January 2011 - Boost - lists.boost.org

combinations and permutations
by Howard Hinnant 06 Jan '11

06 Jan '11

Warming this up for tr2: http://home.roadrunner.com/~hinnant/combinations.html Comments welcome. Real world use welcome. -Howard

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[graph_parallel] Is a distributed directed edge list possible?
by caustik 06 Jan '11

06 Jan '11

Is it currently possible to represent a highly connected graph where any given vertex may contain more directed edges than can be held in a single process' OutEdgeListS? I see that the distributed version of adjacency_list allows vertices to be distributed across multiple processes in a process group, but I don't see the ability to allow directed edges to be distributed across multiple processes. Is this an intentional limitation? caustik

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Re: [boost] [Boost-testing] [ratio] Intel compilers issue : internal error:assertion failed: copy_template_param_expr: bad expressionkind (shared/edgcpfe/il.c, line 12561)
by vicente.botet 05 Jan '11

05 Jan '11

Hi, sorry for cross-posting, but as no body answered on the Boost testing list ... Best, Vicente ----- Original Message ----- From: "vicente.botet" <vicente.botet(a)wanadoo.fr> To: "Running Boost regression tests" <boost-testing(a)lists.boost.org> Sent: Wednesday, January 05, 2011 8:56 AM Subject: [Boost-testing] [ratio] Intel compilers issue : internal error:assertion failed: copy_template_param_expr: bad expressionkind (shared/edgcpfe/il.c, line 12561) > Hi, > > on Intel compilers I have two test mpl_plus_pass.cpp and ratio_ext_pass.cpp that make this error. > > internal error: assertion failed: copy_template_param_expr: bad expression kind (shared/edgcpfe/il.c, line 12561) > > It seems that there is already an Intel ticket associated (tracker number #82149) see http://software.intel.com/en-us/forums/showthread.php?t=56558. > > Do someone know the state of this ticket and a workaround to this error for the failing tests? > > Thanks, > Vicente > _______________________________________________ > Boost-Testing mailing list > Boost-Testing(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-testing

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[BGL] problem w/ push_relabel_max_flow and floating point capacities
by Marc Schafer 05 Jan '11

05 Jan '11

Using the push_relabel_max_flow feature on graphs that have edge capacities in double or single precision often results in a failed assertion (line 706 push_relabel_max_flow.hpp) on debug builds although the answer provided is correct for builds with assertions disabled. The is_flow() method (line 564, push_relabel_max_flow.hpp) performs some consistency checking after the algorithm completes and there is an assertion that it returns true. The comparisons inside is_flow are done using ==, !=, >, and <. Using a locally modified version, I was able to see that all the cases where is_flow returns false are caused by errors on the order of machine precision. I believe the error is a faulty comparison mechanism inside is_flow rather than a problem with my graphs or the push_relabel_max_flow algorithm. -Marc

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[local] request SVN write access
by Lorenzo Caminiti 05 Jan '11

05 Jan '11

Hello, I would like to request write access to Boost SVN so I can commit Boost.Local. Boost.Local status is as follow: 1) Implemented and compiled on both MSVC and GCC. 2) Documented (using QuickBook). 3) There are examples to exercise all library features. 4) No regression tests yet. 5) Not peer-reviewed yet. I am not familiar with the process so I do not know at which point a Boost library under construction is committed into Boost SVN... please let me know if it is a good idea to commit Boost.Local or if I should wait. Thank you. -- Lorenzo

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[Trac] Request to add chrono component.
by Vicente Botet 05 Jan '11

05 Jan '11

Hi, Rene please, could someone add the chrono component on Trac system associated to my account viboes? Thanks, Vicente -- View this message in context: http://boost.2283326.n4.nabble.com/Trac-Request-to-add-chrono-component-tp3… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[Review][Chrono] Boost.Chrono has been ACCEPTED into Boost
by Anthony Williams 05 Jan '11

05 Jan '11

Hi, I am pleased to announce that Boost.Chrono has been ACCEPTED into Boost. There were a reasonable number of reviews this time, and they were unanimous that Boost.Chrono should be accepted. Boost.Chrono provides the time facilities from the upcoming C++0x standard, so is an important base library. A few changes were requested by the reviewers which should be addressed before this library appears in a Boost release. I know that Vicente has already started working on some of these. The requested changes are: * The documentation needs revising to ensure everything is documented, and it is clear which time source is used for each clock type * The use of double underscores in identifiers should be stopped --- such identifiers are reserved for the implementation. * chrono::monotonic_clock will need renaming chrono::steady_clock to match the C++0x draft * the is_monotonic member of the clock types will need renaming is_steady to match the C++0x draft * Remove operator/ for dividing by a duration * Include examples for I/O in non-English languages * Remove "#if 0" blocks * Address all the "TODO" items in the source * Check the license on the time parsing code, and reimplement if the license is incompatible Apologies to the reviewers if I've missed anything. I would like to thank Vicente for submitting the library and those that took the time to write a review. Anthony -- Author of C++ Concurrency in Action http://www.stdthread.co.uk/book/ just::thread C++0x thread library http://www.stdthread.co.uk Just Software Solutions Ltd http://www.justsoftwaresolutions.co.uk 15 Carrallack Mews, St Just, Cornwall, TR19 7UL, UK. Company No. 5478976

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[Trac] Request to add ratio component.
by Vicente Botet 05 Jan '11

05 Jan '11

Hi, please, could someone add the ratio component on Trac system? Thanks, Vicente -- View this message in context: http://boost.2283326.n4.nabble.com/Trac-Request-to-add-ratio-component-tp31… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[BGL] problem w/ push_relabel_max_flow and floating point capacities
by Marc Schafer 05 Jan '11

05 Jan '11

I am still hoping to hear back from somebody regarding the issues described below. Is the intent to support floating point? If we were to make changes that added tolerances to the comparisons, would they be accepted? -Marc From: Marc Schafer Sent: Wednesday, December 22, 2010 4:22 PM To: 'boost(a)lists.boost.org' Subject: [BGL] problem w/ push_relabel_max_flow and floating point capacities Using the push_relabel_max_flow feature on graphs that have edge capacities in double or single precision often results in a failed assertion (line 706 push_relabel_max_flow.hpp) on debug builds although the answer provided is correct for builds with assertions disabled. The is_flow() method (line 564, push_relabel_max_flow.hpp) performs some consistency checking after the algorithm completes and there is an assertion that it returns true. The comparisons inside is_flow are done using ==, !=, >, and <. Using a locally modified version, I was able to see that all the cases where is_flow returns false are caused by errors on the order of machine precision. I believe the error is a faulty comparison mechanism inside is_flow rather than a problem with my graphs or the push_relabel_max_flow algorithm. -Marc

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[Review] Formal Review of Proposed Boost.Chrono Library Starts TOMORROW
by Anthony Williams 05 Jan '11

05 Jan '11

Hi everyone, The review of Vicente Botet's Chrono library starts TOMORROW (November 6th) and lasts until November 15th unless an extension occurs. What is it? ======== Boost.Chrono aims to implement the new time facilities in C++0x, as proposed in N2661 - A Foundation to Sleep On (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2661.htm) That document provides background and motivation for key design decisions and is the source of a good deal of information in this documentation. See the current C++0x working draft at http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2010/n3126.pdf for details of what was accepted. The Boost.Chrono library provides: * A means to represent time durations: managed by the generic duration class . Examples of time durations include days, minutes, seconds and nanoseconds, which can be represented with a fixed number of clock ticks per unit. All of these units of time duration are united with a generic interface by the duration facility. * A type for representing points in time: time_point. A time_point represents an epoch plus or minus a duration. The library leaves epochs unspecified. A time_point is associated with a clock. * Several clocks, some of which may not be available on a particular platform: system_clock, monotonic_clock and high_resolution_clock. A clock is a pairing of a time_point and duration, and a function which returns a time_point representing now. * To make the timing facilities more generally useful, Boost.Chrono provides a number of additional clocks that are thin wrappers around the operating system's time APIs, thereby allowing the extraction of read (wall clock) time, user CPU time, system CPU time, - process_real_cpu_clock, captures real (wall clock) CPU times. - process_user_cpu_clock, captures user-CPU times. - process_system_cpu_clock, captures system-CPU times. - A tuple-like class __process_cpuclock_, that captures real, user-CPU, and system-CPU times together. - A thread_clock thread monotonic clock, when supported by a platform. * Boost.Chrono also includes typeof registration for duration and time_point to permit using emulated auto with C++03 compilers. * Boost.Chrono also provides I/O for duration and time_point. It builds on <boost/ratio/ratio_io.hpp> to provide readable and flexible formatting and parsing for types in <boost/chrono.hpp>. The duration unit names can be customized through a new facet: duration_punct. Getting the library ============= The latest version of this library may be downloaded from vault: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=chrono… SVN: http://svn.boost.org/svn/boost/sandbox/chrono Boost.Chrono depends on Boost.Ratio http://www.boostpro.com/vault/index.php?action=downloadfile&filename=ratio.… and optionaly Boost.System Header Only http://www.boostpro.com/vault/index.php?action=downloadfile&filename=system…. and the docs may be viewed here HTML: http://svn.boost.org/svn/boost/sandbox/chrono/libs/chrono/doc/html/index.ht… PDF: http://svn.boost.org/svn/boost/sandbox/chrono/libs/chrono/doc/chrono.pdf You can get all these information also (which should avoid some long links) from http://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction#Boost.Chrono Writing a review ================ If you feel this is an interesting library, then please submit your review to the developer list (preferably), or to the review manager. Here are some questions you might want to answer in your review: - 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. Anthony Review Manager for the proposed Boost.Chrono library -- Author of C++ Concurrency in Action http://www.stdthread.co.uk/book/ just::thread C++0x thread library http://www.stdthread.co.uk Just Software Solutions Ltd http://www.justsoftwaresolutions.co.uk 15 Carrallack Mews, St Just, Cornwall, TR19 7UL, UK. Company No. 5478976

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