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[smart_ptr] enable_shared_from_this and shared_ptr to a base class
by Adam Romanek 21 Jun '13

21 Jun '13

Hi, I have a question related to using shared_from_this() and a shared_ptr to a base class. Here's a modified version of the enable_shared_from_this usage example from its documentation web page: #include <boost/enable_shared_from_this.hpp> #include <boost/shared_ptr.hpp> #include <cassert> class X { public: virtual void foo() = 0; }; class Y: public X, public boost::enable_shared_from_this<Y> { virtual void foo() { shared_from_this(); } }; int main() { X* x_ptr = new Y; boost::shared_ptr<X> sp(x_ptr); sp->foo(); } First, class Y is now derived from class X. Secondly, shared_ptr's template argument is now X and the parameter to the shared_ptr's constructor is now a pointer to X. Now, calling shared_from_this() in X and/or Y throws boost::bad_weak_ptr. Is this correct behavior? Is it documented somewhere? I know that the example is a bit unrealistic since most of the time shared_ptr is constructed directly from the pointer returned by 'new Y' or created by make_shared() but still, this is something that bothers me. WBR, Adam Romanek

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Re: [Boost-users] [Test]: Problem with simple Boost.Test
by Damien Kick 21 Jun '13

21 Jun '13

On Jun 20, 2013, at 8:38 PM, <boost-users-request(a)lists.boost.org<mailto:boost-users-request@lists.boost.org>> wrote: Date: Thu, 20 Jun 2013 17:01:54 +0000 (UTC) From: Gennadiy Rozental <rogeeff(a)gmail.com<mailto:rogeeff@gmail.com>> To: boost-users(a)lists.boost.org<mailto:boost-users@lists.boost.org> Subject: Re: [Boost-users] [Test]: Problem with simple Boost.Test Message-ID: <loom.20130620T185812-619(a)post.gmane.org<mailto:loom.20130620T185812-619@post.gmane.org>> Content-Type: text/plain; charset=utf-8 thusly:$ ${CXX} -c --std=c++0x -g -I${TARGET}/include cma.cpp -o cma.o $ ${CXX} --std=c++0x -g cma.o ${TARGET}/lib/libboost_test_exec_monitor.a \ ${TARGET}/lib/libboost_unit_test_framework.dylib -o cma I know docs are not ideal but this part is very clear I thought. test_exec_monitor is an old alternative t ounit test framework, which is long deprecated and they definitely do not require each other In this case, I wouldn't fault the docs per se but rather only my impatience in having tried "jumping directly to the subject of [my] interest" but not yet having realized exactly what my subject of interest really is/was nor how far I needed to jump in order to get to it ;-) I had been trying this: $ cat cma.cpp #define BOOST_TEST_MODULE cma #include <boost/test/unit_test.hpp> #include <iostream> #include <ostream> BOOST_AUTO_TEST_CASE(sanity) { std::clog << "Test the world!\n"; } $ ${CXX} -c --std=c++0x -g -I${TARGET}/include cma.cpp -o cma.o $ ${CXX} --std=c++0x -g cma.o ${TARGET}/lib/libboost_unit_test_framework.dylib -o cma Undefined symbols for architecture x86_64: "_main", referenced from: implicit entry/start for main executable ld: symbol(s) not found for architecture x86_64 collect2: error: ld returned 1 exit status $ But when I started reading through more of the documentation and got as far as <http://preview.tinyurl.com/lw7e688>, I realized that I needed to be doing something more like this: $ ${CXX} -c --std=c++0x -g -DBOOST_TEST_DYN_LINK -I${TARGET}/include cma.cpp -o cma.o $ ${CXX} --std=c++0x -g cma.o ${TARGET}/lib/libboost_unit_test_framework.dylib -o cma $ env DYLD_LIBRARY_PATH=${TARGET}/lib ./cma Running 1 test case... Test the world! *** No errors detected $ Thank you, Gennadiy, for having taken the time to respond to my question as well as having taken the time you spent on Boost.Test. ________________________________ This e-mail and any attachments are confidential. If it is not intended for you, please notify the sender, and please erase and ignore the contents.

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Re: [Boost-users] [Test]: Problem with simple Boost.Test
by Damien Kick 21 Jun '13

21 Jun '13

Date: Mon, 17 Jun 2013 23:03:16 +0000 (UTC) From: legalize+jeeves(a)mail.xmission.com<mailto:legalize+jeeves@mail.xmission.com> (Richard) To: boost-users(a)lists.boost.org<mailto:boost-users@lists.boost.org> Subject: Re: [Boost-users] [Test]: Problem with simple Boost.Test Message-ID: <kpo4jk$2ih$2(a)ger.gmane.org<mailto:kpo4jk$2ih$2@ger.gmane.org>> [Please do not mail me a copy of your followup] boost-users(a)lists.boost.org<mailto:boost-users@lists.boost.org> spake the secret code <7364AB234369D348AE1CEBC1A86132DBAD32EA(a)SVLITMX02.shoretel.com<http://SVLITMX02.shoretel.com>> thusly: $ ${CXX} -c --std=c++0x -g -I${TARGET}/include cma.cpp -o cma.o $ ${CXX} --std=c++0x -g cma.o ${TARGET}/lib/libboost_test_exec_monitor.a \ ${TARGET}/lib/libboost_unit_test_framework.dylib -o cma Why are you linking against boost_test_exec_monitor? I've never needed to do that. boost_unit_test_framework should be enough. Interesting. Because I'm finding the following: $ ${CXX} -c --std=c++0x -g -I${TARGET}/include cma.cpp -o cma.o $ ${CXX} --std=c++0x -g cma.o ${TARGET}/lib/libboost_unit_test_framework.dylib -o cma Undefined symbols for architecture x86_64: "_main", referenced from: implicit entry/start for main executable ld: symbol(s) not found for architecture x86_64 collect2: error: ld returned 1 exit status $ But that is also what I'm finding with the system GCC and the Fink install of Boost 1.46, and so that behavior isn't unique my attempt to build/use a Boost with GCC 4.8.0 using --std=c++0x. $ g++ -c -g -I/sw/include cma.cpp -o cma.o $ g++ -g -L/sw/lib cma.o -lboost_unit_test_framework-mt Undefined symbols for architecture x86_64: "_main", referenced from: start in crt1.10.6.o ld: symbol(s) not found for architecture x86_64 collect2: ld returned 1 exit status $ g++ --version i686-apple-darwin11-llvm-g++-4.2 (GCC) 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00) Copyright (C) 2007 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. $ fink list --tab boost1.46 Information about 7237 packages read in 1 seconds. i boost1.46.1.cmake 1.46.1-2 Boost C++ Libraries i boost1.46.1.cmake-shlibs 1.46.1-2 Boost C++ Libraries $ ________________________________ This e-mail and any attachments are confidential. If it is not intended for you, please notify the sender, and please erase and ignore the contents.

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matrix inversion in boost.
by Mohit Singh 20 Jun '13

20 Jun '13

Hi, I am trying to do a simple matrix inversion operation using boost. But I am getting an error. Basically what I am trying to find is inversted_matrix = inverse(trans(matrix) * matrix) But I am getting an error Check failed in file boost_1_53_0/boost/numeric/ublas/lu.hpp at line 299: detail::expression_type_check (prod (triangular_adaptor<const_matrix_type, upper> (m), e), cm2) terminate called after throwing an instance of 'boost::numeric::ublas::internal_logic' what(): internal logic Aborted (core dumped) My attempt: #include <boost/numeric/ublas/matrix.hpp> #include <boost/numeric/ublas/vector.hpp> #include <boost/numeric/ublas/io.hpp> #include <boost/numeric/ublas/vector_proxy.hpp> #include <boost/numeric/ublas/matrix.hpp> #include <boost/numeric/ublas/triangular.hpp> #include <boost/numeric/ublas/lu.hpp> namespace ublas = boost::numeric::ublas; template<class T> bool InvertMatrix (const ublas::matrix<T>& input, ublas::matrix<T>& inverse) { using namespace boost::numeric::ublas; typedef permutation_matrix<std::size_t> pmatrix; // create a working copy of the input matrix<T> A(input); // create a permutation matrix for the LU-factorization pmatrix pm(A.size1()); // perform LU-factorization int res = lu_factorize(A,pm); if( res != 0 ) return false; // create identity matrix of "inverse" inverse.assign(ublas::identity_matrix<T>(A.size1())); // backsubstitute to get the inverse lu_substitute(A, pm, inverse); return true; } int main(){ using namespace boost::numeric::ublas; matrix<double> m(4,5); vector<double> v(4); vector<double> thetas; m(0,0) = 1; m(0,1) = 2104; m(0,2) = 5; m(0,3) = 1;m(0,4) = 45; m(1,0) = 1; m(1,1) = 1416; m(1,2) = 3; m(1,3) = 2;m(1,4) = 40; m(2,0) = 1; m(2,1) = 1534; m(2,2) = 3; m(2,3) = 2;m(2,4) = 30; m(3,0) = 1; m(3,1) = 852; m(3,2) = 2; m(3,3) = 1;m(3,4) = 36; std::cout<<m<<std::endl; matrix<double> product = prod(trans(m), m); std::cout<<product<<std::endl; matrix<double> inversion(5,5); bool inverted; inverted = InvertMatrix(product, inversion); std::cout<<inversion<<std::endl; } -- Mohit "When you want success as badly as you want the air, then you will get it. There is no other secret of success." -Socrates

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[BGL] boykov_kolbogorov_max_flow() classes / groups
by Nil Goyette 20 Jun '13

20 Jun '13

I have been testing the the boykov_kolbogorov_max_flow function in the previous weeks and I have a question that I can't seem to find the answer myself. I asked for it on StackOverflow [1] but nobody answered. Can someone tell me why I get three classes (groups) instead of two? I always get class '0' and '4', and '1' on some cases. I thought a Graph Cut was supposed to output only two classes, so what's the meaning of '1'? Please read the SO question in [1] for more details. Thanks for your time. Nil Goyette [1] http://stackoverflow.com/questions/16905613/3-classes-0-1-4-on-boost-graph-…

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accumulator extended quantil value
by Philipp Kraus 20 Jun '13

20 Jun '13

Hello, I have got created an extended_p_square_quantile into an accumulator, with 3 quantils (0.25, 0.5, 0.75) as a boost::array. How can I get access to the quantil values of the accumulator? For the variance I use accumulator::variance(myacc), but a call with quantil(myacc, 0.5) does not work. Thanks Phil

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boost_1_53_0: no matching function for call to ‘hash_value
by Shailja Kumari 20 Jun '13

20 Jun '13

> Hi , > > I am using boost_1_53_0 for my applications build. The boost_1_53_0 is > throwing the following error message. > > boost_1_53_0/boost/functional/hash/extensions.hpp:269:34: error: no > matching function for call to ‘hash_value(const > Rubedo::Utils::Hashing::HashedString<16>&)’ > return hash_value(val); > ^ > > boost_1_53_0/boost/functional/hash/hash.hpp:187:57: error: no type named > ‘type’ in ‘struct > boost::hash_detail::basic_numbers<Rubedo::Utils::Hashing::HashedString<16> > >’ > > The following code build fine with boost_1_49_0, but have error with > boost_1_53_0 on linux. Do you have fixes for these ? Please let me know. > > Thanks > >

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boost serialisation, PORTABLE_BINARY_ARCHIVE fix required
by avib369 . 20 Jun '13

20 Jun '13

Currently portable binary archive is broken on AIX platforms. The reason is because the default 'char' type is unsigned on this platform. Whereas for most other platforms it is signed, By going through the portable binary and replacing 'char' with 'signed char' this long standing bug is fixed. I have tested the fix on Linux(opensuse103,opensuse113, HPUX, AIX(power6,power7) This is a fairly safe and quick fix, can I please ask the authors of this library to add this fix, for the next version of boost. Here are the changes I made: (flagged under ' // changed ' comment //-------------------------------------------------------- portable_binary_iarchive.hpp void load(signed char & t){ // changed this->primitive_base_t::load(t); } //------------------------------------------------------------- portable_binary_iarchive.cpp void portable_binary_iarchive::load_impl(boost::intmax_t & l, char maxsize){ signed char size; // changed l = 0; this->primitive_base_t::load(size); if(0 == size){ return; } bool negative = (size < 0); ...... // ----------------------------------------------------------------- portable_binary_oarchive.hpp void save(const signed char & t){ // changed this->primitive_base_t::save(t); } // ----------------------------------------------------------- portable_binary_oarchive.cpp void portable_binary_oarchive::save_impl( const boost::intmax_t l, const char maxsize ){ signed char size = 0; // changed if(l == 0){ this->primitive_base_t::save(size); return; } .......... // ------------------------------ Ta, Avi

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[property_tree] Population and Json formatting
by Michael Powell 20 Jun '13

20 Jun '13

Hello, Question about property tree. I've got an "event" concept which I want to serialize to Json through property tree. If I go something like this: ptree tree; tree.set<int>("event.id", 1); Then the resulting Json would look something like this? { "event": { "id": 1 } } or possibly? { "event": { "id" : "1" } } or possibly, with pretty turned off (nicer for message framing). {"event":{"id":"1"}} Thank you... Regards, Michael Powell

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Boost and Norton 360
by Scott Alexander 20 Jun '13

20 Jun '13

Hi, I have just installed boost 1.53 32bit using the Sourceforge Visual Studio installer and my security software (Norton 360) has quarantined three files as being high risk: *boost_math_tr1f-vc110-mt-1_53.dll *boost_thread-vc110-mt-gd-1_53.dll *boost_filesystem-vc110-mt-gd-1_53.dll Does anyone know if this is common? Can I safely restore these files? Thanks, Scott

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