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Pondering Futures
by Tom Brinkman 13 Jan '09

13 Jan '09

Ponderings on the Futures Library: What is the status of Anthony Williams' submission of the futures library to the c++ standards committee? Is it more prudent to wait to find out what the c++ standards committe is going to do first, before adding a possibly incompatible version of the futures library to boost? One could ask, if Anthony's submission is approved by the c++ standards committe, what is the point of adding a "futures" library to boost as well? Is a seperate library needed? What is the advantage of having a root level library called boost::futures? Why would it not be perferable to just extend boost::thread with the additional capabiltity to handle "futures"? Futures are a very useful concept, and I have used them personally. The c++ commitee is correctly considering adding them to the standard. I would be interested in hearing the authors views on their "grand" vision for parallel programming in general and how their "futures" library submissions fit into this vision. tom brinkman

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[fusion] mpl::is_sequence<fusion::vector<> >::type::value should work right?
by Dean Michael Berris 13 Jan '09

13 Jan '09

Hi Guys, I've tried the following minimal test with the latest in trunk and I get an error with GCC 4.2. #include <boost/fusion/container/vector.hpp> #include <boost/static_assert.hpp> int main(int argc, char *argv[]) { BOOST_STATIC_ASSERT((boost::mpl::is_sequence<boost::fusion::vector<> >::type::value)); return EXIT_SUCCESS; } The error is pasted below: /home/dean/boost_trunk/boost/mpl/begin_end.hpp: In instantiation of 'boost::mpl::begin<boost::fusion::vector<boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> >': /home/dean/boost_trunk/boost/mpl/is_sequence.hpp:95: instantiated from 'boost::mpl::is_sequence<boost::fusion::vector<boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> >' fusion_is_sequence_test.cpp:5: instantiated from here /home/dean/boost_trunk/boost/mpl/begin_end.hpp:35: error: invalid use of incomplete type 'struct boost::mpl::begin_impl<boost::fusion::fusion_sequence_tag>' /home/dean/boost_trunk/boost/mpl/begin_end_fwd.hpp:19: error: declaration of 'struct boost::mpl::begin_impl<boost::fusion::fusion_sequence_tag>' fusion_is_sequence_test.cpp: In function 'int main(int, char**)': fusion_is_sequence_test.cpp:5: error: 'type' is not a member of 'boost::mpl::is_sequence<boost::fusion::vector<boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> >' fusion_is_sequence_test.cpp:5: error: template argument 1 is invalid fusion_is_sequence_test.cpp:5: error: template argument 1 is invalid Is this a bug? HTH -- Dean Michael C. Berris Software Engineer, Friendster, Inc.

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[Signals] Early exit on call
by Kisso Bajslovski 12 Jan '09

12 Jan '09

Hi, I wonder if there's any way to end a call early. For example, if we have 4 connections to a signal, and when the first 2nd is called it wants to abort and avoid the calls to the last 2 connections.

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[PhD] todo: use sum() consistently all places ... make it easy to switch to kahanSum() or to optomize
by Thorsten Ottosen 12 Jan '09

12 Jan '09

-Thorsten

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[Review] UUID review results
by Hartmut Kaiser 12 Jan '09

12 Jan '09

Hi all, Some while ago we have had a lively discussion during the review of Andy Thompkin's UUID library. I counted 11 votes, 10 'yes' votes and one 'no' vote. IMHO the 'no' vote has been superseded by the followup discussion and all issues have been resolved. Almost all reviewers stated the UUID library to be very useful. Given the overwhelming number of 'yes' votes the UUID library is accepted for inclusion into Boost. Before inclusion into the Boost SVN Andy will need to fix a couple of minor issues as discussed during the review, some of which are: - POD-ness - lexical_cast - default construction Congratulations to Andy for his effort related to pushing the UUID library forward. I hope to see active development and maintenance of this library in the future. Regards Hartmut Review Manager

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[iostreams]howto replace ostream buffer?
by Larry Evans 11 Jan '09

11 Jan '09

How can one use iostreams::filtering_streambuf to replace the std::basic_streambuf used by cout. I've tried the code in 1st attachment; however, that code produces the output in 2nd attachment. The desired output is shown in 3ird attachment. How should the code be modified to get the desired output? TIA. -regards, Larry Hello World! is_complete=1 3ird Hello! Hello World! is_complete=1 2ND HELLO! 3ird Hello!

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Proposal: Add Loki Library's SafeFormat to Boost:
by Tom Browder 11 Jan '09

11 Jan '09

The last Loki thread I see here is the one from 2002 discussing adding Loki to Boost. I asked Andrei once about doing that specifically for the Loki SafeFormat functions (FPrint, Printf, and SPrintf) and he said FPrintf wasn't good enough yet. However, I find all of them very useful and would love to see them added to the Boost library I know Boost has Format now, but SafeFormat has some advantages over Boost.Format, one of which is that FPrintf can be output to C++ streams as well as to FILE pointers--very handy when one is gradually converting legacy code to using C++ streams. In addition, I find the SafeFormat family much easier to use than Boost.Format. Andrei's original comments regarding FPrintf's shortcomings are here: https://sourceforge.net/forum/message.php?msg_id=4525195 His "Dr. Dobb's Journal" article describing SafeFormat is here: http://www.ddj.com/cpp/184401987 Thank you for your consideration. Warmest regards, -Tom Tom Browder Niceville, Florida USA

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C++03 unique_ptr emulation
by Howard Hinnant 11 Jan '09

11 Jan '09

I've put up a new version of an C++03 emulated unique_ptr here: http://home.roadrunner.com/~hinnant/unique_ptr03.html This is a "boost-ized" emulation (uses boost tools and is in boost namespace), though I have reason to believe it may not work well on VC+ +05 unless the /Za option is used (I've tested only on gcc 4.0). I'm aware of Ion's interprocess version (http://www.boost.org/doc/libs/1_35_0/doc/html/interprocess/interprocess_sma… ), and thank Ion for his support over the years. This new version is not meant to replace Ion's version. It is simply my current best shot at emulating the unique_ptr behavior as specified in the C++0X CD1 draft. Booster's are welcome to take parts of this implementation and use them in places like interprocess/unique_ptr. Or to just use this unique_ptr directly. It consists of only one header: unique_ptr.hpp, and requires only boost headers, not boost cpp files. Basic documentation is included at the link. -Howard

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[GIL] trouble loading image files
by Kenny Riddile 11 Jan '09

11 Jan '09

This is my first time using GIL and I'm having some difficulty loading jpeg and png files. Here's some code: rgb8_image_t image1; jpeg_read_and_convert_image<rgb8_image_t>( "file.jpg", m_image1 ); rgb8_image_t image2; png_read_and_convert_image<rgb8_image_t>( "file.jpg", m_image2 ); Attempting to load the jpeg causes a crash at jpeg_read_header(&_cinfo,TRUE); in jpeg_io_private.hpp. Attempting to load the png causes a similar crash at png_read_info(_png_ptr, _info_ptr); in png_io_private.hpp. I'm using the libjpeg and libpng builds from these sites: http://gnuwin32.sourceforge.net/packages/jpeg.htm http://gnuwin32.sourceforge.net/packages/libpng.htm

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[Test] documentation inconsistencies
by Thorsten Ottosen 10 Jan '09

10 Jan '09

Hi, I was trying to follow the docs at http://www.boost.org/doc/libs/1_37_0/libs/test/doc/html/utf/user-guide/test… I don't want to include everything, so I compile Boost.Test with dynamic linking. In this case I have to include two headers: #define BOOST_TEST_MODULE conditional_cost_experiments #include <boost/test/unit_test.hpp> #include <boost/test/unit_test_suite.hpp> // this one is also needed when linking!!! Maybe it would be better to include the latter header in the first? best regards -Thorsten

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