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

result_of && VC7.1
by Richard Crossley 27 Oct '05

27 Oct '05

Hi, Experimenting with boost::result_of under VC7.1 and 8... --- template <typename T> struct A{ template <typename F> struct result; template <typename U,typename V> struct result<A(U,V)>{ typedef U type; }; template <typename U,typename V> U operator()(U const&,V const&) { return U(); } }; //typedef A<int>::result<A<int>(int,int)>::type result_; typedef boost::result_of<A<… [View More]

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SUN Compiler Feasibility
by Frank Boyle 27 Oct '05

27 Oct '05

Hi Folks, I'm using the sun compiler: CC: Sun WorkShop 6 update 2 C++ 5.3 Patch 111685-15 2003/05/14 I need to generate a high performance logging process and immediately thought of the boost filesystem service. I have downloaded boost_1_33_0. However, I'm getting a lot of compiler problems using the templates which I've since realised are common when using this compiler. i.e. errors relating to boost::iterator_core_access::equal and copious warnings: "/product/3rd_Party/boost/boost_1_33_0/… [View More]

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storing templates in boost::mpl::vector instead of complete types
by Oliver.Kowalke＠infineon.com 27 Oct '05

27 Oct '05

Hello, is it possible to store templates instead of complete types in boost::mpl::vector? I want to compose a class out of templates: template< typename B, typename E, typename Comp > struct Scattered; template< typename B, typename E, typename Comp > struct Scattered : public mpl::deref< B >::type< Comp >, // <<== inherit from the template, Comp == Special public Scattered< typename mpl::next< B >::type, E, Comp > {}; template… [View More]

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Re: [Boost-users] multi-inheritance from elements of mpl::vector?==> inherit_scattered ( for Barton & Nackmann trick)
by Oliver.Kowalke＠infineon.com 27 Oct '05

27 Oct '05

>>no reply - so I found a solution by myself (used for the Barton & >> Nackmann trick)! >> template< typename D > >> struct F >> { >> std::string f() >> { return static_cast< D & >( * this).str_; } >> }; >> >> template< typename D > >> struct G >> { >> std::string g() >> { return static_cast< D & >( * this).str_; } >> }; > >That's not the B&N trick; it's … [View More]

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filesystem library with SparcWorks compiler?
by Chris Newbold 27 Oct '05

27 Oct '05

It appears that the filesystem library and the SparcWorks compiler have some disagreements. I'm running into the same issues as reported on the regression test page here (an example of which is here: http://tinyurl.com/ey5ld) What I'm wondering is if there are any potential patches to Boost to address these problems or if there is some effort to do so. Alternatively, is the SparcWorks compiler just too busted to deal with this library? -Chris

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ptr_vector problem when storing it inside a map
by Oleg Smolsky 27 Oct '05

27 Oct '05

Hi all, I've just started looking at ptr_vector<> and got stuck on the following issue: putting a boost::ptr_vector<Simple> into a map doesn't compile. See the following test case: class Simple { public: virtual ~Simple() { } void foo() { doFoo(); } protected: virtual void doFoo() { } }; void Test() { std::map<std::string, boost::… [View More]

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[ptr_container] warnings about shadowed members
by Samuel Landau 27 Oct '05

27 Oct '05

Hello, I am trying Boost 1.33 ptr_container with GCC 4.0.1 on Linux. When including a ptr_container header (say, ptr_vector.hpp), compiling code with the "-Wshadow" flag, some warnings are issued about shadowed members. I am wondering if this might be a problem, even if my snippet code compiles and seems to run fine so far for me. output example (with boost/ in current directory) : $ cat main.cpp #include <boost/ptr_container/ptr_vector.hpp> int main() {} $ g++ -I. -Wshadow main.cpp ./… [View More]

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[boost-users] [MPL.Math] gcd_impl improved
by Cromwell Enage 27 Oct '05

27 Oct '05

The gcd_impl specialization for integral constants is now based on the binary GCD algorithm. BOOST_STATIC_CONSTANT is now used over typedef at most intermediate steps. You should see much faster compile times, at least for the gcd_lcm test and example programs. Cromwell D. Enage __________________________________ Yahoo! FareChase: Search multiple travel sites in one click. http://farechase.yahoo.com

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Re: [Boost-users] multi-inheritance from elements of mpl::vector? ==> inherit_scattered ( for Barton & Nackmann trick)
by Oliver.Kowalke＠infineon.com 27 Oct '05

27 Oct '05

>Is there a page somewhere that describes the trick, just out of interest >like. C++ Template Metaprogramming, page 205 Modern C++ Design, somewhere AFAIK - Barton & Nackmann trick is used for class composition: template< typename Derived > struct Add { int add() { // B & N-trick: access to the Composed class D & d = static_cast< Derived & >( * this); return d.first() + d.second(); } }; struct First { int first() { return 1; } }; struct Second {… [View More]

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multi-inheritance from elements of mpl::vector?
by Oliver.Kowalke＠infineon.com 27 Oct '05

27 Oct '05

Hi, how is it possible to inherit from all items inside mpl::vector? template< typename V > class multi : .... // ????? {}; typedef multi < mpl::vector< A ,B, C > > multi _t; multi_t m; // m has all public and protected member functions of A, B and C Best Regards, Oliver

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Re: [Boost-users] multi-inheritance from elements of mpl::vector? ==> inherit_scattered ( for Barton & Nackmann trick)
by Oliver.Kowalke＠infineon.com 27 Oct '05

27 Oct '05

no reply - so I found a solution by myself (used for the Barton & Nackmann trick)! cu, Oliver Code: #include <iostream> #include <cstdlib> #include <string> #include <boost/mpl/begin_end.hpp> #include <boost/mpl/deref.hpp> #include <boost/mpl/next.hpp> #include <boost/mpl/vector.hpp> namespace mpl = boost::mpl; //////////////////////////////////// template< typename B, typename E > struct scattered; template< typename B, … [View More]

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plans for boost::sockets library?
by Oliver.Kowalke＠infineon.com 27 Oct '05

27 Oct '05

Hello, is a library for boost::sockets planed? Regards, Oliver

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Re: [Boost-users] multi-inheritance from elements of mpl::vector? ==> inherit_scattered ( for Barton & Nackmann trick)
by Foster, Gareth 27 Oct '05

27 Oct '05

> no reply - so I found a solution by myself (used for the Barton & > Nackmann trick)! > cu, > Oliver > Is there a page somewhere that describes the trick, just out of interest like. Gaz

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Compile boost_wserialization.dll error in CVS of branch RC_1_33_0
by shenhuifeng 27 Oct '05

27 Oct '05

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[Serialization] Fighting code bloat...
by Mats Eklund 27 Oct '05

27 Oct '05

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Re: [Boost-users] Extended Thread object
by Phil Endecott 26 Oct '05

26 Oct '05

>>The actual application is a sort of daemon; a main loop accepts tcp >>connections, and creates a new thread to handle each one. It normally >>wants to "fire and forget" these threads, and I imagine it creating them >>with new() and then letting them dangle, until they eventually terminate >>and delete themselves. > > > I may be missing something here, but if thread lifetime and object > lifetime are not tied, why not create the object on the stack (… [View More]

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"Different" use of shared_ptr/weak_ptr
by Goran Pusic 26 Oct '05

26 Oct '05

Hi all! I am trying to use boost smart pointers for some multithreaded work in the following way: 1. I use shared_ptr to wrap stuff in thread 1 2. I create weak_ptr-s in thread 1 and pass them to thread 2 3. in thread 2, I lock my weak_ptr-s and use stuff I get from there 4. in thread 1 I may destroy my shared_ptr 5. next time I want to lock my weak_ptr, I get NULL and can't use stuff Basically, my idea is to use weak_ptr as sort of transport mechanism between threads, but with "… [View More]

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test: using floating_point_comparison.hpp in precompiled header
by Matt Amato 26 Oct '05

26 Oct '05

I don't know if this is a bug or not, but using boost/test/floating_point_comparison.hpp in a precompiled header under VC71 on Windows yields multiply defined symbol errors for each file using it. The workaround is to not use it in a precompiled header but only in the source files where it is needed. Any ideas? Linking... stdafx.obj : error LNK2005: "struct check_is_close_t::boost::check_is_close_t boost::test_tools::`anonymous namespace'::check_is_close" (?check_is_close@?A0x5e8fa061@… [View More]

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Extended Thread object
by Phil Endecott 26 Oct '05

26 Oct '05

Dear Experts, The boost::thread documentation says: Just as the lifetime of a file may be different from the lifetime of an iostream object which represents the file, the lifetime of a thread of execution may be different from the thread object which represents the thread of execution. In particular, after a call to join(), the thread of execution will no longer exist even though the thread object continues to exist until the end of its normal lifetime. The converse is also possible; if … [View More]

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thread: condition::notify() does not require a lock - why?
by Pete Chapman 26 Oct '05

26 Oct '05

condition::wait requires that a lock is acquired prior to calling it, but condition::notify does not. The Java threading API (which in my limited experience seems similar to boost::thread) requires that a lock is acquired prior to calling Object.notify(). Is this potentially a problem? For example: scoped_lock myLock(myMutex); while (!some_variable) { // Another thread now sets some_variable = true, and // calls myCondition.notify() // then... // will this wait indefinitely? … [View More]

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bind with boost::function
by Eric Pruneau 26 Oct '05

26 Oct '05

Hi Here is my problem. I need to specify a callback function for use with OpenCV cvcam dll. I modified OpenCV to accept a boost::function1<void,IplImage*> instead of a simple void pointer to a function. The function is called by openCv on every frame of a video stream. Im trying to have the callback function member of a class e.g Class A { ... void init() { ... boost::function1<void,IplImage*> Myfunct; Myfunct = boost::bind(&A::Callback, this); … [View More]

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[iostreams] Patch for exception message in mapped_file
by kml＠elreki.net 26 Oct '05

26 Oct '05

Hi! I noticed there's a bug in the detail::cleanup_and_throw() function. It doesn't use the error message passed in the arguments, but always reports "failed getting file size". Please find attached a patch against the CVS version. Cheers, Kim

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[variant] type ambiguity help
by Aaron Griffin 25 Oct '05

25 Oct '05

This isn't a full blown issue really, but it's probably a lack of understanding on my part. variant< typeA, typeB, int, double> v; gives me conversion ambiguities. I can remove the int and it works fine. In an attempt to kludge it, I changed the int to a rational<int>. However, now, "v = 12" is converted to a double, not to the rational. First question, would be, how exactly is the variant choosing to use the double instead of the rational? Does it have anything to … [View More]

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date_time:
by __PPS__ 25 Oct '05

25 Oct '05

Are there better conversion functions from ISO date format (calendar, ordinal, week dates) in basic and/or extended format? Should conversion from invalid iso date like "20050231" fail or produce same results as date(2005,02,31). (I know that it produces the same results, but is it right to convert invalid iso date representation to valid date?) Another thing I noted, some conversion functions accept const std::string &, but most of them accept plain std::string, isn't better to … [View More]

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Problems recognizing directionality of an edge
by Jeffrey Holle 24 Oct '05

24 Oct '05

I am using boost 1.33.0. I'm the guy who is working with spanning trees. I've decided that two graphs are in order. 1. The data graph, of type Graph, is bidirectional. 2. The tree graph, of type Tree, is undirectional. Tree is undirectional because this is the only way that I get expected results from a dfs. However, the direction of the associated edge needs to be recorded as a property in the Tree graph. I'm having difficulty in initializing this property. The problem is that when … [View More]

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[boost-users] [MPL.Math] More major changes
by Cromwell Enage 24 Oct '05

24 Oct '05

A new directory, boost/mpl/math/unsigned_big_integral_, holds everything pertaining to unsigned_big_integral. The corresponding tag and forward declaration also have their own header files now. Also, enlarge_integral and its forward declaration have their own files as well. This should maximize decoupling of the three entities. The big_integral.cpp example and test programs have been updated to reflect these changes. As for double, whole_part and rational_part have been improved, but you'll … [View More]

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[date_time] problem adding negative number of months
by Guido Spahn 24 Oct '05

24 Oct '05

Hello, when adding a negative number of months to a date(y, m, d), an exception "Month number is out of range 1..12" is raised if the resulting month m2 belongs to a year y2 < y and m2 > m. For example date(2005, Jan, 1) + months(-1) fails date(2005, Feb, 1) + months(-1) doesn't fail date(2005, Feb, 1) + months(-2) fails date(2005, Feb, 1) + months(-12) doesn't fail date(2005, Feb, 1) + months(-13) doesn't fail date(2005, Feb, 1) + months(-14) fails I checked it only with … [View More]

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compiler serialization library failed using -sTOOLS=msvc option
by Lee FireStorm 23 Oct '05

23 Oct '05

I have do it in linux as3.0, and all is ok. While I had to compiler boost 1.33 under windows and use the older compilers - MSVC 6. All env set, I think , is well. That is: SET MSVC_ROOT="c:\Program Files\Microsoft Visual Studio\VC98" SET VISUALC="c:\Program Files\Microsoft Visual Studio\VC98" PATH=d:\boost_1_33_0;d:\boost_1_33_0\tools\build\jam_src\bin.ntx86;%PATH% set SPIRIT_ROOT=c:/spirit16 I successfully got some libs as data_time, thread ,regex, etc. Except serialization. I download … [View More]

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[serialization] serializing an stl container.
by Lucas Meijer 23 Oct '05

23 Oct '05

Hey, I've been banging my head against the wall for hours on this one. I'd like to serialize stl containers to an archive. Starting simple: a vector<int> This is what I think I should do: 1) include the proper support header file for the to be serialized container. #include <boost/serialization/vector.hpp> 2) create an archive, can be any type: std::stringstream ss; boost::archive::text_oarchive oa(ss); 3) operator<< my container into this archive: const vector<… [View More]

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Can't link when I use from_string() from date_time
by Renan Polo Montebelo 23 Oct '05

23 Oct '05

-- Sorry if this message is duplicated -- I'm preety new to Boost :-) When I try to compile / link this little program: #include <boost/date_time/gregorian/gregorian.hpp> #include <boost/date_time/posix_time/posix_time.hpp> using namespace boost::gregorian; #include <string> using namespace std; int main() { try { string myString = "2005/10/13"; date myDate( from_string( myString ) ); cout << myDate << endl; } catch ( ... ) { cout << "… [View More]

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How to select the name of class definition instead of variable name in XML archive
by Piyush Kapadia 23 Oct '05

23 Oct '05

In following code - archive results in tag name as T as T is used in BOOST_SERIALIZATION_NVP(T) statement. Instead I want actual type name for T, instead of just T as Tag name, how to achieve this ??? template<class T> void Serialize(const char * filename) { std::ofstream ofs(filename); assert(ofs.good()); boost::archive::xml_oarchive oa(ofs); oa << BOOST_SERIALIZATION_NVP(T); ofs.close(); }

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what happened to the boost vault?
by Robert Ramey 23 Oct '05

23 Oct '05

It seems that the boost vault has a lot less in it than it used to. Is there a reason for this? Robert Ramey

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When to close ofstream in XML serialize
by Piyush Kapadia 23 Oct '05

23 Oct '05

In following function code, ofs.close() results in failure to write last end tag of XML archive, apparently because stream is closed before destructor is executed, so when do we execute ofs.close() ? ofs.flush does not help either or shell we skip executing any flush or close and just return from function ? template<class T> void Serialize(const char * filename) { std::ofstream ofs(filename); assert(ofs.good()); boost::archive::xml_oarchive oa(… [View More]

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[build] problem compiling current cvs
by Chris Hoeppler 23 Oct '05

23 Oct '05

Hi, I don't seem to be able to build a current cvs checkout of boost on a linux system on which I used to be able to build all the boost libraries by invoking 'bjam stage' on the cvs version of a couple of weeks ago. Did something change with respect to the build procedure? Invoking bjam on a clean cvs checkout results in the following output: ~/boost> bjam Building Boost.Regex with the optional Unicode/ICU support disabled. Please refer to the Boost.Regex documentation for more … [View More]

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[general/iostreams/iterators] Why not a forward and/or a random access istream iterator?
by Mats Eklund 22 Oct '05

22 Oct '05

Hello, does anybody know whether there is something fundamentally wrong with designing an istream iterator that conforms with the forward, or even random access, iterator concepts? The std::istream_iterator conforms only with the simplest input iterator concept (stream need not support positioning). If a stream supports positioning, I cannot see why this should not work. If a streamable T has variable size on stream, we could do forward iteration, and if T has a known constant size on the … [View More]

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Re: [Boost-users] Report from Mont Tremblant C++ Committee meeting
by Thore Karlsen 22 Oct '05

22 Oct '05

On Sun, 9 Oct 2005 21:32:30 -0400, "Beman Dawes" <bdawes(a)acm.org> wrote: [...] >String-algo : Interested, but concern over interface and choice of >functions, generic vs basic_string.5.3 separate proposal Any details on this? I love this library, and I would love to see it standardized in some form. Overall I've found the interface and function choices to be excellent (and I'd love to see even more), and I love that it's generic and not limited to basic_string. I use it on … [View More]

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New version of mpl_math in the vault; problems compiling...
by Fredrik Hedman 22 Oct '05

22 Oct '05

Hello, I have been playing around with the examples of this fascinating code. This reports on the problems I have encountered so far. The latest examples are compiled with g++ 3.4.4 and '-Wall -Wno-long-long -pedantic -O2' using using boost-1_33 result in a number of errors: 1) The example in runtime_value.cpp gives boost/mpl/math/number_sign.hpp: No such file or directory This files seems to be missing. 2) The example double.cpp get a *lot* of warnings: mpl/math/… [View More]double_/aux_/integral_exp.hpp:35: warning: comparison between signed and unsigned integer expressions Looking at the offending line it seems that the constants that are shifted should really be unsigned numbers: BOOST_STATIC_CONSTANT( boost::int16_t , exp1 = (number < (1 << (exp16 + exp8 + exp4 + exp2 + 1))) ? 0 : 1 -> BOOST_STATIC_CONSTANT( boost::int16_t , exp1 = (number < (1u << (exp16 + exp8 + exp4 + exp2 + 1))) ? 0 : 1 The same should probably be applied to all the other BOOST_STATIC_CONSTANT in struct integral_exp. Refactor 1u and 65536u into named constants? 3) The example big_integral.cpp complains about extra semicolons. It is the macro BOOST_MPL_MATH_BIG_INTEGRAL_AUX_CONVERT_IMPL_APPLY_RESULT in convert_base10_digits.hpp that is the root cause. By commenting out two ';' in the macro the example compiles and runs just fine: #define BOOST_MPL_MATH_BIG_INTEGRAL_AUX_CONVERT_IMPL_APPLY_RESULT \ BOOST_STATIC_CONSTANT( \ boost::uint32_t \ , a_0_0 = \ BOOST_PP_CAT( \ base10000_digit_ \ , BOOST_PP_DEC(BOOST_MPL_MATH_BIG_INTEGRAL_MANTISSA_SIZE) \ ) \ ); \ BOOST_PP_REPEAT( \ BOOST_PP_DEC(BOOST_MPL_MATH_BIG_INTEGRAL_MANTISSA_SIZE) \ , BOOST_MPL_MATH_BIG_INTEGRAL_AUX_A_0_MACRO \ , a_0_ \ ) /* ; removed extra */ \ BOOST_PP_FOR( \ (0) \ , BOOST_MPL_MATH_BIG_INTEGRAL_AUX_CONVERT_IMPL_PREDICATE_0 \ , BOOST_MPL_MATH_BIG_INTEGRAL_AUX_CONVERT_IMPL_NEXT_STATE_0 \ , BOOST_MPL_MATH_BIG_INTEGRAL_AUX_CONVERT_IMPL_MACRO_0 \ ) \ public: \ BOOST_PP_REPEAT( \ BOOST_MPL_MATH_BIG_INTEGRAL_MANTISSA_SIZE \ , BOOST_MPL_MATH_BIG_INTEGRAL_AUX_CONVERT_IMPL_MACRO_1 \ , digit_ \ ) /* ; removed extra */ \ /**/ -- Best Regards, Fredrik Hedman [View Less]

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[Serialization] Loading from archive
by Sam Contapay 22 Oct '05

22 Oct '05

Sorry I tried to post this through the newsserver gateway. I didn't see the message show up after half and hour so I'm assuming it didn't post correctly as this email address wasn't subscribed. I apologize if it does ----------ORIGINAL EMAIL---------------- I've been trying to get loading from an archive to work for a couple of hours now. Maybe I'm missing something so I can use anyones "eyes" for help. This is a program written using VC7.1 and I do have RTTI on. I am able to save data from a … [View More]

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Bug in XML serialization!!!
by Piyush Kapadia 21 Oct '05

21 Oct '05

Following code results in "unrecognized XML syntax" exception while writing to XML file. However if I change xml_oarchive to text_oarchive or binary_oarchive, it works fine, so I assume it's a bug in xml_oarchive ??? Does any one know how to fix this for xml_oarchive ??? #include <iostream> #include <fstream> #include <boost/archive/text_iarchive.hpp> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/xml_iarchive.hpp> #include <… [View More]boost/archive/xml_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> #include <boost/archive/binary_oarchive.hpp> #include <boost/serialization/vector.hpp> #include <boost/serialization/map.hpp> #include <vector> #include <map> #include <boost/archive/archive_exception.hpp> #include <boost/archive/basic_xml_archive.hpp> class base { protected : std::vector<int> vec; protected : friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & BOOST_SERIALIZATION_NVP(vec); } public : void add(int i) { vec.push_back(i); } int get(int idx) { return vec[idx]; } }; class derived : public base { friend class boost::serialization::access; std::map<std::string, int> hmap; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & BOOST_SERIALIZATION_NVP(boost::serialization::base_object<base>(*this)); ar & BOOST_SERIALIZATION_NVP(hmap); } public : void add(std::string str, int i) { hmap[str] = i; base::add(i); } int get(std::string str) { return hmap[str]; } }; int main(int argc, char* argv[]) { try { derived A; A.add("First", 12); A.add("Second", 34); const derived AA = A; std::ofstream ofs("Test.xml"); assert(ofs.good()); boost::archive::xml_oarchive oa(ofs); oa << BOOST_SERIALIZATION_NVP(AA); ofs.close(); derived B; std::ifstream ifs("Test.xml"); assert(ifs.good()); boost::archive::xml_iarchive ia(ifs); ia >> BOOST_SERIALIZATION_NVP(B); ifs.close(); } catch (boost::archive::xml_archive_exception ex) { std::cerr << " X " << ex.what() << std::endl; } catch (boost::archive::archive_exception ex) { std::cerr << " A " << ex.what() << std::endl; } catch (std::exception ex) { std::cerr << " E " << ex.what() << std::endl; } catch (...) { std::cerr << "Unknown Exception " << std::endl; } return 0; } [View Less]

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[random] spot the stupidity competition
by Nigel Rantor 21 Oct '05

21 Oct '05

Hail all, Thanks for giving us the libraries, now only if we were all smart enough to use them properley the world would be at peace. As it is I've been having some problems with my own code that is wrapped around the random library. I'm playing around with a game I'm making and needed some randomness, games that are predicatble are just a tad boring... I need to generate numbers with lots of different distributions so creating one or two won't really cut it for me, there would have to … [View More]be hundreds. Instead I went and basically ripped the random_number_generator described under decorators into two flavours and then created a bunch of overloaded functions that used them. The generators use a single real engine, currently mt19937;. Basically, everythnig works fine, except that calling seed( n ) on the engine doesn't effect the generators that hold a ref to it, which I found somewhat bizzare. So, after a few tweaks I ripped out the code and dumped it into a minimal test case and can see that the seed( n ) method works just fine when I pull raw numbers out of the engine, but still doesn't seem to effect the generators I've defined. I'm fairly sure this is my problem but I was wondering if anyone would be good enough to take a peek and tell me why exactly this isn't working. I did have a search on Gmane but couldn't find anything that looked related to my problem. I'm not sure what is the done thing on this list so I've attached source, if you want a makefile then I can oblige but it is a fairly small case. The test program reads in three numbers, the seed to use, the number of numbers to generate and the max to use when generating numbers from a distribution. Feeding it different seeds makes the raw number change, but not the others. I have also included the output of two runs to show you what I mean. TIA, N seed : 42 num : 10 max : 1000 seeded rng... 10 raw numbers from rng 1608637542 3421126067 4083286876 787846414 3143890026 3348747335 2571218620 2563451924 670094950 1914837113 10 random integers using rng 795 926 666 119 485 903 904 335 227 185 seed : 727364 num : 10 max : 1000 seeded rng... 10 raw numbers from rng 3240174879 3269238853 3044917573 2953574107 2463698974 2129367301 2064401652 2079989189 3644954707 1971100779 10 random integers using rng 795 926 666 119 485 903 904 335 227 185 #include "random.h" int random_num( int max ) { return int_gen( max ); } int random_num( int min, int max ) { return min + random_num( max ); } long random_num( long max ) { return long_gen( max ); } long random_num( long min, long max ) { return min + random_num( max ); } float random_num( float max ) { return float_gen( max ); } float random_num( float min, float max ) { return min + random_num( max ); } double random_num( double max ) { return double_gen( max ); } double random_num( double min, double max ) { return min + random_num( max ); } #ifndef RANDOM_H #define RANDOM_H #include <boost/random.hpp> using namespace boost; typedef mt19937 rng_type; template<class RNG, class IntType = long> class integer_random_number_generator { public: typedef RNG base_type; typedef IntType argument_type; typedef IntType result_type; integer_random_number_generator( base_type& rng ) : _rng( rng ) {} result_type operator()( argument_type n ) { typedef uniform_int<IntType> dist_type; return variate_generator<base_type&, dist_type>(_rng, dist_type(0, n-1))(); } private: base_type& _rng; }; template<class RNG, class RealType = double> class real_random_number_generator { public: typedef RNG base_type; typedef RealType argument_type; typedef RealType result_type; real_random_number_generator( base_type& rng ) : _rng( rng ) {} result_type operator()( argument_type n ) { typedef uniform_real<RealType> dist_type; return variate_generator<base_type&, dist_type>(_rng, dist_type(0, n-1))(); } private: base_type& _rng; }; static rng_type rng; static integer_random_number_generator<rng_type, int> int_gen( rng ); static integer_random_number_generator<rng_type, long> long_gen( rng ); static real_random_number_generator<rng_type, float> float_gen( rng ); static real_random_number_generator<rng_type, double> double_gen( rng ); int random_num( int max ); int random_num( int min, int max ); long random_num( long max ); long random_num( long min, long max ); float random_num( float max ); float random_num( float min, float max ); double random_num( double max ); double random_num( double min, double max ); #endif /* RANDOM_H */ #include "random.h" #include <iostream> using namespace std; int main( int argc, char ** argv ) { unsigned int seed; int num; int max; int i; cin >> ws >> seed; cin >> ws >> num; cin >> ws >> max; cout << "seed : " << seed << endl; cout << "num : " << num << endl; cout << "max : " << max << endl; rng.seed( seed ); cout << "seeded rng..." << endl; cout << num << " raw numbers from rng" << endl; for( i = 0; i < num; i++ ) { cout << rng() << endl; } cout << num << " random integers using rng" << endl; for( i = 0; i < num; i++ ) { cout << random_num( max ) << endl; } return 0; } [View Less]

2 2

Failures in Solaris/gcc build
by Fernando Mato Mira 21 Oct '05

21 Oct '05

Hello, I built Boost on Solaris 9 with gcc 3.3.3 but I saw many "...failed" messages while building. Also, in the destination lib directory there's no regex library, and I think there should be one. There are only the libraries for: libboost_filesystem libboost_iostreams libboost_prg_exec_monitor libboost_python libboost_signals Thanks

1 0

Boost Test Memory Dumping...
by Matt Amato 20 Oct '05

20 Oct '05

I have a simple Boost program using the unit test framework. When I run the program in debug, I get a dump of memory leaks. I can't find a way to stop these memory leaks from being reported (other than fixing the leaks of course). What is the proper way of disabling this output? I tried using boost::unit_test::unit_test_log.set_threshold_level but that didn't seem to work. Any ideas? Thanks, Matt Running 4 test cases... *** No errors detected Detected memory leaks! Dumping … [View More]

2 1

[Boost on Pocket PC] Is Boost supported on Pocket PC platforms?
by Ansuman Kar 20 Oct '05

20 Oct '05

Hi, I'm a newbie user of Boost libraries. We have a requirement for making our sources work on Win32 and Pocket PC platforms. From my early look inside the boost libraries I can see the serious advantages of using them; but would like to find out which Boost libraries are supported on Pocket PC before using them. Quick searches through google and on boost.org site did not provide authoritative results, so I'm posting this question here - please let me know if a different alias is better … [View More]

3 2

[Boost.Graph] Double sided edge properties in undirected graph
by Ferdi Smit 20 Oct '05

20 Oct '05

What is the easiest (is there any) way to associate an edge property with both edge ends in an undirected graph in the BGL? I would like to iterate over the incident edges of a vertex, and obtain the edge property for that side of the edge the vertex is on. Ie. for A (5) <--E--> (1) B when iterating the incident edges of A, a request for this edge's (E) property would return 5, and when iterating vertex B's incident edge (E) it would return 1. For a directed graph this is simple: … [View More]

1 0

MSVC and PDB files.
by Jonathon Bell 20 Oct '05

20 Oct '05

How do I use BOOST JAM to build and deploy PDB files for both the debug and release configurations of the various BOOST libraries? I'm using the Visual C++ 7.1 Toolset... _________________________________________ //* Jonathon Bell jbell(a)mathsoft.com //* Mathsoft Engineering & Education, Inc //* 101 Main Street, Cambridge, MA, 02142

3 2

Tokenizer: Low value as seperator
by CN 20 Oct '05

20 Oct '05

Hi! Library version 1.33.0. The input string contains null characters. I want to use null character as the seperator. The following code produces only "X". Why "Y" and "Z" are discarded and how to fix this code? ========= #include<iostream> #include<boost/tokenizer.hpp> int main(int argc, char* argv[]) { using namespace std; using namespace boost; string str="X\0Y\0Z"; typedef tokenizer<boost::char_separator<char> > Tok; char_separator<char> sep("\0"); … [View More]

4 6

There is a error in the file licence_info.cpp under tools\bcp
by Huifeng Shen 20 Oct '05

20 Oct '05

The original line 18 is (pay attention the correspond the parentheses) "Copyright|\$c\$|? I compile bcp with vc71 toolset and fails. I change this line with "Copyright|\$c\$|?" It's OK. I also check the code in the CVS, This error is not corrected.

3 4

Regression tests
by John Grabner 20 Oct '05

20 Oct '05

Hi Guys, I remember seeing the regression test laid out in a table on the web somewhere. You could navigate to whichever result you were interested in. can someone point my in the right direction? John.

2 1

Re: [Boost-users] [MultiIndex] Key extraction from a base member
by JOAQUIN LOPEZ MU?Z 20 Oct '05

20 Oct '05

Hello Bruno, thanks for using Boost.MultiIndex! ----- Mensaje original ----- De: Bruno Martínez <br1(a)internet.com.uy> Fecha: Miércoles, Octubre 19, 2005 10:46 pm Asunto: [Boost-users] [MultiIndex] Key extraction from a base member > Hi. > > I have the following problem with MultiIndex. For > > struct Base { > int id; > }; > > struct Der : Base { > }; > > I can't make a key extractor. > [explanation on why it doesnt work snipped] > Maybe … [View More]

2 1

question about subgraphs
by Jeffrey Holle 19 Oct '05

19 Oct '05

I am using boost 1.33.0. I want to use a subgraph to represent a spanning tree of a graph. This application requires adding and deleteing edges to just the tree and not the underlining graph though. Note that this wouldn't violate the requirements of a subgraph, a spanning tree contains all the vertices, and a subset of the edges of the underlining graph. Is it possible to do this, maybe through inheritance?

2 1

[MultiIndex] Key extraction from a base member
by Bruno Martínez 19 Oct '05

19 Oct '05

Hi. I have the following problem with MultiIndex. For struct Base { int id; }; struct Der : Base { }; I can't make a key extractor. This way typedef multi_index_container< Der, indexed_by< ordered_unique<member<Der, int, &Der::id> > >Set; doesn't work because &Der::id is of type pointer to member of Base. This other typedef multi_index_container< Der, indexed_by< ordered_unique<member<Base, int, &Base::id> > >Set; doesn't work … [View More]

1 0

boost::any & Serialization
by Piyush Kapadia 19 Oct '05

19 Oct '05

Why can't we use boost::any for serialization ? Isn't there any work around to make this work ???

2 1

[Serialization]class(type) name in xml archive?
by Sean Huang 19 Oct '05

19 Oct '05

Is it possible to add class(type) name in xml archive? It would be a big help when looking at the xml output (yes, we want to display those files). for example (from demo.xml): <s type="bus_schedule" class_id="0" tracking_level="0" version="2"> ^^^^^^^^^^^^^^^^^ Thanks, Sean

2 3

Boost Birds of Feather @ OOPSLA 05?
by Jeff Garland 18 Oct '05

18 Oct '05

All - I'm going to be in San Diego @ OOPSLA next week and I'm wondering if any Boost users and developers would be interested in getting together for a BOF one evening. Obvious topic of discussion is all things Boost/C++/TR2. Right now I'm thinking Tuesday night would be a good time. Let me know if there is interest and I'll set this up. Jeff Note, I cross-posted to the user and developer list b/c the idea is this would be open to everyone with an interest in Boost.

5 7

FW: custom iterator_adaptor::pointer
by Sigg Christian 18 Oct '05

18 Oct '05

Dear boosters, I'm trying to figure out why there is no way to define the iterator_adaptor's pointer type. I'm trying to write an iterator that concurrently accesses two containers, but the interface should look like it's only one container. Therefore, it is necessary to write my own value, reference and pointer type. However, the iterator_adaptors pointer type is always value*. Is it save to just overload the pointer typedef and reimplement operator->()? I'm not too much of a c++ … [View More]

2 1

Any way to use boost lib standalone?
by Hendrik Bock 18 Oct '05

18 Oct '05

Hello there! I have searched the boost-users mailing-list for quite some time, but found no answer to my question: Is there a possibility to separate a library from the rest of boost? I only want to use the regexp library of boost and i have to include all related header-files plus libs into our company-cvs. Till now i wasn't able to find out, which *.hpp files are needed by boost and which ones aren't. Kind regards, Hendrik Bock

2 2

Boost Graph Library: Python Bindings
by Yu Huang 17 Oct '05

17 Oct '05

Hi guys, I report a small bug related to bgl.file_kind.adjlist. I tried it using an inputfile in the specified format, but got nothing. And i checked the source code, basic_graph.cpp and found on line 129: case gfk_adjlist: break; which means simply not dealing with it at all. I guess those two guys are so busy to fill some codes in it. Thanks, Yu

5 6

Building with Dinkumware Unabridged Library?
by Drumheller, Michael 17 Oct '05

17 Oct '05

There does not seem to be a build option for using Boost with the Dinkumware Unabridged Library. Yet I know there are Boost users who use Dinkumware. Can someone explain? Thanks,

1 0

[unit test framework] Command-line arguments; documentation
by Paul Giaccone 17 Oct '05

17 Oct '05

How do you access command-line arguments in test cases? According to http://boost.org/libs/test/doc/components/utf/index.html: "This function [boost::unit_test::test_suite* init_unit_test_suite ( int argc, char* argv[] )] should create and initialize top level instance of the class test_suite. The NULL pointer returned by the function is treated as a non-initialized test_suite - testing aborted and boost::exit_test_failure is returned. In other case the framework runs created instance … [View More]

3 5

using uBLAS with quantity<> (C++TMP)
by Malte Clasen 17 Oct '05

17 Oct '05

Hi, the book "C++ Template Metaprogramming" by Abrahams and Gurtovoy describes a dimensional analyis framework that enables compile-time checking of physical units. For example dividing a length quantity by a time quantity results in a speed quantity. Now it's tempting to use boost uBLAS with these quantities: A position in space can be expressed as a vector of length quantities etc. But there's one problem: "// uBLAS assumes a common return type for all binary arithmetic operators" (… [View More]

2 1

date_time: Print Holidays Example
by __PPS__ 17 Oct '05

17 Oct '05

Aren't you supposed to delete new'd objects, or you simply rely that nobody is gonna look/use/copy this piece of code? http://tinyurl.com/8wanl

2 2

Failing to compile Boost.Threads 1.33.0 with Borland C++
by Jarl Lindrud 16 Oct '05

16 Oct '05

Hi, I've just upgraded from 1.32.0 to 1.33.0, and now when I try to build Boost. Threads with Borland C++, I just get a lot of errors, as shown below. I've compiled with several other compilers, and it all went fine. I'm using Borland C++ 5.6, the one that comes with Borland C++Builder 6, and I have no problems building Boost.Threads from the 1.32.0 distribution . The regression test table seems to indicate it should work, so what am I missing? Thanks. ***********************************… [View More]*************** E:\Development\boost_1_33_0\libs\thread\build>..\..\..\..\bjam.1.33.0.exe -sTOOL S=borland ...found 556 targets... ...updating 20 targets... borland-C++-action ..\..\..\bin\boost\libs\thread\build\boost_thread.dll\borland \debug\threading-multi\exceptions.obj ..\src\exceptions.cpp: Error E2090 ..\src\exceptions.cpp 71: Qualifier 'thread_exception' is not a clas s or namespace name Error E2040 ..\src\exceptions.cpp 71: Declaration terminated incorrectly Error E2190 ..\src\exceptions.cpp 187: Unexpected } *** 3 errors in Compile *** "H:\Program\Borland\CBuilder6\bin\bcc32" -j5 -g255 -q -c -P -w -Ve -Vx -a8 -b- -DBOOST_THREAD_LIB_NAME=boost_thread -DBOOST_THREAD_BUILD_DLL=1 -v -Od -vi - -tWR -tWD -WM- -tWM -w-8004 -w-8057 -w-8001 -I"..\..\..\bin\boost\libs\threa d\build" -I"H:\Program\Borland\CBuilder6\include" -I"E:\Development\boost_1_33 _0" -o"..\..\..\bin\boost\libs\thread\build\boost_thread.dll\borland\debug\thre ading-multi\exceptions.obj" "..\src\exceptions.cpp" ...failed borland-C++-action ..\..\..\bin\boost\libs\thread\build\boost_thread.d ll\borland\debug\threading-multi\exceptions.obj... borland-C++-action ..\..\..\bin\boost\libs\thread\build\boost_thread.dll\borland \debug\threading-multi\mutex.obj ..\src\mutex.cpp: Error E2312 ..\src\mutex.cpp 44: 'm_critical_section' is not an unambiguous base class of 'mutex' in function mutex::mutex() Error E2451 ..\src\mutex.cpp 46: Undefined symbol 'm_critical_section' in functi on mutex::mutex() Error E2451 ..\src\mutex.cpp 55: Undefined symbol 'm_critical_section' in functi on mutex::~mutex() Error E2451 ..\src\mutex.cpp 63: Undefined symbol 'm_critical_section' in functi on mutex::do_lock() Error E2451 ..\src\mutex.cpp 71: Undefined symbol 'm_critical_section' in functi on mutex::do_unlock() Error E2228 ..\src\mutex.cpp 71: Too many error or warning messages in function mutex::do_unlock() *** 6 errors in Compile *** "H:\Program\Borland\CBuilder6\bin\bcc32" -j5 -g255 -q -c -P -w -Ve -Vx -a8 -b- -DBOOST_THREAD_LIB_NAME=boost_thread -DBOOST_THREAD_BUILD_DLL=1 -v -Od -vi - -tWR -tWD -WM- -tWM -w-8004 -w-8057 -w-8001 -I"..\..\..\bin\boost\libs\threa d\build" -I"H:\Program\Borland\CBuilder6\include" -I"E:\Development\boost_1_33 _0" -o"..\..\..\bin\boost\libs\thread\build\boost_thread.dll\borland\debug\thre ading-multi\mutex.obj" "..\src\mutex.cpp" ...failed borland-C++-action ..\..\..\bin\boost\libs\thread\build\boost_thread.d ll\borland\debug\threading-multi\mutex.obj... borland-C++-action ..\..\..\bin\boost\libs\thread\build\boost_thread.dll\borland \debug\threading-multi\recursive_mutex.obj ..\src\recursive_mutex.cpp: ...interrupted ************************************************** [View Less]

1 0

Which algorith should I use(Boost::reg_ex)?
by Aaron 16 Oct '05

16 Oct '05

I'm writting a program which could evaluate macros in a c++ header file, like this: #define CMD_IS_BASE 0x00001000 #define CMD_GET_ALL_DOMAINNAME (CMD_IS_BASE+0x1) /* Get all domain name from clients*/ After parsing is done, if you input a value(int), the program could tell you the symbol name, symbol meaning (if there is) corresponding to the valude. As to the above example, when you input 1025(or 0x00010001), the program should tell you it's correspond to symbol CMD_GET_ALL_DOMAINNAME, … [View More]

2 1

Build boost using 64 bit flags on hp-ux 11.23 itanium
by Naeem ahmad 15 Oct '05

15 Oct '05

Do any body how to build boost 64 bit version I have tried to use this command to build, but it does not work bjam cflags="-m64" linkflags="-m64" cxxflags="-m64" "-sTOOLS=gcc" install the 32 bit version build ok by default. Naeem Ahmad

2 1

Re: [Boost-users] Errors compiling greg_month.cpp
by D. R. Evans 15 Oct '05

15 Oct '05

A couple of days ago I requested help (below) as to why greg_month.cpp in 1.33.0 was giving errors under VC++ 6.0. Seeing no response, I guess I'll just go back to 1.30.2, which was the version that has been working fine. Sorry to have troubled you. Doc ----- I just upgraded to 1.33.0, and am getting a bunch of compilation errors with the current version of greg_month.cpp: The list of errors starts with: c:\boost\boost_1_33_0\boost\date_time\gregorian\formatters.hpp(34) : error … [View More]

3 2

Exception Stack Trace Question.
by Piyush Kapadia 14 Oct '05

14 Oct '05

Though catch(.) statement allows catching exception not associated with any class, it leads to ambiguous condition as there is no way to have any error message with it. Does Boost provide any means to be able to print stack trace when exception is caught ? In spite of many deficiencies with Java, it let's you access stack trace using printStackTrace() and trace out as what happened and how it happened. This is where C++ std::exception is lacking support and one has to look for such … [View More]

4 3

[spirit] error removal
by Aaron Griffin 14 Oct '05

14 Oct '05

Hi all, This is a contrived example, but the solution should be the same. Assuming I have two rules, like so: section = identifier >> ch_p('{') >> *setting >> ch_p('}'); setting = identifier >> ch_p('=') >> value; // identifier and value are simple, but left off for brevity This should parse something like: somesettings { a = 12 b = "hello whirled" } Now, what I am looking to do is, if the parser fails parsing a value inside a "section", the parsing … [View More]

3 4

Re: [Boost-users] Compilation errors with Intel Compiler 9.0 for Linux
by Olivier Delalleau 14 Oct '05

14 Oct '05

On 14 Oct 2005, boost-users-request(a)lists.boost.org wrote: > > There are many errors like this one. Again, if I remove the include > > command -I/opt/intel/compiler90/include/c++ > > it works fine. Also if I use the intel 8.0 includes it works fine (but > > not intel 8.1). > > > > Any help fixing these errors (actually, mainly the regex one, as this > > is the library I really need) will be much appreciated :) > > I believe this is fixed for … [View More]

1 0

Compilation errors with Intel Compiler 9.0 for Linux
by Olivier Delalleau 14 Oct '05

14 Oct '05

I'm getting some annoying errors when compiling some of the libraries of Boost 1.33.0 with Intel Compiler 9.0 (icpc (ICC) 9.0 20050811) under Linux. Here is what happens when I try to compile (again after a first try which failed to update all targets): ----------------------------------------------------------------------------------- ../boost-jam-3.1.11-1-linuxx86/bjam -sTOOLS=intel-linux --prefix=/RQusagers/delallea/local --builddir=/RQexec/delallea/boost_1330_90 -sPYTHON_VERSION=2.4 --… [View More]with-python-root=/usr/network.ALTIX/python-2.4.1 -sINTEL_VERSION=90 -sINTEL_PATH=/opt/intel/compiler90 install Building Boost.Regex with the optional Unicode/ICU support disabled. Please refer to the Boost.Regex documentation for more information (and if you don't know what ICU is then you probably don't need it). ...found 14461 targets... ...updating 104 targets... intel-linux-C++-action /RQexec/delallea/boost_1330_90/bin/boost/libs/iostreams/build/libboost_iostreams.a/intel-linux/debug/file_descriptor.o /RQMNT/exec1/lisa/delallea/boost_src/boost_1_33_0/boost/iostreams/positioning.hpp(45): error: no suitable conversion function from "mbstate_t" to "std::streampos={std::streamoff={long}}" exists return std::streampos(std::mbstate_t(), off); ^ /RQMNT/exec1/lisa/delallea/boost_src/boost_1_33_0/boost/iostreams/positioning.hpp(45): error: expected a ")" return std::streampos(std::mbstate_t(), off); ^ /RQMNT/exec1/lisa/delallea/boost_src/boost_1_33_0/boost/iostreams/positioning.hpp(51): error: no suitable conversion function from "fpos_t" to "boost::iostreams::stream_offset={intmax_t={long}}" exists return pos; ^ /RQMNT/exec1/lisa/delallea/boost_src/boost_1_33_0/boost/iostreams/positioning.hpp(64): error: expression must have class type return fpos_t_to_offset(pos.seekpos()) + ^ /RQMNT/exec1/lisa/delallea/boost_src/boost_1_33_0/boost/iostreams/positioning.hpp(66): error: expression must have class type stream_offset(std::streamoff(pos.seekpos())); ^ compilation aborted for /RQMNT/exec1/lisa/delallea/boost_src/boost_1_33_0/libs/iostreams/build/../src/file_descriptor.cpp (code 2) . /opt/intel/compiler90/bin/iccvars.sh icpc -c -w1 -g -O0 -I"/RQexec/delallea/boost_1330_90/bin/boost/libs/iostreams/build" -I"/RQMNT/exec1/lisa/delallea/boost_src/boost_1_33_0" -I"/RQMNT/exec1/lisa/delallea/boost_src/boost_1_33_0" -o "/RQexec/delallea/boost_1330_90/bin/boost/libs/iostreams/build/libboost_iostreams.a/intel-linux/debug/file_descriptor.o" "/RQMNT/exec1/lisa/delallea/boost_src/boost_1_33_0/libs/iostreams/build/../src/file_descriptor.cpp" ...failed intel-linux-C++-action /RQexec/delallea/boost_1330_90/bin/boost/libs/iostreams/build/libboost_iostreams.a/intel-linux/debug/file_descriptor.o... ----------------------------------------------------------------------------------- Then other similar errors in iostreams... Now, the important detail: I have in my icpc.cfg the following line: -I/opt/intel/compiler90/include/c++ which forces the Intel compiler to (preferably) use its own includes. Otherwise it uses the g++ standard includes and (at least for the file above) compilation works fine. But I would really prefer to be able to compile Boost using only the Intel code (especially since I need this line in my icpc.cfg for some other non-Boost stuff to compile). Then when compiling the regex library I have other errors. Here is an example of what happens with a specific compile line (here I cleaned my icpc.cfg file): ----------------------------------------------------------------------------------- icpc -I/opt/intel/compiler90/include/c++ -c -w1 -DNDEBUG -DNDEBUG -O3 -openmp -I"/RQexec/delallea/boost_1330_90/bin/boost/libs/regex/build" -I"/RQMNT/exec1/lisa/delallea/boost_src/boost_1_33_0" -o "/RQexec/delallea/boost_1330_90/bin/boost/libs/regex/build/libboost_regex.a/intel-linux/release/threading-multi/instances.o" "/RQMNT/exec1/lisa/delallea/boost_src/boost_1_33_0/libs/regex/build/../src/instances.cpp" /RQMNT/exec1/lisa/delallea/boost_src/boost_1_33_0/boost/regex/v4/instances.hpp(84): error #803: function "boost::match_results<BidiIterator, Allocator>::match_results(const boost::match_results<BidiIterator, Allocator> &) [with BidiIterator=const char *, Allocator=std::vector<boost::sub_match<const char *>, std::allocator<boost::sub_match<const char *>>>::allocator_type]" explicitly instantiated more than once template class BOOST_REGEX_DECL match_results< std::basic_string<BOOST_REGEX_CHAR_T>::const_iterator >; ----------------------------------------------------------------------------------- There are many errors like this one. Again, if I remove the include command -I/opt/intel/compiler90/include/c++ it works fine. Also if I use the intel 8.0 includes it works fine (but not intel 8.1). Any help fixing these errors (actually, mainly the regex one, as this is the library I really need) will be much appreciated :) -- Olivier [View Less]

2 1

[serialization]save object to a previous version
by Li Lirong 14 Oct '05

14 Oct '05

Hi, As I understand, the class versioning system permits a program to load archives created by previous versions of the program. However, is it possible to explicitly save some of objects to a previous version so that previous versions of the program can read the saved archive? Regards, Lirong

2 1

Re: [Boost-users] Report from Mont Tremblant C++ Committee meeting
by Jeff Garland 14 Oct '05

14 Oct '05

On Thu, 13 Oct 2005 12:52:30 -0400, Daryle Walker wrote > On 10/12/05 5:38 AM, "John Maddock" <john(a)johnmaddock.co.uk> wrote: > > [SNIP] > > And for those who think that in-place modification is the way to go: you do > > realise that it's often *slower* than building a new string don't you? > > And what if the string uses more than half of the available space? > (I'm not advocating in-place modification, but just mentioning that > "return a copy" … [View More]

1 0

Is there a boost way to avoid this macro usage?
by Rush Manbert 13 Oct '05

13 Oct '05

Hi all, I posted this question to comp.lang.c++.moderated and got a single reply that basically said "it looks like you need to use macros", but I thought I would ask the same question here, just in case you MPL folks have some tricks up your boost library sleeves. Basically, I need to make an enum and a static array of structures from one data set and I only know one way to do it, and it involves an amount of "trickiness" that some find disturbing. The original post: In the code shown below,… [View More] the CODE_TABLE macro is used to insert a sequence of CODE(codeValue) macros. By changing the definition of CODE(codeValue) right before each usage of CODE_TABLE, I can create an enumeration of codeValues, then use the same CODE_TABLE definition to create a static lookup table that can be used to find information about a codeValue, given its numeric value. In this case, I am finding the name of the enumerated value. In the real application, there are a number of other fields available. (As you can probably tell, I have written a lot of C code in my time.) IMHO, the benefit of this technique is that you only maintain CODE_TABLE. All of the required code bits are generated from it. The downside is that Macros are Evil, the macro-that-is-a-list-of-macros is confusing, and you need to carefully redefine CODE(codeValue) in the proper locations. Additionally, the real application will have multiple classes that each define their own CODE_TABLE contents, so making it all work correctly is a little tricky. My question is this: Is there any method available in C++ that can let me do away with the macros while preserving the nice quality that only one data structure needs to be maintained? Something sophisticated and tricky with templates perhaps? I expect that the fact that I stringize the enum name when creating the lookup table makes a macro the only choice. But, since that is only one component in each lookup table entry in the real code, I might be willing to give it up in order to lose the macros. Here is the code example. Contents of foo.h: ----------------- #define CODE_TABLE \ CODE(FooCodeA) \ CODE(FooCodeB) #define CODE(codeValue) codeValue, class foo { public: typedef enum { // Here comes the first use of CODE_TABLE CODE_TABLE } CodesT; foo (CodesT theCode) : m_code (theCode) {} const char *lookup (void) const; const int getCode (void) const {return m_code;} private: CodesT m_code; typedef struct { CodesT theCode; const char *pTheCodeAsString; } CodeLookupTableT; static CodeLookupTableT m_lookupTable[]; }; Contents of foo.cpp: ------------------- #include "foo.h" // Now we redefine CODE so that we can initialize the // static lookup table #undef CODE #define CODE(codeValue) {codeValue, #codeValue}, foo::CodeTableLookupT foo::m_lookupTable[] = { CODE_TABLE }; // The lookup method that finds the string description // from the numeric code const char *foo::lookup (void) const { for (int i = 0; i < (sizeof m_lookupTable)/(sizeof m_lookupTable[0]); ++i) { if (m_lookupTable[i].theCode == m_code) return m_lookupTable[i].pTheCodeAsString; } return "Unknown code value"; } contents of main.cpp: ------------------- #include <iostream> #include "foo.h" using namespace std; int main (int argc, char * const argv[]) { foo myFoo (foo::FooCodeB); cout << "myFoo with code number....: " << myFoo.getCode() << endl << " looks up the code name as: " << myFoo.lookup() << endl; return 0; } Output from running the program: ------------------------------- myFoo with code number....: 1 looks up the code name as: FooCodeB Thanks, Rush [View Less]

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Hash Map
by Piyush Kapadia 13 Oct '05

13 Oct '05

Is there any faster version of std::map ? I heard there is a faster hashmap implementation, does boost have anything in this regard ?

4 3

[shared_ptr] Two basic questions
by Matthias Kaeppler 13 Oct '05

13 Oct '05

Hello, I have two questions regarding the proper use of boost::shared_ptr; both actually arose after reading http://www.boost.org/libs/smart_ptr/example/shared_ptr_example.cpp 1. In order for some class to work with std::set, you have to supply an operator with "less than" semantics. Why are you instead declaring a "greater than" operator? 2. In your examples, sometimes you're passing a shared_ptr by value, and sometimes by reference-to-const. Which is the better practice? Usually, … [View More]

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[operators] boost::operators-like functionality for methods
by Geoffrey Irving 13 Oct '05

13 Oct '05

Hello, Is it possible to get boost::operator like functionality for general methods? In other words, I'd like to be able to do the following: template<...> struct complete : public ... { void f(){a();} void g(); }; struct C : public complete<...> { void a(); void b(){g();} }; The resulting class C would have methods a,b,g,f. Here C::b refers to the complete::g and complete::f refers to C::a, so the dependencies are circular. It seems like the boost::operators … [View More]

2 1

MPL map / multi index dependency bug
by Zach Laine 13 Oct '05

13 Oct '05

The following code does not compile using gcc 3.4.3. I tried it with the same results using 1.32 and 1.33. Reversing the order of the #includes fixes the problem. Is this a known order dependency? If so, I couldn't find it documented anywhere. #include <boost/multi_index_container.hpp> #include <boost/mpl/map.hpp> int main() { return 0; } Compiler output: In file included from /usr/local/include/boost-1_33/boost/mpl/map/aux_/begin_end_impl.hpp:20, from … [View More]

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[Beginner] Setting up a function which generates normally distributed numbers
by Snorre Jakobsen 13 Oct '05

13 Oct '05

Hello I'm sorry if this is answered in the documentation, but I didn't find it. I want a function which returns a normally distributed number. #include <boost/random.hpp> #include <time.h> using namespace boost; double SampleNormal (double mean, double sigma) { mt19937 rng; // select random number generator rng.seed((unsigned int) time(0)); // seconds since 1970 // select desired probability distribution normal_distribution&… [View More]

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thread-safe iostreams - ideas for implementation ?
by marc 12 Oct '05

12 Oct '05

thread-safe iostreams - ideas for implementation ? I am currently experimenting with the boosth thread/mutex libraries, and did notice that the standard io streams are not thread safe. In the boost examples, this is handles by some global mutexes which are locked before writing to cout, cerr. I would like to have some classes which - behave exactly as cout, cerr and named file out streams - are thread safe mutex locked Are there any ideas on how to do this ?? I have the following … [View More]

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[Review] TR1 library accepted
by Beman Dawes 12 Oct '05

12 Oct '05

John Maddock's TR1 library is accepted by Boost. Coincidentally, ISO has just announced that TR1 unanimously passed its final ballot, and so is now official. There were four reviews of John's submission, all urging acceptance. For most of the relatively few issues raised during review, John has already responded. Unless I missed it, however, John hasn't responded to Jonathan Wakely's review comments yet, anduld do so when he gets a chance. For example: It might be useful to list all the … [View More]

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compiling fails on MacOS X
by Ákos Maróy 12 Oct '05

12 Oct '05

Hi, I'm trying to compile boost 1.33 on MacOS X, and I get a number of failures. I have: $ uname -a Darwin akos-maroys-mac-mini.local 8.2.0 Darwin Kernel Version 8.2.0: Fri Jun 24 17:46:54 PDT 2005; root:xnu-792.2.4.obj~3/RELEASE_PPC Power Macintosh powerpc $ gcc --version powerpc-apple-darwin8-gcc-4.0.0 (GCC) 4.0.0 (Apple Computer, Inc. build 5026) Copyright (C) 2005 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even … [View More]for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. I compiled bjam first (without problems), and then issues the following command (according to the documentation): ./tools/build/jam_src/bin.macosxppc/bjam -sTOOLS=darwin --prefix=/tmp/boost I get the following errors: darwin-Archive-action bin/boost/libs/regex/build/libboost_regex.a/darwin/release/libboost_regex-1_33.a ranlib: file: bin/boost/libs/regex/build/libboost_regex.a/darwin/release/libboost_regex-1_33.a(icu.o) has no symbols ranlib: file: bin/boost/libs/regex/build/libboost_regex.a/darwin/release/libboost_regex-1_33.a(regex_debug.o) has no symbols ranlib: file: bin/boost/libs/regex/build/libboost_regex.a/darwin/release/libboost_regex-1_33.a(w32_regex_traits.o) has no symbols ranlib: file: bin/boost/libs/regex/build/libboost_regex.a/darwin/release/libboost_regex-1_33.a(usinstances.o) has no symbols system-Ranlib bin/boost/libs/regex/build/libboost_regex.a/darwin/release/libboost_regex-1_33.a ranlib: file: bin/boost/libs/regex/build/libboost_regex.a/darwin/release/libboost_regex-1_33.a(icu.o) has no symbols ranlib: file: bin/boost/libs/regex/build/libboost_regex.a/darwin/release/libboost_regex-1_33.a(regex_debug.o) has no symbols ranlib: file: bin/boost/libs/regex/build/libboost_regex.a/darwin/release/libboost_regex-1_33.a(w32_regex_traits.o) has no symbols ranlib: file: bin/boost/libs/regex/build/libboost_regex.a/darwin/release/libboost_regex-1_33.a(usinstances.o) has no symbols darwin-Link-DyLib-action bin/boost/libs/test/build/libboost_prg_exec_monitor.dylib/darwin/debug/shared-linkable-true/libboost_prg_exec_monitor-d-1_33.dylib ld: Undefined symbols: __Z8cpp_mainiPPc /usr/bin/libtool: internal link edit command failed ...failed darwin-Link-DyLib-action bin/boost/libs/test/build/libboost_prg_exec_monitor.dylib/darwin/debug/shared-linkable-true/libboost_prg_exec_monitor-d-1_33.dylib... darwin-Link-DyLib-action bin/boost/libs/test/build/libboost_prg_exec_monitor.dylib/darwin/release/shared-linkable-true/libboost_prg_exec_monitor-1_33.dylib ld: Undefined symbols: __Z8cpp_mainiPPc /usr/bin/libtool: internal link edit command failed ...failed darwin-Link-DyLib-action bin/boost/libs/test/build/libboost_prg_exec_monitor.dylib/darwin/release/shared-linkable-true/libboost_prg_exec_monitor-1_33.dylib... darwin-Link-DyLib-action bin/boost/libs/test/build/libboost_test_exec_monitor.dylib/darwin/debug/shared-linkable-true/libboost_test_exec_monitor-d-1_33.dylib ld: Undefined symbols: __Z9test_mainiPPc /usr/bin/libtool: internal link edit command failed ...failed darwin-Link-DyLib-action bin/boost/libs/test/build/libboost_test_exec_monitor.dylib/darwin/debug/shared-linkable-true/libboost_test_exec_monitor-d-1_33.dylib... darwin-Link-DyLib-action bin/boost/libs/test/build/libboost_test_exec_monitor.dylib/darwin/release/shared-linkable-true/libboost_test_exec_monitor-1_33.dylib ld: Undefined symbols: __Z9test_mainiPPc /usr/bin/libtool: internal link edit command failed ...failed darwin-Link-DyLib-action bin/boost/libs/test/build/libboost_test_exec_monitor.dylib/darwin/release/shared-linkable-true/libboost_test_exec_monitor-1_33.dylib... darwin-Link-DyLib-action bin/boost/libs/test/build/libboost_unit_test_framework.dylib/darwin/debug/shared-linkable-true/libboost_unit_test_framework-d-1_33.dylib ld: Undefined symbols: __Z20init_unit_test_suiteiPPc /usr/bin/libtool: internal link edit command failed ...failed darwin-Link-DyLib-action bin/boost/libs/test/build/libboost_unit_test_framework.dylib/darwin/debug/shared-linkable-true/libboost_unit_test_framework-d-1_33.dylib... darwin-Link-DyLib-action bin/boost/libs/test/build/libboost_unit_test_framework.dylib/darwin/release/shared-linkable-true/libboost_unit_test_framework-1_33.dylib ld: Undefined symbols: __Z20init_unit_test_suiteiPPc /usr/bin/libtool: internal link edit command failed [View Less]

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Errors compiling greg_month.cpp
by D. R. Evans 12 Oct '05

12 Oct '05

I just upgraded to 1.33.0, and am getting a bunch of compilation errors with the current version of greg_month.cpp: The list of errors starts with: c:\boost\boost_1_33_0\boost\date_time\gregorian\formatters.hpp(34) : error C2977: 'date_formatter' : too many template arguments c:\boost\boost_1_33_0\boost\date_time\date_formatting_limited.hpp(114) : see declaration of 'date_formatter' c:\boost\boost_1_33_0\boost\date_time\gregorian\formatters.hpp(40) : see reference to function … [View More]

1 0

Short Mailing List Outage on Thursday 10/13
by Jeff Garland 12 Oct '05

12 Oct '05

FYI -- I believe this will impact Boost-Users as well. ------------------ I am sorry for this short notice but I need to reboot milliways to upgrade its firmware. It will be down for about 1 hour Thursday morning (10/13). - 6:00am-7:00am Pacific US time - 7:00am-8:00am Mountain US time - 8:00am-9:00am Central US time - 9:00am-10:00am Eastern US time - 1:00pm-2:00pm GMT Specifically, the following services provided by the OSL will be unavailable during this timeframe: - All e-mail services … [View More]

1 0

typeof
by Karl Meerbergen 12 Oct '05

12 Oct '05

Hello, Looking at the regression test results, it seems that some typeof tests do not compile on IBM. Did somebody have a look at this? Is this a known problem? Thanks, Karl

2 5

Crash when assign value to regex object
by Aaron 12 Oct '05

12 Oct '05

The code snippet: struct Grepper { int nPriority; boost::regex re; pONGREPFOUNDCALLBACK pOnGrepFoundSymbols; friend bool operator< (const Grepper& g1, const Grepper& g2) { return g1.nPriority > g2.nPriority; } }; if (...){ Grepper gp; if (QueryGreppers(gp)) g_vecGreppers.push_back(gp); } bool QueryGreppers(Grepper& gp) { gp.nPriority = 1; gp.re ="\\s*#define\\… [View More]s+([^\\s]+)\\s+([^/\\r\\n]+)([^\\r\\n]*)"; gp.pOnGrepFoundSymbols = OnGrepSingleLineSymbols; return true; } Program fails at gp.re = ... The call stack is: _CrtIsValidHeapPointer(const void * 0x012e61f8) line 1606 _free_dbg_lk(void * 0x012e61f8, int 1) line 1011 + 9 bytes _free_dbg(void * 0x012e61f8, int 1) line 970 + 13 bytes free(void * 0x012e61f8) line 926 + 11 bytes operator delete(void * 0x012e61f8) line 7 + 9 bytes boost::detail::simple_alloc::deallocate(void * 0x012e61f8, unsigned int 1024) line 213 + 9 bytes boost::detail::allocator_adapter<unsigned char,boost::detail::simple_alloc>::deallocate(unsigned char * 0x012e61f8, unsigned int 1024) line 258 boost::re_detail::raw_storage<boost::detail::allocator_adapter<char,boost::detail::simple_alloc> >::resize(boost::re_detail::raw_storage<boost::detail::allocator_adapter<char,boost::detail::simple_alloc> > * const 0x0012eff0, unsigned int 1120) line 223 boost::re_detail::raw_storage<boost::detail::allocator_adapter<char,boost::detail::simple_alloc> >::extend(boost::re_detail::raw_storage<boost::detail::allocator_adapter<char,boost::detail::simple_alloc> > * const 0x0012eff0, unsigned int 268) line 131 + 27 bytes boost::reg_expression<char,boost::regex_traits<char>,boost::detail::allocator_adapter<char,boost::detail::simple_alloc> >::compile_set_aux(boost::reg_expression<char,boost::regex_traits<char>,boost::detail::allocator_adapter<char,boost::detail::simple_alloc> > * const 0x0012efe8, ...) line 1145 + 17 bytes boost::reg_expression<char,boost::regex_traits<char>,boost::detail::allocator_adapter<char,boost::detail::simple_alloc> >::compile_set_simple(boost::reg_expression<char,boost::regex_traits<char>,boost::detail::allocator_adapter<char,boost::detail::simple_alloc> > * const 0x0012efe8, boost::re_detail::re_syntax_base * 0x012e6534, unsigned long 8, unsigned char 0) line 737 + 48 bytes boost::reg_expression<char,boost::regex_traits<char>,boost::detail::allocator_adapter<char,boost::detail::simple_alloc> >::set_expression(boost::reg_expression<char,boost::regex_traits<char>,boost::detail::allocator_adapter<char,boost::detail::simple_alloc> > * const 0x0012efe8, const char * 0x0846601c `string', const char * 0x08466049, unsigned int 34055) line 1651 + 20 bytes boost::reg_expression<char,boost::regex_traits<char>,boost::detail::allocator_adapter<char,boost::detail::simple_alloc> >::set_expression(boost::reg_expression<char,boost::regex_traits<char>,boost::detail::allocator_adapter<char,boost::detail::simple_alloc> > * const 0x0012efe8, const char * 0x0846601c `string', unsigned int 34055) line 238 + 59 bytes boost::reg_expression<char,boost::regex_traits<char>,boost::detail::allocator_adapter<char,boost::detail::simple_alloc> >::assign(const char * 0x0846601c `string', unsigned int 33031) line 89 + 20 bytes boost::basic_regex<char,boost::regex_traits<char>,boost::detail::allocator_adapter<char,boost::detail::simple_alloc> >::operator=(boost::basic_regex<char,boost::regex_traits<char>,boost::detail::allocator_adapter<char,boost::detail::simple_alloc> > * const 0x0012efe8, const char * 0x0846601c `string') line 356 QueryGreppers(Grepper & {...}) line 35 + 17 bytes What's wrong with it? [View Less]

2 4

[Parameter library]
by Sohail Somani 11 Oct '05

11 Oct '05

Is the prescribed method for the parameter library thread safe? // appears to modify global variables "graph", etc core::depth_first_search(( graph = 'G', visitor = 2, root_vertex = 3.5, index_map = "hello, world", color_map = false)); Thanks

2 1

[iostreams] Problems using filtering_stream and code_converter
by Niklas Wiberg 11 Oct '05

11 Oct '05

Hi, I'm using boost 1.33.0 on windows (VC++6). I would like to use a code_converter to convert internal std::wstring's (which I understand are ucs2 in windows/vstudio, but that shouldn't matter here I guess) to utf-8 when saving to file. Here is the failing code: <code> void main() { typedef boost::iostreams::code_converter<boost::iostreams::file_sink, WideCharToUtf8Cvt> my_sink; std::wstring teststr(L"Blah blah."); boost::iostreams::filtering_wostream out; boost::… [View More]

2 2

BOOST_STATIC_ASSERT
by Edward Grace 11 Oct '05

11 Oct '05

Dear All, I am encountering a problem with BOOST_STATIC_ASSERT, it is producing compile-time errors that are a little cryptic. When using BOOST_STATIC_ASSERT such as class rtm : public matrix<ElementType> { BOOST_STATIC_ASSERT(::boost::is_float<ElementType>::value || ejg::boost::is_complex<ElementType>::value); public: ... ... .. Instantiation of the rtm class with a non float or non complex type, such as: ejg::oned::rtm<char> M; … [View More]

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[Boost.Build] unable to cross-compile 1_33_0
by BRIDGES Dick 11 Oct '05

11 Oct '05

My apologies in advance if this question is only for the jamboost mailing list but I very much need to cross-compile boost_1_33_0 and I can't seem to make this version work. # bjam --v2 --version Boost.Build V2 (Milestone10) Boost.Jam 03.01.11 (I haven't received any responses on the jamboost mailing list so I assume I'm formulating my question incorrectly. If there is something wrong with the way I'm asing this question, would someone please point it out to me?) I am trying to compile a … [View More]

1 0

Re: [Boost-users] BOOST XML serialisation c++ libraries with C#
by Prasad, Shyam 11 Oct '05

11 Oct '05

Hi Has anyone tried using BOOST XML serialisation with C#? Is that feasible? Basically the scenario is a C# front end client talking to a C++ back end server via XML messages both sides using Boost XML Serialisation / Deserialisaion framework. Regards SP

1 0

[serialization][any]Do we have serialization support for boost::any?
by Li Lirong 11 Oct '05

11 Oct '05

Hi, Do we have serialization support for boost::any? If not, how is it possible to serialize boost::any? Regards, Lirong

6 20

[BGL] Multiple adaptations of graph
by Andreas Brinck 11 Oct '05

11 Oct '05

Hi, I have a simple directed graph class (let's call it MyGraph) which I want to adapt for BGL algorithms. I've defined the necessary traits and functions (in_edges, target etc.) and everything works fine. Problem is I want to be able to treat the graph as an undirected graph as well when using some of the BGL algorithms, but since the graph_traits are only templatized on the graph type I can't define a new set of traits since graph_traits<MyGraph> is already defined. The only solution … [View More]

1 0

Bug in boost::regex_match 1.33.0 Win64/cl1400 and Linux/gcc323
by rlop＠gmx.de 11 Oct '05

11 Oct '05

Hello, After upgrading from boost 1.32 to boost 1.33.0, we get an exception in boost::regex_match. The exception is std::runtime_error: Regular expression too big , and only under Win64/cl1400 and RHEL/gcc323 Changing the regex slightly sometimes avoids the exception... Attached a small example, which can be used to reproduce the exception. #include <boost/regex.hpp> int main(void) { boost::regex validValue = boost::regex("([x]{0,64})?"); boost::regex_match("T",… [View More]

3 3

Arrays in Boost::Python
by Wyatt Greenway 11 Oct '05

11 Oct '05

How do I acomplish this: class A { public: int *Buffer; vector<string> Array; A() { this->Buffer = new int[10]; /* Set items in Buffer */} } /* Boost code */ class_<A>("A") .def("Buffer", &A::Buffer) .def("Array", &A::Array) ; /*-----*/ And in python it would look like so: > MyA = A() > print MyA.Buffer[0] > MyA.Array.append("Hello world!") > print MyA.Array[0] ??????? Thanks in advance for any help

2 1

boost::any Question
by Piyush Kapadia 10 Oct '05

10 Oct '05

I am new user of Boost, I tried to use boost::variant first, but in comparison to boost::any performance of boost::variant appears to be around 4 times slower, so settled for boost::any. Also boost::any has cleaner interface but I don't know how to query current type information for boost::any ? My code looks like following map<unsigned int, boost::any> result_table; result_table[1] = 543.434; vector<int> vec; .. Some vec population code; result_table[2] = vec; … [View More]

2 6

[BGL] Simple question about accessing vertex property
by Giulio Veronesi 10 Oct '05

10 Oct '05

Hi, How do I access the vertex_index property of a vertex? Is it necessary to use the get function? More precisaly, let us consider the following: typedef adjacency_list<vecS, vecS, bidirectionalS, no_property, property<edge_weight_t, int> > TGraph; typedef graph_traits<TGraph>::vertex_descriptor TNode; Suppose that 'vertex' is a TNode. Is it correct to do int idx = vertex; to get in idx the vertex_index of vertex? Thanks in adavnce, Giulio

3 2

Boost Serialization Question.
by Piyush Kapadia 10 Oct '05

10 Oct '05

I am able to use Boost XML and TEXT serialization but Binary Serialization fails to read file, though it can write binary file. Is Binary Serialization fully Supported and if so does it work with STD container classes ?

3 2

Re: [Boost-users] __stdcall bind-s with boost::bind andboost::lambda
by Bulygin, Sergey 10 Oct '05

10 Oct '05

boost::lambda::bind<RetType>(..) works like a charm. :) Thanks a lot, Peter! Sergey Peter Dimov wrote: > To bind to __stdcall calling convention function with boost::bind, > there is a macro to define: BOOST_BIND_ENABLE_STDCALL. How can I do > the same (bind to __stdcall-type function) with boost::lambda::bind? You may want to try specifying the return type explicitly as in bind<void>(my_stdcall_function, _1, 0) and see if it helps.

1 0

__stdcall bind-s with boost::bind and boost::lambda
by Bulygin, Sergey 10 Oct '05

10 Oct '05

To bind to __stdcall calling convention function with boost::bind, there is a macro to define: BOOST_BIND_ENABLE_STDCALL. How can I do the same (bind to __stdcall-type function) with boost::lambda::bind? Thank you, Sergey

2 1

Type List Iteration?
by Duane Murphy 10 Oct '05

10 Oct '05

How do I iterate over a type list and call a function? MPL? I have a base class BASE that has several subclasses A, B, C that have special capabilities, but no way to identify those capabilities aside from the type. I would like to determine if an object of type BASE is also of one of the special subclasses: ie void f( BASE* base) { if ( dynamic_cast< A* >( base ) != NULL ) { some_function( dynamic_cast< A* >( base ) ); } else if ( dynamic_cast< B* >(… [View More]

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[mpl] nested lambdas?
by Geoffrey Romer 10 Oct '05

10 Oct '05

Suppose I'm tying to build a nested lambda expression, like so (typename...::type omitted for simplicity): lambda<higher_order_func<lambda<foo<_1> >, _2> > - Is this legal? - Does the _1 refer to the first argument of the inner lambda, or of the outer lambda? - Can the above be overridden? I.e. what if I want to refer to the arguments of both lambdas within the inner lambda?

2 3