August 2009 - Boost-users - lists.preview.boost.org

[boost users][tuple] foreach with tuple
by Oliver Kania 04 Aug '09

04 Aug '09

Hello , I have a problem getting boost foreach to work with a vector of tuples of type tuple<int,int>: #define foreach BOOST_FOREACH .... vector<tuple<int,int> > l_listLeftLines; .... foreach (boost::tuple<int,int>& i_pair, l_listLeftLines) { ..... } The visual studio compiler gives me the following : 1>d:\projects\software\lib_msvc\ptw2ddatalib20\source\ptwfieldcheckalgorithm.cpp(227) : warning C4002: too many actual parameters for macro 'BOOST_FOREACH' 1>d:\projects\software\lib_msvc\ptw2ddatalib20\source\ptwfieldcheckalgorithm.cpp(227) : error C2143: syntax error : missing ')' before '>' ..... and a long tail of more errors best regards, Oliver

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Re: [Boost-users] [boost users][tuple] foreach with tuple
by pete＠pcbartlett.com 04 Aug '09

04 Aug '09

On Tue 04/08/09 09:02 , Matthieu Brucher <matthieu.brucher(a)gmail.com> wrote: >Hi, > >Try with: >foreach ((boost::tuple<int,int>& i_pair), l_listLeftLines) > >The issue is that < and > are not delimiters for the macro, so you >have actually 3 parameters if you don't add the parenthesis. >From memory the extra parentheses solution isn't good enough either. You have to go with one of the workarounds described in the "pitfalls" section of the documentation: http://www.boost.org/doc/libs/1_39_0/doc/html/foreach/pitfalls.html Pete

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[boost users][tuple] foreach problem resolved
by Oliver Kania 04 Aug '09

04 Aug '09

Sry for the trouble folks. This is actually documented: one solution is to predeclare the loop variable : tpl<int,int> i_pair; //4. for both the right and the left spike, get the biggest set. foreach (i_pair, l_listLeftLines) { ... } best regards, Oliver

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variant: bounded types derive from same base class
by Hicham Mouline 04 Aug '09

04 Aug '09

Hello, I have a library with an abstract base class ABC and derived classes D1... Dn. These classes cannot be changed. User code wants to write code that depends on which concrete type the object being passed. User writes: void f( const ABC& abc ) { Tag t = abc.GetTag() ; // Tag is an enum for all the derived types, delivered by the lib Switch (t) { case: case: case: } } /// SO ugly, nevertheless if some case is missing, g++ for e.g. prints warnings I am told this is the visitor pattern I then looked at boost::variant<> The lib could deliver typedef boost::variant<D1, ... , Dn> ABCDerived; and the user could write visitors to visit ABCDerived objects, here the user is enforced to implement all cases in the visitor. but then the function f expects ABC objects. Can I still do: void f( const ABC& abc ) { // how to write code to use the visitors with abc ? } Rds,

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[serialization - newbie] serializing multiple objects in one archive
by Soumen 04 Aug '09

04 Aug '09

Hi, I've to serialize and deserialize multiple objects. Can I serialize them in one archive and deserialize from the same correctly? Say something like following is my save/restore function: void save(boost::archive::binary_oarchive &archive) { string version = tool.getversion(); MyData *data = MyData::instance(); MyDifferentData *differentData = MyDifferentData::instance(); if (data && differentData) { archive << version; archive << data; archive << differentData; } } void restore(boost::archive::binary_iarchive &archive) { string version = tool.getversion(); string serializedToolversion; MyData::cleanup(); MyDifferentData::cleanup(); archive >> serializedToolVersion; if (version == serializedToolVersion) { archive >> (MyData *) MyData::instance(); archive >> (MyDifferentData *) MyDifferentData::instance(); } } Or do I need to serialize each of these into different archives? Regards, ~ Soumen -- View this message in context: http://www.nabble.com/-serialization---newbie--serializing-multiple-objects… Sent from the Boost - Users mailing list archive at Nabble.com.

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bimap intellisense problems in VC++ 2008
by Donald Adu-Poku 03 Aug '09

03 Aug '09

Hi all, I'm having some intellisense problems with with boost::bimaps::bimap of the current boost build (boost 1.39) . The problem is that no intellisense on bimap is generated at all, intellisense goes as far as the boost::bitmaps namespace. My programme however compiles just fine. I have the boost library included in my project (..Programme Files\boost\boost_1_39), linked needed libraries (Programme Files\boost\boost_1_39\lib) and have my include statement (#include <booost/bimap.hpp>). I have also forced the regeneration of the project's intellisense database on suspicion that it might have been corrupted, this however did not resolve the problem . Is there anything I have missed? Thank you //Donald

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Boostcon Keynote (finally!) available.
by Marshall Clow 03 Aug '09

03 Aug '09

at http://boostcon.blip.tv Thank you, everyone, for your patience. More videos from Boostcon will be going up there in the near future. -- Marshall

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reference_wrapper
by er 03 Aug '09

03 Aug '09

Hi All, 1) I don't understand this part of reference_wrapper: template<class T> class reference_wrapper { operator T& () const { return *t_; } }; Could someone please explain it? 2) Is there already a reference wrapper for n-ary functors which exposes the same result_type (if it exists) as the n-ary functor, but whose arguments types are arbitrary (deduced from the arguments)?

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Compiler warnings when using boost::accumulators with gcc
by Rob Wheeler 03 Aug '09

03 Aug '09

If I turn on gcc's -Wextra option when compiling code that uses an accumulator with tag::max, I get a screen full of compiler warnings: [wheeler@cib: /var/tmp/acc] cat acc.cpp #include <iostream> #include <boost/accumulators/accumulators.hpp> #include <boost/accumulators/statistics/stats.hpp> #include <boost/accumulators/statistics/max.hpp> using namespace boost::accumulators; int main() { accumulator_set<double, stats<tag::max> > acc; acc(1.2); acc(2.3); acc(3.4); acc(4.5); std::cout << "Max: " << max(acc) << std::endl; return 0; } [wheeler@cib: /var/tmp/acc] g++ -W -I /opt/ros/include/boost-1_37/ acc.cpp -o acc /opt/ros/include/boost-1_37/boost/concept_check.hpp: In instantiation of ‘boost::UnaryFunction<boost::numeric::functional::as_min<const double, void>, double, const double&>’: /opt/ros/include/boost-1_37/boost/concept/detail/has_constraints.hpp:40: instantiated from ‘const bool boost::concept::not_satisfied<boost::UnaryFunction<boost::numeric::functional::as_min<const double, void>, double, const double&> >::value’ /opt/ros/include/boost-1_37/boost/concept/detail/has_constraints.hpp:43: instantiated from ‘boost::concept::not_satisfied<boost::UnaryFunction<boost::numeric::functional::as_min<const double, void>, double, const double&> >’ /opt/ros/include/boost-1_37/boost/mpl/if.hpp:67: instantiated from ‘boost::mpl::if_<boost::concept::not_satisfied<boost::UnaryFunction<boost::numeric::functional::as_min<const double, void>, double, const double&> >, boost::concept::constraint<boost::UnaryFunction<boost::numeric::functional::as_min<const double, void>, double, const double&> >, boost::concept::requirement<boost::UnaryFunction<boost::numeric::functional::as_min<const double, void>, double, const double&> > >’ /opt/ros/include/boost-1_37/boost/concept/detail/general.hpp:19: instantiated from ‘boost::concept::requirement_<void (*)(boost::UnaryFunction<boost::numeric::functional::as_min<const double, void>, double, const double&>)>’ /opt/ros/include/boost-1_37/boost/accumulators/numeric/detail/function1.hpp:67: instantiated from ‘typename boost::detail::function1<F>::result<boost::detail::function1<F> ()(const A0&)>::type boost::detail::function1<F>::operator()(const A0&) const [with A0 = double, F = boost::numeric::functional::as_min<mpl_::arg<-0x00000000000000001>, boost::numeric::functional::tag<mpl_::arg<-0x00000000000000001> > >]’ /opt/ros/include/boost-1_37/boost/accumulators/statistics/max.hpp:36: instantiated from ‘boost::accumulators::impl::max_impl<Sample>::max_impl(const Args&) [with Args = boost::parameter::aux::arg_list<boost::parameter::aux::tagged_argument<boost::accumulators::tag::accumulator, boost::accumulators::accumulator_set<double, boost::accumulators::stats<boost::accumulators::tag::max, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, void> >, boost::parameter::aux::empty_arg_list>, Sample = double]’ /opt/ros/include/boost-1_37/boost/accumulators/framework/depends_on.hpp:282: instantiated from ‘boost::accumulators::detail::accumulator_wrapper<Accumulator, Feature>::accumulator_wrapper(const Args&) [with Args = boost::parameter::aux::arg_list<boost::parameter::aux::tagged_argument<boost::accumulators::tag::accumulator, boost::accumulators::accumulator_set<double, boost::accumulators::stats<boost::accumulators::tag::max, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, void> >, boost::parameter::aux::empty_arg_list>, Accumulator = boost::accumulators::impl::max_impl<double>, Feature = boost::accumulators::tag::max]’ /opt/ros/include/boost-1_37/boost/accumulators/framework/depends_on.hpp:215: instantiated from ‘static boost::fusion::cons<typename boost::fusion::result_of::value_of<Iterator>::type, typename boost::accumulators::detail::build_acc_list<typename boost::fusion::result_of::next<Iterator>::type, Last, boost::fusion::result_of::equal_to<typename boost::fusion::result_of::next<Iterator>::type,Last>::value>::type> boost::accumulators::detail::build_acc_list<First, Last, false>::call(const Args&, const First&, const Last&) [with Args = boost::parameter::aux::arg_list<boost::parameter::aux::tagged_argument<boost::accumulators::tag::accumulator, boost::accumulators::accumulator_set<double, boost::accumulators::stats<boost::accumulators::tag::max, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, void> >, boost::parameter::aux::empty_arg_list>, First = boost::fusion::mpl_iterator<boost::mpl::v_iter<boost::mpl::v_item<boost::accumulators::detail::accumulator_wrapper<boost::accumulators::impl::max_impl<double>, boost::accumulators::tag::max>, boost::mpl::vector0<mpl_::na>, 0>, 0l> >, Last = boost::fusion::mpl_iterator<boost::mpl::v_iter<boost::mpl::v_item<boost::accumulators::detail::accumulator_wrapper<boost::accumulators::impl::max_impl<double>, boost::accumulators::tag::max>, boost::mpl::vector0<mpl_::na>, 0>, 1l> >]’ /opt/ros/include/boost-1_37/boost/accumulators/framework/depends_on.hpp:234: instantiated from ‘typename boost::accumulators::detail::meta::make_acc_list<Sequence>::type boost::accumulators::detail::make_acc_list(const Sequence&, const Args&) [with Sequence = boost::mpl::v_item<boost::accumulators::detail::accumulator_wrapper<boost::accumulators::impl::max_impl<double>, boost::accumulators::tag::max>, boost::mpl::vector0<mpl_::na>, 0>, Args = boost::parameter::aux::arg_list<boost::parameter::aux::tagged_argument<boost::accumulators::tag::accumulator, boost::accumulators::accumulator_set<double, boost::accumulators::stats<boost::accumulators::tag::max, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, void> >, boost::parameter::aux::empty_arg_list>]’ /opt/ros/include/boost-1_37/boost/accumulators/framework/accumulator_set.hpp:145: instantiated from ‘boost::accumulators::accumulator_set<Sample, Features, Weight>::accumulator_set() [with Sample = double, Features = boost::accumulators::stats<boost::accumulators::tag::max, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, Weight = void]’ acc.cpp:9: instantiated from here /opt/ros/include/boost-1_37/boost/concept_check.hpp:325: warning: non-static reference ‘const double& boost::UnaryFunction<boost::numeric::functional::as_min<const double, void>, double, const double&>::arg’ in class without a constructor

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Re: [Boost-users] boost 1.40 beta
by Guiliani, Florent 03 Aug '09

03 Aug '09

boost-users-request(a)lists.boost.org wrote: > Date: Wed, 29 Jul 2009 14:27:39 +0100 > From: Avi Bahra <avibahra(a)googlemail.com> > Subject: [Boost-users] boost 1.40 beta > To: boost-users(a)lists.boost.org > > Does any know the schedule for release of boost 1.40 beta ? > > Best regards, > Ta, > Avi > According to: http://www.boost.org/development/ it will be the first of August. -- Florent,

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