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Compatibility problems BDS40 vs boost
by Christian Askeland 22 Apr '06

22 Apr '06

Hi all, I am running boost 1.33.1 with BDS 4.0, the Borland compiler. I upgraded to BDS Update pack 2 (released 2006/04/17) yesterday, and the two following lines/files failed to compile: #include <boost/iterator_adaptors.hpp> #include <boost/function.hpp> The code compiled without problems with Update 1. Have anyone else seen this? I'm no expert on compiler quirks, but I know that there are a few workarounds for the BCC compiler in boost. Maybe something has been changed. Regards, ---------------------------------- Christian Askeland ----------------------------------

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[Random] compiler issue with Visual Studio
by David Walthall 22 Apr '06

22 Apr '06

Hello, I am using Visual Studio 7.1.3008. While using the Random library, I ran into an issue with the seed function of mt19937. From what I can gather, the compiler becomes confused about one of the overloads and tries to call the seed function: template<class Generator> void seed(Generator & gen) I couldn't this issue on the list of known issues for this compiler. Is this known. For now, it appears that the work-around is to cast it as an unsigned long. Below is a small test file that demonstrates this issue. Thank you, David Walthall ////// boost_random_error.cpp ////// #include <boost/random/mersenne_twister.hpp> int main() { boost::mt19937 generator(42u); unsigned int uint = 42u; unsigned long int ulong = 42u; generator.seed(static_cast<unsigned int>(42u)); // ok generator.seed(42u); // ok generator.seed(static_cast<unsigned long>(uint)); // ok generator.seed(static_cast<unsigned int>(ulong)); // ok generator.seed(ulong); // ok // comment out the next lines to get it to compile generator.seed(static_cast<unsigned int>(uint)); // error generator.seed(uint); // error (also an error on g++ 3.4.4) return 0; } ////// end of boost_random_error.cpp //////

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[WAVE] bug: generic lexing error
by Andreas Sæbjørnsen 21 Apr '06

21 Apr '06

Using the wave driver reference implementation on the code found at: http://folk.uio.no/andsebjo/bugInducingCode.C I get the following error: bugInducingCode.C(10157): error: generic lexing error: '\000' in input stream This code compiles with g++ and if any line is cut within the file it does not fail with Wave. The code contains only C++ syntax so it is basically a test of the cpplexer. Is this a know problem? This problem occurs in both my two months old CVS version of boost and the 1.3.1 build. Regards, Andreas Saebjoernsen

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boost::function and free template function returning a dependent class template type
by Howard Gardner 21 Apr '06

21 Apr '06

/* This doesn't work. Is it supposed to? If "broken" returns a "ret< int >" or an "x", then it does seem to work right. In case it's a known compiler issue, I'm using: Comeau C/C++ 4.3.3 (Aug 10 2003 15:39:53) for _MS_WINDOWS_x86_Beta8 */ #include "boost/function.hpp" using namespace boost; #include<ostream> using namespace std; template< typename x > struct ret{}; template< typename x > ret< x > broken( x f ) { cout << f << endl; return ret< x >(); } int main() { // function1< ret< int >, int > func; same problem function< ret< int > ( int ) > func = broken< int >; func( 42 ); }

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BGL: std::map<Edge, int> needs the < operator
by Irek Szczesniak 21 Apr '06

21 Apr '06

I'm trying to have a std::map where the key is an edge of a graph, but I get a compilation error. My graph is: typedef boost::adjacency_list <vecS, vecS, undirectedS, property<vertex_name_t, std::string>, property<edge_weight_t, int, property<edge_weight2_t, int> > > Graph; And an edge: typedef graph_traits<Graph>::edge_descriptor Edge; Then I have a map: std::map<Edge, double> m; But when I try this: m[e] = 0 where e is of type Edge, then I get: /usr/lib/gcc/i386-redhat-linux/3.4.4/../../../../include/c++/3.4.4/bits/stl_function.h:227: error: no match for 'operator<' in '__x < __y' Can I use map with the Edge as the key type? If so, what should I do? Thanks for reading. Best, Irek

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[boost-build]error occured when building boost 1.33.1
by lanser 21 Apr '06

21 Apr '06

sorry, my gmail get something wrong, repeat: os: win2k + sp4 compiler: vc6 + sp6 boost 1.33.1 build with: E:\tmp\BOOST_~1>bjam -sTOOLS=msvc "-sMSVC_ROOT=f:\microsoft visual studio\vc98" --with-python-root=f:\python --prefix=f: \Boost --builddir=f:\Boost\build install > d:\boost-install.log i get some errors listed in boost-install.log, please tell me where's wrong, thanks a lot lanser ps: i compress "boost-install.log" with WinRAR 3.0

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[boost-users][build]where is *.lib or *.dll
by lanser 21 Apr '06

21 Apr '06

hi, i build boost under win2k os using bjam -sTOOLS=msvc --prefix=f:\boost --libdir=f:\boost\lib --includedir=f:\boost\include --builddir=f:\boost\build --with-python-root --with-pydebug install after building, i can only see f:\boost\include , where is f:\boost\lib ?? sincerely --szs

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a question about asynchronous I/O
by 李慧霸 21 Apr '06

21 Apr '06

I'm trying to start network programming with boost::asio library, and I come across a question: if I have issued multiple async_read to the same one socket, will the OS execute these IO command out of order? My platform is WinXPSP2+VC2003. lihuiba 2006-04-21

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Re: [Boost-users] BGL: std::map<Edge, int> needs the < operator
by Ovanes Markarian 21 Apr '06

21 Apr '06

Another way would be to implement a global less than operator overload. You can also implement this operator within a class, so that std::less_than is able to call it. Here are some examples... //gloabl operator overlaod sample class Edge { friend bool operator < (const Edge&, const Edge&); public: //your implementation private: //data members }; inline bool operator < (const Edge& e1, const Edge& e2) { return (e1.prop1 < e2.prop1) && (e1.prop2 < e2.prop2) && ...; } //implementig the comaprison operator in the class // if you don't want this operator to be accessible from other classes, // declare the std::less_than<Edge> as friend and make this operator protected class Edge { friend class std::less_than<Edge>; protected: inline bool operator <(const Edge& e) { return (prop1 < e.prop1) && (prop2 < e.prop2) && ...; } //your class implementation }; I do not say that this implementation is better then the one suggested by Dmitry, I would only like to show up all possiblities. Dmitri's implementation is more flexible in regards of compile time type calculations or if you don't have the source code of Edge. My implementation does not involve additional overhead required to create a function object for comparison and delegate comparison through it. In this case the object is only 1 byte big, but if you add additional fields to it memory usage will grow with every comparison. With Kind Regards, Ovanes Markarian > On Fri, April 21, 2006 10:41, Dmitry Bufistov said: >> I'm using the following for a couple of monthes. Seems to work. >> ////////////////////////////////////////// >> struct edge_less_than >> : public std::binary_function<edge_descriptor_t, edge_descriptor_t, >> bool> >> { >> bool operator()(const edge_descriptor_t& __x, >> const edge_descriptor_t& __y) const >> { >> //return __x.second.get_property() < __y.second.get_property(); >> //return &__x < &__y; >> return __x.get_property() < __y.get_property(); >> } >> }; >> >> You can do something better depending of what you need. Possible this >> will help >> http://lists.boost.org/boost-users/2004/08/7579.php >> Regards, >> --dima >> Thomas Costa wrote: >>> write your own total ordering/comparison function object for Edge >>> objects and declare the map type using this function. >>> >>> On Apr 20, 2006, at 7:55 PM, Irek Szczesniak wrote: >>> >>> >> >> >> > > > With Kind Regards, Ovanes Markarian

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Re: [Boost-users] [Graph] bundled properties and connected_components
by Detlef Mages 21 Apr '06

21 Apr '06

Hi, What you are missing is a color map. One solution is to use bundled properties: #include <boost/config.hpp> #include <vector> #include <map> #include <iostream> // for std::cout #include <algorithm> // for std::for_each #include <boost/utility.hpp> // for boost::tie #include <boost/graph/graph_traits.hpp> // for boost::graph_traits #include <boost/graph/adjacency_list.hpp> #include <boost/graph/connected_components.hpp> using namespace boost; struct Node { int index; //****color property****************************** boost::default_color_type m_algo_color; //****color property****************************** }; struct Boundary { double something; }; typedef boost::adjacency_list< boost::setS, boost::listS, boost::undirectedS, Node, Boundary, boost::setS> Graph; int main(int argc, char*argv[]) { Graph g(5); boost::graph_traits<Graph>::vertex_iterator vi, viend; std::vector< int > c( num_vertices(g) ); int num; // manually intialize the vertex index, // because we have listS as vertex list type int n = 0; for (tie(vi, viend) = vertices(g); vi != viend; ++vi, ++n) { g[*vi].index = n; } //****modified call****************************** num = connected_components(g, make_iterator_property_map(c.begin(), get(&Node::index, g)), boost::color_map( get(&Node::m_algo_color, g) )); //****modified call****************************** return 0; } Detlef

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