January 2010 - 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

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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

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[#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

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[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

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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

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[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

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[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

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[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

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[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.

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[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

[Review Results] Boost.Polygon library accepted into boost
by Fernando Cacciola 07 Apr '10

07 Apr '10

Dear Boosters, [first of all allow me to apology for not doing this before. My small consulting bussines suddenly grew out of proportion and now is way over my head, keeping me working/managing 16 hours a day] I am pleased to announce that the Boost.Polygon library from Lucanus Simonson has been accepted into boost provided some of the most critical concerns, detailed below, are addressed first. First of all I would like to thank Lucanus and Intel Corporation for making this work available to all C++ developers around the world. I would also like to thank all the reviewers that participated (in no particular order nor degree of participation) Thomas Klimpel Frank Mori Hess Barend Gehrels Andreas Fabri Jeffrey Hellrung Tim Keitt Markus Werle Paul A. Bristow Robert Stewart Mathias Gaunard Michael Fawcett Steven Watanabe Joachim Faulhaber John Bytheway Sebastian Redl Mika Heiskanen John Phillips Kai Benndorf Hartmut Kaiser Arash Partow Maurizio Vitale Brandon Kohn David Abrahams Gordon Woodhull Daniel James John Maddock Tom Brinkman Bo Persson Mateusz Loskot Christian Henning Jean-Sebastien Stoezel The library had 6 yes votes and 4 no votes. Those who voted no made the following major complains and remarks (they are numbered as I will refer to them back later): Barend Gehrels: (1) According to his benchmarks, intersection algorithms are unnecesarily slow as if something where fundamentally wrong in the design and/or implementation. AFAICT the implication has not been proved or disproved so far, hence I consider it a red herring and cannot take it as a reason for rejecting the library, but it is important to look at it in detail. (2) As a major complain, the library is unusable in those domains where floating point support is a requirement (like GIS). (3) The library should contain some basic polygon geometry algorithms such as convex hull and centriod Phil Endecott: (4) There is no concept checking in the code so it is difficult to adapt. (5) There where too many warnings and build errors (but Luke fixed these) (6a) The documentation needs a better overview of operations supported by the concetps. (6b) It also needs the details on the algorithms complexities. (6c) It also misses the numerical requirements for the coordinate type. (6d) And tutorials. (7) Some operators are ambiguous and it would be better to keep just one of each "flavor". (8) The polygon_data template class is parameterized by a coordiante type rather than a point type. This makes it useless for integration with existing geometric data types Michael Fawcett: (5), (6a), (6d) (9) T9he API should provide versions using output iterators in addition to output container references. (10) Theoreticall the library would be usable with a user defined coordinate type (metting certain requirements now undocumented), for example a fixed point data type, but some details in the internal design and implementation prevents this. (11) As a major complain, the library is unusable in those domains where floating point support is a requirement (like GIS). Hartmut Kaiser: (11), (1) Fernando Cacciola: (12) The name of the library should change to better indicate that is restricted to Integral coordinates and two-dimensions. (13) The documentation must contain a "credits" section acknowledging all the people that participated in the review. For the library to be effectively accepted, points (5),(6a-d),(10), (12) and (13) should properly addressed ((5) is already done AFAICT) It would be quite significant if point (1) where looked into. Once again I thank Lucanus, Intel Corporation and all the reviwers. Best regards -- Fernando Cacciola SciSoft Consulting, Founder http://www.scisoft-consulting.com

4 4

Thread-safe singleton pattern
by Andrew Chinkoff 22 Mar '10

22 Mar '10

I propose thread safe singleton pattern implementation (see http://www.research.ibm.com/designpatterns/pubs/ph-jun96.txt) I have attached "singleton.hpp" to this letter. Below is the test program: #include <stdio.h> #include <singleton.hpp> class A : public boost::Singleton<A> { // // Only Singleton class can create and delete us! // SINGLETON_IS_MY_FRIEND; public: void foo(){ printf("foo!\n"); } A(){ printf("A()\n"); } ~A(){ printf("~A()\n"); } }; void main() { // It is not compiled: //A a = A::Instance(); // That is exactly as it should be used: A::Instance().foo(); } Test program outputs: A() foo! ~A() My question: Does Boost community think that boost::Singleton is convenient (or successful) solution?

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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

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[unordered] unordered_set::erase() complexity bug?
by Stefan Strasser 18 Mar '10

18 Mar '10

I think there is something very wrong with boost's implementation of unordered_set/map. 1 unordered_set<int> s; 2 for(int c=0;c<nr;++c) s.insert(c); 3 for(int c=nr-1;c>=0;--c) s.erase(s.find(c)); results: nr: time 20000: 0m0.244s 40000: 0m0.940s 60000: 0m5.584s 80000: 0m4.232s 100000: 0m34.814s 120000: 0m33.486s the function that's causing this is erase(), which is specified to be O(1) average, O(n) worst. I can't think of a reason why it should be O(n) in this case (perfect hash, erase doesn't rehash). but even if it was, the results should be at worst quadratic. load_factor() is below 1, bucket_count(x) is 1. if line 3 is changed to: 3 for(int c=0;c<nr;++c) s.erase(s.find(c)); 20000: 0m0.008s 40000: 0m0.016s 60000: 0m0.028s 80000: 0m0.032s 100000: 0m0.040s 120000: 0m0.044s as you would expect. even if I do the very same thing as above using Boost.Intrusive (using a load factor of 1), I get expected results: struct element : intrusive::unordered_set_base_hook<>{ ... for(int c=0;c<nr;++c) s.insert(*new element(c)); for(int c=nr-1;c>=0;--c) s.erase(s.find(element(c))); 20000 0m0.008s 40000 0m0.016s 60000 0m0.024s 80000 0m0.024s 100000 0m0.032s 120000 0m0.040s but surprisingly enough, the TR1 implementation shipped with libstdc++ also has a problem like that: 20000: 0m0.368s 40000: 0m1.448s 60000: 0m1.668s 80000: 0m7.160s 100000: 0m7.808s 120000: 0m13.349s am I missing something or is there really the same bug in 2 major implementations of unordered_set? it effectively caused a deadlock in some of my code. I'm using 1.38. no bug report in Trac.

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[inspect] More changes to Inspection Report
by Beman Dawes 09 Mar '10

09 Mar '10

More changes to the Inspection Report: * Line numbers are now shown when a problem is associated with a specific line in a file. * Apple macros clashes now show the specific name causing the problem. * Spacing is optimized so that problems without line numbers don't take up so much report space. See the results at http://boost.cowic.de/rc/inspect-trunk.html Thanks to everyone who commented yesterday! --Beman

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enable_shared_from_this2
by Berserker 09 Mar '10

09 Mar '10

After experiencing some troubles with boost::python and enable_shared_from_this (as already reported in the past by someone to Peter Dimov), I started looking at the new (not documented) class enable_shared_from_this2. I made two changes in init_weak_once and now it seems to support shared_from_this in constructors and shared pointers "reinitialization". The original code (from boost 1.40): void init_weak_once() const { if( weak_this_._empty() ) { shared_this_.reset(static_cast< T* >( 0 ), detail::esft2_deleter_wrapper()); weak_this_ = shared_this_; } } The "patched" code: void init_weak_once() const { // Reinitialization support if( weak_this_.expired() ) { // shared_from_this in costructors support shared_this_.reset(static_cast <T*>(const_cast<enable_shared_from_this2>(this)), detail::esft2_deleter_wrapper()); weak_this_ = shared_this_; } } I know that the static_cast/const_cast is "problematic" on VC6 (and maybe other compilers) but it could be solved using an offset from enable_shared_from_this2 * to T *. I've attached a testcase that shows the problems with the current enable_shared_from_this2 implementation (with the proposed patch it works). Any feedback about this? struct null_deleter { template <typename T> inline void operator()(T *p) const { } }; class EnableThisPtrTester : public boost::enable_shared_from_this2<EnableThisPtrTester> { public: EnableThisPtrTester() { } EnableThisPtrTester(shared_ptr<EnableThisPtrTester> &ptr) { ptr = shared_from_this(); BOOST_CHECK(ptr); } }; BOOST_AUTO_TEST_CASE(test_enable_this_ptr) { { shared_ptr<EnableThisPtrTester> ptr1; shared_ptr<EnableThisPtrTester> ptr2(new EnableThisPtrTester(ptr1)); BOOST_CHECK(ptr1 == ptr2); BOOST_CHECK(ptr1.use_count() == ptr2.use_count()); BOOST_CHECK(ptr1->shared_from_this() == ptr1); BOOST_CHECK(ptr1->shared_from_this().use_count() == ptr1.use_count()); shared_ptr<EnableThisPtrTester> ptr3 = ptr2->shared_from_this(); BOOST_CHECK(ptr2 == ptr3); BOOST_CHECK(ptr2.use_count() == ptr3.use_count()); BOOST_CHECK(ptr1->shared_from_this().use_count() == ptr1.use_count()); } { shared_ptr<EnableThisPtrTester> ptr1; EnableThisPtrTester tester(ptr1); shared_ptr<EnableThisPtrTester> ptr2 = tester.shared_from_this(); BOOST_CHECK(ptr1 == ptr2); BOOST_CHECK(ptr1.use_count() == ptr2.use_count()); ptr1.reset(); ptr2.reset(); } { EnableThisPtrTester tester; { shared_ptr<EnableThisPtrTester> ptr1 = tester.shared_from_this(); shared_ptr<EnableThisPtrTester> ptr2 = tester.shared_from_this(); BOOST_CHECK(ptr1 == ptr2); BOOST_CHECK(ptr1.use_count() == ptr2.use_count()); shared_ptr<EnableThisPtrTester> ptr3(&tester, null_deleter()); BOOST_CHECK(ptr1 == ptr3); BOOST_CHECK(ptr1.use_count() == ptr3.use_count()); shared_ptr<EnableThisPtrTester> ptr4 = tester.shared_from_this(); BOOST_CHECK(ptr4 == ptr1); BOOST_CHECK(ptr4 == ptr3); BOOST_CHECK(ptr1.use_count() == ptr4.use_count()); BOOST_CHECK(ptr3.use_count() == ptr4.use_count()); } BOOST_CHECK(tester.shared_from_this()); } }

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[function] improvements/proposals
by Domagoj Saric 27 Feb '10

27 Feb '10

A while back, in various threads more or less related to the topic, I posted various ideas and/or code contributions to the effect of improving boost::function in terms of efficiency (concentrated on invocation speed, assignement performance/overhead and reducing template and RTTI bloat) and configurability, however there was no "official response" as to whether it was any good, or whether any of it would be accepted or what's wrong with it if not. IMHO the results { - 'Speed': the test presented here http://marc.info/?l=boost&m=118835709647084&w=2 modified to work with boost::signals2 (because it is a header only library/does not require a recompilation of boost if something in boost::function changes) with the dummy mutex/no threading support and a simple recompilation with the new boost::function<> code yielded a ~10% boost, changing the default policy to be nothrow the boost doubled to ~20% - 'Size': my real life project, that uses heavy metaprograming for generating function objects (that as a consequence have _very_ long type names, and thus RTTI records) to assign to boost::functions shrunk by ~10% simply by using the modified boost::function (with RTTI features disabled)...This post http://lists.boost.org/Archives/boost/2009/12/160202.php has more detailed and updated results when my project grew further (with an even bigger difference) } show/hint that there is room for improvement in boost::function and therefor warrant atleast some kind of response (even if along the lines of 'it's no good' or 'there is no time for this now')...which is the reason for (re)posting this (in a separate thread). The relevant threads with more detail are these: http://thread.gmane.org/gmane.comp.lib.boost.devel/196906 http://thread.gmane.org/gmane.comp.lib.boost.devel/194514/focus=195351 since then I've moved the modified code from the vault into the sandbox SVN (under the obvious name "function" :) -- "That men do not learn very much from the lessons of history is the most important of all the lessons of history." Aldous Huxley

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[preprocessor]
by Баграт Асатрян 18 Feb '10

18 Feb '10

Hello. boost.preprocessor library is good, but it does not support in-place preprocessor metafunction composition and argument bindings. I have just implemented such a functionallity as in boost.mpl, and can say that it simplifies preprocessor metaprogramming greatly. If interested, contact me. С уважением, Баграт Асатрян. ---------------------------------------------- Тел.: +(374 94) 69-78-67, E-mail: bagrat_assatrian(a)mail.ru

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[GGL][Polygon][Union] Union returns hole (inner ring) of the expected result as the output polygon (outer ring)
by Mohammad Morshed Alam Helal 09 Feb '10

09 Feb '10

Hi, Union of two polygon_2d returns a hole (inner ring) as result. Where - Input polygons - Polygon 1: A big rectangle with a hexagonal hole inside Polygon 2: A triangle that intersects the hole from inside leaving portion of it in the hole Output polygon - The hexagonal hole without the triangle-portion. Expected output polygon - The big rectangle with current output polygon as hole (inner)as described in this picture. The Union of a rectangle with a hexagonal hole and a triangle intersecting the first polygon ***************************** ***************************** ***************************** ******** ********* ******* **X***** ****** XXX***** ***** XXX****** **** XX ***** ***** ****** ****** ******* ******* ******** ******** ********* ***************************** ***************************** ***************************** returns this polygon, instead of the correct result. ++++++++++++ ++++++++++++++ +++++++++++++++ +++++++++++++++ +++++++++++++++ +++ ++++++++++++++++++ ++++++++++++++++ ++++++++++++++ ++++++++++++ You can use the code bellow to generate the case and some PPM images. You may use a WSQ Viewer to see the polygons. Please let me know any workaround or anything thats I am missing. Thank and regards, Helal // the code void uniontest() // Your main should call it { double L = 200.0; const double outloop[][2] = { {L, L}, {L, -L}, {-L, -L}, {-L, L}, {L, L} }; double R = 100.0; double H = R * sqrt(3.0) / 2; const double inloop[][2] = { {R, 0}, {R/2, -H}, {-R/2, -H}, {-R, 0}, {-R/2, H}, {R/2, H}, {R, 0} }; polygon_2d BIGpoly; //A rectangle with a hexagonal hole in it assign(BIGpoly, outloop); //the rectangle BIGpoly.inners().resize(1); linear_ring<point_2d>& inner = BIGpoly.inners().back(); assign(inner, inloop); //the inner hexagon correct(BIGpoly); //correct the order iff not double a = 20.0; double h = a * sqrt(3.0) / 2; const double t1[][2] = { { 30+0, 10+0}, { 30+a/2, 10+h}, { 30+a, 10+0} }; const double t2[][2] = { { 0, 0}, { a/2, h}, { a, 0} }; const double t3[][2] = { {-10+0, -10+0}, {-10+a/2, -10+h}, {-10+a, -10+0} }; const double t4[][2] = { { 0, -15+0}, { a/2, -15+h}, { a, -15+0} }; const double t5[][2] = { {-50, -40}, {-110, 0}, {-100, 30}, {-50, -40} }; polygon_2d T1, T2, T3, T4, T5, T6; //the triangles assign(T1, t1); correct(T1); assign(T2, t2); correct(T2); assign(T3, t3); correct(T3); assign(T4, t4); correct(T4); assign(T5, t5); correct(T5); std::vector<polygon_2d > P_list, P_union, P_tmp; //the outer shape P_union.push_back(BIGpoly); DumbPPMPrint("c:\\BIGpoly.ppm", P_union.begin(), P_union.size()); //Case 1: floating triangle in hole P_union.clear(); ggl::union_inserter<ggl::polygon_2d >(BIGpoly, T1, std::back_inserter(P_union)); DumbPPMPrint("c:\\case1.ppm", P_union.begin(), P_union.size()); //Case 2: three solid triangle creating a small hole P_union.clear(); P_tmp.clear(); ggl::union_inserter<ggl::polygon_2d >(T2, T3, std::back_inserter(P_tmp)); DumbPPMPrint("c:\\case2_i.ppm", P_tmp.begin(), P_tmp.size()); ggl::union_inserter<ggl::polygon_2d >( (*(P_tmp.begin())), T4, std::back_inserter(P_union)); DumbPPMPrint("c:\\case2.ppm", P_union.begin(), P_union.size()); //Case 3: floating holed-polygon in hole //P_union.clear(); //contains result of case 2 P_tmp.clear(); ggl::union_inserter<ggl::polygon_2d >(BIGpoly, (*(P_union.begin())), std::back_inserter(P_tmp)); DumbPPMPrint("c:\\case3.ppm", P_tmp.begin(), P_tmp.size()); //Case 4: a triangle intersecting the hole from inside P_union.clear(); P_union.push_back(BIGpoly); P_union.push_back(T5); DumbPPMPrint("c:\\case4_pre.ppm", P_union.begin(), P_union.size()); P_union.clear(); ggl::union_inserter<ggl::polygon_2d >( BIGpoly, T5, std::back_inserter(P_union)); DumbPPMPrint("c:\\case4.ppm", P_union.begin(), P_union.size()); P_union.clear(); ggl::union_inserter<ggl::polygon_2d >( T5, BIGpoly, std::back_inserter(P_union)); DumbPPMPrint("c:\\case4_rev_order.ppm", P_union.begin(), P_union.size()); } void DumbPPMPrint(char *name, std::vector<polygon_2d >::iterator it, unsigned int n) { //WSQ Viewer can be of help //http://www.cognaxon.com/index.php?page=wsqview //the holes are black. //the more number of polygons are present at a pixel the brighter the pixel is. unsigned int imgwidth = 512; //pixel width of image unsigned int imgheight = 512; //pixel height of image float width = 400.0; //width of image: 10 units (e.g. meters) float height = 400.0; //height of image: 10 units (e.g. meters) //float width = 6000.0; //width of image: 10 units (e.g. meters) //float height = 6000.0; //height of image: 10 units (e.g. meters) //header FILE *signal = fopen(name, "wt"); fprintf(signal, "P3\n"); fprintf(signal, "# %s\n", name); fprintf(signal, "%d %d\n", imgwidth, imgheight); fprintf(signal, "255\n"); unsigned int x, y, i; float xpos, ypos; // PPM images carry red, green, blue color channels. int val0, val1, val2; std::vector<polygon_2d >::iterator poly; for (y = 0; y < imgheight; y++) { ypos = height/2 - height * y / imgheight; for (x = 0; x < imgwidth; x++) { xpos = width/2 - width * x / imgwidth; val0 = val1 = val2 = 0; //black ggl::point_xy<float> point(xpos, ypos); poly = it; for (i = 0; i < n; i++, poly++) { if( ggl::within( point, (*poly) ) ) { val0 += 255/n; val1 += 255/n; val2 += 255/n; } } //fi_poly // clamp to allowed range if (val0 < 0) val0 = 0; else if (val0 > 255) val0 = 255; if (val1 < 0) val1 = 0; else if (val1 > 255) val1 = 255; if (val2 < 0) val2 = 0; else if (val2 > 255) val2 = 255; fprintf(signal, "%3d %3d %3d ", val0, val1, val2); if (x%16 == 15) fprintf(signal, "\n"); } //fi_x } //fi_y fclose(signal); } //@End_of_Code

2 7

C++ Networking Library Release 0.5
by Dean Michael Berris 09 Feb '10

09 Feb '10

Good day everyone, and I apologize in advance for the shameless plug. That said though, I'd like to announce the availability of version 0.5 of the C++ Network Library (cpp-netlib) on both Github and Sourceforge. For those interested in trying out a header-only being-developed-for-boost-inclusion networking library collection, you can download the latest release from: http://github.com/cpp-netlib/cpp-netlib/downloads or https://sourceforge.net/projects/cpp-netlib/ Active development happens on Github where the official repository is http://github.com/cpp-netlib/cpp-netlib (or via git) git://github.com/cpp-netlib/cpp-netlib.git While the cutting edge "clearing house" repository is the one I host also on Github http://github.com/mikhailberis/cpp-netlib (or via git) git://github.com/mikhailberis/cpp-netlib.git The latest release contains: * An HTTP 1.1 client * An embeddable HTTP 1.0 server template If you're interested in joining in on the development, please join the discussion at the cpp-netlib-devel mailing list at: https://lists.sourceforge.net/mailman/listinfo/cpp-netlib-devel or just fork my Github hosted repository -- then send pull requests when you feel like submitting your work "upstream" to me. We're currently in the process of moving on to implementing an HTTP 1.1 server template (looks like a Java Servlet Container), more efficient HTTP 1.1 client implementations, and other goodies. You can find documentation about cpp-netlib over at http://cpp-netlib.github.com/ Thanks in advance everyone and I hope this helps! -- Dean Michael Berris cplusplus-soup.com | twitter.com/deanberris linkedin.com/in/mikhailberis | facebook.com/dean.berris | deanberris.com

31 123

[contract] Contract Programming Library
by Lorenzo Caminiti 09 Feb '10

09 Feb '10

Hi all, I am thinking to submit a library for Contract Programming (a.k.a. Design By Contract (TM) ) for C++. I have drafted some of the library documentation in Boost-like format: http://dbcpp.sourceforge.net/boost/libs/contract/doc/html/ Comments? Regards, Lorenzo

6 15

[lexical_cast] efficiency
by Domagoj Saric 08 Feb '10

08 Feb '10

'A while back', in the "error_code debate" I used a lexical_cast<> example for demonstrating certain concerns/aspects but the whole post was so long (as usual :) that it was probably read by less than 0.1% of people :) Anyways I'm extracting and reposting this bit now as I think it warrants attention. The first problem is the ('standard') "std::streams vs efficency" issue: - on msvc 9.0 sp1 the single line boost::lexical_cast<int>( "321" ); caused 14 calls to new and 26 calls to EnterCriticalSection() (not to mention vtable initializations, virtual function calls, usage of locales...) the first time it is called, and 3 calls to new and 15 calls to EnterCriticalSection() on subsequent calls...It also caused the binary (which does not otherwise use streams) to increase by 50 kB! ...which is IMNHO abhorrent... (with my usual 'put things in perspective' examples http://www.theprodukkt.com/kkrieger http://www.youtube.com/watch?v=3vzcMdkvPPg :) As a start maybe this problem could be sufficiently "lessened" by providing lexical_cast specializations/overloads that use C library functions (strtol, itoa and the likes) as they suffer less from bloat/performance issues than std::streams. Ideally, IMHO, lexical_cast<> should provide the power/configurability of boost::numeric_cast (so that one can, for example, say I do not need/want to use locales/assume ASCII strings and things like that). The second problem is the use of exceptions (or better of only using exceptions): if, for example, one uses lexical_cast<> deep in the bowels of some parser it is probably "natural" to use a bad_cast exception to report an error to the outside world but if one uses lexical_cast<> to convert a string entered into a widget by a user into an int it would mostly be simpler to have a simple error code if the user entered an invalid string and issue a warning and retry "at the face of the place" (without the need for try-catch blocks)... In other words maybe a dual/hybrid approach of using both exceptions and error codes (through different overloads would be justified). -- "That men do not learn very much from the lessons of history is the most important of all the lessons of history." Aldous Huxley

5 9

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

Re: [boost] boost::mpl::for_each and value_initialized
by Niels Dekker - address until 2010-10-10 07 Feb '10

07 Feb '10

Peter Foelsche wrote: > in boost_1_41_0 there is still an unconditional call to memset in > value_initialized() Fernando Cacciola and I originally added the memset call within value_initialized() for MSVC only, because MSVC's implementation of value-initialization was known to incorrectly leave some bytes uninitialized, in some very relevant use cases. https://svn.boost.org/trac/boost/changeset/39157/trunk/boost/utility/value_… Thereby we also added extra unit tests, which were passed by MSVC by then, because of the memset. But unfortunately they failed on other compilers (GCC, Borland/Codegear and Sun), because of similar value-initialization issues. That's when we thought it was wise to just have the memset call there for all compilers: https://svn.boost.org/trac/boost/changeset/41942/trunk/boost/utility/value_… Do I understand correctly that you want the memset call to be skipped for those compiler versions that have implemented value-initialization entirely correctly? Do you know exactly which compiler versions do implement value-initialization correctly? Personally I do appreciate that the behavior of value_initialized is now exactly the same for all compilers. But I do understand you're concerned about the performance penalty of the memset call, for those compilers that have implemented value-initialization correctly. If so, can you please create a ticket, preferably including a patch? Kind regards, Niels -- Niels Dekker http://www.xs4all.nl/~nd/dekkerware Scientific programmer at LKEB, Leiden University Medical Center

5 8

[chrono] v0.3.1 Support for wide characters
by vicente.botet 07 Feb '10

07 Feb '10

Hi, this new version includes: * Added support for wide characters on formatters. * Added chrono.hpp and stopwatches.hpp header files at the boost level. * Update of the doc taking care of preceding comments. Comments are welcome :) Best, Vicente ----- Original Message ----- From: "vicente.botet" <vicente.botet(a)wanadoo.fr> To: <boost(a)lists.boost.org>; <boost-users(a)lists.boost.org> Sent: Sunday, January 17, 2010 9:14 PM Subject: [chrono] v0.3 New Stopwatch Feature Hi, I'm pleased to announce the new version of the Boost.Chrono library. The implementaton is quite stable; the new interface could suffer of some modifications, renaming, ... as far as you submit some proposals. I would request a formal review soon and I will need a review manager. I know that review managers are hard to find, so if you are interested in the library, please the Review Wizards. The library can be downloaded from http://www.boostpro.com/vault/index.php?action=downloadfile&filename=chrono… and the documentation is online on the sandbox http://svn.boost.org/svn/boost/sandbox/chrono/libs/chrono/doc/html/index.ht…. I've tested it with gcc and MSVC. Previoous version of the library have been testted on Mac, but I'm not able to test this platform. Could someone check if there are some regressions on Mac? New Features: * Process cpu clocks * Independent process cpu clocks for real, user, system process CPU time * Global process cpu clock for real, user, system process CPU time * Stopwatch concept measuring elapsed time between different points in time associated to the operations start, stop, suspend and resume. * stopwatch is a model Stopwatch measuring the elapsed time between the start and the stop operations. * stopwatch_accumulator is a model Stopwatch allowing to accumulate several time samples and give the average, ... * Scoped helper classes allowing to pairwise start/stop operations, suspend/resume and resume/suspend a Stopwatch. * Stopwatch Formatter concept * stopwatch formatter "%ds\n" * stopwatch accumulator formatter "%c times, sum%ss, min%ms, max%Ms, mean%as\n" * time formatter "real %rs, cpu %cs (%p%), user %us, system %ss\n" * digital_time decomposition class separating days, hours,minutes,seconds, nanoseconds from any duration class (looking for a better name) * digital_time formatter "%d days(s) %h:%m:%s.%n\n" * stopwatch_reporter is a convenient generic class reporting elapsed time for the Stopwatch concept. * stopclock<Clock> shortcut stopwatch_reporter<stopwatch<Clcok>> * typeof registration for classes duration and time_point Depreceated Features: * The classes process_times, process_clock, process_timer, timer and run_timer are now deprecated as the preceding additions are more generic. However for backward compatibility they are preserved until inclusion of the library in Boost. Next follows the equivalences: timer<> ~ stopwatch<> process_timer ~ stopwatch<process_cpu_clock> run_timer ~ stopclock<> Bug Fixes * Try to correct warning C4251: 'boost::chrono::run_timer::m_format' : class 'std::basic_string<_Elem,_Traits,_Ax>' needs to have dll-interface to be used by clients of class 'boost::chrono::run_timer', by don't including inlines functions using the std::string m_format. For people that doesn't know it yet, Boost.Chrono library provides: * The C++0x Standard Library's common_type. * The C++0x Standard Library's compile-time rational arithmetic. * The C++0x Standard Library's time utilities, including: * Class template duration * Class template time_point * Clocks: * system_clock * monotonic_clock * high_resolution_clock * typeof registration for classes duration and time_point * Process clocks: * process_real_CPU_clocks, capturing real-CPU times. * process_user_CPU_clocks, capturing user-CPU times. * process_system_CPU_clocks, capturing system-CPU times. * process_cpu_clock, tuple-like class capturing at once real, user-CPU, and system-CPU times. * Stopwatches: * stopwatch, capturing elapsed Clock times. * stopwatch_accumulator, capturing cummulated elapsed Clock times. * scoped helper classes allowing to pairwise start/stop operations, suspend/resume and resume/suspend a Stopwatch. * Stopclocks or Stopwatch reporters: * stopwatch_reporter, convenient reporting of models of Stopwatch results. * stopclock<Clock> shortcut of stopwatch_reporter<stopwatch<Clock>> Best regards, _____________________ Vicente Juan Botet Escribá

7 9

[1.42] The PDF build of the docs for the 1.42 BETA available
by John Maddock 04 Feb '10

04 Feb '10

The PDF build of the docs for 1.42 BETA are now available for download from the sourceforge download page https://sourceforge.net/projects/boost/files/boost-docs/1.42.0/boost_pdf_1_…. Please let me know if you spot any issues, Thanks, John Maddock.

2 1

[gil] trac #3619
by Christian Henning 03 Feb '10

03 Feb '10

Hi there, could someone please tell whether or not this bug still exists. I don't have access to gcc 4.4. This is marked as a showstopper and I would like to get rid of it. Is it a compiler bug maybe? Thanks, Christian

2 1

[multi_index][serialization] save_construct_data not called for multi_index collection
by Felipe Magno de Almeida 03 Feb '10

03 Feb '10

Hi, Boost.Serialization has support for non-default classes using save_construct_data and load_construct_data overloads. These are called before serialization to save and load information that's important for the construction of the object. Unfortunately, multi_index doesn't call these functions when serializing, so serialization of non-default-constructible classes is impossible with multi_index. I wanted to patch it so that it becomes possible, but to be honest I'm a bit lost in the serialization code for multi_index. collections_save_impl calls boost::serialization::save_construct_data_adl before serializing each item in the collection. I'm using boost 1.38.0, is there anyway to do the same for multi_index? Thanks in advance, -- Felipe Magno de Almeida

4 8

crash in boost serialization 1.41
by Est 02 Feb '10

02 Feb '10

Hi All I'm developing an image processing app. In my app, I serialize a boost::ptr_vector of an abstract base class to a polymorphic xml archive. I checked all my polymorphic classes are exported with BOOST_SERIALIZATION_EXPORT and BOOST_SERIALIZATION_ASSUME_ABSTRACT for abstract classes, and it's working correctly with boost 1.38. If I update to boost 1.41, I can save archives without problems. When I try to load the resulting archive, I get a crash: Program received signal EXC_BAD_ACCESS, Could not access memory. Reason: KERN_PROTECTION_FAILURE at address: 0x00000000 boost::archive::detail::basic_iarchive_impl::load_pointer (this=0x1b955a00, ar=@0xbfffe598, t=@0xbfffd8d0, bpis_ptr=0x0) at libs/serialization/src/basic_iarchive.cpp:429 429 class_id_type new_cid = register_type(bpis_ptr->get_basic_serializer()); I can read the archive with my app compiled with boost 1.38. I'm using gcc 4.0.1 on OSX and gcc 4.3 on linux, all 32 bits. I'm not using DLLs. I ran the unit tests of the serialization library. All passed. I'm in the process of extracting a small example that reproduces the crash. Do you have any idea how can I fix it? Thank you. Est. Here is the backtrace: node_t is my abstract base class. #0 boost::archive::detail::basic_iarchive_impl::load_pointer (this=0x1b955a00, ar=@0xbfffe598, t=@0xbfffd8d0, bpis_ptr=0x0) at libs/serialization/src/basic_iarchive.cpp:429 #1 0x005a5506 in boost::archive::detail::basic_iarchive::load_pointer (this=0x0, t=@0x0, bpis_ptr=0x0) at libs/serialization/src/basic_iarchive.cpp:538 #2 0x00043f2e in boost::archive::detail::polymorphic_iarchive_route<boost::archive::naked_xml_iarchive>::load_pointer (this=0xbfffe58c, t=@0xbfffd8d0, bpis_ptr=0x0) at polymorphic_iarchive_route.hpp:65 #3 0x0003d0f9 in boost::archive::detail::load_pointer_type<boost::archive::polymorphic_iarchive>::invoke<ramen::node_t*> (ar=@0xbfffe58c, t=@0xbfffd8d0) at iserializer.hpp:486 #4 0x0003d157 in boost::archive::load<boost::archive::polymorphic_iarchive, ramen::node_t*> (ar=@0xbfffe58c, t=@0xbfffd8d0) at iserializer.hpp:554 #5 0x0003d1a6 in boost::archive::polymorphic_iarchive_impl::load_override<ramen::node_t*> (this=0xbfffe58c, t=@0xbfffd8d4) at polymorphic_iarchive.hpp:137 #6 0x0003d1f8 in boost::archive::detail::interface_iarchive<boost::archive::polymorphic_iarchive>::operator>><boost::serialization::nvp<ramen::node_t*> const> (this=0xbfffe58c, t=@0xbfffd8d4) at interface_iarchive.hpp:61 #7 0x0003d253 in boost::ptr_container_detail::load_helper<boost::archive::polymorphic_iarchive, boost::ptr_container_detail::sequence_config<ramen::node_t, std::vector<void*, std::allocator<void*> > >, boost::heap_clone_allocator> (ar=@0xbfffe58c, c=@0x193b1bd8, n=1) at detail/serialize_reversible_cont.hpp:52 #8 0x0003d2e9 in boost::serialization::load<boost::archive::polymorphic_iarchive, ramen::node_t, boost::heap_clone_allocator, std::allocator<void*> > (ar=@0xbfffe58c, c=@0x193b1bd8) at serialize_ptr_vector.hpp:28 #9 0x0003d327 in boost::serialization::free_loader<boost::archive::polymorphic_iarchive, boost::ptr_vector<ramen::node_t, boost::heap_clone_allocator, std::allocator<void*> > >::invoke (ar=@0xbfffe58c, t=@0x193b1bd8, file_version=0) at split_free.hpp:58 #10 0x0003d349 in boost::serialization::split_free<boost::archive::polymorphic_iarchive, boost::ptr_vector<ramen::node_t, boost::heap_clone_allocator, std::allocator<void*> > > (ar=@0xbfffe58c, t=@0x193b1bd8, file_version=0) at split_free.hpp:74 #11 0x0003d36b in boost::serialization::serialize<boost::archive::polymorphic_iarchive, ramen::node_t, boost::heap_clone_allocator, std::allocator<void*> > (ar=@0xbfffe58c, c=@0x193b1bd8, version=0) at serialize_ptr_vector.hpp:34 #12 0x0003d3a9 in boost::serialization::serialize_adl<boost::archive::polymorphic_iarchive, boost::ptr_vector<ramen::node_t, boost::heap_clone_allocator, std::allocator<void*> > > (ar=@0xbfffe58c, t=@0x193b1bd8, file_version=0) at serialization.hpp:133 #13 0x0003d456 in boost::archive::detail::iserializer<boost::archive::polymorphic_iarchive, boost::ptr_vector<ramen::node_t, boost::heap_clone_allocator, std::allocator<void*> > >::load_object_data (this=0xbcc2f0, ar=@0xbfffe598, x=0x193b1bd8, file_version=0) at iserializer.hpp:173 #14 0x005a5423 in boost::archive::object_id_type::operator= () at basic_archive.hpp:390 #15 0x005a5423 in boost::archive::detail::basic_iarchive_impl::load_object () at libs/serialization/src/basic_iarchive.cpp:391 #16 0x005a5423 in boost::archive::detail::basic_iarchive::load_object (this=0xbfffe598, t=0x193b1bd8, bis=@0xbcc2f0) at libs/serialization/src/basic_iarchive.cpp:529 #17 0x00043f0a in boost::archive::detail::polymorphic_iarchive_route<boost::archive::naked_xml_iarchive>::load_object (this=0xbfffe58c, t=0x193b1bd8, bis=@0xbcc2f0) at polymorphic_iarchive_route.hpp:59 #18 0x00039f93 in boost::archive::detail::load_non_pointer_type<boost::archive::polymorphic_iarchive>::load_standard::invoke<boost::ptr_vector<ramen::node_t, boost::heap_clone_allocator, std::allocator<void*> > > (ar=@0xbfffe58c, t=@0x193b1bd8) at iserializer.hpp:363 #19 0x00039fbc in boost::archive::detail::load_non_pointer_type<boost::archive::polymorphic_iarchive>::invoke<boost::ptr_vector<ramen::node_t, boost::heap_clone_allocator, std::allocator<void*> > > (ar=@0xbfffe58c, t=@0x193b1bd8) at iserializer.hpp:415 #20 0x00039fdb in boost::archive::load<boost::archive::polymorphic_iarchive, boost::ptr_vector<ramen::node_t, boost::heap_clone_allocator, std::allocator<void*> > > (ar=@0xbfffe58c, t=@0x193b1bd8) at iserializer.hpp:554 #21 0x0003a02a in boost::archive::polymorphic_iarchive_impl::load_override<boost::ptr_vector<ramen::node_t, boost::heap_clone_allocator, std::allocator<void*> > > (this=0xbfffe58c, t=@0xbfffdbc4) at polymorphic_iarchive.hpp:137 #22 0x0003a07c in boost::archive::detail::interface_iarchive<boost::archive::polymorphic_iarchive>::operator>><boost::serialization::nvp<boost::ptr_vector<ramen::node_t, boost::heap_clone_allocator, std::allocator<void*> > > const> (this=0xbfffe58c, t=@0xbfffdbc4) at interface_iarchive.hpp:61 #23 0x0003a0ac in boost::archive::detail::interface_iarchive<boost::archive::polymorphic_iarchive>::operator&<boost::serialization::nvp<boost::ptr_vector<ramen::node_t, boost::heap_clone_allocator, std::allocator<void*> > > const> (this=0xbfffe58c, t=@0xbfffdbc4) at interface_iarchive.hpp:68 #24 0x0003aa49 in ramen::dataflow::graph<ramen::node_t>::load<boost::archive::polymorphic_iarchive> (this=0x193b1bd8, ar=@0xbfffe58c, version=0) at graph.hpp:168 #25 0x0003ab9b in boost::serialization::access::member_load<boost::archive::polymorphic_iarchive, ramen::dataflow::graph<ramen::node_t> > (ar=@0xbfffe58c, t=@0x193b1bd8, file_version=0) at access.hpp:101 #26 0x0003abbd in boost::serialization::detail::member_loader<boost::archive::polymorphic_iarchive, ramen::dataflow::graph<ramen::node_t> >::invoke (ar=@0xbfffe58c, t=@0x193b1bd8, file_version=0) at split_member.hpp:54 #27 0x0003abdf in boost::serialization::split_member<boost::archive::polymorphic_iarchive, ramen::dataflow::graph<ramen::node_t> > (ar=@0xbfffe58c, t=@0x193b1bd8, file_version=0) at split_member.hpp:69 #28 0x0003ac01 in ramen::dataflow::graph<ramen::node_t>::serialize<boost::archive::polymorphic_iarchive> (this=0x193b1bd8, ar=@0xbfffe58c, file_version=0) at graph.hpp:175 #29 0x0003ac23 in boost::serialization::access::serialize<boost::archive::polymorphic_iarchive, ramen::dataflow::graph<ramen::node_t> > (ar=@0xbfffe58c, t=@0x193b1bd8, file_version=0) at access.hpp:109 #30 0x0003ac45 in boost::serialization::serialize<boost::archive::polymorphic_iarchive, ramen::dataflow::graph<ramen::node_t> > (ar=@0xbfffe58c, t=@0x193b1bd8, file_version=0) at serialization.hpp:74 #31 0x0003ac83 in boost::serialization::serialize_adl<boost::archive::polymorphic_iarchive, ramen::dataflow::graph<ramen::node_t> > (ar=@0xbfffe58c, t=@0x193b1bd8, file_version=0) at serialization.hpp:133 #32 0x0003ad30 in boost::archive::detail::iserializer<boost::archive::polymorphic_iarchive, ramen::dataflow::graph<ramen::node_t> >::load_object_data (this=0xbcc260, ar=@0xbfffe598, x=0x193b1bd8, file_version=0) at iserializer.hpp:173 #33 0x005a5423 in boost::archive::object_id_type::operator= () at basic_archive.hpp:390 #34 0x005a5423 in boost::archive::detail::basic_iarchive_impl::load_object () at libs/serialization/src/basic_iarchive.cpp:391 #35 0x005a5423 in boost::archive::detail::basic_iarchive::load_object (this=0xbfffe598, t=0x193b1bd8, bis=@0xbcc260) at libs/serialization/src/basic_iarchive.cpp:529 #36 0x00043f0a in boost::archive::detail::polymorphic_iarchive_route<boost::archive::naked_xml_iarchive>::load_object (this=0xbfffe58c, t=0x193b1bd8, bis=@0xbcc260) at polymorphic_iarchive_route.hpp:59 #37 0x000365fb in boost::archive::detail::load_non_pointer_type<boost::archive::polymorphic_iarchive>::load_standard::invoke<ramen::dataflow::graph<ramen::node_t> > (ar=@0xbfffe58c, t=@0x193b1bd8) at iserializer.hpp:363 #38 0x00036624 in boost::archive::detail::load_non_pointer_type<boost::archive::polymorphic_iarchive>::invoke<ramen::dataflow::graph<ramen::node_t> > (ar=@0xbfffe58c, t=@0x193b1bd8) at iserializer.hpp:415 #39 0x00036643 in boost::archive::load<boost::archive::polymorphic_iarchive, ramen::dataflow::graph<ramen::node_t> > (ar=@0xbfffe58c, t=@0x193b1bd8) at iserializer.hpp:554 #40 0x00036692 in boost::archive::polymorphic_iarchive_impl::load_override<ramen::dataflow::graph<ramen::node_t> > (this=0xbfffe58c, t=@0xbfffdf8c) at polymorphic_iarchive.hpp:137 #41 0x000366e4 in boost::archive::detail::interface_iarchive<boost::archive::polymorphic_iarchive>::operator>><boost::serialization::nvp<ramen::dataflow::graph<ramen::node_t> > const> (this=0xbfffe58c, t=@0xbfffdf8c) at interface_iarchive.hpp:61 #42 0x00036714 in boost::archive::detail::interface_iarchive<boost::archive::polymorphic_iarchive>::operator&<boost::serialization::nvp<ramen::dataflow::graph<ramen::node_t> > const> (this=0xbfffe58c, t=@0xbfffdf8c) at interface_iarchive.hpp:68 #43 0x0002c3fb in ramen::composition_t::serialize (this=0x193b1bd8, ar=@0xbfffe58c, version=0) at /Users/est/Devel/ramen/trunk/ramen/app/composition.cpp:193 #44 0x0004570f in boost::serialization::access::serialize<boost::archive::polymorphic_iarchive, ramen::composition_t> (ar=@0xbfffe58c, t=@0x193b1bd8, file_version=0) at access.hpp:109 #45 0x00048387 in boost::serialization::serialize<boost::archive::polymorphic_iarchive, ramen::composition_t> (ar=@0xbfffe58c, t=@0x193b1bd8, file_version=0) at serialization.hpp:74 #46 0x0004574f in boost::serialization::serialize_adl<boost::archive::polymorphic_iarchive, ramen::composition_t> (ar=@0xbfffe58c, t=@0x193b1bd8, file_version=0) at serialization.hpp:133 #47 0x00048436 in boost::archive::detail::iserializer<boost::archive::polymorphic_iarchive, ramen::composition_t>::load_object_data (this=0xbcc410, ar=@0xbfffe598, x=0x193b1bd8, file_version=0) at iserializer.hpp:173 #48 0x005a5423 in boost::archive::object_id_type::operator= () at basic_archive.hpp:390 #49 0x005a5423 in boost::archive::detail::basic_iarchive_impl::load_object () at libs/serialization/src/basic_iarchive.cpp:391 #50 0x005a5423 in boost::archive::detail::basic_iarchive::load_object (this=0xbfffe598, t=0x193b1bd8, bis=@0xbcc410) at libs/serialization/src/basic_iarchive.cpp:529 #51 0x00043f0a in boost::archive::detail::polymorphic_iarchive_route<boost::archive::naked_xml_iarchive>::load_object (this=0xbfffe58c, t=0x193b1bd8, bis=@0xbcc410) at polymorphic_iarchive_route.hpp:59 #52 0x0004835f in boost::archive::detail::load_non_pointer_type<boost::archive::polymorphic_iarchive>::load_standard::invoke<ramen::composition_t> (ar=@0xbfffe58c, t=@0x193b1bd8) at iserializer.hpp:363 #53 0x00043692 in boost::archive::detail::load_non_pointer_type<boost::archive::polymorphic_iarchive>::invoke<ramen::composition_t> (ar=@0xbfffe58c, t=@0x193b1bd8) at iserializer.hpp:415 #54 0x000436b1 in boost::archive::load<boost::archive::polymorphic_iarchive, ramen::composition_t> (ar=@0xbfffe58c, t=@0x193b1bd8) at iserializer.hpp:554 #55 0x00043700 in boost::archive::polymorphic_iarchive_impl::load_override<ramen::composition_t> (this=0xbfffe58c, t=@0xbfffe5c8) at polymorphic_iarchive.hpp:137 #56 0x00043752 in boost::archive::detail::interface_iarchive<boost::archive::polymorphic_iarchive>::operator>><boost::serialization::nvp<ramen::composition_t> const> (this=0xbfffe58c, t=@0xbfffe5c8) at interface_iarchive.hpp:61 #57 0x00043782 in boost::archive::detail::interface_iarchive<boost::archive::polymorphic_iarchive>::operator&<boost::serialization::nvp<ramen::composition_t> const> (this=0xbfffe58c, t=@0xbfffe5c8) at interface_iarchive.hpp:68 #58 0x0004379c in boost::archive::detail::polymorphic_iarchive_route<boost::archive::naked_xml_iarchive>::operator&<boost::serialization::nvp<ramen::composition_t> const> (this=0xbfffe58c, t=@0xbfffe5c8) at polymorphic_iarchive_route.hpp:173

1 1

metaprogramming: associating a type with another type
by DE 02 Feb '10

02 Feb '10

hi boosters while solving my own design problems i accidentally discovered an interesting technique let's assume we want to associate some value (a type) to a newly created type so we can easily access the associated type during metaprogramming let's call the associated type a property then we have the following property types: struct property0 {}; struct property1 {}; struct property2 {}; now we want to access the associated property for an arbitrary type in a natural traits manner: property<arbitrary_type>::type it appears we can implement it almost trivially (if know how) (let's assume we have portable typeof() facility) consider the code //the return type of this function appears to be the default property template<typename type> property0 get_prop(type*); //do not implement! template<typename t> struct property { typedef typeof(get_prop((type*)42) type; }; template<typename type, typename p = typename property<type>::type> struct base { friend p get_prop(type*) { return p(); } }; template<typename type> void foo(const base<type>&) //handles ALL types derived from base { typedef typename property<type>::type associated_property; } template<typename type> void bar(const base<type, property2>&) //handles ONLY types with property2 {} struct s : public expression<s> //default property used here {}; struct s1 : public expression<s1, property1> {}; struct s2 : public expression<s2, property2> {}; int main() { foo(s()); foo(s1()); foo(s2()); //bar(s()); //should not compile //bar(s1()); //should not compile bar(s2()); return 0; } even with the lack of typeof(), given a fixed set of properties it is very easy to implement this technique see working example at http://codepad.org/qXkESprl personally i see it as extremely useful for generic lib writers for some designes (of course if appropriately applied) as well as for users of such libs i would appreciate any thoughts on improvement of this technique within C++98 standard also any thoughts on portability are welcome if you have questions about how and/or why does it work feel free to ask -- Pavel

5 17

[transaction] New Boost.Transaction library under discussion
by vicente.botet 02 Feb '10

02 Feb '10

Hi Stefan, Bob, I've created in the sandbox the transaction directory (http://svn.boost.org/svn/boost/sandbox/transaction/) so we can share our work. I've created also a wiki page (http://svn.boost.org/trac/boost/wiki/BoostTransaction) on which we can compile the result of our discussions, requirements for the library, design, ... If you don't have right access to the Boost wiki pages, please request them throught this ML. Of course, anyone is welcome to participate, or comment on this wiki. HTH, _____________________ Vicente Juan Botet Escribá

8 42

[thread] why crash launching a thread?
by David M. Cotter 01 Feb '10

01 Feb '10

i'm launching a new thread from an existing background thread, BUT it is crashing. i don't know if it happens often yet, but was wondering what could possibly cause this? Thread 10 Crashed: 0 libSystem.B.dylib 0x96ce435d usleep$NOCANCEL$UNIX2003 + 0 1 libSystem.B.dylib 0x96d05a50 abort + 105 2 libstdc++.6.dylib 0x96bb2fda __gnu_cxx::__verbose_terminate_handler() + 433 3 libstdc++.6.dylib 0x96bb117a __cxxabiv1::__terminate(void (*)()) + 10 4 libstdc++.6.dylib 0x96bb11ba __cxxabiv1::__unexpected(void (*)()) + 0 5 libstdc++.6.dylib 0x96bb12b8 __gxx_exception_cleanup(_Unwind_Reason_Code, _Unwind_Exception*) + 0 6 libboost_thread.dylib 0x006af933 boost::thread::start_thread() + 195 7 com.kjams.kjams 0x001281d1 CThreads::Fork(APP_ThreadType, long (*)(void*, long), long (*)(void*, long), void*, char const*) + 1521 8 com.kjams.kjams 0x0012858b CT_Preemptive::call(char const*) + 91 9 com.kjams.kjams 0x00139fc2 CSpooler::Fork_Spool(CSpooler*, bool) + 290 10 com.kjams.kjams 0x0027fd05 CSongImporter::EncodeSong(CSI_PersistantQueData*, CSpooler*) + 1109

5 7

[log] Release Candidate 4 released
by Andrey Semashev 01 Feb '10

01 Feb '10

I'm proud to announce that I've released the fourth candidate of Boost.Log for the review. There were many improvements since the passed year of development. Many of them reflect the discussion of RC3. Here's a short list of major changes: * Substantial documentation improvement. The tutorial section has been reorganized. * Removed rotating file stream. As a replacement, a new file sink has been added, which allows to achieve the same results ans adds a few more features. It is now possible to collect rotated log files in a dedicated directory. * Added a new multifile sink backend. * Added a new ordering asynchronous sink frontend. * The syslog sink backend is now supported on Windows, too. The sink no longer requires native support for POSIX API for syslog, but is able to send syslog packets to a remote server over UDP. * Added support for scoped logging. There is now a distinct log record entity, which is returned by the core as a result of filtring. * Added support for exception control. * Added a new mode of logging, called trivial logging. The more complete change log is available here: http://tinyurl.com/ybcghuf The library with docs, tests and examples has been updated in Boost.Vault: http://tinyurl.com/cm9lum There's SVN repository available on SourceForge project page: http://tinyurl.com/ye23wyh The docs are also available online here: http://tinyurl.com/5e4fd7 Comments are welcome.

9 37

Boost.Atomic request for review/inclusion
by Helge Bahmann 01 Feb '10

01 Feb '10

Hello, First of all I would like to thank for the comments that I have received so far, I have incorporated almost all of them I think. Boost.Atomic is now in a form that I consider calling it a release. It has support for "true" atomic variables on: - gcc/x86, 32-bit (tested on Linux, FreeBSD) - gcc/x86, 64-bit (tested on Linux) - gcc/powerpc32 (tested on Linux, Mac OS X) - gcc/powerpc64 (untested) - generic Win32 (tested with Visual Studio Express on Win XP) For all others it falls back gracefully to locked operation. There is proper quickbook documentation, including a hopefully illustrative example section. If you have an unsupported platform, contact me and I will attempt to provide support for it (usually it is just a matter of testing). Otherwise I would like to request considering the library for inclusion and appreciate any further comments. Everything available as usual at: http://www.chaoticmind.net/~hcb/projects/boost.atomic Best regards Helge

6 12

[Serialization] virtual function and virtual inheritance
by fab 31 Jan '10

31 Jan '10

Hi, I have a compilation error with a virtual function inside a virtual base class. For example, I just add a function f() inside the unit test : "test_diamond.cpp". class base { ... virtual void f() =0; ... }; class derived1 { ... virtual void f(){} ... }; gcc 4.3, returns me an error: error: no unique final overrider for `virtual void base::f()' in `boost::detail::is_virtual_base_of_impl<derived1, final, mpl_::bool_< true> >::X' The same code works properly with msvc 2005. Best regards, Fabien Castan

2 2

RFC: Sequence Properties and Boost Algorithm/Functional
by Grant Erickson 31 Jan '10

31 Jan '10

For a recent project, I needed to inquire about a sequence of objects and make a determination as to whether the sequences were: * Increasing * Strictly Increasing * Decreasing * Strictly Decreasing Looking through STL, Boost documentation, Boost sources and headers and the Boost mailing lists I was able to find neither an existing algorithm or stateful unary predicate functor for accomplishing this for a pair of input iterators. However, I was a bit surprised considering that this seems like a sequence property query that would tend to come up fairly often and serve a general utility. Did I just fail to form the proper search/query or am I overestimating the general utility? Regardless, I forged ahead with the rather naïve implementation (see below), which can be used as a predicate with for_each as shown: const int strictlyIncreasingValues[] = { 1, 2, 3, 4, 5 }; bool isStrictlyIncreasing; isStrictlyIncreasing = std::for_each(strictlyIncreasingValues, strictlyIncreasingValues + 5, is_strictly_increasing<int>()); assert(inStrictlyIncreasing == true); However, acknowledging the inefficient and naïveté of the first implementation, this is probably more algorithm than functional in that for_each with a stateful predicate is wasteful in walking the entire sequence (i.e. if any arbitrary subsequence fails to meet the property predicate criteria, the whole sequence fails). Is a smarter realization of this as an algorithm a potential candidate for boost::algorithm? Naïve, inefficient functional implementation to be used with for_each: #include <functional> #include <boost/function.hpp> template <typename T> struct creasing : public unary_function<T, bool> { protected: typedef unary_function<T, bool> base_type; typedef typename base_type::argument_type argument_type; typedef typename base_type::result_type result_type; typedef boost::function<result_type (const argument_type &a, const argument_type &b)> binary_predicate; creasing(const binary_predicate & inPredicate) : base_type(), mPredicate(inPredicate), mCreasing(true), mInited(false), mLast() { return; } public: result_type operator()(const argument_type & x) { if (mCreasing) { if (mInited) { mCreasing = mPredicate(mLast, x); } else { mCreasing = true; mInited = true; } mLast = x; } return (mCreasing); } operator result_type() const { return (mCreasing); } private: const binary_predicate mPredicate; result_type mCreasing; result_type mInited; argument_type mLast; }; template <typename T> struct is_increasing : public creasing<T> { typedef creasing<T> base_type; typedef typename base_type::argument_type argument_type; is_increasing(void) : base_type(std::less_equal<argument_type>()) {} }; template <typename T> struct is_decreasing : public creasing<T> { typedef creasing<T> base_type; typedef typename base_type::argument_type argument_type; is_decreasing(void) : base_type(std::greater_equal<argument_type>()) {} }; template <typename T> struct is_strictly_increasing : public creasing<T> { typedef creasing<T> base_type; typedef typename base_type::argument_type argument_type; is_strictly_increasing(void) : base_type(std::less<argument_type>()) {} }; template <typename T> struct is_strictly_decreasing : public creasing<T> { typedef creasing<T> base_type; typedef typename base_type::argument_type argument_type; is_strictly_decreasing(void) : base_type(std::greater<argument_type>()) {} }; Regards, Grant

5 5

[atomic] Availability detection
by Andrey Semashev 31 Jan '10

31 Jan '10

Hi, Will there be a way to detect if specific operations over a specific type are available atomically on the current platform? That is, if I know that atomic operations are emulated with locks, I want to fall back to another branch of my code with explicit locks, rather than the emulated atomics.

2 4

codepad code longevity ?
by Joel de Guzman 31 Jan '10

31 Jan '10

Hi, We see more and more people post code using Codepad. Is that good? In the Spirit list, we've had this discussion about longevity of code posted to Codepad: http://article.gmane.org/gmane.comp.parsers.spirit.general/18220 I can't see any information regarding policy on how code is retained. Is there? I've heard they say the post is valid for 24 hours. If that's the case, then we should ban the use of codepad. People here, myself included, need pasted code to be permanent for future reference. Thoughts? Regards, -- Joel de Guzman http://www.boostpro.com http://spirit.sf.net http://www.facebook.com/djowel Meet me at BoostCon http://www.boostcon.com/home http://www.facebook.com/boostcon

6 27

[circular_buffer] Serialization support for circular_buffer
by Brian Wood 31 Jan '10

31 Jan '10

B"H Shalom, Boost, The C++ Middleware Writer now supports marshalling circular_buffers. This is done by transmitting a circular buffer's capacity, then size, followed by it's elements. An example of the code used when marshalling a circular_buffer is here -- http://webEbenezer.net/posts/cirbuf.hh. -- Brian Wood http://www.webEbenezer.net (651) 251-9384

1 0

[asio] [function] Strange corruption error with boost::function and asio
by Zachary Turner 29 Jan '10

29 Jan '10

I'm not sure if I'm experiencing a bug in boost, bug in compiler (VS 9.0 service pack 1), or bug somewhere else, but I'm having trouble reading boost::function code enough to be able to figure out. A little background: I'm using boost::asio to read from a disk, and then boost::asio to write results to a socket. Everything works completely fine most of the time, but in some cases there's an error on my server (which is largely irrelevant here as it's not even written in C++) and the server crashes unexpectedly. I suspect the error is occuring while I'm in the middle of an asynchronous network write, because the very first odd behavior surfaces in my network write completion routine. I can go into more detail about how I'm using boost::function and boost::asio in conjunction if necessary, but for now I'll just post the bare minimum needed to be able to make any sense at all of what I'm doing (which is still alot, my apologies for the length). Anyway: - my completion routine has the following signature: void async_service_write_network::write_data_handler(asio_handler wrapped_handler, boost::system::error_code error, size_t bytes_transferred) - asio_handler (referenced in the previous signature) is defined as follows: typedef boost::function<void (boost::system::error_code, size_t)> asio_handler; Which is exactly the same but contains a wrapped handler at the front so I can privately intercept the handler at various points along the chain, and then have the private handler do arbitrary work then invoke the wrapped handler. I do this with boost::bind as follows asio_handler wrapped_handler = boost::bind( &async_service_write_network::write_data_handler, this, handler, _1, _2); socket_.async_send( buffer, boost::bind( wrapped_handler, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); To explain the odd behavior, I've put a breakpoint in write_data_handler. Quick version if you don't feel like reading, the function arguments seem to be being corrupted either by boost::bind or boost::function. Long version, looking at the values of the arguments shows the following: error {m_val=23843184 m_cat=0x000000000000305d } boost::system::error_code m_val 23843184 int m_cat 0x000000000000305d const boost::system::error_category * boost::noncopyable_::noncopyable {...} boost::noncopyable_::noncopyable __vfptr CXX0030: Error: expression cannot be evaluated So I move one level up the callstack. This puts me in: template<class R, class T, class A1, class A2, class A3 BOOST_MEM_FN_CLASS_F> class BOOST_MEM_FN_NAME(mf3) { //Boost 1.39 mem_fn_template.hpp line 384 R operator()(T * p, A1 a1, A2 a2, A3 a3) const { BOOST_MEM_FN_RETURN (p->*f_)(a1, a2, a3); } } Examining a1, a2, and a3 shows that they are what they appear to be. Walking one more level up the callstack and this is no longer the case: template< class A1, class A2, class A3, class A4 > class list4: private storage4< A1, A2, A3, A4 > { //Bind.hpp line 450 template<class F, class A> void operator()(type<void>, F & f, A & a, int) { unwrapper<F>::unwrap(f, 0)(a[base_type::a1_], a[base_type::a2_], a[base_type::a3_], a[base_type::a4_]); } } Examining the contents of 'a', I see this: - a {...} boost::_bi::list2<boost::system::error_code &,unsigned __int64 &> & - boost::_bi::storage2<boost::system::error_code &,unsigned __int64 &> {a2_=12381 } boost::_bi::storage2<boost::system::error_code &,unsigned __int64 &> - boost::_bi::storage1<boost::system::error_code &> {a1_={...} } boost::_bi::storage1<boost::system::error_code &> - a1_ {m_val=0 m_cat=0x000000014000ac48 } boost::system::error_code & m_val 0 int + m_cat 0x000000014000ac48 system_category_const const boost::system::error_category * a2_ 12381 unsigned __int64 & Somehow this error code is becoming corrupted. It is clearly has an m_val of 0 here, and an m_cat of 0x14000ac48 here, and in the very next function on the call stack, it has an m_val of 23843184, and an m_cat of 0x305d. Am I missing something obvious or is there an actual boost/compiler bug going on here?

1 0

doc for is_lvalue_iterator?
by Neal Becker 29 Jan '10

29 Jan '10

I don't see any doc for is_lvalue_iterator (and related metafunctions)

2 1

type of iterator_facade::value_type
by Neal Becker 29 Jan '10

29 Jan '10

According to iterator_facade doc: typedef remove_const<Value>::type value_type; Why remove_const? This makes it hard to detect if the resulting iterator points to a const value. In order to further adapt such an iterator, I needed to use the reference type instead of the value type to detect constness: typename boost::is_const< typename boost::remove_reference< typename std::iterator_traits<BaseIterator>::reference >::type >::type,

3 2

Review Request: Creasing (Sequence Properties)
by Grant Erickson 28 Jan '10

28 Jan '10

The creasing algorithm templates define four template functions for determining the order properties of sequences, specifically: * Increasing * Decreasing * Strictly Increasing * Strictly Decreasing The implementation is a fairly trivial composition of the STL adjacent_find, not2 and {greater,less,greater_equal,less_equal}. For the purposes of sequence ordering validation, using these templates is more efficient and straightforward than creating a temporary, sorted version of some sequence and comparing it against the original sequence. Example: bool CheckPoints(const Points & inPoints) { const bool strictlyIncreasing = is_strictly_increasing(inPoints.begin(), inPoints.end()); if (!strictlyIncreasing) { cerr << "Points must be in increasing order with " "no duplicate values." << endl; } return strictlyIncreasing; } The review files are available in both Sandbox and Vault: Sandbox: boost/algorithm/creasing.hpp libs/algorithm/creasing/example/creasing_ex.cpp libs/algorithm/creasing/example/Jamfile libs/algorithm/creasing/test/creasing_test.cpp libs/algorithm/creasing/test/Jamfile.v2 Vault: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=creasin g.zip&directory=Algorithms Regards, Grant Erickson

8 23

[Boost.Thread]
by Andrew Chinkoff 28 Jan '10

28 Jan '10

Hi. There is a test program I would to be explained to me: *** BEGIN OF TEST PROGRAM *** #include <stdio.h> #include <boost/thread.hpp> #define USE_SPINLOCKS //#define USE_MUTEXES boost::thread th1; boost::thread th2; boost::mutex mutex; int global_int = 0; bool IsNotEven(int code) { boost::mutex::scoped_lock locker(mutex); bool ret = (code & 1); return ret; } void thread_func() { for(int i = 0; i < 1000000; ++i) { #ifdef USE_MUTEXES if(IsNotEven(global_int)) // (1) #elif defined USE_SPINLOCKS if(__sync_fetch_and_and(&global_int, 1)) // (2) #else ERROR__WRONG_COMPILED; #endif global_int+=9; else global_int+=1; } } int main() { th1 = boost::thread(&thread_func); th2 = boost::thread(&thread_func); th1.join(); th2.join(); printf("global_int = %d\n", global_int); return 0; } *** END OF TEST PROGRAM *** Results of test program: 1) Test program compiled with USE_SPINLOCKS. Outputs are always: "global_int = 10" "global_int = 10" "global_int = 10" 2) Test program compiled with USE_MUTEXES. Outputs differ from each other: "global_int = 10000008" "global_int = 10000000" "global_int = 9763210" Could you explain me why outputs produced with USE_SPINLOCKS compilation differ from USE_MUTEXES ones? And what is the difference between (1) and (2) lines? Best, Andrew. P.S.: I use guest Ubuntu-8.04 installed on VirtualBox. Host OS = Vista.

3 2

detecting a constructor with a specific signature
by Kenny Riddile 28 Jan '10

28 Jan '10

I'm trying to create a type trait to detect the presence of a constructor with a very specific signature. Types passed to this trait will *always* have a constructor of the form: T( const std::string& ); but some of them will have this constructor as well: T( const std::string&, Foo& ); // Second parameter will always be a Foo& I would like to create a type trait that returns true when the second constructor is present. I can't simply do: !is_convertible<std::string, T>::value since that will return false when the second constructor is present since all Ts are convertible from std::string. Is it possible to create such a trait?

6 14

Trunk testing broken (Python and Utility)
by K. Noel Belcourt 28 Jan '10

28 Jan '10

Hi, There's at least two separate problems in trunk. Missing files in the Python library. error: Unable to find file or target named error: 'union.cpp' error: referred from project at error: '../libs/python/test' Missing files in the Utility library, error: Unable to find file or target named error: 'noncopyable_adl_barrier.cpp' error: referred from project at error: '../libs/utility/test' -- Noel

2 1

Range-aware version of min and max
by Zachary Turner 28 Jan '10

28 Jan '10

I am often frustrated by the inability of std::min and std::max to deal with data types of different ranges. For example: boost::uint64_t big = 9876543210ULL; boost::uint32_t small = 12345; boost::uint32_t smallest = std::min(big, small); will generate a compiler warning about possible loss of data due to converting from boost::uint64_t to boost::uint32_t. Obviously such a scenario is impossible since by definition the result can be no larger than the maximum value of a uint32. Previously there was a discussion on the list about adding operators such as is_addable, is_multipliable, is_less_comparable, etc. Using such a class, one could re-write min and max as follows (I'm sure someone will come up with a problem with this, or a better implementation, but anyway the idea should be clear): namespace boost { template<class A, class B> struct min_result { typedef mpl::if_c<(integer_traits<A>::const_max < integer_traits<B>::const_max), A, B>::type type; }; template<class A, class B> struct max_result { typedef mpl::if_c<(integer_traits<A>::const_min > integer_traits<B>::const_min), A, B>::type type; }; template<class A, class B> min_result<A,B>::type min(const A& a, const B& b) { return static_cast<min_result<A,B>::type>((a < b) ? a : b); } template<class A, class B> max_result<A,B>::type max(const A& a, const B& b) { return static_cast<max_result<A,B>::type>((a > b) ? a : b); } I'm sure there's some implementation details I haven't considered, but is there any fundamental reason why an approach like this would be flawed or undesirable? Zach

4 6

Please stay on-topic (was: C++ and quality of software)
by David Abrahams 28 Jan '10

28 Jan '10

This discussion is really not relevant to Boost, is it? At Mon, 25 Jan 2010 14:28:34 -0800, Peter Foelsche wrote: > > > "Marshall Clow" <mclow.lists(a)gmail.com> wrote in message > news:D43C711F-03E0-4A3C-BE40-BA99BE379F30@gmail.com... > > > Exceptions > > ▶ We do not use C++ exceptions. > > > > Run-Time Type Information (RTTI) > > ▶ We do not use Run Time Type Information (RTTI). > > > I think this is an embarrasement for google. > Didn't they claim to hire only very good people? > I would not want to work under these conditions. > > If there is again some security hole due to a buffer overflow, > such an institution could claim, that software using fixed-sized-buffers > would not get their stamp of approval. > And that the customer should be looking and asking for this stamp of > approval when buying software. > > How many fixed sized buffers are in the main OSs? -- Dave Abrahams Meet me at BoostCon: http://www.boostcon.com BoostPro Computing http://www.boostpro.com

1 0

[Serialization] memory leak when serialising a map containing shared_ptrs
by richard bradley 28 Jan '10

28 Jan '10

I'm finding that Boost.Serialization is leaking memory when deserialising std::map<string,boost::shared_ptr<X>>. Maybe this is a sign that my data structures are too complicated? ;-) This wouldn't bother me that much, except that I'm also using Boost.Test, which gives lots of angry messages about leaked memory at the end of my tests (I'm using MSCRT). I've attached a simple test case which demonstrates this. Can anyone shed some light on what's going on here? Have I used any of the libraries incorrectly? Is there anything I can do to fix this? I'm using Visual Studio 2008, and boost 1.41.0 The output from the attached test looks like: =========== Running 1 test case... MyClass @3532504 with 1 children MyClass @3532960 with 1 children Detected memory leaks! Dumping objects -> {800} normal block at 0x0035EDE8, 1 bytes long. Data: < > CD Object dump complete. =========== I've also attached a stack trace which I got by breaking on the non-free'd memory allocation,using "--detect_memory_leak=800" Thanks very much, Rich

1 1

unzip .zip file and browse to compressed files
by Andrej van der Zee 28 Jan '10

28 Jan '10

Hi, I am looking for a way to uncompress a zip-file (which contains multiple files/dirs) and browse through the contents. Does boost provide support for the first part? I looked at iostreams with a zlib uncompressor, but as far as I can see it assumes a single zipped file. Thank you, Andrej

7 7

[Boost.utility]
by Andrew Chinkoff 27 Jan '10

27 Jan '10

Having considered [ http://www.research.ibm.com/designpatterns/pubs/ph-jun96.txt] I propose singleton implementation. I had attached "singleton.hpp" to this letter. Below is the test program: #include <stdio.h> #include <singleton.hpp> class A : public boost::Singleton<A> { // // Only Singleton class can create and delete us! // SINGLETON_IS_MY_FRIEND; public: void foo(){ printf("foo!\n"); } A(){ printf("A()\n"); } ~A(){ printf("~A()\n"); } }; void main() { // It is not compiled: //A a = A::Instance(); // That is exactly as it should be used: A::Instance().foo(); } Test program outputs: A() foo! ~A() I suggest include "singleton.hpp" into "utility.hpp" header that it can be used along with: boost::noncopyable, etc.

14 67

[1.41.0] [filesystem] Undefined references to get_system_category and get_generic_category
by Richard Hadsell 27 Jan '10

27 Jan '10

I am trying to build some code using the 1.41.0 version of the filesystem library. It used to build with version 1.34.1. I am getting errors, when the linker fails to find boost::system::get_system_category and boost::system::get_generic_category. What do I need to do differently to find or build these functions? -- Dick Hadsell 203-992-6320 Fax: 203-992-6001 Reply-to: hadsell(a)blueskystudios.com Blue Sky Studios http://www.blueskystudios.com 1 American Lane, Greenwich, CT 06831-2560

2 2

Are any of these bugs _really_ show stoppers?
by Marshall Clow 27 Jan '10

27 Jan '10

There are 25 bugs in the Trac system which are marked as "showstopper". Are any of these really worth holding up the release for? (and if not, should we reclassify these bugs?) http://svn.boost.org/trac/boost/report/29 986 Problem building Python modules on boost 1.34.0 1215 Boost 1.34.1, mpl: Wrong workaround detection using MinGW32 (or.hpp, line #33)" 2411 bzip2_compressor does not work with filtering_istream,new,Bugs,Boost 1.37.0 2512 interval cosh: wrong result if interval contains 0 (but is not identical to [0,0]) 2513 rint not present in Visual Studio 2008 2164 locate_root wrong under CygWin 2797 Two problems with thread_specific_ptr 2255 Compilation error during arm cross compile - boost 1.36 2883 Boost::signals compile problem with GCC 3.4.5 2958 [patch] changes to make asio compile on vxWorks 2956 vxWorks POSIX quirks for date_time 583 Fixes for build on IBM pSeries for AIX and Linux 426 lambda vs pure virtual functions 3325 Limited support for mapping regions to specific addresses in Linux 738 Memory leaks with signal::connect? 3480 Build fails on Debian: 2.6.18-5-686-bigmem #1 SMP Tue Dec 18 22:34:10 UTC 2007 i686 GNU/Linux 3165 wrong project-config.jam generated for intel-linux 2955 [patch] recursive mutex impossible if pthread_mutexattr_settype not defined 1066 Patch to make Boost.Python compile on SunCC 2185 bjam hangs when building libs/python/examples/quickstart under MacOS X 3716 Application crash when using Boost.Python in a plug-in DLL for that application 3723 gzip_docompressor error - basic_array_source no putback member 2330 thread::interrupt() can be lost if condition_variable::wait() in progress 3735 thread_group::interrupt_all() is unreliable 2226 boost::thread 1.36.0 /clr Link Error LNK2022 Just asking.... -- Marshall P.S. I don't mind fixing 2512 and 2513 - and can do that for 1.43 if people don't want them in 1.42.

3 4

BoostCon Conference Hotel Now Accepting Reservations
by David Abrahams 26 Jan '10

26 Jan '10

Hello Boosters and former BoostCon attendees! The BoostCon website has been updated for 2010, registration is open, and the conference hotel is already prepared to start taking our reservations. If you are planning to go to Boostcon this year, I suggest you take a few minutes to register (http://www.boostcon.com/registration) and make your hotel reservation (http://www.boostcon.com/location/lodging) today. -- Dave Abrahams Meet me at BoostCon: http://www.boostcon.com BoostPro Computing http://www.boostpro.com

1 0

[chrono] v0.3.2 New frequency, lifetime and percentage stopwatch_accumulator features
by vicente.botet 26 Jan '10

26 Jan '10

Hi, I have update the Boost.Chrono library with some minor features, a lot of bug fixes, and started the tutorial with some examples of features interesting people since the last version. New Features: * Added overloading for operator/(Integer/Duration) (used to get the frequency) * Added frequency, lifetime and percentage to the stopwatch_accumulator. The default format is "%c times, sum%ss, min%ms, max%Ms, mean%as, frequency%fherzs, lifetime%ls, percentage=%p%\n", where %c : the counter of the number of times the pair start/stop has been called. %s : the sum of the samples of elapsed time between the call to start/stop. %m : the min of the samples of elapsed time between the call to start/stop. %M : the max of the samples of elapsed time between the call to start/stop. %a : the mean of the samples of elapsed time between the call to start/stop. %f : the frequency of calls to start. %l : the lifetime of the stopwatch_accumulator. %p : the percentage of time spent by this stopwatch respect to its lifetime. Bug Fixes * Specific formatters didn't work completly * Replace duration(0) by duration::zero() on template classes. * suspend didn't work: partial_ not initialized neither taken in account by the elapsed function. The library can be downloaded from http://www.boostpro.com/vault/index.php?action=downloadfile&filename=chrono… and the documentation is online on the sandbox http://svn.boost.org/svn/boost/sandbox/chrono/libs/chrono/doc/html/index.ht…. SVN repository http://svn.boost.org/svn/boost/sandbox/chrono. I would like to thanks particularly Andrew Chinkoff for his suggestion of the frequency feature and all those that have tried the library and reported the bugs they found, either on this ML or personally. I would really appreciate if people having the possibility to test on other platforms/compilers report me how the library works. As you can see the library is already on the review schedule, waiting for a review manager and a date for the review. I expect to add yet some features for the review release as thread clocks, and suspensible clocks i.e. clocks that can be suspended/resumed. Any idea for better naming the concepts/classes is welcome. Hoping this release works better for you, Vicente (See below the contents of preceding releases) ----- Original Message ----- From: "vicente.botet" <vicente.botet(a)wanadoo.fr> To: <boost-users(a)lists.boost.org>; <boost(a)lists.boost.org> Sent: Wednesday, January 20, 2010 11:02 PM Subject: [chrono] v0.3.1 Support for wide characters Hi, this new version includes: * Added support for wide characters on formatters. * Added chrono.hpp and stopwatches.hpp header files at the boost level. * Update of the doc taking care of preceding comments. Comments are welcome :) Best, Vicente ----- Original Message ----- From: "vicente.botet" <vicente.botet(a)wanadoo.fr> To: <boost(a)lists.boost.org>; <boost-users(a)lists.boost.org> Sent: Sunday, January 17, 2010 9:14 PM Subject: [chrono] v0.3 New Stopwatch Feature Hi, I'm pleased to announce the new version of the Boost.Chrono library. The implementaton is quite stable; the new interface could suffer of some modifications, renaming, ... as far as you submit some proposals. I would request a formal review soon and I will need a review manager. I know that review managers are hard to find, so if you are interested in the library, please the Review Wizards. The library can be downloaded from http://www.boostpro.com/vault/index.php?action=downloadfile&filename=chrono… and the documentation is online on the sandbox http://svn.boost.org/svn/boost/sandbox/chrono/libs/chrono/doc/html/index.ht…. I've tested it with gcc and MSVC. Previoous version of the library have been testted on Mac, but I'm not able to test this platform. Could someone check if there are some regressions on Mac? New Features: * Process cpu clocks * Independent process cpu clocks for real, user, system process CPU time * Global process cpu clock for real, user, system process CPU time * Stopwatch concept measuring elapsed time between different points in time associated to the operations start, stop, suspend and resume. * stopwatch is a model Stopwatch measuring the elapsed time between the start and the stop operations. * stopwatch_accumulator is a model Stopwatch allowing to accumulate several time samples and give the average, ... * Scoped helper classes allowing to pairwise start/stop operations, suspend/resume and resume/suspend a Stopwatch. * Stopwatch Formatter concept * stopwatch formatter "%ds\n" * stopwatch accumulator formatter "%c times, sum%ss, min%ms, max%Ms, mean%as\n" * time formatter "real %rs, cpu %cs (%p%), user %us, system %ss\n" * digital_time decomposition class separating days, hours,minutes,seconds, nanoseconds from any duration class (looking for a better name) * digital_time formatter "%d days(s) %h:%m:%s.%n\n" * stopwatch_reporter is a convenient generic class reporting elapsed time for the Stopwatch concept. * stopclock<Clock> shortcut stopwatch_reporter<stopwatch<Clcok>> * typeof registration for classes duration and time_point Depreceated Features: * The classes process_times, process_clock, process_timer, timer and run_timer are now deprecated as the preceding additions are more generic. However for backward compatibility they are preserved until inclusion of the library in Boost. Next follows the equivalences: timer<> ~ stopwatch<> process_timer ~ stopwatch<process_cpu_clock> run_timer ~ stopclock<> Bug Fixes * Try to correct warning C4251: 'boost::chrono::run_timer::m_format' : class 'std::basic_string<_Elem,_Traits,_Ax>' needs to have dll-interface to be used by clients of class 'boost::chrono::run_timer', by don't including inlines functions using the std::string m_format. For people that doesn't know it yet, Boost.Chrono library provides: * The C++0x Standard Library's common_type. * The C++0x Standard Library's compile-time rational arithmetic. * The C++0x Standard Library's time utilities, including: * Class template duration * Class template time_point * Clocks: * system_clock * monotonic_clock * high_resolution_clock * typeof registration for classes duration and time_point * Process clocks: * process_real_CPU_clocks, capturing real-CPU times. * process_user_CPU_clocks, capturing user-CPU times. * process_system_CPU_clocks, capturing system-CPU times. * process_cpu_clock, tuple-like class capturing at once real, user-CPU, and system-CPU times. * Stopwatches: * stopwatch, capturing elapsed Clock times. * stopwatch_accumulator, capturing cummulated elapsed Clock times. * scoped helper classes allowing to pairwise start/stop operations, suspend/resume and resume/suspend a Stopwatch. * Stopclocks or Stopwatch reporters: * stopwatch_reporter, convenient reporting of models of Stopwatch results. * stopclock<Clock> shortcut of stopwatch_reporter<stopwatch<Clock>> Best regards, _____________________ Vicente Juan Botet Escribá

2 2

floating point FUD
by Thomas Klimpel 25 Jan '10

25 Jan '10

Hi, Find attached a small test program that tries to highlight some of the "usual" floating point traps. The essence is the following small function that outputs the results of some "buggy" floating point logic. The rest is just setting up the environment so that the bugs actually get triggered. void buggy_function(double eps = 1e-13, int length = 3, double delta = 1 / 7.0) { using namespace std; double alpha = 1e-13; double beta = eps; double a = length * delta; double b = length * delta; vector<double> inverse; for (int i = 0; i < length; ++i) inverse.push_back(1.0/(2*i+1)); vector<double> sorted; for (int i = 0; i < length; ++i) sorted.push_back(inverse[i]*delta); double t = -delta*sorted.size(); double tt = -sorted.size()*delta; bool t_tt = (abs(t-tt) < eps); bool abs_t = (abs(t) == -t); double c = (1-alpha) * a + alpha * b; double d = (1-beta) * a + beta * b; bool a_c = (a == c); bool b_d = (b == d); vector<bool> equal; for (int i = 0; i < length; ++i) equal.push_back(inverse[i]*delta == sorted[i]); std::cout << "t_tt = " << t_tt << "\nabs_t = " << abs_t << "\na_c = " << a_c << "\nb_d = " << b_d << "\n"; std::cout << "equal = ["; for (int i = 0; i < length; ++i) std::cout << " " << equal[i]; std::cout << " ]\n"; } The hypothetical "naive" programmer might expect the output: t_tt = 1 abs_t = 1 a_c = 1 b_d = 1 equal = [ 1 1 1 ] However, the actual output is not only different from this, but also depends on the compiler, the compiler settings, the current configuration of the floating points unit and the actual headers included directly or indirectly by the compilation unit. g++ test_fp.cpp -g -Wall compiles without warning and executes with output: t_tt = 0 abs_t = 1 a_c = 1 b_d = 1 equal = [ 1 1 1 ] g++ test_fp.cpp -DNDEBUG -O2 -msse2 -Wall compiles without warning and executes with output: t_tt = 0 abs_t = 1 a_c = 1 b_d = 1 equal = [ 1 0 0 ] I created a new project with MSVC9. The debug version compiles with warnings for the things that go badly wrong and executes with output: t_tt = 0 abs_t = 0 a_c = 1 b_d = 1 equal = [ 1 1 1 ] set floating point unit to 'high' precision: t_tt = 0 abs_t = 0 a_c = 1 b_d = 1 equal = [ 1 1 1 ] The release version compiles with warnings for the things that go badly wrong and executes with output: t_tt = 0 abs_t = 0 a_c = 1 b_d = 1 equal = [ 1 1 1 ] set floating point unit to 'high' precision: t_tt = 0 abs_t = 0 a_c = 0 b_d = 1 equal = [ 1 0 0 ] In my case (see the background story below), it was actually the trap represented by the output "abs_t = 0" instead of "abs_t = 1" that caught me on linux64 but worked on win32. (It turned out difficult to reproduce this with gcc, so the test program reproduces this trap with MSVC, even so MSVC warns quite explicitly about it). I think it is a funny exercise to debug the test program and find out what actually goes wrong (which is especially funny since most traps only go wrong with compiler optimization turned on). Regards, Thomas ------------------------ The background story: The recent reviews of [Constrained Value], [Polygon] and [GGL] all featured interesting disagreements over floating point issues: http://lists.boost.org/Archives/boost/2008/12/145655.php http://lists.boost.org/Archives/boost/2008/12/145788.php http://lists.boost.org/Archives/boost/2009/03/149567.php http://lists.boost.org/Archives/boost/2009/08/155767.php http://lists.boost.org/Archives/boost/2009/11/158560.php (These were long threads with many messages and many participants, so please don't misinterpret my choice of unrepresentative messages as any form of statement.) Last Wednesday, I had to give an internal live demo of a feature I just finished. I had done the development mostly on win32, but I wanted to run the demo on linux64, to be able to show examples of realistic size (full chip...). While preparing the presentation, I was surprised to find the accuracy of the results significantly worse than I remembered from my previous tests. I repeated my previous tests on linux64, and found out that there was indeed a problem with my code on linux64. I did the demo on win32, but was asked after the presentation to send the source code to somebody from another group. So I spent most of the night trying to find the problem in my code. When I found out that some code with floating point driven logic (I had written years ago) to analytically integrate radial symmetric functions over rectangular domains was showing unexpected behavior, I decided to postpone the floating point fights with the compiler to the next day. I told this story the next day in a group meeting, and was confronted with much floating point FUD and unrealistic suggestions, basically boiling down to either not writing floating point driven logic in the first place, or commenting it in excessive detail. So I lost my temper and explained that it was difficult enough for me to write this code with floating point driven logic, and that anybody suggesting writing it without floating point driven logic should do so please, because I'm unable to do it. I have to admit that I read "What Every Computer Scientist Should Know About Floating-Point Arithmetic" only superficially: http://www.engrng.pitt.edu/hunsaker/3097/floatingpoint.pdf http://docs.sun.com/source/806-3568/ncg_goldberg.html I also have to admit that I write code with floating point driven logic from time to time in case it seems unavoidable to me, and that this code often has bugs that are only discovered months after the code is already finished. But I never found a bug in such code that would have been a fundamental problem with floating point, but always just the "usual" floating point traps I keep overlooking by mistake. Now somebody will probably suggest that I should at least document the "usual" floating point traps then. So I created the attached small test program showing the "usual" floating point traps I could still remember having overlooked at least once. It was actually more difficult than expected to arrange the code in a way that the bugs are really triggered for typically compiler settings of MSVC and gcc.

9 16

[Quickbook] Integrating Spirit docs
by Hartmut Kaiser 24 Jan '10

24 Jan '10

Hey, Not exactly a question for the main devel list, but I'm not sure, where its best to send it to... What do I need to do in order to integrate the Spirit docs (generated by Quickbook) with Boosts overall doc page (i.e. http://www.boost.org/doc/libs/1_41_0/doc/html/libraries.html)? Regards Hartmut --------------- Meet me at BoostCon www.boostcon.com

2 1

Re: [boost] RFC: Sequence Properties and Boost Algorithm/Functional
by Grant Erickson 24 Jan '10

24 Jan '10

On Fri, 22 Jan 2010 14:13:31 -0800 Jeffrey Hellrung <jhellrung(a)ucla.edu> wrote: On 1/23/10 12:35 AM, boost-request(a)lists.boost.org wrote: >> For a recent project, I needed to inquire about a sequence of objects and >> make a determination as to whether the sequences were: >> >> * Increasing >> * Strictly Increasing >> * Decreasing >> * Strictly Decreasing >> >> Looking through STL, Boost documentation, Boost sources and headers and the >> Boost mailing lists I was able to find neither an existing algorithm or >> stateful unary predicate functor for accomplishing this for a pair of input >> iterators. However, I was a bit surprised considering that this seems like a >> sequence property query that would tend to come up fairly often and serve a >> general utility. Did I just fail to form the proper search/query or am I >> overestimating the general utility? >> >> Is a smarter realization of this as an algorithm a potential candidate for >> boost::algorithm? > > Perhaps std::adjacent_find and std::less is all you need, e.g., to > determine if a sequence is decreasing? > > I.e., a sequence is decreasing iff all adjacent pairs of elements xi, > x[i+1] satisfies xi >= x[i+1] iff no adjacent pair of elements xi, > x[i+1] satisfies xi < x[i+1] (assuming that (!>=) == (<)). On Fri, 22 Jan 2010 15:24:32 -0800 Marshall Clow <mclow.lists(a)gmail.com> wrote: > I've got this floating around from a while back... > > [ examples omitted ] Marshall and Jeff: Thanks for the feedback. Marshall's feedback seems to indicate that, yes, there is likely general utility need for such functions and Jeff, you are correct that these algorithms are trivially composed from std::adjacent_find, std::not2 and std::{greater,less,greater_equal,less_equal}: namespace boost { namespace detail { template <typename ForwardIterator, typename BinaryPredicate> bool is_creasing(ForwardIterator first, ForwardIterator last, BinaryPredicate binary_pred) { return std::adjacent_find(first, last, std::not2(binary_pred)) == last; } } // namespace detail template <typename ForwardIterator> bool is_increasing(ForwardIterator first, ForwardIterator last) { typedef typename std::iterator_traits<ForwardIterator>:: value_type value_type; return detail::is_creasing(first, last, std::less_equal<value_type>()); } [ ... other three instances follow trivially ... ] } // namespace boost Unless there's any other feedback, I'll work on posting an implementation to Boost Vault. Regards, Grant

1 0

Re: [boost] MPL bitand.hpp and iso646.h on MSVC 2008
by Nelson, Erik - 2 24 Jan '10

24 Jan '10

After further research, I saw that this is a duplicate of very similar reports previously. I'm not sure if it's scheduled to be fixed, but it still seems to be a problem in boost v1.41 Thanks Erik

3 3

[lockfree::fifo] Review
by Andrew Venikov 24 Jan '10

24 Jan '10

I decided to start a new thread on this topic since the last thread on the same topic is pretty outdated and not everyone will see it. (you can disregard my reply to the previous thread as this one is more complete) First of all I think that having a library of lock-free algorithms/containers would be greatly beneficial to a great number of boost users. On the other hand, having implemented several lock-free algorithms, I know that it is notoriously hard to get them right. We'll need all the help we can get from knowledgeable people in the field. The implementation needs to be thoroughly reviewed. Let me give the first attempt at that. In this e-mail I'll be primarily concentrating on the algorithm correctness rather than the interface. First, let me start with the choice of the algorithm for the fifo queues: Magued Michael and Michael Scott's "Simple, Fast, and Practical Non-blocking and blocking concurrent queues". I really think it is the best choice. Having said that, however, I need to point out that there some inherent limitation in this algorithm. The first limitation is that you can't peek at the head of the queue without dequeueing the element first, hence you can't get an interface that is conformant with std::queue. But I truly believe that it will be the case with any lock-free queue implementation, hence we should abandon the hope of having a lock-free queue look the same as std::queue Second, this algorithm makes certain assumptions about the ability to access memory that has been freed. The algorithm can try to read memory that has been de-allocated. (See further down for description of how). Several debug implementations of malloc/free store every allocated element on one page and when the element is freed, the page is marked protected for both reading and writing. That means that this algorithm can only work with a subset of custom allocators. Your "free_list" for example can't work with it since it's possible for a node to be freed when you call "deallocate". The "caching_freelist" and "static_freelist" on the other hand work just fine because they never return the memory back to the system. Third, and the biggest limitation, is the algorithm's assumption that you can store a pointer to an element plus an ABA tag in a contiguous memory space that can be passed to a CAS instruction. I believe not all platforms provide a DCAS instruction, that's why you're trying to work around this issue by using "packed pointers", i.e. storing the ABA tag in the part of the pointer that presumably is never used. The problem with that, however, is that some libc implementations of malloc/free do use all the bits in the pointer for their own needs, so you can't assume that you can meddle with them. My experience with this algorithm shows that the safest approach is to use a pre-allocated array for the queue and replace pointers with indexes into the array. Assuming that the size of an index is sufficiently lower than the size of a pointer, you can use the remaining bits to store the ABA tag. This alleviates both point 2 and 3. This does mean however, that the queue can't have an unbound size, the size has to be specified during the queue instantiation. Fourth, on platforms where CAS is implemented using LL/SC (such as PowerPC and MIPS), it is possible to livelock. The problem with LL/SC on most platforms is that the write granulum for marking LL's address as "dirty" isn't just the memory pointed to by LL, but the whole cache line where the memory resides. On these platforms it is important to make sure that each "node" of the queue is located on a separate cache line. Here's the code of your enqueue: bool enqueue(T const & t) { node * n = alloc_node(t); if (n == NULL) return false; for (;;) { atomic_node_ptr tail (tail_); //1 read_memory_barrier(); //2 atomic_node_ptr next (tail->next); //3 if (likely(tail == tail_)) //4 { if (next.get_ptr() == 0) //5 { if ( tail->next.cas(next, n) )//6 { tail_.cas(tail, n); return true; } } else tail_.cas(tail, next.get_ptr()); } } } 1. You're missing write barrier after a call to alloc_node(). Rational: alloc_node sets the "next" pointer of the newly allocated node to NULL. That is a store to shared memory. Setting next pointer to NULL has to be observable to other threads BEFORE they observe the inserted node. If you don't insert a write barrier, it is possible for other threads to see the new element in the list before element's next pointer is initialized with NULL. 2. You've misplaced the read_barrier. Rational: Line 4 checks the validity of the load done on line 3. That means that the read_barrier should be between lines 3 and 4. If you don't have a read_barrier after loading *tail->next, then this load can happen after the load of tail_ on line 4, which defies the purpose of line 4. Here's a scenario that makes it clear: State: queue is well-formed and tail_ points to the last element. 1. Thread A executes line1. State: the queue is unchanged and Thread A has a local copy of tail_ 2. Since there's no read barrier after line 3, loads at lines 3 and 4 happen out-of-order. tail_ is pre-loaded for comparison at line 4. 3. Thread B removes the element pointed by tail_, advances tail_ further State: tail_ is advanced, the old element is removed and given back to the allocator. A's local copy of tail_ becomes stale. 4. Thread A executes line 3 State: A's copy of tail is stale. This copy is used to load memory that has been reclamed by the allocator and possibly modified. The value of the memory happens to be 0. 5. Thread A executes line 4. Since tail_ has been preloaded, line 4 succedes. 6. Line 5 succedes 7. Line 6 succedes. Boom: you've just modified a piece of memory not controlled by the queue. You still need to have a barrier between lines 1 and 3, but here only a data dependency barrier will suffice, which is a weaker form of a read barrier and on most all platforms is a no-op since data dependent loads can be handled by processors automatically. 3. Your tail_ and head_ should be volatile. Furthermore, the getters for you tagged_ptr (like get_ptr, operator->() and operator* ) should return pointers/references to volatile types. Rational: If your tail_ is not volatile, then the compiler is free to load head_ just once and line 4 effectively becomes a no-op. Here's code for your "dequeue": bool dequeue (T * ret) { for (;;) { atomic_node_ptr head (head_); //1 read_memory_barrier(); //2 atomic_node_ptr tail(tail_); //3 node * next = head->next.get_ptr(); //4 if (likely(head == head_)) //5 { if (head.get_ptr() == tail.get_ptr()) //6 { if (next == 0) return false; tail_.cas(tail, next); } else { *ret = next->data; //7 if (head_.cas(head, next)) //8 { dealloc_node(head.get_ptr()); //9 return true; } } } } } 1. Again, you need to put read_barrier between lines 4 and 5. Only data dependency barrier will suffice at line 2. 2. You need to add write barrier after line 7 for the same reason as in the enqueue. Hope this was descriptive, Andy Venikov.

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[1.42.0] Beta 1 available on Sourceforge
by Beman Dawes 23 Jan '10

23 Jan '10

1.42.0 beta 1 is now available. This release contains one new library and numerous bug fixes for existing libraries. For details, including download links, see http://beta.boost.org/users/news/version_1_42_0 The release can also be downloaded directly from SourceForge. See http://sourceforge.net/projects/boost/files/ There are a few known problems in the beta: * An odd 'simplesectsep' tag that doxygen creates which has turned up in the generated documentation, such as at http://tinyurl.com/ygbgkge. * Doxygen isn't expanding some of the macros in Boost.Accumulators. * A nasty bug in Spirit affecting copy construction of rules (rev. 50156) has been tracked down and fixed, but the fix was too late for the beta. These will be fixed in the final release. Please report any other problems by responding to this message on either the users or the main developers mailing lists. Thanks, --The Boost release team

3 3

help detecting presence of operator[]
by Jeffrey Hellrung 23 Jan '10

23 Jan '10

Hi all, I'm trying to perform a compile-time check to determine if a class has an operator[]. I'm using a "trick" I think I've seen in Adobe's library and on this list in the past: -------- BEGIN CODE -------- template< class T > struct has_op_bracket { struct base_t { void operator[]( int ); }; struct derived_t : T, base_t { }; template< void (base_t::*)( int ) > struct sfinae { typedef char type; }; template< class U > static typename sfinae< &U::operator[] >::type is_ambiguous(int); template< class U > static int is_ambiguous(...); static const bool value = sizeof( is_ambiguous< derived_t >(0) ) != 1; }; -------- END CODE -------- The way I understand this working is if T has no operator[], then &derived_t::operator[] unambiguously refers to *base_t::operator[], and so the first is_ambiguous overload is selected. Otherwise, &derived_t::operator[] is ambiguous, which is sufficient (I guess...?) for SFINAE to kick in, and the second is_ambiguous overload is selected. Now given the following definitions of X0 and X1: -------- BEGIN CODE -------- struct X0 { }; struct X1 { void operator[](void*); }; -------- END CODE -------- then the following static assertions pass, as expected: -------- BEGIN CODE -------- BOOST_STATIC_ASSERT(( !has_op_bracket<X0>::value )); BOOST_STATIC_ASSERT(( has_op_bracket<X1>::value )); -------- END CODE -------- However, if X2 is defined as -------- BEGIN CODE -------- struct X2 { template< class T > struct R : T { }; template< class T > typename R<T>::type operator[](T); }; -------- END CODE -------- then has_op_bracket<X2>::value fails to compile on MSVC9, but (according to Dinkum Exam[1]) it does compile just fine on "EDG/C++". The error in MSVC9 is -------- BEGIN OUTPUT -------- error C2516: 'T' : is not a legal base class 1> d:\test\main.cpp(9) : see declaration of 'T' 1> d:\test\main.cpp(9) : see reference to class template instantiation 'X2::R<T>' being compiled 1> with 1> [ 1> T=int 1> ] 1> d:\test\main.cpp(21) : see reference to class template instantiation 'has_op_bracket<T>' being compiled 1> with 1> [ 1> T=X2 1> ] -------- END OUTPUT -------- generated by the following program: -------- BEGIN CODE -------- template< class T > struct has_op_bracket { struct base_t { void operator[]( int ) const; }; struct derived_t : T, base_t { }; template< void (base_t::*)( int ) const > struct sfinae { typedef char type; }; template< class U > static typename sfinae< &U::operator[] >::type is_ambiguous(int); template< class U > static int is_ambiguous(...); static const bool value = sizeof( is_ambiguous< derived_t >(0) ) != 1; // line 9 }; struct X2 { template< class T > struct R : T { }; template< class T > typename R<T>::type operator[](T); }; int main() { has_op_bracket<X2>::value; // line 21 return 0; } -------- END CODE -------- What I don't understand is why MSVC is trying to instantiate R<int>. It seems to be grabbing the int from the parameter type of the member function pointer template parameter in sfinae, which doesn't seem like the right thing to do. I can change that parameter to anything else (as long as it doesn't have a nested type typedef) and the error persists. Is MSVC correct, or is this a compiler bug? Either way, is there an alternative, more portable approach to achieve the desired effect? Thanks in advance, - Jeff [1] http://www.dinkumware.com/exam/default.aspx

2 3

[test] mock objects
by Michael Robinson 23 Jan '10

23 Jan '10

Hi, I am a boost unit test newbie. I have been looking at the documentation and examples and would like to know if there is any documentation that specifically addresses the use of mock objects: I am specifically interested in how to interpret the output of est_example1.cpp and est_example2.cpp; as well as learning what the required format of the expectations log file (.elog) to be used for logged_exp_example.cpp is. Thank you, Mike ____________________________________________________________ Nutrition Improve your career health. Click now to study nutrition! http://thirdpartyoffers.netzero.net/TGL2241/c?cp=U1sp_d8XptT4jkLd7e_KlAAAJ1…

2 2

[typeof] Variadic functions
by Sergey Zubkovsky 22 Jan '10

22 Jan '10

Hi, Here is a patch to support variadic functions in the Boost.Typeof. Can anyone check it and commit? Thank you. Index: register_functions.hpp =================================================================== --- register_functions.hpp (revision 57837) +++ register_functions.hpp (working copy) @@ -18,18 +18,25 @@ #include BOOST_TYPEOF_INCREMENT_REGISTRATION_GROUP() #ifndef BOOST_TYPEOF_LIMIT_FUNCTION_ARITY -#define BOOST_TYPEOF_LIMIT_FUNCTION_ARITY 10 +#define BOOST_TYPEOF_LIMIT_FUNCTION_ARITY 15 #endif enum { FUN_ID = BOOST_TYPEOF_UNIQUE_ID(), - FUN_PTR_ID = FUN_ID + 1 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY), - FUN_REF_ID = FUN_ID + 2 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY), - MEM_FUN_ID = FUN_ID + 3 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY), - CONST_MEM_FUN_ID = FUN_ID + 4 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY), - VOLATILE_MEM_FUN_ID = FUN_ID + 5 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY), - VOLATILE_CONST_MEM_FUN_ID = FUN_ID + 6 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY) + FUN_VAR_ID = FUN_ID + 1 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY), + FUN_PTR_ID = FUN_ID + 2 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY), + FUN_VAR_PTR_ID = FUN_ID + 3 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY), + FUN_REF_ID = FUN_ID + 4 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY), + FUN_VAR_REF_ID = FUN_ID + 5 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY), + MEM_FUN_ID = FUN_ID + 6 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY), + MEM_FUN_VAR_ID = FUN_ID + 7 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY), + CONST_MEM_FUN_ID = FUN_ID + 8 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY), + CONST_MEM_FUN_VAR_ID = FUN_ID + 9 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY), + VOLATILE_MEM_FUN_ID = FUN_ID + 10 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY), + VOLATILE_MEM_FUN_VAR_ID = FUN_ID + 11 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY), + VOLATILE_CONST_MEM_FUN_ID = FUN_ID + 12 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY), + VOLATILE_CONST_MEM_FUN_VAR_ID = FUN_ID + 13 * BOOST_PP_INC(BOOST_TYPEOF_LIMIT_FUNCTION_ARITY) }; BOOST_TYPEOF_BEGIN_ENCODE_NS Index: register_functions_iterate.hpp =================================================================== --- register_functions_iterate.hpp (revision 57837) +++ register_functions_iterate.hpp (working copy) @@ -6,6 +6,12 @@ #define n BOOST_PP_ITERATION() +#if ( n > 1 ) +# define comma , +#else +# define comma +#endif + // function pointers template<class V, class R BOOST_PP_ENUM_TRAILING_PARAMS(n, class P)> @@ -15,6 +21,13 @@ typedef BOOST_TYPEOF_ENCODE_PARAMS(BOOST_PP_INC(n), FUN_PTR_ID + n) type; }; +template<class V, class R BOOST_PP_ENUM_TRAILING_PARAMS(n, class P)> +struct encode_type_impl<V, R(*)(BOOST_PP_ENUM_PARAMS(n, P)comma ...)> +{ + typedef R BOOST_PP_CAT(P, n); + typedef BOOST_TYPEOF_ENCODE_PARAMS(BOOST_PP_INC(n), FUN_VAR_PTR_ID + n) type; +}; + template<class Iter> struct decode_type_impl<boost::mpl::size_t<FUN_PTR_ID + n>, Iter> { @@ -24,6 +37,15 @@ typedef BOOST_PP_CAT(iter, BOOST_PP_INC(n)) iter; }; +template<class Iter> +struct decode_type_impl<boost::mpl::size_t<FUN_VAR_PTR_ID + n>, Iter> +{ + typedef Iter iter0; + BOOST_TYPEOF_DECODE_PARAMS(BOOST_PP_INC(n)) + typedef BOOST_PP_CAT(p, n)(*type)(BOOST_PP_ENUM_PARAMS(n, p)comma ...); + typedef BOOST_PP_CAT(iter, BOOST_PP_INC(n)) iter; +}; + #ifndef BOOST_TYPEOF_NO_FUNCTION_TYPES // function references @@ -35,6 +57,13 @@ typedef BOOST_TYPEOF_ENCODE_PARAMS(BOOST_PP_INC(n), FUN_REF_ID + n) type; }; + template<class V, class R BOOST_PP_ENUM_TRAILING_PARAMS(n, class P)> + struct encode_type_impl<V, R(&)(BOOST_PP_ENUM_PARAMS(n, P)comma ...)> + { + typedef R BOOST_PP_CAT(P, n); + typedef BOOST_TYPEOF_ENCODE_PARAMS(BOOST_PP_INC(n), FUN_VAR_REF_ID + n) type; + }; + template<class Iter> struct decode_type_impl<boost::mpl::size_t<FUN_REF_ID + n>, Iter> { @@ -53,6 +82,13 @@ typedef BOOST_TYPEOF_ENCODE_PARAMS(BOOST_PP_INC(n), FUN_ID + n) type; }; + template<class V, class R BOOST_PP_ENUM_TRAILING_PARAMS(n, class P)> + struct encode_type_impl<V, R(BOOST_PP_ENUM_PARAMS(n, P)comma ...)> + { + typedef R BOOST_PP_CAT(P, n); + typedef BOOST_TYPEOF_ENCODE_PARAMS(BOOST_PP_INC(n), FUN_VAR_ID + n) type; + }; + template<class Iter> struct decode_type_impl<boost::mpl::size_t<FUN_ID + n>, Iter> { @@ -62,6 +98,15 @@ typedef BOOST_PP_CAT(iter, BOOST_PP_INC(n)) iter; }; + template<class Iter> + struct decode_type_impl<boost::mpl::size_t<FUN_VAR_ID + n>, Iter> + { + typedef Iter iter0; + BOOST_TYPEOF_DECODE_PARAMS(BOOST_PP_INC(n)) + typedef BOOST_PP_CAT(p, n)(type)(BOOST_PP_ENUM_PARAMS(n, p)comma ...); + typedef BOOST_PP_CAT(iter, BOOST_PP_INC(n)) iter; + }; + #endif//BOOST_TYPEOF_NO_FUNCTION_TYPES #ifndef BOOST_TYPEOF_NO_MEMBER_FUNCTION_TYPES @@ -83,5 +128,6 @@ #define BOOST_TYPEOF_id VOLATILE_CONST_MEM_FUN_ID #include <boost/typeof/register_mem_functions.hpp> +#undef comma #undef n #endif

2 3

[iostreams 1.42 beta1] gcc warning
by Christoph Duelli 22 Jan '10

22 Jan '10

boost/iostreams/detail/config/unreachable_return.hpp:25:7: warning: no newline at end of file would be great it that could be fixed. Best regards Christoph

1 0

[Polygon] Template error in CodeWarrior when attempting union on polygon_set_data
by Kef Schecter 22 Jan '10

22 Jan '10

I hesitate to mark this as [Polygon] because the error message is in a different part of Boost. However, I have little idea what the actual cause of the problem is or what any of the relevant stuff even means, so I figure [Polygon] is as good as anything at the moment... As before, this is a custom version of CodeWarrior an embedded ARM system, so I have no idea how well it corresponds with other versions of CodeWarrior. Here is a trivial program that illustrates the problem, using the BOOST_VERY_LITTLE_SFINAE patch from the last discussion here: #include <iostream> #define BOOST_VERY_LITTLE_SFINAE #include <boost/polygon/polygon.hpp> using namespace boost::polygon; using namespace boost::polygon::operators; int main() { polygon_set_data<int> ps; ps += rectangle_data<int>(0, 0, 1, 1); return 0; } This results in the following error message : Error : illegal use of template argument dependent type 'T::type' The error occurs in this part of boost/mpl/aux_/preprocessed/plain/and.hpp: template< typename T1, typename T2, typename T3, typename T4 > struct and_impl< true,T1,T2,T3,T4 > : and_impl< BOOST_MPL_AUX_NESTED_TYPE_WKND(T1)::value , T2, T3, T4 , true_ > { }; Any ideas about what's wrong or how to fix it? - Kef

2 3

Re: [boost] boost::mpl::for_each and value_initialized
by Niels Dekker - address until 2010-10-10 22 Jan '10

22 Jan '10

>> Do I understand correctly that you want the memset call to be >> skipped for those compiler versions that have implemented >> value-initialization entirely correctly? Peter Foelsche wrote: > I'm only concerned with boost::mpl::for_each > This function calls a function object by passing an object of the > matching type. > The contents of this object usually do not matter -- and in case they > do, the programmer can write a default constructor to initialize this > object. So there is no need in boost::mpl::for_each to call > value_initialized. So you think the issue can be resolved properly, merely by modifying mpl/for_each.hpp, right? You proposed at http://lists.boost.org/Archives/boost/2009/09/155805.php to modify mpl/for_each.hpp by changing: ! value_initialized<arg> x; ! aux::unwrap(f, 0)(boost::get(x)); Into: ! aux::unwrap(f, 0)(arg()); I see some subtle differences here. First of all, boost::get(x) return a reference to an lvalue, while arg() is an rvalue. Do you think that's okay? Secondly, things *might* go wrong if arg doesn't have a user-declared default-constructor *and* the compiler hasn't correctly implemented value-initialization. That's why Fernando and I added the memset call to boost::value_initialized, of course. But you think the data members of the temporary arg() won't be accessed anyway, right? Unless arg has a user-declared default-constructor? I'm sorry I don't know mpl/for_each.hpp well enough. But if the answer to each of the above questions is yes, I guess your proposal is fine. Kind regards, Niels -- Niels Dekker http://www.xs4all.nl/~nd/dekkerware Scientific programmer at LKEB, Leiden University Medical Center

2 1

MPL bitand.hpp and iso646.h on MSVC 2008
by Nelson, Erik - 2 21 Jan '10

21 Jan '10

If I make a program like #undef BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS #include <iso646.h> #include <boost/mpl/bitand.hpp> I get an error like boost/mpl/aux_/include_preprocessed.hpp(37) : fatal error C1083: Cannot open include file: 'boost/mpl/aux_/preprocessed/plain/&.hpp': No such file or directory And if I change it to #define BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS #include <iso646.h> #include <boost/mpl/bitand.hpp> I get 1>c:\work\boost\boost/mpl/aux_/numeric_op.hpp(86) : error C2332: 'struct' : missing tag name 1>c:\work\boost\boost/mpl/aux_/numeric_op.hpp(86) : error C3306: 'boost::mpl::<unnamed-tag>': unnamed class template is not allowed 1>c:\work\boost\boost/mpl/aux_/numeric_op.hpp(86) : error C2143: syntax error : missing ';' before '&' I think the problem is in boost/mpl/bitand.hpp, where #define AUX778076_OP_PREFIX bitand Is defined. 'bitand' is (nonconformantly) #defined to '&' in VC 2008's iso646.h, borking the definition of AUX778076_OP_PREFIX. The fix seems to be to #define AUX778076_OP_PREFIX to something else that MSVC doesn't stomp on. Thanks Erik

1 0

Any Chances for Boost Stable?
by Artyom 21 Jan '10

21 Jan '10

Hello, This mail is rather discussion of possible future Boost policy rather then concrete features it provides. Is there any chance for Stable Boost version? --------------------------------------------- What do I mean stable? Stable as Qt4, stable as STL Port, or STL. Boost is one of the greatest platforms for development of bleeding edge technologies. Like Boost.Asio is one of the greatest Asynchronous API libraries. On the other hand, this library is extremely unstable: each release breaks compatibility with previous one! When I compile a program or library that uses STL I expect that it would continue to work as long as compiler keeps table ABI (GCC - for years). I can compile great GUI application with Qt and expect from it to work for years and be sure that core Qt library includes updates, bug fixes and so. I can't do it with Boost! -------------------------------------------------------- Is there any chance to create a stable Boost branch that includes: - All libraries included in Tr1 - Various other stable libraries. This branch would keep: stable API and ABI, It may include additional libraries and features as long as they do not break API/ABI. Adopt the code such that different changes would not break ABI. For example, if shared_ptr on specific platform uses mutex or atomic counter, it would not be changed withing release because of new supported feature -- meaning config.hpp should be recompiled similarly as it done with autotools. Adopt pimpl policies of Qt to make sure that classes can be easily extended without breaking them. ------------------------------------ I know that this is lot of work and this is totally different from current Boost policy. But Boost should not be only experimental library... It should be as stable as STLPort or STL. -------------------------------- Do we need Boost.Stable branch? -------------------------------- Artyom

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Boost is complicated. This forum too. (please help about accumulators)
by Mahdavi 21 Jan '10

21 Jan '10

{I beg your pardon if you receive multiple of this. I am not sure about its receive.} I hope I am in a right place. I heard that boost is this and that. I am new to boost but have 10 years of programming experience with c++. It is about 10 hours I am searching for a sample about how can I reach to a histogram. For clarity. Please (please I beg you) write some few line of code how to get a histogram. double s[] = { 0, .5 , .6 , .65 , .45 , .7 , .6 , .65 , .45 , .7 , .59 , .52 } ; I want histogram of s ?? I tried many boost codes but I failed all the time. Please help. -- View this message in context: http://old.nabble.com/Boost-is-complicated.-This-forum-too.-%28please-help-… Sent from the Boost - Dev mailing list archive at Nabble.com.

1 0

[GGL] Can't seem to use equals on multi_polygons
by Kef Schecter 21 Jan '10

21 Jan '10

When I try to use equals() on multi_polygons, the compiler blows up, giving a template error. I've tried this in CodeWarrior and MSVC. Using equals() on two polygon_2d's works fine, but it doesn't like it when I use multi_polygons. Is equals() for multi_polygons not implemented, or am I just missing something? I've attached a test program that demonstrates the problem. (I've defined my own integer-based types, like polygon_2di, because I need this to work on an embedded platform with no FPU. Using polygon_2d and doubles instead shows the same problem, though.) - Kef

2 6

error LNK2005
by Kevin Li 21 Jan '10

21 Jan '10

Hello, when the run boost test cases (Version 1.41.0), I got quite a few LNK2005 errors. Below is an example when run a Data_Time test: msvcprt.lib(MSVCP80.dll) : error LNK2005: "public: __thiscall std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (??0?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@QAE@ABV01@@Z) already defined in dates_as_strings.obj msvcprt.lib(MSVCP80.dll) : error LNK2005: "public: __thiscall std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >::~basic_string<char,struct std::char_traits<char>,class std::allocator<char> >(void)" (??1?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@QAE@XZ) already defined in dates_as_strings.obj It seems to me that there is a conflict between system library and the Boost library, but I am not sure if this is a bug or the Boost library is not correctly built. Any clue would be very appreciated. Best regards, --Kevin _________________________________________________________________

3 5

library for differentiation (interest research)
by DE 21 Jan '10

21 Jan '10

hi all recently i have interested in evaluating of derivatives of complicated functions and discovred that there is a finely developed technique which is called algorithmic differentiation (visit www.autodiff.org if you are interested) the resulting code using an imagined lib may look like this struct { template<typename type> type operator()(type x) //defining function { return sin(x); } } foo; //... double x = 42., f = foo(x), //evaluating function value df = deriv(foo, x); //evaluating derivative value notice that the function' code is untouched the very amazing thing is that the function may be arbitrarily complex it can even be a matrix inversion or eigenvalues evaluation so we get e.g. derivatives of eigenvalues with respect to system parameters gradients, jacobians and higher order derivatives are also possible there are numerous libraries implementing this technique and the questions are: - does it fit into boost collection of libraries? - is it worth building a distinct boost (well-designed) library or adopt a specific lib or to use other (non-boost) libs? and the like personally i am going to investigate the so called tangent mode (or direct mode which is very simple) and probably implement it if i don't find any suitable implementation for my own purposes -- Pavel

2 1

shared_ptr/intrusive_ptr conflict
by Gennadiy Rozental 21 Jan '10

21 Jan '10

Hi, Following snippet fails to compile with gcc 4: ---------------- #include <boost/shared_ptr.hpp> #include <boost/intrusive_ptr.hpp> boost::shared_ptr<void> sharedPtr; template <class T> boost::shared_ptr<T> get_concrete() { return boost::static_pointer_cast<T,void>(sharedPtr); } int main() { boost::shared_ptr<int> p = get_concrete<int>(); } ---------------- due to the presence of intrusive_ptr.hpp. it seems like SFINAE should have kicked in. Any help with how to work this around? Do we need to fix above header? Gennadiy.

2 2

[String Algo] error in ireplace_first or ireplace_all with std::wstring under gcc 3.4.2 (MingW)
by Doug Swanson 20 Jan '10

20 Jan '10

I apologize in advance if this is an inappropriate place to post this question. I posted it to the boost-users list half a week ago and got no replies, so I am trying here instead. The following code compiles and runs without error under g++ in Windows, GCC 3.4.2 (MingW): <code> #include <cstdio> #include <string> #include <boost/algorithm/string.hpp> using namespace std; using namespace boost; int main( void ) { string test = "This is a test"; ireplace_first( test, "test", "success" ); printf( "%s\r\n", test.c_str() ); return 0; } </code> The output is correct: "This is a success". If I change the above code to use a std::wstring instead, it will compile, but it will crash on execution: <code> #include <cstdio> #include <string> #include <boost/algorithm/string.hpp> using namespace std; using namespace boost; int main( void ) { wstring test = L"This is a test"; ireplace_first( test, L"test", L"success" ); printf( "%ws\r\n", test.c_str() ); return 0; } </code> Setting a breakpoint on std::terminate() in gdb gives the following backtrace: Breakpoint 1, 0x00407ae6 in std::terminate() () (gdb) bt #0 0x00407ae6 in std::terminate() () #1 0x00404dc2 in __cxa_throw () #2 0x004021d2 in std::__throw_bad_cast() () #3 0x00434c69 in std::ctype<wchar_t> const& std::use_facet<std::ctype<wchar_t> >(std::locale const&) (__loc=@0x22fe8c) at C:/Applications/Dev-Cpp//bin//../lib/gcc/mingw32//3.4.2//..//..//../../include/c++/3.4.2/bits/locale_facets.tcc:112 #4 0x0043415c in wchar_t std::toupper<wchar_t>(wchar_t, std::locale const&) ( __c=84, __loc=@0x22fe8c) at C:/Applications/Dev-Cpp//bin//../lib/gcc/mingw32//3.4.2//..//..//../../include/c++/3.4.2/bits/locale_facets.h:4553 #5 0x0041648c in bool boost::algorithm::is_iequal::operator()<wchar_t, wchar_t> (wchar_t const&, wchar_t const&) const (this=0x22fe8c, Arg1=@0x3e3df4, Arg2=@0x43702e) at C:/Applications/Boost_new/boost/algorithm/string/compare.hpp:71 #6 0x004163fb in boost::iterator_range<__gnu_cxx::__normal_iterator<wchar_t*, std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> > > > boost::algorithm::detail::first_finderF<wchar_t const*, boost::algorithm::is_iequal>::operator()<__gnu_cxx::__normal_iterator<wchar_t*, std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> > > >(__gnu_cxx::__normal_iterator<wchar_t*, std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> > >, __gnu_cxx::__normal_iterator<wchar_t*, std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> > >) const (this=0x22fe80, Begin={_M_current = 0x3e3df4}, End={_M_current = 0x3e3e10}) at C:/Applications/Boost_new/boost/algorithm/string/detail/finder.hpp:76 #7 0x00413fe8 in void boost::algorithm::find_format<std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >, boost::algorithm::detail::first_finderF<wchar_t const*, boost::algorithm::is_iequal>, boost::algorithm::detail::const_formatF<boost::iterator_range<wchar_t const*> > >(std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >&, boost::algorithm::detail::first_finderF<wchar_t const*, boost::algorithm::is_iequal>, boost::algorithm::detail::const_formatF<boost::iterator_range<wchar_t const*> >) ( Input=@0x22ff50, Finder=@0x22fe80, Formatter={m_Format = {m_Begin = 0x43701e, m_End = 0x43702e, singular = false}}) at C:/Applications/Boost_new/boost/algorithm/string/find_format.hpp:146 #8 0x004141b5 in void boost::algorithm::ireplace_first<std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >, wchar_t[5], wchar_t[8]> (std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >&, wchar_t[5] const&, wchar_t[8] const&, std::locale const&) (Input=@0x22ff50, Search=@0x43702e, Format=@0x43701e, Loc=@0x22ff40) at C:/Applications/Boost_new/boost/algorithm/string/replace.hpp:259 #9 0x004014e8 in main () at test.cpp:11 I am not competent enough with Boost to understand what the call stack is telling me, except that __throw_bad_cast( ) is the source of the crash. ireplace_all gives the same behavior as ireplace_first above. Furthermore, the problem does not arise if I use replace_first or replace_all instead of ireplace_first or ireplace_all. It compiles and runs correctly. Finally, the problem does not arise if I compile using MSVC 2008. It compiles and runs correctly. Does this indicate a problem with gcc (MingW) unicode support? Is there an easy way to circumvent it? Thank you very much for any suggestions!

3 6

[gil] native image format loaders/savers
by Domagoj Saric 20 Jan '10

20 Jan '10

Would a contribution to GIL in the form of alternate 'native' (e.g. using GDI+ on Windows) implementations (to remove the libjpeg, libtiff, libpng and zlib requirements) of image format parsers be accepted? -- "That men do not learn very much from the lessons of history is the most important of all the lessons of history." Aldous Huxley

2 3

[Boost.tracer] library request
by Andrew Chinkoff 20 Jan '10

20 Jan '10

[Boost.tracer] library request is founded on a desire to trace some statistics about program execution. The sample program below demonstrates these statistics. Sample program file: ******** START OF FILE ******** #include <tracer.h> void foo() { TRACE_LIFETIME; usleep(rand() % 100000); } int main() { TRACE_LIFETIME; for(int i = 0; i < 100; ++i) foo(); } ******** END OF FILE ******** Produced log file: ******** START OF FILE ******** All the program time: 05265686 us (micro secs) TRACE POINT: Function: int main() Calls: 0000000001 times Average T between calls: 0000000000 us Average life T: 0005264459 us File: main.cpp Line: 00000009 TRACE POINT: Function: void foo() Calls: 0000000100 times Average T between calls: 0000051665 us Average life T: 0000052606 us File: main.cpp Line: 00000004 ******** END OF FILE ******** Comment: TRACE_LIFETIME is a MACRO that traces some scope statistics, namely: "Function" - the function name where the scope is; "Calls" - number of entries into this scope; "Average T between calls" - average time period between "Calls"; "Average life T" - average time spent in this scope. Conclusion: I think it is reasonable to introduce this trace functionality into (for example) boost::tracer namespace. I had wrote tracer.h and tracer.cpp source files and I wish Boost community to consider them. Thank You.

4 6

[1.42.0] Beta 1 release candidate
by Beman Dawes 20 Jan '10

20 Jan '10

Release candidates for 1.42.0 beta 1 are available at http://boost.cowic.de/rc/ Please download, do a build, and report results here. Also let us know if you spot any problems or have any other comments. Thanks, --Beman

7 8

[date_time] [patch][1.42] Trac #2757 - fix warning
by Sylvester-Bradley, Gareth 20 Jan '10

20 Jan '10

On 19 January 2010 22:14, Marshall Clow wrote: > Downloaded, built w/no errors (a bunch of warnings) here. > Mac OS X 10.6.2, gcc 4.2.1 I guess it's too late to apply the simple patch for date_time from ticket #2757 in 1.42.0, but how about on trunk? This would suppress over 1000 instances of the same warning when compiling my app at /W4 on Windows, VC90; this is the only warning I see! https://svn.boost.org/trac/boost/ticket/2757 The ticket was opened almost a year ago, and FWIW the patch (included at that time) has worked for more than one person. Best regards, 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

1 0

[BoostCon 2010] Final Call for Participation
by Hartmut Kaiser 20 Jan '10

20 Jan '10

Please distribute! -------------------------------- 4th Annual Boost Conference 2010 -------------------------------- Aspen CO, USA, May 10-14, 2010, www.boostcon.com Final Call for Participation -------------------------------- Important dates: Proposal submissions Extended to January 3, 2010 Proposals decisions sent January 25, 2010 (tentative program available) Fully scheduled program available February 10, 2010 Session materials due April 15, 2010 -------------------------------- We invite you to submit session proposals to the 4th Annual Boost Conference: BoostCon 2010 (Aspen CO, USA, May 10-14, 2010). Traditionally the main face-to-face event for all things Boost (www.boost.org) BoostCon 2010 will present leading speakers from the whole C++ community. From using the Boost libraries to writing and maintaining them, from evangelizing to deploying Boost within your organization, from infrastructure and process to vision and mission, and the new C++ Standard, BoostCon brings together the sessions, the colleagues, and the inspiration to support your work with C++ and Boost in particular for the next year. To reflect the breadth of the Boost community, the conference includes sessions aimed at two constituencies: Boost end-users and hard-core Boost library and tool developers. The program fosters interaction and engagement within and across those two groups, with an emphasis on hands-on, participatory sessions. Session topics -------------- Topics of interest include, but are not restricted to, the following: * General tutorial sessions introducing one or more Boost libraries * In-depth sessions on using specific Boost libraries * Case studies on using Boost * Experts panels * Advanced sessions on implementation techniques used within Boost libraries * C++0x and how it will change life for users and library writers * Development workshops to extend or enhance existing Boost libraries * Workshops on design process * Infrastructure workshops such as Build tools, Website, Testing * Concepts and Generic Programming * Hardware and infrastructure presentations focused on how libraries can make better use of the technology * Other topics likely to be of great interest to Boost users and developers Interactive and collaborative sessions are encouraged, as this is the nature of both the on-line Boost community and the style of learning and participation that has proven most successful at such events. Sessions can be tutorial based, with an emphasis on interaction and participant involvement, or workshop based, whether hands-on programming or paper-based, discussion-driven collaborative work. Session formats --------------- Presentations Presentations focus on a practitioner's ideas and experience with anything relevant to Boost and Boost users. Panels Panels feature three or four people presenting their ideas and experiences relating to Boost's relevant, controversial, emerging, or unresolved issues. Panels may be conducted in several ways, such as comparative, analytic, or historic. Tutorials Tutorials are sessions at which instructors teach conference participants specific Boost-relevant skills. Workshops Workshops provide an active arena for advancements in Boost- relevant topics. Workshops provide the opportunity for experienced practitioners to develop new ideas about a topic of common interest and experience. Author's Corner Presentations These were introduced at BoostCon 2008, and were a great success. They are short (30 minute) sessions, focusing on tips on usage and design. In addition, we're looking to uncover the hidden design gems in Boost libraries. Tool Vendors Presentations We actively encourage tool vendors and ISP's to submit proposals for a special Tool Vendors Session Track aimed at products related to Boost and C++ (compilers, libraries, tools, etc.). Other formats may also be of interest. Don't hold back a proposal just because it doesn't fit into a pigeonhole. Submitting a proposal --------------------- Standard Sessions are 90 minutes. You may submit a proposal for fractions or multiples of 90-minutes. Fractional proposals will be grouped into 90 minute sessions covering related topics. Longer sessions, such as tutorials and classes, will be assigned 90 minute, three hour (i.e. half day), or six hour (i.e. full day) time slots. Please include: * The working title. * Type of session: presentation, panel, tutorial, workshop, authors corner, vendor track, other. * A paragraph or two describing the topic covered, suitable for the conference web site. * Proposed length: 10-20 minute short talks, 45 minutes, 90 minutes, half day, full day. * Alternate lengths, if you are willing to make adjustments: 10-20 minute short-talks, 45 minutes, 90 minutes, half-day, full day. * Audience: users, developers, both. * Level: basic, intermediate, advanced. * A biography, suitable for the conference web site. * Your contact information (will not be made public). Submission details ------------------ All submissions have to be done through the EasyChair conference management system: http://www.easychair.org/conferences/?conf=boostcon10. If you have not already registered at EasyChair, you will need to do so in order to submit your proposal. All submissions will go through a peer review process. Authors are invited (but are not required) to submit PDF versions of full papers of up to 10 pages in ACM conference proceedings format (see http://www.acm.org/sigs/publications/proceedings-templates) The full papers are not required unless you want them published in the proceedings. All accepted proposals will be made available in the Association for Computing Machinery (ACM) Digital Library (approval pending). Best papers, after further reviews, will be considered to be book chapters or journal articles in a renowned journal. The session materials go on the BoostCon website and will be available to attendees. For general information on the BoostCon 2010 paper submission or the scope of technical papers solicited, please refer to the conference website at www.boostcon.com. For any other questions about the submission process or paper format, please contact the Program Committee at boostcon10(a)easychair.com. If you have any technical problems with EasyChair, please contact EasyChair for help. Note: Presenters must agree to grant a non-exclusive perpetual license to publish submitted materials, either electronically or in print, in any media related to BoostCon. Hartmut Kaiser, email: hartmut.kaiser(a)gmail.com (Program Committee Chair) David Abrahams, email: dave(a)boostpro.com (Conference Chair) On behalf of the conference organizers

2 1

Re: [boost] Boost library submission (poll for interest)
by Bob Walters 20 Jan '10

20 Jan '10

Sorry for the delay here. Original reply bounced due to 'reply to digest' subject line. On Tue, 5 Jan 2010 21:21:29 +0100, "vicente.botet" <vicente.botet(a)wanadoo.fr> wrote: > I'm interested on a library that has transactional shared memory, but something more general that your containers database in shared memory. Can your library be extendeed to manage with types that are not containers? Currently there is an interface between the trans infrastructure (TI) and the containers allowing the containers to offer transactional operations, and indicate to the TI how they should be logged, committed, etc. This was intended to help make adding containers easier. There isn't really an assumption that transactional objects are containers - they could be anything which adheres to the interface. For example: I'm planning a quick wrapper for types T which makes T transactional for updates done to it via operator=. I need this for integerss that I want to use as sequences in one use of STLdb. (e.g. for key generation.) > If I have understood, the data is stored using Boost.Interprocess. Could you clarify why do you force the stored types to be Serializable? I'm not relying on the durability of the boost interprocess region. Nor am I trying to serialize the shared memory from directly to disk. Stefan has challenged me to do that, and I'm considering a variation which would do that, but it isn't without it's own issues. For now, I went with the approach of using serialization for sending K,V types to logs or checkpoints as a way to avoid those issues. My current concern with direct storage is that (assuming K and V may not be concrete types) it seems like it will require a lot of memory use tracking which could add an unwanted expense to shared memory pointer traversal. > With your library, there are alreasy 3 libraries under construction providing a transactional service (Boost.STLdb, Boost.Persistent and TBoost.STM). The ideal would be to have a single transactional framework with several transactional resources, e.g shared memory resource (Boost.STLdb), persistent resource (Boost.Persistent ), in memory resource (Boost.STM). If I'm not wrong Boost.Persistent contains already a Ressource concept. I would like to see how this transactional framework can be made generic so the three libraries can share the same transaction. Stefan, Bob, are you interesteed in participating on such a framework? Yes. Stefan had suggested this in private e-mails earlier, and I'll have to adapt to fit his interfaces. As I've alluded previously, I would like to see it possible to use Boost.Persistence with my library, as several shortcomings of STLdb would be addressed in that way. Part of doing that involved bringing all transaction control under one manager. Stefans library is the most robust in this sense, so I plan to work with and adapt to his interfaces. > Could you give a link from where to download the code. If you want I can add your library to the Boost Libraries Under Construction page https://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction. Currently it's in subversion only on sourceforge. I'm finishing some changes to the checkpointing mechanism, and I'm going to finish that first. Will let you know when its ready, thereby supporting the under construction entry. If it helps at all, I could move the SVN repository to the sandbox, or post the tarball into the Vault (?)

5 12

[boost-lists][string algo] C++0x string algo.
by Germán Diago 19 Jan '10

19 Jan '10

Hello. I'm using c++0x-enabled c++0x compiler. I was going to use this piece of code: typedef vector< string > split_vector_type; split_vector_type svec; split(svec, str, is_any_of(":")); for c++0x, I shouldn't need to define a typedef to take advantage of that. I think it would be more idiomatic (and way easier to do) to use something like this: auto splitrange = split(str, is_any_of(":")); So I would like to know if it's possible to map split to a range result by default (not a vector, maybe). And it could also be used with a vector if you put it explicitly: auto splitvec = split<vector<string>>(str, ....); I think the whole library should be readapted to return by value. I've spent some time figuring how to use the library because of the out parameters in the arguments. Can anyone tell me if there is any plan to change this? Or if it should be possible? Thanks in advance.

5 11

[random] normal_distribution
by Neal Becker 19 Jan '10

19 Jan '10

According to: http://www.taygeta.com/random/gaussian.html The method we're using is less stable and less computationally efficient than the method presented there. Is this true?

1 0

The boost component dependencies blues
by Stefan Seefeld 19 Jan '10

19 Jan '10

I'm not sure what the best place is for this question, but since it is symptomatic for a general theme (which I have complained about a lot in the past), I'll write it here: I'm trying to generate a boost subset that allows me to build boost.python and its dependencies into my own package. To do that, I ran "bcp python ...". I'm surprised to find all these components in the generated source tree: date_time, graph, mpi, regex, serialization, test, thread. And that's only compiled components (content of lib/). There are many more header-only components (i.e. subdirectories under boost/), such as spirit, variant, property_map, property_tree, dynamic_bitset. Is this really a minimal subset to use boost.python ? I can't quite believe it. In particular, what is boost.mpi doing there, and what boost.serialization (and boost.spirit) ? I'm going to great length to be able to use boost in a production environment, but I have to admit that this is quite unacceptable. :-( Stefan -- ...ich hab' noch einen Koffer in Berlin...

9 24

[math] Comeau can't match math::tools::fmod_workaround
by Mateusz Loskot 19 Jan '10

19 Jan '10

Hi, I'm not sure if I should submit this issue directly to Trac, so I decided to post it here first. Compiling Boost.Math using Comeau + GCC on Linux throws error that suggests mismatch of dobule and long double where single type T is expected: como-linux.compile.c++ ../../../bin.v2/libs/math/build/como-linux/debug/link-static/ellint_3l.o Comeau C/C++ 4.3.10.1 (May 7 2008 12:23:21) for LINUX_INTEL_ELF_Beta Copyright 1988-2008 Comeau Computing. All rights reserved. MODE:non-strict warnings C++ noC++0x_extensions "../../../boost/math/special_functions/ellint_3.hpp", line 185: error: no instance of function template "boost::math::tools::fmod_workaround" matches the argument list argument types are: (double, long double) T rphi = boost::math::tools::fmod_workaround(fabs(phi), T(constants::pi<T>() / 2)); ^ detected during instantiation of "T boost::math::detail::ellint_pi_imp(T, T, T, T, const Policy &) [with T=long double, Policy=c_policies::c_policy]" at line 309 1 error detected in the compilation of "../../../libs/math/build/../src/tr1/ellint_3l.cpp". como -tused -c --long_long -DBOOST_ALL_NO_LIB=1 -D_GNU_SOURCE=1 --no_inlining -O0 -g --exceptions -I"../../.." -I"../../../libs/math/src/tr1" -o "../../../bin.v2/libs/math/build/como-linux/debug/link-static/ellint_3l.o" "../../../libs/math/build/../src/tr1/ellint_3l.cpp" Could any one confirm if it is an error indeed? Should I submit ticket? Best regards, -- Mateusz Loskot, http://mateusz.loskot.net Charter Member of OSGeo, http://osgeo.org

2 10

[Signals2] Using dummy_mutex in a multithreaded program
by Peter Petrov 18 Jan '10

18 Jan '10

Greetings Frank, boosters, Currently using a signal with a boost::signals2:dummy_mutex works well only in single-threaded programs. I'm wondering if it can be made a little more useful. I have an use case with a single global signal, where all slots and connections are setup on program start. Afterwards a bunch of threads are fired, and each of them can call the signal's operator(). There are no more connections added/removed, only signal invocations. According to the workflow described here: http://www.boost.org/doc/libs/1_41_0/doc/html/signals2/thread-safety.html#i… ...it seems that a dummy_mutex should be enough, since the slot list is never modified. It turns out it's not - I'm getting assertion failures in nolock_cleanup_connections() because the _shared_state.unique() requirement is sometimes violated. Because using a real mutex will significantly degrade both performance and concurrency, I'm wondering if this assertion is really necessary. In this case it should be safe to continue even if the uniqueness is violated, because the connection list is never modified. And I think my use case is quite common :) - Peter

2 2

[chrono] v0.3 New Stopwatch Feature
by vicente.botet 18 Jan '10

18 Jan '10

Hi, I'm pleased to announce the new version of the Boost.Chrono library. The implementaton is quite stable; the new interface could suffer of some modifications, renaming, ... as far as you submit some proposals. I would request a formal review soon and I will need a review manager. I know that review managers are hard to find, so if you are interested in the library, please the Review Wizards. The library can be downloaded from http://www.boostpro.com/vault/index.php?action=downloadfile&filename=chrono… and the documentation is online on the sandbox http://svn.boost.org/svn/boost/sandbox/chrono/libs/chrono/doc/html/index.ht…. I've tested it with gcc and MSVC. Previoous version of the library have been testted on Mac, but I'm not able to test this platform. Could someone check if there are some regressions on Mac? New Features: * Process cpu clocks * Independent process cpu clocks for real, user, system process CPU time * Global process cpu clock for real, user, system process CPU time * Stopwatch concept measuring elapsed time between different points in time associated to the operations start, stop, suspend and resume. * stopwatch is a model Stopwatch measuring the elapsed time between the start and the stop operations. * stopwatch_accumulator is a model Stopwatch allowing to accumulate several time samples and give the average, ... * Scoped helper classes allowing to pairwise start/stop operations, suspend/resume and resume/suspend a Stopwatch. * Stopwatch Formatter concept * stopwatch formatter "%ds\n" * stopwatch accumulator formatter "%c times, sum%ss, min%ms, max%Ms, mean%as\n" * time formatter "real %rs, cpu %cs (%p%), user %us, system %ss\n" * digital_time decomposition class separating days, hours,minutes,seconds, nanoseconds from any duration class (looking for a better name) * digital_time formatter "%d days(s) %h:%m:%s.%n\n" * stopwatch_reporter is a convenient generic class reporting elapsed time for the Stopwatch concept. * stopclock<Clock> shortcut stopwatch_reporter<stopwatch<Clcok>> * typeof registration for classes duration and time_point Depreceated Features: * The classes process_times, process_clock, process_timer, timer and run_timer are now deprecated as the preceding additions are more generic. However for backward compatibility they are preserved until inclusion of the library in Boost. Next follows the equivalences: timer<> ~ stopwatch<> process_timer ~ stopwatch<process_cpu_clock> run_timer ~ stopclock<> Bug Fixes * Try to correct warning C4251: 'boost::chrono::run_timer::m_format' : class 'std::basic_string<_Elem,_Traits,_Ax>' needs to have dll-interface to be used by clients of class 'boost::chrono::run_timer', by don't including inlines functions using the std::string m_format. For people that doesn't know it yet, Boost.Chrono library provides: * The C++0x Standard Library's common_type. * The C++0x Standard Library's compile-time rational arithmetic. * The C++0x Standard Library's time utilities, including: * Class template duration * Class template time_point * Clocks: * system_clock * monotonic_clock * high_resolution_clock * typeof registration for classes duration and time_point * Process clocks: * process_real_CPU_clocks, capturing real-CPU times. * process_user_CPU_clocks, capturing user-CPU times. * process_system_CPU_clocks, capturing system-CPU times. * process_cpu_clock, tuple-like class capturing at once real, user-CPU, and system-CPU times. * Stopwatches: * stopwatch, capturing elapsed Clock times. * stopwatch_accumulator, capturing cummulated elapsed Clock times. * scoped helper classes allowing to pairwise start/stop operations, suspend/resume and resume/suspend a Stopwatch. * Stopclocks or Stopwatch reporters: * stopwatch_reporter, convenient reporting of models of Stopwatch results. * stopclock<Clock> shortcut of stopwatch_reporter<stopwatch<Clock>> Best regards, _____________________ Vicente Juan Botet Escribá

4 8

[inspect] Changes to Inspection Report
by Beman Dawes 18 Jan '10

18 Jan '10

The latest run of the trunk inspection report is up at http://boost.cowic.de/rc/inspect-trunk.html Several new features have been added: * References to unknown bookmarks are now detected. * Duplicate bookmarks are now detected. * Each problem detected is reported on a separate line, to make it easier to work with files that have multiple problems. For example, see the errors below in the filesystem library. Comments? --Beman filesystem libs/filesystem/doc/faq.htm: *LINK* unknown bookmark: #global libs/filesystem/doc/i18n.html: *LINK* unknown bookmark: #Footnote *LINK* unknown bookmark: #status libs/filesystem/doc/index.htm: *LINK* unknown bookmark: #path libs/filesystem/doc/reference.html: *LINK* duplicate bookmark: exists *LINK* duplicate bookmark: initial_path *LINK* unknown bookmark: #basic_directory_entry-comparisons *LINK* unknown bookmark: #operator-eq libs/filesystem/test/deprecated_test.cpp: *APPLE-MACROS* violation of Boost apple-macro guidelines on line 21 *APPLE-MACROS* violation of Boost apple-macro guidelines on line 27 libs/filesystem/test/path_test.cpp: *APPLE-MACROS* violation of Boost apple-macro guidelines on line 34 *APPLE-MACROS* violation of Boost apple-macro guidelines on line 43

8 11

[1.42] Release Notes
by Daniel James 18 Jan '10

18 Jan '10

Hi, Just a quick reminder about the release notes. This is the ideal time to add them to 'boost_1_42_0.qbk' in: https://svn.boost.org/svn/boost/website/public_html/beta/feed/history/ Or if you send them to the list and I'll add them for you. It's helpful if they're added before the beta, so that beta testers know what needs testing. thanks, Daniel

2 3

[1.42.0] Ready for beta?
by Beman Dawes 18 Jan '10

18 Jan '10

How do we look for going ahead with the beta? Unless there are concerns, I'll start putting the beta together later today. --Beman

1 0

[interval containers (itl)] found review manager. New release on sourceforge
by Joachim Faulhaber 18 Jan '10

18 Jan '10

Dear list! I am pleased to announce that Hartmut Kaiser now supports my library of interval containers as review manager. Although this was not necessarily intended, the planned date for the review already found it's way into the review schedule. But this is unofficial as long as Hartmut has not done his announcement of the review period. In preparation to the review I have done some improvements mainly for documentation of the extended parts of the itl, so I have uploaded a new release to the itl's project page on sourceforge http://sourceforge.net/projects/itl/ There are a few corrections and additions to the quickbook docs of the core library itl which is submitted for review: http://herold-faulhaber.de/boost_itl/doc/libs/itl/doc/html/index.html For the extended parts there is a doxygen generated documentation http://www.herold-faulhaber.de/itl/index.html that now also contains a commented example for a law based test http://www.herold-faulhaber.de/itl/de__morgan_8cpp.html for people how are interested how this works. Any feed back, comments and suggestions are welcome. Best regards Joachim --------------------------------------------------------------------- Interval Template Library (ITL) | Boost.IntervalContainers --------------------------------------------------------------------- Availability: Project page at sourceforge: http://sourceforge.net/projects/itl/ Boost Vault: http://www.boostpro.com/vault/index.php?&direction=0&order=&directory=Conta… Boost Quickbook documentation (corelibrary itl) http://www.herold-faulhaber.de/boost_itl/doc/libs/itl/doc/html/index.html Doxygen Documentation (extensions itl_xt, validate) http://www.herold-faulhaber.de/itl/index.html The name ITL is provisional and will probably be changed to Boost.IntervalContainers after the review.

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[property_tree] stream_translator <-> lexical_cast
by Domagoj Saric 18 Jan '10

18 Jan '10

By scanning briefly through the property_tree implementation I noticed that it uses its own stream_translator<> class for string-to-other_type and vice verse conversions. The functionality seems very similar/overlapping to that of lexical_cast (and also uses streams), if this is true this part of property_tree should probably be refactored to use lexical_cast so that it gets implicitly 'fixed' when/if lexical_cast gets fixed (regarding the issues outlined in the previous relevant post). -- "That men do not learn very much from the lessons of history is the most important of all the lessons of history." Aldous Huxley

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Boost.Filesystem: basename function is not compatible with POSIX; potential for path-related security issues
by Steve M. Robbins 18 Jan '10

18 Jan '10

Hi, I got the following report [1] for Boost.Filesystem from a Debian user. Before entering into trac, I thought I'd ask whether this deviation from POSIX is by design or is a bug. Thanks, -Steve P.S. The original report is based on Boost 1.40, but I verified the same behaviour on Boost 1.41. [1] http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=565504 ----- Forwarded message from Roger Leigh <rleigh(a)debian.org> ----- Package: libboost-filesystem1.40.0 Version: 1.40.0-5 Severity: important The basename function is not compatible with the POSIX function by the same name: Path POSIX Boost test.real test.real test /usr/bin/perl perl perl /usr/lib lib lib /usr/ usr usr usr usr / / / . . .. .. . The test program is attached. Just compile with g++ -o testbasename -lboost_filesystem testbasename.cc http://www.opengroup.org/onlinepubs/000095399/functions/basename.html ??? It is not stripping trailing backslashes. ??? "if ph.leaf() contains a dot ('.'), returns the substring of ph.leaf() starting from beginning and ending at the last dot (the dot is not included). Otherwise, returns ph.leaf()". This is wrong, shown by the paths returned for "." ("") and ".." (".") above. The latter could lead to reading and writing using the wrong path, which could have security issues if used in a secure context. This might be justification for raising the severity of this bug. Looking at the API reference, it looks like extension() and basename() may be intended to be complementary and are for splitting a filename into its main part and extension part, *not* the directory and filename components of a path. This should probably be explicitly spelled out due to the dangerous confusion which may result if used inappropriately. In particular, "." and ".." definitely need special casing--these are not extension separators and basename should return them intact; extension() should return an empty string. I noticed this when converting schroot to use the boost convenience function instead of my own. For reference, this is my version: std::string sbuild::basename (std::string name, char separator = '/') { // Remove trailing separators std::string::size_type cur = name.length(); while (cur > 0 && name[cur - 1] == separator) --cur; name.resize(cur); // Find last separator std::string::size_type pos = name.rfind(separator); std::string ret; if (pos == std::string::npos) ret = name; // No separators else if (pos == 0 && name.length() == 1 && name[0] == separator) ret = separator; // Only separators else ret = name.substr(pos + 1); // Basename only // Remove any duplicate adjacent path separators return remove_duplicates(ret, separator); } A POSIX-compatible dirname() function would nicely complement a POSIX-compatible basename() function as an addition to boost::filesystem. It looks like these are orthogonal to the existing functionality, however. Regards, Roger -- System Information: Debian Release: squeeze/sid APT prefers unstable APT policy: (550, 'unstable') Architecture: amd64 (x86_64) Kernel: Linux 2.6.32-trunk-amd64 (SMP w/4 CPU cores) Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Versions of packages libboost-filesystem1.40.0 depends on: ii libboost-system1.40.0 1.40.0-5 Operating system (e.g. diagnostics ii libc6 2.10.2-5 Embedded GNU C Library: Shared lib ii libgcc1 1:4.4.2-9 GCC support library ii libstdc++6 4.4.2-9 The GNU Standard C++ Library v3 libboost-filesystem1.40.0 recommends no packages. libboost-filesystem1.40.0 suggests no packages. -- no debconf information #include <libgen.h> #include <boost/filesystem/convenience.hpp> #include <cstring> #include <iostream> #include <iomanip> int main () { const char *paths[] = { "test.real", "/usr/bin/perl", "/usr/lib", "/usr/", "usr", "/", ".", "..", 0 }; std::cout << std::setw(16) << std::left << "Path" << std::setw(16) << std::left << "POSIX" << std::setw(16) << std::left << "Boost" << '\n'; for (const char **path = &paths[0]; *path != 0; ++path) { char *bpath = strdup(*path); std::cout << std::setw(16) << std::left << *path << std::setw(16) << std::left << basename(bpath) << std::setw(16) << std::left << boost::filesystem::basename(*path) << '\n'; free(bpath); } return 0; } _______________________________________________ pkg-boost-devel mailing list pkg-boost-devel(a)lists.alioth.debian.org http://lists.alioth.debian.org/mailman/listinfo/pkg-boost-devel ----- End forwarded message -----

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String literals concatenation issue when using BOOST_CURRENT_FUNCTION
by vicente.botet 16 Jan '10

16 Jan '10

Hi, I want to define a macro as #define BOOST_CHRONO_DIGITAL_TIME_FORMAT(F) "\n" F " tokes %d day(s) %h:%m:%s.%n\n" #define BOOST_CHRONO_DIGITAL_TIME_FUNCTION_FORMAT BOOST_CHRONO_DIGITAL_TIME_FORMAT(BOOST_CURRENT_FUNCTION) I have a compile error with gcc(3.4.4 or 4.4.0) (Boost v1.41) in the following sentence const char* c= "\n" BOOST_CURRENT_FUNCTION " %d day(s) %h:%m:%s.%n\n"; C:\cygwin\boost_1_41_0\libs\chrono\example\digital_time_example.cpp: In function `int f1(long int)': C:\cygwin\boost_1_41_0\libs\chrono\example\digital_time_example.cpp:24: error: expected `;' before "__PRETTY_FUNCTION__" as well as const char* c= "\n" __PRETTY_FUNCTION__ " %d day(s) %h:%m:%s.%n\n"; The same code works as I expected with MSVC. The following code works well with gcc const char* c= "\n" "f" " %d day(s) %h:%m:%s.%n\n"; const char* c2= BOOST_CURRENT_FUNCTION; as well as this one const char* c= "\n" __FILE__" %d day(s) %h:%m:%s.%n\n"; Is there something wrong? Does gcc manage __PRETTY_FUNCTION__ and __FILE__ differently? Does someone knows a workaround? Best, _____________________ Vicente Juan Botet Escribá

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[python] const-correctness and get_signature
by Jim Bosch 16 Jan '10

16 Jan '10

I've been working on an idea to provide optional const-handling in boost.python wrapped classes. It's coming along pretty well, but I've run into one major sticking point: the get_signature functions that extract the argument types of member function pointers into mpl sequences remove any cv-qualification on the hidden 'this' argument. This seems to be intentional - from the comments in python/signature.hpp: // Note that cv-qualification is dropped from // the "hidden this" argument of member functions; that is a // necessary sacrifice to ensure that an lvalue from_python converter // is used. This doesn't actually seem necessary; for a normal wrapped class, the special-case lvalue converter will always be the highest priority, and for a const member function, supporting rvalue converters as a fall-back wouldn't do any harm that I can see (and would help me out considerably). Could this be a relic from before wrapped class lvalue conversions were handled as a special case? Anyhow, if my hypothesis is correct, and there isn't a need to drop the cv-qualifiers in get_signature, I'd like to make a ticket and submit a patch to change it - but I wanted to check here first to see if maybe that breaks something else. Thanks! Jim Bosch

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[release] files from previous releases (was: Re: [ Fusion ] Extra files in "release"?)
by Tobias Schwinger 15 Jan '10

15 Jan '10

Joel de Guzman wrote: > Marshall Clow wrote: >> Hey Joel -- >> >> I noticed that there are a bunch of fusion files that only exist in >> the release branch, and not in the trunk. >> Is that on purpose? > Thanks for reporting! Seems a "release procedure issue" to me; the trunk has apparently been copied over an old release where those files were still present and needed. Those files can be deleted from the release branch (gone from trunk since February 09, last changes on Fusion in June 09). I just read that the release branch is about to freeze so posting to boost.devel for the Release Managers to join in. Also, there might be similar issues for other libraries. >> boost/fusion/functional/adapter/detail/pow2_explode.hpp >> boost/fusion/functional/adapter/detail/pt_def.hpp >> boost/fusion/functional/adapter/detail/pt_undef.hpp >> boost/fusion/functional/adapter/unfused_generic.hpp >> boost/fusion/functional/adapter/unfused_lvalue_args.hpp >> boost/fusion/functional/adapter/unfused_rvalue_args.hpp >> boost/fusion/functional/generation/make_unfused_generic.hpp >> boost/fusion/functional/generation/make_unfused_lvalue_args.hpp >> boost/fusion/functional/generation/make_unfused_rvalue_args.hpp >> >> libs/fusion/doc/html/fusion/functional/adapters/unfused_generic.html >> libs/fusion/doc/html/fusion/functional/adapters/unfused_lvalue_args.html >> libs/fusion/doc/html/fusion/functional/adapters/unfused_rvalue_args.html >> libs/fusion/doc/html/fusion/functional/generation/functions/mk_unfused_genrc.html >> >> libs/fusion/doc/html/fusion/functional/generation/functions/mk_unfused_lvargs.html >> >> libs/fusion/doc/html/fusion/functional/generation/functions/mk_unfused_rvargs.html >> >> libs/fusion/doc/html/fusion/functional/generation/metafunctions/mk_unfused_genrc.html >> >> libs/fusion/doc/html/fusion/functional/generation/metafunctions/mk_unfused_lvargs.html >> >> libs/fusion/doc/html/fusion/functional/generation/metafunctions/mk_unfused_rvargs.html >> >> libs/fusion/test/functional/make_unfused_generic.cpp >> libs/fusion/test/functional/make_unfused_lvalue_args.cpp >> libs/fusion/test/functional/make_unfused_rvalue_args.cpp >> libs/fusion/test/functional/unfused_generic.cpp >> libs/fusion/test/functional/unfused_lvalue_args.cpp >> libs/fusion/test/functional/unfused_rvalue_args.cpp >> Regards, Tobias

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[python] patch modules_init.hpp to expand macros
by Neal Becker 15 Jan '10

15 Jan '10

This patch replaces use of ## and # with BOOST_PP_CAT and BOOST_PP_STRINGIZE. This is needed so that python module names can be programmatically generated. https://svn.boost.org/trac/boost/ticket/3843

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how to compile when using read_graphml
by Alexandre de Morais Amory 15 Jan '10

15 Jan '10

Hi, I've been trying to use the function from read_graphml from BGL. I am using the test case in http://lists.boost.org/Archives/boost/2007/04/119804.php as my first case study. Apparently it compiles ok, but there is a link error. See msg bellow: ====== aamory@gaph14:~/reps/test-tools/bgl/test/sandbox-bgl$ g++ reader_test.cc In file included from /usr/include/c++/4.4/backward/hash_set:59, from /usr/include/boost/graph/adjacency_list.hpp:25, from reader_test.cc:1: /usr/include/c++/4.4/backward/backward_warning.h:28:2: warning: #warning This file includes at least one deprecated or antiquated header which may be removed without further notice at a future date. Please use a non-deprecated interface with equivalent functionality instead. For a listing of replacement headers and interfaces, consult the file backward_warning.h. To disable this warning use -Wno-deprecated. /tmp/ccgvAjHU.o: In function `void boost::read_graphml<boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, VertexProps, boost::property<boost::edge_weight_t, double, boost::no_property>, boost::no_property, boost::listS> >(std::basic_istream<char, std::char_traits<char> >&, boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, VertexProps, boost::property<boost::edge_weight_t, double, boost::no_property>, boost::no_property, boost::listS>&, boost::dynamic_properties&)': reader_test.cc:(.text._ZN5boost12read_graphmlINS_14adjacency_listINS_4vecSES2_NS_9directedSE11VertexPropsNS_8propertyINS_13edge_weight_tEdNS_11no_propertyEEES7_NS_5listSEEEEEvRSiRT_RNS_18dynamic_propertiesE[void boost::read_graphml<boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, VertexProps, boost::property<boost::edge_weight_t, double, boost::no_property>, boost::no_property, boost::listS> >(std::basic_istream<char, std::char_traits<char> >&, boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, VertexProps, boost::property<boost::edge_weight_t, double, boost::no_property>, boost::no_property, boost::listS>&, boost::dynamic_properties&)]+0x3d): undefined reference to `boost::read_graphml(std::basic_istream<char, std::char_traits<char> >&, boost::mutate_graph&)' collect2: ld returned 1 exit status aamory@gaph14:~/reps/test-tools/bgl/test/sandbox-bgl$ ======= I guess there should be some library. Reading the doc in http://www.boost.org/doc/libs/1_38_0/libs/graph/doc/read_graphml.html it says that the lib "bgl-graphml" should be included, but I don't known where to find it. At the /usr/lib there is only the files libboost_graph-mt.a, libboost_graph-mt.so, libboost_graph-mt.so.1.38.0 It seems that the problem is just to correctly define the compilation command ... any help would be much appreciated. configuration: - boost 1.38.0 - ubuntu 9.10 64 bits - g++ 4.4.1 Thanks! Alexandre

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[iterator] iterator_facade reference type problem
by Phil Endecott 15 Jan '10

15 Jan '10

Dear All, I have a problem with boost::iterator_facade. Here's an example: say I'm implementing an associative container that stores a sorted vector of keys and a separate sorted vector of values: template <typename KEY, typename VALUE> class vecmap { std::vector<KEY> keys; std::vector<VALUE> values; I can make an iterator for this that stores one iterator for each of the vectors: class iterator: public boost::iterator_facade<iterator, std::pair<KEY,VALUE>, boost::bidirectional_traversal_tag> { std::vector<KEY>::iterator ki; std::vector<VALUE>::iterator vi; void increment() { ++ki; ++vi; } void decrement() { --ki; --vi; } .... But what do I do about the reference type? I can't use std::pair<const KEY,VALUE>& because I'm not storing the keys and values in that way. It's almost possible to use std::pair<KEY,VALUE> for a const_iterator, but not if you want to allow the user to change the value through the reference. What I think I want to use is std::pair<KEY,VALUE&> i.e. the key is returned by value and only the value is returned by reference. But when I try this I get various cryptic errors about references to references and mpl things. So, has anyone else tried to do something like this? I wonder if boost::reference could be part of the solution. Thanks for any suggestions, Phil.

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[graph][release][1.42] Debug code removal in release branch
by Jeremiah Willcock 15 Jan '10

15 Jan '10

A user reported some debugging code that had been left in Boost.Graph for a couple of releases. It is a simple patch and a really embarrassing bug to leave in. It is change 59005 in trunk: Index: read_graphviz_new.cpp =================================================================== --- read_graphviz_new.cpp (revision 59004) +++ read_graphviz_new.cpp (revision 59005) @@ -764,7 +764,7 @@ typedef boost::detail::graph::node_t vertex; typedef boost::detail::graph::edge_t edge; for (std::map<node_name, properties>::const_iterator i = r.nodes.begin(); i != r.nodes.end(); ++i) { - std::cerr << i->first << " " << props_to_string(i->second) << std::endl; + // std::cerr << i->first << " " << props_to_string(i->second) << std::endl; mg->do_add_vertex(i->first); for (properties::const_iterator j = i->second.begin(); j != i->second.end(); ++j) { mg->set_node_property(j->first, i->first, j->second); @@ -772,7 +772,7 @@ } for (std::vector<edge_info>::const_iterator i = r.edges.begin(); i != r.edges.end(); ++i) { const edge_info& ei = *i; - std::cerr << ei.source << " -> " << ei.target << " " << props_to_string(ei.props) << std::endl; + // std::cerr << ei.source << " -> " << ei.target << " " << props_to_string(ei.props) << std::endl; edge e = edge::new_edge(); mg->do_add_edge(e, ei.source.name, ei.target.name); for (properties::const_iterator j = ei.props.begin(); j != ei.props.end(); ++j) { @@ -782,7 +782,7 @@ std::map<subgraph_name, properties>::const_iterator root_graph_props_i = r.graph_props.find("___root___"); assert (root_graph_props_i != r.graph_props.end()); // Should not happen const properties& root_graph_props = root_graph_props_i->second; - std::cerr << "ending graph " << props_to_string(root_graph_props) << std::endl; + // std::cerr << "ending graph " << props_to_string(root_graph_props) << std::endl; for (properties::const_iterator i = root_graph_props.begin(); i != root_graph_props.end(); ++i) { mg->set_graph_property(i->first, i->second); } May I please put this into the release branch for 1.42? Thank you. -- Jeremiah Willcock

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