October 2008 - Boost-users - lists.preview.boost.org

Using Asio's ICMP support
by David Smith 30 Oct '08

30 Oct '08

Hi, Sorry if this is a silly question, but in Asio's ICMP support, what portion of an ICMP packet will an application supply when sending? What portion of an ICMP packet will an application retrieve when receiving? I get the impression that the whole body of the ICMP packet is supplied/retrieved (only an IP header with the ICMP protocol is prefixed). Is that the right impression? Thanks, David

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Please define _WIN32_WINNT or _WIN32_WINDOWS appropriately
by Jean-Sebastien Stoezel 30 Oct '08

30 Oct '08

Hi, I am compiling Boot 1_35_0 with Visual Studio 2008 under Windows XP, and at compile time I get the following message: Please define _WIN32_WINNT or _WIN32_WINDOWS appropriately Assuming _WIN32_WINNT=0x0501 (i.e. Windows XP target) Following the advice, I then defined the following macro: _WIN32_WINNT=0x0501 However now I get the following errors: d:\program files\microsoft visual studio 9.0\vc\atlmfc\include\afxdlgs.h(235) : error C2504: 'IFileDialogEvents' : base class undefined d:\program files\microsoft visual studio 9.0\vc\atlmfc\include\afxdlgs.h(244) : error C2061: syntax error : identifier 'FDE_SHAREVIOLATION_RESPONSE' d:\program files\microsoft visual studio 9.0\vc\atlmfc\include\afxdlgs.h(246) : error C2061: syntax error : identifier 'FDE_OVERWRITE_RESPONSE' d:\program files\microsoft visual studio 9.0\vc\atlmfc\include\afxdlgs.h(249) : error C2504: 'IFileDialogControlEvents' : base class undefined What macros do really need to be defined? What values should be assigned for Windows XP? Thanks, Jean

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mutex Locks!
by Wesley Khandavalli 29 Oct '08

29 Oct '08

Dear all, i am new to threading. i want to know the following. Given a shared object which is accessed by more than one process, where should we implement the mutex locking? Is it in the shared object or in the critical section of the Processes? If locking is done in process, will it work having different names for the locks in the processes? class A { .......... ........ public: execute() { ......... lock(mutex1) //write data to shared object unlock(mutex1) ......... } }; class B { .......... ........ public: execute() { ......... lock(mutex2) //write data to shared object unlock(mutex2) ......... } }; SharedObject { ........... .......... }; -- Wesley K

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compile problem?
by Wenhao Xu 29 Oct '08

29 Oct '08

Hi everyone, I am a new to boost. When I compile the example of asio_timer, I have a compile error: " g++ -o test_timer test_timer.cpp -I /peter/boost/boost_1_36_0 -lboost_thread-gcc42-mt-1_36 -lboost_system-gcc42-mt-1_36 In file included from /usr/include/c++/4.2/iostream:44, from test_timer.cpp:11: /usr/include/c++/4.2/i486-linux-gnu/bits/c++config.h:149: error: expected constructor, destructor, or type conversion before ‘namespace’ Compilation exited abnormally with code 1 at Tue Oct 28 00:04:58" My compile command is: g++ -o test_timer test_timer.cpp -I /peter/boost/boost_1_36_0 -lboost_thread-gcc42-mt-1_36 -lboost_system-gcc42-mt-1_36 I cannot find the reason. Could you help me? Thanks very much. Best wishes, Wenhao // // time_t_timer.cpp // ~~~~~~~~~~~~~~~~ // // Copyright (c) 2003-2008 Christopher M. Kohlhoff (chris at kohlhoff dot com) // // Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) // #include <boost/asio.hpp> #include <ctime> #include <iostream> struct time_t_traits { // The time type. typedef std::time_t time_type; // The duration type. struct duration_type { duration_type() : value(0) {} duration_type(std::time_t v) : value(v) {} std::time_t value; }; // Get the current time. static time_type now() { return std::time(0); } // Add a duration to a time. static time_type add(const time_type& t, const duration_type& d) { return t + d.value; } // Subtract one time from another. static duration_type subtract(const time_type& t1, const time_type& t2) { return duration_type(t1 - t2); } // Test whether one time is less than another. static bool less_than(const time_type& t1, const time_type& t2) { return t1 < t2; } // Convert to POSIX duration type. static boost::posix_time::time_duration to_posix_duration( const duration_type& d) { return boost::posix_time::seconds(d.value); } }; typedef boost::asio::basic_deadline_timer< std::time_t, time_t_traits> time_t_timer; void handle_timeout(const boost::system::error_code&) { std::cout << "handle_timeout\n"; } int main() { try { boost::asio::io_service io_service; time_t_timer timer(io_service); timer.expires_from_now(5); std::cout << "Starting synchronous wait\n"; timer.wait(); std::cout << "Finished synchronous wait\n"; timer.expires_from_now(5); std::cout << "Starting asynchronous wait\n"; timer.async_wait(handle_timeout); io_service.run(); std::cout << "Finished asynchronous wait\n"; } catch (std::exception& e) { std::cout << "Exception: " << e.what() << "\n"; } return 0; }

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program_options: one-of-set option format
by Ivan Godard 29 Oct '08

29 Oct '08

The boost::program_options library appears to lack the capability for one-of-set options, i.e. one of -a, -b, or -c, but not more than one, returned as an enumeration value in a common result for all the options. Currently I have a function: template<typename T> options_description& oneOf(options_description& od, std::vector<std::string>& names, T& t); which adds options for all the names to "od", with notifiers that update "t" with the "T" enumeration value corresponding to the particular option that the parser finds present using the ordinal position in "names" as a value. However, this is somewhat unsatisfying because detected errors (missing or too many choices) don't feed into the program_options reporting system. It also does not fit with the rather nice syntax used by the program_options library for option declarations. I also looked at using an external parser as supported by program_options, but this seems low-level overkill - you get a raw string to parse, but none of the nice facilities for abbreviation, long or short forms, etc. are usable. Lastly, I considered adding the capability as a native feature of program_options, but while the library is reasonably clean it doesn't seem to be designed to support any inter-option linkages as required for reporting the result and verifying that only one of the set was present. So the question for this list: am I reinventing the wheel here and this oneOf capability already exists somewhere? If not, is there a better approach than my present purely extra-library solution? Thank you Ivan

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boost bind conflicting with socket bind
by Sharad Mittal 29 Oct '08

29 Oct '08

Hello, My Socket code that contains call to "bind" to a port is conflicting with boost::bind in 1.36. It compiles fine under boost 1.34 and 1.35. Interestingly, nothing is included from boost in that file. I am using boost with mingw on Win Xp. The code snippet is as follows: int Socket::BindPort(int family, int address, int port) { sockaddr_in sa; int dwError = RERROR_SUCCESS; memset(&sa, 0, sizeof(sa)); sa.sin_family = family; sa.sin_addr.s_addr = address; sa.sin_port = htons(port); if (bind(s_, (sockaddr *)&sa, sizeof(sockaddr_in)) == SOCKET_ERROR) { dwError = RERROR_SOCKET_BIND_ERROR; LOG (LOG_ERR, "Could not bind socket to port %u", port); BAIL_ON_ERROR (dwError); } error: return dwError; } Here is what I am getting... [g++] [Socket.o]<-[Socket.cpp] E:/msys/1.0/boost/boost_1_36_0/boost/bind.hpp: In instantiation of `boost::_bi::result_traits<boost::_bi::unspecified, unsigned int>': E:/msys/1.0/boost/boost_1_36_0/boost/bind/bind_template.hpp:15: instantiated from `boost::_bi::bind_t<boost::_bi::unspecified, unsigned int, boost::_bi::list2<boost::_bi::value<sockaddr*>, boost::_bi::value<unsigned int> > >' Socket.cpp:98: instantiated from here E:/msys/1.0/boost/boost_1_36_0/boost/bind.hpp:67: error: `unsigned int' is not a class, struct, or union type E:/msys/1.0/boost/boost_1_36_0/boost/bind/bind_template.hpp: In instantiation of `boost::_bi::bind_t<boost::_bi::unspecified, unsigned int, boost::_bi::list2<boost::_bi::value<sockaddr*>, boost::_bi::value<unsigned int> > >': Socket.cpp:98: instantiated from here E:/msys/1.0/boost/boost_1_36_0/boost/bind/bind_template.hpp:15: error: no type named `type' in `struct boost::_bi::result_traits<boost::_bi::unspecified, unsigned int>' E:/msys/1.0/boost/boost_1_36_0/boost/bind/bind_template.hpp:18: error: no type named `type' in `struct boost::_bi::result_traits<boost::_bi::unspecified, unsigned int>' E:/msys/1.0/boost/boost_1_36_0/boost/bind/bind_template.hpp:24: error: no type named `type' in `struct boost::_bi::result_traits<boost::_bi::unspecified, unsigned int>' E:/msys/1.0/boost/boost_1_36_0/boost/bind/bind_template.hpp:30: error: no type named `type' in `struct boost::_bi::result_traits<boost::_bi::unspecified, unsigned int>' E:/msys/1.0/boost/boost_1_36_0/boost/bind/bind_template.hpp:36: error: no type named `type' in `struct boost::_bi::result_traits<boost::_bi::unspecified, unsigned int>' E:/msys/1.0/boost/boost_1_36_0/boost/bind/bind_template.hpp:45: error: no type named `type' in `struct boost::_bi::result_traits<boost::_bi::unspecified, unsigned int>' E:/msys/1.0/boost/boost_1_36_0/boost/bind/bind_template.hpp:51: error: no type named `type' in `struct boost::_bi::result_traits<boost::_bi::unspecified, unsigned int>' E:/msys/1.0/boost/boost_1_36_0/boost/bind/bind_template.hpp:59: error: no type named `type' in `struct boost::_bi::result_traits<boost::_bi::unspecified, unsigned int>' E:/msys/1.0/boost/boost_1_36_0/boost/bind/bind_template.hpp:65: error: no type named `type' in `struct boost::_bi::result_traits<boost::_bi::unspecified, unsigned int>' E:/msys/1.0/boost/boost_1_36_0/boost/bind/bind_template.hpp:74: error: no type named `type' in `struct boost::_bi::result_traits<boost::_bi::unspecified, unsigned int>' E:/msys/1.0/boost/boost_1_36_0/boost/bind/bind_template.hpp:80: error: no type named `type' in `struct boost::_bi::result_traits<boost::_bi::unspecified, unsigned int>' E:/msys/1.0/boost/boost_1_36_0/boost/bind/bind_template.hpp:87: error: no type named `type' in `struct boost::_bi::result_traits<boost::_bi::unspecified, unsigned int>' E:/msys/1.0/boost/boost_1_36_0/boost/bind/bind_template.hpp:93: error: no type named `type' in `struct boost::_bi::result_traits<boost::_bi::unspecified, unsigned int>'

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[Serialization] Runtime checking of types in deserialization
by Frank Winklmeier 29 Oct '08

29 Oct '08

Hi, is there any way to check whether the class type used in deserialization is identical to the class type in the serialization? Below is a simple example, that serializes class "Data" into a text archive and deserializes this archive into class "StringData". If that happens I would like an exception to be thrown. Is this possible? Thanks for any help, Frank #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <iostream> #include <sstream> using namespace std; class Data { public: Data() { for (int i=0; i<100; i++) a[i]=i; }; int a[100]; template<class Archive> void serialize(Archive & ar, const unsigned int) { ar & a; } }; class StringData { public: StringData() {}; string s; template<class Archive> void serialize(Archive & ar, const unsigned int) { ar & s; } }; int main() { ostringstream oss; // Serialize the class const Data d1; { boost::archive::text_oarchive oa(oss); oa << d1; } // Deserialize it using the wrong type StringData d2; { istringstream iss(oss.str()); boost::archive::text_iarchive ia(iss); ia >> d2; } cout << oss.str() << endl; cout << d2.s << endl; } Output: ======= 22 serialization::archive 4 0 0 100 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

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Compiling boost 1.35.0 on ppc64 suse linux
by Karthik Channakeshava 29 Oct '08

29 Oct '08

Hi, I am not able to compile a 64bit version of boost on a ppc64 bit machine with suse linux on it. Can you please point me to some information on this? Thanks in advance, Karthik

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[boost.asio] reading data from serial port [newbie]
by Wojciech L.Jędruch 29 Oct '08

29 Oct '08

Hi Its my first cpp application with boost libs, therefore im asking for some help : The code is written In VS2008 and looks like this : include "stdafx.h" #include <iostream> #include <boost/asio.hpp> #include <boost/asio/serial_port.hpp> #include <boost/thread.hpp> #include <boost/system/error_code.hpp> #include <boost/system/system_error.hpp> #include <boost/bind.hpp> void handler( const boost::system::error_code& error)// Result of operation. //std::size_t bytes_transferred // Number of bytes read. { std::cout << "read" << std::endl; } int _tmain(int argc, _TCHAR* argv[]) { using namespace std; using namespace boost; char read_msg_[512]; /* All programs that use asio need to have at least one boost::asio::io_service object. */ /* This class provides access to I/O functionality. */ /* We declare an object of this type first thing in the main function. */ boost::asio::io_service io; asio::serial_port(io,"COM7"); boost::asio::serial_port::async_read_some(boost::asio::buffer(read_msg_,512) ,handler); return 0; } In line: boost::asio::serial_port::async_read_some(boost::asio::buffer(read_msg_,512) ,handler); Im getting compiler error : 1>c:\praca\visual\projekty\refernecje\refernecje\refernecje.cpp(32) : error C2352: 'boost::asio::basic_serial_port<>::async_read_some' : illegal call of non-static member function 1> c:\program files\boost\boost_1_36_0\boost\asio\basic_serial_port.hpp(595) : see declaration of 'boost::asio::basic_serial_port<>::async_read_some' Can You please explain me what is wrong ? the code is similar to that provided by boost serial port reading example. Thx in advance for help

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Factory pattern ?
by Olivier Tournaire 29 Oct '08

29 Oct '08

Hi all, I am wondering if a factory exists in boost. Any answer ? Best regards, Olivier

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