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BGL: subgraph<..> Problems
by Matthias Kronenberger 06 Jun '02

06 Jun '02

1. How to create a subgraph from a given simple boost graph type? 2. Why are modell subgraph not the same concept as the underlying graph type? Why are not all non-member function defined for the only graph modell adjacence_list<> also available for subgraph? 3. I've defined something like class NG { public: typedef boost::property<boost::vertex_all_t, SomeIterator, Vertex_Property > vertex_SPIterator_Prop; // GridSP_type::iterator typedef Default::Graph<vertex_SPIterator_Prop, Edge_Property>::Subgraph::Undirected Graph; ... }; where struct Default { ..... template<class VertexProperties=boost::no_property, class EdgeProperties=boost::no_property, class GraphProperties=boost::no_property, class EdgeList=boost::hash_setS, class VertexList=boost::listS > struct Graph { ........ struct Subgraph { typedef typename boost::subgraph < boost::adjacency_list<EdgeList, VertexList, boost::undirectedS, boost::property<boost::vertex_index_t,int, VertexProperties>, boost::property<boost::edge_index_t, int, EdgeProperties > ,GraphProperties> > Undirected; }; .... }; and then i'm doing somewhere else { vertex_descriptor v=boost::add_vertex( theGraph); IteratorMap[Prop ] =v; boost::put( boost::vertex_all_t() , theGraph, v, Prop); return v; } I get a nice error with MSVC 6.5 d:\matthias\programmieren\boost\boost\graph\subgraph.hpp(751): error C2679: Binaerer Operator '=': Kein Operator definiert, der einen rechtsseitigen Operator vom Typ 'const _Ht_iter<pair<int const,surrect::PNSurfel<vectorD<float,3>>>,_Nonconst_trait............ (no operator= defined for the type conversion used in put pmap[k] = val;) But using a simple adjacence_list<..> instead of the subgraph< adjacence_list<...> this mess compiles fine. What am i doing wrong? Are there better ways to create a property map containing (const) iterators, that don't modell STL::RandomAccesIterator? Matthias

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RE: [Boost-Users] Re: boost::noncopyable usage question
by Michael Davis 06 Jun '02

06 Jun '02

According to the C++ Standard, 12.8/10, the assignment operator cannot be inherited because if it is not provided, the compiler will provide one implicitly. Or at least, that is my understanding of it. Given this, how can boost::noncopyable work?

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RE: [Boost-Users] boost::noncopyable usage question
by Mark Storer 05 Jun '02

05 Jun '02

This is more of a C++ question than a boost one (which is why I can answer it;). Your deletes are fine. The only way this would cause a problem is to delete through a boost::noncopyable pointer (in which case everything derived from it would leak). I'm guessing the author, Dave Abrahams, didn't think anyone was going to declare a noncopyable*, so decided to pass on that little bit of extra overhead involved in declaring a destructor virtual. Or it could be a mistake. Dave has posted to this list at least once... So tell us, did you mean to leave it non-virtual? --Mark Storer Software Engineer Cardiff Software #include <disclaimer> typedef std::disclaimer<Cardiff> Discard; -----Original Message----- From: Bobby Thomale [mailto:bthomale@mac.com] Sent: Wednesday, June 05, 2002 9:30 AM To: Boost Users List Subject: [Boost-Users] boost::noncopyable usage question I have a simple question about the usage of boost::noncopyable. I think I know the answer, but I am not sure. The noncopyable class defines a non-virtual destructor. Generally speaking, overriding a non-virtual destructor is considered a "bad thing" but in certain cases (like, I am guessing, this one) it is okay and works like you'd expect. Here's what I am worried about: Let's say I have a base class of an inheritance tree that I want to be non-copyable. So I do this: class MyBase : private boost::noncopyable { public: MyBase (); virtual ~MyBase (); ... }; Then I derive from it class A: class A : public MyBase { public: A (); virtual ~A(); }; and define a destructor for class A, too. Does this do what I would expect, ie whether I delete a MyBase* or an A*, it calls the destructors for both A and MyBase like it is supposed to? I suppose the trivial, empty noncopyable destructor never gets called (which is okay) whether I delete a MyBase* or an A*, correct? (Just curious...) -- Bobby --------------------------------------------------------------------- Bobby Thomale Senior Software Developer Inoveon Corporation http://www.inoveon.com/ --------------------------------------------------------------------- Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

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boost::noncopyable usage question
by Bobby Thomale 05 Jun '02

05 Jun '02

I have a simple question about the usage of boost::noncopyable. I think I know the answer, but I am not sure. The noncopyable class defines a non-virtual destructor. Generally speaking, overriding a non-virtual destructor is considered a "bad thing" but in certain cases (like, I am guessing, this one) it is okay and works like you'd expect. Here's what I am worried about: Let's say I have a base class of an inheritance tree that I want to be non-copyable. So I do this: class MyBase : private boost::noncopyable { public: MyBase (); virtual ~MyBase (); ... }; Then I derive from it class A: class A : public MyBase { public: A (); virtual ~A(); }; and define a destructor for class A, too. Does this do what I would expect, ie whether I delete a MyBase* or an A*, it calls the destructors for both A and MyBase like it is supposed to? I suppose the trivial, empty noncopyable destructor never gets called (which is okay) whether I delete a MyBase* or an A*, correct? (Just curious...) -- Bobby --------------------------------------------------------------------- Bobby Thomale Senior Software Developer Inoveon Corporation http://www.inoveon.com/ ---------------------------------------------------------------------

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Tupls browsing...
by Igor Korzinek 04 Jun '02

04 Jun '02

Hi, I did not take a look at the tuple internals, but it seems that there is some head-tail connection probably built in compile time. So can someone from template gurus answer if it makes sense and if it is possible to add some method that will make sequential access possible. Some function that will getNext() or some kind of search within a tuple ? Is it too stupid or just impossible ? Igor

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Is it worth using if I use MSVC
by Igor Korzinek 04 Jun '02

04 Jun '02

Hi, I'm new to boost. The doc I've browsed seems fine and something what I need. I'm focusing on TUPLEs part. So, besides mentioned cref and ref stuff, is there any other issue I can expect with awful (but a must for me) MS VC 6 ? And are there any sample for using this part of boost ? THX, Igor

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Newbie Thread Installation Problem
by gclee46 03 Jun '02

03 Jun '02

(Please excuse me it this is a duplicate post - I tried to send it yesterday and it didn't seem to arrive) I have Boost 1_28_0 and installed the prebuilt version of Jam for Windows. After installing threads with C:\boost_1_28_0>bjam "-sTOOLS=borland" I get, after skipping the pyton stuff, and all the install messages: ...found 390 targets... However when I try to use the thread I get the following: Borland C++ 5.5.1 for Win32 Copyright (c) 1993, 2000 Borland testthread1.cpp: Fatal F1003 \boost_1_28_0\boost/thread/thread.hpp 17: Error directive: Thread support is unavailable! *** 1 errors in Compile *** I believe that I followed all the directions...I'm using Windows XP Home. Any help would be greatly appreciated. Greg

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BGL and MS compilers (VC++ and Wince)
by a_schweitzer 03 Jun '02

03 Jun '02

I am having difficulting getting BGL to compiler with VC++ 6.0 and Windows CE 3.0, platform builder. In both cases I get internal compiler errors, although at different lines in the compiler. VC++ worked when I had all my code in one cpp file. When I broke it out into multiple files I couldn't get it to compile even when I put it back in one file. I have tried the Zm and Z7 switches to no avail. Perhaps I need the service pack? Wince dies much more quickly, I think when it sees adjacency_list.hpp or depth_first_search.hpp. Does anyone have some perspective on how BGL projects with MS work out? Is there any hope for Wince?

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Dynamic Bitset - Upcoming Formal Review
by Mat Marcus 03 Jun '02

03 Jun '02

The formal review of Dynamic Bitset by Chuck Alison and Jeremy Siek will commence on Saturday June 8th and run through Monday, June 17th. The library is currently available at <http://groups.yahoo.com/group/boost/files/dyn_bitset.tar.gz> Below is an excerpt from the library's documentation: The dyn_bitset class represents a set of bits. It provides accesses to the value of individual bits via an operator[] and provides all of the bitwise operators that one can apply to builtin integers, such as operator&& and operator<<. The number of bits in the set is specified at runtime via a parameter to the constructor of the dyn_bitset. Each bit represents either the Boolean value true (set) or false (reset). To toggle a bit is to change the value to true if it is false and to false if it is true. Each bit has a non-negative position pos. The position pos == 0 corresponds to the least significant bit and pos == size() - 1 is the most significant bit. When converting an instance of dyn_bitset to or from an unsigned long, the bit position pos corresponds to the bit value 1 << pos. The dyn_bitset class is nearly identical to the std::bitset class. The difference is that the size of the dyn_bitset (the number of bits) is specified at run-time during the construction of a dyn_bitset object, whereas the size of a std::bitset is specified at compile-time through an integer template parameter. For information about submitting a Formal Review, see http://www.boost.org/more/formal_review_process.htm Please try out the library so that you will be prepared to to say whether or not you think the library should be accepted by Boost during the upcoming review period next week Compiler notes: This library has been tested using the following compiler platforms: Gcc 2.95 and 3.01 Kai C++ Metrowerks Codewarrior 8 (beta, Mac) The library presently requires template friend support and therfore is known not to compile with CodeWarrior 7.2. The library has not been tested with VC++ or Borland. The Formal Review manager will be Mat Marcus.

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Compilation question
by rgalek2002 03 Jun '02

03 Jun '02

Hi, I am a new user of the boost libs, so sorry for the supid questions. I am running into a compilation error while trying to compile listing 2 and listing 3 from Bill Kempf's article at http://www.cuj.com/articles/2002/0205/0205a/0205a.htm, giving simple usage examples of boost threads. 1. When I compile listing 2, the compiler chokes on the lines boost::thread thrd1(count(1)); boost::thread thrd2(count(2)); with the errors listing2.C:27: no matching function for call to `count (int)' listing2.C:28: no matching function for call to `count (int)' As you can see in the listing online, count is defined as 'struct count{...}' Upon perusal of threah.hpp, I see that, indeed, the class thread constructor is looking for a function, not a struct or class as count is defined in this code. Am I missing something, or is the code in error? 2. In listing 2, I get the following errors when compiling: listing3.C:29: no matching function for call to `bind ({unknown type}, int)' listing3.C:31: no matching function for call to `bind ({unknown type}, int)' This is in response to the lines: boost::thread thrd1(boost::bind(&count, 1)); boost::thread thrd2(boost::bind(&count, 2)); Again, am I missing something or what? I have pasted the code directly from the source as provided online. TIA for your help Richard

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