July 2010 - Boost-users - lists.preview.boost.org

[asio] endpoint lifetime requirements with acceptor
by Jeff Flinn 23 Jul '10

23 Jul '10

What is the lifetime requirement of a boost::asio::ip::tcp::endpoint imposed by boost::asio::ip::tcp::acceptor. in particular it's ctor: boost::asio::ip::tcp::acceptor(boost::asio::io_service& io_, const endpoint_type&, bool); The end point is taken by const&. Is it just used, copied, or does the acceptor hold a const&? Are these sorts of issues documented? The only clue I can find is that the endpoint has a copy ctor. I can successfully construct the acceptor, passing in a temporary endpoint which is constructed in place in the acceptor's ctor, which appears to execute on both Win/MSVC8 and Mac/XCode3.2. But if I construct an endpoint further up the call stack passing it by const&, I get a runtime error. Any help appreciated. Thanks, Jeff

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[Boost.Range] Filter adaptor
by Justin Leonard 23 Jul '10

23 Jul '10

I think I'm missing something obvious - but here goes. I'm trying to rewrite the a loop similar to the following using boost::range: [code] boost::range_iterator<Doubles>::type i = boost::begin(first_range); boost::range_iterator<Doubles>::type j = boost::begin(second_range); for( ; i != boost::end(first_range) && j != boost::end(second_range); ++i,++j) { if( f(*i) ) g(*j); } [/code] Is there something similar to: [code] for_each( filtered( second_range,first_range,f ) , g ); [/code] to use in place of the above? Thanks, Justin Leonard

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break and return statement in lambda expression
by Conoscenza Silente 23 Jul '10

23 Jul '10

Hi All I created a lambda expression inside my std::for_each call. Inside it there is code like this one, but I have building error telling me that error: expected primary-expression before ‘break’ error: expected `]' before ‘break’ Do you know what it is and how to fix it? The same applies to return statement Thanks AFG namespace bl = boost::lambda; int a, b; bl::var_type< int >::type a_( bl::var( a ) ); bl::var_type< int >::type b_( bl::var( b ) ); std::for_each( v.begin(), v.end(), ( if_( a_ > _b_ ) [ std::cout << _1, break ] ));

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[program option] accepting list of enumerated values ?
by John Dlugosz 22 Jul '10

22 Jul '10

I want a program to take an option that is one or more values from a short list; i.e. an enumeration. For sake of a simple example, let's use color names: "red", "yellow", "blue", "green", etc. I'd like to validate that only legal strings are passed, and convert them to an enumerated type or integer. Certainly I can write po::value<std::vector<color_t> >, but what's the best way to process the input? The docs shows a brief example of overloading 'validate' but it's not clear. I'd also like a short way to specify multiple colors without repeating the option. Something like --color=red,blue but whatever the natural syntax is. Is a multi-value on one instance of a switch something that's built in? Thanks, --John TradeStation Group, Inc. is a publicly-traded holding company (NASDAQ GS: TRAD) of three operating subsidiaries, TradeStation Securities, Inc. (Member NYSE, FINRA, SIPC and NFA), TradeStation Technologies, Inc., a trading software and subscription company, and TradeStation Europe Limited, a United Kingdom, FSA-authorized introducing brokerage firm. None of these companies provides trading or investment advice, recommendations or endorsements of any kind. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.

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[range] Boost.Range adaptor return types
by Jeremiah Willcock 22 Jul '10

22 Jul '10

I would like to return an adapted Boost.Range from a function and would like to know what return type to put for the function. In my case, I am wrapping a counting_range with transformed(). Is there a metafunction to compute these return types? Should I just be using boost::result_of? The result_of expression is very long because of the nesting (though of course a typedef can help with the inner parts of that). Thank you for your help. -- Jeremiah Willcock

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Support for dimentionality reduction techniques.
by Khaldoun "Hal" Alaqqad 22 Jul '10

22 Jul '10

Hi, I am curious to whether boost provides / supports any of the dimensionality reduction algorithms : 1- Eigen value/ Eigen vector decomposition. 2- Principle component analysis 3- Latent Symantec analysis. 4- MDS Thanks Hal

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Synchronous read from a serial port with timeout?
by Gözde Bahar KOŞ 22 Jul '10

22 Jul '10

Hello, Is there a way to use synchronous read function with a timeout mechanism? I want my code to block on read function till data/error comes from the serial port or timeout expires. How can I do this with asio? Best Regards, Gözde Bahar Koş ###################################################################### Dikkat: Bu elektronik posta mesaji kisisel ve ozeldir. Eger size gonderilmediyse lutfen gondericiyi bilgilendirip mesaji siliniz. Firmamiza gelen ve giden mesajlar virus taramasindan gecirilmekte, guvenlik nedeni ile kontrol edilerek saklanmaktadir. Mesajdaki gorusler ve bakis acisi gondericiye ait olup Aselsan A.S. resmi gorusu olmak zorunda degildir. ###################################################################### Attention: This e-mail message is privileged and confidential. If you are not the intended recipient please delete the message and notify the sender. E-mails to and from the company are monitored for operational reasons and in accordance with lawful business practices. Any views or opinions presented are solely those of the author and do not necessarily represent the views of the company. ######################################################################

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[bind] Possible to use variadic templates with bind?
by Steve Lorimer 22 Jul '10

22 Jul '10

Hi Is it possible to pass variadic template arguments to bind, such that bind uses them as the placeholder arguments (_1, _2, _3 etc) I show my use case below. struct job_queue { // copy f into list for asynchronous envocation by another thread void enqueue(boost::function<void()> f); }; //----------------------------------------------------------------------- // helper class to define correct form of the member function callback template<class T, typename... Args> struct cb { typedef void (T::*type)(Args...); }; // a job defines a callback function which is any member function taking any number of arguments of any type template<class T, typename... Args> class job_t { boost::shared_ptr<job_queue> queue; boost::function<void(Args...)> arg_func; public: job_t(typename cb<T, Args...>::type cb, boost::shared_ptr<T> that, boost::shared_ptr<job_queue> q) : arg_func(boost::bind(cb, that, Args...)), queue(q) {} // normally would be _1, _2, _3, etc void post(Args&... args) { boost::function<void()> f = boost::bind(arg_func, args...); queue->enqueue(f); } };

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boost 1.42 , vs2010 and Vista
by Michał Nowotka 22 Jul '10

22 Jul '10

Hello, I want to install boost 1.42 on my Vista with Visual Studio 2010 from sources. When I invoke bootstrap.bat I get this error: ---------------------------------------------------------------------------------- c:\boost_1_42_0>bootstrap.bat Building Boost.Jam build engine Failed to build Boost.Jam build engine. Please consult bjam.log for furter diagnostics. You can try to obtain a prebuilt binary from http://sf.net/project/showfiles.php?group_id=7586&package_id=72941 Also, you can file an issue at http://svn.boost.org Please attach bjam.log in that case. --------------------------------------------------------------------------------------------------- In the log file I get: --------------------------------------------------------------------------------------------------- Setting environment for using Microsoft Visual Studio 2010 x86 tools. ERROR: Cannot determine the location of the VS Common Tools folder. ### ### Using 'vc10' toolset. ### c:\boost_1_42_0\tools\jam\src>if exist bootstrap rd /S /Q bootstrap c:\boost_1_42_0\tools\jam\src>md bootstrap c:\boost_1_42_0\tools\jam\src>cl /nologo /RTC1 /Zi /MTd /Fobootstrap/ /Fdbootstrap/ -DNT -DYYDEBUG -wd4996 kernel32.lib advapi32.lib user32.lib /Febootstrap\jam0 command.c compile.c debug.c execnt.c expand.c filent.c glob.c hash.c hdrmacro.c headers.c jam.c jambase.c jamgram.c lists.c make.c make1.c newstr.c option.c output.c parse.c pathunix.c regexp.c rules.c scan.c search.c subst.c timestamp.c variable.c modules.c strings.c filesys.c builtins.c pwd.c class.c w32_getreg.c native.c modules/set.c modules/path.c modules/regex.c modules/property-set.c modules/sequence.c modules/order.c command.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set compile.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set debug.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set execnt.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set expand.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set filent.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set glob.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set hash.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set hdrmacro.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set headers.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set jam.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set jambase.c jamgram.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set lists.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set make.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set make1.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set newstr.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set option.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set output.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set parse.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set Generating Code... Compiling... pathunix.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set regexp.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set rules.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set scan.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set search.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set subst.c subst.c(1) : fatal error C1034: stddef.h: no include path set timestamp.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set variable.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set modules.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set strings.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set filesys.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set builtins.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set pwd.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set class.c c:\boost_1_42_0\tools\jam\src\strings.h(8) : fatal error C1034: stddef.h: no include path set w32_getreg.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set native.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set set.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set path.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set regex.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set property-set.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set Generating Code... Compiling... sequence.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set order.c c:\boost_1_42_0\tools\jam\src\jam.h(88) : fatal error C1034: fcntl.h: no include path set Generating Code... --------------------------------------------------------------------------------------------------- Can you tell me what I'm doing wrong? -- Regards Michał Nowotka

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[xpressive] Buffer-boundary matching
by gbinfo＠web.de 22 Jul '10

22 Jul '10

Hi all, it seems that the buffer-boundary-matching expressions "\a", "\z" etc. are missing from xpressive. Can anyone confirm this? regards Gerd ___________________________________________________________ GRATIS für alle WEB.DE Nutzer: Die maxdome Movie-FLAT! Jetzt freischalten unter http://movieflat.web.de

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