December 2006 - Boost-users

serializing enums (and arrays)
by craigp 17 Dec '06

17 Dec '06

I can't figure out how to override serializating enums (and arrays) - without hacking the source code, that is. save_enum_type is defined in boost/archive/detail/oserializer.hpp, and converts them into ints (btw, would longs be safer?). I tried defining a serialize function and specifying the implementation level to object_serializable, but that didn't work (and given how it's defined and used, there seems to be no way of overriding via template specialization). Perhaps save_enum_type and save_array_type could be put into a separate header (out of the archive/detail and maybe into boost/serialization along with vector.hpp, etc)? BTW, thanks for the great library! --craig ____________________________________________________________________________________ Any questions? Get answers on any topic at www.Answers.yahoo.com. Try it now.

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CircularBuffer from the boost-sandbox
by Luca Cappa 17 Dec '06

17 Dec '06

Hi all, I would like to use the circularbuffer class provided by boost-sandbox, and I would like if someone could tell me which are the rules to include the boost-sandbox files (either the .cpp and the .h) in my building process, i.e. should I copy only the relevant files into the actual boost installation directory, or anything else? Greetings, Luca

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Good guide for using Boost with Visual Studio 2005?
by Laran Evans 16 Dec '06

16 Dec '06

I'm an admitted C++ novice, definitely a VS novice. thanks

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atomic_count default constructor
by Clark S. Cox III 16 Dec '06

16 Dec '06

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 A couple of questions: Is there any rational behind the fact that boost::detail::atomic_count doesn't have a default constructor? For what reason is atomic_count an implementation detail, and not available for general use? (i.e. why is it in boost::detail, and not boost::) - -- Clark S. Cox III clarkcox3(a)gmail.com -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFFgxMRXkPInUR5a8wRApfMAJoCiK/xH7K0u2GZnn3QoEk42bqznwCfQ9r0 s60aQuCL2IC1CB1Xi5uhBqQ= =roHz -----END PGP SIGNATURE-----

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Problems installing: "spawn: No such file or directory"
by Laran Evans 16 Dec '06

16 Dec '06

I've got Python 2.5 installed, PYTHON_ROOT is set to C:\Python25 and PYTHON_VERSION is set to 2.5. I manually created C:\Boost, C:\Boost\lib and C:\Boost\include. I get the error output below when I try to build. How do I get past these? --- C:\Documents and Settings\Me\Desktop\boost_1_33_1>vcvars32 C:\Documents and Settings\Me\Desktop\boost_1_33_1>"C:\Program Files\Mic rosoft Visual Studio 8\Common7\Tools\vsvars32.bat" Setting environment for using Microsoft Visual Studio 2005 x86 tools. C:\Documents and Settings\Me\Desktop\boost_1_33_1>bjam "-sTOOLS=vc-8_0" install ****************************************************** Building Boost.Iostreams with bzip2 support disabled. To enable bzip2, consult the Boost.Iostreams documentation ****************************************************** ****************************************************** Building Boost.Iostreams with zlib and gzip support disabled. To enable zlib and gzip, consult the Boost.Iostreams documentation ****************************************************** 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). ...patience... ...patience... ...found 13373 targets... ...updating 4938 targets... MkDir1 bin spawn: No such file or directory C:\Documents and Settings\Me\Desktop\boost_1_33_1>

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Tuple how to get the TYPE of the n-th element?
by Seweryn Habdank-Wojewódzki 16 Dec '06

16 Dec '06

Hi I working with tuples, and that tuples are constructed by K elements. For me interesting are 1-st, 2-nd and 3-rd. 0-th and others not. Inside my procedure I want to know what are the types on the positions 1, 2, 3. How can I get them? The example: somewhere in the code: typedef tuple < std::string, double, double, double, int, std::string > Foo; typedef tuple < std::string, long double, long double, long double, long , std::map<int,std::string> > Bar; My part: template < typename Tuple > // somethink like: typename Tuple::get_type<1> calculate ( Tuple & t ) { // here I need for some calculations know what are the types // on the positions 1,2,3? }; And proposition of usage: calculate ( /*Foo*/ foo ); calculate ( /*Bar*/ bar ); Best regards, -- |\/\/| Seweryn Habdank-Wojewódzki `\/\/'

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boost/regex How do i link/(create libs) with xlC on aix
by Rick Weiss 16 Dec '06

16 Dec '06

I dont mind using g++ to compile but all of our aix libs are created(and compiled for that matter) with xlC. And I cant seem to use g++ for linking to the xlC linked libs. So i guess I need one of two solutions: 1) make regex libs with xlC OR 2) learn how to link to several (so) libs created with g++ and xlC. Any help is appreciated. Thanks Rick Weiss

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shared_ptr reference conversion and const oddity
by Brian Hassink 15 Dec '06

15 Dec '06

Here's the test case... class A { public: A() {} virtual ~A() {} }; class B : public A { public: B() {} }; class X1 { public: X1(const boost::shared_ptr<A>& a) {} virtual ~X1() {} }; class Y1 : public X1 { public: Y1(const boost::shared_ptr& b) : X1(b) {} }; class X2 { public: X2(boost::shared_ptr<A>& a) {} virtual ~X2() {} }; class Y2 : public X2 { public: Y2(boost::shared_ptr& b) : X2(b) {} }; int main(int argc, char** argv) { boost::shared_ptr b(new B()); Y1 y1(b); // ptr const in constructor, compiler ok Y2 y2(b); // ptr not const in constructor, compiler not ok } My question is why conversion of the shared_ptr reference does not work if it is not declared const? Here's the compiler error (gcc 3.4.4 - cygming special)... compiling main.cpp... main.cpp: In constructor `Y2::Y2(boost::shared_ptr&)': main.cpp:31: error: no matching function for call to `X2::X2(boost::shared_ptr&)' main.cpp:23: note: candidates are: X2::X2(const X2&) main.cpp:25: note: X2::X2(boost::shared_ptr<A>&) make: *** [obj/main.o] Error 1 Thanks, Brian

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[graph] leda_graph.hpp and LEDA 5.0.1
by Jens Müller 15 Dec '06

15 Dec '06

The example doesn't work with LEDA 5.0.1 any longer: C++ topo-sort-with-leda.o topo-sort-with-leda.cpp: In function `int main()': topo-sort-with-leda.cpp:14: error: expected init-declarator before '<' token topo-sort-with-leda.cpp:14: error: expected `,' or `;' before '<' token topo-sort-with-leda.cpp:15: error: `graph_t' undeclared (first use this function) topo-sort-with-leda.cpp:15: error: (Each undeclared identifier is reported only once for each function it appears in.) topo-sort-with-leda.cpp:15: error: expected `;' before "leda_g" [Many more errors follow] Compiler is g++ 4.1.0. Has anyone made LEDA 5.0.1 work with a BGL wrapper?

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[BGL] Max (min) cycle ratio
by Dmitry 15 Dec '06

15 Dec '06

Dear all, For a some time I've been using my own implementation for calculating of the minimum cycle ratio of the directed multigraph, it based on the approach described in the paper "Numerical Computation of Spectral Elements in MAX-PLUS algebra" and seems has complexity close to linear in the respect of the edges number (both in memory and time). Does current BGL has some solutions for cycle ratio problem? I would like to try to contribute my "perfect" implementation to BGL if it's possible. What is need to be done for it? WBR, Dima.

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