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Re: [boost] [Bind] How do I get bind to deduce the return type of for_each?
by Thomas Jordan 17 Apr '10

17 Apr '10

> Message: 8 > Date: Thu, 15 Apr 2010 10:51:27 +0100 > From: "Sylvester-Bradley, Gareth" > <Gareth.Sylvester-Bradley(a)eu.sony.com> > To: <boost(a)lists.boost.org> > Subject: Re: [boost] [Bind] How do I get bind to deduce the return > type offor_each? > Message-ID: > <84883B934769D3428C4AE2E403B188800A1A0F9A(a)GBISE0BASMSX02.eu.sony.com> > Content-Type: text/plain; charset="us-ascii" > >> I have been trying to use Boost.bind to create an 'STL algorithm > function >> object' to pass into another, 'higher order,' STL algorithm (e.g., to > pass >> a for_each into a for_each). However, I am struggling to get bind to >> deduce the correct return type of the for_each function object. > > The following might help: > > http://www.boost.org/doc/libs/1_42_0/doc/html/lambda/le_in_details.html# > lambda.nested_stl_algorithms > > > Best regards, > Gareth > Thanks a lot for the suggestion, I did take a look at Lambda library, and I saw that it used some extra type information in its STL algorithm wrappers (the 'sig') to help it figure out the return types. However, I am against using the Lambda library for other reasons, I only want to use the bind library. I'd appreciate some specific advice on how to get the type deduction with the Boost.bind library. Or is this just not possible with Boost.bind?

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(no subject)
by Dan Jiang 16 Apr '10

16 Apr '10

Hi All, I have a question regarding CSR graph. Does anyone know if a CSR graph can be used as input to push_relabel_max_flow or edmonds_karp_max_flow algorithm in BOOST? The existing examples only use adjacency_list with the maximum flow algorithms. I need to use CSR graph with the max flow implementations, but do not know how and if it is feasible at all. If answer is yes, can anyone give a simple example? I am having trouble in setting capacity map and reverse_edge map in CSR before passing it to the max flow algorithms. -Thanks a lot for your time. Dan Jiang _________________________________________________________________ Live connected. Get Hotmail & Messenger on your phone. http://go.microsoft.com/?linkid=9724462

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[xint] Question about suitability, portability, and "Boostiness"
by Chad Nelson 16 Apr '10

16 Apr '10

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Right now, the XInt library uses a pointer to a (privately defined) struct. The struct has several items, including a small array of "quick digits" and a pointer to a dynamically allocated array of digit_t types, both for containing the magnitude of the integer. While trying to find a more efficient way to store things, I came up with this: struct new_data_t { size_t used, allocated; // (other data items) digit_t digits[1]; // Last item in the struct }; It's an old C trick, apparently legitimized in the C99 standard as the "struct hack". For those not familiar with it, the idea is that I'd allocate a single array of digit_t types, of the required size plus sizeof(new_data_t), then just typecast it as a pointer of type new_data_t. Does anyone know if there's any reason not to do this? Maybe some portability or alignment problem with it? - -- Chad Nelson Oak Circle Software, Inc. * * * -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkvD3ZQACgkQp9x9jeZ9/wQLdQCgklN2Xcs0mDAGhsy4n3TX/Bgw JVoAoK+/YEoawXT7Yd0R3++eWLPYZhjr =Jx8O -----END PGP SIGNATURE-----

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Re: [boost] How to construct a reverse_edge_map from CSR
by Dan Jiang 16 Apr '10

16 Apr '10

Hi Jeremiah, Here is the code for this error. Hope it is more readable. typedef compressed_sparse_row_graph<directedS> Traits; struct EdgeProp{ float capacity; float residual_capacity; Traits::edge_descriptor reverse_edge; }; typedef compressed_sparse_row_graph<directedS, property<vertex_index_t, DWORD32>, EdgeProp, // bundled property no_property, // Graph Property DWORD32, // Vertex Type DWORD32> // EdgeIndex Type BOOST_Graph; Errors: C:\Program Files (x86)\boost\boost_1_42\boost/graph/compressed_sparse_row_graph.hpp(1321) : error C2780: 'V boost::target(const incidence_graph_archetype<Vertex,Directed,ParallelCategory,Base>::edge_descriptor &,const boost::incidence_graph_archetype<Vertex,Directed,ParallelCategory,Base> &)' : expects 2 arguments - 1 provided C:\Program Files (x86)\boost\boost_1_42\boost/graph/graph_archetypes.hpp(64) : see declaration of 'boost::target' .\NetFlow.cpp(209) : see reference to function template instantiation 'std::pair<_Ty1,_Ty2> boost::edge<boost::directedS,boost::property<Tag,T>,EdgeProp,boost::no_property,unsigned int,DWORD32>(Vertex,Vertex,const boost::compressed_sparse_row_graph<Directed,VertexProperty,EdgeProperty,GraphProperty,Vertex,EdgeIndex> &)' being compiled with [ _Ty1=boost::detail::csr_edge_descriptor<size_t,size_t>, _Ty2=bool, Tag=boost::vertex_index_t, T=DWORD32, Vertex=unsigned int, Directed=boost::directedS, VertexProperty=boost::property<boost::vertex_index_t,DWORD32>, EdgeProperty=EdgeProp, GraphProperty=boost::no_property, EdgeIndex=DWORD32 ] C:\Program Files (x86)\boost\boost_1_42\boost/graph/compressed_sparse_row_graph.hpp(1321) : error C2780: 'Vertex boost::target(compressed_sparse_row_graph<Directed,VertexProperty,EdgeProperty,GraphProperty,Vertex,EdgeIndex>::edge_descriptor,const boost::compressed_sparse_row_graph<Directed,VertexProperty,EdgeProperty,GraphProperty,Vertex,EdgeIndex> &)' : expects 2 arguments - 1 provided Error line is: if (target(*range.first) == j) C:\Program Files (x86)\boost\boost_1_42\boost/graph/compressed_sparse_row_graph.hpp(1241) : see declaration of 'boost::target' C:\Program Files (x86)\boost\boost_1_42\boost/graph/compressed_sparse_row_graph.hpp(1321) : error C2780: 'Vertex boost::target(const boost::detail::edge_base<Directed,Vertex> &,const boost::adjacency_list<OutEdgeListS,VertexListS,DirectedS,VertexProperty,EdgeProperty,GraphProperty,EdgeListS> &)' : expects 2 arguments - 1 provided C:\Program Files (x86)\boost\boost_1_42\boost/graph/adjacency_list.hpp(530) : see declaration of 'boost::target' C:\Program Files (x86)\boost\boost_1_42\boost/graph/compressed_sparse_row_graph.hpp(1321) : error C2780: 'filtered_graph_base<G>::vertex_descriptor boost::target(filtered_graph_base<G>::edge_descriptor,const boost::filtered_graph_base<G> &)' : expects 2 arguments - 1 provided: Error line is: if (target(*range.first) == j) > > Could you please reformat your code to be more readable? What is the > exact type of your graph, and what are the definitions of the vertex and > edge bundled property classes? > > -- Jeremiah Willcock > _______________________________________________ > Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost _________________________________________________________________ Live connected. Get Hotmail & Messenger on your phone. http://go.microsoft.com/?linkid=9724462

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How to construct a reverse_edge_map from CSR
by Dan Jiang 16 Apr '10

16 Apr '10

Hi All, I am having difficulty in constructing a reverse_edge_map from an existing CSR. My CSR was created as "edges_are_unsorted", I need to create a reverse_edge_map out of it? Here is my attempt:1 BGL_FORALL_EDGES(e, g, BOOST_Graph)2 {3 // Get source and target of the edge4 BOOST_Graph::vertex_descriptor src = boost::source(e, g);5 BOOST_Graph::vertex_descriptor dst = boost::target(e, g);678 // Get reverse edge9 graph_traits<BOOST_Graph>::out_edge_iterator ei, ei_end;10 for (tie(ei, ei_end) = edge_range(dst, src, g); ei != ei_end; ++ei) 11 {12 rev[*e] = *ei;13 break; // I know there is only one reverse edge in my graph14 } 15 } I got compile error on line 10: error C2784: 'std::pair<Config::out_edge_iterator,Config::out_edge_iterator> boost::edge_range(Config::vertex_descriptor,Config::vertex_descriptor,const boost::adj_list_helper<Config,Base> &)' : could not deduce template argument for 'const boost::adj_list_helper<Config,Base> &' from 'BOOST_Graph' where BOOST_Graph is a CSR graph that has been instantiated as "edges_are_unsorted" prior to the loop. Any help is appreciated. -Thanks, Dan _________________________________________________________________ Got a phone? Get Hotmail & Messenger for mobile! http://go.microsoft.com/?linkid=9724464

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Re: [boost] Crypto Proposal
by Chad Seibert 16 Apr '10

16 Apr '10

Hello, > Does this mean you will be converting the source-code of Botan to Boost > standards or you are going to wrap it? > 1. If it is conversions two issues may rise: > a) License Botan is licensed under BSD license with is different from > Boost and all the code you will write for boost would not have > correct license. > b) Conversion to Boost means fork... How do you expect to synchronize > changes in two libraries and most important security updates. > This means lots of work in the live cycle of Boost.Botan I'll fork it, as stated in my proposal (which I sent sometime after the abstract). It'll be relicensed under BSL. As for synchronization, this will have to be done by hand (which I will do for some time). > Additional points: > - Botan uses GNU gmp library licensed under LGPL... Does it fit to > Boost licensing guidelines? It doesn't require gmp and is perfectly capable of working without it. It's available as a plugin, but a default implementation is already included. > - I think that you should be really specific what would be the advantage > of using Boost.Botan library over original Botan one or OpenSSL that > Boost.Asio uses. Here are some: * Tighter integration with Boost (ASIO, and possibly iostreams) * Some functions are considerable faster (such as RSA, which the maintainer purports to be several times faster than OpenSSL. SHA-1 is SSE2 optimized). * There is plugin support for OpenSSL, so ASIO would be modified to use the plugin system (which would use the default implementation or OpenSSL). > You might want to consider adding some discussion to your proposal about the > crypto library in the vault. What features are in the vault Crypto that > might be useful? That aren't useful? Why do you feel that Botan is a better > starting point. The crypto library in the vault contains mostly hash algorithms, which Botan already contains (and some of them e.g. SHA-1 have a SSE optimized version). And Botan contains better documentation and testing. Also, Botan was engineered mostly by a security expert, meaning it is likely to be more secure. It is also being maintained, so security and feature patches will be made. > Your proposal is very ambitious! IMHO, that's not doable in full over the > summer. If you trimmed it down into a more focused feature set (for instance > replacing SSL in ASIO, or adding TLS to ASIO) it would give you a more > realistic chance to finish what you are suggesting. It is very ambitious! But as I say in my draft, it'll be done in two parts. I don't think that porting is unrealistic for the summer part of the project. Many thanks for the feedback, Chad Seibert _________________________________________________________________ The New Busy is not the too busy. Combine all your e-mail accounts with Hotmail. http://www.windowslive.com/campaign/thenewbusy?tile=multiaccount&ocid=PID28…

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Re: [boost] Crypto Proposal
by Chad Seibert 16 Apr '10

16 Apr '10

Here's a response to a question asked on the private review system: The design and architecture is based on dynamic polymorphism, for better or worse. In the process of porting it to Boost.Botan, it would be made static. On the mailing list, someone created a simple project that creates a certificate and the exe grew from 40kb to 1mb. Having static polymorphism would solve this problem. Also, we won't have to pay the runtime penalties for dp (especially since it's not needed - something that Boost libraries have shown time and time again). Looking at other libraries under similar licenses yielded similar results. Crypto++ also uses DP (and has even larger hierarchies) and for simple uses, the entire library get's built and included with project. For example, http://www.cryptopp.com/docs/ref/class_s_h_a1.html. SP will solve this problem, and Botan uses less DP which should make it easier to convert. I couldn't find a valid libtomcrypt homepage, so I don't know how it's structured. The interface of Botan is simple and intuitive. Looking at their sample programs (and other samples), there doesn't seem to be a simpler method to implement the various techniques and still remain flexible. Crypto++ samples seem to be a bit difficult to digest, requiring manual creation of secure memory blocks and ugly dynamic casting. More can be seen here: http://www.cryptopp.com/wiki/Diffie-Hellman. All in all, Botan has a simpler interface and a DP hierarchy that shouldn't be (as) difficult to convert to SP. I wanted to compare against libtomcrypt, but couldn't find a valid implementation. An example of how something might get ported would be the following. Botan.AES_128 has the inheritance hierarchy Botan->SymmetricAlgorithm->BlockCipher->AES->AES_128. Writing this as SP would look like the following (if I understand SP correctly): Before: class SymmetricAlgorithm { void set_key(...) } class BlockCipher: SymmetricAlgorithm { virtual void encrypt(...) virtual void decrypt(...) } class AES: BlockCipher { void encrypt(...); void decrypt(...); } class AES_128: AES { } There is no reason for AES. I'd first remove that class and have AES_128 derive from BlockCipher directly. Converting this to SP yields (sorry, I don't have a compiler to test this atm): template<class BlockCipher> struct SymmetricAlgorithm { void set_key_impl() { static_cast<*BlockCipher>(this)->set_key(); } } template <class AES_128> struct BlockCipher: SymmetricAlgorithm<BlockCipher>{ void set_key(); //More stuff } However, there is one concern. SymmetricAlgorithm is the base class of three major hierarchies: BlockCipher, MessageAuthenticationCode, and StreamCipher. If this inheritance hierarchy stays, it will mean lot's of template metaprogramming (some of which I don't know how to do). In any case, it's easier to work with than Crypto++. For example, SHA1 in Crypto++ has a hierarchy depth of 9; Botan 5. Hope this answers some questions! Glad you are interested in my work! Chad Seibert _________________________________________________________________ The New Busy is not the old busy. Search, chat and e-mail from your inbox. http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:ON:…

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space complexity of push_relabel_max_flow
by Dan Jiang 16 Apr '10

16 Apr '10

Hi All, I am a new BOOST user and like it very much. I have a question regarding space complexity of push_relabel_max_flow. The push_relabel_max_flow is very efficient compared to Edmond's and Karp. In my application, I need to deal with half a million nodes and half a billion arcs. It requires lots of ram (>= 6gb). Two questions: 1) How do I find out space used per node and per arc? 2) My network does not need any reverse edge (currently I set the capacity of reverse edge to 0), is there anyway to not supply reverse edges to save space? 3) Does push_relabel_algorithm dynamically allocates lots of memory (besides the ram required by the input graph, i.e., adjacency_list)? 4) Is it possible to implement custom file-based edge lists so that I could explicitly page to disk when not enough ram is available? How slower would it be? Thanks, Dan Jiang _________________________________________________________________ Hotmail & Messenger. Get them on your phone now. http://go.microsoft.com/?linkid=9724463

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[Bind] How do I get bind to deduce the return type of for_each?
by Thomas Jordan 15 Apr '10

15 Apr '10

Hi, I have been trying to use Boost.bind to create an 'STL algorithm function object' to pass into another, 'higher order,' STL algorithm (e.g., to pass a for_each into a for_each). However, I am struggling to get bind to deduce the correct return type of the for_each function object. I include the relevant bits of the code below. class myClass { public: int func(){return mValue;} private: int mValue; }; //wrapper for STL for_each struct myForEach { template <typename II, typename F> F operator()(II begin, II end, F function) const { return std::for_each(begin, end, function); } }; typedef vector<myClass> vocType; typedef vector<vocType> vovType; //overloaded member functions vocType::begin & end typedef vocType::iterator (vocType::*fnPtr)(); typedef const vocType::iterator (vocType::*constFnPtr)() const; vovType vov(10, vocType(10, myClass())); main() { for_each(vov.begin(), vov.end(), bind< ? >(myForEach(), bind(static_cast<fnPtr>(&vocType::begin),_1), bind(static_cast<fnPtr>(&vocType::end),_1), protect(bind(&myClass::func, _1))) } I tried various things for bind<?>, but was only able to get the code to compile (eventually) on my Unix box when I substituted bind< boost::_bi::protected_bind_t<boost::_bi::bind_t<int, boost::_mfi::mf0<int, myClass>, boost::_bi::list1<boost::arg<1> (*)()> > > > for the bind<?>. I had guessed this might work from studying the compiler error messages. Obviously, this is not an ideal solution! Also, I only used the myForEach wrapper after having first attempted - and similarly failed - to bind the raw STL for_each. Is there any way I can help bind to deduce the correct return type - for either myForEach or std::for_each, or both? WIth Best Regards, Tom Jordan (Software Engineer)

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Permission to merge Interprocess/Intrusive bugfixes for 1.43 in release branch?
by Ion Gaztañaga 15 Apr '10

15 Apr '10

Hi, I know it's a bit late, but I would like to ask if it's possible to merge Interprocess/Intrusive bug-fixes from trunk to release. They've been in trunk for some weeks and tests are ok. Best, Ion

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