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[test] Standalone use with multiple translation units?
by Adam Nielsen 20 May '16

20 May '16

Hi all, I am currently using Boost Test for my test code, however it is always an extreme headache trying to get Boost available on the target platforms I'm using. At the moment due to some environment restrictions it is just not possible to use a recent version of Boost, and since the Test library broke backwards compatibility with 1.59, my code will no longer compile on versions earlier than 1.59. So I am looking to see whether I can avoid the need to compile the full Boost, and just pull in the bits that I need. The Boost Test docs say that the library can be used in single-header mode, however this only works when there is one translation unit. Since my tests are spread across dozens of files, I don't think this will work for me. Is there any way to use this single-header mode, and flag one file as the "primary" one, and others as extras, so that you can use single-header mode across multiple translation units? This would remove the need to do battle with getting the Boost libraries installed on various platforms, which would make it much easier and allow me to spend more time on my code, and less time on writing build scripts. Many thanks, Adam.

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[boost::compute] [OS X 10.11.5] [GeForce GT 750M] Segmentation fault
by Prashant 20 May '16

20 May '16

Hi, Example code to sort a vector on GPU (GeForce GT 750M) generates SEGV. However, it runs fine on Iris Pro (Intel(R) Core(TM) i7-4850HQ CPU). Having said that, it works as long as size of vector being sorted is small(<2 million). The code throws an exception if the size of the vector is less 9 million. Exception: boost/1_61_0/include/boost/compute/command_queue.hpp(453): Throw in function boost::compute::event boost::compute::command_queue::enqueue_write_buffer(const boost::compute::buffer &, size_t, size_t, const void *, const boost::compute::wait_list &) Dynamic exception type: boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector <boost::compute::opencl_error> > std::exception::what: Invalid Value Another observation: if the size of vector is 50 million the sorting works fine, though the timings are worse than Iris Pro. Regards, Prashant ----------------------------Cut here------------------------------------- #include <iostream> #include <vector> #include <algorithm> #include <boost/foreach.hpp> #include <boost/compute/core.hpp> #include <boost/compute/platform.hpp> #include <boost/compute/algorithm.hpp> #include <boost/compute/container/vector.hpp> #include <boost/compute/functional/math.hpp> #include <boost/compute/types/builtin.hpp> #include <boost/compute/function.hpp> #include <boost/chrono/include.hpp> #include <boost/exception/all.hpp> namespace compute = boost::compute; int main(int argc, char* argv[]) { if (argc != 2) { std::cout << "Usage: " << argv[0] << " <size> " << std::endl; return 0; } // generate random data on the host std::vector<float> host_vector(atoi(argv[1])); std::generate(host_vector.begin(), host_vector.end(), rand); std::cout << "===============CPU==================\n"; for (size_t k=0; k<5; k++) { std::vector<float> host_copy_vector(host_vector); auto start = std::chrono::high_resolution_clock::now(); std::sort(host_copy_vector.begin(), host_copy_vector.end()); auto duration = std::chrono::duration_cast<std::chrono::milliseconds> (std::chrono::high_resolution_clock::now() - start); std::cout << "time: iteration ("<< k << ") : " << duration.count() << " ms" << std::endl; } std::vector<compute::platform> platforms = compute::system::platforms(); for(size_t i = 0; i < platforms.size(); i++){ const compute::platform &platform = platforms[i]; std::cout << "Platform '" << platform.name() << "'" << std::endl; std::vector<compute::device> devices = platform.devices(); for(size_t j = 0; j < devices.size(); j++){ const compute::device &device = devices[j]; std::string type; if(device.type() & compute::device::gpu) type = "GPU Device"; else if(device.type() & compute::device::cpu) type = "CPU Device"; else if(device.type() & compute::device::accelerator) type = "Accelerator Device"; else type = "Unknown Device"; if (type != "GPU Device") { std::cout << "Ignoring non GPU devices.\n"; continue; } std::cout << "====\n"; std::cout << " " << type << ": " << device.name() << std::endl; std::cout << "====\n"; compute::context context(device); compute::command_queue queue(context, device); for (size_t k=0; k<5; k++) { compute::vector<float> device_vector(host_vector.size(), context); // copy data from the host to the device compute::copy( host_vector.begin(), host_vector.end(), device_vector.begin(), queue ); auto start = std::chrono::high_resolution_clock::now(); try { compute::sort(device_vector.begin(), device_vector.end(), queue); } catch (boost::exception & e) { std::cerr << diagnostic_information(e); break; } auto duration = std::chrono::duration_cast<std::chrono::milliseconds> (std::chrono::high_resolution_clock::now() - start); std::cout << "time: iteration ("<< k << ") : " << duration.count() << " ms" << std::endl; } std::cout << "====\n"; } } return 0; }

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Boost 1.61.0 has been released
by Rene Rivera 19 May '16

19 May '16

Release 1.61.0 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 four new libraries and numerous enhancements and bug fixes for existing libraries. New Libraries * Compute: Parallel/GPU-computing library, from Kyle Lutz. * DLL: Library for comfortable work with DLL and DSO, from Renato Tegon Forti and Antony Polukhin * Hana: A modern C++ metaprogramming library, from Louis Dionne. * Metaparse: A library for generating compile time parsers parsing embedded DSL code as part of the C++ compilation process, from Abel Sinkovics. For details, including download links, see http://www.boost.org/users/news/version_1.61.0 You can also download directly from SourceForge: http://sourceforge.net/projects/boost/files/boost/1.61.0/ Tom Kent has made pre-built windows binaries, and they are available at: https://sourceforge.net/projects/boost/files/boost-binaries/1.61.0/ 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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DMARC and mailman
by James Sharpe 19 May '16

19 May '16

In June 2016 gmail is going to be changing its DMARC policy to reject any unaligned mail. This means that we will be seeing any mailing list responses from a gmail.com address to be considered spam by any mail server that enforces DMARC. For a while now yahoo.com has had this policy turned on which has meant that yahoo.com addresses have been considered spam. Mailman has released a workaround in version 2.1.18: https://www.mail-archive.com/mailman-users@python.org/msg64098.html The boost mailing list is currently on mailman 2.1.15. I'd strongly suggest that this should be updated as a matter of urgency else we'll find a lot of the conversations on this list will end up in the spam folder... Regards, James

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[boost::python] cannot concatenate 'str' and 'property' objects
by sergei nazarenko 19 May '16

19 May '16

Hello! I have just simple question. python code: a = A() bla = "lala" + a.pp *Traceback (most recent call last):TypeError: cannot concatenate 'str' and 'property' objects* Why it is not work? How make it is work? boost c++ code: #include <boost/python/module.hpp> #include <boost/python/def.hpp> #include <boost/python/class.hpp> #include <boost/python/init.hpp> class A { public: std::string pp; A(): pp("babla") {}; }; using namespace boost::python; BOOST_PYTHON_MODULE (test1) { class_<A> ("A") .def(py::init<>()) .add_property ("pp", &A::pp) ; } Thanks, Sergiy

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Documentation for Boost Range
by Christian Aichinger 19 May '16

19 May '16

Boost Range is a cool library, but it's sometimes hard to see how to actually use it: which headers to include, how to call it, what the return types are. To improve this situation, I wrote full, self-contained code examples for each function in Boost Range. They are available at: https://greek0.net/boost-range The examples also include links to the official docs and the into the library's source code, as well as a list of headers that give access to a specific function. I hope it's useful for other people as well. If you have any ideas for improvement, please let me know. Kind regards, Chris

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Blocking sockets on Windows
by William Riancho 18 May '16

18 May '16

Hello all, I try to implement a simple http server with blocking sockets on Windows. Basically, I have a simple server that just write data to a socket when a network connection occurs before exit. The problem is that the last "socket.send" as no effect if I don't delay the process exit. Writing to this socket is supposed to block until all the data as been written. I have tried to use the completion condition of write, to use the non_blocking method of the socket. I still get the same problem. Note that the problem doesn't occur on Linux. Here is the code: ``` #include <boost/asio.hpp> int main(int argc, char *argv[]) { char *address = "0.0.0.0"; char *port = "8180"; boost::asio::io_service io_service; boost::asio::ip::tcp::acceptor acceptor(io_service); boost::asio::ip::tcp::resolver resolver(io_service); boost::asio::ip::tcp::resolver::query query(address, port); boost::asio::ip::tcp::endpoint endpoint = *resolver.resolve(query); acceptor.open(endpoint.protocol()); acceptor.bind(endpoint); acceptor.listen(); boost::asio::ip::tcp::socket sock(io_service); acceptor.accept(sock); std::string body("Hello, World!"); sock.send(boost::asio::buffer(std::string("HTTP/1.1 200 OK\r\n"))); sock.send(boost::asio::buffer(std::string("Content-Length: ") + std::to_string(body.size()) + "\r\n\r\n")); sock.send(boost::asio::buffer(body)); Sleep(1000); // The body would not be sent without this return 0; } ```

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Review Wizard Report for May 2016
by Ronald Garcia 18 May '16

18 May '16

============================================== Review Wizard Status Report for May 2016 ============================================== News ==== 1. Boost 1.58 Released April 2015. New Libraries: Endian, Sort 2. Metaparse Library Accepted 3. Hana Library Accepted 4. DLL Library Accepted 5. Http Library Rejected 6. Boost 1.59 Released August 2015. New Libraries: Coroutine2, Convert 7. AFIO Library Reviewed 8. Fiber Library Conditionally Accepted 9. Boost 1.60 Released December 2015. New Libraries: Variadic Macro Data 10. Quaternions, Vectors, Matrices Accepted 11. Fit Library Rejected 11. Boost 1.61 Released May 2016. New Libraries: Compute, DLL, Metaparse, Hana 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 reviewed and await reports from their review managers: * AFIO - reviewed August 2015; review manager: Ahmed Charles. The following libraries have been accepted to Boost, but have not yet been integrated into Boost Git: * Contract - accepted September 2012; author: Lorenzo Caminiti. * Quaternions,Vectors,Matrices - accepted December 2015; author: Emil Dotchevski The following libraries have been accepted and submitted to Boost Git, but have not yet appeared in a release: * none The following libraries have been accepted provisionally to Boost, but have not been submitted for mini-review and full acceptance: * none 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) * Block Pointer (M) * Singularity (M) * Extended Complex Numbers (M) * Boost.Range Extensions * Nowide (M) * Array (M) * STL Extensions (M) * Countertree (M) * Process (M) * Application (M) * Edit Distance (M) * Mixin (M) * Dependency Injection (M) * Segmented Tree * Fiber ``(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. 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) 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 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. Dependency Injection -------------------- :Author: :Download: https://github.com/krzysztof-jusiak/di :Documentation: http://krzysztof-jusiak.github.io/di/boost/libs/di/doc/html :Incubator: http://rrsd.com/blincubator.com/bi_library/di-dependency-injection/?gform_p… :Review Manager: Needed :Description: Boost.DI is a dependency injection library improving manual dependency injection by simplifying object instantiation with automatic dependencies injection. Using Boost.DI has many advantages over manual dependency injection. * Reduce boilerplate code (No factories, no objects creation in specific order) * Reduce cost of maintenance effort (Constructor signature change won't affect di configuration) * Reduce testing effort * Give better control of what and how is created (Policies, Providers) * Give better understanding about objects hierarchy (UML Dumper) Segmented Tree -------------- :Author: Chris Clearwater :Download: http://rrsd.com/blincubator.com/bi_library/segmentedtreeseq-2/?gform_post_i… :Repository: http://github.com/det/segmented_tree :Documentation: https://det.github.io/segmented_tree :Review Manager: Glen Fernandes :Description: SegmentedTreeSeq is a sequence data structure like vector and deque that supports efficient random access insert and erase. It is implemented using B+Trees and has an emphasis on speed and a low memory overhead. Fiber ----- :Author: Oliver Kowalke :Download: https://github.com/olk/boost-fiber :Documentation: http://olk.github.io/libs/fiber/doc/html/ :Review Manager: Nat Goodspeed :Description: Boost.Fit is a header-only C++11/C++14 library that provides utilities for functions and function objects. Libraries under development =========================== See The Boost Library Incubator Project at http://blincubator.com for discussion of libraries currently under development.

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Memory deallocation concerning boost::bind, boost::asio and shared_ptr
by Norman Kradepohl 17 May '16

17 May '16

Hi there, my code is allocating memory and never freeing it, even though it should (at least in my opinion). The header looks like this: typedef boost::asio::ssl::stream<boost::asio::ip::tcp::socket> sslSocket_t; class Object { boost::asio::io_service ioService_; boost::asio::ip::tcp::acceptor acceptor_; boost::asio::ssl::context context_; void functionOne(); void functionTwo(shared_ptr<sslSocket_t>& sslSocket, const boost::system::error_code& error) } And my source like this: void Object::functionOne() { for (int i = 0; i < 10; i++) { shared_ptr<sslSocket_t> sslSocket(new sslSocket_t(ioService_, context_)); acceptor_.async_accept(sslSocket->lowest_layer(), boost::bind(&Object::functionTwo, this, sslSocket, boost::asio::placeholders::error)); } acceptor_.cancel(); boost::asio::io_service::work work(ioService_); ioService_.run(); } void functionTwo(shared_ptr<sslSocket_t>& sslSocket, const boost::system::error_code& err) { // Do nothing } So when i call *Object.functionOne()*, memory is getting allocated to the *Object.ioService_* object, in order to be able to call the bound asynchronous method. Then after the loop, all pending asynchronous actions on the acceptor are getting canceled. The appropriate handler is getting invoked as soon as *Object.ioService_.run()* is called (i've been testing that). BUT for some reason, the allocated memory does not get freed. I'm stuck on this problem for a while now, any hint or help would be really appreciated. Btw.: I'm working on debian and looking at "/proc/self/status" -> "VmRSS" to whatch the used memory.

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- Units presentation
by Roman Fratczak 17 May '16

17 May '16

Dears, How to "correctly" display an quantity units for "specific energy" in [kJ/kg] - always? Is there a method for preventing units simplification down to [m2/s2]? Regards Roman

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[proto] grammar to match operator in expression
by Igor R 16 May '16

16 May '16

Hi, Why the following grammar doesn't match dereference, and what's the correct way to do this? Thanks! ////////////////// #include <iostream> #include <boost/proto/proto.hpp> namespace proto = boost::proto; using proto::_; struct has_deref : proto::or_< proto::dereference<_>, proto::nary_expr<_, proto::vararg<has_deref>> > {}; template<class Expr> void test_expr(const Expr &e) { proto::display_expr(e); std::cout << "matches? " << std::boolalpha << proto::matches<Expr, has_deref>::value << std::endl; } int main() { test_expr(proto::lit(1) + *proto::lit(2)); }

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qx(3):
by Silviu P 16 May '16

16 May '16

http://www.granfoundation.org/hmmhjhm.php ***********************Neither a wise man or a _brave man lies down on the tracks of history to wait for the train of the future to run over him.Leana Fargo

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[Boost.Container] Problems in Solaris trying to use class flat_set
by dariomt＠gmail.com 12 May '16

12 May '16

Hi all, Trying to compile the following program is problematic with the Solaris compiler. $ cat kk.cpp #include <boost/container/flat_set.hpp> Yes, it is just one line #include'ing flat_set.hpp - with Boost 1.55.0 the compiler ICE's on me :( $ CC -Iboost/1_55_0 -features=extensions -library=stlport4 kk.cpp >> Assertion: (../lnk/v2mangler.cc, line 776) while processing boost/1_55_0/boost/container/detail/utilities.hpp at line 1036. - and with Boost 1.59.0 I have a compile error: $ CC -Iboost/1_59_0 -features=extensions -library=stlport4 kk.cpp "boost/1_59_0/boost/container/throw_exception.hpp", line 112: Error: Cannot cast from const char* to std::out_of_range. "boost/1_59_0/boost/container/throw_exception.hpp", line 128: Error: Cannot cast from const char* to std::length_error. "boost/1_59_0/boost/container/throw_exception.hpp", line 145: Error: Cannot cast from const char* to std::logic_error. "boost/1_59_0/boost/container/throw_exception.hpp", line 161: Error: Cannot cast from const char* to std::runtime_error. "boost/1_59_0/boost/container/detail/copy_move_algo.hpp", line 997: Error: type is not a member of boost::move_detail::enable_if_c<0, void>. 5 Error(s) detected. Compiler version: $ CC -V CC: Sun C++ 5.10 SunOS_i386 Patch 128229-32 2013/12/04 Any clues?

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Shared memory: private node allocator for a boost::unordered_map
by trafdev 12 May '16

12 May '16

Hello. I'm trying to use a private node allocator for an unordered_map placed in the shared memory: #include <boost/interprocess/managed_shared_memory.hpp> #include <boost/interprocess/containers/map.hpp> #include <boost/unordered_map.hpp> #include <boost/interprocess/allocators/allocator.hpp> #include <boost/interprocess/allocators/private_node_allocator.hpp> #include <functional> #include <utility> int main () { using namespace boost::interprocess; struct shm_remove { shm_remove() { shared_memory_object::remove("MySharedMemory"); } ~shm_remove(){ shared_memory_object::remove("MySharedMemory"); } } remover; managed_shared_memory segment (create_only ,"MySharedMemory" //segment name ,65536); //segment size in bytes typedef int KeyType; typedef float MappedType; typedef std::pair<const int, float> ValueType; typedef private_node_allocator<ValueType, managed_shared_memory::segment_manager> ShmemAllocator; typedef boost::unordered_map<KeyType, MappedType, boost::hash<KeyType>, std::equal_to<KeyType>, ShmemAllocator> MyMap; ShmemAllocator alloc_inst (segment.get_segment_manager()); MyMap *mymap = segment.construct<MyMap>("MyMap") //object name (3, boost::hash<KeyType>(), std::equal_to<KeyType>(), alloc_inst); for(int i = 0; i < 100; ++i){ mymap->insert(std::pair<const int, float>(i, (float)i)); } return 0; } It gives a compilation error: /usr/local/include/boost/unordered/detail/unique.hpp:30:43: error: no type named 'pointer' in 'boost::interprocess::private_node_allocator<boost::unordered::detail::unique_node<boost::interprocess::private_node_allocator<std::__1::pair<const int, float>, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0>, 0>, iset_index>, 64>, std::__1::pair<const int, float> >, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0>, 0>, iset_index>, 64>' A, unique_node<A, T> >::type::pointer node_pointer; What am I doing wrong?

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[boost.lockfree][spsc_queue] runtime sizing and producer's thread
by Sampath Tilakumara 12 May '16

12 May '16

Hi, Two questions on lockfree spsc_queue: 1. Can spsc_queue be dynamically (runtime) sized, and if so how do you correctly do it? * Creating a mpmc queue with size 0 (i.e. queue<T>(0)) creates a dynamically sizes mpmc queue, but doing the same for spsc queue doesn't. * creating a spsc queue with size 10 (i.e. queue<T>(10)) seems to create a fixed sized ring buffer since at high transfer rates, push fails, however the constructor code that takes the size asserts that it's runtime sized. explicit spsc_queue(size_type element_count): base_type(element_count) { BOOST_ASSERT(runtime_sized); } * documentation mentions lockfree::fixed_sized<> in policies, and can also be found in (mpmc) queue.hpp, but it doesn't seem to be in spsc_queue.hpp * all examples I could find on the internet (and documentation) was for fixed size or for mpmc dynamic, but not for spsc dynamic. 2. In a normal (spsc using) program the producer will be a single OS thread; however is it still safe to use on something like an actor framework or fiber framework? (i.e. you only have a single producer object, but it can actually be executed in different threads -- though strictly on one thread at any given time). for example in spsc_queue.hpp there's some code such as: bool push(T const & t, T * buffer, size_t max_size) { const size_t write_index = write_index_.load(memory_order_relaxed); // only written from push thread Refs on actors/fibers: https://en.wikipedia.org/wiki/Fiber_%28computer_science%29 https://en.wikipedia.org/wiki/Actor_model Thank you. Sampath Tilakumara

2 1

FindBoost.cmake does not check for include headers
by j.wuttke 11 May '16

11 May '16

As per cmake 3.5.1, FindBoost.cmake does not check for include headers. Therefore it will give false positives - if a Boost project that only consists of a header file is not installed - if only a libboost* is installed, but not the headers from the corresponding *-dev package. I raised this issue long ago on the cmake bug tracker, and recently again on the cmake mailing list, but got no response. Would perhaps somebody from the Boost community volunteer to look into this issue? Or has already looked into it and could tell us what the problem is?

3 4

Fwd: [proto][variant] variant crashes proto expression
by Igor R 11 May '16

11 May '16

The following code is a slightly modified Proto calc2 example. Instead of doubles I use variant<int, double>, and the expression is just _1 = _2. This code triggers assertion in variant/detail/forced_return.hpp, so it looks like some variant instance gets messed up. It happens when the value returned from proto::eval(*this, ctx) is being copied. It can be reproduced both with MSVC and gcc, with Boost 1.60. Is there any workaround for this issue? Thanks. ////////////// #include <iostream> #include <boost/proto/proto_typeof.hpp> #include <boost/proto/core.hpp> #include <boost/proto/context.hpp> #include <boost/variant.hpp> namespace proto = boost::proto; using proto::_; typedef boost::variant<int, double> var_t; template<typename Expr> struct calculator_expression; // Tell proto how to generate expressions in the calculator_domain struct calculator_domain : proto::domain<proto::generator<calculator_expression> > {}; // Will be used to define the placeholders _1 and _2 template<int I> struct placeholder {}; // Define a calculator context, for evaluating arithmetic expressions // (This is as before, in calc1.cpp) struct calculator_context : proto::callable_context< calculator_context const > { // The values bound to the placeholders var_t d[2]; // The result of evaluating arithmetic expressions typedef var_t result_type; explicit calculator_context(const var_t &d1 = var_t(), const var_t &d2 = var_t()) { d[0] = d1; d[1] = d2; } // Handle the evaluation of the placeholder terminals template<int I> result_type operator ()(proto::tag::terminal, placeholder<I>) const { return d[ I - 1 ]; } }; // Wrap all calculator expressions in this type, which defines // operator () to evaluate the expression. template<typename Expr> struct calculator_expression : proto::extends<Expr, calculator_expression<Expr>, calculator_domain> { explicit calculator_expression(Expr const &expr = Expr()) : calculator_expression::proto_extends(expr) {} BOOST_PROTO_EXTENDS_USING_ASSIGN(calculator_expression<Expr>) // Override operator () to evaluate the expression var_t operator ()() const { calculator_context const ctx; return proto::eval(*this, ctx); } var_t operator ()(const var_t &d1) const { calculator_context const ctx(d1); return proto::eval(*this, ctx); } var_t operator ()(const var_t &d1, const var_t &d2) const { calculator_context const ctx(d1, d2); return proto::eval(*this, ctx); } }; // Define some placeholders (notice they're wrapped in calculator_expression<>) calculator_expression<proto::terminal< placeholder< 1 > >::type> const _1; calculator_expression<proto::terminal< placeholder< 2 > >::type> const _2; // Now, our arithmetic expressions are immediately executable function objects: int main() { BOOST_PROTO_AUTO(expr, _1 = _2); var_t a1(1), a2(2.5); expr(a1, a2); return 0; }

1 0

openmpi with boost::log and some late endl
by Peter Vollmer 11 May '16

11 May '16

I'm working on some Linux systems and boost:log. More in detail: After replacing a handmade solution for logging with boost:log and running it with mpi on a single computer I can observe a strange behavior in console. Normally as i understand it, with autoflush turn on, after streaming a message into the logger it follows a flush followed by an endl and flush. At my scenario after streaming messages on different mpi processes, it seem that the system make a thread change right after flushing my message not after the endl flush. The missing automatic endl isn't lost it will be printed directly after or later but it will be printed. One indication that it has to be a thread change of the system is that an increase of the usable mpi processes increases the presents dramatically. For example on 4 core 8 thread system it occurs with 4 mpi processes something around 1 or 2 times, with 8 it occurs more than 20 times. Is there a solution to prevent this? Thanks Peter

1 0

[proto][spirit] parsing into proto expressions
by Igor R 11 May '16

11 May '16

Hi, Long story short: I would like to create proto expressions at run-time using spirit parsers. Would it be possible? More in details: I'd like to parse disassembler output, creating proto expression template for instruction and its operands. Lets assume we define proto expressions that would allow to express the following asm: "lea eax, [ebx + 2 * ecx]" like this: BOOST_PROTO_AUTO(lea_instr, eax = &*(ebx + 2 * ecx)); // registers and immediates are proto terminals Of course, we can't write such an expression in C++ code, because the actual operands get known after the asm string is parsed. So we can express any "lea" in the code (at compile-time) in a more general form, using placeholders: _1 = &_2; Then, when the parser matches "lea", we need to parse and create at run-time the actual operands, i.e. to substitute _1 with eax and _2 with *(ebx + 2 * ecx). I'd appreciate any pointer! Thanks.

2 2

mpfr_float stack allocation
by Daniel Brake 10 May '16

10 May '16

Hi Boost Users, I use Boost.Multiprecision's wrappers for MPFR, particularly the boost::multiprecision::mpfr_float. I've had good success with this library and its types so far, enjoying performance gains because of expression templates, and easy access to mpfr and gmp for floats, ints, and rationals. However, in my complex number type, I am struggling with named real temporaries in arithmetic operators. I am looking for help with multiplication, and I can generalize to all other operations needing a real temporary later. Here's my current code for multiplication, implemented in terms of *=. /** Complex multiplication. uses a single temporary variable 1 temporary, 4 multiplications */ complex& operator*=(const complex & rhs) { mpfr_float re_cache(real_*rhs.real_ - imag_*rhs.imag_); // cache the real part of the result imag_ = real_*rhs.imag_ + imag_*rhs.real_; real_ = re_cache; return *this; } I am using the naive evaluation formula, for better or worse. But the particular method of evaluation doesn't matter to me right now, it's the temporary variable re_cache used to cache the real part is killing me. Profiling using Allinea, gprof, and Callgrind reveals that a significant percentage of time in the program is consumed creating and destroying re_cache, as well as other temporaries scattered throughout my code. In an effort to eliminate heap allocations, I first tried replacing my using mpfr_float = boost::multiprecision::number<boost::multiprecision::mpfr_float_backend<0,boost::multiprecision::allocate_dynamic>, boost::multiprecision::et_off>; with allocate_stack, just for these named temporary variables. However, the documentation <http://www.boost.org/doc/libs/1_60_0/libs/multiprecision/doc/html/boost_mul…> states that allocate_stack only works in fixed precision, so the 0 digits indicating variable precision should cause problems? I expected 0 digits to fail to compile, but compile it does. The conversion from the type with allocate_stack to allocate_dynamic is not provided by the = operator, so I can write re_cache.convert_to<mpfr_float_dynamic>(). But using variable precision with stack allocation appears to cause all sorts of problems. Everything depending on complex multiplication in my program breaks, indicated by massive failures in my test suite. Thus, I currently regard allocate_stack as a non-solution. My question fundamentally regards how to deal with re_cache and the *= operator for complex multiplication. Anyone have ideas on how to get rid of constant heap de/allocation of re_cache without inducing a ton more arithmetic? Using a static for it is not a solution, both because I anticipate multithreading in this application in the future, and the fact that precision will vary though the run, so I'd have to check the precision of re_cache on every evaluation. The C version of the program I am re-implementing used OpenMP for threads, and used a thread-id-indexed global for re_cache. That solution then forces OpenMP onto anyone wanting to use the complex class in multiple threads. Hence, I view this as a non-solution, too. Again, my initial thought was 'heap allocation is the problem here, so I'll use the stack allocated backend'. But variable precision doesn't appear to work with allocate_stack. And statics are no good. Any thoughts? Thanks for your time, Daniel Brake Postdoc University of Notre Dame Applied and Computational Math and Stats

2 1

Re: [Boost-users] [boost] Boost 1.61.0 Release Candidate 2
by Marshall Clow 09 May '16

09 May '16

On Sat, May 7, 2016 at 4:31 AM, Vladimir Prus <vladimir.prus(a)gmail.com> wrote: > > The second release candidates for the 1.61.0 release are now available at: > > http://boost.cowic.de/rc/boost_1_61_0_rc2.zip > http://boost.cowic.de/rc/boost_1_61_0_rc2.7z > http://boost.cowic.de/rc/boost_1_61_0_rc2.tar.bz2 > http://boost.cowic.de/rc/boost_1_61_0_rc2.tar.gz > > The SHA256 checksums are as follows: > > fa1c34862b7ba8674ed6e064a14667a11830c6252f702d9458451834b74f7815 > boost_1_61_0_rc2.7z > a547bd06c2fd9a71ba1d169d9cf0339da7ebf4753849a8f7d6fdb8feee99b640 > boost_1_61_0_rc2.tar.bz2 > a77c7cc660ec02704c6884fbb20c552d52d60a18f26573c9cee0788bf00ed7e6 > boost_1_61_0_rc2.tar.gz > 02d420e6908016d4ac74dfc712eec7d9616a7fc0da78b0a1b5b937536b2e01e8 > boost_1_61_0_rc2.zip > > The changes relative to RC1 are MSVC fixes for signals2 and graph > libraries. > > 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. > > I successfully built the .bz2 release with Apple's clang with C++03/11/14/1z. -- Marshall

1 0

Boost ASIO steady_timer and date change
by Sabino Colonna 09 May '16

09 May '16

Hello, I'm using a steady_timer to perform an asynchronous wait in the following manner: boost::asio::io_service io_service; boost::asio::steady_timer my_timer(io_service); void onTimeout(const boost::system::error_code& e) { // Print something } ... my_timer.expires_from_now(std::chrono::seconds(600)); my_timer.async_wait(onTimeout); io_service.run(); If system 'date' does not change, everything is ok. But if I change 'date' by hand while the timer is running, it expires before 600 seconds (more or less after 5 minutes) and 'onTimeout' is called. With synchronous wait, all is ok. According to documentation, steady_timer should not be affected by time change. Which may be the problem? Thanks, Sabino

2 2

Re: [Boost-users] Compiler limitation (MSVS 2015 update 2) or real error using boost::async?
by James Swift 06 May '16

06 May '16

Hi, in case anyone wants to play with the example I provided but doesn't have access to MSVC you can do so online here. http://rextester.com/BAX37541 kind regards, James

2 2

converting to float128 from double
by Cooper, Bridgette R D 04 May '16

04 May '16

Hi, I have a function that takes as an argument a vector of doubles and tries to convert it to a vector of float128. When I accumulate the values in the float128 vector it looks like it does double additions and only casts up at the last step. The initial vector is defined as const std::vector<double> The float128 vector is defined as std::vector<float128> epoint(num) And I try to do the casting (inside a loop) via: epoint.at(i)=(float128(e8.at(i))); If I do the accumulation on the original vector with no casting into a float128, I get the same as accumulating the vector that should be of float128 type. How should I be doing the casting? Thanks,

4 13

Compiler limitation (MSVS 2015 update 2) or real error using boost::async?
by James Swift 04 May '16

04 May '16

Hi, I'm getting an error with the following code only with Visual C++. (VS 2015 update 2. I also tried preview of VS 15 but it's the same) Clang and GCC are OK with this but perhaps VS is just more strict but correct? The error is deep in boost internals and I can't work out which object is move only and/or has it's copy constructor deleted or if it's true at all! Any help greatly appreciated. kind regards, James Swift --------------------------------- #define BOOST_THREAD_PROVIDES_FUTURE #define BOOST_THREAD_PROVIDES_FUTURE_CONTINUATION #define BOOST_THREAD_PROVIDES_EXECUTORS #include <boost/thread/future.hpp> class TestEx { public: void submit(std::function<void()>) { } bool try_executing_one() { return false; } bool closed() { return false; } void close() { } }; int main() { TestEx tex; boost::async( tex, [](){}); return 0; } ----------------------------------- 1>------ Build started: Project: BoostFuture, Configuration: Debug Win32 ------ 1> BoostFuture.cpp 1>c:\users\james\documents\visual studio 2015\projects\boostfuture\boostfuture\boost_1_60\boost\thread\future.hpp(3801): error C2280: 'boost::detail::invoker<main::<lambda_4383c995bef90b35d4f40a119c795fc2>,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::null_type,boost::tuples::null_type>::invoker(const boost::detail::invoker<main::<lambda_4383c995bef90b35d4f40a119c795fc2>,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::null_type,boost::tuples::null_type> &)': attempting to reference a deleted function 1> c:\users\james\documents\visual studio 2015\projects\boostfuture\boostfuture\boost_1_60\boost\thread\detail\invoker.hpp(731): note: compiler has generated 'boost::detail::invoker<main::<lambda_4383c995bef90b35d4f40a119c795fc2>,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::null_type,boost::tuples::null_type>::invoker' here 1> c:\users\james\documents\visual studio 2015\projects\boostfuture\boostfuture\boost_1_60\boost\thread\future.hpp(3800): note: while compiling class template member function 'boost::detail::shared_state_nullary_task<Rp,Cont>::shared_state_nullary_task(const boost::detail::shared_state_nullary_task<Rp,Cont> &)' 1> with 1> [ 1> Rp=Rp 1> ] 1> c:\program files (x86)\microsoft visual studio 14.0\vc\include\xutility(287): note: see reference to function template instantiation 'boost::detail::shared_state_nullary_task<Rp,Cont>::shared_state_nullary_task(const boost::detail::shared_state_nullary_task<Rp,Cont> &)' being compiled 1> with 1> [ 1> Rp=Rp 1> ] 1> c:\users\james\documents\visual studio 2015\projects\boostfuture\boostfuture\boost_1_60\boost\thread\future.hpp(3858): note: see reference to class template instantiation 'boost::detail::shared_state_nullary_task<Rp,Cont>' being compiled 1> with 1> [ 1> Rp=Rp 1> ] 1> c:\users\james\documents\visual studio 2015\projects\boostfuture\boostfuture\boost_1_60\boost\thread\future.hpp(3873): note: see reference to function template instantiation 'void boost::detail::future_executor_shared_state<Rp>::init<T,Executor>(Executor &,Fp &&)' being compiled 1> with 1> [ 1> Rp=Rp, 1> T=boost::detail::invoker<main::<lambda_4383c995bef90b35d4f40a119c795fc2>,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::null_type,boost::tuples::null_type>, 1> Executor=TestEx, 1> Fp=boost::detail::invoker<main::<lambda_4383c995bef90b35d4f40a119c795fc2>,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::null_type,boost::tuples::null_type> 1> ] 1> c:\users\james\documents\visual studio 2015\projects\boostfuture\boostfuture\boost_1_60\boost\thread\future.hpp(3873): note: see reference to function template instantiation 'void boost::detail::future_executor_shared_state<Rp>::init<T,Executor>(Executor &,Fp &&)' being compiled 1> with 1> [ 1> Rp=Rp, 1> T=boost::detail::invoker<main::<lambda_4383c995bef90b35d4f40a119c795fc2>,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::null_type,boost::tuples::null_type>, 1> Executor=TestEx, 1> Fp=boost::detail::invoker<main::<lambda_4383c995bef90b35d4f40a119c795fc2>,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::null_type,boost::tuples::null_type> 1> ] 1> c:\users\james\documents\visual studio 2015\projects\boostfuture\boostfuture\boost_1_60\boost\thread\future.hpp(3964): note: see reference to function template instantiation 'boost::future<void> boost::detail::make_future_executor_shared_state<Rp,boost::detail::invoker<main::<lambda_4383c995bef90b35d4f40a119c795fc2>,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::null_type,boost::tuples::null_type>,Executor>(Executor &,Fp &&)' being compiled 1> with 1> [ 1> Executor=TestEx, 1> Fp=boost::detail::invoker<main::<lambda_4383c995bef90b35d4f40a119c795fc2>,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::null_type,boost::tuples::null_type> 1> ] 1> c:\users\james\documents\visual studio 2015\projects\boostfuture\boostfuture\boostfuture.cpp(34): note: see reference to function template instantiation 'boost::future<void> boost::async<TestEx,main::<lambda_4383c995bef90b35d4f40a119c795fc2>>(Executor &,F &&)' being compiled 1> with 1> [ 1> Executor=TestEx, 1> F=main::<lambda_4383c995bef90b35d4f40a119c795fc2> 1> ] ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

1 0

udp::endpoint - port change
by Alexander Carôt 04 May '16

04 May '16

Hello all, probably trivial but I am currently stuck with this: I create a UDP endpoint via udp::resolver::query query(udp::v4(),IP,port); destinationEndpoint = new udp::endpoint(*resolver.resolve(query)); but after the creation I want to change the port without deleting and recreating it with different parameters. How can I do this ? Thanks in advance, best Alex

3 2

Re: [Boost-users] Extending boost graph edge class
by Rafael Gasperetti 03 May '16

03 May '16

Hi, The third option fit in my case. I haver a class that I need to be the edge of the graph, and i have another one that I need to be the vertex. Using this way, My classes Can be used inside the graph to calculate distance, scc, etc. Thanks,Rafael -------- Mensagem original -------- De : Daniel Hofmann <daniel(a)trvx.org> Data: 03/05/2016 19:23 (GMT-03:00) Para: boost-users(a)lists.boost.org Assunto: Re: [Boost-users] Extending boost graph edge class Can you elaborate on "extend the edge class"? Here are some possible interpretations: 1/ You want to optimize the memory consumption for large graphs. The edges and vertices still fit into uint32_t: using graph_t = compressed_sparse_row_graph<directedS, no_property, no_property, no_property, uint32_t /* Vertex */, uint32_t /* EdgeIndex */>; 2/ You want to store arbitrary metadata on your edges and retrieve this edge data based on your graph and a specific edge descriptor: struct edge_data_t { int distance = 0; }; using graph_t = compressed_sparse_row_graph<directedS, no_property, edge_data_t>; // .. auto duration = [&graph](auto edge) { return graph[edge].duration; }; auto total = accumulate(edges(graph) | transformed(duration), 0); This example is using "bundled properties". There is also the possibility to store edge data external to the graph and not couple the edge data's lifetime with the graph (e.g. if you need edge weights for a particular algorithm in your use-case). 3/ You want to provide your own graph representation and make it a model for the BGL graph concepts: http://www.boost.org/doc/libs/1_60_0/libs/graph/doc/leda_conversion.html http://www.boost.org/doc/libs/1_60_0/libs/graph/doc/graph_concepts.html Here are some more BGL examples that should get you started: https://github.com/daniel-j-h/cppnow2016 Cheers, Daniel J H On 05/03/2016 08:37 AM, Rafael Gasperetti wrote: > > > Hi, > My name is Rafael and I need to extend the edge class of de graph part > of the boost lib, but I always find problems trying to do this. Can you > help me with examples and explanations about how to do this? > I read a lotação of places trying to do this but no help was found, > please help me. > > Thanks a lot, > Rafael > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users > _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

1 0

Extending boost graph edge class
by Rafael Gasperetti 03 May '16

03 May '16

Hi,My name is Rafael and I need to extend the edge class of de graph part of the boost lib, but I always find problems trying to do this. Can you help me with examples and explanations about how to do this?I read a lotação of places trying to do this but no help was found, please help me. Thanks a lot,Rafael

2 1

[boost.multiprecision] print cpp_int with a thousands separator
by Tassilo Glander 03 May '16

03 May '16

Dear List, how can I control the thousands separator behavior when streaming a cpp_int to std::cout? I think it is not possible without changing the global locale, as cpp_int.str uses lexical_cast, which uses the global locale object to read the thousands separator character. This prevents me from having a custom formatting like below. Is there another way? Best, Tassilo #include <iostream> #include <locale> #include <iomanip> int main() { struct my_numpunct : std::numpunct<char> { protected : virtual char do_thousands_sep() const override { return '.' ; } virtual std::string do_grouping() const override { return "\03" ; } }; cpp_int testNum(1000); std::cout.imbue( std::locale( std::cout.getloc(), new my_numpunct ) ) ; std::cout << testNum << '\n' ; // still get 1000, desired is 1.000 }

1 0

Multiprecision vector pass to function by reference
by Cooper, Bridgette R D 02 May '16

02 May '16

Hi, I am having some difficulties passing a vector of type std::vector<float128> to a function. I'm getting multiple errors out. The first few of which are: tql2.cpp:13:50: error: 'float128' was not declared in this scope void tql2(const int nm, int n, const std::vector<float128> & d, const std::vector<float128> & e, const std::vector< std::vector<float128> > & z, int ierr) ^ tql2.cpp:13:50: note: suggested alternative: In file included from tql2.cpp:1:0: /home/bcooper/Tarballs/boost_1_57_0/boost/multiprecision/float128.hpp:124:42: note: 'boost::multiprecision::float128' typedef number<float128_backend, et_off> float128; ^ tql2.cpp:13:58: error: template argument 1 is invalid void tql2(const int nm, int n, const std::vector<float128> & d, const std::vector<float128> & e, const std::vector< std::vector<float128> > & z, int ierr) ^ tql2.cpp:13:58: error: template argument 2 is invalid tql2.cpp:13:83: error: 'float128' was not declared in this scope void tql2(const int nm, int n, const std::vector<float128> & d, const std::vector<float128> & e, const std::vector< std::vector<float128> > & z, int ierr) ^ tql2.cpp:13:83: note: suggested alternative: In file included from tql2.cpp:1:0: /home/bcooper/Tarballs/boost_1_57_0/boost/multiprecision/float128.hpp:124:42: note: 'boost::multiprecision::float128' typedef number<float128_backend, et_off> float128; ^ The first few lines of my code are: #include <boost/multiprecision/float128.hpp> #include <boost/math/cstdfloat/cstdfloat_types.hpp> #include <boost/math/cstdfloat/cstdfloat_limits.hpp> #include <boost/math/cstdfloat/cstdfloat_cmath.hpp> #include <boost/math/cstdfloat/cstdfloat_iostream.hpp> extern "C"{ #include <quadmath.h> } #include <iostream> #include <vector> #include <iterator> void tql2(const int nm, int n, const std::vector<float128> & d, const std::vector<float128> & e, const std::vector< std::vector<float128> > & z, int ierr) { using namespace boost::multiprecision; ... } Not sure where I am going wrong? Any advice? Thanks,

2 1

Re: [Boost-users] [boost.multiprecision] export_bits throws on a negative
by Tassilo Glander 02 May '16

02 May '16

Hi John, I opened tickets to track both issues: - Ticket #12170 (new Bugs) boost::multiprecision::export_bits throws on a negative cpp_int number - Ticket #12171 (new Feature Requests) boost::multiprecision should provide a hash function Best, Tassilo

2 1

boost log facility multithreading issue
by David Frank 01 May '16

01 May '16

Greetings,I have 4 threads, in each thread, I created its own log file using boost log facility, different from the ones in other thread.The problem is that the log entries I put into one file in one thread, got into all other log files in other threads, though the boost log instances are not shared among threads. Anyone know how to avoid this? Thanks, David

1 0

boost/multiprecision/float128
by Cooper, Bridgette R D 01 May '16

01 May '16

I'm new to boost. I am trying to use the float128 type for calculating sqrts as a larger part of code, however I am not sure the values obtained are accurate to float128 precision. I have tried running the example for printing log(2) found here, I find the same for sqrt: http://www.boost.org/doc/libs/1_57_0/libs/multiprecision/doc/html/boost_mul… However, the value printed log(2) only agrees to 16 decimal places, i.e. double precision. The value I obtain is 0.693147180559945286226763982995180413 rather than 0.693147180559945309417232121458176575 I'm using: g++ (GCC) 4.8.2 20140120 (Red Hat 4.8.2-15) with boost 1.57.0. Any advice as to what I am doing incorrectly? My compile line is: g++ -I ~/$BOOSTLIB new.cpp -lquadmath -o new Thanks,

3 6

[utility] BOOST_IDENTITY_TYPE drops const-ness of value types
by Nick Stokes 29 Apr '16

29 Apr '16

Looks like const value types, once passed thru BOOST_IDENTITY_TYPE, "becomes" non-const. Like so: // Attempt to implement a multi-argument utility macro, where arguments are // types, parenthesized only when required (by the user, when type has commas) #define ASSERT_EQUAL( t1, t2 ) \ static_assert( std::is_same< \ BOOST_IDENTITY_TYPE((t1)), BOOST_IDENTITY_TYPE((t2)) \ >::value, #t1 " not same as " #t2) // sanity check: static_asserts as expected ASSERT_EQUAL( int, double ); // sanity check: static_assert as expected for types with commas ASSERT_EQUAL( (std::pair<int, double>), (std::pair<double, int>) ); // Here is the failure: this is expected to assert but it doesnt! ASSERT_EQUAL( const int, int ); >From the implementation of BOOST_IDENTITY_TYPE, it is clear why this is happening, as the function signature is independent of const-ness of value type. Is this a bug? Or is this not the way BOOST_IDENTITY_TYPE is supposed to be used? Nick

1 0

linking and including in visual studio
by David Medine 29 Apr '16

29 Apr '16

This is kind of a stupid question, and maybe more of a Windows/Visual Studio question than a boost one, but this has been troubling the back of my mind lately. Having learned to write and compile C++ code on Linux, I am always in the habit of explicitly stating the include and library paths for the compiler to search for, as well as the libraries themselves that need to be linked. However, I am revising some Visual Studio projects that use boost and I realized that the path I gave for 'Additional Library Directories' is $(BOOST_ROOT)/lib, but my version of boost hasn't got this directory (it's actually $(BOOST_ROOT)\libs). I then removed all references to boost from 'Additional Library Directories', and 'Additional Include Directories' and the application builds and runs swimmingly. This leads me to believe, that assigning the BOOST_ROOT environment variable in Windows is the only step that is needed for VS's auto linking magic to link correctly to boost. Am I right here, or is there something I am missing? Cheers, David

7 14

Date and Time with Boost
by Counter Wall 28 Apr '16

28 Apr '16

What I want to do is read a text file containing a text string in ISO 8601 combined date and time in utc format (e.g. 2016-04-26T12:45:05+00:00). I also want to have the freedom to convert this between time zones and have accurate daylight savings time data. Boost::datetime seems to read in the string, but it looks like boost::locale is recommended for time zone conversions and DLS. Is there a way for me to have both?

2 1

Re: [Boost-users] [boost.multiprecision] export_bits throws on a negative number
by Tassilo Glander 28 Apr '16

28 Apr '16

Hi John, thanks for stepping in. I would expect that the export just exports the memory representation of the number - maybe with flipped order via msv_first parameter. Especially, something exported via export_bits and than imported via import_bits should be the same, at least on the same platform. That said, I actually was just looking for a way to implement a hash function and thought it was straightforward to use chunks of char. But I could also compute the hash on the str() output. Tassilo

2 1

[boost.multiprecision] export_bits throws on a negative cpp_int number
by Tassilo Glander 28 Apr '16

28 Apr '16

Dear List, When calling export_bits on a negative boost::multiprecision number based on cpp_int, an exception is thrown from the internal method msb ("testing individual bits in negative values is not supported"). boost::multiprecision::checked_int128_t i (-1); // use negative number std::vector<unsigned char> v; export_bits(i, std::back_inserter(v), 8); // throws How can I extract the content of a boost::multiprecision number? Boost documentation says, export_bits is designed to be used for data exchange, so in my understanding it would be a major flaw, if it cannot export supported values. I learnt that a workaround might be to directly access the backend's limbs, but this way I am accessing internals that may change. http://www.boost.org/doc/libs/master/libs/multiprecision/doc/html/boost_mul… I also asked this on http://stackoverflow.com/questions/36890928/boostmultiprecisionexport-bits-…, but this list is probably the better place. Thanks, Tassilo

2 1

[PBGL] compilation of example/dijkstra_shortest_paths.cpp failed
by Eisuke Kawashima 27 Apr '16

27 Apr '16

Dear all, I tried to compile http://www.boost.org/doc/libs/1_60_0/libs/graph_parallel/example/dijkstra_sh ortest_paths.cpp, an example code of Parallel Boost Graph, resulting in faulure; example/breadth_first_search.cpp has no problem. My environment is: * GCC 4.9.2 * OpenMPI 1.10.2 * boost 1.60.0 * OS: Debian jessie The error, related to template, is long; the summary is: $ mpicxx -std=c++11 -lboost_mpi -lboost_serialization -lboost_system - lboost_graph_parallel dijkstra_shortest_paths.cpp In file included from boost/graph/dijkstra_shortest_paths.hpp:25:0, from dijkstra_shortest_paths.cpp:19: boost/pending/relaxed_heap.hpp: In instantiation of ‘bool boost::relaxed_heap... boost/graph/distributed/crauser_et_al_shortest_paths.hpp:377:54: required from ... boost/graph/distributed/detail/remote_update_set.hpp:148:7: required from ... boost/graph/distributed/crauser_et_al_shortest_paths.hpp:264:37: required from ... boost/graph/breadth_first_search.hpp:76:7: required from ... boost/graph/breadth_first_search.hpp:124:69: required from ... boost/graph/breadth_first_search.hpp:135:64: [ skipping 4 instantiation contexts, use -ftemplate-backtrace-limit=0 to disable ] boost/graph/distributed/dijkstra_shortest_paths.hpp:146:50: required from ... boost/graph/distributed/dijkstra_shortest_paths.hpp:200:45: required from ... boost/graph/dijkstra_shortest_paths.hpp:573:16: required from ... boost/graph/dijkstra_shortest_paths.hpp:595:35: required from ... boost/graph/dijkstra_shortest_paths.hpp:614:14: required from ... dijkstra_shortest_paths.cpp:74:64: required from here boost/pending/relaxed_heap.hpp:194:70: error: cannot convert ‘const value_type {aka const boost::optional<boost::detail::parallel::global_descriptor<long unsigned int> >}’ to ‘bool’ in return bool contains(const value_type& x) const { return groups[get(id, x)]; } ^ "-ftemplate-backtrace-limit=0" flag did not work. How to fix this? -- Eisuke Kawashima

2 4

[boost-users][boost graph] edge_descriptor problem when copy from original graph
by Emerson Xu 26 Apr '16

26 Apr '16

Hi all, I have a boost graph copy problem that has been nagging me for a long time. My question is, is there anyway that I can construct a graph once, and reuse it multiple times, each time I may mutate the graph a bit. I have a class, which creates a boost graph with bundled vertex and edge properties (my own properties, vertices are routers in a network, while edges are logical links between routers). When creating the graph, some helper unordered maps are also created, like mapping from an edge_descriptor to a logical link name, from a router name to a vertex_descriptor, etc. Now there are multiple clients calling some method in the class. Current strategy is to construct a new boost graph instance for every client, and run the service on each graph instance. Now I want to improve the performance by avoiding constructing the graph for every client ( >100 clients are calling it simultaneously). So I am thinking that we can initialize only one base graph, and make it a copy for every client. Then the problem comes, since in the method the client needs use those helper unordered maps, but the data inside the maps are from that original base graph. Even if I use a copy constructor(deep copy) for each graph copy, some graph data is still inconsistent, like the edge_descriptor, for example, I can't use the hashmap with edge_descriptor as key, because this edge_descriptor only points to the memory address of base graph. Best, Emerson

2 1

error when copying blocks into a dynamic_bitset
by Diab Jerius 26 Apr '16

26 Apr '16

Hi, I'm trying to initialize a dynamic_bitset<unsigned char> from a vector of blocks. Here's the code: #include <cstdlib> #include <vector> #include <boost/dynamic_bitset.hpp> typedef boost::dynamic_bitset<unsigned char> BitSet; typedef std::vector<BitSet::block_type> Block; int main(int argc, char* argv[]) { int nbits = atoi( argv[1] ); BitSet bits( nbits ); Block buffer; buffer.resize( bits.num_blocks(), 0xff ); boost::from_block_range(buffer.begin(),buffer.end(), bits ); return 0; } If the bitset size isn't a multiple of sizeof(unsigned char) (here 8) , ~dynamic_bitset() throws an exception. For example: % ./a.out 1 a.out: boost-1.60.0/include/boost/dynamic_bitset/dynamic_bitset.hpp:633: boost::dynamic_bitset<Block, Allocator>::~dynamic_bitset() [with Block = unsigned char; Allocator = std::allocator<unsigned char>]: Assertion `m_check_invariants()' failed. Aborted % ./a.out 8 % ./a.out 15 a.out: boost-1.60.0/boost/dynamic_bitset/dynamic_bitset.hpp:633: boost::dynamic_bitset<Block, Allocator>::~dynamic_bitset() [with Block = unsigned char; Allocator = std::allocator<unsigned char>]: Assertion `m_check_invariants()' failed. Aborted % ./a.out 16 % I see this with 1.59 & 1.60 using either g++ 4.7.2 or Apple LLVM version 6.0 (clang-600.0.57) (based on LLVM 3.5svn) I believe that I'm following the rules for the buffer type and size. Is there something I'm missing? Thanks! Diab

1 0

Compiler errors using boost/program_options with Boost v 1.53 and v 1.59
by Christine Peters 26 Apr '16

26 Apr '16

Dear all, I had to reinstall my boost version as the cluster environment I'm working on has switched from Scientific Linux 6 to CentOS 7. When I'm now compiling my code including the header "#include <boost/program_options>", I will receive the following error message: In file included from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/mpl/aux_/arithmetic_op.hpp:34:0, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/mpl/times.hpp:19, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/mpl/multiplies.hpp:17, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/numeric/conversion/detail/is_subranged.hpp:17, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/numeric/conversion/detail/conversion_traits.hpp:21, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/numeric/conversion/conversion_traits.hpp:13, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/numeric/conversion/converter.hpp:13, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/numeric/conversion/cast.hpp:33, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/lexical_cast/detail/converter_numeric.hpp:37, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/lexical_cast/try_lexical_convert.hpp:34, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/lexical_cast.hpp:32, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/program_options/value_semantic.hpp:14, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/program_options/options_description.hpp:13, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/program_options.hpp:15, from /home/cp652127/EclipseWorkspace/AMD-Geant4.10/amd/externals/g4sipm/sample/include/ParticleSourceMessenger.hh:24, from /home/cp652127/EclipseWorkspace/AMD-Geant4.10/amd/externals/g4sipm/sample/include/AsciiPersistencyHandler.hh:20, from /home/cp652127/EclipseWorkspace/AMD-Geant4.10/amd/externals/g4sipm/sample/include/RunAction.hh:16, from /home/cp652127/EclipseWorkspace/AMD-Geant4.10/amd/externals/g4sipm/sample/src/RunAction.cc:9: /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/mpl/aux_/include_preprocessed.hpp:37:90: fatal error: boost/mpl/aux_/preprocessed/gcc/ostimes.hpp: No such file or directory # include BOOST_PP_STRINGIZE(boost/mpl/aux_/preprocessed/AUX778076_PREPROCESSED_HEADER) ^ compilation terminated. This fatal error occurs with my own boost installation (version 1.59.0) but also with the system default boost (version 1.53.0). It worked properly on Scientific Linux 6. Now, I'm using gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-4), CPU codename Intel Nehalem EX, LINUX, CENTOS 7.2 environment. I would be very glad if someone could help me. It seems that somehow the AUX778076 parameter defined in "boost/1_59_0/include/boost/mpl/times.hpp" is converted to ostimes during the compilation: I've changed, just for testing reasons!, in file "/boost/1_59_0/include/boost/mpl/times.hpp" the line "#define AUX778076_OP_NAME times" to "#define AUX778076_OP_NAME timestest" and then boost is searching for the correct header "timestest.hpp" but in the case of "#define AUX778076_OP_NAME times" it is searching for "ostimes.hpp" instead of "times.hpp". Thanks in advance for your help! Cheers, Christine

2 2

Typo in BGL Subgraph
by Eisuke Kawashima 23 Apr '16

23 Apr '16

Dear all, I submitted the following to boost-docs but have received no response, so also submitting to boost-users. The last part of Boost Graph Library: Subgraph <http://www.boost.org/doc/libs/release/libs/graph/doc/subgraph.html> (since Boost 1.40) > > struct my_vertex { ... }; > typedef property<vertex_index_t, std::size_t, vertex_prop> vertex_prop; > struct my_edge { ... }; > typedef property<edge_index_t, std::size_t, vertex_prop> edge_prop; should be > > struct my_vertex { ... }; > typedef property<vertex_index_t, std::size_t, my_vertex> vertex_prop; > struct my_edge { ... }; > typedef property<edge_index_t, std::size_t, my_edge> edge_prop; Additionally I want you to note how to modify GraphProperties of boost::subgraph (or whether it is not implemented). Regards, -- Eisuke Kawashima email: e.kawaschima(a)gmail.com

2 2

[interprocess] posix_recursive_mutex constructor never called, fails to init mutex
by Adrian Cheater 23 Apr '16

23 Apr '16

This was submitted as a bug (https://svn.boost.org/trac/boost/ticket/12150) but I don't know that this is actually a boost bug, possibly a OSX or clang issue, or maybe I'm just doing something silly, so I'm hoping someone here can shed some light on the issue. I'm trying to use boost's shared memory system to get data from another application, but while it works fine on Ubuntu 15.10 with boost 1.58 and 1.60 on gcc, clang-3.6 and clang-3.7, it throws an exception when it attempts to acquire the mutex lock on OSX because the mutex has not been initialized. Placing a breakpoint in the constructor for the recursive_lock never gets hit, and I'm not sure why. Hopefully someone with more OSX experience can help me sort this out. Thanks very much for your time.

1 0

Compiler does not give error for missing serialize function
by Elizabeta 22 Apr '16

22 Apr '16

Hi I have the following code : class MyClass { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive &ar, const unsigned int version) {} }; class MyClass2 : public MyClass {}; MyClass2* ss = new MyClass2; std::ofstream ofs("C:\\test.xml"); boost::archive::xml_oarchive oa(ofs); oa & boost::serialization::make_nvp("test",ss); I am serializing trough the derived class pointer. The derived class doesnot have serialize function. The Base have. And I was expecting compiler to give me error that MyClass2 doesnot have serialize function. But this code compiles without errors. I am using vs2010. -- View this message in context: http://boost.2283326.n4.nabble.com/Compiler-does-not-give-error-for-missing… Sent from the Boost - Users mailing list archive at Nabble.com.

3 4

[gsoc16] Summer of Code 2016 shall proceed after all
by Niall Douglas 22 Apr '16

22 Apr '16

Dear Boost, We are very glad to announce that non-Google funding has been found to continue the Summer of Code for the following veteran student projects in Summer 2016: A. Boost Document, mentored by Antony Polukhin. Veteran student: Anurag Ghosh https://anuragxel.github.io/boost-document/ B. Boost.Compute, mentored by Kyle Lutz. Veteran student: Jakub Szuppe https://boostorg.github.io/compute/ C. Boost.Http, mentored by Bjorn Reese. Veteran student: Vinícius dos Santos Oliveira https://boostgsoc14.github.io/boost.http/ All three of these projects shall see a Summer of Code as if it were Google Summer of Code following the same timeline, mentor and student stipends, and progress acceptance criteria. Our thanks to the students and mentors for being so patient during the organisation of this funding. This all happened very quickly and much faster than Boost org processes normally happen - it would not have been possible without the efforts of Jon Kalb and Bryce Adelstein Lelbach, the latter of whom wrote up a great funding request worth reading at https://goo.gl/7v3VMK. Thanks are also due to the Boost Steering Committee for moving so quickly to vote on this, and to Boris Schäling for finding sponsorship for this effort. And finally congratulations to the veteran students! Niall and Bryce --- Boost C++ Libraries Google Summer of Code 2016 admin https://svn.boost.org/trac/boost/wiki/SoC2016

3 2

measuring distance between a point and a segment
by Juliette Pera 22 Apr '16

22 Apr '16

Dear all, I am currently trying to use the boost library in order to measure the shortest distance between a point and a list of segments. I am declaring a segment to which I append the two points of my segment and the I calculate the distance from my point P to the segment. xsegment_t segment; geom::append(segment,geom::make_point(A[0],A[1])); geom::append(segment,geom::make_point(B[0],B[1])); double distance2 = geom::distance(segment,geom::make_point(P[0],P[1])); The issue is that I measure every time the same distance even if the segment is different. Does anyone knows from where that issue can come from? Thank you in advance, Juliette Pera

2 8

[units] division with absolute temperature
by João Leal 19 Apr '16

19 Apr '16

Hello, I'm trying to use absolute temperature in some expressions. Unfortunately I'm having some issues with the compilation. For instance, if I divide an absolute temperature by itself I would expect to get 1 dimensionless, however that will cause a compilation error. #include <iostream> #include <boost/units/absolute.hpp> #include <boost/units/io.hpp> #include <boost/units/quantity.hpp> #include <boost/units/systems/si.hpp> #include <boost/units/systems/si/io.hpp> int main(int argc, char** argv) { using namespace boost::units; quantity<si::temperature> rT(273.15 * si::kelvin); // relative temperature quantity<si::dimensionless> v; v = rT / rT; std::cout << v << std::endl; // 1 dimensionless quantity<absolute<si::temperature> > aT(273.15 * absolute<si::temperature>()); // absolute temperature //v = aT / aT; // uncommenting this line will cause compilation errors //std::cout << v << std::endl; // 1 dimensionless return 0; } If I uncomment the line with v = aT / aT, in ubuntu 15.10 with boost 1.58 and gcc 5.2.1, I get the error: (...) /usr/include/boost/units/operators.hpp:81:5: error: no match for ‘operator/’ (operand types are ‘boost::units::absolute<boost::units::unit<boost::units::list<boost::units::dim<boost::units::temperature_base_dimension, boost::units::static_rational<1l> >, boost::units::dimensionless_type>, boost::units::homogeneous_system<boost::units::list<boost::units::si::meter_base_unit, boost::units::list<boost::units::scaled_base_unit<boost::units::cgs::gram_base_unit, boost::units::scale<10l, boost::units::static_rational<3l> > >, boost::units::list<boost::units::si::second_base_unit, boost::units::list<boost::units::si::ampere_base_unit, boost::units::list<boost::units::si::kelvin_base_unit, boost::units::list<boost::units::si::mole_base_unit, boost::units::list<boost::units::si::candela_base_unit, boost::units::list<boost::units::angle::radian_base_unit, boost::units::list<boost::units::angle::steradian_base_unit, boost::units::dimensionless_type> > > > > > > > > > > >’ and ‘boost::units::absolute<boost::units::unit<boost::units::list<boost::units::dim<boost::units::temperature_base_dimension, boost::units::static_rational<1l> >, boost::units::dimensionless_type>, boost::units::homogeneous_system<boost::units::list<boost::units::si::meter_base_unit, boost::units::list<boost::units::scaled_base_unit<boost::units::cgs::gram_base_unit, boost::units::scale<10l, boost::units::static_rational<3l> > >, boost::units::list<boost::units::si::second_base_unit, boost::units::list<boost::units::si::ampere_base_unit, boost::units::list<boost::units::si::kelvin_base_unit, boost::units::list<boost::units::si::mole_base_unit, boost::units::list<boost::units::si::candela_base_unit, boost::units::list<boost::units::angle::radian_base_unit, boost::units::list<boost::units::angle::steradian_base_unit, boost::units::dimensionless_type> > > > > > > > > > > >’) BOOST_TYPEOF_NESTED_TYPEDEF_TPL(nested, (typeof_::make<X>()/typeof_::make<Y>())) (...) I could add something like namespace boost { namespace units { template<class Unit, class X, class Y> struct divide_typeof_helper<quantity<absolute<Unit>, X>, quantity<absolute<Unit>, Y> > { typedef typename divide_typeof_helper<X, Y>::type value_type; typedef typename divide_typeof_helper<Unit, Unit>::type unit_type; typedef quantity <unit_type, value_type> type; }; } } but that would not work in more complex examples, e.g.: #include <boost/units/systems/si/codata/physico-chemical_constants.hpp> (...) using namespace boost::units::si::constants::codata; typedef boost::mpl::divides<boost::units::energy_dimension, boost::units::amount_dimension>::type Ea_dimension; typedef boost::units::unit<Ea_dimension, boost::units::si::system> Ea; quantity<Ea> ea(0); auto x = ea / (R * aT); Any help would be most appreciated, João Leal

2 2

Boost statechart, how can i transit to previous state using deep_history or shallow history
by juls 16 Apr '16

16 Apr '16

I have a difficulty in understanding the boost statechart history functionality. I have the following state machine. struct InButtonPressed : sc::event<InButtonPressed> {}; struct OutButtonPressed : sc::event<OutButtonPressed> {}; struct InButtonPressed : sc::event<InButtonPressed> {}; struct InputProceed: sc::event<InputProceed> {}; struct OutputProceed: sc::event<OutputProceed> {}; struct CancelEvent: sc::event<CancelEvent> {}; struct Proceed: sc::event<Proceed> {}; struct Revert: sc::event<InputProceed> {}; struct RH_StateMachine : bsc::state_machine< RH_StateMachine, Idle > {}; struct Idle : bsc::state< Idle, RH_StateMachine> { Idle(my_context ctx) : my_base(ctx){ std::cout << "[+] Idle" << std::endl; } ~Idle(){std::cout << "[-] leaving Idle state... \n";} typedef boost::mpl::list< bsc::transition< InButtonPressed, Input>, bsc::transition< OutButtonPressed, Output> >reactions; }; struct Input : bsc::state< Input, RH_StateMachine> { Input(my_context ctx) : my_base(ctx){ std::cout << "[+] Input" << std::endl; } ~Input(){std::cout << "[-] leaving Input state... \n";} typedef boost::bsc::transition< CancelEvent, Cancel> >reactions; }; struct Output : bsc::state< Output, RH_StateMachine> { Output(my_context ctx) : my_base(ctx){ std::cout << "[+] Output" << std::endl; } ~Output(){std::cout << "[-] leaving Output state... \n";} typedef boost::bsc::transition< CancelEvent, Cancel> >reactions; }; struct Cancel::bsc::state<Cancel, RH_StateMAchine>{ Cancel(my_context ctx) : my_base(ctx){ std::cout << "[+] Cancel" << std::endl; } ~Cancel(){std::cout << "[-] leaving Cancel state... \n";} typedef boost::mpl::list< bsc::transition< Proceed, CanceledConfirmed>, bsc::transition< Revert, *"PREVIOUS_STATE"*> >reactions; }; How do i implement transitioning to previous state using deep_history or shallow history, when i can transit to a state from many different states? In the above state machine i want to transit from Cancel state to the previous state when the revert event is triggered, but i have already transited in Cancel state from either Input or Output state... Thank you in advance. -- View this message in context: http://boost.2283326.n4.nabble.com/Boost-statechart-how-can-i-transit-to-pr… Sent from the Boost - Users mailing list archive at Nabble.com.

2 1

option to let program_options remove the flags it recognises
by Brice Rebsamen 14 Apr '16

14 Apr '16

I believe it would be good to add an option to program_options to tell it to remove the flags it recognizes. That would allow to make it work with some other parsers such as gflags etc.

1 0

[property_tree] Json parser with invalid JSON string
by Sébastien Gallou 13 Apr '16

13 Apr '16

Hi all, I experience a strange behavior of parsing non-JSON data with JSON parser. I can create a property_tree from a simple non-JSON string, without exception. And serializing back the result throws : boost::property_tree::ptree m_tree; // Non-JSON to ptree using JSON parser std::istringstream is("1"); // Simple value, non-JSON boost::property_tree::json_parser::read_json(is, m_tree); // ==> No exception, I now have a valid ptree object. // ptree back to JSON std::ostringstream buf; boost::property_tree::json_parser::write_json(buf, m_tree, false); // ==> Exception How can I filter input values that will not be serializable later (= verify that input value is well JSON formatted) ? Thanks for your help, S. Gallou

1 0

boost with c++11
by Christian Meesters 13 Apr '16

13 Apr '16

Dear All, Perhaps my question has been covered already, in this case a pointer to the relevant docs / thread would be highly appreciated. However, I have not been able to find the answer on my question: My code makes use of the C++11 standard and the standard libraries. I feel tempted to employ more current features, also beyond C++11, eventually. When downloading the boost 1.60.0 release and compiling with cxxflags='-std=c++11 -march=native' toolset=gcc linkflags=-stdlib=libc++ supplied to b2 compilation of my software (with gcc 5.3.0) leads to a number of warning messages and deprecation messages related to unused variables or redifined symbols, e.g.: - boost_1_60_0/include/boost/system/error_code.hpp:223:36: warning: ‘boost::system::native_ecat’ defined but not used [-Wunused-variable] static const error_category & native_ecat = system_category(); - /boost_1_60_0/include/boost/iostreams/chain.hpp:256:14: warning: ‘template<class> class std::auto_ptr’ is deprecated [-Wdeprecated-declarations] std::auto_ptr<streambuf_t> In file included from /cluster/gcc/5.3.0/include/c++/5.3.0/memory:81:0, from trunk/src/ngs_io.cpp:8: /cluster/gcc/5.3.0/include/c++/5.3.0/bits/unique_ptr.h:49:28: note: declared here template<typename> class auto_ptr; - /usr/include/boost/iostreams/detail/adapter/concept_adapter.hpp:35:7: note: ‘boost::iostreams::detail::concept_adapter<boost::iostreams::basic_gzip_decompressor<> >::concept_adapter(const boost::iostreams::detail::concept_adapter<boost::iostreams::basic_gzip_decompressor<> >&)’ is implicitly deleted because the default definition would be ill-formed: class concept_adapter { ^ etc. And most importantly this error: /usr/include/boost/iostreams/detail/adapter/concept_adapter.hpp:35:7: error: use of deleted function ‘boost::iostreams::basic_gzip_decompressor<>::basic_gzip_decompressor(const boost::iostreams::basic_gzip_decompressor<>&)’ My g++ compiler flags (other than output and source file) are: -c -fopenmp -O3 -march=native -Wall -ansi -pedantic -Wuninitialized -std=c++11 The code compiles fine with a git pull from May last year, yet I do not recall what I have done differently. So, can anybody tell me how to set up boost, such that compilation and linking against C++11 std-libraries works? I understand that Best regards, Christian Meesters

1 0

Boost Log: I can't see syslog messages sent via boost syslog.
by Anatoly G 11 Apr '16

11 Apr '16

Dear members, I have a question about Boost syslog. I"m beginner Boost user. I created attached code and can't understand why it doesn't work. I execute my code on linux Kubuntu 3.13.0 After execution I"m looking for test strings in syslog file: grep "Test" /var/log/syslog But I don't see any line. I tried to execute commands from shell logger "Test from shell" logger -n 127.0.0.1 -t myapp -p user.notice "Test from shell" I see these lines after executing grep on /var/log/syslog I tried to initialize syslog_backend with boost::log::keywords::use_impl = boost::log::sinks::syslog::native instead of boost::log::keywords::use_impl = boost::log::sinks::syslog::udp_socket_based but then I get compile message, native not defined. I found BOOST_LOG_USE_NATIVE_SYSLOG macro which should be defined during Boost build, but I don't understand how to activate this macro in boost build. Can you please suggest what is the problem? Regards, Anatoly.

1 0

[accumulators] nan error of mean
by Ireneusz Szcześniak 08 Apr '16

08 Apr '16

Hi, I'm using Boost.Accumulators to calculate the standard error of a sample mean, and I'm getting a nan (not a number) as a result, while I should be getting a zero or some number close to it. I boiled down the problem to a small sample that I'm attaching. I would appreciate it if someone could help me out here. Thanks, Irek

1 0

[Boost.Container] flat_set constructor with ordered_unique_range
by dariomt＠gmail.com 08 Apr '16

08 Apr '16

Hi list, If I use the flat_set constructor passing ordered_unique_range, does the library assert in debug mode that the passed data range is indeed ordered and unique? I don't seem to find such assert, but I think it would be very useful, to catch programmer errors. Regards

3 2

seekable input filter definition
by Cherotek Music 07 Apr '16

07 Apr '16

Hey, I'm new to boost and need a seekable input filter that will operate on bytes read from an ifstream. This is what I currently have: struct my_filter : boost::iostreams::seekable_filter{ template<typename Source> int get(Source& src) { int byte = boost::iostreams::get(src); if(byte != EOF && byte != boost::iostreams::WOULD_BLOCK) { // Do something with byte } return byte; } template<typename Sink> bool put(Sink&, char) { // No need to actually implement put because this filter is only used with ifstream return true; } template<typename T> std::streampos seek(T& t, boost::iostreams::stream_offset off, std::ios_base::seekdir way, std::ios_base::openmode which = std::ios_base::in | std::ios_base::out) { return boost::iostreams::seek(t, off, way, which); }}; It works but I would like to get rid of the useless put method. The boost documentation here http://www.boost.org/doc/libs/1_60_0/libs/iostreams/doc/concepts/filter.html says there is an InputSeekableFilter refinement of Filter but I can't seem to understand how to use it (there are no input_seekable_filter_tag or input_seekable_filter structs that I could use). Thanks

2 2

[asio] Error code by io_service.run(ec) not the same as in async_read_handler
by Michael Weise 06 Apr '16

06 Apr '16

Hello, my question is about the error code returned by io_service.run_one. I expect the error code returned by run_one to be the same as the one in the handler - but they are not. Inside my handler I check the error code, which is equal to operation aborted: void ConnectionBase::ReadUntilHandler( const boost::system::error_code & ec, std::size_t bytes_transferred) { // ec == boost::asio::error::operation_aborted ... } At some other point I call io_service.run_one, which calls the above handler: ... m_asioService.run_one(ec); assert(ec == boost::asio::error::operation_aborted); ... The assertion fails - for some reason the error code is not the same as in the handler. What's the reason for this? Maybe my assumtion that run_one(ec) returns the error code of the handler is simply wrong? If so, what error does io_service.run(ec) actually report? Thanks for help, Michael PS: boost::asio version is 1.56.0

2 1

Using Boost.ASIO with Boost.Coroutine2
by Carlos Ferreira 06 Apr '16

06 Apr '16

Hello to all! Is it possible to use Boost.ASIO with Boost.Coroutine2? For what I understood upon reading the documentation, using Boost.Corouine2 is preferable, due to issues present in Coroutine that were solved in Coroutine2. The documentation is scarse and I'm having some trouble in making things work. Thank you! -- Carlos Miguel Ferreira Researcher at Telecommunications Institute Aveiro - Portugal Work E-mail - cmf(a)av.it.pt Skype & GTalk -> carlosmf.pt(a)gmail.com LinkedIn -> http://www.linkedin.com/in/carlosmferreira

1 0

[Q] piecewise_construct for boost::container::map::emplace()
by dave m. 05 Apr '16

05 Apr '16

I recently tried (but failed) to use boost::container::map::emplace() with the piecewise_construct tag to forward constructor args as tuples. After some fiddling around, it appears that piecewise_construct is not implemented for boost::container::detail::pair (see boost/container/detail/pair.hpp:151). I couldn't find any discussion in the mailing list archives. Is there a good reason not to use emplace() this way, or unreasonable difficulty in implementing piecewise_construct for pair<U,V>? (I ended up making constructors for my K, V elements that take tuples<>, so emplace() is working for me, but I'm not completely sure that I have avoided all possible copy/move operations. Using gcc-4.9.2, fwiw.) Thanks, dhm

1 0

Re: [Boost-users] [type traits] Using Boost.Geometry with Clang/LLVM & VC14
by degski 05 Apr '16

05 Apr '16

I've successfully compiled Boost 1.61.0 Beta 1 Release Candidate with VC14 (no Clang-Cl.exe) in debug and release. This has exposed the "hacks" I mentioned earlier in this thread. When compiling my test program with Clang-Cl (latest) and VC14, the following errors are reported. (in my hacks I just added std:: to the boost code in the appropriate places, untill Clang stopped complaining. 1>------ Rebuild All started: Project: test, Configuration: Debug x64 ------ 1> In file included from test.cpp:16: 1> In file included from z:\vc\x64\include\boost/geometry.hpp:17: 1> In file included from z:\vc\x64\include\boost/geometry/geometry.hpp:28: 1> In file included from z:\vc\x64\include\boost/geometry/core/coordinate_type.hpp:23: 1> In file included from z:\vc\x64\include\boost/geometry/util/promote_floating_point.hpp:19: 1> In file included from z:\vc\x64\include\boost/type_traits.hpp:62: 1>z:\vc\x64\include\boost/type_traits/has_nothrow_assign.hpp(64,7): error : no template named 'is_assignable'; did you mean 'std::is_assignable'? 1> BOOST_HAS_NOTHROW_ASSIGN(T) 1> ^ 1> z:\vc\x64\include\boost/type_traits/intrinsics.hpp(199,96) : note: expanded from macro 'BOOST_HAS_NOTHROW_ASSIGN' 1> # define BOOST_HAS_NOTHROW_ASSIGN(T) (__has_nothrow_assign(T) && !is_volatile<T>::value && is_assignable<T&, const T&>::value) 1> ^ 1> C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\include\type_traits(577,9) : note: 'std::is_assignable' declared here 1> struct is_assignable 1> ^ 1> In file included from test.cpp:16: 1> In file included from z:\vc\x64\include\boost/geometry.hpp:17: 1> In file included from z:\vc\x64\include\boost/geometry/geometry.hpp:28: 1> In file included from z:\vc\x64\include\boost/geometry/core/coordinate_type.hpp:23: 1> In file included from z:\vc\x64\include\boost/geometry/util/promote_floating_point.hpp:19: 1> In file included from z:\vc\x64\include\boost/type_traits.hpp:63: 1>z:\vc\x64\include\boost/type_traits/has_nothrow_constructor.hpp(26,84): error : no template named 'is_default_constructible'; did you mean 'std::is_default_constructible'? 1> template <class T> struct has_nothrow_constructor : public integral_constant<bool, BOOST_HAS_NOTHROW_CONSTRUCTOR(T)>{}; 1> ^ 1> z:\vc\x64\include\boost/type_traits/intrinsics.hpp(193,80) : note: expanded from macro 'BOOST_HAS_NOTHROW_CONSTRUCTOR' 1> # define BOOST_HAS_NOTHROW_CONSTRUCTOR(T) (__has_nothrow_constructor(T) && is_default_constructible<T>::value) 1> ^ 1> C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\include\type_traits(539,9) : note: 'std::is_default_constructible' declared here 1> struct is_default_constructible 1> ^ 1> In file included from test.cpp:16: 1> In file included from z:\vc\x64\include\boost/geometry.hpp:17: 1> In file included from z:\vc\x64\include\boost/geometry/geometry.hpp:28: 1> In file included from z:\vc\x64\include\boost/geometry/core/coordinate_type.hpp:23: 1> In file included from z:\vc\x64\include\boost/geometry/util/promote_floating_point.hpp:19: 1> In file included from z:\vc\x64\include\boost/type_traits.hpp:74: 1>z:\vc\x64\include\boost/type_traits/has_trivial_assign.hpp(28,7): error : no template named 'is_assignable'; did you mean 'std::is_assignable'? 1> BOOST_HAS_TRIVIAL_ASSIGN(T) 1> ^ 1> z:\vc\x64\include\boost/type_traits/intrinsics.hpp(187,96) : note: expanded from macro 'BOOST_HAS_TRIVIAL_ASSIGN' 1> # define BOOST_HAS_TRIVIAL_ASSIGN(T) (__has_trivial_assign(T) && !is_volatile<T>::value && is_assignable<T&, const T&>::value) 1> ^ 1> C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\include\type_traits(577,9) : note: 'std::is_assignable' declared here 1> struct is_assignable 1> ^ Then there are more errors, but they are either the same as the ones I've reported earlier, or the result of the above errors. Have a good day, degski

4 9

Boost.Fit review Mars 3-20 result
by Vicente J. Botet Escriba 03 Apr '16

03 Apr '16

Hi, I will be out for two weeks and I wanted to at least give the result of the Boost.Fit library review even if I would need more time to have a complete report. Summary ======= The review of the proposed Boost.Fit library ended on Mars 20, 2016. The verdict is: Conditional acceptance (a new review is needed) There were too much concerns about the documentation and what exactly this library is proposing and not enough reviews commenting the design, code and test for each one of the proposed functions. From the review discussion I deduce that there is some interest in the library, and that some people don't understand yet what the library is proposing. Paul has started already to take in account some if the issues raised during the review and a lot of them must be resolved before we re-try a new review. There were some discussion about the name of the library, but there were no consensus. Paul is free to change the name of his library and see how people react. On behalf of the Boost community, I would like to thank Paul Fultz for the work he has put into the Fit library so far. I encourage him to continue to evolve this library and to bring it back for a new review. We had seven 6 formal votes, and 2 more votes without a complete review abbreviated here: Steaven Watanabe: No in his current state Zach Laine : Conditinal acceptance Krzysztof Jusiak: Accepted Artyom Beilis : Rejected Peter Dimov : Accepted (no review) Manuel Sancher : Accepted (no review) Rob Stewart : Conditinal acceptance ??? Louis Dionne : Conditinal acceptance There were other people that participated on the review giving their advice respect to a specific issue. I thank each of these reviewers, and indeed everyone who invested some time participating in the discussions. If you feel that I have misrepresented your position, or have omitted or garbled an important point, please respond: the archived mail thread should accurately reflect the will of the community, even if this message does not. Detailed Report =============== You will need to wait yet for a month before I will be able to do it. On the mean time there are a lot of issues that must be addressed and that are part of the github issues. For more information see: Github:https://github.com/pfultz2/Fit/tree/boost Issues:https://github.com/pfultz2/Fit/issues Documentation:http://pfultz2.github.io/Fit/doc/html/ Hopping this helps, Vicente Botet Escriba

1 0

[Python] exec_file double delete
by Albert Yiamakis 03 Apr '16

03 Apr '16

Hello, Working with Boost 1.58, I am using Boost.Python to interpret python code. eval() and exec() are working as expected, however exec_file results on a double delete upon finishing reading the script. This can be observed in the following minimal: #include <boost/python.hpp> int main() { Py_Initialize(); boost::python::exec_file("foo.py"); } where foo.py contains a single line: print "hello" hello is printed on the screen - i.e. the script is completed before the crash. Valgrind also finds a number of invalid reads in the exec_file line before an invalid free/delete. Is there something I'm missing in exec_file usage, or do you think there might be a mismatch of dependencies? (using boost and python both from my package manager). Thank you, Albert

1 0

Re: [Boost-users] Weird code in lockfree::queue::reserve (compilation error)
by Bjorn Reese 02 Apr '16

02 Apr '16

On 04/02/2016 05:08 PM, Aurelien Regat-Barrel wrote: > I'm trying to use lockfree::queue, and I get a compiler error when calling reserve(). The following code does not compile with VC++ 2015: What error are you getting? Have you checked that the type T you use as the template argument to lockfree::queue<T> fulfills the documented requirements? > void reserve(size_type n) > { > pool.template reserve<true>(n); > } > > And indeed... what does this syntax mean: "pool.template reserve"? You can see it here: The use of the template keyword above is correct. It is used to help the C++ compiler resolve an otherwise ambiguous syntax. See the section "The template disambiguator for dependent names" at: http://en.cppreference.com/w/cpp/language/dependent_name

2 1

Weird code in lockfree::queue::reserve (compilation error)
by Aurelien Regat-Barrel 02 Apr '16

02 Apr '16

Hello, I'm trying to use lockfree::queue, and I get a compiler error when calling reserve(). The following code does not compile with VC++ 2015: void reserve(size_type n) { pool.template reserve<true>(n); } And indeed... what does this syntax mean: "pool.template reserve"? You can see it here: http://www.boost.org/doc/libs/1_60_0/boost/lockfree/queue.hpp Regards, Aurélien Regat-Barrel

1 0

Boost.Spirit's Greedy Fundamental Type Parsers
by Daniel Hofmann 01 Apr '16

01 Apr '16

Suppose I want to parse a list of ";"-separated floating point pairs with "," being the pair separator as in "1,2;3,4". Following this list comes a string literal representing a file extension, such as ".txt". Therefore what I want to successfully parse input like the following: 1,2;3,4.txt (For the record, the input could also be 1.1,2.2;3.3,4.4.txt) The parser I came up with is the 1:1 translation of above's description into the Spirit DSL and shows Spirit's expressive power: ((double_ % ",") % ";") >> ".txt" Unfortunately, the parser fails on the input with the integral values above. Why? Because the fundamental parser for double_ greedily matches on the "4." in "4.txt". Changing the "4" to "4.0" as in 1,2;3,4.0.txt parses successfully (but is not an option as it requires the user to always add a trailing ".0" in case the last digit is integral. I read about Spirit's DSL mapping to Parsing Expression Grammar (PEG) with the choice operator | being evaluated in order. So the next logical step for me was to try making use of it and adapting the parser: (((int_ | double_) % ",") % ";") >> ".txt" which works on 1,2;3,4.txt but no longer on 1,2;3,4.0.txt Is there a way to adapt the parser to handle both cases? I asked this on IRC and got the answer to try a solution based on ((double_ >> ".") | (int_ >> ".")) >> "txt" but when I use use this to parse "4.txt" into a std::vector<double> via parse(first, last, ((double_ >> ".") | (int_ >> ".")) >> "txt", into); the vector contains: {4, 4} and its size() is 2, which I can make no sense of at all (but this may be a different problem). Cheers, Daniel J H

3 4

Is there any ongoing work to support toolset Clang 3.7 with Microsoft CodeGen (v140_clang_3_7)
by forumer＠smartmobili.com 01 Apr '16

01 Apr '16

Hi, Microsoft has released a new toolset mixing clang for the code analysis part and VS2015 for the code generation. https://blogs.msdn.microsoft.com/vcblog/2015/12/04/clang-with-microsoft-cod… https://blogs.msdn.microsoft.com/vcblog/2016/01/20/clang-with-microsoft-cod… Is there any ongoing work to support this new compiler and properly support it ? Thanks

1 0

Re: [Boost-users] [boost] Boost 1.61.0 Beta 1
by Tom Kent 31 Mar '16

31 Mar '16

On Thu, Mar 31, 2016 at 3:05 AM, Vladimir Prus <vladimir.prus(a)gmail.com> wrote: > > The first beta packages for 1.61.0 beta 1 are now available: > <snip> > > It was discovered that the .zip and .7z archives actually have LF line > endings, > at least in some places. Fixing this is not quite trivial, as Travis uses > ancient version of Ubuntu and Git, and is not deemed critical, as most > Windows > editors handle LF just fine. We might do something for the final release, > or > might not. > I would vote for leaving it, I've always thought it would be preferable if all the releases were the same. I think notepad.exe is the only app that still has issues with line endings, though I'd be interested in hearing some history on why was different for the windows releases. Tom

1 0

Looping through variadic macro arguments
by Florian Lindner 31 Mar '16

31 Mar '16

Hello, I have this macro: #define vmacro(expr, ...) \ cout << "n macro = " << BOOST_PP_VARIADIC_SIZE(__VA_ARGS__) << endl; \ cout << BOOST_PP_VARIADIC_ELEM(0, __VA_ARGS__) << endl; \ cout << BOOST_PP_VARIADIC_ELEM(1, __VA_ARGS__) << endl; \ for (int i = 0; i < BOOST_PP_VARIADIC_SIZE(__VA_ARGS__); i++) { \ cout << i << ": " << BOOST_PP_VARIADIC_ELEM(i, __VA_ARGS__) << endl; \ } The VARIADIC_SIZE is correct and I can access elements using BOOST_PP_VARIADIC_ELEM as long as I use a literal. The loop body produces error messages when compiling. BOOST_PP_VARIADICS is 1. The goal is to concatenate all variadic macro arguments to a string. If there a more clever solution, I'm very eager to hear them. Thanks! Florian ERROR MESSAGES: % clang++ -std=c++11 -g3 -rdynamic -ldl test.cpp test.cpp:154:3: error: expected expression vmacro(4, 5, 6); ^ test.cpp:120:26: note: expanded from macro 'vmacro' cout << i << ": " << BOOST_PP_VARIADIC_ELEM(i, __VA_ARGS__) << endl; \ ^ /usr/include/boost/preprocessor/variadic/elem.hpp:26:101: note: expanded from macro 'BOOST_PP_VARIADIC_ELEM' # define BOOST_PP_VARIADIC_ELEM(n, ...) BOOST_PP_CAT(BOOST_PP_VARIADIC_ELEM_, n)(__VA_ARGS__,) ^ 1 error generated. g++ -std=c++11 -g3 -rdynamic -ldl test.cpp In file included from test.cpp:9:0: test.cpp: In function 'void f(int)': test.cpp:120:26: error: expected primary-expression before ')' token cout << i << ": " << BOOST_PP_VARIADIC_ELEM(i, __VA_ARGS__) << endl; \ ^ test.cpp:154:3: note: in expansion of macro 'vmacro' vmacro(4, 5, 6); ^ test.cpp:120:26: error: 'BOOST_PP_VARIADIC_ELEM_i' was not declared in this scope cout << i << ": " << BOOST_PP_VARIADIC_ELEM(i, __VA_ARGS__) << endl; \ ^ test.cpp:154:3: note: in expansion of macro 'vmacro' vmacro(4, 5, 6); ^

2 16

Boost 1.61.0 Beta 1 Release Candidate 2
by Vladimir Prus 31 Mar '16

31 Mar '16

Second set of release candidates for 1.61.0 beta 1 are now available: http://boost.cowic.de/rc/boost_1_61_0_b1_rc2.zip http://boost.cowic.de/rc/boost_1_61_0_b1_rc2.tar.bz2 http://boost.cowic.de/rc/boost_1_61_0_b1_rc2.tar.gz http://boost.cowic.de/rc/boost_1_61_0_b1_rc2.7z 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. The changes from RC1 are: * Top-level directory in the archive matches the name * Zip and 7z archives use CRLF line endings The known issues are: * Documentation build has some wrong-location, extra-files and broken-links issues. * There was a report of Boost.Context issue on OSX Release managers believe these issues are not blocking beta 1. The SHA1 checksums are as follows: 4d3c83d3a802d3dd12d4f2d516b3fcf076f6f6ba boost_1_61_0_b1_rc2.7z 8c6ac7326a3cabcabf6c7876052b73e0d41fc36d boost_1_61_0_b1_rc2.tar.bz2 e82b8ff7c3ad5b08c7dbeac1ea85fcf707a1cd4d boost_1_61_0_b1_rc2.tar.gz 7292e8fdac0566fe098a60a197a5722d381842d3 boost_1_61_0_b1_rc2.zip The SHA256 checksums are as follows: bc8341bfb8c6621319ad9eb732179fc7ec4da35c3cefc31b613f83ec3df10361 boost_1_61_0_b1_rc2.7z c0f06c78c195af9079773a2b250674244f1899ec81e84d5455f0761f1d888a16 boost_1_61_0_b1_rc2.tar.bz2 400fa0949aa201d993bf116461365e5d44904a3f8db6412f4f40f2b4ab490405 boost_1_61_0_b1_rc2.tar.gz d75688ecad601303dda2658e9a3d06f406dd4dc8e2c13c36bdadcac0a11dcffa boost_1_61_0_b1_rc2.zip Thanks! -- The release managers

2 2

Encountering an issue trying to compile on OS X 10.11.4
by Brian Krisler 29 Mar '16

29 Mar '16

Hi, I am trying to compile a package that utilizes boost libraries, and the compilation fails. This is on OS X El Capitan, with clang version: 7.3.0.7030029. Is this a known issue, and is there a work around? In file included from /opt/local/include/boost/signals2/slot_base.hpp:18: /opt/local/include/boost/signals2/detail/foreign_ptr.hpp:42:54: error: reference to 'weak_ptr' is ambiguous template<typename T> struct weak_ptr_traits<std::weak_ptr<T> > ~~~~~^ /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/memory:5035:29: note: candidate found by name lookup is 'std::__1::weak_ptr' class _LIBCPP_TYPE_VIS_ONLY weak_ptr ^ /opt/local/include/boost/signals2/detail/foreign_ptr.hpp:25:30: note: candidate found by name lookup is 'std::weak_ptr' template<typename T> class weak_ptr; ^ /opt/local/include/boost/signals2/detail/foreign_ptr.hpp:42:33: error: redefinition of 'weak_ptr_traits<weak_ptr<type-parameter-0-0> >' template<typename T> struct weak_ptr_traits<std::weak_ptr<T> > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /opt/local/include/boost/signals2/detail/foreign_ptr.hpp:38:33: note: previous definition is here template<typename T> struct weak_ptr_traits<boost::weak_ptr<T> > ^ /opt/local/include/boost/signals2/detail/foreign_ptr.hpp:54:56: error: reference to 'shared_ptr' is ambiguous template<typename T> struct shared_ptr_traits<std::shared_ptr<T> > ~~~~~^ /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/memory:3847:29: note: candidate found by name lookup is 'std::__1::shared_ptr' class _LIBCPP_TYPE_VIS_ONLY shared_ptr ^ /opt/local/include/boost/signals2/detail/foreign_ptr.hpp:24:30: note: candidate found by name lookup is 'std::shared_ptr' template<typename T> class shared_ptr; ^ /opt/local/include/boost/signals2/detail/foreign_ptr.hpp:54:33: error: redefinition of 'shared_ptr_traits<shared_ptr<type-parameter-0-0> >' template<typename T> struct shared_ptr_traits<std::shared_ptr<T> > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /opt/local/include/boost/signals2/detail/foreign_ptr.hpp:50:33: note: previous definition is here template<typename T> struct shared_ptr_traits<boost::shared_ptr<T> > ^ 4 errors generated. Thanks Brian

1 0

Build console_test_runner.cpp in boost-1.60.0
by Sergiy Tkachuk 29 Mar '16

29 Mar '16

Hello, I downloaded sources boost_1_60_0.zip from boost.org I have built boost libraries. After this I tried to build console_test_runner.cpp located at \libs\test\tools\console_test_runner\src\console_test_runner.cpp of boost_1_60_0.zip. I run following command: ..\..\..\..\b2 toolset=msvc-14.0 address-model=64 variant=release debug-symbols=on I run it from the folder \libs\test\tools\console_test_runner\ I got errors, I tried to investigate them. It appears that console_test_runner.cpp contains following line: #include <boost/test/utils/runtime/cla/named_parameter.hpp> I tried to search boost folder for files "named_parameter*.*". I found html-files only. Then I checked Boost.Test repo at https://github.com/boostorg/test, rev. 36c5fe6a5604d0277f6d6a4cf167f95c38095c3c I also didn't found "named_parameter*.*" How can I obtain console_test_runner.exe from console_test_runner.cpp? I am not an expert in building boost, I just need working binaries. Thank you, -- Best wishes, Sergiy

1 0

LynxOS
by Miller, Caleb R 28 Mar '16

28 Mar '16

Has anyone ever used boost with LynxOS? In particular LynxOS-178 using ppc? Thanks, Caleb Caleb R. Miller 314-232-5633 The Boeing Company

1 0

Re: [Boost-users] Boost.Serialization how to use serialize without nvp
by Bjorn Reese 27 Mar '16

27 Mar '16

On 03/23/2016 12:45 PM, gast128 wrote: > We want archives the same for debug and release. So I tried a couple of things: > * use primitive_type: This doesn't work if the type T is a string. Basically > it doesn't come in the 'load(std::wstring &ws)' anymore, since it now routes > to operator<< and then all kinds of nasty thing happens for xml archives. I do not have a solution for you, but I wanted to voice my support for a new level type to ignore a nesting level (but not its content) during serialization.

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ptree json parser is not bidirectionnal
by Sébastien Gallou 25 Mar '16

25 Mar '16

Hi all, I experience a strange behavior of parsing non-JSON data with JSON parser. Take this example : boost::property_tree::ptree m_tree; > // Non-JSON to ptree using JSON parserstd::istringstream is("1"); // Simple value, non-JSON > boost::property_tree::json_parser::read_json(is, m_tree); // ==> No exception ! > // ptree back to JSONstd::ostringstream buf; > boost::property_tree::json_parser::write_json(buf, m_tree, false); // ==> Exception > > Unserializing non-JSON value using JSON parser doesn't raise exception. If you try to serialize the resulted ptree, you now got an exception. Is this behavior normal ? In this case, is there an easy and light mean to check that input value is JSON formatted (Regex ?) ? Thanks for your help, S. Gallou

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How to add child tree into an existing tree.
by Anil Jangam 24 Mar '16

24 Mar '16

Hi, I have the following property tree. propset1 { prop1 2 prop2 5 prop3 60 prop4 7 } I am trying to add couple of child trees to this so that the resulting property tree would look like below. propset1 { prop1 2 prop2 5 prop3 60 prop4 5 childset1 { child1prop1 4 child1prop1 6 child1prop1 9 } childset2 { child2prop1 2 child2prop1 6 child2prop1 7 } } I wrote the following code. // Add General config pt::ptree propset1; propset1.put("propset1.prop1", 2); propset1.put("propset1.prop2", 5); propset1.put("propset1.prop3", 60); propset1.put("propset1.prop4", 7); // Add childset1 config pt::ptree childset1; childset1.add("child1prop1", 4); childset1.add("child1prop2", 6); childset1.add("child1prop3", 9); propset1.add_child("childset1", childset1); // Add childset2 config pt::ptree childset2; childset2.add("child2prop1", 2); childset2.add("child2prop2", 6); childset2.add("child2prop3", 7); propset1.add_child("childset2", childset2); However the above code is resulting into below property tree. propset1 { prop1 2 prop2 5 prop3 60 prop4 5 childset1 { child1prop1 4 child1prop1 6 child1prop1 9 } } propset1 { prop1 2 prop2 5 prop3 60 prop4 5 childset2 { child2prop1 2 child2prop1 6 child2prop1 7 } } Can someone please suggest what is correct use of API? /anil

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Selecting function overloads with boost::overload()
by Reza Jahanbakhshi 23 Mar '16

23 Mar '16

First a little bit of background. Recently I've been using boost.python and I noticed choosing a specific function overload is kind of messy when defining class interfaces or free functions. Consider the following functions and member functions: void fn(int i, float f); int fn(const std::string& str); float car::method(); void car::method(int i, double d); According to boost.python documentation we can add these function using either of following constructs: void (*fn1)(int, float) = fn; int (*fn2)(const std::string&) = fn; def("fn", fn1); def("fn", fn2); float (car::*method1)() = &car::method; void (car::*method2)(int, double) = &car::method; .def("method", method1) .def("method", method2) or to avoid those intermediate variables we can do it directly: def("fn", (void (*)(int, float))fn); def("fn", (int (*)(const std::string&))fn); .def("method", (float(car::*)())&car::method) .def("method", (void (car::*)(int, double))&car::method) Which in my opinion is not readable enough. So I wrote a small utility to make it a little bit more readable. For example: def("fn", overload<void(int, float)>(fn)); def("fn", overload<int(const std::string&)(fn)); .def("method", overload<float()>(&car::method)); .def("method", overload<void(int, double)>(&car::method)); Notice how I gave the desired signature to the overload function and it will choose that exact overload for me. It's not only limited to boost.python and we can use it wherever we need to select a specific overloaded function. For example: auto f = overload<void(int, float)>(fn); Of course it's just a syntactic sugar and you might not find it improving anything at all but in my case it helped my code readability somehow. Now my question. I pasted the whole thing here. As for non-member functions I could implement it relying only on C++11 variadic templates. But for member functions I couldn't find a way to do it without boost.preprocess and using only C++11 variadic template. Here is the full code tested with GCC 5.3.1 (std=C++11), Clang 3.7.0 (std=C++11) and MSVC2015 #include <type_traits> #include <boost/mpl/vector.hpp> #include <boost/preprocessor/arithmetic/inc.hpp> #include <boost/preprocessor/punctuation/comma_if.hpp> #include <boost/preprocessor/repetition.hpp> namespace boost { namespace detail { template <typename SignatureType> struct fn_signature; template <typename ResultType, typename... ArgType> struct fn_signature<ResultType(ArgType...)> { using result_type = ResultType; using arg_type = boost::mpl::vector<ArgType...>; static const std::size_t arg_count = sizeof...(ArgType); using type = ResultType(*)(ArgType...); }; template <typename ClassType, typename SignatureType> struct memfn_signature; template <typename ClassType, typename ResultType, typename... ArgType> struct memfn_signature<ClassType, ResultType(ArgType...)> { using type = ResultType(ClassType::*)(ArgType...); }; } // namespace detail template <typename SignatureType> typename detail::fn_signature<SignatureType>::type overload(typename detail::fn_signature<SignatureType>::type fn) { return fn; } #define BOOST_OVERLOAD_MAX_ARGS_COUNT 5 #define BOOST_OVERLOAD_PP_METHOD_OVERLOAD_ARGS(Z, N, C) BOOST_PP_COMMA_IF(N) typename std::enable_if<detail::fn_signature<SignatureType>::arg_count == C, typename boost::mpl::at_c<typename detail::fn_signature<SignatureType>::arg_type, N>::type>::type #define BOOST_OVERLOAD_PP_METHOD_OVERLOAD_IMPL(Z, N, _) \ template <typename SignatureType, typename ClassType> \ typename detail::memfn_signature<ClassType, SignatureType>::type overload(typename detail::fn_signature<SignatureType>::result_type(ClassType::*memfn)(BOOST_PP_REPEAT(N, BOOST_OVERLOAD_PP_METHOD_OVERLOAD_ARGS, N))) \ { \ return memfn; \ } BOOST_PP_REPEAT(BOOST_PP_INC(BOOST_OVERLOAD_MAX_ARGS_COUNT), BOOST_OVERLOAD_PP_METHOD_OVERLOAD_IMPL, _) #undef BOOST_OVERLOAD_PP_METHOD_OVERLOAD_IMPL #undef BOOST_OVERLOAD_PP_METHOD_OVERLOAD_ARGS #undef BOOST_OVERLOAD_MAX_ARGS_COUNT } // namespace boost The problem is I cannot find a way to force the overload resolution to pick the specific overload and also automatically deduce the ClassType template parameter at the same time. If the language let me to alias a variadic template parameter then it would be possible to do it. For example I could do this: template <typename ClassType, typename ResultType, typename... ArgType> struct memfn_signature<ClassType, ResultType(ArgType...)> { using type = ResultType(ClassType::*)(ArgType...); using result_type = ResultType; *using arg_type = ArgType...;* }; template <typename SignatureType, typename ClassType> typename detail::memfn_signature<ClassType, SignatureType>::type overload(typename detail::memfn_signature<SignatureType>::result_type (ClassType::*memfn)(typename detail::memfn_signature<SignatureType>::arg_type)) { return memfn; } Right now my preprocess implementation works with no problem but It's not a clean implementation. So is there any other way that I can do this. I appreciate your help.

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Boost.Serialization how to use serialize without nvp
by gast128 23 Mar '16

23 Mar '16

Hello all, we basically have a setup like this: #ifdef _DEBUG template <typename T> struct Wrapper { T m_value; }; #define HANDLE(T) Wrapper<T> #else #define HANDLE(T) T #endif We want archives the same for debug and release. So I tried a couple of things: * use primitive_type: This doesn't work if the type T is a string. Basically it doesn't come in the 'load(std::wstring &ws)' anymore, since it now routes to operator<< and then all kinds of nasty thing happens for xml archives. * overload serialize. This is also a failure, since it expects somehow a nvp, which I tried to circumvent since then there is a difference between archives in debug or release. Using 'is_wrapper' doesn't help either template <class Archive, typename T> void serialize(Archive& ar, Wrapper<T>& r, const unsigned int) { ar & r.m_value; // static assert in basic_xml_iarchive::load_override } somehow I must specify raw storage in the serialize function, but load_override and its siblings are all protected. Anyone?

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Sean Parent to Keynote C++Now 2016
by Jon Kalb 22 Mar '16

22 Mar '16

Boost Users, C++Now is announcing that the keynote speaker for our tenth conference will be the keynote that started us off, Sean Parent. http://cppnow.org/2016-conference/announcements/2016/03/22/keynote-announced .html Jon

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windows 10 support in boost
by Hinrich Aue 22 Mar '16

22 Mar '16

Hello, can anybody tell me if boost supports windows 10? And from which version? Hinrich Hinrich Aue Sr. Software Engineer Kofax Development GmbH Wentzinger Strasse 19 79106 Freiburg Germany Tel: +49 761 452 69 57234 Fax: +49 761 452 69 58734 Hinrich.Aue(a)kofax.com blog<http://www.kofax.com/blog/> | twitter<https://twitter.com/Kofax> | linkedin<https://www.linkedin.com/company/kofax> | facebook<https://www.facebook.com/kofax.inc> | talent network<http://www.jobs.net/jobs/Kofax-Inc/join> ________________________________ This communication is only for the use of the intended recipient. It may contain confidential or proprietary information. If you are not the intended recipient or have received this communication in error, please notify the sender via phone and destroy this communication immediately. Kofax Development GmbH Sitz der Gesellschaft: Freiburg i. Brg. Registergericht: Amtsgericht Freiburg i.Br. Registernummer: HRB 7007 Gesch?ftsf?hrer: Bradford Weller, Christian Hefner, Daniel Geiger

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Re: [Boost-users] [boost] Boost 1.61.0 Beta 1 Release Candidate 1
by Daniel James 21 Mar '16

21 Mar '16

On 19 March 2016 at 19:38, Vladimir Prus <vladimir.prus(a)gmail.com> wrote: > > Release candidates for 1.61.0 beta 1 are now available: > > http://boost.cowic.de/rc/boost_1_61_0_b1_rc1.zip > http://boost.cowic.de/rc/boost_1_61_0_b1_rc1.tar.bz2 > http://boost.cowic.de/rc/boost_1_61_0_b1_rc1.tar.gz > http://boost.cowic.de/rc/boost_1_61_0_b1_rc1.7z I've put the documentation on the website. It's linked from the release notes: http://www.boost.org/users/history/version_1_61_0.html

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Confused by boost graph descriptor invalidation
by Paolo Bolzoni 21 Mar '16

21 Mar '16

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Dear list, I have a adjacency_list with OutEdgeList and VertexList as vecS and I do need to split edges. To split an edge is to remove it, replace with two edges with a new vertex in the middle. Since I am changing the graph I want to be sure how the invalidation works and so I read the page in[1], but I am confused by the table "Summary of Descriptor and Iterator Invalidation." The text states the table summarizes which operations cause descriptors and iterators to become invalid, said so what does "OK" means? My feeling is that iterators never become invalid, is that the case? And what "EL=vecS && Directed=directedS" means? It means that you are _fine_ only if you are working with a adjcency_list with OutEdgeList as vecS and Directed=directedS or the opposite (i.e., if you are using such adjcency_list then all iterators become invalid) Yours faithfully, Paolo [1] http://www.boost.org/doc/libs/release/libs/graph/doc/adjacency_list.html -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJW78v4AAoJENxW6b8QprD6Aq4H/jXK9kfFy65yZzzzySsFteS6 V9PFvCyrjzgrbGojMZok3Xxz2fJBvfvomqnzEgDuFy7I1P73dkyL3gbwRoPINQpN Qu/0zqskpWf6gJjnu0/3QtSDRBQ1hvT/ZmfhfoUyh1CSQuxyH+/VQV5V4uaDxymQ /atbZWn8Ry1e4noHlS1l27FvEF+qsxOGaHsqBr1Of5KYvcdWmEqN2PJjqWF87Ev7 +sCY4/aD5rT0n+FLBa/Qk/opblbNYprjCmTgpWjKh4lnRmrHJAJNTQeKwZC+e8Hx SOqW2kAQMRW46/y+VcMnOOv+M5UOxqj0K+EgAWVLaoyAZTJzbSc2E9VQL3fB4AA= =xH7S -----END PGP SIGNATURE-----

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boost linker errors
by Mark 21 Mar '16

21 Mar '16

Hi I am trying to link to a boost library, program_options, using Visual Studio 2015 and I am getting 'lnk2019 unresolved external symbol’ errors. I have built the boost libraries using b2 and built the complete libraries for msvc. The libraries are 32 bit. I have configured visual studio to point at the correct location for both the headers and the libraries, I’ve confirmed this. I am statically linking against libboost_program_options-vc140-mt-sgd-1_60.lib, though I have tried all the other variants of this library, e.g. removed the mt, the gd and the s parts of the name, without effect. I have tried all the different calling convention options in properties, I am building with the /MTd option set, though I have tried others. i have searched the internet thoroughly and cannot find a replication of my problem. Using BOOST_LIB_DIAGNOSTIC confirms that the library is being linked, I see the message in the output window. The errors I am getting are: Severity Code Description Project File Line Suppression State Error LNK2019 unresolved external symbol "void __cdecl simulate(class nemo::Simulation *,unsigned int,unsigned int,class std::basic_ostream<char,struct std::char_traits<char> > &)" (?simulate@@YAXPAVSimulation@nemo@@IIAAV?$basic_ostream@DU?$char_traits@D@std@@@std@@@Z) referenced in function _main NeMo_Test C:\Users\Development\Documents\Visual Studio 2015\Projects\NeMo_Test\NeMo_Test\main.obj 1 Error LNK2019 unresolved external symbol "long __cdecl benchmark(class nemo::Simulation *,unsigned int,unsigned int,class boost::program_options::variables_map &,unsigned int)" (?benchmark@@YAJPAVSimulation@nemo@@IIAAVvariables_map@program_options@boost@@I@Z) referenced in function _main NeMo_Test C:\Users\Development\Documents\Visual Studio 2015\Projects\NeMo_Test\NeMo_Test\main.obj 1 Error LNK2019 unresolved external symbol "class nemo::Configuration __cdecl configuration(class boost::program_options::variables_map &)" (?configuration@@YA?AVConfiguration@nemo@@AAVvariables_map@program_options@boost@@@Z) referenced in function _main NeMo_Test C:\Users\Development\Documents\Visual Studio 2015\Projects\NeMo_Test\NeMo_Test\main.obj 1 Error LNK2019 unresolved external symbol "class boost::program_options::variables_map __cdecl processOptions(int,char * * const,class boost::program_options::options_description const &)" (?processOptions@@YA?AVvariables_map@program_options@boost@@HQAPADABVoptions_description@23@@Z) referenced in function _main NeMo_Test C:\Users\Development\Documents\Visual Studio 2015\Projects\NeMo_Test\NeMo_Test\main.obj 1 Error LNK2019 unresolved external symbol "class boost::program_options::options_description __cdecl commonOptions(void)" (?commonOptions@@YA?AVoptions_description@program_options@boost@@XZ) referenced in function _main NeMo_Test C:\Users\Development\Documents\Visual Studio 2015\Projects\NeMo_Test\NeMo_Test\main.obj 1 Error LNK1120 5 unresolved externals NeMo_Test C:\Users\Development\Documents\Visual Studio 2015\Projects\NeMo_Test\Debug\NeMo_Test.exe 1 I would be very grateful if anyone could provide a clue as to what I am missing or have done wrong. Many thanks

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[Fit] formal review starts today
by Vicente J. Botet Escriba 21 Mar '16

21 Mar '16

Dear Boost community, sorry for the late anounce The formal review of Paul Fultz II's Fit library starts today, 2nd March and ends on 13th March. Fit is a header-only C++11/C++14 library that provides utilities for functions and function objects. Fit is: - Modern: Fit takes advantages of modern C++11/C++14 features. It support both `constexpr` initialization and `constexpr` evaluation of functions. It takes advantage of type deduction, varidiac templates, and perfect forwarding to provide a simple and modern interface. - Relevant: Fit provides utilities for functions and does not try to implement a functional language in C++. As such, Fit solves many problems relevant to C++ programmers, including initialization of function objects and lambdas, overloading with ordering, improved return type deduction, and much more. - Lightweight: Fit builds simple lightweight abstraction on top of function objects. It does not require subscribing to an entire framework. Just use the parts you need. Fit is divided into three components: * Function Adaptors and Decorators: These enhance functions with additional capability. * Functions: These return functions that achieve a specific purpose. * Utilities: These are general utilities that are useful when defining or using functions Fit has been tested on gcc 4.6-4.9, clang 3.4-3.7, and Visual Studio 2015. For more information see: Github:https://github.com/pfultz2/Fit/tree/boost Documentation:http://pfultz2.github.io/Fit/doc/html/ We encourage your participation in this review. At a minimum, kindly state: - Whether you believe the library should be accepted into Boost * Conditions for acceptance - Your name - Your knowledge of the problem domain. You are strongly encouraged to also provide additional information: - What is your evaluation of the library's: * Design * Implementation * Documentation * Tests * Usefulness - Did you attempt to use the library? If so: * Which compiler(s) * What was the experience? Any problems? - How much effort did you put into your evaluation of the review? More information about the review process can be found here:http://www.boost.org/community/reviews.html We await your feedback! Best regards, Vicente J. Botet Escriba

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[Fit] formal review is over
by Vicente J. Botet Escriba 21 Mar '16

21 Mar '16

Hi, The review of the Fit library finished yesterday 20 March. Thanks to all the people who participated in the review, as a reviewer or commenting the threads. I hope to announce the result soon ;-) Best, Vicente P.S. Of course you/we can continue with the discussion and add issues in github that would help to improve the library. For more information see: Github:https://github.com/pfultz2/Fit/tree/boost Documentation:http://pfultz2.github.io/Fit/doc/html/

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Re: [Boost-users] [boost] Boost 1.61.0 Beta 1 Release Candidate 1
by Marshall Clow 20 Mar '16

20 Mar '16

On Sat, Mar 19, 2016 at 12:38 PM, Vladimir Prus <vladimir.prus(a)gmail.com> wrote: > > Release candidates for 1.61.0 beta 1 are now available: > > http://boost.cowic.de/rc/boost_1_61_0_b1_rc1.zip > http://boost.cowic.de/rc/boost_1_61_0_b1_rc1.tar.bz2 > http://boost.cowic.de/rc/boost_1_61_0_b1_rc1.tar.gz > http://boost.cowic.de/rc/boost_1_61_0_b1_rc1.7z > > 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. > Packaging: The .gz file expanded to "boost_master_3a94cde635254f92fa87e0e11ef52d08684b8225", instead of "boost_1_61_0_b1" I successfully built the libraries with Apple's clang compiler. "Apple LLVM version 7.0.2 (clang-700.1.81)" with C++03, C++11, C++14, and c++1z I was not successful building the libraries with clang ToT. Boost.Python, in particular, had compile errors. I don't know if this is a problem in Boost.Python, or in libc++. (probably libc++) I will continue to investigate. In any case, I don't think that this should hold up the beta release. -- Marshall

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[Fit] formal review ends 20th March.
by Vicente J. Botet Escriba 19 Mar '16

19 Mar '16

Hi, There have been some that would be able to write a review next week-end. Others said that they had not enough time. Maybe having an additional week can help. I have not received confirmation from the review withards, but as there is no planned reviews for this week, I propose to continue with the review until 20th. Please take the time to do a review and share your point of view. Best, Vicente Fit is a header-only C++11/C++14 library that provides utilities for functions and function objects. Fit is: - Modern: Fit takes advantages of modern C++11/C++14 features. It support both `constexpr` initialization and `constexpr` evaluation of functions. It takes advantage of type deduction, varidiac templates, and perfect forwarding to provide a simple and modern interface. - Relevant: Fit provides utilities for functions and does not try to implement a functional language in C++. As such, Fit solves many problems relevant to C++ programmers, including initialization of function objects and lambdas, overloading with ordering, improved return type deduction, and much more. - Lightweight: Fit builds simple lightweight abstraction on top of function objects. It does not require subscribing to an entire framework. Just use the parts you need. Fit is divided into three components: * Function Adaptors and Decorators: These enhance functions with additional capability. * Functions: These return functions that achieve a specific purpose. * Utilities: These are general utilities that are useful when defining or using functions Fit has been tested on gcc 4.6-4.9, clang 3.4-3.7, and Visual Studio 2015. For more information see: Github:https://github.com/pfultz2/Fit/tree/boost Documentation:http://pfultz2.github.io/Fit/doc/html/ We encourage your participation in this review. At a minimum, kindly state: - Whether you believe the library should be accepted into Boost * Conditions for acceptance - Your name - Your knowledge of the problem domain. You are strongly encouraged to also provide additional information: - What is your evaluation of the library's: * Design * Implementation * Documentation * Tests * Usefulness - Did you attempt to use the library? If so: * Which compiler(s) * What was the experience? Any problems? - How much effort did you put into your evaluation of the review? More information about the review process can be found here:http://www.boost.org/community/reviews.html

1 1

Boost graph library: brandes_betweenness_centrality() usage
by Sebastian Rinke 18 Mar '16

18 Mar '16

Dear all, I have a question regarding how to use the BGL brandes_betweenness_centrality() function for calculating the vertex betweenness centrality for a directed weighted graph. Below is my small example that fails to compile: —8>— /* Create graph */ typedef property<edge_weight_t, double> EdgeWeightProperty; typedef adjacency_list< vecS, // OutEdgeList vecS, // VertexList directedS, // Directed no_property, // VertexProperties EdgeWeightProperty // EdgeProperties > Graph; Graph graph(num_vertices); /* Add edges … */ std::vector<double> v_centrality_vec(num_vertices(graph), 0.0); // Create the external vertex centrality property map iterator_property_map<std::vector<double>::iterator, identity_property_map> v_centrality_map(v_centrality_vec.begin()); brandes_betweenness_centrality(graph, v_centrality_map, weight_map(get(edge_weight, graph))); —8>— The first compilation error I get is: boost_1_58_0/boost/graph/betweenness_centrality.hpp:248:7: error: no type named 'value_type' in 'struct boost::property_traits<boost::bgl_named_params<boost::adj_list_edge_property_map<boost::directed_tag, double, double&, long unsigned int, boost::property<boost::edge_weight_t, double>, boost::edge_weight_t>, boost::edge_weight_t, boost::no_property> >' centrality_type; ^ When using the following call instead, it compiles: brandes_betweenness_centrality(graph, v_centrality_map); I would be very grateful for any help on this issue. Best regards, Sebastian

1 0

Way to Promise the io_service.run() Is Running
by Bo Zhou 16 Mar '16

16 Mar '16

Hi ! I have a program which has a following logic 1. Start the UDP listening in daemon thread 2. Send the UDP command from main thread, and wait the response, maybe from the local So the program itself might also receive the message from second step. But the problem is, on Windows, the receiving thread will be executed before the main thread starts to send message, so the behaviour is correct. On Linux that's opposite, the main thread will be in deadlock because the 1st thread is not running and 2nd step it's trying to receive something after sending the command. My question, in the main thread of my application, what could I do to detect the io_service is running ? I tried to call m_io_services.stopped() seems the state is not correct, so I'd like to know how can I wait until the event loop in 1st step is running ? Thank you very much !

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[Fit] About supported C++ version
by Vicente J. Botet Escriba 16 Mar '16

16 Mar '16

Hi, I was wondering if Boost.Fit shouldn't be a library as Boost.Hana, a library that makes use of the last C++ version and avoids as much portability issues as possible. Which C++14 features will make the library simpler? Which adopted C++17 features will make the library simpler? Which other C++ features would be missing? Paul I guess that you are using a C++11 compiler and want to support this version, could you confirm? Best, Vicente

2 3

boost-mpi - Serious performance degradation with OpenMPI 1.10.1
by Nolen, Steven Douglas 16 Mar '16

16 Mar '16

My project has been using boost's mpi interface for a number of years and have recently encountered a significant performance obstacle moving to openmpi 1.10.1. We are seeing a factor of 7-10x slowdown in the communication portion of our calculation. Our communication patterns are mostly governed by all-to-one reductions and some all-to-all reductions. Colleagues who call mpi directly have not seen this behavior. We would be willing to work with someone to find a solution. Steve Nolen LANL

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Using Boost.Geometry with Clang/LLVM & VC14
by degski 16 Mar '16

16 Mar '16

GGL does not compile with the combo of Clang/LLVM (http://llvm.org/builds/) and VC14 out of the box. There seem to be comflicts in the resolution of old MSVC bugs and Clang. On windows __clang__ is defined at the same time as _MSVC_VER. Undefining the macro _MSVC_VER before #include <boost/geometry/geometry.hpp> does however solve the problem (in my use case): file: boost/geometry.hpp // Boost.Geometry (aka GGL, Generic Geometry Library) // Copyright (c) 2007-2011 Barend Gehrels, Amsterdam, the Netherlands. // Copyright (c) 2008-2011 Bruno Lalande, Paris, France. // Copyright (c) 2009-2011 Mateusz Loskot, London, UK. // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands. // Use, modification and distribution is subject to the Boost Software License, // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) #ifndef BOOST_GEOMETRY_HPP #define BOOST_GEOMETRY_HPP #if defined(__clang__) && defined(_MSC_VER) #define __BOOST_GEOMETRY_MSVC_CLANG_WORKAROUND__ _MSC_VER #undef _MSC_VER #endif #include <boost/geometry/geometry.hpp> #if defined(__clang__) && defined(__BOOST_GEOMETRY_MSVC_CLANG_WORKAROUND__) #define _MSC_VER __BOOST_GEOMETRY_MSVC_CLANG_WORKAROUND__ #undef __BOOST_GEOMETRY_MSVC_CLANG_WORKAROUND__ #endif #endif // BOOST_GEOMETRY_HPP I've run into similar problems before (cannot remember where) with other boost libraries (which I hacked in other ways). Clang/LLVM with MSVC (and the IDE) works extremely well for a while now. The advantages of Clang/LLVM are well known, no need to spell them out It produces far faster code (almost twice as fast on simple matrix multiplication f.e.. It also gives the best of two worlds as it supports Clang and GCC extensions on Windows (calculated goto), while maintaining (although with a suppressable warning) M$ extensions as well, f.e. in-class template specialization. Clang/LLVM (3.9.0 as it stands) is much faster than Clang/CL2 (CodeGen) (3.7.0). I would herewith like to request the development team to integrate Clang/LLVM on Windows as another supported platform. Have good day to you all, degski -- (\___/) (+'.'+) (")_(") This is Bunny. Copy and paste Bunny into your signature to help him gain world domination!

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Warning message using Boost.Atomic char pointer with GCC 4.8
by Isaac To 16 Mar '16

16 Mar '16

Hi all, It looks like Boost.Atomic (in Boost 1.60) uses constructs that GCC 4.8 (in CentOS 7) really dislike. With the following simple test program... #include <boost/atomic.hpp> int main() { boost::atomic<const char*> p1("abc"), p2; p2 = p1.load(); } What I see is: $ g++ -std=c++11 -I ~/opt/1/include t.cpp In file included from /home/foo/opt/1/include/boost/atomic/detail/atomic_template.hpp:25:0, from /home/foo/opt/1/include/boost/atomic/atomic.hpp:22, from /home/foo/opt/1/include/boost/atomic.hpp:12, from t.cpp:1: /home/foo/opt/1/include/boost/atomic/detail/bitwise_cast.hpp: In instantiation of ‘To boost::atomics::detail::bitwise_cast(const From&) [with To = long unsigned int; From = const char*]’: /home/foo/opt/1/include/boost/atomic/detail/atomic_template.hpp:426:139: required from ‘boost::atomics::detail::base_atomic<T*, void*>::base_atomic(T* const&) [with T = const char; boost::atomics::detail::base_atomic<T*, void*>::value_type = const char*]’ /home/foo/opt/1/include/boost/atomic/detail/atomic_template.hpp:686:101: required from ‘constexpr boost::atomics::atomic<T>::atomic(boost::atomics::atomic<T>::value_arg_type) [with T = const char*; boost::atomics::atomic<T>::value_arg_type = const char*]’ t.cpp:4:40: required from here /home/foo/opt/1/include/boost/atomic/detail/bitwise_cast.hpp:45:5: warning: casting ‘const char* const’ to ‘const char&’ does not dereference pointer [enabled by default] ); ^ The offending code is boost/atomic/detail/bitwise_cast.hpp:45, looking like this: &reinterpret_cast< const char& >(from) Here "from" is of type From = const char*. The code needs to find the address storing the pointer. It reinterprets the pointer as a const char reference, where address is to be found. In actual production code I use -Werror, so this stops the compiler from producing an executable. Most other warnings caused by Boost can be opted out, but apparently not this particular one. Should this be considered too funny a use of the C++ language to be considered a bug? For now I change the const char* to const void* with extra reinterpret_cast's, which the compiler won't complain about. Regards, Isaac

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[Fit] function object variables and ADL
by Vicente J. Botet Escriba 14 Mar '16

14 Mar '16

Hi, Fit library make use of constexpr function object. These function objects don't work well when the user is requiring ADL and the same symbol is used. Next follows an example namespace N1 { struct F1 { void operator()(int) const {} }; constexpr F1 f; } namespace N2 { struct A{}; void f(A) {} } namespace N3 { struct A{}; void f(A) {} } The following find N3::f(A) { N3::A a; f(a); // calls N3::f(A) } Adding another namespace that doesn't introduce a better match works yet { N3::A a; using namespace N2; f(a); // calls N3::f(A) } However a namespace that contains a function object with the smae name even if overload doesn't match make the code ill-formed { N3::A a; using namespace N1; f(a); // compile fails } : error: reference to 'f' is ambiguous f(a); ^ : note: candidate found by name lookup is 'N1::f' constexpr F1 f; ^ : note: candidate found by name lookup is 'N3::f' void f(A) {} boost::fit contains a lot of such a function objects variables, so this means that the user should be careful while introducing the namespace boost::fit, as ADL will not be used for a lot of symbols. This is not something specific to Fit library, Hana and range-v3 make use of a lot of such global function objects. A good stryle will be to use Fit/Hana function objects always qualified with their respective namespapce or an alias. I believe it will be worth adding something in the documentation preventing the users of this case. Best, Vicente

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iostreams: streambuf class fails to compile on type check
by Dan Bloomquist 14 Mar '16

14 Mar '16

I'm trying to insert my own stream buffer into a boost stream. Here is the code <http://hostcode.sourceforge.net/view/5044> At the top are two arbitrary streambuf derived classes I copied from the web that are said to work with the std::stream. They don't work either. My work is in the rtf namespace. In main there is a test with my device, file_source, and std::ifstream derived, they all work. Then I've tried the likes of: rtf::basic_stream< char, char_array_buffer > io_4( input ); rtf::basic_stream< char, outbuf > io_4( input ); and the one I want to work: rtf::basic_stream< char, rtf::rtf_stream_buffer > io_4( input ); they all fail at: { BOOST_STATIC_ASSERT(is_std_io<T>::value); } line 66 in concept_adapter.hpp. All the classes are derived from std::basic_streambuf which is on the list #ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES And I could not find it defined with agent ransack So, I seem to be missing something fundamental and just don't know what it could be. Thanks. Dan.

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errors in polymorphic_iarchive_route.hpp:155 (boost version 1.60)
by Stack User 14 Mar '16

14 Mar '16

I get the following error when compiling code that uses boost version 1.60: In function `boost::archive::detail::polymorphic_iarchive_route<boost::archive::naked_binary_iarchive>::load(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&)': /usr/include/boost/archive/detail/polymorphic_iarchive_route.hpp:155: undefined reference to `boost::archive::basic_binary_iprimitive<boost::archive::naked_binary_iarchive, char, std::char_traits<char> >::load(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&)' Seems like the error is coming from polymorphic_iarchive_route.hpp at line 155: virtual void load(std::string & t){ ArchiveImplementation::load(t); } Can anybody point to a solution for this error? Thanks,

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[Fit] formal review ends today, 13th March.
by Vicente J. Botet Escriba 13 Mar '16

13 Mar '16

Hi, The formal review of Paul Fultz II's Fit library ends today, 13th March. If you had not time to do the review and you plan to do it, please let us know so that we see if the review can be extended. Up to now we had 3 formal review (2 for conditional acceptance and 1 against, not now). I have not done a review myself, but I have created a lot of issues on Github. Best regards, Vicente Fit is a header-only C++11/C++14 library that provides utilities for functions and function objects. Fit is: - Modern: Fit takes advantages of modern C++11/C++14 features. It support both `constexpr` initialization and `constexpr` evaluation of functions. It takes advantage of type deduction, varidiac templates, and perfect forwarding to provide a simple and modern interface. - Relevant: Fit provides utilities for functions and does not try to implement a functional language in C++. As such, Fit solves many problems relevant to C++ programmers, including initialization of function objects and lambdas, overloading with ordering, improved return type deduction, and much more. - Lightweight: Fit builds simple lightweight abstraction on top of function objects. It does not require subscribing to an entire framework. Just use the parts you need. Fit is divided into three components: * Function Adaptors and Decorators: These enhance functions with additional capability. * Functions: These return functions that achieve a specific purpose. * Utilities: These are general utilities that are useful when defining or using functions Fit has been tested on gcc 4.6-4.9, clang 3.4-3.7, and Visual Studio 2015. For more information see: Github:https://github.com/pfultz2/Fit/tree/boost Documentation:http://pfultz2.github.io/Fit/doc/html/ We encourage your participation in this review. At a minimum, kindly state: - Whether you believe the library should be accepted into Boost * Conditions for acceptance - Your name - Your knowledge of the problem domain. You are strongly encouraged to also provide additional information: - What is your evaluation of the library's: * Design * Implementation * Documentation * Tests * Usefulness - Did you attempt to use the library? If so: * Which compiler(s) * What was the experience? Any problems? - How much effort did you put into your evaluation of the review? More information about the review process can be found here:http://www.boost.org/community/reviews.html We await your feedback!

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boost karma qi: skipper concept
by Matwey V. Kornilov 13 Mar '16

13 Mar '16

Hello, I don't fully understand skip parser concepts. I would like to parse key-value list in bash style, like the following: KEY1=VAL1 KEY2="V A L 2" The pairs are separated by one or more space symbols. What is the supposed way to parse such constructions? 1. -(pair % (+space)) 2. *pair with skip=space 3. anything else?

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[INTERPROCESS] Message queues with hex names - in Windows
by Davies, John 11 Mar '16

11 Mar '16

I'm refactoring some code that has a pretty good suite of unit tests. Or at least I think it does, since I wrote them<g>. I have a process that dispatches messages to one or more other processes that have their own message queues. It's just a switchboard. The refactored code works, and runs much faster than the test code I had written before. Much faster. And passes the unit tests. But in the process I see a bunch of stuff in the boost-interprocess folder with long hex names. They get cleaned up when the tests are done. It seems the long hex names come when I'm destructing the queues. So is it part of garbage collection? It only concerns me because other times I saw names like that it was because I was trying to make two input queues with the same name. Thanks, John ________________________________ The information contained in this message may be confidential and legally protected under applicable law. The message is intended solely for the addressee(s). If you are not the intended recipient, you are hereby notified that any use, forwarding, dissemination, or reproduction of this message is strictly prohibited and may be unlawful. If you are not the intended recipient, please contact the sender by return e-mail and destroy all copies of the original message.

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Trouble building boost with Visual Studio 2010 (32 vs 64 bit issue)
by David Aldrich 09 Mar '16

09 Mar '16

Hi I am trying to build Boost 1.60 with Visual Studio 2010 Professional on Windows 10. I use the command: b2 toolset=msvc-10.0 --with-python link=shared and get the following error: python34.lib(python34.dll) : fatal error LNK1112: module machine type 'x64' conflicts with target machine type 'X86' I guess this means I have a conflict of 32-bit and 64-bit libraries. I want to target 32-bit (X86). Do I need to install a 32-bit version of Python? I wonder if that can co-exist with the current version of Python? Best regards David

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Boost python - pointers
by Daniel Burchardt 09 Mar '16

09 Mar '16

Hi, I have problem with pointer in function return. My code: using namespace boost::python; v8::Platform* InitializePlatform() { v8::Platform* platform = v8::platform::CreateDefaultPlatform(); return platform; } BOOST_PYTHON_MODULE(hello) { def("InitializePlatform", InitializePlatform, return_value_policy<manage_new_object>()); } Python code: import hello x = hello.InitializePlatform() Building is ok, but when i try call InitializePlatform i have error: Segmentation fault gdb: (gdb) run test.py Starting program: /usr/bin/python test.py [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". [New Thread 0x7ffff45b8700 (LWP 21739)] Program received signal SIGSEGV, Segmentation fault. 0x00007ffff4924640 in __dynamic_cast () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6

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