September 2004 - Boost - lists.boost.org

[Python] Slice test fails on Intel 8.1 at runtime
by Stefan Slapeta 23 Oct '06

23 Oct '06

This is not a new failure, but the failure is reported for the first time. Please could anybody have a look at it? See http://tinyurl.com/4n2fx Thanks, Stefan

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New implementation of remove_xxx for vintage compilers
by Peder Holt 28 Mar '06

28 Mar '06

Hi. I have started implementing some of the missing type_traits functionality for vintage compilers using typeof. The following are complete, and seem to work flawlessly on VC 6.5 and 7.0: remove_pointer remove_reference remove_bounds The source is available at: http://groups.yahoo.com/group/boost/files/typeof_vintage.zip The use of typeof in this respect, makes remove_xxx much more flexible. Would it be possible to start using this scheme for compilers without partial template specialization support? #define BOOST_MAX_TYPEOF_SIZE 20 #include <boost/test/minimal.hpp> //Include typeof_define.hpp in all header files where new types are added to typeof. #include <boost/typeof/typeof_define.hpp> #include <complex> #include <boost/type_traits/remove_reference.hpp> #include <boost/type_traits/remove_pointer.hpp> #include <boost/type_traits/remove_bounds.hpp> #include <boost/type_traits/is_same.hpp> template<typename A0> struct X {}; template<typename A0,unsigned int A1> struct Y {}; template<typename A0,typename A1,long A2> struct Z {}; BOOST_TYPEOF_DEFINE_TEMPLATE(X,1,(typename)) BOOST_TYPEOF_DEFINE_TEMPLATE(Y,2,(typename,unsigned int)) BOOST_TYPEOF_DEFINE_TEMPLATE(Z,3,(typename,typename,long)) BOOST_TYPEOF_DEFINE_TEMPLATE(std::complex,1,(typename)) int test_main(int, char*[]) { BOOST_TEST((boost::is_same<X<int>* const[8][9],boost::remove_bounds<X<int>* const[5][8][9]>::type>::value)); BOOST_TEST((boost::is_same<Z<X<double&>,Y<bool[4][7],12324>,0>* const*,boost::remove_pointer<Z<X<double&>,Y<bool[4][7],12324>,0>* const**volatile>::type>::value)); //VC7.1 fails to compile remove_reference. BOOST_TEST((boost::is_same<Y<int,345>** const,boost::remove_reference<Y<int,345>** const&>::type>::value)); typedef BOOST_TYPEOF(5.+std::complex<double>(6,7)) result_type; BOOST_TEST((boost::is_same<result_type,std::complex<double> >::value)); return 0; } -- Peder Holt

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RE: [boost] Call for Volunteers: the Synopsis project
by Stefan Seefeld 30 Mar '05

30 Mar '05

Hi Volodya, > From: Vladimir Prus [mailto:ghost@cs.msu.su] > Sent: September 30, 2004 03:04 > Count me as interested. Are you going to base that parser on > OpenC++, which, > IIRC, was used by Synopsis some time ago? Last time a looked > at OpenC++, it > did not even distinguish between ordinary names and > typenames, which makes me > wonder if it's a good parser. You are right, there remains a lot of work to be done. The C++ parser backend of synopsis which we are talking about here is indeed based on OpenC++, but has already undergone lots of improvements. In its original design the parser didn't contain any form of semantic analysis such as symbol lookup to disambiguate certain expressions. For what it had been used so far it was good enough. I'm now working on the features that allow it to get closer to the standard, i.e. constant expression evaluation, symbol (type) lookup, etc. As I said, any help would be very appreciated ! Regards, Stefan

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Name checking in filesystem
by Walter Landry 08 Dec '04

08 Dec '04

Greetings, I have come across an annoying problem with the filesystem library. I have wrapped filesystem with Swig so that I can call it from python. I had to rewrite the filesystem::path implementation a little because Swig can't handle nested classes. In any case, once I got that sorted out, I wanted to do something like p=path(".bar") which doesn't work because filenames starting with a period are not allowed by the default name checking routine. Argh. Unfortunately, I can't figure out how to change the default name checker from python. If I worked at it long enough, I could probably work it out. But I am sure that I don't want to have to run something like path.default_name_check(no_check) at the beginning of every 10 line script. It is a particular piece of functionality (name checking) that just gets in the way. I would wager that most people using boost::filesystem from scripts would not want to have to deal with it, since it is completely different from every other portable, cross platform filesystem API. So to make a long story short, I think the default for boost::filesystem should be not to check for "portable" paths. This is different from a position I took earlier, where I thought that it is ok if I only have to set it once at the beginning. That is acceptable for large programs, but not for small ones. Regards, Walter Landry wlandry(a)ucsd.edu

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[graph] non-recursive version of undirected_dfs
by Synge Todo 24 Nov '04

24 Nov '04

Dear Boosters, I'm posting a non-recursive version of undirected_dfs, which should have advantages in space and time over the current implementation based on recursion, especially for huge graphs. It's a direct counterpart of the non-recursive version of depth_first_search for digraphs. I have confirmed that libs/graph/example/undirected_dfs.cpp as well as my own programs using undirected_dfs reproduce the identical outputs as those with the original recursive version. Best regards, Synge *** boost/graph/undirected_dfs.hpp 6 Aug 2004 05:02:41 -0000 1.1.1.1 --- boost/graph/undirected_dfs.hpp 19 Aug 2004 05:11:32 -0000 1.2 *************** *** 28,38 **** --- 28,106 ---- #define BOOST_GRAPH_UNDIRECTED_DFS_HPP #include <boost/graph/depth_first_search.hpp> + #include <vector> namespace boost { namespace detail { + // Define BOOST_RECURSIVE_DFS to use older, recursive version. + // It is retained for a while in order to perform performance + // comparison. + #ifndef BOOST_RECURSIVE_DFS + + template <typename IncidenceGraph, typename DFSVisitor, + typename VertexColorMap, typename EdgeColorMap> + void undir_dfv_impl + (const IncidenceGraph& g, + typename graph_traits<IncidenceGraph>::vertex_descriptor u, + DFSVisitor& vis, + VertexColorMap vertex_color, + EdgeColorMap edge_color) + { + function_requires<IncidenceGraphConcept<IncidenceGraph> >(); + function_requires<DFSVisitorConcept<DFSVisitor, IncidenceGraph> >(); + typedef typename graph_traits<IncidenceGraph>::vertex_descriptor Vertex; + typedef typename graph_traits<IncidenceGraph>::edge_descriptor Edge; + function_requires<ReadWritePropertyMapConcept<VertexColorMap,Vertex> >(); + function_requires<ReadWritePropertyMapConcept<EdgeColorMap,Edge> >(); + typedef typename property_traits<VertexColorMap>::value_type ColorValue; + typedef typename property_traits<EdgeColorMap>::value_type EColorValue; + function_requires< ColorValueConcept<ColorValue> >(); + function_requires< ColorValueConcept<EColorValue> >(); + typedef color_traits<ColorValue> Color; + typedef color_traits<EColorValue> EColor; + typedef typename graph_traits<IncidenceGraph>::out_edge_iterator Iter; + typedef std::pair<Vertex, std::pair<Iter, Iter> > VertexInfo; + + std::vector<VertexInfo> stack; + + put(vertex_color, u, Color::gray()); + vis.discover_vertex(u, g); + stack.push_back(std::make_pair(u, out_edges(u, g))); + while (!stack.empty()) { + VertexInfo& back = stack.back(); + u = back.first; + Iter ei, ei_end; + tie(ei, ei_end) = back.second; + stack.pop_back(); + while (ei != ei_end) { + Vertex v = target(*ei, g); + vis.examine_edge(*ei, g); + ColorValue v_color = get(vertex_color, v); + EColorValue uv_color = get(edge_color, *ei); + put(edge_color, *ei, EColor::black()); + if (v_color == Color::white()) { + vis.tree_edge(*ei, g); + stack.push_back(std::make_pair(u, std::make_pair(++ei, ei_end))); + u = v; + put(vertex_color, u, Color::gray()); + vis.discover_vertex(u, g); + tie(ei, ei_end) = out_edges(u, g); + } else if (v_color == Color::gray()) { + if (uv_color == EColor::white()) vis.back_edge(*ei, g); + ++ei; + } else { // if (v_color == Color::black()) + ++ei; + } + } + put(vertex_color, u, Color::black()); + vis.finish_vertex(u, g); + } + } + + #else // BOOST_RECURSIVE_DFS + template <typename IncidenceGraph, typename DFSVisitor, typename VertexColorMap, typename EdgeColorMap> void undir_dfv_impl *************** *** 69,74 **** --- 137,145 ---- } put(vertex_color, u, Color::black()); vis.finish_vertex(u, g); } + + #endif // ! BOOST_RECURSIVE_DFS + } // namespace detail template <typename Graph, typename DFSVisitor,

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Any interest in a boost::glob() function?
by Angus Leeming 24 Nov '04

24 Nov '04

Dear all, I've taken Richard Johnson's glob_iterator that he posted to the list back in January and re-written it completely, using Boost.Spirit to transform the input 'glob' into an equivalent regex. The result is a 'boost::glob' function that I believe is fully POSIX-conformant. Example usage: fs::path const starting_directory("."); std::list<fs::path> const matches = boost::glob("../te?t/foo*bar", starting_directory); The docs can be browsed online at http://www.devel.lyx.org/~leeming/globbing/index.html The library can be found at http://www.devel.lyx.org/~leeming/globbing.zip It should unzip to give: boost/glob.hpp boost/detail/glob.hpp libs/glob + ensuing sub directories and files. The code has been tested on Linux (g++ 3.3.2) and on Windows using MinGW/MinSys. There are still a few "issues" that I don't know how to resolve. Any pointers would be most welcome. DOCS ==== * It would be nice to insert a table inside an itemized list item, but quickbook doesn't like doing that. I need to add a separate paragraph. * boostbook/doxygen fails to document the glob_flags enum. * I generate a BOOST_LIB_NAME.html page and would like not to. BUILD ===== I have a couple of targets, lib/glob/example/real_glob.cpp and lib/glob/test/test_real_glob.cpp that I'd like to build only on POSIX machines. (They're wrappers for the system glob function.) Any pointers on how to instruct bjam to do that? REGEX ===== One test is failing on Windows "foo[[:alpha:]]bar". It works when compiled under Linux. Is there anything I should be aware of about Boost.Regex under MinGW/MinSYS? Regards, Angus

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Boost license
by Falk Hueffner 23 Nov '04

23 Nov '04

Hi, the boost license (http://www.boost.org/LICENSE_1_0.txt) does not allow redistributing modified versions. Is that intentional or an oversight? -- Falk

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RE: [boost] recursive mutex and condition
by Ben Hutchings 04 Nov '04

04 Nov '04

James Ahlborn <james.ahlborn(a)med.ge.com> wrote: > hey, > I was wondering if any of the boost developers could tell me > if recursive mutexes are supposed to work with conditions? I don't believe so. If waiting for a condition releases the mutex only once, this can result in deadlock, and if it releases the mutex completely the protected data can be seen while its invariant is broken. There seems to be no right way to use recursive mutexes with condition variables. <snip> > I'm testing this on red hat 7.3 and fedora core 2. My guess as to > why it's broken is because the boost condition uses posix recursive > mutexes There's no such thing. > internally, which also seem to fail the recursive mutex/condition > test (at least on the OS's mentioned above). Anyone have any > thoughts on this? <snip> I think you should avoid using recursive mutexes. Read <http://groups.google.com/groups?selm=3434E6BA.ABD%40zko.dec.com>. Ben.

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RE: [boost] Re: recursive mutex and condition
by Ben Hutchings 04 Nov '04

04 Nov '04

James Ahlborn <james.ahlborn(a)med.ge.com> wrote: > > Ben Hutchings <ben.hutchings <at> businesswebsoftware.com> writes: > > > I don't believe so. If waiting for a condition releases the mutex > > only once, this can result in deadlock, and if it releases the mutex > > completely the protected data can be seen while its invariant is > > broken. There seems to be no right way to use recursive mutexes > > with condition variables. > > umm, using a condition fundamentally implies releasing a mutex and > then reacquiring it. regardless of the mutex type, one needs to make > sure that the invariants are valid when the mutex is released. Yes, I understand all this. <snip> > > I think you should avoid using recursive mutexes. Read > > <http://groups.google.com/groups?selm=3434E6BA.ABD%40zko.dec.com>. > > well, i've programmed significantly in both java and c++ and i think > the poster of that comment is mistaken on many fronts. besides the > obvious bias against java and the seemingly minimal knowledge of how > "synchronized" works in java, "Minimal knowledge"? Does that mean you think he's wrong in fact, or that his opinion about its usefulness is mistaken? > i think the fundamental argument of a recursive mutex being the "lazy > man's mutex" is wrong. In any moderately complex system, trying to > avoid using recursive mutexes adds complexity to the overall design > and eventually breaks the modularity of the system. As I understand it, your reason for using a recursive mutex would be that there are functions that require a weaker invariant and may safely be called from a function that holds the mutex and has broken the normal invariant, but may also be called without the mutex being held. (If a function requires the normal invariant then you need to re-establish that before calling it, and having done so you could safely unlock the mutex, removing the need for it to be recursive.) This means that responsibility for re-establishing the normal invariant for a recursive mutex is divided up between several functions. So how can the single function that waits on the condition re-establish the invariant? Wouldn't that require a gross breach of the modularity you want? <snip> > to return to boost specifically, the implementation of > recursive_mutex and condition seem to imply their combined use. I > see no documentation which says "hey, you should only use condition > with a normal mutex", nor any compiler error when i try to do so. > i see no "fundamental" reason why a recursive mutex and a condition > should not work together (they are quite happy in java). I do. > yet, they don't work, and I'm wondering if that is intended or a > bug in boost. It looks like a documentation bug to me.

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[boost][MPL] Numeric metafunctions protocol/infrastructure
by Cromwell Enage 24 Oct '04

24 Oct '04

Once Tropical Storm Jeanne passes away, I should be through with hurricanes for a while. The latest-and-greatest MPL looks great! The new ability to plug in custom numeric metatypes so that they work with existing numeric ops makes it a definite keeper. The part of my sub-library that I've updated to work with the new MPL is at <http://groups.yahoo.com/group/boost/files/mpl_math.zip>, and has been tested with MinGW 3.2 and MSVC 7.1 (2003 Toolkit). Renaming issues aren't too bad; I just have to remember (for one thing) that reverse_copy is defined at copy.hpp and not reverse_copy.hpp as I originally thought. I also noticed that BOOST_MPL_AUX_TYPEOF is no longer there, but I've managed to eliminate the need for it. A major issue I have is how to properly use numeric_cast in order to make something like the following statement work correctly: typedef plus<int_<1>,fraction_c<long,4,3> >::type fraction_7_over_3; Right now I've made N^2 specializations of plus_impl, where N here means the total number of built-in and custom numeric metatypes. For my sub-library, N==4, which means I've made 16 specializations of plus_impl alone! Factor in the comparison ops as well the arithmetic ops, and my code is starting to look bloated. I've supplied a couple of convenience macros to reduce the copy-and-pasting, but I still think I'm missing something crucial here, and I think that something is how to use (or specialize) numeric_cast. Pointers welcome! Cromwell Enage __________________________________ Do you Yahoo!? New and Improved Yahoo! Mail - 100MB free storage! http://promotions.yahoo.com/new_mail

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