September 2009 - Boost - lists.preview.boost.org

bad include guards
by Steven Watanabe 26 Jan '17

26 Jan '17

AMDG The following pairs of files have identical include guards ./boost/concept_check/general.hpp ./boost/concept/detail/msvc.hpp ./boost/concept_check/msvc.hpp ./boost/concept/detail/msvc.hpp ./boost/filesystem/cerrno.hpp ./boost/cerrno.hpp ./boost/interprocess/containers/tree.hpp ./boost/interprocess/containers/detail/tree.hpp ./boost/mpl/min_max.hpp ./boost/mpl/max.hpp ./boost/mpl/vector/aux_/front.hpp ./boost/mpl/list/aux_/front.hpp ./boost/multi_index/identity_fwd.hpp ./boost/multi_index/identity.hpp ./boost/python/pointee.hpp ./boost/python/detail/pointee.hpp ./boost/spirit/phoenix/closures.hpp ./boost/lambda/closures.hpp ./boost/xpressive/proto/v1_/proto_typeof.hpp ./boost/xpressive/proto/proto_typeof.hpp ./libs/config/test/boost_no_dep_nested_class.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/config/test/boost_no_mem_templates.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/config/test/boost_no_std_allocator.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/conversion/test.hpp ./libs/any/test.hpp ./libs/interprocess/example/print_container.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/interprocess/test/expand_bwd_test_template.hpp ./libs/interprocess/test/allocation_test_template.hpp ./libs/interprocess/test/printcontainer.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/interprocess/test/print_container.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/iostreams/test/detail/utf8_codecvt_facet.hpp ./boost/detail/utf8_codecvt_facet.hpp ./libs/regex/test/regress/test_regex_search.hpp ./libs/regex/test/regress/test_partial_match.hpp ./libs/serialization/test/C.hpp ./libs/serialization/test/A.hpp ./libs/xpressive/perf/regex_comparison.hpp ./libs/regex/performance/regex_comparison.hpp ./tools/inspect/time_string.hpp ./tools/common/time_string.hpp In Christ, Steven Watanabe

5 8

Why no non-null smart pointers?
by Ross MacGregor 29 Apr '14

29 Apr '14

I just created a very small smart pointer libary for our project. It will contain two types of shared pointers: SharedHandle and NullableSharedHandle. SharedHandle will be a shared pointer that cannot be null by ensuring a non-null construction while NullableSharedHandle will basically be a typedef for boost::shared_ptr. I firmly believe that code can be made more reliable by minimizing the use of nullable pointers. To this end, I think it is important that we start using non-null pointer types. Ideally the compiler would be able to understand a non-null pointer and catch bugs at compile time, but I think we can still improve things with a few runtime checks. If we make sure that a shared pointer is constructed with a non-null pointer and ban any reset() type methods, we guarentee that it points to something. This can be beneficial for the following reasons: 1. Any function that uses this type will no longer be burdened with precondition checks to make sure variables of this type are not null. 2. It's type is simply more explicit and better explains its function. 3. Moving the non-null check to the creation phase will reduce the possibility of encountering null pointer exceptions at runtime (assuming there are many more pointer references than constructor calls). So my little pointer library seems to make a lot of sense, but if so why hasn't this simple smart pointer variation made it into boost yet? Has this been discussed somewhere already? My search on non-null smart pointers is not revealing much discussion on the topic. Regards, Ross

9 16

[#pragma once]
by Sid Sacek 18 Nov '12

18 Nov '12

I've worked with the MSVC, Sun and GCC compilers. Each one of them supports #pragma once. Is there any reason to wrap this pragma within #ifdefs? Are there any compilers out there today that don't support this #pragma? #if defined( _MSC_VER ) && ( _MSC_VER >= 1020 ) # pragma once #endif Could we change this coding pattern so that it no longer looks like MSVC is being selfish? -Sid Sacek

17 20

[interprocess] message_queue hangs when another process dies
by Sergei Politov 03 Nov '11

03 Nov '11

Hi, I have found the following problem with message_queue on win32 (MSVC 2008 + Windows Vista). Suppose we have 2 processes, one sends messages to queue, another reads them. When reading process dies (for instance using End process) during message_queue.receive the another process hangs in send. As I found during investigation, it tries to lock interprocess mutex, but it is already locked by dead process. So this message queue instance becomes unusable. I attached the example. Steps to reproduce: 1) Start "mq.exe s" (i.e. with argument s) It outs: sender: $PID 2) Start mq.exe without arguments. It outs: receiver: $PID 0 1 2 3 4 This time sender outs: send done: 3) At this point the message queue is empty and receiver waits for messages. End it with Task Manager. 4) Enter some number in sender console and press Enter. 5) The sender hangs in message_queue.send Best Regards, Sergei

6 13

Re: [boost] [date_time] Time zone improvements
by Rutger ter Borg 25 May '11

25 May '11

Jeff Garland wrote: > Very cool :-) One question -- is there a portable solution where a user > could deploy a files onto a Windows system or is it a Unix only solution? > I'm fine with incorporating a *nix only solution because what your > suggesting will be a nice solution for *nix platforms, but it will need to > be clear that it's not portable. I don't see why it wouldn't be possible to deploy the (big-endian) binary files to any platform. Getting it into this binary form (using zone info compiler zic) may be harder to do cross-platform, but cygwin may help here. [snip] > As the primary maintainer of Boost date-time I can say with certainty that > there is interest in this functionality -- it's long been on my todo list > and I haven't had time to get to it. You can email me privately and we > can discuss all the details of how to get your code incorporated. I'll do! Regards, Rutger

5 9

[serialization] boost/serialization/path.hpp
by Johan Råde 21 Feb '11

21 Feb '11

There is no boost/serialization/path.hpp. I suggest the following: ---------------------------------------------------------------------------------------------------------------- #ifndef BOOST_SERIALIZATION_PATH_HPP #define BOOST_SERIALIZATION_PATH_HPP // MS compatible compilers support #pragma once #if defined(_MSC_VER) && (_MSC_VER >= 1020) #pragma once #endif #include <boost/config.hpp> #include <boost/filesystem/path.hpp> #include <boost/serialization/level.hpp> BOOST_CLASS_IMPLEMENTATION(boost::filesystem::path, boost::serialization::primitive_type) #ifndef BOOST_NO_STD_WSTRING BOOST_CLASS_IMPLEMENTATION(boost::filesystem::wpath, boost::serialization::primitive_type) #endif namespace boost { namespace serialization { template<class Archive, class String, class Traits> void serialize(Archive& ar, boost::filesystem::basic_path<String, Traits>& p, const unsigned int version) { String s; if(Archive::is_saving::value) s = p.string(); ar & boost::serialization::make_nvp("string", s); if(Archive::is_loading::value) p = s; } }} #endif //-------------------------------------------------------------------------------------------------------------- Comments? Any suggested improvements? --Johan Råde

5 11

[C++0x] Emulation of scoped enums
by Beman Dawes 16 Feb '11

16 Feb '11

The improved type safety of the C++0x scoped enum feature is attractive, so I'd like to start using it as it becomes available in compilers. See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2347.pdf for a description. Note that the committee changed the name from strongly typed enums to scoped enums. See the attached for a boost/detail header that provides macro wrappers that use scoped enums if available, otherwise fall back on C++03 namespaces and unscoped enums. It lets a library write: BOOST_SCOPED_ENUM_START(algae) { green, red, cyan }; BOOST_SCOPED_ENUM_END ... BOOST_SCOPED_ENUM(algae) sample( algae::red ); void func(BOOST_SCOPED_ENUM(algae)); and then a user can write: sample = algae::green; func( algae::cyan ); Comments or suggestions appreciated, --Beman // scoped_enum_emulation.hpp ---------------------------------------------------------// // Copyright Beman Dawes, 2009 // Distributed under the Boost Software License, Version 1.0. // See http://www.boost.org/LICENSE_1_0.txt // Generates C++0x scoped enums if the feature is present, otherwise emulates C++0x // scoped enums with C++03 namespaces and enums. The Boost.Config BOOST_NO_SCOPED_ENUMS // macro is used to detect feature support. // // Caution: only the syntax is emulated; the semantics are not emulated and // the syntax emulation doesn't include being able to specify the underlying type. // // See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2347.pdf for a // description of the feature. Note that the committee changed the name from // strongly typed enums to scoped enums. // // Sample usage: // // BOOST_SCOPED_ENUM_START(algae) { green, red, cyan }; BOOST_SCOPED_ENUM_END // ... // BOOST_SCOPED_ENUM(algae) sample( algae::red ); // void foo( BOOST_SCOPED_ENUM(algae) color ); // ... // sample = algae::green; // foo( algae::cyan ); #ifndef BOOST_SCOPED_ENUM_EMULATION_HPP #define BOOST_SCOPED_ENUM_EMULATION_HPP #include <boost/config.hpp> #ifndef BOOST_NO_SCOPED_ENUMS # define BOOST_SCOPED_ENUM_START(name) enum class name # define BOOST_SCOPED_ENUM_END # define BOOST_SCOPED_ENUM(name) name #else # define BOOST_SCOPED_ENUM_START(name) namespace name { enum enum_t # define BOOST_SCOPED_ENUM_END } # define BOOST_SCOPED_ENUM(name) name::enum_t #endif #endif // BOOST_SCOPED_ENUM_EMULATION_HPP

14 27

[process] How to run test cases
by Boris 23 Jan '11

23 Jan '11

As Boost.Process 0.3 has been released it would be great if the test cases are run on various platforms. So far I've tested Boost.Process on WinXP with MSVC 9.0, Cygwin with g++ 3.4.4 and Solaris with g++ 3.4.6 and Sun C++ 5.9. To make it as easy as possible for others to run the test cases here's a short description of how to proceed. Nearly all test cases depend on a program called "helpers". This program is built first and is started by many test cases as a child process. In order to find the program "helpers" the test cases must know its location. As there is no way to get the location at runtime it is hardcoded in the file libs/process/test/misc.hpp. As the location differs depending on what compiler is used YOU MUST CHECK FIRST THE PATH IN libs/process/test/misc.hpp! Otherwise most of the test cases will fail as they look for a program "helpers" in the wrong directory. As of today only those paths are correct and have been tested which are set for Windows, Cygwin and Solaris. Only after you have checked and maybe updated the path in libs/process/test/misc.hpp you should try to build and run the test cases: WinXP/MSVC 9.0 ************** With MSVC 9.0 you only need to open the Visual Studio 2008 Command Prompt, change to the directory with the test cases and run bjam: C:\boost_1_36_0\libs\process\test> ..\..\..\bjam.exe -q Cygwin/GCC 3.4.4 **************** On Cygwin it's important to know if the Boost libraries have been built for the POSIX or Windows API. By default Boost libraries on Cygwin use the Windows API. With the Windows API the Boost.Process test cases are not passed successfully though (there are compiler errors where I'm not sure currently if they are a Boost.Process problem and how they could be fixed). If you want to run the test cases on Cygwin you must (re-)build the Boost libraries to use the POSIX API: $ cd ~/boost_1_36_0 $ ./bjam cxxflags=-DBOOST_POSIX_API Afterwards you can run the test cases: $ cd ~/boost_1_36_0/libs/process/test $ ../../../bjam cxxflags=-DBOOST_POSIX_API -q Solaris/GCC 3.4.6 ***************** At first you have to put the following line in ~/user-config.jam: using gcc : : : <linker-type>sun ; Then start building the Boost libraries: $ cd ~/boost_1_36_0 $ ./bjam --toolset=gcc cxxflags=-mcpu=ultrasparc For the test cases to be passed successfully you must update Boost.Test. Change line 624 in ~/boost_1_36_0/boost/test/impl/execution_monitor.ipp temporarily to: - , m_CHLD_action( SIGCHLD, catch_system_errors, attach_dbg, alt_stack ) + , m_CHLD_action( SIGCHLD, false, attach_dbg, alt_stack ) It is important that the second parameter is false as the signal SIGCHLD should not be handled by the execution monitor and should not be reported as an error. Afterwards the test cases can be run: $ cd ~/boost_1_36_0/libs/process/test $ ../../../bjam --toolset=gcc cxxflags=-mcpu=ultrasparc -q Solaris/Sun C++ 5.9 ******************* Build the Boost libraries with the sun toolset: $ cd ~/boost_1_36_0 $ ./bjam --toolset=sun stdlib=sun-stlport For the test cases to be passed successfully you must update Boost.Test. Change line 624 in ~/boost_1_36_0/boost/test/impl/execution_monitor.ipp temporarily to: - , m_CHLD_action( SIGCHLD, catch_system_errors, attach_dbg, alt_stack ) + , m_CHLD_action( SIGCHLD, false, attach_dbg, alt_stack ) It is important that the second parameter is false as the signal SIGCHLD should not be handled by the execution monitor and should not be reported as an error. If you run the test cases now you'll get this compiler error for one test case: "../../../boost/asio/detail/socket_ops.hpp", line 218: Error: Cannot assign void* to char*. "../../../boost/asio/detail/socket_ops.hpp", line 229: Error: Cannot assign void* to char*. "../../../boost/asio/detail/descriptor_ops.hpp", line 66: Error: Cannot assign void* to char*. "../../../boost/asio/detail/descriptor_ops.hpp", line 72: Error: Cannot assign void* to char*. The bug has been reported to the Boost.Asio mailing list. If you want to build that one test case, too, you need to fix the two files in Boost.Asio 1.36.0 yourself. All the test cases can be built and run with: $ cd ~/boost_1_36_0/libs/process/test $ ../../../bjam --toolset=sun stdlib=sun-stlport -q

4 9

[RangeEx] Where is the current version?
by Mathias Gaunard 19 Apr '10

19 Apr '10

Where is the current version (or a fairly recent version) of RangeEx? I can't find anything on the trunk, the sandbox or the vault.

5 13

[asio] read_until -- possibly misleading documentation?
by Richard Smith 15 Apr '10

15 Apr '10

The documentation for Boost.ASIO (which is otherwise very comprehensive) says of the boost::asio::read_until set of overloads: | Read data into a streambuf until a delimiter is | encountered. <http://www.boost.org/doc/libs/1_35_0/doc/html/boost_asio/reference/read_unt…> What the function actually does is to read blocks of data into the streambuf, and stop when the delimiter is found. This means that frequently data beyond the delimiter will be read into the streambuf. (And this is elaborated in more detail on the individual function's pages, if a reader looks there.) I appreciate that this behaviour is compatible with the documentation, but someone less familiar with ASIO could easily assume that the function will read as far as the delimiter and no further. (And I have just spent a fair amount of time debugging a piece of code where the author had made this assumption.) Could we change the summary documentation to read something like: | Read data into a streambuf at least until a delimiter is | encountered. The implementation may read beyond the | delimiter, but will not block when doing so. While I'm on the subject of ASIO documentation, I can't see any documentation on whether the service_name parameters to the basic_resolver_query constructors are allowed to be port numbers (e.g. "80") or whether they have to be symbolic names (e.g. "http"). Port numbers work, at least on Linux, but it's not clear whether this is something that I should be relying on. Similarly for IPv4 and IPv6 addresses in the host_name parameter. Richard Smith

3 2

Trac XMLRPC support
by Vladimir Prus 21 Mar '10

21 Mar '10

Would it be possible to have XMLRPC plugin installed in Boost Trac instance? See: http://trac-hacks.org/wiki/XmlRpcPlugin The installation appears to be fairly simple (and indeed seems to just work somewhere else). This will allow to use third-party tools to grab tickets from Boost Trac, which will hopefully lead to more issues fixed :-) - Volodya

4 5

boost::mpl::for_each and value_initialized
by Peter Foelsche 08 Feb '10

08 Feb '10

Dear All, what is the use of value_initialized in boost::mpl::for_each? It should be sufficient if the value is initialized by the constructor. value_initialized() calls memset() in before calling the constructor. This memset() is not being optimized away with gnu-c++ 4.4.1. What class does require zeroed memory to work correctly? Peter *** boost_1_40_0/boost/mpl/for_each.hpp Mon Aug 17 22:16:53 2009 --- boost_1_40_0.saved/boost/mpl/for_each.hpp Tue Sep 1 12:54:55 2009 *************** *** 71,78 **** // dwa 2002/9/10 -- make sure not to invoke undefined behavior // when we pass arg. ! value_initialized<arg> x; ! aux::unwrap(f, 0)(boost::get(x)); typedef typename mpl::next<Iterator>::type iter; for_each_impl<boost::is_same<iter,LastIterator>::value> --- 71,78 ---- // dwa 2002/9/10 -- make sure not to invoke undefined behavior // when we pass arg. ! //value_initialized<arg> x; ! aux::unwrap(f, 0)(arg()); typedef typename mpl::next<Iterator>::type iter; for_each_impl<boost::is_same<iter,LastIterator>::value>

5 10

Interest check: Boost.Mock
by Peter Bindels 26 Dec '09

26 Dec '09

Hi all, Over the past three-quarters of a year I've been working (with three friends) on a mocking framework for C++. In our vision, it would be a good complement to Boost.Test for testing classes separate from interfaces required - it would improve the ability to unit-test the classes that tie others together and that implement higher-level algorithms. It does this by creating an object that is "derived" from a given class at runtime, and replacing the functions with functions that redirect to verifying logic. The verifying logic uses basic structures to record expectations and to verify they happened. These ways of creating an object at runtime and modifying it are highly compiler dependant but remarkably portable - as it runs on at least 3 different compiler series (GCC, MSVC, EDG-based) and 5 platforms (Windows XP, Windows CE, Linux, QNX, bare platform), with few modifications. The library has been released under the name "Hippo Mocks" already. I'm interested in submitting it to Boost for three reasons. First of all, I believe that there may be obvious or very interesting optimizations or expansions I do not notice. Second, as Christian has elaborated on already, having the Boost tag on the project makes it more noticed and more used. As it has taken quite a bit of time from me already I would like people to use it. Third, Boost.Test allows testing code but does not support mocking. In the environment of unit testing, anything that is not a base library benefits from mocking by abstracting away details that are irrelevant and that will break your test unnecessarily. For Boost the main changes would be superficial in the naming and in using more default libraries instead of a new implementation. For Hippo Mocks I've decided to make no assumptions in anything over C++98 so there's a full Tuple implementation and so on. If there's an interest I'll spend the evening porting the code to qualify for the Boost coding norms and upload it to the vault (if I can - but that should be OK). I would like you to take a look at the code and tell me what you think of it. Thanks for your time. Kind regards, Peter Bindels

8 10

[TypeTraits] is it possible to add something to boost.type_traits?
by frederic.bron＠alcan.com 17 Dec '09

17 Dec '09

Dear boost implementers, TypeTraits is very useful, thanks you. However, recently, I needed something to know if a type is comparable (with operator<) and that was not in the library. Fortunately, somebody forwarded me an earlier post on the users list where I could find what I wanted. The implementation was inspired from boost/detail/is_incrementable.hpp I have written is_less_comparable, is_less_equal_comparable, is_greater_comparable... inspired from the same source and I wonder if it could be possible to add it to the library as I think it could be helpful for others. I give the source code below (if it is useful) but I am not able to make it fully general as it is in boost/type_traits. In particular, I do not understand all the macros that are used. Regards, F. Bron (See attached file: is_comparable.hpp) Avis : Ce message et toute pièce jointe sont la propriété d'Alcan et sont destinés seulement aux personnes ou à l'entité à qui le message est adressé. Si vous avez reçu ce message par erreur, veuillez le détruire et en aviser l'expéditeur par courriel. Si vous n'êtes pas le destinataire du message, vous n'êtes pas autorisé à utiliser, à copier ou à divulguer le contenu du message ou ses pièces jointes en tout ou en partie. Notice: This message and any attachments are the property of Alcan and are intended solely for the named recipients or entity to whom this message is addressed. If you have received this message in error please inform the sender via e-mail and destroy the message. If you are not the intended recipient you are not allowed to use, copy or disclose the contents or attachments in whole or in part.

11 23

Re: [boost] Formal Review Request: Boost.String.Convert
by Vladimir.Batov＠wrsa.com.au 02 Dec '09

02 Dec '09

I understand we'll never manage to please everyone. Apologies. For now I am settling on the boost::convert interface as I very much agree with the arguments Robert's put forward for it and I feel there is the least disagreement around this interface. Surely boost::convert() has issues of its own. However, I feel the path (convert::to_string->convert::to->convert) how I myself arrived to this logical (IMHO) conclusion seemed reasonable. More so, despite its subtle (to some) directionality the interface has proven to work (as it is essentially the same interface as for lexical_cast). You cannot deny that I made considerable sacrifices (my pets "string" namespace and "to/from" are gone, something I was ready to die :-) for yesterday...). I am hoping the others could make some concessions as well and we would settle on boost::convert()... for now. If some other issues pop up that we missed so far, we'll revisit the issue. It is because I would very much like to move forward and start looking at the functionality and implementation. Do you think it is possible or I am rushing things again? I somewhat cleaned up the implementation (removed to/from, etc.). However, before going forward I'd like to discuss one important thing that's been bugging me since Scott brought it up. Namely, all conversions are now implemented as discriminated functions like // string-to-type conversion template<class TypeOut, class StringIn> typename boost::enable_if_c< !is_string<TypeOut>::value && is_string<StringIn>::value, detail::from_string<StringIn, TypeOut> >::type convert(StringIn const& from_str, TypeOut const& default_value =TypeOut()) { return detail::from_string<StringIn, TypeOut>(from_str, default_value); } However, Scott mentioned that and I feel that might be cleaner if we could implement it as namespace boost { template<class TypeOut, class TypeIn, class Enable =void> class convert; } Then for every conversion we'll be able to encapsulate *complete* implementation in the respective specialization class. Like for string-to-type template< class TypeOut, class StringIn, typename boost::enable_if_c< !is_string<TypeOut>::value && is_string<StringIn>::value, void>::type> class convert { convert(StringIn const& from_str, TypeOut const& default_value =TypeOut()); }; The reason I like it is that it eliminates other support/intermediate classes (like something used-to-called boost::string::value<...> and detail::from_string) and we can do int i = convert(str, -1); // Nothing changed. a 'convert' instance created on the stack and converted to 'int'. convert<int, string> checked(str, -1); // named 'convert' is created. convert<int, string> checked = convert(str, -1); // the same but some might like this syntax better. if (checked.good()) success // we can check the success as ussed to with boost::string::value It feels that approach gives us considerably more room for expansion as some special conversions will be able to have methods only specific to that particular conversion. For this approach to work with algorithms we'll need class convert { static TypeOut apply(TypeIn const&); }; and then std::transform( ints.begin(), ints.end(), std::back_inserter(strings), convert<string, int>::apply); Thanks, Vladimir.

9 63

[thread] #2742 Why the at_thread_exit cleanup function is const?
by vicente.botet 25 Nov '09

25 Nov '09

Hi, Anthony, could you verify the patch and test I have attached to the ticket works for other platforms that cygwin? Thanks, _____________________ Vicente Juan Botet Escribá

2 1

[move][container] Review Request (new versions of Boost.Move and Boost.Container in sandbox and vault)
by Ion Gaztañaga 17 Nov '09

17 Nov '09

Hi to all, I've just uploaded to boost sandbox... http://svn.boost.org/svn/boost/sandbox/move/) and Boost.Vault... http://www.boostpro.com/vault/index.php?action=downloadfile&filename=boost.… ...new versions of libraries Boost.Move and Boost.Container. Online documentation can be found here: Boost.Move http://svn.boost.org/svn/boost/sandbox/move/libs/move/doc/html/index.html Boost.Container http://svn.boost.org/svn/boost/sandbox/move/libs/container/doc/html/index.h… I would like to request a review for both libraries. Boost.Move is quite small (just one header). Boost.Container depends on Boost.Move and Boost.Intrusive so you must download also the post-1.40 version of Intrusive placed in the same package (Boost.Container uses new features from Intrusive not included in Boost 1.40). Just take fresh Boost 1.39 folder and overwrite it with package contents. ************************ What's new in Boost.Move: ************************ ->The library has been modified to support moving rvalues of copyable AND movable types, a limitation of the previous version. This changes where proposed by Klaus Triendl in this thread: http://lists.boost.org/Archives/boost/2009/06/153266.php The library has now new macros to declare copyable and movable types and movable only types. Old macros are still there for backwards compatibility (specially unordered library which was also ported to this move sandbox) but I expect to remove them if current approach is considered better. ->Updated documentation and tests. ************************ What's new in Boost.Container: ************************ -> Added tests and documentation -> Updated the library to the new Boost.Move macros * * * I've tested both libraries in Windows XP using the following compilers: Visual 7.1, Visual 8.0, Visual 9.0, Intel 10.0, Mingw-gcc 4.3 and Mingw-gcc 4.3 in C++0x mode. The library should work on any C++03 conforming compiler Best, Ion

19 95

Boost.Variant is not EqualityComparable
by brook＠biology.nmsu.edu 12 Nov '09

12 Nov '09

I just ran into the case that Boost Variant does not satisfy the EqualityComparable concept. While it provides operator==() and operator<() (and therefore is LessThanComparable), it does not provide operator!=(), which is required for the EqualityComparable concept. Is this by design or oversight? It seems reasonable to expect that a Boost Variant model this concept, but perhaps I am missing something. In case it is by oversight, the following patch seems to provide the missing operator. Cheers, Brook --- boost/variant/variant.hpp.orig 2009-05-13 21:21:59.000000000 -0600 +++ boost/variant/variant.hpp 2009-05-25 19:21:40.000000000 -0600 @@ -1681,6 +1681,8 @@ return rhs.apply_visitor(visitor); } + bool operator!=(const variant& rhs) const { return !(*this == rhs); } + bool operator<(const variant& rhs) const { //

6 7

proposal interval container; ITL moved to the boost sandbox
by Joachim Faulhaber 11 Nov '09

11 Nov '09

Dear boosters, after completion of a lot of boostification work I moved my Interval Template Library to the boost sandbox in the boost project centric form: https://svn.boost.org/trac/boost/browser/sandbox/itl itl boost itl [itl_xt] [validate] libs itl [itl_xt] [validate] I have split up the original library into three parts: (1) itl, (2) itl_xt and (3) validate. Core part 1 'ITL' contains all interval container class templates. Only this part will be prepared for a formal submission. Part 2 'itl_xt' contains extended parts of the original library that do not belong to the core interval container data structures and might be proposed for later extensions. Part 3 'validate' contains the sources for the law based test automaton 'LaBatea' that has been used for an automated check of the ITLs correctness. Parts 2 and 3 do not yet conform boost standards and naming conventions and are not yet intended as contributions to boost. On the core ITL-part I have done the following: + Removed all virtual functions via introduction of mixins + Integrated deeper into boost libraries replacing own code by e.g. boost::type_traits and boost::mpl + Minimized the class template interfaces by transforming member functions into non member function templates. + Made interval containers more interoperable by overloading operators and global function templates. + Wrote a test suite using boost unit test tools. Tested for boost-instance types boost::date_time and boost::rational + Provided jamfiles to build and run examples and tests. + All examples and tests have been compiled, linked and run successfully with msvc_9.0 and gcc_3.4.4(cygwin). Next I am going to write boost style html-documentation. >From the boost web page I don't see a clear recommendation for a preferable way of doing that. Handcoded? Generated with BoostBook? Is there a reference library that has an exemplary standard documentation? Cheers Joachim

3 4

Time for another bug sprint (after 1.41 ships)?
by Marshall Clow 09 Nov '09

09 Nov '09

Earlier this year, we had a "bug sprint", where many people focused on fixing bugs in Boost. We managed to get the # of open tickets down from 800 to about 720. As of today, there are 820 open tickets in Trac. Is it time to focus on swotting bugs again? 1.41 is scheduled for release on 1-November; that's six weeks from yesterday. How about a bug sprint starting on 14-November, finishing on 22- November? That's two weekends - and finishes up before the American Thanksgiving holiday. -- Marshall P.S. This doesn't mean that people have to wait until November to fix bugs ;-) ;-)

12 25

[integer] Compilation failed in Visual Studio
by Adam Badura 28 Oct '09

28 Oct '09

Following simple program: #include <boost/integer_fwd.hpp> int main() { return 0; } does not compile in Visual Studio 2008 with Boost 1.40.0. Compilation errors are following: 1>d:\libraries\boost_1_40_0\boost\integer_fwd.hpp(70) : error C2039: 'long_long_type' : is not a member of 'boost' 1>d:\libraries\boost_1_40_0\boost\integer_fwd.hpp(70) : error C2065: 'long_long_type' : undeclared identifier 1>d:\libraries\boost_1_40_0\boost\integer_fwd.hpp(70) : error C2913: explicit specialization; 'boost::integer_traits' is not a specialization of a class template 1>d:\libraries\boost_1_40_0\boost\integer_fwd.hpp(73) : error C2913: explicit specialization; 'boost::integer_traits' is not a specialization of a class template Adam Badura

6 9

[BGL] Multithread problem inserting edges and exploring the same graph
by Cosimo Calabrese 21 Oct '09

21 Oct '09

Hi to all, I've a problem on BGL. My environment is WinXP, Visual Studio 2005, Boost 1.37. I'm trying to use BGL in the following way. I've a single graph in my application, that is an adjacency_list< vecS, vecS, ... >, and I've 2 kind of threads that work on the graph: - some "Explorer" threads, that executes a Dijkstra's algorithm repeatedly; - some "Integrator" thread, that call the add_edge() function repeatedly. The program often crashes, because it cannot dereference some graph elements, some auto_ptr... The crash isn't sistematic, so I think there's a concurrency problem. I think that the problem is in the use of the vectors in the implementation of the graph. In general, if I've an iterator 'it' that point on an vector's element A, and I insert another element B before A, then the iterator is now invalid. I suppose that it happens something of similar in the graph. If I read the out-edge list of a vertex at the same time that I add another out-edge to the same vertex, the reading may be inconsistent. So I've tried with an adjacency_list< listS, vecS, ... >, because if I add an element to a list, the previous reference are still valid, but I've experienced the same problem again. If what I've said is correct, then I think that with an adjacency_matrix I will not have problems, but I've approximately 5 millions of vertices, and the graph is sparse. I think that is a waste of memory. And what about the exploring time? Another question: if I launch *only* a set of Explorer thread, it seems that there aren't problems with EdgeList = listS and EdgeList = vecS too. Can someone confirm to me that the exploring algorithms, like Dijkstra, don't modify the graph structure? Are they read-only algorithms? Can I safely launch multiple exploration threads simultaneously? Can someone help me? Many thanks in advance, Cosimo Calabrese.

5 24

[utility] auto_buffer v2
by Thorsten Ottosen 07 Oct '09

07 Oct '09

Dear All, Hereby an updated class. Thanks to all who contributed with comments to the first try. I have made the following changes: 1. push_back() overloads are now growing 2. added swap() (boy, was this nasty to implement). I assume the allocator can be wapped without throwing. How do other people copy with this problem? 3. added copy-constructor + copy-assignment 4. made the min capacity equal to N, the number of elements in the stack buffer 5. the size of the internal buffer is now controlled via two policies: template< unsigned N > struct store_n_objects; template< unsigned N > struct store_n_bytes; the default is store_n_objects<256>. The reason is that we don't want the capacity to change just because we compile on a different platform. 6. added comparison operators Comments most welcome! best regards -Thorsten

4 7

[rdb] 0.0.09
by Jean-Louis Leroy 04 Oct '09

04 Oct '09

In this version : * EXISTS * consistency check in INSERT...SELECT * DISTINCT, ALL * transactions The transaction stuff is pellicular. It simply maps to vendor calls. I am hesitating a bit, either make a common interface for the most common operations (like execute) directly in each backend (aside with vendor-specifc calls) or put them in a separate wrapper or even decide that it's not in the scope. There's more redesign in the select from which I think I can get an elegant implementation of vendor-specific features (like LIMIT). The idea is to pass all the data in a fusion map, allowing vendor specific parts of the statement to slip their own data inside it. In fact this also is how DISTINCT works. I dropped the composition of lists via chained calls to operator (). It's all preprocessor-based now. The () chain system was limited by FUSION_MAX_VECTOR_SIZE anyway. I have installed MySQL on my computer. I am still accessing it via ODBC but I'll probably start the native support soon. Yesterday I tried to upload and just when I pushed the upload button the vault server crashed. I suspect that it was my upload that triggered it. J-L

6 15

[Fusion] port to c++0x
by Christopher Schmidt 04 Oct '09

04 Oct '09

I participated in Google's 'Summer of Code' for Boost this year. My project was to port Boost.Fusion to c++0x. The program is over now and I would like to give you a short report on my work and put my code up for comments. In a nutshell, there is rvalue support, native variadic templates are used if possible and the public classes and (meta-) functions are guarded by a set of static asserts that detect most invalid (template) arguments. I also added certain new functionality to provide an easier, faster and more intuitive programming interface. My implementation is pretty much backwards compatible and all test cases pass on gcc 3.4/4.4 and vc 9. Here is a short overview of the most striking changes besides the implementation of raw c++0x support. I removed the deque container and the extension-classes. The deque container is undocumented and, in my opinion, does not go well with the other container due to its intrinsic extension mechanism. There also should not be a performance gain compared to a regular fusion::joint_view in combination with two fusion::vector. The extension classes are pretty much Boost.Proto specific. At the moment they seem to be out of place, especially as they are undocumented, unmaintained and not even part of the regular file structure. I would like to see them either fully documented (with the underlying concept of segmented sequences) or in the detail namespace of Boost.Proto. I added support for associative iterators. An associative forward sequence shall provide an iterator type which implements the extension backend of the intrinsic (meta-)functions fusion::result_of::value_of_data, fusion::deref_data and fusion::result_of::key_of. This has the advantage that all view classes, even fusion::iterator_range, are able to adapt the underlying sequence's associative-ness. fusion::transform_view, as a special case, got an additional template parameter. This parameter specifies whether the view should model either the forward concept only or the associative and the forward concept. This design breaks consistency with Boost.MPL. Unfortunately these changes are crucial and I would rather risk this break with Boost.MPL than missing that important feature. Using the old implementation, there is no way to avoid explicitly converting from a view back to an associative sequence to preserve the associative-ness. This leads to a nasty runtime overhead due to evaluation of every element of the view and copy-/move-constructing it. Besides, other changes include: -If the compiler supports rvalue references, all fusion container have a template constructor (taking either const lvalue or 'templated' rvalue references). -If the compiler supports variadic templates, fusion::cons, fusion::pair and fusion::single_view have a variadic template constructor (taking either const lvalue or 'templated' rvalue references) that allows emplace construction. -The view classes adapt the full category of their underlying sequences. As mentioned above, the associative-ness is preserved, but also, if possible, the random-access or bidirectional trait. -The result_of::-metafunctions accept r- and lvalue references arguments. If an argument is not reference-qualified, it will be considered to be an lvalue reference. All existing extension implementations must be changed to adapt this new behaviour. -The algorithm functions now also take (and correctly forward) non-const reference arguments. -Fusion iterators (with reference compatible sequence types and a very same index) and views (with reference compatible sequence types) have a working operator= that correctly reassigns the underlying sequence references. -Fusion now also adapts MPL iterators. If, and only if, the <boost/fusion/adapted/mpl.hpp>-header is included, mpl sequences and iterators are recognized as fusion sequences and iterators. -There are new headers to adapt std::(tr1::)array or std::(tr1::)tuple. The overall compile-time performance of my code is satisfying. Compiling a compilation unit that includes all possible fusion headers takes on gcc 4.4 slightly more time than the official fusion implementation. If native variadic templates are present, the compilation is a lot faster (usually up to 3 to 6 times), regardless of the value of FUSION_MAX_xxx_SIZE. The compile-time performance of actual fusion code is mixed. The intrinsic container and iterator (meta-)functions compile a little bit slower compared to the official fusion implementation. This is due to explicit removal of the references on the arguments of all result_of::metafunctions and some additional abstraction layer. If the compiler support rvalue references, there has to be a rather ugly and slow type evaluation/transformation to avoid issues with rvalue references on non-array, non-class types (see /support/internal/ref.hpp and 8.5.3p5 of the current c++0x draft for more details). On the other hand, I added several optimizations (such as result preevaluation), and, if variadic templates are present, the actual instantiation of fusion containers is a lot faster. All in all, the compile-time performance is a little bit worse if c++0x features are not present. If c++0x features are present, the code should compile a little bit faster in most cases. For example, the lambda example of the Boost.Proto documentation, which internally heavily relies on Boost.Fusion, takes on my machine 2.6 seconds to compile with the 'old' fusion on gcc 4.4, 3 seconds with my port without -std=c++0x, and 2.1 seconds with c++0x features being present. The overall performance might be even better once Boost.MPL adapts native variadic templates and the compiler supports template aliases. There have been tons of other changes, mostly bugfixes, optimizations (in terms of compile time of course) and removals of redundancy. Whenever I had the choice, I tried to prefer clean, redundancy-free instead of heavily optimized code. The overall performance loss is not noticeable though, and most compile-time optimizations that go beyond the as-little-template-instantiations-as-possible paradigm are pretty much compiler dependent anyway. There is still some work to do. I did not add c++0x-specific test cases and there are several parts of the documentation which need to be updated. By the way, are there any official guidelines for documenting c++03/c++0x-specific differences? For now, I would like to hold off on implementing these changes until Boost.TypeTraits adapts c++0x. Right now I implemented missing or incorrectly behaving trait functions in the fusion::detail-namespace. I would rather like to use the official ones, at least in the documentation and in the test cases. Besides that, I think my implementation is trunk-ready. If there are no objections, I would like to finish the outstanding work as soon as possible, and then merge my code with the trunk. Of course I will provide long-term support for the project. In fact, I would love to become an official fusion maintainer. You can find the code in the boost sandbox (/sandbox/SOC/2009/fusion). If you test the code with a compiler that has decltype support, please use the HEAD of the trunk rather than the official 1.40 distribution package to compile your code. Best regards Christopher

6 17

Review Request: Boost.Itl; The Interval Template Library
by Joachim Faulhaber 03 Oct '09

03 Oct '09

Dear developers, the Interval Template Library is now in a state where I think it does conform the requirements and guidelines for boost libraries fairly well. To decide, whether it's design, implementation and overall usefulness is sufficient to be accepted in the boost libraries collection is now up to you. In the last round of refactoring I concentrated on efficiency and optimization issues. The implementation of the itl's interval containers is still based on std::set and std::map, but algorithms are now exploiting hinted insert and are manipulating intervals and values in place instead of copying in many instances. This way, it has been possible to improve performance significantly. Along the way of implementing optimizations I have documented the complexity guarantees for all important functions of the library's interface. Please note that the original ITL as presented in May 2008 has been split into 3 parts and only the *first* part is submitted for review: itl : Core library, interval containers, SUBMITTED FOR REVIEW Additional parts are: itl_xt : Extensions like histories and generalized crosstables validate: The law based test automaton (LaBatea). A validation tool using laws aka axioms. *itl* is a complete library containing all required ingredients particularly a separate test suite (NOT using LaBatea) and the quickbook documentation. The code is successfully compiled and tested with gcc-3.4.4, 4.1.0, 4.3.2 and msvc-8.0, 9.0. I have uploaded the review version as itl_3_1_0.zip to the vault in section containers. http://www.boostpro.com/vault/index.php?action=downloadfile&filename=itl_3_… Another file itl_plus_3_1_0.zip contains all three parts (itl, itl_xt and validate). http://www.boostpro.com/vault/index.php?action=downloadfile&filename=itl_pl… Reviewers interested in the law based testing part may have to refer to this file to examine those tests. The law base testing examples compile and run with gcc-4.3.2, msvc-8.0 and 9.0. LaBatea does not compile with gcc-4.1.0 or older. The quickbook generated documentation is included in the zip files and is also available online at http://herold-faulhaber.de/boost_itl/doc/libs/itl/doc/html/index.html Sources are also available form the sandbox: https://svn.boost.org/svn/boost/sandbox/itl/ To close my request for review, let me take the opportunity to do some advertisement ;-) focusing on some of the itl's highlights. * The Itl emerged out of real world software development extracting generic functionality from numerous use cases of the date time problem domain. (http://www.herold-faulhaber.de/boost_itl/doc/libs/itl/doc/html/boost_itl/ex…) But the need for the same data structures occurs in other fields as well. E.g. Zachary Turner uses a compressed_bitmap similar to an itl::interval_set to manage very large file system allocation bitmaps and gives more use cases here (http://lists.boost.org/Archives/boost/2009/06/152817.php) * Aggregation on overlap not only provides a useful feature to compute aggregation results on interval_maps like statistics, it also leads to a generalized addition operation on maps that exhibits interesting semantical properties. E.g. (http://herold-faulhaber.de/boost_itl/doc/libs/itl/doc/html/boost_itl/semant…) * The itl's design is based on sets of laws (aka axioms) that are described in the documentation. (http://herold-faulhaber.de/boost_itl/doc/libs/itl/doc/html/boost_itl/semant…) These law sets not only are giving a formal specification of the library. Using the law based testing tool (LaBatea) (https://svn.boost.org/svn/boost/sandbox/itl/boost/validate) allows to validate the library code for every specified law. * For the itl, 18 laws have been validated on the 7 container templates with varying instantiation types for template parameters, running a total of 719 different law instances (each of them for large numbers of randomly generated test data). (https://svn.boost.org/svn/boost/sandbox/itl/libs/validate/example/) This gives everyone a method to check semantical properties of the library in a way that is more powerful than traditional unit tests. To get the 'complete picture' of the library's interface you may want to refer to the synoptic function table first (http://www.herold-faulhaber.de/boost_itl/doc/libs/itl/doc/html/boost_itl/in…) before looking at more specific topics. Hoping to have quickened your appetite to take a closer look at this library before and during the review process. best regards Joachim Faulhaber

6 28

Hello and a quick question.
by S. Brad Daughdrill 02 Oct '09

02 Oct '09

Hello to all, I first want to say hello to all the members. I recently ran across your project, and I am really interested in working with you all. My question is are there an example that use forms? The example I found all seem to be console applications and while they are helpful, I really want my students to start programming with forms (initially at least). They will be using Visual C++ 2008 Express. Thank you for everything ahead of time. Brad *----- S. Brad Daughdrill The University of Alabama B.S. Management Information Systems M.S. Operations/Project Management M.B.A. Financial Risk M.A. Economics (Candidate) 146 Lenora Drive Tuscaloosa, AL 35401 (o) 205.348.7591, Bidgood Hall - 351E (c) 251.510.3089 (e) S.Brad.Daughdrill(a)Gmail.com*

3 2

[rdb] 0.0.10 + documentation
by Jean-Louis Leroy 01 Oct '09

01 Oct '09

I have uploaded a new revision to the vault. The only /visible/ change in the API is the syntax for the insert...select statement. It was `insert_into(table)(cols)(select(...))`, it is now `insert_into(table)(cols).select(...). The syntax engine is beginning to look more and more like a compile-time finite state machine. And there is the beginning of a documentation ! you can view it here : http://www.yorel.be/boost/libs/rdb/doc/html/index.html The tutorial is 2/3 complete for this phase (i.e. sans prepared statements). The structure of the doc is strongly influenced by Fusion's - no wonder, I spent so much time in it ;-) While I like the overall structure, I wonder if the Fusion style is appropriate for a tool that is not so much into meta-programming (well at least on the outside). I documented insert_into in this fashion (see http://www.yorel.be/boost/libs/rdb/doc/html/rdb/sql_subsystem/statements/in…) for a test. If you have opinions, please voice them. J-L

2 2

Re: [boost] On the Road to Aspen (BoostCon 2010)
by pete＠pcbartlett.com 01 Oct '09

01 Oct '09

On Tue 29/09/09 12:22 , Joel de Guzman <joel(a)boost-consulting.com> wrote: > Edouard A. wrote: > > Hi Joel, > > > > You can also create a twitter account and link your Facebook page > to this > > twitter account, mirroring all your facebook status updates to > your twitter > > account. > > > > This increases visibility and give the possibility to your fans to > choose > > the medium they like to follow you. > Thanks, Edouard. Done. BoostCon Facebook Linked to > Twitter (@BoostCon) > http://www.twitter.com/BoostCon Many users of Boost are in corporate environments. Many corporate environments block access to Facebook and/or Twitter (mine blocks both) domains. It'd be great therefore if Boost didn't move too much content there if equivalent

4 4

Double free from UTF
by janm-boost-devel＠transactionware.com 01 Oct '09

01 Oct '09

Hi, I am seeing a double free when using boost-test on: - FreeBSD 7.2-STABLE, amd64 (gcc 4.2.1) with boost 1.39 - Mac OSX 10.6.1, x86_64 (XCode 3.2, gcc 4.2) with boost 1.40 I don't see the problem on Windows XP with Visual C++ 2005 Express. A simple test case is below, just run. The _malloc_options is to make the system malloc() fill memory with 0xa5 on allocation and 0x5a on deallocation. #define BOOST_TEST_MAIN #include <boost/test/included/unit_test.hpp> #include <stdlib.h> const char* _malloc_options = "J"; BOOST_AUTO_TEST_CASE(broken) { BOOST_CHECK(true); } Output: Running 1 test case... *** No errors detected zsh: bus error (core dumped) ./a.out Stack Trace: #0 0x0000000800b1bdee in free () from /lib/libc.so.7 #1 0x000000000043e51c in boost::unit_test::framework_impl::clear (this=0x55ad20) at framework.ipp:133 #2 0x000000000043e652 in ~framework_impl (this=0x55ad20) at framework.ipp:122 #3 0x00000000004110c6 in __tcf_1 () at framework.ipp:222 #4 0x0000000800b6dbb6 in __cxa_finalize () from /lib/libc.so.7 #5 0x0000000800b1f7c7 in exit () from /lib/libc.so.7 #6 0x0000000000404595 in _start () Any ideas? Thanks, Jan Mikkelsen

6 12

Interest in flat_iterator for nested containers?
by Christoph Heindl 01 Oct '09

01 Oct '09

Hi, is there any interest in an iterator that provides a flat view of nested containers? For example ---------- using namespace boost::assign; typedef std::list<int> inner_container_type; typedef std::vector<inner_container_type> outer_container_type; outer_container_type elements(6); elements[1] += 1,2,3; elements[2] += 4,5; elements[4] += 6; BOOST_CHECK(std::equal( make_flat_iterator(elements.begin(), elements.end()), make_flat_iterator(elements.end(), elements.end()), list_of(1)(2)(3)(4)(5)(6).begin()) ); ---------- If so, I'll be glad to share my code with the boost community. I attach my current state of development and a single test suite. The current state of development contains a class named flat_iterator, a make_flat_iterator function and a set of meta-functions to derive required types. flat_iterator derives from boost::iterator_adaptor. It derives an inner_iterator type from the passed iterator to be adapted (outer_iterator type). The value_type of outer_iterator is required to model STL container concept. The value_type passed to boost::iterator_adaptor is const-qualified if the reference type of the outer_iterator or inner_iterator type is const-qualified (please see question 1 below). The traversal category of flat_iterator is bidirectional if the the outer_iterator and inner_iterator type are at least bidirectional. It models forward traversal else (question 2). flat_iterators can be stacked over each other to recursively flatten a hierarchy of arbitrary levels. ---------- using namespace boost::assign; typedef std::list<int> level_0; typedef std::vector<level_0> level_1; typedef std::vector<level_1> level_2; level_2 elements(10); elements[2] += list_of(1)(2); elements[4] += list_of(3)(4); typedef flat_iterator<level_2::iterator> flat_iterator_outer; typedef flat_iterator<flat_iterator_outer> flat_iterator_inner; flat_iterator_outer outer_begin(elements.begin(), elements.end()); flat_iterator_outer outer_end(elements.end(), elements.end()); flat_iterator_inner inner_begin(outer_begin, outer_end); flat_iterator_inner inner_end(outer_end, outer_end); BOOST_CHECK(std::equal(inner_begin, inner_end, list_of(1)(2)(3)(4).begin())); ---------- Open questions: * Currently the the value_type passed to boost::iterator_adaptor is const qualified based on required reference type of the outer_iterator, which renders the code for input iterators unusable, right? What's the best way to achieve const correctness? * The traversal category of flat_iterator is supposed to be the 'greatest common divisor' of the inner and outer iterator type. Is there a meta-function in boost that provides that type? Currently bidirectional traversal is chosen if both, inner and outer iterator, are at least of bidirectional traversal. Else forward traversal is chosen (which is of course incorrect when incrementable is passed). * Stacking flat_iterators to flatten out a hierarchy of arbitrary levels is possible but currently requires a lot of typing. I think that applying some recursive meta-functions to generate a correct iterator types for such situations should be possible but is beyond my current knowledge of meta-programming. Kind regards, Christoph

2 8

boost::variant and "Current Approach: Temporary Heap Backup" vs "An Initial Solution: Double Storage"
by Peter Foelsche 01 Oct '09

01 Oct '09

1) boost::variant and "Current Approach: Temporary Heap Backup" vs "An Initial Solution: Double Storage" Please provide both solutions. A potential heap allocation may prevent certain application areas. 2) I also do not understand that exception safety requires that the variant is never empty (e.g. empty() returning always false). What is the use of calling the constructor (of which type btw?) if somebody creates an unintialized variant variable? Or: In the following piece of code is the std::string constructor being called? boost::variant<std::string, int> s; Thanks Peter

2 8

Re: [boost] On the Road to Aspen (BoostCon 2010)
by Pete Bartlett 29 Sep '09

29 Sep '09

I'm sorry somehow my message was sent before I was ready... I wrote: >Many users of Boost are in corporate environments. Many corporate environments block access to Facebook and/or >Twitter (mine blocks both) domains. >It'd be great therefore if Boost didn't move too much content there if equivalent .. functionality is available on boost.org. I understand that many will think the problems lie with unenlightened corporate policies rather than boost, but the latter has a rich and noble history of BOOST_WORKAROUNDing the mistakes of others :-). Pete

1 0

[smart_ptr] comparison of intrusive_ptr objects
by Dmitry Vinogradov 29 Sep '09

29 Sep '09

Does anybody know why intrusive_ptr has ==, != and < operators, but the rest ones are missing (i.e. >, <=, >=)? It makes hard to use intrusive_ptr in generic code.

4 3

Using some of Boost on i5/OS but still problems
by Jon Brisbin 29 Sep '09

29 Sep '09

I was able to use Boost FOREACH in my tests, now I'm trying to use Boost optionals in a C++ ILE module. The compiler is yelling at me, though: "/home/jbrisbin/include/boost/optional/optional.hpp", line 434.66: CZP0210(30) "T" is not a base class of "basic_string<char,std::char_traits<char>,std::allocator<char> >". "/home/jbrisbin/include/boost/optional/optional.hpp", line 434.10: CZP0700(0) The previous message was produced while processing "boost::optional_detail::optional_base<std::basic_string<char,std::char_ traits<char>,std::allocator<char> > >::destroy_impl(is_not_reference_tag)". "/home/jbrisbin/include/boost/optional/optional.hpp", line 408.9: CZP0700(0) The previous message was produced while processing "boost::optional_detail::optional_base<std::basic_string<char,std::char_ traits<char>,std::allocator<char> > >::destroy()". "/home/jbrisbin/include/boost/optional/optional.hpp", line 237.24: CZP0700(0) The previous message was produced while processing "boost::optional_detail::optional_base<std::basic_string<char,std::char_ traits<char>,std::allocator<char> > >::~optional_base()". "/home/jbrisbin/include/boost/optional/optional.hpp", line 145.7: CZP0700(0) The previous message was produced while processing "boost::optional_detail::optional_base<std::basic_string<char,std::char_ traits<char>,std::allocator<char> > >::__dftbdt()". "/home/jbrisbin/include/boost/optional/optional.hpp", line 522.5: CZP0700(0) The previous message was produced while processing "boost::optional<std::basic_string<char,std::char_traits<char>,std::allo cator<char> > >::~optional()". "/home/jbrisbin/include/boost/optional/optional.hpp", line 454.7: CZP0700(0) The previous message was produced while processing "boost::optional<std::basic_string<char,std::char_traits<char>,std::allo cator<char> > >::__dftdt()". "/home/jbrisbin/src/boosttest.cpp", line 6.5: CZP0700(0) The previous message was produced while processing "main(int, char **)". Any hints on what I need to hack here? This seems to be a problem with: void destroy_impl ( is_not_reference_tag ) { get_ptr_impl()->T::~T () ; m_initialized = false ; } I understand what's happening, I'm just not sure how to make the i5/OS compiler happy with this. I keep running into little quirks like this where the AS400 needs a little different treatment. IBM says Boost won't work on the AS400, which I'm finding to be inaccurate at best. It DOES work, just not everything straight out of the box. Lots of things work fine, but some need a little bit of tweaking. What else can I try to get the destructor called? Jon Brisbin Portal Webmaster NPC International, Inc.

2 2

On the Road to Aspen (BoostCon 10)
by Joel de Guzman 29 Sep '09

29 Sep '09

Hi, The road to Aspen starts now. I've been to all three BoostCon events since its inaugural conference in 2007. I can tell you, the experience is definitely amazing. I've been a Boost developer since 2001. Boost is like a virtual family to me. From 2001, I've known and collaborated with countless people, many of which I haven't actually met, until the first BoostCon in 2007. Amazing people like Hartmut Kaiser, Dan Marsden, Eric Niebler, to name a few, were just names. Before BoostCon, I often wished to get to see the faces behind the names. It was exhilarating to finally meet these folks, have a couple of beer (and Pizza!), talk about C++, library development, the wondrous mountains of Aspen, the trees, the bears and coyotes (hah!). If this looks too much like a friendly post, well, it is! I'd like to break a bit from the highly technical discussions taking place in these mailing lists and point you to a FaceBook group named, ermm, "BoostCon" :-) http://www.facebook.com/group.php?gid=125839305706 My task is to invite you guys to join in. You do not have to be a former BoostCon attendee. Everyone here is invited to join. If you want to see the "faces" behind the names, get to know more of the people behind Boost, get to know more friends that share your passion for Boost, C++, templates, etc., in a more relaxed venue, this is the place. If you have even the slightest inkling to attend a future conference, well, join in. Here we can discuss things like sharing rooms to cut cost, where to find the best food in town, car pooling etc. In preparation time prior to the conference, we can discuss matters like which kind of talks you want to see, keynote speakers you'd be interested in seeing, etc. For past BoostCon attendees, here’s a chance to meet up again. Hey, even if you are not planning to attend, I'd like to invite you anyway. Consider this group as a friendly face of Boost :-). Hopefully, the friendly atmosphere will make you attend anyway ;-) Cheers, -- Joel de Guzman http://www.boostpro.com http://spirit.sf.net

3 5

Pretty type_info::name string?
by Emil Dotchevski 28 Sep '09

28 Sep '09

Do we have in Boost something that would attempt to return the pretty version (meaning, it'd fall back to returning the ugly version) of the std::type_info::name string? Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode

6 5

Trunk tests broken, missing file
by Belcourt, Kenneth 27 Sep '09

27 Sep '09

error: Unable to find file or target named error: 'algorithm/nview.cpp' error: referred from project at error: '../libs/fusion/test'

2 1

[fusion] inconsistency in size metafunction
by Jean-Louis Leroy 27 Sep '09

27 Sep '09

Consider : #include <boost/fusion/include/vector.hpp> #include <boost/fusion/include/push_back.hpp> #include <boost/fusion/include/size.hpp> #include <boost/mpl/assert.hpp> #include <boost/type_traits/is_same.hpp> int main() { using namespace boost; using namespace fusion; typedef vector<int, int> seq1; typedef result_of::push_back<vector<int>, int>::type seq2; BOOST_MPL_ASSERT((is_same<result_of::size<seq1>::type, result_of::size<seq2>::type>)); } One would not expect this to fail, however it does : 'boost::mpl::assertion_failed' : cannot convert parameter 1 from 'boost::mpl::failed ************boost::is_same<T,U>::* ***********' to 'boost::mpl::assert<false>::type' 1> with 1> [ 1> T=boost::mpl::int_<2>, 1> U=boost::mpl::integral_c<int,2> 1> ] J-L

2 2

Boost.Iterator filter_iterator issues
by Christoph Heindl 27 Sep '09

27 Sep '09

Hi, I think I've found an issue with boost::filter_iterator when decrementing a valid iterator without having any predicate evaluating to true on its way back. filter_iterator.hpp line# 93 states void decrement() { while(!this->m_predicate(*--(this->base_reference()))){}; } which will ?clearly? pass beyond the initial start iterator if no predicate evaluates to true. Is it a requirement for the iterator being adapted by filter_iterator to catch decrements past the containers begin range? The following test will iterate 'iter' past containers begin iterator which will trigger a debug assertion on MSVC. template<class _Iterator> void dec_iterator(_Iterator iter) { BOOST_CHECK(*iter == 2); --iter; // iterates past begin } BOOST_AUTO_TEST_CASE(test_filter_iterator) { using namespace boost::assign; typedef std::vector<int> container_type; container_type values = list_of(0)(1)(2); dec_iterator(boost::make_filter_iterator(std::bind2nd(std::greater<int>(), 1), values.begin(), values.end())); } Please help me clarifying this issue. Best regards, christoph

2 2

[fusion] useful as_variant in spirit2
by Christian Holmquist 26 Sep '09

26 Sep '09

Good day everyone, The function in boost\spirit\home\support\detail\as_variant.hpp seems to have no dep. on spirit, and it's a useful utility that would fit into fusion/support/as_variant.hpp> IIUC it's a meta function that computes a variant<T0, ..., TN> from a fusion sequence<T0, ..., TN>. I think there's no reason for a runtime counterpart, i.e. as_variant<Seq>::type is a valid expression but as_variant(Seq) and result_of::as_variant<Seq>::type is not. Thus, the function is already complete. Does it seem reasonable to you to include in fusion? The work of moving it would be to only update the docs, as spirit2 probably does excessive testing of this function anyway. I could collect the docs from other parts of fusion, and put together a separate test file if needed. All real work is already done, just presentation and formality that is lacking. Have a nice weekend, Christian

5 4

Tools for singleton or monostate or alternative
by Mateusz Loskot 25 Sep '09

25 Sep '09

Hi, I would like to kindly ask for advice in finding tools within Boost collection that could help me to solve my problem. I'm developing a library (it will be used as dynamic-linked library). I need to manage a bunch of related values (numbers) globally. All values are shared across a client process, by its all threads, so thread-safety is under consideration. Mostly, a client needs to read the values (defaults) and sometimes, very rarely, a client needs to re-set the values. I consider to implement it using singleton or monostate pattern with thread-safety (and DLL-safety in mind), so actually Tobias Schwinger's Singleton library [1] would solve this problem well. However, I would prefer something from the Boost collection - Tobias' lib hasn't been approved [2], quite pity as Boost lacks of such tool, IMHO. Also, I've considered digging out singleton stuff from the boost::pool::detail, but I'm not convinced to this idea. I haven't found anything related to monostate patter in Boost. Would anyone suggest a tool available in Boost that would be usable to wrap up some basic but robust solution for my problem? By the way, any plan for update and another round of review of Tobias' library? [1] http://torjo.com/tobias/index.html [2] http://lists.boost.org/boost-announce/2008/01/0171.php Best regards, -- Mateusz Loskot, http://mateusz.loskot.net Charter Member of OSGeo, http://osgeo.org

2 2

[rdb] Uploaded 0.0.07
by Jean-Louis Leroy 25 Sep '09

25 Sep '09

This version features : * insert...set syntax (but no insert...select yet) * update [where] * delete from [where] * create and drop follow the same syntax pattern as the others * attempts to simplify the internals (in insert - select still needs a second look) * some concept checks It's *beginning* to look like something one could use in simple real apps. What's missing before it qualifies is imo `like', 'exists' and transactions. That should not take long. This version compiles with msvc9 and gcc 4.4.1. I tested on Win32 with an Access db via ODBC. The sql engine tests pass on Linux but I have not tried the ODBC test suite on Unix yet. If somebody tries it, please tell me. I have changed the naming scheme : first number is major revision ; second is the milestone (crud with direct execution ; transactions ; prepared statements ; dialects ; constraints ; dynamic sql - which btw I am now nearly sure I can fit elegantly in my framework ; views). Third number is just there for getting ++'ed. The test suite is still the doc but after the transactions I'll begin documenting. Probably with QuickBook. It's funny to see that some people are still downloading 0.04. As I write this the downlaod count bumped to 21 :-D To avoid confusion due to the change in the versioning scheme I deleted the old versions. J-L

4 10

[interprocess][multi_index] emplace() is not sufficient for maps
by Thorsten Ottosen 25 Sep '09

25 Sep '09

Hi Ion and Joaquín, This issue is related to node-based containers. I think you both have added emplace() to provide efficient in-place construction. However, I often encounter a situation where emplace() is not sufficient for me. The situation is characterized by the need to calculate the key after the mapped value (a heavy object) has been placed in the pair. To calculate the key the mapped value needs to be modified (the key is calculated as a side-effect). I therefore suggest that we add a new function: typedef ... map; map m; map::node_ptr p = m.get_node_ptr(<like emplace, but only for constructing the mapped value>); p->pair.first = modify( p->pair.second ); m.insert( boost::move(p) ); Thoughts? -Thorsten

5 21

Boost build problem
by Emil Dotchevski 25 Sep '09

25 Sep '09

I'm trying to use <link>static and <runtime-link>static with my own code, which depends on boost filesystem, and I have the problem that the linker is passed libboost_filesystem-vc80-mt-sgd-1_41.lib while the debug\link-static\runtime-link-static folder has libboost_filesystem-vc80-sgd-1_41.lib. (I've built bjam from the latest trunk sources and I'm using the latest trunk revision of boost build.) HALP! :) Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode

5 7

[rdb] Uploaded 0.0.08
by Jean-Louis Leroy 24 Sep '09

24 Sep '09

Tonight: * insert...where (but doesn't check consistency between insert list and values returned form select) * like J-L

1 1

boost::variant -- this code compiles fine -- I think it should not compile
by Peter Foelsche 24 Sep '09

24 Sep '09

#include <boost/variant.hpp> struct test { }; int main(int argc, char **argv) { boost::variant<std::string, int, double> s; boost::get<test>(s); return 0; }

2 1

Matrix Library
by Cem Kalyoncu 24 Sep '09

24 Sep '09

As a part of our graphics study, we have built a 2D matrix class to implement few matrix operation. After the study we have expanded our aim for matrix operations system and started building a matrix and possibly a math library. Currently matrix library is quite near to the finish. To make it as generic as possible, we have used templates. Current state of the project can be accessed from http://sourceforge.net/projects/mathlibcpp/ (SVN: https://mathlibcpp.svn.sourceforge.net/svnroot/mathlibcpp/) A simple search revealed that there is no matrix module for boost libraries. We are willing to resolve compatibility issues and lend our support this module. However, before taking any action, I would like to ask your opinions. Thanks in advance, Cem Kalyoncu Following functions exists in the library: Set/Get/GetData/() Resize/GetSize/GetCols/GetRows isSquare/isIdentity Compare/==/!= =/Copy constructor/CopyTo [Row|Col|]Min/Max/Average/Sum/Median [Row|Col]MinIndex/MaxIndex SortRows RemoveCol/RemoveRow matrix operators (+, -, *, +=, -=, *=) scalar operator (+, -, /, *, +=, -=, *=, /=) Transpose/Determinant/Inverse/Minor/Cofactor/Adjoint Uses a managedbuffer and allows temporary matrixes which are not copied Identity/ZeroFilled/RandomFilled/RobertsCross/SobelX|Y conversion to string and output to a stream is supported

5 4

pool allocation
by Stefan Strasser 24 Sep '09

24 Sep '09

I took a closer look at Boost.Pool today to replace some default allocation of small objects. what I found there was a little disappointing, at least for my use case. the object_pool has 2 major downsides: - no dynamic block allocation - destroying one(!) object is O(N), with N being the number of unused objects in the pool so I wrote some code for my own use. I'm not suggesting this code should be added to boost, but something like it. struct A{ ... }; { pool<A,100> pool; A *a; for(int c=0;c<250;++c){ a=pool.new_(); // O(1) } pool.delete_(a); //O(1), destructs } //destruction of 249 objects, O(N) this allocates 3 memory blocks. but it also has one pointer memory overhead per object, to achieve constant time deletion. but you can use that pointer while the object is in use, which was what lead to this code: I needed to store unused boost.intrusive nodes: struct A : intrusive::[s]list_base_hook<>{ ... }; { [s]list_pool<A,[s]list_base_hook<>,100> pool; //same as above } this has no memory overhead, as the list hook can be used by the pool. here's the code: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=intrus…

3 4

[asio] Mixing of sync and async calls
by Roland Schwarz 24 Sep '09

24 Sep '09

Is it legal to mix async and sync function calls? (I was not able to find the answer in the doc.) E.g. socket.async_read_some(buf); socket.write_some(otherbuf); Also when in a blocking sync call, will it be possible to "cancel" it from another thread, e.g. by posting to the io_service which will invoke a close on the socket? Thank you in advance. -- _________________________________________ _ _ | Roland Schwarz aka. speedsnail |_)(_ | sip:speedsnail@ekiga.net | \__) | mailto:roland.schwarz@chello.at ________| http://www.blackspace.at

2 2

[BGL] read_graphviz()/read_graphml() and subgraphs
by Giuseppe Di Guglielmo 24 Sep '09

24 Sep '09

Dear all, I read on the 'read_graphviz()' page in BGL library doc http://www.boost.org/doc/libs/1_40_0/libs/graph/doc/read_graphviz.html * read_graphviz treats subgraphs as syntactic sugar. It does not reflect subgraphs as actual entities in the BGL. Rather, they are used to shorten some edge definitions as well as to give a subset of all nodes or edges certain properties. For example, the DOT graphs digraph { a -> subgraph {b -> c} -> e } and digraph { a -> b -> e ; a -> c -> e ; b -> c} are equivalent. Is this actually true? Can I read sub-graph from DOT description and obtain a subgraph object? http://www.boost.org/doc/libs/1_40_0/libs/graph/doc/subgraph.html Eventually are subgraph supported by 'read_graphml()' function? http://www.boost.org/doc/libs/1_40_0/libs/graph/doc/read_graphml.html Thanks, G.

1 0

[multi_index] Missing mutex lock?
by Anatoly Pinchuk 23 Sep '09

23 Sep '09

Possible traversal and modifications of a safe container iterators list inside safe_mode::detach_equivalent_iterators function are not protected with locking like the following one in safe_iterator_base::detach function. #if defined(BOOST_HAS_THREADS) boost::detail::lightweight_mutex::scoped_lock lock(cont->mutex); #endif Unless some kind of synchronization is provided by callers of the safe_mode API, the list above can be traversed/modified and modified concurrently in BOOST_HAS_THREADS environment. It would be great if somebody can confirm or deny that there is the access synchronization problem. Regards, Anatoly

3 5

Re: [boost] scoped_ptr deleter
by Berserker 22 Sep '09

22 Sep '09

Stewart, Robert wrote: > That change creates multiple, distinct classes. > shared_ptr<T,boost::checked_deleter<T>> is not the same as shared_ptr<T,my_deleter<T>>. > By embedding the deleter in the shared_ptr with type erasure, > shared_ptr<T> is shared_ptr<T> is shared_ptr<T>, regardless of the deleter. Sure and that's the point :) As I wrote, since the "noncopyable nature" of scoped_ptr (shared_ptr is copiable by design), the creation of distinct classes isn't a problem. I think that the "real problem" here is to provide a solution that doesn't require extra memory overhead. _________________________________________________________________ Gossip, Sport, Notizie... Accendi la Messenger TV! http://www.messenger.it/messengerTV.aspx

9 24

Re: [boost] [Boost-users] Parallel BGL status in Boost
by Craig Henderson 22 Sep '09

22 Sep '09

> Nick Edmonds wrote: > >> On Sat, Sep 12, 2009 at 9:42 PM, Nick Edmonds > <ngedmond(a)cs.indiana.edu> wrote: > >> > >>> yet). There's also a very nascent project to do multi-core/highly > >>> multi-threaded BGL, starting from the BGL sources as opposed to > PBGL. > >> > >> Any pointers ? It would be nice if they look at using the map-reduce > >> library (boost candidate) > >> > > It's very early stages so no, no docs/code yet, it's basically some > new PhD students in my lab with me and another post-doc mentoring > them. I would anticipate that map-reduce is too > coarse-grained/BSP-like to capture the fine grained dependencies we > need to capture to get good performance in a memory-bandwidth bound > domain like sparse graphs, but I'll mention it and see if they want to > write a sample algorithm with it and run some numbers. We're > investigating a few different options for organizing/parallelizing the > work, including starting from scratch. > > It would be nice to see how the map-reduce library performs though. > Do you have any performance data for using it on highly multi-threaded > architectures (Sun Niagara, Cray XMT, anything with >8 cores really)? > Hi Nick, the Map/Reduce library is available in the sandbox and in the vault. The performance is as much down to the implementation of the map and reduce tasks as the framework itself. Jose has compared performance of my library with Standford University's Pheonix implementation and the performance is comparable (http://lists.boost.org/Archives/boost/2009/08/155759.php) I have tested the library on MS Windows on servers with 16-cores and performance has scaled well - if you get the input's segregated sufficiently to avoid contention. I don't yet have any benchmarks, but am looking for some suitable algorithms if you're interested in contributing. Regards -- Craig

1 0

Creating a new toolset for System i *SRVPGMs
by Jon Brisbin 22 Sep '09

22 Sep '09

We're integrating our C++ development with our RPG/400 development and since we use Boost on the PC end, we'd really like to use Boost on the AS400/System i integration stuff. I can successfully compile service programs on the 400 that use boost header-only libraries (with some minor tweaking of the Boost source...I'm finding various things that have to be changed to accommodate the 400 compiler) using the "ixlc" compiler. I think what I need to do to use Boost.Build on the 400 is to create a new toolset that is like gcc, but uses the "ixlc" and "ixlclink" commands to compile *MODULEs and *SRVPGMs. I'm just not familiar enough with Boost.Build to figure out how to do this. I'm actually a Java programmer and not even very experienced in C++, though I've been a unix geek for a long time, so I'm very familiar with the build tools. Since the library/file(member) convention of working with these files on the 400 doesn't translate directly across to files on a unix-like filesystem, I'm thinking I'll have to have directories that correspond to libraries and the source file basename that corresponds to the object name. For example, source file: cpplib/mycpptest.cpp would be compiled using "ixlc" like: ixlc -ocpplib/mycpptest -qdbgview=all -qprint (other options) cpplib/ mycpptest.cpp this would create a *MODULE object called "MYCPPTEST" in library "CPPLIB". How would I translate this to a boost build toolset that I could use by writing a Jamfile like the following...? module cpplib/mycpptest : cpplib/mycpptest.cpp ; srvpgm cpplib/mycpptest : cpplib/mycpptest cpplib/myothrmod ; at some point, I'd probably like to specify a default library, but I can probably do that by using variables in my project's root file. Can anyone help me with this, even though you may not have direct experience with the AS400 (it would be great if there were boost developers who worked on or with 400's, though! ;)? Jon Brisbin Portal Webmaster NPC International, Inc.

1 0

[serialization] serialize shared_from_this() pointer
by Zoran Cvetkov 22 Sep '09

22 Sep '09

Does someone have experience serializing a class that inherits from a shared_from_this() pointer? If I just do nothing I am getting 0 pointer during deserialization. What would be the proper syntax for serializing it, if it's needed?

1 0

review request: addition to type_traits library of is_less_comparable<T> and others
by Frédéric Bron 22 Sep '09

22 Sep '09

Hi folks, I would like to propose to your review the following addition to the type_traits library. The addition is attached to this email and also available in the sandbox at https://svn.boost.org/trac/boost/browser/sandbox/type_traits The purpose of the addition is to add type traits to detect if type T is comparable in the sens of <, <=, >, >=, == or != operators, i.e. if t1<t2 has a sens when t1 and t2 are of type T (same for <=, >, >=, ==, !=). The following traits are added: is_equal_to_comparable<T> is_greater_comparable<T> is_greater_equal_comparable<T> is_less_comparable<T> is_less_equal_comparable<T> is_not_equal_to_comparable<T> The names are based on the corresponding names of the standard template library (<functional> header, section 20.3.3 of the standard). The compilation has been tested with g++ 4.3.2 and icpc 10.0 on linux 64 bits, g++ 3.4.4 on cygwin, mingw32 3.4.4 on cygwin. I must add that I did not invent the code (I obtained some help from the boost mailing list) but I put it together in a form that should be acceptable to boost. Regards, Frédéric

8 23

Possible submission: Dynamic library policy loading library?
by Rob Meijer 22 Sep '09

22 Sep '09

In the Open Computer Forensics Architecture library ( http://sourceforge.net/projects/ocfa/ ), a simple template sub library is used for policy loading with shared libraries. This stuff is currently buried in a large library, and it would seem prety usefull to extract this sub library into an enviroment (like boost) where it can be used within a wider scope. To show apptoximately how this sub library is used, I've taken a few lines from a part of OcfaLib that uses this functionality: The below example is used to load an implementation of the abstract TreeGraphFactory class within a loadable library "libtesttreegraph.so" with a constructor function named "constructor" in it. std::string module="testtreegraph"; //Define a type for the constructor. typedef SinglePointerConstructor< TreeGraphFactory, std::map< std::string,misc::Scalar > > CTreegraphType; //Define a type for the policy loader. typedef PolicyLoader<CTreegraphType> PLTreeGraph; //Create a new policy loader object for a given module and constructor function name. PLTreeGraph *mPolicyLoader=new PolicyLoader<CTreegraphType>(module,"constructor"); //Fetch the constructor from the policy loader. CTreegraphType *constructor = mPolicyLoader->constructor(); //Construct an object using the constructor TreeGraphFactory * mActiveFileSystem =(*constructor)(attributes); For more info, the relevant headers in the ocfa source tree are: OcfaLib/inc/misc/PolicyLoader.hpp OcfaLib/inc/misc/VoidToFunction.hpp It probably needs some work on portability and needs more constuctor templates to be fully generically usable, but I feel this has the potential to be a very usefull extention to boost. Do you people feel this should be further explored and submitted as a possible extension for boost? Rob

1 0

Feed pointers to a container, however use the member of the data type which pointer refer to
by 路邓 22 Sep '09

22 Sep '09

Dear All: In the following codes, I feed the container with B*, however I user the member of B as the index. Can somebody explain to me how this work out? And It seems that if smart pointers are feeded into the container, it still works out. #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */ #include <boost/multi_index_container.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/member.hpp> #include <iostream> using namespace boost::multi_index; class B { public: int idx; }; typedef boost::multi_index_container< B*, indexed_by< ordered_unique< BOOST_MULTI_INDEX_MEMBER(B, int, idx) > > >Container; int main() { Container container; B* p1 = new B; B* p2 = new B; p1->idx = 2; p2->idx = 1; container.insert(p1); container.insert(p2); Container::iterator iter; for(iter=container.begin();iter!=container.end();iter++) { B* tmp = (*iter); std::cout << tmp->idx << std::endl; } return 0; } ___________________________________________________________ 好玩贺卡等你发，邮箱贺卡全新上线！ http://card.mail.cn.yahoo.com/

2 1

Feed pointers to a container, however use the member of the data type which pointer refer to as an index
by 路邓 22 Sep '09

22 Sep '09

Dear All: In the following codes, I feed the container with B*, however I user the member of B as the index. Can somebody explain to me how this work out? And It seems that if smart pointers are feeded into the container, it still works out. #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */ #include <boost/multi_index_container.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/member.hpp> #include <iostream> using namespace boost::multi_index; class B { public: int idx; }; typedef boost::multi_index_container< B*, indexed_by< ordered_unique< BOOST_MULTI_INDEX_MEMBER(B, int, idx) > > >Container; int main() { Container container; B* p1 = new B; B* p2 = new B; p1->idx = 2; p2->idx = 1; container.insert(p1); container.insert(p2); Container::iterator iter; for(iter=container.begin();iter!=container.end();iter++) { B* tmp = (*iter); std::cout << tmp->idx << std::endl; } return 0; } 好玩贺卡等你发，邮箱贺卡全新上线！ ___________________________________________________________ 好玩贺卡等你发，邮箱贺卡全新上线！ http://card.mail.cn.yahoo.com/

1 0

[variant]anyone working on variadic template version?
by Larry Evans 22 Sep '09

22 Sep '09

Is anyone working on a variadic template version of variant, i.e. one that defined as: template<typename... T>class variant; instead of: template < typename T0 = detail::variant::void_ , typename T1 = detail::variant::void_ ... , typename T19 = detail::variant::void_ > class variant; ? I'm thinking of attempting that, but I'd hate to waste time if someone else has already done it or made some progress on it. Although BoostCon09 did have a workshop on CXX0x: http://www.boostcon.com/community/wiki/show/Start/HandsOnCXX0x/ the sandbox directory for that: https://svn.boost.org/svn/boost/sandbox/boost0x didn't appear to use the variadic template feature in variant: https://svn.boost.org/svn/boost/sandbox/boost0x/boost/variant/variant_fwd.h… TIA. -regards, Larry

3 6

[rdb] 0.04
by Jean-Louis Leroy 21 Sep '09

21 Sep '09

I have uploaded a new version of my relational database library to the vault. It implements the ideas I described in another thread. This time it even puts things in a real (odbc) database and retrieves them. I see that 12 have downloaded the previous versions. If you have time please send me feedback. Have you been able to compile it ? Has anybody tried on Unix or with other compilers ? Please note: * It's a work in progress ; for the curious only. * I develop on Windows with Visual Studio Express 2008. There is a solution file in the msvc dir. Nothing bjam works yet. * Currently the doc is the test suite Jean-Louis Leroy

3 8

[rdb] 0.05 - also a fusion problem
by Jean-Louis Leroy 21 Sep '09

21 Sep '09

This upload is mostly for fixing an embarassing bug that the test suite would have detected if I had not put a "return 0" in the middle of it. In addition I have restructured the tests into suites and cases. Jam files begin to work, at least they allow me to build with bjam from the boost tree. While I'm at it, here's the bug, in case somebody has an idea. I have to initially create my fusion::list's of expressions and tables with `push_back(list<>(), val)' instead of just `make_list(val)', otherwise I get access violations. I see in the debugger that the first element of my list is damaged during the next function call, most probably because a reference to a temporary was created along the way. Has anybody had this kind of problem ? I use boost 1.39. J-L

1 0

Problems testing compiling on AS400/i5/whatever
by Jon Brisbin 21 Sep '09

21 Sep '09

I'm using the QSH environment on AS400 and the "ixlc" compiler (basically just CRTCPPMOD), trying to compile the following test program: #include <iostream> #include <boost/foreach.hpp> int main(int argc, char** argv) { std::string hello = "Hello, world!"; BOOST_FOREACH( char ch, hello ) { std::cout << ch << std::endl; } return (EXIT_SUCCESS); } Which results in the following errors: The compilation failed. /home/jbrisbin/include/boost/type_traits/is_member_pointer.hpp Line 000054 "/home/jbrisbin/include/boost/type_traits/ is_member_pointer.hpp", line 54.63: CZP0403(30) "template <class T, class U> struct boost::is_member_pointer" is alread ERROR 1 001 /home/jbrisbin/include/boost/type_traits/is_member_pointer.hpp Line 000055 "/home/jbrisbin/include/boost/type_traits/ is_member_pointer.hpp", line 55.63: CZP0403(30) "template <class T, class U> struct boost::is_member_pointer" is alr ERROR 1 001 /home/jbrisbin/include/boost/type_traits/is_member_pointer.hpp Line 000056 "/home/jbrisbin/include/boost/type_traits/ is_member_pointer.hpp", line 56.63: CZP0403(30) "template <class T, class U> struct boost::is_member_pointer" ERROR 1 001 2 000051 The full text of the error complains that these are already defined. Does anyone have pointers or tricks that could point me in the right direction to compile programs that use header-only Boost libs on the AS400? Any help would be appreciated! :) Jon Brisbin Portal Webmaster NPC International, Inc.

1 0

[PBGL] and [MTGL]
by Cosimo Calabrese 21 Sep '09

21 Sep '09

Hi to all, I open this discussion as a "branch" of "[BGL] Multithread problem inserting edges and exploring the same graph". Can someone tell me if the PBGL and MTGL can help me? I report my problem below, for sake of comfort. Thanks in advance, Cosimo Calabrese. ************************************************** I've a problem on BGL. My environment is WinXP, Visual Studio 2005, Boost 1.37. I'm trying to use BGL in the following way. I've a single graph in my application, that is an adjacency_list< vecS, vecS, ... >, and I've 2 kind of threads that work on the graph: - some "Explorer" threads, that executes a Dijkstra's algorithm repeatedly; - some "Integrator" thread, that call the add_edge() function repeatedly. The program often crashes, because it cannot dereference some graph elements, some auto_ptr... The crash isn't sistematic, so I think there's a concurrency problem. [...] **************************************************

2 1

Python 3 support has landed on boost trunk
by Stefan Seefeld 21 Sep '09

21 Sep '09

Hi there, as some of you may know, Haoyu Bai has worked over the summer on Python 3 support for Boost.Python. This work happened on a branch, which I merged back into trunk last night. Now we need to set up testers to run the testsuite with some Python 3 variant, as that is a new platform to track. I will see whether I can set one up on one of my machines. Regards, Stefan -- ...ich hab' noch einen Koffer in Berlin...

3 4

[filesystem] Compatibility with STLPort
by Andrey Semashev 21 Sep '09

21 Sep '09

Hi, I've created ticket #3241 some time ago, with a patch attached. It's about Boost.Filesystem compatibility with STLPort expression templates feature. So far no activity has appeared on it, although the fix is trivial. Is it OK if I go ahead and commit the patch? PS: Ticket URL is https://svn.boost.org/trac/boost/ticket/3241

3 6

unsigned long vs unsigned int vs std::size_t (32b platform)
by Christoph Mathys 21 Sep '09

21 Sep '09

Hello! First: I'm working on 32b Linux (gcc 4.2.4) and 32b XP (Visual Studio 9 SP1). I tried to switch from stdint.h to boost/cstdint.hpp, but had to find out that this is not as straight forward as I thought. The compilers handle 'unsigned int' and 'unsigned long' as different types, even though on 32b it is AFAIK the same type. This by itself is OK, but gcc and VS9 seem to disagree in where it comes to defining std::size_t. The result is that the code at the end compiles on visual studio, but not on gcc: asdf.cpp: In function ‘void someFunc(size_t)’: asdf.cpp:6: error: redefinition of ‘void someFunc(size_t)’ asdf.cpp:5: error: ‘void someFunc(uint32_t)’ previously defined here asdf.cpp: In function ‘int main(int, char**)’: asdf.cpp:16: error: call of overloaded ‘someFunc(long unsigned int&)’ is ambiguous asdf.cpp:4: note: candidates are: void someFunc(uint16_t) asdf.cpp:5: note: void someFunc(uint32_t) In the stdint.h we used for visual studio previously, this error did not occur because uint32_t was typedefd to 'unsigned __int32'. Now, the questions are: - should boost::uint32_t be typedefed to the same thing that std::size_t is on 32b platforms? - Is the size of std::size_t fixed or dependant on the platform it is used on? - Did I do something wrong and there is a much better way of doing it avoiding those problems in the first place? #include <boost/static_assert.hpp> #include <boost/cstdint.hpp> void someFunc(boost::uint16_t) { } void someFunc(boost::uint32_t) { } void someFunc(std::size_t) { } int main(int, char**) { BOOST_STATIC_ASSERT(sizeof (unsigned long) == sizeof (unsigned int)); BOOST_STATIC_ASSERT(sizeof (unsigned long) == sizeof (std::size_t)); unsigned long ul = 42; unsigned int ui = 1337; std::size_t st = 2; someFunc(ul); someFunc(ui); someFunc(st); return 0; }

5 7

[repost][multi_index][serialization][Huang-Vista-x86_32_intel] Help with weird test failure
by joaquin＠tid.es 21 Sep '09

21 Sep '09

Hi, my first attempt went unanswered, reposting in the hope it'll bring more attention this time around: Huang-Vista-x86_32_intel toolset, which runs Intel 11.1 for Window, has this weird error on the serialization test for Boost.MultiIndex: Running 1 test case... ../libs/multi_index/test/test_serialization_template.hpp(82): error in "test_main_caller( argc, argv )": check all_indices_equal(m,m2) failed unknown location(0): fatal error in "test_main_caller( argc, argv )": std::exception: invalid signature (http://tinyurl.com/nd89x2 ) What I find weird is the throwing of invalid_signature, a Boost.Serialization exception that, according to docs, indicates that the beginning of a serialization file is not correct. I can't see how a problem with serializing multi_index_containers can lead to a file signature error. Any clue? Maybe the toolset maintainer can run this manually and provide more info? Thank you in advance, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

1 0

[Foreach] Proposal to simplify using Boost.Foreach with maps
by Chris Purcell 20 Sep '09

20 Sep '09

As documented in the manual ("Pitfalls"), BOOST_FOREACH is a little awkward to use with associative containers. I've used the following in the past to simplify my own code, and wondered if it was suitable to add to the Boost Foreach library proper. std::map<int, int> my_map; BOOST_FOREACH_PAIR(int key, int value, my_map) std::cout << key << " : " << value << "\n"; The BOOST_FOREACH_PAIR macro is a clone of the BOOST_FOREACH macro with an extra for loop in it to assign both first and second from each pair in the map. If either is not wanted, ignore from Boost.Tuples can be used: std::vector<int> values; BOOST_FOREACH(boost::tuples::ignore, int value, my_map) values.push_back(value); References can be used just as with BOOST_FOREACH, to create a modifying loop: BOOST_FOREACH_PAIR(int key, int& value, my_map) value += key; There are a few alternatives to my solution that I have seen: (1) Predeclare a pair and use it each time around the loop: std::pair<int, int> kv; BOOST_FOREACH(kv, my_map) std::cout << kv.first << " : " << kv.second << "\n"; This adds overhead from copying pairs, and does not give meaningful names to the two halves of the pair. It also has no simple extension to a mutating loop that I am aware of. (2) Typedef the value type of the map before the loop, and use .first and .second: typedef std::pair<const int, int> KeyValue; BOOST_FOREACH(KeyValue const& kv, my_map) std::cout << kv.first << " : " << kv.second << "\n"; This removes the copying overhead, and is easy to change to a mutating loop, but still does not meaningfully name the key and value (3) Use Boost.Tuple's tie to turn the single assignment of BOOST_FOREACH into a double assignment: int key, value; BOOST_FOREACH(boost::tie(key, value), my_map) std::cout << key << " : " << value << "\n" This gives meaningful names, but has copying overhead (albeit not in this simple example). It also has no simple extension to a mutating loop that I am aware of. The key objection to all of these alternatives, from my point of view, is simply that they are unnecessarily complicated. The new macro is much cleaner. Implementation of BOOST_FOREACH_PAIR is simple: turn the innermost assignment loop of BOOST_FOREACH into a pair of loops, one assigning key, one value. Cheers, Chris Purcell

6 11

[polygon] late review
by Gordon Woodhull 20 Sep '09

20 Sep '09

Hi all, Sorry this is late - I intended to participate in the discussion, but the review schedule happened to intersect with an offline vacation. (Plus day job, school starting, etc.) Thank you, Luke, for submitting what I think is a very good start toward a Boost geometry library. I do not think the library is ready for inclusion in Boost at this time, but I believe it will be with further improvements. I would almost vote for acceptance with conditions, but the list is long and I think the concepts merit more discussion. Unfortunately I have not had time to take an in-depth look at the library; I have read some of the documentation and examples and it looks useable. So this is mostly a non-technical review of the issues raised by others. Also I offer a bit of "meta-review" of the review process for libraries that will continue to evolve and merge with other libraries. My application domain is mainly graph drawing (network visualization) but I might also use this in 2D screen graphics and games. For these purposes, the restriction to two dimensions is acceptable, and even the restriction to integer coordinates is mostly acceptable. However, I think the library name should reflect these restrictions. It will be some time (if ever) before a library can claim to be The geometry or polygon library. Boost has no merge process (if that's even possible), and neither Polygon nor GGL subsumes the other, so I think they should eventually be accepted in parallel, and merge concepts and algorithms over time. As I see it, this library provides two major contributions: 1. A set of concepts for VLSI and other 45/90 degree applications which can in the future be extended or bridged to other geometric problem domains, e.g. GIS, 3D, n-dimensional. 2. An extremely robust and (I believe) efficient polygon intersection algorithm. The interface still needs some work, but the concepts are a valuable first pass at defining this domain. I want to see some system of libraries that supports rectangles through arcs all the way up to splinegons. This isn't that, but I am patient. I will be interested to compare the advantages of concepts for polygons with holes versus the runtime version in GGL. I don't agree that accepting a library where the concepts/interface are incomplete or even wrong will pollute a future generalized geometry library. This library will just have to improved over time, and influenced by libraries from other domains. To mention just one specific interface problem: I don't like rect - int meaning shrink the rectangle. I think that everyone is going to have strong opinions about what operators they like and dislike and I hope that some future geometry library will allow choosing different sets for different domains. The intersection algorithm is very, very cool and I hope the ideas can be extended someday by someone to provide robust intersection of arcs and splines. I don't yet understand whether this is possible. I agree with those who would like to see lazier evaluation to run the intersection algorithm on as much as possible. Luke and Barend, I'm sorry but I don't believe either of your benchmarks. I think you are choosing problems that suit each of your libraries. This is understandable, but we will need to build a comprehensive suite of examples from many different domains to learn which algorithms are actually faster in which situations. Meta-review I admire the Boost process for protecting authorial control over libraries. However, one consequence is that two very important requirements, maintenance and cooperation, are only ensured indirectly by vigorous debate. 1. Maintenance. This is not really addressed by the Boost rules or review process, except to remind authors that they will be responsible for maintenance or for finding a new maintainer. There is no way to compel authors to respond to their users except for the threat of library removal which IIUC has almost never happened. So one of my essential criteria in reviewing a library - I've only reviewed one other library but followed many other reviews closely - is the attitude of the author toward changes requested. Users are inevitably going to have new requirements. Luke definitely seems willing to make the changes that are needed to get this into Boost, and I trust that he'll continue to help it adapt. I am slightly concerned that Intel will not allow the library to depend on Boost because I think that will slow down improvement. In particular I think operator customization and lazy evaluation would be helped by using Proto. I hope Intel will allow this. Or maybe that's the scope of a different library. 2. Cooperation. Boost has no rules or process for making libraries work together, never mind merging them. Maybe there is some work to be done here. But people will naturally want to make their libraries compatible if they're under the same umbrella. Competition is also a healthy human drive, but it's especially productive when there is some basis of cooperation, as I think there is between Luke and Barend, despite how nerves may have frayed during this review. I hope that both libraries are accepted, when ready, and that the authors and others interested in a "universal" Boost geometry library work to find the commonalities and connections. Fervently waiting, Gordon

2 2

Formal Review: Boost.Polygon starts today August 24, 2009
by Fernando Cacciola 20 Sep '09

20 Sep '09

Dear Developers, The formal review of the Boost.Polygon library by Lucanus Simonson starts today, August 24, 2009 and will finish September 2, 2009. I really hope to see your vote and your participation in the discussions on the Boost mailing lists! --------------------------------------------------- About the library: The boost polygon library provides algorithms focused on manipulating planar polygon geometry data. Specific algorithms provided are the polygon set operations (intersection, union, difference, disjoint-union) and related algorithms such as polygon connectivity graph extraction, offsetting and map-overlay. These so-called Boolean algorithms are of significant interest in GIS (Geospatial Information Systems), VLSI CAD as well al other fields of CAD, and many more application areas, and providing them is the primary focus of this library. The polygon library is not intended to cover all of computational geometry in its scope, and provides a set of capabilities for working with coordinates, points, intervals and rectangles that are needed to support implementing and interacting with polygon data structures and algorithms. Specifically, 3d and non-Cartesian/non-planar geometry is outside of the scope of the polygon library The design philosophy behind the polygon library was to create an API for invoking the library algorithms it provides on user geometry data types that is maximally intuitive, minimally error-prone and easy to integrate into pre-existing applications. C++-concepts based template meta-programming combined with generic operator overloading meets these design goals without sacrificing the runtime or memory efficiency of the underlying algorithms. This API makes the following code snippet that operates on non-library geometry types possible: void foo(list<CPolygon>& result, const list<CPolygon>& a, const list<CPolygon>& b, int deflateValue) { CBoundingBox domainExtent; using namespace boost::polygon::operators; boost::polygon::extents(domainExtent, a); result += (b & domainExtent) ^ (a - deflateValue); } The source is available at http://svn.boost.org/svn/boost/sandbox/gtl/boost/polygon/ And the documentation is at http://svn.boost.org/svn/boost/sandbox/gtl/doc/index.htm --------------------------------------------------- Please always state in your review, whether you think the library should be accepted as a Boost library! Additionally please consider giving feedback on the following general topics: - 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? Best Regards Fernando Cacciola Review Manager

30 142

SQL client library ?
by Jean-Louis Leroy 19 Sep '09

19 Sep '09

What's the situation with SQL client libraries (similar to Rogue Wave's DBTools.h++) ? I know that there's a boost_sql_cli in the Vault, but it doesn't seem to make much progress. I have also heard about plans to bring Soci into Boost. Thanks, Jean-Louis

19 42

Error building Boost.MPI on WinXP with MPICH2
by Craig Henderson 19 Sep '09

19 Sep '09

I am trying to build Boost.MPI for the first time. I've downloaded and installed MPICH2 on my Windows XP machine, and added "using mpi ;" to tools/build/v2/user-config.jam file, and the mpich2/bin to the path. When I run bjam, I get the following output. ------------------------------------------------------ C:\root\Development\Library\Boost\boost_1_39_0>..\bjam --with-mpi The system cannot find the path specified. The system cannot find the path specified. The system cannot find the path specified. MPI auto-detection failed: unknown wrapper compiler mpic++ Please report this error to the Boost mailing list: http://www.boost.org You will need to manually configure MPI support. WARNING: No python installation configured and autoconfiguration failed. See http://www.boost.org/libs/python/doc/building.html for configuration instructions or pass --without-python to suppress this message and silently skip all Boost.Python targets Building C++ Boost. ------------------------------------------------------ The environment runs for building all other Boost libraries. Any ideas what's wrong or how to diagnose the problem? Thanks -- Craig Craig Henderson http://www.craighenderson.co.uk http://www.siteupdatenotification.com

1 0

cannot pass objects of non-POD type ‘class boost::detail::shared_count’ through ‘...’; call will abort at runtime
by Dave Steffen 19 Sep '09

19 Sep '09

Hi Folks [ Sorry if this gets posted twice; my company email server changed my email address, and I think my first post got bounced. Argh.] Just tried to compile my project with GCC 4.3 and Boost 1.40. (It compiles and works just fine with Boost 1.38.) As part of a home-built thread-locking shared pointer thing, we have this code: /// Constructor from pointer to complete type template<class Y> explicit shared_locking_ptr( Y * p ): px( p ), pn( p ) // Y must be complete { boost::detail::sp_enable_shared_from_this( pn, p, p ); } which now produces this result: ../util/thread/shared_locking_ptr.hpp:57:9: warning: cannot pass objects of non-POD type ‘class boost::detail::shared_count’ through ‘...’; call will abort at runtime In Boost 1.38, the relevent code in shared_ptr.hpp was this AFAICT: #ifdef _MANAGED [ ... ] #else // _MANAGED [...] inline void sp_enable_shared_from_this( shared_count const & /*pn*/, ... ) { } #endif // _MANAGED In 1.40, it's been changed to #ifdef _MANAGED [...] #else // _MANAGED inline void sp_enable_shared_from_this( ... ) { } #endif // _MANAGED Does anyone know why the change? Has anybody else seen this problem? It seems to me that GCC is correct, and that although it's an empty function so it doesn't matter anyway, the earlier version is preferable. Alternately, does anyone know of a way to silence GCC's warning? -- Dave Steffen, Ph.D - Software Engineer Numerica Corporation (www.numerica.us <http://www.numerica.us/> ) 4850 Hahns Peak Drive, Suite 200 Loveland, Colorado 80538 main (970) 461-2000 x 227 direct (970) 612-2327 fax (970) 461-2004 Email: dave.steffen(a)numerica.us

4 4

[iostreams][bug] Uncaught exception in destructor when using file_descriptor
by Sylvester-Bradley, Gareth 19 Sep '09

19 Sep '09

https://svn.boost.org/trac/boost/ticket/2932 I hope it's appropriate to ping the list about this issue, which was reported 4 months ago and has not been fixed in 1.39.0 or on the trunk. If closing a file descriptor fails, file_descriptor::impl::~impl() (or file_descriptor_impl::~file_descriptor_impl() on the trunk) throws an exception. This has the potential to happen during stack unwinding, causing immediate std::terminate(). Since the fix appears to be a trivial addition of try { /*...*/ } catch (...) {} it'd be a shame if this wasn't fixed in 1.40.0. Cheers, Gareth ************************************************************************ The information contained in this message or any of its attachments may be confidential and is intended for the exclusive use of the addressee(s). Any disclosure, reproduction, distribution or other dissemination or use of this communication is strictly prohibited without the express permission of the sender. The views expressed in this email are those of the individual and not necessarily those of Sony or Sony affiliated companies. Sony email is for business use only. This email and any response may be monitored by Sony to be in compliance with Sony's global policies and standards

2 2

Policy related to the time between a library is accepted and released?
by vicente.botet 18 Sep '09

18 Sep '09

Hi, On "Past Review Results and Milestones" (http://www.boost.org/community/review_schedule.html) we see the following There are 3 libraries accepted more than 1 year ago that are commited on trunk but not yet on release . * Property Tree Marcin Kalicinski May 20, 2006 * Forward (fast-track) Tobias Schwinger John Torjo December 3, 2007 - December 7, 2007 * Factory (fast-track) Tobias Schwinger John Torjo December 17, 2007 - December 21, 2007 There are 2 libraries accepted more than 1 year ago but not yet commited on trunk. * Time Series Eric Niebler August 17, 2007 * Floating Point Utilities Johan Råde Mars 8, 2008 There are 2 libraries accepted provisionally more than 1 year ago but without any outcome. * Switch Steven Watanabe January 13, 2008 * Phoenix Joel de Guzman Hartmut Kaiser September 21, 2008 - September 30, 2008 I understand that the authors have a lot of other things to do, but one year seems to me a good delay. Should't Boost have a policy related to the time between a library is accepted and released? If yes, which one? Best regards, Vicente

1 0

Need help with workaround for MSVC bug
by Emil Dotchevski 18 Sep '09

18 Sep '09

On MSVC, the following correct code produces error C2896: 'void operator ||(T,void (__cdecl *)(tag<X>))' : cannot use function template 'void bar(tag<X>)' as a function argument. struct foo { }; template <int X> struct tag { }; template <int X> void bar( tag<X> ) { } template <class T,int X> void operator||(T, void(*)(tag<X>)) { } int main() { foo()||bar<1>; } My goal is to have an operator|| overload that deduces tag<X> implicitly, but without using parenthesis, that is, foo()||bar<1>() wouldn't be satisfactory. Doesn't seem possible, but still I decided to ask. Any ideas? Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode

6 8

[type_traits] warning free is_signed on g++
by Edd Dawson 18 Sep '09

18 Sep '09

Hello, When using boost::is_signed<> on types such as unsigned int and unsigned long, various recent versions of g++ (MinGW 4.4.0 and Apple's 4.0.1, at least) spit out a warning: warning: comparison of unsigned expression < 0 is always false Would there be any harm in changing boost::detail::is_signed_helper in boost/type_traits/is_signed.hpp as follows? template <class T> struct is_signed_helper { typedef typename remove_cv<T>::type no_cv_t; // BOOST_STATIC_CONSTANT(bool, value = (static_cast<no_cv_t>(-1) < 0)); BOOST_STATIC_CONSTANT(bool, value = (static_cast<no_cv_t>(-1) < 1)); }; This change gets rid of the warnings emitted by g++. Kind regards, Edd

3 2

Boost on MSVC without Microsoft Extensions
by Craig Henderson 17 Sep '09

17 Sep '09

I am trying to build a client program using Boost on MSVC8 with the "Disable Language Extensions" /Za compilation flag. visual.hpp contains the following code // disable Win32 API's if compiler extentions are // turned off: // #ifndef _MSC_EXTENSIONS # define BOOST_DISABLE_WIN32 #endif win32.hpp contains: #ifndef BOOST_DISABLE_WIN32 // WEK: Added #define BOOST_HAS_FTIME #define BOOST_WINDOWS 1 #endif So, the preprocessor defines BOOST_DISABLE_WIN32 and doesn't define BOOST_WINDOWS. This doesn't sound right, and causes problems with Boost.ASIO where the Windows header files are conditionally included using #if defined(BOOST_WINDOWS) || defined(__CYGWIN__) which clearly evaluates FALSE. I consider this a bug in the boost config compiler detection rather than the asio library. Has anyone compiled with /ZA on MSVC? Thanks -- Craig Craig Henderson <http://craighenderson.co.uk/> http://www.craighenderson.co.uk http://www.siteupdatenotification.com

2 1

[task] new version 0.3.0
by k-oli＠gmx.de 17 Sep '09

17 Sep '09

I've uploaded a new version of boost.task - I hope someone will give me some feedback. regards, Oliver

1 0

cannot pass objects of non-POD type ‘class boost::detail::shared_count’ through ‘...’; call will abort at runtime
by Dave Steffen 17 Sep '09

17 Sep '09

Peter Dimov wrote: > I wrote: >> >>( Just tried to compile my project with GCC 4.3 and Boost 1.40. (It >> compiles and works just fine with Boost 1.38.) >> >> As part of a home-built thread-locking shared pointer thing, we have >> this code: [...] > > The signature of sp_enable_shared_from_this has changed, it now takes a > pointer to a shared_ptr as its first argument. Look at the current > shared_ptr constructor: > > template<class Y> > explicit shared_ptr( Y * p ): px( p ), pn( p ) // Y must be complete > { > boost::detail::sp_enable_shared_from_this( this, p, p ); > } > > Relying on implementation details has its maintenance costs. :-) Yeah. There are actually much better ways to do this now, like Boost threads and some other things, that weren't available when we started the project. It's also true that some refactoring would make the whole point moot, but I was really hoping to avoid tackling that on the current contract. > You'll probably need to refactor shared_locking_ptr to contain (or > privately derive from) a shared_ptr. ... which, arguably, we could have done in the first place. I'm inclined to refactor the whole issue out of our code at this point. :-) Anyway, thanks for the reply. I'm off to refactor. -- Dave Steffen - Software Engineer Numerica Corporation (www.numerica.us <http://www.numerica.us/> ) 4850 Hahns Peak Drive, Suite 200 Loveland, Colorado 80538 main (970) 461-2000 x 227 direct (970) 612-2327 fax (970) 461-2004 Email: dave.steffen(a)numerica.us k

1 0

[DateTime] valgrind warns on uninitialized jump
by Christoph Duelli 17 Sep '09

17 Sep '09

[from strings_from_facet.hpp, line 52] for (int m=0; m < 12; m++) { tm tm_value; tm_value.tm_mon = m; stringstream_type ss; ostream_iter_type oitr(ss); std::use_facet<time_put_facet_type>(locale).put(oitr, ss, ss.fill(), &tm_value, &*outfmt.begin(), &*outfmt.begin()+outfmt.size()); months.push_back(ss.str()); } valgrind (3.5.0, run on Linux, gcc 4.1.2, libstdc++ 6.0.8) reports: ==13166== 1 errors in context 1 of 1: ==13166== Conditional jump or move depends on uninitialised value(s) ==13166== at 0x41D793D: strftime_l (in /lib/libc-2.4.so) ==13166== by 0x40EE600: std::__timepunct<char>::_M_put(char*, unsigned int, char const*, tm const*) const (in /usr/lib/libstdc++.so.6.0.8) ==13166== by 0x40AC9DA: std::time_put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::do_put(std::ostreambuf_iterator<char, std::char_traits<char> >, std::ios_base&, char, tm const*, char, char) const (in /usr/lib/libstdc++.so.6.0.8) ==13166== by 0x40AAD95: std::time_put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::put(std::ostreambuf_iterator<char, std::char_traits<char> >, std::ios_base&, char, tm const*, char const*, char const*) const (in /usr/lib/libstdc++.so.6.0.8) The "error" goes away when tm_value.tm_hour is initialized to 0. (No idea why. Might be a bug in libstdc++) Best regards

1 0

Formal Review of Boost.Polygon is halfway through and no actual reviews so far
by Fernando Cacciola 17 Sep '09

17 Sep '09

Dear Developers, The formal review of the Boost.Polygon is halfway through and, while there was some useful discussion, there are still no "actual" reviews (where you clearly vote for inclusion and rejection). If you are interested in a geometric oriented library please try to make the time to post a formal review by the end of September 2 :) Best regards Fernando Cacciola Review Manager

4 7

Boost Review - changes to code being reviewed during the review?
by Paul A. Bristow 17 Sep '09

17 Sep '09

During most reviews, authors make changes to the code being reviewed. Some have questioned if this is 'allowed'. IMO, this is not only allowed but highly desirable - otherwise we will never get anywhere! But it can lead to confusion about exactly what is being reviewed. Now that we have SVN that keeps all changes and allows reasons to be recorded in the log, would it be useful for reviewers to quote the revision of the code that they are reviewing? Reviewers might include updates to say if the authors changes had solved problems, or changed their views. Paul --- Paul A. Bristow Prizet Farmhouse Kendal, UK LA8 8AB +44 1539 561830, mobile +44 7714330204 pbristow(a)hetp.u-net.com

1 0

Graph cut questions
by David Doria 17 Sep '09

17 Sep '09

1) If I do this: (with any of the max_flow algorithms, kolmogorov is just used as an example) double flow = kolmogorov_max_flow(g, SourceNode, SinkNode); I get the value of the max flow, but how do I tell which nodes of g belong to the "source side" of the graph and which nodes belong to the "sink side"? (thinking of it as a min cut rather than a max flow problem) 2) Is it possible to tell the max flow algorithm to use multiple sources/sinks? 3) The max_flow functions seem to require a source and sink to be specified. Shouldn't you be able to find the minimum cut that partitions the graph into two parts even without specifying a source/sink? 4) Currently you must use a bidirectional graph, and specify an edge_reverse_t in the graph traits, then set the reverse edge for every edge. a) this is pretty complicated for someone who is unfamiliar with generic programming. b) If an undirected graph is used, the algorithm should automatically take care of adding these reverse edges if they are required for the cut to be performed. Can these be considered as feature requests if they are not currently possible? I have not found a more promising graph library for c++, so it would be nice if BGL could be molded into the one everyone would like to use! Thanks, David

2 4

Re: [boost] [GIL] image rescale algorithms
by Est 16 Sep '09

16 Sep '09

Nicolas, One last, small thing. I would rename bicubic_filter in filters.hpp to mitchell_filter. Bicubic filter is a common name for bspline or photoshop style filters and mitchell is different. I think rgba32f_pixel_t is a good model for hdr pixels. I don't see the 0..1 range in floating point channels as limits. And GIL does not enforce them in any way. They only define a mapping between integer and floating point channels. In this case (rescale), clamping is an "artifact" of using integer channels and filters with possibly negative weights. I did some informal profiling, on a dual core machine, using the bicubic filter, I got this Big images: rescale serial took 9167.86 milliseconds (9.16786 sec) rescale parallel took 5055.94 milliseconds (5.05594 sec) Small images: rescale serial took 1923.46 milliseconds (1.92346 sec) rescale parallel took 1104.4 milliseconds (1.1044 sec) Est.

2 1

[GIL] image rescale algorithms
by Nicolas Lelong 16 Sep '09

16 Sep '09

Hi, I'm still working on updating my image management codebase, and I noticed that GIL does come only with by a very limited image rescaling/resampling algorithm (in gil/extension/numeric/resample.hpp) which does proper filtering for upsampling an image. As I need more robust image resampling, I came up with a source code for GIL, inspired by FreeImage implementation<http://freeimage.cvs.sourceforge.net/viewvc/freeimage/FreeImage/Source/Free…>; this code is available here :: http://code.google.com/p/rotoglup-scratchpad/source/browse/trunk/#trunk/rtg… This implementation is certainly not as generic as it could be, and could certainly benefit from 'gil concept checking' and various improvements ; I tried to make the code more 'readable' than 'efficient', and as I'm not really at ease with template metaprogramming, I may have missed a few points. For example, I think the mechanism I use to select the intermediate pixel format (used to store the averaged pixels during resizing) may be improved, and that there must be a way to let the user select a better pixel format if needed. I came up with virtual rescale view type, that allows to seamlessly rescale virtual views of any kind - it is not very efficient, but can be proved useful. I tried, as much as possible, to provide access to separable rescale functions (X & Y) so that users can control when/how (or whether) they should allocate the intermediate view for image rescaling. Feel free to use this work, and I'd be very happy to have some feedback on things that could be improved. The main functions defined are, in rescale.hpp<http://code.google.com/p/rotoglup-scratchpad/source/browse/trunk/rtgu/image…>:: // horizontal rescale only, rescale src view into dst view, matching dst view width template <typename SrcView, typename DstView, typename Filter> inline void rescale_cols(const SrcView& src, const DstView& dst, const Filter& filter); // vertical rescale only, rescale src view into dst view, matching dst view height template <typename SrcView, typename DstView, typename Filter> inline void rescale_rows(const SrcView& src, const DstView& dst, const Filter& filter); // rescale src view into dst view, matching dst view dimensions template <typename SrcView, typename DstView, typename Filter> inline void rescale(const SrcView& src, const DstView& dst, const Filter& filter); in rescale_any_view.hpp<http://code.google.com/p/rotoglup-scratchpad/source/browse/trunk/rtgu/image…>:: template <typename ViewTypes, typename Filter> inline void rescale_any_view(any_image_view<ViewTypes>& src, any_image_view<ViewTypes>& dst, const Filter& filter); in rescale_virtual_view.hpp<http://code.google.com/p/rotoglup-scratchpad/source/browse/trunk/rtgu/image…>:: // view factories template <typename SourceView, typename Filter> typename rescale_x_view_type<SourceView>::view_t rescale_x_view(SourceView const& view, typename SourceView::coord_t dst_width, const Filter& filter); template <typename SourceView, typename Filter> typename rescale_y_view_type<SourceView>::view_t rescale_y_view(SourceView const& view, typename SourceView::coord_t dst_height, const Filter& filter); template <typename SourceView, typename Filter> typename rescale_view_type<SourceView>::view_t rescale_view(SourceView const& view, typename SourceView::coord_t dst_width, typename SourceView::coord_t dst_height, const Filter& filter); and a few filters<http://code.google.com/p/rotoglup-scratchpad/source/browse/trunk/rtgu/image…>are provided. Cheers, Nicolas. **

2 4

Boost regression failure
by Christopher Jefferson 16 Sep '09

16 Sep '09

I hope I have reported this problem to the right place, apologises if I am wrong. I am currently unable to execute the regression tester (run.py). The important part of the error seems to be: error: Unable to find file or target named error: 'test_check.cpp' error: referred from project at error: '../libs/serialization/test' It was suggested on IRC this was introduced by: r56224 | ramey | 2009-09-16 00:23:51 +0400 (Wed, 16 Sep 2009) | 2 lines I enclose my full bjam.log: notice: found boost-build.jam at /Users/hudson/temp-test/boost/boost- build.jam notice: loading Boost.Build from /Users/hudson/temp-test/tools_bb notice: Searching /etc /Users/hudson /Users/hudson/temp-test/tools_bb / Users/hudson/temp-test /Users/hudso n/temp-test/tools_bb /Users/hudson/temp-test/tools_bb/kernel /Users/ hudson/temp-test/tools_bb/util /Users/ hudson/temp-test/tools_bb/build /Users/hudson/temp-test/tools_bb/ tools /Users/hudson/temp-test/tools_bb/co ntrib /Users/hudson/temp-test/tools_bb/. for site-config configuration file site-config.jam . notice: Loading site-config configuration file site-config.jam from / Users/hudson/temp-test/tools_bb/site- config.jam . notice: Searching /Users/hudson /Users/hudson/temp-test/tools_bb / Users/hudson/temp-test /Users/hudson/tem p-test/tools_bb /Users/hudson/temp-test/tools_bb/kernel /Users/hudson/ temp-test/tools_bb/util /Users/hudso n/temp-test/tools_bb/build /Users/hudson/temp-test/tools_bb/tools / Users/hudson/temp-test/tools_bb/contrib /Users/hudson/temp-test/tools_bb/. for user-config configuration file user-config.jam . notice: Loading user-config configuration file user-config.jam from / Users/hudson/user-config.jam . notice: will use '/usr/bin/g++' for darwin, condition <toolset>darwin-4.0.1 notice: using strip :: <toolset>darwin-4.0.1 :: /usr/bin/strip notice: using archiver :: <toolset>darwin-4.0.1 :: /usr/bin/libtool notice: available sdk :: <toolset>darwin-4.0.1/<macosx- version>10.3 :: /Developer/SDKs/MacOSX10.3.9.sdk notice: available sdk :: <toolset>darwin-4.0.1/<macosx- version>10.4 :: /Developer/SDKs/MacOSX10.4u.sdk notice: available sdk :: <toolset>darwin-4.0.1/<macosx- version>10.5 :: /Developer/SDKs/MacOSX10.5.sdk ===============MPI Auto-configuration=============== Found recent LAM-MPI or Open MPI wrapper compiler: mpic++ MPI compilation flags: -D_REENTRANT -I/usr//include MPI link flags: -Wl,-u,_munmap -Wl,-multiply_defined,suppress -L/usr// lib -lmpi_cxx -lmpi -lopen-rte -lope n-pal -lutil MPI build features: <define>_REENTRANT <include>/usr//include <library-path>/usr//lib <find-shared-library>mpi_cxx <find-share d-library>mpi <find-shared-library>open-rte <find-shared-library>open- pal <find-shared-library>util <linkf lags>-Wl,-u,_munmap <linkflags>-Wl,-multiply_defined,suppress MPI launcher: mpirun -np ==================================================== notice: iostreams: using prebuilt zlib notice: iostreams: using prebuilt bzip2 notice: [python-cfg] Configuring python... notice: [python-cfg] Checking interpreter command "python"... notice: [python-cfg] running command '"python" -c "from sys import *; print 'version=%d.%d\nplatform=%s\np refix=%s\nexec_prefix=%s\nexecutable=%s' % (version_info [0],version_info[1],platform,prefix,exec_prefix,ex ecutable)" 2>&1' notice: [python-cfg] ...requested configuration matched! notice: [python-cfg] Details of this Python configuration: notice: [python-cfg] interpreter command: "python" notice: [python-cfg] include path: "/System/Library/Frameworks/ Python.framework/Versions/2.5/include/pyt hon2.5" notice: [python-cfg] library path: "/System/Library/Frameworks/ Python.framework/Versions/2.5/lib/python2 .5/config" "/System/Library/Frameworks/Python.framework/Versions/2.5/ lib" notice: [python-cfg] framework directory is "/System/Library/ Frameworks/Python.framework" warning: Building Boost.Regex with the optional Unicode/ICU support disabled. note: Please refer to the Boost.Regex documentation for more information note: this is a strictly optional feature. warning: Graph library does not contain optional GraphML reader. note: to enable GraphML support, set EXPAT_INCLUDE and EXPAT_LIBPATH to the note: directories containing the Expat headers and libraries, respectively. error: Unable to find file or target named error: 'test_check.cpp' error: referred from project at error: '../libs/serialization/test'

2 1

doxygen doc / STL container unit test
by Stefan Strasser 16 Sep '09

16 Sep '09

I have two questions regarding boost library development: 1. this page: http://www.boost.org/doc/libs/1_35_0/doc/html/boostbook/getting/started.html explains how to set up the boost documentation system and write BoostBooks. what I find missing is how to generate the typical boost class synposis with doxygen. I also can't find doxygen configuration files or anything of that sort in the boost tree. how do you go about integrating automatically generated documentation into a BoostBook? 2. boost implements quite a few STL containers. is there a unit test that can test my STL container for conformity? say, I have a container that models the concept of a std::list, I'd like to change a typedef to my type, run the test and know that it behaves like advertised. Does anything like that already exist? thank you

5 10

[1.40.0] Compilation errors in Visual Studio
by Adam Badura 16 Sep '09

16 Sep '09

I experienced compilation problems with Boost 1.40. I am using Visual Studio 2005 and 2008. On both Boost compiles and links fine but is unusable in other code due to compilation errors. Currently I have access to errors produced on 2008 and it would be troublesome to get errors for 2005 (but if needed I will do it) - however the are the same (as to the message): 1>d:\libraries\boost_1_40_0\boost\integer_fwd.hpp(70) : error C2039: 'long_long_type' : is not a member of 'boost' 1>d:\libraries\boost_1_40_0\boost\integer_fwd.hpp(70) : error C2065: 'long_long_type' : undeclared identifier 1>d:\libraries\boost_1_40_0\boost\integer_fwd.hpp(70) : error C2913: explicit specialization; 'boost::integer_traits' is not a specialization of a class template 1>d:\libraries\boost_1_40_0\boost\integer_fwd.hpp(73) : error C2913: explicit specialization; 'boost::integer_traits' is not a specialization of a class template and so on... It is hard for me to tell which header causes the error but if requested I will look for this. 1.39 was just fine in both environments. The external (non-Boost) code did not change in the mean time. Any help? Adam Badura

7 10

[Endian] Version 0.10 available - Binary I/O added
by Beman Dawes 16 Sep '09

16 Sep '09

Version 0.10 of the Endian Integers library is available. Docs: http://mysite.verizon.net/beman/endian-0.10/libs/integer/doc/endian.html Zip: http://mysite.verizon.net/beman/endian-0.10.zip Sandbox: http://svn.boost.org/svn/boost/sandbox/endian This version adds binary I/O for both endian integers (<boost/integer/endian_binary_stream.hpp>) and C++ built-in types + std::string (<boost/integer/endian_binary_stream.hpp>). Support for C++0x features has also been added, ensuring that an Endian integer on C++0x is a POD. Comments appreciated! My Endian TODO list is pretty well cleared, so there are comments to the contrary, the library will be submitted for formal review in a few days. --Beman

3 4

(no subject)
by Berserker 16 Sep '09

16 Sep '09

Dmitry Goncharov wrote: > The difficulty that your example demonstrates is caused by the nature > of template template parameters. scoped_ptr should not be blamed for that. I agree, moreover I think that the advantages of this patch (often required in the list) justify the 1% use cases of Andrey Semashev's sample that in my opinion can be simplified in this way: template<typename T, typename P> void make_ptr(P &p) { p.reset(new T()); } _________________________________________________________________ Scopri tutti i servizi Windows Live, guarda i video http://www.windowslive.it/videoGallery.aspx

1 0

Re: [boost] scoped_ptr deleter
by Berserker 15 Sep '09

15 Sep '09

Andrey Semashev wrote: > I'd opt for this change if it wouldn't affect the interface in the breaking way. > Otherwise, I like the way it is. I just tested your sample and thanks to the default template value (boost::checked_deleter) it does compile. Are you sure it breaks the interface? _________________________________________________________________ Scopri tutti i servizi Windows Live, guarda i video http://www.windowslive.it/videoGallery.aspx

3 2

[lexical_cast] lexical_cast does not throw bad_lexical_cast
by Carlos Rafael Giani 15 Sep '09

15 Sep '09

Hi, I've noticed that sometimes lexical_cast does not throw bad_lexical_cast. Instead, it throws 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::bad_lexical_cast> >'. A catch clause expecting a bad_lexical_cast fails here. What seems confusing to me is that the lexical_cast docs do mention "catch (bad_lexical_cast &)" as correct code (http://www.boost.org/doc/libs/1_39_0/libs/conversion/lexical_cast.htm) The solution that worked for me was to catch boost::exception instead. Am I missing something here? I consulted the documentation, but still have no answer. It also seems that I am not alone with this problem; http://www.nabble.com/Porting-from-boost_1_33-to-boost_1_36-exception-td197… and http://archives.free.net.ph/message/20090715.183116.374b4777.en.html at least indicate this for me. regards, Carlos Rafael Giani

2 1

enabling/disabling floating point exceptions
by Gennadiy Rozental 15 Sep '09

15 Sep '09

Hi guys, I am looking to complete cross platform implementation of enabling/disabling logic in boost::execution_monitor. It looks like there is no standard interface available. I'm using _controlfp interface now on Windows. I also found these non-standard extensions: * feenableexcep/fedisableexcept available with glib 2.2 * fesettrapenable avaialble in Dinkumware (implementation of STL?) and HP * sun has something called fex_set_handling. not sure when it's available though * header fpu_control.h. Not sure where it's available though. * MAC OS X has something called _MM_SET_EXCEPTION_MASK in xmmintrin.h It also seems that in some cases the switch is compile time only (using compilation option). Would anyone care to extend this list/comment on it's applicability and/or correctness? Another change I am considering is to split floating point exception catching from other system exceptions. It seems perfectly valid scenario to set catch_system_error to false (thus avoid catching access violations etc) but still willing to catch and process floating point exception. What do you think? Gennadiy

4 4

Re: [boost] scoped_ptr deleter
by Berserker 15 Sep '09

15 Sep '09

Stewart, Robert wrote: > I'm sorry, I read your post too quickly, seeing "shared_ptr" > where you wrote "scoped_ptr." No problem :) > That, of course, requires nothing more than a static member > function in the supplied deleter type as your proposal implies. I suggested a "deleter" (default boost::checked_deleter) instead of a static function because imho an operator()(T *p) is a preferable approach (it doesn't require a "specific" function name) and moreover boost::checked_deleter is already there :) I really hope this patch will be applied. _________________________________________________________________ Gossip, Sport, Notizie... Accendi la Messenger TV! http://www.messenger.it/messengerTV.aspx

1 0

scoped_ptr deleter
by Berserker 15 Sep '09

15 Sep '09

I know it has been asked in the past, but I still don't understand why scoped_ptr lacks this feature. The "noncopyable nature" of scoped_ptr allows to support deleters with simply an extra template parameter (default value is boost::checked_deleter): this change doesn't require extra memory overhead (like in shared_ptr) and it consists of 2 lines. template<class T, class D = boost::checked_deleter> // first patch line class scoped_ptr { // ... public: ~scoped_ptr() { // ... deleter()(ptr); // second patch line, instead of boost::checked_delete } }; Any hope to apply this patch? _________________________________________________________________ Gossip, Sport, Notizie... Accendi la Messenger TV! http://www.messenger.it/messengerTV.aspx

3 2

Re: [boost] scoped_ptr deleter
by Berserker 15 Sep '09

15 Sep '09

A fix to my previous post, the first patch line should be: class D = boost::checked_deleter<T> instead of: class D = boost::checked_deleter Obvously the same implementation is applicable to boost::scoped_array using boost::checked_array_deleter _________________________________________________________________ Le tue Emoticon ti sembrano poche? Scaricane di nuove! http://intrattenimento.it.msn.com/emoticon/

1 0

fixed documentation
by Frank Birbacher 14 Sep '09

14 Sep '09

Hello! I made two small changes to docs: https://svn.boost.org/svn/boost/sandbox-branches/birbacher/fix_documentation c56200 spelling in docs for graph c56201 enhancement for asio docs ip v4 and v6 to_bytes() I will notify the maintainers of the projects. Frank

1 0

non-branching min()
by DE 14 Sep '09

14 Sep '09

i'd like to present some kind of micro optimization towards pipelined cpus traditionaly min() has an implementation like template<typename type> inline type min(type a, type b) { return a<b ? a : b; } this function (even if inlined) introduces a branch in a sequence of instructions though branch prediction algorithms do exist they will guess at most 50% of them because routine input is arbitrary since a wrong branch prediction causes pipeline stall i thought that such a useful routine like min() MUST have non-stalling (read 'non-branching') implementation i thought hard and in the end recalled a simple implementation which is called LUT (for 'look-up table') here's what i finally got: template<typename type> inline type min(type a, type b) { const type c[2] = {a, b}; return c[b<a]; } intuitively this implementation should work slower than the first one but in real life it runs faster (roughly by a factor of 2 for 4 byte types on core2duo) here's a test code: #include <vector> int main() { typedef int type; const int n = 1000000; std::vector<type> v1(n), v2(n); //filling v1 and v2 somehow type min = BIG_VALUE; for (size_t i = 0; i<n; ++i) a = min(a, min(v1[i], v2[i])); //searching minima of v1 and v2 return 0; } however for 'double' it runs ~2% slower (i think it's because creating a lut for 2 elements 8 bytes each is slower than a branch on c2d) nevertheless i think it's a great approach at least for ints also max() can implemented very similar you may skip the rest example of usage imagine we want to implement a symmetric matrix that stores only half of its elements (say upper triangle) a00 a01 a02 --- a11 a12 --- --- a22 then access requests to the lower triangle elements would be redirected to upper triangle ones here we have a constraint that actually we only have access to elements a(i, j) where i<=j must always be true (look at indices above) if we use a branch like //... return i<=j ? a(i, j) : a(j, i); we get a pipeline stall almost every time we want to access an arbitrary element however if we rewrite it carefully as //... const size_t m = min(i, j); //non-branching min() here return a(m, m + abs(int(i) - int(j))); //abs() is also //non-branching we get rid of branches at all! and we can hope a pipelined cpu will handle it better than the other (branched) implementation -- pavel

9 14

Re: [boost] Are warnings acceptable artifacts from builds?
by Vinnie 14 Sep '09

14 Sep '09

>From http://sqlite.org/testing.html#coverage "Static analysis means analyzing code at or before compile-time to check for correctness. Static analysis consists mostly of making sure SQLite compiles without warnings, even when all warnings are enabled. SQLite is developed primarily using GCC and it does compile without warnings on GCC using the -Wall and -Wextra flags. There are occasional reports of warnings coming from VC++, however. Static analysis has not proven to be helpful in finding bugs. We cannot call to mind a single problem in SQLite that was detected by static analysis that was not first seen by one of the other testing methods described above. On the other hand, we have on occasion introduced new bugs in our efforts to get SQLite to compile without warnings. Our experience, then, is that static analysis is counter-productive to quality. In other words, focusing on static analysis (being concerned with compiler warnings) actually reduces the quality of the code. Nevertheless, we developers have capitulated to pressure from users and actively work to eliminate compiler warnings. We are willing to do this because the other tests described above do an excellent job of finding the bugs that are often introduced when removing compiler warnings, so that product quality is probably not decreased as a result."

16 31

[pool] Thread specific pool allocator
by James Bremner 14 Sep '09

14 Sep '09

I develop code to run on multiple processor machines. Moderate use of the standard template library (STL) containers cause programs to slow down when the work is split between threads running on different processors. This is because the STL default memory allocator is a thread-safe singleton and causes contention between the threads. The memory allocator provided by boost::pool_allocator is also a thread safe singleton. I have coded a thread specific memory allocator based on boost::pool and boost:thread_specific_pointer. My allocator creates a new instantiation for each thread it is used in, and so avoids contention between threads. The containers created with this allocator must be used carefully, not written to by more than one thread, because the allocator is not thread-safe ( that is the point! ) - however they provide dramatic performance improvements when my code runs on multiple processors. I do not expect my coding is to the high standard of the boost libraries, but I do believe it shows that something very useful can be done with a few lines of code. Any chance of a boost:thread_specific_pool_allocator in the near future? James Bremner

7 11

[serialization] Calling basic_streambuf::sync in basic_binary_iprimitive destructor
by Andrey Upadyshev 14 Sep '09

14 Sep '09

Hi, All! Anybody knows, does we really need to call std::basic_streambuf::sync in boost::archive::basic_binary_iprimitive destructor? Is it possible to not call it? I ask it because the call of sync with file stream buffer leads to skipping of the unreaded input data. I think it is not good, or al least it must be clear described in documentation, that binary_iarchive when used with file stream skips to the end of a stream. Andrey Upadyshev P.S. Sorry for my English

2 2

Re: [boost] C++ Manifesto
by christophe henry 13 Sep '09

13 Sep '09

> Why is there no Boost.ANTLR? Good question. I mean, if Spirit seems to you such a disservice to the community that you write the xth post about it, why not show how to do it right? I'm sure we would all benefit from it, because right now, I haven't read anything constructive in this post. At least Joel spent lots of time to offer a great library to the C++ community and I think he deserves better than such unconclusive criticism as "I think that it represents a disservice to the C++ community". Seeing from his user base, I respectfully allow myself some to disagree on that point. Now the challenge is simple: Make it better and you'll earn yourself some respect. Don't provide any alternative and land from now on in my spam box. Regards, Christophe _________________________________________________________________ Show them the way! Add maps and directions to your party invites. http://www.microsoft.com/windows/windowslive/products/events.aspx

2 1

[thread] Obtaining thread id on Windows
by Agustín K-ballo Bergé 13 Sep '09

13 Sep '09

I've found a need to retrieve a thread id rather than a thread handle on Windows. There is no documented way to get it from the handle on XP (see http://social.msdn.microsoft.com/Forums/en-US/vcgeneral/thread/89728ee1-d9d… ). Would it make sense to add a get_native_id member function? Thank you. Agustín K-ballo Bergé.-

2 3

[variadic_templates][mpl]announcement:sandbox now has variadic_templates directory
by Larry Evans 12 Sep '09

12 Sep '09

There is now a sandbox directory for variadic templates: https://svn.boost.org/trac/boost/browser/sandbox/variadic_templates The tests in variadic_templates/libs/mpl/test/Jamfile have all passed. Some of those tests have been slightly modified to accommodate the variadic template version of mpl sequences. BTW, it's important to apply the gcc patch mentioned here: https://svn.boost.org/trac/boost/browser/sandbox/variadic_templates/README.… All sequences have been changed to use a new template: foldr_pack whose last argument is a parameter pack. That change also required a new binary template for each sequence: X_item_fold where X is one of: v l s m One reason for that change was to highlight the similarites of the sequences. Some other fold additions were: foldr_iter.hpp foldl_iter.hpp The foldr and foldl correspond roughly to iter_fold and reverse_iter_fold (or the other way around, I can't remember which). The reason for these additions is that they reflect more closely the way foldr and foldl are done in haskell, as indicated by the comments in the .hpp files. One useful application of the pattern expansion mentioned in section 3.6.1 of: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2242.pdf is their use to easily define SEQ_c in terms of SEQ, where SEQ is any sequence. For example: template < typename Integral , Integral... Values > struct list_c : list < integral_c<Integral,Values>... > { typedef Integral value_type; }; Another addition is package_range_c.hpp which can be used to do something similar to range_c. The main motivation for this was the make_indexes on p. 16 of: http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2006/n2080.pdf It was used in a prototype tuple implementation in: variadic_templates/libs/mpl/sandbox/tuple_non_recur.package_range_c.cpp Package_range_c was also useful in the implementation of unpack_args. A really interesting application of these pattern expansions might be another implementation of the cross_product template: http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?CPPTM_Answer… The reason I think it would be useful is because the expansion of: integral_c<Integral,Values>... results in: integral_c<Integral,Value1> integral_c<Integral,Value2> ... integral_c<Integral,ValueN> where ValueI is the i-th element in Values... Now this is a cross product of a single element, Integral, with each element in Values...; hence, I would think that it would be a simple matter to just repeat this for any number of elements. IOW, instead of integral_c, there could be: template<typename Left, typename...Rights> struct pair_rights : pair<Left,Rights>... {}; and then that, somehow, could be done for each element in some list of Left's. Would somebody like to try this? Hope somebody else finds this useful. -regards, Larry

1 0

[iterators] zip_iterator requires random_access_iterator?
by Dean Michael Berris 12 Sep '09

12 Sep '09

Hi Everyone, According to the documentation (http://www.boost.org/doc/libs/1_40_0/libs/iterator/doc/zip_iterator.html) All iterator types in the argument IteratorTuple shall model Readable Iterator. When I use a BidirectionalIterator (list<...>::iterator) zip_iterator fails to compile, while when I use a RandomAccessIterator (vector<...>) it compiles just fine. I have a nesting like this: make_filter_iterator( filter(), make_zip_iterator( make_tuple( container.begin(), make_transform_iterator( container.begin(), function() ) ) ) The first line in the error logs is: /home/dean/boost/boost/iterator/detail/minimum_category.hpp: In instantiation of ‘boost::detail::minimum_category_impl<false, false>::apply<boost::detail::iterator_category_with_traversal<std::input_iterator_tag, boost::bidirectional_traversal_tag>, boost::random_access_traversal_tag> I'm using Boost SVN trunk updated to revision 56153 -- did I find a bug? HTH -- Dean Michael Berris blog.cplusplus-soup.com | twitter.com/mikhailberis linkedin.com/in/mikhailberis | facebook.com/dean.berris | deanberris.com

1 0

Build files locations, try 2
by Vladimir Prus 12 Sep '09

12 Sep '09

Some time ago, I have raised the concern that CMakeList.txt files violate directory structure requirements. See: http://thread.gmane.org/gmane.comp.lib.boost.devel/189496/ Back then, the discussion did not lead anywhere, and no further progress was made for 2.5 months. So, let me try to phrase this a bit differently. Is it fine with everybody if I move Jamfiles out of 'build' folder of every library one level higher? Thanks, Volodya

4 4

MSVC decorators still in autoconfig?
by Stephan Menzel 11 Sep '09

11 Sep '09

Hi, I am just about to migrate to 1.40 and I noticed the changed naming scheme. So the TOOLSET and BOOST_LIB_VERSION defines are missing when I build the libs (even when using layout=tagged in bjam) but the autoconfig, specifically auto_link.hpp, still includes this in MSVC's autolink feature. So as far as I can see autolink will not work in Windows, right? At least, it doesn't for me unless I change auto_link.hpp line 312 so skip this. Is this a bug or am I overlooking something important? Cheers, Stephan

3 4

C++ Manifesto
by Christian Schladetsch 11 Sep '09

11 Sep '09

I wrote: A problem seems to be that we are trying to be meta-meta when meta- alone suffices. > The GCC frontend hasn't been integrated into mainline GCC, the LLVM > frontend is beta and similarly lives out of tree. A substantial, > incompatible, rewrite of the language is currently in progress. > The same can be said for C++0x. And LLVM is not in beta w.r.t Apple. > > I've used D for some fun side projects, it is a nicer language than C++. > However, would I suggest using it at work, and risking a major, long-living > software project on it? Unfortunatly not yet, and most people I've > personally spoken to agree. > I am speaking out of my backside when I say anything on this matter, as I have not written anything substantial in D. But my original point remains: why not? There are no tablets written in stone stating Thou Shalt Write In C++. Sure, there are many people that are "language lawyers" and understand the finer intricacies of ADL and that is their livelihood. Great for them. Most of us understand (or could understand) most of boost. It isn't that hard - most of the "chicanery" is to do with xplat systems creating code-paths that even the original authors don't understand. The rest of the magic is in Spirit and similar expression-template-based systems that are only hard to understand because of their working domain. If they were written procedurally, they would be fine, or if they were written in ML they would be fine but because they are written in a strange mixture of bastardised C++ they are esoteric and deemed to be "excellent C++". I'm sorry. I don't think that Spirit is excellent C++. I think it is terribly clever C++ and I think that it represents a disservice to the C++ community. Further, I think it has singularly set back language development by years. The damage is untold - if only there was active C++ support for a system like ANTLR for the past few years rather than Spirit then maybe we wouldn't be in the mess we are in now. To be clear, I don't mean any disrespect to Joel or to the Spirit2 code-base per se. I just don't think that the C++ compiler was ever meant to be a language tool. I personally have witnessed at least two groups of coders reject a DSL-based solution because they thought that to do so "correctly" would mean using Boost.Spirit, which was beyond them. Meanwhile, ANTLR has no C++ support. It's a crying shame. Why is there no Boost.ANTLR? The question then stands: why stick with C++ for everything? What can D do in similar circumstances? (I know the immediate answer is "we don't use D" but can we please put that aside for a year). I don't know. I haven't used it. I have nothing to do with Digital Mars or Alex. I care only about writing effective code. I feel that C++?? is becoming just that. It doesn't matter that I can (eventually) understand the latest boost library, or the latest boost technique. What matters is what is the best way to write efficient code? Because I can agree with you, when you think that you are writing a lot of boilerplate nonsense to get basic things done. Move semantics and the problems that Ion is having is a case in point. I don't mean to be a misery-guts, but after having looking deeply at the issues I really don't see a way that it can be done without a language change. C++ is a fine language, but seriously, the authors didn't have any idea on how we'd use it and the differences are compounding exponentially. When C++ is no longer the best way (and yes, that is a "when" not an "if"), I would like to think that I am open-minded enough to be on that wave. Is that time sooner rather than later? Say you want to write a parser/AST walker/executor for a basic language with scoped variables and continuations. Is Boost.Spirit the best way to do so? Is it *really*? Say you want to write an object factory with persistent objects. Is Boost.Serialisation and Boost.Function the best way forward? How will you you store the functions? Say you want automatic resource management. shared_ptr<> doesn't cut it. It is too slow for single-threaded and at the same time doesn't deal with cycles. Say you want to write a geometry library. Ok, stop right there.... Is Boost.Graph the best way to make a basic DAG? I've tried all these systems. They work, there is no doubt. Do they work well, in practice? Has there been any real-world review of the efficacy of boost libraries in general? I'm sure there has, as many here could attest, but this is a biased sample set. I wonder how much and what aspects of boost are used in the wider community? I for one use foreach, shared_ptr, unordered, mpl, some fusion, and other bits and pieces. No-one in my team uses anything other than foreach and shared_ptr - and there is a lot of confusion I have to deal with relating to their use of weak_ptr<> and locking etc with that. It seems that 5 years ago I had to argue that boost was Ok to use, and I still feel like I am saying the same things. I am approaching the stage where I wonder why I continue to apologise for it. What do you use? Which parts of boost are good to use with least impact? This has turned into a manifesto against boost. I didn't mean that to be the case when I started, but so be it. I come from the real world, and there are real programmers that just don't know and don't want to deal with problems they can't solve. As a lead, I have to make technology decisions and I am clearly frustrated with the potential of both boost and C++ in general. Sometimes I think that it would be easier to just change language completely to C#/asm or D/C++/asm. I am in the position now to decide what will be the language for the next game made in company A. I am strongly tempted to make the core in C# with callouts to C++ libs for physics and render. Personally, after 20-odd years and still seeing the likes of Lucanus swing on the rope with his geometry lib, it makes me wonder if C++ is really what the real-time world needs. Regards, Christian.

9 10

scoped_allocator_ptr
by Felipe Magno de Almeida 11 Sep '09

11 Sep '09

Hi, Is there an interest in a scoped_ptr that receives a Allocator parameter? I've been needing this in some libraries I've been developing. It could use EBO for the Allocator parameter to have the same size as scoped_ptr for empty Allocators. I need a move_ptr with a Allocator parameter too. But I rather let somebody else write for now. Thanks, -- Felipe Magno de Almeida

3 6

Control of the file location for the boost::interprocess::managed_shared_memory object
by Michael Watkins 11 Sep '09

11 Sep '09

Is it possible to control the exact location of the file that is backing the shared memory created by boost::interprocess::managed_shared_memory? The issue occurs under Windows (it has not been tried yet under Linux). The problem is two processes attempting to connect to the same shared memory segment between two accounts, in specific from a program running as a service (using the system account) and a program running under a user account. The user account is running a program that needs to interface to the database that the service created. Everything seems to work fine, but the service will open the shared memory backing file in the global temp directory while the user account will open the file in their local settings temporary directory. Therefore two different segments are opened. The interim solution is to use boost::interprocess::managed_windows_shared_memory to create the shared memory, but the desire is to use the generic version for cross-platform compatibility. If the full file path could be specified when creating the memory segment, it would solve the problem. Michael Watkins _________________________________________________________________ Windows Live™: Keep your life in sync. http://windowslive.com/explore?ocid=PID23384::T:WLMTAGL:ON:WL:en-US:NF_BR_s…

2 4

[multi_index][serialization][Huang-Vista-x86_32_intel] Help with weird test failure
by joaquin＠tid.es 11 Sep '09

11 Sep '09

Huang-Vista-x86_32_intel toolset, which runs Intel 11.1 for Window, has this weird error on the serialization test for Boost.MultiIndex: Running 1 test case... ../libs/multi_index/test/test_serialization_template.hpp(82): error in "test_main_caller( argc, argv )": check all_indices_equal(m,m2) failed unknown location(0): fatal error in "test_main_caller( argc, argv )": std::exception: invalid signature (http://tinyurl.com/nd89x2) What I find weird is the throwing of invalid_signature, a Boost.Serialization exception that, according to docs, indicates that the beginning of a serialization file is not correct. I can't see how a problem with serializing multi_index_containers can lead to a file signature error. Any clue? Maybe the toolset maintainer can run this manually and provide more info? Thank you in advance, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

1 0

[warnings] Are warnings acceptable artifacts from builds?
by Sid Sacek 11 Sep '09

11 Sep '09

Just curious, when I use certain libraries, I get compiler warnings. Are these simply acceptable during a build, or should they be reported to somebody ? The latest warning I'm seeing are: Warning 4 warning C4245: 'initializing' : conversion from 'int' to 'const boost::detail::mask_uint_t<8>::least', signed/unsigned mismatch C:\Trunk.3.1\ThirdParty\boost\crc.hpp 377 Warning 5 warning C4245: 'initializing' : conversion from 'int' to 'const boost::detail::mask_uint_t<16>::least', signed/unsigned mismatch C:\Trunk.3.1\ThirdParty\boost\crc.hpp 400 Regards, -Sid Sacek

13 52

[Boost.Breakable] Any interest in a Boost Breakable library?
by Pierre Morcello 11 Sep '09

11 Sep '09

Hello, I propose a set of macros that allow to break anywhere. Example of use of the main macro : // do something... BOOST_BREAKABLE { if (test1) { break; } if (test2) { break; } std::cout<<"this is never reached if test1==true or test2==true. "<<std::endl; // do something... } // here the program continues ... Is there any interest in such a library? Best regards, Pierre Morcello

20 44

Re: [boost] non-branching min()
by Phil Endecott 10 Sep '09

10 Sep '09

DE wrote: > template<typename type> inline > type min(type a, type b) > { > const type c[2] = {a, b}; > return c[b<a]; > } How well this performs compared to the conventional ?: implementation will depend on how the arguments are distributed. If the outcome is skewed, then branch prediction will make the conventional implementation faster. If the outcome is 50/50 (and not correlated with some other branch), then your code may do better. > here's a test code: > > #include <vector> > int main() > { > typedef int type; > const int n = 1000000; > std::vector<type> v1(n), v2(n); > //filling v1 and v2 somehow > type min = BIG_VALUE; > for (size_t i = 0; i<n; ++i) > a = min(a, min(v1[i], v2[i])); //searching minima of v1 and v2 > return 0; > } So the min(v1[i],v2[i]) is 50/50 (assuming that you fill the arrays with random values), while min(a,...) will be skewed to normally prefer the second arg after the first few cycles. Perhaps you can confirm that your code does better for the former and worse for the latter by testing e.g. a = std::min(a, my::min(v1[i], v2[i])); Is there some reason why a compiler cannot do your optimisation automatically when you write ?: expressions? Regards, Phil.

1 0

[Test] Memory leak with boost v1.40 under gcc 4.2 for x86_64 in Snow Leopard
by S Roderick 10 Sep '09

10 Sep '09

[First time poster to boost] Compiling for the default x86_64 produces a memory leak in the test framework, but the same program compiled for i386 does not. Mac OS X Snow Leopard gcc 4.2 with macports boost 1.40.0 (same memory leak seen in v1.39 macports also). The memory leak only occurs with multiple test cases or test suites. Set the define in my test program to remove the extra test case, and the leak dissappears. Could not find this problem on the list, nor the 'net. Output is: <code> sroderick@mp tmp $ g++ -o boost-test-i386 -arch i386 /opt/code/tmp/ boost-test.cpp -I/opt/local/include -g sroderick@mp tmp $ g++ -o boost-test -arch x86_64 /opt/code/tmp/boost- test.cpp -I/opt/local/include -g sroderick@mp tmp $ ./boost-test Running 2 test cases... *** No errors detected boost-test(75819) malloc: *** error for object 0x3000100300780: pointer being freed was not allocated *** set a breakpoint in malloc_error_break to debug Abort trap sroderick@mp tmp $ ./boost-test-i386 Running 2 test cases... *** No errors detected </code> gdb backtrace for x86_64 program is: <code> (gdb) bt #0 0x00007fff83180096 in __kill () #1 0x00007fff832210c2 in abort () #2 0x00007fff83138215 in free () #3 0x000000010006979e in boost::unit_test::framework_impl::clear (this=0x1000d99c0) at framework.ipp:133 #4 0x000000010006989c in boost::unit_test::framework_impl::~framework_impl (this=0x1000d99c0) at framework.ipp:122 #5 0x000000010006ae0e in __tcf_1 () at framework.ipp:225 #6 0x00007fff831443f4 in __cxa_finalize () #7 0x00007fff8314430c in exit () #8 0x0000000100009703 in start () at unit_test_parameters.ipp:172 </code> Program is: <code> #define BOOST_TEST_MODULE example #include <boost/test/included/unit_test.hpp> BOOST_AUTO_TEST_SUITE( test_suite ) BOOST_AUTO_TEST_CASE( test_case1 ) { // BOOST_ERROR( "some error 1" ); BOOST_CHECK( true ); } BOOST_AUTO_TEST_SUITE_END() #if 1 BOOST_AUTO_TEST_CASE( test_case_on_file_scope ) { BOOST_CHECK( true ); } #endif </code>

1 0

Iterators Must Go (Ahead)
by Andrei Alexandrescu 10 Sep '09

10 Sep '09

Hello, I wrote an article about D's ranges, contrasting them to other iteration idioms. Those who'd be interested in reviewing the article, please send me email. (I may not be able to reply to all requests.) Bear in mind that the article is rather long - about the size of two usual magazine articles. Thanks, Andrei

7 6

[unordered] please don't allocate memory in the default constructor
by Thorsten Ottosen 10 Sep '09

10 Sep '09

Hi Jeremy, I think this a really bad idea to allocate in the default construtor. The user can always call rehash() on the empty container, just like when we call reserve() for vector. Thanks -Thorsten

5 8

[PropertyTree] Help tracking down test failure.
by Sebastian Redl 10 Sep '09

10 Sep '09

Hi, If you look at the PTree regression results: http://www.boost.org/development/tests/trunk/developer/property_tree.html you'll see that the test_property_tree test currently fails on a log of platforms, especially Darwin. An assertion fails. Since I cannot reproduce the error on any of my systems, could someone who can please send me a stack trace, and perhaps a debug print of the two objects involved? Here's the test output of one runner: http://www.boost.org/development/tests/trunk/developer/output/minion-mpi-bo… I'd like the debug representations of 'this' and 'o', please. Thank you, Sebastian

1 1

[mpl] ForwardIterator concept recursion
by Marcin Zalewski 10 Sep '09

10 Sep '09

I have been trying to implement a concept for mpl ForwardSequence, and besides the lack of const expr requirements in the latest version of concepts I have stumbled across the problem of concept recursion. One example of such recursion is the ForwardIterator [1] concept. The requirement on the next::type type is that it must be a ForwardIterator. One could try to write a concept like that: concept ForwardIteratorStatic<typename I> { typename deref; typename next; requires ForwardIteratorStatic<next>; } But for the above concept, the ConceptGCC compiler gives an error. Also, this should not compile according to the latest concepts proposal that states that a concept is not defined until the closing brace of the concept body. As for now, I think that one can try to apply technique described by Doug [2]: concept IteratorStatic<typename I> { } concept ForwardIteratorStatic<typename I> : IteratorStatic { typename deref; typename next; requires IteratorStatic<next>; } But to get to my question finally, I wonder if the recursion in mpl is intentional and thought out, or is it an accident that should be re-examined. If the decision was indeed thought out, I really wonder what would be a reasonable semantics of concept recursion. Cheers, Marcin [1] http://www.boost.org/doc/libs/1_40_0/libs/mpl/doc/refmanual/forward-iterato… [2] http://www.osl.iu.edu/MailArchives/conceptgcc/2007/03/0084.php

3 3

Re: [boost] [GIL] image rescale algorithms
by Est 10 Sep '09

10 Sep '09

Hi Nicolas, I used your code in Ramen (http://sourceforge.net/projects/ramenhdr/) It works great. Thank you. And now, some feedback... I think filters should be a small separate GIL extension. They are useful also for other image resampling algorithms. In clamp_channel_fn I added an overload like this: template <typename SrcChannel, typename T, typename S, typename U> void operator()(const SrcChannel& src, scoped_channel_value<T,S,U>& dst) { typedef typename channel_traits<scoped_channel_value<T,S,U>>::value_type dst_value_t; dst = dst_value_t( src); } to avoid clamping floating point channels. Another option would be to clamp only negative values. I think template <typename PixelType> struct create_accum_pixel_type : public create_accum_pixel_type<PixelType> {}; can be replaced with template <typename PixelType> struct create_accum_pixel_type {}; I had to add some typenames in front of accum_pixel_t in rescale_rows, rescale_cols and rescale to build with gcc. and I made a parallel version using Intel TBB. It's here: http://ramenhdr.svn.sourceforge.net/viewvc/ramenhdr/trunk/extern/gil/extens… Est.

2 1

[sandbox] git?
by k-oli＠gmx.de 09 Sep '09

09 Sep '09

Is a official git-repo available? boost vault uses svn

3 2

[cmake] revision 50756 failed to merge some file properties
by JOAQUIN M. LOPEZ MUÑOZ 09 Sep '09

09 Sep '09

Hi, this is a repost of a message that went unnoticed three months ago: http://lists.boost.org/boost-cmake/2009/06/0592.php and that's causing problems when merging CMake-specific stuff from trunk to release, as discussed at: http://lists.boost.org/Archives/boost/2009/08/154996.php http://lists.boost.org/Archives/boost/2009/08/155003.php CMakeLists.txt and related files in trunk do have a "svn_keywords" property with value "Id", while the counterparts in the release branch are missing this property. I guess this was an oversight when applying revision 50756: https://svn.boost.org/trac/boost/changeset/50756 Unless fixed, this is going to pop up again when the release manager prepares for 1.41. Thank you, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

6 9

Re: [boost] Are warnings acceptable artifacts from builds?
by pete＠pcbartlett.com 09 Sep '09

09 Sep '09

On Wed 09/09/09 15:19 , Maciej Sobczak <prog(a)msobczak.com> wrote: > If a given user has a strict policy of > not > having *any* warnings during their build, then that policy is enough > to > prevent them from using Boost. I'm pretty sure that this scenario is > not > something that library authors would easily accept. > Regards, With gcc, we have chosen to include Boost using -i_system rather than -i so that /all/ Boost-generated warnings are suppressed, on the grounds that Boost developers know what they are doing and that all warnings are thus spurious. I'm interested if others think this approach is too cavalier.

2 1

Re: [boost] [warnings] Are warnings acceptable artifactsfrom builds?
by pete＠pcbartlett.com 09 Sep '09

09 Sep '09

"Stewart, Robert" <Robert.Stewart(a)sig.com> wrote: >I regularly code with two-up emacs buffers, 80 columns each. That approach also permits me to print source code -- which I do not infrequently -- >without hard to follow line breaks. Consequently, I like the 80 column limit and am frustrated by code that exceeds that limit. Printing landscape may ease your frustration somewhat.

1 0

Interest request for pointer+bit compression optimization
by vicente.botet 09 Sep '09

09 Sep '09

Hi, I have recently found in the blog of Joaquin the following optimization consisting in embed a bit into the representation of a pointer. Please read it, it is not too long (http://bannalia.blogspot.com/2008/11/optimizing-red-black-tree-color-bits.h…) I was wondering if it would be interesting to provide some generic template classes making easier this kind of optimization. We can define two templates (See below) template <typename E> struct bit_ref; template <typename T> struct pointer_ref; So instead of having enum color_type{red=false,black=true}; class rb_node { private: color_type color_; regular_rb_node_header* parent; color_type& color(){return color_;}? color_type color()const{return color_;}? rb_node*& parent(){return parent_;}? rb_node* parent() const{return parent_;} } we can compress the colot_type and the rb_node* as follows class rb_node { private: uintptr_type parentcolor_; public: bit_ref<color_type> color(){return bit_ref<color_type>(&parentcolor_);} color_type color()const{return bit_ref<color_type>(&parentcolor_);} pointer_ref<rb_node> parent(){return pointer_ref<rb_node>(&parentcolor_);} rb_node* parent() const {return pointer_ref<rb_node>(&parentcolor_);} }; Next follows the definition of the template classes template <typename E> struct bit_ref { bit_ref(uintptr_type* r_):r(r_){} operator E() const { return E(*r&uintptr_type(1)); } bit_ref& operator=(E c) { *r&=~uintptr_type(1); *r|=uintptr_type(c); return *this; } bit_ref& operator=(const bit_ref& x) { return operator=(x.operator T()); } private: uintptr_type* r; }; template <typename T> struct pointer_ref { pointer_ref(uintptr_type* r_):r(r_){} operator T*() const { return (T*)(void*)(*r&~uintptr_type(1)); } pointer_ref& operator=(T* p) { *r=((uintptr_type)(void*)p)|(*r&uintptr_type(1)); return *this; } pointer_ref& operator=(const pointer_ref& x) { return operator=(x.operator T*()); } pointer_ref operator->()const { return operator T*(); } private: uintptr_type* r; }; Thanks Joaquin for sharing simple things like this one, stable_vector and others in your Bannalia blog. _____________________ Vicente Juan Botet Escribá

12 27

Boost.CrashReport?
by Boris Schaeling 09 Sep '09

09 Sep '09

I'm looking for a C++ library which comes close to what I imagine to be the ideal crash reporting library Boost.CrashReport. :) Firefox seems to use google-breakpad but maybe some of you have been using other (C++?) libraries. Or did anyone start to work on something like Boost.CrashReport (not that I found anything in the vault)? I don't need a library to upload automatically a crash report to a website. But if an application crashs I want to tell a user to send me file X in directory Y to avoid explaining who Dr. Watson is or what 'ulimit -c' does. Boris

2 4

Boost.Swap docs missing mention of header!
by David Abrahams 09 Sep '09

09 Sep '09

http://www.boost.org/doc/libs/1_40_0/libs/utility/swap.html doesn't tell me what I need to include in order to use boost::swap. -- Dave Abrahams BoostPro Computing http://www.boostpro.com

4 4

[filesystem] Windows long paths (and also API differences)
by Adam Badura 09 Sep '09

09 Sep '09

In a simple test program I used create_directories with long path (longer then MAX_PATH being equal to 260 on my machine). ANSI version (for char) threw an exception but before reaching MAX_PATH (somewhere around 255 characters however I did not test exactly). UNICODE version (for wchar_t) created as many directories as it could (as many as would make ANSI version not throw) and skipped rest without throwing anything. This seems bad. Why is it so? And is the MAX_PATH file system limitation on Windows or is it just a limitation for some API functions? Also by the way I wanted to ask why signatures of many functions differ from the documentation. For example no function takes error code parameter and thus always throws on failure (excluding the above example...). In some places I would prefer to have that parameter instead. Also copy_file does not take the third parameter allowing it to do replacing. Why is it so? I am using Boost 1.39 (1.40 does not work for me somehow, when I try to use it it gives compilation errors as I already mentioned in a previous thread) and Visual Studio 2005 on Vista machine. Adam Badura

2 2

Re: [boost] [serialization] Linker errors in trunk
by Hartmut Kaiser 08 Sep '09

08 Sep '09

> Sorry, resending as it ended up on the wrong list... > > ----------------------------- > > Since the latest changes in trunk I'm seeing linker errors while > linking with the serialization library (VS2005 SP1, > boost_serialization-vc80-mt-gd-1_40.lib): > > runtime_support.obj : error LNK2001: unresolved external symbol > "__declspec(dllimport) public: __thiscall > boost::archive::archive_exception::archive_exception(enum > boost::archive::archive_exception::_exception_code,char const *,char > const *)" > (__imp_??0archive_exception@archive@boost@@QAE@W4_exception_code@012@PB > D1@Z) > > (note the leading underscore in _exception_code) > > Which is really strange as this symbol is the only missing one. > > OTOH, the library exports the symbol: > > boost::archive::archive_exception::archive_exception( > enum boost::archive::archive_exception::exception_code, > char const *,char const *); > > (note the missing underscore in exception_code) > > If I change the first parameter of the archive_exception constructor to > be a 'int' everything builds fine. Ok, I solved it. The MS header file excpt.h has a #define exception_code _exception_code which leads to problems if not consistently included. Doh! What a mess. The bottom line is, that archive_exception.cpp needs to be compiled with exactly the same windows headers included (excpt.h gets included by windows.h) as any sources including archive_exception.hpp, which is generally not possible to ensure. The only fail-proof way I could see is to always have #if defined(BOOST_WINDOWS) #include <excpt.h> #endif inside archive_exception.hpp, globally mapping exception_code to _exception_code. Patch attached. Ok to commit? Regards Hartmut

4 9

Re: [boost] [Boost.Function] How about parallel functions?
by Kasra 08 Sep '09

08 Sep '09

>> Hi, >> >> I required to call few functions is separate threads and use the >> results. However, the code for this looks really ugly, you have to create >> threads, then join the threads when ever you require the result of the >functions. >> >> So I have created a boost.parallel_function library that does this >> seamlessly just like invoking a normal function and it only joins the >> thread when the value of the function result type is required. Is this >> library of any interest to any one? >> >> Here is the a hello world example: >> >> #include <cstdlib> >> #include <limits> >> #include <boost/parallel_function.hpp> >> using namespace boost; >> >> int F0() >> { >> volatile int x = 0; >> for(int i=0; i<std::numeric_limits<int>::max()/1024; i++) >> x ^= std::rand(); >> return (int)x; >> } >> >> >> int F2(int y) >> { >> volatile int x = 0; >> for(int i=0; i<std::numeric_limits<int>::max()/512; i++) >> x ^= std::rand(); >> return (int)x ^ y; >> } >> >> int main() >> { >> typedef boost::parallel_function< void ( ) > f0_type; >> typedef boost::parallel_function< void (int) > f1_type; >> >> f0_type f0( &::F0 ); >> f1_type f1( &::F1 ); >> >> f0_type::result_type r0 = f0(); >> f1_type::result_type r1 = f1(32); >> >> // use r0 and r1 as if they are int >> r0 += 34; >> int value = r1 *= r0 + 452; >> >> std::cout << "Hello world " << value << std::endl; >> >> return 0; >> } > >The Boost.Task library should provides the features you need. > >int main() { > > boost::task::handle<int> f0 = boost::task:async(boost:task(F0),boost::task::new_thread()); > boost::task::handle<int> f1 = boost::task:async(boost:task(F1,32),boost::task::new_thread()); > int r0=f0.get(); > int r1=f1.get(); > > r0 += 34; > int value = r1 *= r0 + 452; > > std::cout << "Hello world " << value << std::endl; > > return 0; >} > >This library is under the review schedule and will be reviewed soon. I'm >interested on the details of your implementation to compare with >Boost.Task. It will be also useful if you can take a look to Boost.task and >try so see it provides every thing you need. > >Best, >Vicente I have taken a partial look at Boost.task, however, what I don't like about the syntax is the following: > int r0=f0.get(); > int r1=f1.get(); Current implementation (hack) would make 'f0' and 'f1' the same type 'int' (in this example). So the .get() part could be omitted altogether; which seems a lot like thread.join() call! Which is accomplished by a simple implicit conversion operator to the reference of the type. A little out of topic discussion, why is there an atomic library within task? because boost.thread has one (I think). Atomic library should be written so it becomes more coherent and reduces the code size. With Best Regards Mr. Kasra Nassiri Department of Mathematics & Computer Science Imperial College London

3 2

[Graph] 1.40 Static Link Issue
by Gordon Smith 07 Sep '09

07 Sep '09

There seems to be an unused bool in fruchterman_reingold.hpp: bool vertex_migration = false; Which will cause link errors if included in more than one statically linked library. Gordon.

2 1

Move notes
by David Abrahams 07 Sep '09

07 Sep '09

Hi Ion, A few things I noticed looking through move.hpp in the sandbox 1. you static_cast in one direction but reinterpret_cast in the other. Why? 2. I think move_iterator's operator-> return type is wrong; maybe make the pointer type be the underlying iterator type instead? 3. I think its operator[] can be wrong for some iterators. See http://www.boost.org/doc/libs/1_40_0/libs/iterator/doc/iterator_facade.html… 4. bool-valued traits should be derived from an MPL integral constant, e.g. template <class T> struct is_whatever : mpl::bool_< (some compile-time expression ) > {}; Cheers, -- Dave Abrahams BoostPro Computing http://www.boostpro.com

3 4

[optional] compatibility with arrays
by Craig Henderson 07 Sep '09

07 Sep '09

I am using boost::optional but have hit a problem with arrays. Using MSVC8, the definition boost::optional<char[R] > foo_; produces a compilation error: boost_1_39_0\boost/optional/optional.hpp(315) : error C2075: 'Target of operator new()' : array initialization needs curly braces boost_1_39_0\boost/optional/optional.hpp(314) : while compiling class template member function 'void boost::optional_detail::optional_base<T>::construct(const char (&))' with [ T=char [3] ] boost_1_39_0\boost/optional/optional.hpp(455) : see reference to class template instantiation 'boost::optional_detail::optional_base<T>' being compiled with [ T=char [3] ] There is no mention of non-arrays in the type requirements, so I don't know if this is specific to MSVC8, or a general/known problem? I have overcome the problem using boost::array boost::optional<boost::array<char,R> > foo_; Is there an opportunity to detect an array and substitute a boost::array for the given type? Thanks -- Craig Craig Henderson <http://craighenderson.co.uk/> http://www.craighenderson.co.uk http://www.siteupdatenotification.com

1 0

Re: [boost] [Boost.Function] How about parallel functions?
by Kasra 07 Sep '09

07 Sep '09

The example is fine thanks. However, it has syntax errors! more like typepos :D -- Kasra

1 0

Arbitrary precision arithmetic
by Scott Johnson 07 Sep '09

07 Sep '09

Greetings. This is my first post to the mailing list, so I'll try not to act stupid. :) The recent release of Boost (1.39.0), in the boost::rational library documentation, broadly hints at (and expresses a fond wish for) an arbitrary-precision integer ("bignum") library; however none currently exists within Boost. There are numerous such libraries out in the wild (many targeted towards C); though some of them are under incompatible licenses. (One interesting starting point would be libtommath, by Tom St. Denis; it appears to be a pretty robust and functional C library; which now has a C++ wrapper--albeit one that doesn't meet boost standards. It also contains numerous other useful number-theoretic functions, many of which appear to not be dependeing on the underlying bigint type. And it's in the public domain, or at least appears to be...) Searching through the mailing list, I've seen numerous references to creating such a thing, some of them dating back nearly ten years--but none yet seems to exist. This is something, I think, which would be Really Useful to add to boost. I wasn't able to locate any current boost project or proposal to create such a thing--though it's certainly possible I looked up the wrong keyword(s). So, my possibly impertinent newbie question: Is anyone (seriously) working on such a thing, for inclusion in boost? Are there any nasty (political) obstacles to such a thing being added? Thanks! -- engineer_scotty (no, not that one) If life gives you lemons, drink Hefeweizen

12 21

problems with recursive_timed_mutex and scoped lock wont compile in version 1.39
by Clark Sims 07 Sep '09

07 Sep '09

I can compile the following code fine in boost 1.33.1 but it generates compiler errors in version 1.39. I am using visual studio 2005. I will post the code, and then post the compiler errors: #include <iostream> #include <boost/thread/thread.hpp> #include <boost/thread/xtime.hpp> #include <boost/thread/recursive_mutex.hpp> using namespace std; //using namespace boost; using boost::mutex; using boost::thread; using boost::recursive_timed_mutex; using boost::xtime; boost::recursive_timed_mutex hello_mutex; void hello( int thread_id, int iter) { cerr << thread_id << " : " << iter << endl; } void rand_xtime( xtime* xt) { xtime_get( xt, boost::TIME_UTC); //xt.nsec += (rand() % 1000000000); xt->sec += 1 + rand()%5; } void say_hello( int thread_id) { for (int iter=0; iter<5; iter++) { xtime xt; rand_xtime( &xt); thread::sleep(xt); rand_xtime( &xt); { recursive_timed_mutex &refer_hello = hello_mutex; const xtime& refer_xt = xt; recursive_timed_mutex::scoped_timed_lock lock1( refer_hello, refer_xt); if (lock1) { hello( thread_id, iter); } } } } void hello1() { say_hello( 1); } void hello2() { say_hello( 2); } int main() { boost::thread thrd1(hello1); boost::thread thrd2(hello2); thrd1.join(); thrd2.join(); return 0; } Microsoft (R) Program Maintenance Utility Version 8.00.50727.42 Copyright (C) Microsoft Corporation. All rights reserved. Warning: cannot find Makefile.TimedMutex.dep cl.exe /nologo /Ob0 /W3 /EHs /MD /GR /I ".." /D NDEBUG /D WIN32 /D _CONSOLE /FD /c /Fo"Release\TimedMutex\I386\TimedMutex.obj" "TimedMutex.cpp" TimedMutex.cpp c:\boost_1_39\boost\thread\win32\basic_recursive_mutex.hpp(64) : error C2679: binary '+' : no operator found which takes a right-hand operand of type 'const boost::xtime' (or there is no acceptable conversion) c:\boost_1_39\boost/date_time/posix_time/date_duration_operators.hpp(31): could be 'boost::posix_time::ptime boost::posix_time::operator +(const boost::posix_time::ptime &,const boost::gregorian::months &)' [found using argument-dependent lookup] c:\boost_1_39\boost/date_time/date_duration_types.hpp(132): or 'boost::gregorian::date boost::date_time::months_duration<base_config>::operator +(const boost::gregorian::date &,const boost::date_time::months_duration<base_config> &)' [found using argument-dependent lookup] with [ base_config=boost::gregorian::greg_durations_config ] c:\boost_1_39\boost/date_time/posix_time/date_duration_operators.hpp(75): or 'boost::posix_time::ptime boost::posix_time::operator +(const boost::posix_time::ptime &,const boost::gregorian::years &)' [found using argument-dependent lookup] c:\boost_1_39\boost/date_time/date_duration_types.hpp(244): or 'boost::gregorian::date boost::date_time::years_duration<base_config>::operator +(const boost::gregorian::date &,const boost::date_time::years_duration<base_config> &)' [found using argument-dependent lookup] with [ base_config=boost::gregorian::greg_durations_config ] c:\boost_1_39\boost/date_time/time.hpp(139): or 'boost::posix_time::ptime boost::date_time::base_time<T,time_system>::operator +(const boost::gregorian::date_duration &) const' with [ T=boost::posix_time::ptime, time_system=boost::posix_time::posix_time_system ] c:\boost_1_39\boost/date_time/time.hpp(159): or 'boost::posix_time::ptime boost::date_time::base_time<T,time_system>::operator +(const boost::posix_time::time_duration &) const' with [ T=boost::posix_time::ptime, time_system=boost::posix_time::posix_time_system ] while trying to match the argument list '(boost::system_time, const boost::xtime)' c:\boost_1_39\boost/thread/locks.hpp(364) : see reference to function template instantiation 'bool boost::detail::basic_recursive_mutex_impl<underlying_mutex_type>::timed_lock<boost::xtime>(const Duration &)' being compiled with [ underlying_mutex_type=boost::detail::basic_timed_mutex, Duration=boost::xtime ] c:\boost_1_39\boost/thread/locks.hpp(363) : while compiling class template member function 'bool boost::unique_lock<Mutex>::timed_lock(const boost::xtime &)' with [ Mutex=boost::recursive_timed_mutex ] TimedMutex.cpp(36) : see reference to class template instantiation 'boost::unique_lock<Mutex>' being compiled with [ Mutex=boost::recursive_timed_mutex ] NMAKE : fatal error U1077: '"c:\Program Files\Microsoft Visual Studio 8\VC\BIN\cl.exe"' : return code '0x2' Stop.

1 0

Testing down
by K. Noel Belcourt 07 Sep '09

07 Sep '09

Hi, I'm sorry to report that over the weekend the machine and file systems running Boost testing failed. I'm working on resurrecting the testing on another system but it may be tomorrow before testing comes back online. I apologize for the disruption. -- Noel Belcourt

1 0

[Graph] 1.40 Static Link Issue
by Gordon Smith 07 Sep '09

07 Sep '09

There seems to be an unused bool in fruchterman_reingold.hpp: bool vertex_migration = false; Which will cause link errors if included in more than one statically linked library. Gordon.

1 0

[mpi] non-char strings
by Isidor Zeuner 07 Sep '09

07 Sep '09

The last two checkouts I installed both failed passing strings through boost::mpi communication methods when the element type was not char. So maybe someone besides me will have use for the attached patch which makes it work again. I assume this way of passing strings isn't here to stay anyway since boost::serialization also handles strings. Best regards, Isidor

3 5

Release branch test results with MPI dropped on floor
by Steve M. Robbins 06 Sep '09

06 Sep '09

Hi, Now that 1.40 is out, can we get the release branch testing result scripts fixed so that they understand MPI runs? c.f. http://lists.boost.org/Archives/boost/2009/08/155466.php http://lists.boost.org/boost-testing/2009/08/6353.php Thanks, -Steve

4 4

[hs] Quickbook highlighting doesn't work in KDE 4.3
by Andrey Semashev 06 Sep '09

06 Sep '09

I'm not sure it's the right place for this, so sorry if it's off-topic. I'm trying to use Boost.HS* with Kate from KDE 4.3 on Ubuntu 9.04 but it doesn't work. There appears no "boost::hs" group in the Toost->Highlighting menu, neither does it color the quickbook files. Have anyone run into such kind of problems? PS: I successfully used Boost.HS with previous KDE versions (4.1 for sure, not sure about 4.2). This tool really helps to document the library, many thanks to the author. * http://www.drivehq.com/web/matias.capeletto/boost_hs/doc/html/index.html

2 2

Failures for GCC 4.4.1 with gnu++0x
by Beman Dawes 06 Sep '09

06 Sep '09

9 19

[Boost.Function] How about parallel functions?
by Kasra 06 Sep '09

06 Sep '09

Hi, I required to call few functions is separate threads and use the results. However, the code for this looks really ugly, you have to create threads, then join the threads when ever you require the result of the functions. So I have created a boost.parallel_function library that does this seamlessly just like invoking a normal function and it only joins the thread when the value of the function result type is required. Is this library of any interest to any one? Here is the a hello world example: #include <cstdlib> #include <limits> #include <boost/parallel_function.hpp> using namespace boost; int F0() { volatile int x = 0; for(int i=0; i<std::numeric_limits<int>::max()/1024; i++) x ^= std::rand(); return (int)x; } int F2(int y) { volatile int x = 0; for(int i=0; i<std::numeric_limits<int>::max()/512; i++) x ^= std::rand(); return (int)x ^ y; } int main() { typedef boost::parallel_function< void ( ) > f0_type; typedef boost::parallel_function< void (int) > f1_type; f0_type f0( &::F0 ); f1_type f1( &::F1 ); f0_type::result_type r0 = f0(); f1_type::result_type r1 = f1(32); // use r0 and r1 as if they are int r0 += 34; int value = r1 *= r0 + 452; std::cout << "Hello world " << value << std::endl; return 0; } With Best Regards Mr. Kasra Nassiri Department of Mathematics & Computer Science Imperial College London

3 2

Bug in date_time::subsecond_duration
by Jon Spencer 06 Sep '09

06 Sep '09

There is a needless loss of range in the constructor of date_time::subsecond_duration. The argument is multiplied by the resolution of the base_duration, which could potentially overflow, and then divided by frac_of_second. The patch below reduces the amount of overflow and is identical if one resolution is an integer multiple of the other. The same technique is used elsewhere in the file. Also see this posting on the subject (http://lists.boost.org/boost-users/2008/10/41763.php) --- boost/date_time/time_duration.hpp +++ boost/date_time/time_duration.hpp @@ -267,7 +267,7 @@ public: typedef typename base_duration::traits_type traits_type; explicit subsecond_duration(boost::int64_t ss) : - base_duration(0,0,0,ss*traits_type::res_adjust()/frac_of_second) + base_duration(0,0,0,traits_type::res_adjust()<frac_of_second?ss/(frac_of_second/traits_type::res_adjust()):ss*(traits_type::res_adjust()/frac_of_second)) {} };

1 0

Weak pointer to object not managed by a shared_ptr
by Mateusz Loskot 05 Sep '09

05 Sep '09

Hi, One of the smart pointer techniques [1] explains use of weak_ptr pointer to object not managed by a shared_ptr. [1] http://www.boost.org/doc/libs/1_40_0/libs/smart_ptr/sp_techniques.html I'm wondering what would be practical use case of that? Is it a part of any of known idioms or patterns? Also, is it valid to assume that this technique can extend lifetime of X so of the internal integral X::i_ ? Here is a simple test case based on the technique explained in the smartptr docs [1] with my questions marked using XXX tag: /// begin of program /////////////////////////////////////////////// #include <exception> #include <iostream> #include <boost/shared_ptr.hpp> #include <boost/weak_ptr.hpp> using namespace std; using namespace boost; struct null_deleter { void operator()(void const *) const { std::cout << "deleter\n"; } }; class X { public: explicit X(int i): this_(this, null_deleter()), i_(i) {} X(X const & rhs): this_(this, null_deleter()), i_(rhs.i_) {} X & operator=(X const & rhs) { i_ = rhs.i_; return *this; } weak_ptr<X> get_weak_ptr() const { return this_; } int get_i() const { return i_; } private: shared_ptr<X> this_; int i_; }; int main() { try { shared_ptr<X> spx; { X x1(7); // XXX: lifetime is extended here? spx = shared_ptr<X>(x1.get_weak_ptr()); } // XXX: No exception. x1 is still alive, so the pointer valid? cout << spx->get_i() << std::endl; } catch (bad_weak_ptr const& e) { cerr << e.what() << endl; } catch (exception const& e) { cerr << e.what() << endl; } catch (...) { cerr << "unknown error\n"; } return 0; } /// end of program /////////////////////////////////////////////// No exception is thrown and I can It seem that the lifetime of x1, automatic object, has been extended beyond its "natural" scope. Am I correct? However, if I replace retrival of shared_ptr with weak_ptr then of course bad_weak_ptr exception is thrown: shared_ptr<X> spx; weak_ptr<X> wpx; { X x1(7); wpx = x1.get_weak_ptr(); } spx = shared_ptr<X>(wpx); cout << spx->get_i() << std::endl; I'm having problems with understanding of what causes the extention of lifetime of X (so of internal X::i_ object). Is this mechanism similar to binding r-value to "const reference"? I would appreciate if anyone could help me to understand it. References to the C++ standard would be great too. Best regards, -- Mateusz Loskot, http://mateusz.loskot.net Charter Member of OSGeo, http://osgeo.org

7 9

[ptr_container] Questionable strong guarantee of ptr_map::insert()
by Kazutoshi Satoda 05 Sep '09

05 Sep '09

Hi, With current implementation of ptr_map::insert(), if an exception is thrown, the objected pointed by the passed pointer is deleted. Is this really providing strong guarantee as documented? I understand strong guarantee as described here. http://www.boost.org/community/exception_safety.html > The strong guarantee: that the operation has either completed > successfully or thrown an exception, leaving the program state exactly > as it was before the operation started. I think ptr_map::insert() doesn't provide this guarantee because deleting the object is a change of the program state. As more concrete problem, see the attached code. I couldn't find any way to provide strong guarantee for delayed_inserter::insert_ready() using ptr_map. I want ready_value unchanged if an exception is thrown during the insertion. Looking for a solution on a similar situation, I found constructors of shared_ptr. Its documentation clearly says that "If an exception is thrown, delete p is called". And for auto_ptr version, it provides strong guarantee by taking the auto_ptr as non-const reference. I think ptr_map::insert() should follow this manner; document the deletion on exception for raw pointer version, and provide strong guarantee with insert(const key_type& key, std::auto_ptr& x) . The the auto_ptr& version can be a better replacement of the raw pointer version. The required temporary of auto_ptr, instead of key_type, is more expressive (about the purpose of the temporary), and matches the Best Practices shown in the documentation of shared_ptr. http://www.boost.org/libs/smart_ptr/shared_ptr.htm#BestPractices But, introducing the auto_ptr& version seems to cause some change of behavior in client codes using the current pass-by-value version. Is it valid to request (create a ticket) for strong guaranteed (taking auto_ptr&) version while having this compatibility concern? Regards. -- k_satoda #include <memory> #include "boost/ptr_container/ptr_map.hpp" namespace ptr_map_insert_strong_guarantee_demo { class value { public: explicit value(int source); // ... }; class delayed_inserter { public: // ... // This is called from context that knows key and source of value, // but doesn't know the time of insertion. void ready_new(int key, int source) { // OK. // This implementation offers strong guarantee for this call. std::auto_ptr<value> new_value(new value(source)); ready_key = key; ready_value = new_value; } // This is called from context which doesn't know key and value, // but knows the time of insertion. void insert_ready() { if (ready_value.get() != 0) { // I want to offer strong guarantee for this call, // but boost::ptr_map deosn't provide the way to do that; // *** ready_value is deleted when an exception is thrown. *** map.insert(ready_key, ready_value); } } // ... private: int ready_key; std::auto_ptr<value> ready_value; boost::ptr_map<int, value> map; // ... }; }

8 17

[lockfree] how many items are queued?
by Oliver Kowalke 05 Sep '09

05 Sep '09

lockfree.fifo provides the info if the queue is empty or not. is it possible to provide a function std::size_t size() const - returning how many items are queued at a specific timepoint? regards, Oliver -- Jetzt kostenlos herunterladen: Internet Explorer 8 und Mozilla Firefox 3 - sicherer, schneller und einfacher! http://portal.gmx.net/de/go/chbrowser

5 9

PropertyTree automated tests
by Sebastian Redl 04 Sep '09

04 Sep '09

Hi, There are no test results at all for the proptree library on trunk. There isn't even a row in the table for it. Why is that so? Sebastian

2 2

wait-free fast-pathed, bounded-time, 100% starvation-free rw-mutex...
by Chris M. Thomasson 04 Sep '09

04 Sep '09

I was wondering if the following invention of mine might be of use to Boost: http://software.intel.com/en-us/forums/intel-threading-building-blocks/topi… (please __read_all__; thank you) Here are some performance numbers wrt my algorithm versus NPTL on Linux (fedora 10), and OpenSolaris: http://groups.google.com/group/comp.programming.threads/msg/3e7531657a11baf0 My invention has some very interesting properties that simply do not exist for 99% of all the other rw-mutex algorithms I have seen to date. It's 100% starvation free and has bounded wait time for readers and writers. Heck, even the Microsoft rw-mutex algorithm in Vista does not come close to that: http://msdn.microsoft.com/en-us/library/aa904937(VS.85).aspx They clearly state that their algorithm is not fair. The algorithm I have observed in OpenSolaris does not meet this goal as well. Another nice property is that the algorithm has wait-free fast-paths. If readers hit a fast-path, then they are going to get wait-free access to the protected data-structure. The same goes for writers. The underlying operation is a single atomic fetch-and-add operation: http://software.intel.com/en-us/forums/intel-threading-building-blocks/topi… In fact, the algorithm only needs fetch-and-add; no stupid CAS-loops are required. Please take not that there are absolutely no loops in the algorithm; this is one reason why it's bounded time and starvation free. Also, it has conditional reader-to-writer upgrades and non-conditional writer-to-reader downgrade capabilities. This is something that does not exist in the Microsoft implementation, or even the OpenSolaris, or basically any Linux implementation I have observed. Same goes for OSX. Therefore, I think this particular algorithm might be of use to Boost. Any thoughts? Thank you all for you're valuable time; I really do appreciate it! :^)

4 14

1.40 regex
by Jonathan Brannan 04 Sep '09

04 Sep '09

I have code that comes out clean in 1.39 (as unit-test and under valgrind), but under 1.40 it's not clean in valgrind and it crashes when run normally (malloc(): memory corruption). I'm trying to write a reproducer that is smaller than what I have, but incase something pops out at someone (or can point me where my code might be wrong), here is the valgrind output: Running 16 test cases... ==25074== Invalid write of size 8 ==25074== at 0x4E7D4A8: boost::shared_ptr<boost::re_detail::named_subexpressions_base<char> >::shared_ptr() (shared_ptr.hpp:182) ==25074== by 0x4E813C1: boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char cons t*, std::string> > > >::match_results(std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > > const&) (match_results.hpp:77) ==25074== by 0x5811371: boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator <char const*, std::string> > >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::construct_init(boost::basic_regex<char, boost::regex_traits<char, boost::cpp_rege x_traits<char> > > const&, boost::regex_constants::_match_flags) (perl_matcher_common.hpp:73) ==25074== by 0x4E856D2: boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator <char const*, std::string> > >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::perl_matcher(__gnu_cxx::__normal_iterator<char const*, std::string>, __gnu_cxx::_ _normal_iterator<char const*, std::string>, boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_i terator<char const*, std::string> > > >&, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags, _ _gnu_cxx::__normal_iterator<char const*, std::string>) (perl_matcher.hpp:366) ==25074== by 0x4E8583A: bool boost::regex_search<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > >, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >(__gnu_cxx::__normal_iterator<char const*, std::string>, __gnu_cxx::__normal_iterat or<char const*, std::string>, boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char c onst*, std::string> > > >&, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags, __gnu_cxx::__no rmal_iterator<char const*, std::string>) (regex_search.hpp:55) ==25074== by 0x4E85BEF: boost::regex_token_iterator_implementation<__gnu_cxx::__normal_iterator<char const*, std::string>, char, boost::regex_traits<char, boost::cpp_regex _traits<char> > >::init(__gnu_cxx::__normal_iterator<char const*, std::string>) (regex_token_iterator.hpp:109) ==25074== by 0x4E8AC07: boost::regex_token_iterator<__gnu_cxx::__normal_iterator<char const*, std::string>, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::regex_token_iterator(__gnu_cxx::__normal_iterator<char const*, std::string>, __gnu_cxx::__normal_iterator<char const*, std::string>, boost::basic_regex<char, boost::regex _traits<char, boost::cpp_regex_traits<char> > > const&, int, boost::regex_constants::_match_flags) (regex_token_iterator.hpp:200) ==25074== by 0x45D99C: application_ut_suite::test_logon::test_method() (application_ut.cpp:139) ==25074== Address 0x6a64588 is 0 bytes after a block of size 56 alloc'd ==25074== at 0x4C2506C: operator new(unsigned long) (in /usr/lib64/valgrind/amd64-linux/vgpreload_memcheck.so) ==25074== by 0x5811362: boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator <char const*, std::string> > >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::construct_init(boost::basic_regex<char, boost::regex_traits<char, boost::cpp_rege x_traits<char> > > const&, boost::regex_constants::_match_flags) (perl_matcher_common.hpp:73) ==25074== by 0x4E856D2: boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator <char const*, std::string> > >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::perl_matcher(__gnu_cxx::__normal_iterator<char const*, std::string>, __gnu_cxx::_ _normal_iterator<char const*, std::string>, boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_i terator<char const*, std::string> > > >&, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags, _ _gnu_cxx::__normal_iterator<char const*, std::string>) (perl_matcher.hpp:366) ==25074== by 0x4E8583A: bool boost::regex_search<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > >, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >(__gnu_cxx::__normal_iterator<char const*, std::string>, __gnu_cxx::__normal_iterat or<char const*, std::string>, boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char c onst*, std::string> > > >&, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags, __gnu_cxx::__no rmal_iterator<char const*, std::string>) (regex_search.hpp:55) ==25074== by 0x4E85BEF: boost::regex_token_iterator_implementation<__gnu_cxx::__normal_iterator<char const*, std::string>, char, boost::regex_traits<char, boost::cpp_regex _traits<char> > >::init(__gnu_cxx::__normal_iterator<char const*, std::string>) (regex_token_iterator.hpp:109) ==25074== by 0x4E8AC07: boost::regex_token_iterator<__gnu_cxx::__normal_iterator<char const*, std::string>, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::regex_token_iterator(__gnu_cxx::__normal_iterator<char const*, std::string>, __gnu_cxx::__normal_iterator<char const*, std::string>, boost::basic_regex<char, boost::regex _traits<char, boost::cpp_regex_traits<char> > > const&, int, boost::regex_constants::_match_flags) (regex_token_iterator.hpp:200) ==25074== by 0x442E4F: application_ut_suite::(anonymous namespace)::Test_Setup::Test_Setup(std::istream&, unsigned long) (application_ut.cpp:96) ==25074== by 0x45D99C: application_ut_suite::test_logon::test_method() (application_ut.cpp:139) ==25074== by 0x45F620: _ZN20application_ut_suiteL18test_logon_invokerEv (application_ut.cpp:133) ==25074== ==25074== Invalid write of size 8 ==25074== at 0x46CE8A: boost::detail::shared_count::shared_count() (shared_count.hpp:71) ==25074==:regex_traits<char, boost::cpp_regex_traits<char> > > const&, int, boost::regex_constants::_match_flags) (regex_token_iterator.hpp:200) ==25074== by 0x442E4F: application_ut_suite::(anonymous namespace)::Test_Setup::Test_Setup(std::istream&, unsigned long) (application_ut.cpp:96) ==25074== Address 0x6a64590 is 8 bytes after a block of size 56 alloc'd ==25074== at 0x4C2506C: operator new(unsigned long) (in /usr/lib64/valgrind/amd64-linux/vgpreload_memcheck.so) ==25074== by 0x5811362: boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::construct_init(boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags) (perl_matcher_common.hpp:73) ==25074== by 0x4E856D2: boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::perl_matcher(__gnu_cxx::__normal_iterator<char const*, std::string>, __gnu_cxx::__normal_iterator<char const*, std::string>, boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::_cxx::__normal_iterator<char const*, std::string>, boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > > >&, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags, __gnu_cxx::__normal_iterator<char const*, std::string>) (regex_search.hpp:55) ==25074== by 0x4E85BEF: boost::regex_token_iterator_implementation<__gnu_cxx::__normal_iterator<char const*, std::string>, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::init(__gnu_cxx::__normal_iterator<char const*, std::string>) (regex_token_iterator.hpp:109) ==25074== by 0x4E8AC07: boost::regex_token_iterator<__gnu_cxx::__normal_iterator<char const*, std::string>, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::regex_token_iterator(__gnu_cxx::__normal_iterator<char const*, std::string>, __gnu_cxx::__normal_iterator<char const*, std::string>, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, int, boost::regex_constants::_match_flags) (regex_token_iterator.hpp:200) ==25074== by 0x442E4F: application_ut_suite::(anonymous namespace)::Test_Setup::Test_Setup(std::istream&, unsigned long) (application_ut.cpp:96) ==25074== by 0x45D99C: application_ut_suite::test_logon::test_method() (application_ut.cpp:139) ==250ub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::construct_init(boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags) (perl_matcher_common.hpp:73) ==25074== by 0x4E856D2: boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::perl_matcher(__gnu_cxx::__normal_iterator<char const*, std::string>, __gnu_cxx::__normal_iterator<char const*, std::string>, boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > > >&, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags, __gnu_cxx::__normal_iterator<char const*, std::string>) (perl_matcher.hpp:366) ==25074== by 0x4E8583A: bool boost::regex_search<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > >, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >(__gnu_cxx::__normal_iterator<char const*, std::string>, __gnu_cxx::__normal_iterator<char const*, std::string>, boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > > >&, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags, __gnu_cxx::__normal_iterator<char const*, std::string>) (regex_search.hpp:55) ==25074== by 0x4E85BEF: boost::regex_token_iterator_implementation<__gnu_cxx::__normal_iterator<char const*, std::string>, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::init(__gnu_cxx::__normal_iterator<char const*, snstants::_match_flags) (regex_token_iterator.hpp:200) ==25074== by 0x442E4F: application_ut_suite::(anonymous namespace)::Test_Setup::Test_Setup(std::istream&, unsigned long) (application_ut.cpp:96) ==25074== by 0x45D99C: application_ut_suite::test_logon::test_method() (application_ut.cpp:139) ==25074== by 0x45F620: _ZN20application_ut_suiteL18test_logon_invokerEv (application_ut.cpp:133) ==25074== Address 0x6a64598 is not stack'd, malloc'd or (recently) free'd **25074** new/new[] failed and should throw an exception, but Valgrind cannot throw exceptions and so is aborting instead. Sorry. ==25074== at 0x4C22E23: (within /usr/lib64/valgrind/amd64-linux/vgpreload_memcheck.so) ==25074== by 0x4C250C8: operator new(unsigned long) (in /usr/lib64/valgrind/amd64-linux/vgpreload_memcheck.so) ==25074== by 0x4E84680: __gnu_cxx::new_allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > >::allocate(unsigned long, void const*) (new_allocator.h:92) ==25074== by 0x4E846AF: std::_Vector_base<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > > >::_M_allocate(unsigned long) (stl_vector.h:144) ==25074== by 0x4E8A4AE: std::vector<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*tor.tcc:395) ==25074== by 0x4E8A61E: std::vector<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > > >::insert(__gnu_cxx::__normal_iterator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> >*, std::vector<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > > > >, unsigned long, boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > const&) (stl_vector.h:792) ==25074== by 0x4E8A73B: boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > > >::set_size(unsigned long, __gnu_cxx::__normal_iterator<char const*, std::string>, __gnu_cxx::__normal_iterator<char const*, std::string>) (match_results.hpp:399) ==25074== by 0x4E8B1BF: boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::find_imp() (perl_matcher_common.hpp:263) ==25074== by 0x5810D0A: boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::find() (perl_matcher_common.hpp:229) ==25074== by 0x4E85846: bool boost::regex_search<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::string> > >, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >(__gnu_cxx::__normal_iterator<char const*, std::string>, __gnu_cxx::__normal_iterator<char const*, std::string>, boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::string>, std::allocator<boost:::regex_traits<char, boost::cpp_regex_traits<char> > >::init(__gnu_cxx::__normal_iterator<char const*, std::string>) (regex_token_iterator.hpp:109) ==25074== by 0x4E8AC07: boost::regex_token_iterator<__gnu_cxx::__normal_iterator<char const*, std::string>, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::regex_token_iterator(__gnu_cxx::__normal_iterator<char const*, std::string>, __gnu_cxx::__normal_iterator<char const*, std::string>, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, int, boost::regex_constants::_match_flags) (regex_token_iterator.hpp:200) ==25074== ==25074== ERROR SUMMARY: 3 errors from 3 contexts (suppressed: 3 from 1) ==25074== malloc/free: in use at exit: 64,694 bytes in 500 blocks. ==25074== malloc/free: 590 allocs, 89 frees, 103,110 bytes allocated. ==25074== For counts of detected errors, rerun with: -v ==25074== searching for pointers to 500 not-freed blocks. ==25074== checked 402,856 bytes. ==25074== ==25074== LEAK SUMMARY: ==25074== definitely lost: 0 bytes in 0 blocks. ==25074== possibly lost: 7,480 bytes in 190 blocks. ==25074== still reachable: 57,214 bytes in 310 blocks. ==25074== suppressed: 0 bytes in 0 blocks. ==25074== Rerun with --leak-check=full to see details of leaked memory.

2 2

[1.41.0] Release branch open for merges
by Beman Dawes 04 Sep '09

04 Sep '09

The release branch (https://svn.boost.org/svn/boost/branches/release) is open for merging all stable changes from trunk, including bug fixes and major upgrades to existing libraries. Breaking changes should be coordinated via the mailing list with the developers of the other libraries affected. New libraries may be added, but require permission of a release manager. In other words, except for new libraries, merging changes *does not* need permission from a release manager. I.e. just do it! The release schedule is more aggressive than usual on the front end so that we can maintain our quarterly release schedule: * September 13, 2009: branches/release closed for new libraries and breaking changes to existing libraries. Still open for bug fixes and other routine changes to all libraries. * September 20, 2009: Release managers start QA checks. * October 4, 2009: branches/release closed for major code changes. Still open for serious problem fixes and docs changes. * October 11, 2009: branches/release closed for all library changes except when specific permission given by release manager(s). * October 18, 2009: Beta release target date. Further betas and/or release candidates as feedback dictates. * November 1, 2009: Release ship date. Links relating to this release: * Google Calendar with the release schedule: <http://www.boost.org/development/index.html>. * Release schedule explanation: <http://svn.boost.org/trac/boost/wiki/ReleaseSchedule>. * Release practices for developers: <http://svn.boost.org/trac/boost/wiki/ImprovingPractices>. -- The release managers

3 3

Re: [boost] question about TMP
by DE 04 Sep '09

04 Sep '09

for those who is still interested i thought about types that a library user can actually use and finally came to this decision one can use something like //don't look at syntax, check out the concept matrix<double> m; //general rectangular dense matrix matrix<double, sparse> sp; //rectangular sparse matrix square<double> sq; //square matrix, although one might square<double, symmetric> sym; //use the following types which square<double, upper_triang> ut; //model corresponding concepts square<double, lower_triang> lt; //i.e. symmetric, upper- & lower //triangular matrices square<double, symmetric | sparse> sparse_sym; //also this square<double, lower_triang | sparse> sparse_lt;//might be useful band<double> b; //guess... band<double, symmetric> bs; //why not? //etc... all these types provide strict explicit interfaces e.g. - 'square' provides 'resize(size_t)' member but not 'resize(size_t, size_t)' - 'band' provides useful 'bandwidth()' member and 'diagonal(int)' member which returns diagonal (might be useful for implementing a band solver) -- Pavel

1 0

optional<optional<T>>
by Andrei Alexandrescu 04 Sep '09

04 Sep '09

Hello, I'm defining an "optional" type for D's standard library modeled similarly to Boost.optional. An interesting question came up - should optional<optional<T>> fold itself into optional<T>, or is "double optional" an interesting concept of its own? I thought I'd ask here because by now there's a significant body of experience with optional<T>. I perused the online documentation and the forum and couldn't find information about that specific detail. Thanks, Andrei

14 22

Re: [boost] [ublas] Extending type_traits for use with Boost Units
by Matthias Schabel 04 Sep '09

04 Sep '09

> Am Wednesday 26 August 2009 schrieb Manoj Rajagopalan: >> Hi UBLAS developers, >> >> I have begun using Boost Units which was introduced in boost v >> 1.36. I am working on extending UBLAS to support physically >> dimensioned types and I have provided a short example below. >> >> This can be achieved efficiently if a few extensions to UBLAS >> type_traits are allowed and I was wondering if anyone would object to >> this. An example of such an extension would be the introduction of >> "sqrt_type" as the type for the square root operation. This would be >> the return type for type_traits<T>::type_sqrt(). For arithmetic types >> like float and double the template can be partially specialized so >> that sqrt_type is float or double but for physically dimensioned >> types like quantity<length,double>, sqrt_type can be set to >> quantity<length^(1/2), double>. > > This is a good idea. Could you prepare a patch and a small example > program? > >> I have already adapted most of vector_expression.hpp for use with >> these dimensioned quantities with work-arounds for these extensions >> but this is getting ugly and unwieldy. > > is it possible to deduct the square_type from operator*()? E.g., using > return type deduction (see detail/returntype_deduction and > promote_traits from traits.hpp) You might also want to get in touch with Steven Watanabe. I believe he has done some work toward making UBLAS and Boost.Units interoperable. Matthias

2 1

Re: [boost] [Polygon] What does this error mean?
by Phil Endecott 03 Sep '09

03 Sep '09

Dear Luke (& others), Here's some test code, followed by the errors that I get when I try to compile it. It boils down to some confusion about whether set is a type or a function. Am I doing something that isn't allowed? Thanks for any suggestions. #include <boost/polygon/polygon.hpp> template<typename COORD_T> struct Box { typedef COORD_T coord_t; coord_t x0; coord_t y0; coord_t x1; coord_t y1; }; typedef int screen_coord_t; typedef Box<screen_coord_t> screen_box_t; namespace boost { namespace polygon { template <> struct geometry_concept<screen_box_t> { typedef rectangle_concept type; }; template <> struct rectangle_traits<screen_box_t> { typedef screen_coord_t coordinate_type; typedef std::pair<screen_coord_t,screen_coord_t> interval_type; static inline interval_type get(const screen_box_t& rectangle, orientation_2d orient) { return (orient==HORIZONTAL) ? std::make_pair(rectangle.x0,rectangle.x1) : std::make_pair(rectangle.y0,rectangle.y1); } }; }; }; typedef boost::polygon::polygon_90_set_data<screen_coord_t> markers_t; markers_t markers; void draw_marker(screen_box_t sb) { using namespace boost::polygon::operators; markers |= sb; } /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/4.1.2/bits/stl_set.h: In function ‘typename boost::enable_if<typename boost::polygon::gtl_and_3<boost::polygon::y_r_assign, typename boost::polygon::is_mutable_rectangle_concept<typename boost::polygon::geometry_concept<T>::type>::type, typename boost::polygon::is_rectangle_concept<typename boost::polygon::geometry_concept<T2>::type>::type>::type, rectangle_type_1>::type& boost::polygon::assign(rectangle_type_1&, const rectangle_type_2&) [with rectangle_type_1 = boost::polygon::rectangle_data<int>, rectangle_type_2 = Box<int>]’: /usr/local/src/gtl/boost/polygon/detail/iterator_geometry_to_set.hpp:34: instantiated from ‘boost::polygon::iterator_geometry_to_set<boost::polygon::rectangle_concept, rectangle_type>::iterator_geometry_to_set(const rectangle_type&, boost::polygon::direction_1d, boost::polygon::orientation_2d, bool) [with rectangle_type = Box<int>]’ /usr/local/src/gtl/boost/polygon/polygon_90_set_data.hpp:137: instantiated from ‘void boost::polygon::polygon_90_set_data<T>::insert(const geometry_type&, bool, boost::polygon::orientation_2d) [with geometry_type = Box<int>, T = int]’ /usr/local/src/gtl/boost/polygon/polygon_90_set_data.hpp:113: instantiated from ‘void boost::polygon::polygon_90_set_data<T>::insert(iT, iT, boost::polygon::orientation_2d) [with iT = const Box<int>*, T = int]’ /usr/local/src/gtl/boost/polygon/detail/polygon_90_set_view.hpp:318: instantiated from ‘typename boost::enable_if<typename boost::polygon::gtl_and<boost::polygon::operators::y_ps90_pe, typename boost::polygon::is_polygon_90_set_type<polygon_set_type_2>::type>::type, boost::polygon::polygon_90_set_data<coordinate_type> >::type& boost::polygon::operators::operator+=(boost::polygon::polygon_90_set_data<coordinate_type>&, const geometry_type_2&) [with coordinate_type_1 = int, geometry_type_2 = Box<int>]’ /usr/local/src/gtl/boost/polygon/detail/polygon_90_set_view.hpp:329: instantiated from ‘typename boost::enable_if<typename boost::polygon::gtl_and<boost::polygon::operators::y_ps90_be, typename boost::polygon::is_polygon_90_set_type<polygon_set_type_2>::type>::type, boost::polygon::polygon_90_set_data<coordinate_type> >::type& boost::polygon::operators::operator|=(boost::polygon::polygon_90_set_data<coordinate_type>&, const geometry_type_2&) [with coordinate_type_1 = int, geometry_type_2 = screen_box_t]’ testpoly.cc:41: instantiated from here /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/4.1.2/bits/stl_set.h:71: error: ‘template<class _Key, class _Compare, class _Alloc> class std::set’ is not a function, /usr/local/src/gtl/boost/polygon/point_concept.hpp:77: error: conflict with ‘template<class T, class coordinate_type> void boost::polygon::set(T&, boost::polygon::orientation_2d, coordinate_type, typename boost::enable_if<typename boost::polygon::is_mutable_point_concept<typename boost::polygon::geometry_concept<T>::type>::type, void>::type*)’ /usr/local/src/gtl/boost/polygon/rectangle_concept.hpp:192: error: in call to ‘set’ /usr/local/src/gtl/boost/polygon/detail/iterator_geometry_to_set.hpp:34: instantiated from ‘boost::polygon::iterator_geometry_to_set<boost::polygon::rectangle_concept, rectangle_type>::iterator_geometry_to_set(const rectangle_type&, boost::polygon::direction_1d, boost::polygon::orientation_2d, bool) [with rectangle_type = Box<int>]’ /usr/local/src/gtl/boost/polygon/polygon_90_set_data.hpp:137: instantiated from ‘void boost::polygon::polygon_90_set_data<T>::insert(const geometry_type&, bool, boost::polygon::orientation_2d) [with geometry_type = Box<int>, T = int]’ /usr/local/src/gtl/boost/polygon/polygon_90_set_data.hpp:113: instantiated from ‘void boost::polygon::polygon_90_set_data<T>::insert(iT, iT, boost::polygon::orientation_2d) [with iT = const Box<int>*, T = int]’ /usr/local/src/gtl/boost/polygon/detail/polygon_90_set_view.hpp:318: instantiated from ‘typename boost::enable_if<typename boost::polygon::gtl_and<boost::polygon::operators::y_ps90_pe, typename boost::polygon::is_polygon_90_set_type<polygon_set_type_2>::type>::type, boost::polygon::polygon_90_set_data<coordinate_type> >::type& boost::polygon::operators::operator+=(boost::polygon::polygon_90_set_data<coordinate_type>&, const geometry_type_2&) [with coordinate_type_1 = int, geometry_type_2 = Box<int>]’ /usr/local/src/gtl/boost/polygon/detail/polygon_90_set_view.hpp:329: instantiated from ‘typename boost::enable_if<typename boost::polygon::gtl_and<boost::polygon::operators::y_ps90_be, typename boost::polygon::is_polygon_90_set_type<polygon_set_type_2>::type>::type, boost::polygon::polygon_90_set_data<coordinate_type> >::type& boost::polygon::operators::operator|=(boost::polygon::polygon_90_set_data<coordinate_type>&, const geometry_type_2&) [with coordinate_type_1 = int, geometry_type_2 = screen_box_t]’ testpoly.cc:41: instantiated from here /usr/local/src/gtl/boost/polygon/rectangle_concept.hpp:192: error: no matching function for call to ‘set(boost::polygon::rectangle_data<int>&, boost::polygon::orientation_2d_enum, std::pair<int, int>)’ /usr/local/src/gtl/boost/polygon/detail/iterator_geometry_to_set.hpp:34: instantiated from ‘boost::polygon::iterator_geometry_to_set<boost::polygon::rectangle_concept, rectangle_type>::iterator_geometry_to_set(const rectangle_type&, boost::polygon::direction_1d, boost::polygon::orientation_2d, bool) [with rectangle_type = Box<int>]’ /usr/local/src/gtl/boost/polygon/polygon_90_set_data.hpp:137: instantiated from ‘void boost::polygon::polygon_90_set_data<T>::insert(const geometry_type&, bool, boost::polygon::orientation_2d) [with geometry_type = Box<int>, T = int]’ /usr/local/src/gtl/boost/polygon/polygon_90_set_data.hpp:113: instantiated from ‘void boost::polygon::polygon_90_set_data<T>::insert(iT, iT, boost::polygon::orientation_2d) [with iT = const Box<int>*, T = int]’ /usr/local/src/gtl/boost/polygon/detail/polygon_90_set_view.hpp:318: instantiated from ‘typename boost::enable_if<typename boost::polygon::gtl_and<boost::polygon::operators::y_ps90_pe, typename boost::polygon::is_polygon_90_set_type<polygon_set_type_2>::type>::type, boost::polygon::polygon_90_set_data<coordinate_type> >::type& boost::polygon::operators::operator+=(boost::polygon::polygon_90_set_data<coordinate_type>&, const geometry_type_2&) [with coordinate_type_1 = int, geometry_type_2 = Box<int>]’ /usr/local/src/gtl/boost/polygon/detail/polygon_90_set_view.hpp:329: instantiated from ‘typename boost::enable_if<typename boost::polygon::gtl_and<boost::polygon::operators::y_ps90_be, typename boost::polygon::is_polygon_90_set_type<polygon_set_type_2>::type>::type, boost::polygon::polygon_90_set_data<coordinate_type> >::type& boost::polygon::operators::operator|=(boost::polygon::polygon_90_set_data<coordinate_type>&, const geometry_type_2&) [with coordinate_type_1 = int, geometry_type_2 = screen_box_t]’ testpoly.cc:41: instantiated from here /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/4.1.2/bits/stl_set.h:71: error: ‘template<class _Key, class _Compare, class _Alloc> class std::set’ is not a function, /usr/local/src/gtl/boost/polygon/point_concept.hpp:77: error: conflict with ‘template<class T, class coordinate_type> void boost::polygon::set(T&, boost::polygon::orientation_2d, coordinate_type, typename boost::enable_if<typename boost::polygon::is_mutable_point_concept<typename boost::polygon::geometry_concept<T>::type>::type, void>::type*)’ /usr/local/src/gtl/boost/polygon/rectangle_concept.hpp:193: error: in call to ‘set’ /usr/local/src/gtl/boost/polygon/rectangle_concept.hpp:193: error: no matching function for call to ‘set(boost::polygon::rectangle_data<int>&, boost::polygon::orientation_2d_enum, std::pair<int, int>)’

6 12

[1.41.0] New libraries?
by Beman Dawes 03 Sep '09

03 Sep '09

Are there any new libraries that will be ready for 1.41.0? There is a New Library Checklist that needs to be gone over with the release managers before merging new libraries into branches/release. See http://svn.boost.org/trac/boost/wiki/ReleasePractices/ManagerCheckList#NewL… Thanks, --Beman

2 1

[graph] quickbook reference docs and formatting
by Andrew Sutton 03 Sep '09

03 Sep '09

Jeremiah, Nick, others with opinions.... Two questions: First, I need a second opinion on some formatting alternatives for the quickbook docs w.r.t the documentation of member/non-member functions of the graph classes. These should be mostly buildable - there are some errors about missing links, but they aren't fatal. Let me know if there are issues building them. I got the doc toolchain working a while ago and I'm afraid to mess with it. I may not have the same set up as everybody else. Hopefully I do. The HTML docs give a flat listing with each function separated by a HR element, which is effective (although not especially navigable). Other lib**raries (e.g., Boost.Filesystem) present a similar listing although without the HR's to divide the content. I've tried putting these in a table to improve readability, and it works a little but, but I don't have enough control over the table to prevent auto-wrapping, which can break a function declaration line in weird places. So what's better: a flat listing or a table? Is there a third option? Generating reference docs via Doxygen (like ProgramOptions) probably isn't a viable solution since there's a lot of metaprogramming and atypical class construction going on in the BGL. Second, all of the reference docs for graph classes cite their associated types via the graph_traits and property_map templates. For most of these types, this strikes me as superfluous at best and slightly disingenuous at worst. Traits classes are only required in a generic context, not when working with a concrete type. If your graph class defines a nested type, vertex_iterator, why not use it directly? I feel that the reference documentation for data structures would be better served by focusing on the specifics of the data structure, not its generic interfaces. That's what the concepts are for. Thoughts? Andrew Sutton andrew.n.sutton(a)gmail.com

2 1

[date_time, Boost 1.40.0]
by Christoph 03 Sep '09

03 Sep '09

including boost/date_time/posix_time/posix_time.hpp or boost/date_time/gregorian/gregorian.hpp gives lots of warning for the following line(s): (boost/date_time/gregorian/conversion.hpp; posix_time, tooo) line 44 std::tm datetm = {}; // zero initialization is needed for extension members, like tm_zone I admit I don't understand the comment. Is it possible to fix that (correctly) such that including the header does not produce like 20 warnings in each .cpp file including the header? (I am using linux running gcc 4.1.2) Best regards Christoph

4 5

[serialization] using boost::serialization::collection_size_type and backwards compatibility
by joaquin＠tid.es 03 Sep '09

03 Sep '09

An observant colleague has noticed that Boost.MultiIndex serialization uses std::size_type instead of the adviced boost::serialization::collection_size_type: https://svn.boost.org/trac/boost/ticket/3365 My question is: if I just change std::size_type with boost::serialization::collection_size_type in Boost.MultiIndex serialization code, will backwards compatibility be preserved, i.e. will users be able to load archives saved with the old std::size_type variant? If not, what's the suggested way to handle this issue? Thank you, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

3 3

compile-time for-loop
by klaus triendl 03 Sep '09

03 Sep '09

I wonder whether a compile-time for-loop is useful enough so that it would get included in the mpl library; it's very similar to what fold does but it can be used for computations with types other than sequence containers. The loop construct takes a start value, a loop condition and a function calculating the next start value for the next loop recursion and additionally a state together with a binary operation serving as loop body: namespace boost { namespace mpl { template< typename Start, typename UnaryLoopTest, typename BinaryNext , typename State, typename BinaryOp > struct for_: eval_if< // loop as long as the loop condition yields true typename apply< UnaryLoopTest, typename Start::type >::type, // next loop iteration: recursive call for_< // calculate next loop value typename apply< BinaryNext, State, typename Start::type >::type, // pass on UnaryLoopTest and pass on BinaryNext UnaryLoopTest, BinaryNext, // calculate next state typename apply< BinaryOp, State, typename Start::type >::type, // pass on BinaryOp BinaryOp >, // loop termination if loop condition yields false State > {}; } } // That's an example how to use the for-loop: using namespace boost; template<typename T, T N> struct cross_total: mpl::for_< // start mpl::integral_c<T, N>, // loop condition mpl::not_equal_to<mpl::_1, mpl::integral_c<T, 0> >, // calculate next value mpl::divides<mpl::_2, mpl::int_<10> >, // state = current cross sum of already iterated digits mpl::int_<0>, // binary function is loop body: crosstotal += digit mpl::plus< mpl::_1, mpl::modulus<mpl::_2, mpl::int_<10> > > >::type {}; </code> More useful may be to calculate a number's digits for any base, which can be used to calculate the required maximum storage size for a type (I know that there's std::numeric_limits<> but this one would be more general). Klaus Triendl

4 6

[Polygon] performance
by Simonson, Lucanus J 03 Sep '09

03 Sep '09

Performance has become a critical aspect of this review with the revelation that Barend claims significant performance advantage with his recent implementation. I would like to address this issue directly and, unfortunately, I must do so by addressing Barend's implementation and comparing it to my own, which I would have preferred to avoid. I realize that this comparison of the two algorithms may appear confrontational. My intention is to focus on technical issues to allow people to understand Barend's performance claims in the context of what the two algorithms have in common and how they differ. My understanding of Barend's algorithm is based solely on what he has told me, and he refused to tell me enough to allow me to implement it myself, so if I am in error in my description of it I trust he will promptly correct me. First, I do not believe that Barend's implementation is numerically robust when instantiated with float or double. Successfully passing tests is not proof that his algorithm will not generate self intersecting polygons at its output. Specifically, it is my understanding that his algorithm snaps intersection points to the floating point grid at the end of computation when he writes out output polygons. This means that edges may move laterally a distance dependent on the exponent of the floating point value of the result. In floating point coordinates a vertex may lie arbitrarily close to a nearby edge. Even a very small lateral movement of that edge due to loss of precision in the floating point representation has the potential to cross a nearby vertex and interduce self intersection in the output polygons. Since "simple polygons" is a common precondition to many algorithms (including Barend's own) it is simply unacceptable for there to be any chance of this post condition not being satisfied. Note that infinite precision floating point calculations don't solve this problem if you convert the output to regular floating point at some later stage, which is the common way the algorithm's output would be consumed. Second, Barend has stated that his algorithm does the same thing as mine. This is simply not true. Barend's algorithm imposes quite a few preconditions on its inputs (non-self intersecting being just one example) while mine imposes none. The two arguments of a boolean operation in my library may be any number of intersecting and overlapping polygons, Barend requires that all polygons be simple and non-overlapping. My algorithm accepts a broader range of inputs, which makes it more general and more powerful than Barend's algorithm and a better algorithm to use in a generic interface where preconditions become concept requirements for input geometry data. Furthermore, my algorithm has more output modes such as trapezoidization and keyholing as well as the flexibility to perform n-layer operations such as connectivity extraction and map overlay. Barend's algorithm does not. Comparing Barend's intersection algorithm to my own is not an apples to apples comparision, it is an apple to fruit basket which happens to contain an apple comparision. For these two reasons I think we should take Barend's performance claims with a grain of salt. When compared to other libraries that are known to be numerically robust (GPC, CGAL, Geos) my library is sometimes slower, sometimes faster in Barend's own benchmarking. Only Barend's algorithm is always faster in his benchmarking. However, if Barend's library has the potential to produce self intersecting output it is not even in the same class as these others. My benchmark data can be reproduced using the forcgal.cpp file in the sandbox/gtl directory. I provided it when Andreas asked. I admit that my algorithm could be faster. For the benchmarks I performed I estimated it could be up to 10X faster. For Barend's benchmarks with many pointed star polygons which result in O(n^2) pathological performance of my admittedly suboptimal line segment intersection algorithm that number might be higher sill. I would prefer that the focus of the review be the concept interfaces (function declarations) and how the typesystem is implemented so that we can decide whether it is a good model for a generic geometry API. Changes to eg. the line intersection algorithm or internals of polygon_set_data class can be made without breaking code that depends on the library API. If someone implements a true drop in replacement for my polygon intersection algorithm (or just for line segment intersection) and licenses it under the boost license we can drop it in if it is faster and all any user should notice is that the library is faster in a new release of boost. I don't think there are any decisions I made in the design or implementation of the concept type system or library interfaces that prevent or even make difficult such a change to its implementation details. Overall, I don't think we should view this review as an either or Boost.Polygon now or GGL later decision. There is no reason both libraries cannot be accepted in due time. Barend has made quite a bit a progress since boostcon and I am genuinely happy for him for what he has achieved. Thanks, Luke

3 2

Formal Review of Boost.Polygon extended one more week: until September 9, 2009
by Fernando Cacciola 02 Sep '09

02 Sep '09

Dear developers, The review of Boost.Polygon was initially scheduled to end today. However, the discussions are in their best moment only now so the review period was extended by one week, until September 9, 2009 (that is next Wednesday). Best Fernando Cacciola Review Manager

1 0

[pool] patch to make pool support zero sized allocations.
by Steven Watanabe 02 Sep '09

02 Sep '09

AMDG The patch at https://svn.boost.org/trac/boost/attachment/ticket/386/pool.patch allows the pool classes to support zero sized allocation, by returning a null pointer. std::vector sometimes allocates a zero sized block, so this is necessary for pool_allocator. Returning a null pointer is the simplest solution and I'm that the standard allows an allocator to return the null pointer when asked for a block of zero elements. Okay to commit? In Christ, Steven Watanabe

1 1

Re: [boost] [mpl, units] rational and static_rational
by Matthias Schabel 02 Sep '09

02 Sep '09

> I am looking for a template library that can handle compile time > rationals, ideally with a similar interface to mpl::int_ and that > plays well with boost::rational (the dynamic type). > > First I found boost/mpl/math/rational_c.hpp but soon I realized that > it doesn't work with basic operations like mpl::plus, it doesn't even > simplify reducible fractions (i.e. 2/4 -> 1/2), in fact it looks like > it is just the storage of two (static) integers. Is this something > that will be developed in the future or am I using it in the wrong > way? > > Then I found boost::units::static_rational which is more promising, > because it simplifies fractions and works with mpl::plus, but it is > not integrated with boost::rational nor has an interface similar to > that of mpl metatypes. > > Is there a way of extending mpl::math::rational_c with the existing > libraries in boost, or a simple way to make > boost::units::static_rational have an interface similar to mpl and > also have a value type that returns it runtime boost::rational value? I certainly would have no objection to repackaging the static_rational type used in Boost.Units as an MPL type that plays nicely with Boost.Rational. My advice would be to put together a functional implementation and propose it for a mini-review. We could easily typedef units::static_rational -> mpl::rational_ in the units library. Matthias

1 0

[polygon] Overload resolution for operators fails
by Joachim Faulhaber 02 Sep '09

02 Sep '09

Hi Luke and polygonists, trying to set up some law based tests for boost::polygon I faced difficulties with the overload resolution of operators under msvc-9. This is the code sniplet where the problems occur: ----------------------------------------------------------- #include <boost/validate/laws/law.hpp> #include <boost/polygon/polygon.hpp> // Here I map a PolygonSet class to geometry_concepts according to // the docs: #include <boost/itl_xt/custom_polygon.hpp> namespace boost{namespace itl { template <typename Type> class PolygonCommutativity : public Law<PolygonCommutativity<Type>, LOKI_TYPELIST_2(Type,Type), LOKI_TYPELIST_2(Type,Type)> { // a o b == b o a . . . bool holds() { using namespace boost::polygon; using namespace boost::polygon::operators; Type value_a = this->template getInputValue<operand_a>(); Type value_b = this->template getInputValue<operand_b>(); Type left = value_a; left += value_b; // Compiler fails to find the appropriate overload // but // this works self_assignment_boolean_op<Type,Type,0>(left, value_b); // and also this works boost::polygon::operators::operator+=<Type,Type>(left, value_b); // and this boost::polygon::operators::operator+=(left, value_b); . . . return equivalence(left, right); } }; ----------------------------------------------------------- moreover, if my custom PolygonSet conainer implements an operator += this operator is *silently* chosen by the compiler, so the wrong addition function is called! Contrary to the traditional understanding of a concept, that defines *requirements* for a parameter class it can use, we have to take care here, that the client class *does not* implement certain operations. I am afraid this is not a good thing. I hope this is fixable, may be the error is on my side but I can't see it yet. Regards Joachim

2 2

[property_tree] Still no support for space
by Preston A. Elder 02 Sep '09

02 Sep '09

I noticed property_tree just got updated in the SVN repository. As per my previous email, RapidXML was upgraded from 1.0 -> 1.13. All well and good. This did fix problems with whitespace handling in previous versions - or more correctly, it split the functionality so it was controlled by 2 different flags. However, in addition to this, the flags passed to RapidXML have changed. Specifically, now the flags parse_normalize_whitespace and parse_trim_whitespace are both passed to RapidXML. And there is no way to disable this. In fact, there is no way to adjust space parsing at all in property_tree. The reason this is of concern to me is this. There is no way to get this to work: <field> <field> or <field>] <field> or <field> </field> None of which will output the space in the result. RapidXML doesn't parse an XSL file, nor does it understand xml:space. So even the following will not work: <field xml:space="preserve"> </field> or <field xml:space="preserve">] </field> In short, could you PLEASE adjust the RapidXML (which is still the default XML parser) options not to mangle the living heck out of all spaces, or provide the ability for the user to specify the behavior they want (like you do with comments). I should also mention that RapidXML defaults both parse_normalize_whitespace and parse_trim_whitespace to off. I did my own testing, adjusting the flags to RapidXML. If I leave parse_normalize_whitespace ON, but turning off parse_trim_whitespace, the <field> </field> and <field>] </field> examples above work. No adjustment either of these settings will make <field> </field> work. PreZ

2 1

boost::regex Library crashes in MSVC8.0
by Naren Ramakrishnan 02 Sep '09

02 Sep '09

Hi, I am Boost novice and am trying to build a sample application from boost examples. The following is the environment details OS: Winxp sp2. Boost version : 1.40.0 Compiler / IDE : MSVC8.0/ Visual Studio 2005 I built the boost libraries using the above compiler using the bjam.exe tool and installed boost using the same tool(bjam.exe install). When I run the program(given below) by linking against libboost_regex-vc80-mt-1_39.lib with the following define flags(/D BOOST_REGEX_MATCH_EXTRA /D BOOST_REGEX_NO_LIB), I get a crash with the following message Unhandled exception at 0x00401e73 in BOOST TEST.exe: 0xC0000005: Access violation reading location 0x6c707849. Stack Trace is > BOOST TEST.exe!std::vector<boost::sub_match<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<boost::sub_match<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> > > > >::~vector<boost::sub_match<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<boost::sub_match<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> > > > >() Line 1088 C++ BOOST TEST.exe!std::vector<boost::sub_match<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<boost::sub_match<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> > > > >::_Destroy(boost::sub_match<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> > > * _First=0x00383888, boost::sub_match<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> > > * _Last=0x78138cd9) Line 1083 + 0x1d bytes C++ BOOST TEST.exe!std::vector<boost::sub_match<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<boost::sub_match<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> > > > >::~vector<boost::sub_match<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<boost::sub_match<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> > > > >() Line 1096 C++ BOOST TEST.exe!std::vector<boost::sub_match<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<boost::sub_match<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> > > > >::_Destroy(boost::sub_match<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> > > * _First=0x00387c80, boost::sub_match<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> > > * _Last=0x00387cbc) Line 1083 + 0x1d bytes C++ BOOST TEST.exe!boost::match_results<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> >,std::allocator<boost::sub_match<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> > > > >::~match_results<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> >,std::allocator<boost::sub_match<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char> > > > >() Line 81 + 0x83 bytes C++ BOOST TEST.exe!print_captures(const std::basic_string<char,std::char_traits<char>,std::allocator<char> > & regx={...}, const std::basic_string<char,std::char_traits<char>,std::allocator<char> > & text={...}) Line 44 + 0x22 bytes C++ BOOST TEST.exe!main(int __formal=, int __formal=) Line 48 + 0x3c bytes C++ BOOST TEST.exe!__tmainCRTStartup() Line 586 + 0x17 bytes C The program is #include "stdafx.h" #include <boost/regex.hpp> #include <iostream> using namespace boost; void print_captures(const std::string& regx, const std::string& text) { boost::regex e(regx); smatch what,w; std::cout << "Expression: \"" << regx.c_str() << "\"\n"; std::cout << "Text: \"" << text.c_str() << "\"\n"; if(boost::regex_search(text, what, e, boost::match_perl)) { unsigned i, j; std::cout << "** Match found **\n Sub-Expressions:\n"; for(i = 0; i < what.size(); ++i) std::cout << " $" << i << " = \"" << what[i].str().c_str() << "\"\n"; std::cout << " Captures:\n"; for(i = 0; i < what.size(); ++i) { std::cout << " $" << i << " = {"; j=0; for(j = 0; j < what.captures(i).size(); ++j) { if(j) std::cout << ", "; else std::cout << " "; std::cout << "\"" << what.captures(i)[j].str().c_str() << "\""; } std::cout << " }\n"; } } else { std::cout << "** No Match found **\n"; } } int main(int , char* []) { print_captures("Microsoft ", " Microsoft Internet Explorer"); print_captures("(.*)bar|(.*)bah", "abcbar"); print_captures("(.*)bar|(.*)bah", "abcbah"); print_captures("^(?:(\\w+)|(?>\\W+))*$", "now is the time for all good men to come to the aid of the party"); return 0; } However when I compile and run this program against boost libraries available in sourceforge under boost-binaries, it works fine. I am sure I am missing something. Could you please help me out Thanks Naren

3 4

Boost.FileSystem talk from BoostCon now available
by Marshall Clow 01 Sep '09

01 Sep '09

at <http://blip.tv/file/2541291> More to come as I dig myself out..... -- Marshall

1 0

[serialization] working around the pointer_conflict exception?
by T. Farago 01 Sep '09

01 Sep '09

I have implemented the serialise library of BOOST to my own classes. Using a single entry point it recursively goes through every member and saves the values. Of course initial implementation yielded the pointer_conflict expression as for example while going through objects A,B,C object A may have a pointer to B, and only afterwards is B actually saved. I tried - and thought - to fix this by using a two-phased approach. First I save all the actual objects from the entry point, secondly only the pointers. eg save_objects = true; ar & my_object; save_objects = false; ar & my_objects; and inside every class: class A { public: int a; int *b; serialise() { if (save_objects) { ar & a; } else { ar & b; } } }; This seemed sound but only during debugging did I realise that the second run of the serialiser doesn't do anything since my_object is already saved. So this won't work. Does anyone have better ideas on solving this problem, or has encountered and already solved this issue? -- Using Opera's revolutionary e-mail client: http://www.opera.com/mail/

2 2

Boost Polygon library Review
by Kai Benndorf 01 Sep '09

01 Sep '09

Dear developers, we are currently evaluating the boost polygon library as a possible replacement for our currently used package for polygon boolean operations. Because the review process is soon at an end i want to inform you of our experiences so far. For short, i vote for inclusion of the polygon lib into boost. We are evaluating it in the scope of an analysis tool out of the EDA field. One task in this tool is to determine overlays of copper planes on a pcb. For this we need the plane intersection functionality. We have integrated the boost polygon lib currently to use it in parallel to our old library. Up to now we have found no errors in the calculated plane intersections, and there are some quite complicated planes, with complicate holes on the test pcb. This is very promising and the results seem to be reliable. We used the library on Windows XP, MSVC 2008, only. No compilation problems occured. Double vs. integer coordinates. Our planes are described with double coordinates in mm. We convert them for the boost polygon lib to integer by multiplying them with a constant factor. A first try with an factor of 1e5 leaded to an error (overflow?). With a factor of 1e4 this error vanished. Our first approach was to use the polygon and polygon with hole classes provided by the library and copy our coordinates into them. It works, but the creation of the objects with the set( itBegin, itEnd) functions was really slow, especially for copying the holes into the polygon. Our current approach is with some own intermediate polygon and polygon with holes classes, which allocates the necessary memory on creation. This is a lot faster and is really usable. A third and still better approach would be to use the same polygon classes as in the rest of our application, but i postponed this for now. The performance seems to be slower than our old library, but this is not really evaluated yet, there can e.g. still be conversion penalties. The documentation was sufficient enough to integrate the library in our application, but surely can be better. Because i'm not experienced in such an extensive template usage as it is done in the polygon lib, i omit comments about the design of the library. But at least it proved, that it can really be used to work reliable on external polygon objects. Best regards Kai Benndorf

2 1

windows timeout implementation
by Gennadiy Rozental 01 Sep '09

01 Sep '09

Hi, I have windows timeout support implemented for boost::execution monitor. It requires multithreading and thus introduces additional dependencies. I am thinking of making it available with compile time flag. Any comments/suggestions are welcome. Gennadiy

4 4

[GSoC] Boost.Python py3k support project final report
by Haoyu Bai 01 Sep '09

01 Sep '09

Hi, As GSoC is officially finished, this is the final report of the Boost.Python py3k(Python 3) support project. The goal of this project is to provide seamless support for Python 2 and 3 in Boost.Python. So extension modules using Boost.Python can be easily migrated to Python 3. The SVN branch is located at: https://svn.boost.org/svn/boost/sandbox-branches/bhy/py3k/ Status ===== Currently, all the BPL test cases passed when running under Python 3, and there are almost no change for most of the test cases. To support the Python 3 unicode string, some of the default converts between PyString and C/C++ strings are changed to convert between PyUnicode and C/C++ strings. Support for py3k in Boost.Build is done. Also, a piece of document is written in the "News" part of BPL document. API Changes ========== There are some minor API changes: 1) Introduced object.contains where x.contains(y) is equivalent to Python code y in x. Now dict.has_key is just a wrapper of object.contains. 2) When building against Python 3, str.decode will be removed. 3) When building against Python 3, the original signature of list.sort, which is: void sort(object_cref cmpfunc); will change to: void sort(args_proxy const &args, kwds_proxy const &kwds); This is because in Python 3 list.sort requires all its arguments be keyword argument. So you should call it like this: x.sort(*tuple(), **dict(make_tuple(make_tuple("reverse", true)))); // This is equivalent to the Python call x.sort(reverse=true) 4) When building Boost.Python against Python older than 2.6, the following macros will be defined in Boost.Python header: # define Py_TYPE(o) (((PyObject*)(o))->ob_type) # define Py_REFCNT(o) (((PyObject*)(o))->ob_refcnt) # define Py_SIZE(o) (((PyVarObject*)(o))->ob_size) These are macros defined in Python >=2.6 header. We defined for Python < 2.6 so when you are using Boost.Python, these macros will be always available. Please refer to PEP 3123 (http://www.python.org/dev/peps/pep-3123/) for details about these macro. Building and Testing =============== To build Boost.Python with Python 3, first write your user-config.jam contains these line: using python : 2.6 ; using python : 3.2 ; where the "2.6" and "3.2" should be replaced by the actual version of Python 2 and Python 3 on your system, respectively. Then call "bjam", it will build out a "libboost_python.so" and a "libboost_python3.so". The latter one is the Boost.Python library built against Python 3. To run test cases against Python 3, what you need to do is to switch into the libs/python/test, then run: bjam python=3.2 It will automatically call the "2to3" tool to convert the Python source code in test case to Python 3 syntax. So we only need to maintain the test cases in Python 2. Further Works =========== I'm going to merge the py3k branch back to trunk. After the merge, more tests can be done to check is there any regression, also some people may want to start to use it to make your projects run on Python 3. Then I can get some bug report and feedback, thus more improvement is expected. Thanks! -- Haoyu BAI School of Computing, National University of Singapore.

2 1