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Re: [Boost-users] [Proto] automaitcally convert class to proto literal
by Daniel Oberhoff 05 Jan '09

05 Jan '09

> Daniel Oberhoff a Ã©crit : > > I might have gotten the terms wrong. But the way I got it working now is > > with using proto::lit which turns things into literals. I tried > > subclassing terminal with my array class, but that way the tree did not >> keep a reference to the array, and thus could not be evaluated as such. > Just make a array_data class that contains your data and make your user > level array class extends terminal<array_data>::type. The vec3 example > in the doc is exacly this and I used variations of this for like 4 or 5 > array like DSEL since proto is available. Ok, I looked into that. Works better than my previous approaches. Though I would like it much better if I don't have to split my class into an internal data class and a user interface, since I would like to use the whole interface in the proto evaluators. Also, since the extends mechanism makes the data class end up a member of the derived class it is hard to access the derived class from the base class. Is this fundamentally impossible? Naively I would like to write: class array : public proto::extends< proto::terminal< array >::type, array > { [...] }; though this is not possible since the extends mechanism makes the expr class a member of the extending class, and thus the class would have to contain itself in the end, which is, of course, impossible. -- --- Daniel Oberhoff Fraunhofer FIT Schloss Birlinghoven 53754 Sankt Augustin, Germany Tel.: +49-(0)-2241-14-3486 Fax.:+49 (0) 2241/14-2080

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[BGL] vertex_index_t, edge_index_t?
by Geoff Hilton 05 Jan '09

05 Jan '09

Quick question: Given an arbitrary graph of type: typedef boost::adjacency_list< boost::listS, //out edge list selector boost::vecS, //vertex list selector boost::bidirectionalS, //directedness selector VertexPropertyWrapper_type, EdgePropertyWrapper_type> Graph_type; Where: typedef boost::property< boost::vertex_index_t, unsigned long long, MyVertexProperty> VertexPropertyWrapper_type; And: typedef boost::property< boost::edge_index_t, unsigned long long, MyEdgeProperty> EdgePropertyWrapper_type; How does setting edge/vertex_index_t as an interior property affect..anything? I saw in a post on this list somewhere a while ago that this was a necessary workaround for something or other (that which I don't recall now). In the post it actually said to use "int" (or was it unsigned int?) rather than unsigned long long but in any case I left it as unsigned long long and it hasn't affected anything negatively thus far so I left it that way. I believe I put it at unsigned long long because the type that was suggested for the *_index_t happened to match a weight type used in the post, but whether that was intentionally and implicitly or unintentionally and explicitly I don't remember. Thank you, Geoff

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[BGL] Bundled properties and property maps
by Alex Brooks 05 Jan '09

05 Jan '09

Hi, I've used BGL before for representing graphs, but this is my first time with an algorithm. I've been stuck for many hours trying to define a property map with bundled properties, I'd really appreciate some help. I'm using gcc4.3, boost 1.34. An example program and the compiler error are: ------------------------------------------------------------- #include <boost/graph/graph_traits.hpp> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/astar_search.hpp> using namespace std; class Point { public: double p_[2]; }; struct EdgeProp { double cost; }; typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, Point*, EdgeProp> Graph; typedef boost::graph_traits<Graph>::vertex_descriptor VertexRef; class AStarHeuristic : public boost::astar_heuristic<Graph, double> { public: double operator()( VertexRef vertex ) const {return 0.0;} }; // exception for termination struct FoundGoal {}; // // A* Visitor that terminates when we reach the goal // class AStarVisitor : public boost::default_astar_visitor { public: AStarVisitor( const VertexRef &goal ) : goal_(goal) {} template <class Graph> void examine_vertex( VertexRef vertex, Graph &g ) { if( vertex == goal_ ) throw FoundGoal(); } private: VertexRef goal_; }; bool searchThroughGraph( const Graph &graph, VertexRef start, VertexRef goal, std::vector<VertexRef> &shortestPath ) { AStarHeuristic aStarHeuristic; AStarVisitor aStarVisitor( goal ); typedef boost::property_map<Graph, double EdgeProp::*>::type EdgeWeightMap; EdgeWeightMap edgeWeightMap = get(&EdgeProp::cost, graph); std::vector<VertexRef> predecessors(num_vertices(graph)); try { astar_search( graph, start, aStarHeuristic, boost::weight_map(edgeWeightMap). predecessor_map(&predecessors[0]). visitor(aStarVisitor) ); } catch ( const FoundGoal& ) { shortestPath.clear(); for ( VertexRef vertex = goal;; vertex = predecessors[vertex] ) { shortestPath.push_back( vertex ); if ( predecessors[vertex]==vertex ) break; } std::reverse( shortestPath.begin(), shortestPath.end() ); return true; } // If we get to here, we couldn't reach the goal return false; } int main() { Graph graph; std::vector<VertexRef> path; searchThroughGraph(graph,0,1,path); return 0; } ------------------------------------------------------------- /home/a.brooks/shh/src/libs/prm/test/stupid.cpp: In function ‘bool searchThroughGraph(const Graph&, VertexRef, VertexRef, std::vector<unsigned int, std::allocator<unsigned int> >&)’: /home/a.brooks/shh/src/libs/prm/test/stupid.cpp:64: error: conversion from ‘boost::bundle_property_map<const boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, Point*, EdgeProp, boost::no_property, boost::listS>, boost::detail::edge_desc_impl<boost::undirected_tag, unsigned int>, EdgeProp, const double>’ to non-scalar type ‘searchThroughGraph(const Graph&, VertexRef, VertexRef, std::vector<unsigned int, std::allocator<unsigned int> >&)::EdgeWeightMap’ requested ------------------------------------------------------------- Does anyone know what might be wrong? More generally, I'm a bit mystefied by the "<Graph, double EdgeProp::*>::type" syntax -- can anyone give me any pointers about what this syntax means, or where I can look it up? (googling for colon-colon-star doesn't help much). I also tried pattern-matching from the documentation page about bundled properties (the weight_map(get(&Highway::miles, map)) example) but couldn't get this to compile either. Is this example correct? Thanks very much in advance, Alex

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Boost multiindex: Usage of erase
by Ramesh 05 Jan '09

05 Jan '09

Hello Joaquin, I am trying to erase members of a container selectively, I get a compile error (no matching function found) at the point where I use erase (highlighted line) below: Could you please point out whats wrong with the usage? Thanks /Ramesh Here is the code: ------------- struct MyMap { Adapter *pAdapter; unsigned long timestamp; MyMap(Adapter * param_Adp, unsigned long param_timestamp ): pAdapter(param_Adp), timestamp(param_timestamp) {} ~MyMap(){ pAdapter = 0; timestamp = 0; } }; struct pAdapter{}; struct timestamp{}; typedef multi_index_container< MyMap, indexed_by < ordered_unique< tag <pAdapter>, BOOST_MULTI_INDEX_MEMBER(MyMap, Adapter *, pAdapter) >, ordered_unique< tag <timestamp>,BOOST_MULTI_INDEX_MEMBER(MyMap, unsigned long, timestamp) > > > tMap; class ACtr { private: tMap AContainer; public: // Constructor ACtr(); //Destructor ~ACtr(); //Remove stale bool pruneBad(); }; bool ACtr::pruneBad { for ( tMap::index_iterator<timestamp>::type it = AContainer.get<timestamp>().begin(), it_end = AContainer.get<timestamp>().end();it != it_end; count++) { it = AContainer.erase(it); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ } } ----

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Re: [Boost-users] [Proto] automaitcally convert class to proto literal
by Daniel Oberhoff 05 Jan '09

05 Jan '09

Joel Falcou wrote: > Daniel Oberhoff a écrit : > > Hi, > > > > I am stilly trying o get my array computation DSEL up and running. > > The basic grammar is in place, what I am fighting with is protfying my > > literals. I.e. I have an array class, and I want the following > > expression: > > > > A(_i,_j) > > > > to become a function(literal<Array>(A), index_placeholder<0>, > > index_placeholder<1>) > Why A should be a litteral and not terminal ? I might have gotten the terms wrong. But the way I got it working now is with using proto::lit which turns things into literals. I tried subclassing terminal with my array class, but that way the tree did not keep a reference to the array, and thus could not be evaluated as such. Subclassing literal did not work because I did not find a way to actually have the literal take a reference to the array itself. I could of course use a placeholder syntax, and pass in the actual arrays at evaluation time but I want expressions to work "in-place", i.e. I want to be able to write A(_i,_j) = B(_i) * C(_j); and that to just be evaluated as it stands there. Enabling placeholders could be a useful feature, but that would be relatively easy to add. -- --- Daniel Oberhoff Fraunhofer FIT Schloss Birlinghoven 53754 Sankt Augustin, Germany Tel.: +49-(0)-2241-14-3486 Fax.:+49 (0) 2241/14-2080

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Bus error side effect from boost::logging
by Allen Cronce 05 Jan '09

05 Jan '09

I'm tracking down an intermittent bus error under Mac OS X 10.5.6 that happens when formatting a double as a string. The crash can happen when outputting to a stream, when calling printf, or when using boost::format. Of course the crash only happens in our release build, which always makes things more fun ;-) Here's a sample routine that can trigger the bus error in our unit test: --snip-- int TestDoubleFormatBusError(void) { std::cout << "\nTesting double format problem..." << std::endl; uint64_t testMicroseconds = 100000; double delta = 179; double percentOff; percentOff = (delta / testMicroseconds) * 100; std::cout << percentOff; // <-- This is where the crash sometimes happens. return 0; } --snip-- I'm pretty sure that there's nothing wrong with the above code, but I'm open to suggestions. After binary chopping, I determined that the crash only happens after invoking John Torjo's experimental boost::logging. If I disable logging, the problem goes away. Has anyone seen this problem? John, do you have any suggestions for understanding and resolving the crash? Thanks in advance. Best, -- Allen Cronce

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Re: [Boost-users] Compile error OSX Callback problem for
by Bill McLean 04 Jan '09

04 Jan '09

Marshall, Thanks for the reply. You have touched upon an issue that I'm not sure how to solve. The general problem is how to use boost::function and boost::bind to register a member callback function for a c style library. A proxy function that has signature of the c callback function and the correct instance of the class containing the member function to call. Any thoughts or approaches to solve it. Bill

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Re: [Boost-users] Boost.Lambda: failure to compile with std::set, OK withstd::vector, bug?
by Anders Dalvander 04 Jan '09

04 Jan '09

> Hi, > > Compiling the code below with std::vector goes OK, the std::set variant does not compile: > > All elements in a std::set are const, so you need to make the print member function const: struct Integer { Integer(int anInt) : integer(anInt){} bool operator<( const Integer& anInteger) const { return integer < anInteger.integer;} void print() const {std::cout << integer << std::endl;} int integer; }; Regards, Anders Dalvander

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[Proto] automaitcally convert class to proto literal
by Daniel Oberhoff 04 Jan '09

04 Jan '09

Hi, I am stilly trying o get my array computation DSEL up and running. The basic grammar is in place, what I am fighting with is protfying my literals. I.e. I have an array class, and I want the following expression: A(_i,_j) to become a function(literal<Array>(A), index_placeholder<0>, index_placeholder<1>) (simplified for readability, but the point should be clear). it works like this: proto::lit(A)(_i,_j) so how can I automate the turning of my array instance into a literal? I have access to the class definition and I tried subclassing terminal and literal and the PROTO_EXTENDS macro. The former two had no effect on my problem, and the latter didn't compile ( I tried various combindations of Expr and Derived parameters). Any ideas? Daniel

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packaging boost-1.37.0 for "LTIB"?
by Robert P. J. Day 04 Jan '09

04 Jan '09

i want to package the latest version of boost for the LTIB software package so, to make a long story short, here's the RPM packaging spec file for an older version: =========================== cut here ============================ %define pfx /opt/freescale/rootfs/%{_target_cpu} %define __unzip unzip -a Summary : c++ libraries Name : boost Version : 1.31.0 Release : 1 Vendor : Freescale Packager : Stuart Hughes Group : System Environment/Libraries Source : %{name}_1_31_0.tar.bz2 Patch0 : boost-1.31.0-regex-patch-20040503.zip License : Boost (distributable) BuildRoot : %{_tmppath}/%{name} %Description %{summary} %Prep %setup -n %{name}_1_31_0 cd $RPM_BUILD_DIR/%{name}_1_31_0/boost/regex/v4 %{__unzip} -o $RPM_SOURCE_DIR/boost-1.31.0-regex-patch-20040503.zip %Build %Install rm -rf $RPM_BUILD_ROOT mkdir -p $RPM_BUILD_ROOT/%{pfx}/%{_prefix} (cd tools/build/jam_src && ./build.sh) BJAM=`find tools/build/jam_src/ -name bjam -a -type f` PYTHON_VERSION=`python -V 2>&1 |sed 's,.* $[0-9]\.[0-9]$$\.[0-9]$\?.*,\1,'` PYTHON_FLAGS="-sPYTHON_ROOT=%{_prefix} -sPYTHON_VERSION=$PYTHON_VERSION" $BJAM $PYTHON_FLAGS -sTOOLS=gcc -sBUILD="debug release" --prefix=$RPM_BUILD_ROOT/%{pfx} %{_prefix} install %Clean rm -rf $RPM_BUILD_ROOT %Files %defattr(-,root,root) %{pfx}/* ==================== cut here ================= so, a couple short questions that might save me some time before i dig into the source: 1) does 1.37.0 still require a "regex" patch? apparently, the patch mentioned above was to address some regex issues identified after 1.31.0 was released? i'm ready to assume that anything that significant has been resolved since then. 2) i'm also assuming that JAM is required for that final packaging step so that part of the spec file is still relevant. in other words, other than dropping the regex patch and updating the version number, does the above spec file look about right for 1.37.0? i'm about to give it a try. thanks. rday -- ======================================================================== Robert P. J. Day Linux Consulting, Training and Annoying Kernel Pedantry: Have classroom, will lecture. http://crashcourse.ca Waterloo, Ontario, CANADA ========================================================================

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