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

bad include guards
by Steven Watanabe 26 Jan '17

26 Jan '17

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

5 8

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

29 Apr '14

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

9 16

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

18 Nov '12

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

17 20

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

03 Nov '11

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

6 13

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

25 May '11

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

5 9

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

21 Feb '11

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

5 11

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

16 Feb '11

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

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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

4 9

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

19 Apr '10

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

5 13

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

15 Apr '10

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

3 2

Trac XMLRPC support
by Vladimir Prus 21 Mar '10

21 Mar '10

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

4 5

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>

5 10

[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

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

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

02 Dec '09

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

9 63

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

25 Nov '09

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

2 1

Preliminary submission: generic linear algebra algorithms library Boost LA
by Emil Dotchevski 23 Nov '09

23 Nov '09

I remember some past discussions on this mailing list about the need for similar library in Boost, so I hope it is OK to skip the interest query and request a preliminary review for Boost LA. Boost LA provides a set of generic linear algebra algorithms, primarily for working with vectors and matrices of static size. The library also defines vector and matrix data types, however it allows users to introduce their own types by specializing the vector_traits and matrix_traits templates. Documentation and source code available at http://www.revergestudios.com/boost-la, released under the Boost Software License. Thanks, Emil Dotchevski

9 25

[BGL] [variant] problem (and perhaps solution?) with strong_components.hpp and variant
by Nil Geisweiller 17 Nov '09

17 Nov '09

Hi, it seems the problem is indeed a conflict between the get function of variant.hpp and the get function of two_bit_color_map. After renaming get by getTEST in 1) two_bit_color_map.hpp line 61 2) breadth_first_search.hpp line 78 3) property_map.hpp line 164 the compiling error has disappeared. Of course it is certainly not the right way to fix that bug, maybe wrapping two_bit_color_map get (and alike) function name under some namespace... but I'm not confident enough to take such decision. Maybe there is a better way. Please if someone is more knowledgeable could help me fix that bug. Thanks for your help Nil On Tue, Oct 27, 2009 at 7:31 AM, Nil Geisweiller <ngeiswei(a)googlemail.com> wrote: > Hi, > > I resend that email with the right title header. > > ---------- Forwarded message ---------- > From: Nil Geisweiller <ngeiswei(a)googlemail.com> > Date: Sun, Oct 25, 2009 at 6:11 PM > Subject: [Graph] problem with strong_components.hpp and variant > To: boost(a)lists.boost.org > > > Hi, > > it seems there is a conflict between strong_components.hpp and > variant, maybe the method boost::get is wrongly overloaded. > > The problem occurs with 1.40 but not with 1.37, and it is still occurs > with the last svn. > > I attach a minimal code to reproduce the bug + compile error > > ###### > test.cpp > ###### > > //uncomment the line below to get the bug > #include <boost/graph/strong_components.hpp> > #include <boost/variant.hpp> > > typedef boost::variant < int, float > intorfloat; > > int main() { > int i(2); > intorfloat iof(i); > return boost::get<int>(iof); //problem is here > } > > ########### > compile error > ########### > > a-lin@a-lin-desktop:~/OpenCog/test/bin$ make > [100%] Building CXX object CMakeFiles/test.dir/test.cpp.o > In file included from /usr/include/boost/graph/graph_concepts.hpp:17, > from /usr/include/boost/graph/depth_first_search.hpp:18, > from /usr/include/boost/graph/strong_components.hpp:17, > from /home/a-lin/OpenCog/test/test.cpp:2: > /usr/include/boost/property_map/property_map.hpp: In instantiation of > ‘boost::property_traits<int>’: > /usr/include/boost/graph/two_bit_color_map.hpp:46: instantiated from > ‘boost::two_bit_color_map<int>’ > /home/a-lin/OpenCog/test/test.cpp:10: instantiated from here > /usr/include/boost/property_map/property_map.hpp:31: error: ‘int’ is > not a class, struct, or union type > /usr/include/boost/property_map/property_map.hpp:32: error: ‘int’ is > not a class, struct, or union type > /usr/include/boost/property_map/property_map.hpp:33: error: ‘int’ is > not a class, struct, or union type > /usr/include/boost/property_map/property_map.hpp:34: error: ‘int’ is > not a class, struct, or union type > make[2]: *** [CMakeFiles/test.dir/test.cpp.o] Error 1 > make[1]: *** [CMakeFiles/test.dir/all] Error 2 > make: *** [all] Error 2 > > Is it a bug? Thanks a lot! > Nil >

4 5

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

17 Nov '09

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

19 95

[Locale] Boost.Locale - preliminary code
by Artyom 16 Nov '09

16 Nov '09

Hello, I'm working on Boost.Locale project. Source code and some basic examples can be found here: https://cppcms.svn.sourceforge.net/svnroot/cppcms/boost_locale/trunk/ It still lacks of documentation and some features. It is mostly tested under Linux gcc-4.3 and it seems to work under MSVC-9 (however I had less tested it). General description: ==================== Boost.Locale is a library that brings high quality localization facilities in C++ way. It uses `std::locale`, and `std::locale` facets in order to pro- vide localization in transparent and C++ aware way to user. C++ has quite good base for localization via existing C++ locale facets: `std::num_put`, `std::ctype`, `std::collate` etc.. But they are very limited and sometimes buggy by design. The support of localization varies between different operating systems and incompatible between them. On the other hand, there is great, well debugged, high quality, widely used ICU library that gives all of the goodies but, it has very old API that mimics Java behavior, it is completely ignores STL and provides useful API only for UTF-16 encoded text, ignoring other popular Unicode encodings like UTF-8 and UTF-16, or limited national character sets like Latin1. Boost.Locale provides the natural glue between C++ locales framework, iostreams and powerful ICU library in following areas: - Correct case conversion, case folding and normalization (DONE) - Collation including support of 4 Unicode collation levels. (DONE) - Date and time formatting and parsing including support of timezones and calendars other then Gregorian. (DONE) - Number formatting, spelling and parsing (DONE) - Monetary formatting and parsing (DONE) - Powerful message formatting including support plural forms, using GNU catalogs. (DONE) - Character, word, sentence and line-break boundary analysis. (TODO) - Support of 8-bit character sets like Latin1 and UTF-8 encoded text. (DONE) - Support of `char`, `wchar_t` and C++0x `char16_t`, `char32_t` strings and streams. (DONE) ------------------------------------------------------------ FYI, It is still work in progress but 90% of the job is done. Please take a look on it --- especially experts in Windows programming. I would glad if someone explains me the process of submission and what should be done for it. I know that it is not yet Boost ready but it goes fast in this direction. Best, Artyom.

4 5

[mirror] C++0x version of the reflection library available
by Matus Chochlik 14 Nov '09

14 Nov '09

Dear list, I would like to announce that a new (alpha) version of the Mirror reflection library, re-written nearly completely from scratch in C++0x, is available at sourceforge.net for those interested, the code can be checked out from the SF repository: https://mirror-lib.svn.sourceforge.net/svnroot/mirror-lib/trunk/impl documentation pre-built with doxygen and DOT is available here: http://kifri.fri.uniza.sk/~chochlik/mirror-lib/html/ Based on a year and a half of user experience with the previous version (the one in Boost sandbox) there have been made several important changes. Just to mention a few: - The meta-objects should be more consistent with the base-level language - There is a run-time layer with an run-time interface very similar to the compile-time interface - Meta-object categories for tag dispatching have been added - "Local" names having parts of the nested name specifier stripped away if the Mirror's "using namespace" directive is used on the current (or parent) scope - C++0x features are extensively used to make things more straightforward - etc. This version does not yet implement all features from the previous version, like inherited class members, visitor-based traversals, meta-constructors and factory generators. These will be added in the near future. The library has been tested only with gcc (version 4.5.0 20091010) so I would be glad to hear about experiences with other compilers supporting C++0x. I would also appreciate any feedback, suggestions or other contributions. best regards, Matus

2 3

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

12 Nov '09

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

6 7

[BGL] Trying to get a correclty working Parallel BFS code
by Sandeep Gupta 11 Nov '09

11 Nov '09

Hi All, I have spent significant effort on parallel bfs. Currently its almost working. I would really appreciate some help to get it running correctly. I have attached the code (self contained and requires no input file). I think I have followed all the guidelines regarding distributed property maps mentioned in the docs ( http://www.osl.iu.edu/research/pbgl/documentation/graph/breadth_first_searc… ). I am out of ideas of where things can could have gone wrong. The correct output of input graph 0 --> 1 2 1 --> 2 3 2 --> 3 3 --> 4 6 4 --> 5 5 --> 6 --> should be Node ID : Level 0 : 0 1 : 1 2 : 1 3 : 2 4 : 3 5 : 4 6 : 3 But when ran with 2 processes the output comes out to be Node ID : Level 0 : 0 1 : 1 2 : 1 3 : 2 4 : 3 5 : 4294967295 6 : 3 Not sure why this is happening. Any suggestions or pointers would indeed be quite appreciated. Thanks for your time. -Sandeep

3 23

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

11 Nov '09

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

3 4

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

09 Nov '09

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

12 25

[function] "paranoia" vs efficiency
by Domagoj Saric 09 Nov '09

09 Nov '09

As far as I can see boost::function<>::operator() performs: if (this->empty()) boost::throw_exception(bad_function_call()); before invoking the stored function (object)... My question is why or why only this "checked"/"safe" approach/method of invocation exists? Because this: - causes (extra) code branching - causes the compiler to insert exception throwing and handling code in surrounding/calling code (which need not otherwise be if the function stored in the boost function instance is itself nothrow) - inserts a call to the bad_function_call constructor - disables the compiler from inlining the function (MSVC atleast) - disables NVRO (MSVC atleast, http://msdn.microsoft.com/en-us/library/ms364057(VS.80).aspx#nrvo_cpp05_top… ) while at the same time I would most often consider calling a "null-function-pointer" a programmer error (that would therefor need to be "handled" with an assert not an exception), not a runtime 'unpredictable' exception... ...IMO the default should be not to include this check (i.e. use an assert) and provide a safeInvoke() type of method for those users and cases that actually require/want this type of check/behaviour... ...or atleast "it would be welcomed" if a non-checking unsafeInvoke() type of method would be provided for those that are 'sure' that the boost::function<> object is valid (for example in the line before i've just performed the same check to decide whether to call the function object or not)... -- "That men do not learn very much from the lessons of history is the most important of all the lessons of history." Aldous Huxley

8 18

[system][filesystem v3] Question about error_code arguments
by Beman Dawes 07 Nov '09

07 Nov '09

A POSIX sub-group is looking at C++ bindings for POSIX. They are talking about a filesystem library binding at least loosely based on Boost.System, Boost.Filesystem, and C++ TR2. In looking at http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2838.html, "Library Support for Hybrid Error Handling (Rev 2)", they are concerned about specifying hybrid error handling like this: void f(error_code& ec=throws()); They would rather see it specified like this: void f(error_code* ec=0); One particular concern is that as currently worded, the N2838 proposal requires throws() return a null reference, which they see as relying on undefined behavior. I wasn't at the meeting where the LWG asked that a null reference be mandated; my reading of the standard is that it is unclear if returning a null reference is or isn't undefined behavior. Some of the core folks seem to think it is undefined, but compilers accept it. Although the reference form is usual for C++, the use of anything other than the default is limited, and usually in low-level code at that. Although I could personally live with either form, I'm leaning slightly toward the pointer form. Regardless, I'd like to hear Boosters views on the two interfaces above. Which do you prefer? Why? --Beman

24 102

New boost packaging suggestion for windows
by Julian Bangert 06 Nov '09

06 Nov '09

Hello, yesterday I tried to download the boostpro binaries for windows and I had to download over a gigabyte to get all configurations for VS 2008. Sadly the version also was outdated and in general not that great ( e.g. Installer quite bad to handle and you have to register to download ) . So I decided to build from source and package it for a few friends who also needed these binaries. I managed to compress boost_1_40 ( no source except headers, no python AFAIK , but everything else you get with a standard build ) from over 900MB down to 37MB by using 7z. I uploaded it here https://obliviononline.com/pub/boost/boost_1_40_0.7z . Should boost use this form of releasing binaries in the future for windows ? Alternatively, you could endorse this form, like boostpro is endorsed right now and I could host it on google code, etc . An easy to set up ( just unzip this file ) binary distribution would make compiling boost-dependent software much easier. I would be willing to distribute future releases compatible with VS 2005 and 2008 in this form. Yours, Julian Bangert __________ Information from ESET NOD32 Antivirus, version of virus signature database 4551 (20091028) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com

12 20

[1.41.0] Release branch closed for all changes; beta RC tomorrow
by Beman Dawes 05 Nov '09

05 Nov '09

The release branch is closed for all changes. Unless someone objects strenuously, I'll build a release candidate for the beta tomorrow (Tuesday) morning, eastern US time. --Beman

8 14

loglite - A logging library
by JD 04 Nov '09

04 Nov '09

Hello, It's been a while since a discussion about logging hasn't ran on the boost mailing list. I have a small logging library implementing some of the requirements that were previously deemed desirable during the discussion we had here a couple of years ago. Find it here : http://code.google.com/p/loglite/ I've removed all mention to boost in the code, cause I've made some design choice that wouldn't fit with the boost philosophy. Please have a look and let me know what you think could be improved. An example : [example removed because of the now infamous anti-top-posting gmane feature] Regards, JD

7 14

Build boot 1.40.0 on IBM z/OS (EBCDIC)
by norbert.hanke＠bluewin.ch 03 Nov '09

03 Nov '09

Hi folks, I am trying to build boost on the IBM Mainframe on z/OS USS. I successfully modified the jam bootstrap script and have a running bjam binary now. But when trying to build the boost libraries, I get the error below. Does anybody have a hint what to look for? EBCDIC character encoding on my machine might be the reason: digits 0-9 are encoded as character values 240-249, but I have no idea where to start looking. regards, Norbert > ./bjam /home/u250672/boost_1_40_0/tools/build/v2/util/numbers.jam:22: in numbers.check from module numbers error: 03 in 03 1 17 error: is not a number /home/u250672/boost_1_40_0/tools/build/v2/build/version.jam:50: in version-less from module version /home/u250672/boost_1_40_0/tools/build/v2/build/version.jam:102: in version.check-jam-version from module version /home/u250672/boost_1_40_0/tools/build/v2/util/path.jam:172: in join from module path /home/u250672/boost_1_40_0/tools/build/v2/util/path.jam:207: in path.root from module path /home/u250672/boost_1_40_0/tools/build/v2/util/path.jam:247: in path.glob from module path /home/u250672/boost_1_40_0/tools/build/v2/tools/types/register.jam:25: in load from module types/register /home/u250672/boost_1_40_0/tools/build/v2/kernel/modules.jam:283: in import from module modules /home/u250672/boost_1_40_0/tools/build/v2/tools/stage.jam:19: in load from module stage /home/u250672/boost_1_40_0/tools/build/v2/kernel/modules.jam:283: in import from module modules /home/u250672/boost_1_40_0/tools/build/v2/tools/builtin.jam:25: in load from module builtin /home/u250672/boost_1_40_0/tools/build/v2/kernel/modules.jam:283: in import from module modules /home/u250672/boost_1_40_0/tools/build/v2/build-system.jam:11: in load from module build-system /home/u250672/boost_1_40_0/tools/build/v2/kernel/modules.jam:283: in import from module modules /home/u250672/boost_1_40_0/tools/build/v2/kernel/bootstrap.jam:138: in boost-build from module /home/u250672/boost_1_40_0/boost-build.jam:16: in module scope from module

2 3

Temporary objects
by DE 03 Nov '09

03 Nov '09

hi all unfortunately i'm totally out of time now so i only write my proposal and an example forgive me for that the code #include <algorithm> template<typename type> class temporary : public type { temporary() : type() {} temporary(temporary &a) : type() { using std::swap; swap(static_cast<type&>(*this), static_cast<type&>(a)); } template<typename other> temporary(const other &a) : type(a) {} temporary &operator=(temporary &a) { using std::swap; swap(static_cast<type&>(*this), static_cast<type&>(a)); return *this; } template<typename other> temporary &operator=(const other &a) { type::operator=(a); return *this; } }; example1 temporary<huge_type> foo(const huge_type &a) {//returning temporary object temporary<huge_type> ret; //or even 'ret(a)' //doing something... return ret; } //... huge_type result; result = foo(bar); //somewhere in code only one copy operation -- assignment operator return by value copying overhead is eliminated with help of swap() example2 struct my_type { //... my_type(temporary<my_type> &a) { this->swap(a); } //... my_type &operator=(temporary<my_type> &a) { this->swap(a); return *this; } //... }; temporary<my_type> process(const my_type &item) { temporary<my_type> ret; //processing item... return ret; } //... my_type result = process(item); //somewhere in code //or result = process(item); no temporary object handling overhead at all return by value, copy-construct and assign from temporary objects for free! thank you for attention

7 21

Parallel Tree Merge
by Biddiscombe, John A. 03 Nov '09

03 Nov '09

If I have a representation of a tree and I have sub-portions of it spread across a number of processes (but the whole tree represents a well-formed and simple tree structure). Is there a reasonably straightforward way of doing this using BGL or PBGL. I had hoped that it might be as simple as defining some templated tree structure and using the add operator after gathering pieces onto one node. (The tree structure could be represented as XML where the root would exist on all processes, different sub-nodes and leaves and would occur on different processes - a simple xml merge would probably suffice for my needs right now). If examples using boost libraries ((p)BGL/MPI) or other similar combination exist and anyone can point me to resources I'd be most grateful. (I'm not an expert with BGL so will need some do some learning...) Thanks JB -- John Biddiscombe, email:biddisco @ cscs.ch http://www.cscs.ch/ CSCS, Swiss National Supercomputing Centre | Tel: +41 (91) 610.82.07 Via Cantonale, 6928 Manno, Switzerland | Fax: +41 (91) 610.82.82

3 3

#3541 Support <boost/ptr_map.hpp>
by Olaf van der Spek 02 Nov '09

02 Nov '09

Hi, https://svn.boost.org/trac/boost/ticket/3541 Could a forward header file be created such that #include <boost/ptr_map.hpp> works? The extra ptr_container directory is hard to remember..., I always have to look it up. boost/ptr_* looks much more natural. Greetings, Olaf

21 62

The C++ Post-Processor
by Christian Schladetsch 02 Nov '09

02 Nov '09

Hello, This is a general post about C++. Why is it that the pre-processor (PP) is the source of so much disdain, and yet it is the first resource exploited to 'fix' problems with C++? Why has the PP received so little attention over the years, from its early use as M4? This is a message to the powers that be: the PP is a powerful tool. It provides a 'context-cutting' mechanism for creating and extending solutions. It is a true "meta-programming" system built right into C++. No other language I can think of has a PP. This is often viewed as being a good thing, but I wonder more and more as I get older that a good PP is in fact needed to span some otherwise very difficult boundaries. Other languages are "dynamic" inasmuch as they reflect classes and allow for runtime changes to types and instances. I think we all here agree that this ability is counter to building firm, safe and efficient software. But the PP is similar to that, allowing a degree of dynamicy not otherwise available. Specifically, by exposing concepts to the PP we can leverage reflection and synthesis while building on inheritance and conglomeration. I don't have a point as such; I just wanted to raise the idea of developing M4 and the PP past where it is. There is a lot of low-hanging fruit there. This is evidenced by the fact that a lot of other languages are or can be transliterated to C++. Rather than thinking of C++ as the output, we could be thinking of C++ as the input. Perhaps a way forward for C++ is a good PP and a standards-based implementation of C++ in C++ so it can embed itself. I've written a number of languages, and in each I've had to address the issue of pre-processing. The latest attempts have resulted in a system where it parses and executes via AST input to produce an output that is then parsed by the same system to produce an AST that is then walked to eventually produce machine code. I think this model is best, and would be delighted to see some similar movements in the PP/C++. We have Boost.Wave to start with... Why not give it real Expressions? Loops? Scopes? Classes? Templates? memory management? IO? Is there any interest in a Boost.C++ ? Regards, Christian

15 30

[optional] layout
by Domagoj Saric 01 Nov '09

01 Nov '09

why is boost::optional laid out so that the bool comes before the object's placeholder/storage? this takes up to 7 extra bytes of storage with default alignement and, more importantly, it forces pointer offset adjustment/calculation when accessing a boost::optional<> through a pointer (and trying to access the actual contained object)... it also makes life harder for those of us keen to hackery ;) because it makes the address of an optional different from the address of the actual object within the optional... ps. it would be 'cool' if all of the functionality from boost::optional<> not related to the 'is initialized' bool (conditional destruction, etc...) could be extracted into a separate class (usefull for cases where you have to delay/in-place construct an object but are certain that you will construct it by the point where it needs to be used or destroyed...so you do not need the 'conditional' overhead)... -- "That men do not learn very much from the lessons of history is the most important of all the lessons of history." Aldous Huxley

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Re: [boost] loglite - A logging library (JD)
by Tan, Tom (Shanghai) 01 Nov '09

01 Nov '09

> Please have a look and let me know what you think could be improved. The first thing I notice is that it does not support std::wstring directly. It's a big problem in my case I use wide-character in all my applications, which simplifies dealing with UTF-16 adopted by Modern Windows platforms. If I need to any string info from my program, I'll have to convert from UTF16(represented as std::wstring) to UTF8 so that it could be working well with LOGLITE. That's inconvenient. Offtopic, I am expecting boost::filesystem V3 for this very same reason.

3 2

[ANN] CLI command line interface compiler for C++
by Boris Kolpackov 29 Oct '09

29 Oct '09

Hi, I am pleased to announce the first public release of CLI. CLI is an open-source (MIT license), cross-platform command line interface compiler for C++. It allows you to specify the options that your program supports, their types, and default values. For example: include <string>; class options { bool --help; std::string --name = "example"; unsigned int --level | -l = 5; }; This specification can then be automatically translated to C++ classes that implement parsing of the command line arguments and provide a convenient and type-safe interface for accessing the extracted data. For example: #include <string> class options { public: options (int argc, char** argv); options (int argc, char** argv, int& end); bool help () const; const std::string& name () const; unsigned int level () const; ... }; int main (int argc, char* argv[]) { options o (argc, argv); if (o.help ()) print_usage (); if (o.level () > 4) cerr << "name is " << o.name () << endl; ... } It is easy to start using CLI in your application since there are no external dependencies. You can compile your command line interface to C++ and simply add the generated files to your project's source code. For a five minute introduction to CLI, see the "Hello World" example in the CLI Getting Started Guide: http://www.codesynthesis.com/projects/cli/doc/guide/#2 More information, documentation, and source code distributions are available from the project's web page: http://www.codesynthesis.com/projects/cli/ Enjoy, Boris -- Boris Kolpackov, Code Synthesis Tools http://codesynthesis.com/~boris/blog Open-source XML data binding for C++: http://codesynthesis.com/products/xsd XML data binding for embedded systems: http://codesynthesis.com/products/xsde

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Re: [boost] [Boost-users] at_thread_exit() never getting called
by vicente.botet 29 Oct '09

29 Oct '09

Hi, ----- Original Message ----- From: "cowwoc" <cowwoc(a)bbs.darktech.org> To: <boost-users(a)lists.boost.org> Sent: Wednesday, October 28, 2009 7:33 PM Subject: Re: [Boost-users] at_thread_exit() never getting called > > > I think https://svn.boost.org/trac/boost/ticket/2739 prevents it from > working. > > Gili > > > Steven Watanabe-4 wrote: >> >> AMDG >> >> cowwoc wrote: >>> I am registering boost::this_thread::at_thread_exit() against one of my >>> threads. When the main thread exits using "return 0" the at_thread_exit >>> hook >>> never gets invoked. Is this normal? >> >> It's supposed to work for the main thread... For me yes, but it dosn't works. The example attached to the ticket show the problem. >>> Is there a way to hook the main thread >>> shutting down? >>> >> >> On windows you can use on_thread_exit(). >> The patch worked when I summited it. Anthony, I've see that you have started to integrate the patch for the thread attributes. Do you plan to integrate this patch also? Thanks, Vicente

2 4

what is the interest of In Place factory
by rodrigue pons 29 Oct '09

29 Oct '09

Hello, I was looking about the boost In Place Factory to resolve a problem i got, and there is something i don't understand: what is the advantage of this lib? For example: I get a class A, wich constructor is: A( int, const string& ); And an another class, C, that contains an A*. C provides a method to construct this A*: void C::BuildA( int i, const string & str ); wich will be called this way: instance_of_C.BuildA( 1, "test" ); If now i use the boost In Place Factory, the member function C::BuildA will become: template<class InPlaceFactoryT> void C::BuildA( InPlaceFactoryT const& factory ) wich will be called this way: instance_of_C.BuildA( 1, "test" ); We can see here that with or wothout the In Place Factory, the code is exactly the same. So i guess there is something i didn't understand. But what?

2 2

boost.math
by rodrigue pons 29 Oct '09

29 Oct '09

Hello, i need to implement the computation of huges series. These series are made of floats, and thus the error propagates. The problem is that the main constrain is the execution time, thus i must use the more "native" type possible. Is boost.math offer a solution to minimize this error? Which type of float (float, double, any structure?) must i use? Thanks.

5 10

[spirit][regex] rxstrlit/regex_p with wchar_t strings
by Adam Badura 29 Oct '09

29 Oct '09

Is it possible to use rxstrlit/regex_p with wide character strings (wchar_t based)? Or even better, with arbitrary char type/char traits pair? I tried this with suggested example (http://www.boost.org/doc/libs/1_40_0/libs/spirit/classic/example/fundamenta…) and after converting to wchar_t what was required and compiling it run successfully. But it generated a lot of warnings about converting wchar_t to char in headers that looked like regex headers. So I guess it worked only because the wchar_ts in the example are actually chars. If I changed the example to use wchar_t which have no corresponding char values the example would likely fail. In the end I have a string with templated char type and traits type (just like with string and iostream library). And I want to match it against grammar build from (among others) strings with the same char type and traits type. Can I force regex in Spirit to do that? Adam Badura

1 0

Why BOOST_HAS_DECLSPEC is not defined under MingW?
by Artyom 29 Oct '09

29 Oct '09

Hello, I've noticed following lines under boost/config/platform/win32.hpp #if !defined(__GNUC__) && !defined(BOOST_HAS_DECLSPEC) # define BOOST_HAS_DECLSPEC #endif Why? GCC provides support of declspec, Why it is specifically undefined? It can auto-export symbols but it does not work when static members involved. Thanks, Artyom

1 0

Re: [boost] New boost packaging suggestion for windows
by Julian Bangert 29 Oct '09

29 Oct '09

Hello, > Sadly, the only point being discussed so far is the online registration. > What I find to be at least as annoying is the size of the package. And > by that I'm not (only) referring to the memory or bandwidth. The most > important issue is the burden of having to deal with such an amount of > data, even if I'm only interested into a relatively small part of boost. > My package contains everything in one archive. These 37MB offer quite good compression and you can choose what you wish to extract. > I wonder whether there is still any thought or even effort spent on > breaking boost up into individual components that can be built, tested, > and ultimately also packaged separately. Any news on that ? > > Thanks, > Stefan > Well, a lot of Linux distributions already have this ( all the libboost- packages in debian for examples ) . In W32 it is possible even with BoostPro and in my distribution you can selectively extract libs. Tell me if this is wanted/appreciated and I can write a GUI frontend to automatically install components. I just uploaded the files to 2 sites for distribution, at least one of which should be up at any given time: 1) ( the mirror, but the preferred location ) http://boost-win-bin.googlecode.com/files/boost_1_40_0-vc9-preview.7z* 2) ( main site, but not on a good machine) https://obliviononline.com/pub/boost/ *After a few people confirm that this works for them they should be considered stable and I would build for other C versions as well. Then they could also be mentioned in getting started. * *Thanks, Julian Bangert __________ Information from ESET NOD32 Antivirus, version of virus signature database 4553 (20091028) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com

2 1

[dbc] Interest in Design By Contract for C++?
by Lorenzo Caminiti 29 Oct '09

29 Oct '09

Hello all, Is there any interest in a library that supports Design By Contract (DBC) for C++? All DBC features of the Eiffel programming language are supported by this library, among others: 1) Optional compilation and runtime checking of preconditions, postconditions, and invariants. 2) Subcontracting for derived classes. 3) Use of "old" in postconditions. 4) Automatic contract documentation (integrated with doxygen or similar tools). EXAMPLE This is part of the Stack4 DBC example presented for Eiffel in the book "Object Oriented Software Construction", B. Meyer, 1997. It has been coded for C++ using this library. #include <dbc.hpp> // This library. template<typename T> class Stack4 DBC_INHERIT_OBJECT(Stack4<T>) { public: Stack4(const int& n): capacity_(0), count_(0), representation_() DBC_CONSTRUCTOR( (private) (template)(Stack4)( (const int&) (n) ), { // Constructor preconditions. DBC_ASSERT(n >= 0, "non negative capacity"); }, { // Constructor postconditions. DBC_ASSERT(self.now.capacity() == n.now, "capacity set"); DBC_ASSERT(self.now.empty(), "is empty"); }, { // Constructor body. capacity_ = n; representation_.resize(capacity_); }) virtual ~Stack4() DBC_DESTRUCTOR( (public) (virtual) (template)(Stack4)(), { // Destructor body (do nothing). }) void remove() DBC_MEM_FUN( (public) (void) (template)DBC_COPYABLE(Stack4) (remove)(), { // Member function preconditions. DBC_ASSERT(!self.empty(), "not empty"); }, { // Member function postconditions. DBC_ASSERT(!self.now.full(), "not full"); DBC_ASSERT(self.now.count() == (self.old.count() - 1), "count decreased"); }, { // Member function body. --count_; }) ... // The rest of the Stack4 class. private: int capacity_; int count_; std::vector<T> representation_; DBC_INVARIANT(Stack4, { DBC_ASSERT(self.count() >= 0, "count non negative"); DBC_ASSERT_STREAM(self.count() <= self.capacity(), "count no greater than capacity", err << "count " << self.count() << " bounded by capacity " << self.capacity()); DBC_ASSERT( self.capacity() == int(self.representation_.capacity()), "capacity consistent with vector capacity"); DBC_ASSERT(self.empty() == (self.count() == 0), "empty when no elements"); if (self.count() > 0) DBC_ASSERT( self.representation_.at(self.count() - 1) == self.item(), "if positive count, item at top"); }) }; Example Notes: a) The somewhat strange syntax of the macro-based API (i.e., DBC_CONSTRUCTOR(), DBC_DESTRUCTOR(), and DBC_MEM_FUN()) uses a C++ preprocessor sequence of tokens "(public) (void) (template) ..." (this library internally uses Boost.Preprocessor to implement these macros). This library also provides a code-based API (dbc::fun::constr<>, dbc::fun::destr<>, and dbc::fun::mem<>) that can be used instead of the macro-based API but more setup code needs to be written by the programmers. b) This library also internally uses Boost.MPL mainly for typetraits, to support "old" in postconditions but only for types marked DBC_COPYABLE(), and for static assertions checking for library missuses (e.g., incorrect preprocessor sequence of tokens passed to the macro-based API). c) This library requires contracts to be written together with the class declaration (as contracts are part of the class specification). The class definition (function body) instead can either be written together with the contracts in the class declaration (like in the example above) or it can be written separately from the class declaration (i.e., this library maintains for function bodies the same C++ feature that allows to separate function's declaration and definition). Cheers, Lorenzo

5 9

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

28 Oct '09

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

6 9

[thread][thread_specific_ptr]
by Sid Sacek 28 Oct '09

28 Oct '09

In VC++ and GCC a user creates global TLS like this: VC++ __declspec( thread ) int tls_1; GCC __thread int tls_2; But using the boost library boost::thread_specific_ptr< int > tls_3; doesn't provide an initialized global variable as one would expect from thread-local-storage. Using tls_3 crashes the program if it's not pre-initialized to some object. The implication is that every time a new thread is created, it needs to first instantiate all global TLS objects. Am I not understanding the intentions of this class? Is there a proper or intended way of using this class? I couldn't find any example code in the boost archives. Thanks, -Sid

2 2

Can we suppress integer_traits warnings?
by John Maddock 27 Oct '09

27 Oct '09

If you have a program that simply includes boost/integer_traits.hpp and is compiled with g++ -pedantic you get a bunch of warnings: ./boost/integer_traits.hpp:164:57: warning: use of C99 long long integer constant ./boost/integer_traits.hpp:164:73: warning: use of C99 long long integer constant ./boost/integer_traits.hpp:170:62: warning: use of C99 long long integer constant ./boost/integer_traits.hpp:170:62: warning: use of C99 long long integer constant And no matter where I insert __extension__ I can't seem to get gcc to suppress these:-( Any ideas? BTW I'm asking because this came to me as a - somewhat misplaced - bug report: https://svn.boost.org/trac/boost/ticket/1451. Thanks, John.

7 17

[task in sandbox] memory leak?
by Jeffrey Hellrung 27 Oct '09

27 Oct '09

All: A colleague of mine is trying to use the proposed Boost.Task library in the sandbox, but he is observing some memory leaks. See forwarded email below and attached cpp file. Does anyone have any information or suggestions for him? I agreed to query the list for him, but if this becomes too involved, I'll ask him to subscribe and communicate directly. Thanks! - Jeff -------- Original Message -------- Subject: Boost.task memory leak Date: Tue, 27 Oct 2009 15:14:44 -0700 From: Paul Jones <pajones(a)gmail.com> To: Jeffrey Hellrung <jhellrung(a)ucla.edu> References: <7f0a1570910271324o3dcb2d9xb361501267b7a5db(a)mail.gmail.com> This code leaks memory on my system: - gcc version 4.4.1 (Ubuntu 4.4.1-4ubuntu8) - Boost 1.40 - boost.task-0.3.0 When this code is run you can observe the program's allocated memory steadily increasing in the system monitor. The output displays the number of (undestroyed) functor objects when all the pool has completed all of its tasks. This seems to be capped at 64, so this isn't the source of the leak. The maintainer's name is Oliver Kowalke. But I couldn't find his email address. Paul

1 0

asio library
by Peter Foelsche 27 Oct '09

27 Oct '09

Out of curiousity (reading somebody comment here regarding socket calls) I looked into the asio library and found the following example code below. My question is: What is the use of the socket object created in the first line? I think this line must always be followed by some more code. Because of this it does not make sense, that a library exports this functionality. boost::asio::ip::tcp::socket socket(io_service); boost::system::error_code ec; socket.open(boost::asio::ip::tcp::v4(), ec); if (ec) { // An error occurred. }

4 7

Proposal for Library to perform dependency injection
by Adam Young 27 Oct '09

27 Oct '09

Having had a career that has bounced me between a few languages, I have had the opportunity to work with a couple of tools in the Java world that didn't see, to have analogues in C++. One of these is the inversion of control containers, of which Spring is one of the best known. Ken Fowler suggested the term "Dependency Injection" as a way to better describe how inversion of control is performed, and I prefer his term. I've written a fairly simple dependency injection framework in C++ that seems to make proper use of the C++ Language. It is not attempting to do any COM like component model. Rather, it allows the developer the ability to cleanly separate the Object usage from the construction policy. I've posted the code on Sourceforge at https://sourceforge.net/projects/cpp-resolver/. I have not yet taken the time to get it into proper format for a Sandbox project, but will do that next if there seems to be enough interest in the project. I wrote up the philosophy behind the design here: http://adam.younglogic.com/?p=146 The code is currently g++ only, although I've attempted to use only core language constructs. It has no dependencies on other libraries other than stl collections. Any constructive feed back will be most appreciated. Adam

2 2

[conversion] Release v0.4: Replace function template specialization by ADL
by vicente.botet 27 Oct '09

27 Oct '09

Hi, I have just released the version 0.4 of Boost.Conversion , which includes since my last publicly announced version 0.3: Replace function template specialization by ADL A Source class is convertible to a Target class if: * Either: A function with the signature convert_to<Target>(Source const&, boost::dummy::type_tag<To> const&) is available via argument dependent lookup * Or: A template specialization of boost::conversion::convert_to<Target, Source> exists for Target and Source * Or: Target is copy constructible from Source (default implementation) The template function convert_to allows to convert a source type to a target type, using argument dependent lookup to select a specialized convert_to function if available. If no specialized convert_to function is available, boost::conversion::convert_to is used. The generic convert_to function requires that the elements to be converted are assignable and copy constructible. It is implemented using the Target copy construction from a Source or the Source conversion operator Target - this is sometimes unavailable. For standard types, we can not add a specialized convert_to function on the namespace std. The alternative to using argument dependent lookup in this situation is to provide a template specialization of boost::conversion::convert_to for every pair of standard types that requires a specialized convert_to. You can found all the detail for dowloading, documentation, ... in http://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction#Boost.Conve… I'd appreciate it if people could take a look, test it on their compiler and give me some feedback. Thanks to Edward Diener for showing me that multiple assignments should be taken in account. Thanks also to Jeffrey Hellrung and Robert Stewart for showing me that Boost.Conversion should use also ADL. BTW, I'm looking for a review manager. Anyone around here who would like to volunteer? Best regards, _____________________ Vicente Juan Botet Escribá

1 0

[system][filesystem v3] A possible error_code argument compromise
by Scott McMurray 27 Oct '09

27 Oct '09

2009/10/20 Beman Dawes <bdawes(a)acm.org>: > > One particular concern is that as currently worded, the N2838 proposal > requires throws() return a null reference, which they see as relying > on undefined behavior. > So it sounds like the idea solution is something that looks like a reference to the caller, for shortness of typing, but looks like a pointer to the implementation, to ease checking and avoid the weirdness of null references. struct optional_error_code_ref { optional_error_code_ref() : p_() {} optional_error_code_ref(optional_error_code_ref const &ecr) : p_(ecr.p_) {} optional_error_code_ref(error_code &r) : p_(&r) {} error_code &operator*() const { return *p_; } error_code *operator->() const { return p_; } operator safe_bool() const { return safe_bool(p_); } private: error_code *p_; }; Then the call is done the same was as before: error_code ec; foo(ec); But it's obvious to check, and never deals in null references: void foo(optional_error_code_ref ec = optional_error_code_ref()) { ... if (ec) { ec->value = bar; } else { throw bar_exception(); } ... } It would of course be better spelt qux<error_code&>, but I'm not sure exactly what name that should be. ~ Scott (Hopefully the subject change will get us out of the exceptions vs error codes quagmire.)

2 2

[python] AttributeError
by Okko Willeboordse 27 Oct '09

27 Oct '09

Running Boost 1.40 ( Windows server 2003/XP, Visual Studio 2008) Given; #include<boost/python.hpp> struct Foo{ static int bar; }; int Foo::bar=3; BOOST_PYTHON_MODULE(foo){ boost::python::class_<Foo>("Foo",boost::python::init<>()) .def_readonly("bar",Foo::bar); } With Python 2.6.3 and 2.6.4 I get; >c:\Python26\python.exe -c "import foo" Traceback (most recent call last): File "<string>", line 1, in <module> AttributeError: 'Boost.Python.StaticProperty' object attribute '__doc__' is read-only Also; >python Python 2.6.4 (r264:75708, Oct 26 2009, 08:23:19) [MSC v.1500 32 bit (Intel)] on win32 Type "help", "copyright", "credits" or "license" for more information. >>> import foo Traceback (most recent call last): File "<stdin>", line 1, in <module> AttributeError: 'Boost.Python.StaticProperty' object attribute '__doc__' is read-only >>> import foo >>> dir(foo.Foo) ['__class__', '__delattr__', '__dict__', '__doc__', '__format__', '__getattribute__', '__hash__', '__init __', '__instance_size__', '__module__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr_ _', '__sizeof__', '__str__', '__subclasshook__', '__weakref__'] So importing foo for the second time succeeds but foo.Foo holds no bar With Python < 2.6.3 everything works as expected. See also http://mail.python.org/pipermail/cplusplus-sig/2009-August/014747.html

1 0

[Graph] problem with strong_components.hpp and variant
by Nil Geisweiller 27 Oct '09

27 Oct '09

Hi, it seems there is a conflict between strong_components.hpp and variant, maybe the method boost::get is wrongly overloaded. The problem occurs with 1.40 but not with 1.37, and it is still occurs with the last svn. I attach a minimal code to reproduce the bug + compile error ###### test.cpp ###### //uncomment the line below to get the bug #include <boost/graph/strong_components.hpp> #include <boost/variant.hpp> typedef boost::variant < int, float > intorfloat; int main() { int i(2); intorfloat iof(i); return boost::get<int>(iof); //problem is here } ########### compile error ########### a-lin@a-lin-desktop:~/OpenCog/test/bin$ make [100%] Building CXX object CMakeFiles/test.dir/test.cpp.o In file included from /usr/include/boost/graph/graph_concepts.hpp:17, from /usr/include/boost/graph/depth_first_search.hpp:18, from /usr/include/boost/graph/strong_components.hpp:17, from /home/a-lin/OpenCog/test/test.cpp:2: /usr/include/boost/property_map/property_map.hpp: In instantiation of ‘boost::property_traits<int>’: /usr/include/boost/graph/two_bit_color_map.hpp:46: instantiated from ‘boost::two_bit_color_map<int>’ /home/a-lin/OpenCog/test/test.cpp:10: instantiated from here /usr/include/boost/property_map/property_map.hpp:31: error: ‘int’ is not a class, struct, or union type /usr/include/boost/property_map/property_map.hpp:32: error: ‘int’ is not a class, struct, or union type /usr/include/boost/property_map/property_map.hpp:33: error: ‘int’ is not a class, struct, or union type /usr/include/boost/property_map/property_map.hpp:34: error: ‘int’ is not a class, struct, or union type make[2]: *** [CMakeFiles/test.dir/test.cpp.o] Error 1 make[1]: *** [CMakeFiles/test.dir/all] Error 2 make: *** [all] Error 2 Is it a bug? Thanks a lot! Nil

1 1

[interprocess] mapped_file with wide filename on Windows
by Cory Nelson 27 Oct '09

27 Oct '09

Could the mapped_file constructor allow a wchar_t filename on Windows? Or some cross-platform way to get Unicode support? -- Cory Nelson http://int64.org

2 2

[string]
by remi.chateauneu＠gmx.de 26 Oct '09

26 Oct '09

Hi, Is there any interest for a class for computing Levenshtein and Damerau distances ? It is inspired from http://en.wikipedia.org/wiki/Levenshtein_distance with some enhancements: - The buffer can be reused thanks to a class, avoiding reallocations. - Only one buffer of twice the size of the longest string is necessary (Instead of the product of the size of the two input sequences). (Three times the size for Damerau distance). - It works with any input iterator category for one string, any iterator except input_iterator for the second string. - The distance type is templatized (Allowing to use short ints to save buffer space). - Any type of element can be used (Not only chars). - More efficient than the other implementations I could find on the web, completely inlined (Specific care to maximize memory locality). - The cost function can be specified with a functor (Insertion, deletion, replacement, transposition). - Tested with GCC 3.2.3 and 4.2.3, Visual C++ 2005. There was a proposal for such a function two years ago (edit_distance), but maybe this one, being faster, might be of interest for the string algorithms library ? The code is not very big so please let me attach it here. Thanks /* boost levenshtein.hpp header file * * Copyright Remi Chateauneu 2009 * Distributed under the Boost Software License, Version 1.0. (See * accompanying file LICENSE_1_0.txt or copy at * http://www.boost.org/LICENSE_1_0.txt) * * $Id: $ * * Idea by x */ #ifndef BOOST_LEVENSHTEIN_HPP #define BOOST_LEVENSHTEIN_HPP #include <string.h> #include <vector> namespace boost { /// Given a distance formula, levenshtein or damerau, does some processing of the input parameters. template< class Distance, class Formula > class distance_base { /// This uses Curiously recurring template pattern template < class Iter1, class Iter2 > inline Distance distance_noswap( Iter1 begS1, Iter1 endS1, Iter2 ptrS2, size_t len2 ) { return static_cast< Formula * >(this)->distance_noswap( begS1, endS1, ptrS2, len2 ); }; public: /// If both lengths are available, we can swap to increase speed. template < class Iter1, class Iter2 > Distance distance_swap( Iter1 begS1, Iter1 endS1, size_t len1, Iter2 begS2, Iter2 endS2, size_t len2 ) { /// The longer string should go to the inner loop return ( len1 < len2 ) ? distance_noswap( begS1, endS1, begS2, len2 ) : distance_noswap( begS2, endS2, begS1, len1 ); }; /// For plain containers. We assume that 'size()' has a constant cost. template < class Container1, class Container2 > Distance operator()( const Container1 & s1, const Container2 & s2 ) { return distance_swap( s1.begin(), s1.end(), s1.size(), s2.begin(), s2.end(), s2.size() ); }; /// For plain C-style strings. No need to create a temporary string. Distance operator()( const char * ptrS1, const char * ptrS2 ) { size_t len1 = strlen(ptrS1); size_t len2 = strlen(ptrS2); return distance_swap( ptrS1, ptrS1 + len1, len1, ptrS2, ptrS2 + len2, len2 ); }; /// If no iterator is an input_iterator, we may be able to swap them for performance. template< class Iter1, class Iter2 > Distance distance_iterator( Iter1 beg1, Iter1 end1, std::forward_iterator_tag, Iter2 beg2, Iter2 end2, std::forward_iterator_tag ) { return distance_swap( beg1, end1, std::distance( beg1, end1 ), beg2, end2, std::distance( beg2, end2 ) ); }; /// If the first iterator only is an input_iterator, then process it. template< class Iter1, class Iter2 > Distance distance_iterator( Iter1 beg1, Iter1 end1, std::input_iterator_tag, Iter2 beg2, Iter2 end2, std::forward_iterator_tag ) { return distance_noswap( beg1, end1, beg2, std::distance( beg2, end2 ) ); }; /// If the first iterator only is an input_iterator, then swap them first. template< class Iter1, class Iter2 > Distance distance_iterator( Iter1 beg1, Iter1 end1, std::forward_iterator_tag, Iter2 beg2, Iter2 end2, std::input_iterator_tag ) { return distance_noswap( beg2, end2, beg1, std::distance( beg1, end1 ) ); }; /// According to the type of iterator, not all operations are possible. template< class Iter1, class Iter2 > Distance operator()( Iter1 beg1, Iter1 end1, Iter2 beg2, Iter2 end2 ) { return distance_iterator( beg1, end1, typename std::iterator_traits< Iter1 >::iterator_category(), beg2, end2, typename std::iterator_traits< Iter2 >::iterator_category() ); }; }; // distance_base /// A user functor must have this interface. /// NOTE: The distance must always be positive. template< class Distance, class Char > struct dummy_functor { /// Char subsitution. Distance operator()( Char, Char ) const ; /// Char insertion or deletion. The cost /// is the same for both cases otherwise the distance /// would not be commutative. Distance operator()( Char ) const ; /// Char transposition (Option, for Damerau only). /// This does not depends on the character. Distance operator()(void) const ; }; /// Default functor for the most common case. It is never instantiated. /// Equivalent to a cost of '1' for character insertion, deletion or substitution. struct distance_null_functor {}; /// Specialization for the default case, for performance. /// This wraps a user functor, and compute the core test of Levenshtein distance. template < class Distance, class Functor > class cell_min { /// A user can specify the cost of char insertion, deletion and substitution. /// It must match the interface of dummy_functor. Functor _ftor ; public: cell_min() {}; cell_min( const Functor & refFtor ) : _ftor( refFtor ) {}; /// The cost of character insertion and deletion are the same otherwise /// it would not be commutative, and would not be a distance. template< class Char > Distance min_levenshtein( const Distance & distIJ, const Distance & distI1J, const Distance & distIJ1, const Char & chrLeft, const Char & chrRight ) { return std::min( distIJ + _ftor( chrLeft, chrRight ), std::min( distI1J + _ftor( chrLeft ), distIJ1 + _ftor( chrRight ) ) ); }; /// The operator without argument computes the cost of a transposition /// and does not depend on the transposed characters. /// Damerau is tested on top of Levenshtein comparison. Distance min_damerau( const Distance & prevDiag, const Distance & currDiag ) { return std::min( Distance( prevDiag + _ftor() ), currDiag ); }; }; // cell_min /// Does the core comparison of Levenshtein distance when no /// user functor is provided. This is the most common case /// and must be the fastest. template < class Distance > class cell_min< Distance, distance_null_functor > { public: cell_min() {}; cell_min( const distance_null_functor & ) {}; /// Here we save two additions, than if the general class were used. template< class Char > Distance min_levenshtein( const Distance & distIJ, const Distance & distI1J, const Distance & distIJ1, const Char & , const Char & ) const { return 1 + std::min( distIJ, std::min( distI1J, distIJ1 ) ); }; /// The usual cost of a transposition can be set to 1. /// Damerau is tested on top of Levenshtein comparison. Distance min_damerau( const Distance & prevDiag, const Distance & currDiag ) const { return std::min( prevDiag, currDiag + 1 ); }; }; // cell_min (Specialization) /// Most of times, Distance is 'unsigned int'. template< class Distance > class distance_buffer { /// TODO: Use temporary buffer. std::vector< Distance > _buffer ; size_t _sz ; public: distance_buffer() : _sz(0) {}; void resize( size_t sz ) { if( sz <= _sz ) return ; _buffer.resize( sz ); _sz = _buffer.size(); }; Distance * start(void) { return &_buffer[0]; } }; // distance_buffer /// This wraps a buffer which can be reused, because buffer allocations are costly. /// The distance may be char, short, int: This can reduce the buffer size. /// TODO: Do not resize the buffer but use the stack if less than X elements. /// TODO: Use a specific buffer allocation. template < class Distance = unsigned int, class Functor = distance_null_functor > class levenshtein : public distance_base< Distance, levenshtein< Distance, Functor > > { /// This wraps a user-provided optional functor. cell_min< Distance, Functor > _minFtor ; /// Max size: Twice the longest string + 2. distance_buffer< Distance > _buffer ; public: levenshtein() {}; levenshtein( const Functor & refFtor ) : _minFtor( refFtor ) {}; /// The size of the first range is not needed, any iterator type will do. template < class Iter1, class Iter2 > Distance distance_noswap( Iter1 begS1, Iter1 endS1, Iter2 ptrS2, size_t len2 ) { typedef typename std::iterator_traits< Iter1 >::value_type Char ; /// The buffer contains two lines of distance. _buffer.resize( 2 * ( len2 + 1 ) ); Distance * localPtr = _buffer.start() ; for(unsigned j = 0; j <= len2; ++j) { localPtr[ 2 * j ] = (Distance)j; } const Distance * endPtr = localPtr + 2 * len2 ; /// One cell out of two is associated to one line, the other to the next line. /// The two lines are swapped at each loop. for( unsigned i = 1; ; ) { localPtr = _buffer.start() ; localPtr[1] = Distance(i++) /* i,j+1 */ ; Char chr1 = *begS1++ ; // Restart from the beginning of the second string. for( Iter2 currS2 = ptrS2 ; localPtr != endPtr ; localPtr += 2 ) { const Char chr2 = *currS2++ ; Distance costDiag = localPtr[ 0 ]; /// Optimisation: The distance cannot increase if the chars are identical. if( chr1 != chr2 ) { /// Good data locality in four contiguous cells of the buffer. costDiag = _minFtor.min_levenshtein( costDiag, /* i,j */ localPtr[ 2 ] /* i+1,j */, localPtr[ 1 ] /* i,j+1 */, chr1, chr2 ); } localPtr[ 3 ] = costDiag ; } /// The loop is unrolled two steps by two. if( begS1 == endS1 ) { /// After an even number of half-loops (and lines). return localPtr[ 1 ] /* i+1,j+1 */ ; } /// This starts an odd line. localPtr = _buffer.start() ; localPtr[0] = Distance(i++) /* i,j+1 */ ; chr1 = *begS1++; // Restart from the beginning of the second string. for( Iter2 currS2 = ptrS2 ; localPtr != endPtr ; localPtr += 2 ) { const Char chr2 = *currS2++ ; Distance costDiag = localPtr[ 1 ]; /// Optimisation: The distance cannot increase if the chars are identical. if( chr1 != chr2 ) { /// Good data locality in four contiguous cells of the buffer. costDiag = _minFtor.min_levenshtein( costDiag, /* i,j */ localPtr[ 3 ] /* i+1,j */, localPtr[ 0 ] /* i,j+1 */, chr1, chr2 ); } localPtr[ 2 ] = costDiag ; }; if( begS1 == endS1 ) { /// After an odd number of lines. return localPtr[ 0 ] /* i+1,j+1 */ ; } } /// Should never happen. return Distance(0); }; // distance_noswap }; // levenshtein /// This wraps a buffer which can be reused, because buffer allocations are costly. /// The distance may be char, short, int: This can reduce the buffer size. template < class Distance = unsigned int, class Functor = distance_null_functor > class damerau : public distance_base< Distance, damerau< Distance, Functor > > { /// This wraps a user-provided optional functor. cell_min< Distance, Functor > _minFtor ; /// Max size: Twice the longest string + 2. distance_buffer< Distance > _buffer ; public: damerau() {}; damerau( const Functor & refFtor ) : _minFtor( refFtor ) {}; /// The size of the first range is not needed, any iterator will do. template < class Iter1, class Iter2 > Distance distance_noswap( Iter1 begS1, Iter1 endS1, Iter2 ptrS2, size_t len2 ) { typedef typename std::iterator_traits< Iter1 >::value_type Char ; /// The buffer contains two lines of distance. _buffer.resize( 3 * ( len2 + 3 ) ); Distance * localPtr = _buffer.start() ; for(unsigned j = 0; j <= len2; ++j) { localPtr[ 3 * j] = (Distance)j; } /// One cell out of two is associated to one line, the other to the next line. int offPrev = 2, offCurr = 0, offNext = 1 ; Char chr1, chr1_prev ; /// The three lines are shifted at each loop. for( unsigned i = 1; begS1 != endS1 ; chr1_prev = chr1, ++begS1, ++i, offCurr = offNext, offNext = offPrev, offPrev = offPrev == 2 ? 0 : offPrev + 1 ) { Distance * localPtr = _buffer.start() ; localPtr[offNext] = Distance(i) /* i+1,j */ ; chr1 = *begS1 ; Char chr2, chr2_prev ; Iter2 currS2 = ptrS2 ; for(unsigned j = 0; j < len2; chr2_prev = chr2, ++currS2, ++j, localPtr += 3 ) { chr2 = *currS2 ; Distance costDiag = localPtr[ offCurr ] /* i,j */ ; /// Optimisation: The distance cannot increase if the chars are identical. /// NOTE: Without this test, a valid transposition could not be checked. if( chr1 != chr2 ) { /// Good data locality in four contiguous cells of the buffer. costDiag = _minFtor.min_levenshtein( costDiag, localPtr[ 3 + offCurr ], localPtr[ offNext ], chr1, chr2 ); /// If beyond the first column and line, check for a transposition. /// This makes sense only if the current chars are different. if( ( i > 1 ) && ( j > 0 ) && ( chr1 == chr2_prev ) && ( chr1_prev == chr2 ) ) { costDiag= _minFtor.min_damerau( costDiag, localPtr[ offPrev - 3 ] /* i-1,j-1 */ ); } } localPtr[ 3 + offNext ] = costDiag /* i+1,j+1 */ ; } } return _buffer.start()[ 3 * len2 + offCurr ]; }; // distance_noswap }; // damerau } // namespace boost #endif /* BOOST_LEVENSHTEIN_HPP */ #include <iostream> #include <string> #include <list> #include <vector> #include <iterator> #include "levenshtein.hpp" using namespace std ; /// This can be later used for creating combinations of tests. static void tst_perf(size_t nbLoops) { static const char * tst[] = { "a", "c", "bc", "abc", "bcdef", "abcdegh", "acdeghi", "acedghi", "abcdfgi", "abcfgi", "abcfig" }; const size_t nbTst = sizeof(tst)/sizeof(tst[0]); boost::levenshtein<int> tmpLev ; boost::damerau<int> tmpDam ; while( nbLoops-- ) { for( size_t i = 0 ; i < nbTst ; ++i ) { for( size_t j = i + 1 ; j < nbTst ; ++j ) { int distLev = tmpLev( tst[i], tst[j] ); int distDam = tmpDam( tst[i], tst[j] ); }; }; } } // http://en.wikibooks.org/wiki/Algorithm_Implementation/Strings/Levenshtein_d… template <class T> size_t edit_distance(const T& s1, const T& s2) { const size_t len1 = s1.size(), len2 = s2.size(); vector<vector<unsigned int> > d(len1 + 1, vector<unsigned int>(len2 + 1)); d[0][0] = 0; for(unsigned int i = 1; i <= len1; ++i) d[i][0] = i; for(unsigned int i = 1; i <= len2; ++i) d[0][i] = i; for(unsigned int i = 1; i <= len1; ++i) for(unsigned int j = 1; j <= len2; ++j) d[i][j] = std::min( std::min(d[i - 1][j] + 1, d[i][j - 1] + 1), d[i - 1][j - 1] + (s1[i - 1] == s2[j - 1] ? 0 : 1) ); return d[len1][len2]; } /// Classical implementation. For comparing results. size_t levenshtein_dist(const std::string & source, const std::string & target) { const size_t n = source.length(); const size_t m = target.length(); if (n == 0) return m; if (m == 0) return n; vector<vector<size_t> > matrix(n + 1, vector<size_t>(m + 1,0)); for (size_t i = 0; i <= n; i++) { matrix[i][0]=i; } for (size_t j = 0; j <= m; j++) { matrix[0][j]=j; } for (size_t i = 1; i <= n; i++) { char s_i = source[i-1]; for (size_t j = 1; j <= m; j++) { char t_j = target[j-1]; int cost; if (s_i == t_j) { cost = 0; } else { cost = 1; } size_t above = matrix[i-1][j]; size_t left = matrix[i][j-1]; size_t diag = matrix[i-1][j-1]; size_t cell = std::min( above + 1, std::min(left + 1, diag + cost)); matrix[i][j]=cell; } } return matrix[n][m]; } /// Classical implementation. For comparing results. size_t damerau_dist(const std::string & source, const std::string & target) { const size_t n = source.length(); const size_t m = target.length(); if (n == 0) return m; if (m == 0) return n; vector<vector<size_t> > matrix(n + 1, vector<size_t>(m + 1,0)); for (size_t i = 0; i <= n; i++) { matrix[i][0]=i; } for (size_t j = 0; j <= m; j++) { matrix[0][j]=j; } for (size_t i = 1; i <= n; i++) { char s_i = source[i-1]; for (size_t j = 1; j <= m; j++) { char t_j = target[j-1]; int cost; if (s_i == t_j) { cost = 0; } else { cost = 1; } size_t above = matrix[i-1][j]; size_t left = matrix[i][j-1]; size_t diag = matrix[i-1][j-1]; size_t cell = std::min( above + 1, std::min(left + 1, diag + cost)); // Step 6A: Cover transposition, in addition to deletion, // insertion and substitution. This step is taken from: // Berghel, Hal ; Roach, David : "An Extension of Ukkonen's // Enhanced Dynamic Programming ASM Algorithm" // (http://www.acm.org/~hlb/publications/asm/asm.html) if( (i > 1) && (j > 1) && (source[i-2] == t_j) && (s_i == target[j-2]) ) { cell = std::min( cell, matrix[i-2][j-2] + 1 ); } matrix[i][j]=cell; } } return matrix[n][m]; } struct TstData { const char * _left ; const char * _right ; unsigned int _lev ; unsigned int _dam ; }; /// We can check whether the result is OK. static const TstData tst_array[] = { { "a","c", 1, 1 }, { "a","bc", 2, 2 }, { "ab","ba", 2, 1 }, { "a","abc", 2, 2 }, { "a","bcdef", 5, 5 }, { "a","abcdegh", 6, 6 }, { "a","acdeghi", 6, 6 }, { "a","acedghi", 6, 6 }, { "a","abcdfgi", 6, 6 }, { "a","abcfgi", 5, 5 }, { "a","abcfig", 5, 5 }, { "c","bc", 1, 1 }, { "c","abc", 2, 2 }, { "c","bcdef", 4, 4 }, { "c","abcdegh", 6, 6 }, { "c","acdeghi", 6, 6 }, { "c","acedghi", 6, 6 }, { "c","abcdfgi", 6, 6 }, { "c","abcfgi", 5, 5 }, { "c","abcfig", 5, 5 }, { "bc","abc", 1, 1 }, { "abcd","badc", 3, 2 }, { "bc","bcdef", 3, 3 }, { "bc","abcdegh", 5, 5 }, { "bc","acdeghi", 6, 6 }, { "bc","acedghi", 6, 6 }, { "bc","abcdfgi", 5, 5 }, { "bc","abcfgi", 4, 4 }, { "bc","abcfig", 4, 4 }, { "abc","bcdef", 4, 4 }, { "abc","abcdegh", 4, 4 }, { "abc","acdeghi", 6, 6 }, { "abc","acedghi", 6, 6 }, { "abc","abcdfgi", 4, 4 }, { "abc","abcfgi", 3, 3 }, { "abc","abcfig", 3, 3 }, { "bcdef","abcdegh", 3, 3 }, { "bcdef","acdeghi", 4, 4 }, { "bcdef","acedghi", 5, 5 }, { "bcdef","abcdfgi", 4, 4 }, { "bcdef","abcfgi", 4, 4 }, { "bcdef","abcfig", 4, 4 }, { "abcdegh","acdeghi", 2, 2 }, { "abcdegh","acedghi", 4, 3 }, { "abcdegh","abcdfgi", 2, 2 }, { "abcdegh","abcfgi", 3, 3 }, { "abcdegh","abcfig", 3, 3 }, { "acdeghi","acedghi", 2, 1 }, { "cadeghi","acedghi", 3, 2 }, { "acdeghi","abcdfgi", 3, 3 }, { "acdeghi","abcfgi", 4, 4 }, { "acdeghi","abcfig", 5, 5 }, { "acedghi","abcdfgi", 4, 4 }, { "acedghi","abcfgi", 4, 4 }, { "acedghi","abcfig", 5, 5 }, { "abcdfgi","abcfgi", 1, 1 }, { "abcdfgi","abcfig", 3, 2 }, { "abcfgi","abcfig", 2, 1 } }; static const size_t nbArr = sizeof(tst_array)/sizeof(tst_array[0]); static boost::levenshtein<int> staticLev ; static boost::damerau<int> staticDam ; /// This is for checking the assembly code generated. static int assembly_levenshtein( const char * a, const char * b ) { return staticLev( a, b ); } static void tst_values(void) { for( size_t i = 0; i < nbArr ; ++i ) { const TstData * p = tst_array + i ; size_t valL = staticLev( p->_left, p->_right ); size_t valD = staticDam( p->_left, p->_right ); size_t edtL = edit_distance( std::string(p->_left), std::string(p->_right) ); size_t oldL = levenshtein_dist( p->_left, p->_right ); size_t oldD = damerau_dist( p->_left, p->_right ); if( ( valL != p->_lev ) || ( oldL != p->_lev ) || ( edtL != p->_lev ) ) { std::cout << "Error L:" << "\tvalL=" << valL << "\tp->lev=" << p->_lev << "\toldL=" << oldL << "\tedtL=" << edtL << "\tp->left=" << p->_left << "\tp->right=" << p->_right << "\n" ; }; if( ( valD != p->_dam ) || ( oldD != p->_dam ) ) { std::cout << "Error D:" << "\tvalD=" << valD << "\tp->dam=" << p->_dam << "\toldD=" << oldD << "\tp->left=" << p->_left << "\tp->right=" << p->_right << "\n" ; }; }; } int main( int argC, const char ** argV ) { tst_values(); if( argC > 1 ) { int nbTst ; sscanf( argV[1], "%d", &nbTst ); tst_perf(nbTst); }; /// So it it not optimized away. std::cout << assembly_levenshtein << "\n" ; }; /// This is for checking the assembly code generated. int assembly_damerau( const char * a, const char * b ) { return staticLev( a, b ); } /// This tests some specific compile-time conditions. template< class Formula > static int compile_formula(Formula refFrm) { std::list< char > chrLst ; vector< char > chrVec ; std::istream_iterator<char> chrStrm ; refFrm( chrLst, chrVec ); refFrm( chrStrm, chrStrm, chrVec.begin(), chrVec.end() ); refFrm( chrLst.begin(), chrLst.end(), chrStrm, chrStrm ); }; struct my_functor { short operator()( char a, char b ) const { return 2 ; }; short operator()( char a ) const { return 1 ; }; short operator()(void) const { return 1 ; }; }; /// This tests some specific compile-time conditions. static int compile_test(void) { boost::levenshtein<int> tmpLev ; compile_formula( tmpLev ); boost::damerau<long long> tmpDam ; compile_formula( tmpDam ); boost::levenshtein<short,my_functor> tmpLevF ; compile_formula( tmpLevF ); my_functor tmpFunc ; boost::damerau<short, my_functor> tmpDamF( tmpFunc ) ; compile_formula( tmpDamF ); };

2 1

boost 1.39 to 1.40 difference: missing toolset and threading tag from library filename?
by Todd Lovette 26 Oct '09

26 Oct '09

Is there a difference in the naming conventions of the libboost_*.so files from boost 1.39 to boost 1.40.0? When I build the boost 1.39 libs they have filenames like... "libboost_thread-gcc44-mt-1_39.so" ..but when I build boost 1.40.0 all the libs filenames are like so... "libboost_thread.so" Did the library naming change in 1.40 or are their new compile options to enable the library naming feature? Build options: (both used on 1.39 & 1.40.0) ------------------------- ./bootstrap.sh --prefix=/usr --libdir=/usr/lib64 ./bjam threading=multi System ------------- Slamd64 12.1(x86_64) using gcc 4.4.2 Any help would be appticiated! Todd :-)

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[test] Errors #including test/floating_point_comparison.hpp
by Emil Dotchevski 26 Oct '09

26 Oct '09

The log below shows a warning and 3 errors in test/predicate_result.hpp from Comeau C++ 4.3.10. Is this easy to fix? (Incidentally, I am not using boost/test, I only need floating_point_comparison.hpp -- shouldn't floating point comparison be independent from boost/test?) Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode como-win.compile.c++ ..\..\..\..\..\..\bin\dev\boost-la\libs\la\test\col_matrix_test.test\como-win-4.3.10\debug\link-static\col_matrix_test.obj "C:\code\dev\boost-trunk\boost/test/utils/basic_cstring/basic_cstring.hpp", line 60: warning #68-D: integer conversion resulted in a change of sign enum npos_type { npos = static_cast<size_type>(-1) }; ^ "C:\code\dev\boost-trunk\boost/test/predicate_result.hpp", line 62: warning #54-D: too few arguments in macro invocation BOOST_READONLY_PROPERTY( bool, (predicate_result) ) p_predicate_value; ^ "C:\code\dev\boost-trunk\boost/test/predicate_result.hpp", line 62: error #40: expected an identifier BOOST_READONLY_PROPERTY( bool, (predicate_result) ) p_predicate_value; ^ "C:\code\dev\boost-trunk\boost/test/predicate_result.hpp", line 62: error #277: invalid friend declaration BOOST_READONLY_PROPERTY( bool, (predicate_result) ) p_predicate_value; ^ "C:\code\dev\boost-trunk\boost/test/predicate_result.hpp", line 62: error #65: expected a ";" BOOST_READONLY_PROPERTY( bool, (predicate_result) ) p_predicate_value; ^

1 0

boost policy against inline friend functions?
by Stefan Strasser 26 Oct '09

26 Oct '09

I've noticed boost::shared_ptr and other classes avoid using inline friend functions, e.g. operator < in class shared_ptr scope: public: template<class Y> bool _internal_less(shared_ptr<Y> const & rhs) const { return pn < rhs.pn; } in namespace scope: template<class T, class U> inline bool operator<(shared_ptr<T> const & a, shared_ptr<U> const & b) { return a._internal_less(b); } what's wrong with template<class Y> friend bool operator<(shared_ptr<Y> const & rhs) const { return pn < rhs.pn; } in class shared_ptr? compiler compatibility? other reasons? should boost libraries avoid inline friend functions in general?

5 6

[conversion] Motivation for two NEW generic conver_to and assign_to functions
by vicente.botet 26 Oct '09

26 Oct '09

Hi, I would like to share with you what motivated me to add two new free template functions convert_to<> and assign_to<> on the Boost.Conversion. I've needed recently to convert from boost::chrono::time_point<Clock, Duration> to boost::posix_time::ptime and from boost::chrono::duration<Rep, Period> to boost::posix_time::time_duration. This kind of conversions are needed quite often when you use code from two different libraries that have implemented the same concept using of course different representations and have hard coded the library interface to its own implementation. Well this is a normal situation, we can't avoid. Life is life. Quite often we need to convert unrelated types `Source` and `Target`. As these classes are unrelated, neither of them offers conversion operators to the other. Usually we get it by defining a specific function such as Target ConvertToTarget(Source& v); In my case I started by defining template <typename Rep, typename Period> boost::posix_time::time_duration convert_to_posix_time_time_duration( const boost::chrono::duration<Rep, Period>& from); template <typename Clock, typename Duration> posix_time::ptime convert_to_posix_time_ptime(const chrono::time_point<Clock, Duration>& from); Imagine now that you need to convert a `std::pair<Source, Source>` to a `std::pair<Target, Target>`. The standard defines conversions of pairs if the related types are C++ convertible: template <typename T1, typename T2> struct pair { ... template<class U, class V> //requires Constructible<T1, const U&> && Constructible<T2, const V&> std::pair(const pair<U, V>& p); template<class U , class V> //requires HasAssign<T1, const U&> && HasAssign<T2, const V&> std::pair& operator=(const std::pair<U , V>& p); ... }; But here the types Target and Source are not convertible other than using a specific function. Well we can again define a specific function std::pair<Target,Target> ConvertToPairOfTarget(std::pair<Source,Source>& v) { return std::make_pair(ConvertToTarget(v.fisrt), ConvertToTarget(v.second)); } While the `ConvertToTarget` could be specific, the `ConvertToPairOfTarget` should be generic template <typename Target1, typename Target2, typename Source1, typename Source2) std::pair<Target1,Target2> ConvertToPair(std::pair<Source1,Source2>& v); In order to do that we need that the pair template parameters define a common function, let it call `convert_to`: template <typename Target, typename Source) Target convert_to(Source& v); Thus `ConvertToPair` can be defined as template <typename Target1, typename Target2, typename Source1, typename Source2) std::pair<Target1,Target2> ConvertToPair(std::pair<Source1,Source2>& v) { return std::make_pair(convert_to<Target1>(v.fisrt), convert_to<Target2>(v.second)); } We need to specialize the `convert_to` function for the specific classes `Source` and `Target`. We can do it as follows template <> Target convert_to<Target, Source>(Source& v) {return ConvertToTarget(v);} In my case I need template <typename Rep, typename Period> boost::posix_time::time_duration convert_to<posix_time_time_duration, boost::chrono::duration<Rep, Period> > (const boost::chrono::duration<Rep, Period>& from) { return convert_to_posix_time_time_duration(from); } template <typename Clock, typename Duration> boost::posix_time::ptime convert_to<posix_time_ptime, chrono::time_point<Clock, Duration> > (const boost::chrono::time_point<Clock, Duration>& from) { return convert_to_posix_time_ptime(from); } So now I can convert std::pair<chrono::time_point<Clock, Duration>, boost::chrono::duration<Rep, Period> > to std::pair<boost::posix_time::ptime, boost::posix_time::time_duration> using the `ConvertToPair` function. What about converting `std::pair<Source,std::pair<Source,Source> >` to `std::pair<Target,std::pair<Target,Target> >`? The issue now is that `convert_to(std::make_pair<to, std::make_pair<to,to> >)` do not compiles because the conversion of `std::pair` is named `ConvertToPair`. So we need to specialize the function `convert_to` for pairs. template <typename T1, typename T2, typename S1, typename S2) static std::pair<T1,T2> convert_to<std::pair<Target1,T2>, std::pair<S1,S2> >( std::pair<Source1,Source2>& from) { { return std::pair<T1,T2>(convert_to<T1>(from.first), convert_to<T2>(from.second)); } There is still a last point. The preceding design works well with unrelated classes, but what about classes that already define some kind of conversion, using a constructor or a conversion operator. Do we need to make specialization for these conversion? The answer is no. We need just to define the default implementation of convert_to function to just return the explicit conversion. template < typename Target, typename Source> Target convert_to(const Source& from) { return Target(from); } With compilers supporting partial specialization of function templates there is no major problem. For the others, we need to use a trick; as it allows partial specialization of classes we can define convert_to by as relying to a specific function of a class, as follows: namespace partial_specialization_workaround { template < typename Target, typename Source > struct convert_to { static Target apply(const Source& val); }; } template < typename Target, typename Source > Target convert_to(const Source& val) { return partial_specialization_workaround::convert_to<Target,Source>::apply(val); } So now we can specialize `partial_specialization_workaround::convert_to` for pairs as follows: namespace partial_specialization_workaround { template <typename Target1, typename Target2, typename Source1, typename Source2) struct convert_to< std::pair<Target1,Target2>, std::pair<Source1,Source2> > { static std::pair<Target1,Target2> apply(std::pair<Source1,Source2>& v) { { return std::pair<T1,T2>(convert_to<T1>(from.first), convert_to<T2>(from.second)); } }; } Conclusion Classes or algorithms relying on a conversion by copy-construction or by the conversion operator can be made more generic by relaying in a function that explicitly states this conversion. Thus, instead of requiring Target(from) require convert_to<Target>(from) The same applies to classes or algorithms relying on the assignment operator. So instead of requiring to = from require assign_to(to, from); The default implementation of assign_to relies on the assignment operator template < typename Target, typename Source > To& assign_to(Target& to, const Source& from) { to = from; return to; } and with the workaround namespace partial_specialization_workaround { template < typename Target, typename Source > struct assign_to { static To& apply(Target& to, const Source& from) { to = from; return to; } }; } template < typename Target, typename Source > To& assign_to(Target& to, const Source& from) { return partial_specialization_workaround::assign_to<Target,Source>::apply(to, from); } For classes that are explicitly convertible and having a self assignment operator it is easy to make a specialization of assign_to as follows. to = convert_to<Target>(from); The rationale is that if there was not a copy constructor from a Source seems reasonable to think that there will not be an assignment operator. So in most of the cases, once we have specialized the convert_to function we recover a reasonable implementation for the assign_to function. When doing multiple assignments we use to do a = b = c; With assign_to we could do assign_to(a, assign_to(b, c)); and if we find this not really readable we can try with tie(a) = tie(b) = c; The behavior of tie recall the tie function of Boost.Tuple, but instead assigning multiple variable at once, assign only one by calling assign_to. So one of the advantages of using this common functions is uniformity. The other is that now we are able to find all the explicit conversions to one type, as we can do with explicit casts. We can even generalize this, so classes or algorithms relying on a member function, can be made more generic by relaying on a free function. The default function implementation could just call to the member function with the equivalent prototype, but this is out of the scope of this library. Note that this is already the case of the free functions as swap(), begin(), next(), end(), ... What about changing the C++ standard? C++1x has added explicit conversion operators, but they must always be defined in the Source class. The same applies to the assignment operator, it must be defined on the Target class. What it will interesting is to be able to add constructors and assignments operators to the class std::pair, so we can say that two pairs are convertible if the parameters are explicitly convertible using a convert_to function template<class U , class V> //requires HasConvertTo<T1, const U&> && HasConvertTo<T2, const V&> std::pair& operator=(const std::pair<U , V>& p) { return std::make_pair(convert_to<T1>(p.first), convert_to<T1>(p.second)); } But this is not possible. We can not add operators to a class from outside. A more generic alternative could be to make an evolution to the standard, so the convertible concept takes car of extrinsic conversions. We could be able to implicitly or explicitly add extrinsic conversion operators between unrelated types. Assignment operators could also be specialized. template < typename To, typename From > operator To(const From& val); template < typename To, typename From > To& operator=(To& to, const From& from); For example we could specialize the conversion from as chrono::time_point<Clock, Duration> to posix_time::ptime follows template < class Clock, class Duration> operator boost::posix_time::ptime(const boost::chrono::time_point<Clock, Duration>& from) { typedef boost::chrono::time_point<Clock, Duration> time_point_t; typedef boost::chrono::nanoseconds duration_t; typedef boost::duration_t::rep rep_t; rep_t d = boost::chrono::duration_cast<duration_t>(from.time_since_epoch()).count(); rep_t sec = d/1000000000; rep_t nsec = d%1000000000; return boost::posix_time::from_time_t(0)+ boost::posix_time::seconds(static_cast<long>(sec))+ boost::posix_time::nanoseconds(nsec); } The convert_to and the assign_to functions preted to be a library solution to the convertibility of unrelated types problem. Best regards, _____________________ Vicente Juan Botet Escribá

5 12

[rfc] a library for gesture recognition, speech recognition, and synthesis
by Stjepan Rajko 26 Oct '09

26 Oct '09

Hello, For the past few years I've been working on the AME Patterns library - a generic library for modeling, recognition and synthesis of sequential patterns. So far it's been applied mostly to gesture recognition (e.g., recognition of mouse gestures, full body gestures from video or motion capture data, accelerometer gestures), but recently it has also shown some good results on speech datasets. It can also be used to synthesize the same kinds of patterns it can recognize (e.g., you could use it to synthesize a gesture or speech, or purely numerical patterns). The library provides support for hidden Markov models and other related models. The design is concept-based, and the library uses the Boost Graph Library, Boost.Range (including the RangeEx extension), Boost.Fusion, Boost.Math, Boost.Random, and other boost libraries. The documentation for the library is available here: http://ame4.hc.asu.edu/amelia/patterns/ However, the documentation is lacking, so I'm curious to know which parts of the functionality (if any) are of interest to the boost community, so I know what parts of the documentation to focus on. I am also considering proposing a presentation of this library to BoostCon. The library is currently released under the GPL, which I realize is not acceptable to some. Please let me know your thoughts. If anyone is interested in using this library, please let me know what you'd like to use it for and I'd be happy to help you get started. Kind regards, Stjepan

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[conversion] How to repere assignement to a variable? (was [property] interest in C# like properties for C++?)
by vicente.botet 26 Oct '09

26 Oct '09

Hi, in the thread about C# like properties we were talking about the advantage to be able to repere assignation to properties. I said that, another way to repare the assignments is to use a free function assign_to, like we use the free function swap, or the cast family functions. assign_to(a.p_X, 1); assign_to call by default the assignment operator. If we want transitive assignation a = b = c; we could do assign_to(a, assign_to(b, c)); and if we find this not really readable we can try with tie(a) = tie(b) = c; tie is a template function returning an ca_wrapper. template <typename T> ca_wrapper <T> tie(T& r) { return ca_wrapper<T>(r); } ca_wrapper is responsable to transforming the assignation and operator conversion on a call to assign_to and no more. template <typename T> class ca_wrapper { T& ref_; public: ca_wrapper(T& r) : ref_(r) {} template <typename U> T& operator =(U const& u) { return assign_to(ref_, u); } template <typename U> operator U() { return convert_to(ref_, u); } }; The advantage of having a specific function is that we can specialize the assign_to function for unrelated classes. The Boost.Conversion library (on the review schedule) defines two free functions convert_to and assign_to which by default use the conversion operator and the assignment. We can see convert_to as a getter and assign_to as a setter. The major advantage is that with a uniform syntax, the user can however specialize them to do conversion and assignations between unrelated types. I don't know if tie is a good name to manage with assignation of a variable, I have taken the name from the Boost.Tuple? Regards, _____________________ Vicente Juan Botet Escribá P.S. tie and ca_wrapper are new features of Boost.Conversion v.0.3

2 3

boost design details
by wildinto wildinto 26 Oct '09

26 Oct '09

hi all, because i'm studying the generic programming, i just want to study boost to get the most useful skills, but i can't find any design details about boost. such as boost bind, so, anyone who can tell where i can find the design details about the design of each boost lib ? thanks very much! best regards, Thunder

1 0

[BGL] [Property Map] PropertyGraph concept
by Cosimo Calabrese 26 Oct '09

26 Oct '09

Hi to all, I've taked a look to the PropertyGraph concept, and it defines the following valid expression: get(p, g, x) and its return type: boost::property_traits<Map>::*value_type* Also the docs of Property Map library says that the get() function return the property *by value*, making a copy of the property. But looking to the \boost\graph\detail\adjacency_list.hpp file, I've noticed that the return value of the get function is: typename boost::property_traits< typename boost::property_map<typename Config::graph_type, Property>::type >::*reference* Why this difference? Or they are the same think? Which is the correct specific? Thanks in advance, Cosimo Calabrese.

2 1

[RegEx] Performance degradation since 1.36
by Dave Vest 26 Oct '09

26 Oct '09

I've just downloaded boost 1.40, compiled the libraries, and re-compiled our application. Part of our application uses regular expressions extensively to search through source code and the performance appears to be up to 5 x slower in release mode than with the 1.36 libraries. Boost source (no modifications) compiled with Visual Studio 2008 on Win 7. (Note: 1.36 was compiled with VS 2008 on Win Vista.) bjam debug release --with-thread --with-regex --with-date_time link=static Regex creation: boost::regex::flag_type flags = boost::regex::perl | boost::regex::optimize | boost::regex::icase); boost::regex * pengine = new boost::regex(strSampleExpression, flags); .. Regex use: boost::regex_iterator<char const*> itMatch(pszStr, pszStr + nStrLen, *pengine); boost::regex_iterator<char const*> itEnd; if ( itMatch != itEnd ) { . } A simple for(int i=0;i<100000;++i) loop test shows huge differences. Any ideas why 1.40 is so much slower? Some change in default traits or some documentation note I've missed?

1 0

[PBGL] Distributed BFS example : input and outpu
by Sandeep Gupta 26 Oct '09

26 Oct '09

Hello, I am trying to understand how the example libs/graph_parallel/example/breadth_first_search.cpp works. I am not able to understand (neither find any documentation for it) the input and output of the program. To the best of my understanding a valid input to this program is graph/test/ weighted_graph.gr. What's the format for the input. And why does the output of BFS dependent upon the number of process in the mpirun argument. Would greatly appreciate any explanation or relevant pointers. -thanks Sandeep

1 0

[Test] Building with Comeau C/C++ 4.3.10.1 fails
by Mateusz Loskot 25 Oct '09

25 Oct '09

Hi, Where can I find current status what Boost libraries compile using Comeau C/C++ compiler? I've tried to build Boost.Test and it fails. Is this a known issue? Should I submit a ticket with detailed errors log? Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

2 3

tuple<T,T,...> generator meta-function
by Emre Turkay 23 Oct '09

23 Oct '09

Hi folks, How can I do this in a better way? template <typename T, size_t N> struct make_tuple { }; template <typename T> struct make_tuple<T, 1> { typedef boost::tuple<T> type; }; template <typename T> struct make_tuple<T, 2> { typedef boost::tuple<T, T> type; }; template <typename T> struct make_tuple<T, 3> { typedef boost::tuple<T, T, T> type; }; template <typename T> struct make_tuple<T, 4> { typedef boost::tuple<T, T, T, T> type; }; // ... Thanks, emre

4 3

Re: [boost] [property] interest in C# like properties for C++?
by Stefan Strasser 23 Oct '09

23 Oct '09

Not trying to beat a dead horse, but this is yet another reason to keep the parenthesis syntax: name().size() -- Ursprüngl. Mitteil. -- Betreff: Re: [boost] [property] interest in C# like properties for C++? Von: Olaf van der Spek <olafvdspek(a)gmail.com> Datum: 23.10.2009 07:44 On Fri, Oct 23, 2009 at 1:30 AM, Edward Diener <eldiener(a)tropicsoft.com> wrote: > Of course you can support reference properties along with value properties. > It is just very hard, if not impossible, to support both kinds using the > same template class. So really one would not a separate template class to > support reference properties. Maybe I should've said class reference. Take std::string for example. I'd be very interested if you've got code that supports for example name.size() where name is your reference property class. name->size() is no problem, but I'd like to have name.size(). Olaf _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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[random] seeding with arbitrary integers
by Steven Watanabe 23 Oct '09

23 Oct '09

AMDG Currently, some PRNGs cannot be seeded with certain values. For example, the seed for linear_congruential cannot be a multiple of the modulus if the offset is zero. lagged_fibonacci also cannot be seeded with 0, because it uses minstd_rand0. Since linear_congruential already tries to wrap the seed to fit in the range, I'd like to change it so that any seed works. The other generator that needs to be changed is linear_feedback_shift. linear_feedback_shift cannot be seeded with a small integer. What I've done is to add the minimum value to the seed, if the seed is too small. I'm not sure that this is a good solution, since this means that there are a few (and only a few) seeds that result in identical generators. Thoughts? Would it be better to wrap the values to make them fit in range instead? At least this would be consistent with linear_congruential. I've attached a patch with these changes and test cases. See also: http://svn.boost.org/trac/boost/ticket/3516 which prompted this investigation. In Christ, Steven Watanabe

7 18

[asio] help windows.h not littering namespace
by Bjoern Thiel 23 Oct '09

23 Oct '09

Hallo, in socket_types.hpp instead of ... # if defined(__CYGWIN__) # if !defined(__USE_W32_SOCKETS) # error You must add -D__USE_W32_SOCKETS to your compiler options. # endif // !defined(__USE_W32_SOCKETS) # if !defined(NOMINMAX) # define NOMINMAX 1 # endif // !defined(NOMINMAX) # endif // defined(__CYGWIN__) # include <winsock2.h> ... I suggest something like ... # if defined(__CYGWIN__) # if !defined(__USE_W32_SOCKETS) # error You must add -D__USE_W32_SOCKETS to your compiler options. # endif // !defined(__USE_W32_SOCKETS) # endif // defined(__CYGWIN__) # if !defined(NOMINMAX) # define NOMINMAX 1 # define BOOST_NOMINMAX_DEFINED 1 # endif // !defined(NOMINMAX) # include <winsock2.h> # if defined(BOOST_NOMINMAX_DEFINED) # undef NOMINMAX # undef BOOST_NOMINMAX_DEFINED # endif // defined(BOOST_NOMINMAX_DEFINED) ... Thanks. Bjoern Thiel

1 0

[libboost_regex-1_32.dylib] Validating Email address using Regx failing in boost
by Arun 23 Oct '09

23 Oct '09

Hi All, I am using boost regex libraries (libboost_regex-1_32.dylib) for validation of strings. The regular expression string i use is as below. string expr = "^((?>[a-zA-Z\\d!#$%&'*+\\-/=?^_`{|}~]+\\x20*|\"((?=[\\x01-\\x7f])[^\"\\\\]|\\\\[\\x01-\\x7f])*\"\\x20*)*(?<angle><))?((?!\\.)(?>\\.?[a-zA-Z\\d!#$%&'*+\\-/=?^_`{|}~]+)+|\"((?=[\\x01-\\x7f])[^\"\\\\]|\\\\[\\x01-\\x7f])*\")@(((?!-)[a-zA-Z\\d\\-]+(?<!-)\\.)+[a-zA-Z]{2,}|\\[(((?(?<!\\[)\\.)(25[0-5]|2[0-4]\\d|[01]?\\d?\\d)){4}|[a-zA-Z\\d\\-]*[a-zA-Z\\d]:((?=[\\x01-\\x7f])[^\\\\\\[\\]]|\\\\[\\x01-\\x7f])+)\\])(?(angle)>)$"; When i make a call boost::regex regExpr(expr); it is throwing what(): Invalid preceding regular expression. I got the regular expression from http://regexlib.com/REDetails.aspx?regexp_id=711 and converted into std::string. If i print the string onto a terminal, the string exactly matches with the regular expression ^((?>[a-zA-Z\d!#$%&'*+\-/=?^_`{|}~]+\x20*|"((?=[\x01-\x7f])[^"\\]|\\[\x01-\x7f])*"\x20*)*(?<angle><))?((?!\.)(?>\.?[a-zA-Z\d!#$%&'*+\-/=?^_`{|}~]+)+|"((?=[\x01-\x7f])[^"\\]|\\[\x01-\x7f])*")@(((?!-)[a-zA-Z\d\-]+(?<!-)\.)+[a-zA-Z]{2,}|\[(((?(?<!\[)\.)(25[0-5]|2[0-4]\d|[01]?\d?\d)){4}|[a-zA-Z\d\-]*[a-zA-Z\d]:((?=[\x01-\x7f])[^\\\[\]]|\\[\x01-\x7f])+)\])(?(angle)>)$ I am not able to find why boost is telling the string as invalid regular expression. I work in Mac OS X Leopard, and use boost_1_32. Any ideas? Thanks Arun Reply Forward New window Print all « Back to Sent Mail Archive Report spam Delete Move to Inbox Labels More actions 1 of 598 Older › Use free POP access to download your messages to Outlook or devices that support POP. Learn more You are currently using 1306 MB (17%) of your 7382 MB. Last account activity: 9 minutes ago at this IP (125.16.133.35). Details Gmail view: standard | turn off chat | older version | basic HTML Learn more ©2009 Google - Terms - Privacy Policy - Google Home

4 7

[asio] icmp example not working on Windows 2000
by Wolfgang Fertsak 23 Oct '09

23 Oct '09

Hello! The icmp example provided with the asio-library in 1.40 throws a system error with code 10044 "The support for the specified socket type does not exist in this address family." when compiled with _WIN32_WINNT 0x0500 and executed on an Win2000 machine. The error comes from the gai_echeck()-function in socket_ops.hpp which is called with family AF_INET and socktype SOCK_RAW: inline int gai_echeck(const char* host, const char* service, int flags, int family, int socktype, int protocol) { .... switch (family) { case AF_UNSPEC: break; case AF_INET: case AF_INET6: if (socktype != 0 && socktype != SOCK_STREAM && socktype != SOCK_DGRAM) return EAI_SOCKTYPE; ... I have attached the callstack for call to gai_echeck() I'm using Visual Studio 2005 and boost 1.39 (although the example is from boost 1.40) I changed the return value of gai_echeck() back to 0 in the debugger and then the rest of the icmp(ping) example ran without any apparent problems. Best regards, Wolfgang boost::asio::detail::socket_ops::gai_echeck(const char * host=0x0012fad0, const char * service=0x0012faa8, int flags=0, int family=2, int socktype=3, int protocol=1) Line 1380 C++ boost::asio::detail::socket_ops::getaddrinfo_emulation(const char * host=0x0012fad0, const char * service=0x0012faa8, const addrinfo * hintsp=0x0012fa78, addrinfo * * result=0x0012faf0) Line 1441 + 0x1d bytes C++ boost::asio::detail::socket_ops::WspiapiGetAddrInfo(const char * host=0x0012fad0, const char * service=0x0012faa8, const addrinfo * hints=0x0012fa78, addrinfo * * result=0x0012faf0, boost::system::error_code & ec={...}) Line 1801 + 0x15 bytes C++ boost::asio::detail::resolver_service<boost::asio::ip::icmp>::resolve(boost::shared_ptr<void> & __formal={...}, const boost::asio::ip::basic_resolver_query<boost::asio::ip::icmp> & query={...}, boost::system::error_code & ec={...}) Line 147 + 0x51 bytes C++ boost::asio::ip::resolver_service<boost::asio::ip::icmp>::resolve(boost::shared_ptr<void> & impl={...}, const boost::asio::ip::basic_resolver_query<boost::asio::ip::icmp> & query={...}, boost::system::error_code & ec={...}) Line 105 + 0x1b bytes C++ boost::asio::ip::basic_resolver<boost::asio::ip::icmp,boost::asio::ip::resolver_service<boost::asio::ip::icmp> >::resolve(const boost::asio::ip::basic_resolver_query<boost::asio::ip::icmp> & q={...}) Line 98 + 0x1d bytes C++ pinger::pinger(boost::asio::io_service & io_service={...}, const char * destination=0x00324199) Line 32 + 0x1a bytes C++ main(int argc=2, char * * argv=0x00324170) Line 155 + 0x16 bytes C++

1 0

boost-test and Mac 10.6
by Mike Tegtmeyer 23 Oct '09

23 Oct '09

Does anyone know anything about boost test crashing on Mac 10.6? Unless I'm missing something, it is completely broken for 1.40 and trunk. There is a Ticket #2889 (closed Bugs: fixed) for malloc errors that looks awfully similar to what I'm seeing. file is: rotor:~ tegtmeye$ cat boost_test.cc #define BOOST_TEST_MODULE footest test #include <boost/test/unit_test.hpp> BOOST_AUTO_TEST_CASE( test1 ) { BOOST_CHECK( true ); } BOOST_AUTO_TEST_CASE( test2 ) { BOOST_CHECK( true ); } BOOST_AUTO_TEST_CASE( test3 ) { BOOST_CHECK( true ); } BOOST_AUTO_TEST_CASE( test4 ) { BOOST_CHECK( true ); } rotor:~ tegtmeye$ g++ boost_test.cc /usr/local/lib/libboost_unit_test_framework.a rotor:~ tegtmeye$ ./a.out Running 4 test cases... *** No errors detected a.out(69716) malloc: *** error for object 0x30001002002e0: pointer being freed was not allocated *** set a breakpoint in malloc_error_break to debug Abort trap

3 3

[intrusive] rtti_base class proposition
by Ireneusz Szpilewski 22 Oct '09

22 Oct '09

Hi, Here is my idea for this little class: class rtti_base { virtual void _dummy() {} }; Every class deriving from rtti_base can be queried by means of RTTI, in particular rtti_base class and dynamic_cast can be used in similar way as IUnknown and QueryInterface() in COM Object Model rtti_base* could be used as a "smart" void* pointer - we can get type information, and use it in heterogenic containers as in: std::list<rtti_base*> beings; we can iterate through beings and call Cat::GiveMilk() for cats but Girl::Kiss() for girls. :-) The main purpose of this class is to set some standard name for that pointer type. Ireneusz Szpilewski

7 27

Re: [boost] linking on OSX
by David M. Cotter 22 Oct '09

22 Oct '09

>> please be explicit, are you saying i should type exactly this: >> >> ./bjam macosx-version-min=10.4 architecture=combined >> linkflags="-Wl,-force_cpusubtype_ALL" --with-thread -a -n install > > I don't know how to use bjam, nor do I have any wish to learn, so I > can't help you with its command line arguments. > Did doing that give you -Wl,-force_cpusubtype_ALL for the g++ > command that creates libboost_thread.dylib? apparently the extra -Wl is not necessary, since when i leave it off, it still gets sent, probably due to the macosx-min-version flag. WITH: > ./bjam macosx-version-min=10.4 architecture=combined linkflags="-Wl -force_cpusubtype_ALL" --with-thread -a -n install "g++" -dynamiclib -Wl,-single_module -install_name "libboost_thread.dylib" -o "bin.v2/libs/thread/build/darwin-4.2.1/ release/architecture-combined/macosx-version-min-10.4/threading-multi/ libboost_thread.dylib" "bin.v2/libs/thread/build/darwin-4.2.1/release/ architecture-combined/macosx-version-min-10.4/threading-multi/pthread/ thread.o" "bin.v2/libs/thread/build/darwin-4.2.1/release/architecture- combined/macosx-version-min-10.4/threading-multi/pthread/exceptions.o" "bin.v2/libs/thread/build/darwin-4.2.1/release/architecture-combined/ macosx-version-min-10.4/threading-multi/pthread/once.o" - headerpad_max_install_names -mmacosx-version-min=10.4 -Wl,-dead_strip - no_dead_strip_inits_and_terms -arch i386 -arch ppc -Wl - force_cpusubtype_ALL note: see it's in there TWICE? is the problem that i'm missing a comma? WITHOUT: > ./bjam macosx-version-min=10.4 architecture=combined linkflags="- force_cpusubtype_ALL" --with-thread -a -n install "g++" -dynamiclib -Wl,-single_module -install_name "libboost_thread.dylib" -o "bin.v2/libs/thread/build/darwin-4.2.1/ release/architecture-combined/macosx-version-min-10.4/threading-multi/ libboost_thread.dylib" "bin.v2/libs/thread/build/darwin-4.2.1/release/ architecture-combined/macosx-version-min-10.4/threading-multi/pthread/ thread.o" "bin.v2/libs/thread/build/darwin-4.2.1/release/architecture- combined/macosx-version-min-10.4/threading-multi/pthread/exceptions.o" "bin.v2/libs/thread/build/darwin-4.2.1/release/architecture-combined/ macosx-version-min-10.4/threading-multi/pthread/once.o" - headerpad_max_install_names -mmacosx-version-min=10.4 -Wl,-dead_strip - no_dead_strip_inits_and_terms -arch i386 -arch ppc -force_cpusubtype_ALL

2 3

[conversion] Release v0.3 : Changing the order of assign_to parameters + `tie' function
by vicente.botet 22 Oct '09

22 Oct '09

Hi, I have just released the version 0.3 of Boost.Conversion , which includes since my last publicly announced version 0.1: Version 0.3.0, Oct 22, 2009 Changing the order of to and from parameters on assign_to + Added `tie' function Incopatibility: * Changing the order of to and from parameters on assign_to. * Now boost/conversion/convert_to.hpp and boost/conversion/assign_to.hpp files are separated. New Features: * Added <boost/conversion.hpp> global file. * Added mca() function. * Added convert_to_via function. Test: * Added test for the new features Version 0.2.0, Mai 16, 2009 Adding array + fusion::tuples + Adaptation to Boost 1.39 New Features: * conversion between boost::array of explicitly convertible types. * conversion between Boost.Fusion sequences of explicitly convertible types. You can found all the detail for dowloading, documentation, ... in http://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction#Boost.Conve… I'd appreciate it if people could take a look, test it on their compiler and give me some feedback. Best regards, _____________________ Vicente Juan Botet Escribá

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Re: [boost] linking on OSX
by David M. Cotter 21 Oct '09

21 Oct '09

please be explicit, are you saying i should type exactly this: ./bjam macosx-version-min=10.4 architecture=combined linkflags="-Wl,- force_cpusubtype_ALL" --with-thread -a -n install cuz that didn't do anything On Oct 21, 2009, at 11:03 AM, Peter O'Gorman wrote: > On 10/21/2009 12:26 PM, David M. Cotter wrote: >> you can see that the build system is in fact emitting the correct >> command for linking, however it is apparently being ignored on PPC > >> >> malkier:lib davec$ otool -f -v ./libboost_thread.dylib >> Fat headers >> fat_magic FAT_MAGIC > >> architecture *ppc7400* >> cputype CPU_TYPE_POWERPC >> cpusubtype *CPU_SUBTYPE_POWERPC_7400* >> capabilities 0x0 > >> >> so i'm dead in the water on this project. any insight or help that >> solves this would win you free mac Karaoke software. :) and my >> gratitude. >> > > Change it to -Wl,-force_cpusubtype_ALL, the flag is not passed along > by gcc to the linker. > > If you build all your object files with the -mmacosx-version-min > flag, as far as I know, you shouldn't be getting ppc7400 in the > cpusubtype. > > Peter > -- > Peter O'Gorman > http://pogma.com

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

21 Oct '09

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

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Re: [boost] Preliminary submission: generic linear algebra algorithms library Boost LA
by Daniel Pfeifer 21 Oct '09

21 Oct '09

Hi Emil, I had a look at the documentation and examples of your library and I think it is awesome so far. Your library could be a C++ complement to the builtin vector and matrix types and functions of GLSLang. (see http://www.opengl.org/registry/doc/GLSLangSpec.1.50.09.pdf pages: 23, 53ff, 60, 81ff). Since you already have mastered swizzling, implementing the rest should be peanuts. My wishlist: * component wise multiplication and division of two vectors implemented as operators (as in GLSL). * all the vector and matrix related functions described in chapter 8 of the GLSL spec. * operator[] As for the name: If LA is too misleading, I would propose "kd-math" or "math-kd". There already is another project called math3d, and since your library is not limited to three dimensions, kd (as in kd-tree) suits quite well in my opinion. cheers, Daniel Emil Dotchevski wrote: > I remember some past discussions on this mailing list about the need > for similar library in Boost, so I hope it is OK to skip the interest > query and request a preliminary review for Boost LA. > > Boost LA provides a set of generic linear algebra algorithms, > primarily for working with vectors and matrices of static size. The > library also defines vector and matrix data types, however it allows > users to introduce their own types by specializing the vector_traits > and matrix_traits templates. > > Documentation and source code available at > http://www.revergestudios.com/boost-la, released under the Boost > Software License. > > Thanks, > Emil Dotchevski > _______________________________________________ > Unsubscribe & other changes: > http://lists.boost.org/mailman/listinfo.cgi/boost

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Re: [boost] linking on OSX
by David M. Cotter 21 Oct '09

21 Oct '09

okay i've stared at the doc for bjam but can find NOTHING which indicates how to tell it to build for 10.4 anyone have an idea on that? >>> This load command (see mach-o/loader.h) is LC_DYLD_INFO_ONLY. >>> >>> I can only guess, but did you compile boost with -mmacosx-version- >>> min=10.6, but built your app with an earlier deployment target, >>> and when you attempt to run it, you're doing so on Leopard? >> >> i did not specify a min version when i built. so what should i >> do? this is what i suspect: >> >> re-build boost using -mmacosx-version-min=10.4 >> >> and all will be well? > > Should work, though I don't know if you'll also have to point boost > at the 10.4 SDK with -isysroot. I suspect not.

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BOOST_FOREACH like macro for map
by mobi phil 21 Oct '09

21 Oct '09

Hello, new to this list... did not find anything similar on net. One of the annoyances with std::map is that if you work with const maps, then there is no "one line" code to get an element knowing the key. given the map const map<string, string> aStringMap; I cannot write const string &s = aStringMap["key"]; process(s); I should write: map<string, string>::const_iterator it=aStringMap.find("key") if( it != aStringMap.end() ) { process(it->second) } so would be nice to have a macro like BOOST_CONSTMAPFIND(aStringMap, "key", data) { processResult( data ); } the version if(BOOST_CONSTMAPFIND(l_map, l_key, l_data) ) { } Seems to be impossible to implement -- rgrds, mobi phil being mobile, but including technology http://mobiphil.com

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Re: [boost] linking on OSX
by David M. Cotter 21 Oct '09

21 Oct '09

okay we now know what the problem is, the question for the BOOST folk is: how do i do this with bjam? On Oct 20, 2009, at 7:23 PM, Chris Suter wrote: > Hi David, > > On Wed, Oct 21, 2009 at 1:03 PM, David M. Cotter <me(a)davecotter.com> > wrote: > okay. everything is working fantastically, however, it won't run on > G3 machine running 10.4.11 > it works perfectly on a G4 PPC machine also running 10.4.11 > > is there some way to "tune" bjam to emit G3-compatible code? > cuz i'm getting this: > > Host Name: TAZ-2 > Date/Time: 2009-10-20 05:56:18.099 -0700 > OS Version: 10.4.11 (Build 8S165) > Report Version: 4 > > Command: FooBar Pro > Path: /Applications/FooBar Pro.app/Contents/MacOS/FooBar Pro > Parent: WindowServer [310] > > Version: FooBar Pro 1.0d50r33 (1.0) > > PID: 445 > Thread: Unknown > > Link (dyld) error: > > Library not loaded: @loader_path/../SharedSupport/ > libboost_thread.dylib > Referenced from: /Applications/FooBar Pro.app/Contents/MacOS/ > FooBar Pro > Reason: no suitable image found. Did find: > /Applications/FooBar Pro.app/Contents/MacOS/../SharedSupport/ > libboost_thread.dylib: no matching architecture in universal wrapper > /Applications/FooBar Pro.app/Contents/MacOS/../SharedSupport/ > libboost_thread.dylib: no matching architecture in universal wrapper > > This is most likely because you're only building for G4 machines and > greater. If you run otool -f -v <binary>, you'll probably see > cpusubtype set to CPU_SUBTYPE_POWERPC_7400 (which basically means G4 > or greater). > > To fix, as a minimum, you need to make sure that your deployment > target is set to 10.4 or less and make sure your architecture > setting is ppc rather than ppc7400. > > Kind regards, > > Chris

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[interprocess] new problem with move-aware containers
by Thorsten Ottosen 20 Oct '09

20 Oct '09

Hi Ion, I'm using the boost::interprocess::multiset from trunk with vc9. After updating, some of my code stopped working. I use a set like multiset<const Node*,SomePredicate> and when calling set.insert( &obj ) I get compile errors. Specifically in interprocess\detail\move.hpp(79) I don't understand the details of these move-emulation tricks, but the compiler complains that T=U* for some U is not a legal base class. AFAICT, the compiler is right: template <class T> class rv : public T { rv(); ~rv(); rv(rv const&); void operator=(rv const&); }; -Thorsten

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bzip with spreadsort
by Steven Ross 20 Oct '09

20 Oct '09

I've added fasterbzip2-1.0.5.zip to the Boost Vault as an example application of the Spreadsort hybrid radix sorting algorithm. As bzip is written in C, I couldn't use the template library directly and had to modify the source. Using the Spreadsort algorithm causes a measurable speed improvement on Windows for the first 100MB of wikipedia from: http://cs.fit.edu/~mmahoney/compression/textdata.html<http://cs.fit.edu/%7Emmahoney/compression/textdata.html> along with other data I tested. Please note that bzip doesn't spend all its time compressing, already has two stages of radix sort, and has specialized and manually inlined comparison functions, so it's heavily optimized to begin with and improvements are minor.

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[mpl] Is there anyone working on mpl with variadic templates ?
by luozhiyuan 20 Oct '09

20 Oct '09

Is it possible that BOOST_MPL_LIMIT_/seq/_SIZE can be removed when we have variadic templates ?

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[bitfield] Pre-review request
by vicente.botet 19 Oct '09

19 Oct '09

Hi all, I have adapted the Boost.Bitfield library from Emile Cormier with its permision and I have requested the Review Wizards to include Boost.Bitfield on the review schedule. The library is now quite stable. Even if there were not too much interest in the Boost ML, only 140 dowloads from the Boost Vault, the version on which it is based had more that 1500 downloads, so I suppose that the subject interest a lot of people. I really think Boost.Bitfield is the complement the Boost.Endian library to manage with all the endian issue, allowing to mange not only endian interger issues, but also endian bitfield issues. I hope that including it on the review schedule will generate more interest and help me to improve the library. I would appreciate it if people could participate to this Pre-review, reading the documentation, testing on their compiler, .... Every comment is wellcome. BTW, I'm looking for a review manager. Thanks for all, Vicente Boost.Bitfield Author(s): Vicente J. Botet Escribá, Emile Cormier Download: `Boost Vault: <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=bitfie…> Boost Sandbox: https://svn.boost.org/svn/boost/sandbox/bitfield Documentation: https://svn.boost.org/svn/boost/sandbox/bitfield/libs/bitfield/doc/index.ht… Html doc also included the Vault package Categories: Portability, Integer Description: Portable bitfields traits. Boost.Bitfield consists of: * a generic bitfield traits class providing generic getter and setter methods. * a BOOST_BITFIELD_DCL macro making easier the definition of the bitfield traits and the bitfield getter and setter functions. Example declaration: struct Rgb565 { uint16_t storage; BOOST_BITFIELD_DCL(uint16_t, storage, unsigned char, red, 0, 4); BOOST_BITFIELD_DCL(uint16_t, storage, unsigned char, green, 5, 10); BOOST_BITFIELD_DCL(uint16_t, storage, unsigned char, blue, 11,15); }; Example usage: Rgb565 r; r.storage= 0xffff; // Write to a bitfield. Note that parenthesis are needed around the bitfield r.red() = 23; // Read from a bitfield unsigned char b = r.blue(); In a near future the library could add the following if the users consider it useful. * Add bitfields group * Used to easily manipulate groups of bitfields the same way as does C bitfields, but in a portable manner. Example declaration: struct Rgb565 { struct red {}; struct green {}; struct blue {}; typedef bitfields<mpl::vector< member<unsigned char, red, 5>, member<unsigned char, green, 6>, member<unsigned char, blue, 5> > > type; }; Example usage: Rgb565::type r = make_bitfields<Rgb565::type, 1,2,3>; // Write to a bitfield. r.get<Rgb565::red>() = 23; //or r.set<Rgb565::red>(23); // Read from a bitfield Rgb565::at<Rgb565::blue>::value_type b = r.get<Rgb565::blue>(); * Add pointer_plus_bits * Based on a.. The article of Joaquin Optimizing red-black tree color bits, b.. the implementation of Ion pointer_plus_bits from Boost.Intrusive , and c.. Clang's QualType smart pointer This class will allows to use the unsused bits of a pointer to reduce the size of the nodes containing pointers and bits and sometimes improving also the performances. I have not reached yet the interface I would like to have. For the moment we can do typedef pointer_plus_bits<int*,1,bool>::type pint_and_bool; int i=0; pint_and_bool v1; ASSERT_EQUALS(v1.pointer(),0); ASSERT_EQUALS(v1.small_int(),false); pint_and_bool v2(&i, true); ASSERT_EQUALS(v2.pointer(),&i); ASSERT_EQUALS(v2.small_int(),true); v1.pointer()=v2.pointer(); v1.small_int()=true; ASSERT_EQUALS(v1.pointer(),&i); ASSERT_EQUALS(v1.small_int(),true); typedef pointer_plus_bits< pointer_plus_bits<int*,1,bool>::type ,1, bool>::type pint_and_bool_bool pint_and_bool_bool v1; ASSERT_EQUALS(v1.small_int(),false); ASSERT_EQUALS(v1.pointer().get_pointer(),0); ASSERT_EQUALS(v1.get_pointer().get_pointer(),0); ASSERT_EQUALS(v1.get_pointer().small_int(),false);

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[interthreads] Pre-review request
by vicente.botet 19 Oct '09

19 Oct '09

Hi, I have requested the Review Wizards to include Boost.Interthreads library on the review schedule. Even if there were not too much interest for this library on this ML, there were more than 1000 dowloads from the Boost Vault. I'm open to reduce the scope of the library, if there are some parts that are not enough generic. I would appreciate it if people could participate to this Pre-review, reading the documentation, testing on their compiler, .... Every comment will help me a lot to improve the library. BTW, I'm looking for a review manager. Thanks in advance, Vicente InterThreads __________ :Author: Vicente J. Botet Escribá :Review Manager: ??? :Download: `Boost Vault: <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=intert…> Boost Sandbox: https://svn.boost.org/svn/boost/sandbox/interthreads Documentation: https://svn.boost.org/svn/boost/sandbox/interthreads/libs/interthreads/doc/… Html doc also included the Vault package :Description: Boost.InterThreads extends Boost.Threads adding thread setup/cleanup decorator, thread specific shared pointer, thread keep alive mechanism and thread tuples. * thread decorator: thread_decorator allows to define setup/cleanup functions which will be called only once by thread: setup before the thread function and cleanup at thread exit. * thread specific shared pointer: this is an extension of the thread_specific_ptr providing access to this thread specific context from other threads. As it is shared the stored pointer is a shared_ptr instead of a raw one. * thread keep alive mechanism: this mechanism allows to detect threads that do not prove that they are alive by calling to the keep_alive_point regularly. When a thread is declared dead a user provided function is called, which by default will abort the program. * thread tuple: defines a thread groupe where the number of threads is know statically and the threads are created at construction time. * set_once: a synchonizer that allows to set a variable only once, notifying to the variable value to whatever is waiting for that. * thread_tuple_once: an extension of the boost::thread_tuple which allows to join the thread finishing the first, using for that the set_once synchronizer. * thread_group_once: an extension of the boost::thread_group which allows to join the thread finishing the first, using for that the set_once synchronizer. (thread_decorator and thread_specific_shared_ptr) are based on the original implementation of threadalert written by Roland Schwarz.

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[spirit] Support for one-pass iterators?
by Andrey Semashev 19 Oct '09

19 Oct '09

Hi, I'm trying to use Boost.Spirit.Classic to parse a text file content (or, to be more generic, a content that is read from an STL stream). I created a grammar that would fit the content, but I'm not sure which iterator I should pass to the parse function. The parser does not guarantee that it will read the content only in one pass, and I'm sure my actors will want to read the content themselves as they are called. So, obviously, istream_iterator/istreambuf_iterator will not work. Is there a tool in Boost.Spirit that would provide content buffering during the parse? If not, what can be suggested to solve this problem? BTW, the content is line-aligned, i.e. each line is syntactically distinct from others. I was thinking about writing a loop of readline/parse combo but I'm not sure how efficient it would be with regard to the grammar definition construction/destruction within the parse function. Are these concerns valid? Thanks.

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Re: [boost] C# LINQ-like library: Boost.Qlang.
by Germán Diago 18 Oct '09

18 Oct '09

> Hi, > I read you mail on boost concerning QLang. I just wanted to say I was > wondering (not very seriously) how to do such system, and you come with a > very clean first try. > Basically it's done with some metaprogramming to get the exact return type of a query. For example, if I put as an argument in a select a pointer to member data, I extract that pointer to member's type and put it in a tuple, without const, volatile and removing the reference. I also use filter_iterator and transform_iterator from boost to filter sequences based on the where lambda. Just a suggestion : it would be great if the user of the qlang could select > a tuple of value as a return value. (let's say I want to select the string > member "_name", a copy of the pointeur "this", and an int "_age" for example > from a set of objects. I suppose returning a tuple for example (or some > other type than those of the members) could be very interesting. > I don't know very well what you mean by returning a tuple of value as a return value. For now, what the libraries does is, if you write: from(somerange).select(full_object); it will return a select_ object which will generate a copy of the full object. if you write: from(somerange).select(&MyStruct::a_, &MyStruct::b_); it will return a select_ object which will return a std::tuple<type of a_ without const and without reference, type of b_ without const and without reference>. Boost.Qlang allows you to return tuples right now, the problem is that those tuples (for now) are just 1-element tuples. But in the future they will be arbitrary tuples. A copy of the this pointer does not make sense I think. Since every piece of data is immutable (data is always generated based on the select arguments), if you want the this pointer, you will have to return full_object (a copy). So you cannot get the this pointer directly. You can manipulate that query and write it back where it belongs if you want to modify some object.

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[filesystem] truncate() function?
by Beman Dawes 18 Oct '09

18 Oct '09

There was a request on the users list for a file truncate() function similar to the POSIX function of the same name. Since Windows provides a function with virtually identical semantics, this seems like a reasonable request. The POSIX spec includes: "If the request would cause the file size to exceed the soft file size limit for the process, the request shall fail and the implementation shall generate the SIGXFSZ signal for the process." I have no knowledge of or experience with POSIX signals, so need advice. Does the POSIX implementation need to do anything to cope with the possibility of a SIGXFSZ signal? If so what? Thanks, --Beman

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[build] How to ignore Jamfiles?
by Sergey Zubkovsky 17 Oct '09

17 Oct '09

Hi, I there a way to ignore Jamfiles that are located in some subdirectories at a whole project's directory layout? Regargs, Sergey Zubkovsky

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[Proto][MPL]Missing ADL barrier in MPL
by Joel Falcou 17 Oct '09

17 Oct '09

I've just hit a spurrious ADL resolution using MPL and Proto. I made a new function called size that took a proto expression and I get the compiler to complain about ambiguity between mpl::size<T> and my own size() function. I tried to add ADL Barrier to size by looking at how it was used in other MPL components but it still fail to resolve the proper symbol under gcc 4.3. Any idea on what to do to fix that ?

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[1.41] Release Notes
by Daniel James 17 Oct '09

17 Oct '09

Hello everyone, Since we've more or less entered feature freeze, it's time to add any updates to the release notes. As always, you can just email me a line or two and I'll add it, ideally including the Trac tickets that have been fixed. Or if you want to do it yourself, the release notes directory is: https://svn.boost.org/svn/boost/website/public_html/beta/feed/history/ It would be best if you could do this before Sunday so that your changes will be included in the beta notes. thanks, Daniel

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Re: [boost] [1.40.0] Compilation errors in Visual Studio
by jeremyShiers 17 Oct '09

17 Oct '09

I had the same problem the options you have listed include /Za which means disable language extensions (c/c++ ; Language ; Disable Lanauge Extensions = yes in visual studio) I changed this and it compiled who knows why changing from boost_1_39 to 1_40 should expose this. cheers Jeremy Yes, I join to this question. My setup: - VS2005 and try to compile QuantLib. - boost_1_40 Yes, I join to this question. My setup: - VS2005 and try to compile QuantLib. - boost_1_40 -- View this message in context: http://www.nabble.com/-1.40.0--Compilation-errors-in-Visual-Studio-tp253364… Sent from the Boost - Dev mailing list archive at Nabble.com.

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