October 2010 - Boost-users - lists.preview.boost.org

Proto domains shenanigans
by joel falcou 13 Oct '10

13 Oct '10

OK, I have a situation in which proto domain/subdomain could help me but i can't wrap my head around a proper solution. Here is the deal, i have various sub EDSL that goes like: - constants EDSL provides named consatnts (like zero_, one_, pi_ etc) that are meant to be terminal usable in any other EDSL en provide a type based way to know which constant is beging used and provide optimization in came it helps (e.g detecting x < zero_ in SIMD EDSL to replace with the SSSE3 corresponding fused operation) - a SIMD vector EDSL - various container based EDSL : table (multidim array), vector, matrix and tensor, polynom and rigid_transform. The rules I want to have is : - constant can mix with any other EDSL - SIMD don't mix with anybody - table mix with every other container and make them evaluates as table (e.g matrix * table == elementwise product and not matrix product) - vector, matrix, tensor can mix - polynom can mix with table but not with vector, matrix, tensor - rigid_transform van mix with table and matrix However i can't find any combination of domain definition that satisfy all. Is there some systematic methodologies to not fail at that ?

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[asio] DNS query
by for-gmane 13 Oct '10

13 Oct '10

Hi, is it possible to do DNS queries with asio? (for example getting the MX record(s) of a domain)

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[units] quantities with system abstraction "any<length>"
by alfC 13 Oct '10

13 Oct '10

Hi, In order to avoid reinventing the wheel I was wondering if there is any effort or there was any attempt to further abstract boost::units::quantities from its unit system but with a given dimension. That is, an object that can hold any boost::units::quantity<unit<Dimension, System> > with a given Dimension fir any System. For example (names are not ideal) any<length_dimension> a1 = 2.*si::meter; // RHS is type quantity<si::length> any<length_dimension> a2 = 2.*cgs::centimeter; //RHS is type quantity<cgs::length> any<length_dimension> b1 = 2.3 * si::second; // ERROR. or can hold any other quantity with length dimension (from any system). A sort of boost::variant<quantity<Dimension, system1> , quantity<Dimension, system2>, ... >, (but since the list is of type is not well defined maybe variant is not an options.) I know that there are some unresolved issues, for example, what is the result of a1 + a2, for which I have some solutions in mind. Anyway I just was wondering if this was tried before. And if not, what would be the best way to achieve it (boost::any? boost::variant?). (Note that all quantity<Unit> types has always the sizeof a double.) Alfredo

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Boost serialization through base class
by Joe Drumm 13 Oct '10

13 Oct '10

Hi, I've tried using the most basic example I can find in the documentation to serialize a class using a pointer to a polymorphic base. However, it only serializes the base class. I'm currently on 1.34.1. Am I missing something obvious? Sample code below: class base { public: friend class boost::serialization::access; template<class Archive> void serialize(Archive& ar, const unsigned int) { } }; class derived : public base { public: derived() : foo(5) { } friend class boost::serialization::access; template<class Archive> void serialize(Archive& ar, const unsigned int) { boost::serialization::base_object<base>(*this); ar & BOOST_SERIALIZATION_NVP(foo); } int foo; }; BOOST_CLASS_EXPORT_GUID(base, "base") BOOST_CLASS_EXPORT_GUID(derived, "derived") TEST(OMSTestSuite, BasicDeserializeTest) { std::ofstream ofs("test.out"); boost::archive::xml_oarchive toa(ofs); base *b = new derived; toa & BOOST_SERIALIZATION_NVP(b); }

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[String algo] Breaking change between 1.41 and 1.44 in split
by Christophe Henry 13 Oct '10

13 Oct '10

Hi, I noticed a breaking change in the split function when the input string is empty. Consider the following example: #include <string> #include <vector> #include <iostream> #include <boost/algorithm/string/split.hpp> #include <boost/algorithm/string/classification.hpp> int main() { std::vector<std::string> result; std::string empty_string; boost::algorithm::split( result, empty_string,boost::algorithm::is_any_of( "\t" ),boost::algorithm::token_compress_off); std::cout << "result size: " << result.size() << std::endl; return 0; } With boost 1.41 I get: result_size: 1 With 1.44 I get: result_size: 0 Meaning that splitting an empty string now has a new meaning. All I found to this subject was that 1 seems to be the correct answer (http://lists.boost.org/Archives/boost/2005/07/90266.php) Furthermore, there has been, according to the release notes, no change to string algo since the 1.41. This brings me to the question, before I start updating my code, is this change a design decision or an accident? Thanks, Christophe

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[Accumulators] How to define the initial value ?
by Adrien Todeschini 13 Oct '10

13 Oct '10

Hi everyone, As the code of weighted_sum_impl constructor is [ in header <boost/accumulators/statistics/weighted_sum.hpp> ] template<typename Args> weighted_sum_impl(Args const &args) : weighted_sum_( args[parameter::keyword<Tag>::get() | Sample()] * numeric::one<Weight>::value ) { } and the template parameter Tag is defined as tag::sample namespace tag { struct weighted_sum : depends_on<> { typedef accumulators::impl::weighted_sum_impl<mpl::_1, mpl::_2, tag::sample> impl; }; } How can I define this tagged argument when initializing the accumulator_set ? ( Indeed, weighted_sum_impl constructor is called at this point ) Thanks in advance for your help. Adrien

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[serialization] Deserialization of a float whose value is infinite throws an archive_exception ("stream error")
by Luca 12 Oct '10

12 Oct '10

Hello, using the Boost.Serialization library version 1.43, I saved to an XML archive a float number which has a value of infinite; then loading that XML file leads to a boost::archive::archive_exception, exception.what() return "stream error". The source code to reproduce the problem is the following: #include <boost/serialization/serialization.hpp> #include <sstream> #include <boost/archive/xml_woarchive.hpp> #include <boost/archive/xml_wiarchive.hpp> #include <iostream> struct XXX { friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & BOOST_SERIALIZATION_NVP(mValue); } float mValue; };//struct int main() { std::wstringstream lSS; boost::archive::xml_woarchive oa(lSS); XXX xxx; float zero = 0.f; xxx.mValue = 1 / zero; oa << BOOST_SERIALIZATION_NVP(xxx); std::wcout<<"saved:"<<lSS.str() << std::endl; boost::archive::xml_wiarchive ia(lSS); ia >> BOOST_SERIALIZATION_NVP(xxx); std::wcout<<"loaded:"<<lSS.str() << std::endl; return 0; } Using gcc 4.4.4 on Linux/Debian the mValue member is saved as: <mValue>inf</mValue> while on Visual Studio 2005 on Windows XP sp2 the mValue member is saved as: <mValue>1.#INF</mValue> I see that the value of infinite has a different representation, (and this could be the main motivation behind the choice to not support them), but this lead to a situation in which a properly saved archive is not loadable by the library itself. As far I can see, the issue is at this line 209 of \libs\serialization\src\basic_xml_grammar.ipp parse_info<BOOST_DEDUCED_TYPENAME std::basic_string<CharType>::iterator> result = boost::spirit::parse(arg.begin(), arg.end(), rule_); return result.hit; where the parse function fails since result.hit is equal to false. I resolved the issue by checking all the data preventing accurately any infinite value before it is saved to an xml archive, but I wonder if this problem belongs to the library itself or not. Greetings, Luca

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[asio]How to insure async handles not be called after calling deadline_timer::cancel()?
by 鑫炜廖 12 Oct '10

12 Oct '10

The document says, If the timer has already expired when cancel() is called, then the handlers for asynchronous wait operations will: have already been invoked; or have been queued for invocation in the near future. These handlers can no longer be cancelled, and therefore are passed an error code that indicates the successful completion of the wait operation. Does this mean that async handlers may be called after calling deadline_timer::cancel() (say, the second curcumstance) ? If yes, it seems make things unintuitive, eg. delete the resources that associate with handlers after cancel(). Is there any way to suppress or identify these handlers? thx.

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Re: [Boost-users] boost 1.44.0 undefined reference to boost::filesystem2::no_check
by Asif Fayyaz 12 Oct '10

12 Oct '10

No, that issue is a bit different and I have already included <boost/filesystem.hpp> I am again posting the code: --------------------------------Sample application source: #include <stdio.h> #include <boost/filesystem.hpp> int main() { std::string m_FileName(boost::filesystem::path("testfile1.txt", boost::filesystem::no_check).native_file_string()); printf("Testboost.....%s\n", m_FileName.c_str()); return 0; } -------------------------------- Asif ---------- Replied message ---------- From: Igor R <boost.li...(a)gmail.com> Date: Oct 11, 5:57 pm Subject: boost 1.44.0 undefined reference to boost::filesystem2::no_check To: BOOST Archives > Any one?? > any idea? > Waiting for response in this regard. There was a similar issues here: http://permalink.gmane.org/gmane.comp.lib.boost.user/62789 Doesn't it apply your case? do you include <boost/filesystem.hpp>? _______________________________________________ Boost-users mailing list Boost-us...@lists.boost.orghttp:// lists.boost.org/mailman/listinfo.cgi/boost-users

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Distance/size of boost ranges for std::set.
by Matthew Gwynne 12 Oct '10

12 Oct '10

Hi, I'm working within a C++ library which makes extensive use of the range concept, and also of boost::size. The current version of the library makes use of boost 1_38, however, updating to the newer versions of boost, I've had to replace boost::size with boost::distance as some of the ranges involved, such as std::set don't have random access iterators. However, this presents a problem - it's not really acceptable within our application to have linear time complexity for the size operation on sets when the size member function of the set container is constant time, so I'm looking for some advice. Are we misusing the range concept here and should be using something else? Everything other than this matches up nicely, and it's only the time complexity with regards to boost::distance that will cause problems. Should we simply be extending the boost::size function with additional overloaded versions specific to std::set if we wish to use it in this way (is this reasonable?)? Thanks in advance! Matthew Gwynne

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[shared_ptr] Better support for allocators
by Alex Dubov 12 Oct '10

12 Oct '10

Greetings. shared_ptr<> can be constructed with both custom allocator and deleter. However, there's an unfortunate shortcoming: if the held object needs to do some unusual housekeeping on itself during destruction, it needs to store an additional copy of the allocator or rely on some other custom functionality. It would be considerably more convenient, if shared_ptr<> could invoke a custom deleter with allocator (optionally) supplied: virtual void sp_counted_impl_pda::dispose() { d_(p_, a_); } Another handy alternative is to be able to obtain the allocator out of shared_ptr<> explicitly, in a manner similar to get_deleter(). Tr1 implementation actually constructs a proxy deleter object around the user supplied one, which inherits from allocator, but it's impossible to obtain a reference to it from the outside.

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Variadic Macro Data library in the Boost sandbox
by Edward Diener 12 Oct '10

12 Oct '10

This may interest end-users who use macros/Boost PP in their own code to do preprocessor metaprogramming. I have put in the Boost sandbox the Variadic Macro Data library, or VMD. This library supplies variadic macro functionality and integrates variadic macros with the Boost PP library without changing the latter in any way. The library in the sandbox is in the variadic_macro_data folder. The library is a header-only library of macros. There is documentation and tests and the appropriate jamfiles for both. To build the documentation you need doxygen but I have also provided documentation in an html subfolder. Access to the Boost sandbox is explained on the Boost web site at http://www.boost.org/community/sandbox.html. The main use of the library is to be able to pass variadic data to macros, and in particular to extract variadic data elements or convert variadic data to Boost PP data types for use by Boost PP. The library also enhances the functionality of Boost PP tuple data. Installation is simply to take the boost and lib subfolders of the library and copy them to a Boost installation, preferable the trunk where support for variadic macros has been added in Boost config in the form of a BOOST_NO_VARIADIC_MACROS which is defined for compilers/versions which do NOT support variadic macros. To use the macros in the library, just "#include <boost/variadic_macro_data/VariadicMacroData.hpp>". Compilers which support variadic macros are gcc 3.0 and above and VC8 and above among a few others. You could also use the library on any installed Boost installation if the compiler you are using supports variadic macros. There is a discussion in the doc of why you might choose to use variadic macros rather than a Boost PP data type in a macro tailored for end-users. Comments, suggestions, and bug reports are welcome. Edward Diener

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[array][bind] Binding boost array to a boost function
by Ryan McConnehey 11 Oct '10

11 Oct '10

I'm trying to bind a boost array to be called at a later time. This is giving me a lot of errors. Is what I'm attempting possible? Ryan template<typename T, std::size_t U> class Sorter { private: typedef boost::function<void(boost::array<T, U> & a)> t_SortFunction; t_SortFunction m_SortFunction; public: Sorter(t_SortFunction func) : m_SortFunction(func) {} bool sort(boost::array<T, U> & a) { m_SortFunction(a); } }; template<typename T, std::size_t U> void quicksort(boost::array<T, U> & a) { } int main(int argc, char* argv[]) { Sorter shell(boost::bind(quicksort, _1)); return 0; }

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[filesystem][v3] remove_all and system::error_code error?
by valblade 11 Oct '10

11 Oct '10

Hi everyone, First of all, I want to thanks boost::filesystem contributors for their amazing work. I have a question in the recent filesystem V3. when using boost::uintmax_t remove_all(const path& p, system::error_code* ec=0); like this : ----------- listing ----------------------- remove_all("C:\\test_path_to_delete"); ------------- end listing --------------- the "C:\\test_path_to_delete" (and its descendent) is successfully deleted (as described in documentation) but when I use it like this : ----------- listing ----------------------- boost::system::error_code ec; remove_all("C:\\test_path_to_delete", ec); ------------- end listing --------------- The directory (and it descendent) aren't removed at all. I have investigated and, I found the following : boost::uintmax_t remove_all_aux(const path& p, fs::file_status sym_stat, error_code* ec) { boost::uintmax_t count = 1; if (!fs::is_symlink(sym_stat)// don't recurse symbolic links && fs::is_directory(sym_stat)) { for (fs::directory_iterator itr(p); itr != end_dir_itr; ++itr) { fs::file_status tmp_sym_stat = fs::symlink_status(itr->path(), *ec); HERE=> if (ec != 0 && ec) return count; count += remove_all_aux(itr->path(), tmp_sym_stat, ec); } } remove_file_or_directory(p, sym_stat, ec); return count; } This function is called by remove_all. Here, ec is passed by address. When remove_all("C:\\test_path_to_delete"); is called, &ec = 0 (default argument) so the check if (ec != 0 && ec) will never hit. But when called with remove_all("C:\\test_path_to_delete", ec); ec is allocated and &ec != 0, the check if (ec != 0 && ec) is allways true, and the function returns at the first iteration, I'm maybe wrong, but, isn't this what you meant to do? if (ec != 0 && *ec) return count; Sorry if I have misunderstood something... Thanks again.

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Re: [Boost-users] boost 1.44.0 undefined reference to boost::filesystem2::no_check
by Asif Fayyaz 11 Oct '10

11 Oct '10

Any one?? any idea? Waiting for response in this regard. Asif -- Muhammad Asif Fayyaz Address: 42A:10 Kista Allevag. 16455 Kista Stockholm Sweden. Mobile: (+46)0707446631 Profile: http://www.isk.kth.se/~mafayyaz/

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[asio] accepting all connections in a seperate thread - how?
by for-gmane 11 Oct '10

11 Oct '10

My server app needs to be "highly responsive". Ie. it shall handle connection attemps with a higher priority. Currently it has the following problem: if a handler function like the one below takes too much time, then unfortunately no new connections will be handled as long as the operation below lasts (ie. new connections have to wait). Which alternatives are there to solve this problem? (I was thinking of doing the accept in a seperate thread, but not sure how and whether that would work?) void session::handle_read(const boost::system::error_code& error, size_t bytes_transferred) { if (!error) { // PROBLEM HERE: // ... a lengthy job here blocks the whole app (ie. new connections have to wait) // ... which coding/design alternatives would solve this problem? boost::asio::async_write(socket_, boost::asio::buffer(data_, bytes_transferred), boost::bind(&session::handle_write, this, boost::asio::placeholders::error)); } else { delete this; } }

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AIX and Boost.PropertyTree
by Will Mason 10 Oct '10

10 Oct '10

Hello, I'm using Boost 1.42, IBM XL C++ 10.1, and AIX 5.3. I'm running into trouble building code that uses Boost.PropertyTree. I get errors compiling the following code, which works fine on numerous other platforms: boost::property_tree::ptree pt; pt.put(LOG_FILE_KEY, props.log_file_name()); pt.put(LOG_LEVEL_KEY, props.log_level()); pt.put(LOG_NAME_KEY, props.log_name()); pt.put(LOG_FILE_SIZE_MAX_KEY, props.log_file_max_size()); pt.put(LOG_TO_CONSOLE_KEY, props.log_to_console()); pt.put(MESSAGE_MAX_KEY, props.message_max_size()); pt.put(SCAN_THREADS_KEY, props.scan_threads()); std::ostringstream prop_info; boost::property_tree::ini_parser::write_ini(prop_info, pt); The errors, all of which are attributed to the last line of code above, are: "/home/wmason/src/cap-aix/fim/../opt/include/aix/boost/v1.42/boost/property_tree/detail/ptree_implementation.hpp", line 55.28: 1540-0129 (S) The qualifier "subs" is not defined in the current scope. "/home/wmason/src/cap-aix/fim/../opt/include/aix/boost/v1.42/boost/property_tree/detail/ptree_implementation.hpp", line 78.34: 1540-0129 (S) The qualifier "subs" is not defined in the current scope. "/home/wmason/src/cap-aix/fim/../opt/include/aix/boost/v1.42/boost/property_tree/detail/ptree_implementation.hpp", line 91.42: 1540-0716 (S) The template argument "boost::iterator" does not match the template parameter "class Iterator". "/home/wmason/src/cap-aix/fim/../opt/include/aix/boost/v1.42/boost/property_tree/detail/ptree_implementation.hpp", line 101.42: 1540-0274 (S) The name lookup for "const_iterator" did not find a declaration. "/home/wmason/src/cap-aix/fim/../opt/include/aix/boost/v1.42/boost/property_tree/detail/ptree_implementation.hpp", line 101.42: 1540-1226 (I) Declarations for non-dependent names are resolved in the template definition. "/home/wmason/src/cap-aix/fim/../opt/include/aix/boost/v1.42/boost/property_tree/detail/ptree_implementation.hpp", line 101.42: 1540-1227 (I) "const_iterator" does not depend on a template argument. "/home/wmason/src/cap-aix/fim/../opt/include/aix/boost/v1.42/boost/property_tree/detail/ptree_implementation.hpp", line 116.51: 1540-0129 (S) The qualifier "subs" is not defined in the current scope. "/home/wmason/src/cap-aix/fim/../opt/include/aix/boost/v1.42/boost/property_tree/detail/ptree_implementation.hpp", line 138.45: 1540-0129 (S) The qualifier "subs" is not defined in the current scope. "/home/wmason/src/cap-aix/fim/../opt/include/aix/boost/v1.42/boost/property_tree/detail/ptree_implementation.hpp", line 78.34: 1540-0129 (S) The qualifier "subs" is not defined in the current scope. "/home/wmason/src/cap-aix/fim/../opt/include/aix/boost/v1.42/boost/property_tree/ini_parser.hpp", line 231.45: 1540-0700 (I) The previous message was produced while processing "class boost::property_tree::basic_ptree<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> >,struct std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >::const_iterator". The release notes for Boost 1.42 at http://www.boost.org/users/news/version_1_42_0 claim that my combination of OS, compiler and Boost version are supported. I was wondering if anyone might know of a way around this problem besides not using Boost.PropertyTree. Thanks very much for any help, Will

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[fusion] deduce type of resulting vector from a transformation
by alfC 10 Oct '10

10 Oct '10

Hi, (I keep struggling with Boos.Fusion.) How do I deduce the type of the vector resulting from the transformation of another vector? I have a source vector of different types, e.g. vector<quantity<si::length>, quantity<si::mass>, quantity<si::time> > and I have a transformation that is well defined and returns another type depending on the original type. The question is how do I generate a vector type that is the result of the given transformation. I though that result_of::transform was the function to obtain the result but it turns not because it returns a type transform_view instead of a vector. vector< ... > v1; T? v2(transform(v1, transformation())); i.e. what is the type of T as a fusion::vector as deduced from the type of v1 and the transformation type? -- Thank you, Alfredo-- Below is the illustrative code: #include<boost/array.hpp> #include <boost/fusion/container.hpp> #include <boost/fusion/algorithm/transformation/zip.hpp> #include <boost/units/systems/si.hpp> #include<iostream> using std::clog; using std::endl; using namespace boost::fusion; using namespace boost::units; // this is the transformation struct divide{ template <typename SignatureT> struct result; template<class Q> struct result<divide(Q const&)>{ typedef typename divide_typeof_helper<Q, quantity<si::time> >::type type; }; template<typename Q> typename result<divide(Q const&)>::type operator()(Q const& q) const { return q/quantity<si::time>(1.*si::second); } }; int main(){ typedef vector< quantity<si::length>, quantity<si::mass>, quantity<si::time> > source_type ; source_type v1(1.*si::meter, 2.*si::kilogram, 3.*si::second); clog << "v1: " << at_c<0>(v1) << ", "<< at_c<1>(v1) << ", " << at_c<2>(v1) << endl; // how can I deduce the result_type from the type "divide"? // here manually defined typedef vector< divide_typeof_helper<quantity<si::length>, quantity<si::time> >::type, divide_typeof_helper<quantity<si::mass>, quantity<si::time> >::type, divide_typeof_helper<quantity<si::time>, quantity<si::time> >::type > result_type ; result_type v2( boost::fusion::transform(v1, divide() ) ); clog << "v2: " << at_c<0>(v2) << ", "<< at_c<1>(v2) << ", " << at_c<2>(v2) << endl; return 0; }

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[boost-install]update old version to new one by 'bjam install'
by hongleij 10 Oct '10

10 Oct '10

i have install 1.43 version in my system,after use “./bjam install” to intall boost1.44,i met the following error. [root@localhost gridcast]# g++ -o datetime datetime_tcp_async_server.cpp -lpthread -lboost_system -L/usr/local/lib datetime_tcp_async_server.cpp:142:2: 警告：文件未以空白行结束 /tmp/ccjG0R2d.o: In function `__static_initialization_and_destruction_0(int, int)': datetime_tcp_async_server.cpp:(.text+0x16c): undefined reference to `boost::system::get_system_category()' datetime_tcp_async_server.cpp:(.text+0x176): undefined reference to `boost::system::get_generic_category()' datetime_tcp_async_server.cpp:(.text+0x180): undefined reference to `boost::system::get_generic_category()' datetime_tcp_async_server.cpp:(.text+0x18a): undefined reference to `boost::system::get_generic_category()' datetime_tcp_async_server.cpp:(.text+0x194): undefined reference to `boost::system::get_system_category()' /tmp/ccjG0R2d.o: In function `boost::asio::error::get_system_category()': datetime_tcp_async_server.cpp:(.text._ZN5boost4asio5error19get_system_categoryEv[boost::asio::error::get_system_category()]+0x7): undefined reference to `boost::system::get_system_category()' /tmp/ccjG0R2d.o: In function `boost::system::error_code::error_code()': datetime_tcp_async_server.cpp:(.text._ZN5boost6system10error_codeC1Ev[boost::system::error_code::error_code()]+0x10):undefined reference to `boost::system::get_system_category()' collect2: ld 返回 1 so i delete /usr/local/include/boost dir ,and rerun ”./bjam install” -bash-3.2# g++ datetime_tcp_async_server.cpp -lpthread datetime_tcp_async_server.cpp:142:2: warning: no newline at end of file /tmp/ccQeKssV.o: In function `__static_initialization_and_destruction_0(int, int)': datetime_tcp_async_server.cpp:(.text+0x176): undefined reference to `boost::system::generic_category()' datetime_tcp_async_server.cpp:(.text+0x182): undefined reference to `boost::system::generic_category()' datetime_tcp_async_server.cpp:(.text+0x18e): undefined reference to `boost::system::system_category()' /tmp/ccQeKssV.o: In function `boost::system::get_system_category()': datetime_tcp_async_server.cpp:(.text._ZN5boost6system19get_system_categoryEv[boost::system::get_system_category()]+0x5): undefined reference to `boost::system::system_category()' /tmp/ccQeKssV.o: In function `boost::system::error_code::error_code()': datetime_tcp_async_server.cpp:(.text._ZN5boost6system10error_codeC1Ev[boost::system::error_code::error_code()]+0x17): undefined reference to `boost::system::system_category()' collect2: ld returned 1 exit status --------------------------------- the name changed from `boost::system::get_generic_category()' to `boost::system::generic_category()',so it seems if i already have an old version of boost,i need remove it clearly to reinstall the new one by myself.

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[boost.datetime] query
by Sean Farrow 10 Oct '10

10 Oct '10

Hi: Is it possible to return a number representing the date. Like you can with COleDateTime.m_dt; Any help appreciated. Regards Sean.

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[asio] How to get informed about failed connection attempts?
by for-gmane 10 Oct '10

10 Oct '10

The following code (from the examples) accepts a connection and calls the handler handle_accept(). But it calls the handler only if the connection attempt (internally) succeeds. The handler gets not called if the connection fails (for example when an ssl-connection-attempt fails due to wrong keys etc.). What should I do to get informed also about such failed connection attempts? acceptor_.async_accept(new_session->socket(), boost::bind(&server::handle_accept, this, new_session, boost::asio::placeholders::error));

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Memory usage
by Olivier Tournaire 10 Oct '10

10 Oct '10

Hi all, Is there a (portable) way with boost libs to check memory usage? Best regards, Olivier

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Http Server 3 example with SSL, ie. https
by for-gmane 09 Oct '10

09 Oct '10

Hi, has anybody extended the Http Server 3 example with SSL, ie. https? Are there any other simple https-server examples based on asio?

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AIX large file support
by Will Mason 09 Oct '10

09 Oct '10

Hello, I'm using Boost 1.42, IBM XL C++ 10.1, and AIX 5.3. On AIX the way to enable large file support is to define _LARGE_FILES on the compiler command line. When I attempt to build Boost with this definition, I see errors like the following: "/home/wmason/src/cap-aix/fim/../opt/include/aix/boost/v1.42/boost/date_time/date_parsing.hpp", line 50.21: 1540-0215 (S) The wrong number of arguments have been specified for "tolower(int)". This causes catastrophic failure of Boost to build. Fortunately, by poking around the sources I found that I can enable large file support in Boost on AIX with IBM's compiler by defining _LARGEFILE64_SOURCE. Although this bypasses IBM's recommended way of enabling large file support, it does work to build Boost with large file support. The problem is that my product enables large file support the normal way, which leads me back to the above error when I try to build. I could just manually enable large file support in my code, but this causes portability problems. Not all operating systems support large files the same way, so trying to do it manually on every system will be a headache. Our portability strategy involves enabling large file support the normal way on every system, which in many cases, including AIX's, involves defining things on the command line. Is there any way to use normal large file support on AIX and not have Boost go down in flames? Thanks very much for any help, Will

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[proto] Can't use template domain class with BOOST_PROTO_BASIC_EXTENDS
by joel falcou 09 Oct '10

09 Oct '10

Trying to use template domain class with BOOST_PROTO_BASIC_EXTENDS ends up in an error leading to the fact this ligne in the macro is incorrect when the Domain is template: BOOST_PROTO_BASIC_EXTENDS_(Expr, Derived, Domain) typedef void proto_is_aggregate_; typedef Domain::proto_generator proto_generator; Obviously this is alckign a typename before Domain::proto_generator if Domain is actually a template class. Thing is used to work before ( aorund 1.40) so I guess somethign changed around here. I guess a details meta-function extracting the domain will fix that or am I wrong ? namespace boost { namespace proto { template<class Domain> generator_of { typedef typename Domain::proto_generator type; }; } } BOOST_PROTO_BASIC_EXTENDS_(Expr, Derived, Domain) typedef void proto_is_aggregate_; typedef typename generator_of<Domain>::type proto_generator; Or is it ?

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