December 2006 - Boost-users - lists.preview.boost.org

Re: [Boost-users] BOOST_ASSERT and others
by Maarten Nieber 15 Dec '06

15 Dec '06

I use the trick assert( 2 + 2 == 4 || "Adding numbers failed!" ) This will probably work for BOOST_ASSERT as well. Kind regards Maarten ----- Original Message ---- From: Gennadiy Rozental <gennadiy.rozental(a)thomson.com> To: boost-users(a)lists.boost.org Sent: Thursday, December 14, 2006 4:03:15 PM Subject: Re: [Boost-users] BOOST_ASSERT and others "abir basak" <abirbasak(a)gmail.com> wrote in message news:elr59r$sho$1@sea.gmane.org... > > Hi, > Hi, if any assert is there like BOOST_ASSERT or assert where I can > pass a custom message to print on assert failure ? > i.e. something like > BOOST_ASSERT(condition, message) > > Also, is there any debug print version for boost? > Something like, I want a message should be printed only when the > application is running in DEBUG version (whatever flag the system > provides for that). > The message can be cout or printf kind of thing. A little safety is > better sometimes like debug print can't change the value of the variable > etc. > Thanks Google for smart_assert. There was one by john torjo. Gennadiy _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Computing a path while traversing a graph with a search algorithm
by Roger Leigh 15 Dec '06

15 Dec '06

Hi folks, I've written a program which makes use of the Boost Graph library to construct a graph. I've then attached properties to both the vertices and edges, giving a result like this: http://www-users.york.ac.uk/~rl522/test.pdf However, I want to now search the graph in order to do this: 1. When the edge is the last, i.e. the outdegree of the target is 0: 2. Total the edge values for all the edges followed to get here all the way back to the root, and add 19. 3. If this total is the same value as the root node value, set a particular property on each vertex those edges are connected to. I've tried a depth_first_search using a Visitor. I wanted to push each edge onto a temporary vector as I found it, and then pop it when the algorithm backtracked, but this doesn't work. The aim here was to know the path taken to get to a particular edge when that edge was found. I'm completely new to using graphs (I'm actually a Biologist), and I think I'm missing how I should really be using the depth_first_search or breadth_first_search visitors to do what I need. It also doesn't appear to like me using the visitor to alter the properties on the vertices or edges during the search. Is this allowed? I'm not altering the graph, just wanting to set a few property values (internally stored, in this case). I would be very grateful for any ideas or suggestions for approaching this problem. Many thanks, Roger Leigh PS. This is the visitor I wrote, but this appears to be completely wrong. The full source is at http://www-users.york.ac.uk/~rl522/massgraph-0.1.0.tar.gz (ms_analysis.cc|h). class peak_visitor : public boost::default_dfs_visitor { public: peak_visitor(double target_mass, ms_analysis::vertex_set& vs, std::vector<ms_analysis::edge_stack>& v): target_mass(target_mass), vs(vs), v(v), s() {} template < typename Edge, typename Graph > void tree_edge(Edge e, Graph & g) { s.push_back(e); double smass = 0.0; for (ms_analysis::edge_stack::const_iterator pos = s.begin(); pos != s.end(); ++pos) { smass += g[*pos].aa_data.get_distance(); std::cout << g[*pos].aa_data.get_distance() << '\t'; } std::cout << std::endl; smass += 19.0; std::cout << "T=" << target_mass << ", S=" << smass << std::endl; if (smass > target_mass - 0.5 && smass <= target_mass + 0.5) { for (ms_analysis::edge_stack::const_iterator pos2 = s.begin(); pos2 != s.end(); ++pos2) { ms_analysis::graph::vertex_descriptor v1, v2; v1 = source(e, g); v2 = target(e, g); // Setting properties fails to compile. //g[v1].valid = true; //g[v2].valid = true; vs.insert(v1); vs.insert(v2); } } v.push_back(s); } } template < typename Edge, typename Graph > void back_edge(Edge e, const Graph & g) { // This is *never* called. std::cout << "BACK" << std::endl; s.pop_back(); } double target_mass; ms_analysis::vertex_set vs; std::vector<ms_analysis::edge_stack>& v; ms_analysis::edge_stack s; }; -- .''`. Roger Leigh : :' : Debian GNU/Linux http://people.debian.org/~rleigh/ `. `' Printing on GNU/Linux? http://gutenprint.sourceforge.net/ `- GPG Public Key: 0x25BFB848 Please GPG sign your mail.

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The fibonacci heap is behaving strange
by Magnus Ekdahl 15 Dec '06

15 Dec '06

Hi, I put in 0,1,2,3,4 into a Fibonacci heap, manipulate some and get 0,2,4,1,25 back. With the relaxed heap I get 0,2,4,1,3 back, which is as expected with my code. AFAIK this is due to a bug in the Fibonacci heap? Anyway here is code adopted from the cvs (fibonacci_heap.cpp) that reproduces the result on two different machines (intel/amd), where the programs are compiled using g++ 4.0.4. Any help in clearing out this confusing result is appreciated :) #include <iostream> #include <cstdlib> #include <vector> #include <boost/pending/Fibonacci_heap.hpp> #include <boost/pending/relaxed_heap.hpp> #include <boost/graph/graph_utility.hpp> #include <boost/pending/indirect_cmp.hpp> using namespace std; using namespace boost; int main(int argc, char *argv[]) { typedef indirect_cmp<unsigned*,std::less<unsigned> > ICmp; unsigned current; const unsigned N=5; vector<unsigned> w(N); ICmp cmp(&w[0], std::less<unsigned>()); Fibonacci_heap<unsigned, ICmp> Q(N, cmp); //relaxed_heap<unsigned, ICmp> Q(N, cmp); Q.push(0); current=Q.top(); cout << current << " "; Q.pop(); w[1]=180428938; Q.push(1); w[2]=84693088; Q.push(2); w[3]=168169277; Q.push(3); w[4]=171463691; Q.push(4); current = Q.top(); cout << current << " "; Q.pop(); w[3]=164976049; Q.update(3); w[4]=59651664; Q.update(4); current = Q.top(); cout << current << " "; Q.pop(); w[1]=71988538; Q.update(1); w[3]=118964142; Q.update(3); current = Q.top(); cout << current << " "; Q.pop(); w[3]=42423833; Q.update(3); current = Q.top(); cout << current << " "; Q.pop(); return EXIT_SUCCESS; }

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[Boost] formal release dates for 1.34
by Andy Stevenson 15 Dec '06

15 Dec '06

Hi, Got any firm dates for when 1.34 will be released formally as the main boost distribution and what will/will not be in it in terms of libraries? Andy Stevenson Andy Stevenson CEO Fujitsu Telecommunications Europe Limited Tel: +44 121 717 6440 P Please consider the environment - do you really need to print this email?

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composite key, want to use compatible key on part of it
by bert hubert 15 Dec '06

15 Dec '06

Hi everybody, I have this boost::multi_index container (I'm very very happy with boost::multi_index!): typedef multi_index_container< CacheEntry, indexed_by < ordered_unique< composite_key< CacheEntry, member<CacheEntry,string,&CacheEntry::d_qname>, member<CacheEntry,uint16_t,&CacheEntry::d_qtype> >, composite_key_compare<CIStringCompare, std::less<uint16_t> > >, sequenced<> > > cache_t; For details on CacheEntry, see http://wiki.powerdns.com/cgi-bin/trac.fcgi/browser/trunk/pdns/pdns/recursor… What I want to do is use a compatible key ('char *') to search only on d_qname. I've tried: struct string_char_comp { bool operator()(const char* x, const tuple<string,uint16_t>& )const { return false; // bogus, just compile testing } bool operator()(const tuple<string,uint16_t>&, const char* x )const { return false; } }; Followed by: cache_t d_cache; // ... d_cachecache=d_cache.equal_range(qname.c_str(), string_char_comp()); But this doesn't compile with famously huge template errors (I've shortened boost::multi_index to bi::): ord_index_ops.hpp:87: error: no match for call to `(const string_char_comp) (bi::composite_key_result<bi::composite_key<MemRecursorCache::CacheEntry, bi::member<MemRecursorCache::CacheEntry, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, &MemRecursorCache::CacheEntry::d_qname>, bi::member<MemRecursorCache::CacheEntry, short unsigned int, &MemRecursorCache::CacheEntry::d_qtype>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >, const char* const&)' These errors make me wonder if what I want is even possible - unless I make my comparison function accept a composite_key_result with lots of bi internals in it. Joaquin? -- http://www.PowerDNS.com Open source, database driven DNS Software http://netherlabs.nl Open and Closed source services

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[Graph] clear_vertex() bug?
by Silvia Richter 15 Dec '06

15 Dec '06

Hi, I'm new to Boost, and hope you can help me. When the attached source file is compiled with: gcc version 3.2.3 20030502 (Red Hat Linux 3.2.3-47.fc4) or gcc version 3.3.6 (Ubuntu 1:3.3.6-13ubuntu2) or gcc version 4.0.4 20060630 (prerelease) (Ubuntu 4.0.3-4), then running the program gives a segfault on line 27. When compiled with: gcc version 4.0.2 20051125 (Red Hat 4.0.2-8), no error occurs. To my understanding, no error should occur: I am using "listS" for both edges and vertices in adjacency_list. According to the documentation, clear_vertex() should not invalidate the adjacency_iterator in this case. However, in my code that's exactly what happens. I call adjacent_vertices() on a vertex A, which gives me an adjacency_iterator. Then I remove all edges from A by calling clear_vertex(). Then I want to use the adjacency_iterator obtained previously to check the new degrees of all (previous) neighbours of the removed vertex v. But the program crashes with a segmentation fault, when I try to use the iterator. Has anyone experienced this before? Is that a bug of the library? Cheers, Silvia -------------------------------------------------------------------------- This email and any attachments may be confidential. They may contain legally privileged information or copyright material. You should not read, copy, use or disclose them without authorisation. If you are not an intended recipient, please contact us at once by return email and then delete both messages. We do not accept liability in connection with computer virus, data corruption, delay, interruption, unauthorised access or unauthorised amendment. This notice should not be removed.

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Re: [Boost-users] [bjam]BorlandC++BuilderX problem staging Boost
by Jerry Schreiber 14 Dec '06

14 Dec '06

Rene Rivera wrote: >Use: > bjam -sTOOLS=borland stage >Or possibly: > bjam -sTOOLS=borland-5_6_4 stage >Or perhaps you just made a mistake in typing in "Borland" instead of >"borland" above? I tried "borland", worked the same as "Borland" which I used before, but "borland-5_6_4" made a substantial difference. Rene Rivera wrote: >You need to add that directory to your library search path when linking >your own programs. I've added the C:\Boost\boost_1_33_1\libs to the "-L" library search path (only had the parent directory previously). But I still get: Fatal: Unable to open file 'LIBBOOST_FILESYSTEM-BCB-S-1_33_1.LIB' In examining the output from the bjam using borland-5_6_4, I now see references to "HardLink stage\lib\libboost_filesystem-bcb56-s.lib", but no references to "libboost_filesystem-bcb-s-1_1_33_1.lib". I also see several "...skipped <@boost!lib>boost_filesystem-bcb56.lib for lack of <@boost!lib>boost_filesystem-bcb56-1_33_1.lib..." I'll attach all of the bjam output which I was able to trap. Jerry Schreiber

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Boost: issue with Threads and Mutexes
by Séverin Lemaignan 14 Dec '06

14 Dec '06

Hello, I'm Severin Lemaignan, software engineer at the INRIA french public research center. We are working on automation in public transportation. All our project is currently a pretty big C++/CLI-based piece of software, and we are relying more and more on Boost for low-level operations like threading. We ran very recently into a problem with Boost mutexes: We compile the project with Visual Studio 2005 (with the /clr flag), and everything was fine until we (re-)enabled precompiled headers. After that, the program still compiled and linked but it crashed as soon as started with a 0xc000007b error (namely "The application failed to initialize properly"). After futher investigation, we discovered it's due to the way we use "#pragma unmanaged" and "#pragma managed". The Boost headers were simply included in a "managed" part of the code while Boost methods (especially mutexes) were called in a "unmanaged" part. Hence causing the crash. The Boost library never complained at compile time. Maybe it should detect inconsistent use of managed/unmanaged pragma and warn the user ? We found another pratical (but unexpected) solution to the issue: instanciate a Boost::thread before the mutex. It solved the run-time crash. If someone has an explaination... Best regards, Séverin Lemaignan

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in-depth iterator
by Guillaume Chereau 14 Dec '06

14 Dec '06

Hello everyone, I have a question concerning the boost::iterator library. Here is my situation : I have a Tree structure that looks like that : template<class T> struct Node : public std::vector<Node<T> > { T value; }; I'd like to create an iterator that would yield all the values of such a structure. And also being able to prevent the iterator from going into some branches. The interface should look like this : template<class T> struct Policy { bool go_inside(const Node& node) { return True; }; }; Node<int> my_tree; ... depth_iter<int, Policy> iter(my_tree, Policy()); for (; depth_iter++; depth_iter != my_tree.end()) { .... } I can't find an easy way to create this "depht_iter" class. Doesn't the boost::iterator library gives some way to create in-depth iterators ? Is there a way to use the boost::graph library ? Thanks in advance Guillaume

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updating mpl::map to 1.34
by Ovanes Markarian 14 Dec '06

14 Dec '06

Hi! I would like to update mpl::map and mpl algorithms to 1.34 release candidate libs. What is the best way to do it? If there an archive of currently tested boost libs available or which CVS label should I use for new mpl version. Is it sufficient to replace boost/mpl directory in the installed boost libs? Currently I have problems when iterating (mpl::for_each, mpl::max_element) through mpl::map sequences. With Kind Regards, Ovanes Markarian

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