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

Finite state machine
by arcolight 07 Sep '14

07 Sep '14

Hi all. I have a question about participation in boost libraries. In my embedded project I'm using finite state machine and I tried to use one of the boost implementations of FSM, but they are too big and complex. Main disadvantage of them is usage of dynamic memory allocation, that I can't afford on my CPU and many dependencies, that I can't use on my CPU. CPU is ARM Cortex-M4 with 128K memory, I've no operating system in my project. I have write my own FSM implementation without dynamic memory and dependencies, it's more simple, than boost libraries, but, of course, not so powerful. I've used C++11 standard, specifically variadic templates. My question - Is there some interest in such FSM implementation for boost developers? I'll be very grateful for advice. P.S.: I'm sorry for my english, it's not my native language.

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Autolinking broken in master
by Agustín K-ballo Bergé 06 Sep '14

06 Sep '14

There's a report that autolinking is broken for a fresh recursive checkout of master, due to b2 generating 1.57 libraries while boost/version.hpp still reports the version as 1.56. This commit setting BOOST_VERSION in Jamroot made it to master: https://github.com/boostorg/boost/commit/d9cf98c2074cf8a27017170375c5c825e4… While the corresponding commit for boost/version.hpp didn't: https://github.com/boostorg/config/commit/34e1c7416be2ede7d86f3dcc093a84580… Regards, -- Agustín K-ballo Bergé.- http://talesofcpp.fusionfenix.com

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[iterator] Merge to master
by Andrey Semashev 06 Sep '14

06 Sep '14

Hi, There were lots of changes to Boost.Iterator develop in the last few months. The tests look green for quite some time now. Could these changes be merged to master? I need those changes to merge next/prior in Boost.Utility.

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sqlpp11, 3rd iteration
by Roland Bock 04 Sep '14

04 Sep '14

Dear Boosters, Quite a bit has happened since last I reported about sqlpp11 in this forum [1,2]. I have incorporated a lot of the feedback you gave me, hopefully bringing the library closer to a reviewable state. Source: https://github.com/rbock/sqlpp11 Doku: https://github.com/rbock/sqlpp11/wiki (not at all formal yet) I am hoping for more feedback both here and live at CppCon (http://sched.co/1r4lue3) Here are some noteworthy changes: _Restructuring:_ The code has undergone a major restructuring, leading to a much simpler and thereby much more flexible way to define the structure of SQL statements. As a result, it would now be quite simple to add vendor specific features sqlpp11 connector libraries. Dominique Devienne mentioned array binding for inserts, Johan Baltié mentioned hierarchical searches (both features of Oracle). If you are interested in writing a connector and adding such features, please let me know, I'll walk you through it. _NULL handling:_ Enabled by the restructured code and spurred by the library quince by Michael Shepanski, sqlpp11 can now calculate which result fields can or cannot be NULL. Speaking of which, handling NULL for result values has been discussed a lot. The library now has compile-time configurable behavior, you can choose between an std::optional-like interface and mapping NULL to the trivial value of the result type, e.g. 0 for numbers or "" for strings, see also https://github.com/rbock/sqlpp11/wiki/NULL _Connectors:_ Matthijs wrote a new postgresql connector from scratch, see https://github.com/matthijs/sqlpp11-connector-postgresql The sqlite3 connector received a bunch of corrections, thanks to dirkvdb _Compilers:_ Known to compile with clang>=3.1 and gcc>=4.8. I currently cannot test with MSVC or Intel or others, but if you happen to have the latest top notch version of any of those, I'd be interested in what they have to say about sqlpp11. Cheers, Roland [1]: http://lists.boost.org/Archives/boost/2013/11/208388.php [2]: http://lists.boost.org/Archives/boost/2014/02/211206.php

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[move][unique_ptr] c++14 unique_ptr comes to town
by Ion Gaztañaga 03 Sep '14

03 Sep '14

Hi to all, We've discussed about a boostified version of std::unique_ptr several times in later years. I decided we could not continue with this hole in the Boost toolset and implemented in Boost.Move a unique_ptr that follows the C++14 interface. Commit here: SHA-1: e1da7c5ca1162841f643331af891a9a730eba118 http://github.com/boostorg/move/commit/e1da7c5ca1162841f643331af891a9a730eb… This implementation is also usable from C++03, and apart from the general limitations of the Boost.Move machinery, it should be really uesful for C++03 users. I would like to make this implementation the official boost::unique_ptr implementation, but until the community approves this, it's in boost::movelib namespace (boost::move it's a function so I needed to tweak the namespace name). I would like to thank Howard Hinnant for his great public implementation of the emulated unique_ptr published here: http://home.roadrunner.com/~hinnant/unique_ptr03.html I've ported and refactored Howard's extensive testsuite to implement boost test cases. Really useful to detect many implementation errors and details. I've found unique_ptr much harder to write than I expected. The standard text is really detailed and helps implementors, but things like allowed conversion between pointers and deleters and several ICEs and different SFINAE parties on many compilers made the work quite entertaining. The API is taken from the draft n3797 and the implementation has some differences with the standard. The main reason for this is that I wanted to make unique_ptr as lightweight as possible avoiding external dependencies, as it's interesting to implement idioms like PIMPL. Main attributes and differences with the standard: -> Implemented in two headers: <boost/move/unique_ptr.hpp> and <boost/move/make unique.hpp>. -> <boost/move/unique_ptr.hpp>: Boost.Move is the only heavyweight dependency. Not even that, as unique_ptr.hpp only uses boost/move/utility_core.hpp, that does not depend on any external library excepct BoostConfig and StaticAssert. No TypeTraits, MPL and others. Only Boost.Config, BOOST_STATIC_ASSERT and BOOST_ASSERT are used in the implementation. No standard library headers used (no pointer_traits, memory or other utilities). -> <boost/move/make unique.hpp>: Boost.PP is used in compilers without variadic templates. This is the main reason to have a separate make_unique.hpp header and avoid pulling Boost.PP for c++03 users that only want to have C++11 unique_ptr. -> unique_ptr's "operator <" is implemented as x.get() < y.get() instead of std::less<CT>(). std::less requires <funcional>. std::common_type requires C++11 standard library or some partial emulation based on Boost.TypeOf. I don't think 99,99% of users will notice the difference. For raw pointers, in all our platforms comparisons provide strict weak ordering. If a smart pointer writer specializes std::less for its smart pointer, it should be a law against that. -> It's assignable from literal 0. I found some problems in some compilers trying to write a constructor for that. -> nullptr support is conditional on !defined(BOOST_NO_CXX11_NULLPTR) but I think really should have a Boost nullptr for C++03 compilers. Let's put Meyer's nullptr (http://en.wikibooks.org/wiki/More_C%2B%2B_Idioms/nullptr) in Boost for BOOST_NO_CXX11_NULLPTR compilers. -> unique_ptr<T[]> is convertible to other types when conversion is considered safe. This means that unique_ptr<T[]> is convertible to unique_ptr<const volatile T[]>. Conversion from T[] to U[] is considered safe if remove_cv<T> is the same type as remove_cv<U> and unique_ptr<T[]>::pointer is convertible to unique_ptr<U[]>::pointer. This is a feature that might go to C++17 (http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#2118). Safe conversions in reset() and constructors from pointers are also implemented in unique_ptr<T[]>. I tested the implementation in GCC{4.4, 4.6, 4.7, 4.8} Clang3.4 and MSVC{7.1, 8.0, 9.0, 10.0, 11.0, 12.0} in 32/64 bits, debug/release and C++03/C++11 modes (where applicable). The class documentation is generated with Boost.Move documentation and the most part of it is taken from the standard. I haven't added a tutorial to Boost.Move but I plan to it based on Howard's c++03 unique_ptr tutorial. I hope you find this addition to Boost.Move useful. If you think the implementation is good enough to be the official boost::unique_ptr implementation living in Boost.SmartPtr, porting should be easy, except for the documentation part. That would require either combining somehow handwritten and Quickbook produced documentation or writing new docs for unique_ptr. Best, Ion

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Default documentation settings
by Glen Fernandes 03 Sep '14

03 Sep '14

What is the value of chunk.section.depth used, for those Boost libraries whose documentation is supplied only in QBK form (not the generated HTML from the QBK)? It appears to be 1, i.e. my sections-within-sections are not broken into separate pages. If so, could we make the default <xsl:param>chunk.section.depth=2? Glen

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Can't file issues on trac with Chrome
by legalize+jeeves＠mail.xmission.com 03 Sep '14

03 Sep '14

[Please do not mail me a copy of your followup] Attempting to file a bug report gives me this message: "Captcha Error Submission rejected as potential spam (StopForumSpam says this is spam (username)) Trac thinks your submission might be Spam. To prove otherwise please provide a response to the following." ...but there is no captcha displayed in Chrome. If I attempt again in IE, then the captcha is displayed and I can enter the number and proceed. -- "The Direct3D Graphics Pipeline" free book <http://tinyurl.com/d3d-pipeline> The Computer Graphics Museum <http://computergraphicsmuseum.org> The Terminals Wiki <http://terminals.classiccmp.org> Legalize Adulthood! (my blog) <http://legalizeadulthood.wordpress.com>

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[fusion] Help co-maintaining Fusion modules
by Joel de Guzman 03 Sep '14

03 Sep '14

Hi Y'all, I need help in maintaining Fusion modules, especially those that are co-authored by someone else. For example, the Fusion Invoke module was authored by Tobias Schwinger who is unfortunately inactive now. I need help in maintaining the code, for instance, to adapt to C++11 and C++14. Case in point: https://svn.boost.org/trac/boost/ticket/10443 For that matter, I'd also like to take this opportunity to invite folks here to help out in some more aspects of the libraries I am involved with: Spirit, Fusion and Phoenix. If anyone is interested, please email me privately. THANKS! Regards, -- Joel de Guzman http://www.ciere.com http://boost-spirit.com http://www.cycfi.com/

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[spinlock] concurrent_unordered_map is ready for review
by Niall Douglas 02 Sep '14

02 Sep '14

Dear Boost, CC: Howard, Jonathan for N3645 enhancements It has taken me far longer than I expected, however I believe that proposed boost::concurrent_unordered_map is ready for community feedback, with its unit test suite passing all green on the thread sanitiser and 92% coverage including exception safety tests. The main documentation page with the API and a lengthy explanation of the caveats in this design can be viewed at https://ci.nedprod.com/view/Boost%20Thread-Expected-Permit/job/Boost.S pinlock%20Test%20Linux%20GCC%204.8/doxygen/classboost_1_1spinlock_1_1c oncurrent__unordered__map.html Performance improves linearly to CPU cores at a slope of about 0.9. I only have four core hardware available to me, if someone could tell me how it scales to eight cores or more I would be very interested. Source code is at https://github.com/ned14/boost.spinlock. Tested on GCC 4.8, clang 3.4 and VS2013. Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

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Unable to find the boost.fsm library and turnstile example
by Aniket Pugaonkar 02 Sep '14

02 Sep '14

Hi, I wanted to implement a simple fsm using boost. i read the boost fsm doc http://boost-extension.redshoelace.com/docs/boost/fsm/doc/state_machine.html http://boost-extension.redshoelace.com/docs/boost/fsm/doc/reference.html but I couldnt locate the header files. Are the fsm library and other template classes located in boost statechart folder ? When I did a find in the subdirectories, I found this: boost version: 1.55 find . -name state_machine.hpp ./boost/msm/back/state_machine.hpp ./boost/spirit/home/support/detail/lexer/state_machine.hpp ./boost/statechart/state_machine.hpp ./libs/mpl/example/fsm/state_machine.hpp (1) Which one should I use to implement a simple FSM? (2) Also I couldnt find the turnstile example which they said is supposed to be in libs/fsm/examples/Turnstile folder. Can anyone please tell me the correct path and location ? [1]: http://boost-extension.redshoelace.com/docs/boost/fsm/doc/state_machine.html Regards Aniket -- Thanks and regards, Aniket Pugaonkar

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