June 2014 - Boost-users - lists.preview.boost.org

[asio]remote_endpoint throws exception
by higashiyama＠ncad.co.jp 16 Jun '14

16 Jun '14

Hi, I wrote TCP client program using boost::asio. OS: Debian GNU/Linux (x86_64) Boost: 1.49 I use asio::ip::tcp::socket::async_conect function and I called ip::tcp::socket::remote_endpoint at async_connect callback. Like this: // async_resolve handler void my_class::handle_resolve(const boost::system::error_code& error, boost::asio::ip::tcp::resolver::iterator endpoint_iterator) { if (!error) { socket_.async_connect(endpoint, strand_.wrap(...)); } } void my_class::handle_connect(const boost::system::error_code& error, boost::asio::ip::tcp::resolver::iterator endpoint_iterator) { if (!error) { // socket_ is my_class member. socket_.remote_endpoint(); // throw exception ! } ... } ip::tcp::socket::remote_endpoint sometime throws boost::system::system_error exception (error message is "remote_endpoint: Transport endpoint is not connected"). But async_connect is successfully completed. Why does remote_endpoint function throw exception? Thank you,

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[boost::filesystem] Improvement/Suggestion for copy()
by Kyle Ketterer 15 Jun '14

15 Jun '14

Hello all, I was curious about the possible implementation of a progress call back for the copy() ( and related functions) in ::filesystem. With WinAPI you can use CopyFileEx with the possibility of a progress call back. It would be nice to have this ability "out of the box" in boost's namespace. This would be especially be useful for transferring larger files. Thoughts? Thanks

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[geometry] how to using UDT
by Olaf Peter 15 Jun '14

15 Jun '14

Hello, I try to catch some failures using an own user defined type (UDT), but it doesn't compile e.g. it's hardcoded to use std::sqrt: boost_1_55_0/boost/geometry/strategies/cartesian/distance_pythagoras.hpp:165:13: error: no matching function for call to 'sqrt(core::my_type<double>)' further, is there a way to adapt templated points? BOOST_GEOMETRY_REGISTER_POINT_2D(point_type, point_type::coordiante_type, bg::cs::cartesian, x, y) got errrors. Thanks, Olaf

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BGL performance: is pool_allocator possible and does it help iteration performance?
by Jeremy Murphy 15 Jun '14

15 Jun '14

Hi, I'm implementing a graph algorithm that requires a lot of repeated iteration over a graph as it builds it. So I wonder about cache misses. Is it possible to use a pooled allocator with the vector/list that gets used in the VertexList and EdgeList properties of adjacency_list? If there are other techniques for improving search/iteration performance (at the cost of insertion), I'd also be interested. Thanks! Jeremy

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Boost Library Incubator recommended by steering committee
by Beman Dawes 14 Jun '14

14 Jun '14

The Boost Library Incubator (www.blincubator.com) is a web site conceived, designed, and implemented to alleviate the log-jam of libraries waiting to be reviewed by Boost. It helps new library submitters through the process, encourages development of an initial user base, and accumulates feedback in the form of comments, test results and Boost style reviews. The Boost Steering Committee has voted to recommend using the Boost Library Incubator as a prelude to getting a library reviewed by Boost. The Steering Committee recommends libraries currently in the Boost review queue be added to the Incubator by their developers. The relationship between Boost and the Incubator is purely informal, but there as several things Boosters can do to help make the Incubator a success. Authors can submit their libraries and respond to feedback. Users can experiment with submitted libraries and provide feedback on their experience. WordPress/php developers can contribute enhancements to the Boost Library Incubator implementation. The steering committee extends its thanks to Robert Ramey for launching the Boost Library Incubator! --The Boost Steering Committee

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[utility] prior(it, n) for n being an unsigned type
by Adam Romanek 13 Jun '14

13 Jun '14

Hi! I've just finished investigating an issue in my code which led it to an assert/abort in certain cases. It turned out it was caused by the use of boost::prior(it, n) where n was unsigned int with some non-zero value. I found a question [1] on the mailing list back in 2004 which describes this issue. Additionally a solution to this problem was also posted in one of the replies [2]. My question is - why hasn't it made into the repository yet? The current behavior of boost::prior(it, n) when n is unsigned type is far from the one expected by its potential users so I think it should either be properly documented (warned) or fixed immediately. Am I not seeing something? WBR, Adam Romanek [1] http://lists.boost.org/Archives/boost/2004/02/61556.php [2] http://lists.boost.org/Archives/boost/2004/02/61578.php

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std::limits compile errors with boost
by David Frank 13 Jun '14

13 Jun '14

Anyone has seen this?: In file included from ../include/boost/lockfree/detail/freelist.hpp:12, from ../include/boost/lockfree/queue.hpp:24, from test.cpp:2: /usr/local/powerpc-linux-gnu/include/c++/4.3.2/limits:287:22: error: macro "min" requires 2 arguments, but only 1 given Thanks

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<boost::wave> Memory issue when using wave to run a file parser service
by Yong Huang 12 Jun '14

12 Jun '14

Hi all, I run into a memory issue when uses boost wave library. My application runs as a *service *that parses c files. In each individual run, it calls in the wave library through a sub-function call to process one file. I noticed that some memory is not released from wave after each run. The consequence is that the memory usage of the application keeps increasing till the system breaks down. I could reproduce the problem with a simple modification of the quick_start sample code shipped with the boost wave library. (attached below). My system is win64 and I see the problem with both 1.49 and 1.55. (built with b2 toolset=msvc-11.0 address-model=64 --build-type=complete) Something I found during the investigation: * The problem is gone if I build the application with link<static>. (Unfortunately, this is not an option for me) * From the memory usage pattern, it seems that there is a memory pool in place that should have been released after each turn. When repeatedly passing a 4MB file, the memory usage (taken from task maneger) is: 99,700K, 198,404K, 395,404K, 395408K, and 789,396K. When running with static link, the memory usage after each run is: 1800K, 2480K, 2480K, .... The maximum usage is 8300K. Is there any workaround with the problem? Thanks, Yong ------------------------------------- begin of the code --------------------------------------------------- #define BOOST_WAVE_SERIALIZATION 0 // enable serialization #define BOOST_WAVE_BINARY_SERIALIZATION 0 // use binary archives #define BOOST_WAVE_XML_SERIALIZATION 1 // use XML archives /////////////////////////////////////////////////////////////////////////////// /////////////////////////////////////////////////////////////////////////////// // Include Wave itself #include <boost/wave.hpp> /////////////////////////////////////////////////////////////////////////////// // Include the lexer stuff #include <boost/wave/cpplexer/cpp_lex_token.hpp> // token class #include <boost/wave/cpplexer/cpp_lex_iterator.hpp> // lexer class // sub-function that calls into wave int do_it(std::string filename) { boost::wave::util::file_position_type current_position; std::ifstream instream(filename); std::string instring; instream.unsetf(std::ios::skipws); instring = std::string(std::istreambuf_iterator<char>(instream.rdbuf()), std::istreambuf_iterator<char>()); typedef boost::wave::cpplexer::lex_token<> token_type; typedef boost::wave::cpplexer::lex_iterator<token_type> lex_iterator_type; typedef boost::wave::context<std::string::iterator, lex_iterator_type> context_type; typedef boost::wave::cpplexer::lex_token<> TokenType; typedef boost::wave::cpplexer::lex_iterator<TokenType> LexIterator; LexIterator aIter(instring.begin(), instring.end(), TokenType::position_type( filename.c_str()), boost::wave::language_support( boost::wave::support_cpp | boost::wave::support_option_long_long ) ); LexIterator endIter; for (; aIter != endIter; ) { (*aIter).get_value(); ++aIter; } return 0; } int main(int argc, char *argv[]) { int aNum = 1; for (;;) { do_it("c:\\memleak.txt"); std::cout << "Process the file again (0/1)? \n"; scanf("%d", &aNum); if (aNum == 0) { printf("\nYou entered zero so we stop!\n"); return 0; } } return 0; }

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[python] TypeError when left side is noncopyable
by Igor R 12 Jun '14

12 Jun '14

I'm trying to expose an operator: struct my_class : boost::noncopyable {}; my_class &operator <<(my_class &e, int i); // in the module definition: class_<my_class, boost::noncopyable>("my_class") .def(self << int()) ; However, an attempt to invoke this operator in python causes the following error: TypeError: No to_python (by-value) converter found for C++ type: my_class I guess this is related to the fact my_class is noncopyable, isn't it? Is there a workaround for this issue? Thanks.

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Meeting C++ Schedule released
by Jens Weller 12 Jun '14

12 Jun '14

Hello C++ & Boost Community, since last week the schedule for Meeting C++ is released: http://meetingcpp.com/index.php/schedule14.html Like last year Meeting C++ will feature 21 Talks in 3 Tracks, the conference will be opened by Scott Meyers, the closing Keynote will be given by Hartmut Kaiser. This years Theme Track is "Scientific Programming with C++". Also, if your are a student, you have the chance to participate in our student program which will give 50 Students access to the conference: http://meetingcpp.com/index.php/newsreader/items/meeting-cpp-2014-the-stude… kind regards, Jens Weller

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