March 2014 - Boost - lists.preview.boost.org

[GSOC 2014] Boost.Thread / Work-Stealing-Thread-Pool
by Shuxiong Ye 30 Mar '14

30 Mar '14

Hi boost community, My name is Shuxiong Ye, and I am applying GSOC2014. My proposal is here[1]. There are very few comments on it. Any suggestions or questions will be welcome to improve it. Thanks. [1] https://google-melange.appspot.com/gsoc/proposal/review/student/google/gsoc… Shuxiong Ye

2 3

New numeric data type proposal
by Damian Alberto Vicino 30 Mar '14

30 Mar '14

Hi, I work in a simulation tools' research group and we developed a basic data type for handling time representation that we want to share. The data type is kind of a mix between MultiPresicionFloatingPoint and Rational. We are using this kind of data type in concrete simulator implementations because of a theoretic problem with the formalisms we implement, in which the floating point error can not be bounded. We published a paper in Simutools14 a few days ago explaining how this unbound errors are reached under a specific formalism (DEVS) and why they are not easy to detect. I can share the paper if someone interested in the details, or provide some toy examples to discuss. And we are working in showing same kind of errors in other formalisms. A simplified version of the proposed data type is: Number<N, D, M, E> where in the common case the four are some integer-like type. The number can be interpreted as N/D * M * 2^E where N and D are never modified unless required for operation of compatibility. Compatibility operation is called when an operation between 2 numbers having different N/D happens. It can also be thought as a variable radix MPFP. We choose this implementation because when used as replacement of integer or float, it doesn’t decrease significantly the performance. It only decrease significantly when operating with values that were not representable in any of those (if we simplify N/D). I will love to discuss implementation details, alternative ideas to handle the problem (this one worked for us, but sure there is other options too that may be more generic or performant in generic scenarios). Also, I’m up to code the whole thing, and to share the naive implementation we got in our simulator so far to start the discussion. Best regards, Damian Vicino

3 11

[spirit] How to detect Spirit.Qi expressions?
by Andrey Semashev 30 Mar '14

30 Mar '14

Hi, Is there a way to detect at compile time that a certain type is a Boost.Spirit.Qi parser? That includes template expressions and grammars. Basically, I want to detect if qi::parse(b, e, expr) would be a sensible thing to do. I tried this: boost::is_same< typename proto::domain_of< ExpressionT >::type, spirit::qi::domain > But domain_of returns default_domain for Boost.Spirit.Qi template expressions.

2 2

Getting fully uptodate
by Paul A. Bristow 29 Mar '14

29 Mar '14

Sync SHA-1: 44d48257a7eb39837880afb81ceb2153e86e5a8c * Changed Boost.Log to Boost.Sync in the supported compilers section. Fixes #9388. Current HEAD detached, you are working on (no branch). Do you want to create branch now? Chose "no" [detached HEAD 3a9d142] deletions 37 files changed, 4971 deletions(-) delete mode 100644 include/boost/sync/condition_variables/condition_variable.hpp delete mode 100644 include/boost/sync/condition_variables/cv_status.hpp delete mode 100644 include/boost/sync/condition_variables/notify_all_at_thread_exit.hpp delete mode 100644 include/boost/sync/detail/condition_variables/basic_condition_variable_windows.h pp delete mode 100644 include/boost/sync/detail/condition_variables/condition_variable_posix.hpp delete mode 100644 include/boost/sync/detail/condition_variables/condition_variable_windows.hpp delete mode 100644 include/boost/sync/detail/config.hpp delete mode 100644 include/boost/sync/detail/footer.hpp delete mode 100644 include/boost/sync/detail/header.hpp delete mode 100644 include/boost/sync/detail/interlocked.hpp delete mode 100644 include/boost/sync/detail/link_config.hpp delete mode 100644 include/boost/sync/detail/mutexes/basic_mutex_windows.hpp delete mode 100644 include/boost/sync/detail/mutexes/mutex_posix.hpp delete mode 100644 include/boost/sync/detail/mutexes/mutex_windows.hpp delete mode 100644 include/boost/sync/detail/pthread.hpp delete mode 100644 include/boost/sync/detail/system_error.hpp delete mode 100644 include/boost/sync/detail/throw_exception.hpp delete mode 100644 include/boost/sync/detail/time_traits.hpp delete mode 100644 include/boost/sync/detail/time_units.hpp delete mode 100644 include/boost/sync/detail/tss.hpp delete mode 100644 include/boost/sync/detail/waitable_timer.hpp delete mode 100644 include/boost/sync/detail/weak_linkage.hpp delete mode 100644 include/boost/sync/exceptions/lock_error.hpp delete mode 100644 include/boost/sync/exceptions/resource_error.hpp delete mode 100644 include/boost/sync/exceptions/runtime_exception.hpp delete mode 100644 include/boost/sync/exceptions/wait_error.hpp delete mode 100644 include/boost/sync/locks/lock_guard.hpp delete mode 100644 include/boost/sync/locks/lock_guard_fwd.hpp delete mode 100644 include/boost/sync/locks/lock_options.hpp delete mode 100644 include/boost/sync/locks/shared_lock.hpp delete mode 100644 include/boost/sync/locks/shared_lock_fwd.hpp delete mode 100644 include/boost/sync/locks/unique_lock.hpp delete mode 100644 include/boost/sync/locks/unique_lock_fwd.hpp delete mode 100644 include/boost/sync/locks/upgrade_lock.hpp delete mode 100644 include/boost/sync/locks/upgrade_lock_fwd.hpp delete mode 100644 include/boost/sync/mutexes/mutex.hpp delete mode 100644 include/boost/sync/traits/is_condition_variable_compatible.hpp Success (78 ms @ 29-Mar-14 15:49:53) All appears OK, I:\modular-boost\libs\sync>git status HEAD detached from 44d4825 nothing to commit, working directory clean but the Tortoise GIT folder icon for /libs/sync is still red (Red ! icon means "modified"?) so I have committed to develop and it is still red :-( Fumbling, I have tried a git.exe submodule update --init -- "libs/sync" No submodule mapping found in .gitmodules for path 'libs/sync' git did not exit cleanly (exit code 1) (875 ms @ 29-Mar-14 17:09:10) Suggestions as to what I am misunderstanding/doing wrong to get develop branch to a fully uptodate state? Paul PS I have a similar problem with /tools/regression/build where there appear to be no modifications and nothing to revert, but the build folder icon is red, leaving me uneasy that a red face will follow ;-) I've added the build vcide folder items and committed and finally the icon is green. This doesn't feel something that I should have to do in order to get uptodate... so I must be missing something. It would be quicker to clone from scratch! Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 01539 561830 07714330204

2 2

Post-git forking process
by Sohail Somani 29 Mar '14

29 Mar '14

Hey all, Often, I find bugs in Boost that I need to patch manually before the next release. What I used to do before was keep a copy of Boost in my source tree which made this easier: just patch it directly. This made it easy to modify, but annoying to post patches and honestly, they just got lost most of the time. With Git, it should become easier to contribute said patches as well as pull in whichever particular changes I need. However when I attempted such a fork recently, I was a bit lost. As I understood it, the process should have been: 1. Create a fork of https://github.com/boostorg/boost and use this fork in my project 2. Create a fork of the library/libraries I wanted to patch 3. Update the submodules in my boostorg/boost fork to point to my forked libraries 4. Post a pull request for the respective libraries. Once the changes have been accepted, point back to the official boostorg repo I failed terribly, no doubt due to PEBKAC. Is there a chance that someone could write a tutorial or a how-to guide for the recommended process of forking Boost with Git? The main thing I need is the ability to have a patched version of Boost that I can use while the patches are being reviewed/accepted/rejected. Thanks, Sohail

6 20

[variant] assign and access the assigned value simultaneously
by feverzsj 28 Mar '14

28 Mar '14

hi list, for common case: boost::variant<Val,...> var; var = val; Val& v = boost::get<Val>(var); why not supply a interface like: Val& v = var.assign(val); for simplity, and the unnecessary "get" is also elimited. regards -- View this message in context: http://boost.2283326.n4.nabble.com/variant-assign-and-access-the-assigned-v… Sent from the Boost - Dev mailing list archive at Nabble.com.

5 5

1.56 release
by Barend Gehrels 27 Mar '14

27 Mar '14

Hi, The last message about the release schedule was (if I see it correctly) at January 15, and the calendar is empty. Is there more news about the release planning? I'm especially interested in the planning for the 1.56 release. Thanks, Barend Gehrels

9 16

[Parallel Algorithms] Queries regarding the Boost. Thread / Parallel Algorithms
by Naveen 27 Mar '14

27 Mar '14

Hi, I am look into various available reduction algorithms available to make a performance comparison for boost threads. I made a decent search on all the documents available for various reduction algorithms. If there are any specific implementations, please share the details. Regards, *NAVEEN* | Mobile: 832-720-2393 | about.me <http://about.me/naveen.namashivayam> |

1 0

Creating a new(-ish) library in modular boost ?
by Paul A. Bristow 26 Mar '14

26 Mar '14

I have fumbled (and stumbled) trying to create a revised-possibly-to-be-proposed for Boost library in the new modular boost format. So far I have created a folder /modular-boost/svg_plot And copied all the files into it in the new modular format and got the library working OK (compiling, tests, examples, docs etc). Then I created my repository by doing I:\modular-boost\libs>git init svg_plot Initialized empty Git repository in I:/modular-boost/libs/svg_plot/.git/ Then I GIT Added various files, and committed these to my repository. (Should I have pushed?) I tried to tell git to ignore some files like log files, etc (but I don't get a .gitignore file when I think I should - the Tortoise GIT window has various options like .gitignore in the repos root, but no 'OK' button, just a close??? I have a .gitignore at /modular-boot/ but it does not contain the files to ignore (and I would not expect it to). I've set the GITHub default storage directory to \modular-boost\libs but a scan for repos only find modular-boost I went to my GITHUB page and followed the invitation to drag the svg_plot repository onto the page. Some files are listed (but ones I want to ignore) and then all options are unresponsive or greyed out and eventually GITHUB hangs and then crashes :-( So both GIT and I are confused ! Can anyone suggest what sequence of actions I should take to set this up? Thanks Paul Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 01539 561830 07714330204

2 2

[range] Proposal: addition of front(), back(), at(), operator[]
by Adam Wulkiewicz 26 Mar '14

26 Mar '14

Hi, I propose to add the functions described below to the Boost.Range. I found the use of those very convenient WRT the corresponding use of begin() and end(), and a lot more readable. 1. front() returning the reference to the first element precondition (assert): !empty(rng) return *begin(rng); 2. back() returning the reference to the last element precondition (assert): !empty(rng) For BidirectionalRange return *(--end(rng)); For SinglePassRange it could iterate over the range and return the reference to the last element 3. at() returning the reference to the i-th element of the range precondition (throw std::out_of_range or assert): index < size(rng) For RandomAccessRange return *(begin(rng) + index); For SinglePassRange it could iterate over the range and return the required element For me, non-throwing at() would be more useful however this behavior won't be intuitive. So the following should also be provided: 4. sub(), subscript(), el(), element(), at_index(), at_(), index(), indexed(), access(), operator[], ...? the implementation of indexing operator[] same as 3 but instead of throwing an assert would be used The use of operator[] could be similar to this: { using boost::range::subscript_operator; rng[index]; } So not very convenient. But maybe you have a better idea? Regards, Adam

6 14