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

bad include guards
by Steven Watanabe 26 Jan '17

26 Jan '17

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

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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.

5 13

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

15 Apr '10

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

3 2

[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

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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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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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>

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[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

[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

[msm] scalability
by Christophe Henry 12 Jan '10

12 Jan '10

Hi Simon, > I think it would be worthwhile talking a little more about compile time performance in the documentation. You're right, I could explain more in the documentation. Unfortunately, the answer is not straightforward. The compilation time (and how far the compiler plays with us) depends on a number of factors: 1) the compiler 2) the compiler version 3) even your hardware (I get very different compile times on 2 different machines with the same processor) 4) the state machine structure and the chosen front-end 1) usually, g++ crashes later than VC and needed fewer workarounds 2) Surprisingly, g++4.2 > g++ 4.4. VC10 > VC9 > VC8 3) you will need RAM, especially with VC8 4) the compile-time is proportional to the number of transitions in the transition table and to the depth of the state machine (meaning submachine of submachine of...). EUML will cost you much more with VC than g++ as it implies a metaprogramming layer above the standard metaprogramming of the standard front-end and because the underlying decltype/typeof seems much better implemented with g++ (if you don't count the generated code size). A small test with VC9 in Release mode (and no other code) gave me: 20 transitions => 11s 30 transitions => 16s 40 transitions => 22s 50 transitions => 31s This is just to give you an idea as it can greatly depend on the factors named above. > Also I'd like to see some suggestions of how to improve compile times (and how factors including the number of entries in a transition table affect the compile time). There is just one solution: reduce the number of transitions. The best way to do it is using orthogonal regions. For example, if you see in your diagram many transitions to a single state based on the same event, you should factor them all into a second region. Adding submachines could help in some cases. On one hand, the compiler now has to generate code for a second machine, OTOH it reduces the number of transitions in the main one. This will only help if your submachine handles a small number of events, as Msm will add a row in the main table for every event of the submachines. If you can in exchange reduce the number of transitions, it can help. > Is there provision to split a machine across multiple compilation units (I assume not)? You unfortunately assume correctly, as what costs compile-time really is the heavy metaprogramming. > You include instructions for how to increase the maximum size of an MPL vector, but this only works up to 50 entries. What do we need to do to increase this further? This is pretty simple, we need to: - add a vector60/70/80....hpp in mpl/vector. - add a map60/70....hpp in mpl/map. - if more than 50 states, add vector60/70....hpp in fusion/vector This is pretty simple. If that helps, I can add them into the Msm sandbox as I already wrote them. We could also request a feature in the MPL. You will however not manage to increase the size of the transition table forever. At some point will almost every compiler crash in a big cloud of dark smoke. To give you an idea, I usually manage: - 60-80 transitions max with VC9. The exact point is variable on a number of different factors which are hard to understand. - probably less with VC8. VC8 will also quite fast need > 2GB RAM. - 80 transitions with g++4.2. It could probably manage more but I ran out of RAM. - 50-60 with g++4.4. Why 4.4 is in this case less good than 4.2 is a mystery to me. - In Debug mode, you'll see the compiler give up faster - Euml will also have an influence. > Euml looks really cool, but I'm getting an ICE when using it with 36 transitions in EumlSimple.cpp (12 and 24 work fine though) VC8 only has limited support for eUML for 3 reasons: - less than perfect metaprogramming capabilities - bad support for SFINAE - VC problems with decltype/typeof So yes, I would advise eUML for VC8 for only small state machines and without using complicated functors as actions/guards. VC9 would work much better, VC10 better than VC9 too (so Microsoft seems to be working on it). >One of my favourite features of boost::statechart is state local storage. It looks like this would have to be done manually in msm? Yes, this is not supported yet. However, Msm has always been developed very user-oriented and what users ask, they usually get it. Msm has from the beginning greatly gained from clever people suggesting new features and I will not stop the development after the review, whatever the outcome is. If you'd like a feature, I'd be happy to discuss a solution with you and implement it in the next version, thus making Msm more useful. > The library is looking really powerful and expressive (not to mention fast!) for small state machines. Thanks. This is the reason for the compile-times ;-) Christophe

5 5

[Boost.Build] Unexpected MSVC linker error
by Sergey Zubkovsky 08 Jan '10

08 Jan '10

Hi, I'm using bjam and VC++2008 Express Edition to build date_time library, for example. When I try to link it with my project I have the error: LINK : fatal error LNK1104: cannot open file 'boost_date_time-vc90-mt-gd-1_40.lib' The bjam's command line options are : --layout=tagged toolset=msvc The name of the genereated lib file is "boost_date_time-mt-gd.lib". The error doesn't occur if the "--layout" option is "versioned" or "system". It seems to me that the cause of this behavior is the following text in the file "boost\config\auto_link.hpp": #ifndef BOOST_AUTO_LINK_NOMANGLE # pragma comment(lib, BOOST_LIB_PREFIX BOOST_STRINGIZE(BOOST_LIB_NAME) "-" BOOST_LIB_TOOLSET BOOST_LIB_THREAD_OPT BOOST_LIB_RT_OPT "-" BOOST_LIB_VERSION ".lib") # ifdef BOOST_LIB_DIAGNOSTIC # pragma message ("Linking to lib file: " BOOST_LIB_PREFIX BOOST_STRINGIZE(BOOST_LIB_NAME) "-" BOOST_LIB_TOOLSET BOOST_LIB_THREAD_OPT BOOST_LIB_RT_OPT "-" BOOST_LIB_VERSION ".lib") # endif #else # pragma comment(lib, BOOST_STRINGIZE(BOOST_LIB_NAME) ".lib") # ifdef BOOST_LIB_DIAGNOSTIC # pragma message ("Linking to lib file: " BOOST_STRINGIZE(BOOST_LIB_NAME) ".lib") # endif #endif "-" BOOST_LIB_VERSION ".lib" is always added in the "pragma comment" directive, if BOOST_AUTO_LINK_NOMANGLE is undefined, of cause. Is this a bug? How can I workaround it if this is not a bug? Thank you.

4 6

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

26 Dec '09

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

8 10

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

17 Dec '09

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

11 23

[property] interest in C# like properties for C++?
by Peder Holt 17 Dec '09

17 Dec '09

I have implemented a prototype support for properties in C++. It has no space overhead as it manages to deduce the this pointer of the class owning it. Code sample: #include <boost/static_assert.hpp> #include <boost/property.hpp> #include <iostream> class class_with_property { public: //Implement property template template<typename Base> class property_with_a_sensible_name : public Base { public: void set(const double& a) { //Implement setting of the variable here. m_var=a; //You can access the owner of the property's this value by calling self(), e.g. self()->refresh(); } const double& get() const { return m_var; } private: double m_var; }; void refresh() { std::cout << "Refreshed"; } //Instantiate property template. These can be reused. BOOST_PROPERTY(class_with_property,property_with_a_sensible_name,property_name); }; //And usage: void test() { class_with_property cls; cls.property_name=54.3; BOOST_STATIC_ASSERT(sizeof(class_with_property)==sizeof(double)); } The trick used is the following: class my_class { public: class property_x { public: my_class* self() { //Find offset of member relative to my_class size_t offset=size_t(&((my_class*)0)->x); //Use this to deduce the address of my_class return reinterpret_cast<my_class*>(size_t(this)-offset); } }; property_x x; }; It currently support: Read/Write properties Read properties Write properties Not supported yet: indexed properties operator overloads for properties, e.g. my_class.property*my_class.property will currently fail. Regards Peder

17 64

Any interest in static plugins?
by Dave van Soest 16 Dec '09

16 Dec '09

Hi all, I created a template-based header-only library for creating static plugin systems. I'm wondering whether there would be any interest to include such a library in Boost. About static plugins: Static plugins are not as common as dynamic plugins, but they have some useful applications. Static plugins are a way to extend the functionality of a program or library without having to change the existing source files, just by adding a source file or object file, which is then linked statically against the already existing object files. Some reasons you might be doing this: - You don't have permission to change the existing source files. - You don't have the source files, only the object and header files. - You don't want to have to change existing sources every time you extend functionality. - Simply including or excluding the object file from the linking process adds or removes functionality from the program or library, leaving no traces inside. - Different configurations can be build easily this way. - Testing only the required functionality without having to build the full application. - And some other advantages it shares with dynamic plugins. If there appears to be any interest I will post more information and some code and code examples. Best regards, Dave van Soest

9 30

[function] Using boost::function when rtti is not available
by David Genest 15 Dec '09

15 Dec '09

Hi, Reposting this from the user mailing list, as it generated no comments. I am in a gaming build environment that has traditionally turned off rtti because of space and portability issues. But, I would like to use the very useful boost::function. On MSVC boost::function works, but fails on g++ for the ps3. I have read on the lists that it is possible to implement a rtti-less version, and that this is even wanted in the future. See: http://article.gmane.org/gmane.comp.lib.boost.devel/192378 And http://article.gmane.org/gmane.comp.lib.boost.devel/191945 I know of a lot of people that would like this dependency on rtti removed. My question to the list is: did anyone have a try at an implementation and could share it ? I have toyed with boost::function and sp_typeinfo.hpp and tried to replace occurrences of type_info in function_base.hpp, but I don't have enough understanding to finish the work and my early attempts have failed. As my current understanding goes, the function type could be generated with the sp_typeinfo trick. Is the sp_typeinfo.hpp route a viable one ? Thank you, David.

4 13

Review Request: boost.lockfree
by Tim Blechmann 14 Dec '09

14 Dec '09

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 hi all, since my first review request for boost.lockfree [1] was completely ignored, here a second version for review. the main differences are bug fixes provided by various people, trying to run boost.lockfree on different compilers/platforms. the original review request was: i would like to submit a small library of lock-free data structures for review. boost.lockfree provides implementations of lock-free data structures. lock-free data structures can be accessed by multiple threads without the necessity of blocking synchronization primitives such as guards. lock-free data structures can be used in real-time systems, where blocking algorithms may lead to high worst-case execution times, to avoid priority inversion, or to increase the scalability for multi-processor machines. boost.lockfree provides: * boost::lockfree::fifo, a lock-free fifo queue * boost::lockfree::stack, a lock-free stack updated links: the code is available from the boost vault: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=boost_… and from my personal git repository: git://tim.klingt.org/boost_lockfree.git http://tim.klingt.org/git?p=boost_lockfree.git the documentation is available at: http://tim.klingt.org/boost_lockfree/ would be nice if someone could add this library to the review schedule or even would be willing to manage a review ... best, tim [1] http://article.gmane.org/gmane.comp.lib.boost.devel/192779 - -- tim(a)klingt.org http://tim.klingt.org Avoid the world, it's just a lot of dust and drag and means nothing in the end. Jack Kerouac -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAksLtukACgkQdL+4qsZfVssO7wCfel+ro8wr9TXA5fCHdq3+Dv0z 47sAniqHVyaQ4m4vOwr1SyRp9liUr9Dh =FZao -----END PGP SIGNATURE-----

12 18

[rdb] 0.2.02
by Jean-Louis Leroy 14 Dec '09

14 Dec '09

I have uploaded a new release to the vault. It contains : * support for the float type. Internals have been cleaned up to make it easier to add new types * SQLGetData is not used anymore, result_set uses bound variables to read results I am a bit concerned about compilation time. Guess I'll have to take a look at the template profiler as well. I use float_ (note: underscore) for the variable type for receiving float values (and the length/null indicator). I am a bit tempted to switch to a convention that would prevent clashes with C++ names, e.g. Float or FLOAT. This would solve the problem of `select` clashing with the socket function from the C lib, e.g. : SELECT(p.id, p.name).FROM(p) ... Opinions on this ? Jean-Louis

6 9

Review Queue Needs Attention
by Tom Brinkman 11 Dec '09

11 Dec '09

Paul A. Bristow said >> Yes - *exposure* is the key to inspiring authors to refine their contributions. >> I've argued for some time for a 'experimental' or 'candidate' status. >> (And a state not damned with faint praise like 'unstable' - which is perhaps >> better described as 'likely_to_be_improved' rather than actively 'not stable'). >> We'd need a simpler review process to agree to put a library into this >> 'candidate state' from the 'sandbox state'. >> This would mean that when libraries are reviewed for full acceptance, they >> should have received much more use, feedback and refinement, and be really ready >> for use by those who want a 'release quality' stable product - including decent >> documentation. Agreed. Here is the current review queue. 1) Lexer Ben Hanson 2) Shifted Pointer Phil Bouchard 3) Logging John Torjo 4) Join Yigong Liu 5) Pimpl Vladimir Batov 6) Task Oliver Kowalke 7) Endian Beman Dawes 8) Meta State Machine (MSM) Christophe Henry 9) Conversion Vicente Botet 10) Sorting Steven Ross 11) GIL.IO Christian Henning 12) AutoBuffer Thorsten Ottosen 14) Log Andrey Semashev 15) String Convert Vladimir Batov 16) Move Ion Gaztañaga 17) Containers Ion Gaztañaga 18) Interval Containers Joachim Faulhaber 19) Type Traits Extensions Frédéric Bron 20) Interthreads Vicente Botet 21) Bitfield Vicente Botet 22) Lockfree Ivo 23) Faster Signam slots Helge Bahmann The number of review requests is far outstripping the number of volunteer review managers. Considering about six libraries per year are getting reviewed, this is well over a three year back log. And this does not even include some other libraries that have been discussed, but not included. There are alot of good ideas here, they should not be ignored. Some of these libraries have been in the queue for over 18 months. My idea to fix this is well known. I would like something similar to Paul's approach. Those of you who have argued against a "non-stable" branch of boost, how would you propose fixing this "review queue" problem.

11 25

review request: addition to type_traits library of is_less_comparable<T, U> and others
by Frédéric Bron 09 Dec '09

09 Dec '09

I would like to propose to your review the following addition to the type_traits library (at https://svn.boost.org/trac/boost/browser/sandbox/type_traits and http://dl.free.fr/tK0BwIzYy) The purpose of the addition is to add type traits to detect if types T and U are comparable in the sens of <, <=, >, >=, == or != operators, i.e. if t<u has a sens when t is of type T and u of type U (same for <=, >, >=, ==, !=). The following traits are added: is_equal_to_comparable<T,U> is_greater_comparable<T,U> is_greater_equal_comparable<T,U> is_less_comparable<T,U> is_less_equal_comparable<T,U> is_not_equal_to_comparable<T,U> The names are based on the corresponding names of the standard template library (<functional> header, section 20.3.3 of the standard). The code has the following properties: * returns true if t<u is meaningful and returns a value convertible to bool * returns false if t<u is meaningless. * fails with compile time error if t<u is meaningful and returns void (a possibility to avoid compile time error would be to return true with an operator, trick but this has little sens as returning false would be better) The compilation has been tested with g++ 4.3.2 and icpc 10.0 on linux 64 bits, g++ 3.4.4 on cygwin, mingw32 3.4.4 on cygwin. Regards, Frédéric

15 54

Meta State Machine library review starts Monday
by David Abrahams 07 Dec '09

07 Dec '09

Dear all, With apologies for making this announcement so close to the review start date... The review of the Boost.Msm library starts this Monday, November 23rd and ends the December 6th. Msm was written by Christophe Henry, inspired in part by the example in the book "C++ Template Metaprogramming" (http://boostpro.com/mplbook) About the library: Msm (Meta State Machine) is a library allowing the user to easily define high-performance, straightforward and readable UML2 finite state machines, while respecting the principles of efficiency and declarativeness of the original example. To that end, Msm offers several Domain-Specific Embedded Languages that strive to closely emulate a standard UML diagram. Msm supports a broad range of UML features: - state entry/exit - transition actions/guards - composite states - history - orthogonal regions - terminate states - deferred events - explicit entry/fork - entry/exit pseudostates - anonymous transitions - transition conflicts And several non-standard features to make the developer's life easier (interrupt states, query about the current state(s)). Msm (in its current version, 2.0) can be found: * in the sandbox (http://svn.boost.org/svn/boost/sandbox/msm/) * or in the vault: (http://www.boostpro.com/vault/index.php?directory=Msm) Everybody on this list is invited to participate in this formal review. I hope to see your review of Msm, including your vote on acceptance, and I welcome your participation in the ensuing discussions on the Boost developers' mailing list. Please always include in your review a vote as to whether the library should be accepted into Boost. Additionally please consider giving feedback on the following general topics: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? - With what compiler? - Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Regards, -- Dave Abrahams Meet me at BoostCon: http://www.boostcon.com Review Manager BoostPro Computing http://www.boostpro.com

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GGL review (JTF)
by Jonathan Franklin 07 Dec '09

07 Dec '09

=== What is your evaluation of the design? === The design seems to adequately capture important geometric concepts, such as dimensionality and coordinate systems, as well as numerical precision, etc. The 4-type overload for assign (center + radius for a sphere) deviates from the semantics of the 2-/3-arg versions, which I dislike. I have not reviewed any of the extensions, so perhaps there is a good reason doing this... Other than the fact that more people will probably use center+radius than 4-d polygons. Then again, assign is parameterized by the geometry type, so this is probably just an omission. Issues w/ units continue to nag at the back of my mind. However, specifying units for specific geometries (e.g. radians), and requiring consistency of units within a given geometry seems appropriate. Any design issues that would prevent strong robustness guarantees (without drastic refactoring) in the future should be identified and fixed prior to release. I *think* we are okay here, but have not put sufficient effort to make that call (because I don't need it). === What is your evaluation of the implementation? === I didn't have time to review the implementation, other than general poking-around in the code. I was happy to note that some of the functionality already works for k-dimensional euclidean geometries, even though it is technically not supported at the moment. And by k-dimensional, I mean k=4. :-) I didn't have time to push the limits. === What is your evaluation of the documentation? === In a nutshell, the documentation is inadequate, and IMO must be completed prior to release. I'm not sure whether it is best to require a mini-review, or some other process. A few anecdotes that illustrate the problem: The example code on the main page didn't compile, which isn't a problem in and of itself. However, it took an inspection of random code in the separate Examples section, and inductive reasoning to determine that I needed some additional includes beyond ggl.hpp to make the snippets work. I suggest a direct link to a working example program anywhere example code snippets are provided. I also had a bit of difficulty getting several algorithms to work, like union/intersection. The concepts were decently documented, however, translating the concepts to working code took some leg-work. The doxygen documentation seems incomplete. I expected a tab for functions, like union_inserter, but was only able to drill down to the functions by looking at the header docs. An algorithms page seems apropos. However, I couldn't find a page listing the available algorithms. I arrived at the union_inserter page via the doxygen-generated union.hpp header page. Average and worst case performance, as well as any known/suspected numerical issues or other bugs (such as the non-minimal result returned by union_inserter) IMO *must* be listed in the docs for each algorithm. This is the trade-off for not providing a 100% robustness guarantee. Even then, the pre/post conditions for algorithms must be specified, which seemed to be lacking from the docs. A note (personal opinion) regarding Doxygen documentation: Doxygen is best suited for a reference manual. For a User's/Programmer's guide, not so much. === What is your evaluation of the potential usefulness of the library? === This is a generally useful library across *many* domains. In particular, I am excited to make use of this library at work in our graphics/visualization infrastructure code, as well as our actual GIS features. In my academic research, I plan to make use of this library in statistical machine learning/data mining algorithms. However, it is a shame that the library lacks a first-class spatial index capability in it's present state (e.g. what is up for review). Even a relatively naive reference implementation using an R-tree would be useful to me. === Did you try to use the library? === Yup. * With what compiler? g++ (Ubuntu 4.4.1-4ubuntu8) 4.4.1 * Did you have any problems? The internal headers #include <ggl/blah.hpp>, which requires a -I<BOOST_ROOT>/boost directive, in addition to the usual -I required to find the boost headers. This needs to be fixed prior to release, such that only -I<BOOST_ROOT> is required. I am assuming that this is broken for the same reason that Barends chose not to put ggl in the boost namespace. Other than having to use the 'find' command to locate the appropriate headers for inclusion, and other documentation-related issues listed elsewhere in this review, I didn't experience much difficulty using the library. === How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? === On average, a couple hours a day, over the course of a week. Admittedly, I squandered too many hours justifying my own use case on the ML, which may have been better spent reviewing the implementation, and/or writing useful test cases. === Are you knowledgeable about the problem domain? === I have been a casual user (and occasional developer) of Computational Geometry and GIS algorithms at my current job for ~ 4 years. I have also taken a few (recent) graduate-level C.G. and numerical analysis courses. === Miscellany === The existing GGL mailing list(s) should probably be moved to boost/boost-users, and/or a boost-ggl list. Unless there is a compelling reason to maintain an external list (i.e. paid support, etc) , this will best serve the GGL users/developers. === Do you think the library should be accepted as a Boost library? === Yes, contingent on meeting a minimum level of documentation, as determined by the review manager and/or community. Thanks for putting so much work into this library! Jon

5 7

[Review] GGL review starts today, November 5th
by Hartmut Kaiser 07 Dec '09

07 Dec '09

Hi all, The formal review of the Generic Geometry Library (GGL) starts today, November 5, 2009 and will finish November 15, 2009. GGL is being developed by Barend Gehrels, Bruno Lalande and Mateusz Loskot, with substantial input from this Boost mailing list. ------------------------------------------------ About the library: GGL defines concepts for geometries and implements some algorithms on such geometries. GGL is header-only, and can be applied in all software where geometry plays a small or a larger role. Users of the library can use just only one function, such as distance: int a[2] = {1,1}; int b[2] = {2,3}; double d = ggl::distance(a, b); Library users can also use the library in combination with std::vector, boost::tuple's and boost::ranges, such as: std::vector<boost::tuple<double, double, double> > line; line.push_back(boost::make_tuple(1, 2, 3)); line.push_back(boost::make_tuple(4, 5, 6)); line.push_back(boost::make_tuple(7, 8, 9)); double length = ggl::length(line); GGL can also be used in combination with custom or legacy geometries, adapting them to the library specializing traits classes or using registration macro's. Formally, GGL contains a dimension-agnostic, coordinate-system-agnostic and scalable kernel, based on concepts, meta-functions and tag-dispatching. On top of that kernel, algorithms are built: area, length, perimeter, centroid, convex hull, intersection (clipping), within (point in polygon), distance, envelope (bounding box), simplify, transform, convert, and more. The library is also designed to support high precision arithmetic numbers, such as GMP. The GGL might be used in all domains where geometry plays a role: mapping and GIS, gaming, computer graphics and widgets, robotics, astronomy... The core is designed to be as generic as possible and support those domains. However, for now the development has been mostly GIS-oriented. The GGL team proposes an extension model, very similar to what is used by GIL. The proposal as it is in the Boost Sandbox included three extensions: - SVG because it is used in the samples and to generate the documentation - WKT because it is used in the tests - The geographic coordinate system because it is used in some of the examples, also showing how other coordinate systems can be implemented There are more extensions, not included now, a.o.: - Spatial index - Map projections The proposed GGL has seen four previews, many discussions and many changes in design and implementation, based on those discussions. Previews were published on this list January '08, March'08, October'08 and February'09. GGL can be found in the sandbox https://svn.boost.org/svn/boost/sandbox/ggl/formal_review, including source code, examples, unit tests and documentation. Documentation can also be found online: http://geometrylibrary.geodan.nl/formal_review ------------------------------------------------------- Everybody on this list is invited to participate in this formal review. I hope to see your review of this library, including your vote, and I welcome your participation in the discussions on the Boost mailing list. Please always state in your review, whether you think the library should be accepted as a Boost library. Additionally, please consider giving feedback on the following general topics: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Regards Hartmut Review Manager ------------------- Meet me at BoostCon http://boostcon.com

20 78

[chrono] type_traits/common_type and integer/ratio
by Vicente Botet Escriba 06 Dec '09

06 Dec '09

Hi, I'm looking on how to continue with the Boost.Chrono library and I would like to know if * Boost.TypeTraits could take care of the common_type class template. * Boost.Integer could take care of the ratio class template. In this way Boost.Chrono will contain only the time related facilities, duration, time_point and Clocks. In order to minimize the task and been able to purpose as soon as possible the library for review I would like to concentrate on the implementation of the standard proposal and let for a future release the facilities Beman added as * Class template timer, with typedefs: * `system_timer` * `monotonic_timer` * `high_resolution_timer` * Process clocks and timers: * `process_clock`, capturing real, user-CPU, and system-CPU times. * `process_timer`, capturing elapsed real, user-CPU, and system-CPU times. * `run_timer`, convenient reporting of process_timer results. What do you think about this approach? Best, Vicente -- View this message in context: http://old.nabble.com/-chrono--type_traits-common_type-and-integer-ratio-tp… Sent from the Boost - Dev mailing list archive at Nabble.com.

6 19

Notice: Boost.Atomic (atomic operations library)
by Helge Bahmann 05 Dec '09

05 Dec '09

Hello, as promised I have started extracting an atomic operations library. Current state is available at: http://www.chaoticmind.net/~hcb/projcets/boost.atomic It implements boost::atomic<TYPE> which faithfully mimics std::atomic<TYPE> as specified in the C++0x draft standard. As allowed by the standard, operations transparently fall back to locking when the underlying architecture does not support the requested operation, so the library already contains a "fallback" implementation that works an all platforms (using mutex from boost::thread). It currently natively supports gcc/x86, gcc/powerpc and gcc/alpha (I can vouch for the correctness of the implementations on these targets). It contains some entirely untested support for building implementations from CAS operations on other systems (e.g. _InterlockedCompareExchange on win), so I would greatly appreciate any feedback if it works/doesn't on any particular platform. There is some preliminary documentation, but not in boostdoc format -- after unsuccessfully struggling with bjam/boostbook & friends for a few hours I simply gave up and reverted to trusty old doxygen :( Is there any step-by-step guide on how to create, build and document a new library? I could really use that as the boost build and documentation system is pretty alien to an autotools-accustomed guy like me. Best regards Helge

10 33

[explore] Library Proposal: Container Streaming
by Jeffrey Faust 03 Dec '09

03 Dec '09

Jared McIntyre, Danny Havenith, and myself, with support from Jeff Garland have developed a library to stream standard containers to output streams. We would like to submit this for review. The requirements for this library were gathered at the BoostCon 2007 Library in a Week sessions. An initial review was held and further requirements were gathered at BoostCon 2008. Everything can be found in the boost vault <http://www.boostpro.com/vault/> . Here is a direct link to explore.zip <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=ex plore.zip&directory=&> . Some quick examples: #include <boost/explore.hpp> # include ... // simple vector example std::vector<int> vi; vi.push_back(1); vi.push_back(2); vi.push_back(3); std::cout << vi; // prints [1, 2, 3] // lets do some containers in containers std::vector<std::vector<int> > vvi; vvi.push_back(vi); vvi.push_back(vi); std::cout << vvi; // prints [[1, 2, 3], [1, 2, 3]] // associative containers std::map<std::string, int> si_map; si_map["hello"] = 1; si_map["world"] = 2; std::cout << si_map; // prints [hello:1, world:2] // containers of complex types std::list<date> dl; // date from boost::gregorian dl.push_back(date(2007, Jan, 1)); dl.push_back(date(2007, Jan, 3)); std::cout << dl; // prints [2007-Jan-1, 2007-Jan-3] // how about some boost container types: boost::array<std::string, 2> sa2; sa2[0] = "one"; sa2[1] = "two"; std::cout << sa2; // prints [one, two] Jeffrey Faust

27 56

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

02 Dec '09

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

9 63

[fiber] new version in vault
by Oliver Kowalke 01 Dec '09

01 Dec '09

I've uploaded a new version of boost.fiber - main features are: - multiple schedulers can be used in one thread - user can provide its own scheduler implementation as template argument to class scheduler - classes disable_interruption and restore_interruption moved into namespace boost::this_fiber regards, Oliver

6 29

BOOST_MSVC vs. _MSC_VER wrt #pragma warning
by Emil Dotchevski 01 Dec '09

01 Dec '09

I understand that BOOST_MSVC is needed to detect MSVC because other compilers besides MSVC define _MSC_VER. But what about #ifdefing #pragma warning, should it use _MSC_VER or BOOST_MSVC? The reason why the ifdefing is needed is to prevent GCC and other compilers issuing a warning about #pragma warning, but presumably compilers that have _MSC_VER defined wouldn't warn about that, would they? -- Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode

2 1

[1.42.0] Release branch open for merges
by Beman Dawes 01 Dec '09

01 Dec '09

The release branch (https://svn.boost.org/svn/boost/branches/release) is open for merging all stable changes from trunk, including bug fixes and major upgrades to existing libraries. Breaking changes should be coordinated via the mailing list with the developers of the other libraries affected. New libraries may be added, but require permission of a release manager. In other words, merging *does not* require permission from a release manager, except for new libraries. Boost Calendar with the release schedule: http://www.boost.org/development/index.html Release schedule explanation: http://svn.boost.org/trac/boost/wiki/ReleaseSchedule Release practices for developers: http://svn.boost.org/trac/boost/wiki/ImprovingPractices -- The Release Managers, Beman Dawes Daniel James Eric Niebler Rene Rivera Vladimir Prus

3 3

[msm] Review
by Christophe Henry 01 Dec '09

01 Dec '09

Hi Juraj, First of all, thank you for being the first one to write a review. I imagine it's not an easy thing. Thank you also for bringing a few very interesting points to the discussion. I'm happy to build on them and hope to finally start some discussion. >MSM does lack some of the SC functionality. >There is no state-local storage in SC sense, as all states are >constructed when main state machine is constructed. This can be easily >worked around though. As this point is being brought for the second time, I'd like to spend some time on it. You already have state local storage with msm, just not like with SC. Like SC, msm defines states as classes, meaning they can have data. There is however one important difference with SC. Msm builds all the states upon state machine creation. States are not destroyed until state machine destruction. This has advantages and disadvantages: - states must be default-constructible - you might need to heap allocate the state data if you cannot initialize it at state construction. + speed: states don't need to be constructed again and again. Constructing a state (and its attributes) each time it becomes active can be costly, even if memory allocation can be optimized. + your state data is always available. In my experience, state data is not only needed in the entry or when the next event is processed, but during a transition or even at some time after a transition. This means, that you have, during a transition, access to data from the source or the target state. + combined with the visitor, you can at any time access data from the currently active state and build a generic way to do something with state data. + you can build examples like the iPodSearch where states keep iterators to some container, thus keeping information from an iteration to the next one. + you avoid having data released inside a destructor. Knowing that destructors should not throw, it makes your life easier. + on_entry is templatized, giving you more leeway to add event-specific handling. + your event data is not lost upon state entry Msm's handling is hard to emulate with SC, on the other hand, SC's handling is easy to emulate with Msm. It has its drawbacks but all considered, I think it is a superior solution. >It is impossible to stop event from propagation (SCs discard_event()) >without actually changing state. It is true. At the moment you cannot. Actually, I don't think UML foresees this possibility. OTOH, I think it is an interesting one and will be happy to borrow it from SC. I think that using the transition table is one of Msm's biggest strengths so I offer to add a row or a functor allowing event propagation to be stopped. You could even give it a guard, thus allowing fine-grained transition conflict resolution. > You cannot conditionally defer an event. Again you're right. I think UML doesn't foresee this either, but I also like it and will also borrow it from SC. You offered the idea of a d_row (deferred row) or dg_row (the same with a guard). I think it is the best possibility with the simplest front-end and makes deferred events a first-class citizen, being in the transition table and coming into play during conflict resolution. For the functor and eUML front-ends I think it could be done as an execution row. Something like: State1() + Event1() / defer_() Seems an interesting starting point. >There seem to be some differences on how event deferral is handled when > composite states are used. This part is a still bit mysterious to me. I will add a part about the dispatch algorithm to the documentation. >Aesthetically - I'm not a great fan of one big fat html documentation > and would prefer to have it broken down and cross-referenced as most > boost libraries docs are organized, but this is just a minor issue. If Msm is accepted into Boost, I'd probably move to BoostBook anyway, so this will be done at this time. > The author seems masochistic enough to try to tackle this. :) Sure :) and I don't mind the term at all :) Thanks for the review and the very good points you brought during the last weeks! Regards, Christophe

3 2

Re: [boost] [msm] Review
by Christophe Henry 30 Nov '09

30 Nov '09

Hi Sebastian, > I know nothing about MSM and very little about state machines in > general, but if all states are constructed at SM instantiation time, > would it be possible to pass the SM constructor a tuple of constructed > states that are copied/moved into the internal states? In theory it'd be possible because MSM stores the states in a fusion::set, which can be constructed from a forward sequence. And according to the fusion doc, a tuple can be adapted to a forward sequence. So I suppose it'd work. The problem would be to find an acceptable syntax because a msm::back::state_machine already has a templated constructor used to pass arguments to the front-end, for example: struct player_ : public msm::front::state_machine_def<player_> { player_(int some_value){…} } typedef msm::back::state_machine<player_ > player; player p(3); So we'd need to pass the tuple as extra argument, the first or the last one and add a bit of SFINAE to check if this argument is a tuple. > Would it be worth the effort? I don't know. It has never been requested so it's hard to know, but I find the idea quite interesting. Let's make a quick poll (which I'll shamelessly use as a way to make the review slightly more alive). Would someone make use of this feature? Christophe

1 0

Re: [boost] Meta State Machine library review starts Monday
by Christophe Henry 30 Nov '09

30 Nov '09

> Why the transition table uses non-type template parameter for actions > and guards instead of using a agreed function name for handling events > in states? Thinking further about it, do you mean like Statechart's react function? It'd be possible of course, I even imagined adding a SC-like frontend. The problem is, when your fsm becomes bigger, you might find out that following what your fsm is doing is harder because you have to look in many different places in your code. On the opposite, having more information in the transition table will help you have a better view of the structure of your state machine when it gets bigger. The other drawback (in my opinion) of SC's react, is that it automatically forces on you some forward state declaration as a state will need to know all of its possible followers. It also prevents reuse of states or composites in another fsm. And finally, my biggest worry about such a react function is that it becomes harder to build a GUI which can generate your code from a diagram and next to impossible to parse back the code into a model, so it 's not an ideal approach for Model-Driven development. A transition table, on the other side, makes it pretty simple to build a tool whose job is model <-> code development (both ways). Regards, Christophe

1 0

[program_options] Formatting; split at space
by Chard 30 Nov '09

30 Nov '09

Function: format_paragraph File: options_description.cpp, line 423: if (last_space != line_begin) { // is last_space within the second half ot the // current line if ((unsigned)distance(last_space, line_end) < (line_length - indent) / 2) // "- indent" ? { line_end = last_space; } } I'm given to understand that the code around here is designed to split the description at a space, iff the space occurs at least half-way through the description text. The code currently subtracts the indent from the line_length, where the line_length (within format_paragraph) represents the space available for the description (indent has already been subtracted from line_length at the beginning of format_paragraph). The result is that the longer the option names, the less chance of the split occurring at a space within the description. Was this the intention? E.g. if an option is 40 chars long, then there is no chance of it splitting at a space (for 80 column default).

2 1

property_tree equal_range causes compiler error
by YuQian Zhou (周宇前) 30 Nov '09

30 Nov '09

add to boost/libs/property_tree/examples/debug_settings.cpp: line 55 pt.equal_range("debug.level"); then compile: ~/boost/libs/property_tree/examples$ g++ -I../../../ debug_settings.cpp -o debug_settings ../../../boost/property_tree/detail/ptree_implementation.hpp: In member function ‘std::pair<typename boost::property_tree::basic_ptree<Key, Data, KeyCompare>::assoc_iterator, typename boost::property_tree::basic_ptree<Key, Data, KeyCompare>::assoc_iterator> boost::property_tree::basic_ptree<Key, Data, KeyCompare>::equal_range(const Key&) [with Key = std::basic_string<char, std::char_traits<char>, std::allocator<char> >, Data = std::basic_string<char, std::char_traits<char>, std::allocator<char> >, KeyCompare = std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >]’: debug_settings.cpp:55: instantiated from here ../../../boost/property_tree/detail/ptree_implementation.hpp:449: error: ‘class boost::multi_index::detail::bidir_node_iterator<boost::multi_index::detail::ordered_index_node<boost::multi_index::detail::index_node_base<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::property_tree::basic_ptree<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::allocator<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::property_tree::basic_ptree<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > > > > >’ has no member named ‘base’ ../../../boost/property_tree/detail/ptree_implementation.hpp:449: error: ‘class boost::multi_index::detail::bidir_node_iterator<boost::multi_index::detail::ordered_index_node<boost::multi_index::detail::index_node_base<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::property_tree::basic_ptree<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::allocator<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::property_tree::basic_ptree<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > > > > >’ has no member named ‘base’

2 1

Can someone with Visual Studio take a look at bug #1076, please?
by Marshall Clow 30 Nov '09

30 Nov '09

There is a test case attached to the bug: https://svn.boost.org/trac/boost/ticket/1076 Thanks! -- Marshall

3 3

Status of the bug sprint....
by Marshall Clow 30 Nov '09

30 Nov '09

for Thursday, November 19th. Yesterday, 859 open tickets. Today, 861 open tickets. That's not the direction that we want to go, folks. ;-) -- Marshall

7 26

Compiler Warnings Tests
by Paul A. Bristow 30 Nov '09

30 Nov '09

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] > On Behalf Of Robert Ramey > Sent: Friday, November 27, 2009 5:07 PM > To: boost-users(a)lists.boost.org > Cc: boost(a)lists.boost.org > Subject: Re: [Boost-users] Compiler warnings from Macs, IBM acc, Borland, Comeau, > Metroworks, et al - are they a Problem? > > I know this suggestion has been made but I want to expand a little on it. > > a "library" - warning policy test. This would be just like any other > library as far as the testing system goes. It would have maybe > 10? small compile only tests which would emit warnings or not. > The source would describe which warning is in fact being tested. > > Presumably, the test matrix would permit one to look at the warning > messages. (I'm not sure that the current one does this). > > In anycase, it would permit the test matrix be used to check > the warning status for each warning on each compiler at > a specified warning level. > > I see this as the only way to get a real grip on how these things > vary among the array of compiler's we might use. > > I realize that it would be some work, but I would think it wouldn't > be all that much more - if any - than that which has already been > expended on the wiki. It would have the great advantage of > being relatively free of "maintainence by hand". It would automate > the whole process of determining the status of different compilers > in this area. OK I can see some merit in this (now I understand your proposal a bit more). And I'm starting a new thread for Compiler Warnings Tests The Microsoft docs examples might be a good start? // C4244_level4.cpp // compile with: /W4 == actually warnings = all (warnings = errors will allow normal fail testing if it isn;t possible to check for warnings?) // AND MS extensions off? int aa; unsigned short bb; int main() { int b = 0, c = 0; short a = b + c; // C4244 bb += c; // C4244 bb = bb + c; // C4244 bb += static_cast<unsigned short>(aa); // C4244 bb = bb + static_cast<unsigned short>(aa); // OK } So are you proposing a collection of these, with versions that should compile and others that should not, for example: int main() { int b = 0, c = 0; short a = b + c; // C4244 } and another with int main() { int b = 0, c = 0; short a = static_cast<short>(b + c); // OK - NO C4244 } all run by a jamfile.v2. Or am I still misunderstanding you? Vicente has said he will think about it. I will also give it some more thought. Paul --- Paul A. Bristow Prizet Farmhouse Kendal, UK LA8 8AB +44 1539 561830, mobile +44 7714330204 pbristow(a)hetp.u-net.com --- Paul A. Bristow Prizet Farmhouse Kendal, UK LA8 8AB +44 1539 561830, mobile +44 7714330204 pbristow(a)hetp.u-net.com

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[buiild] stop on first error
by Vladimir Prus 30 Nov '09

30 Nov '09

As of today, if you run: ./bootstrap.sh ./bjam in trunk, then the build will immediately stop on any error. The same is true with bootstrap.bat on Windows. The previously behaviour was to continue building other targets that don't depend on the failed one. The "keep going" behaviour has some good properties, for experienced users, but for new users of Boost, it was sufficiently confusing: - It's easy to miss compilation error, and then you learn that something has failed at the end of build - There's no clean at-the-end summary of what has failed, and what to do - Some users don't even know how to capture build output for further analysis, and the build output, with all the errors, can easily overflow scrollback buffers of console windows The new behaviour is implemented by writing an option into project-config.jam. Anybody who wants the old behaviour can edit that file, or pass --keep-going on the command line. The change does not affect regression tests. - Volodya

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[filesystem][iostreams][program_options] linker issues on msvc
by Alexander Arhipenko 30 Nov '09

30 Nov '09

Guys, We use boost.build not only for building boost but also to create own binary packages. For a long time I observe linker errors on msvc due to lack of usage requirements in Jamfile's. Issue is reproduced when somebody builds executable like this: exe foo : main.cpp /boost/filesystem ; #or /boost/program_options or /boost/iostreams Following trivial patch resolves these issues: Index: libs/program_options/build/Jamfile.v2 =================================================================== --- libs/program_options/build/Jamfile.v2 (revision 57802) +++ libs/program_options/build/Jamfile.v2 (working copy) @@ -1,6 +1,9 @@ project boost/program_options : + usage-requirements + <link>shared:<define>BOOST_PROGRAM_OPTIONS_DYN_LINK=1 + : source-location ../src ; @@ -17,4 +20,4 @@ <link>shared:<define>BOOST_PROGRAM_OPTIONS_DYN_LINK=1 # tell source we're building dll's ; Index: libs/filesystem/build/Jamfile.v2 =================================================================== --- libs/filesystem/build/Jamfile.v2 (revision 57802) +++ libs/filesystem/build/Jamfile.v2 (working copy) @@ -11,6 +11,7 @@ project boost/filesystem : source-location ../src : usage-requirements # pass these requirement to dependents (i.e. users) + <library>/boost/system <link>shared:<define>BOOST_FILESYSTEM_DYN_LINK=1 <link>static:<define>BOOST_FILESYSTEM_STATIC_LINK=1 ; @@ -29,4 +30,4 @@ : ; Index: libs/iostreams/build/Jamfile.v2 =================================================================== --- libs/iostreams/build/Jamfile.v2 (revision 57802) +++ libs/iostreams/build/Jamfile.v2 (working copy) @@ -7,7 +7,11 @@ # See http://www.boost.org/libs/iostreams for documentation. -project /boost/iostreams : source-location ../src ; +project /boost/iostreams + : usage-requirements + <link>shared:<define>BOOST_IOSTREAMS_DYN_LINK=1 + : source-location ../src + ; # The biggest trick in this Jamfile is to link to zlib and bzip2 when # needed. To configure that, a number of variables are used, which must Regards

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Crazy Borland/Codegear long long behaviour?
by John Maddock 30 Nov '09

30 Nov '09

I'm having a load of trouble getting Boost.Integer to play nice with the Borland/Codegear compilers, for example given: void print_val(long long l) { std::cout << std::hex << static_cast<int>((l & 0xFFFFFFFF00000000LL) >> 32); std::cout << std::hex << static_cast<int>((l & 0xFFFFFFFFLL)) << std::endl; } And then: static const long long MaxValue = SCHAR_MAX; static const long long sll = _LLONG_MAX; const long long cll = _LLONG_MAX; long long ll = _LLONG_MAX; BOOST_TEST(MaxValue <= ::boost::integer_traits<boost::long_long_type>::const_max); // fails BOOST_TEST(MaxValue <= _LLONG_MAX); // passes BOOST_TEST(MaxValue <= sll); //fails BOOST_TEST(MaxValue <= cll); // fails BOOST_TEST(MaxValue <= ll); // passes print_val(_LLONG_MAX); // OK prints 7fffffffffffffff print_val(ll); // OK prints 7fffffffffffffff print_val(sll); // Oh no, prints ffffffffffffffff print_val(cll); // Oh no, prints ffffffffffffffff So as soon as a long long is declared const (whether static or not) it seems to be incapable of actually holding a sensible value!! Anyone got any ideas what's going on or any workarounds? Thanks, John. PS I'm still using Borland-5.8.2, but judging by the test matrix results the latest versions have similar issues.

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Re: [boost] Meta State Machine library review starts Monday
by Christophe Henry 29 Nov '09

29 Nov '09

Hi Felipe, > Why the transition table uses non-type template parameter for actions > and guards instead of using a agreed function name for handling events > in states? I'm not sure I understand the question. Please excuse (and correct) me if I miss the point. You mean, why not remove action and guards from the transition table and delegate all handling to a state (source or target)? Well, you can do this if you want, as there are already such methods defined, on_entry and on_exit. So theoretically you could use a _row, which has only source state / event / target state and delegate all work to on_entry and on_exit. It would work in some cases. However, you could also have the following: _row< State1, event1, State3>, _row< State2, event2, State3> and maybe _row< State1, event3, State4> Now you have a problem in State1 and 3. State3 can be the target of 2 transitions from 2 states and State1 can be the source of 2 transitions to 2 states. Where to add the common handling? It'll fatally end with some if/else on the event type. If you carefully choose your on_entry/exit, action and guard you will avoid this and get cleaner code with on_entry and on_exit (called each time a state is entered/left independently of the event) doing the work common to all transitions and the action/guard the work specific to one event. To be honest, as on_entry and on_exit are templatized on the event you could use SFINAE to handle event-specific tasks and get rid of actions and guards anyway but SFINAE isn't everybody's tool. If you feel good with them, then sure, why not? > That should get the transition table a lot smaller and maybe even > faster for not using a pointer (though speed-wise, that's a wild > guess). Luckily Msm allows you both ways :) You have a valid point with your wild guess. I'm unsure myself why but if you use the functor-based frontend, which is doing strictly the same, you will see some speed gain (about 20%) compared to the pointer version. I hope I could answer the question satisfactorily. Regards, Christophe

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