September 2021 - Boost - lists.boost.org

Can we create boost-config
by Sreeraj K 06 Sep '21

06 Sep '21

*[I initialially raised this question in https://github.com/boostorg/boost/issues/548 <https://github.com/boostorg/boost/issues/548>, but @mclaw recommended this mailing list.]* Similar to many other packages (eg: curl, krb5, pcre, xml2, xslt etc..), can we also ship boost-config that would provide the installation options ? We can probably start with something like this ? $ /usr/bin/boost-config --help Usage: boost-config [ options ] Options: --cflags print compiler options --ldflags print linker options --prefix print the boost prefix --version print the boost version --help print this usage summary $ /usr/bin/boost-config --version 1.66.0 $ /usr/bin/boost-config --cflags -I/usr/include $ /usr/bin/boost-config --ldflags -L/usr/lib64 -Wl,-R/usr/lib64 Thanks.

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[Asio] Propose optimization patch for QNX OS.
by Alex Steshkin 06 Sep '21

06 Sep '21

Hello, By default on QNX OS the select_reactor class is used, which uses the POSIX select() to wait for I/O and write to a pipe to interrupt the wait. Neither select() nor pipes are efficient on QNX OS. We propose to introduce new ionotify_reactor class for QNX OS, which uses ionotify() and pulses instead of select() and pipes. If you are interested in this patch please let me know how to proceed with it: - what repo and branch should I use for this patch? - what is mandatory test set should be done for this patch? - what documentation should be updated to reflect this patch? Thanks, Alex Steshkin ---------------------------------------------------------------------- This transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. Any use of this information by anyone other than the intended recipient is prohibited. If you have received this transmission in error, please immediately reply to the sender and delete this information from your system. Use, dissemination, distribution, or reproduction of this transmission by unintended recipients is not authorized and may be unlawful.

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Fwd: Reg, Boost lib dijkstra_shortest_paths for ECMP paths
by kathireswaran thanuskodi 06 Sep '21

06 Sep '21

Hi Team, I came across the boost lib to identify the shortest paths in an network using vertex/edge properties, and have using dijkstra_shortest_paths method with predecessor_map concept with that able to get the shortest path in the graph. Have a requirement like to know about multiple shortest paths also if present, for example below find the below network diagram with 4 edges, A ------- B | | | | D ------- C Edges -> (A,B), (A,D), (B,C), (C,D) with equal distance 1. With the predecessor_map as of now able to get path as A->B->C so that the parent of C is noted as B. In this example we have ECMP(equal cost multiple path) from src A to destination C, tried to search for existing lib to achieve fetching all the paths but unfortunately unable to identify the way. kindly guide how to get such kind of multiple path info with the existing library itself or not. If there exists how to get those info. *<code snip>* const int num_nodes = 4; enum nodes { A, B, C, D}; Edge edge_array[] = { Edge(A, B), Edge(B, C), Edge(A, D), Edge(C,D) }; int weights[] = { 1, 1, 1,1 }; int num_arcs = sizeof(edge_array) / sizeof(Edge); graph_traits<graph_t>::vertex_iterator i, iend; graph_t g(edge_array, edge_array + num_arcs, weights, num_nodes); property_map<graph_t, edge_weight_t>::type weightmap = get(edge_weight, g); // Manually intialize the vertex index and name maps property_map<graph_t, vertex_index_t>::type indexmap = get(vertex_index, g); property_map<graph_t, vertex_name_t>::type name = get(vertex_name, g); int c = 0; for (boost::tie(i, iend) = vertices(g); i != iend; ++i, ++c) { indexmap[*i] = c; name[*i] = 'A' + c; } vertex_descriptor s = vertex(A, g); property_map<graph_t, vertex_distance_t>::type d = get(vertex_distance, g); property_map<graph_t, vertex_predecessor_t>::type p = get(vertex_predecessor, g); dijkstra_shortest_paths(g, s, predecessor_map(p).distance_map(d)); std::cout << "distances and parents:" << std::endl; graph_traits < graph_t >::vertex_iterator vi, vend; for (boost::tie(vi, vend) = vertices(g); vi != vend; ++vi) { std::cout << "distance(" << name[*vi] << ") = " << d[*vi] << ", "; std::cout << "parent(" << name[*vi] << ") = " << name[p[*vi]] << std:: endl; } std::cout << std::endl; *<code snip>* *<output>* distances and parents: distance(A) = 0, parent(A) = A distance(B) = 1, parent(B) = A*distance(C) = 2, parent(C) = B <<<<<<<<<<<<<<<* distance(D) = 1, parent(D) = A Regards, Kathir

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Documentation is not updating since June 10
by Nikita Kniazev 03 Sep '21

03 Sep '21

https://www.boost.org/doc/libs/develop/doc/html/accumulators.html Last revised: June 10, 2021 at 02:32:49 GMT https://www.boost.org/doc/libs/master/doc/html/accumulators.html Last revised: June 10, 2021 at 15:48:57 GMT I thought it was related to the regression matrix not being updated but that was fixed while documentation is still stale.

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