July 2009 - Boost-users - lists.preview.boost.org

asio async_write bad address error
by Thomas Klein 19 Jul '09

19 Jul '09

Hi there, I'm trying to use boost asio to transfer large objects through a tcp socket. I'm using the Serialization code from the asio documentation as reference. I got a transfer problem and can't find any clue, I'm posting here as a last resort. If someone has a little time to point out my mistakes I'll be really gratefull ! Here is a tgz of a code sample : http://archon.adept.free.fr/asioproblem.tgz In the archive you'll find a server and a client directory. in each directory you'll find a compile.sh file you'll have to adapt to your configuration. In the file asiotestserver/TcpConnection.cpp line 131 you''ll find a comment explaining the transfer problem. Thanks a lot in advance !

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[test] BOOST_*_EQUAL against constants
by Alexander Lamaison 19 Jul '09

19 Jul '09

A common scenario in my tests is comparing some unsigned value against a constant (most often 0 or 1): BOOST_REQUIRE_EQUAL(cbRead, 0); However, this generates a warning on MSVC complaining about a signed/unsigned mismatch (full message included at end): c:\boost\test\test_tools.hpp(536) : warning C4389: '==' : signed/unsigned mismatch c:\boost\test\test_tools.hpp(560) : see reference to function template instantiation 'boost::test_tools::predicate_result boost::test_tools::tt_detail::equal_impl(const Left &,const Right &)' being compiled with [ Left=ULONG, Right=int ] I can obviously cast the 0 constant to an unsigned it but it's getting tedious doing this every time. Surely there must be a better way? Is there some way to force the comparison to interpret constants as being of whatever type they are being compared to? Thanks. Alex c:\program files\boost\boost_1_38\boost\test\test_tools.hpp(536) : warning C4389: '==' : signed/unsigned mismatch c:\program files\boost\boost_1_38\boost\test\test_tools.hpp(560) : see reference to function template instantiation 'boost::test_tools::predicate_result boost::test_tools::tt_detail::equal_impl(const Left &,const Right &)' being compiled with [ Left=ULONG, Right=int ] c:\program files\boost\boost_1_38\boost\test\test_tools.hpp(575) : see reference to function template instantiation 'boost::test_tools::predicate_result boost::test_tools::tt_detail::equal_impl_frwd::call_impl(const Left &,const Right &,boost::mpl::false_) const' being compiled with [ Left=ULONG, Right=int ] c:\program files\boost\boost_1_38\boost\test\test_tools.hpp(523) : see reference to function template instantiation 'boost::test_tools::predicate_result boost::test_tools::tt_detail::equal_impl_frwd::operator ()(const Left &,const Right &) const' being compiled with [ Arg0=ULONG, Arg1=int, Left=ULONG, Right=int ] c:\users\awl03\documents\visual studio 2005\projects\swish_feature_write\test\provider\stream_write_test.cpp(202) : see reference to function template instantiation 'bool boost::test_tools::tt_detail::check_frwd(Pred,const boost::unit_test::lazy_ostream &,boost::test_tools::const_string,size_t,boost::test_tools::tt_detail::tool_level,boost::test_tools::tt_detail::check_type,const Arg0 &,const char *,const Arg1 &,const char *)' being compiled with [ Pred=boost::test_tools::tt_detail::equal_impl_frwd, Arg0=ULONG, Arg1=int ]

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A question on member functions when using lambda expression. Can anyone with kindness help me?
by fmingu 19 Jul '09

19 Jul '09

I am using Dev-C++ with lambda expression and building a DLL. In Dev-C++, when the program is used as a exe.It works fine. But I want to make it a class (i.e.classA in the following)in a DLL for other exes to use it. And the error occured: In dll.cpp: ................ void classA::a() ......................... (while_loop(bind(&isprime,_1)==false, ++var(result))(middlevalue); ...................... where bool isprime(int) is also a member function of classA. But the complier told me that: ISO C++ forbids taking the address of an unqualified non-static member function to form a pointer to member function. I do not know how to solve it. Can anyone with kindness help me?

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[Fusion] Understanding Fusion
by Robert Jones 19 Jul '09

19 Jul '09

Hi All I'm very much a Fusion newbie, just getting may head around it, so a really basic question! >From the intro page, when we write #include <boost/fusion/sequence.hpp> #include <boost/fusion/include/sequence.hpp> vector<int, char, std::string> stuff for_each(stuff, print_xml()); am I correct in believing that there is no loop involved in the for_each, and that this resolves, at compile time, to a linear list of function calls? Thanks, - Rob.

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BGL: graphml converter
by Caligula 18 Jul '09

18 Jul '09

Hi, Does anyone know if there is software to convert graphml format to pdf?

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BGL: graphml caption
by Caligula 18 Jul '09

18 Jul '09

Hi, Does anyone know how to add a caption (in BGL) to the graphml output produced by the following line? write_graphml(cout, g, dpp, true);

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Boost filesystem get_temporary_file()
by Craig Henderson 18 Jul '09

18 Jul '09

I cannot find any function in the Boost.Filesystem library to get a temporary filename. There has been some discussion about this functionality on the lists many years ago - did anything come of this? I need a cross-platform way to do this and was hoping boost would provide it :) Thanks -- Craig Craig Henderson <http://craighenderson.co.uk/> http://www.craighenderson.co.uk http://www.siteupdatenotification.com

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compilation error with mpl transform
by Zachary Turner 18 Jul '09

18 Jul '09

Is the following supposed to work? I feel like I'm missing something obvious: typedef boost::mpl::vector<int, float, double> vec_type; template<template<class T>, class U> struct parameterize { typedef T<U> type; }; template<class T> class wrapper { }; typedef boost::mpl::transform<vec_type, parameterize<wrapper, boost::mpl::_1> > wrapped_vec; When I do this I get compile errors on MSVC 9.0. However if I remove the template template and hardcode T to wrapper in struct parameterize, it works fine.

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Fusion container from MPL typelist?
by Zachary Turner 18 Jul '09

18 Jul '09

Suppose I have a boost::mpl::vector<...> and I want a boost::fusion::vector<...> whose types correspond exactly to the types in the mpl::vector. Is there a simple way to go about this? It seems like all the methods of constructing a fusion vector require me to manually specify the individual types as the parameters to fusion::vector<>.

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[filesystem] support for reading symlinks?
by Nils Krumnack 17 Jul '09

17 Jul '09

Hi all, I was wondering whether there was any support for reading the contents of a symlink in the filesystem library, i.e. the path to the file it points to. I saw that back in 2006 somebody submitted a patch that would (among other things) do this. However the patch seems never to have made it into the main trunk. Of course that is fairly easy to implement that myself, but if there is a standard implementation I'd rather use that. Thanks in advance, Nils

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