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Re: [Boost-users] [Graph] Adjacency list scalability with a Dijks tra algorithm
by Florian.PONROY＠fr.thalesgroup.com 25 Mar '09

25 Mar '09

Hi Andrew, Would you please tell me which part of the documentation I should rely on to use a std::map as you'd suggested? I should actually admit I'm not yet familiar with the BGL :-) -----Message d'origine----- De : boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org]De la part de Andrew Sutton Envoyé : mercredi 25 mars 2009 17:25 À : boost-users(a)lists.boost.org Objet : Re: [Boost-users] [Graph] Adjacency list scalability with a Dijkstra algorithm Here is the problem: I would have imagined that, in my case, boost::num_vertices(graph) would have returned 6, but it actually returns the higher vertex number + 1, that is... 4243 ! So each of my vector has a size of 4243 * sizeof(tVertex) bytes... Is there a way to handle that? I probably misuse the API, but it would be better if the container would be dimensioned to the actual number of vertices, since I am in a CPU and memory constraint environment... You're confusing the notions of "index" and "descriptor". With the vertex set using vecS, the descriptor of a vertex is the same as its index -- hence the confusion. Therefore, when you call add_edge(4242, 1, ...), the graph thinks you mean the vertex whose descriptor is 4242 and resizes itself accordingly. You have to remember - whatever the examples may indicate - that you should never actually use a literal value and descriptors interchangeably. This isn't documented very well, either. You could use a std::map to associate your own identifiers with vertex descriptors. Andrew Sutton andrew.n.sutton(a)gmail.com <mailto:andrew.n.sutton@gmail.com>

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Statechart problem
by Iwan Sanders 25 Mar '09

25 Mar '09

LS, I've implemented a state machine (synchronous) with a couple of states and their events. Its purpose is to implement an USDT CAN stack. Because the lower level driver (made that too) passes the incoming CAN messages through a callback function I needed to derive one state in the state machine from: a) the expected boost state base b) my own interface which handles the callback for new messages (observer) The state machine is performing well with one exception, hence this email. The callback function is a member of a struct which is derived from a & b and it is called by the CAN driver. But then when I want to notify the state that the machine is currently in with a post_event this event seems to be discarded even though it should react on it (the machine state has transitions defined for this event and the current state is that state). I also tried using the transit call but that doesn't do anything either. It is just this one member-function that is the problem and before rewriting the state-machine to an asynchronous state machine I wanted to consult some other users. Regards, Iwan Sanders

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Re: [Boost-users] [asio] Disable nagle algorithm on Windows XP
by 张亚霏 25 Mar '09

25 Mar '09

try native WSA API "setsockopt" with the TCP_NODELAY option. if it still does not work, there may be something wrong with your windows xp. or debug the asio ------------------ best wishes to you 张亚霏 ------------------ Original ------------------ From: "Tobias J?hnel"<tjaehnel(a)gmail.com>; Date: Wed, Mar 25, 2009 10:58 PM To: "boost-users"<boost-users(a)lists.boost.org>; Subject: Re: [Boost-users] [asio] Disable nagle algorithm on Windows XP Hi Igor, thanks for your reply. I guess you mean setting non_blocking_io to false. Tried to enter those lines, but still have no change: boost::asio::socket_base::non_blocking_io command(false); socket.io_control(command); Tobias On Wed, Mar 25, 2009 at 3:07 PM, Igor R <boost.lists(a)gmail.com> wrote: >> I'm already using blocking sockets as suggest in above document. > > According to that document, you should not enocounter this problem > when using blocking sockets. Probably your socket is not blocking? > To make a socket blocking you should write something like this: > boost::asio::socket_base::non_blocking_io command(true); > socket.io_control(command); > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users > _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Re: [Boost-users] [asio] ip::tcp::socket - differences between send &write_some
by 张亚霏 25 Mar '09

25 Mar '09

after referring the source code, i hardly found difference between ip::tcp::socket::send & ip::tcp::socket::write_some, but about some arguments. "socket_ops::send" directly invokes system call:"sendmsg" to send message. ------------------ best wishes to you 张亚霏 ------------------ Original ------------------ From: "Lennyk"<lennyk430(a)gmail.com>; Date: Wed, Mar 25, 2009 04:59 PM To: "boost-users"<boost-users(a)lists.boost.org>; Subject: [Boost-users] [asio] ip::tcp::socket - differences between send &write_some Hi, What is the difference in implementation between the ip::tcp::socket::send & ip::tcp::socket::write_some on Linux sys sockets? What kind of system calls are used in both calls? Thanks! _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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[asio] Disable nagle algorithm on Windows XP
by Tobias Jähnel 25 Mar '09

25 Mar '09

Hi, I'm developing a TCP-Client using boost::asio and discovered that ACKs to responses from the server are sent with some delay (~200ms) and I get the data not before this ACK has been sent. When I disable nagle in registry as described by Microsoft it works fine. (See: http://support.microsoft.com/kb/823764) To avoid those registry hacks I want to find another way to get rid of this latency. I'm already using blocking sockets as suggest in above document. I also tried to set the no_delay option but this has no effect at all. boost::asio::ip::tcp::no_delay option(true); socket.set_option(option); == Code Snippets == I use the boost asio library as follows: // open connection (from synchronous TCP daytime client example) boost::asio::io_service io_service; tcp::resolver resolver(io_service); tcp::resolver::query query(ipaddress, port); tcp::resolver::iterator endpoint_iterator = resolver.resolve(query); tcp::resolver::iterator end; boost::system::error_code error = boost::asio::error::host_not_found; while (error && endpoint_iterator != end) { socket.close(); socket.connect(*endpoint_iterator++, error); } // send some data boost::asio::write(socket, boost::asio::buffer(package, size)); // reception is done inside a thread while(true) { // receive data size_t length = socket.read_some(boost::asio::buffer(resp), error); if (error == boost::asio::error::eof) { // Connection closed cleanly by peer. // ... do sth. } else if (error) { // Some error has happened // ... do sth. } // ... process received data and notify main thread to send the next piece of data } ======= Thank you for all suggestions. Tobias

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Re: [Boost-users] [corrected]How to delay the initialisation of a member in a C++ base class until the ctor of derived class is executed?
by Zhi Tan 25 Mar '09

25 Mar '09

> Date: Wed, 25 Mar 2009 20:13:02 +1100 > From: Alex MDC <alex.mdc(a)gmail.com> > > Since you're passing the size into the derived constructor, why don't you > just pass it through to the base constructor? > > class base > { > public: > base(size_t array_size):size(array_size) > { > p_array.reset(new unsigned char[size]); > } > private: > size_t size; > boost::shared_array<unsigned char> p_array; > }; > > class derived > { > public: > derived(size_t array_size):base(array_size) > { > } > }; > > > Will that work for you? Exactly. Thank you.

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Re: [Boost-users] Boost-users Digest, Vol 1945, Issue 2
by tom tan 25 Mar '09

25 Mar '09

From: Matthieu Brucher <matthieu.brucher(a)gmail.com> >Perhaps simply: > >class base >{ >public: > base(size_t size):size(size), p_array(new unsigned char[size]){} >private: > size_t size; > boost::shared_array<unsigned char> p_array; >}; > >And then: > >class derived:public base >{ >public: > derived(size_t array_size):base(array_size) > { > } >}; > >Do not declare size and p_array again, they will be different than the >ones in the base class... but in this case array_size is re-assigned after p_array was allocated, thus not reflecting the size of the allocated buffer; What I wished to achieve is: 1) the buffer is allocated inside the base class while 2) the size is designated inside the derived class. >From: Christopher Currie <christopher(a)currie.com> >Also, shared_ptr won't work for arrays, you'll want to used >"shared_array" instead. That's right, I was thinking of shared_array while I was typing, but ... >You might also think twice about this, and decide if having a shared >copy of the buffer is really what you want, or if you're just using >the smart pointer for memory management. If so, consider using >"scoped_array" and defining a copy constructor with the appropriate >semantics. >If you go this route, you may just as well stick with 'vector'. It's >less work, and probably far less overhead than you think. I need some dynamically allocated space that can later be casted to C pointers, so that it can be passed to a Win32 API function that accepts C pointers only. vectors are dynamic, but they don't cast to C arrays naturally. In fact, I am wrapping that API in C++. is there a better way?

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How to convert graphtraits<Graph>::in_edge to graphtraits<Graph>::edge
by Phani Deepak 25 Mar '09

25 Mar '09

hi, i have stored some bundled properties for an edge. * class EdgeProperties { public: int targetI;// Terminal No. interms of target node int sourceI;// Terminal No. interms of source node EdgeProperties(int s,int t):sourceI(s-1),targetI(t-1) { } };* my Graph is : *typedef boost::adjacency_list<boost::listS,boost::listS,boost::bidirectionalS, EdgeProperties *> Graph; Graph g; * Now iam iterating through in_edges of some vertex v; *graphtraits<Graph>::in_edge_iterator iedge_s,iedge_end; for(boost::tie(iedge_s,iedge_end) = boost::in_edges(v,g); iedge_s!=iedge_end; ++iedge_s){ EdgeProperties *ep = g[*iedge_s]; // <==== **Line 10** cout << ep->sourceI << endl; // <==== **This is giving segmentation fault;** } * I checked the *ep* pointer. it is coming out as null in line 10; is there any problem while using *in_edge_descriptor* as *edge_descriptor**( for g[edge_descriptor]* ) in *Line 10* ?? * *please help. - Phani. * *

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[corrected]How to delay the initialisation of a member in a C++ base class until the ctor of derived class is executed?
by tom tan 25 Mar '09

25 Mar '09

Here's the scenario: I want define a base class that allocate some buffer once for all derived classes, while the size of the buffer varies among different derived classes. I could achieve it in this way: class base { public: base():size(), p_array(0){} private: size_t size; boost::shared_array<unsigned char> p_array; }; in the derived class: class derived { public: derived(size_t array_size):size(array_size) { p_array.reset(new unsigned char[size]); } }; However, in order to simplify the design of the derived class, I really want to put this line: p_array.reset(new unsigned char[size]); to somewhere in the base class, thus writing it only once. In other words,I wished to achieve this: 1) the buffer is allocated inside the base class while 2) the size is designated inside the derived class. Is there any C++ design pattern could achieve it? Thanks

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Re: [Boost-users] [asio] ip::tcp::socket - differences between send &write_some
by 张亚霏 25 Mar '09

25 Mar '09

concerning ... ------------------ best wishes to you 张亚霏 ------------------ Original ------------------ From: "Lennyk"<lennyk430(a)gmail.com>; Date: Wed, Mar 25, 2009 04:59 PM To: "boost-users"<boost-users(a)lists.boost.org>; Subject: [Boost-users] [asio] ip::tcp::socket - differences between send &write_some Hi, What is the difference in implementation between the ip::tcp::socket::send & ip::tcp::socket::write_some on Linux sys sockets? What kind of system calls are used in both calls? Thanks! _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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[asio] ip::tcp::socket - differences between send & write_some
by Lennyk 25 Mar '09

25 Mar '09

Hi, What is the difference in implementation between the ip::tcp::socket::send & ip::tcp::socket::write_some on Linux sys sockets? What kind of system calls are used in both calls? Thanks!

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Is there a way to delay the initialisation of a member in a C++ base class until the ctor of the derived class is executed?
by tom tan 25 Mar '09

25 Mar '09

Here's the scenario: I want define a base class that allocate some buffer once for all derived classes, while the size of the buffer varies among different derived classes. I could achieve it in this way: class base { public: base():size(), p_array(0){} private: size_t size; boost::shared_ptr<unsigned char> p_array; }; in the derived class: class derived { public: derived(size_t array_size):size(array_size) { p_array.reset(new unsigned char[size]); } private: size_t size; boost::shared_ptr<unsigned char> p_array; }; However, in order to simplify the design of the derived class, I really want to put this line: p_array.reset(new unsigned char[size]); to somewhere in the base class, thus writing it only once. Is there any C++ design pattern could achieve it? Thanks

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linking agaisnt boost
by arun ramakrishnan 25 Mar '09

25 Mar '09

A nube question . I have been trying to understand the whole link process in VC++ . I use visual studio 8. I was trying to install the prebuild boost libs from boostpro and I tried to build my source against 1) , 2) and 3) . The three are. 1)Multithread, static runtime libboost_thread-vc80-mt-s-1_38.lib 2)Multithread libboost_thread-vc80-mt-1_38.lib 3)Multithread , DLL boost_thread-vc80-mt-1_38.dll boost_thread-vc80-mt-1_38.lib I expected there to be Multithreaded static lib and then a multithreaded dynamic shared dll . Just 2 of them , not 3 . Could someone explain the need for 3 and not just 2. OR point me to a article or something please . I have vaguely figured that 1) static boost and static CRT . 2) static boost and dynamic CRT. 3) dynamic boost and dynamic CRT. am i right ? I believe boost automatically picks up the right libs based on your project . So , when i tried to build a simple project using these libs . while using the /MT option for code generation , 1) was used as I expected it to. while using the /MD option for code generation , it linked to 2) . I am not able to build using 3) , in spite of a lot of probing into the VC8 configuration options . Also , what configuration would be needed to make my project use the boost dll i.e 3). thanks in advance .

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Re: [Boost-users] BoostCon 2009 Schedule Now Live
by Paul 25 Mar '09

25 Mar '09

I beg you to recorded the conference on video/audio for those who aren't able to make the trip ... 2009/3/25 David Abrahams <dave(a)boostpro.com> > The official schedule is now live at http://www.boostcon.com/program! A > few highlights of the "mouth-watering content" (in the words of one > enrollee) are: > > * A keynote address from Andrei Alexandrescu called "Iterators Must Go." > It's sure to be provocative! > > * Troy Straszheim's presentations on how high-energy physicists are > using Boost to process massive datasets as they go "Icefishing for > Neutrinos" and on Kamasu, his library for offloading computation to > your machine's GPU. > > * Two hands-on sessions where we'll start recoding parts of Boost for > C++0x, applying rvalue references, variadic templates, decltype, and > advanced SFINAE capabilities using the latest GCC. > > * "Practical C++ Test-Driven Development with Boost.Test and Bmock," by > Asher Sterkin > > * A session on compiler construction using Boost.Spirit v2, from Hartmut > Kaiser and Joel de Guzman > > The complete list of sessions covers a wide range of other Boost and > C++-related topics. It is available at > http://www.boostcon.com/program/sessions. Please have a look, and > please, sign up for the conference! Remember, registration for the > whole week is just $599 before April 1st. > > -- > Dave Abrahams > BoostPro Computing > http://www.boostpro.com > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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Looking for guidance on how best to use Boost ASIO in this scenario
by console shark 24 Mar '09

24 Mar '09

I have the following scenario: Up to 1000 client users. 1 Server (or multiple instances of a server). The server(s) read a set of 5-15 incoming data feeds that update as often as 10 to 50 times per second. Each feed is updating at a different interval, as information comes in (essentially random). The server processes the data as it arrives from these feeds and when it finds a useful piece of information, it sends a message to some subset of the 1000 clients. The clients are not all interested in the same thing. It could be that each client has a different interest, and it could be that many times per second each client will need to be notified of that interest. That should be the worst case scenario, as meaningful changes in information probably won't require updates to the client that often, even though the 5-15 feeds are constantly updating. So what is the best way to structure this design using ASIO? Should the 1000 clients actually be set up as servers, and the server really just contact them by connecting each time there is an update that interest them? Or should the 1000 clients all connect with a permanent connection, polling for updates? Thanks for any advice.

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[boost-users][exception] BOOST_THROW_EXCEPTION returns
by Igor R 24 Mar '09

24 Mar '09

Hello all, A function throws boost::exception as follows: //.... typedef boost::error_info<struct tag_action, std::string> action_name; BOOST_THROW_EXCEPTION(error() << action_name(name)); return 0; Both BOOST_NO_EXCEPTIONS and BOOST_EXCEPTION_DISABLE are *not* defined. The excpetion is not catched anywhere. However, the thread continues running! If I put breakpoint at "return 0;" it's hit, and I can continue stepping the code. I run the program under MSVC 9.0, in debug mode, and I see "First-chance exception" and "Unhandled exception" notifications issued by the debugger. Isn't it wrong behavior, or I miss something? Thanks, Igor'.

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BoostCon 2009 Schedule Now Live
by David Abrahams 24 Mar '09

24 Mar '09

The official schedule is now live at http://www.boostcon.com/program! A few highlights of the "mouth-watering content" (in the words of one enrollee) are: * A keynote address from Andrei Alexandrescu called "Iterators Must Go." It's sure to be provocative! * Troy Straszheim's presentations on how high-energy physicists are using Boost to process massive datasets as they go "Icefishing for Neutrinos" and on Kamasu, his library for offloading computation to your machine's GPU. * Two hands-on sessions where we'll start recoding parts of Boost for C++0x, applying rvalue references, variadic templates, decltype, and advanced SFINAE capabilities using the latest GCC. * "Practical C++ Test-Driven Development with Boost.Test and Bmock," by Asher Sterkin * A session on compiler construction using Boost.Spirit v2, from Hartmut Kaiser and Joel de Guzman The complete list of sessions covers a wide range of other Boost and C++-related topics. It is available at http://www.boostcon.com/program/sessions. Please have a look, and please, sign up for the conference! Remember, registration for the whole week is just $599 before April 1st. -- Dave Abrahams BoostPro Computing http://www.boostpro.com

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Find last modified date of file
by Thor Andreas Tangen 24 Mar '09

24 Mar '09

Hi Is it possible by using boost to find the last modified date of a file? I looked in filesystem, but could not find it there. Thanks Thor Andreas

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[boost-users][exception] BOOST_THROW_EXCEPTION returns
by Igor R 24 Mar '09

24 Mar '09

Hello all, A function throws boost::exception as follows: //.... typedef boost::error_info<struct tag_action, std::string> action_name; BOOST_THROW_EXCEPTION(error() << action_name(name)); return 0; Both BOOST_NO_EXCEPTIONS and BOOST_EXCEPTION_DISABLE are *not* defined. The excpetion is not catched anywhere. However, the thread continues running! If I put breakpoint at "return 0;" it's hit, and I can continue stepping the code. I run the program under MSVC 9.0, in debug mode, and I see "First-chance exception" and "Unhandled exception" notifications issued by the debugger. Isn't it wrong behavior, or I miss something? Thanks, Igor'.

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Integrating boost into project version control
by Kenneth Porter 24 Mar '09

24 Mar '09

I have an existing C++ project that uses a few 3rd party libraries. It's maintained in a Subversion repository and the libraries are imported into the repository using the Subversion "vendor branch" paradigm together with Subversion "externals". I want to add Boost to the project, and am looking for guidance from others who have a project in Subversion: Should I import Boost sources into my repo, rebuilding on each developer's system as part of the normal whole-project build, or should I install a binary distro of Boost on each developer's system? The former guarantees that the repo always contains the source used to build our binaries, but at the cost of longer build times to build Boost each time the project is built. I'm currently building with Visual Studio 2005 and 2008, and will eventually be cross-compiling for an embedded Linux system.

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[lambda] extending lambda functions
by alfC 24 Mar '09

24 Mar '09

For some application I need to sum the complex modulus of a collection of elements. In short, I want to be able to replace the lambda expression _1 + bind(&std::norm<double>, _2) by something more natural like _1 + llnorm(_2) For that I use std::accumulate and the lambda library, like in the next working example; #include<boost/lambda/lambda.hpp> #include<boost/lambda/bind.hpp> using namespace boost::lambda; int main(){ using boost::lambda::_1; using boost::lambda::_2; std::vector<std::complex<double> > v(3); v[0]=1.; v[1]=2.; v[2]=3.; double result=std::accumulate(v.begin(), v.end(), double(0.), _1 + bind(&std::norm<double>, _2)); std::cout<<result<<std::endl; return 0; } the question is what do I have to do to be able to use the following syntax instead _1 + llnorm(_2) where llnorm is something I have to define (globally) somewhere else. The question is, how do I have to define llnorm to have the desired effect? The ideal syntax for me would be to be able to say std::norm(_2) or std::norm<double>(_2), but that may not be possible due to name conflict, is it? I am clueless because I don't even know even what is the (C++) type of the argument that would be taken by llnorm. Thanks, Alfredo

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selecting a type (tag) based on a runtime enum value
by Hicham Mouline 24 Mar '09

24 Mar '09

Hello, I have a templated function Engine, that takes 3 template arguments, these are tags T1, T2, T3, T4. I have an typedef enum { e1, e2, e3, e4 } E to element ei corresponds the type Ti ... const E e // switch (e) { case e1: Engine< Metafct1<T1>::type, Metafct2<T1>::type, Metafct3<T1>::type >::Process( .... ); break; case e2: Engine< Metafct1<T2>::type, Metafct2<T2>::type, Metafct3<T2>::type >::Process( .... ); break; ... } Is there a shorter way of writing this... For now I only have 4 in the enum, but I may have more later? regards,

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Seg fault while adding 2nd edge to the graph
by Phani Deepak 24 Mar '09

24 Mar '09

hi, i started using BGL for my project. strangely all the examples i tried to learn BGL worked fine. But when i write the actual code for my project, it started giving me this error. Problem: While adding second edge to the boost graph using boost::add_edge(u,v,g) it is giving out a seg fault. Please help with this prob. Iam also attaching the code that's giving the error /*********Code that's giving this error****************/ #include<iostream> #include<vector> #include<string> #include<queue> #include<stdlib.h> #include<string> #include<sstream> #include<boost/graph/graph_traits.hpp> #include<boost/graph/adjacency_list.hpp> class Node{ public: std::string id; double Energy; Node() {} }; class EdgeProperties { public: int targetI; int sourceI; EdgeProperties(int s,int t):sourceI(s),targetI(t) { } }; typedef boost::adjacency_list<boost::listS,boost::listS,boost::bidirectionalS, Node *,EdgeProperties *> Graph; typedef boost::graph_traits<Graph> GraphTraits; typedef GraphTraits::vertex_descriptor Vertex; typedef GraphTraits::edge_descriptor Edge; namespace boost { Vertex getVertexbyId(std::string id,Graph g){ std::cout << "getVID called for " << id << std::endl; fflush(stdout); GraphTraits::vertex_iterator vstart,vend; for(boost::tie(vstart,vend) = boost::vertices(g); vstart!=vend; vstart++) { if(g[*vstart]->id == (id)) return *vstart; } std::cout << "Critical Error: |" << id << "| referencing node not present in graph " << std::endl; return NULL; } } int main(){ Graph g; // populate Graph with all the vertices and edges. std::cout << "* Populating graph with Vertices and Edges " << std::endl; fflush(stdout); Vertex v = boost::add_vertex(g); g[v] = new Node(); g[v]->id = "xor_1"; g[v]->Energy = 2.3; std::cout << "Inserted xor_1" << std::endl; fflush(stdout); v = boost::add_vertex(g); g[v] = (new Node()); g[v]->id = "and_1"; g[v]->Energy = 1.9; std::cout << "Inserted and_1" << std::endl; fflush(stdout); v = boost::add_vertex(g); g[v] = (new Node()); g[v]->id = "i_1"; std::cout << "Inserted i_1" << std::endl; fflush(stdout); // add Edges std::pair<Edge,bool> e; EdgeProperties *ep = new EdgeProperties(1,1); e = boost::add_edge(boost::getVertexbyId("i_1",g),boost::getVertexbyId("and_1",g),ep,g); std::cout << "Inserted Edge 1" << std::endl; fflush(stdout); ep = new EdgeProperties(1,2); e = boost::add_edge(boost::getVertexbyId("i_1",g),boost::getVertexbyId("xor_1",g),ep,g); std::cout << "Inserted Edge 2" << std::endl; fflush(stdout); } /*******************************************************/ - Phani.

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[Q] better 'typedef'
by V S P 24 Mar '09

24 Mar '09

I have read somewhere that boost provides a better typedef. Something that allows to use the 'underlying class' but it is not a macro for example I want to define typedef std::wstring cvarchar_t to use for ODBC/Unicode db access (on win32) and then specialize some templates for this type that would behave differently then wstring I cannot remember what that mechanism was called. Also, sorry, for mixing this question in: is UTF-8 a more 'standard' encoding if I want to interface from my C++/boost programs to ODBC and to Boost.Python on Windows and FreeBSD (I have problems figuring out how to support the difference between UTF-16 on windows/wstring and Unix UTF-32 wstring ... while the unicode ODBC drivers are all 2-byte strings) thanks in advance -- V S P toreason(a)fastmail.fm -- http://www.fastmail.fm - Same, same, but different...

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proper erasing from ptr_vector
by Archie14 23 Mar '09

23 Mar '09

I have ptr_vector<A> lst; When I need to erase element from this container - should I just do A* el; iterator it = std::find (lst.begin(), lst.end(), el); lst.erase(it); or A* el; iterator it = std::find (lst.begin(), lst.end(), el); delete lst.erase(el);

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