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[review] [sort] Sort library review manager results
by Edward Diener 27 Nov '14

27 Nov '14

This is the results from the recent review of the Sort library of Steven Ross. First I would like to thank all those who made comments during the review, whether or not they officially gave a final Yes or No vote to whether the Sort library should be accepted as a Boost library. This list includes: Niall Douglas, Julian Gonggrijp, Phil Endecott, Vladimir Prus, Mathias Gaunard, Jeremy Murphy, Peter Dimov, Robert Ramey, Adam Walling, Anthony Polukhin, Phil Endecott, Paul Bristow, Thijs (M.A.) van den Berg Dupuis Etienne, and Frank Gennari If I have missed anyone I do apologize. Secondly I would like to thank Steven Ross for patiently answering all of the review comments to the best of his ability. My tally of Yes and No votes for acceptance are: Yes votes (5) : Niall Douglas ( conditional ), Julian Gonggrijp ( conditional ), Frank Gennari, Phil Endecott, Paul Bristow. No votes (3) : Vladimir Prus, Adam Walling ( conditional ), Anthony Polukhin I believe the condtional Yes vote from Julian Gonggrijp was completely met in the discussions of issues with Steven Ross and the conditional Yes vote from Niall Douglas was almost completely met in the discussion with Steven Ross about the issues mentioned, and enough to maintain his Yes vote. I want to also mention that the conditional No vote by Adam Walling has an implied Yes vote to it if the Sort library were one among other sort implementations. Since my final decision is not entirely based on the Yes and No votes I want to adumbrate some of the major issues brought up by the review without necessarily focussing on every one of the people who brought them up initially, as well as my own reactions to them as Review Manager. 1) The first major issue was whether a library whose basic merit lies in its algorithm and its speed/space constraints needs better theoretical backing. A number of reviewers discussed this after it was brought up. I tend to agree with reviewers that while the best theoretical basis is always desirable, it is not necessary for a Boost library whose empirical evidence can be and has been measured by its implementor and can be measured by any user. Furthermore Steven Ross has provided an extensive discussion in his documentation, as well as his original paper, about the theoretical merits of his technique. While much of this discussion is probably beyond the understanding of any but sorting experts and afficionados enough of it adequately explains the basic ideas behind SpreadSort for those who understand and have knowledge of basic sorting ideas and popular sorting techniques. 2) An important issue is the need for the Sorting library to provide extensive timing charts/tables comparing SpreadSort to at least std::sort ( and possibly other popular mainstream sorts ) with both different numbers of sort keys and different initial unsorted distributions. Steven Ross has been providing these charts/tables in the 'develop' branch of the library. 3) Connected to the previous issue is that a number of reviewers asked for better documentation on the conditions in which SpreadSort will show a marked improvement in speed compared to std::sort, as well as any condition(s) where SpreadSort performs worse than std::sort. While Steven Ross has explained that generally SpreadSort will fall back to using std::sort for some cases ( low N ), I too feel that the documentation needs to be more extensive for the average user in attempting to delineate the conditions where SpreadSort works best. 4) A really important issue discussed by a number of reviewers involves the creation of a synthetic radix, where most users of sorting algorithm are used to comparison based sorting functors. While the documentation provides information on the various individual sorts, as well as examples, I also feel that a discussion in the documentation of how to use SpreadSort when sorting structs/classes with multiple keys of different types would be invaluable. In other words, what and if are the common techniques for using SpreadSort with complicated keys which, when using comparison-based sorting, can be represented fairly easily be a functor. 5) Niall Douglas brought up the issue of exception guarantees when using SpreadSort, and I concur. The documentation should be stronger specifying what happens during the sorting algorithms if an exception occurs and/or does the sorting algorithm itself ever throw any exceptions and, if so, under what conditions. Steven Ross mentioned that he is adding exception guarantee information to his docs. 6) Many reviewers did not like the idea that the library should be called Sort when it is basically implementing a single sorting algorithm called SpreadSort. Alternate suggestions are: a) The library should be called SpreadSort. b) The library can be called Sort only if other sorting algorithms are added to it. c) The library can be called Sort with the proviso that it serves as a general library for sorting algorithms potentially added to it in the future. d) The library should be part of the Boost Algorithm library. Steven Ross mentioned other potential sorting implementations as part of the Sort library, under that general name, but all providing a good deal of extra work. These included a copy-based stable sorting algorithm, an LSD radix sorting, and an OpenMP based parallel implementation. Other reviewers mentioned some of the same types of sorting implementations and a few reviewers remarked that they also have created sorting implementations of their own. While I will give my own view at the end, I would like to mention here that I strongly believe that each sorting implementation needs to be reviewed separately for acceptance into Boost and never automatically added to a general library, whether it be called Sort or Algorithm or whatever. 7) Random issues brought up in comments I will mention, which have importance but which I do not believe are absolutely intrinsic yet still might be considered. a) C++11 techniques in general and inline namespaces in particular. b) A version that can work with less than random access. c) Optimizations for small sets of data ( Steven Ross has already addressed this to an extent in the 'developer' branch of the library ). d) Possible documentation of using SpreadSort as a subsort for parallel sorting techniques and possible discusion in the docs about SpreadSort and parallel sorts. e) General O() information in docs. f) SpreadSort examples hoisted directly into docs using Quickbook technique and updating the Spreadort docs to use Quickbook. Review Result: Based on the voting for acceptance or not, based on the discussions during the review period, and based on Steven Ross's responses, I have decided that Steven Ross's library should be accepted into Boost. My main reason for my decision, aside from the votes and comments and specific issues discussed, is twofold: 1) There is a general consensus that Steven Ross has an excellent understanding of sorting techniques and algorithms and will support and refine his library for the benefit of programmers. 2) The empirical tests show that SpreadSort offers an improvement over std::sort, significantly in the area of large data sets, and this could be a major benefit to programmers. I do not know if the review manager has a say in this but based on the remarks of the reviewers I would like to see the library as accepted be named 'SpreadSort' rather than just 'Sort'. I do think that Boost can have a library called 'Sort' but I agree with the general consensus that a 'Sort' library needs more than one type of sorting algorithm. I would like to see other people, who mentioned in the reviews/comments that they have their own sorting implementation, also submit their own implementations to Boost and, if this happens and they are accepted, I can see combining them with 'SpreadSort' into a general Boost sorting library called 'Sort' in the future.

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Boost not compiling with arm-cross-compiler
by ustulation 27 Nov '14

27 Nov '14

{Ubuntu 14.04 64 bits, arm-g++ compiler 4.9 one that comes with google's ndk r10c) (The compiler has --sysroot pointing to platform android-14, and -march=armv7-a) on using arm cross-compiler for compiling boost I get the following error in "*socket_ops.ipp*": *<1> for all function (templates) of this type:* template <typename SockLenType> inline int call_getsockname(SockLenType msghdr::*, socket_type s, socket_addr_type* addr, std::size_t* addrlen) { SockLenType tmp_addrlen = (SockLenType)*addrlen; int result = ::getsockname(s, addr, &tmp_addrlen); *addrlen = (std::size_t)tmp_addrlen; return result; } /some-path/thirdparty/boost/boost_1_55_0_Android/boost/asio/detail/impl/socket_ops.ipp:1639: error: invalid conversion from 'int*' to 'socklen_t* {aka unsigned int*}' [-fpermissive] int result = ::getsockname(s, addr, &tmp_addrlen); ^ On changing the line to: int result = ::getsockname(s, addr, (socklen_t*)tmp_addrlen); it compiles fine ofcourse but i don't know if this is what is to be done. *<2> And in "mapped_region.hpp": /some-path/thirdparty/boost/boost_1_55_0_Android/boost/interprocess/mapped_region.hpp:49: error: sys/shm.h: No such file or directory # include <sys/shm.h> //System V shared memory... ^ * and points to: # if defined(BOOST_INTERPROCESS_XSI_SHARED_MEMORY_OBJECTS) # include <sys/shm.h> //System V shared memory... # endif in that file. Here are the flags in my user-config.jam file: using gcc : android : @AndroidNDKSrcDir@/bin/arm-linux-androideabi-g++ : <archiver>@AndroidNDKSrcDir@/bin/arm-linux-androideabi-ar <compileflags>-fexceptions <compileflags>-frtti <compileflags>-fPIC <compileflags>-std=c++11 <compileflags>-ffunction-sections <compileflags>-funwind-tables <compileflags>-D__ARM_ARCH_5__ <compileflags>-D__ARM_ARCH_5T__ <compileflags>-D__ARM_ARCH_5E__ <compileflags>-D__ARM_ARCH_5TE__ <compileflags>-Wno-psabi <compileflags>-march=armv5te <compileflags>-mtune=xscale <compileflags>-msoft-float <compileflags>-mthumb <compileflags>-Os <compileflags>-fomit-frame-pointer <compileflags>-fno-strict-aliasing <compileflags>-finline-limit=64 <compileflags>-I@AndroidNDKSrcDir@/include/c++/4.9 <compileflags>-Wa,--noexecstack <compileflags>-DANDROID <compileflags>-D__ANDROID__ <compileflags>-DNDEBUG <compileflags>-O2 <compileflags>-g <compileflags>-I@AndroidNDKSrcDir@/sysroot/usr/include <architecture>arm <compileflags>-fvisibility=hidden <compileflags>-fvisibility-inlines-hidden <compileflags>-fdata-sections <cxxflags>-D__arm__ <cxxflags>-D_REENTRANT <cxxflags>-D_GLIBCXX__PTHREADS ; *What is the way forward for those two errors - <1> and <2> above ?* -- View this message in context: http://boost.2283326.n4.nabble.com/Boost-not-compiling-with-arm-cross-compi… Sent from the Boost - Users mailing list archive at Nabble.com.

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[boost::accumulators::impl::immediate_mean_impl<Sample, Tag>::operator()<Args>] c++/cli
by It neophyte 26 Nov '14

26 Nov '14

Hi While computing a variance on my dataset, I end up with: error C2677: binary '+' : no global operator found which takes type 'System::Object ^const ' (or there is no acceptable conversion) The error message point to the line 65 of mean.hpp (see below piece of code). Can someone explain what's going wrong? Thanks template<typename Args> // line 59 void operator ()(Args const &args) //line 60 { // line 61 std::size_t cnt = count(args); // line 62 this->mean = numeric::fdiv( // line 63 (this->mean * (cnt - 1)) + args[parameter::keyword<Tag>::get()] // line 64 , cnt // line 65 ); // line 66 } // line 67 my code: #pragma once#include "stdAfx.h"#include "math.h"#include <boost/accumulators/accumulators.hpp>#include <boost/accumulators/statistics/stats.hpp>#include <boost/accumulators/statistics/variance.hpp> ..... accumulator_set< double, stats<tag::variance> > acc_variance; DataRow^i; for (int i=1;i-1<dbdataset->Rows->Count-1;i++){ dbdataset->Rows[i-1]["DataRet"]=log(System::Convert::ToDouble(dbdataset- >Rows[i-1]["Pop"])/System::Convert::ToDouble(dbdataset->Rows[i]["Pop"])); acc_variance(dbdataset->Rows[i-1]["DataRet"]); lblvol->Text = Convert::ToString(sqrt(variance(acc_variance))); }

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boost::filesystem::extension crashes on Linux
by Jürgen Simon 26 Nov '14

26 Nov '14

Hello, I have a crash with boost 1.56 that happens on SUSE Linux for me (uname -a : Linux r105b.meteo.uni-bonn.de 3.7.10-1.28-desktop #1 SMP PREEMPT Mon Feb 3 14:11:15 UTC 2014 (c9a2c6c) x86_64 x86_64 x86_64 GNU/Linux) The crash happens in filesystem::extension() when listing a file from the following directory: $ ls -la core total 29802736 drwxr-xr-x 2 simon users 4096 Nov 25 14:40 . drwxr-xr-x 7 simon users 4096 Nov 25 15:05 .. -rw-r--r-- 1 simon users 30517985568 Nov 14 2013 rico.out.xy.core.nc As you can see there’s only one file in there that ends on “.nc”. The following code crashes on Linux but works fine on OSX (with the same data): fs::path f = fs::path(source_path); std::string extension = fs::extension(f); The GDB backtrace is: #0 0x00007fffe09403d5 in raise () from /lib64/libc.so.6 #1 0x00007fffe0941858 in abort () from /lib64/libc.so.6 #2 0x00007fffe11438cd in __gnu_cxx::__verbose_terminate_handler() () from /usr/lib64/libstdc++.so.6 #3 0x00007fffe11419c6 in ?? () from /usr/lib64/libstdc++.so.6 #4 0x00007fffe11419f3 in std::terminate() () from /usr/lib64/libstdc++.so.6 #5 0x00007fffe1141c1e in __cxa_throw () from /usr/lib64/libstdc++.so.6 #6 0x00007fffe119336d in std::__throw_runtime_error(char const*) () from /usr/lib64/libstdc++.so.6 #7 0x00007fffe115e844 in std::locale::facet::_S_create_c_locale(__locale_struct*&, char const*, __locale_struct*) () from /usr/lib64/libstdc++.so.6 #8 0x00007fffe1153774 in std::locale::_Impl::_Impl(char const*, unsigned long) () from /usr/lib64/libstdc++.so.6 #9 0x00007fffe11547af in std::locale::locale(char const*) () from /usr/lib64/libstdc++.so.6 #10 0x00007ffff753036f in boost::filesystem::path::codecvt() () from /usr/local/lib/libboost_filesystem.so.1.55.0 #11 0x00007ffff75307ff in boost::filesystem::path::begin() const () from /usr/local/lib/libboost_filesystem.so.1.55.0 #12 0x00007ffff7530f88 in boost::filesystem::path::compare(boost::filesystem::path const&) const () from /usr/local/lib/libboost_filesystem.so.1.55.0 #13 0x00007ffff75310f4 in boost::filesystem::path::extension() const () from /usr/local/lib/libboost_filesystem.so.1.55.0 #14 0x0000000000448adb in boost::filesystem::extension (p=...) at /usr/local/include/boost/filesystem/convenience.hpp:36 Any ideas how to circumvent this problem? Jürgen

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[Boos-users][Boost.accumulators.Statistics.variance.hpp]: How to Compute Sample Volatility on data stored in DataTable
by It neophyte 26 Nov '14

26 Nov '14

Hi Do you know how can I compute a sample volatility of the returns held in a particular column of my db Datable? Any code illustration would be appreciated. Best,

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[accumulators->Statistics] How to Compute Sample Volatility_c++ Windows Form app
by It neophyte 25 Nov '14

25 Nov '14

Dear All Do you know how can I compute the sample volatility (sqrt(variance)) of the returns held in my Datable? For information, my db object contains a column "Return" which has been filled with values. DataTable^db=gcnew DataTable(); Thanks in advance Heron

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Re: [Boost-users] fusion: map
by MM 25 Nov '14

25 Nov '14

Hi, At the point of _defining_ a fusion::map, do the key types have to be known or can they just be forward declared at that point? Rds,

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Phoenix V2
by Mathieu Champlon 25 Nov '14

25 Nov '14

Hello, Has Phoenix V2 been removed from Boost 1.57 ? I used to be able to find it under boost/spirit/home/phoenix but it seems it's no longer the case. Thanks, MAT.

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Re: [Boost-users] lockfree::spsc_queue & move semantics
by Thomas Danckaert 24 Nov '14

24 Nov '14

From: Bjorn Reese <breese(a)mail1.stofanet.dk> Subject: Re: [Boost-users] lockfree::spsc_queue & move semantics Date: Mon, 10 Nov 2014 20:39:24 +0100 > On 11/09/2014 09:49 PM, Thomas Danckaert wrote: >> I'd like to use a spsc_queue of unique_ptr's to bigger objects, to >> transfer ownership between threads. That way, I can create/allocate an > > This limitation inherited from atomic, and I am afraid that it is a > bit more complicated than adding a move constructor. Fortunately, > there > is a C++ proposal to address the problem: > > http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4058.pdf Is this really the issue here? What I'm trying to do is not the same as what's discussed in the proposal, as the reading/writing of the unique_ptr doesn't have to be an atomic operation in my case. I just want to push a unique_ptr onto the queue, and spsc_queue can store all kinds of objects, which are not atomic either. It only uses atomic operations to keep track of the write and read indices, and those parts of the code don't need to be modified to make this work. As far as I see, the main problem storing unique_ptr's (or any other non-copyable but moveable object), is that the code relies on a copy constructor to store objects in its internal buffer. I added an overload using a move constructor and that seems to work (though I'm quite new to multi-threading or lockfree programming, so I could be missing some potential issues). Thomas

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[Asio] null_buffers problem
by lin li 24 Nov '14

24 Nov '14

Hi, guys. I have some problem with null_buffers in Asio. According to the document, 'A null_buffers operation doesn't return until the I/O object is "ready" to perform the operation'. However, when I tried to use it in a asynchronous read, it keeps returning after all data has been received and the other end has closed the socket! So here is my questions: 1. what is "ready" exactly? 2. If we use null_buffers with async_read_some, will it detect some errors like disconnection and pass the error code to the completion handler?

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[serialization] Customizing serialization of boost::variant
by Elizabeta 22 Nov '14

22 Nov '14

Hi When serialization boost::variant, in the xml archive 'which' element is included that specify the number of the type that appears in the boost::variant at compile time. I need to include in the archive also the name of the type for debugging purpose . Anyone have idea how to do that -- View this message in context: http://boost.2283326.n4.nabble.com/serialization-Customizing-serialization-… Sent from the Boost - Users mailing list archive at Nabble.com.

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NT² 3.0 and Boost.SIMD - Stable release
by Joel Falcou 21 Nov '14

21 Nov '14

The first stable release of the 3.x series of MetaScale’s open-source software is available: NT² 3.0. It also includes its spin-off project, Boost.SIMD (not yet a Boost library). Many Issues have been closed since last beta. The main focus of this release cycle was to fix performances issues and to stabilize some parts of the API. Next step will be to separate NT2 and Boost.SIMD into separate repositories, thus making one more step toward Boost.SIMD submission into review. [ http://www.metascale.org/nt%C2%B2-3-0-and-boost-simd ] *Changes & Bug Fixes:* - Major performance improvements in both libraries - Added experimental support for the HPX runtime for parallelization on shared memory systems - Optimizations of many elemental functions, in particuler log/ex, frexp/ldexp and cbrt - More advanced shuffle pattern recognition for SIMD - Fixed issues with Visual Studio 2013 - More functions are force-inlined to ensure good performance - New functions for conversion between types and mixing of vectors of different sizes - Demo applications usable as benchmarks - Better handling of errors when an unsupported function is called - New API for custom memory allocators Full changelog is available at https://github.com/MetaScale/nt2/releases/tag/3.0.0. *How to get it ?* - Source and binary packages can be downloaded here: http://nt2.metascale.org/downloads - The release is also available on Github : https://github.com/MetaScale/nt2/releases - The main master branch is still under development : https://github.com/MetaScale/nt2

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Thread prioritization
by Alexander Carôt 20 Nov '14

20 Nov '14

Hello all, is it correct that boost does not offer thread prioritization ? I am dealing with an application with a number of threads, which all depend on the realtime-scheduled sound card callback thread. These threads must have the same realtime scheduling priority. Is there a way to achieve this ? Thanks in advance, best Alex >

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[BGL] [push_relabel_max_flow] multigraphs ?
by Pablo Madoery 20 Nov '14

20 Nov '14

I was wondering if the push_relabel_max_flow algorithm can be used in multigraphs. I mean, can I have two vertices joined by two edges: one in a direction an the other in the opposite direction with equal capacities ( 1000 for example ). It is clear in the documentation that the reverse edge must exist for each edge in the graph, so there must be 4 edges in the case I am describing. but the question is: does the algorithm works properly for this case ?

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[BGL] [push_relabel_max_flow]
by Pablo Madoery 19 Nov '14

19 Nov '14

Hello, I am having trouble using the push_relabel_max_flow algorithm when i put std::numeric_limits<double>::max() as capacity attribute in some edges. is there a maximum value that I can use as capacities. which ?. This is the example I am using : #include <iostream> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/push_relabel_max_flow.hpp> #include <boost/graph/graphviz.hpp> using namespace std; using namespace boost; struct vertexInfo { }; struct edgeInfo { double capacity; double residualCapacity; double flow; adjacency_list_traits<vecS, vecS, bidirectionalS>::edge_descriptor rev; edgeInfo() { residualCapacity = 1000; } }; typedef adjacency_list<vecS, vecS, bidirectionalS, vertexInfo, edgeInfo> Graph; typedef Graph::edge_descriptor edge_d; const char* names[] = { "SV", "L1", "L2", "L3", "L4", "ET"}; template<typename Vertex> void create_edge(Graph& g, Vertex v0, Vertex v1, double capacity) { //the algorithm requires that for each edge u-v in the graph, the edge v-u also exists Graph::edge_descriptor ep0 = (add_edge(v0, v1, g)).first; Graph::edge_descriptor ep1 = (add_edge(v1, v0, g)).first; g[ep0].capacity = capacity; g[ep0].rev = ep1; g[ep1].capacity = 0; // the capacity of v-u needs to be 0 g[ep1].rev = ep0; } int main() { Graph graph; Graph::vertex_descriptor SV = add_vertex(graph); Graph::vertex_descriptor L1 = add_vertex(graph); Graph::vertex_descriptor L2 = add_vertex(graph); Graph::vertex_descriptor L3 = add_vertex(graph); Graph::vertex_descriptor L4 = add_vertex(graph); Graph::vertex_descriptor ET = add_vertex(graph); create_edge(graph, SV, L1, std::numeric_limits<double>::max()); create_edge(graph, SV, L2, std::numeric_limits<double>::max()); create_edge(graph, SV, L3, std::numeric_limits<double>::max()); create_edge(graph, SV, L4, std::numeric_limits<double>::max()); create_edge(graph, L3, ET, 1000); create_edge(graph, L4, L3, 1000); create_edge(graph, L2, L3, 1000); create_edge(graph, L1, L2, 1000); // arcos de vuelta create_edge(graph, L3, L4, 1000); create_edge(graph, L3, L2, 1000); create_edge(graph, L2, L1, 1000); std::cout << "Max flow: " << push_relabel_max_flow(graph, SV, ET, get(&edgeInfo::capacity, graph), get(&edgeInfo::residualCapacity, graph), get(&edgeInfo::rev, graph), get(boost::vertex_index, graph)) << std::endl; graph_traits<Graph>::vertex_iterator vi, vi_end; graph_traits<Graph>::out_edge_iterator ei, ei_end; cout.precision(20); for (tie(vi, vi_end) = vertices(graph); vi!= vi_end; ++vi) { for (tie(ei, ei_end) = out_edges(*vi, graph); ei != ei_end; ++ei) { graph[*ei].flow = graph[*ei].capacity - graph[*ei].residualCapacity; if (graph[*ei].capacity > 0) { std::cout << names[*vi] << " " << names[target(*ei, graph)] << " " << (graph[*ei].capacity - graph[*ei].residualCapacity) << "/" << graph[*ei].capacity << std::endl; } } } cout<<"end"<<endl; return 0; } ----------------------------------------------------------------------------------------------------------------------------- And this is the exception: /home/madoery/boost_1_55_0/boost/graph/push_relabel_max_flow.hpp:706: typename boost::property_traits<CapacityEdgeMap>::value_type boost::push_relabel_max_flow(Graph&, typename boost::graph_traits<Graph>::vertex_descriptor, typename boost::graph_traits<Graph>::vertex_descriptor, CapacityEdgeMap, ResidualCapacityEdgeMap, ReverseEdgeMap, VertexIndexMap) [with Graph = boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, vertexInfo, edgeInfo>, CapacityEdgeMap = boost::adj_list_edge_property_map<boost::bidirectional_tag, double, double&, long unsigned int, edgeInfo, double edgeInfo::*>, ResidualCapacityEdgeMap = boost::adj_list_edge_property_map<boost::bidirectional_tag, double, double&, long unsigned int, edgeInfo, double edgeInfo::*>, ReverseEdgeMap = boost::adj_list_edge_property_map<boost::bidirectional_tag, boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int>, boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int>&, long unsigned int, edgeInfo, boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int> edgeInfo::*>, VertexIndexMap = boost::vec_adj_list_vertex_id_map<vertexInfo, long unsigned int>, typename boost::property_traits<CapacityEdgeMap>::value_type = double, typename boost::graph_traits<Graph>::vertex_descriptor = long unsigned int]: Assertion `algo.is_flow()' failed. Thank You

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More than strange performance test results of Boost.MultiIndex
by Ernest Zaslavsky 19 Nov '14

19 Nov '14

I was rewriting our production code since there were performance concerns and switched from our monstrous std::map to boost multi_index_containers which looked exactly what we need. Then when running performance tests I've noticed that once I use composite_key which includes string the performance drops in orders of magnitude, to be precise, 5 orders. Which, I would say, not reasonable at all. So I created a minimal repro case to post here and ran it on Coliru. Surprise! This behavior does not reproduce on GCC, moreover, the composite key with string for some reason was searched twice faster than int only composite. To me it sounds like a bug or in Boost.MultiIndex MS specific implementation (if such exists) or in MSVC. Tech details: VS2012, Win7x64. The code was compiled and linked targeting x64 architecture. Test output on my local machine: Populating data. Index size: 999999 Running FlyweightMICTest::deepTest Checking getTestData perf. 999999 sum of all IDs. 1M calls took 0 seconds or 125ns per call. ------------------------------------------------------------- Populating data. Index size: 999999 Running FlyweightMICTestWithString::deepTest Checking getTestData perf. 99 sum of all IDs. 99 calls took 1 seconds or 10132326ns per call. =============================================================== Coliru output (live example can be found here http://coliru.stacked-crooked.com/a/ef76d297279f15a8) Populating data. Index size: 999999 Running deepTest Checking getTestData perf. 999999 sum of all IDs. 1M calls took 0 seconds or 395ns per call. ------------------------------------------------------------- Populating data. Index size: 999999 Running deepTest Checking getTestData perf. 999999 sum of all IDs. 999999 calls took 0 seconds or 181ns per call. =============================================================== [Read More]<http://feeds.feedburner.com/~r/sizmek-blog/~6/1> [http://www.sizmek.com/Sizmek.png]<http://www.sizmek.com/>

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Re: [Boost-users] Boost-users Digest, Vol 3971, Issue 2
by vibhor aggarwal 18 Nov '14

18 Nov '14

Thanks for the message Joaquin! I am running the boost invariant checks for multi-index and something which took a minute is now taking a full day to run. Any how, I haven't had any of the assertions fail in 5 iterations which completed so far and I have moved to version 1.57.0 Will get back if I see any issues with this again. On Thursday, 13 November 2014 10:30 PM, "boost-users-request(a)lists.boost.org" <boost-users-request(a)lists.boost.org> wrote: Send Boost-users mailing list submissions to boost-users(a)lists.boost.org To subscribe or unsubscribe via the World Wide Web, visit http://lists.boost.org/mailman/listinfo.cgi/boost-users or, via email, send a message with subject or body 'help' to boost-users-request(a)lists.boost.org You can reach the person managing the list at boost-users-owner(a)lists.boost.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Boost-users digest..." Today's Topics: 1. Re: [Mutli-Index, InterProcess] Multi-index stability issue with interprocess? (Joaquin M Lopez Munoz) 2. [Graph] A* with heterogeneous heuristics (Sensei) 3. 1.57.0 link errors (missing ctor/dtor for boost::archive::detail::shared_ptr_helper) (David Abdurachmanov) 4. [BGL] Shortest-Path subject to length constraint (Yun Liu) ---------------------------------------------------------------------- Message: 1 Date: Thu, 13 Nov 2014 10:41:08 +0000 (UTC) From: Joaquin M Lopez Munoz <joaquin(a)tid.es> To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] [Mutli-Index, InterProcess] Multi-index stability issue with interprocess? Message-ID: <loom.20141113T111909-42(a)post.gmane.org> Content-Type: text/plain; charset=utf-8 vibhor aggarwal <vibhor.aggarwal <at> yahoo.com> writes: > > I am creating a multi-index [...] and storing that in a managed > memory mapped file (boos::interprocess) [...] > All the data is first inserted into the multi-index once and then it > is read from the muti-index with a query [...] > > boost::tie(l, u) = m_p_mi_ts->get<0>(). > equal_range(boost::make_tuple(i, j)); > > We are testing this whole process over and over again (each iteration > is a new run of the process), and once in every 50 or so iterations > we get a segment fault inside boost on firing the query. Here is the > boost part of the stack from the core dump: With so little information, I can only guess: the crash is hapenning at a very superficial level into equal_range, namely when dereferencing the container's header node (the top of the rb-tree ordered indices are based on). This suggests that the container layout is seriously screwed; possible reasons: * Memory overwrites from some adjacent structure * File corruption (?) * m_p_mi has been changed somewhere * Some sort of overrun within the memory-mapped file It'd be best if you could provide a testing case for this or some more context. If this is not an option, you can activate Boost.MultiIndex invariant-checking mode: http://www.boost.org/libs/multi_index/doc/tutorial /debug.html#invariant_check which will assert as soon as some internal corruption is detected (caveat: this mode will reduce performance drastically). Joaqu?n M L?pez Mu?oz Telef?nica ------------------------------ Message: 2 Date: Thu, 13 Nov 2014 12:41:32 +0100 From: Sensei <senseiwa(a)gmail.com> To: boost-users(a)lists.boost.org Subject: [Boost-users] [Graph] A* with heterogeneous heuristics Message-ID: <546498EC.6070204(a)gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Dear all, I haven't given up in trying to implement an A* algorithm with BGL. My problem is theoretically simple, as in some previous posts. Given a graph of letters, and a word, find the path in the graph that minimizes the distance between the letters of the word and the nodes in the graph. It's best to show an example: /* * B H * / \ / * A---D---F---G---I * \ /\ * C E * * input: A E I O U * result: A D F G I */ With that graph, my heuristic should take into account not just the letter in the graph per se, but the *corresponding* one in the input word. So, starting with "AEIOU" the search will: - expand A (A in **A**EIOU) - find B, C, D - expand D (closest to E in A**E**IOU) - find D, F - expand F (closest to I in AE**I**OU) - find G - expand G (only one, closest to O in AEI**O**U) - find H, I - expand U (closest to U in AEIO**U**) This settings could also be more complicated, adding weights to edges, but for now I am happy with this problem. What I've done now? Implementing my own A* algorithm, by hand. Of course this might work, but I'd prefer using BGL's facilities. I must say that I am quite confused about BGL's data structures, as for instance in the A* cities example (1), we need to create a weight map, so what if I don't need weights? Moreover, predecessors and distances are instantiated with a std::vector, but what happens if I need to operate on a very large graph, for instance 200M nodes? Moreover, what will happen when I will distribute the graph over a cluster with Boost Parallel Graph? ... Ok maybe this is too ahead of the time! :) Basically, I'd need to replicate my A* ugly by-hand implementation with custom visitors and custom heuristics. Below you may find my failed attempt. I need some help with this, because I find the documentation a little bit hard to understand, especially when some newbie like me approaches Boost :) Failures in my code: I can't get to define a non-weighted graph, and the call to the A* search is cryptic: I don't have weights. Should I define fake ones for instance all equal to 1? I really hope you guys can help me in this, my code works, but using BGL would be best! Thanks! (1) http://www.boost.org/doc/libs/1_57_0/libs/graph/example/astar-cities.cpp #include <iostream> #include <unordered_map> #include <vector> #include <string> #include <utility> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/breadth_first_search.hpp> #include <boost/graph/depth_first_search.hpp> #include <boost/graph/astar_search.hpp> typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS > graph; typedef boost::graph_traits<graph>::edge_iterator edge_iterator; // Custom A* heuristic template <class Graph, class CostType> class bestmatch_heuristic : public boost::astar_heuristic<Graph, CostType> { public: typedef typename boost::graph_traits<Graph>::vertex_descriptor Vertex; bestmatch_heuristic() { }; CostType operator()(Vertex u) { std::cout << ">>>> h(" << u << ") = " << 1 << std::endl; return 1; } private: }; // Used to end the A* search algorithm struct end_astar { }; // Custom A* visitor template <class Vertex> class bestmatch_visitor : public boost::default_astar_visitor { public: bestmatch_visitor(Vertex goal) : destination_(goal) { }; template<class Graph> void discover_vertex(Vertex u, const Graph &g) { std::cout << "discover " << u << std::endl; } template <class Graph> void examine_vertex(Vertex u, Graph& g) { std::cout << "examine " << u << std::endl; if (u == destination_) throw end_astar(); } private: Vertex destination_; }; int main() { /* * B H * / \ / * A---D---F---G---I * \ /\ * C E * * input: A E I O U * result: A D F G I */ std::unordered_map<char, std::size_t> letters; auto getletter = [](std::size_t i) -> char { return 'A' + i; }; for (int i = 'A'; i <= 'I'; i++) letters[i] = i - 'A'; graph g; boost::add_edge(letters['A'], letters['B'], g); boost::add_edge(letters['A'], letters['C'], g); boost::add_edge(letters['A'], letters['D'], g); boost::add_edge(letters['B'], letters['D'], g); boost::add_edge(letters['C'], letters['D'], g); boost::add_edge(letters['D'], letters['E'], g); boost::add_edge(letters['D'], letters['F'], g); boost::add_edge(letters['F'], letters['G'], g); boost::add_edge(letters['G'], letters['H'], g); boost::add_edge(letters['G'], letters['I'], g); edge_iterator ei, ee; for (boost::tie(ei, ee) = boost::edges(g); ei != ee; ei++) { std::cout << getletter(boost::source(*ei, g)) << " -> " << getletter(boost::target(*ei, g)) << std::endl; } // Heuristics bestmatch_heuristic<graph, int> h; // Predecessors std::vector<graph::vertex_descriptor> p(boost::num_vertices(g)); try { #if 0 boost::astar_search_tree(// Graph g, // Start node letters['A'], // Heuristics bestmatch_heuristic<graph, int>(), // Predecessor map boost::predecessor_map(boost::make_iterator_property_map(p.begin(), boost::get(boost::vertex_index, g)))); #endif } catch (end_astar e) { } } ------------------------------ Message: 3 Date: Thu, 13 Nov 2014 10:07:07 +0100 From: David Abdurachmanov <david.abdurachmanov(a)gmail.com> To: boost-users(a)lists.boost.org Cc: amey(a)rrsd.com Subject: [Boost-users] 1.57.0 link errors (missing ctor/dtor for boost::archive::detail::shared_ptr_helper) Message-ID: <C512A56C-8078-438E-BDBC-376A9EF590F9(a)gmail.com> Content-Type: text/plain; charset="us-ascii" Hi, I am moving to Boost 1.57.0 and having issues with some code related to serialization. https://github.com/cms-sw/cmssw/blob/CMSSW_7_3_X/CondFormats/Serialization/… https://github.com/cms-sw/cmssw/blob/CMSSW_7_3_X/CondFormats/Serialization/… In both cases the problem is here: #if BOOST_VERSION >= 103500 #include <boost/archive/shared_ptr_helper.hpp> #endif [snip] #if BOOST_VERSION >= 103500 // mix-in helper class for serializing shared_ptr , public boost::archive::detail::shared_ptr_helper #endif A similar (or the same) problem is reported here: http://boost.2283326.n4.nabble.com/Serialization-link-error-in-1-56-td46668… It seems that ctor/dtor are not exported anymore: /testSerializationDQMObjects.o: In function `eos::portable_oarchive::portable_oarchive(std::ostream& , unsigned int)': testSerializationDQMObjects.cpp:(.text._ZN3eos17portable_oarchiveC2ERSoj[_ZN3eos17portable_oarchiveC5ERSoj]+0x54): undefined reference to `boost::archive::detail::shared_ptr_helper: :shared_ptr_helper()' testSerializationDQMObjects.cpp:(.text._ZN3eos17portable_oarchiveC2ERSoj[_ZN3eos17portable_oarchiveC5ERSoj]+0x1c1): undefined reference to `boost::archive::detail::shared_ptr_helper ::~shared_ptr_helper()' boost::serialization::shared_ptr_helper does not seem to be a drop-in replacement at first look. There is also 'shared_ptr_helper_base', but is only available in the implementation file. Is such mix-in class still available in a new Boost version? Thanks, david

1 0

Iostreams: how can I control my (ostream) filter?
by Akim Demaille 16 Nov '14

16 Nov '14

Hi! I'm trying to use Boost.Iostream to create a filter that will escape some characters (typically backslash must be backslashed). This is to conform with the syntax of an output format that requires some portions to be escaped this way. But other place must be left untouched. My problem is I don't find a means to "talk" to my filter. My first attempt used two streams: the "real" ostream and the filtered one that wraps it. Of course it failed: both streams are not synchronized, and buffers are flushed at different moments resulting in scrambled output. I don't want to flush too often (I got to keep my throughput high), so that's ruled out. My second attempt was to introduce an xalloc-based custom iomanip to enable/disable the processing in my filter. But my problem is that in my filter, I don't know how to reach the final ostream and fetch it pword, so I failed to have it work. From the syntax point of view (from the caller viewpoint) that was my favorite approach. In my third attempt, I have to boolean variable living in the caller frame, taken as a bool& by my filter's actor, and checked in its "write" function to decide whether to escape or not. This looks worrying (bool& members don't look nice), and anyway does not work nicely, again, with buffers: the asynchrony between setting/unsetting the boolean and using it breaks everything. So, what are the good options? I think I really needed something like an iomanipulator which ensures that "sequentiality" is preserved, but how should I do that? Thanks in advance! PS/ One not-good-option would be to have my filter try to "parse" what it is outputting to decide what's the current state, and whether it should escape or not. First, things become uselessly complex, and second, anyway that's not right; for instance when I'm in a string, double-quotes should be escaped, or mark the end of the string. The filter cannot know which kind of double-quote it just saw, but I know, so _I_ should change the state at that time, not it.

2 4

Why does `boost::asio::deadline_timer` allocate a `timer_queue` instance for each `deadline_timer` object?
by Wang Danqi 16 Nov '14

16 Nov '14

Hi I am looking into the implementation of `boost::asio::deadline_timer`, based on boost 1.52. As described in [the article on highscore](http://en.highscore.de/cpp/boost/asio.html#asio_extensions), it is implemented in three parts: * `deadline_timer`, the i/o object * `deadline_timer_service`, the service * `detail::deadline_timer_service`, the service implementation There will be a single instance of `deadline_timer_service` serving many `deadline_timer` objects. An instance of `detail::deadline_timer_service` is created for each `deadline_timer` object. Moreover, the timers are scheduled by a scheduler, which is usually a reactor (i.e. `epoll_reactor` on Linux in most cases). There is a `timer_queue_` member of type `timer_queue` in `detail::deadline_timer_service` which is a heap that stores scheduled timers. This means that there will be one instance of `timer_queue` for each `deadline_timer` object. Multiple `timer_queue` objects can be added to the scheduler by `add_timer_queue()`, and they are managed by a class `timer_queue_set`. My question is, why `asio` create multiple queues to handle timers? What is the drawback if we have a single timer queue instance in the scheduler that all timers can share? Please note that I am asking about the `boost::asio::deadline_timer`, not the example in the highscore link. I have posted this question on stackoverflow previously [here](http://stackoverflow.com/q/26922754/930095) -- Best wishes, Wang Danqi

2 2

Re: [Boost-users] lockfree::spsc_queue & move semantics
by quang.trinh＠gmail.com 15 Nov '14

15 Nov '14

------Original Message------ From: Bjorn Reese Sender: Boost-users To: boost-users(a)lists.boost.org ReplyTo: boost-users(a)lists.boost.org Subject: Re: [Boost-users] lockfree::spsc_queue & move semantics Sent: Nov 10, 2014 2:39 PM On 11/09/2014 09:49 PM, Thomas Danckaert wrote: > I'd like to use a spsc_queue of unique_ptr's to bigger objects, to > transfer ownership between threads. That way, I can create/allocate an This limitation inherited from atomic, and I am afraid that it is a bit more complicated than adding a move constructor. Fortunately, there is a C++ proposal to address the problem: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4058.pdf _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users Sent from my BlackBerry device on the Rogers Wireless Network

1 0

How to track boost::asio pending handlers
by Thierry Morigault 14 Nov '14

14 Nov '14

Hi, I am debugging a huge application with numbers of handlers posted in a boost::asio::io_service, running on Windows 7, Visual Studio 2012 and with boost 1.55. My problem is that the io_service doesn't stop because of pending handlers ... And i can't know what are precisely these handlers : there is only a function in boost::io_service which give the number of pending handlers. Is there a way to display the name of the different pending handlers in the io_service ? It can be so helpful ! I know the macro BOOST_ASIO_ENABLE_HANDLER_TRACKING but this only prints the boost::asio internal functions names (async_accept, async write etc.), and not my proper posted handlers.

1 0

[BGL] Shortest-Path subject to length constraint
by Yun Liu 13 Nov '14

13 Nov '14

Hi all, apologies in advance if this question is trivial; I couldn't find anything like it asked previously in the mailing list. My question is, if I have a directed graph (with non-negative edge weights, to keep things simple for now), I would like to find the shortest-cost path from a source node to target node, but with the constraint on the maximum number of edges allowed. For example, if I have the graph with vertices {A,B,C,D} and edges: A->B (cost 1), B->C (cost 1), C->D (cost 1), A->D (cost 1000), but I have the constraint that my path should only be a maximum of 2 edges, the correct solution would still be A->D with cost 1000. Looking through the previous BGL examples, say with bellman-ford or Dijkstra, it did not seem immediately obvious how to enforce this stipulation. Thanks again for any ideas! -Yun

1 0

[Graph] A* with heterogeneous heuristics
by Sensei 13 Nov '14

13 Nov '14

Dear all, I haven't given up in trying to implement an A* algorithm with BGL. My problem is theoretically simple, as in some previous posts. Given a graph of letters, and a word, find the path in the graph that minimizes the distance between the letters of the word and the nodes in the graph. It's best to show an example: /* * B H * / \ / * A---D---F---G---I * \ /\ * C E * * input: A E I O U * result: A D F G I */ With that graph, my heuristic should take into account not just the letter in the graph per se, but the *corresponding* one in the input word. So, starting with "AEIOU" the search will: - expand A (A in **A**EIOU) - find B, C, D - expand D (closest to E in A**E**IOU) - find D, F - expand F (closest to I in AE**I**OU) - find G - expand G (only one, closest to O in AEI**O**U) - find H, I - expand U (closest to U in AEIO**U**) This settings could also be more complicated, adding weights to edges, but for now I am happy with this problem. What I've done now? Implementing my own A* algorithm, by hand. Of course this might work, but I'd prefer using BGL's facilities. I must say that I am quite confused about BGL's data structures, as for instance in the A* cities example (1), we need to create a weight map, so what if I don't need weights? Moreover, predecessors and distances are instantiated with a std::vector, but what happens if I need to operate on a very large graph, for instance 200M nodes? Moreover, what will happen when I will distribute the graph over a cluster with Boost Parallel Graph? ... Ok maybe this is too ahead of the time! :) Basically, I'd need to replicate my A* ugly by-hand implementation with custom visitors and custom heuristics. Below you may find my failed attempt. I need some help with this, because I find the documentation a little bit hard to understand, especially when some newbie like me approaches Boost :) Failures in my code: I can't get to define a non-weighted graph, and the call to the A* search is cryptic: I don't have weights. Should I define fake ones for instance all equal to 1? I really hope you guys can help me in this, my code works, but using BGL would be best! Thanks! (1) http://www.boost.org/doc/libs/1_57_0/libs/graph/example/astar-cities.cpp #include <iostream> #include <unordered_map> #include <vector> #include <string> #include <utility> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/breadth_first_search.hpp> #include <boost/graph/depth_first_search.hpp> #include <boost/graph/astar_search.hpp> typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS > graph; typedef boost::graph_traits<graph>::edge_iterator edge_iterator; // Custom A* heuristic template <class Graph, class CostType> class bestmatch_heuristic : public boost::astar_heuristic<Graph, CostType> { public: typedef typename boost::graph_traits<Graph>::vertex_descriptor Vertex; bestmatch_heuristic() { }; CostType operator()(Vertex u) { std::cout << ">>>> h(" << u << ") = " << 1 << std::endl; return 1; } private: }; // Used to end the A* search algorithm struct end_astar { }; // Custom A* visitor template <class Vertex> class bestmatch_visitor : public boost::default_astar_visitor { public: bestmatch_visitor(Vertex goal) : destination_(goal) { }; template<class Graph> void discover_vertex(Vertex u, const Graph &g) { std::cout << "discover " << u << std::endl; } template <class Graph> void examine_vertex(Vertex u, Graph& g) { std::cout << "examine " << u << std::endl; if (u == destination_) throw end_astar(); } private: Vertex destination_; }; int main() { /* * B H * / \ / * A---D---F---G---I * \ /\ * C E * * input: A E I O U * result: A D F G I */ std::unordered_map<char, std::size_t> letters; auto getletter = [](std::size_t i) -> char { return 'A' + i; }; for (int i = 'A'; i <= 'I'; i++) letters[i] = i - 'A'; graph g; boost::add_edge(letters['A'], letters['B'], g); boost::add_edge(letters['A'], letters['C'], g); boost::add_edge(letters['A'], letters['D'], g); boost::add_edge(letters['B'], letters['D'], g); boost::add_edge(letters['C'], letters['D'], g); boost::add_edge(letters['D'], letters['E'], g); boost::add_edge(letters['D'], letters['F'], g); boost::add_edge(letters['F'], letters['G'], g); boost::add_edge(letters['G'], letters['H'], g); boost::add_edge(letters['G'], letters['I'], g); edge_iterator ei, ee; for (boost::tie(ei, ee) = boost::edges(g); ei != ee; ei++) { std::cout << getletter(boost::source(*ei, g)) << " -> " << getletter(boost::target(*ei, g)) << std::endl; } // Heuristics bestmatch_heuristic<graph, int> h; // Predecessors std::vector<graph::vertex_descriptor> p(boost::num_vertices(g)); try { #if 0 boost::astar_search_tree(// Graph g, // Start node letters['A'], // Heuristics bestmatch_heuristic<graph, int>(), // Predecessor map boost::predecessor_map(boost::make_iterator_property_map(p.begin(), boost::get(boost::vertex_index, g)))); #endif } catch (end_astar e) { } }

1 0

[Mutli-Index, InterProcess] Multi-index stability issue with interprocess?
by vibhor aggarwal 13 Nov '14

13 Nov '14

I am creating a multi-index on three members of a class (two int32_t and one std::pair<int32_t, int32_t> and storing that in a managed memory mapped file (boos::interprocess). I am using GCC 4.8.2 for compilation and boost version 1.56.beta1All the data is first inserted into the multi-index once and then it is read from the muti-index with a query on the first two int32_t values (There is no concurrency and insertion and query is being done within the same process). The mutliindex is defined as: typedef bmi::multi_index_container < Trace, bmi::indexed_by < bmi::ordered_non_unique < bmi::composite_key < Trace, BOOST_MULTI_INDEX_MEMBER(Trace, int32_t, m_x), BOOST_MULTI_INDEX_MEMBER(Trace, int32_t, m_y), BOOST_MULTI_INDEX_MEMBER(Trace, int_pair_t, m_volume) > > > , managed_mapped_file::allocator<Trace>::type > trace_set_t; The query is: boost::tie(l, u) = m_p_mi_ts->get<0>().equal_range(boost::make_tuple(i, j)); We are testing this whole process over and over again (each iteration is a new run of the process), and once in every 50 or so iterations we get a segment fault inside boost on firing the query. Here is the boost part of the stack from the core dump: #0 0x00002b748b6ac0ec in boost::interprocess::offset_ptr<boost::multi_index::detail::ordered_index_node<boost::multi_index::detail::index_node_base<Seismic::Data::Trace, boost::interprocess::allocator<Seismic::Data::Trace, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>, 0ul>, boost::interprocess::iset_index> > > >, long, unsigned long, 0ul>::get() const () at /glb/data/ifshou_cdis05/projects/cdis/installed/boost/1.56.0.beta1/usr/local/include/boost/interprocess/offset_ptr.hpp:346#1 0x00002b748b6a8934 in boost::interprocess::offset_ptr<boost::multi_index::detail::ordered_index_node<boost::multi_index::detail::index_node_base<Seismic::Data::Trace, boost::interprocess::allocator<Seismic::Data::Trace, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>, 0ul>, boost::interprocess::iset_index> > > >, long, unsigned long, 0ul>::operator*() const () at /glb/data/ifshou_cdis05/projects/cdis/installed/boost/1.56.0.beta1/usr/local/include/boost/interprocess/offset_ptr.hpp:360#2 0x00002b748b6a5932 in boost::multi_index::multi_index_container<Seismic::Data::Trace, boost::multi_index::indexed_by<boost::multi_index::ordered_non_unique<boost::multi_index::composite_key<Seismic::Data::Trace, boost::multi_index::member<Seismic::Data::Trace, int, &(Seismic::Data::Trace::m_x)>, boost::multi_index::member<Seismic::Data::Trace, int, &(Seismic::Data::Trace::m_y)>, boost::multi_index::member<Seismic::Data::Trace, std::pair<int, int>, &(Seismic::Data::Trace::m_volume)>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, mpl_::na, mpl_::na>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::interprocess::allocator<Seismic::Data::Trace, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>, 0ul>, boost::interprocess::iset_index> > >::header() const () at /glb/data/ifshou_cdis05/projects/cdis/installed/boost/1.56.0.beta1/usr/local/include/boost/multi_index_container.hpp:525#3 0x00002b748b6a3250 in boost::multi_index::detail::index_base<Seismic::Data::Trace, boost::multi_index::indexed_by<boost::multi_index::ordered_non_unique<boost::multi_index::composite_key<Seismic::Data::Trace, boost::multi_index::member<Seismic::Data::Trace, int, &(Seismic::Data::Trace::m_x)>, boost::multi_index::member<Seismic::Data::Trace, int, &(Seismic::Data::Trace::m_y)>, boost::multi_index::member<Seismic::Data::Trace, std::pair<int, int>, &(Seismic::Data::Trace::m_volume)>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, mpl_::na, mpl_::na>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::interprocess::allocator<Seismic::Data::Trace, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>, 0ul>, boost::interprocess::iset_index> > >::final_header() const () at /glb/data/ifshou_cdis05/projects/cdis/installed/boost/1.56.0.beta1/usr/local/include/boost/multi_index/detail/index_base.hpp:212#4 0x00002b748b6a022c in boost::multi_index::detail::ordered_index<boost::multi_index::composite_key<Seismic::Data::Trace, boost::multi_index::member<Seismic::Data::Trace, int, &(Seismic::Data::Trace::m_x)>, boost::multi_index::member<Seismic::Data::Trace, int, &(Seismic::Data::Trace::m_y)>, boost::multi_index::member<Seismic::Data::Trace, std::pair<int, int>, &(Seismic::Data::Trace::m_volume)>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, std::less<boost::multi_index::composite_key_result<boost::multi_index::composite_key<Seismic::Data::Trace, boost::multi_index::member<Seismic::Data::Trace, int, &(Seismic::Data::Trace::m_x)>, boost::multi_index::member<Seismic::Data::Trace, int, &(Seismic::Data::Trace::m_y)>, boost::multi_index::member<Seismic::Data::Trace, std::pair<int, int>, &(Seismic::Data::Trace::m_volume)>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > >, boost::multi_index::detail::nth_layer<1, Seismic::Data::Trace, boost::multi_index::indexed_by<boost::multi_index::ordered_non_unique<boost::multi_index::composite_key<Seismic::Data::Trace, boost::multi_index::member<Seismic::Data::Trace, int, &(Seismic::Data::Trace::m_x)>, boost::multi_index::member<Seismic::Data::Trace, int, &(Seismic::Data::Trace::m_y)>, boost::multi_index::member<Seismic::Data::Trace, std::pair<int, int>, &(Seismic::Data::Trace::m_volume)>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, mpl_::na, mpl_::na>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::interprocess::allocator<Seismic::Data::Trace, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>, 0ul>, boost::interprocess::iset_index> > >, boost::mpl::vector0<mpl_::na>, boost::multi_index::detail::ordered_non_unique_tag>::header() const () at /glb/data/ifshou_cdis05/projects/cdis/installed/boost/1.56.0.beta1/usr/local/include/boost/multi_index/ordered_index.hpp:973#5 0x00002b748b69cbed in std::pair<boost::multi_index::detail::bidir_node_iterator<boost::multi_index::detail::ordered_index_node<boost::multi_index::detail::index_node_base<Seismic::Data::Trace, boost::interprocess::allocator<Seismic::Data::Trace, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>, 0ul>, boost::interprocess::iset_index> > > > >, boost::multi_index::detail::bidir_node_iterator<boost::multi_index::detail::ordered_index_node<boost::multi_index::detail::index_node_base<Seismic::Data::Trace, boost::interprocess::allocator<Seismic::Data::Trace, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>, 0ul>, boost::interprocess::iset_index> > > > > > boost::multi_index::detail::ordered_index<boost::multi_index::composite_key<Seismic::Data::Trace, boost::multi_index::member<Seismic::Data::Trace, int, &(Seismic::Data::Trace::m_x)>, boost::multi_index::member<Seismic::Data::Trace, int, &(Seismic::Data::Trace::m_y)>, boost::multi_index::member<Seismic::Data::Trace, std::pair<int, int>, &(Seismic::Data::Trace::m_volume)>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, std::less<boost::multi_index::composite_key_result<boost::multi_index::composite_key<Seismic::Data::Trace, boost::multi_index::member<Seismic::Data::Trace, int, &(Seismic::Data::Trace::m_x)>, boost::multi_index::member<Seismic::Data::Trace, int, &(Seismic::Data::Trace::m_y)>, boost::multi_index::member<Seismic::Data::Trace, std::pair<int, int>, &(Seismic::Data::Trace::m_volume)>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > >, boost::multi_index::detail::nth_layer<1, Seismic::Data::Trace, boost::multi_index::indexed_by<boost::multi_index::ordered_non_unique<boost::multi_index::composite_key<Seismic::Data::Trace, boost::multi_index::member<Seismic::Data::Trace, int, &(Seismic::Data::Trace::m_x)>, boost::multi_index::member<Seismic::Data::Trace, int, &(Seismic::Data::Trace::m_y)>, boost::multi_index::member<Seismic::Data::Trace, std::pair<int, int>, &(Seismic::Data::Trace::m_volume)>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, mpl_::na, mpl_::na>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::interprocess::allocator<Seismic::Data::Trace, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>, 0ul>, boost::interprocess::iset_index> > >, boost::mpl::vector0<mpl_::na>, boost::multi_index::detail::ordered_non_unique_tag>::equal_range<boost::tuples::tuple<int, int, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >(boost::tuples::tuple<int, int, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> const&) const () at /glb/data/ifshou_cdis05/projects/cdis/installed/boost/1.56.0.beta1/usr/local/include/boost/multi_index/ordered_index.hpp:556 Any idea what might be happening? Thanks

2 1

1.57.0 link errors (missing ctor/dtor for boost::archive::detail::shared_ptr_helper)
by David Abdurachmanov 13 Nov '14

13 Nov '14

Hi, I am moving to Boost 1.57.0 and having issues with some code related to serialization. https://github.com/cms-sw/cmssw/blob/CMSSW_7_3_X/CondFormats/Serialization/… https://github.com/cms-sw/cmssw/blob/CMSSW_7_3_X/CondFormats/Serialization/… In both cases the problem is here: #if BOOST_VERSION >= 103500 #include <boost/archive/shared_ptr_helper.hpp> #endif [snip] #if BOOST_VERSION >= 103500 // mix-in helper class for serializing shared_ptr , public boost::archive::detail::shared_ptr_helper #endif A similar (or the same) problem is reported here: http://boost.2283326.n4.nabble.com/Serialization-link-error-in-1-56-td46668… It seems that ctor/dtor are not exported anymore: /testSerializationDQMObjects.o: In function `eos::portable_oarchive::portable_oarchive(std::ostream& , unsigned int)': testSerializationDQMObjects.cpp:(.text._ZN3eos17portable_oarchiveC2ERSoj[_ZN3eos17portable_oarchiveC5ERSoj]+0x54): undefined reference to `boost::archive::detail::shared_ptr_helper: :shared_ptr_helper()' testSerializationDQMObjects.cpp:(.text._ZN3eos17portable_oarchiveC2ERSoj[_ZN3eos17portable_oarchiveC5ERSoj]+0x1c1): undefined reference to `boost::archive::detail::shared_ptr_helper ::~shared_ptr_helper()' boost::serialization::shared_ptr_helper does not seem to be a drop-in replacement at first look. There is also 'shared_ptr_helper_base', but is only available in the implementation file. Is such mix-in class still available in a new Boost version? Thanks, david

1 0

[serialization] Treatment of corrupt archives - assert vs. exception throw
by Gabriel Redner 12 Nov '14

12 Nov '14

Hi folks, I'm dealing with binary archives which may have been corrupted enroute to my code. My naive expectation was that the serialization library should throw an exception when it encounters something in the input stream it doesn't understand (in which case my code can react gracefully). But, I've found that: 1. There exist cases where serialization will just assert and bring down the process 2. The documentation suggests that an exception should be thrown, but I didn't find any strong statement of this, so I am not sure whether it is a contract of the library. My first and most pressing question is: is it a guarantee of the library that invalid input should result in an exception and not an assert? If this is not so, I think it should be documented much more clearly. If it is so, then this message is a bug report. There's an assert in archive/basic_binary_iprimitive.hpp:98 that can be triggered if the bytes in the archive which represent a bool actually contain a value other than 0 or 1. One can trigger this in a test case like so (on x86_64 Linux, at least): ========== #include <boost/archive/binary_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> #include <fstream> int main() { { std::ofstream of("archive.bin", std::ios_base::binary); boost::archive::binary_oarchive oa(of); unsigned char i = 2; oa << i; } { std::ifstream f("archive.bin", std::ios_base::binary); boost::archive::binary_iarchive ia(f); bool b; // note different type than what was saved, but same size ia >> b; // assert! } } ========== Let me know if this is a bug that I should report to the tracker, or a feature. Thanks, -Gabe

3 3

BGL - shortest widest path
by Mark Fanara 12 Nov '14

12 Nov '14

I am trying to find the "shortest-widest path" between a single source and target node in an undirected graph (less than 25 nodes). (In my case, a shortest widest path is the maximum bandwidth path. If there are several such paths, it is the one with the least number of hops.) See W i k i p e d i a entry on "Widest path problem" I have successfully used dijkstra_shortest_paths() with a custom combine() function to find the maximum bandwidth path, however this does not take into account the possibility of more than one path with the same maximum bandwidth. In that case, I am looking for the one with the fewest hops. I am not clear on the meaning of some of the graph theory terms --- Is the problem I am trying to solve similar too, or the same as, a maximum flow problem? If so, as I am using an undirected graph, which boost algorithm should I use and how should I create a directed graph from my undirected graph? Would really appreciate an example, perhaps something that prints the resulting vertices in from-source-to-sink order.

1 0

[Test] failure linking tests dynamically
by Latimerius 11 Nov '14

11 Nov '14

Hello, I'm evaluating Boost.Test. I did the initial evaluation using the header-only variant and now I'd like to move to dynamic linking the Test library for a larger-scale deployment. However, all attempts so far failed due to Undefined symbols for architecture x86_64: "_main", referenced from: implicit entry/start for main executable ld: symbol(s) not found for architecture x86_64 I'd put it down to my lack of experience with Test, or Boost in general, however I noticed that my libs/test/example's don't seem to build either. I'm on OS X Yosemite. I compile Boost with ./bootstrap.sh --prefix=<my_dir> ./b2 cxxflags="-stdlib=libc++" linkflags="-stdlib=libc++" ./b2 install As this doesn't seem to compile the necessary .dylibs I added <define>BOOST_TEST_DYN_LINK=1 <link>shared to the "requirements" section of the first target in libs/test/build/Jamfile.v2 and rebuilt just Boost.Test. Although I don't actually know what I was doing, this did seem to build the Boost.Test dynamic libraries, which tests are however failing to link against. The result looks the same on 1_56_0 and 1_57_0. Could someone please help me find the problem? I'm dubious about my building procedure in particular, could someone give me a complete sequence of steps necessary to build Boost with Boost.Test ready to be linked dynamically? I check the documentation, which is good and detailed but deals with various aspects in isolation and doesn't give a newcomer a good idea of the overall process. Cheers!

2 4

boost.container.vector::operator==() bug?
by niXman 10 Nov '14

10 Nov '14

Hi, https://github.com/boostorg/container/blob/master/include/boost/container/v… Explained: if ( !(1 != 1) ) Another question is, why 'memcmp()' not used for vectors of fundamental types? -- Regards, niXman ___________________________________________________ Dual-target(32 & 64-bit) MinGW-W64 compilers for 32 and 64-bit Windows: http://sourceforge.net/projects/mingw-w64/ ___________________________________________________ Another online IDE: http://liveworkspace.org/

4 10

lockfree::spsc_queue & move semantics
by Thomas Danckaert 10 Nov '14

10 Nov '14

I'd like to use a spsc_queue of unique_ptr's to bigger objects, to transfer ownership between threads. That way, I can create/allocate an object in a non-realtime thread, then transfer ownership to a realtime thread using a lockfree queue, and, using another queue, pass on the unique_ptr to another thread that takes care of cleanup when the realtime thread no longer needs the it. For example: boost::lockfree::spsc_queue<unique_ptr<string>, boost::lockfree::capacity<10> > cb; Unfortunately, spsc_queue does not use move semantics (methods to push onto the queue take parameters as const reference and construct a copy in the queues internal storage), so i can not cb.push() a unique_ptr<string> onto my queue. Is it reasonable to want to add this, and if so, what would be the best place to submit a request? (I managed to get a simple example working by adding rvalue reference overrides of the queue's push() methods, and using std::move in the pop() method) bool push(T && t) { }; Also, I noticed that the destructor for the spsc_queue (with size fixed at compile-time) does not run destructors for it's contents. What could be the reason for this? Thomas

2 1

[scope_exit] 1.57 MSVC C4003 warning
by Filip Konvička 10 Nov '14

10 Nov '14

Hi, Any use of BOOST_SCOPE_EXIT in 1.57 seems to emit warning C4003 on MSVC 2012 and 2013: warning C4003: not enough actual parameters for macro 'BOOST_PP_EXPAND_I' Uncomment either line to suppress the warning. Is BOOST_PP_VARIADICS enabled by mistake for MSVC (especially 2013)? Should I explicitly set BOOST_PP_VARIADICS=0 for MSVC? Despite the warning, the code appears to work fine (i.e., the block of code gets properly called). Thanks, Filip #include <boost/version.hpp> #if defined(_MSC_VER) && BOOST_VERSION==105700 //#pragma warning(disable:4003) //#define BOOST_PP_VARIADICS 0 #endif #include <boost/scope_exit.hpp> #include <iostream> int main(int argc, char* argv[]) { int x=0; BOOST_SCOPE_EXIT((x)) { std::cout << "here " << x << std::endl; } BOOST_SCOPE_EXIT_END return 0; }

3 5

boost property tree for recursive structures
by Maurizio Vitale 10 Nov '14

10 Nov '14

Hello everybody, I'm trying to use the boost property tree library to represent recursive data structures, but although I can get the dumped json to look reasonable, I cannot traverse the ptree in any ways I've tried. The code below, compiles and run, except for the call to Dump in DumpAssign. Is there a way to traverse arbitrary trees where values can be themselves ptrees? I'm about to throw the towel and go with boost::seriaization, but I did like the traversal mechanisms property trees offer. Any suggestion? Thanks, Maurizio #include <boost/any.hpp> #include <boost/assign/list_of.hpp> #include <boost/foreach.hpp> #include <boost/property_tree/json_parser.hpp> #include <boost/property_tree/ptree.hpp> #include <boost/property_tree/xml_parser.hpp> #include <iostream> #include <string> #include <vector> #include <map> using boost::property_tree::ptree; using boost::assign::list_of; using boost::assign::map_list_of; using namespace std; ptree Op(string type, ptree a1, ptree a2) { ptree pt; // pt.put_value(type); pt.put("type", type); ptree args; args.push_back(make_pair("", a1)); args.push_back(make_pair("", a2)); pt.add_child("args", args); return pt; } ptree Net(string name) { ptree pt; pt.put("type", "net"); pt.put("name", name); return pt; } ptree Assign(ptree lhs, ptree rhs) { ptree pt; pt.put("type", "assign"); pt.add_child("lhs", lhs); pt.add_child("rhs", rhs); return pt; } string Dump(ptree::value_type e); string DumpConcat(ptree::value_type e) { string result = "{"; bool first = true; BOOST_FOREACH(const ptree::value_type& child, e.second.get_child("args")) { if (not first) { result += ", "; first = false; } result += Dump(child); } return result + "}"; } string DumpNet(ptree::value_type e) { return e.second.get<std::string>("name"); } string DumpAssign(ptree::value_type e) { string result = "assign "; // HOW TO HAVE A RECURSIVE CALL TO Dump(lhs) HERE? result += Dump(?); return result; } string DumpNop(ptree::value_type) {return "NOP";} string Dump(ptree::value_type e) { static std::map<string, string(*)(ptree::value_type)> dump = map_list_of ("net", DumpNet) ("concat", DumpConcat) ("assign", DumpAssign) ("nop", DumpNop) ; string type = e.second.get<string>("type", "nop"); return dump[type](e); } int main(int, char**) { ptree pt; ptree a1; a1.push_back(make_pair("", Assign( Op("concat", Op("concat", Net("a1"), Net("a1")), Net("w")), Net("a2")))); pt.add_child("operators", a1); cout << "=============\n"; write_json(std::cout, pt); cout << "=============\n"; BOOST_FOREACH(const ptree::value_type& e, pt.get_child("operators")) { cout << "> " << Dump(e); } }

1 0

Boost.Python shared_ptr bug?
by Christoff Kok 10 Nov '14

10 Nov '14

Hi, I found an issue when accessing a shared_ptr C++ object in Python using Boost.Python. When I try to access an attribute of the shared_ptr object read from an C++ object, I get an error telling me that the attribute does not exist. When I use raw pointers instead of shared_ptr, then there is no issue. Also, when using raw pointers, accessing an item in a list of base class objects returns the object in as the derived most class. This is wanted. When I use shared_ptrs however, the derived most object is of the base class type. This is not wanted. I am sure the Boost.Python developers should be aware of these two issues by now. If so, is there any plans to fix this? If so, when? Below is a test showing this issue: *Raw pointers:* #include<memory> #include<vector> struct Vehicle{ virtual ~Vehicle(){} int testAttribute; }; struct Boat: public Vehicle { virtual ~Boat(){} int testBoatAttribute; }; struct Garage { std::vector<Vehicle*>& vehicleList() { return m_VehicleList; } std::vector<Vehicle*> m_VehicleList; }; #include <boost/python.hpp> #include <boost/python/suite/indexing/vector_indexing_suite.hpp> BOOST_PYTHON_MODULE(garage_ext) { using namespace boost::python; class_<Garage>("Garage") .def("vehicleList", &Garage::vehicleList, return_internal_reference<1>()); class_<Vehicle,Vehicle*,boost::noncopyable>("Vehicle", no_init) .def_readwrite("testAttribute", &Vehicle::testAttribute); class_<Boat,Boat*,bases<Vehicle>>("Boat") .def_readwrite("testBoatAttribute", &Boat::testBoatAttribute); implicitly_convertible<Boat*, Vehicle*>(); class_<std::vector<Vehicle*> >("stl_vector_Vehicle_ptr") .def(vector_indexing_suite<std::vector<Vehicle*>>()); } *Shared pointers:* #include<memory> #include<vector> #include <boost/shared_ptr.hpp> struct Vehicle{ virtual ~Vehicle(){} friend bool operator==(const Vehicle& lhs, const Vehicle& rhs) { return true; } int testAttribute; }; struct Boat: public Vehicle { virtual ~Boat(){} friend bool operator==(const Boat& lhs, const Boat& rhs) { return true; } int testBoatAttribute; }; struct Garage { friend bool operator==(const Garage& lhs, const Garage& rhs) { return true; } std::vector<boost::shared_ptr<Vehicle>>& vehicleList() { return m_VehicleList; } std::vector<boost::shared_ptr<Vehicle>> m_VehicleList; }; #include <boost/python.hpp> #include <boost/python/suite/indexing/vector_indexing_suite.hpp> BOOST_PYTHON_MODULE(garage_ext){ using namespace boost::python; class_<Garage>("Garage") .def("vehicleList", &Garage::vehicleList, return_internal_reference<1>()); class_<Vehicle,boost::shared_ptr<Vehicle>,boost::noncopyable>("Vehicle", no_init) .def_readwrite("testAttribute", &Vehicle::testAttribute); class_<Boat,boost::shared_ptr<Boat>, bases<Vehicle>>("Boat") .def_readwrite("testBoatAttribute", &Boat::testBoatAttribute); implicitly_convertible<boost::shared_ptr<Boat>, boost::shared_ptr<Vehicle>>(); class_<std::vector<boost::shared_ptr<Vehicle>> >("stl_vector_Vehicle_ptr") .def(vector_indexing_suite<std::vector<boost::shared_ptr<Vehicle>>>()); } *Python test:* from garage_ext import * g = Garage() l = g.vehicleList() newboat = Boat() newboat.testAttribute = 3 newboat.testBoatAttribute = 5 l.append(newboat) print(type(l[0])) print(str(hasattr(l[0],"testAttribute"))) print(str(l[0].testAttribute)) b = l[0] print(type(b)) print(str(b.testBoatAttribute)) print("Done.") *Raw pointer result:* <class 'garage_ext.Boat'> True 3 <class 'garage_ext.Boat'> 5 Done. *Shared pointer result:* <class 'garage_ext.*Vehicle*'> *// Expected it to be Boat as with Raw pointers* Traceback (most recent call last): File "test_garage.py", line 9, in <module> print(str(hasattr(l[0],"testAttribute"))) *// Expected attribute to exist as with Raw pointers. Note: dir(l[0]) shows that it has the attribute. Accessing the attribute however throws an error.* Boost.Python.ArgumentError: Python argument types in None.None(Vehicle) did not match C++ signature: None(Vehicle {lvalue}) Kind Regards, Christoff

1 0

MSM library: documentation graphics
by Ricardo Cruz 09 Nov '14

09 Nov '14

Dear all, I am considering adopting boost MSM library for the statecharts in my project. It looks awesome. The documentation has several graphical representations of the state machines: http://www.boost.org/doc/libs/1_57_0/libs/msm/doc/HTML/index.html They look automatically generated. Are they? If so, what tool was used? I did not find that information anywhere in the documentation. Sorry if I miss it. Best wishes, Ricardo Cruz

2 1

Bidirectional breadth first search?
by Amanda Robson 08 Nov '14

08 Nov '14

Hi Does anyone know if Boost already supports bidirectional breadth first search? If not, how feasible would it be to extend boost’s bfs implementation to become bidirectional? Thanks. Amanda

1 0

iterator adaptor not inheriting pointer typedef
by Matei David 08 Nov '14

08 Nov '14

Hi, I have some questions about the Boost Iterator library. I've recently discovered the "hard way", meaning through impenetrable TMP error messages :), that when using boost::iterator_adaptor, the derived iterator type does not (always??) inherit the pointer typedef of the base iterator type. I mean, the iterator_adaptor glue class does not have this typedef. So, for example, I have a Base_Iterator type with: Base_Iterator::pointer != Base_Iterator::value_type* If I do: class Derived_Iterator : public boost::iterator_adaptor< Derived_Iterator, Base_Iterator > {...} then, strangely I find: Derived_Iterator::value_type == Base_Iterator::value_type (OK) Derived_Iterator::pointer == Base_Iterator::value_type* != Base_Iterator::pointer (not OK) I looked at the documentation, and I did find a mention of this, but only for iterator_facade, here: http://www.boost.org/doc/libs/develop/libs/iterator/doc/iterator_facade.html The corresponding page for iterator_adaptor does not mention the pointer typedef at all. While for facade using a plain pointer seems ok (no other reasonable default), I would argue that for adaptor this is not ok. Is this expected behaviour or a bug? Within the same setting, and in what could be a related issue, I also found that the intermediate boost::iterator_adaptor<> class does not seem to contain the default/common sense definition: Base_Iterator operator->() const { return this->base(); } I didn't look inside the source code of boost::iterator_adaptor, but I found a situation where I have to put this definition explicitly inside Derived_Iterator for my code to compile (without it, it doesn't). Does this sound like expected behaviour? Thanks M

2 2

Flyweight: constexpr user defined literals
by Akim Demaille 07 Nov '14

07 Nov '14

Hi all, Hi Joaquin, I'm using flyweights of strings (aka symbols) for my "format" arguments: a key that specifies the kind of output that should be produced by the printing routines. Sometimes, I have code that roughly resembles to: print_entry_(src, dst, o, dot2tex_ ? symbol("latex") : symbol("text")); My question is: do we have constexpr constructors with Flyweight in such a way that I could have something like: print_entry_(src, dst, o, dot2tex_ ? "latex"sym : "text"sym); and have a single construction of these guys not matter how many times I go throw this piece of code, or should I build them once for all in say a member? print_entry_(src, dst, o, dot2tex_ ? sym_latex : sym_text); I've seen nothing about "constexpr" in the doc.

2 1

Re: [Boost-users] iterator_facade Boost 1.57
by Matei David 07 Nov '14

07 Nov '14

On Tue, 04 Nov 2014 14:07:09 +0000 (UTC) gast128 wrote: > Dear all, > > Just trying out 1.57, since we are already 5 releases behind due to > all kinds of compilation errors with Boost and our software. Below > simplified code doesn't compile on vs2010: > > template <typename DerivedType> > struct IteratorFacade : public boost::iterator_facade<DerivedType, > int, std::random_access_iterator_tag> > { > typedef boost::iterator_facade<DerivedType, int, > std::random_access_iterator_tag> base; > > IteratorFacade (); > virtual ~IteratorFacade (); > > friend class boost::iterator_core_access; > > reference dereference () const; > }; > > struct MyIteratorFacade : IteratorFacade<MyIteratorFacade> > { > }; > > What do I wrong? Hi, I'm gcc 4.9.1 on Ubuntu 14.04. The reason this doesn't compile is that the "reference" typedef is contained in the glue class boost::iterator_facade, which is a base class of IteratorFacade<MyIteratorFacade>. When you write "reference" inside the later, the name is not being looked up in the base class. So you should write: typename base::reference dereference() const; If you want to use "reference" in many places in IteratorFacade<>, pull the typedef from its base with: typedef typename base::reference reference; or, if using C++11: using typename base::reference; Note: whether you pull it up or not, you can always get the typedef as IteratorFacade<...>::reference, or MyIteratorFacade::reference in your case. (See the example below, where I'm not pulling it up, but I can still find it.) I would also add the observation that your construct creates an unusual derivation. Usually, the iterator class you want to define has boost::iterator_facade as its direct base. In your case, boost::iterator_facade is the base of the base of your iterator class (so, 2 levels down): MyIteratorFacade : IteratorFacade<MyIteratorFacade> : boost::iterator_facade<MyIteratorFacade, ...> I'm not sure this would cause any problems, just be on the lookout for missing constructors. For example, this compiles just fine for me: #include <type_traits> #include <boost/iterator/iterator_facade.hpp> struct MyIteratorFacade : public boost::iterator_facade<MyIteratorFacade, int, std::random_access_iterator_tag> { typedef boost::iterator_facade<MyIteratorFacade, int, std::random_access_iterator_tag> base; MyIteratorFacade (); virtual ~MyIteratorFacade (); friend class boost::iterator_core_access; typename base::reference dereference() const; }; static_assert(std::is_same< MyIteratorFacade::value_type, int >::value, "MyIteratorFacade::value_type != int"); static_assert(std::is_same< MyIteratorFacade::reference, int& >::value, "MyIteratorFacade::reference != int&"); static_assert(std::is_same< MyIteratorFacade::pointer, int* >::value, "MyIteratorFacade::pointer != int*"); static_assert(std::is_same< std::iterator_traits<MyIteratorFacade>::value_type, int >::value, "iterator_traits<MyIteratorFacade>::value_type != int"); static_assert(std::is_same< std::iterator_traits<MyIteratorFacade>::reference, int& >::value, "iterator_traits<MyIteratorFacade>::reference != int&"); static_assert(std::is_same< std::iterator_traits<MyIteratorFacade>::pointer, int* >::value, "iterator_traits<MyIteratorFacade>::pointer != int*"); I compile with: g++ -Wall -Wextra -pedantic -std=c++11 -I${BOOST_INCLUDE_1_57} -c (I'm only using c++11 for static_assert.) M

1 0

Boost.Python C++ pointer object to python: Attribute does not exist.
by Christoff Kok 07 Nov '14

07 Nov '14

Hi, I'm struggling with the following issue in a boost.python implementation: I have a list of std::shared_ptr in C++, I am accessing this list from Python. - When I access an element in the list, the elements does not have any attributes apparently. I get an error trying to access an attribute, hasattr returns false on the attribute, but dir informs me that it exist. - When I change the C++ implementation from shared_ptr to raw ptr's everything works as expected. - I want to use shared_ptrs for what I feel: obvious reasons. Below is the C++ code and the Python code. ################### ### garage_ext.cpp ### ################### #include<memory> #include<vector> namespace boost { template<class T> T* get_pointer(std::shared_ptr<T>& p){ return p.get(); }} struct Vehicle{ virtual ~Vehicle(){} friend bool operator==(const Vehicle& lhs, const Vehicle& rhs) { return true; } int testAttribute; }; struct Boat: public Vehicle { virtual ~Boat(){} friend bool operator==(const Boat& lhs, const Boat& rhs) { return true; } int testBoatAttribute; }; struct Garage { friend bool operator==(const Garage& lhs, const Garage& rhs) { return true; } std::vector<std::shared_ptr<Vehicle>>& vehicleList() { return m_VehicleList; } std::vector<std::shared_ptr<Boat>>& boatList() { return m_BoatList; } std::vector<std::shared_ptr<Vehicle>> m_VehicleList; std::vector<std::shared_ptr<Boat>> m_BoatList; }; #include <boost/python.hpp> #include <boost/python/suite/indexing/vector_indexing_suite.hpp> class BoatWrap : public Boat, public boost::python::wrapper<Boat> { public: static std::shared_ptr<Boat> cast(std::shared_ptr<Vehicle> const& v) { return std::dynamic_pointer_cast<Boat>(v); } }; BOOST_PYTHON_MODULE(garage_ext) { using namespace boost::python; class_<Garage>("Garage") .def("vehicleList", &Garage::vehicleList, return_internal_reference<1>()) .def("boatList", &Garage::boatList, return_internal_reference<1>()) ; class_<Vehicle, std::shared_ptr<Vehicle>,boost::noncopyable>("Vehicle", no_init) .def_readwrite("testAttribute", &Vehicle::testAttribute) ; class_<BoatWrap,std::shared_ptr<Boat>,bases<Vehicle>>("Boat") .def("cast", &BoatWrap::cast) .staticmethod("cast") .def_readwrite("testBoatAttribute", &Boat::testBoatAttribute) ; implicitly_convertible<std::shared_ptr<Boat>,std::shared_ptr<Vehicle>>(); class_<std::vector<std::shared_ptr<Vehicle>> >("stl_vector_Vehicle_ptr") .def(vector_indexing_suite<std::vector<std::shared_ptr<Vehicle>> >()); class_<std::vector<std::shared_ptr<Boat>> >("stl_vector_Boat_ptr") .def(vector_indexing_suite<std::vector<std::shared_ptr<Boat>> >()); } ##################### ### Python test code ### ##################### g = Garage() l = g.boatList() newboat = Boat() l.append(newboat) boatFromList = l[0] print(type(boatFromList)) print(str(hasattr(newboat,"testBoatAttribute"))) dir(boatFromList) # The following line throws the error. print(str(hasattr(boatFromList,"testBoatAttribute"))) I created a cast method for boat. If I cast l[0] to Boat using: boatFromList = Boat.cast(l[0]) print(str(hasattr(boatFromList,"testBoatAttribute"))) works. This is all very strange to me. It feels very buggy. Could someone please help me clarify the reason for this behavious? Regards, Christoff

1 0

reference_wrapper on Boost 1.57
by gast128 06 Nov '14

06 Nov '14

This gives also a compilation error on vs2010: void F() { boost::reference_wrapper<float (* const)(float)> wrap(&cosf); //std::reference_wrapper<float (* const)(float)> wrap(&cosf); //ok } 1>KTestCuj2005June1.cpp(182): error C2248: 'boost::reference_wrapper<T>::reference_wrapper' : cannot access private member declared in class 'boost::reference_wrapper<T>' 1> with 1> [ 1> T=float (__cdecl *const )(float) 1> ] 1> C:\work sdk\boost_1_57_0\boost/core/ref.hpp(85) : see declaration of 'boost::reference_wrapper<T>::reference_wrapper' 1> with 1> [ 1> T=float (__cdecl *const )(float) 1> ] ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

1 1

Boost on Google+
by Vladimir Prus 06 Nov '14

06 Nov '14

Hi, I've created a Google+ community for Boost, and everybody is welcome to join here: https://plus.google.com/communities/106814259809358442744 I don't have any great plan here, but a lot of tech people are active on G+, so why not? -- Vladimir Prus CodeSourcery / Mentor Embedded http://vladimirprus.com

1 0

boost 1.57: MS VS2008: unknown pragma in type_index.hpp
by Andreas Wehrmann 05 Nov '14

05 Nov '14

Hi! I've just compiled boost 1.57 with MS VS2008 x86 and this warning came all over the place: main\lib\boost_1_57_0\boost\type_index.hpp(37) : warning C4068: unknown pragma Still, the compilation went fine and everything seems to work as usual. It's just somewhat annoying because this warning pops up very often when I compile my applications. Regards, Andreas

2 1

[Optional] Possible bug with VS2008
by dariomt＠gmail.com 05 Nov '14

05 Nov '14

Hi, The following minimal test case does not compile with VS2008 (using Boost 1.55) #include <boost/optional.hpp> struct A { int T; }; int main() { boost::optional<A> a; } The error is, edited for clarity: boost\optional\optional.hpp(479) : error C2523: 'A::~T' : destructor tag mismatch boost\optional\optional.hpp(479) : while compiling class template member function 'void boost::optional_detail::optional_base<T>::destroy_impl(boost::optional_detail::optional_base<T>::is_not_reference_tag)' with [ T=A ] boost\optional\optional.hpp(500) : see reference to class template instantiation 'boost::optional_detail::optional_base<T>' being compiled with [ T=A ] main.cpp(8) : see reference to class template instantiation 'boost::optional<T>' being compiled with [ T=A ] After much head-scratching, I found out the culprit: the name of the integer member!! The compiler confuses the name of member 'T' with the name of the template parameter 'T' when trying to invoke its destructor... The offending code is void destroy_impl ( is_not_reference_tag ) { get_ptr_impl()->T::~T() ; m_initialized = false ; } Given that I cannot change struct A, is there a way to fix this? Is this a compiler bug or a Boost.Optional bug? Thanks in advance!

1 0

Spirit with UI Tools
by Philipp Kraus 05 Nov '14

05 Nov '14

Hello, I would like to create a small parser with Boost.Spirit. I have run the short examples and everything works well, so I would like to create my own LL grammar. In my case I need also for documentation a EBNF or something else and in the best case I can would like to create the EBNF first and transform this into the Spirit LL grammar code. Did you know any tools to do this? My first idea is to use AntLR to create the grammar but imho it creates a LR grammar. Can you recommend a tool to define the grammar structure and generate the Spirit code? Thanks a lot Phil

3 6

Boost.Variant on Boost 1.57
by gast128 04 Nov '14

04 Nov '14

hello all, I get a compilation error with Boost.Operators and boost.Variant on vs2010: struct KFoo : boost::totally_ordered<KFoo> { }; bool operator<(const KFoo&, const KFoo&); bool operator==(const KFoo&, const KFoo&); void Foo() { boost::variant<KFoo> var; var.swap(var); } 1>C:\work sdk\boost_1_57_0\boost/variant/detail/move.hpp(60): error C2668: 'boost::swap' : ambiguous call to overloaded function 1> C:\work sdk\boost_1_57_0\boost/core/swap.hpp(54): could be 'void boost::swap<T,T>(T1 &,T2 &)' [found using argument-dependent lookup] 1> with 1> [ 1> T=T0, 1> T1=T0, 1> T2=T0 1> ] 1> C:\work sdk\boost_1_57_0\boost/variant/detail/move.hpp(44): or 'void boost::detail::variant::move_swap_fallback::swap<T,T>(T1 &,T2 &)' anyone?

1 0

bjam building with error
by NtVisigoth 04 Nov '14

04 Nov '14

Hello, I cannot compile bjam.exe and I see error. I have googled and I see my trouble here: Name: "Build.bat does not autodetect msvc on 64-bit Windows when building bjam" URL: https://svn.boost.org/trac/boost/ticket/1091 To reproduce: 0. cd <boos libraries directory> 1. Start cmd.exe. 2. Then start bootstrap.bat I see: d:\projects\cpp-workspace\boost-libraries>bootstrap.bat Building Boost.Build engine \\Vim\\vim74\\";c:\portable-programs\adt-bundle-windows-x86_64\sdk\\platform-tools;c:\portable-progr ams\adt-bundle-windows-x86_64\sdk\\tools" was unexpected at this time. d:\projects\cpp-workspace\boost-libraries\tools\build\src\engine> What can I do to compile bjam ?

1 0

problem with #include <boost/thread.hpp>
by Grison PG Pierre (External DEXIA-US) 04 Nov '14

04 Nov '14

Hello, I encounter a problem with the Thread library. The library works fine when I use it in a .exe project. It means it has been correctly built. Then I try to use the same library in an DLL project (so as to build a XLL object thanks to the XLW library). But as soon as I add the line #include <boost/thread.hpp> to my project, even if it compile without any problem, I get the following message when I debug my project through Excel: The file you are trying to open, "mylibrary.xll" is in a different format than specified by the file extension, Verify that the file is not corrupted [...]. Do you want to open the file now? And I can no more use my C++ functions in Excel. Do you have already encounter this problem? I use VS2010. I have tried both Multi-threaded Debug DLL (/MDd) and Multi-threaded DLL (/MD) options. My solution includes two other static libraries and also with the classic RunInterfaceGenerator XLW-project (the one which is executed when debugging). Regards, Pierre

2 1

iterator_facade Boost 1.57
by gast128 04 Nov '14

04 Nov '14

Dear all, Just trying out 1.57, since we are already 5 releases behind due to all kinds of compilation errors with Boost and our software. Below simplified code doesn't compile on vs2010: template <typename DerivedType> struct IteratorFacade : public boost::iterator_facade<DerivedType, int, std::random_access_iterator_tag> { typedef boost::iterator_facade<DerivedType, int, std::random_access_iterator_tag> base; IteratorFacade (); virtual ~IteratorFacade (); friend class boost::iterator_core_access; reference dereference () const; }; struct MyIteratorFacade : IteratorFacade<MyIteratorFacade> { }; What do I wrong?

1 0

Re: [Boost-users] Boost 1.57.0 has been released
by Tom Kent 04 Nov '14

04 Nov '14

> > Release 1.57.0 of the Boost C++ Libraries is now available. > These open-source libraries work well with the C++ Standard Library, and > are usable across a broad spectrum of applications. > The Boost license encourages both commercial and non-commercial use. > This release contains no new libraries and numerous enhancements and bug > fixes for existing libraries. > For details, including download links, see > http://www.boost.org/users/news/version_1.57.0 > You can also download directly from SourceForge: > http://sourceforge.net/projects/boost/files/boost/1.57.0/ > To install this release on your system, see > http://www.boost.org/doc/libs/release/more/getting_started/index.html > Thanks, > --The Boost release team > Vladimir Prus > Rene Rivera > Marshall Clow > Eric Niebler > Daniel James > Beman Dawes The corresponding windows binaries for msvc-8.0 (SP1), msvc-9.0 (SP1), msvc-10.0 (SP1), msvc-11.0 (Update 4) and msvc-12.0 (Update 3) in 32 & 64 bit versions are now also available from sourceforge. https://sourceforge.net/projects/boost/files/boost-binaries/1.57.0/ Tom Kent

1 0

Re: [Boost-users] [Boost-announce] Boost 1.57.0 has been released
by Marshall Clow 04 Nov '14

04 Nov '14

> Hi Marshall, > > I wonder if the "Beta Issues” section on the release notes page (http://www.boost.org/users/history/version_1_57_0.html) is correct,… Looks like a copy-paste leftover from the beta version. Several people reported this. Thank you. It has been fixed. — Marshall

1 0

Boost 1.57.0 has been released
by Marshall Clow 03 Nov '14

03 Nov '14

Release 1.57.0 of the Boost C++ Libraries is now available. These open-source libraries work well with the C++ Standard Library, and are usable across a broad spectrum of applications. The Boost license encourages both commercial and non-commercial use. This release contains no new libraries and numerous enhancements and bug fixes for existing libraries. For details, including download links, see http://www.boost.org/users/news/version_1.57.0 You can also download directly from SourceForge: http://sourceforge.net/projects/boost/files/boost/1.57.0/ To install this release on your system, see http://www.boost.org/doc/libs/release/more/getting_started/index.html Thanks, --The Boost release team Vladimir Prus Rene Rivera Marshall Clow Eric Niebler Daniel James Beman Dawes

4 3

[Test] How to log output to both stdout in HRF and to a file in XML?
by Martin Ba 03 Nov '14

03 Nov '14

As asked on SO: http://stackoverflow.com/questions/26505229/how-to-log-boost-test-output-to… I would like to enable logging of Boost.Test output to *both* the stdout/sterr and to a logfile. However, I would also like to have the stdout logging be in HumanReadableFormat and only the file output be in XML format. Generating a report file seems to be addressed [here][1]. ([official docs][2]) Choosing the format can be done in [various ways][3], but it seems one is stuck with either HRF or XML? ----------- Rationale: When running tests on or [Jenkins][4] server, the [xUnit plugin][5] [requires][6] the **log** XML output (as opposed to the *report* XML output -- `log_level` vs. `report_level`). However, the in-progress log output (in HRF) is highly valuable *while* the tests are running on the server, to detect hanging tests or to a quick manual check of where the tests currently are. So I want an in-progress HRF log for the tests and at the end I need an XML file containing the `<TestLog>...</TestLog>` output of Boost.Test (not the `<TestResult>` output). Do note that we run both unit as well as integration tests via Boost.Test, so some of them are quite long-running. [1]: http://stackoverflow.com/questions/3786639/what-is-the-better-way-to-genera… [2]: http://www.boost.org/doc/libs/1_44_0/libs/test/doc/html/utf/user-guide/test… [3]: http://www.boost.org/doc/libs/1_44_0/libs/test/doc/html/utf/user-guide/runt… [4]: http://jenkins-ci.org/ [5]: https://wiki.jenkins-ci.org/display/JENKINS/xUnit+Plugin [6]: https://issues.jenkins-ci.org/browse/JENKINS-13686

2 1

ASIO: Windows/Linux/Mac socket inter-operability
by Joost Kraaijeveld 03 Nov '14

03 Nov '14

Hi, I have a C/S-application that uses ASIO-sockets. The application runs fine if I try to connect between 2 Windows or 2 Linus or 2 Mac machineas. However, it fails to work with a "reset by peer" error if I try to connect between Windows and Linux, Windows and Mac or Linux and Mac. Is there anything known about problems wrt inter-os connections, and if so, is there a solution for this? TIA -- Groeten, Joost Kraaijeveld Molukkenstraat 14 6524NB Nijmegen tel: 024-3607445 / 06-51855277

3 7

Boost IOStream - Buffer as an input stream
by Lloyd 03 Nov '14

03 Nov '14

Hi, We am trying to use a buffer as an input stream. For that we have used "basic_array_source" like this boost::iostreams::basic_array_source<BYTE> source(mem_ptr,size); boost::iostreams::stream<boost::iostreams::basic_array_source <BYTE>> streamReader; streamReader.open(source, std::ios::binary); But this method does not give input-stream related methods (functions like seekg), instead it give methods related to output stream (seekp). Can you please tell what is wrong with this approach? Thanks, Lloyd

1 0

[1.57.0] Release candidates available
by Marshall Clow 03 Nov '14

03 Nov '14

[ Please disregard previous message; apparently I am brain-dead this morning. The uploaded files are correct, though. ] Release candidate files for 1.57.0 are available at http://boost.cowic.de/rc/ As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. This helps ensure the candidates build OK before we push them out to SourceForge. The files (and associated md5s) are: MD5 (./boost_1_57_0_rc1.7z) = 17c98dd78d6180f553fbefe5a0f57d12 MD5 (./boost_1_57_0_rc1.tar.bz2) = 1be49befbdd9a5ce9def2983ba3e7b76 MD5 (./boost_1_57_0_rc1.tar.gz) = 25f9a8ac28beeb5ab84aa98510305299 MD5 (./boost_1_57_0_rc1.zip) = 5e040e578e3f0ba879da04a1e0cd55ff Thanks! -- The release managers P.S. Release notes are here: http://www.boost.org/users/history/version_1_57_0.html

3 3

[Asio] null_buffer behaviors
by lin li 03 Nov '14

03 Nov '14

Hi, guys. In the doc of asio, it says 'A null_buffers operation doesn't return until the I/O object is "ready" to perform the operation'. But when I use it on a server side socket, i.e. a socket created by "accept" call when a new connection has arrived. It seems to return immediately even the other end has not started to send the data yet. Is this normal?

1 0

How to know whether a boost heade has been included?
by Vincenzo Romano 03 Nov '14

03 Nov '14

I thought I could check for the symbol BOOST_VERSION to be defined. But, as of v1.55, it's not the case at least for the <boost/any.hpp> header. Any hint? Thanks in advance.

1 0

[boost.variant] accessing variant with pattern-matching instead of visitors
by Roger 02 Nov '14

02 Nov '14

Hi! The CppCon 2014, Yuriy Solodkyy had an interesting talk "Accept no visitors"(*). It presents an alternative accessing technique for variant data-type. It basically use pattern matching syntax, similar to that in functional languages, instead of visitors. I think this would be a great benefit for boost::variant data-type... being able to access variables from the same scope, group states similar in behavior, and take care of the loop unrolling for dispatching oneself. Especially when using variant as polymorphism, like the other interesting CppCon 2014 talking, Jason Lucas "Polymorphism with Unions" (**) covered. Would it be worth to implement a tiny pattern-matching library for boost::variant itself? Has anyone elaborated with this? Thanks for any hints! /perrog * Yuriy Solodkyy "Accept no visitors, http://youtu.be/QhJguzpZOrk ** Jason Lucas "Polymorphism with Unions", http://youtu.be/uii2AfiMA0o

1 0

(no subject)
by Johnny McCullough 01 Nov '14

01 Nov '14

I'm new to boost, and I'm wondering about the best / most efficient way to transfer a large dataset via boost::asio. I've retrieved a datasetfrom a database (Cassandra) and I'm using boost asio to provide a network service that responds to queries. So I have a client socket and a dataset. I have to iterate the dataset, perform some simple formatting (e.g. csv, json, xml), then write it out to the client socket. But there's a lot of data. Perhaps gigabytes. So my initial thoughts were the producer / consumer pattern - the producer writing to a streambuf and the consumer async_write-ing it out to the client's socket. But I'm not sure this is a good approach - I know that streambuf isn't threadsafe and so managing the streambuf with locks may well become a performance bottleneck. Obviously, I don't want to replicate what may be gigabyte(s) of data from a resultset into a buffer just so it can be written out to a socket, So should I write this data synchronously straight to the socket instead? What's the best approach to solving this kind of problem? thanks for your consideration

2 1

From: giridhar
by giridhar 31 Oct '14

31 Oct '14

Hi boost http://mountpleasanthomebuilder.com/brother.php?produce=z3ueg5w3x3gg giridhar Sent from my iPhone

1 0

[1.56.0] Release candidates available
by Marshall Clow 31 Oct '14

31 Oct '14

Release candidate files for 1.65.0 are available at http://boost.cowic.de/rc/ As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. This helps ensure the candidates build OK before we push them out to SourceForge. The files (and associated md5s) are: MD5 (./boost_1_57_0_rc1.7z) = 17c98dd78d6180f553fbefe5a0f57d12 MD5 (./boost_1_57_0_rc1.tar.bz2) = 1be49befbdd9a5ce9def2983ba3e7b76 MD5 (./boost_1_57_0_rc1.tar.gz) = 25f9a8ac28beeb5ab84aa98510305299 MD5 (./boost_1_57_0_rc1.zip) = 5e040e578e3f0ba879da04a1e0cd55ff Thanks! -- The release managers P.S. Release notes are here: http://www.boost.org/users/history/version_1_57_0.html

1 0

[PropertyTree][variant] Reading JSON into a recursive variant.
by Arindam Mukherjee 31 Oct '14

31 Oct '14

I have a recursive variant definition that can handle JSON data. Is there a way to read JSON data using PropertyTree into a recursive JSON? Here is the variant defn. #define BOOST_VARIANT_NO_FULL_RECURSIVE_VARIANT_SUPPORT #include <boost/variant.hpp> JSONNullType {}; boost::variant<std::string, double, bool, JSONNullType> jsonToken; typedef boost::make_recursive_variant< std::string, double, JSONNullType, std::map<std::string, boost::recursive_variant_>, std::vector<boost::recursive_variant_> >::type JSONValue; Regards, Arindam

1 0

[Boost.Test]: How I can write custom external main ?
by NtVisigoth 29 Oct '14

29 Oct '14

Hi, Everybody! I've 2 questions about Boost.Test usage. My general cpp-source file appmain.cpp: // more lines with "#include"-constructions #define BOOST_TEST_MODULE TestMain #include <boost/test/unit_test.hpp> My suite-source file suite1.cpp: #include <boost/test/unit_test.hpp> BOOST_AUTO_TEST_SUITE(FooFooSuite) BOOST_AUTO_TEST_CASE(testBarBarBar) { // more lines } BOOST_AUTO_TEST_SUITE_END() Questions #1: How can write external main in my general cpp-file appmain.cpp? I want usage exe-file like : test.exe d:\test-files\ Questions #2: I see these lines in the boost.test documentation: boost::unit_test::framework::master_test_suite().argc boost::unit_test::framework::master_test_suite().argv This args and argv global, are these ? Can I use this in different suites without save to global variable ? P.S.: I sorry for my English.

1 0

[type_traits] Check if implicit conversion from one type to another is possible
by Aaron Levy 29 Oct '14

29 Oct '14

Which is the correct type trait to use to check if an element of type T can be assigned to an element of type U. Is it any of the following: boost::is_convertible<T, U> std::is_assignable<U, T> Now boost::is_convertible<double, int>::value is true while std::is_assignable<int, double>::value is false. What does this signify? -- Aaron Levy aaron.levy(a)yandex.com

1 0

bjam hangs on select (in develop branch)
by Alain Miniussi 28 Oct '14

28 Oct '14

Hi, I am trying to test Boost.MPI with Intel's implementation and I am stuck while trying to run simple tests through bjam. Bjam is hangs on the select (not pselect ?) instruction of the unix exec_wait. As far as processes are concerned: PID USER PR NI S %CPU TIME+ PPID COMMAND ....................... 16882 alainm 20 0 S 0.0 0:01.61 6507 bjam 16899 alainm 20 0 T 0.0 0:00.00 16882 sh 16900 alainm 20 0 Z 0.0 0:00.00 16899 mpiexec.hydra <defunct> ....... bjam calls a generated shell (below) which calls a mpiexe.hydra which work perfectly fine outside bjam. The mpiexec.hydra dies the the shell refuses to let it go. the shell script, generated by bjam, is: =============================================== [alainm@gurney engine]$ more /proc/16899/cmdline /bin/sh LD_LIBRARY_PATH="/gpfs/scratch/alainm/view/boost/bin.v2/libs/mpi/build/intel-linux/debug:/gpfs/scratch/alainm/view/boost/bin.v2/libs/serialization/build/intel-linux/debug:/softs/ intel/composer_xe_2015.0.090/bin/lib:/softs/intel/composer_xe_2015.0.090/lib/intel64:$LD_LIBRARY_PATH" export LD_LIBRARY_PATH status=0 if test $status -ne 0 ; then echo Skipping test execution due to testing.execute=off exit 0 fi mpiexec.hydra -n 2 "../../../bin.v2/libs/mpi/test/broadcast_stl_test-2.test/intel-linux/debug/broadcast_stl_test-2" blob > "../../../bin.v2/libs/mpi/test/broadcast_stl_test-2.te st/intel-linux/debug/broadcast_stl_test-2-run.output" 2>&1 status=$? echo >> "../../../bin.v2/libs/mpi/test/broadcast_stl_test-2.test/intel-linux/debug/broadcast_stl_test-2-run.output" echo EXIT STATUS: $status >> "../../../bin.v2/libs/mpi/test/broadcast_stl_test-2.test/intel-linux/debug/broadcast_stl_test-2-run.output" if test $status -eq 0 ; then cp "../../../bin.v2/libs/mpi/test/broadcast_stl_test-2.test/intel-linux/debug/broadcast_stl_test-2-run.output" "../../../bin.v2/libs/mpi/test/broadcast_stl_test-2.test/intel- linux/debug/broadcast_stl_test-2-run" fi verbose=0 if test $status -ne 0 ; then verbose=1 fi if test $verbose -eq 1 ; then echo ====== BEGIN OUTPUT ====== cat "../../../bin.v2/libs/mpi/test/broadcast_stl_test-2.test/intel-linux/debug/broadcast_stl_test-2-run.output" echo ====== END OUTPUT ====== fi exit $status [alainm@gurney engine]$ ================================================= Note that select only test for the subprocess output, at the hanging point mpiexec.hydra is done with its outputs. Any idea ? Alain PS: there was a cmake based project some time ago, is it still active or is bjam here to stay ?

2 18

[Boost.Polygon] Union filling holes
by Julien Nicoulaud 27 Oct '14

27 Oct '14

Hi all, I am using boost/polygon to do unions of multiple polygons, and I lose holes that were in the input after the assign() operation. Here is code that demonstrates the issue: // Create outer contour Point outer[] = {gtl::construct<Point>(0, 0), gtl::construct<Point>(0, 10), gtl::construct<Point>(10, 10), gtl::construct<Point>(10, 0)}; // Create inner contour Point inner[] = {gtl::construct<Point>(2, 2), gtl::construct<Point>(8, 2), gtl::construct<Point>(8, 8), gtl::construct<Point>(2, 8)}; // Define inner contour as a polygon polygon_with_holes_data<long> input_poly_inner; gtl::set_points(input_poly_inner, inner, inner+4); // Put inner polygon in a list vector<polygon_with_holes_data<long> > inners; inners.push_back(input_poly_inner); // Create input polygon as outer contour + inner polygon list polygon_with_holes_data<long> input_poly; gtl::set_points(input_poly, outer, outer+4); gtl::set_holes(input_poly, inners.begin(), inners.end()); // Create input polygon set, insert input polygon polygon_set_data<long> input_poly_set; input_poly_set.insert(input_poly); // Create output polygon set, assign input polygon set vector<polygon_with_holes_data<long> > output_poly_set; assign(output_poly_set, input_poly_set); // Print result std::cout << output_poly_set.size() << " polys" << std::endl; std::cout << output_poly_set[0].size_holes() << " holes" << std::endl; This prints: 1 polys 0 holes Any idea what I am doing wrong ? Kind regards, Julien Nicoulaud

2 2

1.57.0 beta 1 is in a new location
by Marshall Clow 27 Oct '14

27 Oct '14

Tom Kent pointed out that I put the beta 1 files in a folder that we traditionally use for Windows binaries, so I have moved the beta files to https://sourceforge.net/projects/boost/files/boost/1.57.0.beta.1/ These are the same files as last Monday - merely in a new location. If you have already downloaded and tested the beta, thanks! - no need to do it again. — Marshall

1 0

[Geometry] Packing algorithm for r-tree?
by Jeremy Murphy 27 Oct '14

27 Oct '14

I see that a fourth node splitting algorithm for bulk loading is documented in the Introduction to spatial indexes but not listed elsewhere (such as Creation and Modification). Is it hiding in the library somewhere or is the introduction just a tantalizing sneak preview? Thanks, cheers. Jeremy

2 5

BGL, cut set
by Mads Jensen 27 Oct '14

27 Oct '14

Hi, I'm looking into how you can quickly find the cut set of a graph without having to loop over the colormap as a vector. I'm using the http://www.boost.org/doc/libs/1_56_0/libs/graph/doc/edmonds_karp_max_flow.h… (the example provided does mostly what I want, except that it uses a vector, and not a regular map). Boykov Kolmogorov also has the colormap parameter. It seems that associative_property_map could be used, but I don't really see how? Hints on how to do this will be appreciated. A lot of the examples of the Boost graph library use the preprocessor with a check similar to: #if defined(BOOST_MSVC) && BOOST_MSVC <= 1300 What's so special about this? Thank you, -- Med Venlig Hilsen / Kind regards, Mads Jensen

1 0

[Serialization] Deserialization of base class fails
by Torsten Wylegala 25 Oct '14

25 Oct '14

Hi, I'm currently trying to serialize and deserialize a derived class using boost::archive::xml_iarchive/xml_oarchive Version 1.52. Everything works fine as long as I serialize and deserialize the same class (Example 1). The attributes of the derived class and the base class are both serialized and the deserialized correctly and requestPackageOut equals requestPackageIn (the base-class attributes are equal too). But if I serialize the derived class "RequestPackage" and try to deserialize it into the base-class "Package" (Example 2) I'm getting an "input stream error" exception while trying to deserialize with ia >> BOOST_SERIALIZATION_NVP(*package);. I'm quite new to this topic and found a lot of posting but none of them seems to match and solve my exact problem. It would by very nice if somebody could help me with that. Background information: I want to use xml-serialized objects for data exchange via network and want all the packages to inherit from Package-class which carries "packageId" and therefore give me the chance to identify the incoming xml-objects and handle every package based on this id. If some information is missing I will do my best to provide it later. Torsten Example 1: int main(int argc, char** argv){ std::cout << "Started!" << std::endl; std::string serializedObject; RequestPackage requestPackageOut; RequestPackage requestPackageIn; requestPackageOut.setPackageId(3); requestPackageIn.setPackageId(0); Serializer::serialize(&serializedObject,&requestPackageOut); Serializer::deserialize(&serializedObject,&requestPackageIn); return 0; } Example 2: int main(int argc, char** argv){ std::cout << "Started!" << std::endl; std::string serializedObject; Package package; RequestPackage requestPackageOut; RequestPackage requestPackageIn; requestPackageOut.setPackageId(3); requestPackageIn.setPackageId(0); Serializer::serialize(&serializedObject,&requestPackageOut); Serializer::deserialize(&serializedObject,&package); return 0; } The Rest: namespace Serializer{ template <typename T> int serialize(std::string *serializedObject, T *package){ int returnValue = 0; std::ostringstream objectOss; boost::archive::xml_oarchive oa(objectOss); try { oa << BOOST_SERIALIZATION_NVP(package); } catch (boost::archive::archive_exception const& ex) { returnValue = 1; } serializedObject->assign(objectOss.str()); return returnValue; }; template <typename T> int deserialize(std::string *serializedObject, T *package){ int returnValue = 0; std::istringstream objectIss(*serializedObject); boost::archive::xml_iarchive ia(objectIss); try { ia >> BOOST_SERIALIZATION_NVP(*package); } catch (boost::archive::archive_exception const& ex) { std::cerr << "Error: " << ex.what() << std::endl; std::cerr.flush(); returnValue = 1; } return returnValue; }; } class RequestPackage : public Package{ private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(Package); ar & BOOST_SERIALIZATION_NVP(requestId); } int requestId; public: int getRequestId() const; void setRequestId(int requestId); }; class Package{ private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & BOOST_SERIALIZATION_NVP(packageID); } int packageID; public: int getPackageId() const; void setPackageId(int packageId); };

2 1

Boost Serialization
by Abraham, Marshel 25 Oct '14

25 Oct '14

I am trying to Serialize a class : StartPeerSessionRequest::StartPeerSessionRequest() { mProtocolVersion = 1*10000 + 14*100 + 4; mSessionFlags = 1; mMaxResponseLength = 0; mMake = "MyMake"; mModel = "MyModel"; mSerialNumber = "10000"; mTrackDelay = 0; mHeadUnitModel = "Headunit"; mCarModelYear = "2014"; mVin = "1234567980"; mVehicleMileage = 1000; mShoutFormat = 3; mNotificationInterval = 1; } template <class Archive> void StartPeerSessionRequest::serialize(Archive &ar, const unsigned int version) { ar & mProtocolVersion; ar & mSessionFlags; ar & mMaxResponseLength; ar & mMake; ar & mModel; ar & mSerialNumber; ar & mTrackDelay; ar & mHeadUnitModel; ar & mCarModelYear; ar & mVin; ar & mVehicleMileage; ar & mShoutFormat; ar & mNotificationInterval; } void StartPeerSessionRequest::save() { boost::archive::binary_oarchive oa(serlreq, boost::archive::no_header); oa << (*this); /*cout<<"\n binary_oarchive :"<<serlreq.size();*/ boost::archive::text_oarchive ota(serializedRequest, boost::archive::no_header); ota<<(*this); cout<<"\n text_oarchive :"<<serializedRequest.str()<<"size :"<<serializedRequest.str().size(); } serializedRequest.str.size() provides me a length of 87 actually it should provide me 65 bytes.( I ve counted u can figure that out from the constructor ) I suspect it is appending lengths in between. I have tried using text_archive also it doesnt work. What I need is to just plain serialize class members as it is. I guess i need to use some traits or wrappers, or boost::serialization::binary_object Please let me know Thanks Regards Marshel Abraham 3097146

2 2

"event-driven" async-receive
by Alexander Carôt 25 Oct '14

25 Oct '14

Hello all, I have question regarding the async_receive_from – operation (using UDP): Right now I have a thread, which triggers the receive call in constant intervals. This works allright if the sender sends data in the same interval or larger intervals. However, if the send intervals are (much) smaller (or if multiple senders exist) the receive-operation is not triggered often enough. Eventually I’d like the receiving socket to behave in an „event-driven “ manner – so, whenever data is there the receive-handler should be invoked. I used to work with Qt, which works this way (via signals/slots) but since I moved to boost I wonder how I can reproduce this behavior. Can anyone tell how to approach this ? Thanks in advance, best Alex

3 3

Applying Boost Phoenix to infinite sequence
by Aaron Levy 24 Oct '14

24 Oct '14

Is there a way to use Boost Phoenix to define an infinite sequence and evaluate specific terms of it, compute partial sums, etc? I am looking for pointers to specific libraries or examples. -- Aaron Levy aaron.levy(a)yandex.com

1 1

cross compile for arm setup (solved)
by John Davis 24 Oct '14

24 Oct '14

Hello I appreciate the assistance. Below is the script and results for building boost with a cross compiler. It appears to work. -------------------------- #!/bin/bash # place this script in the $BOOST_ROOT directory and invoke it like so: # ./doit.sh # Clean up any stuff left over from a previous build rm -rf /opt/xxx/boost/include rm -rf /opt/xxx/boost/lib # edit /opt/xxx/yyy/boost/boost_1_51_0/tools/build/v2/user-config.jam to add the following line # using gcc : 4.3arm : arm-linux-gnueabi-g++ : <architecture>arm <target-os>linux ; # edit /opt/xxx/yyy/boost/boost_1_51_0/tools/build/v2/user-config.jam to remove the following line # using gcc ; # Ensure we are in host development environment and not using the cross compiler. # # Later we modify path and CROSS_COMPILE variables. # Here we are just ensuring we start properly, # make sure our path does not use the cross compiler at beginning export PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/opt/java6/bin:/opt/java6/db/bin:/opt/java6/jre/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl export CROSS_COMPILE= # In this stage, we are using the host compiler. # setup env variable for $BOOST_DIR # I'm not sure if this is being used, but set it just in case. export BOOST_ROOT=/opt/xxx/yyy/boost/boost_1_51_0 # Its important that the next step is run from $BOOST_DIR/tools/build/v2 aka /opt/xxx/yyy/boost/boost_1_51_0/tools/build/v2 cd $BOOST_ROOT/tools/build/v2 # NOTE: ask if we have removed gcc and replaced gcc with cross compiler in user-config.jam am I really # invoking gcc-arm below? Its not in my path at this point. ./bootstrap.sh --with-toolset=gcc echo current working directory is $PWD # checkpoint exit # At this point, /opt/xxx/boost is still empty. # # The ./bootstrap.sh script executed above in the tools/build/v2 directory # is complete and gives the following output: # #Bootstrapping the build engine with toolset gcc... engine/bin.linuxx86_64/bjam # #Bootstrapping is done. To build and install, run: # # ./b2 install --prefix=<DIR> # # !!! ERROR # We can't run b2 at this point, because we don't have the cross compiler in # our path yet. It dies looking for arm-linux-gnueabi-g++ # Furthermore, even though we were running in the tools/build/v2 directory # the explicit path of running ./b2 in the current directory is wrong. # Instead it should be run from the root directory. # This command failed at this point, try it again later with different CWD and # different options. #./b2 toolset=gcc install --prefix=/opt/xxx/boost #exit # At this point in the script, we have preconfigured the build of the libraries using # the cross compiler, the build tools which run on the host to build the libraries # are built (according to docs. where they are located is beyond me) , and our original project-config.jam file is still in place since # we issued bootstrap.sh in the v2 subdirectory. We need to change working # directories back to the root. # It builds b2 in the tools driectory. Maybe this is what the docs are referring to above? #cd $BOOST_ROOT #echo current working directory is $PWD #exit # We are switching to the cross compiler at this point, ensure it is in the # path first. # Setup path so that gcc from cross compiler is first in the path # also specify cross_compiler env variable in case its used. # # this will find the cross compiler for those who dont use the prefix, ie. gcc export PATH=/opt/arm/usr/local/arm-linux-gnueabi/bin:$PATH # this will find the cross compiler for those who use the prefix, ie. arm-linux-gnueabi-gcc export PATH=/opt/arm/usr/local/bin:$PATH # this will set the cross compiler prefix for those who use it. This export # is not used by Boost.Build but keep it here for our app which uses boost. export CROSS_COMPILE=arm-linux-gnueabi- # since we installed boost.build stuff to /opt/xxx/boost # in the step above, add that to the path for the next step as well. # Its currently empty but maybe it needs to be set during the next step. export PATH=/opt/xxx/boost/bin:$PATH # build boost.build so that we can build boost or are we building boost at this point? # # WARNING!!! # Specify an install directory so that it doesn't put the results in /usr/local/bin. # Even if you dont specify install as an option to ./b2 it will attempt to copy files to /usr/bin # in the following step! # # /opt/xxx/boost is where we want results. Our code will this dir in order to use boost. # /opt/xxx/yyy/boost/boost_1_51_0 is the top of the boost src. We are building beneath there. #./b2 --toolset=gcc-4.3arm --prefix=/opt/xxx/boost # hmm. I did not get any .a or .so after that last step. Try to add a install parameter. #./b2 toolset=gcc-4.3arm --prefix=/opt/xxx/boost --build-type=complete --layout=versioned # hmm. I did not get any .a or .so after that last step. Try to add a install parameter. # Above we use --with-toolset=, here we use just toolset= # It was suggested to use the additional options below (i'm not sure why, consider them later.) # --without-python # -sNO_BZIP2=1 ./b2 toolset=gcc-4.3arm --without-python --debug-configuration --prefix=/opt/xxx/boost --build-type=complete --layout=versioned install # running b2 using above syntax from the tools/v2/build directory, we have the following in the /opt/xxx/boost dir: # the version of b2 here is x86_64 # /opt/xxx/boost/bin/b2 # /opt/xxx/boost/bin/bjam # /opt/xxx/boost/share/boost-build/ whole subtree cd $BOOST_ROOT echo current working directory is $PWD /opt/xxx/boost/bin/b2 toolset=gcc-4.3arm --without-python --debug-configuration --prefix=/opt/xxx/boost --build-type=complete --layout=versioned install # At this point, we have the cross compiler in our path first. We are good to go for building our code using boost # with the cross compiler. ------------------------------------------------------------- -- John F. Davis 6 Kandes Court Durham, NC 27713 919-888-8358 独树一帜

1 0

Map Binary archive problem May be a bug?
by Joshua Nocturne 24 Oct '14

24 Oct '14

On my phone, so I try my best to describe my problem. std::map<int,int> myMap; for(int i = 0; i != 30; i++) myMap.insert( make_pair(i,i+1) ); ofstream ofs("test"); binary_oarchive oa(ofs); oa<<myMap; ofs.close(); ofs.clear(); myMap.clear(); Ifstream ifs("test"); binary_iarchive ia(ifs); ia>>myMap; This code will throw an exception "input stream error". But if reducing the size of map like this for(int i = 0;i != 20; i++) It will run successful. Cause I can't figure it out so I seek your help. Look forward to your reply.

2 1

Inserting in a boost::interprocess::map
by Hemanth Choudary M V (RBEI/ETA1) 24 Oct '14

24 Oct '14

Hi, I have the following boost::interprocess::map: std::shared_ptr<boost::interprocess::map<size_t,boost::interprocess::managed_shared_memory*> > memoryMap; I insert into the map in the following manner: memoryMap ->insert( std::make_pair (i, new boost::interprocess::managed_shared_memory(boost::interprocess::create_only, "MemoryMap", 128))); Compilation is successful. But there is the following run-time error during insert: "memory access violation occurred at address -----------, while attempting to read inaccessible data" Is there anything missing? Mit freundlichen Grüßen / Best regards Hemanth Choudary M V RBEI/ETA1 Tel. +49 7113423 2875 [cid:image001.gif@01CFEF7A.B28D3180] [cid:image002.gif@01CFEF7A.B28D3180]<https://www.facebook.com/BoschIndia> [cid:image003.gif@01CFEF7A.B28D3180] <https://twitter.com/boschindia> [cid:image004.gif@01CFEF7A.B28D3180] <http://www.linkedin.com/company/bosch-engineering-and-business-solutions?tr…>

1 0

[Boost.TypeTraits] Which was the first Boost release that included make_signed?
by dariomt＠gmail.com 24 Oct '14

24 Oct '14

Looking at Boost.TypeTraits documentation it seems that boost/type_traits/ make_signed.hpp was added in version 1.35.0, but I can't find any reference to that change in the release notes. Which was the first Boost release that included make_signed?

3 2

Pattern issue with boost::regex
by Tal Shnaiderman 24 Oct '14

24 Oct '14

Hi All, I have a question regarding boost::regex pattern recognition and groups I created the following code, in it i created a pattern and a string to match: 1 2 3 4 5 6 p = "((a b (f+\\.))d d(\\3))"; str="a b ffff.d dfff."; boost::regex pattern(p, boost::regex::icase&boost::regex::extended &~boost::regex::no_bk_refs); bool match = boost::regex_match(str, pattern); cout << str << ((match)?"-Pattern is legal":"-Pattern is illegal" )<< endl; Pattern is illegal I'm saw that my result is 'Pattern is illegal' because the group \\3 that refers to (f+\\.) isn't equal to it. if I change the input to str="a b ffff.d dffff."; The pattern is legal. In other words my original plan was to use the \\3 instead of writing the pattern; p = "((a b (f+\\.))d d(f+\\.))"; But I can see that in the original pattern it simply expect the same output to reappear Is there a way I can use the group naming not to copy the (f+\\.) group? Thanks, I hope my Q is clear since I'm new to the regex topic.

3 2

cross compile boost for arm TRY2 (Possibly solved)
by John Davis 24 Oct '14

24 Oct '14

Hello Here is a more succient attempt at building boost with a cross compiler. It appears to work. I'm not certain if it works at this point though. Please take a look and comment. Here is the script: --------------------------------------------------------------- #!/bin/bash # edit /opt/xxx/yyy/boost/boost_1_51_0/tools/build/v2/user-config.jam to add the following line # using gcc : 4.3arm : arm-linux-gnueabi-g++ : <architecture>arm <target-os>linux ; # Later we modify path, make sure our path does not use the cross compiler at beginning export PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/opt/java6/bin:/opt/java6/db/bin:/opt/java6/jre/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl # In this stage, we are using the host compiler. # setup env variable for $BOOST_DIR # I'm not sure if this is being used, but set it just in case. export BOOST_ROOT=/opt/xxx/yyy/boost/boost_1_51_0 # this is run from $BOOST_DIR/tools/build/v2 aka /opt/xxx/yyy/boost/boost_1_51_0/tools/build/v2 # in this case, I do not think you invoke the cross compiler. I think at this point, you are building # code for the host development machine. ./bootstrap.sh --with-toolset=gcc # setup path so that gcc from cross compiler is first in the path # also specify cross_compiler env variable in case its used. # # this will find the cross compiler for those who dont use the prefix, ie. gcc export PATH=/opt/arm/usr/local/arm-linux-gnueabi/bin:$PATH # this will find the cross compiler for those who use the prefix, ie. arm-linux-gnueabi-gcc export PATH=/opt/arm/usr/local/bin:$PATH # this will set the cross compiler prefix for those who use it export CROSS_COMPILE=arm-linux-gnueabi- # build boost.build so that we can build boost or are we building boost at this point? # # WARNING!!! # Specify an install directory so that it doesn't put the results in /usr/local/bin. # Even if you dont specify install as an option to ./b2 it will attempt to copy files to /usr/bin # in the following step! # # /opt/xxx/boost is where we want results. Our code will this dir in order to use boost. # /opt/xxx/yyy/boost/boost_1_51_0 is the top of the boost src. We are building beneath there. ./b2 --toolset=gcc-4.3arm --prefix=/opt/xxx/boost # at this point, we have the cross compiler in our path first. We are good to go for building our code using boost # with the cross compiler. -------------------------- -- John F. Davis 6 Kandes Court Durham, NC 27713 919-888-8358 独树一帜

2 1

[Log] record_ostream too restrictive due to non-copyability, non-assignability?
by Latimerius 23 Oct '14

23 Oct '14

Hello, I'm trying to migrate from an existing solution to Boost.Log. So far I've been able to emulate all important features of the existing library - except one. The existing library supported submitting a log message in multiple statements. This is useful when the message being composed has conditional parts, when a part of it is composed in a loop or even a different function, something like this: auto logmsg = log (Channel::CORE, Severity::DEBUG); logmsg << "unconditional part"; if (condition) logmsg << " conditional part"; for (auto element : container) logmsg << element; logging_subroutine (logmsg); logmsg << endmsg; To that end I extracted a structure from the manual_logging() function from the Boost.Log documentation to hold the state of the message being composed: struct log_msg_state { my_logger & logger; logging::record rec; logging::record_ostream strm; ... <constructor & destructor definition> ... }; Having done this, I can emulate most of the above example fairly easily by defining a bunch of operator<<() overloads for the log_msg_state. However, I've been struggling with record_ostream. It was a bit of a challenge even to initialise it in the constructor - we can't use the initialiser list as we have to make sure first that our logging::record is valid. On the other hand, in the ctor body when the check can be performed, it's too late as record_ostream has already been constructed already and as it turns out, you can't do much with a constructed instance - no usual stuff like if (rec) strm = logging::record_ostream (rec); works! Fortunately, I've been able to hack around it like this: if (rec) new (&strm) logging::record_ostream (rec); Not pretty but has been working well so far! However, I've failed to find a solution for returning my log_msg_state (and thus record_ostream) from a function. The non-copyability, non-assignability, non-moveability are always getting in the way. (Note also that I do NOT want to hold a pointer to record_ostream in my log_msg_state and allocate it dynamically - that would certainly make things easier but I don't want to penalise each and every log message with a dynamic allocation for no good reason.) Could someone please advise me how to get the functionality I need, a solution or a work-around at least? Thanks in advance pvl

1 0

unused parameter warning
by Kevin Molcard 23 Oct '14

23 Oct '14

Hi all, in some boost libraries I am using, there are compilation warnings complaining about unused parameter. For instance: boost/signals2/detail/auto_buffer.hpp:102:45: warning: unused parameter 'size' I'd like to get rid of the warnings. What is the best way to proceed? Should I send a merge request in github or something else? Thanks in advance Kevin

1 0

using boost in cross compiler environment. intel host and arm target
by John Davis 22 Oct '14

22 Oct '14

Hello I have some code for arm which I would like to use with boost. The boost libraries I am interested in are not header only and thus require building. I have downloaded the boost tarfile and I have read the following two webpages relative but I am still confused. Here is a summary of the two urls and where I am confused. http://www.boost.org/doc/libs/1_56_0/more/getting_started/ This url has the following procedure which seems to use the host default compiler to build boost. Easy Method for Building and Installing Boost Binary Libraries. step 1: $ cd $BOOST_DIR step 2: $ ./bootstrap.sh --help step 3: $ ./bootstrap.sh --prefix=path/to/installation/prefix ( Other docs specify for this step: $ ./b2 --build-dir=/tmp/build-boost toolset=gcc stage (optional --build-type=complete) Also says that --stagedir=/path/to/install/special/stage/target/library/binaries I'm not certain what the stage components are or what the stage part is. ) $ ./b2 install “This will leave Boost binaries in the lib/ subdir of the installation prefix.” The only customization mentioned here is for where you want your results to be placed. step 4: Add path/to/installation to my $PATH environment variable. http://www.boost.org/doc/libs/1_51_0/doc/html/bbv2/tasks.html#bbv2.tasks.cr… The section is on common tasks for boost build, in particular in the section is task on cross compilation. Boost.Build supports cross compilation with gcc toolset. When using gcc, you first need to specify your cross compiler in user-config.jam for example: using gcc : arm : arm-none-linux-gnueabi-g++; This looks good, i'm thinking I need to edit a user-config.jam file. After that, if the host and target os are the same, for example linux, you can just repeat this compiler version to be used: b2 toolset=gcc-arm Regarding the user-config.jam file. These are the notes I took while reading: http://www.boost.org/doc/libs/1_51_0/doc/html/bbv2/overview.html#bbv2.overv… On startup, boost.build searches and reads two config files: site-config.jam and user-config.jam. Alternatively, the docs say you can edit the one at the top of the boost.build directory. In my case, I believe that would be $BOOST_DIR/tools/build/v2 directory rather than $BOOST_DIR. This directory has five .jam files: boost-build.jam, bootstrap.jam, build-system.jam, Jamroot.jam, site-config.jam and user-config.jam. Then I started thinking maybe editing this file will build boost.build for running on arm. I don't want to run boost.build on arm. I want it to use the cross compiler to build boost so that the libs will work with code that runs on arm. Summary, this is what I think I need to do. Please correct me where I am wrong. 1. using the tarfile I've downloaded, copy the $BOOST_DIR/tools/build/v2/user-config.jam file to my /home/davis directory. 2. edit the ~/user-config.jam file (I wish I could put this file in the $BOOST_DIR tree rather than my home dir) to use the cross compilers I have in my /opt/arm directory. 3. With the /opt/arm/ compiler directory in my path and in the $BOOST_DIR/tools/build/v2 directory issue the commands to build boost 3.a. $ ./bootstrap.sh --prefix=path/to/installation/prefix --with-toolset=gcc-arm 3.b this should add a b2 program in the path/to/installation/prefix dir. /path/to/installation/prefix will actually be /opt/arm/boot.build. This should have the boost build tool I build that runs on intel but is set to build boost for arm. 4. Change directory to $BOOST_DIR 4.a $ /path/to/installation/prefix/b2 --build-dir=/tmp/build-boost toolset=gcc-arm or literally /opt/arm/boot.build/bin?/b2 -build-dir=/tmp/build-boost toolset=gcc-arm 4.c $ /path/to/installtion/prefix/b2 install -- John F. Davis 6 Kandes Court Durham, NC 27713 919-888-8358 独树一帜

1 0

Flyweight: wrapping shared_ptr
by Akim Demaille 22 Oct '14

22 Oct '14

Hi all, I'd like to add hash-consing on top of my hiearchy-based AST implementation, which uses shared_ptr (I'm in C++11) to guarantee value semantics (the pointee is const). Below is a tiny version that would help me see if using Boost.Flyweight is adequate. It works, but it is not transparent, because I have to explicitly call '.get()' on my flyweights to deference to the pointers. So for instance my code reads: size_t hash() const { size_t res = 0; hash_combine(res, boost::hash_value(op)); hash_combine(res, l.get()->hash()); hash_combine(res, r.get()->hash()); return res; } where I expect to have l->hash(), not l.get()->hash(). I have tried deriving from flyweight to add an operator->, but it fails horribly. I realize that it is suboptimal to use flyweight on top of shared_ptr, as I get two reference counters. Yet this change is less invasive than migrating my AST hierarchy to using variants as is done in the example of the documentation. What would be the right approach? Thanks a lot.

3 11

Problem with bundled BGL properties
by alev mutlu 21 Oct '14

21 Oct '14

Hi all, I am new to BGL and the followings are snippets from my code. When I compile my code I get the following error. Any suggestions, error: no match for ‘operator=’ in ‘city_name.boost::vec_adj_list_vertex_property_map<Graph, GraphPtr, ValueType, Reference, Tag>::operator[] [with Graph = boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, relation, boost::property<boost::edge_name_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::no_property>, boost::no_property, boost::listS>, GraphPtr = boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, relation, boost::property<boost::edge_name_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::no_property>, boost::no_property, boost::listS>*, ValueType = boost::detail::error_property_not_found, Reference = boost::detail::error_property_not_found&, Tag = boost::vertex_name_t](v1) = r’ /home1/mutlu/boost/include/boost-1_37/boost/pending/detail/property.hpp:21: note: candidates are: boost::detail::error_property_not_found& boost::detail::error_property_not_found::operator=(const boost::detail::error_property_not_found&) struct argument{ int is_variable; string value; }; struct relation{ string relation_name; vector<argument> arguments; }; typedef property<edge_name_t, std::string> EdgeNameProperty; typedef adjacency_list<vecS, vecS, directedS, relation, EdgeNameProperty> Graph; int main(){ Graph g; property_map<Graph, vertex_name_t>::type city_name = get(vertex_name, g); property_map<Graph, edge_name_t>::type edge_value = get(edge_name, g); typedef graph_traits<Graph>::vertex_descriptor Vertex; typedef graph_traits<Graph>::edge_descriptor Edge; Vertex v1; v1 = add_vertex(g); city_name[v1]= r; } error: no match for ‘operator=’ in ‘city_name.boost::vec_adj_list_vertex_property_map<Graph, GraphPtr, ValueType, Reference, Tag>::operator[] [with Graph = boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, relation, boost::property<boost::edge_name_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::no_property>, boost::no_property, boost::listS>, GraphPtr = boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, relation, boost::property<boost::edge_name_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::no_property>, boost::no_property, boost::listS>*, ValueType = boost::detail::error_property_not_found, Reference = boost::detail::error_property_not_found&, Tag = boost::vertex_name_t](v1) = r’ /home1/mutlu/boost/include/boost-1_37/boost/pending/detail/property.hpp:21: note: candidates are: boost::detail::error_property_not_found& boost::detail::error_property_not_found::operator=(const boost::detail::error_property_not_found&)

1 0

1.57.0 beta 1 release candidates available for testing
by Marshall Clow 21 Oct '14

21 Oct '14

Release candidate files for 1.57.0 beta 1 are available at http://boost.cowic.de/rc/ As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. This helps ensure the candidates build OK before we push them out to SourceForge. The files (and associated md5s) are: MD5 (boost_1_57_0_b1_rc1.7z) = 8633fbf5ebb7eaabcb0f309c14646ae3 MD5 (boost_1_57_0_b1_rc1.tar.bz2) = 8e76f98146793f0fbd2492a9151c405b MD5 (boost_1_57_0_b1_rc1.tar.gz) = d41ff3ffb36ac84ff5bf34f799308907 MD5 (boost_1_57_0_b1_rc1.zip) = 8a844dc36284247b2e936f2120e118b2 Thanks! -- The release managers

7 17

1.57.0 beta 1 is now available
by Marshall Clow 20 Oct '14

20 Oct '14

Boost release 1.57.0 beta 1 is now available from SourceForge See http://sourceforge.net/projects/boost/files/boost-binaries/1.57.0.beta.1/ This release contains no new libraries. For details of what's in the release, see http://www.boost.org/users/history/version_1_57_0.html. Note that the links to files on this web page are for the final release - use the SourceForge link above to get the beta files. Please download the beta, give it a try, and report any problems you encounter. Thanks, -- The Boost Release Team P.S. There are a couple of known problems with this beta: * There are problems building with MSVC 8.0 * There are some problems with range/detail/any_iterator.hpp. These will be fixed before the release.

1 0

Boost 1.56 with QT creator, “LNK1104: cannot open file 'libboost_unit_test_framework-vc100-mt-gd-1_56.lib'”
by Kavita 20 Oct '14

20 Oct '14

Hello, I am working on a project of boost unit testing framework using QT creator. I have written a small test program and trying to link "libboost_unit_test_framework-vc100-mt-gd-1_56.lib". This library is present at specified path. But program fails to compile giving said linking error. I searched on net and found that, error should go with "#define BOOST_ALL_NO_LIB". But then, I am getting below error: main.obj:-1: error: LNK2019: unresolved external symbol "class boost::unit_test::test_suite * __cdecl init_unit_test_suite(int,char * * const)" (?init_unit_test_suite@@YAPAVtest_suite@unit_test@boost@@HQAPAD@Z) referenced in function _main The above function is a part of "libboost_unit_test_framework-vc100-mt-gd-1_56.lib". I have written same unit tests using VS 2010 and with the same boost libraries. The program worked properly with expected behavior. What could be possibly going wrong with the usage of boost on QT ? Please help ! -Thanks

6 6

[Log] Writing empty messages with the attributes as the actual payload
by Scott Mueller 17 Oct '14

17 Oct '14

Hello Boost.Users! I'm trying to integrate Boost logging with an existing message infrastructure. In this infrastructure, I have an existing schema that looks like this: Severity Timestamp Process source (much like "channel") Process component (more like a "sub-channel") Message ID A vector of arguments The message is rendered by looking up the message ID to receive the following information: formatting string ("This is an example of %1 message type. The arguments can look like this %4, 3, 2"), the expected argument types which are potentially convertible if the underlying type is different, and so on. I guess what I'm asking is whether or not a logging source can accept the arguments as defined by a compile-time defined schema in the form of attributes with an empty message. Can the logging core route message records defined in this way properly? Is such a thing supported? I'm in the process of writing something up to do this, but I'd like to know in advance whether or not "empty" messages with a bunch of attributes set can get routed to supported sinks. Thanks in advance for your help! Best regards, M. Scott Mueller

1 0

boost serialisation 1.56, why does library version change, when no change in library ?
by avib369 . 16 Oct '14

16 Oct '14

At boost 1.53 the library version was 10, however at boost 1.56 it has jumped to 11. I have not seen any documentation/release notes about boost serialisation changes. What has changed in boost serialisation to merit this change ? The documentation in $BOOST_ROOT/libs/serialization/basic_archive.cpp describes the changes to boost library version, however it does *not* describe why it jumped from 10 -> 11. Any help appreciated. Ta, Avi

2 1

[thread] linux.hpp, BOOST_HAS_PTHREAD_YIELD, BOOST_HAS_SCHED_YIELD
by Rob Conde 16 Oct '14

16 Oct '14

Using boost 1.55, Ubuntu 12.04, gcc 4.6 I'm building boost on linux using the lsb sdk. I was getting the failure (paraphrased): pthread_yield not declared in libs/thread/src/thread.cpp 513 The documentation for pthread_yield (http://man7.org/linux/man-pages/man3/pthread_yield.3.html) says: This call is nonstandard, but present on several other systems. Use the standardized sched_yield(2)<http://man7.org/linux/man-pages/man2/sched_yield.2.html> instead. If I change boost/config/platform/linux.hpp to define BOOST_HAS_SCHED_YIELD instead of BOOST_HAS_PTHREAD_YIELD Then sched_yield is used instead and the build finishes properly. I'm posting this for two reasons: 1. To help others running into the same issue 2. To question whether linux.hpp should be updated officially as I did above 3. If not, why Thanks, Rob Conde

1 0

Boost.Python: Polymorphism downcasting
by Christoff Kok 16 Oct '14

16 Oct '14

Hi, I have a list of base classes in C++, I want to access them in Python as a list of their derived most classes. Is there a build in means to cater for this in Boost.Python? I've made an example the problem I ma facing: // ------------------------------- Code ----------------------------------// #include<memory> #include<iostream> #include<vector> namespace boost { template<class T> T* get_pointer(std::shared_ptr<T>& p){ return p.get(); }} struct Vehicle{ virtual ~Vehicle(){} friend bool operator==(const Vehicle& lhs, const Vehicle& rhs) { return true; }}; struct Boat: public Vehicle{ virtual ~Boat(){} friend bool operator==(const Boat& lhs, const Boat& rhs) { return true; } char const* testBoatSpecificMethod() { return "Floating."; } }; struct Truck: public Vehicle{ virtual ~Truck(){} friend bool operator==(const Truck& lhs, const Truck& rhs) { return true; } char const* testTruckSpecificMethod() { return "Trucking."; } }; class Garage { public: Garage() {}; ~Garage() {}; char const* test() { std::string temp = "Vehicle List Size: " + std::to_string(m_VehicleList.size()); return temp.c_str(); } friend bool operator==(const Garage& lhs, const Garage& rhs) { return true; } std::vector<Vehicle>& vehicleList() { return m_VehicleList; } private: std::vector<Vehicle> m_VehicleList; }; #include <boost/python.hpp> #include <boost/python/suite/indexing/vector_indexing_suite.hpp> BOOST_PYTHON_MODULE(garage_ext) { using namespace boost::python; class_<Garage>("Garage") .def("test", &Garage::test) .def("vehicleList", &Garage::vehicleList, return_internal_reference<1>()); class_<Vehicle,std::shared_ptr<Vehicle>>("Vehicle"); class_<Boat,std::shared_ptr<Boat>,bases<Vehicle>>("Boat") .def("testBoatSpecificMethod", &Boat::testBoatSpecificMethod); class_<Truck,std::shared_ptr<Truck>,bases<Vehicle>>("Truck") .def("testTruckSpecificMethod", &Truck::testTruckSpecificMethod); implicitly_convertible<std::shared_ptr<Boat>,std::shared_ptr<Vehicle>>(); implicitly_convertible<std::shared_ptr<Truck>,std::shared_ptr<Vehicle>>(); class_<std::vector<Vehicle> >("stl_vector_Vehicle") .def(vector_indexing_suite<std::vector<Vehicle> >()); } // --------------------------- Test Script -------------------------------// import garage_ext g = garage_ext.Garage() l = g.vehicleList() l.append(garage_ext.Boat()) print "Expecting a Boat object:" print str(l[0]) print g.vehicleList()[0].testBoatSpecificMethod() garage_ext.f2("Done.") // ------------------------------ Output ---------------------------------// Expecting a Boat object <garage_ext.Vehicle object at 0x7fb17a3bfb50> Traceback (most recent call last): File "test_garage.py", line 7, in <module> print g.vehicleList()[0].testBoatSpecificMethod() AttributeError: *'Vehicle' object has no attribute 'testBoatSpecificMethod'* *'Vehicle' object has no attribute 'testBoatSpecificMethod'* Here I want Vehicle to be a Boat object. If there is not a build in or recommended/known Boost.Python means to handle this problem, I'm thinking of wrapping the list (Lots of accessors to be wrapped in my library.) with a get accessor returning a boost::python::list, storing the derived most types. Getting the derived most type possibly by calling overriden 'getAsDerivedClass' method. I would like to avoid this. I dislike having to add python usage specific methods to the library, for our design and vision values / reasons. Kind Regards, Christoff

1 1

BGL - maximum_adjacency_search - assignedVertices
by Adam Celick 14 Oct '14

14 Oct '14

I was looking at the implementation of maximum_adjacency_search algorithm and got confused by the assignedVertices local variable. It is defined as a set of vertex descriptors and is being iterated over inside the main loop (lines 168-184) but it is never inserted into. So the for loop will always skip. It looks to me as if that part of the code can be eliminated. Am I missing something? Thanks, Adam

1 0

Generating kuratowski subgraph with external edge index map
by Amir Hassan 13 Oct '14

13 Oct '14

Hi! I have a graph which i test for planarity and in case the test fails i want to generate the kuratowski subgraph. I have code that used to compile with boost graph 1.36 but doesn't with 1.56. I guess the problem has to do with the type of the edge index map. you can find code and error messages here: http://stackoverflow.com/questions/26346343/c-boost-graph-generating-kurato… Help is greatly appreciated! greets, amir

1 0

[interprocess 1.42] Copy multiple variables into shared memory
by Michael Behnke 13 Oct '14

13 Oct '14

Hello, I'm trying to write multiple variables one by one into a mapped_region, but somehow I fail. Here is the Code I worked on so far: boost::interprocess::shared_memory_object shm_obj(boost::interprocess::open_or_create, "Test", boost::interprocess::read_write); shm_obj.truncate(1000); boost::interprocess::mapped_region region(shm_obj, boost::interprocess::read_write, 0, 0); uint32_t size = 33; uint32_t type = 666; std::string data("I'm a Test!"); uint32_t* start_ptr_int = &(static_cast<uint32_t*> (region.get_address())[0]); std::memcpy(start_ptr_int, &size, sizeof (uint32_t)); start_ptr_int = &(static_cast<uint32_t*> (region.get_address())[4]); std::memcpy(start_ptr_int, &type, sizeof (uint32_t)); char* start_ptr_char = &(static_cast<char*> (region.get_address())[8]); std::memcpy(start_ptr_char, data.c_str(), data.length()); uint32_t sizeOfData; std::memcpy(&sizeOfData, &(static_cast<uint32_t*> (region.get_address())[0]), sizeof (uint32_t)); uint32_t typeOfData; std::memcpy(&typeOfData, &(static_cast<uint32_t*> (region.get_address())[4]), 4); char* revData = new char[sizeOfData]; std::memcpy(revData, &(static_cast<char*> (region.get_address())[sizeof (uint32_t) * 2]), sizeOfData); First I write an uint32_t into the region at index 0. Afterwards, I'm writing another uint32_t at position 4 (assuming the first uint32_t took the bytes 0 - 3). Last I write a string into the region, at index 8. Reading the first uint32_t again from shared memory works fine, as does reading the string (the last variable). But if I try to read the second variable (uint32_t) the data is not what I expected. I know that the problem is memcpy, somehow my syntax does not work. Unfortunately I could not find a matching example, cause mostly memset is used to explain the functionality of boost::mapped_region. I have to write lots of data into shared memory (structured like size1|type1|data1|...|sizeN|typeN|dataN) but still can't figure out how to do this the right way. Any suggestions are greatly appreciated. Kind regards Michael Behnke -- Bachelorand ________________________________________________________ ADITION technologies AG Schwarzwaldstraße 78b 79117 Freiburg http://www.adition.com T +49 / (0)761 / 88147 - 30 F +49 / (0)761 / 88147 - 77 SUPPORT +49 / (0)1805 - ADITION (Festnetzpreis 14 ct/min; Mobilfunkpreise maximal 42 ct/min) Eingetragen beim Amtsgericht Düsseldorf unter HRB 54076 Vorstände: Andreas Kleiser, Jörg Klekamp, Marcus Schlüter Aufsichtsratsvorsitzender: Joachim Schneidmadl UStIDNr.: DE 218 858 434

1 0

Boost Locale – accessing ICU functions directly
by Caroline Beltran 10 Oct '14

10 Oct '14

I recently began using Boost Locale traversing and boundary analysis of Unicode strings. I’ve used some of the features available for case conversion, i.e.: to_upper(), which appears to wrap ICU’s toUpper() function. I didn’t find Boost Locale wrappers for other ICU functions such as u_isalpha() or u_isalnum(). How can I these ICU functions? Thank you!

1 0

Are shared memory files distributable?
by Rajalakshmi Iyer 10 Oct '14

10 Oct '14

Hello, Is it possible to create a shared memory file using Boost Interprocess (with STL containers) and distribute it to several machines for reading and modifying independently? Thanks Raj -- @BlisMedia <http://twitter.com/BlisMedia> www.blismedia.com <http://blismedia.com> This email and any attachments to it may be confidential and are intended solely for the use of the individual to whom it is addressed. Any views or opinions expressed are solely those of the author and do not necessarily represent those of BlisMedia Ltd, a company registered in England and Wales with registered number 06455773. Its registered office is 3rd Floor, 101 New Cavendish St, London, W1W 6XH, United Kingdom. If you are not the intended recipient of this email, you must neither take any action based upon its contents, nor copy or show it to anyone. Please contact the sender if you believe you have received this email in error.

2 1

[make_shared] How to use boost::make_shared with more than 9 arguments
by dariomt＠gmail.com 10 Oct '14

10 Oct '14

I could patch my local copy with several more overloads (I need up to 12 parameters) but, is there a better way? I cannot change the constructor of the class to group parameters (as recommended in StackOverflow). Of course this is for C++03 Regards

2 1

Re: [Boost-users] Flyweight: wrapping shared_ptr
by Joaquin M Lopez Munoz 10 Oct '14

10 Oct '14

> De: Boost-users [mailto:boost-users-bounces@lists.boost.org] > En nombre de Akim Demaille > Enviado el: martes, 07 de octubre de 2014 18:27 > Para: Boost Users List > Asunto: Re: [Boost-users] Flyweight: wrapping shared_ptr > > Le 7 oct. 2014 à 18:18, Joaquín Mª López Muñoz <joaquin(a)tid.es> a écrit : > > > An alternative would be to use some sort of cloning smart pointer to > > spare the reference count, but it's not clear to me this would be > > faster than > > shared_ptr: > > > > * element exists: shared_ptr creation is slower than clone_ptr > > creation > > * element does not exist: shared_ptr creation and copy is probably > > faster than clone_ptr creation and cloning. > > Yes, indeed. A slightly smarter approach involves a cloning class that accepts a const Base& and does only clone on copy, thus avoiding dynamic memory allocation when the element already exists. This can be nicely wrapped up as follows: template<typename Base> class poly_holder { public: poly_holder(const Base& x):p(&x),dlt(false){} poly_holder(const poly_holder& x):p(x.p->clone()),dlt(true){} poly_holder& operator=(const poly_holder& x) { Base* q=x.p->clone(); if(dlt)delete p; p=q; dlt=true; return *this; } ~poly_holder(){if(dlt)delete p;} operator const Base&()const {return *p;} private: const Base* p; bool dlt; }; template<typename Base> class poly_flyweight:public boost::flyweight<poly_holder<Base>> { public: using super=boost::flyweight<poly_holder<Base>>; using super::super; const Base& operator*() const{return base();} const Base* operator->()const{return &base();} private: const Base& base()const{return this->get();} }; template<typename Base> std::size_t hash_value(const poly_flyweight<Base>& x) { return boost::hash<const Base*>()(&*x); } template<typename Base> bool operator==( const poly_flyweight<Base>& l,const poly_flyweight<Base>& r) { return static_cast<boost::flyweight<poly_holder<Base>>>(l)== static_cast<boost::flyweight<poly_holder<Base>>>(r); } template<typename Base> bool operator!=( const poly_flyweight<Base>& l,const poly_flyweight<Base>& r) { return !(l==r); } I've rewritten your test case to take advantage of this poly_flyweight thing, cleaning up some unnecessary hash and operator== overloads along the way and without resorting to the intermediate Exp_ type; see: http://coliru.stacked-crooked.com/a/76e87531b65d44f9 > Is there anyway Flyweight could have supported the operator-> natively? > It seems that with some SFINAE under the hood, it would work, don't you think? Yep, that would be possible, the only reason I didn't do it is to not clutter the interface. Also, some std classes such as (C++17) std::optional implement operator* differently, without the extra dereference required by smart pointer semantics. Joaquín M López Muñoz Telefónica

3 20

Boost.Geometry, probable bug in point_on_surface
by Petr Doubrava 10 Oct '14

10 Oct '14

#include <boost/geometry.hpp> #include <boost/geometry/geometries/point_xy.hpp> #include <boost/geometry/geometries/polygon.hpp> void test_point_on_surface() { typedef boost::geometry::model::point<double, 2, boost::geometry::cs::cartesian> Point; boost::geometry::model::polygon<Point> poly; boost::geometry::read_wkt("POLYGON((1074699.93 703064.65, 1074702.10 703054.62, 1074704.53 703061.40, 1074703.90 703064.58, 1074699.93 703064.65))",poly); boost::geometry::correct(poly); Point point; boost::geometry::point_on_surface(poly,point); //computed point isn't on the surface of polygon //[0] 1074839.1013086310 double //[1] 703154.77900308778 double bool res = boost::geometry::within(point,poly); // res is false }

2 2

[property_tree] Failure with Boost 1.56
by beet 10 Oct '14

10 Oct '14

Dear all, with the release of Boost 1.56, on Ubuntu 14.04 (g++ 4.8.2, 64 bit), code like the following suddenly fails to compile: pt::xml_writer_settings<char> settings('\t', 1); pt::write_xml(someFileName, ptr_out, std::locale(), settings); "pt" is obviously an alias for boost::property_tree. The error message I'm getting is /opt/boost156/include/boost/property_tree/detail/xml_parser_writer_settings.hpp:38:35: error: 'char' is not a class, struct, or union type typedef typename Str::value_type Ch; I can see the following possibly relevant change in property_tree: In Boost 1.55, from xml_parser.hpp: ----------------------------------- template<typename Ptree> void write_xml( const std::string & , const Ptree & , const std::locale & = std::locale() , const xml_writer_settings<typename Ptree::key_type::value_type >& = xml_writer_settings<typename Ptree::key_type::value_type >() ); In Boost 1.56, same header: --------------------------- template<typename Ptree> void write_xml( const std::string & , const Ptree & , const std::locale & = std::locale() , const xml_writer_settings<typename Ptree::key_type > & = xml_writer_settings<typename Ptree::key_type >() ); So xml_writer_settings is now given a Ptree::key_type instead of a Ptree::key_type::value_type which I assume is the reason for the above error. Is there a portable way to specify the type of indention character in write_xml ? Best Regards, Beet

2 1