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A* search on Implicit graph (search tree)
by Nicholas Dahm 01 Sep '14

01 Sep '14

Hi All, I'm trying to run an A* search using boost's astar_search, but I'm running into issues with 'const'. I'm trying to add the examine_vertex(my_vdesc_type &v, my_graph_type &g) function, but of course boost says that I need to make it const like examine_vertex(my_vdesc_type &v, const my_graph_type &g) However since I'm searching an implicit graph, I need to call add_vertex(g) within this function. But then I of course get an error because i'm trying to do add_vertex(const my_graph_type &g) which is invalid. I've read the example astar_maze.cpp which CLAIMS to be implicit but certainly doesn't appear to be. I've also seen the pdf at http://cs.krisbeevers.com/research/astar_bgl04.pdf which says you need to basically create non-const versions of a bunch of functions. Considering that http://www.boost.org/doc/libs/1_56_0/libs/graph/doc/astar_search.html says that "A* is particularly useful for searching implicit graphs", I'm assuming that boost ALREADY HAS some way of actually searching implicit graphs. Any ideas? cheers Nick

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Re: [Boost-users] [graph] Unique vertices using setS
by Nicholas Dahm 01 Sep '14

01 Sep '14

>On Wed, Aug 27, 2014 7:24 PM EDT Nicholas Dahm wrote: > >>Is there any place where I could enforce unique properties? (i.e. not add a new vertex if it's properties are the same as an existing vertex) > >Not that I know of. > >>My graph is actually an implicit search tree for an A* search so there's lots of nodes which will be revisited via different paths. My current thought is to create the new vertex (which is a search tree state), then simply iterate through all existing vertices to see if any are identical in properties. However if the vertices were sorted by their properties in a set (i.e. weakly ordered), this would be much faster. > >Do you need to store the explored part of the search tree explicitly? You could instead use a custom graph type with your choice of vertex descriptor, then use associative_property_map to check for multiple visits to the same state. No need to store the explored part. I have exactly zero clue on how to create a custom graph type with a special vertex descriptor. At current I've gotten around it by having a "set" of vertex descriptors which use a custom "less" function which actually checks the vertex bundled properties instead of the descriptor. It's not the perfect solution but it wasn't very ugly either so it'll do. If you have a link to info on how to create custom graph types with special vertex descriptors please do let me know cheers Nick

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Review Wizard Status Report for August 2014
by Ron Garcia 30 Aug '14

30 Aug '14

============================================== Review Wizard Status Report for August 2014 ============================================== News ==== 1. Fiber Accepted Provisionally. January 2014. 2. Align Accepted. April 2014. 3. TypeIndex Accepted. May 2014. 4. Convert Accepted. June 2014. 5. Boost 1.56 Released -- New Libraries: Align, TypeIndex Open Issues =========== The following libraries have review managers, but have not yet been scheduled for review: * Range Extensions - added May 2012; review manager: Neil Groves. The following libraries have been accepted to Boost, but have not yet been integrated into Boost Git: * Contract - accepted September 2012; author: Lorenzo Caminiti. The following libraries have been accepted and submitted to Boost Git, but have not yet appeared in a release: * Convert - accepted June 2014; author: Vladimir Batov. The following libraries have been accepted provisionally to Boost, but have not been submitted for mini-review and full acceptance: * Fiber - accepted provisionally January 2014; author Oliver Kowalke. General Announcements ===================== As always, we need experienced review managers. Please take a look at the list of libraries in need of managers and check out their descriptions. In general review managers are active boost participants, including library contributors, infrastructure contributors, and other mailing list participants with a substantial track record of constructive participation. If you can serve as review manager for any of them, email Ron Garcia or John Phillips, "rxg at cs dot ubc dot ca" and "johnphillipsithica at gmail dot com" respectively. We are also suffering from a lack of reviewers. While we all understand time pressures and the need to complete paying work, the strength of Boost is based on the detailed and informed reviews submitted by you. If you are interested in reviewing a library but won't have time during the review period, you can always prepare your review ahead of time. No rule says you can only work on a review during the review period. A link to this report will be posted to www.boost.org. If you would like us to make any modifications or additions to this report, please email Ron or John. The review schedule is an unordered list of the libraries awaiting review. As such, any library on the schedule can be reviewed once the developer is ready, a review manager has been secured, and the manager, developer, and wizards agree on a date to schedule the review. Review Schedule =============== * Join (M) * Sorting (M) * Quaternions, Vectors, Matrices (M) * Block Pointer (M) * Singularity (M) * Extended Complex Numbers (M) * Metaparse (M) * Boost.Range Extensions * Nowide (M) * Array (M) * STL Extensions (M) * Countertree (M) * Process (M) * Asynchronous File I/O (M) * Application (M) * Edit Distance (M) * Mixin (M) ``(M)`` marks libraries that need review managers. -------------------- Join ---- :Author: Yigong Liu :Review Manager: Needed :Download: http://channel.sourceforge.net/ :Description: Join is an asynchronous, message based C++ concurrency library based on join calculus. It is applicable both to multi-threaded applications and to the orchestration of asynchronous, event-based applications. It follows Comega's design and implementation and builds with Boost facilities. It provides a high level concurrency API with asynchronous methods, synchronous methods, and chords which are "join-patterns" defining the synchronization, asynchrony, and concurrency. Sorting ------- :Author: Steven Ross :Review Manager: Needed :Download: https://github.com/boost-vault/Sorting :Description: A grouping of 3 templated hybrid radix/comparison-based sorting algorithms that provide superior worst-case and average-case performance to std::sort: integer_sort, which sorts fixed-size data types that support a rightshift (default of >>) and a comparison (default of <) operator. float_sort, which sorts standard floating-point numbers by safely casting them to integers. string_sort, which sorts variable-length data types, and is optimized for 8-bit character strings. All 3 algorithms have O(n(k/s + s)) runtime where k is the number of bits in the data type and s is a constant, and limited memory overhead (in the kB for realistic inputs). In testing, integer_sort varies from 35% faster to 2X as fast as std::sort, depending on processor, compiler optimizations, and data distribution. float_sort is roughly 70% faster than std::sort. string_sort is roughly 2X as fast as std::sort. Quaternions, Vectors, Matrices ------------------------------ :Author: Emil Dotchevski :Review Manager: Needed :Download: http://www.revergestudios.com/boost-qvm/ :Description: QVM defines a set of generic functions and operator overloads for working with quaternions, vectors and matrices of static size. The library also defines vector and matrix data types, however it allows users to introduce their own types by specializing the q_traits, v_traits and m_traits templates. Block Pointer ------------- :Author: Phil Bouchard :Review Manager: Needed :Download: https://svn.boost.org/svn/boost/sandbox/block_ptr/ :Description: Deterministic memory manager of constant complexity capable of handling cyclic collections. Singularity ----------- :Author: Ben Robinson :Review Manager: Needed :Download: https://github.com/cppmaven/Singularity :Description: The Singularity Design Pattern allows you to restrict any class to a single instance. Unlike the infamous Singleton, Singularity gives you direct control over the lifetime of the object, does not require you to grant global access to the object, nor does it limit you to the default constructor for that object. Extended Complex Numbers ------------------------ :Author: Matthieu Schaller :Review Manager: Needed :Download: http://code.google.com/p/cpp-imaginary-numbers/ :Description: The library is an extension of the std::complex class addressing two issues: 1. The standard does not guaranty the behaviour of the complex class if instantiated with types other than float/double/long double. 2. Some calculation where pure imaginary numbers (i.e. multiples of sqrt(-1)) appear are unnecessarily slowed down due to the lack of support for these numbers. The code I submit contains two interleaved classes boost::complex and boost::imaginary which can be instantiated with any type T provided T overloads the usual arithmetic operators and some basic (real) mathematical functions depending on which complex function will be used. It is thus an extended version of Thorsten Ottosen's n1869 proposal (http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2005/n1869.html) Metaparse --------- :Author: Abel Sinkovics :Review Manager: Needed :Download: http://abel.web.elte.hu/metaparse/metaparse.zip :Description: Metaparse is a library for constructing parsers parsing at compile-time based on template metaprogramming. The parsers built with the library take boost::mpl::strings as input and can produce - types - objects (types with public static members) - callable C++ functions (types with public static method) - template metafunction classes as output (based on the input being parsed). On compilers supporting constexpr the library provides the following syntactic sugar for writing the input of the parsers: BOOST_STRING("this is a string") The library can be used for implementing DSLs in C++, including DSLs making C++ template metaprogramming easier (see examples). Range Extensions ---------------- :Author: Akira Takahashi :Review Manager: Neil Groves :Download: https://github.com/faithandbrave/OvenToBoost :Description: This project adds some features of the Oven Range Library to Boost.Range. Features: - Additional Range Adaptors (taken, taken_while, dropped, dropped_while, elements, elements_key, memoized, outdirected) - Extensions for using Lambda (regular function, regular operator) - Infinite Range (iteration function) - and additional range utilities. Nowide ------ :Author: Artyom Beilis :Review Manager: Needed :Download: http://cppcms.com/files/nowide/ :Description: This library makes cross platform Unicode aware programming easier. It provides an implementation of standard C and C++ library functions, such that their inputs are UTF-8 aware on Windows without requiring to use Wide API. Array ----- :Author: Brian Smith :Review Manager: Needed :Download: https://github.com/BrianJSmith/Array :Description: The array class is a C++11 compatible implementation of static multidimensional arrays. STL Extensions -------------- :Author: Vadim Stadnik :Review Manager: Needed :Download: https://github.com/vstadnik/stl_ext_adv_review :Description: The proposed library [stl_ext_adv] offers augmented array based B+ trees and STL containers that support the interfaces of the C++03 sequences and associative containers. The library offers a number of extensions and performance improvements that are not available in C++03 and C++11 standard containers. Countertree ----------- :Author: Francisco Jose Tapia :Review Manager: Needed :Download: https://dl.dropbox.com/u/8437476/works/countertree_code_doc.zip :Description: This library is an implementation of a binary red-black counter tree. This tree have an additional counter in each leaf. This permit the access to the elements by the position, like in a vector. It is a random access container with random access iterators. COUNTERTREE This kind of trees have an additional counter in each leaf. This permit the access to the elements by the position, like in a vector. It is a random access container with random access iterators. With unordered information we have a vector with the same speed inserting and deleting in any position (O(log N)). With ordered information, we have the classes set, multiset, map and multimap, with identical interface than the STL classes, with the plus of access to the elements by position, like in a vector. The iterators are random access , and you can subtract them. SUBALLOCATOR The suballocator is a layer between the allocator and the data structures, compatible with any allocator with the STL definition. The suballocator replace to the allocator in the allocation of equal size elements. It provides speed, return the unused memory and decrease the memory used by the program and improve the cache performance due to the data locality improvement ( 30% of improvement of speed respect the std::allocator with GCC 4.7) Process ------- :Author: Boris Schaeling :Review Manager: Needed :Download: http://www.highscore.de/boost/process0.5/process.zip :Description: Boost.Process is a library to manage system processes. It can be used to: * create child processes * setup streams for child processes * communicate with child processes through streams (synchronously or asynchronously) * wait for processes to exit (synchronously or asynchronously) * terminate processes Asynchronous File I/O --------------------- :Author: Niall Douglas and Paul Kirth :Review Manager: Needed :Download: https://github.com/BoostGSoC/boost.afio/archive/boost-peer-review.tar.gz :Description: Boost.AFIO is a linear scalable, batch, chainable, asynchronous closure execution engine with an almost wait free implementation extending Boost.ASIO and Boost.Thread specialised as a portable asynchronous file i/o implementation library. Implementation of this first version has been kept as simple as possible (~ 1000 active LOC) at the cost of some performance, though with a good compiler you can expect 25-50% of the performance of using raw Boost.ASIO. Application ----------- :Author: Renato Tegon Forti :Review Manager: Needed :Download: https://github.com/retf/Boost.Application :Documentation: http://www.dokfile.com/appbeta4/docs/libs/application/doc/html/index.html :Description: Application provides an application environment, or start point to any people that want a basic infrastructure to build an system application on Windows or Unix Variants (e.g. Linux, MacOS). Application uses behaviours modeled using 'aspects' concept proposed by 'Vicente J. Botet Escriba', that allow easy extension and customization of library components. The application modes uses these components internally to achieve the user desirable behaviours. Application provide many useful ready-to-use features, e.g: * Run application as Windows Service; * Run application as UNIX/POSIX Daemon; * Plugin extension system; * Process(executable) Single instance Instantiation support; * Application SIGNAL/Callbacks customization; * Windows Service Setup feature; * And many others. Edit Distance ------------- :Author: Erik Erlandson :Review Manager: Needed :Download: https://github.com/erikerlandson/algorithm/tree/edit_distance/sequence :Description: The edit distance is the length of the shortest (or least-cost) edit script from one sequence to another, where an edit script is defined as a sequence of insertion, deletion and (optionally) substitution operations. The function implementing the edit distance is named edit_distance. This function will return the edit distance between two sequences, where sequences may be any valid range object supporting forward iteration. The edit_distance function will also, if requested, return the edit script. Mixin ----- :Author: Borislav Stanimirov :Download: https://github.com/iboB/boost.mixin :Documentation: http://ibob.github.io/boost.mixin/ :Review Manager: Needed :Description: Boost.Mixin is a library that allows the composition and modifications of polymorphic types at run time. Types and objects are constructed out of building blocks called mixins. The library uses the type boost::mixin::object as a placeholder, whose instances can be extended with existing classes (mixins), thus providing a particular instance with the functionality of all those types. Accessing the newly formed type's interface is made through messages: stand-alone functions generated by the library, which can be thought of as methods. This is given while also having full abstraction between the interface and the definition of types. An existing feature in another language similar to Boost.Mixin and also an inspiration for the library are the mixins in Ruby. The library also has similarities with the pattern entity-component-system. Libraries under development =========================== See http://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction for a current listing of libraries under development.

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[msm] forward declaration of state machine with non-default constructor
by caligano 29 Aug '14

29 Aug '14

Hi, I want to forward declare a state machine which has a non-default constructor. I found this example here: http://stackoverflow.com/a/10922799/678093 But I can't call the non-default constructor of the state machine. I either get - "error: call of overloaded ‘fsm(int)’ is ambiguous" (if inheriting constructors using C++11) or - "error: no matching function for call to ‘wrapper::fsm::fsm(int)" What can I do about it? Thanks, Manuel Example: ------------------------ // wrapper.h #include <boost/msm/front/state_machine_def.hpp> #include <boost/msm/back/state_machine.hpp> #include <boost/shared_ptr.hpp> class wrapper { wrapper(); struct fsm; boost::shared_ptr<fsm> player_fsm; }; ------------------------ // wrapper.cpp #include "wrapper.h" struct player_ : public boost::msm::front::state_machine_def<player_> { player_(int some_value) {} }; struct wrapper::fsm : public boost::msm::back::state_machine<player_> { using boost::msm::back::state_machine<player_>::state_machine; }; wrapper::wrapper() : player_fsm(new fsm(100)) { } ------------------------

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Re: [Boost-users] [graph] Unique vertices using setS
by Jeremiah Willcock 29 Aug '14

29 Aug '14

On Wed, Aug 27, 2014 7:24 PM EDT Nicholas Dahm wrote: >Is there any place where I could enforce unique properties? (i.e. not add a new vertex if it's properties are the same as an existing vertex) Not that I know of. >My graph is actually an implicit search tree for an A* search so there's lots of nodes which will be revisited via different paths. My current thought is to create the new vertex (which is a search tree state), then simply iterate through all existing vertices to see if any are identical in properties. However if the vertices were sorted by their properties in a set (i.e. weakly ordered), this would be much faster. Do you need to store the explored part of the search tree explicitly? You could instead use a custom graph type with your choice of vertex descriptor, then use associative_property_map to check for multiple visits to the same state. -- Jeremiah Willcock

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Cannot use Boost.Croutines with range based for
by Mueller-Roemer, Johannes Sebastian 29 Aug '14

29 Aug '14

Hi, I am (again) having issues with the Boost.Coroutines library. Aside from yet another new API, the coroutines no longer work with range based for. Even though the examples include range based for! With the following code (taken directly from the documentation and added the includes and main): #include <boost/coroutine/asymmetric_coroutine.hpp> #include <iostream> int main() { boost::coroutines::asymmetric_coroutine<int>::pull_type source( [&](boost::coroutines::asymmetric_coroutine<int>::push_type& sink){ int first=1, second=1; sink(first); sink(second); for(int i=0;i<8;++i){ int third=first+second; first=second; second=third; sink(third); } } ); for(auto i : source) std::cout << i << " "; } I get this error: D:\projects\combinators\coro_test.cpp: In function 'int main()': D:\projects\combinators\coro_test.cpp:20:15: error: 'begin' was not declared in this scope for(auto i : source) ^ D:\projects\combinators\coro_test.cpp:20:15: note: suggested alternatives: In file included from D:\projects\combinators\coro_test.cpp:1:0: D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/coroutine/asymmetric_coroutine.hpp:2255:1: note: 'std::begin' begin( boost::coroutines::push_coroutine< R > & c) ^ In file included from D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/range/functions.hpp:18:0, from D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/range.hpp:18, from D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/coroutine/asymmetric_coroutine.hpp:17, from D:\projects\combinators\coro_test.cpp:1: D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/range/begin.hpp:106:61: note: 'boost::range_adl_barrier::begin' inline BOOST_DEDUCED_TYPENAME range_iterator<const T>::type begin( const T& r ) ^ D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/range/begin.hpp:106:61: note: 'boost::range_adl_barrier::begin' D:\projects\combinators\coro_test.cpp:20:15: error: 'end' was not declared in this scope for(auto i : source) ^ D:\projects\combinators\coro_test.cpp:20:15: note: suggested alternatives: In file included from D:\projects\combinators\coro_test.cpp:1:0: D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/coroutine/asymmetric_coroutine.hpp:2260:1: note: 'std::end' end( boost::coroutines::push_coroutine< R > & c) ^ In file included from D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/range/functions.hpp:19:0, from D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/range.hpp:18, from D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/coroutine/asymmetric_coroutine.hpp:17, from D:\projects\combinators\coro_test.cpp:1: D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/range/end.hpp:100:61: note: 'boost::range_adl_barrier::end' inline BOOST_DEDUCED_TYPENAME range_iterator<const T>::type end( const T& r ) ^ D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/range/end.hpp:100:61: note: 'boost::range_adl_barrier::end' mingw32-make[2]: *** [CMakeFiles/coro-test.dir/coro_test.cpp.obj] Error 1 mingw32-make[1]: *** [CMakeFiles/coro-test.dir/all] Error 2 mingw32-make: *** [all] Error 2 For completeness sake: I am using MinGW-w64 with GCC 4.9.1 and the -std=c++11 flag Regards, Johannes S. Mueller-Roemer -- Johannes S. Mueller-Roemer, MSc Wiss. Mitarbeiter - Interactive Engineering Technologies (IET) Fraunhofer-Institut für Graphische Datenverarbeitung IGD Fraunhoferstr. 5 | 64283 Darmstadt | Germany Tel +49 6151 155-606 | Fax +49 6151 155-139 johannes.mueller-roemer(a)igd.fraunhofer.de | www.igd.fraunhofer.de

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[filesystem] : How to get a parametrized basic_string from filesystem::path
by Vincent R. 28 Aug '14

28 Aug '14

Hi, I am trying to modify an existing code to keep the possibility to use string or wstring, so I have changed the definition to parametrize it as shown below (Path inherits from path): template <class TChar> bool GetFileList(const std::basic_string<TChar>& i_strBaseDir, std::vector<std::basic_string<TChar> >& o_FileList) { boost::system::error_code ec; Path thePath(i_strBaseDir); boost::filesystem::directory_iterator iter(thePath, ec); if (! ec) { boost::filesystem::directory_iterator iter_end; for (; iter != iter_end; ++ iter) { boost::system::error_code ec; // This is to avoid an exception in case of any error if(!boost::filesystem::is_directory(iter->path(), ec)) //find file and not directory { std::basic_string<TChar> strFile = iter->path().????); // HOW TO DO IT o_FileList.push_back(strFile); } } } return (o_FileList.size() != 0); } My problem is with the following line : std::basic_string<TChar> strFile = iter->path().??????; I have solved like that (without testing it) : template <typename CharT, typename T> std::basic_string<CharT> string_cast(const T& r) { std::basic_ostringstream<CharT> stream; stream.imbue(std::locale::classic()); stream << r; return stream.str(); } std::basic_string<TChar> strFile = string_cast<TChar>(iter->path()); but since it uses some stream we might loose some performance. I have found another string_cast here : http://codereview.stackexchange.com/questions/1205/c-string-cast-template-f… that might be better in terms of performance. Do you have some other suggestion ? Wouldn't be interesting to add a boost::string_cast that would allow to convert from templated methods from/to string/wstring ? Thanks

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[graph] Unique vertices using setS
by Nicholas Dahm 27 Aug '14

27 Aug '14

Hi All, I'm trying to create a graph with unique vertices using setS for vertices, but it doesn't seem to be working. To test it I've made a simple example simply using int's for the vertex properties: typedef boost::adjacency_list<boost::setS, boost::setS, boost::undirectedS, int, int> gtype; typedef boost::graph_traits<gtype>::vertex_descriptor gvd; gtype gr; int v1 = 4; gvd vd1 = add_vertex(v1, gr); gvd vd2 = add_vertex(v1, gr); printf("vd1: %ld, gr[vd1]: %d\n", vd1, gr[vd1]); printf("vd2: %ld, gr[vd2]: %d\n", vd2, gr[vd2]); printf("num_vertices: %d\n", num_vertices(gr)); Output: vd1: 17473168, gr[vd1]: 4 vd2: 17473248, gr[vd2]: 4 num_vertices: 2 So my graph has two vertices represented by the int 4, suggesting it's not a set! Any idea what I'm missing? Is the set for vertex descriptors, but the vertices themselves stored elsewhere? cheers Nick

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Re: [Boost-users] [graph] Unique vertices using setS
by Jeremiah Willcock 27 Aug '14

27 Aug '14

On Wed, Aug 27, 2014 2:47 AM EDT Nicholas Dahm wrote: >Hi All, > >I'm trying to create a graph with unique vertices using setS for vertices, but it doesn't seem to be working. > >To test it I've made a simple example simply using int's for the vertex properties: > > typedef boost::adjacency_list<boost::setS, boost::setS, boost::undirectedS, int, int> gtype; > typedef boost::graph_traits<gtype>::vertex_descriptor gvd; > > gtype gr; > int v1 = 4; > gvd vd1 = add_vertex(v1, gr); > gvd vd2 = add_vertex(v1, gr); > printf("vd1: %ld, gr[vd1]: %d\n", vd1, gr[vd1]); > printf("vd2: %ld, gr[vd2]: %d\n", vd2, gr[vd2]); > printf("num_vertices: %d\n", num_vertices(gr)); > >Output: > > vd1: 17473168, gr[vd1]: 4 > vd2: 17473248, gr[vd2]: 4 > num_vertices: 2 > >So my graph has two vertices represented by the int 4, suggesting it's not a set! Any idea what I'm missing? Is the set for vertex descriptors, but the vertices themselves stored elsewhere? There is a difference between vertex descriptors and properties. There are no requirements that property values are unique for any graph type; those are up to you to set however you want. If gr[vd1] and gr[vd2] had the same address, that would be a problem. However, you initialized both of those property slots with the same value 4, and the graph type has no issue with you doing that. One reason for this is that the same graph can have multiple vertex and edge properties, and so you might want some of them to be unique and some not, so the graph type would not know where to enforce uniqueness. -- Jeremiah Willcock > >cheers > >Nick >_______________________________________________ >Boost-users mailing list >Boost-users(a)lists.boost.org >http://lists.boost.org/mailman/listinfo.cgi/boost-users

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[geometry] Buffer (with strategy) to offset polygons
by Olivier Tournaire 27 Aug '14

27 Aug '14

Dear all, I have used successfully the buffering algorithm to offset a shapefile of 2D polygons. However, there are 4 polygons (amongst nearly 4000) in my SHP does are not successfully processed. They do not have topology or orientation errors. I use GDAL 1.9 to read the SHP, boost 1.56 precompiled binaries from sourceforge on a 64bit windows 7. If someone is willing to have a look at the problem, I can share the files and the code I use. Here is a quick overview: typedef double coordinate_type; typedef boost::geometry::model::d2::point_xy<coordinate_type> point_xy_type; typedef boost::geometry::model::polygon<point_xy_type> polygon_type; boost::geometry::strategy::buffer::end_flat end_strategy; boost::geometry::strategy::buffer::point_square point_strategy; boost::geometry::strategy::buffer::side_straight side_strategy; boost::geometry::strategy::buffer::distance_symmetric<coordinate_type> distance_strategy(buffer_distance); boost::geometry::strategy::buffer::join_miter join_strategy(buffer_distance); polygon_type p; boost::geometry::model::multi_polygon<polygon_type> result; // Build a polygon_type from OGRPolygon OGRLinearRing* exteriorRing = polygon->getExteriorRing(); for(int i=0;i<exteriorRing->getNumPoints();++i) { OGRPoint pt; exteriorRing->getPoint(i,&pt); p.outer().push_back( point_xy_type(pt.getX(), pt.getY()) ); } for(int i=0;i<polygon->getNumInteriorRings();++i) { OGRLinearRing* interiorRing = polygon->getInteriorRing(i); polygon_type::ring_type ring; for(int j=0;j<interiorRing->getNumPoints();++j) { OGRPoint pt; interiorRing->getPoint(j,&pt); ring.push_back( point_xy_type(pt.getX(), pt.getY()) ); } p.inners().push_back(ring); } boost::geometry::buffer(p, result, distance_strategy, side_strategy, join_strategy, end_strategy, point_strategy); if(result.size() == 0) { int indexID = feature->GetFieldIndex("ID"); cout << "No result build for polygon with ID " << feature->GetFieldAsString(indexID) << endl; } else { typedef boost::geometry::strategy::distance::pythagoras<coordinate_type> pythagoras_distance_strategy; typedef boost::geometry::strategy::distance::projected_point<coordinate_type, pythagoras_distance_strategy> projected_point_strategy; boost::geometry::strategy::simplify::douglas_peucker<point_xy_type, projected_point_strategy> dp; OGRPolygon poly; for(size_t i=0;i<result.size();++i) { polygon_type result_i = result[i]; polygon_type result_i_simplified; boost::geometry::simplify(result_i, result_i_simplified, 0.1, dp); { OGRLinearRing ring; for(size_t j=0;j<result_i_simplified.outer().size();++j) ring.addPoint( result_i_simplified.outer()[j].x(), result_i_simplified.outer()[j].y() ); poly.addRing(&ring); } { OGRLinearRing ring; for(size_t j=0;j<result_i_simplified.inners().size();++j) { for(size_t k=0;k<result_i_simplified.inners()[j].size();++k) { ring.addPoint( result_i_simplified.inners()[j][k].x(), result_i_simplified.inners()[j][k].y() ); } poly.addRing(&ring); } } } Note that I use a simplification algorithm after buffering to remove colinear points. Hope you could help. Best regards, Olivier

3 9

Re: [Boost-users] Cannot use Boost.Croutines with range based for
by Mueller-Roemer, Johannes Sebastian 27 Aug '14

27 Aug '14

Adding the following namespace boost { namespace coroutines { using boost::begin; using boost::end; } } solves the problem, however this would seem to indicate that the provided begin and end are in the wrong namespace and therefore do not take part in ADL. Should I report this as a bug? Doesn't seem to be intended. -- Johannes S. Mueller-Roemer, MSc Wiss. Mitarbeiter - Interactive Engineering Technologies (IET) Fraunhofer-Institut für Graphische Datenverarbeitung IGD Fraunhoferstr. 5 | 64283 Darmstadt | Germany Tel +49 6151 155-606 | Fax +49 6151 155-139 johannes.mueller-roemer(a)igd.fraunhofer.de | www.igd.fraunhofer.de From: Mueller-Roemer, Johannes Sebastian Sent: Wednesday, August 27, 2014 12:57 To: 'boost-users(a)lists.boost.org' Subject: Cannot use Boost.Croutines with range based for Hi, I am (again) having issues with the Boost.Coroutines library. Aside from yet another new API, the coroutines no longer work with range based for. Even though the examples include range based for! With the following code (taken directly from the documentation and added the includes and main): #include <boost/coroutine/asymmetric_coroutine.hpp> #include <iostream> int main() { boost::coroutines::asymmetric_coroutine<int>::pull_type source( [&](boost::coroutines::asymmetric_coroutine<int>::push_type& sink){ int first=1, second=1; sink(first); sink(second); for(int i=0;i<8;++i){ int third=first+second; first=second; second=third; sink(third); } } ); for(auto i : source) std::cout << i << " "; } I get this error: D:\projects\combinators\coro_test.cpp: In function 'int main()': D:\projects\combinators\coro_test.cpp:20:15: error: 'begin' was not declared in this scope for(auto i : source) ^ D:\projects\combinators\coro_test.cpp:20:15: note: suggested alternatives: In file included from D:\projects\combinators\coro_test.cpp:1:0: D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/coroutine/asymmetric_coroutine.hpp:2255:1: note: 'std::begin' begin( boost::coroutines::push_coroutine< R > & c) ^ In file included from D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/range/functions.hpp:18:0, from D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/range.hpp:18, from D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/coroutine/asymmetric_coroutine.hpp:17, from D:\projects\combinators\coro_test.cpp:1: D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/range/begin.hpp:106:61: note: 'boost::range_adl_barrier::begin' inline BOOST_DEDUCED_TYPENAME range_iterator<const T>::type begin( const T& r ) ^ D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/range/begin.hpp:106:61: note: 'boost::range_adl_barrier::begin' D:\projects\combinators\coro_test.cpp:20:15: error: 'end' was not declared in this scope for(auto i : source) ^ D:\projects\combinators\coro_test.cpp:20:15: note: suggested alternatives: In file included from D:\projects\combinators\coro_test.cpp:1:0: D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/coroutine/asymmetric_coroutine.hpp:2260:1: note: 'std::end' end( boost::coroutines::push_coroutine< R > & c) ^ In file included from D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/range/functions.hpp:19:0, from D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/range.hpp:18, from D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/coroutine/asymmetric_coroutine.hpp:17, from D:\projects\combinators\coro_test.cpp:1: D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/range/end.hpp:100:61: note: 'boost::range_adl_barrier::end' inline BOOST_DEDUCED_TYPENAME range_iterator<const T>::type end( const T& r ) ^ D:/libs/mingw-amd64/boost_1_56_0/include/boost-1_56/boost/range/end.hpp:100:61: note: 'boost::range_adl_barrier::end' mingw32-make[2]: *** [CMakeFiles/coro-test.dir/coro_test.cpp.obj] Error 1 mingw32-make[1]: *** [CMakeFiles/coro-test.dir/all] Error 2 mingw32-make: *** [all] Error 2 For completeness sake: I am using MinGW-w64 with GCC 4.9.1 and the -std=c++11 flag Regards, Johannes S. Mueller-Roemer -- Johannes S. Mueller-Roemer, MSc Wiss. Mitarbeiter - Interactive Engineering Technologies (IET) Fraunhofer-Institut für Graphische Datenverarbeitung IGD Fraunhoferstr. 5 | 64283 Darmstadt | Germany Tel +49 6151 155-606 | Fax +49 6151 155-139 johannes.mueller-roemer(a)igd.fraunhofer.de<mailto:johannes.mueller-roemer@igd.fraunhofer.de> | www.igd.fraunhofer.de<http://www.igd.fraunhofer.de>

1 0

[Smart Pointer] Reference counting when you don't want to manage memory [Honeywell Internal]
by Hickman, Steve (AdvTech) 26 Aug '14

26 Aug '14

Classification: Honeywell Internal Smart pointers (as in http://www.boost.org/doc/libs/1_56_0/libs/smart_ptr/smart_ptr.htm ) assume that the action you want to perform when the count goes to zero is to free the memory pointed to. That isn't the only use for reference counting. Why doesn't the Smart Pointer library decouple the reference counting from the action to be taken and provide a generic reference counting mechanism that will call an arbitrary function when the count goes to zero? The default can be "delete" to provide the expected memory management capability but it would provide a robust mechanism for those who need other capabilities. Reviewing the <boost/shared_ptr.hpp> code, it appears this decoupling already exists - through the use of boost::checked_delete and boost::checked_deleter (<boost/checked_delete.hpp>). It just doesn't appear to be documented. Why not document this so others know how to use it? Steve Hickman System Architect, Flight Deck of the Future 480-236-8367 ============================================================================================================================================================================================================ This message classified as Honeywell Internal by Hickman, Steve (AdvTech) on Tuesday, August 26, 2014 at 12:35:32 PM. The above classification labels are in accordance with the Honeywell Corporate Classification Policy. The information contained in this electronic message is confidential and intended only for the use of the individual/entity named above, and the information may be privileged. If you, the reader of this message, are not the intended recipient or an employee or agent responsible to deliver this message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please immediately notify the sender and delete the original message. ============================================================================================================================================================================================================

3 3

Multi-Index: custom iterator
by Sensei 26 Aug '14

26 Aug '14

Dear all, I'm not yet satisfied with my MultiIndex games, so now I am trying to do something that is purely cosmetic. However, I have *no idea* how I can do this. How can I build a custom iterator on a MultiIndex? The objective is simple. As you may recall, I am building a MultiIndex with 128 bits, indexing them by MSB, LSB, and HSB (in the middle). It works like a charm. Now I'd like to write something like this (or similar): auto it = storage.myfind<byMSB>(MSB(value128bits)); for (; i != it.end(); i++) In essence, I'd like to hide the get<> and everything I am using right now (as shown below). So I need an iterator for this data structure: typedef __uint128_t Storage; // Indexing placeholders struct byMSB { }; struct byHSB { }; struct byLSB { }; // Storage type with indexing typedef boost::multi_index::multi_index_container< Storage, boost::multi_index::indexed_by< // Hashed by subject/predicate/object boost::multi_index::hashed_non_unique<boost::multi_index::tag<byMSB>, boost::multi_index::global_fun<Storage, soSub, &Data::msb>>, // 0 boost::multi_index::hashed_non_unique<boost::multi_index::tag<byHSB>, boost::multi_index::global_fun<Storage, soPre, &Data::hsb>>, // 1 boost::multi_index::hashed_non_unique<boost::multi_index::tag<byLSB>, boost::multi_index::global_fun<Storage, soObj, &Data::lsb>> // 2 > > DataStorage; DataStorage storage_; With your suggestions I've achieved to find all items by MSB, but sincerely, now I don't know how to write a custom iterator for this type. The code for finding elements is this: //typedef typename DataStorage::template nth_index<0>::type byHashedIndex; //typedef typename DataStorage::template index<byMSB>::type byHashedIndex; //byHashedIndex &p = storage_.template get<byMSB>(); auto &p = storage_.template get<byMSB>(); auto q = p.equal_range(subject(v)); while (q.first != q.second) { std::cout << " EQID " << *(q.first) << " | " << msb(*(q.first)) << " | " << hsb(*(q.first)) << " | " << lsb(*(q.first)) << std::endl; l.push_back(*(q.first)); q.first++; } Note: I *have* written iterators, but they were much easier (for instance char*). This is far too complex for making my way on my own! From the code above, I guess I have begin() and end() point to an equal_range output .first and .second. But what will the "pointer" I need in the iterator will be? Of course, my first attempt is a complete failure: // Iterator template <class T> class iterator : public std::iterator<std::input_iterator_tag, Storage> { typedef typename DataStorage::template index<T>::type byHashedIndex; byHashedIndex &p; // Default constructor iterator() : p(storage_.get<T>()) { }; // Copy constructor iterator(const iterator& i) : p(i.p) { }; // Pre-increment ++it iterator& operator++() { ++p; return *this; }; // Post-increment it++ iterator operator++(int) {iterator tmp(*this); operator++(); return tmp; }; // Equality bool operator==(const iterator& rhs) { return p == rhs.p; }; // Non-equality bool operator!=(const iterator& rhs) { return p != rhs.p; }; // Access Storage& operator*() { return *p; }; // Difference iterator operator-(int i) { return iterator(p - i); }; // Addition iterator operator+(int i) { return iterator(p + i); }; }; Can you point me in the right direction? Thanks!

2 3

"newbie" Build Boost Matrix
by Ismael Fadiga 25 Aug '14

25 Aug '14

hi all After executing the below sql query in c++, the printed results are: WITH rnum AS (SELECT s.ISN, s.Date, ClosedPrice, row_number() OVER (partition BY s.ISN ORDER BY s.ISN, s.Date DESC) AS rownumber FROM SecurityData s INNER JOIN PortfolioHoldings p ON s.ISN = p.ISN WHERE p.Pfid = 1876) SELECT DISTINCT ISN, Date, ClosedPrice FROM rnum WHERE rownumber <= 250)) //ID Date Price US345 2014-08-17 342 US345 2014-08-16 310 ... FR123 2014-08-17 18.20 FR123 2014-08-16 15 Does anyone know how to build a price matrix for the IDs like:? |342 18.20| MAT=|310 15 | |... ... | Your feedback would be very appreciated Cheers

2 5

[ConceptCheck] Same type concept
by Robert Jones 25 Aug '14

25 Aug '14

I'd like a concept check to check for two types being the same type. I can see how to write such a concept, but this is such an obvious requirement that either there should be one already, or there's some blindingly obvious reason why you never need one, a reason that escapes me. A little guidance would be appreciated. Thanks, Rob.

3 3

Re: [Boost-users] [Chrono] The default BOOST_CHRONO_VERSION is still 1
by DonM 24 Aug '14

24 Aug '14

-------- Original Message -------- Subject: Re: [Boost-users] [Chrono] The default BOOST_CHRONO_VERSION is still 1 From: "Vicente J. Botet Escriba" <vicente.botet(a)wanadoo.fr> Date: 8/23/2014 6:28 AM To: boost-users(a)lists.boost.org > > Le 23/08/14 01:41, DonM a écrit : >> The docs (boost_1_56_0/doc/html/chrono/reference.html) say: >> >> "The default value for BOOST_CHRONO_VERSION will be changed to 2 since Boost 1.55. " >> >> However, it still has the value 1 in both 1.55 and 1.56. >> >> Not a big deal, I just noticed and figured I'd mention it. >> > Hi, > > I must remove this comment as as there is a incompatibility this will break user code. I planned to do a smooth trarnsition, but there were some complains. > > Thanks for pointing this issue, > Vicente Are you saying that you never intend to change the default value? That would be a mistake, in my opinion. Version 2 is much better -- the I/O stuff works. If users need backwards compatibility, they can define version 1, but encourage people to use version 2. Just my $0.02. Don

2 1

[move] Movable but not copyable bug?
by Mostafa 24 Aug '14

24 Aug '14

Given the following code, if (1) is uncommented then it fails to compile under C++03 mode yet works in C++11 mode. If commented out, then it compiles successfully under both modes. (g++ 4.8.2 is being used) Is this behavior expected or a bug? #include <boost/move/core.hpp> #include <boost/move/utility.hpp> struct Foo { Foo(int x, int y) {} Foo(BOOST_RV_REF(Foo) rhs) {} private: //Purposefully declared and not defined. Foo & operator=(Foo); private: BOOST_MOVABLE_BUT_NOT_COPYABLE(Foo) }; template <typename T> struct Bar { Bar() : f(0, 1) {} // (1) // Bar(Bar const & rhs) // : f(rhs.f) // {} Bar(BOOST_RV_REF(Bar) rhs) : f(::boost::move(rhs.f)) {} private: //Purposefully declared and not defined. Bar & operator=(Bar); private: BOOST_COPYABLE_AND_MOVABLE(Bar) private: T f; }; Foo f1() { // (2) // Foo f(0, 1); // return f; // (3) return Foo(0, 1); } Bar<Foo> f2() { return Bar<Foo>(); } int main() { // Foo f( f1() ); Bar<Foo> b(Bar<Foo>()); return 0; }

2 2

BGL: boost::astar_search_no_init
by Georg Gast 24 Aug '14

24 Aug '14

Hi there! Currently i try to implement an astar search with BGL and boost. My graph is infinite, so i searched for an example of astar_search_no_init and found this: http://lists.boost.org/boost-users/2012/03/73707.php I am on gcc-4.9.0 and boost 1.52.0 on linux. I try to compile the above example and get the following error which i cant decipher ... make gcc -std=c++11 example.cpp -o example example.cpp: In function 'int main(int, char**)': example.cpp:274:140: error: no matching function for call to 'boost::associative_property_map<default_map<std::pair<XY, XY>, unsigned int> >::associative_property_map(default_map<std::pair<XY, XY>, unsigned int>)' . weight_map(boost::associative_property_map<default_map<std::pair<XY,XY>,unsigned> >(default_map<std::pair<XY,XY>,unsigned>(1))) I added the code as an attachement. For me it seems that this line is not ok .... but i currently have no clue how to fix it ... try { astar_search_no_init(g, start, distance_heuristic<XYGraph>(goal) , visitor(astar_goal_visitor(goal)) . distance_map(d) . predecessor_map(boost::ref(p)) . weight_map(boost::associative_property_map<default_map<std::pair<XY,XY>,unsigned> >(default_map<std::pair<XY,XY>,unsigned>(1)) // < --- line 274 . vertex_index_map(boost::associative_property_map<std::map<XY,unsigned> >(std::map<XY,unsigned>())) . rank_map(boost::associative_property_map<std::map<XY,unsigned> >(std::map<XY,unsigned>())) . color_map(boost::associative_property_map<std::map<XY,boost::default_color_type> >(std::map<XY,boost::default_color_type>())) . distance_compare(std::less<unsigned>()) . distance_combine(std::plus<unsigned>()) ); with clang 3.4 i get this error line. clang --std=c++11 example.cpp -o ex example.cpp:274:26: error: no matching conversion for functional-style cast from 'default_map<std::pair<XY, XY>, unsigned int>' to 'boost::associative_property_map<default_map<std::pair<XY, XY>, unsigned int> >' . weight_map(boost::associative_property_map<default_map<std::pair<XY,XY>,unsigned> >(default_map<std::pair<XY,XY>,unsigned>(1)) So what ant the author of this code do? Allocate a property map of size 1? Currently i dont see the forrest, there are so many trees in my view .... Any help would be appreciated! Thank you! Georg

1 0

[Chrono] The default BOOST_CHRONO_VERSION is still 1
by DonM 23 Aug '14

23 Aug '14

The docs (boost_1_56_0/doc/html/chrono/reference.html) say: "The default value for BOOST_CHRONO_VERSION will be changed to 2 since Boost 1.55. " However, it still has the value 1 in both 1.55 and 1.56. Not a big deal, I just noticed and figured I'd mention it. Don

2 1

Boost.ASIO calling handler guarantees
by Фёдор Трушкин 23 Aug '14

23 Aug '14

Hello, Dear All, I'm playing with Boost.ASIO framework and failed to find a complete answer on the following question. Under which circumstances is it guaranteed that asynchronous operation completion handler is called? Plainly speaking, is this example code correct? void my_handler(const error_code &ec) { if(!ec) { /* process successful operation */ } else { /* process failed operation */ } try { async_write(port, my_handler2) } catch(...) { // processing failure to execute asynchronous operation } } Obviously here I rely heavily upon the above mentioned guarantee. Looking at least at async_write() implementation, it cannot be relied upon: - async_write executes a chain of boost::asio::detail::write_op() operations: - if asio_handler_allocate() may throw then - write_op::stream_.async_write_some() may throw then - write_op.handler_() might never be called So, either we should never rely on this assumption, or there's a bug in async_write(). Not relying on this assumption what is the reliable way of building applications with Boost.Asio? Sincerely yours, Fedor Trushkin

3 3

Installing 1.56 on Fedora 20
by Robert Jones 22 Aug '14

22 Aug '14

It's been a while since I've installed Boost. Running this command on a completely vanilla Fedora 20 b2 --prefix=~/local/boost-1.56.0 --layout=tagged link=shared threading=multi,single install Finally says... ...failed updating 58 targets... ...skipped 12 targets... ...updated 12214 targets... Is this normal? Thx, Rob.

3 5

exercism.io -- crowd-sourced mentorship C++ track online
by legalize+jeeves＠mail.xmission.com 22 Aug '14

22 Aug '14

[Please do not mail me a copy of your followup] Hi Boost-ers, Katrina Owens has created <http://exercism.io>, a web site designed to help programmers get better at their craft through crowd-sourced mentorship. The whole thing is free and open source and all you need to participate is a github account. I have contributed a basic set of completed exercises to enable the C++ language track. I would love for people from the boost community to participate in the C++ track. I had fun doing the initial set of exercises. Most of them could be completed in under 20 minutes, although the intention is that they increase in difficulty as you progress through them. For each exercise you are presented with the problem statement and a set of Boost.Test unit tests. The goal is to get a program that achieves the function and is expressive and readable. First you get all the tests passing in order to achieve the desired function, but then revise the code to get it to be more expressive and idiomatic in the language. It's that last part where the crowd-sourced mentorship comes into play -- once you've submitted your solution for a problem to the website, you'll be able to view the solutions other people have submitted for the same exercise in the same language. You can mentor them in how to write more expressive, idiomatic C++11 code. Who knows, maybe you'll also improve your C++11 skills by reading feedback from others on your submissions. Feel free to comment here or file an issue on the exercism.io github repository <http://github.com/exercism/exercism.io> if you think the C++ track needs more or better instructions or helpful links. -- "The Direct3D Graphics Pipeline" free book <http://tinyurl.com/d3d-pipeline> The Computer Graphics Museum <http://computergraphicsmuseum.org> The Terminals Wiki <http://terminals.classiccmp.org> Legalize Adulthood! (my blog) <http://legalizeadulthood.wordpress.com>

4 5

Serializing std::vector<double>**
by salman arshad 22 Aug '14

22 Aug '14

Hello, I want to serialize std::vector<double>**. I tried but may be I did not look into right places but I can serialize a std::vector<double>* without any problem but not a pointer to a pointer to vector. I think I am doing something really stupid here or missing something. Any help is highly appreciated. Regards, Salman Arshad

2 1

[review] Formal review period for VMD library begins today, Aug 21, and ends Sat, Aug 30
by Steven Watanabe 21 Aug '14

21 Aug '14

AMDG The formal review of the VMD library by Edward Diener starts today, Aug 21st and is scheduled to continue until Aug 30th. About VMD =============== The Variadic Macro Data library is a library of variadic macros which enhance the functionality in the Boost preprocessor library ( Boost PP ). The main focus of the library is the parsing/identifying of a subset of C++ preprocessor data types and of all Boost PP data types. This allows enhanced preprocessor metaprogramming based on the type of macro input. The library may also be seen as a repository for future enhancements to the Boost PP library functionality using variadic macros. Where to get it =============== The library is available on github at https://github.com/eldiener/variadic_macro_data Review guidelines ================= Reviews should be submitted to the developer list (boost(a)lists.boost.org) with '[vmd]' in the subject. Or if you don't wish to for some reason, you can send them privately to me. If so, please let me know whether or not you'd like your review to be forwarded to the list. For your review you may wish to consider the following questions: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? And finally, every review should answer this question: - Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. In Christ, Steven Watanabe

1 0

A library for "string chains"?
by legalize+jeeves＠mail.xmission.com 21 Aug '14

21 Aug '14

[Please do not mail me a copy of your followup] For a motivating example, see this gist: <https://gist.github.com/LegalizeAdulthood/7b67968bd93fbd4f9dbb> It uses boost::mapped_file to map a mail message into memory and then proceeeds to parse it. This is simply an example, but I think this hacked up parser comes fairly close to handling the full RFC2822 message, ignoring MIME extensions. <https://tools.ietf.org/html/rfc2822> I hacked it up from memory of mail message format rules and a single example message, so don't consider it production quality :-). The intention here is to parse a file without copying it's input text into any buffers. Notice that this parser builds structure from a buffer by identifying interesting substrings as (b,e) pointer pairs. A more traditional approach would have involved at least 2 more copies: one that gets the data from the file system into the stream buffer and another one that copies the data from the stream buffer into a std::string. The extra copying can take significant amounts of time when processing thousands of mail messages. Mail messages tend to be short, so mapping them into memory is not such a big deal. Obviously there is a lifetime relationship between the mapped file (the source character buffer) and the associated strings. For my use case, I'm not interested in being able to write to the strings, just read from them. (If you look closely you'll see that I "cheat" and add a few segments into my string that are associated with const char* C-style strings, but they too are read-only.) I'm interested to know if anyone is aware of a "string chain" library that provides a (read-only) API similar to std::string, but is fundamentally just managing (b,e) pointer pairs into some larger buffer. Boost.Test has a funky string class hiding in it called basic_cstring, but it wasn't created for this purpose. -- "The Direct3D Graphics Pipeline" free book <http://tinyurl.com/d3d-pipeline> The Computer Graphics Museum <http://computergraphicsmuseum.org> The Terminals Wiki <http://terminals.classiccmp.org> Legalize Adulthood! (my blog) <http://legalizeadulthood.wordpress.com>

6 12

[Serialization] 1.56.0 - unregistered_class exception while using EXPORTs
by Todd Seiler 20 Aug '14

20 Aug '14

I've been pulling my hair out for a couple of days trying to get this to work. When I serialize something from a base pointer, it throws an "unregistered_class" exception. I know the type of object that's being serialized and that class has "BOOST_CLASS_EXPORT_KEY" in the header and "BOOST_CLASS_EXPORT_IMPLEMENT" in the cpp file with the same name. In the save and load functions I also have: boost::serialization::void_cast_register( static_cast<Derived*>(NULL), static_cast<Base*>(NULL)); The base class is an abstract base class with one pure virtual function method. But here are the differences: 1) I tried using the "ASSUME_ABSTRACT....." macro. That didn't do anything for me. 2) The abstract base class also has a cpp file with some code in it. I'm not sure if that matters or not... Here's the thing. I can get the derived class's "save" method to be called with this code: std::ofstream o(case_path_ + "/" + file_name); if (o.good()) { // MUST HAVE THIS boost::serialization::void_cast_register<Derived, Base>( static_cast<Derived*>(NULL), static_cast<Base*>(NULL)); boost::archive::polymorphic_text_oarchive oa(o); boost::archive::polymorphic_oarchive & oa_interface = oa; oa_interface << base_ptr; } Having the void_cast_register() there sort of defeats the purpose though. I shouldn't need to pre-register them. In all the examples, I see the void_cast_register() inside of the "save" and "load" methods, which is what I have already. All my serialization code resides in cpp files. Also, the serialization code resides in a static lib. But the archive creation and the action to serialize is performed in a dynamic lib. I am also using polymorphic archives everywhere. I've also forced template instantiation of all serialization code and polymorphic archive interface stuff. Any clue?

3 4

[Serialization] 1.56.0 - How to serialize polymorphic base class data without derived data
by Todd Seiler 20 Aug '14

20 Aug '14

Basically, I'm looking to serialize a base class that's polymorphic, from a base class pointer, without it calling the derived class's serialize functions... Here is my setup: class RenderableMesh : public BasicMesh, public DynamicRenderable; Basically, I don't want it to serialize RenderableMesh or DynamicRenderable given a "basicMesh" pointer. The reason is because "DynamicRenderable" derives from a class inside the "Ogre3D" engine which does a bunch of memory management automatically. Basically, when I compile, it tells me it's missing operator delete, because Ogre overloads operator new or something I don't completely understand... I'm okay with serializing the BasicMesh, and then just recreating the RenderableMesh when it's deserialized. Which is what I'm going to have to do anyways because I don't want to change the Ogre3D SDK header files. It's probably super simple... If I don't implement it, it complains telling me the derived class is not registered... Which is correct. If I try to implement, it says operator delete is missing. Any ideas?

1 0

[build] Cannot build from develop anymore
by Marcel Raad 19 Aug '14

19 Aug '14

Hi, last time I tried to build Boost from develop (a few weeks ago) with MSVC, it worked perfectly. Now I get the following errors on two different Windows 7 machines with both MSVC14 CTP3 and MSVC12.3: boost/tools/build/src/build\virtual-target.jam:1099: in virtual- target.register-actual-name from module virtual-target error: Duplicate name of actual target: <pstage\lib>libboost_system-vc140- mt-1_57.lib error: previous virtual target { common%common.copy-libboost_system-vc140- mt-1_57.lib.STATIC_LIB { msvc%msvc.archive-libboost_system-vc140- mt-1_57.lib.STATIC_LIB { msvc%msvc.compile.c++-error_code.obj.OBJ { error_code.cpp.CPP } } } } error: created from ./stage-proper error: another virtual target { common%common.copy-libboost_system-vc140- mt-1_57.lib.STATIC_LIB { msvc%msvc.archive-libboost_system-vc140- mt-1_57.lib.STATIC_LIB { msvc%msvc.compile.c++-error_code.obj.OBJ { error_code.cpp.CPP } } } } error: created from ./stage-proper error: added properties: <asynch-exceptions>on error: removed properties: <asynch-exceptions>off boost/tools/build/src/build\virtual-target.jam:484: in actualize-no-scanner from module object(file-target)@14375 boost/tools/build/src/build\virtual-target.jam:134: in class@virtual- target.actualize from module object(file-target)@14375 boost/tools/build/src\build-system.jam:720: in load from module build-system boost\tools\build\src/kernel\modules.jam:289: in import from module modules boost\tools\build\src/kernel/bootstrap.jam:139: in boost-build from module boost\boost-build.jam:17: in module scope from module Does anyone have any idea what Boost.Build is trying to tell me?

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Re: [Boost-users] boost serialisation, just including shared_ptr.hpp causes compile error on Linux/gcc 4.5
by avib369 . 19 Aug '14

19 Aug '14

Adding the two missing includes has indeed fixed the problem, as suggested in https://svn.boost.org/trac/boost/ticket/10348 #include <boost/serialization/singleton.hpp> #include <boost/serialization/extended_type_info.hpp> Thanks, Avi

1 0

support for OpenMPI 64bit in modular-boost?
by Alle Meije Wink 19 Aug '14

19 Aug '14

Using the git repository (currently 1.57) of modular boost in Windows 7, compiling with MinGW64 and masm/ml64 (from the WDK v7) is successful but with the following warnings at the start: (1) warning: Graph library does not contain MPI-based parallel components. note: to enable them, add "using mpi ;" to your user-config.jam (2) warning: skipping optional Message Passing Interface (MPI) library. note: to enable MPI support, add "using mpi ;" to user-config.jam. note: to suppress this message, pass "--without-mpi" to bjam. note: otherwise, you can safely ignore this message. warning: No python installation configured and autoconfiguration note: failed. See http://www.boost.org/libs/python/doc/building.html note: for configuration instructions or pass --without-python to note: suppress this message and silently skip all Boost.Python targets After installing Open MPI 64-bit ( Windows installer of version 1.6.2 http://www.open-mpi.org/software/ompi/v1.6/downloads/OpenMPI_v1.6.2-2_win64… ), including adding it to the system-wide path, I have tried to re-build boost with MPI by, after running bootstrap gcc adding the line using mpi ; to the file project-config.jam in the boost directory (there is no file user-config.jam or a directory tools/build/v2 in the latest version or so it seems). Now the b2 command produces this output: The system cannot find the path specified. The system cannot find the path specified. The system cannot find the path specified. The system cannot find the path specified. The system cannot find the path specified. MPI auto-detection failed: unknown wrapper compiler mpic++ Please report this error to the Boost mailing list: http://www.boost.org You will need to manually configure MPI support. It continues to build the boost libraries, but still without MPI support. I am advised to manually configure MPI, but I'm pretty sure that is what I have just done. (the binaries are in the directory C:\Users\amwink\usr\local\OpenMPI_v1.6.2-x64\bin -- no spaces) Does anyone know what the problem is here? Is something wrong with this particular mpic++ binary that boost cannot handle? Happy to provide outputs/logs if that helps.

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boost serialisation, just including shared_ptr.hpp causes compile error on Linux/gcc 4.5
by avib369 . 18 Aug '14

18 Aug '14

I did not see boost serialisation in the list of lib that had changed. So its surprising that it now broken ? It appears simply including it cause problems #include <boost/serialization/shared_ptr.hpp> cause gcc.compile.c++ bin/gcc-4.5/debug/test/TestStr.o In file included from /var/tmp/ma0/boost/boost_1_56_0/boost/serialization/shared_ptr.hpp:28:0, from test/TestStr.cpp:27: /var/tmp/ma0/boost/boost_1_56_0/boost/serialization/shared_ptr_helper.hpp: In static member function ‘static const boost::serialization::extended_type_info* boost::serialization::shared_ptr_helper<SPT>::non_polymorphic::get_object_type(U&)’: /var/tmp/ma0/boost/boost_1_56_0/boost/serialization/shared_ptr_helper.hpp:107:22: error: ‘singleton’ is not a member of ‘boost::serialization’ /var/tmp/ma0/boost/boost_1_56_0/boost/serialization/shared_ptr_helper.hpp:110:13: error: expected ‘(’ before ‘>’ token /var/tmp/ma0/boost/boost_1_56_0/boost/serialization/shared_ptr_helper.hpp:110:14: error: ‘::get_const_instance’ has not been declared /var/tmp/ma0/boost/boost_1_56_0/boost/serialization/shared_ptr_helper.hpp: In static member function ‘static const boost::serialization::extended_type_info* boost::serialization::shared_ptr_helper<SPT>::polymorphic::get_object_type(U&)’: /var/tmp/ma0/boost/boost_1_56_0/boost/serialization/shared_ptr_helper.hpp:117:20: error: ‘singleton’ is not a member of ‘boost::serialization’ /var/tmp/ma0/boost/boost_1_56_0/boost/serialization/shared_ptr_helper.hpp:120:13: error: expected ‘(’ before ‘>’ token /var/tmp/ma0/boost/boost_1_56_0/boost/serialization/shared_ptr_helper.hpp:120:14: error: ‘::get_const_instance’ has not been declared /var/tmp/ma0/boost/boost_1_56_0/boost/serialization/shared_ptr_helper.hpp: In member function ‘void boost::serialization::shared_ptr_helper<SPT>::reset(SPT<T>&, T*)’: /var/tmp/ma0/boost/boost_1_56_0/boost/serialization/shared_ptr_helper.hpp:152:30: error: invalid use of incomplete type ‘const struct boost::serialization::extended_type_info’ /var/tmp/ma0/boost/boost_1_56_0/boost/serialization/shared_ptr_helper.hpp:42:7: error: forward declaration of ‘const struct boost::serialization::extended_type_info’ /var/tmp/ma0/boost/boost_1_56_0/boost/serialization/shared_ptr_helper.hpp:167:30: error: invalid use of incomplete type ‘const struct boost::serialization::extended_type_info’ /var/tmp/ma0/boost/boost_1_56_0/boost/serialization/shared_ptr_helper.hpp:42:7: error: forward declaration of ‘const struct boost::serialization::extended_type_info’ /var/tmp/ma0/boost/boost_1_56_0/boost/serialization/shared_ptr_helper.hpp:168:30: error: invalid use of incomplete type ‘const struct boost::serialization::extended_type_info’ /var/tmp/ma0/boost/boost_1_56_0/boost/serialization/shared_ptr_helper.hpp:42:7: error: forward declaration of ‘const struct boost::serialization::extended_type_info’ "g++" -ftemplate-depth-128 -fPIC -O0 -fno-inline -Wall -g -fPIC -DDEBUG -I"../ACore/src" -I"/var/tmp/ma0/boost/boost_1_56_0" -c -o "bin/gcc-4.5/debug/test/TestStr.o" "test/TestStr.cpp" Are there any workarounds ? Ta, Avi

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[BGL] Algorithm Objects
by Pierre Talbot 18 Aug '14

18 Aug '14

Hello, In the BGL documentation (challenge section, see http://www.boost.org/doc/libs/1_56_0/libs/graph/doc/challenge.html) a bullet point is: "Explore the use of Algorithm Objects as an alternative to the current approach with visitors." Do you have any links or explanations about the "Algorithm Objects" concept? Thanks, Pierre Talbot

2 1

Boost.Xpressive
by Goran 17 Aug '14

17 Aug '14

Hi all, I'll have to check large CSV text files (up to several GB) and check them with Xpressive. As far as I can see, the only way to do is to load the whole file into a std::string and hand over to Xpressive. I don't want to do that because my files are too big. So, how can I open a CSV file in text mode, get bidirectional iterators and hand them over to Xpressive? Regards Goran

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[Serialization] 1.56.0 - polymorphic archive saving std::shared_ptr<>, no member named "get_helper"
by Todd Seiler 17 Aug '14

17 Aug '14

I'm trying to serialize a std::shared_ptr using a polymorphic archive interface, but it complains about no "get_helper". Specifically clang states: "<removed_for_posting>/boost_1_56_0/boost/serialization/shared_ptr.hpp:253:21: No member named 'get_helper' in 'boost::archive::polymorphic_iarchive'" I tried including "boost/serialization/shared_ptr_helper.hpp", but this didn't seem to have what I needed. I did see the new stuff in "boost/serialization/shared_ptr.hpp" regarding std::shared_ptr<>, so I'm hopeful. Most of what I'm doing requires the serialization code to be inside of dll's or dylibs, so I believe I'm going down the correct path in using polymorphic archives... void save(std::shared_ptr<developer> p) { std::ofstream of("archiv.txt"); boost::archive::polymorphic_text_oarchive oa(of); boost::archive::polymorphic_oarchive & oa_interface = oa; oa_interface << p; } void load() { std::ifstream i("archiv.txt"); boost::archive::polymorphic_text_iarchive ia(i); boost::archive::polymorphic_iarchive & ia_interface = ia; std::shared_ptr<developer> p; ia_interface >> p; std::cout << p->getName() << std::endl; std::cout << p->age() << std::endl; std::cout << p->language() << std::endl; std::cout << p->getLangVer() << std::endl; } The compiler error specifically points to this function in shared_ptr.hpp template<class Archive, class T> inline void load( Archive & ar, std::shared_ptr< T > &t, const unsigned int /*file_version*/ ){ // The most common cause of trapping here would be serializing // something like shared_ptr<int>. This occurs because int // is never tracked by default. Wrap int in a trackable type BOOST_STATIC_ASSERT((tracking_level< T >::value != track_never)); T* r; ar >> boost::serialization::make_nvp("px", r); boost::serialization::shared_ptr_helper<std::shared_ptr> & h = ar.template get_helper< shared_ptr_helper<std::shared_ptr> >(); h.reset(t,r); } Any suggestions?

2 1

Do not understand about creating a vector of vector using Boost::interprocess libraries
by 张国熙 16 Aug '14

16 Aug '14

Dear everyone, I've just begun learning to use IPC in boost. Here I want to create a vector of vector<std::complex<double>>, that is to say, a matrix of complex. I read the section "containers of containers" in manual, and try to write something as the following: #include <boost/interprocess/containers/vector.hpp> #include <boost/interprocess/allocators/allocator.hpp> #include <boost/interprocess/managed_shared_memory.hpp> #include <complex> typedef boost::interprocess::allocator<std::complex<double>, boost::interprocess::managed_shared_memory::segment_manager> ComplexAllocator; typedef boost::interprocess::vector<std::complex<double>,ComplexAllocator> ComplexVector; typedef boost::interprocess::allocator<ComplexVector, boost::interprocess::managed_shared_memory::segment_manager> ComplexVectorAllocator; typedef boost::interprocess::vector<ComplexVector,ComplexVectorAllocator> ComplexMatrix; int main () { struct shm_remove { shm_remove() { boost::interprocess::shared_memory_object::remove("MySharedMemory"); } ~shm_remove(){ boost::interprocess::shared_memory_object::remove("MySharedMemory"); } } remover; boost::interprocess::create_only_t tag; boost::interprocess::managed_shared_memory segment(tag, "MySharedMemory", 65536); const ComplexVectorAllocator alloc_inst (segment.get_segment_manager()); ComplexMatrix *m = segment.construct<ComplexMatrix> ("M")(alloc_inst); m->resize(4); segment.destroy<ComplexMatrix>("M"); return 0; } However, it could not compile. And the error message is too long for me to understand. Is there anyone knowing how to fix this? Best wishes, Guoxi

2 1

from: giridhar
by giridhar 16 Aug '14

16 Aug '14

Hi boost http://taigamewap.net/draw.php?byytqavgmq2568uya giridhar

1 0

Error Messages when compiling Boost with VS2008 Professional on Windows 7
by Danny K 15 Aug '14

15 Aug '14

I regularly compile boost with bzip2 and zlib for use under Visual Studio. Usually it is not an issue but with the last couple of versions I get a strange error message. I was hoping someone might tell me what I am doing wrong or if it is nothing to worry about. I get the error message: "The system cannot find the path specified." I've search the boost forums and the web and can't find any traffic about this problem. the output of one of the compiler statements: compile-c-c++ bin.v2\libs\atomic\build\msvc-9.0\debug\address-model-64\architecture-x86\link-static\threading-multi\lockpool.obj The system cannot find the path specified. lockpool.cpp msvc.archive bin.v2\libs\atomic\build\msvc-9.0\debug\address-model-64\architecture-x86\link-static\threading-multi\libboost_atomic-vc90-mt-gd-1_56.lib The system cannot find the path specified. common.copy D:\id\vs2008\x64\lib\boost-1_56\libboost_atomic-vc90-mt-gd-1_56.lib The error message is printed throughout the output of the build. My build command within the "Visual Studio 2008 x64 Command Prompt. "d:/bld/build/boost_1_56_0/tools/build/src/engine/bin.ntx86_64/b2.exe " -sZLIB_SOURCE="D:/bld/build/zlib-1.2.8" -sBZIP2_SOURCE="D:/bld/build/bzip2-1.0.6" --prefix="D:/bld/install/vs2008" --libdir="D:/bld/install/vs2008/vs2008/x64/lib/boost-1_56" --includedir="D:/bld/install/vs2008/include" toolset=msvc-9.0 --build-type=minimal --layout=versioned architecture=x86 address-model=64 -a install Any suggestions/thoughts? As always any help is greatly appreciated. wr, Danny K I've attached the entire log that resulted from compiling boost.

1 0

Globbing library?
by Andrew Marlow 15 Aug '14

15 Aug '14

Hello everybody, Is there a globbing facility in boost? If not, are there any plans to add one? Please note that globbing is related to matching strings that correspond to file system objects functionality is neither regular expressions, nor is it file system related. Therefore it does not belong in regexp, expressive or bfs. IMO. Globbing is pattern matching using conventions that grew up with unix but have been widely copied to other operating systems and environments. The rules for the patterns are very different to regular expressions and somewhat simpler. I have written a directory iterator for my own use and I currently employ boost regexp for file name matching on unix. But i would very much prefer that it use globbing. The code is portable, via ifdefs, and in the windows branch I am able to use true globbing due to a facility in the win32 API.

5 10

[1.56] PDF documentation available
by John Maddock 14 Aug '14

14 Aug '14

The PDF build of Boost's documentation for 1.56 is now available from the usual address: https://sourceforge.net/projects/boost/files/boost-docs/1.56.0/ Note that it includes only the subset of Boost libraries whose documentation is quickbook/docbook based. John Maddock.

3 2

catch real time signals
by Halim DJERROUD 14 Aug '14

14 Aug '14

hi, I try to intercept real-time signals (SIGMIN + 1, SIGMIN +2 ...) it works when I send a signal (kill -35 PID) it works well only if i send one signal, when i send another signal or same signal second time (kill -35 PID) the pogram does not intercept the signal I feel that run () stops the service after having received the first signal Thank you for your help, Here are the code: #define SIG1 (SIGRTMIN + 1) #define SIG1 (SIGRTMIN + 2) ... class Agent { ... signal_handler(const boost::system::error_code& error, int signal_number) {...} ... } ... boost::asio::signal_set signals(io_serv); signals.add(SIG1) signals.add(SIG2) ... signals.async_wait( boost::bind(&Agent::signal_handler, this, boost::asio::placeholders::error, boost::asio::placeholders::signal_number)); io_serv.run(); for (;;) { std::this_thread::yield(); } (I use Linux and g++) -- Merci d'avance Halim DJERROUD

2 2

[boost::interprocess] named_recursive_mutex lock owner identification
by Frank Bergemann 14 Aug '14

14 Aug '14

2 1

Boost Library Writers Workshop at CPP Con 2014
by Robert Ramey 14 Aug '14

14 Aug '14

Have you been lurking out there in cyberspace all these years? Slaving away on your fantastic new library for boost? Stuck, discouraged, concerned about getting ripped apart on the mailing list? Well, this is for you !!!! The Boost Library Writers Workshop http://rrsd.com/blincubator.com/open-content/ . Share your library and get it critiqued by you peer group - other unsung authors battling the same daemons. Best of all you can attend this workshop without being registered at the conference - to attend this workshop all you have to do is ... attend!. That's right, it's absolutely free. That's right free. And not free like in free software. Really free like "free beer". (note: there is no free beer). So if you're in the area and you want to get your library off your chest because it's weighing you down, keeping you awake, ruining your love life attend this workshop. Spaces are limited so signup now at the above web page. Robert Ramey -- View this message in context: http://boost.2283326.n4.nabble.com/Boost-Library-Writers-Workshop-at-CPP-Co… Sent from the Boost - Users mailing list archive at Nabble.com.

1 0

boost::serialization: 'serialize' is not a member of 'Eigen::internal::workaround_msvc_stl_support<T>'
by LynnC 13 Aug '14

13 Aug '14

Boost 1.50 MSVS 2010 My problem occurs when I attempt to serialize pcl::PointCloud<pcl::PointXYZ> g...specifically g.points which is std::vector<Point, Eigen::aligned_allocator<Point> > pcl::PointCloud<Point>::points. I have the following code: #ifndef SERIALIZATIONSUPPORT_H #define SERIALIZATIONSUPPORT_H #include <pcl/point_cloud.h> #include <pcl/io/pcd_io.h> #include <pcl/point_types.h> // needed for pcl::PointXYZ Point #include <boost/serialization/base_object.hpp> #include <boost/serialization/utility.hpp> #include <boost/serialization/list.hpp> #include <boost/serialization/assume_abstract.hpp> #include <boost/serialization/vector.hpp> typedef pcl::PointXYZ Point; namespace boost { namespace serialization { template<class Archive> void serialize(Archive & ar, pcl::PointCloud<Point>& g, const unsigned int version) { ar & g.points; } template<class Archive> void serialize(Archive & ar, Point& g, const unsigned int version) { ar & g.getVector3fMap().data()[0]; ar & g.getVector3fMap().data()[1]; ar & g.getVector3fMap().data()[2]; } } // namespace serialization } // namespace boost #endif /* SERIALIZATIONSUPPORT_H */ Error received: error C2039: 'serialize' : is not a member of 'Eigen::internal::workaround_msvc_stl_support<T>' Special notes...no problems with my code when compiling on Ubuntu 12.04 LTS using Boost 1.48. Only a problem when compiling on Windows. Any idea as to why I would be receiving this? I already have a method for serializing Point. Shouldn't that be enough? -- View this message in context: http://boost.2283326.n4.nabble.com/boost-serialization-serialize-is-not-a-m… Sent from the Boost - Users mailing list archive at Nabble.com.

2 2

composite_key with array member
by Uthpal Urubail 13 Aug '14

13 Aug '14

I am looking for a container where I have to use 5-10 keys to get the value. I am trying to write something like below.. Can some one help to solve this? struct entry { int a[10]; int id; }; using boost::multi_index_container; using namespace boost::multi_index; typedef multi_index_container< entry, indexed_by< ordered_non_unique< composite_key< entry, member<entry,unsigned int,&entry::a> ???? > >, ordered_unique< member<entry,unsigned int,&entry::id> > > > book; Regards, UJ

2 1

[BGL] Question about using remove_edge() in boost graph library
by Yi-Ping Huang 12 Aug '14

12 Aug '14

Dear boost-users: I just start learning boost graph library and have a basic problem on using the remove_edge function in boost graph library. I would like to remove an edge in a multigraph. For a graph with two edges connect vertice 0 and 1, I would like to remove one of them, but kept the other. According to the user guide, remove_edge(u ,v , g) removes all occurrences of (u ,v). So I should use remove_edge(e ,g) instead. Here, e is a valid edge descriptor. For a single graph, g, I am able to perform both remove_edge(u ,v , g) and remove_edge(e ,g) operation. However, when I want to generalize the implementation to fit my need by putting graphs in a vector container, I got segmentation fault for remove_edge(e ,graph_list[0]). (The compiler show no warning message.) On the other hand, remove_edge(u,v,g) works perfectly. I am not sure what's the difference between those two syntax causes this problem. I really want to make remove_edge(e,g) and vector container work at the same time. So any suggestion that can help my bypass this difficulty is appreciated. Thanks a lot!! Yi-Ping

1 0

Allocation/deallocations during boost serialization (tracking help?)
by miles_c＠verizon.net 12 Aug '14

12 Aug '14

1 0

asio::ip::tcp iostream wrong byte count read for last packet
by Steve Coleman 12 Aug '14

12 Aug '14

I just started out with Boost and was writing a little binary file transfer app and ran into a little problem, so I would appreciate if someone could kindly point out what I am doing wrong here. My problem is in getting the correct byte count read in the final packet received. My last frame always returns the size of the buffer, not the number of bytes read into the buffer. Isn't iostream::gcount(() meant for this? If not, what is the correct 'Boost' way of doing this? int spool_binary_data() { boost::asio::ip::tcp::endpoint dataServerEndpoint(boost::asio::ip::tcp::v4(), PMMS_TRANSFER_PORT_NUMBER); boost::asio::ip::tcp::acceptor acceptor(dataServer, dataServerEndpoint); boost::asio::ip::tcp::iostream dataServerStream; acceptor.accept(*dataServerStream.rdbuf()); char buffer[2048]; std::streamsize nbytes = sizeof(buffer); FILE * pFile = fopen ("binary.out","w"); // count = getavailable(this->native_socket) ?? // stream->rdbuf()->available() ?? while ( dataServerStream.read((char*)&buffer, nbytes) ) { int bytes_read = dataServerStream.gcount(); // always 2048 std::cout << "bytes read " << bytes_read << std::endl; fwrite(buffer,1,bytes_read,pFile); } dataServerStream.close(); fclose(pFile); }

2 3

Basic question about using remove_edge() in boost graph library
by Yi-Ping Huang 11 Aug '14

11 Aug '14

Dear boost-users: I just start learning boost graph library and have a basic problem on using the remove_edge function in boost graph library. I would like to remove an edge in a multigraph. For a graph with two edges connect vertice 0 and 1, I would like to remove one of them, but kept the other. According to the user guide, remove_edge(u ,v , g) removes all occurrences of (u ,v). So I should use remove_edge(e ,g) instead. Here, e is a valid edge descriptor. For a single graph, g, I am able to perform both remove_edge(u ,v , g) and remove_edge(e ,g) operation. However, when I want to generalize the implementation to fit my need by putting graphs in a vector container, I got segmentation fault for remove_edge(e ,graph_list[0]). I really want to make remove_edge(e,g) and vector container work at the same time. So any suggestion that can help my bypass this difficulty is appreciated. Thanks a lot!! Yi-Ping *************************Here is the complete code************************* #include <iostream> #include <utility> #include <algorithm> #include <vector> #include "boost/graph/graph_traits.hpp" #include "boost/graph/adjacency_list.hpp" using namespace boost; typedef adjacency_list<vecS, vecS, undirectedS> UndirectedGraph; typedef boost::graph_traits<UndirectedGraph>::edge_iterator edge_iterator; int graph_show(UndirectedGraph &g); int main(int argc, char *argv[]) { UndirectedGraph g; typedef boost::graph_traits<UndirectedGraph>::edge_descriptor edge_descriptor; edge_descriptor ed; std::vector<edge_descriptor> edge_list; std::vector<std::vector<edge_descriptor> > graph_edge_list; std::vector<UndirectedGraph> graph_list; int nb=0; int Nl=4; bool inserted; while(nb<Nl) { tie(ed,inserted)=add_edge(nb,nb+1,g); edge_list.push_back(ed); tie(ed,inserted)=add_edge(nb,nb+1,g); edge_list.push_back(ed); graph_edge_list.push_back(edge_list); nb=nb+1; graph_list.push_back(g); } std::cout<<"size of the graph vector is: "<<graph_list.size()<<std::endl; remove_edge(graph_edge_list[0][0],graph_list[0]);//This is where the problem shows. //I got Segmentation fault (core dumped) //remove_edge(0,1,graph_list[0]); /*Remove edges by assigning vertices works fine, but that is not what I need.*/ for (int ig = 0; ig < Nl; ++ig) { std::cout<<"graph#"<<ig<<std::endl; std::cout<<"Size of edge_list is: "<<graph_edge_list[ig].size()<<std::endl; graph_show(graph_list[ig]); } std::cout<<"Success"<<std::endl; return 0; } int graph_show(UndirectedGraph &g) { std::cout<<"Number of edges is : "<<boost::num_edges(g)<<std::endl; std::cout<<"Number of vertices is : "<<boost::num_vertices(g)<<std::endl; std::pair<edge_iterator,edge_iterator> ei=edges(g); for (edge_iterator edge_iter = ei.first; edge_iter!=ei.second; ++edge_iter) { std::cout<<"("<< boost::source(*edge_iter,g)<<","<<boost::target(*edge_iter,g)<<")"<<std::endl; } typedef boost::graph_traits<UndirectedGraph>::vertex_iterator iter_v; std::cout<<"vertices(g)={ "; for (std::pair<iter_v,iter_v> p = vertices(g); p.first != p.second; ++p.first) { std::cout<< *p.first; std::cout<<" "; } std::cout<<"}"<<std::endl; return 0; }

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[String algorithms] User defined finders and predicates
by Aaron Levy 11 Aug '14

11 Aug '14

Are there good examples of writing user defined finders and predicates for functions such as find_token? Aaron

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Boost 1.56.0 has been released
by Marshall Clow 11 Aug '14

11 Aug '14

Release 1.56.0 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 one new library and numerous enhancements and bug fixes for existing libraries. === Modularization === Boost version control has migrated to a system using git submodules. This shouldn't make too much of a difference to users, although the directory structure is now a bit different. Parts of some libraries have been moved into different modules, and several new modules have been extracted from existing code. All header paths should remain the same. The new modules are: • Assert: Customizable assert macros. Maintained by Peter Dimov. • Core: Core utilities used by other libraries, with minimal dependencies. Maintained by Peter Dimov, Glen Fernandes and Andrey Semashev. • Lexical_Cast: General literal text conversions, such as an int represented a string, or vice-versa, from Kevlin Henney. • Throw_Exception: A common infrastructure for throwing exceptions from Boost libraries, from Emil Dotchevski. • Winapi: Windows API declarations without <windows.h>, for internal Boost use. === New Libraries === • Align: Memory alignment functions, allocators, and adaptors, from Glen Fernandes. • Type_Index: Runtime/Compile time copyable type info, from Antony Polukhin. For details, including download links, see http://www.boost.org/users/news/version_1.56.0 You can also download directly from SourceForge: http://sourceforge.net/projects/boost/files/boost/1.56.0/ 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

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