main Thread boost::asio::detail::win_thread::join Worker Thread _threadstartex `io_worker_thread'::`2'::com_init::~com_init Worker Thread _threadstartex _endthreadex Worker Thread _TppWaiterpThread@4 _ZwWaitForMultipleObjects@20 Worker Thread _TppWorkerThread@4 _NtWaitForWorkViaWorkerFactory@8 Worker Thread _TppWorkerThread@4 _NtWaitForWorkViaWorkerFactory@8 RPC Thread RPC Callback Thread _NtDelayExecution@8 Worker Thread _TppWorkerThread@4 _ZwWaitForSingleObject@12 ----------------------------------------------- ntdll.dll!_ZwWaitForSingleObject@12() ntdll.dll!_ZwWaitForSingleObject@12() kernel32.dll!_WaitForSingleObjectExImplementation@12() kernel32.dll!_WaitForSingleObject@8() AxEuroATLib_debug.dll!boost::asio::detail::win_thread::join() AxEuroATLib_debug.dll!boost::asio::detail::win_iocp_io_service::shutdown_service() AxEuroATLib_debug.dll!boost::asio::detail::service_registry::~service_registry() AxEuroATLib_debug.dll!boost::asio::detail::service_registry::`scalar deleting destructor'() AxEuroATLib_debug.dll!boost::asio::io_service::~io_service() AxEuroATLib_debug.dll!`dynamic atexit destructor for 'io_service''() AxEuroATLib_debug.dll!_CRT_INIT(void * hDllHandle=0x5b880000, unsigned long dwReason=0, void * lpreserved=0x00000000) AxEuroATLib_debug.dll!__DllMainCRTStartup(void * hDllHandle=0x5b880000, unsigned long dwReason=0, void * lpreserved=0x00000000) AxEuroATLib_debug.dll!_DllMainCRTStartup(void * hDllHandle=0x5b880000, unsigned long dwReason=0, void * lpreserved=0x00000000) ntdll.dll!_LdrpCallInitRoutine@16() ntdll.dll!_LdrpUnloadDll@8() ntdll.dll!_LdrUnloadDll@4() KernelBase.dll!_FreeLibrary@4() ole32.dll!77229562() [Frames below may be incorrect and/or missing, no symbols loaded for ole32.dll] ole32.dll!77229593() ole32.dll!772295a7() ole32.dll!772298bf() ole32.dll!77229805() ole32.dll!77229a8c() msvbvm60.dll!7294b681() msvbvm60.dll!72946299() msvbvm60.dll!7294613e() user32.dll!_InternalCallWinProc@20() + 0x23 bytes user32.dll!_UserCallWinProcCheckWow@32() + 0xb7 bytes user32.dll!_SendMessageWorker@24() + 0x112 bytes user32.dll!_SendMessageA@16() + 0x4c bytes msvbvm60.dll!7294b5f6() msvbvm60.dll!7294a9cf() user32.dll!_NtUserPeekMessage@20() + 0x15 bytes msvbvm60.dll!7294a95c() msvbvm60.dll!7294a8e2() msvbvm60.dll!7294a6cf() msvbvm60.dll!7294a63f() msvbvm60.dll!7294a5e1() msvbvm60.dll!7294a51d() msvbvm60.dll!7294a4e8() msvbvm60.dll!72943644() EuroATLibTest.exe!___vbaS() + 0xa bytes BASIC ntdll.dll!___RtlUserThreadStart@8() + 0x27 bytes ntdll.dll!__RtlUserThreadStart@8() + 0x1b bytes How can I solve? Regards, Daniele.

1 0

[asio] Problem implementing a line-based protocol
by Hannes Brandstätter-Müller 18 Jan '11

18 Jan '11

I am trying to write a server and client that use a line-based text protocol for communication. It works rather well now, but there is some weird problem: One of my messages loses the first 4 characters. (reproducible, but I don't do anything special in that one case, I think) boost::asio::async_read_until is used to read the line into a boost::asio::streambuf the socket is a boost::asio::local::stream_ protocol::socket std::string msg; std::istream is(&buffer); std::getline(is, msg); I looked at the buffer.size(), the size reported to the handler function and compared it to the length of the message, which looks consistant, so I don't assume that the read call read some characters over the \n. (but that would be the only logical explanation) * there are no multiple read operations on the socket * I reuse the same buffer for multiple async_read_until calls Does anyone have a code snippet that can help me figure out what could be stuck and lost in the buffer, or where else the problem could be?

2 7

issue when using boost::tokensizer with std::wstring.
by Sean Farrow 18 Jan '11

18 Jan '11

Hi: I'm trying to use boost::tokenizer and have included boost/tokenizer.hpp. I get the errors below when trying to compile the following code: std::wstring TokensStr(Item); boost::tokenizer<> Tokens(TokensStr); Item, is defined as a BSTR. the errors are: 1>c:\program files\boost\boost\tokenizer.hpp(59): error C2664: 'std::_String_const_iterator<_Elem,_Traits,_Alloc>::_String_const_iterator(const std::_String_const_iterator<_Elem,_Traits,_Alloc> &)' : cannot convert parameter 1 from 'std::_String_const_iterator<_Elem,_Traits,_Alloc>' to 'const std::_String_const_iterator<_Elem,_Traits,_Alloc> &' with [ _Elem=char, _Traits=std::char_traits<char>, _Alloc=std::allocator<char> ] and [ _Elem=wchar_t, _Traits=std::char_traits<wchar_t>, _Alloc=std::allocator<wchar_t> ] and [ _Elem=char, _Traits=std::char_traits<char>, _Alloc=std::allocator<char> ] Reason: cannot convert from 'std::_String_const_iterator<_Elem,_Traits,_Alloc>' to 'const std::_String_const_iterator<_Elem,_Traits,_Alloc>' with [ _Elem=wchar_t, _Traits=std::char_traits<wchar_t>, _Alloc=std::allocator<wchar_t> ] and [ _Elem=char, _Traits=std::char_traits<char>, _Alloc=std::allocator<char> ] No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called d:\work\access for everyone\sibelius access\sibeliusaccessserver\sibeliusaccess.cpp(231) : see reference to function template instantiation 'boost::tokenizer<>::tokenizer<std::wstring>(const Container &)' being compiled with [ Container=std::wstring ] 1>c:\program files\boost\boost\tokenizer.hpp(59): error C2664: 'std::_String_const_iterator<_Elem,_Traits,_Alloc>::_String_const_iterator(const std::_String_const_iterator<_Elem,_Traits,_Alloc> &)' : cannot convert parameter 1 from 'std::_String_const_iterator<_Elem,_Traits,_Alloc>' to 'const std::_String_const_iterator<_Elem,_Traits,_Alloc> &' with [ _Elem=char, _Traits=std::char_traits<char>, _Alloc=std::allocator<char> ] and [ _Elem=wchar_t, _Traits=std::char_traits<wchar_t>, _Alloc=std::allocator<wchar_t> ] and [ _Elem=char, _Traits=std::char_traits<char>, _Alloc=std::allocator<char> ] Reason: cannot convert from 'std::_String_const_iterator<_Elem,_Traits,_Alloc>' to 'const std::_String_const_iterator<_Elem,_Traits,_Alloc>' with [ _Elem=wchar_t, _Traits=std::char_traits<wchar_t>, _Alloc=std::allocator<wchar_t> ] and [ _Elem=char, _Traits=std::char_traits<char>, _Alloc=std::allocator<char> ] No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called Does anyone know how I can solve these errors. Any help appreciated. Regards Sean.

2 3

[boost::python] iterator from member container
by Ralf Goertz 18 Jan '11

18 Jan '11

Is ist possible to have a class that has a map as member like struct Foo { std::map<string,int> bar; }; and then something like class_<Foo>("Foo") .def("__iter__", iterator<std::map<string,int>()); so that in python an object foo of type Foo can be used like this for i in foo: <do something with the bar iterator i> ? Ralf

2 1

Spirit : Is possible to build rule step by step?
by Andrea Fontana 17 Jan '11

17 Jan '11

I'm trying to write a small example using spirit. I can write a rule in this way: my_rule = lit("example") | lit("example2"); Also in this way: std::string ex("example") std::string ex2("example2"); my_rule = lit(ex) | lit(ex2)) Is there a way to do this: std::string ex("example") std::string ex2("example2"); my_rule = lit(ex); my_rule = my_rule | lit(ex2)); I need to append strings from an array... Maybe I miss something from docs.

3 2