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a new release of Join - asynchronous concurrency library
by Yigong Liu 15 Jul '08

15 Jul '08

Hello, I just uploaded a new version of Join library to Vault under Concurrent Programming. Based on the feedback from list, the following changes are made: . add schedulers as actor's template policy class . add timed synchronous calls . add doc and samples for port based API . add more doc about Join internals. For people who are not familiar with the librayr. Here is a simple description: Join is an asynchronous, message based C++ concurrency library based on join calculus. It is applicable both to multi-threaded applications and to the orchestration of asynchronous, event-based applications. It follows Comega's design and implementation and builds with Boost facilities. It provides a high level concurrency API with asynchronous methods, synchronous methods, and chords which are "join-patterns" defining the synchronization, asynchrony, and concurrency. website and download: http://channel.sourceforge.net Any comments and suggestions are highly appreciated. Thanks Yigong

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Streaming Lambda functions
by Robert Jones 14 Jul '08

14 Jul '08

Is it possible to invoke user defined streaming operators within boost lambda functions? In this style #include <iostream> #include <map> #include "boost/lambda/lambda.hpp" using namespace std; ostream & operator << ( ostream & ostrm, pair<string, string> const & input ); ostream & operator << ( ostream & ostrm, map<string, string> & inputs ) { using namespace boost :: lambda; for_each ( inputs.begin( ), inputs.end( ), ostrm << _1 << '\n' ); return ostrm; } Is this basically undoable, or am I doing it wrong? Also, does the online Comeau compiler understand the boost include directives? Thanks, Rob.

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z/OS supported
by Dr. Franz Fehringer 14 Jul '08

14 Jul '08

Hello all, Is z/OS (recent version assumed) with USS (Unix System Services) a supported configuration with respect to the boost library components? Cheers Franz

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Re: [boost] Bind question, is there any way to implicitly go through a reference_wrapper?
by Michael Goldshteyn 14 Jul '08

14 Jul '08

Sorry, post got garbled, here it is again: #include <boost/bind.hpp> #include <boost/ref.hpp> #include <string> // Define a simple class for our example class Crayon { public: explicit Crayon(const std::string &color=std::string()):m_color(color) {} const std::string &GetColor() const {return m_color;} private: std::string m_color; }; int main(int argc, char *argv[]) { using namespace std; using namespace boost; Crayon cr("blue"); boost::reference_wrapper<const Crayon> crefCr(cr); // This compiles std::string color(boost::bind(&Crayon::GetColor,_1)(cr)); // This also compiles, using an explicit get on crefCr std::string colorFromConstRef(boost::bind(&Crayon::GetColor,boost::bind(&boost::referenc e_wrapper<const Crayon>::get,_1))(crefCr)); // This doesn't compile, however, even though the reference_wrapper class template has // an overloaded operator T& () const function std::string colorFromConstRef2(boost::bind(&Crayon::GetColor,_1)(crefCr)); }

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unmerged changes in boost function
by Emil Dotchevski 14 Jul '08

14 Jul '08

I can see that the new allocator semantics in boost::function have not been merged into the release branch. I would volunteer to do the merge but it seems like there are some other changes that I'm not familiar with. Doug, how should this be handled? I would hate 1.36 to go out without the new allocator support for boost::function as I already have code that depends on it. :) Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode

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[function][release] outdated boost/function/detail/prologue.hpp header causing regressions in MSVC++ 9.0
by joaquin＠tid.es 14 Jul '08

14 Jul '08

Hello, Just in case this is going unnoticed: Boost.Function is having regressions at the release branch for MSVC++ 9.0, see for instance: http://tinyurl.com/5h2wl5 Seems the problem is simply that function_template.hpp was last merged to the branch release later than boost/function/detail/prologue.hpp (merged at 41356) so that the release does not have revisions 44030 and 44056 of this last header, resulting in the lack of a necessary inclusion of <boost/type_traits/is_void.hpp>. HTH, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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base64 filter works incorrect if sorce string length % 3 != 0
by Игорь Палагута 14 Jul '08

14 Jul '08

Hello, I have the following code: #include <boost/archive/iterators/binary_from_base64.hpp> #include <boost/archive/iterators/base64_from_binary.hpp> #include <boost/archive/iterators/insert_linebreaks.hpp> #include <boost/archive/iterators/remove_whitespace.hpp> #include <boost/archive/iterators/transform_width.hpp> #include <string> #include <exception> #include <iostream> int main() { using namespace boost::archive::iterators; typedef insert_linebreaks< base64_from_binary< transform_width< std::string::const_iterator, 6, sizeof( char ) * 8 > > ,72 > to_base64_type; typedef transform_width< binary_from_base64< remove_whitespace< std::string::const_iterator > >, sizeof( char ) * 8, 6 > to_binary_type; std::string hello_ = "hello"; std::string base64_hello_( to_base64_type( hello_.begin() ) , to_base64_type( hello_.end() ) ); std::cout << base64_hello_ << std::endl; try { std::string hello_recovered_( to_binary_type( base64_hello_.begin() ) , to_binary_type( base64_hello_.end() ) ); std::cout << hello_recovered_ << std::endl; } catch ( const std::exception& e_ ) { std::cerr << e_.what() << std::endl; } return 0; } During base64 decode we have following exception: "attempt to decode a value not in base64 char set". We have the problem because source string hello_ = "hello", has length % 3 != 0, otherwise we don't have this exception. As I know in this case we should add appropriate number of special symbol like '='. I can add '=' manually, but boost base64 decode can't process them, and we also have exception If we have insert_linebreaks/remove_whitespace filter perhaps we also should have some symmetric filter for text padding? Do we have padding filter in boost? Or perhaps it will be in future? Thanks

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detecting ODR violations
by Steven Watanabe 14 Jul '08

14 Jul '08

AMDG I've been trying to work out a way to cause an explicit error if configuration macros are defined differently in different translation units. I really wish I could cause a link error, but the best I've been able to come up with so far is a runtime error // test_odr.hpp #ifndef TEST_ODR_HPP_INCLUDED #define TEST_ODR_HPP_INCLUDED #include <iostream> #include <cstdlib> #ifndef SOME_MACRO #define SOME_MACRO true #endif template<bool> struct test_odr { static bool value; }; template<bool b> bool test_odr<b>::value = SOME_MACRO; namespace { struct test_odr_impl_t { test_odr_impl_t() { if(test_odr<true>::value != SOME_MACRO) { std::cerr << "Error: SOME_MACRO defined differently in two translation units.\n"; std::abort(); } } }; test_odr_impl_t test_odr_impl; } #endif // test_odr1.cpp #include "test_odr.hpp" int main() {} // test_odr2.cpp #define SOME_MACRO false #include "test_odr.hpp" Comments? Any better ideas? In Christ, Steven Watanabe

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[intrusive] Problem with EDG base compilers in strict Ansi mode.
by Markus Schöpflin 14 Jul '08

14 Jul '08

Hello, currently any_test and doc_any_hook fail on Tru64/CXX with the following errors: cxx: Error: ../boost/intrusive/detail/any_node_and_algorithms.hpp, line 276: class template "boost::intrusive::any_algorithms<VoidPointer>" has no member "unlink_not_available_for_any_hooks" (notmember) any_algorithms<VoidPointer>::unlink_not_available_for_any_hooks(); -----------------------------------^ cxx: Error: ../boost/intrusive/detail/any_node_and_algorithms.hpp, line 283: class template "boost::intrusive::any_algorithms<VoidPointer>" has no member "swap_nodes_not_available_for_any_hooks" (notmember) any_algorithms<VoidPointer>::swap_nodes_not_available_for_any_hooks(); -----------------------------------^ AFAICT this is the only EDG based compiler which tests in strict Ansi mode, adding -strict_ansi to the other EDG based compilers (acc for example) would probably lead to the same error. Attached patch contains a proposed fix for this. It checks for __EDG__ and __STD_STRICT_ANSI to enable the fix and works for me locally. The patch should replace the compile error by a link error, because in strict Ansi mode EDG doesn't allow you to refer to non-existing names. OK to apply? Regards, Markus Index: detail/any_node_and_algorithms.hpp =================================================================== --- detail/any_node_and_algorithms.hpp (revision 46676) +++ detail/any_node_and_algorithms.hpp (working copy) @@ -269,6 +269,11 @@ static bool unique(const_node_ptr node) { return 0 == node->node_ptr_1; } + +#if defined(__EDG__) && defined(__STD_STRICT_ANSI) + static void unlink(node_ptr); + static void swap_nodes(node_ptr l, node_ptr r); +#else static void unlink(node_ptr) { //Auto-unlink hooks and unlink() call for safe hooks are not @@ -282,6 +287,7 @@ //what algorithm they must use from unlink them from the container any_algorithms<VoidPointer>::swap_nodes_not_available_for_any_hooks(); } +#endif }; } //namespace intrusive

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[thread] lockable traits and concepts classes adding proposal
by vicente.botet 14 Jul '08

14 Jul '08

Hello boosters , While writtig a generic library I have needed some lockable traits and concepts to be chacked with BCCL. If you think that these classes are of general use it will be a pleasure for me, if Anthony accepts, to included them on the Boost.Thread library. Otherwise I will left them in my Sync library. For the moment all is defined in a sync (as synchronization) namespace and directory but this is without importance. Attached a short introduction (in quickbook format- sorry I can not attach the html file) as well as the header files (which should with gcc 3.4 on cygwin) Of course all this is subject to discusion, naming and file structure changes, ... For each one of the mutex in the thread library, we need to * make the mutex inherit from the helper lock_traits_base or * have nested typedefs or * specialize each one of the traits templates As an external library I have do this in a non-intrusive way as for example: template<> struct timed_interface_tag<boost::mutex> { typedef hasnt_timed_interface_tag type; }; template<> struct reentrancy_tag<boost::mutex> { typedef non_recursive_tag type; }; template<> struct category_tag<boost::mutex> { typedef exclusive_lock_tag type; }; template<> struct scope_tag<boost::mutex> { typedef multi_threaded_tag type; }; But if included in the Thread library it will be better to use one of the intrusive methods. I have also defined other classes that could be of general interest. * A make_lockable class will make Lockable/ShareLocakble/UpgradeLocable the derived class depending on the Lock parameter. This class could be the base of a monitor class. It can be used as follows: class X : public make_lockable<boost::mutex> { } X x; unique_lock<X> lock(x); * a ..._synchronization_family set of classes that can be used as follows: template <class SyncFamily> message_queue; typedef message_queue<thread_synchonization_family> my_mt_message_queue; typedef message_queue<null_synchonization_family> my_st_message_queue; The null_synchonization_family needs a null_mutex and a null_condition classes. There is already something similar in Boost::Interprocess. * To finish, I'm working on a filter_matching_lockables meta-function which take as parameter a vector of lockables types and will filter the lockables types not satisfying a list of traits. The use shoul be somthing like typedef filter_matching_lockables<vector<boost::mutex, boost::recursive_mutex, ...>, mpl::and_<is_exclusive_lock<_>, mpl::not_<is_recursive_lock<_> > >::type candidates. and a find_best_lock which choose between the lockables given as parameter the best one following a given criteria. Of course, there is yet a lot of work to do, add lock concepts, lockable and lock concept traits, document, tests, document, tests ... between others. As you see there is nothing new, neither complex, only some helper classes making easier the construction of higher abstraction levels, and that currently are missing in boost. Have a good code reading and please let me know what do you think. _____________________ Vicente Juan Botet Escriba

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