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[iostreams] Inconsistency of "faiture" of writes in Sinks and filters
by Artyom 02 Nov '10

02 Nov '10

Hello, I implement the sink device that sometimes may fail on writes. When Sink is implemented it should throw an exception on fault. To notify the stream on error. However it is not always works this way. I've got the exception to "leak" to the main program when I combine in the filter gzip_comressor() filter that writes to output device that its Sink is full. When I call reset on the filter the exception in leaking to the program instead of being caught. Is it bug or (accidental) feature? On the other hand, if I don't throw but rather return 0, I get into infinite loop in the boost::iostreams::non_blocking_adapter::write when I call filter.reset(). So I how can I write a sink device that reports errors? In following example the exception is caught when filter.reset() is called: #include <boost/iostreams/stream.hpp> #include <boost/iostreams/filtering_stream.hpp> #include <boost/iostreams/filter/gzip.hpp> #include <boost/iostreams/tee.hpp> #include <iostream> class my_small_device : public boost::iostreams::sink { int count; public: my_small_device() : count(1000) {} std::streamsize write(char const *d,std::streamsize n) { if(count < n) throw std::runtime_error("Device is full"); count-=n; return n; } }; int main() { try { using namespace boost::iostreams; boost::iostreams::stream<my_small_device> output(my_small_device(),10); { boost::iostreams::filtering_ostream filter; filter.push(gzip_compressor()); filter.push(output); for(int i=0;i<10000000;i++) { if(!(filter << i << '\n')) { std::cerr << "Fail!" << std::endl; break; } } std::cout << "Closing filter" << std::endl; filter.reset(); } std::cout << "ok" << std::endl; return 0; }catch(std::exception const &e) { std::cerr << "Catched " << e.what() << std::endl; return 1; } } Thanks, Artyom

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Issues with intel's compiler and newer builds of GCC
by Bryce Lelbach 02 Nov '10

02 Nov '10

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 While working on getting icc to not choke on Serialization (the Boost test boxes indicated that icc was failing to build with the addition of my changes), I came across a very nasty bug the occurs when using icc with version 4.5 or higher of GNU's standard library - GNU's <iomanip> uses what are either illegal or C++0x semantics which icc doesn't support. Serialization uses <iomanip>, and icc seems to select the latest version of libstd++ installed on a Linux machine as it's default standard library (I have been unable to find an Intel standard library - I'm assuming such a thing doesn't exist). When using an older version of libstd++, icc + Serialization compiled fine. I removed all uses of IO parameterized manipulators in Serialization (there were only maybe half a dozen cases)*, and got icc to compile Serialization with libstd++ v4.5. Is there any chance the linux/darwin Intel build bots can be set up to use libstd++ v4.4, if they're not already using it? Intel is apparently aware of this issue, but it won't be fixed until their next major release (http://software.intel.com/en-us/forums/showthread.php?t=74691) If the build bots aren't using v4.5 of GNU's standard library, then I'm at a loss as to why Serialization is failing to build on them. My only other thought is that the timeout for the build cycle is too low - the failures indicate that the error is a timeout after 300 seconds. On a more general note, is Intel on Linux/Darwin a "supported" Boost compiler? Unless I've missed something, Intel doesn't provide a standard library, and I find it a bit troubling that they ship their compiler to use GNU's standard library by default. Intel is far behind GCC in C++0x support, and newer versions of the GNU standard library have been making increasing use of GCC's C++0x support. Unless icc starts shipping with an older version of libstd++/use a compiler neutral standard library such as the Apache standard library/starts to catch up with GCC's C++0x support, I imagine that using icc to compile C++ code that makes use of the standard library will become increasing difficult. * I also had to modify proto/debug.hpp to not use <iomanip>. Eric, when I was having an issue with typeinfo in proto/debug.hpp a couple days ago, you mentioned that proto/debug.hpp shouldn't be included by proto/proto.hpp? If that's accurate, is there any chance that change could be made, and if not, can I commit my changes to proto/debug.hpp or send them to you as a patch for review? - -- Bryce Lelbach aka wash http://groups.google.com/group/ariel_devel -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAky+c7cACgkQO/fqqIuE2t4DZQCfUnhGAsqX4GDZu3Ze7BvrPBRL XRkAn33vWcTm1RuXk2iuQWH0+bp+RVUf =mHwK -----END PGP SIGNATURE-----

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[build_extensions][patch] General update and minor fixes
by Mateusz Loskot 02 Nov '10

02 Nov '10

Hi, First, I'm not sure if this is the right place to send patch to the build_extensions which live in the sandbox, I'm continuing to have complete build of Boost.GIL tests on Linux with 3rd-party dependencies configured using the build_extensions. It's trial and error process during which I've applied number of updates to .jam scripts for raster support libraries. The patch summary: zlib: added/removed .c source files jpeg: added/removed .c source files libtiff: - added missing tif_unix.c for <target-os>linux (not sure why <target-os>unix: could not kick in) - configure #define integral types required by tiffiop.h - added tiffxx target with C++ wrapper library (tif_stream.cxx) I have successfully used the extensions with the following libraries: jpeg-8a libpng-1.4.1 tiff-3.9.2 zlib-1.2.4 with GCC 4.4.5 on Linux 64-bit. I'm quite sure some of the changes could be mastered in much better way, but I lack of Boost.Build zen. Best regards, -- Mateusz Loskot, http://mateusz.loskot.net Charter Member of OSGeo, http://osgeo.org Member of ACCU, http://accu.org

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[gil][io_new] Problems with templates
by Christian Henning 01 Nov '10

01 Nov '10

Hi there, problems have been resolved. Thanks to everyone who tried helping! Regards, Christian

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[range] - Proposal to change the indexed range adaptor
by Neil Groves 01 Nov '10

01 Nov '10

Fellow maintainers and developers, Having gained experience using the Boost.Range library changes I submitted for Boost 1.43, I have become dissatisfied with my indexed adaptor. Currently the underling index_iterator has a return type identical to the wrapped iterator, and the index is extracted via a method call on the iterator. While this works for the case where one is writing algorithms to explicitly utilise the underlying iterator, it is clearly a poor design choice since it severly limits the interoperation with other algorithms. I feel that I have made a mistake. I propose that a breaking change is made to the index range adaptor so that it returns a pair<original_reference_type, index_type>. How do you feel about this change? Do you have alternative suggestions? Regards, Neil Groves

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boost::optional - rvalue references
by Daniel Larimer 01 Nov '10

01 Nov '10

I have been looking to optimize my code using rvalue references when they are supported; however, I currently use boost::optional which does not know how to handle / forward rvalue references. In fact even the in_place() utilities do not work to forward the rvalue into the proper constructor. My latest profiling shows that assigning a large vector to an optional is eating up 5% of my CPU time and I could replace this with a std::move() if boost::optional supported it. I have attached an updated optional.hpp with the minimum changes necessary to support the following: test v ( 99 ); test A ( 400 ); boost::optional<test> i2(std::move(v)); i2 = std::move(A); Such that if test were a vector and 99 and 400 were the sizes, the end result is v & A are of size 0 and i2 is of size 400 and no copy constructors are called (only moves). What is the plan for updating more of boost to take advantage of rvalue references?

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Get PID from local socket?
by Rush Manbert 01 Nov '10

01 Nov '10

I am using boost ASIO to do socket communications between an app and a daemon running on the same machine. The communications go through a Unix Domain Socket on the Mac and a named pipe on Windows. I'm looking for a way that the client app could obtain the PID of the daemon process, starting with the connected socket. I have tried calling local_endpoint() and remote_endpoint(), but the only information there seems to be the socket path (at least on the Mac). My google searches have turned up nothing, and they actually suggest that there is no way to achieve this on the Mac, even if I were using the "normal" socket API. Does anyone know whether this is possible and how to do it? Thanks, Rush

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[gsoc] Boost.Process done
by Boris Schaeling 31 Oct '10

31 Oct '10

Here are the results of the Boost.Process project within this year's Google Summer of Code program: We have a complete library to manage system processes now! If you like to play around with the library download the ZIP file from <http://www.highscore.de/boost/gsoc2010/process.zip>. As it's a header-only library simply copy the files to your Boost folder. If you like to quickly check the documentation click on <http://www.highscore.de/boost/gsoc2010/>. The library is now complete and basically ready for a review. As there have been so many Boost.Process drafts before (after all the first version was created 2006) this library's version number is 0.4. This will somehow make it possible to refer to the various drafts if it's necessary. For now I would appreciate if the library's test cases are run on as many platforms as possible. After copying the files from the ZIP file to the Boost folder change to libs/process/test/ and run bjam - that's all! What has been changed? * All previous Boost.Process drafts including Ilya's 2008 version from the vault have been thoroughly studied to create a better version. From the multiple Boost.Process drafts which have been floating around since 2006 we took the best ideas and created a new unified version. * The design and implementation of the library have been simplified. The library's API is smaller, and the implementation is easier to understand. It should be possible to benefit from this library as quickly as possible. Even developers who have no experience in managing system processes should be able to do so easily. * There are no POSIX and Windows specific classes anymore (posix_context, posix_child, win32_context, win32_child etc. have been dropped). Instead of trying to support each and every feature platforms provide extension points have been defined. They enable library users to "link in" those platform specific features they are interested in. * For the first time there is full support for synchronous and asynchronous operations. While asynchronous operations are built on top of Boost.Asio synchronous operations can be utilized without that library. Developers don't need to include any Boost.Asio headers and don't need to learn about Boost.Asio if they don't need asynchronous operations. * Stream behaviors define if and how standard streams can be used by a child process. While the various stream behaviors were defined as an enumeration or a boost::variant in previous Boost.Process drafts they are now implemented as classes. This makes it possible for developers to create new stream behaviors. * The code to start child processes on POSIX platforms has been carefully adapted to support multi-threaded applications (it turned out that this code was wrong in all Boost.Process drafts so far). The documentation explains what you need to take care of if you want to create child processes in a multi-threaded application on POSIX platforms. * The documentation is new and has been shortened and simplified. There is a user guide which can be read in 10 minutes and introduces all the major features of the library. The documentation is now also based on Quickbook. * The test cases have been restructured to simplify them. They can now be run without patching Boost.Test and without setting a path to a helper executable in the source files - it's now all automatic. They are all passed successfully with MSVC 9 (2008) and g++ 4.2.1. What is currently missing? * Pipelines are not (yet) supported. If you have been using boost::process::launch_pipeline() there is nothing in this Boost.Process draft you can use instead. Depending on feedback this feature will be added again (there was simply no time yet to do this). We hope that after four years, two Google Summer of Code programs and countless drafts this new version will finally become the official Boost.Process library so many have been waiting for. Boris and Felipe

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[rational] PATCH: Use ordered_euclidean_ring_operators
by Mario Lang 30 Oct '10

30 Oct '10

Hi. Below is a patch which makes rational.hpp use grouped arithmetic operators. While we are at it, use ordered_euclidean_ring_operators instead of just ordered_field_operators. While it might sound strange at first, mod can make sense even for rational numbers. For instance, Common Lisp, which has a native rational type, works fine if mod is used on rational numbers... template <typename IntType> rational<IntType>& rational<IntType>::operator%= (const rational<IntType>& r) { return *this -= r * floor(rational_cast<double>(*this / r)); } I am aware that the use of floor() is probably problematic. I am all open for comments and suggestions for improvements. -- Thanks, ⡍⠁⠗⠊⠕

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[graph] PATCH to eliminate gcc 4.2 warnings when compiling boost/graph/read_dimacs.hpp
by Daniel Trebbien 30 Oct '10

30 Oct '10

Attached is a patch that changes the definition of `err_message` in boost/graph/read_dimacs.hpp@66260 from: static char *err_message[] to: static const char *err_message[] This will eliminate the warnings that were recorded at: http://www.boost.org/development/tests/trunk/developer/output/Sandia-gcc-4-… Daniel

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