June 2012 - Boost - lists.preview.boost.org

[Who's using boost?] Sankel Software
by David Sankel 08 Jun '12

08 Jun '12

Sankel Software Sankel Software has been using boost for over 10 years to develop high performance and customized CAD/CAM applications, industrial control, computer artistry, and business software. If it wasn't for Boost, we would have stopped using C++ long ago. Its libraries allow us to write more concise code and, more importantly, give us the tools to implement higher level constructs such as denotational semantics based, top-down program design. Home Page: http://sankelsoftware.com Here is a list of the libraries we currently use: - Boost.Any - Boost.Serialization - Boost.Array - Boost.Assign - Boost.Bind - Boost.Integer - Boost.DateTime - Boost.Foreach - Boost.Function - Boost.Fusion - Boost.Variant - Boost.Optional - Boost.LexicalCast - Boost.SmartPtr - Boost.Math - Boost.MPL - Boost.MultiIndex - Boost.Operators - Boost.Signals2 - Boost.Thread - Boost.Tuple - Boost.TypeTraits - Boost.Utility - David -- David Sankel Sankel Software www.sankelsoftware.com 585 617 4748 (Office)

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[1.50.0] Release branch open for bug fixes and doc updates
by Beman Dawes 07 Jun '12

07 Jun '12

The final release is scheduled for Monday, June 25th. The release candidate is scheduled to to be built Thursday, June 21st. That gives us two weeks to apply post-beta bug fixes and doc updates. Let's try a slightly more streamlined procedure for this post-beta period; until Monday, June 18th permission is not required to merge bug fixes and documentation updates. Starting June 18th permission of a release manager is required for all merges. As always, New libraries and new features are not allowed during a post-beta period. Thanks, --Beman

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[1.50] Can't build quickbook PDF docs.
by John Maddock 07 Jun '12

07 Jun '12

Just a note that the quickbook docs don't build as a PDF due to XML validation failures at the FO stage: fop.render.pdf ..\..\bin.v2\tools\quickbook\doc\msvc-10.0\debug\link-static\threading-multi\quickbook.pdf M:/download/programs/xep/xep.bat ..\..\bin.v2\tools\quickbook\doc\msvc-10.0\debug\link-static\threading-multi\quickbook.fo ..\..\bin.v2\tools\quickbook\doc\msvc-10.0\debug\link-static\threading-multi\quickbook.pdf (document [system-id file:/M:/data/boost/branches/release/doc/pdf/../../bin.v2/tools/quickbook/doc/msvc-10.0/debug/link-static/threading-multi/quickbook.fo] (validate [error] Element 'fo:block' cannot be a child of 'fo:root'. [error] Element 'fo:block' cannot be a child of 'fo:root'. [error] Element 'fo:block' cannot be a child of 'fo:root'. [error] Attribute 'space-before.optimum' cannot occur at element 'fo:block'. [error] Attribute 'space-before.minimum' cannot occur at element 'fo:block'. [error] Attribute 'space-before.maximum' cannot occur at element 'fo:block'. [error] Attribute 'id' cannot occur at element 'fo:inline'. [error] Attribute 'break-before' cannot occur at element 'fo:block'. [error] Attribute 'id' cannot occur at element 'fo:block'. [error] Attribute 'margin-left' cannot occur at element 'fo:block'. [error] Attribute 'font-family' cannot occur at element 'fo:block'. [error] Attribute 'keep-together.within-column' cannot occur at element 'fo:block'. [error] Attribute 'keep-with-next.within-column' cannot occur at element 'fo:block'. [error] Attribute 'font-family' cannot occur at element 'fo:block'. [error] Attribute 'font-weight' cannot occur at element 'fo:block'. [error] Attribute 'keep-with-next.within-column' cannot occur at element 'fo:block'. [error] Attribute 'space-before.minimum' cannot occur at element 'fo:block'. [error] Attribute 'space-before.optimum' cannot occur at element 'fo:block'. [error] Attribute 'space-before.maximum' cannot occur at element 'fo:block'. [error] Attribute 'text-align' cannot occur at element 'fo:block'. [error] Attribute 'start-indent' cannot occur at element 'fo:block'. [error] Attribute 'marker-class-name' cannot occur at element 'fo:marker'. [error] Element 'fo:marker' should be a descendant of 'flow'. [error] Attribute 'font-size' cannot occur at element 'fo:block'. [error] Attribute 'id' cannot occur at element 'fo:inline'. [error] Attribute 'internal-destination' cannot occur at element 'fo:basic-link'. [error] Attribute 'color' cannot occur at element 'fo:inline'. [error] Attribute 'space-before.optimum' cannot occur at element 'fo:block'. [error] Attribute 'space-before.minimum' cannot occur at element 'fo:block'. [error] Attribute 'space-before.maximum' cannot occur at element 'fo:block'. [error] Attribute 'id' cannot occur at element 'fo:block'. [error] Attribute 'border-color' cannot occur at element 'fo:block'. [error] Attribute 'border-width' cannot occur at element 'fo:block'. [error] Attribute 'border-style' cannot occur at element 'fo:block'. [error] Attribute 'padding-left' cannot occur at element 'fo:block'. [error] Attribute 'padding-right' cannot occur at element 'fo:block'. [error] Attribute 'padding-top' cannot occur at element 'fo:block'. [error] Attribute 'padding-bottom' cannot occur at element 'fo:block'. [error] Attribute 'widows' cannot occur at element 'fo:block'. [error] Attribute 'orphans' cannot occur at element 'fo:block'. [error] Attribute 'font-size' cannot occur at element 'fo:block'. [error] Attribute 'hyphenate' cannot occur at element 'fo:block'. etc. Any ideas? Thanks, John.

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status of sp_counted_base_solaris.hpp
by Graham Bennett 07 Jun '12

07 Jun '12

Hi all, I'm interested in getting boost::shared_ptr to use atomic ops on Solaris. I notice there is an implementation using the OS-provided atomics in boost/detail/sp_counted_base_solaris.hpp, but it doesn't seem to be included. According to this thread: http://lists.boost.org/Archives/boost/2006/07/107144.php, it seems the reason might be that it wasn't possible to come up with a proper preprocessor condition to include it on the right versions of Solaris. I'm considering modifying my boost installation to include this header on Solaris - does anyone know of any issues with the code, or can they confirm that it has been well tested? Are there any other reasons for its omission? Thanks, Graham -- Graham Bennett

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[review] Multiprecision review scheduled for June 8th - 17th, 2012
by Jeffrey Lee Hellrung, Jr. 07 Jun '12

07 Jun '12

Hi all, The review of the proposed Boost.Multiprecision library authored by John Maddock and Christopher Kormanyos has been scheduled for June 8th - June 17th, 2012 and will be managed by myself. >From the Introduction: -------- "The Multiprecision Library provides *User-defined* integer, rational and floating-point C++ types which try to emulate as closely as practicable the C++ built-in types, but provide for more range and precision. Depending upon the number type, precision may be arbitrarily large (limited only by available memory), fixed at compile time values, for example 50 decimal digits, or a variable controlled at run-time by member functions. The types are expression-template-enabled for better performance than naive user-defined types." -------- And from the original formal review request from John: -------- Features: * Expression template enabled front end. * Support for Integer, Rational and Floating Point types. Supported Integer backends: * GMP. * Libtommath. * cpp_int. cpp_int is an all C++ Boost licensed backend, supports both arbitrary precision types (with Allocator support), and signed and unsigned fixed precision types (with no memory allocation). There are also some integer specific functions - for Miller Rabin testing, bit fiddling, random numbers. Plus interoperability with Boost.Rational (though that loses the expression template frontend). Supported Rational Backends: * GMP * libtommath * cpp_int (as above) Supported Floating point backends: * GMP * MPFR * cpp_dec_float cpp_dec_float is an all C++ Boost licensed type, adapted from Christopher Kormanyos' e_float code (published in TOMS last year). All the floating point types, have full std lib support (cos sin exp, pow etc), as well as full interoperability with Boost.Math. There's nothing in principal to prevent extension to complex numbers and interval arithmetic types (plus any other number types I've forgotten!), but I've run out of energy for now ;-) Code is in the sandbox under /big_number/. Docs can be viewed online here: http://svn.boost.org/svn/boost/sandbox/big_number/libs/multiprecision/doc/h… -------- I hope everyone interested can reserve some time to read through the documentation, try the code out, and post a formal review, either during the formal review window or before. I expect to conduct the review in the "traditional" manner, i.e., entirely within the regular boost developers' mailing list (boost(a)lists.boost.org) I will send a reminder of review process details closer to the review window. Thanks! - Jeff

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1.50.0 beta 1 Beta release available
by Beman Dawes 06 Jun '12

06 Jun '12

Boost release 1.50.0 beta 1 is now available from SourceForge See http://sourceforge.net/projects/boost/files/ This release contains 4 new libraries (Algorithm, Functional/OverloadedFunction, LocalFunction, Utility/IdentityType) and numerous enhancements and bug fixes for existing libraries. For details of what's in the release, see http://beta.boost.org/users/history/version_1_50_0.html. Note that the links to files on this web page are for the final release - use the SourceForge link above to get the beta files. Please download the beta, give it a try, and report any problems you encounter. Thanks, -- The Boost Release Team

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[1.50.0] Beta 1 release candidates available for testing
by Beman Dawes 06 Jun '12

06 Jun '12

Release candidate files for 1.50.0 beta 1 are available at http://boost.cowic.de/rc/ As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. This helps ensure the candidates build OK before we push them out to SourceForge. Thanks, --Beman --PS: I tested the 7z version, and it built without errors on Win7/VC++ Express 2010 sp1

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Re: [boost] [review] Multiprecision review scheduled for June 8th - 17th, 2012
by John Maddock 06 Jun '12

06 Jun '12

>>Let us know as soon as you have some results. > > Tested the time taken to run through all the Boost.Math Bessel function > tests, with type double, real_concept (a simple wrapper around double from > Boost.Math's test suite) and mp_number<float_backend<double> > (a trivial > mp_number backend that wraps a floating point type): > > Time for double = 0.0157549 seconds > Time for real_concept = 0.0166421 seconds > Time for float_backend<double> = 0.0408635 seconds > Time for float_backend<double> - no expression templates = 0.0253047 > seconds > > So as you can see, expression templates are a dis-optimization for such > simple types, and even without them you take a noticeable hit: I'm a > little disappointed by this, but not that surprised, mp_number is a rather > heavyweight solution for lightweight types if you see what I mean. > > In any case I'll have a look at the assembly to see if there are any > obvious non-optimizations going on. >From a quick casual look it appears as though the extra time is going in functions not expanded inline - that's certainly the case for the expression template unpacking code. Seems like there may be some small opportunity for optimization of the comparison operators as well (i.e. not evaluating in terms of a compare() function). However, that latter case is only appropriate for exceptionally lightweight backends, for most typical extended precision backends, non of this will make the slightest difference at all... John.

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[COUNTERTREE + SUBALLOCATOR ] New Version
by Francisco José Tapia 05 Jun '12

05 Jun '12

Hi this message is to announce the new version of the [countertree + suballocator] library. You can find in (http://dl.dropbox.com/u/8437476/works/countertree/index.html)<http://dl.dropbox.com/u/8437476/works/countertree/index.html> When I was writing the document explaining the allocator's algorithm. I reexamined my code , and It run well and have an easy interface , but the internal design was obscure and difficult to understand. Due this, I decided redesign it in order to make it clear and easy to understand. I changed too the version of the GCC compiler form the 4.6 to 4.7, and the machine used for the benchmarks. My old computer, where I developed the code, had a good cache but a bad bus memory (Single channel 533Mz), and this introduce a distortion in the comparison of some algorithms. The new machine is a QuadCore with 8M of cache and 8G dual channel 1066 MHz. The results obtained are more similar to the obtained in a modern machine. I added a new point to the documentation explaining the additional features of the countertree set, multiset, map and multimap with two examples. You can find in ( http://dl.dropbox.com/u/8437476/works/countertree/ordered.html#functionality) For the people who don't know this project, this is a description : *COUNTERTREE* This library is an implementation of a binary red-black counter tree. This tree have an additional counter in each leaf. This permit the access to the elements by the position, like in a vector. It is a random access container with random access iterators . With this tree we have vectors (cntree::vector_tree) with identical interface than std::vector. The vector_tree have the same speed inserting and deleting in any position (all the operations are O(log N)).It is slower than std:vector inserting and deleting at end, but much faster for to insert and delete in any other position. With ordered information, we have in the cntree namespace the classes set, multiset, map and multimap, with identical interface than the STL classes, with the plus of access to the elements by position, like in a vector. The iterators are random access , and you can subtract two iterators in a O(log N) time for to know the number of nodes between them (even with the end( ) and rend( ) iterators) *SUBALLOCATOR* The allocator is the data structure defined in the STL, as interface between the data structures and the memory provided by the Operating System (O.S.). The allocator manages the memory received from the Operating System, and the memory requested in the allocate operations and the memory returned in the deallocate operations. To write an allocator for to manage a wide range of size elements and a big number of elements (several millions) of each size in a fast way, it's a very difficult task. When the number of elements grows, many allocators begin to have speed problems. For to improve the speed allocating of the small size elements, many allocators request to the Operating System big chucks of memory. With this, the allocator don't need request memory to the operating system for each allocation. But many allocators don't return well the unused chucks of memory to the Operating System and the memory used by the allocator is the maximum used, never decrease . These allocators are named pool allocators. If you have a small number of elements, you have a small problem, small resources and small time operations. But, if you have several millions of elements allocated, perhaps you are using several GB of memory. Running a program with GB of memory don't used, because the allocator don't return the memory request, is a great waste of resources. This problem is specially important in two environments : - When you have a limited resources, as occurs in the mobile phones, pads , tablets... - When the programs must run continuously in a multitask environment If you use an allocator for the allocation of variable size elements, and a pool allocator for the allocation of fixed size elements, this improve the speed, but increase the memory consumption, which is the sum of the maximum memory of the pool allocator and the memory used by the allocator. If the pool allocator don't return to the Operating System the unused memory, this can't be reused by the allocator. The *suballocator is a solution to these problems*, and others memory problems described in the suballocator page. The suballocator is a layer between the allocator and the data structures, compatible with any allocator with the STL definition. The suballocator request memory to the allocator, and return to it when unused. With the suballocator a) *We have a very fast allocation* *(around 2 times faster than the std::allocator of GCC 4.7, CLANG 3.0 and 3 times than Visual Studio 10 *See details in the *Suballocator Benchmark<http://dl.dropbox.com/u/8437476/works/countertree/suballocator.html#benchma…> *)* b) *Return memory to the allocator, for to be used by others types of data*. Many allocators, return this memory to the Operating System, and decrease the memory used by the program, *( as you can see in the *Suballocator Benchmark <http://dl.dropbox.com/u/8437476/works/countertree/suballocator.html#benchma…> *)* c) *You can use with any allocator if it is according with the STL definition*. The suballocator provides speed and memory management to any allocator d) Even the time of the allocation is a small part of the time spent in the insertion in a std::set, the suballocator obtain time reductions over over the 30% respect the std::allocator. The secret is the cache performance due to the data locality improvement. *COUNTERTREE + SUBALLOCATOR* The join of the two ideas provide us data structures with a suballocator built-in. They are, in the namespace cntree, the vector_tree_pool, set_pool, multiset_pool,map_pool and multimap_pool, with identical interface than the STL classes but better performance. Tray it. It fast, useful and easy to understand and use,. They are the STL classes with a few additional functions. I had checked this code with GCC 4.7 (32 and 64) , CLANG/LLVM 3.0 and Visual Studio 1010 (32 and 64). If you find any error or problem in the code , the documentation or in any other part ( as friendly do Mr Rene Rivera in the first version). Please mail me ( fjtapia(a)gmail.com) or if you mail Boost, please insert [countertree] in the head of the message. Some days I have not time to read all messages arrived to my mail, but if I see that I detect and respond first. If you have some idea, or have any comment, please mail me, always two legs run more than only one in the pursuit of the goal, to be useful to the community of programmers in the same way than our predecessors had been useful to us. Sincerely yours Francisco Tapia fjtapia(a)gmail.com

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[Who's Using Boost?] FaceBook
by Brian Wood 05 Jun '12

05 Jun '12

Thanks for the link. I notice Folly has an IntrusiveList derived from boost::intrusive::list. We have a nickname for boost::intrusive::list also -- ilist. Perhaps there are others who have done the same? Shalom, Brian Wood Ebenezer Enterprises http://webEbenezer.net

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[bind] Move Parameters?
by Daniel Larimer 05 Jun '12

05 Jun '12

Say I have some synchronous code like this: vector<data> v; some_method( std::move(v) ) Now I want to call to make that some_method call asynchronous so what I really want is function<void()> f = bind( some_method, boost::rref( std::move(v) ) ) asio_io_service.post(f); // performs async move of v into some_method asio_io_service.post(f); // undefined, or throw bound parameter has already moved... As far as I can tell there is no current support for anything like this, and I think it could be very useful. Dan

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Re: [boost] [git/modularization] Suggested names for branches?
by Sean Chittenden 04 Jun '12

04 Jun '12

> The three branches in question, with the git-flow names in parens, > were the main development branch (develop), release prep branches (?), > and the branch with actual releases (master). > > Is there a better usual convention for these names? I have a vague > memory of someone mentioning "master" for the main development branch, > "release" for the branch with the actual releases, and maybe > "beta-x.xx.x" for release prep branches. re: git flow branch names, I'd advocate for their use simply because it matches all of the external training material (videos, docs, flow charts, etc) available regarding the use of git flow (and it reduces the friction for getting initially setup). I agree that they aren't ideal and much prefer the naming convention used by the FreeBSD project (where branch names indicate a stable API, 9-STABLE, 8-STABLE, etc., vs -CURRENT), but I'd stick with the default names for now and then in a release or three consider changing from the defaults to something boost specific. -sc # Initialize default git flow branches git flow init -d # From project/.git/config [gitflow "branch"] master = master develop = develop [gitflow "prefix"] feature = feature/ release = release/ hotfix = hotfix/ support = support/ versiontag = -- Sean Chittenden sean(a)chittenden.org

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folly (Facebook's open source C++ library)
by Tudor Bosman 04 Jun '12

04 Jun '12

https://www.facebook.com/notes/facebook-engineering/folly-the-facebook-open… I'm Tudor, one of the folly developers. I'll try to answer your questions or poke the appropriate people :) Re: "NO EXCEPTIONS" in the README -- the README file was intended for internal Facebook contributors (hence stray references to internal paths), and "NO EXCEPTIONS" referred to "no exceptions to the rules above", NOT "no C++ exceptions". Will fix / clarify / remove soon. -Tudor.

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[Who's Using Boost?] FaceBook
by Dave Abrahams 04 Jun '12

04 Jun '12

as noted in https://www.facebook.com/notes/facebook-engineering/folly-the-facebook-open… -- Dave Abrahams BoostPro Computing http://www.boostpro.com

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asio::epoll_reactor::complete_operations_and_timers() - thread saftey
by Hite, Christopher 04 Jun '12

04 Jun '12

I thought I'd take a look at the epoll_reactor implementation. I thinking of using asio proactor style code to use kernel bypass libraries. I wanted to see how you do async IO with a pool of threads. I think I see a bug. None of the operations there done outside of the lock seem thread safe. They unsafely modify linked lists. lock.unlock(); read_op_queue_.complete_operations(); write_op_queue_.complete_operations(); except_op_queue_.complete_operations(); Chris

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[python] run python script from bjam
by lcaminiti 03 Jun '12

03 Jun '12

Hello all, I build a Boost.Python module and install it using bjam as follow: python-extension pydef : deduced_params_pydef.cpp : <library>/boost/python//boost_python <library>/boost/regex//boost_regex <link>shared:<define>BOOST_REGEX_DYN_LINK=1 ; install pydef_install : pydef : <install-dependencies>on <install-type>SHARED_LIB <install-type>PYTHON_EXTENSION <location>. ; I the same dir I have a python script deduced_params_pydef.py which will import the module and test it. How do I run the python script automatically from bjam so to fully compile and test the module that my code generates? Something like (this doesn't work of course): # Make sure pydef target is built first, then runs python deduced_params_pydef.py run-py pydef_install : deduced_params_pydef.py ; Thanks a lot. --Lorenzo -- View this message in context: http://boost.2283326.n4.nabble.com/boost-python-run-python-script-from-bjam… Sent from the Boost - Dev mailing list archive at Nabble.com.

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boost.unordered undocumented methods
by niXman 03 Jun '12

03 Jun '12

Hello! In the documentation for boost-1.49.0 the following methods are not documented: https://github.com/ryppl/boost-svn/blob/master/boost/unordered/unordered_ma… https://github.com/ryppl/boost-svn/blob/master/boost/unordered/unordered_ma… https://github.com/ryppl/boost-svn/blob/master/boost/unordered/unordered_ma… https://github.com/ryppl/boost-svn/blob/master/boost/unordered/unordered_ma… https://github.com/ryppl/boost-svn/blob/master/boost/unordered/unordered_se… https://github.com/ryppl/boost-svn/blob/master/boost/unordered/unordered_se… https://github.com/ryppl/boost-svn/blob/master/boost/unordered/unordered_se… https://github.com/ryppl/boost-svn/blob/master/boost/unordered/unordered_se… -- Regards, niXman ___________________________________________________ Dual-target(i686/x86_64) MinGW compilers for i686/x86_64 hosts: http://sourceforge.net/projects/mingwbuilds/

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Is there interest in copyable type_info that does not require RTTI (was: Is there interest in typeid(TYPE).name() like function that does not require RTTI)
by Antony Polukhin 03 Jun '12

03 Jun '12

Hi, There is a detail/sp_typeinfo.hpp which is not documented, and has some drawbacks. This header provides type_info like class that can be used with RTTI disabled. I am proposing to refactor this header, move it to utility/template_info.hpp and document it as a separate utility. Refactored header will provide classes template_info_ptr, template_info<T>, type_info_ptr and free function get_template_info<T>() Advantages: 1) more portable and reliable than detail::sp_typeinfo (no sp_typeid_<T>::ti_ public static variable) 2) copyable type_info like classes 3) has all the type_info functions + name_demangle 4) works with disabled RTTI 5) better functionality: no need to write macros like: #if defined( BOOST_NO_TYPEID ) # define BOOST_FUNCTION_COMPARE_TYPE_ID(X,Y) ((X)==(Y)) #elif (defined(__GNUC__) && __GNUC__ >= 3) \ || defined(_AIX) \ || ( defined(__sgi) && defined(__host_mips)) # include <cstring> # define BOOST_FUNCTION_COMPARE_TYPE_ID(X,Y) \ (std::strcmp((X).name(),(Y).name()) == 0) # else # define BOOST_FUNCTION_COMPARE_TYPE_ID(X,Y) ((X)==(Y)) #endif 6) user can explicitly chose between template_info+template_info_ptr and type_info+type_info_ptr 7) no macro (get_template_info<T>() instead of &BOOST_SP_TYPEINFO(T) ) Disadvantages: 1) Does not work with variables (but you can still use BOOST_TEMPLATE_INFO_PTR(BOOST_TYPEOF(var))) 2) BOOST_CURRENT_FUNCTION produces long strings, and that could lead to code bloat when RTTI disabled Some usage examples: int main () { // Portable way that works with and without RTTI: copyable_type_info t1 = get_template_info<std::string>(); copyable_type_info t2 = get_template_info<int>(); // class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > std::cerr << t1.name_demangled() << '\n'; // int std::cerr << t2.name_demangled() << '\n'; // false std::cerr << (t1 == t2) << '\n'; // true std::cerr << (t1 != t2) << '\n'; copyable_type_info t1_copy = t1; // .?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@ std::cerr << get_template_info<std::string>().name() << '\n'; // class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > std::cerr << get_template_info<std::string>().name_demangled() << '\n'; // explicitly using no-RTTI methods // int>::name_begin(void) std::cerr << template_info<int>::name_begin() << '\n'; // int std::cerr << template_info<int>::name_demangled() << '\n'; // class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >::name_begin(void) std::cerr << template_info<std::string>::name_begin() << '\n'; // class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > std::cerr << template_info<std::string>::name_demangled() << '\n'; template_info_ptr p1 = template_info<int>::construct(); template_info_ptr p2 = template_info<std::string>::construct(); std::cerr << (p1 == p2) << '\n'; std::cerr << (p1 != p2) << '\n'; } If there is interest, I can commit code to sandbox and request for review. P.S.: As I know, Boost.Function, Boost.Shared_ptr and Boost.Exception use code similar to what I am proposing. Following libraries use typeid() and can benefit from using proposed classes: Boost.MSM, Boost.Math, Boost.Test, Boost.Graph, Boost.Units, Boost.XPressive, Boost.Any, Boost.Statechart -- Best regards, Antony Polukhin

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[filesystem] Linker error against std::codecvt in VS2012 RC
by Lars Viklund 02 Jun '12

02 Jun '12

Hi list, I foolishly installed the Visual Studio 2012 RC yesterday night and made an overnight build of Boost. It seems like there's something awry, as I'm getting a mysterious linker error in Filesystem's path.obj [1], even in a fresh empty testbed project. I'm linking Boost statically and the CRT dynamically. If I link the CRT statically, the linker error goes away. Has anyone else installed this software and can reproduce this problem? I'm building Boost against trunk, r78785. I dread to think of the horror that I will have go through in actually reporting a bug against the runtime itself :( [1] 1>libboost_filesystem-vc110-mt-gd-1_50.lib(path.obj) : error LNK2001: unresolved external symbol "protected: virtual int __thiscall std::codecvt<wchar_t,char,int>::do_length(int const &,char const *,char const *,unsigned int)const " (?do_length@?$codecvt@_WDH@std@@MBEHABHPBD1I@Z) -- Lars Viklund | zao(a)acc.umu.se

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[msm]entry point pseudo states and events (Re: [msm] orthogonal region and event consume)
by Takatoshi Kondo 02 Jun '12

02 Jun '12

Hi Christophe, I changed the subject. Current topic isn't concerned with orthogonal region directly. On Thu, May 31, 2012 at 5:43 AM, Christophe Henry <christophe.j.henry(a)googlemail.com> wrote: > Hi Takatoshi, > > >>> I read your ticket. Note that it's not UML-conform to have 2 transitions >>> originating from Entry1 (11-08-06.pdf §15.3.8 page 551). >>> After reading the Standard again twice, I realized that no example >>> provided >>> there displays any event on both transitions, which is really bad if it's >>> what they mean. I need to have a look at other literature. > > >> I read the section that you mentioned carefully. My interpretation of >> UML specification is different from yours. >> It's really difficult to explain my interpretation. So, I draw the >> diagram. See the attached file. >> Am I misunderstanding? > > > I will not pretend I have the perfect understanding of the Standard. Here's > my take. I also saw the sentence on top of your diagram and didn't fully > understand it when reading the Standard. There is also the following > sentence in the Standard: > > "An entry pseudostate is used to join an external transition terminating on > that entry point to an internal transition > emanating from that entry point". > > Which sounds logical because on your diagram the regions would not be > orthogonal. > > This means you cannot have transitions triggered by different events leading > to the entry point, not can you have different transitions leaving it. You > will need more entry points. > > Caution: I am far from being sure I got it right. That's why I precised my > definition of it in the doc. The implemented solution has the advantage that > you have the normal transition handling, including multiple transitions and > guards, events with data, base events, etc. > What you don't have is entry in multiple regions, which only the fork > currently provides, at the cost of lesser encapsulation. > Correct or not, this is the part of the Standard I chose to implement pseudo > entries. > > To be honest, I'm not of fan of pseudo entries. I prefer the vastly superior > solution of entering a submachine the "normal" way, then letting a > templatized, enable_if'd on_entry of the submachine do something clever with > the event at compile-time. Aha! I completely overlooked such approach. For example, we can choose the initial state in submachine using mpl and initial_state typedef instead of using entry_pseudo_state. I believe that I've understood your design decisions. I also think that following the UML standard blindly is not essential. >> My goal is to improve sub-machines' re-usability. If we want to reuse >> sub-machines in another state machines, sub-machines shouldn't know >> the outside information. > > > I agree but is it the case? I mean, if you send normal events to your > submachine through your outer machine, it also needs to know them, right? > I understand this as: "hi, I'm a submachine and I provide the following > entry points: Entry1 requires Event1, Entry2 requires Event2, etc.". A bit > like function parameters. I wanted to explain that as follows: "hi, I'm a submachine and I provide the following entry points: Entry1 accepts any events. Because I don't care that. " Let me introduce more practical example that requires entry_pseudo_state. ScanFinger.png is a sub-machine. This sub-machine's primary purpose is to scan fingerprint. Before scanning, the sub-machine checks that finger is alive or not. But it's optional. To skip this check procedure, the entry point pseudo state ScanOnly is provided. FingerPrintRegister.png is the parent state machine. It uses ScanFinger as a sub-machine twice. In this scenario, alive checking is not required. So, the parent machine uses ScanOnly enty_pt. In another scenario, not mentioned here, might require the normal entry into ScanFinger to check the finger is alive. ScanFinger machine doesn't care about outer event. In FingerPrintRegister, the states RightScnning and LeftScanning have different incoming events for ScanOnly entry points. But any events are accepted. And then, it's not referred. Based on your suggestion, I introduce the base event class. As long as the incoming event of entry point is not "none", this approach works good. struct AnyEvent {}; struct Completed: public AnyEvent {}; struct StartButtonPressed: public AnyEvent {}; (See 39_FingerPrintExampleBaseEvent.cpp) If the incoming event is "none", the transition is stopped. Sometimes I want to use "none" as incoming event for entry point in the same sub-machine. And it is impossible that msm::front::none inherits user event classes such as AnyEvent. I'm trying to find better approach to solve the above problem. Thanks, Takatoshi >> See my second mail in this thread. My solution using templates >> (entry_pseudo_event_template.cpp) requires the template parameters >> same as the number of entry point pseudo states in sub-machine. It's >> acceptable but if outgoing transition would be able to use none, I >> would remove the template parameters. > > >> In the above case, it is not required to support multiple incoming >> transitions to one entry pseudo state. Because the instances of >> sub-machine are different. > > > In this case, maybe I could interest you in defining a base event class for > Event1 and Event2, then making this base event the event triggering the > inside transition. Your first example would be changed this way: > > struct BaseEvent {}; > struct Event1: public BaseEvent {}; > ... > msmf::Row < Entry1, BaseEvent, State2_2, msmf::none, msmf::none > > > > > Regards, > Christophe > > _______________________________________________ > Unsubscribe & other changes: > http://lists.boost.org/mailman/listinfo.cgi/boost

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Interest in double-ended priority queue? (priority_deque)
by Nathaniel McClatchey 02 Jun '12

02 Jun '12

Details: Template-based container adapter. Mimics std::priority_queue interface and requirements. O(1) read and O(log n) delete of either end of queue. O(n) create and merge. Functions for unordered access and mutating of elements. Remaining development: Further optimization. Note: Implementation is similar to but independent from http://lists.boost.org/Archives/boost/2011/12/188848.php

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Standardization of Boost (and other) libraries
by Beman Dawes 01 Jun '12

01 Jun '12

The C++ standards committee has set up a discussion forum (also accessible via email) to help those preparing language and library proposals. Requests for feedback, help, champions, and anything else related to proposals is on topic. https://groups.google.com/a/isocpp.org/forum/#!forum/std-proposals Note that this is a different URL than mentioned at C++Now! - language and library proposal groups have since been combined into a single group. After some false starts, discussion has started in earnest. The first two requests for feedback were on proposals for Boost.Any and Boost.Optional. If you are interested in proposing a Boost library for standardization, you probably want to check out std-proposals. --Beman

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Re: [boost] [review] Multiprecision review scheduled for June 8th - 17th, 2012
by John Maddock 01 Jun '12

01 Jun '12

>>* What is the type of boost::multiprecision::number_category<B>::type for >>all the provided backends? Could the specialization for >>boost::multiprecision::number_category<B>::type be added in the >>documentation of each backend? and why not add also B::signed_types, >>B::unsigned_types, B::float_types, B::exponent_type? > > OK. On second thoughts, the members of B::signed_types etc are basically implementation details - optimizations if you will. Rather than listing the types explicitly I'd prefer some more weasel wording along the lines of "This type will interoperate natively with any signed or unsigned built in integer type no wider than a long - this means for example that multiplying by a integer literal is more efficient than constructing an mpz_int temporary from the integer and then multiplying. Likewise for the other arithmetic operations." John.

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Re: [boost] [filesystem] Linker error against std::codecvt in VS2012 RC
by Stewart, Robert 01 Jun '12

01 Jun '12

Peter Dimov wrote: > Lars Viklund wrote: > > > [1] 1>libboost_filesystem-vc110-mt-gd-1_50.lib(path.obj) : > > error LNK2001: unresolved external symbol "protected: virtual > > int __thiscall std::codecvt<wchar_t,char,int>::do_length(int > > const &,char const *,char const *,unsigned int)const " > > (?do_length@?$codecvt@_WDH@std@@MBEHABHPBD1I@Z) > > Well, you could start by preparing a simple test program that > calls std::codecvt in the same way path.obj does, to eliminate > Boost as a factor. If do_length is indeed not present in the > dynamic runtime, this would probably be a showstopper bug > against the RC, so it will get noticed. :-) If that's not the problem, verify that you built Boost.Filesystem using the same CRT. _____ Rob Stewart robert.stewart(a)sig.com Software Engineer using std::disclaimer; Dev Tools & Components Susquehanna International Group, LLP http://www.sig.com ________________________________ IMPORTANT: The information contained in this email and/or its attachments is confidential. If you are not the intended recipient, please notify the sender immediately by reply and immediately delete this message and all its attachments. Any review, use, reproduction, disclosure or dissemination of this message or any attachment by an unintended recipient is strictly prohibited. Neither this message nor any attachment is intended as or should be construed as an offer, solicitation or recommendation to buy or sell any security or other financial instrument. Neither the sender, his or her employer nor any of their respective affiliates makes any warranties as to the completeness or accuracy of any of the information contained herein or that this message or any of its attachments is free of viruses.

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