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[tree] associative containers
by Cromwell Enage 03 Nov '11

03 Nov '11

I've been studying the tree proposal to see how I could write adaptors in my tree_node library (now at version 0.2 in the sandbox) that conform to the current concepts. Is there anything in the proposal that is analogous to a PairAssociativeContainer? My tree_node library defines an AssociativeTreeNode concept and a couple of models that I've found to be useful, e.g. for implementing decision tree learning algorithms. Cromwell D. Enage

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[1.48][math] Permission to merge to release branch
by John Maddock 03 Nov '11

03 Nov '11

I'd like to merge this Clang fix to release if possible: https://svn.boost.org/trac/boost/changeset/75152 The change basically just moves code from one header to another, so it's defined at the point of first use. Thanks, John.

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[BGL] How to provide a vertex_index property for my graph
by ShNaYkHs ShNaYkHs 03 Nov '11

03 Nov '11

Hello, Since my graph use setS as a VertexList, I have to either provide a vertex_index property map for my graph to be able to use some functions requiring a vertex_index (e.g. write_graphviz). My graph is defined as: typedef adjacency_list<setS, setS, undirectedS, NodeData, EdgeData> Graph; Where NodeData and EdgeData are structures. Can you please give me a very simple example of how to provide a vertex_index property map for my graph ? I mean, since an adjacency_list that uses listS or setS as the vertex container does not automatically provide this vertex_id property, how can I add it to the code bellow ? I tried to use an associative_property_map to include index for vertices, but it doesn't work (errors): #include <boost/graph/iteration_macros.hpp> #include <boost/graph/adjacency_list.hpp> using namespace std; using namespace boost; struct NodeData { int label; float influance; /* etc ... */ }; struct EdgeData { int age; /* etc ... */ }; typedef map<vecS, size_t> IndexMap; IndexMap mapIndex; associative_property_map<IndexMap> propmapIndex(mapIndex); typedef adjacency_list<setS, setS, undirectedS, NodeData, EdgeData> Graph; typedef Graph::vertex_descriptor NodeID; typedef Graph::edge_descriptor EdgeID; int main() { Graph g; NodeID n0 = add_vertex(g); g[n0].label = -1; NodeID n1 = add_vertex(g); g[n1].label = -1; EdgeID edge; bool ok; tie(edge, ok) = boost::add_edge(n0, n1, g); if (ok) g[edge].age = 10; int i=0; BGL_FORALL_VERTICES(v, g, Graph) { put(propmapIndex, v, i++); } return 0; } Thanks for answer.

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Boost.Algorithm design question
by Marshall Clow 03 Nov '11

03 Nov '11

So, what do people prefer (and why?): template<typename InputIterator, typename V> bool none_of_equal ( InputIterator first, InputIterator last, V const &val ) { for ( ; first != last; ++first ) if ( val == *first ) return false; return true; } or template<typename InputIterator, > bool none_of_equal ( InputIterator first, InputIterator last, iterator_traits<InputIterator>::value_type const &val ) { for ( ; first != last; ++first ) if ( val == *first ) return false; return true; } In the first case, I think there's (possible) conversion from V to iterator_traits<InputIterator>::value_type each time through the loop. In the second case, there is not. Of course, the (mythical?) smart compiler would do the conversion once and save the result for reuse. -- Marshall Marshall Clow Idio Software <mailto:mclow.lists@gmail.com> A.D. 1517: Martin Luther nails his 95 Theses to the church door and is promptly moderated down to (-1, Flamebait). -- Yu Suzuki

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[1.48.0 Beta 1][fusion] MacTypes.h conflict with nil
by Jeff Flinn 03 Nov '11

03 Nov '11

reposted from "[1.48.0] Beta 1 is now available from SourceForge" thread for better visibilty. Mac 10.6 Xcode 3.2.6 gcc 4.2: In compiling our application, upgrading from boost_1_44_0 I get conflicts with MacTypes.h define of nil when compiling cons_fwd.hpp from fusion. Any thoughts? Jeff

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Interest in boost.deepcopy
by Allan Johns 02 Nov '11

02 Nov '11

Just gauging initial interest in a boost.deepcopy library, analogous to deepcopy in python. Each type would register deepcopy behaviour with the library (there are similarities to boost.serialize). Boost.deepcopy would supply out-of-the-box registration for pod types, pointer types, arrays, stl containers and common boost containers. Example: template<typename T> void deepcopy(deepcopycontext& ctxt, const T& obj) { ...; } Why not use boost::serialize and serialize into memory then out again I hear you say? That's a great approach, but only when every object requires the same deepcopy behaviour (also, it's not too optimal). The problem is, I need specific behaviour in some types. Specifically, I need copy-on-write behaviour for a Buffer class that I'm using. For example: void deepcopy(deepcopycontext& ctxt, const Buf& b) { if(!ctxt.contains(&b)) { Buf b2(b); // doesn't copy the buf data, just holds a shared ptr internally. Data is only cloned when b/b2 is written to ctxt.insert(&b, b2); } } I attempted to model this a while ago using boost.serialize, but it turned out pretty clunky, I started needing a few decorator classes for special cases, etc. Apologies for the oversimplified examples above, just wanting to get interest in the jist of it. Please let me know if this overlaps with existing boost functionality also (I'm not aware of anything atm). Feedback appreciated. Thx, Allan

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[ratio] Request for permission to merge to release branch
by Vicente J. Botet Escriba 02 Nov '11

02 Nov '11

Hi, I want to merge https://svn.boost.org/trac/boost/changeset/75240 to the release branch. The modifications are minor and correct to tickets: https://svn.boost.org/trac/boost/ticket/5724 and https://svn.boost.org/trac/boost/ticket/6082. Best, Vicente

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[multi_array] Ticket#4874 "multi_array compile errors using Visual C++ 2010 in debug mode"
by Stephan T. Lavavej 02 Nov '11

02 Nov '11

Hi Boost devs, VC10 users are occasionally encountering https://svn.boost.org/trac/boost/ticket/4874 and reporting it to MS. For example, see http://connect.microsoft.com/VisualStudio/feedback/details/687655/compilati… where I've explained what's going on (I wrote this analysis back in Feb 2010 and I believe it's still correct): The problem is that multi_array iterators report themselves as input iterators, which can't be written to (e.g. as the destination of a copy()). Under IDL=0, copy() doesn't actually care how its destination iterator is marked with an iterator category tag, it just tries to write to the destination iterator, and that works. Under IDL > 0, copy() wants to know whether its source and destination iterators are both random-access, in which case it can perform a range check and unwrap the destination iterator for increased performance. It does this by overloading foo(input_iterator_tag, output_iterator_tag) and foo(random_access_iterator_tag, random_access_iterator_tag) and calling foo(category(source), category(destination)). If both source and destination are random-access, both overloads are viable (i.e. callable) and the second overload is preferred, so it's actually called. Otherwise, source is required to be at least an input iterator (maybe stronger) and destination is required to be at least an output iterator (maybe stronger) so the first overload must be viable and the second overload will be non-viable, so the first overload wins by default. However, if the destination is not marked as an output iterator or stronger, then the first overload is non-viable as well as the second, so overload resolution fails and boom. Thanks, Stephan T. Lavavej Visual C++ Libraries Developer

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boost mapped_file issue
by dophine 02 Nov '11

02 Nov '11

Hi all, I try to use memory map file. However, I don't know why the readsome return 0. It is fine if I use getline. int main(int argc,char *argv[]) { boost::iostreams::mapped_file_source source(argv[1]); boost::iostreams::stream<boost::iostreams::mapped_file_source> input(source); while(!input.eof()) { char b[1]; streamsize iRet = input.readsome(b, 1); cout << iRet << endl; cout << b[iRet]; } //std::string line; //while(std::getline(input, line)) { // std::cout << "Line: " << line << std::endl; //} return 1; } -- View this message in context: http://boost.2283326.n4.nabble.com/boost-mapped-file-issue-tp3971495p397149… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[locale] Premission to merge clang bugfix changeset to release tree
by Artyom Beilis 02 Nov '11

02 Nov '11

Hello, I'd like to ask a permission to merge a changeset 75174 from trunk to release tree. It is a fix of build issue under clang-2.9 and clang-3.0. See: https://svn.boost.org/trac/boost/changeset/75174 The changeset itself: ------------------------- Index: /trunk/libs/locale/src/posix/codecvt.cpp =================================================================== --- /trunk/libs/locale/src/posix/codecvt.cpp (revision 73382) +++ /trunk/libs/locale/src/posix/codecvt.cpp (revision 75174) @@ -135,5 +135,5 @@ // maybe illegal or may be double byte - char inseq[3] = {seq0 , begin[1], 0}; + char inseq[3] = { static_cast<char>(seq0) , begin[1], 0}; char *inbuf = inseq; size_t insize = 3; ------------------------- It solves build issues as I can see at trunk tests. Thanks, Artyom Beilis -------------- CppCMS - C++ Web Framework: http://cppcms.sf.net/ CppDB - C++ SQL Connectivity: http://cppcms.sf.net/sql/cppdb/

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[atomic] comments
by Tim Blechmann 01 Nov '11

01 Nov '11

hi helge and others, ... has been rather quiet about the boost.atomic review, so i want to raise a view issues: shared memory support: the fallback implementation relies on the spinlock pool that also used by the smart pointers. however this pool is per-process, so the fallback implementation won't work in shared memory. can this be changed/fixed? atomic::is_lock_free(): is_lock_free is set to either `true' or `false'. however in some cases, there are alignment constraints (iirc, 64bit atomics on ia32/x86_64 require a 64bit alignment). afaict there are not precautions to take care of this, are there? compile-time vs run-time dispatching: some instructions are not available on every CPU of a specific architecture. e.g. cmpxchg8b or cmpxchg16b are not available on all ia32/x86_64 cpus. i would appreciate if these instructions would not be used before performing a CPUID check, whether these instructions are really available (at least in a legacy mode) cmpxchg16b: currently cmpxchg16b doesn't seem to be supported. this instruction is required for some lock-free data structures (e.g. there is a dequeue algorithm, that requires a pair of tagged pointers). maybe this can be a starting point to discuss boost.atomic ... cheers, tim

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Re: [boost] [atomic] comments
by Helge Bahmann 01 Nov '11

01 Nov '11

> > > > > e.g. i would not trust on accessing sockets from a > > > > > real-time thread. > > > > > > > > what makes you believe that message channels in real-time systems > > > > were > > > > designed so dumb as to make them unusable for real-time purposes? > > > > > > life would be so much easier for me, if the users of my software would > > > not run on off-the-shelf operating systems ;) > > > > and what makes you believe that the performance characteristics of > > sockets in off-the-shelf operating systems is unsuitable for real-time, > > while the process scheduling characteristics of process scheduling in > > off-the-shelf operating systems is suitable for real-time? > > i cannot comment on windows, but both osx and linux provide ways to > schedule a thread at a priority that it won't be preempted by any other > thread, so the process scheduler won't interfere. that answers the second part but not the first (and is getting off-topic from atomic operations) > > > > right, but the standard implementation for gcc does not use a > > > > spinlock > > > > per object (see __atomic_flag_for_address) which turns all of this > > > > moot - there is NO guarantee for std::atomic to be safe > > > > interprocess, period> > > > > > > well, i'd say this is a problem of gcc's implementation of std::atomic. > > > this doesn't justify that boost.atomic does not follow the suggestion > > > of the standard. > > > > the standard says "should" not "must" -- the gcc guys have not made this > > decision without good reasons, and I agree with these reasons > > > > note that there is also trouble lurking with run-time selection of > > whether something like atomic<uint64_t> is atomic via cmpxchg8b: do you > > really want to make this at minimum 12 bytes in size (though effectively > > occupying 16 due to alignment) just to save the room for the > > rarely-if-ever used per-object spinlock? same with atomic<128> and > > cmpxchg16b ? > > i don't really care about the size of an atomic<>. but I *do* care and believe it or not there are people writing applications that are memory-bound (doubling the overhead of the reference count in each of several millions of objects is *not* funny) > one other point for > runtime selection is compatibility. e.g. you may have two binaries, one is > compiled with support for double-width CAS, the other one without. with > compile-time dispatching the behavior would be undefined, with run-time > selection, it would be handled gracefully ... I don't quite understand the point -- quite obviously nothing good will happen if the applications do not agree on a protocol, and there is nothing that can be salvaged if they do agree on the objects being lock-free, fine if they do agree on the objects not being lock-free, well then explicit locking is faster anyways and you should use your "locked" reference implementation of the data structure that you surely wrote to run suitable regression tests of your lock-free data structure > > 2. What is wrong with implementing boost::interprocess::atomic<T> that > > specializes to boost::atomic<T> when possible and uses an interprocess > > lock otherwise? > > will you provide an implementation? people were asking for > boost::interprocess support during the boost.lockfree review. the only > missing feature is the atomic<> implementation. no problem Best regards Helge

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[config] clang.hpp is not up-to-date
by Michel Morin 01 Nov '11

01 Nov '11

boost/config/compiler/clang.hpp is not up-to-date. For example, BOOST_NO_AUTO_DECLARATIONS is *always* defined (even if clang supports this feature). Is it worth fixing this on the release branch? P.S. I can make a patch, but before doing that I'd like to confirm whether __has_feature(cxx_auto_type) means that multi-declarator auto is supported or not. The following page says nothing about multi-declarator auto. http://clang.llvm.org/docs/LanguageExtensions.html Doug? Regards, Michel

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Silly Boost.Locale default narrow string encoding in Windows
by Alf P. Steinbach 01 Nov '11

01 Nov '11

When I engage the compiler-in-my-mind to the example given at http://cppcms.sourceforge.net/boost_locale/html/ namely <code> #include <boost/locale.hpp> #include <boost/filesystem/path.hpp> #include <boost/filesystem/fstream.hpp> int main() { // Create and install global locale std::locale::global(boost::locale::generator().generate("")); // Make boost.filesystem use it boost::filesystem::path::imbue(std::locale()); // Now Works perfectly fine with UTF-8! boost::filesystem::ofstream hello("שלום.txt"); } </code> then it fails to work when the literal string is replaced with a `main` argument. A conversion is then necessary and must be added. It breaks the principle of least surprise. It breaks the principle of not paying for what you don't (want to) use. I understand, from discussions elsewhere, that the author(s) have chosen a narrow string encoding that requires inefficient & awkward conversions in all directions, for political/religious reasons. Maybe my understanding of that is faulty, that it's no longer politics & religion but outright war (and maybe that war is even over, with even Luke Skywalker dead or deadly wounded). However, I still ask: why FORCE INEFFICIENCY & AWKWARDNESS on Boost users -- why not just do it right, using the platforms' native encodings. Cheers, - Alf

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[unordered] 1.48 beta1 fails to compile with MSVC 2010 SP 1, error C2027: use of undefined type 'boost::type'
by Johan Lindvall 01 Nov '11

01 Nov '11

After trying out beta 1, I am seeing some failures with unordered containers, see attached file. Microsoft (R) C/C++ Optimizing Compiler Version 16.00.40219.01 for x64 The code compiles without problems under 1.47.0. Unfortunately, I cannot yet publish the source code that triggers this problem. Any hints where to start investigating this? -- /Johan.

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[multi_array] typed subarray from raw memory
by Maxim Yanchenko 01 Nov '11

01 Nov '11

Hi, While using multi_array, I found I frequently need a way to view some memory which is a multi-dimensional array and I don't know the type of the element, but I know its size and I know that this element has a member of the type I need (and I know the offset). So I need to be able to write something like struct A { double x, y; }; void* p = mmap(...); size_t el_size = size_of_element_in_p; size_t offset = offset_of_A_inside_element; boost::multi_array_typed_view<A, NumDims> my_view(p, extents, el_size, offset ); and have a standard multi_array-compatible interface. Also, with existing multi_arrays of known types, this feature will give a way to create views of element's members (the closest we have now is a strided view but it only works if the element size is a multiple of the member size). I filed a Feature Request for multi_array (https://svn.boost.org/trac/boost/ticket/6073) but I wonder if there are any other possibilities around, and I'd also like to know what the community think of necessity of this feature. Thanks, Maxim

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Re: [boost] [Tokenizer] Compile error with lots of missing binary operator statments
by Collin Day 31 Oct '11

31 Oct '11

Previously, I had posted what I thought was a bug. I did not think to do this originally, but I just tried a simple Hello World program that included boost/tokenizer.hpp. It compiled fine. I then looked at where the sample code was pulling headers from, and it appears that the download included old boost headers it was including instead of 1.47.0. I completley missed this. I apologize - and take back the error - there is none :) Thanks!

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[Tokenizer] Compile error with lots of missing binary operator statments
by Collin Day 31 Oct '11

31 Oct '11

Hi all, make[1]: Entering directory `/home/collin/projects/Cpp/plugins/PluginFramework/projects/plugin_framework' mkdir -p build/Debug/GNU-Linux-x86 g++ -c -g -DPF_PLATFORM_LINUX -DAPR_DECLARE_STATIC -DAPU_DECLARE_STATIC -I../../include/ -I../../include/darwin86 -I.. -o build/Debug/GNU-Linux-x86/Path.o Path.cpp In file included from ../../include/boost/mpl/apply.hpp:23:0, from ../../include/boost/iterator/iterator_facade.hpp:34, from ../../include/boost/iterator/iterator_adaptor.hpp:15, from ../../include/boost/token_iterator.hpp:21, from ../../include/boost/tokenizer.hpp:20, from Path.cpp:4: ../../include/boost/mpl/apply_wrap.hpp:81:31: error: missing binary operator before token "(" ../../include/boost/mpl/apply_wrap.hpp:173:31: error: missing binary operator before token "(" In file included from ../../include/boost/mpl/bind.hpp:27:0, from ../../include/boost/mpl/lambda.hpp:18, from ../../include/boost/mpl/apply.hpp:25, from ../../include/boost/iterator/iterator_facade.hpp:34, from ../../include/boost/iterator/iterator_adaptor.hpp:15, from ../../include/boost/token_iterator.hpp:21, from ../../include/boost/tokenizer.hpp:20, from Path.cpp:4: ../../include/boost/mpl/apply_wrap.hpp:81:31: error: missing binary operator before token "(" ../../include/boost/mpl/apply_wrap.hpp:173:31: error: missing binary operator before token "(" In file included from ../../include/boost/mpl/lambda.hpp:18:0, from ../../include/boost/mpl/apply.hpp:25, from ../../include/boost/iterator/iterator_facade.hpp:34, from ../../include/boost/iterator/iterator_adaptor.hpp:15, from ../../include/boost/token_iterator.hpp:21, from ../../include/boost/tokenizer.hpp:20, from Path.cpp:4: ../../include/boost/mpl/bind.hpp:364:31: error: missing binary operator before token "(" ../../include/boost/mpl/bind.hpp:531:31: error: missing binary operator before token "(" In file included from ../../include/boost/mpl/lambda.hpp:22:0, from ../../include/boost/mpl/apply.hpp:25, from ../../include/boost/iterator/iterator_facade.hpp:34, from ../../include/boost/iterator/iterator_adaptor.hpp:15, from ../../include/boost/token_iterator.hpp:21, from ../../include/boost/tokenizer.hpp:20, from Path.cpp:4: ../../include/boost/mpl/aux_/full_lambda.hpp:230:31: error: missing binary operator before token "(" In file included from ../../include/boost/iterator/iterator_facade.hpp:34:0, from ../../include/boost/iterator/iterator_adaptor.hpp:15, from ../../include/boost/token_iterator.hpp:21, from ../../include/boost/tokenizer.hpp:20, from Path.cpp:4: ../../include/boost/mpl/apply.hpp:138:31: error: missing binary operator before token "(" make[1]: *** [build/Debug/GNU-Linux-x86/Path.o] Error 1 make[1]: Leaving directory `/home/collin/projects/Cpp/plugins/PluginFramework/projects/plugin_framework' make: *** [.build-impl] Error 2 I looked on the web, and everything that looks remotley like this said it was a problem with GCC > 4.4, but was fixed in boost 1.37. I have tried with both gcc 4.4.6 and 4.5.3. I don't think I am missing anything since it is just an include file, but I could be wrong. any help would be appreciated. I tried the boost users mailing list with no luck after a couple of days. This is a more detailed example - it looks as though the same problem repeats for many files. Would it be appropriate to file a bug if I can't find any answers here? Thanks!

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[math][distributions] superfluous checking of parameters?
by Thijs (M.A.) van den Berg 31 Oct '11

31 Oct '11

The boost math distributions check validity of distribution the same parameters multiple times. E.g. in normal.hpp, class normal_distribution, the constructor, normal_distribution(RealType mean = 0, RealType sd = 1) : m_mean(mean), m_sd(sd) { // Default is a 'standard' normal distribution N01. static const char* function = "boost::math::normal_distribution<%1%>::normal_distribution"; RealType result; detail::check_scale(function, sd, &result, Policy()); detail::check_location(function, mean, &result, Policy()); } however, those are *again* checked in e.g. the pdf() non member function inline RealType pdf(const normal_distribution<RealType, Policy>& dist, const RealType& x) { ... if(false == detail::check_scale(function, sd, &result, Policy())) { return result; } ... } Why is that? It's done in a consistent way across all distributions. Can we remove the check inside the non member functions that are already checked in the constructor?

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[proto] Recent (rvalue support) changes in proto causes a whole bunch of regressions in Spirit
by Joel de Guzman 31 Oct '11

31 Oct '11

Hi, This code: #include <boost/spirit/include/qi.hpp> int main() { namespace qi = boost::spirit::qi; qi::rule<char const*> r; r %= (+qi::char_); return 0; } no longer works as expected. r %= (+qi::char_) becomes a no-op. Before it calls either: template <typename Expr> friend rule& operator%=(rule& r, Expr const& expr); // non-const version needed to suppress proto's %= kicking in template <typename Expr> friend rule& operator%=(rule& r, Expr& expr); Both defined in the rule class. Correct me if I'm wrong, but it seems the changes in proto forces us to support rvalue refs, but we are not ready for that yet and it's too late in the release cycle. Thoughts? Regards, -- Joel de Guzman http://www.boostpro.com http://boost-spirit.com

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[c++1] BOOST_NOEXCEPT macros?
by Beman Dawes 31 Oct '11

31 Oct '11

Since Boost already has BOOST_NO_NOEXCEPT and at least one compiler (GCC) supports C++11 noexcept, I'd like to start using it in Boost code. So how about a <boost/detail/noexcept.hpp> header with the usual boilerplate and this: #ifndef BOOST_NO_NOEXCEPT # define BOOST_NOEXCEPT # define BOOST_NOEXCEPT_IF(Predicate) #else # define BOOST_NOEXCEPT no_except # define BOOST_NOEXCEPT_IF(Predicate) no_except(Predicate) #endif As was pointed out in a previous thread, there isn't any reliable C++03 alternative for either of these two, so nothing is attempted, and that's OK in C++03 code. We could also define BOOST_NOEXCEPT_OPERATOR(Predicate), and have it fall back to true in C++03 code. I'm not expert enough to know if that is reliable or even useful, so am not proposing it. Comments? --Beman

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[interprocess] native Windows cond_var + mutex
by Dan Brown 31 Oct '11

31 Oct '11

Hi, Attached is a patch to implement interprocess_condition and interprocess_mutex natively on Windows. Following are some detailed notes. I hope this isn't too awkward of a time for a submission like this - I realize there's a lot of 1.48 activity going on. One more note about the patch - IIRC, some patch utils won't create directories. This patch is intended to be applied to boost/interprocess and relies on a new directory boost/interprocess/sync/win32. Background I started out by looking at http://www.cs.wustl.edu/~schmidt/win32-cv-1.html. This appears to be from the late '90s and is the basis for ACE's cond_var implementation. The solution in section 3.4 is arguably the most correct implementation. However, this solution relies on the atomicity of SignalObjectAndWait(). SOAW() may have been atomic for unicore systems common at the time but from what I've read is not atomic for multicore (it prevents context switches on a single core but ignores concurrent threads on other cores), and win32 documentation backs this up. While the paper argues that this leads to unfairness, I don't think the solution is correct without this atomicity. Wait/signal/wait problem One problem that I came across is what I'll call the wait/signal/wait problem. Setting the state, thread 1 is waiting on a condition and thread 2 has just completed cond_signal. Without an atomic SOAW(), thread 1 may release the external mutex without obtaining the associated semaphore. Another thread, thread 3, may obtain the external lock and find the cond_var signaled and behave correspondingly. This I believe is incorrect - a waiter which obtains the external mutex after the signaler has exited signal()should not find cond_var signaled. This situation is unlikely but it makes assumptions about the scheduler that I am not comfortable with. If there's a flaw in my reasoning hopefully someone will point that out. This solution This solution is structurally somewhat similarly to the paper's solution. One point to note is that notify_one()/signal() blocks on an event in the same manner as notify_all()/broadcast(). There may be a solution which does not block the signaler while wake-processing is occurring, but I saw additional complexity on that path and decided to forgo it for the time being. I hope the solution is correct but have only testing to validate. I haven't used any formal methods to back it up. Maybe I'll construct a Petri net sometime. That's always .. fun. I throw this solution on the mercy of the court. External mutex I have yet to see production examples of cond_var use where signalers do not hold the external mutex while they signal, but this use case is allowed by POSIX. My original solution (if it is in fact a solution) relies on some particular external mutex being held by all waiters and signalers for some particular condition variable. I recently added two mutexes to solve that situation but I have only minimal testing experience with that recent addition. Use of these new locks is demarcated with WIN32_POSIX_SEMANTICS. Interprocess vs. Intraprocess I'm not sure if there is support for process-specific synchronization objects in boost.interprocess, but if support is present or was added at some future time this could help optimize things for win32. At the moment win32 interprocess mutexes rely on assigning random names to mutexes (only named mutexes can cross platform boundaries in win32), and all mutex operations have to look up the mutex by this name. Interprocess seems to have been designed primarily with pthreads in mind, and things get a little awkward on Windows in this regard. Similarly, it would be nice to be able to use the native condition variables that win32 added for Vista+, but these can't be used across processes according to the documentation, and so can't be used AFAICT for inteprocess_condition. Correspondingly, an intraprocess_mutex would be able to forgo the win32 mutex name lookups. Miscellaneous Not all interprocess tests currently pass. There are some additional variations of mutex like the upgradable/sharable, etc., that I haven't looked at in detail. I'm hoping that this patch goes far enough that it'll have some momentum. I'm happy to either complete this work in the future or help whoever undertakes the task, but I may not be able to justify much of my time to the task in the short term to my employer. I realized a little too late that I didn't keep formatting entirely consistent with the existing code. Apologies. Hopefully it's only the opening block curlies. Thanks. Dan

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[C++ Now! 2012] Call for Submissions
by Brian Wood 30 Oct '11

30 Oct '11

Hartmut Kaiser: > The C++ Now! Conference is dedicated to discussion and education > about C++, an open and free language and standard. It costs a lot to buy a copy of the standard now! Hope conference goes well and maybe I can attend someday. -- Brian Wood Ebenezer Enterprises http://webEbenezer.net

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[BGL] How to provide a vertex_index property for my graph
by ShNaYkHs ShNaYkHs 30 Oct '11

30 Oct '11

Hello, Since my graph use setS as a VertexList, I have to either provide a vertex_index property map for my graph to be able to use some functions requiring a vertex_index (e.g. write_graphviz). My graph is defined as: typedef adjacency_list<setS, setS, undirectedS, NodeData, EdgeData> Graph; Where NodeData and EdgeData are structures. Can you please give me a very simple example of how to provide a vertex_index property map for my graph ? I mean, since an adjacency_list that uses listS or setS as the vertex container does not automatically provide this vertex_id property, how can I add it to the code bellow ? I tried to use an associative_property_map to include index for vertices, but it doesn't work (errors): #include <boost/graph/iteration_macros. hpp> #include <boost/graph/adjacency_list.hpp> using namespace std; using namespace boost; struct NodeData { int label; float influance; /* etc ... */ }; struct EdgeData { int age; /* etc ... */ }; typedef map<vecS, size_t> IndexMap; IndexMap mapIndex; associative_property_map<IndexMap> propmapIndex(mapIndex); typedef adjacency_list<setS, setS, undirectedS, NodeData, EdgeData> Graph; typedef Graph::vertex_descriptor NodeID; typedef Graph::edge_descriptor EdgeID; int main() { Graph g; NodeID n0 = add_vertex(g); g[n0].label = -1; NodeID n1 = add_vertex(g); g[n1].label = -1; EdgeID edge; bool ok; tie(edge, ok) = boost::add_edge(n0, n1, g); if (ok) g[edge].age = 10; int i=0; BGL_FORALL_VERTICES(v, g, Graph) { put(propmapIndex, v, i++); } return 0; } Thanks for answer.

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[C++ Now! 2012] Call for Submissions
by Hartmut Kaiser 30 Oct '11

30 Oct '11

INAUGURAL C++ NOW! CONFERENCE 2012 Aspen CO, USA, May 14-18, 2012, www.cppnow.org CALL FOR SUBMISSIONS We invite you to submit session proposals to the Inaugural C++ Now! Conference: C++Now! 2012 (Aspen CO, USA, May 14 - 18, 2012). Based on the successful traditions of 5 years of BoostCon, which was the main face-to-face event for all things C++ and Boost (www.boost.org) C++Now! 2012 will present leading speakers from the whole C++ community. The conference name is changing to C++ Now! to reflect the current value of the language, the focus on its new state (from the new Standard), and the need to continually look to the future so the language remains useful to the C++ community. The focus of this conference will be the new C++11 language Standard and as usual Boost: what's new in C++, its Standard library, and in the Boost libraries, how to write and maintain them, how to evangelize or to deploy Boost within your organization. The new C++ Standard, but also the infrastructure and process of Boost, its vision and mission - no matter what you are interested in, it all comes together in the C++Now! sessions. Meet the colleagues, and feel the inspiration to support your work with C++ and Boost for the next year. The C++ Now! Conference is dedicated to discussion and education about C++, an open and free language and standard. Our Conference will focus on discussion and education about open source software usage and developments in the C++ developer and user community. To reflect the breadth of the C++ and Boost communities, the conference includes sessions aimed at three constituencies: C++ and Boost end-users, hard-core Boost library and tool developers, and researchers pushing the boundaries of computation. The program fosters interaction and engagement within and across those groups, with an emphasis on hands-on, participatory sessions. As a multi-paradigm language, C++ is a melting pot where the most compelling ideas from other programming communities are blended in powerful ways. Historically, some of the most popular sessions at C++Now! have highlighted these concepts, from DSLs to functional programming to transactional memory and more. Bring your C#, Python, Ruby or Haskell influences to bear in an environment that will broaden their exposure. IMPORTANT DATES New proposal submissions due: January 10th, 2012. Proposals decisions sent (tentative program available): February 17th, 2012. Fully scheduled program available: February 25th, 2012. Session materials due: April 15th, 2012. BEST PRESENTATION AWARDS We know how much effort it takes to prepare talks for our conference. For this reason we will award the best presentations in the following categories: Best Presentation, Best Short Presentation, Best Tutorial, and Best Workshop. The awards will be given based on the audience's voting. Each award will include the author's name listed on the cover of the C++Now! website for that year and a plaque containing all the C++Now! conference information. SESSION TOPICS Topics of interest include, but are not restricted to, the following: * C++11 and how it changes life for users and library writers * General tutorial sessions on C++11, the C++11 Standardslibrary, and one or more Boost libraries * In-depth sessions on using specific Boost libraries * Case studies on using Boost * Experts panels * Advanced sessions on implementation techniques used within Boost libraries * Development workshops to extend or enhance existing Boost libraries * Workshops on design process * Infrastructure workshops such as Build tools, Website, Testing * Concepts and Generic Programming * Hardware and infrastructure presentations focused on how libraries can make better use of the technology * Software development tools and their application to C++ and or Boost * Other topics likely to be of great interest to Boost users and developers Interactive and collaborative sessions are encouraged, as this is the style of learning and participation that has proven most successful at such events. Sessions can be tutorial based, with an emphasis on interaction and participant involvement, or workshop based, whether hands-on programming or paper-based, discussion-driven collaborative work. SESSION FORMATS Presentations Presentations focus on a practitioner's ideas and experience with anything relevant to C++11, Boost and users. Panels Panels feature three or four people presenting their ideas and experiences relating to C++11 and Boost's relevant, controversial, emerging, or unresolved issues. Panels may be conducted in several ways, such as comparative, analytic, or historic. Tutorials Tutorials are sessions at which instructors teach conference participants specific skills relevant to C++11 and Boost. Workshops Workshops provide an active arena for advancements in Boost-relevant topics. Workshops provide the opportunity for experienced practitioners to develop new ideas about a topic of common interest and experience. Author's Corner These were introduced at BoostCon 2008, and were a great Presentations success They are short (30 minute) sessions, focusing on tips on usage and design. In addition, we're looking to uncover the hidden design gems in Boost libraries. Tool Vendors We actively encourage tool vendors and ISP's to submit Presentations proposals for a special Tool Vendors Session Track aimed at products related to Boost and C++ (compilers, libraries, tools, etc.). Other formats may also be of interest. Don't hold back a proposal just because it doesn't fit into a pigeonhole. SUBMITTING A PROPOSAL Standard Sessions are 60 minutes. You may submit a proposal for fractions or multiples of 90-minutes. Fractional proposals will be grouped into 60 minute sessions covering related topics. Longer sessions, such as tutorials and classes, will be assigned 90 minute, three hour (i.e. half day), or six hour (i.e. full day) time slots. Please include: * The working title. * Type of session: presentation, panel, tutorial, workshop, authors corner, vendor track, other. * A paragraph or two describing the topic covered, suitable for the conference web site. * Proposed length: 10-20 minute short talks, 45 minutes, 90 minutes, half day, full day. * Alternate lengths, if you are willing to make adjustments: 10- 20 minute short-talks, 45 minutes, 90 minutes, half-day, full day. * Audience: users, developers, both. * Level: basic, intermediate, advanced. * A biography, suitable for the conference web site. * Your contact information (will not be made public). SUBMISSION DETAILS All submissions should be made through the EasyChair conference management system: http://www.easychair.org/conferences/?conf=cppnow2012. If you have not already registered at EasyChair, you will need to do so in order to submit your proposal. All submissions will go through a peer review process. Authors are invited (but are not required) to submit PDF versions of full papers of up to 10 pages in ACM conference proceedings format (see http://www.acm.org/sigs/publications/proceedings-templates) The full papers are not required unless you want them published in the proceedings. All accepted proposals will be made available in the Association for Computing Machinery (ACM) Digital Library (approval pending). Best papers, after further reviews, will be considered to be book chapters or journal articles in a renowned journal. The session materials go on the C++Now! website and will be available to attendees. For general information on the C++Now! 2012 paper submission or the scope of technical papers solicited, please refer to the conference website at www.cppnow.org. For any other questions about the submission process or paper format, please contact the Program Committee at cppnow2012(a)easychair.com. If you have any technical problems with EasyChair, please contact EasyChair for help. Note: Presenters must agree to grant a non-exclusive perpetual license to publish submitted materials, either electronically or in print, in any media related to C++ Now!. Hartmut Kaiser, email: hartmut.kaiser(a)gmail.com (Program Committee Chair) Dave Abrahams, email: dave(a)boostpro.com (Conference Chair) On behalf of the conference organizers

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