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Overloading boost::hash_value GCC
by André Santee 01 Jul '11

01 Jul '11

I'm having a hard time trying to compile my code here. What I'm doing is to overload the boost::hash_value function to use boost::unordered_map with a custom Vector2 class. My code: // Vector2 hash function namespace boost { inline std::size_t hash_value(Vector2 const& p) { std::size_t seed = 0; boost::hash_combine(seed, p.x); boost::hash_combine(seed, p.y); return seed; } } // namepace boost boost::unordered_map<Vector2, EntityList, boost::hash<Vector2> > buckets;[/code] It compiles and run fine on msvc 9.0 but gcc says the function does not exist (it looks like to me that it does exist!). error message: Compile++ thumb : Application <= BucketManager.cpp In file included from /boost/functional/hash/hash.hpp:510, from /boost/functional/hash.hpp:6, from /boost/unordered/unordered_map.hpp:17, from BucketManager.h:35, from BucketManager.cpp:24: /boost/functional/hash/extensions.hpp: In member function 'size_t boost::hash<T>::operator()(const T&) const [with T = math::Vector2]': /boost/unordered/detail/unique.hpp:183: instantiated from 'typename boost::unordered_detail::hash_unique_table<T>::value_type& boost::unordered_detail::hash_unique_table<T>::operator[](const typename T::key_type&) [with T = boost::unordered_detail::map<math::Vector2, boost::hash<math::Vector2>, std::equal_to<math::Vector2>, std::allocator<std::pair<const math::Vector2, std::list<RenderEntity*> > > >]' /boost/unordered/unordered_map.hpp:406: instantiated from 'T& boost::unordered_map<K, T, H, P, A>::operator[](const K&) [with K = math::Vector2, T = std::list<RenderEntity*>, H = boost::hash<math::Vector2>, P = std::equal_to<math::Vector2>, A = std::allocator<std::pair<const math::Vector2, std::list<RenderEntity*> > >]' BucketManager.cpp:128: instantiated from here /boost/functional/hash/extensions.hpp:176: error: no matching function for call to 'hash_value(const math::Vector2&)' /boost/functional/hash/hash.hpp:136: note: candidates are: size_t boost::hash_value(bool) /boost/functional/hash/hash.hpp:141: note: size_t boost::hash_value(char) /boost/functional/hash/hash.hpp:146: note: size_t boost::hash_value(unsigned char) /boost/functional/hash/hash.hpp:151: note: size_t boost::hash_value(signed char) /boost/functional/hash/hash.hpp:156: note: size_t boost::hash_value(short int) /boost/functional/hash/hash.hpp:161: note: size_t boost::hash_value(short unsigned int) /boost/functional/hash/hash.hpp:166: note: size_t boost::hash_value(int) /boost/functional/hash/hash.hpp:171: note: size_t boost::hash_value(unsigned int) /boost/functional/hash/hash.hpp:176: note: size_t boost::hash_value(long int) /boost/functional/hash/hash.hpp:181: note: size_t boost::hash_value(long unsigned int) /boost/functional/hash/hash.hpp:187: note: size_t boost::hash_value(wchar_t) /boost/functional/hash/hash.hpp:194: note: size_t boost::hash_value(boost::long_long_type) /boost/functional/hash/hash.hpp:199: note: size_t boost::hash_value(boost::ulong_long_type) /boost/functional/hash/hash.hpp:313: note: size_t boost::hash_value(float) /boost/functional/hash/hash.hpp:318: note: size_t boost::hash_value(double) /boost/functional/hash/hash.hpp:323: note: size_t boost::hash_value(long double) make: *** -- André Santee | Desenvolvedor de games andre.santee(a)jera.com.br | +55 67 8127-9528 [image: Facebook]<http://www.facebook.com/pages/Jera-Software-Agil/127079757331746> [image: Facebook] <http://twitter.com/decosantee> [image: Flickr]<http://www.flickr.com/jerasoftware> [image: LinkEdin] <http://www.linkedin.com/companies/jera?trk=fc_badge> <http://www.jera.com.br/>

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problems on iterating over a fusion sequence
by Olaf Peter 01 Jul '11

01 Jul '11

Hi, in the example below, the loop runs forever. What is the reason for this? I'm using trunk 72818 Thanks, Olaf

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Fwd: boost bind
by candy.chiu.ad＠gmail.com 01 Jul '11

01 Jul '11

> Hi, > A boost::bind statement in my code generated the following compilation > error: > 1>Compiling... > 1>CmsPayOffReplication.cpp > 1>.\CmsPayOffReplication.cpp(79) : error C2665: 'boost::bind' : none of > the 2 overloads could convert all the argument types > 1> C:\DiskE\OpenSource\boost_1_45_0\boost/bind/bind.hpp(1420): could > be 'boost::_bi::bind_t > boost::bindarg,QuantLib::Date,QuantLib::Period,QuantLib::Period,QuantLib::Rate>(boost::type,F,A1,A2,A3,A4,A5)' > 1> with > 1> [ > 1> R=double, > 1> F=QuantLibInterface::YieldCurveUtility *, > 1> > L=boost::_bi::list5arg,boost::_bi::valueQuantLib::Date>,boost::_bi::value,boost::_bi::value,boost::_bi::valueRate>>, > 1> T=QuantLibInterface::YieldCurveUtility, > 1> I=1, > 1> A1=boost::arg, > 1> A2=QuantLib::Date, > 1> A3=QuantLib::Period, > 1> A4=QuantLib::Period, > 1> A5=QuantLib::Rate > 1> ] > 1> C:\DiskE\OpenSource\boost_1_45_0\boost/bind/bind.hpp(1512): > or 'boost::_bi::bind_t > boost::bindarg,QuantLib::Date,QuantLib::Period,QuantLib::Period,QuantLib::Rate>(F,A1,A2,A3,A4,A5,A6)' > 1> with > 1> [ > 1> R=boost::_bi::unspecified, > 1> F=double, > 1> L=boost::_bi::list6bi::valueYieldCurveUtility > *>,boost::arg,boost::_bi::value,boost::_bi::value,boost::_bi::valuePeriod>,boost::_bi::valueQuantLib::Rate>>, > 1> T=QuantLibInterface::YieldCurveUtility, > 1> I=1, > 1> A1=QuantLibInterface::YieldCurveUtility *, > 1> A2=boost::arg, > 1> A3=QuantLib::Date, > 1> A4=QuantLib::Period, > 1> A5=QuantLib::Period, > 1> A6=QuantLib::Rate > 1> ] > 1> while trying to match the argument list '(overloaded-function, > QuantLibInterface::YieldCurveUtility *, boost::arg, const QuantLib::Date, > const QuantLib::Period, const QuantLib::Period, QuantLib::Rate)' > 1> with > 1> [ > 1> I=1 > 1> ] > I replicated the set up of the objects in simpler project, and the bind > statement compiled successfully. Can anyone shred some light on the cause > of the error? > Here is how I call boost::bind > QuantLib::Date date; > QuantLib::Period p1,p2; > QuantLib::Rate rate; > // initialization of date, p1, p2, rate > boost::functionYieldTermStructure>) > > priceWithCurve = boost::bind( > &YieldCurveUtility::priceSwap, > &YieldCurveUtility::instance(), _1, > date, period1, period2, rate ); > Thank you.

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[Boost-log v1][Boost 1_46_1][MinGW 4.4.0][Windows 7] Finaly builded (partially) !!!
by Aman Feri 01 Jul '11

01 Jul '11

Hello I finally partially builded Boost_log v1 with Boost 1_46_1 using MinGW (gcc 4.4.0) on windows 7. It's a great victory for me, because it took a long time. I contribute here, if anyone need it or is able to make it work better. -------------- Error 1 -------------- Title : Compiling Boost_log v1 with Boost 1_46_1 including Filesystem v3 Symptom : error: 'external_string_type' is not a member of 'boost::filesystem3::wpath' Fix : using Filesystem_version 2 (thanks http://stackoverflow.com/questions/6076405/what-is-boost-log-how-to-get-it-… ) (don't forget to #define BOOST_FILESYSTEM_VERSION 2 in your projects using Boost_log) -------------- Error 2 -------------- Title : Using windows path Symptom : "windres.exe" + "C:\Program is not recognize as a valid command" (free translation) Fix : reinstalling MinGW, in a directory without space allowed bjam to find windres.exe -------------- Error 3 -------------- Title : (maybe a boost log v1 bug ?) Symptom : libs\log\src\event_log_backend.cpp:55: error: external linkage required for symbol 'boost::log_mt_nt5::sinks::event_log::success' because of 'dllexport' attribute Fix (seams to work, but confirmation still needed) : replace libs\log\src\event_log_backend.cpp line 55/56/57/58 from : BOOST_LOG_EXPORT const event_type_t ... to extern BOOST_LOG_EXPORT const event_type_t ... -------------- Error 4 -------------- Title : comeback of error 1 Symptom : Error 1 reproduce only on "release" build (but debug was build) Fix : no fix. Already spended 4 hours on this. I just use debug dll. Note : it implies i use debug dll for filesystem, system, thread and regex too (maybe implying i use both debug and release version in my final project) -------------- Error 5 -------------- Title : linking my project (the one that use boost log) with signle threaded instead of multi threaded Symptom : undefined reference to `boost::log_mt_nt5::basic_attribute_set<char>::~basic_attribute_set()' Fix : link your project using log v1 with libboost_log-mgw44-mt-d-1_46_1.dll not libboost_log-mgw44-d-1_46_1.dll (note the -d for "debug because i couldn't build the release cf error 4) Have a nice build !

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Problem with dijkstra_shortest_paths
by Stephen Woodbridge 01 Jul '11

01 Jul '11

Hi all, I am C programmer floundering in a C++ world! I have the function that I call from C that builds a graph, runs dijkstra_shortest_paths(), then extracts the results and passes them back to a C array of structs. Code is in pastebin: http://pastebin.com/xi7vLpTx This seems to work and everything looks ok, EXCEPT the edge ids are not correct. I suspect this is because I'm not doing something correctly and I have been messing with this for a couple weeks without success, so I think its time to ask for help. So in the function: graph_add_edge(G &graph, int id, int source, int target, float8 cost) id is the edge id source is the node id at the start of the edge target is the node_id at the end of the edge cost is the cost to traverse the edge from source to target I would really appreciate it if someone could look at this and point out what I might be doing wrong. Thanks in advance, -Steve

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Meta State Machine PseudoExit transitions
by Johan Gielens 01 Jul '11

01 Jul '11

Hello, I'm trying to implement a PseudoExitState in my boost meta state machine. This is the situation: http://i55.tinypic.com/2a83yar.png. Currently, when going from Transport to either Situation A or B, it throws an "no_transition" in the SubState for the "convertible event" needed by the PseudoExit state. (This is event6 in the example described below) According to the documentation (http://www.boost.org/doc/libs/1_46_1/libs/msm/doc/HTML/ch03s02.html#d0e930) and the corresponding example, there should be some kind of transition triggered by "event6" from SubState2 to Substate1 (see http://www.boost.org/doc/libs/1_46_1/libs/msm/doc/HTML/examples/DirectEntry…, in the transition table for SubFsm2). I don't see an arrow in the state diagram between SubState2 and SubState1, nor can I figure out why I would want such a transition. In my SubState's transition table, I have defined the transition from Transport to PseudoExit1 and 2: g_row< Transport , Sensor , Exit1 , &SubFront::SDownstreamCheck >, g_row< Transport , Sensor , Exit2 , &SubFront::SDownstreamNoCheck > and in the TopState from PseudoExit1 and 2 to SituationA and B: _row< Sub::exit_pt< SubFront::Exit1 > , TransportDone , SituationA >, _row< Sub::exit_pt< SubFront::Exit2 > , TransportDone , SituationB >, So do i have to handle an "TransportDone" event in the SubState? And what are my Start and End states? I would appreciate your help :) Best Regards, Johan

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Re: [Boost-users] Boost-users Digest, Vol 2769, Issue 5
by Tom Tan 01 Jul '11

01 Jul '11

------------------------------ > > Date: Thu, 30 Jun 2011 15:00:13 -0400 (EDT) > From: Jeremiah Willcock <jewillco(a)osl.iu.edu> > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] [Graph]questions regarding > boost::graph::adjacency_list constructor prototype > > On Thu, 30 Jun 2011, Tan, Tom (Shanghai) wrote: > > > > > While studying boost.graph, I stumbled upon this constructor definition: > > > > ????template <class EdgeIterator> > > > > ??? adjacency_list(EdgeIterator first, EdgeIterator last, > > > > ????????????????????????? vertices_size_type n, > > > > ????????????????????????? edges_size_type = 0, > > > > ????????????????????????? const GraphProperty& p = GraphProperty()) > > > > ????? : Base(n, first, last), m_property(new graph_property_type(p)) > > > > { } > > > > I have 2 questions here: > > > > -????????? What does ?edges_size_type = 0,? means here?? Assigning a value to a TYPE, instead of a parameter? Can > > anyone please point me to an explanation of this grammar usage? > > It's like if the code was "edges_size_type x = 0", but since the parameter > is not used, removing the name avoids compiler warnings. Nice to know this trick. Never knew that the 'x' can be omitted in this case. > > > > > -????????? Why the necessary of edges_size_type = 0 parameter,? since there?s a range pair of ?EdgeIterator first, > > EdgeIterator last?? > > It is not necessary, since the value of that parameter is never used. It > is probably there match the interface of some other constructor, either in > adjacency_list or some other graph class. I guessed so but it's better to confirmed. Thanks for the help. -Tom

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[Range] Select forward or reverse traversal at compile time?
by Alastair Rankine 01 Jul '11

01 Jul '11

Given a bidirectional range R, is it possible to select at compile time whether we want to iterate forwards or backwards? Below is a test app. At the commented line, I would like to transparently construct a forward or reverse range, ie either [begin(range), end(range)] or [rbegin(range), rend(range)] respectively, depending on the definition of the Reversed template parameter. Just to be clear, the desired output is: forward: abc reversed: abc I can make this work by using a functor class with partial specialisation to construct the iterator_range, using begin/end or rbegin/rend respectively. But it's a bit ugly and it would seem like something that boost range would provide anyway? (Note that boost::reverse() is NOT what I am after.) #include <boost/assign/list_of.hpp> #include <boost/range/algorithm/copy.hpp> #include <boost/range.hpp> #include <vector> #include <iostream> template <typename Reversed, typename Range> std::string Print(const Range& range) { typedef boost::iterator_range< typename boost::mpl::eval_if< Reversed, boost::range_reverse_iterator<const Range>, boost::range_iterator<const Range> >::type> IterRange; // want to convert it to a forward range here IterRange forwardRange(range); std::string result; boost::copy(forwardRange, std::back_inserter(result)); return result; } int main(int argc, char* argv[]) { using boost::assign::list_of; std::vector<char> a = list_of('a')('b')('c'); std::vector<char> b = list_of('c')('b')('a'); std::cout << "forward: " << Print<boost::mpl::false_>(a) << std::endl << "reversed: " << Print<boost::mpl::true_>(b) << std::endl; return 0; }

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[Graph]questions regarding boost::graph::adjacency_list constructor prototype
by Tan, Tom (Shanghai) 30 Jun '11

30 Jun '11

While studying boost.graph, I stumbled upon this constructor definition: template <class EdgeIterator> adjacency_list(EdgeIterator first, EdgeIterator last, vertices_size_type n, edges_size_type = 0, const GraphProperty& p = GraphProperty()) : Base(n, first, last), m_property(new graph_property_type(p)) { } I have 2 questions here: - What does "edges_size_type = 0," means here? Assigning a value to a TYPE, instead of a parameter? Can anyone please point me to an explanation of this grammar usage? - Why the necessary of edges_size_type = 0 parameter, since there's a range pair of "EdgeIterator first, EdgeIterator last"? Does anyone have an answer? Thanks.

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ptime input_facet error with %f flag at converting string to ptime (1.36, 1.44)
by Sören Freudiger 30 Jun '11

30 Jun '11

Hello I have problems with reading the time fraction at converting from string to ptime. Here is the regarding soruce code: |#include <iostream> #include <string> #include <boost/date_time.hpp> #include <boost/date_time/posix_time/posix_time.hpp> #include <boost/date_time/gregorian/gregorian.hpp> #include <boost/date_time/posix_time/conversion.hpp> int main( int, char * ) { using namespace std; using namespace boost; using namespace boost::posix_time; using namespace boost::local_time; using namespace boost::gregorian; time_facet* output_facet= new time_facet(); time_input_facet* input_facet= new time_input_facet(); stringstream sstream; sstream.imbue(locale(locale::classic(), output_facet)); sstream.imbue(locale(sstream.getloc() , input_facet)); string format("%d/%m/%Y %H:%M:%S.%f"); //example works fine without %f!!! output_facet->format( format.c_str() ); input_facet->format( format.c_str() < /span>); ptime dt= microsec_clock().local_time(); sstream.str(""); sstream<< dt; cout<< sstream.str() << end l; string time_string= sstream.str(); ptime tgtDt( boost::date_time::not_a_date_time); sstream.str( time_string.c_str() ); sstream>> tgtDt; cout<< tgtDt<< endl; }| The program runs fine without the %f inside the format string. But with %f tgtDt is "not-a-date-time". I use boost 1.44 and the doc says %f shold work, because every input incompatible format flag is marked bei "!" in the documentation. Any ideas how to get the frac part out of a string?

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