September 2008 - Boost - lists.boost.org

[Boost][config] Missing file?
by K. Noel Belcourt 20 Sep '08

20 Sep '08

Hi, The tests are all failing due to a missing file. error: Unable to find file or target named error: '../no_nested_friendship_fail.cpp' error: referred from project at error: '/private/tmp/kbelco/boost/boost/libs/config/test/all' Thanks. -- Noel

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Revision history limit?
by Robert Jones 19 Sep '08

19 Sep '08

How far back does the revision history go? I want to examine changes between 1.33.1 and current, but the revision tracker doesn't seem to find the changes I'm looking for. Thanks - Rob.

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[config] BOOST_NO_RTTI patch for the release branch
by Emil Dotchevski 19 Sep '08

19 Sep '08

Please someone take a look at this patch for boost/config for the release branch, which merges the recently added BOOST_NO_RTTI support from trunk, and commit it if everything is OK. Thanks, Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode

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Re: [boost] Answers re BENUM library for automated enum streaming
by Tony D 19 Sep '08

19 Sep '08

Hi all, Should I expect any further feedback re BENUM? David, Marcus: we've discussed specific issues (portability of variadic macros, smart_enum features) - do you have further questions, comments re my replies, or recommended actions before submission for formal review? Should I be doing more to pursue suggestions or solicit feedback? Is anyone else currently reviewing the code in the vault, experiment with usage in a real system, or planning to do so? If so, can we keep in touch re progress? If I don't hear anything to the contrary this week, I'll start doing the preparations for requesting a formal review, specifically my TODO list currently looks like: - better (HTML) docs / simpler usage examples, - clean up comment in headers (doxygen style?)/copyrights, - optimise Info_Container value-to-identifier resolution (have resisted early optimisation as design/functional changes might invalidate), - add a few representative container/feature combinations in easier-to-use macros. BTW / I stumbled across an old submission for "boost_enum" - it seems to "go the whole hog" and address some of the bit-masking issues BENUM does (though not as flexibly ;-P). This contrasts with smart_enum's relative simplicity but cleanliness. I love simplicity (I wrote a cut-down version of BENUM for my introspective preprocessor project which only supports incrementing-from-0 enumerations and no bit masking/ORing because I didn't like the idea of all the extra baggage/inefficiencies), but I think people look to boost for reasonably generic and comprehensive solutions. But, boost_enum work seemed to peter out. smart_enum petered out. Both had much more early interest displayed than BENUM. Should I consider the "enum" space a dead end - "abandon all hope ye who enter here"? Am I wasting everyone's time? My theory is that BENUM has greater potential for widespread end-user acceptance and actual use (despite less portability) because of its enum-like notation, and that that makes BENUM worth pursuing. A view I'd welcome comments on. Thanks, Tony

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[dataflow] new component: multichain
by Manuel Jung 19 Sep '08

19 Sep '08

Hey Stepjan, I'm developing a new component, a multichain, which should be able to chain different components together. Well the fusion and mpl libraries are somewhat new to me, but here ist my approach. I have some problems: When the MultiChain Component is constructed, nothing seems to get constructed, nor connected. Not even the constructors are being called? I really don't have insight, how you relay the signals to chain and from the cahin to the next component. I just copied it from chain.hpp. So i can not connect my multichain at the moment. Please see the example attached. Kind Regards Manuel

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How to implement a reader-writer lock with quick response to writer?
by Bill David 19 Sep '08

19 Sep '08

Question: How to implement a reader-writer lock with quick response to writer? I am using boost1.35.0.( I know 1.36.0 is available, but I failed to build regex in 1.36.0 with VC8. Have you also met this problem in your environment?) I have the following requirements: 1.There are several reader threads and a single writer thread. The writer thread will update shared data periodically. And reader threads may read shared data at any time. 2.As long as writer thread try to update data, all reader thread should be blocked as soon as possible. 3.And reader thread should be blocked during data updating. 4.But reader threads can't be interrupted when they are reading. (i.e. all upcoming reader threads should be blocked, but writer still need wait till the last reader thread in reading finished.) How to implement above scenario with quick response to writer thread? I tried to write the following program to test shared_mutex, but it seems it can't meet my requirement: #include <iostream> using namespace std; #include <boost/thread/shared_mutex.hpp> #include <boost/thread/thread.hpp> #include <boost/thread/xtime.hpp> using namespace boost; boost::shared_mutex rw_mutex; int g_i = 1; void sleep(int iSec) { boost::xtime xt; boost::xtime_get(&xt, boost::TIME_UTC); xt.sec += iSec; boost::thread::sleep(xt); } void read() { while (true) { rw_mutex.lock_shared(); cout << g_i << endl; sleep(3); rw_mutex.unlock_shared(); } } int main() { boost::thread_group threads; for (int i = 0; i < 3; i++) threads.create_thread(read); sleep(1); rw_mutex.lock(); cout << "lock" << endl; g_i = 2; cout << "update g_i to " << g_i << endl; sleep(5); cout << "unlock" << endl; rw_mutex.unlock(); threads.join_all(); } The problem to above solution is it can't respond to writer thread as soon as possible, and only in rare case, it can respond to writer thread in about 6 seconds. The following is a possible output I have gotten: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 lock update g_i to 2 unlock 222 2 2 2 The writer thread should wait no more than 6 seconds, but it seems it can wait more than 20 seconds. Can shared_mutex meet such kind of scenario? If not, do you have any other suggestion?

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multidimensional interval library?
by Roland Schwarz 19 Sep '08

19 Sep '08

Is there a straight forward way to use the interval library for multi dimensions? Specifically I want to express 3d boxes and want to test for intersection and the like. -- _________________________________________ _ _ | Roland Schwarz |_)(_ | aka. speedsnail | \__) | mailto:roland.schwarz@chello.at ________| http://www.blackspace.at

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Is there a parameter to build without compiler version info in the target library name?
by Bill David 19 Sep '08

19 Sep '08

By default, the compiled library have a name like: libboost_thread-gcc41-mt.a but I don't want the gcc41 information in the name as I may need modify my makefile to switch to another environment with gcc4.3. So is there a parameter in bjam to suppress the compiler version info in target library name? Or how will you solve this kind of problem?

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<boost/numeric/ublas/matrix.hpp> includes <iostream>. Is it better not to do so?
by Peng Yu 19 Sep '08

19 Sep '08

Hi, It seems that <boost/numeric/ublas/matrix.hpp> includes <iostream>. I remember that it is better not to include <iostream> but something like <ostream> and <istream>, or even simply <iosfwd>. I'm wondering if this issue shall be corrected in the future version of ublas. Thanks, Peng #include <boost/numeric/ublas/matrix.hpp> int main () { std::cout << "Hello" << std::endl; }

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How to submit a package to boost? (solving quartic, cubic and quadratic equations)
by Peng Yu 18 Sep '08

18 Sep '08

Hi, I made a small utility package that solves quartic, cubic and quadratic equations analytically. It give the multiplicity of the roots and tells whether the roots are zero, no-zero real or non real. I think it is appropriate to submit the package to boost. It might fits the following utility http://www.boost.org/doc/libs/1_35_0/libs/math/doc/sf_and_dist/html/math_to… I'm wondering how to submit my package to boost. Thanks, Peng

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