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Re: [Boost-users] How do I get boost to work with vs.net 2005 ?
by Sohail Somani 24 Jun '05

24 Jun '05

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Mart marvin > Sent: Friday, June 24, 2005 12:20 PM > To: boost-users(a)lists.boost.org > Subject: [Boost-users] How do I get boost to work with vs.net 2005 ? > > > I downloaded the executable from sourceforge, but I'm at a > loss how to get > the libraries to be recognized by VS.NET. I googled but > nothing that works > turned up. I'm desperate to try and play with the boost > libraries and am > eager to get started with them. Can someone describe it step by step > command by command? http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?Installin gBoost Doesn't get much better than that.

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Re: [Boost-users] Boost-users Digest, Vol 588, Issue 2
by Frank Hess 24 Jun '05

24 Jun '05

On Thursday 23 June 2005 05:41 pm, boost-users-request(a)lists.boost.org wrote: > Message: 9 > Date: Thu, 23 Jun 2005 17:45:25 +0100 > From: Paul Johnson <gt54-boost(a)cyconix.com> > Subject: [Boost-users] Replacing a reference with a shared_ptr? > To: boost-users(a)lists.boost.org > Message-ID: <42BAE725.2080907(a)cyconix.com> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > I'm deriving from a base class in a library I use (in other words, I > > can't change it), and this class declares: > > virtual string& getFilename(void) const; > > virtual void setFilename(const string&); > > The base class itself doesn't declare a member to store the file name; > it just ignores 'setFilename', and returns an empty string for > 'getFilename'. > > I'd like to implement these routines, but I don't want to have a string > reference in my derived class. If possible, I'd like to use a > shared_ptr<string>. However, I can't see a simple way to do this. Why are you bothering with pointers or references? Why can't you just put a string in your class? string myString; virtual string& getFilename(void) const {return myString;} virtual void setFilename(const string&) {myString = string;} -- Frank

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shared_ptr misuse?
by Jason House 23 Jun '05

23 Jun '05

I have the contents of a shared pointer getting corrupted by a default constructor of another object. My best guess as to how this could be happening is that I am using references to shared pointers for coding convenience. Is it possible for code like the following to cause a problem? { boost::shared_ptr<my_class> &x = a.b.c.d.e.f.g; if (x.get() == NULL) { pointer_empty(); } else { other_actions(x->get()); } } PS: I found this in a header file (#define BOOST_VERSION 103000)

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Replacing a reference with a shared_ptr?
by Paul Johnson 23 Jun '05

23 Jun '05

I'm deriving from a base class in a library I use (in other words, I can't change it), and this class declares: > virtual string& getFilename(void) const; > virtual void setFilename(const string&); The base class itself doesn't declare a member to store the file name; it just ignores 'setFilename', and returns an empty string for 'getFilename'. I'd like to implement these routines, but I don't want to have a string reference in my derived class. If possible, I'd like to use a shared_ptr<string>. However, I can't see a simple way to do this. The original string is supplied by me to the library, which eventually calls my 'setFilename'. So, I could start with a shared_ptr, and use operator() to supply the library with a reference to the string. However, when the string& gets back to my 'setFilename', there's no obvious way to get back to the original shared_ptr. Have I missed something? Is there a clean way to implement this with shared_ptr<string>? Thanks.

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python like generators in C++
by Paul Elliott 23 Jun '05

23 Jun '05

I consider the following equation: Threads + some template code = iterators that act like python generators in C++! Has anyone implemented this in boost? Thank You -- Paul Elliott 1(512)837-1096 pelliott(a)io.com PMB 181, 11900 Metric Blvd Suite J http://www.io.com/~pelliott/pme/ Austin TX 78758-3117

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1.32 installation: where is the smart_ptr lib?
by Paul Johnson 23 Jun '05

23 Jun '05

Sorry for the dumb question... Just installed boost following the instructions on boost.org, and I can't find the smart_ptr library. I downloaded the 1.32 .bz file, and bjam, and installed on Linux/RHEL4. I've now got 189 boost libraries in /usr/local/lib, and 32 in /usr/lib. However, the only base libraries seem to be date_time, filesystem, prg_exec_monitor, program_options, python, regex, serialisation, signals, test_exec_monitor, thread, unit_test_framework, and wserialisation, some of which aren't even listed on the libraries page at boost.org. Where's smart_ptr? None of these libraries appear to have it. The smart_ptr headers are in /usr/local/include/boost-1_32/boost, as expected (but why 2 levels down? Surely I'm not expected to #include <boost-1_32/boost/xx.hpp??) Cheers.

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bcp error
by Ronald Sipkema 23 Jun '05

23 Jun '05

hi, when trying to use bcp as follows: "bcp --list build" I get the following error: **** exception(205): std::runtime_error: Bad file name: ../boost.css Any idea what's happening? Other module lists )for example regex) work just fine. --Ronald

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date_time problem: where are fractional seconds?
by Serge Skorokhodov 23 Jun '05

23 Jun '05

Hi, The following code (boost 1.32, MSVC.NET 2003): ptime pt = from_iso_string("20030912T211733.01204"); cout << pt << endl; cout << to_simple_string(pt) << endl; cout << to_iso_extended_string(pt) << endl; cout << to_iso_string(pt) << endl; cout << pt.time_of_day().fractional_seconds() << endl; time_duration td = pt.time_of_day(); cout << to_iso_string(td) << endl; cout << to_simple_string(td) << endl; cout << td.fractional_seconds() << endl; yealds: 2003-Sep-12 21:17:33 2003-Sep-12 21:17:33 2003-09-12T21:17:33 20030912T211733 0 211733 21:17:33 0 Is the fractional part of time (.01204) absent by design? I failed to find it out from the documentation? Is there a workaround? TIA -- Serge

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[bind / lambda] binding a factory funtion instead of an value
by Bertolt Mildner 23 Jun '05

23 Jun '05

Lets say i need a functor of type typedef boost::function1<Ret, Arg1> Functor; and i have a function Ret Foo(Arg1 a, Arg2 b); Creating a Functor object is easy if i have a Arg2 object Arg2 arg2; Functor f(boost::bind<Ret>(&Foo, _1, arg2); But what if i want to create the Arg2 object in the functor when it is used? Like i have a function Arg2 CreateArg2(); and i don't want Functor f(boost::bind<Ret>(&Foo, _1, CreateArg2()); but something like Functor f(boost::bind<Ret>(&Foo, _1, &CreateArg2); so that f(arg1) = Foo(arg1, CreateArg2()); I have a vague feeling that lambda might have a solution to this, but i don't know how! Bertolt

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[BGL] overlaying a graph-like structure
by martin f krafft 22 Jun '05

22 Jun '05

I am looking at the possibility to use BGL for the structural representation of an artificial neural network: nodes would be neurons, edges would be synapses. The advantage for me would be that I don't have to worry about complexity of the graph structure. For this to work, I need to be able to strap behaviour and data onto the edges and nodes. The bundled properties interfaces seems to be a good way to do this, but there is something fundamental that I am apparently not understanding: What is an edge descriptor, what is a vertex descriptor? From the code: typedef typename boost::ct_if_t<is_rand_access, std::size_t, vertex_ptr>::type vertex_descriptor; vertex descriptors are indices or pointers. And typedef detail::edge_desc_impl<directed_category, vertex_descriptor> edge_descriptor; and edge is actually a struct containing source and target vertex, and a property pointer (void*). There does not seem to be a way to get the property object from an edge descriptor without casting to the expected type. Thus, vertex and edge descriptors are really just minimal and provide absolutely no way to access the relevant data through their interface. Instead, BGL expects people to have access to the containing graph object, to be able to call functions like target(), out_edges(), or operator[] to get at the downstream vertex/edge, or a vertex'/edge's properties. In the context of my application, I know have two options: adopt the graph-centric perspective of BGL, in which the graph object is needed to answer any questions about the graph, even about single components therein, or to strap a layer on top of all this to return to proper object encapsulation: - where a node knows about its incident edges - where an edge knows about its source and target vertices - where both give access to the associated properties. If I wanted to go the latter way, I'd have to store an additional 8 bytes (descriptor + graph references) with each object, which is just a waste if you ask me. However, there seems to be no other way as I cannot derive from vertex/edge descriptors. Does anyone have any experience with folding BGL into an existing graph-like structure? My ideal solution would be my neuron and synapse classes derived from the vertex and edge descriptors, such that I can treat them like components of the graph as well as neural components. From looking at the LEDA stuff, I guess the way to do this is to modify the graph traits to replace edge and node descriptors with custom classes. If I take care to model the behaviour of the existing edge and node descriptors wrt their interfaces, I shouldn't actually need to override the public Graph API, right? Is it sensible to derive from detail::edge_desc_impl, or should detail::* stuff not be touched outside of BGL code? Thanks for any comments, thoughts, suggestions, pointers. -- martin; (greetings from the heart of the sun.) \____ echo mailto: !#^."<*>"|tr "<*> mailto:" net@madduck invalid/expired pgp subkeys? use subkeys.pgp.net as keyserver! spamtraps: madduck.bogus(a)madduck.net "i have smoked pot. it is a stupid business, like masturbation." -- thomas pynchon

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