- Boost-users - lists.boost.org

[phoenix] accumulate with data member binding
by Christian Henning 03 Nov '08

03 Nov '08

Hi there, the following snippet doesn't compile which surprises me a little. Could somebody tell what's wrong? #include <algorithm> #include <vector> #include <numeric> #include <boost/spirit/include/phoenix_core.hpp> #include <boost/spirit/include/phoenix_operator.hpp> #include <boost/spirit/include/phoenix_bind.hpp> using namespace boost::phoenix; using namespace boost::phoenix::arg_names; using namespace std; struct point { double _prob; double _x; }; int _tmain(int argc, _TCHAR* argv[]) { std::vector< point > d; double sum_prob = std::accumulate( d.begin() , d.end() , 0.0 , bind( &point::_prob, arg1 ) ); return 0; } I'm using Visual Studio 2005. This is the error I'm getting: error C2296: '.*' : illegal, left operand has type 'double' [snip] Thanks ahead, Christian

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Re: [Boost-users] [Graph] newbie to graph (Andrew Sutton) (Phillip Jones)
by Lior Weizman 03 Nov '08

03 Nov '08

Hello, Applying the suggestion below: > > > struct Node { > std::string name; > long index; > boost::default_color_type color; > long distance; > graph_traits<Graph>::edge_descriptor predecessor; > }; > > struct Arc { > long capacity; > long residual; > graph_traits<Graph>::edge_descriptor rev; > }; > > With the following call: > > flow = kolmogorov_max_flow(g, s, t, > capacity_map(get(&Arc::capacity, g)). > residual_capacity_map(get(&Arc::residual, g)). > reverse_edge_map(get(&Arc::rev, g)). > predecessor_map(get(&Node::predecessor, g)). > color_map(get(&Node::color, g)). > distance_map(get(&Node::distance, g)). > vertex_index_map(get(&Node::index, g)) > ); > > Resulted with many errors.But I think I found the right way. The following code compiles without errors or warnings: ----------------CODE---------------------------- #include <boost/config.hpp> #include <iostream> #include <string> #include <boost/graph/kolmogorov_max_flow.hpp> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/write_dimacs.hpp> #include <boost/graph/read_dimacs.hpp> using namespace boost; struct Arc; struct Node; typedef adjacency_list<vecS,vecS,directedS,Node,Arc> Graph; struct Arc { long capacity; long residual_capacity; Graph::edge_descriptor reverse; }; struct Node { std::string name; Graph::edge_descriptor predecessor; default_color_type color; long distance; long index; }; int main() { typedef Graph::vertex_descriptor vertex_descriptor; typedef Graph::edge_descriptor edge_descriptor; typedef std::pair<edge_descriptor, bool> EdgePair; typedef std::pair<int,int> Pair; Graph g; property_map<Graph, long Arc::*>::type capacity = get(&Arc::capacity, g); property_map<Graph, long Arc::*>::type res_capacity = get(&Arc::residual_capacity, g); property_map<Graph, Graph::edge_descriptor Arc::*>::type reverse = get(&Arc::reverse,g); property_map<Graph,Graph::edge_descriptor Node::*>::type predecessor = get(&Node::predecessor,g); property_map<Graph,default_color_type Node::*>::type color = get(&Node::color,g); property_map<Graph,long Node::*>::type distance = get(&Node::distance,g); property_map<Graph,long Node::*>::type index = get(&Node::index,g); long flow; vertex_descriptor s, t; Pair edge_array[6] = { Pair(0,1), Pair(0,2), Pair(0,3), Pair(2,4), Pair(1,3), Pair(4,3), }; EdgePair edge_desc_obj; EdgePair edge_from_first=add_edge(edge_array[0].first,edge_array[0].second,g); g[edge_from_first.first].capacity=1; for (int i = 1; i < 5; ++i){ edge_desc_obj=add_edge(edge_array[i].first, edge_array[i].second,g); g[edge_desc_obj.first].capacity=i+1; } EdgePair edge_to_last=add_edge(edge_array[5].first,edge_array[5].second,g); g[edge_to_last.first].capacity=4; char str[2]; int i=0; vertex_descriptor v1=*vertices(g).first,v2=*vertices(g).second; while (v1!=v2) { sprintf(str,"%d",i); g[v1].name=str; v1++; i++; } edge_descriptor from_s,to_t; from_s=edge_from_first.first; to_t=edge_to_last.first; s=source(from_s,g); t=target(to_t,g); flow = kolmogorov_max_flow(g,capacity,res_capacity,reverse,predecessor,color,distance,index,s,t); return 0; } -----------------------------END OFCODE----------------- However when trying to run this code I receive "Segmentation error". (this error does not appear when I remove the call to kolmogorov) I work under linux and I tried to compile with both g++ and g++-3.3 The valgrind output can be found at: http://www.cs.huji.ac.il/~lweizm45/valgring_output.txt Any suggestions? Lior

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[BGL] how to call Dijkstra
by Sandeep Gupta 03 Nov '08

03 Nov '08

*Hi Tristram Thanks for the reply. I tried the short version too as you suggestedbut the error doesn't go away: Attached below is the new code snippet and the related error. Thanks sandeep std::map<Vertex, Vertex> pred; boost::associative_property_map< std::map<Vertex, Vertex> > pred_map(pred); std::map<Vertex, size_type> dist; boost::associative_property_map< std::map<Vertex, size_type> > dist_map(dist); std::map<Vertex, size_type> weight; boost::associative_property_map< std::map<Vertex, size_type> > weight_map(weight); Vertex v; boost::dijkstra_shortest_paths(G, v, pred_map, dist_map, weight_map); error: no matching function for call to 'dijkstra_shortest_paths(Graph&, leda::node_struct*&, boost::associative_property_map<std::map<leda::node_struct*, leda::node_struct*, std::less<leda::node_struct*>, std::allocator<std::pair<leda::node_struct* const, leda::node_struct*> > > >&, boost::associative_property_map<std::map<leda::node_struct*, int, std::less<leda::node_struct*>, std::allocator<std::pair<leda::node_struct* const, int> > > >&, boost::associative_property_map<std::map<leda::node_struct*, int, std::less<leda::node_struct*>, std::allocator<std::pair<leda::node_struct* const, int> > > >&)' * >Hello >You don't need to call dijkstra and specify all the templates as most >of them have default values, and it's much more convinient to use >named parameters: >boost::dijkstra_shortest_paths(graph, start_node, > boost::predecessor_map(predmap) > .distance_map(distmap) > .weight_map(weightmap) > ); >} On Thu, Oct 30, 2008 at 9:00 PM, Sandeep Gupta <gupta.sandeep_at_[hidden]> wrote: > Hi, > I am missing something regarding the correct calling convention for > Dijkstra algorithm. Here is the relevant part of the code: > > typedef boost::associative_property_map< std::map<Vertex, int> > > intmapt; > typedef boost::associative_property_map< std::map<Vertex, Vertex> >> nodemapt; > dijkstra_visitor<null_visitor> mynullvis; > dijkstra_shortest_paths<Graph, dijkstra_visitor<null_visitor>, > nodemapt, intmapt, intmapt, nodemapt, std::less<int>, > std::plus<int>, std::numeric_limits<int>, std::numeric_limits<int> > > (G, v, predmap, distmap, weightmap, indexmap, std::less<int>(), > std::plus<int>(), std::numeric_limits<int>::max(), 0, mynullvis); > > I get an error as no matching function call dijkstra_shortest_paths. > Appreciate some pointers as what could possibly be wrong. > > Thanks > sandeep >

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Overloading the new and delete operators
by Jacob Holm 03 Nov '08

03 Nov '08

I have overloaded the new and delete operator, then I found this in the source code: // note: this should really be a member of the load_ptr function // below but some compilers still complain about this. template<class T> struct heap_allocator { #if 0 // note: this fails on msvc 7.0 and gcc 3.2 template <class U, U x> struct test; typedef char* yes; typedef int* no; template <class U> yes has_op_new(U*, test<void* (*)(std::size_t), &U::operator new>* = 0); no has_op_new(...); template<class U> T * new_operator(U); T * new_operator(yes){ return (T::operator new)(sizeof(T)); } T * new_operator(no){ return static_cast<T *>(operator new(sizeof(T))); } static T * invoke(){ return new_operator(has_op_new(static_cast<T *>(NULL))); } #else // while this doesn't handle operator new overload for class T static T * invoke(){ return static_cast<T *>(operator new(sizeof(T))); } #endif }; If I am using a msvc that this does not fail on, is there anything wrong with implementing this code, or will I get a bunch of errors or "hidden" bugs? Also, are there any plans on implementing this in a future release(I am guessing it is a work in progress issue)? Thanks in advance. /Jacob Holm

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big integer and rayleigh distribution
by Hakan Calim 03 Nov '08

03 Nov '08

Dear list, i have a collection of big integers like this 1221868803.60525. I use this values in a Rayleigh distribution to simulate a problem. Now I will develop a application which simulate this problem. This application is time critical. It should trigger alerts. So my questions are: 1. Which lib from Boost can I use? 2. Which data type from this lib can I use for this big integer? 3. Is this lib high performance dependent? Best regards, Hakan Calim

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[Proto] Accessing inner types in transform
by Joel Falcou 03 Nov '08

03 Nov '08

Let's say I have a grammar which have the following terminal proto::terminal<std::pair<_,_>> I want to retrieve the first type of the pair in the terminal. Can I write : when< terminal< pair<_,_> >, _value::first()> or should I wrote a small meta-function that extract this type ? when< terminal< pair<_,_> >, first_(_value)> TIA -- ___________________________________________ Joel Falcou - Assistant Professor PARALL Team - LRI - Universite Paris Sud XI Tel : (+33)1 69 15 66 35

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Hashing boost.Tokenizer and Tokenizer euqlity
by Sean Farrow 03 Nov '08

03 Nov '08

Hi: Two queries: 1. Does boost.Tokenizer support the = operator or do I need to write my own. if yes, wha is the best way of doing this, can I use std::equal? 2. I need to write a hashin function for boost.tokenizer? What is the best was of doing this? What information within Tokenizer to write a hash function. Chers Sean.

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Boost:Bind//Boost:Function -- Need some help with a constructor trying to bind to a function
by Charles Milutinovic 03 Nov '08

03 Nov '08

I am struggling to try to get bind/function working like I want. Some code first though: 1. We have a POD object. namespace POD{ class POD{};} 2. We have another class that wants to do something with a POD*. namespace Alpha{ class MethodsInHere{ void doesSomething(POD::POD* arg0){} };} 3. We have a third class, essentially a function handler, that has a boost::function reference whose signature matches the method in #2, and a constructor which wants to set the reference. namespace EventHandler{ class EventHandler{ public: EventHandler(boost::function<void (POD::POD*)>& function): assign_to_me(function){} boost::function<void (POD::POD*)>& assign_to_me; };} 4. Finally, we have an initialization class. This class wants to instantiate the EventHandler object, and to do so needs to bind the method in #2 to pass in as an argument. POD::POD* instance = new POD::POD(); Alpha::MethodsInHere mih; EventHandler eh(boost::bind(&Alpha::MethodsInHere::doesSomething, ????, _1)) -------- My question is basically if this is possible. I was having a ton of trouble getting this to work, and after digging through some docs it seems like the '?????' in line of code in #4 needs to be a reference to eh . . . which isn't constructed yet. If I'm wrong, please tell me how to construct this bind properly. If I'm right, what sort of workaround could solve this?

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Boost + STLPort + msvc8.0
by Gould, Richard Kenneth 03 Nov '08

03 Nov '08

I've read the boost build manual section on building with STLPort and a number of other posts, but nothing seems to help. I have modified user_config.jam to contain using stlport : 5.1.6 : c:\\projects\\STLPort-5.1.6\\stlport c:\\projects\\STLPort-5.1.6\\lib ; and am building with bjam --build-dir="c:\temp\build-boost" --toolset=msvc-8.0 stdlib=stlport-5.1.6 threading=multi --with-serialization -a -d2 release stage However, it fails to build libboost_serialization-vc80-mt-p-1.36.0.lib, with errors propagating from ====== BEGIN OUTPUT ====== EXIT STATUS: -1073741515 ====== END OUTPUT ====== ...failed testing.capture-output c:\projects\build-boost\boost\bin.v2\libs\config\test\all\no_std_locale_ pass.test\msvc-8.0\release\stdlib-stlport-5.1.6\threading-multi\no_std_l ocale_pass.run... I've tried various versions of Boost and STLPort in various combinations, all with the same results. Any insights much appreciated. Kind regards Richard Gould This email and any attachments are confidential and may also be privileged. If you are not the addressee, do not disclose, copy, circulate or in any other way use or rely on the information contained in this email or any attachments. If received in error, notify the sender immediately and delete this email and any attachments from your system. Emails cannot be guaranteed to be secure or error free as the message and any attachments could be intercepted, corrupted, lost, delayed, incomplete or amended. Standard Chartered PLC and its subsidiaries do not accept liability for damage caused by this email or any attachments and may monitor email traffic. Standard Chartered PLC is incorporated in England with limited liability under company number 966425 and has its registered office at 1 Aldermanbury Square, London, EC2V 7SB. Standard Chartered Bank ("SCB") is incorporated in England with limited liability by Royal Charter 1853, under reference ZC18. The Principal Office of SCB is situated in England at 1 Aldermanbury Square, London EC2V 7SB. In the United Kingdom, SCB is authorised and regulated by the Financial Services Authority under FSA register number 114276. If you are receiving this email from SCB outside the UK, please click http://www.standardchartered.com/global/email_disclaimer.html to refer to the information on other jurisdictions.

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Re: [Boost-users] Boost:Bind//Boost:Function -- Need some help with a constructor trying to bind to a function
by Alan M. Carroll 03 Nov '08

03 Nov '08

I would think the value in the constructor should be bind(&Alpha::MethodsInHere::doesSomething, mih, _1) When you bind a non-static method, the first argument must be something with which you can call the method. That would not be eh. Of course, you have will have lifetime or copy issues with mih, but I presume you have arrangements for that and we're just seeing some simplified code. At 02:48 PM 11/2/2008, you wrote: >4. Finally, we have an initialization class. This class wants to instantiate the EventHandler object, and to do so needs to bind the method in #2 to pass in as an argument. > >POD::POD* instance = new POD::POD(); >Alpha::MethodsInHere mih; >EventHandler eh(boost::bind(&Alpha::MethodsInHere::doesSomething, ????, _1)) > >-------- > >My question is basically if this is possible. I was having a ton of trouble getting this to work, and after digging through some docs it seems like the '?????' in line of code in #4 needs to be a reference to eh . . . which isn't constructed yet.

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