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unix tools
by gast128 12 Feb '13

12 Feb '13

Hello all, since Boost has marvelous cross platform libraries, wouldn't it be an idea to rewrite all the standard commandline unix tools (e.g. cp, grep, ps, ls, diff) in c++ with Boost? Libraries like program options, filesystem and regex already fullfill a lot of the functionality. Only thing left is a person with a good knowledge of the syntax of the cmd line tools and ofc a lot of time:). I mainly use Windows and i really miss these tools from time to time. And yes there is Cygwin but I would prefer just the tools without changing my environment.

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[Chrono] Memory leak in Chrono?
by Don 12 Feb '13

12 Feb '13

Boost 1.53 Chrono version 2 VC 2008 Win7-64 If I #include <boost/chrono.hpp> and run my program, on program exit the VC debugger reports about 40 memory leaks. I don't have to actually use chrono, just include the header. A little trial-and-error with #include statements tracked this down to boost\chrono\io\duration_units.hpp. It looks like there are a couple of "new" allocations in the constructor for duration_units_default_initializer_t that are never deleted. As a test I added a destructor that did delete[] on them, and that fixed the memory leaks. However, there is some logic with the initialized_ variable in the constructor that leads me to suspect that this is not a viable solution for real code. :-) Can anyone suggest a better solution for this? Or failing that, give me any ideas about what this code is actually doing and/or how I might proceed? There is a good chance that someone will say "that's not a real memory leak, it's allocated once and never deleted, but it goes away when your program exits. Don't worry about it". The problem with that answer is that when you have 40 or 50 memory leaks that are "normal", everyone stops paying any attention to the memory leak report and you start adding (unintentionally) real memory leaks in your code. Thanks for your help, Don

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[Preprocessor] Comma in sequence element
by Adam Badura 12 Feb '13

12 Feb '13

I have following code: #include <boost/preprocessor/seq/enum.hpp> #include <boost/preprocessor/seq/transform.hpp> template< int I, int J > struct Base { }; #define SEQ ( 1 ) ( 2 ) ( 3 ) ( 4 ) #define OP( s, data, elem ) Base< elem, elem > struct Derived : BOOST_PP_SEQ_ENUM( BOOST_PP_SEQ_TRANSFORM( OP, nil, SEQ ) ) { }; The Derived has bases classes generated from a sequence (SEQ). The bases classes themselves are instantiations of Base template type. I expected the code to be preprocessed into something like (just the important part): struct Derived : Base< 1, 1 >, Base< 2, 2 >, Base< 3, 3 >, Base< 4, 4 > { }; but instead it is preprocessed into: struct Derived : Base< 1, Base< 2, Base< 3, Base< 4 { }; This obviously is caused by Base being template with to parameters and thus having a comma. Adding parenthesis around Base in OP solves the issue by generating expected code fully. But it still does not compile because parenthesis are not allowed in that place (base classes list). Is there any other workaround? How to deal with it?

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udp::socket::socket() vs udp::socket::open()
by Chris Stankevitz 11 Feb '13

11 Feb '13

Hello, The UDP async server example opens the udp socket like so: a) udp::socket::socket(io_service, udp::endpoint(udp::v4(), 13)) Boost's comment regarding this invocation: * This constructor creates a datagram socket and automatically opens it bound * to the specified endpoint on the local machine. The protocol used is the * protocol associated with the given endpoint. Please consider the udp::socket constructor that takes only an io_service: b) explicit basic_datagram_socket(boost::asio::io_service& io_service) Commented as: * This constructor creates a datagram socket without opening it. The open() * function must be called before data can be sent or received on the socket. And finally, udp::socket::open: (c) void open(const protocol_type & protocol = protocol_type()); Please note that (a) takes an endpoint while (c) takes a protocol. === Question: How can I effectively call (a) using the two-part invocation (b) then (c)? Answer: 1) Just call udp::socket::open(endpoint(udp::v4(), 13)); 2) This is impossible because (a) takes a endpoint while (c) wants a protocol 3) Why would you want to do that you moron? 4) Why don't you write your own udp::socket::open that takes an endpoint if you are so smart? Try giving back to the community instead of just taking. You are a leech and not worthy of reading this mailing list let alone posting to it. 5) none of the above Note: (1) fails with error: no matching function for call to 'boost::asio::basic_datagram_socket<boost::asio::ip::udp>::open(boost::asio::ip::udp::endpoint)' Thank you, Chris

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Extracting subgrapshs
by dheeraj_kumar 11 Feb '13

11 Feb '13

Hello, It will very helpfull if anybody provide some sample code for Extracting list of subgraps's from a Graph. Regards, Dheeraj -- View this message in context: http://boost.2283326.n4.nabble.com/Extracting-subgrapshs-tp4642616.html Sent from the Boost - Users mailing list archive at Nabble.com.

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modifying default compiler path
by Mahmood Naderan 11 Feb '13

11 Feb '13

Hi I have an old version of boost 1.33.1. I want to build it with a custom gcc binary whih is in a path other than default. I could not find the page on the web so I paste the first part of the gcc-tools.jam form tools/build/v1/gcc-tools.jam. # singleton variables... set-as-singleton GCC_ROOT_DIRECTORY GCC_BIN_DIRECTORY GCC_INCLUDE_DIRECTORY GCC_STDLIB_DIRECTORY ; flags gcc GCC_BIN_DIRECTORY : $(GCC_BIN_DIRECTORY) ; flags gcc GCC_INCLUDE_DIRECTORY : $(GCC_INCLUDE_DIRECTORY) ; flags gcc GCC_STDLIB_DIRECTORY : $(GCC_STDLIB_DIRECTORY) ; GCC_BIN_DIRECTORY ?= $(GCC_ROOT_DIRECTORY)$(SLASH)bin ; GCC_BIN_DIRECTORY ?= "" ; # Don't clobber tool names if GCC_ROOT_DIRECTORY not set GCC_STDLIB_DIRECTORY ?= $(GCC_ROOT_DIRECTORY)$(SLASH)lib ; # Make sure this gets set "on" the target flags gcc GCC_BIN_DIR : $(GCC_BIN_DIRECTORY) ; In this part I can modify the default gcc/g++ to my own using the variables which are defined in the comment section. However I don't know How to do that. For example, I write GCC_BIN_DIRECTORY=/opt/gcc-4.1.2/installed But that gives me this error: rule GCC_ROOT_DIRECTORY=/opt/gcc-4.1.2/installed unknown in module So how can I do that? Regards, Mahmood

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[Thread] 1.53 fails to compile working code
by Szymon Gatner 10 Feb '13

10 Feb '13

Hello, following minimal code compiles fine with 1.52 and BOOST_THREAD_VERSION defined to 3 but gives compilation error with 1.53 release (Visual Studio 2008 SP1, Win 7): #include <boost/move/move.hpp> #include <boost/thread/future.hpp> class Dummy { public: Dummy& operator=(BOOST_RV_REF(Dummy) other); Dummy& operator=(BOOST_COPY_ASSIGN_REF(Dummy) other); BOOST_COPYABLE_AND_MOVABLE(Dummy); }; Dummy createDummy(); int main() { boost::future<Dummy> df = boost::async(&createDummy); } Error message: 1>------ Build started: Project: boost_153_test, Configuration: Debug Win32 ------ 1>Compiling... 1>main.cpp 1>c:\devel\boost_1_53_0\boost\thread\future.hpp(661) : error C2665: 'boost::detail::future_traits<T>::init' : none of the 2 overloads could convert all the argument types 1> with 1> [ 1> T=Dummy 1> ] 1> c:\devel\boost_1_53_0\boost\thread\future.hpp(525): could be 'void boost::detail::future_traits<T>::init(boost::scoped_ptr<T> &,Dummy &)' 1> with 1> [ 1> T=Dummy 1> ] 1> c:\devel\boost_1_53_0\boost\thread\future.hpp(530): or 'void boost::detail::future_traits<T>::init(boost::scoped_ptr<T> &,boost::rv<T> &)' 1> with 1> [ 1> T=Dummy 1> ] 1> while trying to match the argument list '(boost::scoped_ptr<T>, const Dummy)' 1> with 1> [ 1> T=Dummy 1> ] 1> c:\devel\boost_1_53_0\boost\thread\future.hpp(655) : while compiling class template member function 'void boost::detail::future_object<T>::set_value_at_thread_exit(const T &)' 1> with 1> [ 1> T=Dummy 1> ] 1> c:\devel\boost_1_53_0\boost\thread\future.hpp(1542) : see reference to class template instantiation 'boost::detail::future_object<T>' being compiled 1> with 1> [ 1> T=Dummy 1> ] 1> c:\devel\boost_1_53_0\boost\thread\future.hpp(1415) : see reference to class template instantiation 'boost::shared_future<R>' being compiled 1> with 1> [ 1> R=Dummy 1> ] 1> c:\devel\boost_1_53_0\boost\thread\future.hpp(1413) : while compiling class template member function 'boost::future<R>::future(boost::rv<T> &)' 1> with 1> [ 1> R=Dummy, 1> T=boost::future<Dummy> 1> ] 1> c:\users\bravo\documents\visual studio 2008\projects\boost_153_test\boost_153_test\main.cpp(19) : see reference to class template instantiation 'boost::future<R>' being compiled 1> with 1> [ 1> R=Dummy 1> ] 1>Build log was saved at "file://c:\Users\Bravo\Documents\Visual Studio 2008\Projects\boost_153_test\boost_153_test\Debug\BuildLog.htm" 1>boost_153_test - 1 error(s), 0 warning(s) ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ========== Btw: why BOOST_THREAD_VERSION is still 2 when documentation says it is 4.0.0 as of boost 1.53? Regards, Szymon Gatner -- Szymon Gatner The Lordz Games Studio www.thelordzgamesstudio.com

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[Interprocess] WIN32 define case unaccessible ?
by Antoine Pédron 10 Feb '13

10 Feb '13

Hello, I'm using Boost.Interprocess in order to get a single portable source code between Windows and Linux using Mutexes and Shared Memory. Documentation says that, for Windows, the API default behaviour is emulation with mapped files, which is the case (:D). Though, having a look at interprocess' headers, i encountrered this case : from D:\Libraries\boost\boost_1_51\boost\interprocess\sync\named_mutex.hpp : ____________________________________________________________________________ #if defined(BOOST_INTERPROCESS_NAMED_MUTEX_USES_POSIX_SEMAPHORES) #include <boost/interprocess/sync/posix/named_mutex.hpp> #define BOOST_INTERPROCESS_USE_POSIX_SEMAPHORES #elif !defined(BOOST_INTERPROCESS_FORCE_GENERIC_EMULATION) && defined (BOOST_INTERPROCESS_WINDOWS) #include <boost/interprocess/sync/windows/named_mutex.hpp> #define BOOST_INTERPROCESS_USE_WINDOWS #else #include <boost/interprocess/sync/shm/named_mutex.hpp> #endif ____________________________________________________________________________ A case where BOOST_INTERPROCESS_FORCE_GENERIC_EMULATION is not defined and BOOST_INTERPROCESS_WINDOWS is, meaning that i can use Windows standard API. My problem is that i want to use this case and i wonder how to reach it. The former file includes boost/interprocess/detail/workaround.hpp where both symbols are defined : ____________________________________________________________________________ #if defined(_WIN32) || defined(__WIN32__) || defined(WIN32) #define BOOST_INTERPROCESS_WINDOWS #define BOOST_INTERPROCESS_FORCE_GENERIC_EMULATION #define BOOST_INTERPROCESS_HAS_KERNEL_BOOTTIME ____________________________________________________________________________ and i can't see an #undef anywhere to get into the case i want. Thanks in advance, Antoine

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Testing whether result_of<F(U)> is a valid expression
by oswin krause 08 Feb '13

08 Feb '13

Hi, Is it possible to evaluate, whether a certain argument type given to a functor will lead to a valid expression with the result_of template? i am trying to achieve the following, maybe there is a better way to do it: template<class T, class F> Container< typename boost::result_of<F(T)>::type > transform( Container<T> c, F f, std::disable_if<valid_expression<F(Block<T>) > >::type* dummy = 0 ){ //slow default implementation Container<T> res(c.size()); std::transform(c.begin(),c.end(),res.begin(),f): return res; } //blocked implmentation of transform template<class T, class F> Container< typename boost::result_of<F(T)>::type > transform( Container<T>, F functor, std::enable_if<valid_expression<F(Block<T>) > >::type* dummy = 0 ){ //functor supports fast implementation Container<T> res(c.size()); std::transform(c.blocks().begin(),c.blocks().end(),res.blocks().begin(),functor): return res; } the question is, how valid_expression<F(Block<T>) > could be implemented and right now the only mechanism which get's close to what i want would be checking result_of<F(Block<T>)> is valid. Greetings, Oswin

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Re: [Boost-users] How do you compile Boost C++ code in Ubuntu?
by Giovanni 08 Feb '13

08 Feb '13

Greetings All, Thank you so much, Mr. Maddock. I was able to compile my program successfully and resolve my linking errors with your help. Also, thank you very much, Mr. Loskot! I appreciate all the precious time that you have spent to help me out. Have an awesome weekend! Regards On Fri, Feb 8, 2013 at 8:20 AM, John Maddock <boost.regex(a)virgin.net> wrote: > It is a quirk of GCC that the libraries used by a source file must appear > *after* the source file. Nothing to do with Boost really... > > John. On Fri, Feb 8, 2013 at 9:45 AM, Mateusz Loskot <mateusz(a)loskot.net> wrote: > On 8 February 2013 16:03, Giovanni <giovanni.ong(a)comsoc.org> wrote: >> I followed your instructions to link the libraries, with the >> "-lboost_filesystem -lboost_system" sequence of linking the >> aforementioned Boost C++ libraries. >> >> However, I cannot resolve the linking error. I have included a >> snippet from my Terminal session below. > > No idea what's wrong really and have no time to investigate it. > But, I've done quick test on Ubuntu 10.04 using Boost 1.40 > installed from its packages and small sample from this book > http://en.highscore.de/cpp/boost/errorhandling.html > and it worked for me: > > Here is my console log: > > mloskot@vb-ubuntu104-x64:~/tmp$ /usr/bin/lsb_release -d > Description: Ubuntu 10.04.4 LTS > > mloskot@vb-ubuntu104-x64:~/tmp$ cat bsystem.cpp > #include <boost/system/error_code.hpp> > #include <iostream> > #include <string> > > class application_category : > public boost::system::error_category > { > public: > const char *name() const { return "application"; } > std::string message(int ev) const { return "error message"; } > }; > > application_category cat; > > int main() > { > boost::system::error_code ec(14, cat); > std::cout << ec.value() << std::endl; > std::cout << ec.category().name() << std::endl; > } > > mloskot@vb-ubuntu104-x64:~/tmp$ g++ -L/usr/lib -lboost_system bsystem.cpp > mloskot@vb-ubuntu104-x64:~/tmp$ ./a.out > 14 > application > > mloskot@vb-ubuntu104-x64:~/tmp$ ldd ./a.out |grep boost > libboost_system.so.1.40.0 => /usr/lib/libboost_system.so.1.40.0 > (0x00007f2df87b6000) > > > Perhaps something has changed in later versions. > I have no time to dig it deeper, sorry. > > Best regards,

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