April 2006 - Boost - lists.boost.org

New Code Of Summer project
by Carlo Wood 01 May '06

01 May '06

Hi, I just subbed. Before, I was only on boost-users, where there was a single mail about Code of Summer 2006. That mail said that if you had a new idea for a project, then you could add it to the wiki. I've added it to the wiki now, but I suppose it has to be approved too more or less. See http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?Google_Summe… -- Carlo Wood <carlo(a)alinoe.com>

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Including thread.hpp causes coredump on AIX
by Chris Grayson 30 Apr '06

30 Apr '06

#include <iostream> #include "Class1.h" #include <boost/thread/thread.hpp> main () { std::cout << "starting main()" << std::endl; Class1 c; c.noop(); std::cout << "exiting main() normally" << std::endl; } #include <iostream> #include "Class1.h" #include <boost/thread/thread.hpp> void Class1::noop () { std::cout << "entering Class1::noop()" << std::endl; try { std::cout << "..throwing exception" << std::endl; throw (2.1); } catch (...) { std::cout << "..caught exception in Class1.noop()" << std::endl; } std::cout << "..leaving Class1.noop()" << std::endl; return; } class Class1 { public: void noop(); };

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[Boost Review] Property Tree Library
by Thorsten Ottosen 30 Apr '06

30 Apr '06

Dear All, I have the great pleasure to announce that the formal boost-review of Marcin Kalicinski Property Tree Library begins now (the 18th of April) and runs through the 27th of April. Introduction ------------ This fairly high-level library consists of the following facilities: 1. a generic recursive property-tree data-structure 2. generic conversions to/from this data-structure from/to a. xml-files b. ini-flies c. json-files d. windows registry files As an example of how powerful the library is, consider this tutorial: - http://kaalus.atspace.com/ptree/doc/index.html#five_minute_tutorial The library may be downloaded from - the boost file vault http://boost-consulting.com/vault/ (property_tree_rev5.zip) - tinyurl: http://tinyurl.com/fkt7r - boost sandbox: http://www.boost.org/more/mailing_lists.htm#sandbox (look in boost/property_tree and libs/property_tree) The documentation may be viewed online at - http://kaalus.atspace.com/ptree/doc/index.html If your find the above interesting, please consider submitting a review to the boost developer mailing list: - http://www.boost.org/more/mailing_lists.htm#main You might end up using several hours on a review, but the end result could be a superb library that will save you weeks of work. Notes for reviewers ------------------- When writing your review, you may wish to consider the following questions: * What is your evaluation of the design? * What is your evaluation of the implementation? * What is your evaluation of the documentation? * What is your evaluation of the potential usefulness of the library? * Did you try to use the library? With what compiler? Did you have any problems? * How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? * Are you knowledgeable about the problem domain? And finally, every review should answer this question: * Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. In particular, consider if you can answer the following questions: - was the library suitable for your daily xml-tasks? If not, what was missing? - was the library's performance good enough? If not, can you suggest improvements? - was the library's design flexible enough? If not, how would you suggest it should be redesigned to broaden its scope of use? best regards Thorsten Ottosen, Review Manager

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Re: [boost] [Boost-users] portable uuid generator
by Tim Blechmann 30 Apr '06

30 Apr '06

hi andy, to use your guid library with gcc-4.1, i had to change it according to the attached patch ... cheers ... tim -- TimBlechmann(a)gmx.de ICQ: 96771783 http://www.mokabar.tk After one look at this planet any visitor from outer space would say "I want to see the manager." William S. Burroughs

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[Boost Review] Property tree review
by Jeff Hardy 30 Apr '06

30 Apr '06

I'm going to vote YES on inclusion of the Property Tree library. It has its faults, but I think it's useful enough right now to be part of Boost. * What is your evaluation of the design? The most valuable parts of the library are the parsers and the path functions. I agree with what others have mentioned: the paths should be seperate from the tree. I would be using it to parse various file formats into a tree, and then use my own path language on top of that. For me, then, the parsers are the most important part of this library. Having a (mostly) common structure is very nice. The reading and writing interface is as simple as possible; navigating the tree is also resonably simple. * What is your evaluation of the implementation? I didn't inspect the implementation closely, but I did notice some things during use. I don't like how XML attributes are stored. It should at least be an option to treat <x y="1" z="2" /> and <x> <y>1</y> <z>2</z> </x> as the same structure, without the "<xmlattrs>" node. If there's a confilict between an attribute name and a child element name, then reading/writing should fail. The ability to preserve comments in a file would be very nice. * What is your evaluation of the documentation? A bit sparse. The reference was mostly what I used, but more examples in the docs is always a good idea. A better "mission statement" about what the library is for would help as well; right now, it's not very clear what the author thinks the library is trying to do. The tree descriptions used in the descriptions of the parsers are not very clear; specifying what is in child.second.data() and what is in child.first should be explicit. An example of directly manipulating the tree (without using get()/put()) would be useful as well. * What is your evaluation of the potential usefulness of the library? As a general XML parser, it's not very useful (no namespaces, etc.); as a generic tree, it's not very useful (not general enough). As a utility for parsing various file formats into similar data structures (and writing them back), it's useful. Loading program configuration seems to be the primary goal, and it does that well enough. Trying to get the library to do other things might be stretching it too far. * Did you try to use the library? With what compiler? Did you have any problems? Yes, with MSVC 8. I had no problems beyond my own reading incomprehension. * How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? I adapted the backend of my own configuration system (which previously used TinyXML) to use property trees. However, I didn't use the get*() functions, since I have my own path system already built. * Are you knowledgeable about the problem domain? Resonably. I plan on using the library whether it is accepted into Boost or not, and I'd like to thank Marcin for his work. -Jeff Hardy

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[SoC] new bcp
by Felipe Magno de Almeida 30 Apr '06

30 Apr '06

Hi, I would like to propose creating a new bcp tool. Using the BGL and Wave for handling better the dependencies. Would it have any chance of getting accepted? How much people need this? Thanks, -- Felipe Magno de Almeida

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Google Summer of Code -- Call for Participation / Schedule
by Jeff Garland 30 Apr '06

30 Apr '06

All - (cross-posted to the user list so the larger Boost community sees this) Readers of the developer list may have seen that Boost has been accepted as a participating organization. See http://code.google.com/soc/boost/about.html for the initial Boost Summer of Code page. Now for the hard part. We have a fairly tight schedule to get organized on project proposals and student applications: May 1, 2006: - Application period opens for student proposals May 8, 2006: -Student proposals due by 17:00 Pacific Daylight Time If you are interested in mentoring or doing a project please let us know as soon as possible. If you have project ideas, please update: http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?Google_Summe… If you want to mentor or are planning a student application please either post to the list or to the moderators list (see http://www.boost.org/more/moderators.html for details). Thx! Jeff

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[shmem] New bugfix version in Boost Vault and sandbox cvs
by Ion Gaztañaga 30 Apr '06

30 Apr '06

Hi to all, I've just uploaded to Boost Vault a new version of Shmem (0.92). You can download it here: http://boost-consulting.com/vault/index.php?direction=&order=&directory=Mem… Online documentation here: http://ice.prohosting.com/newfunk/boost/libs/shmem/ Changes in 0.92: ----------------- * Solved bugs in flat_xxx insert functions. * Solved ambiguous windows native function calls with some header orderings. * Changed named_mutex to support scoped_lock. * Added missing <exceptions.hpp> include in named_mutex. * Added get_instance_type, get_instance_length and get_instance_name functions to front-ends. Warning: -------- Peter Johson has detected a problems with Vc8 and global optimization (/Og). Some tests have shown a possible compiler bug. vc7.1 has no problems with /Og. I'm investigating this but meanwhile I recommend disabling /Og (which is deprecated in vc8) when using Shmem. Special thanks to Peter Johnson, Harold Pirtle and Jan Stetka for their help on this version. Regards, Ion

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is_reference current implamentation (why so complex?)
by Dmitry Sychov 30 Apr '06

30 Apr '06

Hello, On my VC 8.0 I've successfully rewrote "is_reference" implementation (from is_reference.hpp) http://www.boost.org/doc/html/boost_typetraits/reference.html#boost_typetra… down to the following: //////////////////////////////////////////////////////////////////// // IMPLEMENTATION template <class T> struct _wrapper {}; template <class T> T& is_ref_fn(_wrapper<T>); char is_ref_fn(...); template <class T> struct _is_ref { static bool const value = sizeof is_ref_fn( _wrapper<T>()) == 1; }; // USAGE void main() { bool is_ref_false = _is_ref<int>::value; bool is_ref_true = _is_ref<int&>::value; } //////////////////////////////////////////////////////////////////// I understand original code - but it uses "is_reference_helper1" and "is_reference_helper2" for the same thing - ie to distingwish between fn pointer size and char size but this could be done in "one pass" (see my is_ref_fn(..) above) also why to compare against fn ptr type and char type when we can compare against 'T' type reference (sizeof(T&) >= 4) and char (sizeof(char) == 1) (see my code) Is it just because on some platforms sizeof(char) != 1 ? If yes we can change 'char' to object with size >= sizeof(T&) to avoid this. Please comment on this. Thanks, Dmitry

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Possible class submission: Sparse Array
by Spencer Collyer 30 Apr '06

30 Apr '06

I'd like to canvas opinions on whether it is worth submitting a class I've developed to Boost. It is a policy-based sparse array class. I'm aware there is a sparse_vector class in the uBLAS library, but when I looked at it it didn't seem to offer the degree of flexibility I needed, so I developed my own. Like a lot of things, it grew a little during development, but I've tried to keep the interface as close to std::vector as seemed sensible. To try and make it as flexible as possible, I've implemented it using four policies, as follows: bounds: This determines what the bounds on the sparse_array are, and how values that exceed them are handled. For example, the 'unbounded' policy allows virtually any positive value of the subscript type to be used, 'bounded' only allows values within the (compile-time specified) max value and throws if a subscript exceeding this is given, while 'clamped' makes such value equal to the max value. iterator: This determines how the limits on iterators are defined. So it is possible to specify that iteration should be over the whole range of the sparse_array, or that it should only be from the lowest assigned subscript to the highest assigned subscript. value: This policy is currently used to define the default value for unassigned elements of the sparse_array, and also to determine how default values are handled in cases such as assigning from one sparse_array to another. storage: This allows the user to specify how the underlying storage for the sparse_array is handled. Currently I only have one policy defined (std_map, which unsurprisingly uses a std::map for the storage), but policies to use hash maps or something akin to Loki's AssocVector could be easily defined. I'd like to know if people would be interested in seeing such a class in Boost before I plunge into writing up the documentation (which is currently pretty sparse, and consists primarily of the comments in the code) and finishing off all the test programs prior to submission. -- <<< Eagles may soar, but weasels don't get sucked into jet engines >>> 5:43pm up 39 days 5:16, 19 users, load average: 0.06, 0.05, 0.04 Registered Linux User #232457 | LFS ID 11703

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