August 2007 - Boost - lists.preview.boost.org

[graph] SoC update
by Andrew Sutton 05 Sep '07

05 Sep '07

To those interested, // sorrt Alas summer is over. and the students have returned to clog the hallowed (and somewhat narrow) halls of my building... No more quiet days in my lab hacking out Boost.Graph code and documentation. On the brighter side, I have finished - at least to the satisfaction of mentor Jeremy Siek and myself - the goals that I had originally planned for my Summer of Code project. The end results are: - Two new graph classes (undirected and directed) which are intended to make the library more approachable for new developers - A suite of graph measures including degree and closeness centrality, mean geodesic distance, eccentricity, and clustering coefficients. - An algorithm for visiting all cycles in a directed graph (Tiernan's from 1970ish). It works for undirected graphs too, but reports cycles twice (one for each direction). - An algorithm for visiting all the cliques a graph (Bron&Kerbosch). Works for both directed and undirected. - Derived graph measures radius and diameter (from eccentricity) and girth and circumference (from Tiernan), and clique number (from Bron&Kerbosch). - An exterior_property class that helps hides some of the weirdness with exterior properties. - A constant-valued property map - useful for naturally unweighted graphs. - A noop-writing property map - useful when you have to provide an argument, but just don't care about the output. There are also a couple of other informal introductions that need to be polished, documented and tested. These include: - Graph cores - Implemented by David Gleich (@Stanford University) - Deterministic graph generators - capable of creating or inducing specific types of graphs over a vertex set (e.g., star graph, wheel graph, prism graph, etc). There are several other specific types that could be added to this, but I haven't had the time just yet. There are also some introductions in this package that can - or probably should be - backported to existing code. Specifically, issues dealing with vertex and edge indices and how they are mapped into exterior properties. There are also a couple of changes to the current codebase that can be immediately applied. Specifically, this includes new and updated concept checking classes and a completely new archetype system for concept coverage testing. I've also written quickbook docs for much of the new code - and have been slowly folding the older docs in - it's a long process. Also, if you aren't on a Linux box, you can't build the new docs since I'm using Makefiles, graphviz and latex to generate images. So, the up-to- date stuff is here: http://warhol.sdml.cs.kent.edu/~asutton/boost/libs/graph/doc/html/ Most of the "good" docs are toward the bottom of the ToC. I have more to say on the topic, but I will split it into a second email since this is pretty long. Andrew Sutton asutton(a)cs.kent.edu

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SVN update issue
by Vladimir Prus 05 Sep '07

05 Sep '07

Hi, in SVN trunk checkout I'm getting this: ghost@wind:~/Work/Boost/boost-svn/tools/boostbook$ svn up -r38168 svn: REPORT request failed on '/svn/boost/!svn/vcc/default' svn: Target path does not exist I *think* this is caused by renamed of trunk to devel and back to trunk that I observe in "svn log". However, I'm not sure what's the right way to do what I want. Any ideas? - Volodya

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SVN performance issues
by Vladimir Prus 04 Sep '07

04 Sep '07

I have just run this: svn diff http://svn.boost.org/svn/boost/branches/RC_1_34_0/boost/tools/build/v2 http://svn.boost.org/svn/boost/trunk/tools/build/v2 > RC_HEAD.diff and it took about 13 mins. On another machine (with another network), it took 15 mins. I've asked for confirmation on IRC, and two people are at 11 and 13 mins as a write this (and still running). Is there some network or setup issue with SVN server? Maybe the apache connection limit is set too low? - Volodya

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Clang: Open-source C/C++ front end under development
by Doug Gregor 03 Sep '07

03 Sep '07

Hello fellow Boosters, The need for an extensible, complete open-source C++ parser has been discussed on Boost over the years. There are myriad projects that parse approximations to C++ suitable for specific tasks (e.g., documentation generation), but there has never been a community project meant to handle all of C++ or serve as a common platform for new C++ tools. That is going to change, and I hope Boost will be involved. Apple has begun development of "Clang", which aims to be a high- quality C/C++ parser and compiler. Clang is designed as a library for C++ tools, from IDE-supported tools like indexing, searching, and refactoring to documentation tools, static checkers, and a full C++ front end to the Low Level Virtual Machine (LLVM). LLVM is an advanced, open-source compiler infrastructure supporting all of the back-end functionality needed for a C++ compiler. Like LLVM, Clang is written in a modern C++ style, with a clean separation between the different phases of translation in C++ (lexical analysis, parsing, semantic analysis, lowering, code generation, etc.), all of which make Clang a pleasure to work with. Clang is still in the early stages of development. At present, it parses and type-checks most of C, with code generation for some simple constructs. C++ support is not available yet, but Apple has dedicated significant resources to making Clang a successful C++ parser and compiler. That said, Clang needs our help. Collectively, Boost developers have more knowledge about and a deeper understanding of C++ than any other community within C++. We have the C++ expertise to help implement the language well, and the library-design savvy to help build powerful, accessible interfaces that simplify the task of building new and improved tools for C++. The Clang team is asking for help implementing C and C++ features and are very open to new contributors. Clang has the potential to be a top-notch, open-source C++ compiler and tool platform, from which we would all benefit. Let's help Clang get there sooner! Links: Clang: http://clang.llvm.org/ LLVM: http://llvm.org/ Steve Naroff's talk motivating Clang: - Video: http://llvm.org/devmtg/2007-05/09-Naroff-CFE.mov - Slides: http://llvm.org/devmtg/2007-05/09-Naroff-CFE.pdf Clang announcement: http://lists.cs.uiuc.edu/pipermail/llvmdev/2007- July/009817.html Cheers, Doug

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Can some check fix for #766; note on bug reports
by Daryle Walker 03 Sep '07

03 Sep '07

I just fixed and closed the issue at <http://svn.boost.org/trac/boost/ticket/766> with <http://svn.boost.org/trac/boost/changeset/39062>. The changes were only in the comments, but could someone else give them the once over to make sure I didn't mess anything up. BTW, this bug report affected two separate components independently. And the issue with the second component was added via a comment. Please don't do either one of these. It complicates issue assignment. -- Daryle Walker Mac, Internet, and Video Game Junkie darylew AT hotmail DOT com

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Simple yet interesting object factory
by Marco Costalba 03 Sep '07

03 Sep '07

This is a simple yet interesting object factory. Main points are: - Support for many class hierarchies at the same time - Object constructor arguments with generic type - Object constructor overloading - Support for user supplied 'object create' functions - Dynamic class registering/unregistering - No RTTI or special library requirements, only an associative container is used. - And finally the most important: 100% type safe also at runtime Especially constructor overloading and runtime type safety are two niceties you won't find easily googling around. You can view as HTML page a simple and commented test program here: http://digilander.libero.it/mcostalba/simple_factory/main.cpp.html A page with the source is here: http://digilander.libero.it/mcostalba/simple_factory/simple_factory.hpp.html Below are the links to the actual files: http://digilander.libero.it/mcostalba/simple_factory/main.cpp http://digilander.libero.it/mcostalba/simple_factory/simple_factory.hpp I'm sorry if you find the comments a bit "entry level", but they are intended for a wider audience. Finally there are a couple of bugs that I won't reveal ;-) they are not easy to spot and fixing them will complicate the code. Because this is intended more as a presentation of the ideas then production code I will fix them when I'll be confident design is sound. Anyhow I keep a separated test framework with about 40 tests to exercise the factory under different paths. So I would say this is 'working' code. Any comment or hint on how to improve the design or implementation would be very appreciated. Thanks Marco

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Help wanted: porting/testing the Math Toolkit to MacOS X
by John Maddock 02 Sep '07

02 Sep '07

Any MacOS X experts willing to run some tests on the Math Toolkit, and/or help track down any porting issues? The latest code is in the sandbox under "math_toolkit", last time the tests were run on that platform there were still some unresolved issues with the Mac's strange long double type to be resolved... I'd like to get these nailed down if possible before we do a first post-review release. Many thanks, John Maddock.

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Macro/Typedef for the biggest integer for template parameters
by Daryle Walker 01 Sep '07

01 Sep '07

We've talked about this problem off and on for years now, and I'm wondering if we can finally solve it. Many compilers supply built-in integer types beyond (unsigned) long int, but someone told me that there's no guarantee that those super-long types are suitable for use in a value-based template parameter. I'm wondering if we can develop typedefs, maybe in "boost/cstdint.hpp", that describe the largest suitable signed and unsigned built-in integer types that can be used as value-based template parameters. On basically-standard compilers, this would be "unsigned long" and "long". I'm thinking that we could default to boost::[u]intmax_t, and #case it for particular compilers after they choke on not being able to use "long long" or "__int64_t" in a template. (We could test in advance to minimize hardship.) -- Daryle Walker Mac, Internet, and Video Game Junkie darylew AT hotmail DOT com

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[Boost.MPI] How to use with processes on different machines?
by Manuel Jung 01 Sep '07

01 Sep '07

Hi, I would like to know, how i can use Boost.MPI for IPC between different PCs. It is described in the introduction: "Unlike communication in threaded environments or using a shared-memory library, Boost.MPI processes can be spread across many different machines, possibly with different operating systems and underlying architectures." Is there an example, how its done? I cant find one. Or isn't implemented yet? Kind Regards Manuel Jung

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[constrained-value] additional features
by Martin Dowie 01 Sep '07

01 Sep '07

I've managed to download this now (thanks!) and I've played about with added support for floats/doubles. I'd also quite like the idea of being able to retrieve the range of a constrained value so that I can use them in other more constrained values - e.g. degrees in a circle => [0, 359] but sometimes only half a circle is appropriate [0, 179]. I'd like to be able to model this, e.g. typedef bounded_int<int, 0, 359>::type degrees_in_circle; typedef bounded_int<int, degrees_in_circle::first, 180>::type degrees_in_semicircle; That's a bit contrived but hopefully you get my drift. Ada uses 'First and 'Last to get this sort of value and I've always found these sort of attributes (or 'traits') very useful. Cheers -- Martin

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