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multi_array: error: expected primary-expression before ‘)’
by Valmor de Almeida 31 Aug '10

31 Aug '10

Hello, I am trying from the multi_array web site doc: typedef boost::multi_array<double,3> array_type; array_type A(boost::extents[3][4][2],boost::fortran_storage_order); and getting the following compile-time error: g++ img2hermes2dmsh.cpp In function ‘int main()’: error: expected primary-expression before ‘)’ token Any insights? I am using boost-1.41 on gentoo linux. Thanks, -- Valmor

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download question
by Stanisław Findeisen 31 Aug '10

31 Aug '10

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Comparing boost bind object with a pointer to member function
by jej 31 Aug '10

31 Aug '10

Hello, Is is possible to compare a pointer to member function with a function object returned by boost bind? I have a class with several different functions; for each member function I use boost bind to bind the function object to several args. At the point where I want call the function object, I would like to check which member function it's been bound to, and decide whether or no it should be executed. For example, I would like the second comparison in the code snippet below to return "Bind match." For any other member function of foo it should return "Bind not match." Thanks. int main(int, char**) { Data d(1, 2); Foo fx, fy; //typedef void (Foo::*foofunctwo_t)(const Data&); //foofunctwo_t del1 = &Foo::FuncTwo; boost::function<void (Foo*, const Data&)> bf(&Foo::FuncTwo); if(bf == &Foo::FuncTwo) { cout << "match" <<endl; } else { cout << "no match" << endl; } boost::function<void (const Data&)> boundfunc = boost::bind(&Foo::FuncTwo, &fx, _1); if(boundfunc == &Foo::FuncTwo) { cout << "Bind match" << endl; } else { cout << "Bind not match" << endl; } return 0; }; -- View this message in context: http://old.nabble.com/Comparing-boost-bind-object-with-a-pointer-to-member-… Sent from the Boost - Users mailing list archive at Nabble.com.

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Overloading boost::for_each()
by Jeremiah Willcock 31 Aug '10

31 Aug '10

There are several container types (such as typical deque implementations, if you have access to their internals) that can have for_each() implemented for them in a way that is faster than using iterators and a generic for_each() function. Is there a way to take advantage of that in Boost.Range, such as by overloading boost::for_each()? Is there some kind of Iterable concept that doesn't require actual iterators or allows them to be slow? Would it be worthwhile to add one? Are there any other techniques that would be useful instead, such as always calling for_each() unqualified in my code and using ADL to find custom versions (like is done for swap)? I am not interested in making Boost.Range algorithms use this new concept, but there are places in my own code that could use for_each() rather than explicit loops if that was faster. Thank you for any answers or advice. -- Jeremiah Willcock

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asio HTTP client example always returns error 400
by G S 31 Aug '10

31 Aug '10

Hi all. I copied the boost::asio HTTP client example code: http://live.boost.org/doc/libs/1_39_0/doc/html/boost_asio/example/http/clie… and just replaced the argv stuff with a hard-coded domain name and "index.html". It appears to make the socket connection OK, but the response to the request is 400 ("bad request"). Is there something wrong with this request? boost::asio::streambuf request; std::ostream request_stream(&request); request_stream << "GET " << "index.html" << " HTTP/1.0\r\n"; request_stream << "Host: " << "musicobsession.com" << "\r\n"; request_stream << "Accept: */*\r\n"; request_stream << "Connection: close\r\n\r\n"; It doesn't matter what host I use (as long is it's real). Thanks for any insight!

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[log] cost of record instantiation
by Matthias Vallentin 31 Aug '10

31 Aug '10

Hello, I am trying to understand the cost of log record instantiation. Say I have a global severity logger with several levels, of which the debug level produces a lot of output and record creation is expensive. Because the overhead should only incur when actually logging in debug mode, I would like to know how costly the level check is. That is, in the following code // The custom logger class here accommodates multiple severity // loggers for different facilities. #define LOG(level, facility) \ BOOST_LOG_SEV(global::logger->get(facility), level) LOG(debug, core) << ... some expensive construction would the stream expression be instantiated regardless of the logging level, yet simple be discarded when being in level lower than debug? (I am asking because I recall they are not streamed in a lazy fashion.) If this is the case, preventing the construction of the stream expression would need a different logging mechanism, e.g., /// Expensive logging when in Debug mode. #ifdef DEBUG #define LOGD(facility) \ LOG(log::debug, facility) #endif // Not being compiled. LOGD(core) << ... some expensive constrution However, this design does not have a uniform approach to logging, which makes it less attractive. Any thoughts? Matthias

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[Boost.DateTime][Boost.Python] Year out of valid range error when streaming via Python module
by SamuelG 31 Aug '10

31 Aug '10

This problem occurs at a higher level but I've tried to strip it back. I've reproduced this problem GCC 4.3.4, Python 2.6.5 and Boost 1.41.0 32bit and 64bit Debians/Ubuntu. The problem does not seem to happen on Windows XP. I have embedded the Python interpreter in the attached http://old.nabble.com/file/p29579563/run_python.cpp run_python.cpp . When running this with the attached script http://old.nabble.com/file/p29579563/test.py test.py and which uses a test module http://old.nabble.com/file/p29579563/test_date_time.cpp test_date_time.cpp , the following Boost.DateTime error occurs: $ run_python test.py out() - entry out() - to_simple_string(): 2010-Aug-31 14:30:33.439172000 out() - manual format: 2010-Aug-31 14509:17:19.172000 out() - oss.str(): 2010-Aug-31 14509:17:19.172000 out() - now: Traceback (most recent call last): File "test.py", line 6, in <module> test_date_time.output() IndexError: Year is out of valid range: 1400..10000 However, when running the same script via python it is fine: $ python test.py out() - entry out() - to_simple_string(): 2010-Aug-31 14:30:31.208160000 out() - manual format: 2010-Aug-31 14:30:31.208160000 out() - oss.str(): 2010-Aug-31 14:30:31.208160000 out() - now: 2010-Aug-31 14:30:31.208160000 out() - exit Note that the time stamp in the first example is corrupt. Note also that the valid range error does not occur when using the date and time facets manually but when streaming the ptime object to std::cerr. The problem first arose for me when using Boost.Log with separate Python modules via *both* run_python and /usr/bin/python. See http://sourceforge.net/projects/boost-log/forums/forum/710022/topic/3748054 http://sourceforge.net/projects/boost-log/forums/forum/710022/topic/3748054 For this simple case, /usr/bin/python seems okay but the run_python error is identical to what happens in our proper application (where Boost.Log is used and multiple Python modules loaded). Has anyone witnessed similar behaviour? Or can they please test my example out? Thanks for any help, Sam -- View this message in context: http://old.nabble.com/-Boost.DateTime--Boost.Python--Year-out-of-valid-rang… Sent from the Boost - Users mailing list archive at Nabble.com.

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Re: [Boost-users] boost::asio SSL connection thru proxy server
by Kumar, Akhilesh 31 Aug '10

31 Aug '10

Hi All, Considering that nobody replied my question I am wondering if anybody who has knowledge of this kind of problem has seen my previous message/question. I really need help on this issue if anybody has any thought on this pls. reply. Thanks, Akhilesh Kumar From: Kumar, Akhilesh Sent: Monday, August 23, 2010 5:10 PM To: 'boost-users(a)lists.boost.org' Subject: boost::asio SSL connection thru proxy server Hi, I am writing a boost socket client using boost::asio to do secure HTTP (HTTPS) communication. I Implemented my client based on the code sample based on (http://www.boost.org/doc/libs/1_39_0/doc/html/boost_asio/example/ssl/client…) with little changes as I am using sync socket. My client woks fine, when I am connecting to server directly, but I am not sure what changes I need to make when my communication going thru proxy. The unsecure connection(HTTP) work fine thru proxy, and here is what I do for unsecure connection, 1. Initialize boost socket(IO service and other stuff). 2. Resolve and Connect to Proxy server. 3. Start writing to actual server(HTTP send request). 4. Start uploading/downloading. 5. Close Socket. But I can't use this above procedure for (SSL) secure connection as I need to do handshaking with the server before I can write anything if my understanding is correct. Can somebody give me some pointer or code sample or step I need to do when I am doing secure connection thru proxy server. Just to clarify Microsoft WinInet does do (secure) HTTPS connection thru same proxy fine. If providing my code sample I am using for SSL might help understand the problem I can provide that. Thanks in advance for any help. Akhilesh Kumar

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Re: [Boost-users] Boost.Serialization: Restoring object state (preventcreation of a new object)?
by ray＠maya-studio.com 30 Aug '10

30 Aug '10

>> Just avoid serialization through a pointer, serialize either the >> object or a reference to the object. Thanks, Robert. Serializing through a reference seems to be the only viable solution in my case. However, I'm not able to make it work (I didn't find any specific information about references in the library documentation - except for member variables) . For example: A a; ... A& aRef = a; ia & BOOST_SERIALIZATION_NVP(aRef);; // Throws an exception in load_override

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[parameter] Using named parameter types in return type
by Jeremiah Willcock 30 Aug '10

30 Aug '10

In BOOST_PARAMETER_FUNCTION, one argument to specify is the return type of the function. How do I refer to the types deduced for the named parameters in the return type? I am creating a factory function for a class template (similar to std::make_pair) and would like to use named parameters for it. I did not see any obvious way to do this in the documentation. Is there a way? A documented name for the ArgPack? I am using C++0x so it would be OK to have a solution that requires that. -- Jeremiah Willcock

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