February 2011 - Boost-users

XInt formal review forthcoming
by Vladimir Prus 25 Feb '11

25 Feb '11

Boosters, the review of Boost.XInt library, by Chad Nelson, is scheduled to start on Wednesday, March 2, and will run through Friday, March 11. I will be serving as review manager. Over the years, arbitrary precision arithmetics has been a hot topic on Boost mailing lists, but now we have a concrete proposal that may become an official Boost library. So, block the time on your calendar, and get ready. Thanks, -- Vladimir Prus Mentor Graphics +7 (812) 677-68-40

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obtaining the current timezone
by Sean Farrow 25 Feb '11

25 Feb '11

Hi: Is there a way using boost.datetime to obtain the current time zone. If not given the platform dependent nature of this what is the best way to write this so as to allow potential future integration in to the date time library. Regards Sean.

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[asio] using io completion ports
by Sean Farrow 25 Feb '11

25 Feb '11

Hi: Are there any examples in boost.asio that useio completion ports, and automatically obtain the queued input from them asynchronously? Cheers Sean.

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Bug in boost::phoenix ?
by Nicolas Savoire 25 Feb '11

25 Feb '11

I am using boost::phoenix lambda functions and I am observing some weird behaviours when compiling with optimizations (-O3). The first issue is that compiling the following piece of code Compiling: const float x = 1.0f; const float y = 1.0f; std::cout << (arg1+arg2)(x,y); with g++ -Wall gives the warning: boost_1_46_0/boost/spirit/home/phoenix/operator/arithmetic.hpp:74:5: warning: returning reference to temporary And I suspect a bug in the project I am working on is a consequence of this. It is as if a boost::for_each( rng, lambda_fun ) was optimized out. I have opened a ticket on this issue: https://svn.boost.org/trac/boost/ticket/5190 I suspect the issue comes from the type deduction inside phoenix. I first discovered the issue with boost 1.45.0, but it still here in 1.46.0. The other issue I am facing is similar. Consider the following code: namespace bp = boost::phoenix; using boost::phoenix::arg_names::arg1; int i=0; int a[] = {0}; template<class UnaryFunction> inline void foo( UnaryFunction fun ) { fun(i); } int main() { foo( bp::ref(a)[arg1]++ ); std::cout << a[0] << " "; (bp::ref(a)[arg1]++)(i); std::cout << a[0] << "\n"; } Compiled without optimizations, it corectly prints: 1 2 Whereas compiled with g++-4.5.1 -O3 with boost 1.45.0, it prints: 0 1, as if the first lambda invocation was removed. The issue disappears if I use g++-4.4 or boost 1.46.0. I tracked the changes between boost 1.45.0 and 1.46.0, and it seems related to https://svn.boost.org/trac/boost/changeset/66411 applying the part of the changeset concerning: fusion/support/detail/is_mpl_sequence.hpp fusion/support/is_sequence.hpp fusion/support/sequence_base.hpp to boost 1.45.0 fixes the issue, but I can't see how this is related to the bug I observed. Is it a compiler bug, a phoenix bug or a mistake in my code ? Thanks, nicolas

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Android NDK bjam toolset
by a b 25 Feb '11

25 Feb '11

Hello to everyone, I am interested if there is Android NDK support as a toolset in bjam, to build android binaries And if there is, some documentation would be also usefull. Thanks

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[config] platform macro
by Sean Farrow 25 Feb '11

25 Feb '11

Hi: What is the platform macro if boost is built on a win64 machine? I'm currently using this to detect the platform and selectively include files/file content and need to build on a win64 box. Any help appreciated. Cheers Sean.

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[1.46] PDF Build of the docs available
by John Maddock 25 Feb '11

25 Feb '11

A PDF build of Boost's documentation for 1.46 is now available from: http://sourceforge.net/projects/boost/files/boost-docs/1.46.0/ Note that this only includes that subset of Boost which uses quickbook/boostbook/docbook for documentation. Enjoy, John.

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[Serialisation] Using wide character
by Vincent Capicotto 25 Feb '11

25 Feb '11

Hi, first sorry for my bad English. I try to use wide characters with archive to serialize into xml, and I don't know the good way to do this. Until now, we used serialization with ASCII characters and it works fine. This is the part of the code for the ASCII: *std::ifstream oInputStream(szXmlDefinition.c_str()); boost::archive::xml_iarchive oXmlInputArchive(oInputStream); oXmlInputArchive >> SERIALIZE_MEMBER(szNomObjet, oObjet );* For the UNICODE I try to use wiarchive like this : *std::wistringstream oInputStream(szXmlDefinition.c_str()); boost::archive::xml_wiarchive oXmlInputArchive(oInputStream); oXmlInputArchive >> SERIALIZE_MEMBER(szNomObjet, oObjet );* but Visual C++ 2005 doesn't find xml_wiarchive during the link operation. Is it the good way to use wides character with archive and serialisaztion or not ? Please helpe me :) Thx This email is confidential. If you are not the intended recipient you must not disclose or use the information contained in it. If you have received this email in error please notify us immediately by return email and delete this email and any attachments. Vix Technology is not responsible for any changes made to this email or any attachments, other than those made by Vix Technology, or for the effect of the changes on the meaning of the email or any attachments. Vix Technology accepts no liability for any damage caused by this email or any attachments due to viruses, interference, interception, corruption or unauthorised access.

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License information
by Daniele Niero 24 Feb '11

24 Feb '11

Hi All, I have read the boost license and I think I can do what I need, but to be sure I prefer to ask your opinion. I'm working at a very small project and I would like to keep the dependencies to external library as more contained as possible. I'm now in the situation where I need boost::any class... Do you think I can simply take the boost/any.hpp file, including both license and author copyright and modify it to make it compile in my project. Am I violation the license if I do so? Thanks for your time, Dan

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input format library
by Daniel Neuberger 24 Feb '11

24 Feb '11

Is there any work being done on an input format library for Boost? Something similar to Boost.Format but for input rather than output? Google tells me that this has been discussed before, but I couldn't find any resolution of the issue. I'm interested because I need something like sscanf, but want it to be more powerful and safer (like Boost.Format vs. fprintf). I know there are workarounds using Boost.Spirit, Boost.Regex, std::istream, and boost::lexical_cast, but in my mind, none of those are a complete solution for this problem. Thanks. - Daniel

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