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Request for comments on changes to the dynamic_bitset docs
by Gennaro Prota 07 Jul '08

07 Jul '08

Hi, I just fixed the dynamic_bitset docs for issue #1591; the problem is with a couple of duplication of sentences of this kind: Note that the expression b1 & b2 is equivalent to creating a temporary copy of b1, using operator&=, and returning the temporary copy. I think such sentences are almost without meaning and should simply be dropped. The only concern is for "breaking a contract" in this case, though frankly I don't see what the user could sensibly rely upon. And "equivalent" is so generic, anyway. In case you agree with removing the sentences, would you note that in the section "Changes from previous version(s)"? -- Genny

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[bimap] Excessive Compilation Memory Usage with VC8 - 1.35.0
by Bryan Petty 07 Jul '08

07 Jul '08

Hi, I've run into some serious problems getting my application to build after adding some usage of boost::bimap. In my application's case, a single bimap of any type causes the VC8 compiler to use more than 1GB of extra ram than it does normally (which is around 1GB). It compiles without errors, and runs flawlessly, but if I add a second bimap of any type elsewhere in my code, the additional ram usage becomes a problem and the build fails due to lack of sufficient memory to finish the compilation. These bimaps are declared and defined in a static library linked to my application which is setup with pre-compiled headers for that library. The compilation generally takes the most ram during compilation of the pre-compiled headers, and that's where this fails. This seems especially weird since from what I can tell, bimap is simply an implementation of boost::multi_index for a specific purpose, and we already make use of 4 different multi_index containers throughout our application without any memory consumption issues. I've taken the time to test this with a new skeleton Win32 project, and used the simple bimap example included with Boost. Without bimap, cl.exe only peaks at 3.25MB committed (measured with Process Monitor) in debug mode, but when I copy in the simple bimap example it peaks at 325MB committed in debug, and 148MB committed in release. I don't see anywhere near these kind of numbers with GCC on x86 linux, g++ stays around 3MB. System: Windows XP, VC8, 2GB RAM, Boost 1.35.0 One user on #boost experienced similar numbers when compiling with VC9 as well. When I add more bimaps in the simple example, it doesn't add as much of a jump as the first does, but it's still fairly significant (from 325MB to 360MB in debug with the second bimap). I have no idea how to go about debugging this. Regards, Bryan Petty

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Reassigning tickets #1531 and #1591 to me?
by Gennaro Prota 07 Jul '08

07 Jul '08

Hi guys, I sent the same request yesterday, to the Moderators address, but didn't get any reply (sorry if this duplication causes any inconvenience): could someone with sufficient privileges reassign tickets #1531 and #1591 to me, so that I can close them? Or should I ask Jeremy? Thanks, -- Genny

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How do I configure MPI?
by Daryle Walker 07 Jul '08

07 Jul '08

I'm trying out Boost.Build. I used to get warnings like: //=================================== warning: Graph library does not contain optional GraphML reader. note: to enable GraphML support, set EXPAT_INCLUDE and EXPAT_LIBPATH to the note: directories containing the Expat headers and libraries, respectively. warning: skipping optional Message Passing Interface (MPI) library. note: to enable MPI support, add "using mpi ;" to user-config.jam. note: to suppress this message, pass "--without-mpi" to bjam. note: otherwise, you can safely ignore this message. Building Boost.Regex with the optional Unicode/ICU support disabled. Please refer to the Boost.Regex documentation for more information (don't panic: this is a strictly optional feature). //=================================== I added a "using mpi ;" line, and now I'm getting errors like: //=================================== MPI auto-detection failed: unknown wrapper compiler mpic++ Please report this error to the Boost mailing list: http://www.boost.org You will need to manually configure MPI support. //=================================== So, how do I configure MPI support? Do I have to set up GraphML support first? -- Daryle Walker Mac, Internet, and Video Game Junkie darylew AT hotmail DOT com

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determining if an object is faster to pass by value or const reference
by Michael Marcin 07 Jul '08

07 Jul '08

In general noone would write a function that took an int by const reference because doing so doesn't make sense from a performance standpoint. However often times we pass these trivial types to functions generically written to take const T&. It seems like type traits would make it simple to overload based on this convention. However I don't see a type trait that is fit for this use case. The has_trivial_copy trait would seem promising but it could return true for large pod objects that you wouldn't want to copy. The is_scalar trait seems promising but it will return false for lightweight user defined types and be suboptimal. Using has_trivial_copy together with some sizeof limit seems promising but a bit hand wavy. Is there a trait designed for this use case I'm overlooking? Thanks, Michael Marcin

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Boost.Process 0.2 released
by Boris 07 Jul '08

07 Jul '08

I stumbled over Boost.Process some months ago. The library was created as a Google Summer of Code project in 2006 (see http://www.netbsd.org/~jmmv/process/) As I needed the functionality provided by this library and didn't manage to contact the author I went through the code myself to tidy it up, fix various bugs, convert the documentation to DocBook etc. I also added one minor but important improvement: With Boost.Asio 1.1 it's now possible to use asynchronous I/O (on Windows the macro BOOST_PROCESS_WINDOWS_USE_NAMED_PIPE must be defined as on Windows only named pipes support asynchronous I/O). I've been using the library myself only on Windows so far where it seems to work fine. I didn't make any tests yet on a POSIX platform. I didn't update the documentation yet much either. And I have no idea how to integrate the samples and test programs into Boost.Build (there are two Jamfiles but don't be surprised if they don't work :). As this library wasn't touched for nearly 2 years I don't know if there is any interest at all. As I had tidied up the code now anyway for my own purposes I provide a new snapshot for the community. You can find everything (including a link to download version 0.2) here: http://www.highscore.de/boost/process/ Boris

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[test] test_tools.hpp: gcc-warnings patch
by Juergen Hunold 07 Jul '08

07 Jul '08

Hi ! The attached patch fixes two gcc warnings about unused parameters in BOOST_TEST_DONT_PRINT_LOG_VALUE. Okay to commit to trunk ? Yours, Jürgen -- * Dipl.-Math. Jürgen Hunold ! Ingenieurgesellschaft für * voice: ++49 511 262926 57 ! Verkehrs- und Eisenbahnwesen mbH * fax : ++49 511 262926 99 ! Lister Straße 15 * juergen.hunold(a)ivembh.de ! www.ivembh.de * * Geschäftsführer: ! Sitz des Unternehmens: Hannover * Prof. Dr.-Ing. Thomas Siefer ! Amtsgericht Hannover, HRB 56965 * PD Dr.-Ing. Alfons Radtke !

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[metagraph] definition
by Gordon Woodhull 07 Jul '08

07 Jul '08

I just have to share this little insight: finally, a concise definition. A metagraph is a system of objects where the types of the objects (classes) and the relations between them (e.g. pointers, mappings, containers) can be described in a graph called a pattern. In the C++ implementation, the patterns are metadata, which allows static typing and static polymorphism and moves the abstraction penalty to compile time (when the pattern is known at coding time). Patterns and their implementation code are combined into larger patterns; the "total pattern" is what actually gets instantiated. The library allows implementation of hypergraphs, subgraphs, various nested/mixed/ clustered layout schemes, constraints on graphs, and generally graphs- of-graphs, hence the name metagraph. Can any static analysis fans out there tell me if there's already a name for this? Note that in this definition, metagraph is something which already exists in lots of forms. This library proposes (for now) to implement the data structures in a nicer way and (in the future) to describe and access existing structures in a consistent way. My profuse apologies for continuing to talk about code that doesn't yet exist. Soon, soon. Cheers, Gordon

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Re: [boost] [integer] Can anyone double-check this test?
by Vladimir Prus 07 Jul '08

07 Jul '08

Daryle Walker wrote: > I'm trying to tweak Boost.Integer, and I noticed that only 3 of the 6 > test files there are being used. I changed the jam-file there, but I > don't use Boost.Build myself, so can someone here confirm that the > changes work. You can check out the exact changes with Change-set > 47123 at <http://svn.boost.org/trac/boost/changeset/47123>. In other words, you've checked in something, and you don't know if that works? You really better learn how to use Boost.Build -- for the mainstream toolsets and operating systems, it's trivial. - Volodya

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Graph library noise in logs
by Emil Dotchevski 07 Jul '08

07 Jul '08

Isn't it a good idea to remove these messages from the Graph library Jamfile? warning: Graph library does not contain optional GraphML reader. note: to enable GraphML support, set EXPAT_INCLUDE and EXPAT_LIBPATH to the note: directories containing the Expat headers and libraries, respectively. warning: skipping optional Message Passing Interface (MPI) library. note: to enable MPI support, add "using mpi ;" to user-config.jam. note: to suppress this message, pass "--without-mpi" to bjam. note: otherwise, you can safely ignore this message. IMO this information belongs in the documentation. At present it is displayed every time I build anything that uses Boost, even if it doesn't use Graph. Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode

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