November 2010 - Boost - lists.preview.boost.org

[clang] Using a stable clang for testing
by Daniel James 16 Nov '10

16 Nov '10

Hi, I posted about this on the testing list, but got no response, so I thought I'd try again here. To properly support clang, we need at least one release tester to use the stable clang release. According to config_info (which is at libs/config/test/config_info.cpp) the stable version is: "Clang version 2.8 (branches/release_28)", but the release tests are using "Clang version 2.8 (trunk 111264)" and "Clang version 2.9 (trunk 119008)". Would it be possible for someone to use the released version? Daniel

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[netlib] 0.8-beta now available!
by Dean Michael Berris 16 Nov '10

16 Nov '10

Hi Everyone, advanced apologies for cross-posting. I've just tagged and uploaded archives of the cpp-netlib 0.8-beta which features: * An asynchronous server template, allowing for server-side streaming of data, asynchronous writing and reading facilities for server-side handlers, and a thread pool implementation that's temporarily using Boost.Asio's io_service for application-specific asynchronous handlers to run from. * A `ready(...)` wrapper to check for whether an asynchronous client's response is ready. The documentation has also been updated to feature a brand-new reference manual detailing the implementation, caveats, and public API of the HTTP client and server templates. You can go ahead and download the 0.8-beta and report issues you find either directly to me or through the mailing lists (Boost.User, Boost.Devel, and the cpp-netlib developers mailing lists). The target release for 0.8 will be this Friday, November 19, 2010. As usual, you can download the 0.8-beta package from GitHub at: https://github.com/cpp-netlib/cpp-netlib/downloads You can also check out the documentation for 0.8-beta at: http://cpp-netlib.github.com/0.8-beta Thanks everyone and I look forward to most appreciated feedback! -- Dean Michael Berris deanberris.com

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[parameter] Boost.Parameter Constructors in Template Classes
by Dean Michael Berris 16 Nov '10

16 Nov '10

Hi Everyone, I'm not sure whether this is more appropriate for the users list or the developers list so I sent the email to both. I'm using Boost's SVN Trunk r66609 and I tried to compile the (attached) file to follow the pattern described by the Boost.Parameter tutorial (http://www.boost.org/doc/libs/1_44_0/libs/parameter/doc/html/index.html#par…) but unfortunately I get an error deep in the preprocessor code that Boost.Parameter uses. What I'm trying to do is to make a template class support parameterized constructors, and only have optional parameters and no required ones. The idea is: template <class Tag> struct base; template <class Tag> struct derived : base<Tag> { BOOST_PARAMETER_CONSTRUCTOR(...); }; Has anybody been able to make this work? Thanks and I definitely hope to hear from you soon. PS. I am also going to file this as a bug in Boost.Parameter so that it doesn't get lost in the mailing list churn. ;) -- Dean Michael Berris deanberris.com

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[Review] Formal Review of Proposed Boost.Chrono Library LAST DAY TODAY
by Anthony Williams 15 Nov '10

15 Nov '10

Hi everyone, The review of Vicente Botet's Chrono library is underway; TODAY IS THE LAST DAY. If you haven't already submitted a review, please do so today. 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> (subject to Vicente rewriting the parsing code under the BSL). 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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[function] function wrapping with no exception safety guarantee
by Daniel Walker 15 Nov '10

15 Nov '10

Hi all, A few weeks ago, there was a request to remove boost::function's dependency on boost::throw_exception when the user ensures that boost::function is always initialized before attempting a call. https://svn.boost.org/trac/boost/ticket/4646 Providing an alternative invocation method in addition to the call operator is an unattractive solution for many reasons; e.g. boost::function would be less function-like syntacticly. Instead, why not provide an alternative function wrapper with no exception safety guarantee and no dependency on boost::throw_exception? Thanks to Boost.Function's implementation design, which uses preprocessor metaprogramming to generate many function wrappers with different arities, it is simple to generate a function wrapper with no exception safety guarantee. I have submitted a feature request with a patch that implements boost::unsafe_function -- a function wrapper with no exception safety guarantee -- along with tests and updated documentation. https://svn.boost.org/trac/boost/ticket/4720 unsafe_function's API and semantics are identical to boost::function except that the behavior of operator() is undefined when uninitialized. Also, swap, constructor and assignment operators have been added to allow an unsafe_function to wrap the target of a boost::function and vice versa. unsafe_function is primarily useful in certain environments in which exceptions and/or compiler optimizations are unavailable, such as some embedded systems. On contemporary PC hardware, unsafe_function typically would not have an advantage over boost::function. For example, with object code generated by gcc -O2, I could only detect a ~1% difference between the two in terms of runtime costs using a simple benchmark; i.e. less than a nanosecond. However, with -O1, unsafe_function costs ~15% less than boost::function due to the lack of overhead from the strong exception safety guarantee. Thoughts? Daniel Walker

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[1.45][thread] TSS showstopper?
by John Maddock 15 Nov '10

15 Nov '10

The recent changes to Boost.Thread in both Trunk and Release branches have broken one of the regex tests: testing.capture-output ..\..\..\bin.v2\libs\regex\test\regex_regress_threaded.test\msvc-10.0\debug\asynch-exceptions-on\threading-multi\regex_regress_threaded.run ====== BEGIN OUTPUT ====== TSS Initialisation failed with message: boost::thread_resource_error **** error return code: -1 ******** errors detected; see standard output for details ******** EXIT STATUS: 1 ====== END OUTPUT ====== I assume it's quite likely that if this effects the regex lib, then it will equally impact on user code that uses thread_specific_pointer? Regards, John.

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Re: [boost] [Boost-commit] svn:boost r66577 - trunk/libs/numeric/ublas/test
by Jürgen Hunold 15 Nov '10

15 Nov '10

Hi David, This commit On Sunday, 14. November 2010 20:34:07 david.bellot(a)gmail.com wrote: > Author: david.bellot > Date: 2010-11-14 14:34:04 EST (Sun, 14 Nov 2010) > New Revision: 66577 > URL: http://svn.boost.org/trac/boost/changeset/66577 > > Log: > update jamfile > > Text files modified: > trunk/libs/numeric/ublas/test/Jamfile.v2 | 2 ++ > 1 files changed, 2 insertions(+), 0 deletions(-) > > Modified: trunk/libs/numeric/ublas/test/Jamfile.v2 > ============================================================================ --- trunk/libs/numeric/ublas/test/Jamfile.v2 (original) > +++ trunk/libs/numeric/ublas/test/Jamfile.v2 2010-11-14 14:34:04 EST > (Sun, 14 Nov 2010) @@ -134,4 +134,6 @@ > ] > [ run test_assignment.cpp > ] > + [ test_boost_ublas_size_0.cpp > + ] > ; just broke the test. First, the call is totally wrong, should read "run test_boost-..." ../libs/numeric/ublas/test/Jamfile.v2:138: in modules.load rule test_boost_ublas_size_0.cpp unknown in module Jamfile</home/hunold/src/devel/boost/libs/numeric/ublas/test>. Second,test_boost_ublas_size_0.cpp is missing from svn. error: Unable to find file or target named error: 'test_boost_ublas_size_0.cpp' error: referred from project at error: '.' Please add at least the missing file. 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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[1.45] Where are we in the release process?
by John Maddock 14 Nov '10

14 Nov '10

I'm asking because someone's just assigned a Boost.Interval issue to me: https://svn.boost.org/trac/boost/ticket/4799#comment:1 Seems like there is a trivial fix in Trunk, but as the library appears not to have been maintained for while, it looks like none of the patches that some folks have applied to Trunk have been merged to release :-( On a related note, I believe there are quite a few old and unmerged changes to the Utility lib as well. We really need to figure out a better way of dealing with this... John.

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Minimizing Dependencies within Generic Classes for Faster and Smaller Programs
by vicente.botet 14 Nov '10

14 Nov '10

Hi, I have found this paper "Minimizing Dependencies within Generic Classes for Faster and Smaller Programs" http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2911.pdf quite iteresting. The gain in performances and reduced space could be considerable. I was wondering if Boost should not take this as a guideline and whether the Boost authors would check his libraries to see if this technique could improve its performances, in particular for all the container and the the forthcomming Boost.Container libraries. I would be interested in knowing if this has been adopted for C==0x containers. Good reading, _____________________ Vicente Juan Botet Escribá http://viboes.blogspot.com/

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Standard stream from C fopen()
by Claude 14 Nov '10

14 Nov '10

Hi! I Use this code for make a standard stream from a C fopen() FILE* : FILE *fd = fopen("Prova", "w"); if (fd) { // io::stream_buffer<io::file_descriptor_source> fpstream (fileno(fd)); //std::istream in (&fpstream); istream in = boost::iostreams::file_descriptor(fileno(fd)); } But I obtain an error (G++ on Linux Ubuntu): [...] error: conversion from ‘boost::iostreams::file_descriptor’ to non-scalar type ‘std::istream’ requested| [...] error: call of overloaded ‘path(const int&)’ is ambiguous| [...] Why? What is the correct method? -- View this message in context: http://boost.2283326.n4.nabble.com/Standard-stream-from-C-fopen-tp3040002p3… Sent from the Boost - Dev mailing list archive at Nabble.com.

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