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Re: [Boost-users] [boost] [release] Boost 1.66.0 Release Candidate 2
by Daniel James 14 Dec '17

14 Dec '17

On 14 December 2017 at 15:02, Olaf van der Spek <ml(a)vdspek.org> wrote: > On Thu, Dec 14, 2017 at 2:03 PM, Daniel James via Boost > <boost(a)lists.boost.org> wrote: >> The second release candidates for the 1.66.0 release are now available at: >> >> <https://dl.bintray.com/boostorg/prerelease/> > > Repository path missing or not specified. Sorry, should be: https://dl.bintray.com/boostorg/release/1.66.0/source/

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Newbie: BGL & planar graphs
by ano kato 13 Dec '17

13 Dec '17

Hello everyone! I am using BGL to test for the planarity of drawings of graphs. The coordinates are hardcoded into the source code. Here's what the graph should look like: <https://i.imgur.com/UGA0mRB.png>. This definitely isn't planar and yet is_straight_line_drawing() returns 1! I'm quite confused. Am I doing something wrong? Thank you to anyone who replies. #include <iostream> #include <vector> #include <boost/graph/adjacency_list.hpp> #include <boost/property_map/property_map.hpp> #include <boost/graph/is_straight_line_drawing.hpp> using namespace boost; typedef struct { size_t x,y; } coord_t; int main(void) { typedef adjacency_list<vecS, vecS, undirectedS, property<vertex_index_t, int> > graph; graph Moser(7); add_edge(0,1,Moser); add_edge(0,6,Moser); add_edge(0,4,Moser); add_edge(1,6,Moser); add_edge(1,2,Moser); add_edge(2,6,Moser); add_edge(2,5,Moser); add_edge(2,3,Moser); add_edge(3,4,Moser); add_edge(4,5,Moser); graph G(Moser); int k = num_vertices(G); typedef std::vector<coord_t> cvec; typedef boost::iterator_property_map <cvec::iterator, property_map<graph, vertex_index_t>::type // ? > foo_t; cvec v(num_vertices(G)); foo_t drawing(v.begin(), get(vertex_index, G)); coord_t x[k]; x[0].x = 20; x[0].y = 10; x[1].x = 50; x[1].y = 10; x[2].x = 58; x[2].y = 52; x[3].x = 00; x[3].y = 30; x[4].x = 35; x[4].y = 50; x[5].x = 12; x[5].y = 51; x[6].x = 70; x[6].y = 30; graph_traits<graph>::vertex_iterator vi, vi_end; for(boost::tie(vi, vi_end) = vertices(G); vi != vi_end; ++vi) put(drawing, *vi, x[*vi]); if(is_straight_line_drawing(G,drawing)) std::cout << "This is a straight line planar drawing!" << std::endl; return 0; }

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(Newbie) Embedded programming, memory pools, and allocate_shared()
by Steven Boswell II 13 Dec '17

13 Dec '17

I apologize for bothering the mailing-list with this newbie question, but after searching the Net for several days, I still can't find the answers I'm looking for. I am considering using Boost for a project I'm doing on an embedded system.I can't seem to find a lot of discussion on the particulars of Boost in embedded systems, just a few here and there.The biggest relevant limitation in embedded programming is on dynamic memory allocation -- the usual pattern is to allocate all necessary memory in "startup" phases, e.g. launching the program, loading the next playing-field in a game application, etc. I believe I can do what I want with allocate_shared() and fixed-size memory pools.The first big issue I have is trying to figure out the size of the objects that'll be allocated from the pool.I don't want to just allocate a raw block of memory; I want to allocate a block with space for a certain number of objects of a homogeneous type.But an object_pool for a type T doesn't accurately reflect what allocate_shared() is going to try to create.From much digging around, it looks like it's actually creating a subclass of boost::detail::sp_counted_base, e.g. boost::detail::sp_counted_impl_pd<P,D>, boost::detail::sp_counted_impl_pda<P,D,A>, etc.It seems like I'm not supposed to refer to that class directly, but I don't know how else to get the size of individual objects for my pool-allocator.Also, navigating all the template-parameters needed by these classes is proving to be mind-twisting. Probably just because I'm seeing it for the first time. Another example of where I need to track down the implementation class is with async-operation handlers in Boost::ASIO, e.g. completion handlers for socket's async_read_some(), generic handlers passed to io_service::post(), and so on. In the case of socket::async_read_some(), there's an example in boost/doc/html/boost_asio/example/cpp03/allocation/server.cpp which shows how to allocate completion-handlers from a pool, but not how to get the size of the necessary completion-handler class. It appears the class is boost::asio::detail::reactive_socket_recv_op<>. Again, this doesn't seem to be a public class, nor can I find a nice public typedef for it. Can anyone advise me on how to use Boost in this way?All of the Boost memory-pools I've seen so far either just allocate chunks of raw memory, or they allocate non-shared variants of objects.A memory-pool with a given number of spaces for the final object type seems like a defensible, traditional solution, but it doesn't seem that Boost makes that easy.Am I way off base here? Thanks for any help. -Steven

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[thread] clock_gettime warning on OS X
by James Walker 13 Dec '17

13 Dec '17

I'm getting a warning in the file boost/thread/pthread/timespec.hpp pointing out that clock_gettime is only available on macOS 10.12 and later. This code is being compiled on macOS 10.13, but should be compatible with macOS versions back to 10.7. How can I fix it? Maybe change the setting of BOOST_THREAD_USEFIXES_TIMESPEC, which I don't see any documentation for?

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[SmartPtr] local_weak_ptr?
by Rob Conde 11 Dec '17

11 Dec '17

How are boost::local_shared_ptr and boost::weak_ptr intended to be used together? I expected a local_weak_ptr, but it's not there so I'm wondering how you would (correctly) use local_shared_ptr and weak_ptr, or if you need local_weak_ptr and this is just still on the TODO list? Thanks, Rob Conde

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boost::container::string: ambiguous overload for 'operator!='
by niXman 10 Dec '17

10 Dec '17

Hi, using gcc-7.2 in C++17 mode and boost-1.65.1 I get the "ambiguous overload for 'operator!='" error: test here: http://coliru.stacked-crooked.com/a/3fd8fb94c0d1aec2 the same error for 'operator==' -- Regards, niXman ___________________________________________________ Work for Bitcoins ___________________________________________________ Dual-target(32 & 64-bit) MinGW-W64 compilers for 32 and 64-bit Windows: https://sf.net/p/mingw-w64/

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[release] Boost 1.66.0 Release Candidate 1
by Daniel James 09 Dec '17

09 Dec '17

The release candidates for the 1.66.0 release are now available at: <https://dl.bintray.com/boostorg/release/1.66.0/source/> The in progress release notes are: <http://www.boost.org/users/history/in_progress.html> Library documentation is available at: <http://www.boost.org/doc/libs/1_66_0/> The SHA256 checksums are as follows: c9d29486dd12f19d321da65eb5f0a157ec0f0edfd4701ade48c644310c8f0676 boost_1_66_0_rc1.7z 6232f7e7873b2d1f112fb62c726f7066e9a7e0643ed2aac7d31d20bf5749fbc0 boost_1_66_0_rc1.tar.bz2 30ad6d1c7380d6e6a87ce1bc54388ab957de67a2e8fa44dd3c106eafad0f6ac2 boost_1_66_0_rc1.tar.gz cd2c64f243c89e04329e94f3b803f0744171b44fee7a8b4e3256b3a625dcbd1c boost_1_66_0_rc1.zip 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.

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Errors while trying to build boost::priority_queue
by Ram 09 Dec '17

09 Dec '17

Hi, When I try to build "priority_queue_example.cpp" it get these warnings(and so errors) pointing to "priority_queue_example.h" on the line where my priority_queue is declared. The warnings are, 1> priority_queue_example.cpp 1>c:\Projects\lib\boost\boost\heap\detail\stable_heap.hpp(102): error C2220: warning treated as error - no 'object' file generated 1>c:\Projects\lib\boost\boost\heap\detail\stable_heap.hpp(102): warning C4100: 'rhs' : unreferenced formal parameter 1> c:\Projects\lib\boost\boost\heap\detail\stable_heap.hpp(102) : while compiling class template member function 'boost::heap::detail::size_holder<false,size_t>::size_holder(const boost::heap::detail::size_holder<false,size_t> &)' 1> c:\Projects\lib\boost\boost\heap\detail\stable_heap.hpp(189) : see reference to function template instantiation 'boost::heap::detail::size_holder<false,size_t>::size_holder(const boost::heap::detail::size_holder<false,size_t> &)' being compiled 1> c:\Projects\lib\boost\boost\heap\detail\stable_heap.hpp(151) : see reference to class template instantiation 'boost::heap::detail::size_holder<false,size_t>' being compiled 1> c:\Projects\lib\boost\boost\heap\priority_queue.hpp(65) : see reference to class template instantiation 'boost::heap::detail::heap_base<T,myObjectPtrCompare,false,unsigned __int64,false>' being compiled 1> with 1> [ 1> T=myObject * 1> ] 1> c:\Projects\priority_queue_example.h(193) : see reference to class template instantiation 'boost::heap::priority_queue<myObject *,boost::heap::compare<myObjectPtrCompare>,boost::parameter::void_,boost::parameter::void_,boost::parameter::void_>' being compiledcompare<ObjectPtrCompare>,boost::parameter::void_,boost::parameter::void My priority_queue is declared as, mutable boost::heap::priority_queue<myObject*, boost::heap::compare<myObjectPtrCompare> > hp; Can you please help me fix this, I have been trying to for 2 days. Not sure what this means. This is my comparison class defined, struct myObjectPtrCompare { bool operator()(const myObject* lhs, const myObject* rhs) const { return (lhs->getProp() < rhs->getProp()); } }; Thanks!

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boost::priority_queue help
by Ram 09 Dec '17

09 Dec '17

Created a boost::priority_queue with my comparison operation defined. Here is how my priority_queue looks, boost::heap::priority_queue<myObject*, boost::heap::compare<myObjectPtrCompare> > max_heap; My comparison is defined as, struct myObjectPtrCompare{ bool operator()(const myObject* lhs, const myObject* rhs) const { return (lhs->getTime() < rhs->getTime()); }}; I have used it as, myObject* obj1 = static_cast<myObject*>(base1); 'base1' is an object of class 'myBase'(base class of myObject) myObject and getTime() within it used for comparision are defined as, class myObject : public myBase { Time getTime() const { return time; }... ...} Compiling this gives me this error, c:\Projects\pq_test.cpp(27): error C2662: 'void boost::heap::priority_queue<myObject*,boost::heap::compare<myObjectPtrCompare>,boost::parameter::void_,boost::parameter::void_,boost::parameter::void_>::push(myObject *const &)' : cannot convert 'this' pointer from 'const boost::heap::priority_queue<myObject *,boost::heap::compare<myObjectPtrCompare>,boost::parameter::void_,boost::parameter::void_,boost::parameter::void_>' to 'boost::heap::priority_queue<myObject *,boost::heap::compare<myObjectPtrCompare>,boost::parameter::void_,boost::parameter::void_,boost::parameter::void_> &'1> Conversion loses qualifiers Using Visual Studio 2013 C++. I understand that I am doing something wrong with const correctness, but I am not able to figure out what is wrong. Any help is appreciated. TIA!

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boost::priority_queue const correctness problem, help needed
by Ram 08 Dec '17

08 Dec '17

Created a boost::priority_queue with my comparison operation defined. Here is how my priority_queue looks, boost::heap::priority_queue<myObject*, boost::heap::compare<myObjectPtrCompare> > max_heap; boost::heap::priority_queue<myObject*, boost::heap::compare<myObjectPtrCompare> > max_heap; My comparison is defined as, struct myObjectPtrCompare { bool operator()(const myObject* lhs, const myObject* rhs) const { return (lhs->getTime() < rhs->getTime()); } }; I have used it as, myObject* obj1 = static_cast<myObject*>(base1); 'base1' is an object of class 'myBase'(base class of myObject) myObject and getTime() within it used for comparision are defined as, class myObject : public myBase { Time getTime() const { return time; } .... } Compiling this gives me this error, c:\Projects\pq_test.cpp(27): error C2662: 'void boost::heap::priority_queue<myObject*,boost::heap::compare<myObjectPtrCompare>,boost::parameter::void_,boost::parameter::void_,boost::parameter::void_>::push(myObject *const &)' : cannot convert 'this' pointer from 'const boost::heap::priority_queue<myObject *,boost::heap::compare<myObjectPtrCompare>,boost::parameter::void_,boost::parameter::void_,boost::parameter::void_>' to 'boost::heap::priority_queue<myObject *,boost::heap::compare<myObjectPtrCompare>,boost::parameter::void_,boost::parameter::void_,boost::parameter::void_> &' 1> Conversion loses qualifiers Using Visual Studio 2013 C++. I understand that I am doing something wrong with const correctness, but I am not able to figure out what is wrong. Any help is appreciated. TIA!

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boost.test fails to zip custom datasets
by Georgios Sermaidis 08 Dec '17

08 Dec '17

I am trying to understand how to use datasets with the boost.test library. I am following the documentation here <http://www.boost.org/doc/libs/1_65_1/libs/test/doc/html/boost_test/tests_or…> and have created my dataset as follows: namespace bdata = boost::unit_test::data; struct test_set { class iterator { int m_a; public: iterator() : m_a(0){} void operator++() { ++m_a; } int operator*() const { return m_a; } }; using sample = int; enum {arity = 1}; auto begin() const { return iterator{}; } bdata::size_t size() const { return 5; // let's assume only 5 numbers } }; namespace boost { namespace unit_test { namespace data { namespace monomorphic { template <> struct is_dataset<test_set> : std::true_type{}; }}}} which is very simple and iterates numbers from 0 to 4. The following simple test compiles and runs just fine: // this works as expected and prints 0, 1, 2, 3, 4 BOOST_DATA_TEST_CASE( example_test1, test_set(), my_datum) { std::cout << my_datum << std::endl; } However, when I try to zip <http://www.boost.org/doc/libs/1_65_1/libs/test/doc/html/boost_test/tests_or…> two such datasets it fails to compile (Apple LLVM version 9.0.0 (clang-900.0.38)): // error: invalid operands to binary expression ('typename data::result_of::make<test_set>::type' (aka 'test_set') and 'test_set') test_set() ^ test_set(), // ~~~~~~~~~~~^~~~~~~~~~~~~ BOOST_DATA_TEST_CASE( example_test2, test_set() ^ test_set(), my_datum1, my_datum2) { std::cout << my_datum1 << " " << my_datum2 << std::endl; } Is what I am trying to do legal? If so, what is the correct way to achieve it? Thank you for your help! Live code here <https://wandbox.org/permlink/6CI286mynvVCjQdW>

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Easy install doesn't
by Jean-Louis Leroy 07 Dec '17

07 Dec '17

I downloaded the current version of boost from here: http://www.boost.org/users/download/ (the Unix tgz) Then I religiously followed these instructions: http://www.boost.org/doc/libs/1_61_0/more/getting_started/unix-variants.htm… It didn't install much of anything useful...just stuff in /usr/local/share/boost-build, apparently the build system. No headers were installed, no libs were built or installed... I tried to install from debian packages and that failed miserably too but that's another story... Help please?

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[iostreams] file_descriptor doesn't retry on EINTR
by David Roberts 30 Nov '17

30 Nov '17

Hi, I have found that the file_descriptor class in Boost.Iostreams does not retry on EINTR. The relevant code is in libs/iostreams/src/file_descriptor.cpp. A bug was raised for this 7 years ago: https://svn.boost.org/trac10/ticket/4913 <https://svn.boost.org/trac10/ticket/4913> There is a patch attached to that bug that makes the file_descriptor_impl::read method retry on EINTR. If something like this were implemented then something similar should also be done to retry in the file_descriptor_impl::write method. I could have a go at submitting a PR to make both the read and write methods retry if interrupted. But before I do this, is there any other history I should be aware of, like a good reason why EINTR is not currently handled? Many thanks, David

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boost::asio::buffer bug with string literal
by Martijn Otto 29 Nov '17

29 Nov '17

When using boost::asio::buffer with a string literal the terminating null character is included in the buffer size, leading to bugs like accidentally sending out a null character. We could fix this by adding something like this to buffer.hpp: /// Create a new non-modifiable buffer that represents the given character array. /** * @returns A const_buffer value equivalent to: * @code const_buffer( * static_cast<const void*>(data), * (N - 1) * sizeof(char)); @endcode */ template <std::size_t N> inline BOOST_ASIO_CONST_BUFFER buffer( const char (&data)[N]) BOOST_ASIO_NOEXCEPT { return BOOST_ASIO_CONST_BUFFER(data, (N - 1) * sizeof(char)); } But this might cause trouble when using a const char array that is not null-terminated, since we then basically drop the last character. Would this be the best approach?

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[Spirit.Qi] failing to parse IP address octets
by Michael Powell 27 Nov '17

27 Nov '17

Hello, I've got the following parsers which are failing to find the correct attributes. I tried to parse in terms of uint_parser<uint8_t, 10, 1, 3>() at first, but this was not working properly. So I tried the following: _octet_rule = lexeme[ char_('0') | (char_('1') >> -(digit >> -digit)) | (char_('2') >> -((char_('0', '4') >> -(digit)) | (char_('5') >> -(char_('0', '5'))) | char_('6', '9') ) ) | (char_('3', '9') >> -digit) ]; Which is presently failing to find all three digits in the "20\d"-"24\d" use case. Octet itself parses correctly when I use this rule: _octet_rule >> !(char_); My octet test cases verify the entire range of 0-255 successfully, as well as the following invalid cases: VerifyOctet(-1, invalid_); VerifyOctet(1990, invalid_); VerifyOctet(2550, invalid_); VerifyOctet("255.", invalid_); VerifyOctet(256, invalid_); VerifyOctet(999, invalid_); VerifyOctet("abc", invalid_); VerifyOctet(123.456, invalid_); Converted to corresponding string, i.e. "1990" or "123.456". But when I combine that into the IP address rule, the test results occur: _octet_rule >> repeat(3)[char_('.') >> _octet_rule]; And the test results: CHECK_THAT( y, Equals(x) ) with expansion: "145.23.183.47" equals: "145.231.183.47" with message: Verifying address >>> 145.231.183.47 <<< FAILED: CHECK_THAT( y, Equals(x) ) with expansion: "189.21.29.11" equals: "189.211.29.11" with message: Verifying address >>> 189.211.29.11 <<< FAILED: CHECK_THAT( y, Equals(x) ) with expansion: "90.60.32.24" equals: "90.60.32.246" with message: Verifying address >>> 90.60.32.246 <<< FAILED: CHECK_THAT( y, Equals(x) ) with expansion: "22.59.144.140" equals: "223.59.144.140" with message: Verifying address >>> 223.59.144.140 <<< IP address test data is randomly generated, or combinatorially if I wanted to wait for all 4.3B or so test cases. However, I figure that as long as the Octet rule is working, it is reasonable to expect the Address rule may also work. Not sure why those last digits are being dropped, however. Or how the 1's can succeed where the 2's are failing. Any suggestions, Spirit folks? Thanks! Cheers, Michael Powell

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[serialization] property_tree::ptree bpta back-end, json, forward (upward) compatibility
by Sergey Spiridonov 27 Nov '17

27 Nov '17

Hi Current binary, text and xml archive back-ends allow to implement backward compatibility. This means that it is possible to read old serialization files with the new version of the serialization code, with the help of the version of the class which is stored in archive itself. Unfortunately forward compatibility is not possible to implement with the existing archive backends. Suppose we have class A with one field. struct A { template<class Archive> inline void serialize(Archive & ar, const unsigned int version ) { ar & BOOST_SERIALIZATION_NVP(field); } int field; }; Later we want to add a new field2. To be able to load the previously created file we need can use versioning. struct A { template<class Archive> inline void serialize(Archive & ar, const unsigned int version ) { ar & BOOST_SERIALIZATION_NVP(field); if(version > 0) { ar & BOOST_SERIALIZATION_NVP(field2); } } int field; int field2; }; BOOST_CLASS_VERSION(A, 1) But if we want the opposite, to load the old class from the file which was created from the new class (for example, if we use serialization to communicate between new and old version of application on the network), existing backends will fail. Why? The reason is that they expect certain field in certain order and do not allow unexpected unknown fields. Although with text and binary backend it is difficult to do, because field names are not stored, but xml backend has names for every field, so it can simply skip unknown fields. Unfortunately this is not implemented. I created [1] simple experimental archive which allows forward(upward) compatibility. It stores data in boost::property_tree::ptree (instead of std::stream), which, in turn, can be saved to json, if necessary. If the file which is loaded, has additional unknown fields (from future version), they will be ignored. [1] https://github.com/sena73/ptree_archive Intermediate storage of data in ptree has its advantages and disadvantages. Of course, this slows down things and requires more memory. On other hand, it allows to get upward compatibility automatically easily and even to process data before (or without) loading it into the target class. Also we get json and info storage for free. With little modification xml backend from property_tree can be used. Sure, it must be possible to create a version of boost::archive::xml which will be also capable to keep upward compatibility without necessity to load things into the property_tree first. Binary and text archives must be extended with field names to allow field skipping. -- Best regards, Sergey Spiridonov

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[release] Boost 1.66.0 Beta 1
by Daniel James 24 Nov '17

24 Nov '17

Boost release 1.66.0 beta 1 is now available at: <https://dl.bintray.com/boostorg/beta/1.66.0.beta.1/source/> The SHA256 checksums are as follows: e7b23e638e8c3a9da1512439385b04850829cea7bd56d8398677c096857d830b boost_1_66_0_b1.7z 5d0405eb73bd609ebcd54bbc96d4f1e2d97c51b96c4703706695ddd94f942d6b boost_1_66_0_b1.tar.bz2 f0f455e39bc47b2b670a17cb221687506e9a22dc478956d3d8aabb9cb835a7dc boost_1_66_0_b1.tar.gz 694c8b9e902b7981670bce166f675f3875c19326936db51aabd98d2ddfea9b45 boost_1_66_0_b1.zip For details of what's in the release, see <http://www.boost.org/users/history/version_1_66_0.html>. Please download the beta, give it a try, and report any problems you encounter. Thanks, -- The Boost Release Team

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how to build boost binary libraries for GCC in windows 10
by Renfan Luo 23 Nov '17

23 Nov '17

Hi All As VS supports OpenMP2.0 only, I have to use GCC instead for my project with parallelisation in coding. I have downloaded Cygwin and installed the GCC 6.4.0 then updated it to the latest version 5.5.0 on my windows 10. All those binary libraries I built up in VS 2017, I guess, cannot be usable for GCC, so it may be necessary to rebuild them for boost 1.65.1 for GCC. Could you guys show me how to build them? Cheers Renfan

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function template argument deduction with std::tuple
by Ireneusz Szcześniak 23 Nov '17

23 Nov '17

Hi, I have a problem related to function template argument deduction with std::tuple (with boost::tuple too). I attach a file with the complete source you can compile. Below I describe the code. I have a template function declaration: > template <typename T> > auto > get_cost(const T &); Then I define my template types: > template <typename Graph> > using Vertex = typename Graph::vertex_descriptor; > > template <typename Graph> > using Label = std::tuple<Vertex<Graph>>; I define the specialization of the get_cost function for the Label type: > template <typename Graph> > auto > get_cost(const Label<Graph> &l) > { > return std::get<0>(l); > } I can define alright a variable of type Label: > struct graph > { > using vertex_descriptor = unsigned; > }; > > Label<graph> l; But I cannot use the templated function: > get_cost(l); I get this error: > error: use of 'auto get_cost(const T&) [with T = > std::tuple<unsigned int>]' before deduction of 'auto' I got this error with GCC HEAD 8.0.0 20171113 and Clang HEAD 6.0.0 (I used wandbox.org) Some other type definitions and their specializations of the get_cost function compile. For a struct derived from the std::tuple: > template <typename Graph> > struct Label1: std::tuple<Vertex<Graph>> > { > }; > > template <typename Graph> > auto > get_cost(const Label1<Graph> &l) > { > return std::get<0>(l); > } For a member of type std::tuple: > template <typename Graph> > struct Label2 > { > std::tuple<Vertex<Graph>> t; > }; > > template <typename Graph> > auto > get_cost(const Label2<Graph> &l) > { > return std::get<0>(l.t); > } For a member of type Vertex<Graph>: > template <typename Graph> > struct Label3 > { > Vertex<Graph> m_v; > }; > > template <typename Graph> > auto > get_cost(const Label3<Graph> &l) > { > return l.m_v; > } I would like to use the Label type, i.e., because it has the constructor and operators already defined, which I need. I would appreciate it if someone could explain what is going wrong here. Best, Irek

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Building b2 --prefix include directory not quite
by Michael Powell 22 Nov '17

22 Nov '17

Hello, So the B2 help indicates that the include directory should be whatever "<prefix>/include" is. So, I'm setting my prefix accordingly, something like, "/path/to/installed/boost-1.65.1", however, the include directory ends up being something a little more like this: "/path/to/installed/boost-1.65.1/include/boost-1_65_1". This looks like a bug to me. Can I set the --includedir myself and correct this during my build? Thank you... Cheers, Michael Powell

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[Interprocess] Waiting thread termination causes deadlock
by Markus Bonk 22 Nov '17

22 Nov '17

Hi, I am having issues with boost::interprocess::ipcdetail::spin_condition::do_wait_timed deadlocking. The issue occurs when a thread that is waiting due to a call to interprocess_condition_any::wait() terminates unexpectedly and interprocess_condition_any::notify_all() is called (from any process). The cause of the deadlock is not that the terminating thread held a lock – it doesn’t because it is waiting, but that spin_condition::m_num_waiters is never decremented to zero because one of the threads is no longer waiting and so the enter mutex is not freed. I have tried BOOST_INTERPROCESS_ENABLE_TIMEOUT_WHEN_LOCKING, however as far as I can see this only tells me that the deadlock is there. Are there any suggestions how I can recover from spin_condition not freeing the enter mutex? Or perhaps some way of avoiding the issue? Markus ________________________________ Markus Bonk Senior Software Engineer [cid:image19ab5c.GIF@24a568cc.448b8dc0] 3Dconnexion GmbH Clarita-Bernhard-Str. 18 81249 München Germany Tel: +49 (89) 897 45 42 - 70 Fax: +49 (89) 897 45 42 - 50 markus_bonk(a)3dconnexion.com<mailto:markus_bonk@3dconnexion.com> www.3dconnexion.com<http://www.3dconnexion.com> Geschäftsführer: Antonio Pascucci Sitz der Gesellschaft: München Registergericht: München HRB 99232

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Adding Lzma support to b2 invocation
by Michael Powell 22 Nov '17

22 Nov '17

Hello, So I've got LZMA downloading, have the include in hand, as well as what I presume are either object files and/or a DLL. Just need to know how to integrate that with my B2 invocation. Something like: -sLZMA_INCLUDE="/path/to/lzma/include" ? And then, how to include the object file with the linkage, or the DLL(s). And necessarily in which architecture/address-model. Otherwise, I am getting close to building. Around the corner from that is Locale support from ICU (?), which I've got downloading as well ATM. Cheers, Michael Powell

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Re: [Boost-users] Building boost b2 lzma options
by Michael Powell 21 Nov '17

21 Nov '17

Next errors seem to be lzma related. Is this along the same lines as with Zlib and bzip2? To avoid confusion, this is 1.65.1, as well; not the announced 1.66. Thanks! On Mon, Nov 20, 2017 at 1:41 PM, Nelson, Erik - 2 via Boost-users <boost-users(a)lists.boost.org> wrote: > Michael Powell Sent: Monday, November 20, 2017 1:24 PM >> >> I am building Boost and making progress. Thus far wondering what >> >> options to provide my B2. I added the zlib include path to the >> >> include="...;/path/to/zlib;...", and now seems to be wanting the LIB >> >> path? > > I use > > "-sBZIP2_SOURCE=/path/to/bzip2/src" "-sZLIB_SOURCE=/path/to/zlib/src" > > And it adds the source to the build. > > ---------------------------------------------------------------------- > This message, and any attachments, is for the intended recipient(s) only, may contain information that is privileged, confidential and/or proprietary and subject to important terms and conditions available at http://www.bankofamerica.com/emaildisclaimer. If you are not the intended recipient, please delete this message. > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > https://lists.boost.org/mailman/listinfo.cgi/boost-users

3 5

Building boost b2 zlib options
by Michael Powell 20 Nov '17

20 Nov '17

Hello, I am building Boost and making progress. Thus far wondering what options to provide my B2. I added the zlib include path to the include="...;/path/to/zlib;...", and now seems to be wanting the LIB path? LINK : fatal error LNK1181: cannot open input file 'z.lib' LINK : fatal error LNK1181: cannot open input file 'zlib.lib' LINK : fatal error LNK1181: cannot open input file 'zll.lib' LINK : fatal error LNK1181: cannot open input file 'zdll.lib' Which option is that for B2? After that, it is on to finding bzip? fatal error C1083: Cannot open include file: 'bzlib.h': No such file or directory Is there a source download similar to that of zlib? I think I'm pretty close but for a handful of obscurish third party dependencies. Thanks! Cheers, Michael Powell

4 9

Could guys help on OpenMP odeint 'for' statement error
by Renfan Luo 20 Nov '17

20 Nov '17

Hi All I have just started an OpenMP application example in VS2017 platform (/* Boost libs/numeric/odeint/examples/openmp/lorenz_ensemble_simple.cpp). When switch on Properties->C/C++->Language->Open MP Support-> Yes (/openmp), it has a build error Severity Code Description Project File Line Suppression State Error C3016 'i': index variable in OpenMP 'for' statement must have signed integral type OpenMP-test1 c:\users\renfanluo\source\repos\openmp-test1\openmp-test1\openmptest1.cpp 35 If When switch off Properties->C/C++->Language->Open MP Support-> Yes (/openmp) to No (/openmp), then the error goes off. However, "No" means OpenMP is switched off, which is not what I want. It is understood that in the for statement, the variables can be assigned with data type before, the errors associated with these user defined for statement will go off but the similar error shown below remain the same for boost header files. Severity Code Description Project File Line Suppression State Error C3016 'i': index variable in OpenMP 'for' statement must have signed integral type Test-OpenMP2 C:\boost_1_65_1\boost\numeric\odeint\external\openmp\openmp_range_algebra.hpp 72 Could you guys have any ideas of how to fix this problem? Best regards Renfan

1 0

[python::numpy] Access Violation when initializing numpy
by Christian Henning 18 Nov '17

18 Nov '17

Hi all, On Windows 10 with Visual Studio 2017 I', trying to run the following code in x64 debug configuration: #include <iostream> #include <boost/python.hpp> #include <boost/python/numpy.hpp> namespace p = boost::python; namespace np = boost::python::numpy; int main() { Py_Initialize(); np::initialize(); p::tuple shape = p::make_tuple(3, 3); np::dtype dtype = np::dtype::get_builtin<float>(); np::ndarray a = np::zeros(shape, dtype); return 0; } In the line np::initialize(); I'm getting a Exception thrown at 0x0000000066E43B15 (python36.dll) in test.exe: 0xC0000005: Access violation reading location 0x0000000000000025. occurred Inside boost::python::numpy::intialize() the exception is thrown when trying to execute the line: PyObject *numpy = PyImport_ImportModule("numpy.core.multiarray"); Does anyone know why that would happen or how to debug the issue further? I have installed all packages via pip and executed the python code as described in https://www.scipy.org/getting-started.html. Thanks ahead! Christian

1 1

[python] Linker error when initializing numpy
by Christian Henning 18 Nov '17

18 Nov '17

Hi all, I have the latest boost from the master branch and built everything including python. I can see that two python related libs were built: libboost_python3-vc141-mt-gd-x64-1_66.lib libboost_numpy3-vc141-mt-gd-x64-1_66.lib For compiling python I use vcpkg and it's generating python3_d.lib for debug and python3.lib for release. The cpp code I like to compile is: #include <iostream> #include <boost/python.hpp> #include <boost/python/numpy.hpp> namespace p = boost::python; namespace np = boost::python::numpy; int main() { Py_Initialize(); np::initialize(); return 0; } A few issues: 1) linker is looking for "boost_python3-vc141-mt-gd-x64-1_66.lib" but I got "libboost_python3-vc141-mt-gd-x64-1_66.lib" Please tell me how to fix that. For now I just copied the libboost* files and renamed them. 2) Linker error: "__declspec(dllimport) void __cdecl boost::python::numpy::initialize(bool)" How can I resolve that? Thanks, Christian

4 6

Conan-center package.
by Philippe Groarke 17 Nov '17

17 Nov '17

Are there any plans to release an official Boost package on Conan-Center? If not, any specific reason? It would really help Windows builds and facilitate enterprise adoption. Thank you & good day.

1 0

Weird compilation error when using boost::geometry
by 邓尧 16 Nov '17

16 Nov '17

Hi, I have implemented my own "point" as specified by the point concept http://www.boost.org/doc/libs/1_59_0/libs/geometry/doc/html/geometry/refere… When I use it along with boost::geometry::model::polygon/multi_polygon, GCC refuses to compile, tested on GCC 4.9/5.2. What's even more weird is that CLANG 3.6 would happy accept my code. BTW, the Point implementation is part of a large project, it difficult to replace it with boost::geometry::model::point. Here is my code: Point.hpp > #ifndef RAPTOR_POINT_HPP_INCLUDED_ > > #define RAPTOR_POINT_HPP_INCLUDED_ > > >> #include <boost/mpl/int.hpp> > > #include <boost/geometry/core/access.hpp> > > #include <boost/geometry/core/cs.hpp> > > #include <boost/geometry/core/coordinate_type.hpp> > > #include <boost/geometry/core/coordinate_system.hpp> > > #include <boost/geometry/core/coordinate_dimension.hpp> > > #include <boost/geometry/geometries/polygon.hpp> > > #include <boost/geometry/multi/geometries/multi_polygon.hpp> > > >> namespace raptor { > > >> template<typename T, int tDimension = 2> > > class Point { > > public: > > Point() = default; > > >> Point(T a, T b) { > > data[0] = a; > > data[1] = b; > > } > > >> Point(T a, T b, T c) { > > data[0] = a; > > data[1] = b; > > data[2] = c; > > } > > >> T& operator [] (long index) { > > return data[index]; > > } > > >> const T& operator [] (long index) const { > > return data[index]; > > } > > >> private: > > T data[tDimension]; > > }; > > >> using CubicPoint = Point<long, 3>; > > using PlanarPoint = Point<long>; > > using SphericalPoint = Point<double>; > > >> template<typename T> > > using Polygon = boost::geometry::model::polygon<T>; > > >> template<typename T> > > using PolySet = boost::geometry::model::multi_polygon<Polygon<T>>; > > >> } // namespace raptor > > >> namespace boost { namespace geometry { namespace traits { > > >> template<typename Type, std::size_t tDimension> > > struct tag<::raptor::Point<Type, tDimension>> { > > typedef point_tag type; > > }; > > >> template<typename Type, std::size_t tDimension> > > struct coordinate_type<::raptor::Point<Type, tDimension>> { > > typedef Type type; > > }; > > >> template<typename Type, std::size_t tDimension> > > struct coordinate_system<::raptor::Point<Type, tDimension>> { > > typedef boost::geometry::cs::cartesian type; > > }; > > >> template<typename Type, std::size_t tDimension> > > struct dimension<::raptor::Point<Type, tDimension>> > > : public boost::mpl::int_<tDimension> { > > // EMPTY > > }; > > >> template<typename Type, std::size_t tDimension, std::size_t tIndex> > > struct access<::raptor::Point<Type, tDimension>, tIndex> { > > static Type get(const ::raptor::Point<Type, tDimension>& p) { > > return p[tIndex]; > > } > > >> static void set(::raptor::Point<Type, tDimension>& p, > > const Type& value) { > > p[tIndex] = value; > > } > > }; > > >> }}} // namespace boost::geometry::traits > > >> #endif // RAPTOR_POINT_HPP_INCLUDED_ > > A real simple main.cpp: > #include "Point.hpp" > > >> int main() { > > raptor::Polygon<raptor::SphericalPoint> pl; > > raptor::PolySet<raptor::SphericalPoint> set; > > return sizeof(pl) + sizeof(set); > > } > > > GCC compilation error: g++ main.cpp -std=c++14 > In file included from /usr/include/boost/geometry/core/access.hpp:20:0, from Point.hpp:5, from main.cpp:1: /usr/include/boost/geometry/core/point_type.hpp: In instantiation of > 'struct boost::geometry::traits::point_type<raptor::Point<double> >': /usr/include/boost/geometry/core/point_type.hpp:66:17: required from > 'struct boost::geometry::core_dispatch::point_type<void, > raptor::Point<double> >' /usr/include/boost/geometry/core/coordinate_type.hpp:58:62: required from > 'struct boost::geometry::core_dispatch::coordinate_type<void, > raptor::Point<double> >' /usr/include/boost/geometry/core/coordinate_type.hpp:92:25: required from > 'struct boost::geometry::coordinate_type<raptor::Point<double> >' /usr/include/boost/geometry/geometries/concepts/point_concept.hpp:90:54: > required from 'class boost::geometry::concept::Point<raptor::Point<double> > >' /usr/include/boost/concept/detail/has_constraints.hpp:32:62: required by > substitution of 'template<class Model> boost::concepts::detail::yes > boost::concepts::detail::has_constraints_(Model*, > boost::concepts::detail::wrap_constraints<Model, (& Model:: constraints)>*) > [with Model = boost::geometry::concept::Point<raptor::Point<double> >]' /usr/include/boost/concept/detail/has_constraints.hpp:42:5: required from > 'const bool > boost::concepts::not_satisfied<boost::geometry::concept::Point<raptor::Point<double> > > >::value' /usr/include/boost/concept/detail/has_constraints.hpp:45:31: required > from 'struct > boost::concepts::not_satisfied<boost::geometry::concept::Point<raptor::Point<double> > > >' /usr/include/boost/mpl/if.hpp:67:11: required from 'struct > boost::mpl::if_<boost::concepts::not_satisfied<boost::geometry::concept::Point<raptor::Point<double> > > >, > boost::concepts::constraint<boost::geometry::concept::Point<raptor::Point<double> > > >, boost::concepts::requirement<boost::concepts::failed************ > boost::geometry::concept::Point<raptor::Point<double> >::************> >' /usr/include/boost/concept/detail/general.hpp:50:8: required from 'struct > boost::concepts::requirement_<void > (*)(boost::geometry::concept::Point<raptor::Point<double> >)>' /usr/include/boost/geometry/geometries/ring.hpp:60:5: required from > 'class boost::geometry::model::polygon<raptor::Point<double>, true, true, > std::vector, std::vector, std::allocator, std::allocator>' main.cpp:4:42: required from here /usr/include/boost/geometry/core/point_type.hpp:45:5: error: no matching > function for call to 'assertion_failed(mpl_::failed************ > (boost::geometry::traits::point_type<raptor::Point<double> > >::NOT_IMPLEMENTED_FOR_THIS_POINT_TYPE::************)(mpl_::assert_::types<raptor::Point<double>, > mpl_::na, mpl_::na, mpl_::na>))' BOOST_MPL_ASSERT_MSG ^ /usr/include/boost/mpl/assert.hpp:82:5: note: candidate: template<bool C> > int mpl_::assertion_failed(typename mpl_::assert<C>::type) int assertion_failed( typename assert<C>::type ); ^ /usr/include/boost/mpl/assert.hpp:82:5: note: template argument > deduction/substitution failed: /usr/include/boost/geometry/core/point_type.hpp:45:5: note: cannot > convert > 'boost::geometry::traits::point_type<Geometry>::NOT_IMPLEMENTED_FOR_THIS_POINT_TYPE48::assert_arg<raptor::Point<double> > >()' (type 'mpl_::failed************ > (boost::geometry::traits::point_type<raptor::Point<double> > >::NOT_IMPLEMENTED_FOR_THIS_POINT_TYPE::************)(mpl_::assert_::types<raptor::Point<double>, > mpl_::na, mpl_::na, mpl_::na>)') to type 'mpl_::assert<false>::type {aka > mpl_::assert<false>}' BOOST_MPL_ASSERT_MSG ^ In file included from > /usr/include/boost/geometry/core/coordinate_type.hpp:21:0, from /usr/include/boost/geometry/core/access.hpp:24, from Point.hpp:5, from main.cpp:1: /usr/include/boost/geometry/core/point_type.hpp: In instantiation of > 'struct boost::geometry::core_dispatch::point_type<void, > raptor::Point<double> >': /usr/include/boost/geometry/core/coordinate_type.hpp:58:62: required from > 'struct boost::geometry::core_dispatch::coordinate_type<void, > raptor::Point<double> >' /usr/include/boost/geometry/core/coordinate_type.hpp:92:25: required from > 'struct boost::geometry::coordinate_type<raptor::Point<double> >' /usr/include/boost/geometry/geometries/concepts/point_concept.hpp:90:54: > required from 'class boost::geometry::concept::Point<raptor::Point<double> > >' /usr/include/boost/concept/detail/has_constraints.hpp:32:62: required by > substitution of 'template<class Model> boost::concepts::detail::yes > boost::concepts::detail::has_constraints_(Model*, > boost::concepts::detail::wrap_constraints<Model, (& Model:: constraints)>*) > [with Model = boost::geometry::concept::Point<raptor::Point<double> >]' /usr/include/boost/concept/detail/has_constraints.hpp:42:5: required from > 'const bool > boost::concepts::not_satisfied<boost::geometry::concept::Point<raptor::Point<double> > > >::value' /usr/include/boost/concept/detail/has_constraints.hpp:45:31: required > from 'struct > boost::concepts::not_satisfied<boost::geometry::concept::Point<raptor::Point<double> > > >' /usr/include/boost/mpl/if.hpp:67:11: required from 'struct > boost::mpl::if_<boost::concepts::not_satisfied<boost::geometry::concept::Point<raptor::Point<double> > > >, > boost::concepts::constraint<boost::geometry::concept::Point<raptor::Point<double> > > >, boost::concepts::requirement<boost::concepts::failed************ > boost::geometry::concept::Point<raptor::Point<double> >::************> >' /usr/include/boost/concept/detail/general.hpp:50:8: required from 'struct > boost::concepts::requirement_<void > (*)(boost::geometry::concept::Point<raptor::Point<double> >)>' /usr/include/boost/geometry/geometries/ring.hpp:60:5: required from > 'class boost::geometry::model::polygon<raptor::Point<double>, true, true, > std::vector, std::vector, std::allocator, std::allocator>' main.cpp:4:42: required from here /usr/include/boost/geometry/core/point_type.hpp:66:17: error: no type named > 'type' in 'struct boost::geometry::traits::point_type<raptor::Point<double> > >' >::type type; ^ In file included from > /usr/include/boost/geometry/geometries/polygon.hpp:26:0, from Point.hpp:10, from main.cpp:1: /usr/include/boost/geometry/geometries/concepts/point_concept.hpp: In > instantiation of 'class > boost::geometry::concept::Point<raptor::Point<double> >': /usr/include/boost/concept/detail/has_constraints.hpp:32:62: required by > substitution of 'template<class Model> boost::concepts::detail::yes > boost::concepts::detail::has_constraints_(Model*, > boost::concepts::detail::wrap_constraints<Model, (& Model:: constraints)>*) > [with Model = boost::geometry::concept::Point<raptor::Point<double> >]' /usr/include/boost/concept/detail/has_constraints.hpp:42:5: required from > 'const bool > boost::concepts::not_satisfied<boost::geometry::concept::Point<raptor::Point<double> > > >::value' /usr/include/boost/concept/detail/has_constraints.hpp:45:31: required > from 'struct > boost::concepts::not_satisfied<boost::geometry::concept::Point<raptor::Point<double> > > >' /usr/include/boost/mpl/if.hpp:67:11: required from 'struct > boost::mpl::if_<boost::concepts::not_satisfied<boost::geometry::concept::Point<raptor::Point<double> > > >, > boost::concepts::constraint<boost::geometry::concept::Point<raptor::Point<double> > > >, boost::concepts::requirement<boost::concepts::failed************ > boost::geometry::concept::Point<raptor::Point<double> >::************> >' /usr/include/boost/concept/detail/general.hpp:50:8: required from 'struct > boost::concepts::requirement_<void > (*)(boost::geometry::concept::Point<raptor::Point<double> >)>' /usr/include/boost/geometry/geometries/ring.hpp:60:5: required from > 'class boost::geometry::model::polygon<raptor::Point<double>, true, true, > std::vector, std::vector, std::allocator, std::allocator>' main.cpp:4:42: required from here /usr/include/boost/geometry/geometries/concepts/point_concept.hpp:93:10: > error: 'value' is not a member of > 'boost::geometry::dimension<raptor::Point<double> >' enum { ccount = dimension<Geometry>::value }; ^ Where is the problem ? or it's a GCC bug ? Thanks

3 4

Could guys help me on a boost MPI link error
by Renfan Luo 16 Nov '17

16 Nov '17

Hi All I have built boost binary library on my PC workstation in windows 10 using VS 2017 for boost 1.65.1 successfully for application of MPI in my project. I had a simple test for MPI which worked perfectly. So I moved to a further test using boost example "odeint-v2/examples/mpi/phase_chain.cpp", which is applied to solve ODE with MPI capacity. When I tried to build the project, it gives me an error Severity Code Description Project File Line Suppression State Error LNK1112 module machine type 'x86' conflicts with target machine type 'x64' MPI-test2 C:\Users\renfanluo\source\repos\MPI-test2\MPI-test2\libboost_mpi-vc141-mt-1_65_1.lib(environment.obj) 1 I googled, then I went to properties->Linker->Advanced->Target Machine, changed to "MachineX86 (/MACHINE:X86)", then rebuild the project, now the error changes to Severity Code Description Project File Line Suppression State Error LNK1112 module machine type 'x64' conflicts with target machine type 'x86' MPI-test2 C:\Users\renfanluo\source\repos\MPI-test2\MPI-test2\x64\Release\MPItest2.obj 1 So this shows that simply changing the target machine setting in VS will not work. Could you guys give me some indications of how to fix this problem. Best regards Renfan

2 1

Boost.Chrono custom I/O
by Leo Cacciari 15 Nov '17

15 Nov '17

Hi, I'm using boost.chrono in a project and I need some non-standard input-output. First of all, I need to print days as days. Consider the following code namespace testing { typedef boost::chrono::duration<long double,boost::ratio<86400>> day; } int main(int argc,char *argv[]) { using namespace testing; day d(10.5); std::cout << "Value: " << d << std::endl; } This prints Value: 10.5 [86400/1]seconds Which is obviously right; but I'd rather have: Value 10.5 days Obviously, a solution is to define operator<<(ostream&,const & day), however I'd rather use the facet approach, which looks like easier to extend to parsing and more flexible (e.g. allowing to print the above value as "10.5 days" somewhere and as "10.5 d" elsewhere.) If I understand the documentation, I must define a subclass of boost::chrono::duration_units and then imbue the facet into the stream. Is this right? Where can I found some guidelines on how to do that? Thanks for the help lc -- Leo Cacciari Aliae nationes servitutem pati possunt. Populi Romani est propria libertas.

1 0

[Beast] Problems in getting started with Beast
by Sharklaser Lasershark 14 Nov '17

14 Nov '17

Hello! I'm migrating a project from libcurl to Beast. I'm trying to compile http_client_async.cpp <https://github.com/boostorg/beast/blob/develop/example/http/client/async/ht…>, but 110 errors come from "file_win32.ipp" and "file_win32.hpp", mostly missing declarations and members. I'm using Visual Studio 2017 (warning level 4). Here is what I have done: 1. Downloaded and set up boost 1.65.1 according to the "getting started" tutorial <http://www.boost.org/doc/libs/1_65_1/more/getting_started/windows.html> - Built all binaries - Verified header only example and binary-dependent example 2. Downloaded beast/include/boost <https://github.com/boostorg/beast/tree/develop/include/boost> from GitHub and moved the folder and .hpp to - C:\Program Files\boost\boost_1_65_1\boost 3. Started an empty project and pasted in the http_client_async.cpp <https://github.com/boostorg/beast/blob/develop/example/http/client/async/ht…> example. I have spent too many days trying to get this up and running. Any help would be greatly appreciated! Kind regards

2 1

help on how to build mpi library
by Renfan Luo 14 Nov '17

14 Nov '17

I am a new user of boost and have downloaded 1.65.1 and unzipped it to my C:\local\boost_1_65_1. Then chose the "MPI nearest neighbour coupled phase chain." Example, file "phase_chain.cpp" as my first test in VS2015, I have got a link error message "Error LNK1104 cannot open file 'libboost_mpi-vc141-mt-1_65_1.lib" . I have checked the boost root directory and sub-directories and did not this library file. Hope guys can suggest how I build mpi library and install it to windows.

3 3

Customized installation
by mahmood n 11 Nov '17

11 Nov '17

Hi, It is possible to build one or two targets instead of all? When I run ../b2 install --prefix=/somewhere It build all libraries. Assume I only want filesystem. Is that possible or they all depend on each other? Regards, Mahmood

2 1

error categories point to invalid data with boost log and asio
by priv＠mariusherzog.net 11 Nov '17

11 Nov '17

I have the following problem while using boost asio together with boost log and clang 3.9.0. When I want to print an error code for example passed to me by a asio completion handler, my program crashes. This is because the error category points to invalid data. If I put a breakpoint in get_misc_error category which is called upon program startup, the local static error category already contains junk data. When I compile with gcc 5.4.0 this error does not occur. Also if I do not link against boost log everything works fine as well. I use linux, and link all boost libraries dynamically. Boost version is 1.62.0. Would it help if I maybe link boost log statically? Is there anything else I can do?

1 0

[signals2] Connect to overloaded slots
by Florian Lindner 10 Nov '17

10 Nov '17

Hello, this code compiles just fine: #include <boost/signals2.hpp> #include <iostream> // void slot() { std::cout << "No args slot called." << std::endl; } void slot(int i) { std::cout << "Int " << i << " arg slot called." << std::endl; } int main(int argc, char **argv) { boost::signals2::signal<void(int)> s; s.connect(&slot); return 0; } However, when I uncomment the slot() function, it does not do so, anymore: boostsignals.cpp:78:5: error: no matching member function for call to 'connect' s.connect(&slot); ~~^~~~~~~ /usr/include/boost/signals2/detail/signal_template.hpp:689:18: note: candidate function not viable: no overload of 'slot' matching 'const boost::signals2::signal<void (int), boost::signals2::optional_last_value<void>, int, std::less<int>, boost::function<void (int)>, boost::function<void (const boost::signals2::connection &, int)>, boost::signals2::mutex>::slot_type' (aka 'const slot<void (int), boost::function<void (int)> >') for 1st argument connection connect(const slot_type &slot, connect_position position = at_back) ^ /usr/include/boost/signals2/detail/signal_template.hpp:693:18: note: candidate function not viable: requires at least 2 arguments, but 1 was provided connection connect(const group_type &group, ^ Is there a way to make it working with overloaded slot functions? Thanks, Florian

2 1

(no subject)
by giridhar 08 Nov '17

08 Nov '17

Hi Boost http://bit.ly/2hcH687 giridhar

1 0

Warning "declares a non-template function"
by mahmood n 06 Nov '17

06 Nov '17

Hi, A program needs boost > 1.58. So, I used boost-1.60 with gcc-4.8. However, as I compile the program, I get many warnings similar to /home/mahmood/boost_1_60_0/boost/mpl/set/aux_/item.hpp(47): warning: "char (&operator||(const boost::mpl::s_item<T, Base> &, boost::mpl::aux::type_wrapper<T> *))[boost::mpl::next<Base::order>::type::value]" declares a non-template function -- add <> to refer to a template instance /home/mahmood/boost_1_60_0/boost/mpl/set/aux_/item.hpp(48): warning: "boost::mpl::aux::no_tag operator%(const boost::mpl::s_item<T, Base> &, boost::mpl::aux::type_wrapper<T> *)" declares a non-template function -- add <> to refer to a template instance Lines are BOOST_MPL_AUX_SET_OVERLOAD( order_tag_, ORDER_BY_KEY, s_item, aux::type_wrapper<T>* ); BOOST_MPL_AUX_SET_OVERLOAD( aux::no_tag, IS_MASKED, s_item, aux::type_wrapper<T>* ); Does that mean I have to change that to aux::type_wrapper< >* ? Regards, Mahmood

2 1

Under ubuntu, How to purge default boost-v1.58 then switch to the built version without any damages?
by Alex Luya 06 Nov '17

06 Nov '17

Under ubuntu 16,04 I have*built latest boost 1.65**.1 like this*: |./bootstrap.sh --prefix=/usr/local ./b2 sudo ./b2 install sudo ldconfig ***then when building something against boost,I got the**se errors:* /usr/local/include/boost/serialization/access.hpp: In instantiation of ‘static void boost::serialization::access::serialize(Archive&, T&, unsigned int) [with Archive = boost::archive::text_oarchive; T = std::array<std::__cxx11::basic_string<char>, 10ul>]’: /usr/local/include/boost/serialization/serialization.hpp:68:22: required from ‘void boost::serialization::serialize(Archive&, T&, unsigned int) [with Archive = boost::archive::text_oarchive; T = std::array<std::__cxx11::basic_string<char>, 10ul>]’ /usr/local/include/boost/serialization/serialization.hpp:126:14: required from ‘void boost::serialization::serialize_adl(Archive&, T&, unsigned int) [with Archive = boost::archive::text_oarchive; T = std::array<std::__cxx11::basic_string<char>, 10ul>]’ /usr/local/include/boost/archive/detail/oserializer.hpp:150:40: required from ‘void boost::archive::detail::oserializer<Archive, T>::save_object_data(boost::archive::detail::basic_oarchive&, const void*) const [with Archive = boost::archive::text_oarchive; T = std::array<std::__cxx11::basic_string<char>, 10ul>]’ /usr/local/include/boost/archive/detail/oserializer.hpp:103:1: required from ‘class boost::archive::detail::oserializer<boost::archive::text_oarchive, std::array<std::__cxx11::basic_string<char>, 10ul> >’ /usr/local/include/boost/archive/detail/oserializer.hpp:255:13: required from ‘static void boost::archive::detail::save_non_pointer_type<Archive>::save_standard::invoke(Archive&, const T&) [with T = std::array<std::__cxx11::basic_string<char>, 10ul>; Archive = boost::archive::text_oarchive]’ /usr/local/include/boost/archive/detail/oserializer.hpp:310:22: required from ‘static void boost::archive::detail::save_non_pointer_type<Archive>::invoke(Archive&, const T&) [with T = std::array<std::__cxx11::basic_string<char>, 10ul>; Archive = boost::archive::text_oarchive]’ /usr/local/include/boost/archive/detail/oserializer.hpp:534:18: required from ‘void boost::archive::save(Archive&, T&) [with Archive = boost::archive::text_oarchive; T = const std::array<std::__cxx11::basic_string<char>, 10ul>]’ /usr/local/include/boost/archive/detail/common_oarchive.hpp:70:22: required from ‘void boost::archive::detail::common_oarchive<Archive>::save_override(T&) [with T = const std::array<std::__cxx11::basic_string<char>, 10ul>; Archive = boost::archive::text_oarchive]’ /usr/local/include/boost/archive/basic_text_oarchive.hpp:83:9: required from ‘void boost::archive::basic_text_oarchive<Archive>::save_override(T&) [with T = const std::array<std::__cxx11::basic_string<char>, 10ul>; Archive = boost::archive::text_oarchive]’ /usr/local/include/boost/archive/detail/interface_oarchive.hpp:70:9: required from ‘Archive& boost::archive::detail::interface_oarchive<Archive>::operator<<(const T&) [with T = std::array<std::__cxx11::basic_string<char>, 10ul>; Archive = boost::archive::text_oarchive]’ examples/user_code/openpose_recognition.cpp:867:89: required from here /usr/local/include/boost/serialization/access.hpp:116:9: error: ‘struct std::array<std::__cxx11::basic_string<char>, 10ul>’ has no member named ‘serialize’ t.serialize(ar, file_version); ^ compilation terminated due to -Wfatal-errors. Makefile:478: die Regel für Ziel „.build_release/examples/user_code/openpose_recognition.o“ scheiterte make: *** [.build_release/examples/user_code/openpose_recognition.o] Fehler 1 make: *** Auf noch nicht beendete Prozesse wird gewartet … | |*I think ubuntu is still use default boost that installed by apt-get,so I tried to pur**ge it * sudo apt-get purge libboost1.58-dev| *the output asks me to remove a lot of stuffs **that depend on libboost1.58-dev **like these:* Die folgenden Pakete wurden automatisch installiert und werden nicht mehr benötigt: docutils-common fltk1.3-doc fluid gazebo7 gazebo7-common gazebo7-plugin-base gir1.2-gtk-2.0 libapr1 libapr1-dev libaprutil1 libaprutil1-dev libarmadillo6 libassimp-dev libassimp3v5 libboost-atomic1.58.0 libboost-chrono1.58.0 libboost-context1.58.0 libboost-coroutine1.58.0 libboost-graph-parallel1.58.0 libboost-graph1.58.0 libboost-locale1.58.0 libboost-log1.58.0 libboost-math1.58.0 libboost-mpi-python1.58.0 libboost-mpi1.58.0 libboost-python1.58.0 libboost-random1.58.0 libboost-regex1.58.0 libboost-signals1.58.0 libboost-test1.58.0 libboost-thread1.58.0 libboost-timer1.58.0 libboost-tools-dev libboost-wave1.58.0 libboost1.58-tools-dev libbullet-dev libbulletcollision2.83.6 libbulletdynamics2.83.6 libbulletsoftbody2.83.6 libbz2-dev libcollada-dom2.4-dp-dev libcollada-dom2.4-dp0 libconsole-bridge-dev libconsole-bridge0.2v5 libcurl4-openssl-dev libdap-dev libdap17v5 libdapclient6v5 libdapserver7v5 libepsilon1 libflann-dev libflann1.8 libfltk-cairo1.3 libfltk-forms1.3 libfltk-images1.3 libfltk1.3-dev libfreeimage-dev libfreeimage3 libfreexl1 libgazebo7 libgdal-dev libgdal1i libgeos-3.5.0 libgeos-c1v5 libgeos-dev libgl2ps-dev libgtest-dev libgtk2.0-dev libgts-0.7-5 libgts-bin libgts-dev libhdf4-0-alt libhdf4-alt-dev libhdf5-mpi-dev libignition-math2 libignition-math2-dev libinput-dev libjs-jquery-ui libjsoncpp-dev libjxr0 libkmlbase1 libkmldom1 libkmlengine1 libldap2-dev liblinearmath2.83.6 liblog4cxx-dev liblog4cxx10-dev liblog4cxx10v5 liblz4-dev libminizip1 libnetcdf-c++4 libnetcdf-cxx-legacy-dev libnetcdf-dev libnetcdf11 libogdi3.2 libogre-1.9.0v5 libopenni-dev libopenni-sensor-pointclouds0 libopenni0 ....... ,and it may cause a lot of damage if continuing,so the question is |*How to purge default boost-v1.58 then switch to the built version without any damages?*|

3 2

[asio] Does ssl::stream allow multiple pending async operations?
by Phil Sean 06 Nov '17

06 Nov '17

The documentation for ssl::stream says: "Shared objects: Unsafe. The application must also ensure that all asynchronous operations are performed within the same implicit or explicit strand." Does this mean we have to wait for an async operation to finish before another is started (for read/read, read/write, and write/write)? (Async operations refer to async_read_some() and async_write_some(), not the composed operations.) If so, is the operation said to have finished when the handler is invoked or when the handler returns? That is: void handler( const boost::system::error_code& error, std::size_t bytes_transferred ) { // Does the operation finish here ... } // or here? If not, what's the difference between the async operations of ip::tcp::socket and ssl::stream then (as strand just avoids concurrency for the thread-unsafe)? I came across different views on this problem. This answer[1] suggests that simply using the same strand (ie. no concurrency) will suffice. Another one[2] says multiple pending asynchronous operations can be problematic for ssl::stream even if no concurrency occurs. Thanks. [1] https://stackoverflow.com/questions/27212123/executing-asynchronous-operati… [2] https://stackoverflow.com/questions/15352472/using-boosts-ssl-asio-code-asy…

4 5

Spirit: how to force backtracking
by Stian Zeljko Vrba 04 Nov '17

04 Nov '17

I have the following grammar rule: value = (int_ % ',') | *ascii::print; The intention is to parse either a comma-separated list of integers or a string. The rule as such fails in cases like "123ABC", which should be parsed as string. >From the description of the | operator, I would expect the parser to backtrack and try the other alternative when it sees that the first alternative does not match the input. However, I get a parse error instead (this rule is a part of a larger grammar), I guess because the first alternative matches the single integer but the rest of the grammar cannot be matched. How to rewrite the grammar to resolve this ambiguity, or force spirit to backtrack if the first alternative of 'value' cannot be matched?

3 3

[locale] how to read a local date from an istream?
by Frédéric 02 Nov '17

02 Nov '17

Hi, With boost::locale we can output a localized date: double d=...; std::cout<<boost::locale::as::date<<d; but how can I read a date from a string? std::cin>>boost::locale::as::date>>d; does not work. It stops reading at the first "/". For example, this small program #include <iostream> #include <sstream> #include <boost/locale/formatting.hpp> #include <boost/locale/generator.hpp> int main(int argc, char **argv) { boost::locale::generator gen; gen.categories(); auto loc = gen(""); double date = 5.; // default value to see if it changes std::istringstream iss("2/11/2017"); // November 1st, 2017 in French iss.imbue(loc); iss >> boost::locale::as::date >> boost::locale::as::local_time >> date; std::cout.imbue(loc); std::cout << "as_posix: " << boost::locale::as::posix << date << "\n" << "as_date: " << boost::locale::as::date << date << "\n"; return 0; } outputs as_posix: 2 as_date: 01/01/1970 instead of as_posix: 1509617233 (may be different) as_date: 02/11/2017 F

1 0

Re: [Boost-users] Many undefined references for libboost_filesystem
by mahmood n 01 Nov '17

01 Nov '17

I used another gcc version 4.5 (Ubuntu 11.04) and it works without any problem! I don’t know what is wrong with gcc-4.6. Though the problematic platform was Kubuntuu 12.04. I am know trying with Ubuntu 12.04 which uses gcc-4.6 to see if it is really a gcc problem or the platform! Sent from Mail for Windows 10 From: Alex Perry Sent: Wednesday, October 18, 2017 4:45 PM To: mahmood n Subject: RE: [Boost-users] Many undefined references for libboost_filesystem Actually one other thought (though you may well have solved this by now). Are you sure that the boost libraries you are attempting to link to are using the same abi? Ie how were they built. I only glanced at the github stuff you pointed too but I think I remember that the last commit was 5 years ago or some such – so probably wasn’t using C++11. I note you are using an old (54) version of boost whilst the current is (65) so about 5 years ago as well – but that probably supported being built with c++11.so you might need to rebuild them if they were using a different version of the C++ standard (or any abi breaking change such as 32 vs 64 bit, static runtime vs dynamically loaded etc). Under windows boost normally encodes the abi into the library name and you just automagically (using a msvc extension) link to the appropriate one. That is not the normal way on linux since gcc doesn’t have autolinking so you normally end up sticking them into a separate lib directory and swapping the -L path depending on which abi you want Again though please note this is not boost specific – is just standard C / C++ / Fortran or any obj/link based language issues with building dependencies – (and why most have swapped to using cmake rather than vanilla make to avoid the pain). A. From: Alex Perry Sent: 17 October 2017 16:14 To: 'mahmood n' <nt_mahmood(a)yahoo.com> Subject: RE: [Boost-users] Many undefined references for libboost_filesystem Dropped the rest of the boost list since I’m sure not many are interested! > I didn’t want to have another pain for “finding how the verbose variable is set in the Makefile”!!! Not hard that one… just add it to the command line when you call make make verbose=1 ….. > The libraries do exist, so why on earth it can not link :( > mahmood@vb:AES$ g++ -fPIC -L/home/mahmood/boost_1_54_0/stage/lib -lboost_filesystem -lboost_system -m64 -o /home/mahmood/gpgpu-sim_distribution/ispass2009-benchmarks/bin/release/AES obj/x86_64/release/aescuda.cpp.o obj/x86_64/release/aesCudaUtils.cpp.o obj/x86_64/release/aesHost.cu.o -L/usr/local/cuda/lib64 -L/home/mahmood/NVIDIA_GPU_Computing_SDK/C/src//../lib -L/home/mahmood/NVIDIA_GPU_Computing_SDK/C/src//../common/lib/linux -L/home/mahmood/NVIDIA_GPU_Computing_SDK/C/src//../../shared//lib -lcudart -L/usr/local/cuda/lib64 -L/home/mahmood/NVIDIA_GPU_Computing_SDK/C/src//../lib -L/home/mahmood/NVIDIA_GPU_Computing_SDK/C/src//../common/lib/linux -L/home/mahmood/NVIDIA_GPU_Computing_SDK/C/src//../../shared//lib -lcudart -lcutil_x86_64 -lshrutil_x86_64 …. Nope the computer is telling you they don’t exist on those paths as given – unfortunately the computer is more likely to be correct than you on this! You have a lot of library paths being set there – possibly you have multiple versions of boost libraries so its finding the wrong one first so you have a version conflict Possibly the simplest way is create a noddy test and play with the command line till you work out what the problem is http://rextester.com/live/JDVHT54458 That will give you similar compile errors without -lboost_filesystem -lboost_system added to the compile line. Obviously that is using clang rather than gcc which you are using but the syntax and principles are pretty much the same between any c++ compiler HTH A.

5 6

Boost graph library algorithms - is it possible to use previous solutions to "warm start" a new related problem
by F1E2D3 F1E2D3 29 Oct '17

29 Oct '17

Hello, I am primarily an Operations Researcher, and prior to boost, was writing my own C++ code for specific network flow problems. I am now hoping to transition to boost::graph completely for my network flow problem solution needs. However, I have one major concern. In linear programming (I use CPLEX https://www.ibm.com/us-en/marketplace/ibm-ilog-cplex as my primary linear programming (LP) solver), once a problem is solved, say a Dijkstra's shortest path problem, the solver maintains the optimal basis. Then, if some problem parameter changes, the linear program need not be solved from scratch, but the current basis is first tested for optimality for the new problem as well. An example of this would be an increase in the cost of an arc that does not feature on the optimal path from source to destination in a shortest path problem. This increase in cost does not change the optimal path, and hence, it would be wasteful to solve this problem again from scratch. Does boost::graph have this capability that LP solvers have? I posted this question first on stack overflow and am posting it here now. The question was not completely answered there. A working code and small example are provided there. I am giving the link below. https://stackoverflow.com/questions/46986312/are-boostgraph-algorithms-capa… Any help will be appreciated. Thanks.

1 0

[review][DoubleEnded] Review Results
by Thorsten Ottosen 27 Oct '17

27 Oct '17

Dear users and members of Boost, I'm happy to to announce that Benedek Thaler's Boost.DoubleEnded is /conditionally/ accepted into Boost provided that it can be integrated smoothly with Boost.Container. There are several other conditions, some major and some minor which I will outline below. For now, I would like to thank everyone that participated with reviews and comments. We didn't have that many reviews, but the reviewers did spend a lot of time both on review and the following discussions. Special thanks also goes to Benedek for his hard work. It is not too often that a GSOC code ends with something of this quality. Two of the world's expert C++ container developers used phrases like "solid" and "everything looks clean and beautiful" about the implementation, "tests look very good, corner cases and all", "The reference section is very good". Congratulations, Benedek. ============== A path forward ============== Ion has most kindly accepted the idea of merging the library into Boost.Container. This consists of A. taking selected elements from batch_deque and adding them to boost::container::deque. B. putting devector into boost.container after changes have been applied to code and documentation C. back-porting the devector code to C++03 (C) does not need to happen immediately, that is, we can have a release where devector is available in a C++11 version. Ion has also most kindly agreed to help with this process. I will help write a new introduction that focuses on the main principles of devector. We also have a number of benchmarks which we can gather and use for a small section of on that topic. I'll leave it to you and Ion to work out the details. ========================== Detailed comments devector ========================== Apart from the merging with Boost.Container, the most heard complaint was about the "fat", the non-essential parts if the interface, that could be removed. This includes -- Remove the direct support for small buffer optimization form devector. When the time comes, provide small_devector similar to the way we have vector/small_vector (there is no requirement that small_devector is provided). -- remove all of the following: - all constructors that uses reserve_only_tag, - all constructors that uses unsafe_uninitialized_tag, - void unsafe_uninitialized_resize_front(size_type); - void unsafe_uninitialized_resize_back(size_type); - unsafe_push_front(...); - unsafe_push_back(...); -- add instead - constructors that uses default_init_t like boost.container - resize versions that uses default_init_t - T& unchecked_emplace_back(...) noexcept(...) - T& unchecked_emplace_front(...) noexcept(...) At some point, I hope we can upgrade default_init_t to mean no construction for all trivially copyable types. There was a wish for more symmetry in devector and so functions that break symmetry or can appear ambiguous should be removed. This means we should remove: -- capacity() There is no need for front_capacity() and back_capacity(). We could remove reserve(), but then we can't use devector with a flat_set. Reserve() should not be an alias for reserve_back() though, but controlled by the policy. We could remove resize(), but even deque has it where it means resize_back(). I totally agree it would be ideal to remove all of reserve(),resize(),capacity(),clear(), but I see no easy way we can use devector with flat containers if we remove the first and the last. Unless we start deprecating stuff in boost::deque/boost::vector and provide new consistent alternatives, we will never get a 100% satisfactory solution. At the end of the day, we need to be pragmatic, so if deprecation is not on the table, this seems the best we can do. Since we don't want two allocations implied by calling reserve_back() and reserve_front(), you can add a mechanism for doing that. That is, you can provide -- reserve( new_capacity ); -- reserve_front( new_front_capacity ) -- reserve_back( new_back_capacity ) -- reserve( new_front_capacity, new_back_capacity ) or, since reserve() is such a weird beast, simply provide -- reserve( new_capacity ); // for flat containers -- anticipate_front( new_front_elements ) -- anticipate_back( new_back_elements ) -- anticipate( new_front_elements, new_back_elements ) to get rid of the funky -- container.reserve_front( container.size() + new_front_elements ) dance. There were suggestions for shrink_back/front_to_fit, but since we are trying to remove fat, I suggest that we wait for a use-case. There were also suggestions that clear() should be amended. As the growth (or resizing policy) mandates what clear does, we need a way to escape. The minimal change that allows that is to provide -- clear( front_free_capacity ) which gives full power to the user. You may provide clear_back() as clear(0) and clear_front() as clear(c.size()+c.front_free_capacity()+c.back_free_capacity()). Ideally, clear() would have been removed entirely like capacity()/resize(), but like reserve(), it just seems like impossible when we start using it with flat containers. Other minor comments: - drop strong exception safety guarantees and do it like boost.container - prefer to make iterator a type (should be easy with reuse from boost::container::vector - allocator should not be inherted from - make clear O(1) amortized gurantees depend on growth policy - consider calling growth policy for resizing policy - make sure SFINAE works properly with constructors - make the default growth factor 2 (as we heard from Sean Parent: no factor below 2 is empirically good) - consider renaming front_free_capacity to free_front_capacity. Rationale: "front_capacity" is a concept, noun, and "free" is the adjective. Ditto for back_free_capacity. - remove size_type from growth policy and take it from the allocator - make the allocator template argument the 2nd argument - fix remaning TODO in code - documentation should not sell devector as drop-in replacement for vector, but rather stress it is not - the allocator supports needs to be improved. I guess doing it the Boost.Container way ensures that (ask Daniel James for help) - exception-safety issues pointed out by Ion - postconditions of insert/erase needs to specify behavior to front_free_capacity/back_free_capcity - use of local containers should be avoided - rotate should be avoided - delegate range move operations to those defined in Boost.Container - make sure all functions excepting non-overlapping range uses memcpy (not just memmove). This includes: - range constructor - copy-constructor - copy-assignment - range-assignment - range insert - destructor should used std::has_trivial_destructor to avoid loop in that case to make sure all compilers optimize it away (similar for erase). There is one final puzzle and that is the growth policy. I hope we can finalize that by testing Joaquin's and Ion's suggestions over the coming weeks. ============================= Detailed comments batch_deque ============================= For deque, the comments were similar, although there was far less to discuss than for devector. All agreed that one should be able to control the segment size. - stable_insert was not needed. - segment iteration was good, but should be usable with range-based for loop. The segment iterator should return a segment type if possible, and the segment should have begin(),end(),size() members. - since boost::deque already has a resize with default_init_t, that should be sufficient to provide fast serialization load for trivial types. No need for - resize_front - resize_back - unsafe_uninitialized_resize_front - unsafe_uninitialized_resize_back - reserve - shrink_to_fit() - capacity() The following are still needed for optimal code (or code that can be known not to reallocate, or for better locality in deserialization, avoiding double initialization) - free_front_capacity; - free_back_capacity; - reserve_front - reserve_back - unchecked_emplace_front - unchecked_emplace_back Boost.Container's unit-tests should be extended with those from batch_deque where it makes sense. Since segmented iteration was somewhat faster, it should be use internally where it makes sense. In particular - copy-constructor - copy-assignment - destructor As for devector, all constructor/functions that iterate over non-overlapping ranges should use memcpy. destructor should use is_trivially_destructible to ensure it is optimized away (similar for erase). ====================== Serialization comments ====================== I suggest that the default versions just do what Boost.Serialization does, perhaps just replacing resize with resize with default_init_t. That ensures it works correctly for all archive types. It also needs to use make_nvp() so the output is identical to std::vector. We will then talk to Robert about how we can take advantage of the binary archive in a correct fashion. ====================== kind regards Thorsten, review manager

3 3

[Container] Does deque allocate memory in default constructor?
by dariomt＠gmail.com 25 Oct '17

25 Oct '17

It seems std::deque implementations are allowed to allocate in the default constructor [1] However, boost::container::deque I think does not allocate in the default constructor, but the docs are not explicit about it. I can see in the docs: *Throws*: If allocator_type's default constructor throws. Which would mean that it cannot throw due to memory exhaustion, so it cannot allocate memory. Is my reasoning right? If yes, would it be possible to make this explicit in the docs? I think it is relevant, because it might be the deciding factor for switching from std::deque to boost::container::deque (as it might be my case). Thanks! [1] https://stackoverflow.com/questions/40203494/why-does-stddeque-allocate-mem…

2 1

Fwd: Boost compilation problems
by Berkus Karchebnyy 24 Oct '17

24 Oct '17

Hello, in attempt to build boost for android with more or less reasonable strict settings (-Werror) I uncovered some bugs which I cannot report on github because these projects have Issues disabled. I will post them here in hopes they will eventually reach appropriate maintainers. == ONE: boost.containers == clang-darwin.compile.c android-build/boost/bin.v2/ libs/container/build/clang-darwin-5.0~x86/debug/address- model-32/link-static/target-os-android/threading-multi/alloc_lib.o In file included from libs/container/src/alloc_lib.c:19: libs/container/src/dlmalloc_ext_2_8_6.c:1097:8: error: variable 'ret' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes- uninitialized] if (!PREACTION(m)) { ^~~~~~~~~~~~~ libs/container/src/dlmalloc_ext_2_8_6.c:1125:11: note: uninitialized use occurs here return ret; ^~~ libs/container/src/dlmalloc_ext_2_8_6.c:1097:4: note: remove the 'if' if its condition is always true if (!PREACTION(m)) { ^~~~~~~~~~~~~~~~~~~ libs/container/src/dlmalloc_ext_2_8_6.c:1095:4: note: variable 'ret' is declared here boost_cont_malloc_stats_t ret; ^ 1 error generated. "/usr/local/opt/android-ndk/android-ndk-r16-beta1// toolchains/llvm/prebuilt/darwin-x86_64/bin/clang++" "-DBOOST_AC_USE_PTHREADS" "-DBOOST_SP_USE_PTHREADS" "-fvisibility=hidden" "-fvisibility-inlines-hidden" "-Wno-unused-local-typedef" -x c -O0 -g -O0 -fno-inline -Wall -g --target=i686-none-linux-android --gcc-toolchain=/usr/local/opt/android-ndk/android-ndk- r16-beta1//toolchains/x86-4.9/prebuilt/darwin-x86_64 --sysroot=/usr/local/opt/android-ndk/android-ndk-r16-beta1//sysroot -isystem /usr/local/opt/android-ndk/android-ndk-r16-beta1// sources/cxx-stl/llvm-libc++/include -isystem /usr/local/opt/android-ndk/ android-ndk-r16-beta1//sources/cxx-stl/llvm-libc++abi/include -isystem /usr/local/opt/android-ndk/android-ndk-r16-beta1//sources/android/support/include -isystem /usr/local/opt/android-ndk/android-ndk-r16-beta1//sysroot/usr/include -isystem /usr/local/opt/android-ndk/android-ndk-r16-beta1// sysroot/usr/include/i686-linux-android -DANDROID -D__ANDROID_API__=21 -ffunction-sections -funwind-tables -fstack-protector-strong -fno-limit-debug-info -fPIC -no-canonical-prefixes -mstackrealign -Wa,--noexecstack -Wformat -Werror=format-security -Wall -Werror -Wshadow -march=i686 -DBOOST_ALL_NO_LIB=1 -DBOOST_CONTAINER_STATIC_LINK=1 -D_LITTLE_ENDIAN -I"." -c -o "android-build/boost/bin.v2/ libs/container/build/clang-darwin-5.0~x86/debug/address- model-32/link-static/target-os-android/threading-multi/alloc_lib.o" "libs/container/src/alloc_lib.c" == TWO: boost.serialization and monty python == (cue Benny Hill music) clang-darwin.compile.c++ android-build/boost/bin.v2/ libs/serialization/build/clang-darwin-5.0~x86/debug/ address-model-32/link-static/target-os-android/threading- multi/polymorphic_iarchive.o In file included from libs/serialization/src/polymorphic_iarchive.cpp:20: In file included from ./boost/archive/polymorphic_iarchive.hpp:32: ./boost/archive/detail/iserializer.hpp:69:7: error: macro expansion producing 'defined' has undefined behavior [-Werror,-Wexpansion-to-defined] #if ! DONT_USE_HAS_NEW_OPERATOR ^ ./boost/archive/detail/iserializer.hpp:63:12: note: expanded from macro 'DONT_USE_HAS_NEW_OPERATOR' || defined(__SUNPRO_CC) && (__SUNPRO_CC < 0x590) \ ^ ./boost/archive/detail/iserializer.hpp:212:9: error: macro expansion producing 'defined' has undefined behavior [-Werror,-Wexpansion-to-defined] #if DONT_USE_HAS_NEW_OPERATOR ^ ./boost/archive/detail/iserializer.hpp:63:12: note: expanded from macro 'DONT_USE_HAS_NEW_OPERATOR' || defined(__SUNPRO_CC) && (__SUNPRO_CC < 0x590) \ ^ 2 errors generated. "/usr/local/opt/android-ndk/android-ndk-r16-beta1// toolchains/llvm/prebuilt/darwin-x86_64/bin/clang++" "-DBOOST_AC_USE_PTHREADS" "-DBOOST_SP_USE_PTHREADS" "-fvisibility=hidden" "-fvisibility-inlines-hidden" "-Wno-unused-local-typedef" -x c++ -ftemplate-depth-255 -fvisibility=hidden -fvisibility-inlines-hidden -std=c++14 -O0 -g -O0 -fno-inline -Wall -g --target=i686-none-linux-android --gcc-toolchain=/usr/local/opt/android-ndk/android-ndk- r16-beta1//toolchains/x86-4.9/prebuilt/darwin-x86_64 --sysroot=/usr/local/opt/android-ndk/android-ndk-r16-beta1//sysroot -isystem /usr/local/opt/android-ndk/android-ndk-r16-beta1// sources/cxx-stl/llvm-libc++/include -isystem /usr/local/opt/android-ndk/ android-ndk-r16-beta1//sources/cxx-stl/llvm-libc++abi/include -isystem /usr/local/opt/android-ndk/android-ndk-r16-beta1//sources/android/support/include -isystem /usr/local/opt/android-ndk/android-ndk-r16-beta1//sysroot/usr/include -isystem /usr/local/opt/android-ndk/android-ndk-r16-beta1// sysroot/usr/include/i686-linux-android -DANDROID -D__ANDROID_API__=21 -ffunction-sections -funwind-tables -fstack-protector-strong -fno-limit-debug-info -fPIC -no-canonical-prefixes -mstackrealign -Wa,--noexecstack -Wformat -Werror=format-security -Wall -Werror -Wshadow -march=i686 -DBOOST_ALL_NO_LIB=1 -D_LITTLE_ENDIAN -I"." -c -o "android-build/boost/bin.v2/libs/serialization/build/ clang-darwin-5.0~x86/debug/address-model-32/link-static/ target-os-android/threading-multi/polymorphic_iarchive.o" "libs/serialization/src/polymorphic_iarchive.cpp" == THREE: boost.program_options == clang-darwin.compile.c++ android-build/boost/bin.v2/ libs/program_options/build/clang-darwin-5.0~x86/debug/ address-model-32/link-stati c/target-os-android/threading-multi/cmdline.o libs/program_options/src/cmdline.cpp:104:41: error: declaration shadows a field of 'boost::program_options::detail::cmdline' [-Werror ,-Wshadow] cmdline::init(const vector<string>& args) ^ ./boost/program_options/detail/cmdline.hpp:139:34: note: previous declaration is here std::vector<std::string> args; ^ libs/program_options/src/cmdline.cpp:508:48: error: declaration shadows a field of 'boost::program_options::detail::cmdline' [-Werror ,-Wshadow] cmdline::parse_long_option(vector<string>& args) ^ ./boost/program_options/detail/cmdline.hpp:139:34: note: previous declaration is here std::vector<std::string> args; ^ libs/program_options/src/cmdline.cpp:545:49: error: declaration shadows a field of 'boost::program_options::detail::cmdline' [-Werror,-Wshadow] cmdline::parse_short_option(vector<string>& args) ^ ./boost/program_options/detail/cmdline.hpp:139:34: note: previous declaration is here std::vector<std::string> args; ^ libs/program_options/src/cmdline.cpp:611:47: error: declaration shadows a field of 'boost::program_options::detail::cmdline' [-Werror,-Wshadow] cmdline::parse_dos_option(vector<string>& args) ^ ./boost/program_options/detail/cmdline.hpp:139:34: note: previous declaration is here std::vector<std::string> args; ^ libs/program_options/src/cmdline.cpp:632:58: error: declaration shadows a field of 'boost::program_options::detail::cmdline' [-Werror,-Wshadow] cmdline::parse_disguised_long_option(vector<string>& args) ^ ./boost/program_options/detail/cmdline.hpp:139:34: note: previous declaration is here std::vector<std::string> args; ^ libs/program_options/src/cmdline.cpp:663:47: error: declaration shadows a field of 'boost::program_options::detail::cmdline' [-Werror,-Wshadow] cmdline::parse_terminator(vector<string>& args) ^ ./boost/program_options/detail/cmdline.hpp:139:34: note: previous declaration is here std::vector<std::string> args; ^ libs/program_options/src/cmdline.cpp:683:55: error: declaration shadows a field of 'boost::program_options::detail::cmdline' [-Werror,-Wshadow] cmdline::handle_additional_parser(vector<string>& args) ^ ./boost/program_options/detail/cmdline.hpp:139:34: note: previous declaration is here std::vector<std::string> args; ^ 7 errors generated. "/usr/local/opt/android-ndk/android-ndk-r16-beta1// toolchains/llvm/prebuilt/darwin-x86_64/bin/clang++" "-DBOOST_AC_USE_PTHREADS" "-DBOOST_SP_USE_PTHREADS" "-fvisibility=hidden" "-fvisibility-inlines-hidden" "-Wno-unused-local-typedef" -x c++ -std=c++14 -O0 -g -O0 -fno-inline -Wall -g --target=i686-none-linux-android --gcc-toolchain=/usr/local/opt/android-ndk/android-ndk- r16-beta1//toolchains/x86-4.9/prebuilt/darwin-x86_64 --sysroot=/usr/local/opt/android-ndk/android-ndk-r16-beta1//sysroot -isystem /usr/local/opt/android-ndk/android-ndk-r16-beta1// sources/cxx-stl/llvm-libc++/include -isystem /usr/local/opt/android-ndk/ android-ndk-r16-beta1//sources/cxx-stl/llvm-libc++abi/include -isystem /usr/local/opt/android-ndk/android-ndk-r16-beta1//sources/android/support/include -isystem /usr/local/opt/android-ndk/android-ndk-r16-beta1//sysroot/usr/include -isystem /usr/local/opt/android-ndk/android-ndk-r16-beta1// sysroot/usr/include/i686-linux-android -DANDROID -D__ANDROID_API__=21 -ffunction-sections -funwind-tables -fstack-protector-strong -fno-limit-debug-info -fPIC -no-canonical-prefixes -mstackrealign -Wa,--noexecstack -Wformat -Werror=format-security -Wall -Werror -Wshadow -march=i686 -DBOOST_ALL_NO_LIB=1 -D_LITTLE_ENDIAN -I"." -c -o "android-build/boost/bin.v2/libs/program_options/build/ clang-darwin-5.0~x86/debug/address-model-32/link-static/ target-os-android/threading-multi/cmdline.o" "libs/program_options/src/ cmdline.cpp" The entire set of compile flags and NDK version can be seen in the provided snippets. Thanks. -- Sr. Software Engineer [image: twilio] <http://www.twilio.com/?utm_source=email_signature> EMAIL berkus(a)twilio.com

1 0

Help needed in learning to use Boost.Asio
by Osman Zakir 24 Oct '17

24 Oct '17

I want to learn how to use Boost.Asio so I can then create an abstraction layer over it for HTTP and create a server and client. I need it for a web app I want to make. I know C++ isn’t a good choice for this sort of thing, but it’s still growing and getting better, so I wonder if there’s really no hope for it becoming a better choice for web development. Especially if someone were to propose a networking library for boost that also provides support for the HTTP protocol and maybe also RESTful services out of the box. Libraries in Boost have a high chance of making it into the standard, after all, so this could be a good idea. I’ve heard from many people that C++ is a waste of time, especially if one wants to get into web development and make a lot of money. Most people who want to web development are abandoning C++ in favor of languages Python that provide better support for web development. I don’t like this and I hope that C++ will also become better for the job soon so that it can pull back programmers that have left it for other languages. That’s also the reason why I want to use C++ here. I’m hoping that the Networking TS would be standardized and that the standardizing committee would also do something to make C++ overall better for the web, preferably as good as Python if possible. The difficulty of getting into and using C++ is also overly-exaggerated but it seems to be more because of C++ programmers not making their code simple and beautiful enough, so it’s also the language users’ fault. I want to try to change the negative views that people have of C++, as well. By the way, would it be a good idea to send an email asking about the future of C++, especially for web development, to Dr. Stroustrup if I can find a way to contact him? I know he’s a busy man and I’m also reluctant to this, but since he’s also on the standard-making committee, if he finds some free time to reply to my email, he should be able to tell me what to expect about C++ and its future. I’m sorry if this email got too long, though. Best regards. Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10

5 7

boost asio
by Sharma, Nishant 23 Oct '17

23 Oct '17

Hi, I have created an Asynchronous TCP server and client and it works fine. Since it is asynchronous, it uses API's like async_read, async_write etc.. Is it possible that the same code be used to do "synchronous" communication which results in blocking any further task in the queue unless the current i/o task is complete ? I have attached the example hereby. It has two folder for server and client.. First the server needs to be run and then the client. Best Regards, Nishant Sharma

3 5

boost fileystem issue
by Olivier Tristan 20 Oct '17

20 Oct '17

Hi Guys, I would like to bump this particular issue that is quite annoying for me. Basically it crashes as soon as you call boost::filesystem::exists in the ctor of a static variable initialized at program startup https://svn.boost.org/trac10/ticket/12987 Looks like there was a fix 4 month ago but this hasn't been pushed into the trunk yet Any idea how to push the process forward ? Thanks ! -- Olivier Tristan Research & Development www.uvi.net

2 2

Reconnecting a SSL socket correctly
by David Demelier 18 Oct '17

18 Oct '17

Hello, I'm trying to reconnect a SSL socket (using ssl::stream with tcp::socket) that has been closed only remotely. It looks like a shutdown on my client causes "stream truncated" error so I have no idea how can I connect my client socket again. I was thinking of just creating a new instance but the stream class is not copyable. Do you have any recommandations? Regards, -- David

2 1

[asio] null reference in epoll_reactor
by Phil Sean 18 Oct '17

18 Oct '17

Hi, Running the tutorial async TCP server (http://www.boost.org/doc/libs/1_65_1/doc/html/boost_asio/tutorial/tutdaytim…) or any other asynchronous operation in valgrind yields an error like this: = Syscall param epoll_pwait(sigmask) points to unaddressable byte(s) = epoll_pwait (in /usr/lib/libc-2.26.so) = boost::asio::detail::epoll_reactor::run(bool, boost::asio::detail::op_queue<boost::asio::detail::task_io_service_operation>&) (in /.../server) = boost::asio::detail::task_io_service::do_run_one(boost::asio::detail::scoped_lock<boost::asio::detail::posix_mutex>&, boost::asio::detail::task_io_service_thread_info&, boost::system::error_code const&) (in /.../server) = boost::asio::detail::task_io_service::run(boost::system::error_code&) (in /.../server) = boost::asio::io_service::run() (in /.../server) = main (in /.../server) = Address 0x0 is not stack'd, malloc'd or (recently) free'd I suspect it's due to some recent changes because it didn't use to be an error. Boost version is 1.65.1(Arch Linux). Thank you.

2 2

git clone of boost
by Tim Burgess 18 Oct '17

18 Oct '17

Hi, Just been trying to find the address to clone boost, but was unsuccessful. Can anybody help me out please? Best wishes. Tim Burgess

2 1

Re: [Boost-users] Many undefined references for libboost_filesystem
by Mahmood N 17 Oct '17

17 Oct '17

Hi Daniel, I tried some other versions based on the release date of the project and boosts. I tried 1.38 and 40 and 42 and 44 and 46. All of them return some undefined references. How can i find which boost version is used in the project? Regards, Mahmood -------------------------------------------- On Sat, 10/14/17, Daniel Anderson <wonixen(a)gmail.com> wrote: Subject: Re: [Boost-users] Many undefined references for libboost_filesystem To: boost-users(a)lists.boost.org Cc: "Mahmood N" <nt_mahmood(a)yahoo.com> Date: Saturday, October 14, 2017, 12:53 AM you are probably using the wrong version of filesystem, or maybe of boost. often those projects need a specific boost version. 2017-10-13 14:24 GMT-04:00 Mahmood N via Boost-users <boost-users(a)lists.boost.org>: > Hi, > > I am trying to build a suite as described at > https://github.com/gpgpu-sim/ispass2009-benchmarks > > Some of the benchmarks use boost. For example, AES/Makefile has > > > > LINKFLAGS := -L$(BOOST_LIB) -lboost_filesystem > > > > Also, the Makefile.ispass-2009 in the root folder has the following settings > > > > SETENV=export BINDIR=$(BINDIR); \ > > export ROOTDIR=$(NVIDIA_COMPUTE_SDK_LOCATION)/C/src/; \ > > export BINSUBDIR=$(BINSUBDIR); \ > > export BOOST_LIB=/home/mahmood/boost_1_46_0/lib; \ > > export BOOST_ROOT=/home/mahmood/boost_1_46_0/include; \ > > export BOOST_VER=""; \ > > export OPENMPI_BINDIR=/usr/bin/; > > > > > > I manually built boost_1_46_0 with the steps described at > http://www.boost.org/doc/libs/1_46_1/doc/html/bbv2/installation.html > > The installations was successful and I can see lib/ and include/ folders > > > > mahmood@vb:boost_1_46_0$ find lib -name libboost_system* > > lib/libboost_system.so.1.46.0 > > lib/libboost_system.so > > lib/libboost_system.a > > mahmood@vb:boost_1_46_0$ find lib -name libboost_filesystem* > > lib/libboost_filesystem.so > > lib/libboost_filesystem.a > > lib/libboost_filesystem.so.1.46.0 > > > > > > > > However, as I run “make -f Makefile.ispass-2009”, I get many undefined > errors about libboost_filesystem. Please see below > > > > > > > > export > BINDIR=/home/mahmood/gpgpu-sim_distribution/ispass2009-benchmarks/bin/; > export ROOTDIR=/home/mahmood/NVIDIA_GPU_Computing_SDK/C/src/; export > BINSUBDIR=release; export BOOST_LIB=/home/mahmood/boost_1_46_0/lib; export > BOOST_ROOT=/home/mahmood/boost_1_46_0/include; export BOOST_VER=""; export > OPENMPI_BINDIR=/usr/bin/; make noinline=0 -C AES > > make[1]: Entering directory > `/home/mahmood/gpgpu-sim_distribution/ispass2009-benchmarks/AES' > > obj/x86_64/release/aesCudaUtils.cpp.o: In function > `readFromFileForm(boost::filesystem3::path&, std::vector<unsigned int, > std::allocator<unsigned int> >&)': > > aesCudaUtils.cpp:(.text+0x97d): undefined reference to > `boost::filesystem3::detail::status(boost::filesystem3::path const&, > boost::system::error_code*)' > > obj/x86_64/release/aesCudaUtils.cpp.o: In function > `readFromFileNotForm(boost::filesystem3::path&, char*, unsigned int)': > > aesCudaUtils.cpp:(.text+0xe81): undefined reference to > `boost::filesystem3::detail::status(boost::filesystem3::path const&, > boost::system::error_code*)' > > obj/x86_64/release/aesCudaUtils.cpp.o: In function > `getFileSize(boost::filesystem3::path&)': > > aesCudaUtils.cpp:(.text+0x1244): undefined reference to > `boost::filesystem3::detail::status(boost::filesystem3::path const&, > boost::system::error_code*)' > > aesCudaUtils.cpp:(.text+0x1257): undefined reference to > `boost::filesystem3::detail::file_size(boost::filesystem3::path const&, > boost::system::error_code*)' > > obj/x86_64/release/aesCudaUtils.cpp.o: In function > `initAesCuda(std::basic_string<char, std::char_traits<char>, > std::allocator<char> >, unsigned char*, unsigned int, > std::basic_string<char, std::char_traits<char>, std::allocator<char> >, > char*, unsigned int)': > > aesCudaUtils.cpp:(.text+0x1c54): undefined reference to > `boost::filesystem3::path::wchar_t_codecvt_facet()' > > aesCudaUtils.cpp:(.text+0x1cab): undefined reference to > `boost::filesystem3::path::wchar_t_codecvt_facet()' > > aesCudaUtils.cpp:(.text+0x1ce5): undefined reference to > `boost::filesystem3::detail::status(boost::filesystem3::path const&, > boost::system::error_code*)' > > aesCudaUtils.cpp:(.text+0x1d02): undefined reference to > `boost::filesystem3::detail::status(boost::filesystem3::path const&, > boost::system::error_code*)' > > obj/x86_64/release/aesCudaUtils.cpp.o: In function > `_GLOBAL__sub_I_aesCudaUtils.cpp': > > aesCudaUtils.cpp:(.text.startup+0x2b): undefined reference to > `boost::system::generic_category()' > > aesCudaUtils.cpp:(.text.startup+0x37): undefined reference to > `boost::system::generic_category()' > > aesCudaUtils.cpp:(.text.startup+0x43): undefined reference to > `boost::system::system_category()' > > obj/x86_64/release/aescuda.cpp.o: In function `_GLOBAL__sub_I_aescuda.cpp': > > aescuda.cpp:(.text.startup+0x68b): undefined reference to > `boost::system::generic_category()' > > aescuda.cpp:(.text.startup+0x697): undefined reference to > `boost::system::generic_category()' > > aescuda.cpp:(.text.startup+0x6a3): undefined reference to > `boost::system::system_category()' > > collect2: ld returned 1 exit status > > make[1]: *** > [/home/mahmood/gpgpu-sim_distribution/ispass2009-benchmarks/bin//release/AES] > Error 1 > > make[1]: Leaving directory > `/home/mahmood/gpgpu-sim_distribution/ispass2009-benchmarks/AES' > > make: *** [default] Error 2 > > > > > > > > Any thought on that? > > > Regards, > Mahmood > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > https://lists.boost.org/mailman/listinfo.cgi/boost-users -- Daniel L'action accède à la perfection quand, bien que vivant, vous êtes déjà mort Bunan

6 14

Many undefined references for libboost_filesystem
by Mahmood N 13 Oct '17

13 Oct '17

Hi, I am trying to build a suite as described at https://github.com/gpgpu-sim/ispass2009-benchmarks Some of the benchmarks use boost. For example, AES/Makefile has LINKFLAGS := -L$(BOOST_LIB) -lboost_filesystem Also, the Makefile.ispass-2009 in the root folder has the following settings SETENV=export BINDIR=$(BINDIR); \ export ROOTDIR=$(NVIDIA_COMPUTE_SDK_LOCATION)/C/src/; \ export BINSUBDIR=$(BINSUBDIR); \ export BOOST_LIB=/home/mahmood/boost_1_46_0/lib; \ export BOOST_ROOT=/home/mahmood/boost_1_46_0/include; \ export BOOST_VER=""; \ export OPENMPI_BINDIR=/usr/bin/; I manually built boost_1_46_0 with the steps described at http://www.boost.org/doc/libs/1_46_1/doc/html/bbv2/installation.html The installations was successful and I can see lib/ and include/ folders mahmood@vb:boost_1_46_0$ find lib -name libboost_system* lib/libboost_system.so.1.46.0 lib/libboost_system.so lib/libboost_system.a mahmood@vb:boost_1_46_0$ find lib -name libboost_filesystem* lib/libboost_filesystem.so lib/libboost_filesystem.a lib/libboost_filesystem.so.1.46.0 However, as I run “make -f Makefile.ispass-2009”, I get many undefined errors about libboost_filesystem. Please see below export BINDIR=/home/mahmood/gpgpu-sim_distribution/ispass2009-benchmarks/bin/; export ROOTDIR=/home/mahmood/NVIDIA_GPU_Computing_SDK/C/src/; export BINSUBDIR=release; export BOOST_LIB=/home/mahmood/boost_1_46_0/lib; export BOOST_ROOT=/home/mahmood/boost_1_46_0/include; export BOOST_VER=""; export OPENMPI_BINDIR=/usr/bin/; make noinline=0 -C AES make[1]: Entering directory `/home/mahmood/gpgpu-sim_distribution/ispass2009-benchmarks/AES' obj/x86_64/release/aesCudaUtils.cpp.o: In function `readFromFileForm(boost::filesystem3::path&, std::vector<unsigned int, std::allocator<unsigned int> >&)': aesCudaUtils.cpp:(.text+0x97d): undefined reference to `boost::filesystem3::detail::status(boost::filesystem3::path const&, boost::system::error_code*)' obj/x86_64/release/aesCudaUtils.cpp.o: In function `readFromFileNotForm(boost::filesystem3::path&, char*, unsigned int)': aesCudaUtils.cpp:(.text+0xe81): undefined reference to `boost::filesystem3::detail::status(boost::filesystem3::path const&, boost::system::error_code*)' obj/x86_64/release/aesCudaUtils.cpp.o: In function `getFileSize(boost::filesystem3::path&)': aesCudaUtils.cpp:(.text+0x1244): undefined reference to `boost::filesystem3::detail::status(boost::filesystem3::path const&, boost::system::error_code*)' aesCudaUtils.cpp:(.text+0x1257): undefined reference to `boost::filesystem3::detail::file_size(boost::filesystem3::path const&, boost::system::error_code*)' obj/x86_64/release/aesCudaUtils.cpp.o: In function `initAesCuda(std::basic_string<char, std::char_traits<char>, std::allocator<char> >, unsigned char*, unsigned int, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, char*, unsigned int)': aesCudaUtils.cpp:(.text+0x1c54): undefined reference to `boost::filesystem3::path::wchar_t_codecvt_facet()' aesCudaUtils.cpp:(.text+0x1cab): undefined reference to `boost::filesystem3::path::wchar_t_codecvt_facet()' aesCudaUtils.cpp:(.text+0x1ce5): undefined reference to `boost::filesystem3::detail::status(boost::filesystem3::path const&, boost::system::error_code*)' aesCudaUtils.cpp:(.text+0x1d02): undefined reference to `boost::filesystem3::detail::status(boost::filesystem3::path const&, boost::system::error_code*)' obj/x86_64/release/aesCudaUtils.cpp.o: In function `_GLOBAL__sub_I_aesCudaUtils.cpp': aesCudaUtils.cpp:(.text.startup+0x2b): undefined reference to `boost::system::generic_category()' aesCudaUtils.cpp:(.text.startup+0x37): undefined reference to `boost::system::generic_category()' aesCudaUtils.cpp:(.text.startup+0x43): undefined reference to `boost::system::system_category()' obj/x86_64/release/aescuda.cpp.o: In function `_GLOBAL__sub_I_aescuda.cpp': aescuda.cpp:(.text.startup+0x68b): undefined reference to `boost::system::generic_category()' aescuda.cpp:(.text.startup+0x697): undefined reference to `boost::system::generic_category()' aescuda.cpp:(.text.startup+0x6a3): undefined reference to `boost::system::system_category()' collect2: ld returned 1 exit status make[1]: *** [/home/mahmood/gpgpu-sim_distribution/ispass2009-benchmarks/bin//release/AES] Error 1 make[1]: Leaving directory `/home/mahmood/gpgpu-sim_distribution/ispass2009-benchmarks/AES' make: *** [default] Error 2 Any thought on that? Regards, Mahmood

2 1

[coroutine] MinGW: terminate called after throwing an instance of 'boost::context::detail::forced_unwind'
by Jan Niklas Hasse 13 Oct '17

13 Oct '17

Hi :) I've tried to compile this simple Boost.Coroutine example: #include <iostream> #include <boost/coroutine2/all.hpp> void foo(boost::coroutines2::asymmetric_coroutine<void>::push_type& yield) { for (int i = 0; i < 10; ++i) { std::cout << i << std::endl; yield(); } } int main() { boost::coroutines2::asymmetric_coroutine<void>::pull_type coroutine(foo); for (int i = 0; i < 5; ++i) { coroutine(); } } On Linux this works as expected, just as on Windows with Visual Studio. But when I cross-compile on Linux using i686-w64-mingw32-g++ src/main.cpp -lboost_context-mt The resulting exe crashes with: 0 1 2 3 4 5 6 terminate called after throwing an instance of 'boost::context::detail::forced_unwind' abnormal program termination There's a similar problem on StackOverflow: https://stackoverflow.com/questions/45569418/how-to-use-boost-context-corre… But I'm having the crash only with the cross-compiled version, not MSVC. Am I doing something wrong? Or might this be a bug in Fedora's mingw32-boost package?

1 0

1.65.1 as modular packages on Conan.io
by Rene Rivera 13 Oct '17

13 Oct '17

Following on with the announcement before CppCon of the 1.64.0 modular packages here we are with more. I'm pleased to announce that the 1.65.1 Boost C++ Libraries are now available individually using the Conan package manager. There's even some improvements for the 1.64.0 package also :-) Find out more from the Bincrafters post here <http://bit.ly/2g6VEpp>[1]. For help using the packages you can bug the Bincrafters team in the #Conan CppLan Slack channel <http://bit.ly/2ykeqC0>[2]. Conan is a C/C++ (and more) package manager that supports an open ended set of build system and tool integrations including: VisualStudio, Xcode, CLion, Ninja, QMake, Premake, and yes even CMake <http://bit.ly/2xzhpbg>[3]. [1] <https://bincrafters.github.io/2017/10/13/Conan-Packages-Boost-1-65-1/> [2] <https://cpplang.now.sh/> [3] <http://docs.conan.io/en/latest/integrations.html> -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net

1 0

boost::filesystem and writing to Windows programdata structure
by Tim Burgess 12 Oct '17

12 Oct '17

Hi, I've an application that has been working fine under Windows 7, but I'm now fixing up for running on later Windows versions. I've been hitting unhandled exceptions when writing to c:\programdata\(my company)\(my app name)\ and understand that this is due to the permissions for such folders being more restrictive on Windows 8, 8.1 and 10. My research seems to indicate that I can modify my installer to set up my folders with appropriate permissions at install-time, but I'd prefer to use boost::filesystem to check folder/file permissions then change them at run-time, if necessary using appropriate csidl values. Can anybody offer any advice, please? Best wishes. Tim Burgess

4 5

[stacktrace] Trace information from GetExceptionInformation()?
by Nat Goodspeed 11 Oct '17

11 Oct '17

In an __except() filter expression (Microsoft Structured Exception), it's legal to call GetExceptionInformation() to retrieve a pointer to an _EXCEPTION_POINTERS struct. A little bit of Google searching turned up a few recipes for walking the stack information indirectly provided by that _EXCEPTION_POINTERS data. Would it be reasonable to have a Microsoft-specific stacktrace constructor accepting _EXCEPTION_POINTERS*? Or perhaps a factory function? I would like to be able to capture the platform-specific _EXCEPTION_POINTERS information, but then, once I have it in hand, engage the rest of the Boost.Stacktrace functionality. Apologies if this has already been asked and answered. If so, please simply point me to the previous discussion. Thank you!

2 1

boost::interprocess::managed_mapped_file filename
by Markus Bonk 10 Oct '17

10 Oct '17

Hi, Unfortunately wmanaged_mapped_file constructors use char instead of wchar for the filename. This causes big problems on windows where %appdata% and %localappdata% include the user name which may include Unicode characters that after conversion result in the windows ‘A’ methods failing to find the referenced file. I don’t know of any work around except using Unicode filenames. Does anyone know of a way around this. Are there any plans of making wmanaged_mapped_file use wchar for the filenames? Markus ________________________________ Markus Bonk Senior Software Engineer [cid:imageac7178.GIF@91f798f8.4ca4a8b2] 3Dconnexion GmbH Clarita-Bernhard-Str. 18 81249 München Germany Tel: +49 (89) 897 45 42 - 70 Fax: +49 (89) 897 45 42 - 50 markus_bonk(a)3dconnexion.com<mailto:markus_bonk@3dconnexion.com> www.3dconnexion.com<http://www.3dconnexion.com> Geschäftsführer: Antonio Pascucci Sitz der Gesellschaft: München Registergericht: München HRB 99232

1 0

Compiling boost with optional _GLIBCXX_DEBUG support
by Jayesh Badwaik 09 Oct '17

09 Oct '17

Hi, How to compile boost so that compilation of user programs both with _GLIBCXX_DEBUG and without _GLIBCXX_DEBUG is supported? Currently, if I compile boost with _GLIBCXX_DEBUG then I cannot compile my programs without this flag, and vice versa. The actual error comes from program_options attached in a file. I gather from the interweb that the error is well known, however, I could not find instructions to compile boost such that both options are supported. -- Cheers Jayesh Badwaik https://www.jayeshbadwaik.in

2 2

[review] The review period of Boost.DoubleEnded has ended -- thanks to all involved
by Thorsten Ottosen 09 Oct '17

09 Oct '17

Dear users and members of Boost, We are now done with the review of Benedek Thaler's Boost.DoubleEnded library. Many thanks to all those involved in discussions and reviews. It will take me some time to digest all the feedback and get back with the review results. kind regards Thorsten, review manager -- Best regards, Thorsten Jørgen Ottosen, Ph.D. Director of Research +45 23308797 Dezide (www.dezide.com)

1 0

[asio] "reverse" stream?
by Phil Sean 07 Oct '17

07 Oct '17

Hi, Is there a stream (or other implementation) in asio that reverses the next layer and the read()/write() layer of another stream? For example, a reverse ssl::stream would send/receive data in clear text, but read()/write() operations should rather expect encrypted data. Thanks.

2 1

[geometry] Best Fit Plane
by Manoj Lnu 07 Oct '17

07 Oct '17

Is there a function available in boost geometry to find the best fit plane ? I have a set of 3D points as input. Thanks, Manoj

2 1

Memory usage of boost::unordered_multimap and boost::unordered_multimap
by Ram 06 Oct '17

06 Oct '17

Hi, I need help in determining the amount of memory used by boost::unordered_multimap and boost::unordered_multimap. We have a large code base and we have some optimizations done using boost::unordered_multimap and boost::unordered_multimap. The speed it really good, but we want to measure the amount of space it is occupying. Can somebody please help with that? I would not be able to change to use a custom new/delete. Thanks

3 5

Why no mpl::_double?
by Florian Lindner 06 Oct '17

06 Oct '17

Hello, is there a reason why there are only integral types in the boost MPL, no double or alike? http://www.boost.org/doc/libs/1_65_1/libs/mpl/doc/refmanual/numeric.html What is the best way to achieve: template<> struct getArg<Multiquadrics> : boost::mpl::double_<1e-3> {}; so that it is compatible with mpl::list? besides just writing the struct myself :-) Thanks, Florian

1 0

[stacktrace] Test failures with Xcode 9
by Nat Goodspeed 06 Oct '17

06 Oct '17

I've just started building Boost 1.65.1 Stacktrace. On Mac with Xcode 9, I'm dismayed that it has failed a couple of its own self-tests. Lengthy (albeit snipped) output follows. darwin.compile.c++ bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/test.o "g++" -O3 -Wall -pedantic -g -dynamic -gdwarf-2 -fexceptions -Wno-long-long -Wno-inline -fPIC -arch x86_64 -DBOOST_STACKTRACE_GNU_SOURCE_NOT_REQUIRED -O3 -fPIC -gdwarf-2 -stdlib=libc++ -mmacosx-version-min=10.9 -iwithsysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk/ -DLL_RELEASE=1 -DLL_RELEASE_FOR_DOWNLOAD=1 -DNDEBUG -DPIC -DLL_DARWIN=1 -DLL_OS_DRAGDROP_ENABLED=1 -DCARES_STATICLIB -DLIB_NDOF=1 -Wno-c99-extensions -Wno-unused-const-variable -Wno-unused-function -Wno-unused-local-typedef -Wno-variadic-macros -std=c++14 -DBOOST_ALL_NO_LIB=1 -DBOOST_STACKTRACE_USE_ADDR2LINE -DNDEBUG -I"." -I"/Users/nat/linden/3p-boost-64/boost/stage/packages/include" -I"/Users/nat/linden/3p-boost-64/boost/stage/packages/include/zlib" -c -o "bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/test.o" "libs/stacktrace/test/test.cpp" darwin.compile.c++ bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/test_impl.o "g++" -O3 -Wall -pedantic -g -dynamic -gdwarf-2 -fexceptions -Wno-long-long -Wno-inline -fPIC -arch x86_64 -DBOOST_STACKTRACE_GNU_SOURCE_NOT_REQUIRED -O3 -fPIC -gdwarf-2 -stdlib=libc++ -mmacosx-version-min=10.9 -iwithsysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk/ -DLL_RELEASE=1 -DLL_RELEASE_FOR_DOWNLOAD=1 -DNDEBUG -DPIC -DLL_DARWIN=1 -DLL_OS_DRAGDROP_ENABLED=1 -DCARES_STATICLIB -DLIB_NDOF=1 -Wno-c99-extensions -Wno-unused-const-variable -Wno-unused-function -Wno-unused-local-typedef -Wno-variadic-macros -std=c++14 -DBOOST_ALL_NO_LIB=1 -DBOOST_STACKTRACE_USE_ADDR2LINE -DNDEBUG -I"." -I"/Users/nat/linden/3p-boost-64/boost/stage/packages/include" -I"/Users/nat/linden/3p-boost-64/boost/stage/packages/include/zlib" -c -o "bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/test_impl.o" "libs/stacktrace/test/test_impl.cpp" darwin.link bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho "g++" -o "bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho" "bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/test.o" "bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/test_impl.o" -g -Wl,-dead_strip -no_dead_strip_inits_and_terms -arch x86_64 testing.capture-output bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho.run status=0 if test $status -ne 0 ; then echo Skipping test execution due to testing.execute=off exit 0 fi "bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho" > "bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho.output" 2>&1 < /dev/null status=$? echo >> "bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho.output" echo EXIT STATUS: $status >> "bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho.output" if test $status -eq 0 ; then cp "bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho.output" "bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho.run" fi verbose=0 if test $status -ne 0 ; then verbose=1 fi if test $verbose -eq 1 ; then echo ====== BEGIN OUTPUT ====== cat "bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho.output" echo ====== END OUTPUT ====== fi exit $status ====== BEGIN OUTPUT ====== ... 0# foo1(int) in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho 1# foo2(int, std::__1::pair<boost::stacktrace::basic_stacktrace<std::__1::allocator<boost::stacktrace::frame> >, boost::stacktrace::basic_stacktrace<std::__1::allocator<boost::stacktrace::frame> > > (*)(int)) in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho 2# foo1(int) in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho 3# foo2(int, std::__1::pair<boost::stacktrace::basic_stacktrace<std::__1::allocator<boost::stacktrace::frame> >, boost::stacktrace::basic_stacktrace<std::__1::allocator<boost::stacktrace::frame> > > (*)(int)) in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho ... 14# foo1(int) in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho 15# foo2(int, std::__1::pair<boost::stacktrace::basic_stacktrace<std::__1::allocator<boost::stacktrace::frame> >, boost::stacktrace::basic_stacktrace<std::__1::allocator<boost::stacktrace::frame> > > (*)(int)) in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho 16# void test_nested<15ul>() in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho 17# main in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho libs/stacktrace/test/test.cpp(200): test 'min_size > 2' failed in function 'void test_frame()' ' 0# foo1(int) in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho 1# foo2(int, std::__1::pair<boost::stacktrace::basic_stacktrace<std::__1::allocator<boost::stacktrace::frame> >, boost::stacktrace::basic_stacktrace<std::__1::allocator<boost::stacktrace::frame> > > (*)(int)) in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho 2# foo1(int) in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho 3# foo2(int, std::__1::pair<boost::stacktrace::basic_stacktrace<std::__1::allocator<boost::stacktrace::frame> >, boost::stacktrace::basic_stacktrace<std::__1::allocator<boost::stacktrace::frame> > > (*)(int)) in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho ... 300# foo1(int) in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho 301# foo2(int, std::__1::pair<boost::stacktrace::basic_stacktrace<std::__1::allocator<boost::stacktrace::frame> >, boost::stacktrace::basic_stacktrace<std::__1::allocator<boost::stacktrace::frame> > > (*)(int)) in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho 302# void test_nested<300ul>() in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho 303# main in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho ' 0# foo1(int) in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho 1# foo2(int, std::__1::pair<boost::stacktrace::basic_stacktrace<std::__1::allocator<boost::stacktrace::frame> >, boost::stacktrace::basic_stacktrace<std::__1::allocator<boost::stacktrace::frame> > > (*)(int)) in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho 2# foo1(int) in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho 3# foo2(int, std::__1::pair<boost::stacktrace::basic_stacktrace<std::__1::allocator<boost::stacktrace::frame> >, boost::stacktrace::basic_stacktrace<std::__1::allocator<boost::stacktrace::frame> > > (*)(int)) in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho ... 300# foo1(int) in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho 301# foo2(int, std::__1::pair<boost::stacktrace::basic_stacktrace<std::__1::allocator<boost::stacktrace::frame> >, boost::stacktrace::basic_stacktrace<std::__1::allocator<boost::stacktrace::frame> > > (*)(int)) in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho 302# void test_nested<300ul>() in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho 303# main in /Users/nat/linden/3p-boost-64/boost/bin.v2/libs/stacktrace/test/addr2line_ho.test/darwin-4.2.1/release/debug-symbols-on/addr2line_ho libs/stacktrace/test/test.cpp(282): test 'boost::stacktrace::stacktrace(1, 1).size() == 1' failed in function 'int main()' 2 errors detected. EXIT STATUS: 1 ====== END OUTPUT ======

1 3

[Units]
by CD Clark 06 Oct '17

06 Oct '17

I am trying to create a set of units to use in a library, but I having trouble getting IO to work for some of them. Here is a simple example that demonstrates the problem. ============================ #include<iostream> #include <boost/units/systems/si.hpp> #include <boost/units/systems/si/io.hpp> using namespace boost::units; // short hand for meter namespace t { typedef si::length m; } namespace i { BOOST_UNITS_STATIC_CONSTANT( m, t::m ); } // centimeter namespace t { typedef make_scaled_unit< si::length, scale< 10, static_rational<-2> > >::type cm; } namespace i { BOOST_UNITS_STATIC_CONSTANT( cm, t::cm ); } // meter squared namespace t { typedef multiply_typeof_helper< m, m>::type m_m; } namespace i { BOOST_UNITS_STATIC_CONSTANT( m_m, t::m_m ); } // centimeter squared namespace t { typedef multiply_typeof_helper< cm, cm>::type cm_cm; } namespace i { BOOST_UNITS_STATIC_CONSTANT( cm_cm, t::cm_cm ); } // meter centimeter namespace t { typedef multiply_typeof_helper< m, cm>::type m_cm; } namespace i { BOOST_UNITS_STATIC_CONSTANT( m_cm, t::m_cm ); } // override default output, which prints "c(m^2)" namespace boost { namespace units { inline std::string name_string(const t::m_cm&) { return "meter centimeter"; } inline std::string symbol_string(const t::m_cm&) { return "m cm"; } } } // trying to overload output for centimeter squared namespace boost { namespace units { inline std::string name_string(const t::cm_cm&) { return "centimeter squared"; } inline std::string symbol_string(const t::cm_cm&) { return "cm^2"; } } } int main(int argc, char *argv[]) { std::cout << i::m << std::endl; std::cout << i::cm << std::endl; std::cout << i::m_m << std::endl; std::cout << i::m_cm << std::endl; //std::cout << i::cm_cm << std::endl; // this won't compile quantity<t::m_m> a1(100*i::cm_cm); std::cout << a1<< std::endl; // should be 0.01 m^2 quantity<t::m_m> a2(100*i::m_cm); std::cout << a2<< std::endl; // should be 1 m^2 return 0; } ============================ Basically, I am just trying to create a convenient set of short hands. Unit types are put in a 't' namespace and instances are put in a 'i' namespace with the same name. This works fine for doing calculations and conversions with the units, but I am having trouble with getting output to work for some of them. In the example above I create a centimeter unit by scaling the meter. Then I create three different area units with the product_typeof_helper struct: meter squared, meter centimeter, and centimeter squared. Conversions work for all three of these, but output will not work for the centimeter squared unit. The program above outputs m cm m^2 m cm 0.01 m^2 1 m^2 If I uncomment the line that tries to print i::cm_cm it won't compile. I get an error that says 'symbol' is not a member of ... and points at a line that says str += Begin::item::symbol() I can't understand why it doesn't work for a product of two scaled units. cdclark

2 4

Re: [Boost-users] boost::process
by Chris Rodgers 05 Oct '17

05 Oct '17

To answer my own question - this is one working possibility using boost::process::extend... #include <boost/process.hpp> #include <boost/process/extend.hpp> int main() { boost::filesystem::path myPath(".........toRun.exe......."); auto set_own_window = [](auto & exec) { exec.creation_flags |= boost::detail::winapi::CREATE_NEW_CONSOLE_; std::cerr << "in set_own_window" << std::endl; /* just for debugging */ }; bp::child c(myPath, "argument1", boost::process::extend::on_setup=set_own_window); return 0; } This works. Is it the right approach, or is there a better way? Best wishes, Chris. On 05/10/2017 17:14, Chris Rodgers wrote: > Hi, > > I'm trying to use Boost 1.65.1's boost::process::child in a Windows > console program. > > At the moment, the child process is launched in the same console window > as the parent. > > Is there an option to make a new console window for the child? > > The pre-boost-incorporation version of boost::process seemed to allow > manipulation of the startupInfo struct directly (e.g. > https://stackoverflow.com/questions/43582022/boostprocess-hide-console-on-w…) > and then a win32_launch call. But this seems to have been removed now? > > Any tips gratefully received. > > Thanks, > > Chris. >

1 0

PolyCollection requiring copyable
by d3fault 05 Oct '17

05 Oct '17

I'm impressed with PolyCollection. I use the list<interface*> strategy tons in my projects, and I didn't think NOT using a pointer there was even possible... but somehow you managed. It also makes sense why PolyCollection is faster to execute etc, the tutorial was well written. The only 'con' is that it requires a copy constructor. You mention later that some copy traits thing can be used to move the "copy code" outside of the class, but I am questioning the need for copying altogether. Is "copying" of the polymorphic types necessary for: a) Technical requirement otherwise it wouldn't compile b) Design decision because you think it's superior and helpful c) To facilitate copying of the PolyCollection object itself ....? If (b) or (c), can there be a slightly altered version of PolyCollection which does not allow/require copying? I'm completely fine (and even happier) _not_ being able to copy the PolyCollection. When I use the list<interface*> strategy, I tend to consider the list to be the owner of it's objects (and delete them when the list is deleted). There should be PolyCollection::emplace and the poly instances should "live" in the PolyCollection. Accessing the poly instances should be by [const] reference only (isn't this already the case? what benefit does the copy constructor bring?!?). I didn't examine the source so maybe it's (a) after all, in which case I apologize for wasting precious time, bandwidth, and disk space. d3fault

5 11

boost::process
by Chris Rodgers 05 Oct '17

05 Oct '17

Hi, I'm trying to use Boost 1.65.1's boost::process::child in a Windows console program. At the moment, the child process is launched in the same console window as the parent. Is there an option to make a new console window for the child? The pre-boost-incorporation version of boost::process seemed to allow manipulation of the startupInfo struct directly (e.g. https://stackoverflow.com/questions/43582022/boostprocess-hide-console-on-w…) and then a win32_launch call. But this seems to have been removed now? Any tips gratefully received. Thanks, Chris.

1 0

looking for a memory leak in an asio based application
by David Medine 05 Oct '17

05 Oct '17

I know that the answer to this question is /always/ 'no'. But is it possible, just possible that one can leak memory out of boost::asio? Let me explain. I work on an open source client/server data streaming library for multi-modal data streaming called labstreaminglayer (https://github.com/sccn/labstreaminglayer) At the core of the data transmission architecture is boost::asio. Now, to avoid calling collisions, the original author of the library shipped the source code with a name-mangled version of boost. Over the years this has yet to be updated so we are still relying on boost 1.57. The memory leak starts on the server side after a client is connected to it. This went undetected for years because it is very very slow and it depends on the sampling rate of the data stream. LSL (labstreaminglayer) is widely used in the neurophysiological research community (for whom the tool was intended), but normally in that field you are not sending samples faster than 500 Hz or so. But some devices are now available that offer relatively high sampling rates (e.g. Brain Products' actiCHamp can go as fast as 100kHz). The amount of memory that leaks seems to depend on how often data is sent, not how much data is send at a time. So, when the data is flowing quickly, the leak is severe. I am 99.99% sure that the allocation of memory for all the data I am sending is getting deallocated correctly. I don't see any leaking memory according to Visual Studio's diagnostic tools, nor can Deleaker spot anything. However, when I look at a server process in task manager, I can see the memory rising. I tried the asio::io_service::work trick (https://stackoverflow.com/questions/32258890/c-boost-asio-async-send-to-mem…) on my io_services, but this didn't have any effect. I have not gone through the whole pipeline yet, but I've been at this for two harrowing days already. So I just thought I would ask the list if anyone has seen anything like this before or if there has been any slow-leak fixes in boost (particularly asio) since 1.57 (I didn't see anything in the logs, but maybe I missed something). Due to the state of the project at this moment, it is non-trivial to update the name-mangled boost to another version, but it is far less trivial than the needle-in-a-haystack game I am playing right now. So, if someone can say with authority a boost update will fix everything I'll just do that and be happy. It's a long-shot, I know.

2 1

Bost Logging
by Mário Costa 04 Oct '17

04 Oct '17

Hi, I'm havving a bad time trying to figure out how to add and log custom keywords using boost/log. I havent been able to understand how exactly attribute keywords (BOOST_LOG_ATTRIBUTE_KEYWORD) bind with logging e.g. using BOOST_LOG_STREAM_WITH_PARAMS(logger, (??) (??)). For instance, if I define a keyword line_number, BOOST_LOG_ATTRIBUTE_KEYWORD(line_number, "LineNumber", unsigned int) and add it to the formmater logging::formatter formatter = expr::stream << "[" << line_number << "]" How do I use BOOST_LOG_STREAM_WITH_PARAMS(logger, (??)) Tanking an exemple from the severities, I should use a keyword parameter defining something like BOOST_PARAMETER_KEYWORD(sometag, line_number) then I should be able to use BOOST_LOG_STREAM_WITH_PARAMS(logger, (line_number = 10)) But those things just don add up together. I for sure missing the logics of the logging ... Thanks for any help! Cheers, mc

1 0

[geometry] Get points within certain radius?
by Florian Lindner 03 Oct '17

03 Oct '17

Hello, first of all thanks for the repliest to my previous geometry question! What is the best, especially fastest way to get all points within a certain radius of a point? Using the iterator method with nearest(pt, X) highly depends on X. Since I don't know this number, I have to guess it rather high. for (auto it = rtree.qbegin(bgi::nearest(point, results)) ; it != rtree.qend() ; ++it) { std::ignore = it; break; } results = 10 => time = 3.0s results = 100 => time = 22.6s results = 200 => time = 71.4s results = 300 => time = 153.2s though I always use just one result. The loop is inside another loop, not depending on results, so of course, the times are multiples of the actual times for that query. But clearly, choosing high numbers for results is not feasible. Another idea is to use the within() query with a circle of a radius. But bg seems to have no circle or sphere model. A workaround would be to use a box instead of a sphere. That means I have to test the results again, whether they are actually contained in th sphere. Alternatively, I could use the satisfies predicate. But wouldn't I give up all spatial information? This predicate needs to compare all vertices, don't it? It does include the knowledge, that when one point is discarded, all other points with a greater distance will discarded too. According to https://stackoverflow.com/questions/22909171/boostgeometry-nearest-neighbor…, the way to go seems to be to combine within(boundingBox) and satisfies(). Any other ideas? Thanks, Florian

2 1

[test] Is standalone use possible?
by Adam Nielsen 02 Oct '17

02 Oct '17

Hi all, I'm in the process of trying to remove the Boost dependency from my project, as it is causing too many difficulties for non-developers trying to run my code. This has been mostly solved by switching to C++11 and using the std:: implementations instead, however rather than rewrite all my unit tests I am hoping I can use a standalone version of Boost.Test, and distribute the code alongside my own. Unfortunately I am not quite sure how to extract the Test library out of the main Boost distribution. I have compiled "bcp" and used it to copy "test" into a new folder, but it seems to copy a huge chunk of Boost as well, including a bunch of libraries (system, thread, date_time, etc.) and I end up with 29 MB of source files, which seems wrong (especially considering my own codebase is barely 500 kB). Am I doing something wrong? I was hoping to use the header-only version of Boost.Test and this does seem to work when I #include the system-wide version of Boost (and don't link to any libraries), so it would seem that I don't need all those libraries that bcp copies. Is there any other way to access a slimmed-down standalone version of Boost.Test? Many thanks, Adam.

6 12

ק
by Ami Tavory 29 Sep '17

29 Sep '17

1 0

Enhancing the boost::asio::connect() socket interface
by martin doc 29 Sep '17

29 Sep '17

(apologies if this should be on -developers...) The connect() interface provided by boost caters to most common use and through access to the socket, various options can be managed without much hindrance. But there's one situation that boost does not handle well - when it is desirable to specify the local address to bind to. Going back to C, the usual program flow in this situation is something like this: fd = socket() bind(fd, local ip address) connect(fd, remote ip address) As boost::asio::connect() closes an open socket passed to it before making the remote connection, it's not possible to pass connect() a prebaked socket. In fact the amount of code required to use boost when binding a socket to a local address is more complicated than simply not using boost. What I'd like the boost community to consider is extending boost::asio to provide one or more variants of connect() that allows for a local endpoint (whether or not as an iterator I'll leave to others to debate but this isn't necessary - and then there's the M*N behavior or paired to decide) to be supplied in addition to the remote endpoint. I suppose I'm open minded as to whether or not the local address is supplied as an Iterator/endpoint as an extra arg or whether connect() is adopted to take endpoint pairs. Thoughts?

5 4

Analogous to DESTDIR for Boos installation
by Leo Cacciari 29 Sep '17

29 Sep '17

Hi, I need to prepare a binary distribution of Boost for deploying on company hosts. For this, I need to configure libraries with a prefix of say /usr/local, doing as per documentation ./bootstrap.sh --prefix=/some/path where /some/path is the actual path where the libraries and header flles will be installed on the various hosts. To prepare the package to be distributed (the actual packaging system used is irrelevant here, simply assuming a tar.gz would do) I need, however, to "install" everything under some other path, say /path/to/package/content. When using gnu packages, I usually do something like ./configure --prefix=/some/path make make DESTDIR=/path/to/package/content install and then I can prepare and distribute my package. I'm unable to find an analogous procedure for Boost. More exactly, I do not found a way to invoke the install phase of b2 with a different prefix than the one specified to the stage phase through the --prefix options to boostrap.sh I solved the problem in a unsatisfactory way by manually copying the files from both the source and the build directory to the content folder, but I'd really like to have an automated way to do it. Is this possible? If yes, how? And if not, does anyone have a better idea than manual copying? Thanks for the help -- Leo Cacciari Aliae nationes servitutem pati possunt. Populi Romani est propria libertas.

2 1

[review] The review period of Boost.DoubleEnded has been extended with one week. Now ends 7th of October.
by Thorsten Ottosen 28 Sep '17

28 Sep '17

Dear users and members of Boost, People have been requesting extra time for the review of Boost.DoubleEnded. We therefore continue one week extra, so the final date will be October the 7th. kind regards Thorsten Original review announcement ------------------------------------------ I'm proud to announce that the formal review of Benedek Thaler's Boost.DoubleEnded library starts today, September 21, and runs through September 30. This library is the result of Benedek's participation in Google Summer of Code 2015. The library may be downloaded from https://github.com/erenon/double_ended and the documentation may be found here: http://erenon.hu/double_ended/ Anyone is welcome to post a review and/or take part in subsequent discussions (see below for review guidelines). Introduction ------------ This is a container library that provides two containers: A. boost::devector B. boost::batch_deque Both containers provides efficient push_front and push_back operations, hence the name DoubleEnded. The boost::devector class can be seen as an extension of std::vector with efficient support for push_front (so boost::devector provides contiguous storage). In addition, it provides a customizable small buffer optimization like boost::small_vector(*). It furthermore allows for customization of the growth factor such that the user can decide if a reallocation should allocate 1.5 or 2 or whatever more memory. And finally it provides new functionality that does not exist in normal vector implementations -- this functionality allow the class to excel in performance in certain situations like serialization or transfer of data from sources that require a preallocated buffer. The boost::batch_deque is similar to std::deque, but with two important twists. Like std::deque, it provides reference stability when calling push_front/push_back. Reference stability is crucial for programs that uses intrusive containers e.g. using Boost.Intrusive (**). boost::batch_deque has the following main advantages: 1. It allows the user to specify the segment size 2. It allows for external iteration over the segments Taken together, they provide a very efficient and flexible basis for intrusive containers. Access to the segments also increases performance for tasks such as serialization. Finally, boost::batch_deque may be seen as an efficient alternative to std::vector if you want to replace a percent-wise memory overhead with a constant memory overhead and have no need for contiguous storage. Review guidelines ----------------- Please provide in your review whatever information you think is valuable to understand your final choice of ACCEPT or REJECT including Boost.DoubleEnded as a Boost library. Please be explicit about your decision. Some other questions you might want to consider answering: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With which compiler(s)? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? More information about the Boost Formal Review Process can be found here: http://www.boost.org/community/reviews.html Kind regards Thorsten, Review manager (*) boost::small_vector: https://tinyurl.com/ycslp4ot (**) http://www.boost.org/doc/libs/1_64_0/doc/html/intrusive.html -- Best regards, Thorsten Jørgen Ottosen, Ph.D. Director of Research +45 23308797 Dezide (www.dezide.com)

1 0

[geometry] Runtime dimensionality
by Florian Lindner 28 Sep '17

28 Sep '17

Hello, I just started yesterday looking into boost.geometry to use on our own legacy system of Vertices (Points) in Meshes. I'm quite impressed how easy it is to adapt to existing code and got it working (with some workarounds) really quick. However, some problems remain. We have a Vertex object, with a dimension determined at runtime. The actual position is saved as VECTOR_T (usually an Eigen::VectorXd (double vector of arbitrary dimension)). One can get the coordinates using "const Eigen::VectorXd& Vertex::getNormal()" I was able to adapt to geometry by adding getters/setts for the dimensions: double getX() and getY() and BOOST_GEOMETRY_REGISTER_POINT_2D_GET_SET(mesh::Vertex, double, cs::cartesian, getX, getY, setX, setY) and it works! But in theory the vertices can be of arbitrary dimension, in practice it's usually 1, 2 or 3. What is the best way to adapt our Vertex object to geometry? - Change our Vertex so that it meets the model::point requirements. It worked so far, for the access I use: template<size_t Dimension> struct access<Vertex, Dimension> { static double get(Vertex const& p) { return p.getCoords()[Dimension]; } static void set(Vertex& p, double const& value) { Eigen::VectorXd vec = p.getCoords(); vec[Dimension] = value; p.setCoords(p); } }; In our code we rarely set the entries of an vector, so the code is a but ugly. Will likely change that to a compile-time get<Dim>() as a member of Vertex. My biggest problem is the dimensionality template<> struct dimension<Vertex> : boost::mpl::int_<2> {}; but I have no idea currently how to get that for an Eigen::VectorXd at compile-time? Do you have any idea? Thanks! Florian

5 8

Problem updating code to boost 1.64
by Tim Burgess 26 Sep '17

26 Sep '17

Hi, I have an application that I'm resurrecting. I originally coded it using Visual Studio 2010 with the boost that was current at the time (not sure what version that was). The following line of code used to build fine: if (CurrentAction[ 0].As <std::wstring>().compare( wstrFunctionName) == 0) With my current boost 1.64, I get the following error: >c:\users\tim\projects\surfacereader\screenreaderfunctionsdlg.cpp(146): error C2039: 'As': is not a member of 'boost::any' The intent of the code is as follows: If CurrentAction[ 0] (which is a boost::any) contains an std::wstring value, compare it to wstrFunctionName. Can anybody offer some guidance, please? Best wishes. Tim Burgess

2 1

[review][Fit] Review Results
by Matt Calabrese 24 Sep '17

24 Sep '17

Hello everyone, It is my privilege to announce that the Boost library count will once again be incremented as Paul Fultz II's library Fit has been accepted into Boost without conditions. Further details about this decision follow, but before that I'd like to thank Paul for all of the hard work he has put into Fit. Thanks also to everyone who participated in the review, with additional thanks to Vicente who was the review manager for the previous Fit review and who also provided a very detailed review and discussion during this review period. //////////////////////////////////////////////////////////////////////////////// Overview //////////////////////////////////////////////////////////////////////////////// Complete Reviews Considered: Zach Laine: Accept Vicente J. Botet Escriba: Accept John P. Fletcher: Accept Robert Ramey: Accept Jason Rice: Accept Barrett Adair: Accept Lee Clagett: Accept Glen Fernandes: Accept Louis Dionne: Accept Partial Reviews/Discussions Considered: Edward Diener Andrea Bocci Further Discussions (Previous Review): Steven Watanabe Peter Dimov Vladimir Batov Gavin Lambert Rob Stewart Bjorn Reese Manu Sanchez Artyom Beilis //////////////////////////////////////////////////////////////////////////////// Summary //////////////////////////////////////////////////////////////////////////////// Though not all responders reviewed every single aspect of the library, the reviews together adequately covered everything that is necessary for a decision to be made. This decision is made with additional confidence coming from usage of the library by some reviewers going back since during or before the initial review in early 2016. //////////////////////////////////////////////////////////////////////////////// Improvements Since Previous Review //////////////////////////////////////////////////////////////////////////////// This time around we received several more complete reviews than in the previous review period making it easier to be confident in a decision. A couple of notable changes since the 2016 review include: * Improved documentation * Default semantics for "capture" no longer try to determine whether to capture by reference or by value based on the argument being an lvalue or an rvalue (users can still get this via basic_capture) * Improved ADL awareness (internal calls are qualified) Throughout all of the discussions in this second review period, there were no explicit rejections of the library as a whole, though there were several recommendations from participants. A selection of those are listed here, though no changes are strictly required for acceptance: //////////////////////////////////////////////////////////////////////////////// Current Concerns //////////////////////////////////////////////////////////////////////////////// ////////// Design concerns: * Inheritance from user-callables has some potential pitfalls * Generated "infix" operators are "gimmicky" and don't add much value/may cause confusion * Placeholders should live in their own namespace ////////// Documentation concerns (not a complete list): * More examples requested * It is not always clear what files need to be #included for certain facilities in early examples * Better rationale for ConstFunctionObjects * Raw code is not linked from the examples ////////// Suggested name changes from reviewers: * Suggested rename of "partial()" to "partial_apply()" or "curry()" * Suggested rename of "conditional()" to "invoke_first()" or "call_first_of()" * Suggested rename of "apply" to "invoke" * Refer to "Callables" instead as "Invocables" (due to C++17 direction) * Library name "Fit" is not indicative of what it provides //////////////////////////////////////////////////////////////////////////////// Regarding the Author //////////////////////////////////////////////////////////////////////////////// Paul has been active in the Boost community for several years now. He is aware of his responsibilities going forward and I am confident that he will be a reliable maintainer for Fit for the foreseeable future (or whatever the library may be called). //////////////////////////////////////////////////////////////////////////////// Comments on the Name Boost.Fit //////////////////////////////////////////////////////////////////////////////// Note that what I say here is my personal opinion as a member of the community and does not necessarily reflect the opinions of others in the community nor of those in the steering committee. A few reviewers voiced that they would like to see a change of the library name "Fit". While multiple people did suggest this, my opinion is that this should be up to the author to choose whether or not he will change the name before it is added to boost and so I do not think it would be appropriate for us to strictly require or encourage such a change. If the author found the arguments against the name compelling, then he is welcome to change the name, but he should not feel obligated to do so. As a quick note on that, we have several high quality and highly regarded libraries in Boost with names that may not directly tell users what the library is for. Based on their popularity, I do not believe that it has significantly negatively affected their usage or ability to be found. A library name also may be important to an author as a creative outlet and I think it would be... poor form us to force such a change in this particular case and in other cases unless there are very strong reasons (i.e. the name is overly or intentionally misleading or there are legal concerns). I am not convinced that the current name is misleading enough to strictly require a change. As for existing precedent, some examples of libraries already in Boost with names that do not directly tell the user what the library is for include some of Boost's most highly regarded libraries such as Boost.Spirit (including Qi and Karma), Boost.Phoenix, Boost.Wave, Boost.Hana, and the recently accepted Boost.Beast. //////////////////////////////////////////////////////////////////////////////// Thanks again to everyone who participated in this review and in the previous review, and once again, congratulations to Paul on his library's acceptance into Boost. -- -Matt Calabrese -- -Matt Calabrese

1 0

[review] The review of Boost.DoubleEnded starts today: September 21 - September 30
by Thorsten Ottosen 21 Sep '17

21 Sep '17

Dear users and members of Boost, I'm proud to announce that the formal review of Benedek Thaler's Boost.DoubleEnded library starts today, September 21, and runs through September 30. This library is the result of Benedek's participation in Google Summer of Code 2015. The library may be downloaded from https://github.com/erenon/double_ended and the documentation may be found here: http://erenon.hu/double_ended/ Anyone is welcome to post a review and/or take part in subsequent discussions on the boost developer list (see below for review guidelines). Introduction ------------ This is a container library that provides two containers: A. boost::devector B. boost::batch_deque Both containers provides efficient push_front and push_back operations, hence the name DoubleEnded. The boost::devector class can be seen as an extension of std::vector with efficient support for push_front (so boost::devector provides contiguous storage). In addition, it provides a customizable small buffer optimization like boost::small_vector(*). It furthermore allows for customization of the growth factor such that the user can decide if a reallocation should allocate 1.5 or 2 or whatever more memory. And finally it provides new functionality that does not exist in normal vector implementations -- this functionality allow the class to excel in performance in certain situations like serialization or transfer of data from sources that require a preallocated buffer. The boost::batch_deque is similar to std::deque, but with two important twists. Like std::deque, it provides reference stability when calling push_front/push_back. Reference stability is crucial for programs that uses intrusive containers e.g. using Boost.Intrusive (**). boost::batch_deque has the following main advantages: 1. It allows the user to specify the segment size 2. It allows for external iteration over the segments Taken together, they provide a very efficient and flexible basis for intrusive containers. Access to the segments also increases performance for tasks such as serialization. Finally, boost::batch_deque may be seen as an efficient alternative to std::vector if you want to replace a percent-wise memory overhead with a constant memory overhead and have no need for contiguous storage. Review guidelines ----------------- Please provide in your review whatever information you think is valuable to understand your final choice of ACCEPT or REJECT including Fit as a Boost library. Please be explicit about your decision. Some other questions you might want to consider answering: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With which compiler(s)? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? More information about the Boost Formal Review Process can be found here: http://www.boost.org/community/reviews.html Kind regards Thorsten, Review manager (*) boost::small_vector: https://tinyurl.com/ycslp4ot (**) http://www.boost.org/doc/libs/1_64_0/doc/html/intrusive.html

1 0

Linker error when using Boot regex on AIX
by Jyoti Sharma 18 Sep '17

18 Sep '17

I am using boost_1_61_0. In my code I have: #include <boost/regex.hpp> static boost::regex testxp("["); I have these libraries: libboost_regex.a libboost_regex.so I can see these libraries have symbols: LIBRARY: Shared object libboost_regex.so: 136 symbols imported. LIBRARY: Shared object libboost_system.so: 7 symbols imported. To build my program I have added these linking options: -Wl,-bnoquiet -Wl,-Bstatic -lboost_regex -lboost_system -Wl,-Bdynamic But I get this error during linking: ld: 0711-317 ERROR: Undefined symbol: .boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::do_assign(char const*, char const*, unsigned int) But that symbol is there: machine:/home> nm libboost_regex.so nm libboost_regex.so |grep do_assign ._ZN5boost11basic_regexIcNS_12regex_traitsIcNS_16cpp_regex_traitsIcEEEEE9do_assignEPKcS7_j T 268508592 machine:/home> c++filt ._ZN5boost11basic_regexIcNS_12regex_traitsIcNS_16cpp_regex_traitsIcEEEEE9do_assignEPKcS7_j .boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::do_assign(char const*, char const*, unsigned int)

2 3

Last Day for Boost Community Dinner Sign up
by Jon Kalb 18 Sep '17

18 Sep '17

Boost Users, Today is the last day to register for the Boost Community Dinner at CppCon. http://sched.co/Bhcr You do not need to be registered to attend CppCon to register for the Boost Community Dinner: https://cppcon.org/registration/ If you are going to be in the Seattle area a week from Tuesday, join us for a rare face-to-face get together of the Boost Community. See you there. Jon

1 0

[fiber] pooled_fixedsize_stack
by DePizzottri 14 Sep '17

14 Sep '17

Hi, I'm trying to replace fixedsize_stack with pooled_fixedsize_stack in my application witch spawns many fibers to reduce allocations, and got random crashes. For reproduction it is enough to replace fixedsize_stack with pooled_fixedsize_stack in performance\fiber\skynet_stealing_detach.cpp. Playing with stack size parameter does not help. Can anyone give some tip how to use pooled stack with fiber correctly? -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Users-f2553780.html

3 5

Help trying to compile boost 1_65_1 on Windows (Visual Studio 2017) with LZMA filter support
by Diego Luna 12 Sep '17

12 Sep '17

Hello everyone, this is my first post. Like the subject says, I need some help compiling boost 1_65_1 on Windows (Visual Studio 2017) on 64 bits with LZMA filter support. I've been compiling boost on Windows and Linux for some time without any problems, but the LZMA support in Windows, caused me some problems. I've downloaded and compiled the LZMA lib (XZ utils from https://tukaani.org/xz/) producing static (lib) and shared(dll+lib) libraries, in release and debug variants, then I have written the following user config jam (I think the problem is in the syntax of the file): ########################################## ## Using Python 3.6 (64 bits). ## using python : 3.6 : C:\\APPS\\PROGRAMMING\\Python36-64\\python.exe : C:\\APPS\\PROGRAMMING\\Python36-64\\include : C:\\APPS\\PROGRAMMING\\Python36-64\\libs : <address-model>64 ; ## Using lzma library 5.2.3. ## ## using lzma : 5.2.3 : <name>liblzma <include>C:\\APPS\\PROGRAMMING\\LIBRARIES\\lzma\\include <search>C:\\APPS\\PROGRAMMING\\LIBRARIES\\lzma\\lib64 : <variant>release <link>shared ; using lzma : 5.2.3 : <name>liblzmad <include>C:\\APPS\\PROGRAMMING\\LIBRARIES\\lzma\\include <search>C:\\APPS\\PROGRAMMING\\LIBRARIES\\lzma\\lib64 : <variant>debug <link>shared ; using lzma : 5.2.3 : <name>liblzma_static <include>C:\\APPS\\PROGRAMMING\\LIBRARIES\\lzma\\include <search>C:\\APPS\\PROGRAMMING\\LIBRARIES\\lzma\\lib64 : <variant>release <link>static ; using lzma : 5.2.3 : <name>liblzma_staticd <include>C:\\APPS\\PROGRAMMING\\LIBRARIES\\lzma\\include <search>C:\\APPS\\PROGRAMMING\\LIBRARIES\\lzma\\lib64 : <variant>debug <link>static ; ########################################## The command line for the actual compiling (after bootstrap), (omitting the path to the other libraries for shortness, those are linked\compiled without any problem) is: .\b2 -j6 --user-config=.\user-config-64.jam --build-type=complete -q -sZLIB_SOURCE="%ZLIB_ROOT%" -sBZIP2_SOURCE="%BZIP2_ROOT%" -sICU_PATH="%ICU_LIB%" toolset=msvc-14.1 link="static,shared" threading=multi ^ variant="debug,release" architecture=x86 address-model=64 runtime-link=shared stage --debug-symbols=on --debug-store=database --debug-configuration -d2 The output is: notice: found boost-build.jam at E:/DATA/TMP/boost/boost_1_65_1/boost-build.jam notice: loading Boost.Build from E:/DATA/TMP/boost/boost_1_65_1/tools/build/src notice: Searching 'C:\WINDOWS' 'C:\Users\bakaneko' 'C:\APPS\TOOLS\UNIX-HOME' 'C:\Users\bakaneko' 'E:\DATA\TMP\boost\boost_1_65_1\tools/build/src' 'E:/DATA/TMP/boost/boost_1_65_1/tools/build/src/kernel' 'E:/DATA/TMP/boost/boost_1_65_1/tools/build/src/util' 'E:/DATA/TMP/boost/boost_1_65_1/tools/build/src/build' 'E:/DATA/TMP/boost/boost_1_65_1/tools/build/src/tools' 'E:/DATA/TMP/boost/boost_1_65_1/tools/build/src/contrib' 'E:/DATA/TMP/boost/boost_1_65_1/tools/build/src/.' for site-config configuration file 'site-config.jam'. notice: Configuration file 'site-config.jam' not found in 'C:\WINDOWS' 'C:\Users\bakaneko' 'C:\APPS\TOOLS\UNIX-HOME' 'C:\Users\bakaneko' 'E:\DATA\TMP\boost\boost_1_65_1\tools/build/src' 'E:/DATA/TMP/boost/boost_1_65_1/tools/build/src/kernel' 'E:/DATA/TMP/boost/boost_1_65_1/tools/build/src/util' 'E:/DATA/TMP/boost/boost_1_65_1/tools/build/src/build' 'E:/DATA/TMP/boost/boost_1_65_1/tools/build/src/tools' 'E:/DATA/TMP/boost/boost_1_65_1/tools/build/src/contrib' 'E:/DATA/TMP/boost/boost_1_65_1/tools/build/src/.'. notice: Loading explicitly specified user configuration file: E:\DATA\TMP\boost\boost_1_65_1\user-config-64.jam notice: Searching 'E:\DATA\TMP\boost\boost_1_65_1' for user-config configuration file 'user-config-64.jam'. notice: Loading user-config configuration file 'user-config-64.jam' from 'E:/DATA/TMP/boost/boost_1_65_1'. notice: [python-cfg] Configuring python... notice: [python-cfg] user-specified version: "3.6" notice: [python-cfg] user-specified cmd-or-prefix: "C:\APPS\PROGRAMMING\Python36-64\python.exe" notice: [python-cfg] user-specified includes: "C:\APPS\PROGRAMMING\Python36-64\include" notice: [python-cfg] user-specified libraries: "C:\APPS\PROGRAMMING\Python36-64\libs" notice: [python-cfg] user-specified condition: "<address-model>64" notice: [python-cfg] Checking interpreter command "C:\APPS\PROGRAMMING\Python36-64\python.exe"... notice: [python-cfg] running command 'DIR /-C /A:S "C:\APPS\PROGRAMMING\Python36-64\python.exe" 2>&1' notice: [python-cfg] running command 'C:\APPS\PROGRAMMING\Python36-64\python.exe -c "from sys import *; print('version=%d.%d\nplatform=%s\nprefix=%s\nexec_prefix=%s\nexecutable=%s' % (version_info[0],version_info[1],platform,prefix,exec_prefix,executable))" 2>&1' notice: [python-cfg] ...requested configuration matched! notice: [python-cfg] Details of this Python configuration: notice: [python-cfg] interpreter command: "C:\APPS\PROGRAMMING\Python36-64\python.exe" notice: [python-cfg] include path: "C:\APPS\PROGRAMMING\Python36-64\include" notice: [python-cfg] library path: "C:\APPS\PROGRAMMING\Python36-64\libs" notice: [python-cfg] DLL search path: "C:\APPS\PROGRAMMING\Python36-64" notice: [python-cfg] Checking for NumPy... notice: [python-cfg] running command 'C:\APPS\PROGRAMMING\Python36-64\python.exe -c "import sys; sys.stderr = sys.stdout; import numpy; print(numpy.get_include())"' notice: [python-cfg] NumPy enabled notice: [lzma] Using pre-installed library notice: [lzma] Condition <link>shared <variant>release notice: [lzma] Using pre-installed library notice: [lzma] Condition <link>shared <variant>debug notice: [lzma] Using pre-installed library notice: [lzma] Condition <link>static <variant>release notice: [lzma] Using pre-installed library notice: [lzma] Condition <link>static <variant>debug notice: Searching '.' for project-config configuration file 'project-config.jam'. notice: Loading project-config configuration file 'project-config.jam' from '.'. notice: [msvc-cfg] msvc-14.0 detected, command: 'C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\cl.exe' notice: [msvc-cfg] msvc-11.0 detected, command: 'C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\bin\cl.exe' notice: [msvc-cfg] msvc-14.1 detected, command: 'C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\VC\Tools\MSVC\14.11.25503\bin\HostX64\arm\cl.exe' notice: will use 'C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\VC\Tools\MSVC\14.11.25503\bin\HostX64\arm\cl.exe' for msvc, condition <toolset>msvc-14.1 'notice: [generate-setup-cmd] 14.1 is 14.1' 'notice: [generate-setup-cmd] 14.1 is 14.1' 'notice: [generate-setup-cmd] 14.1 is 14.1' 'notice: [generate-setup-cmd] 14.1 is 14.1' notice: [msvc-cfg] condition: '<toolset>msvc-14.1/<architecture>/<address-model>', setup: 'call "C:\Users\bakaneko\AppData\Local\Temp\b2_msvc_14.1_vcvars32_.cmd" >nul ' notice: [msvc-cfg] condition: '<toolset>msvc-14.1/<architecture>/<address-model>32', setup: 'call "C:\Users\bakaneko\AppData\Local\Temp\b2_msvc_14.1_vcvars32_.cmd" >nul ' notice: [msvc-cfg] condition: '<toolset>msvc-14.1/<architecture>x86/<address-model>', setup: 'call "C:\Users\bakaneko\AppData\Local\Temp\b2_msvc_14.1_vcvars32_.cmd" >nul ' notice: [msvc-cfg] condition: '<toolset>msvc-14.1/<architecture>x86/<address-model>32', setup: 'call "C:\Users\bakaneko\AppData\Local\Temp\b2_msvc_14.1_vcvars32_.cmd" >nul ' notice: [msvc-cfg] condition: '<toolset>msvc-14.1/<architecture>/<address-model>64', setup: 'call "C:\Users\bakaneko\AppData\Local\Temp\b2_msvc_14.1_vcvarsx86_amd64_.cmd" >nul ' notice: [msvc-cfg] condition: '<toolset>msvc-14.1/<architecture>x86/<address-model>64', setup: 'call "C:\Users\bakaneko\AppData\Local\Temp\b2_msvc_14.1_vcvarsx86_amd64_.cmd" >nul ' notice: [msvc-cfg] condition: '<toolset>msvc-14.1/<architecture>ia64/<address-model>', setup: 'call "C:/Program Files (x86)/Microsoft Visual Studio/2017/Enterprise/VC/Auxiliary/Build/vcvarsall.bat" >nul ' notice: [msvc-cfg] condition: '<toolset>msvc-14.1/<architecture>ia64/<address-model>64', setup: 'call "C:/Program Files (x86)/Microsoft Visual Studio/2017/Enterprise/VC/Auxiliary/Build/vcvarsall.bat" >nul ' notice: [msvc-cfg] condition: '<toolset>msvc-14.1/<architecture>arm/<address-model>', setup: 'call "C:\Users\bakaneko\AppData\Local\Temp\b2_msvc_14.1_vcvarsx86_arm_.cmd" >nul ' notice: [msvc-cfg] condition: '<toolset>msvc-14.1/<architecture>arm/<address-model>32', setup: 'call "C:\Users\bakaneko\AppData\Local\Temp\b2_msvc_14.1_vcvarsx86_arm_.cmd" >nul ' notice: [zlib] Building zlib from source as boost_zlib notice: [zlib] Condition notice: [zlib] found zlib source in C:\APPS\PROGRAMMING\LIBRARIES\zlib\src_inc notice: [bzip2] Building bzip from source as boost_bzip2 notice: [bzip2] Condition notice: [bzip2] found bzip source in C:\APPS\PROGRAMMING\LIBRARIES\bzip2\src notice: [lzma] Using pre-installed library notice: [lzma] Condition Performing configuration checks - 32-bit : yes - arm : no - mips1 : no - power : no - sparc : no - x86 : yes - symlinks supported : no - junctions supported : yes - hardlinks supported : yes - C++11 mutex : yes - Boost.Config Feature Check: cxx11_auto_declarations : yes - Boost.Config Feature Check: cxx11_constexpr : yes - Boost.Config Feature Check: cxx11_defaulted_functions : yes - Boost.Config Feature Check: cxx11_final : yes - Boost.Config Feature Check: cxx11_hdr_mutex : yes - Boost.Config Feature Check: cxx11_hdr_tuple : yes - Boost.Config Feature Check: cxx11_lambdas : yes - Boost.Config Feature Check: cxx11_noexcept : yes - Boost.Config Feature Check: cxx11_nullptr : yes - Boost.Config Feature Check: cxx11_rvalue_references : yes - Boost.Config Feature Check: cxx11_template_aliases : yes - Boost.Config Feature Check: cxx11_thread_local : yes - Boost.Config Feature Check: cxx11_variadic_templates : yes - icu (64-bit) : yes warning: Graph library does not contain MPI-based parallel components. note: to enable them, add "using mpi ;" to your user-config.jam - lzma : yes - iconv (libc) : no - iconv (separate) : no - native-atomic-int32-supported : yes - message-compiler : yes - native-syslog-supported : no - pthread-supports-robust-mutexes : no - compiler-supports-visibility : no - compiler-supports-ssse3 : yes - compiler-supports-avx2 : yes - gcc visibility : no - long double support : yes warning: skipping optional Message Passing Interface (MPI) library. note: to enable MPI support, add "using mpi ;" to user-config.jam. note: to suppress this message, pass "--without-mpi" to bjam. note: otherwise, you can safely ignore this message. - libbacktrace builds : no - addr2line builds : no - WinDbg builds : yes - WinDbgCached builds : yes - lzma : yes (cached) - lzma : yes - lzma : yes (cached) Component configuration: - atomic : building - chrono : building - container : building - context : building - coroutine : building - date_time : building - exception : building - fiber : building - filesystem : building - graph : building - graph_parallel : building - iostreams : building - locale : building - log : building - math : building - metaparse : building - mpi : building - program_options : building - python : building - random : building - regex : building - serialization : building - signals : building - stacktrace : building - system : building - test : building - thread : building - timer : building - type_erasure : building - wave : building ...patience... ...patience... ...patience... ...patience... ...patience... ...found 29592 targets... ...updating 2728 targets... ... When the compiling is done the related libraries (iostream) are: boost_iostreams-vc141-mt-1_65_1.dll boost_iostreams-vc141-mt-1_65_1.lib boost_iostreams-vc141-mt-gd-1_65_1.dll boost_iostreams-vc141-mt-gd-1_65_1.lib libboost_iostreams-vc141-mt-1_65_1.lib libboost_iostreams-vc141-mt-gd-1_65_1.lib The problem is that both, "boost_iostreams-vc141-mt-gd-1_65_1.dll" and "boost_iostreams-vc141-mt-1_65_1.dll" were linked to the debug version of the LZMA dll (libzmad.dll), and examining the log, both "libboost_iostreams-vc141-mt-gd-1_65_1.lib" and "libboost_iostreams-vc141-mt-1_65_1.lib" were statically linked to the debug version of the static LZMA library (liblzma_staticd.lib). I tried with some more combinations in the user jam file, but without success, and in most cases failing to detect LZMA. If you require any further information to help find the problem, please, let me know, I'd appreciate any help with this problem. Sorry for my English, best regards, Diego. P.S: The config log can be found here: config.log <https://www.dropbox.com/s/kkut7kuka2jgi57/config.log?dl=0>.

1 0

Re: [Boost-users] [stacktrace] Getting a stacktrace from unhandled exception in windows
by Don 12 Sep '17

12 Sep '17

-------- Original Message -------- Subject: Boost-users Digest, Vol 4770, Issue 1 From: boost-users-request(a)lists.boost.org To: boost-users(a)lists.boost.org Date: 9/10/2017 10:56 PM > Subject: Re: [Boost-users] [stacktrace] Getting a stacktrace from unhandled exception in windows > From: Stian Zeljko Vrba <vrba(a)quine.no> > Date: 9/10/2017 10:54 PM > > Unless you need the stacktrace to be logged to a text file, I suggest you look at this system-provided >facility: https://msdn.microsoft.com/en-us/library/windows/desktop/bb787181(v=vs.85).… ><https://msdn.microsoft.com/en-us/library/windows/desktop/bb787181%28v=vs.85…> > > ...> IOW, you can get out more information than with boost.stacktrace with zero coding. > >> *Sent:* Monday, September 11, 2017 1:27:47 AM >> *To:* boost-users(a)lists.boost.org >> *Subject:* [Boost-users] [stacktrace] Getting a stacktrace from unhandled exception in windows >>>> I am trying use boost stacktrace to get a stack dump when my program encounters an unhandled exception >> under windows. I have installed a signal handler as described in the stacktrace documentation, and it >> gets called. However, the resulting stack trace is after everything has been unwound. >> >> For example, when I force a failure by dereferenceing a null pointer many levels down in my function >> hierarchy, the stack trace shows: >> >> 0# boost::stacktrace::detail::this_thread_frames::safe_dump_to_impl<char const *> at f:\home\tools\boost\boost\stacktrace\safe_dump_to.hpp:68 >> 1# boost::stacktrace::safe_dump_to at f:\home\tools\boost\boost\stacktrace\safe_dump_to.hpp:120 >> 2# my_signal_handler at f:\home\test\main.cpp:233 >> 3# 0x5171407B >> 4# my_signal_handler at f:\home\test\main.cpp:235 >> 5# 0x51713883 >> 6# __tmainCRTStartup at f:\dd\vctools\crt_bld\self_x86\crt\src\crtexe.c:603 >> 7# WinMainCRTStartup at f:\dd\vctools\crt_bld\self_x86\crt\src\crtexe.c:403 >> 8# BaseThreadInitThunk in kernel32 >> 9# RtlInitializeExceptionChain in ntdll >> 10# RtlInitializeExceptionChain in ntdll >> >> This is not particularly helpful, of course -- I want to know the call stack at the point of the >> failure. Is there any way to get that? What am I missing? Thanks for the suggestion, but yes, I want to log the data to a log file. It seems from the stacktrace documentation that this should work. Don

1 0

[stacktrace] Getting a stacktrace from unhandled exception in windows
by Don 11 Sep '17

11 Sep '17

I am trying use boost stacktrace to get a stack dump when my program encounters an unhandled exception under windows. I have installed a signal handler as described in the stacktrace documentation, and it gets called. However, the resulting stack trace is after everything has been unwound. For example, when I force a failure by dereferenceing a null pointer many levels down in my function hierarchy, the stack trace shows: 0# boost::stacktrace::detail::this_thread_frames::safe_dump_to_impl<char const *> at f:\home\tools\boost\boost\stacktrace\safe_dump_to.hpp:68 1# boost::stacktrace::safe_dump_to at f:\home\tools\boost\boost\stacktrace\safe_dump_to.hpp:120 2# my_signal_handler at f:\home\test\main.cpp:233 3# 0x5171407B 4# my_signal_handler at f:\home\test\main.cpp:235 5# 0x51713883 6# __tmainCRTStartup at f:\dd\vctools\crt_bld\self_x86\crt\src\crtexe.c:603 7# WinMainCRTStartup at f:\dd\vctools\crt_bld\self_x86\crt\src\crtexe.c:403 8# BaseThreadInitThunk in kernel32 9# RtlInitializeExceptionChain in ntdll 10# RtlInitializeExceptionChain in ntdll This is not particularly helpful, of course -- I want to know the call stack at the point of the failure. Is there any way to get that? What am I missing? Thanks, Don

2 2

Re: [Boost-users] [boost] Fit review - viboes
by P F 10 Sep '17

10 Sep '17

> On Sep 10, 2017, at 4:53 AM, Vicente J. Botet Escriba <vicente.botet(a)wanadoo.fr> wrote: > > > First sorry for the formatting of my original post. > > Le 09/09/2017 à 22:22, P F a écrit : >> >>> On Sep 9, 2017, at 6:27 AM, Vicente J. Botet Escriba via Boost <boost(a)lists.boost.org <mailto:boost@lists.boost.org>> wrote: >>> >>> Wondering if some parts should be moved to Boost.TypeTraits or reused from there (is_callable). >> >> But would that imply a C++98 compatible trait? Of course, I don’t see a reason to dump every trait used in boost into Boost.TypeTraits. > > I'm not talking about any traits. is_callable is special in the sense there is an equivalent in the C++ standard (is_invocable). > I don't think we should require that all the traits in Boost.Traits should be compatible C++98 when we are already in C++17. Ah yes, but I don't see why they need to be in Boost.TypeTraits. >> >>> >>> I'm missing the std::invoke function. >> >> What do you mean? std::invoke is provided by C++17. There is fit::apply, which will work like std::invoke except fit::apply also uses constexpr and is defined as a function object(so it can be passed to other functions). > > Why not call it invoke? I was trying to stay consistent with boost libraries. >>> If the user can use those classes the documentaion must document them. I guess they are useful to build other adaptors. It is not clear whether the defined functions would use SFINAE or just fail when used with types that don't respect the requirements. While I'm generally for SFINAE, I understand that it will not be the case in order to improve the compile time. >> >> The goal is to be as transparent as possible. So if `foo(f)(x)` is equivalent to `f(x)`, then if `f(x)` causes substitution failure, then `foo(f)(x)` causes substitution failure. The same is true for constexpr and noexcept on compilers that support those well enough. > > E.g. > > assert(compose(f, g)(xs...) == f(g(xs...))); > > If f and g don't compose, would compose(f, g) SFINAE the operator() or just compile fail. If `f(g(xs…))` is a substitution failure then `compose(f, g)(xs…)` is a substitution failure. > > If it SFINAE, I could use compose(f, g) to check if f and g are composable. You need to check `compose(f, g)(xs…)`. >> >>> It is not clear if the functions can be final function objects or not. >> >> They can be. There is no such restriction mentioned for the `Callable` or `ConstCallable` concept. > > Oh, I see it now. > > I believe there is however an issue when you have more than one final function objet. Do you have a test with two function objects? > If I remember the issue was because we can not inherit from two wrapper classes doing perfect forwarding. > If you don't have the issue, I will base my implementation of the proposed overload on your implementation ;-) I added tests with two final objects and see no problem. I am not sure the issue you were seeing. >>> >>> Possible files contains details that could be shared in Boost or used from other Boost libraries >>> >>> https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/move.hpp <https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/move.hpp> - I believe Hana use something like this also to reduce the dependencies (compile footprint) >>> https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/forward.… <https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/forward.…> >> >> Well hana uses a static_cast. Here, I use a macro which uses a static_cast if possible, and then I fallback to a function on compilers that can’t handle the static_cast. > > What I mean is that IMHO Boost should solve these issues in a single way. If we don't want to use directly e.g. <utility> because it is heavy, we should provide the lighter components in Boost. I don't believe it is a good approach to redefine them in each library that needs such basic facilities.. Yes, I agree there should be a library for this. However, this doesn’t exists yet. In the future, I can factor this out and put it in a separate library, but right now, I am proposing the Fit library. >> >>> https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/noexcept… <https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/noexcept…> >>> https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/and.hpp <https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/and.hpp> - I believe Hana use something like this also to reduce the dependencies (compile footprint) >> >> Well, I dont know of a library in boost that implements the fast_and algorithm that works on gcc 4.6+ and msvc. > > We have std::conditional. If we have a better option (for some compiler version) this should go to the Core library as any library could profit from it. It should not go into Core, there should be a separate library for this. If we just dump random stuff into Core, it will become like Utility. > This is a basic feature. >> >>> https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/compress… <https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/compress…> >> >> I dont know of a library that implements this. There is Boost.CompressedPair, but that implementation wouldn’t work at all for the Fit library. > > My comment included shared. If your compressed pair is better, we should improve Boost.CompressedPair. Perhaps, but this class is to solve very specific cases for the Fit library, so its built and tested around that. Some compilers have problems dealing with complex inheritance when using constexpr, so it is not as aggressive about empty optimization as Boost.CompressedPair. >>> >>> Quite good butthe description of the semantic of the provided functions would need some extra wording. Maybe a section that states that the semantic expression is part of the constraints on the types. >> >> What do you mean is part of the constraints on the type? > > Usually we describe the expressions that the types must support on the requirements. You use a semantic clause as requirement. What I mean is that the semantic clause implies the expression must be well formed and so is a requirement on the concerned types. The expression is not required to be well-formed. > That is the semantic expression is used to define what the function does and is also contains constraints of a not named Concept. What I would like is split the requirements and what the function does. It doesn’t describe requirements on the types as those are listed in the documentation already. Rather it is showing the semantically equivalent behavior. So when you write `compose(f, g)(xs…)` you could paste `f(g(xs…))` and the program should be practically equivalent even when the replacement happens in a decltype, noexcept, constexpr, or substitution failure. >> >>> >>> *Documentation:* >>> >>> In general: >>> >>> * Navigation only from the top of the page >>> >>> * Hyper links missing. >>> >>> * There is no link to real code from the examples. >> >> Most of the examples are a full running program that can be pasted in. > > Humm, I don't see the include on the code fragments, the needed using namespace, … Those don’t, I will try to setup a more fuller example. >> >>> >>> >>> In particular: >>> >>> *http://pfultz2.github.io/Fit/doc/html/doc/src/gettingstarted.html* <http://pfultz2.github.io/Fit/doc/html/doc/src/gettingstarted.html*> >>> >>> An explanation of the BOOST_FIT_LIFT limitations would be more than welcome. >> >> Good point. > Could you tell us here what they are? in detail? The limitation is in constexpr, but this only applies to c++14. This is because `BOOST_FIT_LIFT` uses a generic lambda. >> >>> >>> Typo: last right parenthesis in >>> >>> // Pipable sum >>> BOOST_FIT_STATIC_LAMBDA_FUNCTION(sum) = pipable([](auto x, auto y) >>> { >>> return x + y; >>> }); >>> >>> It is not clear if the following is correct in the body of a function >>> >>> auto sum = pipable([](auto x, auto y) >>> { >>> return x + y; >>> }; >> >> That needs to be corrected. > > Could you confirm that the previous code without using the BOOST_FIT_STATIC_FUNCTION is valid? Which one? You can’t write `BOOST_FIT_STATIC_FUNCTION(sum)` in c++14, however, in c++17 that is possible. > If yes I believe that the documentation could use this form as far as it is inside the body of a function. I was trying to demonstrate how to write functions other people can use. >>> >>> >>> *http://pfultz2.github.io/Fit/doc/html/doc/src/example_overloading.html* <http://pfultz2.github.io/Fit/doc/html/doc/src/example_overloading.html*> >>> >>> Typo: >>> >>> Before >>> // Check that T has member function for operator* and ope > >>> After // Check that T has member function for operator* and operator-> > > Note the typo above. Yea got it. >> *http://pfultz2.github.io/Fit/doc/html/doc/src/more_examples.html* <http://pfultz2.github.io/Fit/doc/html/doc/src/more_examples.html*> >>> >> >>> >>> My question is how both pipe operator overloads interact. >> >> How so? > > My bad. Each overload applies to different types, so that there shouldn't be no conflict. > > BTW, is operator|() defined only for pipable_adaptor<F>? Essentially yes. > > Could the user define a function object that is a pipable_adaptor for your library and it is also a pipable_xxx for the range library? What do you mean? > >> >>> >>> >>> >> >>> >>> Static Function Adaptor >>> >>> I would say "It has an additional requirement that the *class****function* is |DefaultConstructible|:" > > Don't forget this one. got it. >>> >>> >>> >>> *http://pfultz2.github.io/Fit/doc/html/doc/src/concepts.html* <http://pfultz2.github.io/Fit/doc/html/doc/src/concepts.html*> >>> ConstFunctionObject >>> >>> I would like to note that this concept is not representable using the Concept TS as it is quantifying universally on the Ts (args) parameters. >>> >>> The same applies to UnaryFunctionObject, BinaryFunctionObject >>> >>> Wondering if the documentation should use the term Concepts then. >> >> The purpose of the Concepts section is to document the type requirements. The current standard may not be able to check those type requirements in its current form, but there could be future versions of C++ that can check these type requirements. > > No, they couldn't if they are based on the Concept TS. The Concept TS doesn't have universal quantification, and I believe it wouldn't never had it from what the authors think about this feature. I agree, but it doesn’t mean we won’t have a future sematic-based concepts added that actually will help simplify generic programming. >> >>> >>> >>> The use of expresion "Is an object with ..." is confusing. What are we qualifying the type or the instance? >> >> This means the type is an object(ie scalar, array, union, or class). Of course, an array or union cannot have a call operator, so this only applies to classes and scalars that are pointers. > I believe it is better to use the term "type" here. It is a “type” but fulfills the requirements of `std::is_object`. >> >>> >>> EvaluatableFunctionObject >>> >>> It is not clear why this kind of FunctionObjects is useful >> >> This mainly used by the `fit::eval` and `fit::apply_eval` functions. > > I mean, it is not clear in this section, and some clarification is needed here. >> >>> >>> >>> Callable >>> >>> I believe we have moved to call this Invocable in the standard. But again, I believe that you want to quantify universally the arguments, isn't it? >> >> That is possible to check with the current C++(hence `is_callable`). This should be renamed to `Invocalbe` and `is_invocable`. > > Well is_invocable requires to know the type of the arguments. I believe that your Callable doesn't require to know with with types the function can be called. Could you confirm? Callable needs the type of the arguments, that is how `is_callable` is written. >>> >>> UnaryCallable >>> The name doesn't convey that it is *Const*Callable > > Any concern here? Since there is no standard UnaryCallable, I thought maybe I could sneak const in. I guess not. I will rename them to UnaryConstCallable. >>> >>> *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/compose.html <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/compose.html> *The requirements don't state clearly the constraints on the input parameters of f and the result of g, except by the semantic expression. This is a general remark. I suspect that you mean the semantic expression must be well formed. But, is this SFINAE friendly or is this a requirement? >> >> It is sfinae-friendly. > Could you add it to the reference documentation. This is an important feature. > In the standard they use "This function should not participate in overload resolution until ... or something like that. Is this really necessary? I think I would need to document when I change the semantic equivalence of the expression, not when I preserve it. I think it would be better in the definitions section to discuss the transparency aspect of the adaptors. >>> >>> Typo "Proposal for C++ Proposal for" >>> P0051 original proposal uses overload_linearly/overload (as Boost.Hana) instead of conditional/match. Wondering if those names aren't more clear. >> >> I really hate the name overload_linearly. Its long and doesn’t describe what it does. > > I don't find that conditional/match describe what they do. This is the eternal naming issue :) Its called `match` so it picks the best match using C++ overload resolution. Its also used for a form of pattern matching in visitors. I could use the name `overload`, but there a different ways of overloading. This is why I chose `match`. Its called `conditional` because it takes functions with conditions, and picks the first one. Perhaps the name `select` or `prefer` could be used. I am not sure. >>> >>> *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/implicit.html* <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/implicit.html*> >>> >>> Is implicit a StaticFunctionAdaptor? >> >> Yes. >> >>> Shouldn't StaticFunctionAdaptors have Functions as parameters? >> >> What do you mean? > That implicit has a template, not a class :( I should make the definition more flexible then. >> >>> Why this pattern respect the DRY principle (we don't repeat S), I believe it abuses of implicit conversions. >> >> Well, there is a caveat when someone uses ``auto`, like in your example: >> >> auto ptr = create_msg(); > yes, this is the caveat of returning a proxy that is convertible to anything. Could you warm the user in the documentation of this possible bad usage? >> >> There is a guard to prevent this, but it doesn’t work in C++17. > Could you elaborate? The guaranteed elision is in C++17 prevents this. As the class returned can only be copied by implicit conversion, by the copy elision makes this possible. >> >>> http://pfultz2.github.io/Fit/doc/html/include/boost/fit/indirect.html <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/indirect.html> >>> Wondering if it could be worth adding some preconditions as I guess that the function call >>> >>> indirect(f)(xs...) >>> >>> will be undefined if f is null >> >> That is true if `f` is a pointer, but is not true for all dereference operators. > > For example? http://pfultz2.github.io/Fit/doc/html/doc/src/faq.html#q-is-the-reinterpret… >>> *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/mutable.html <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/mutable.html> *Example of bad usage would be welcome.**Why Fit uses always const? **Why not use a reference to the function object instead? >> >> There is no way to safely manage the lifetime with a reference. > I was talking of reference_wrapper. > > IIUC, mutable should be used *only* to wrap existing functions that where no const but that don't modify the object (but it is a3rd party code and cannot be changed). I'm wrong? I believe, or if the mutations dont matter(perhaps it is just a cache). >>> Is there a safe way to use MutableFunctionObjects with Fit? >> >> Yes, you can use `std::ref. > > But reference_wrapper is a ConstFunctionObject. > I mean when mutable_ is safe? The 3rd party use case? Yes pretty much. > Do you have a good example of MutableFunctionObject that is safe? Well if the mutations don’t matter. Perhaps there is a cache, and so if the value isn’t there it just recomputes it. > After all I wonder if Mutable is the correct name. In C++ mutable means modifiable by a const function. I'll suggest NonConst as the function applicable to non-const objects. Well mutable is an actual keyword in the language, that is why I chose that. >>> http://pfultz2.github.io/Fit/doc/html/include/boost/fit/protect.html <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/protect.html> It is not clear to me what this useful for. Could you elaborate? >> >> When you want `bind` or `lazy` to capture a bind expression instead of evaluating it. > > and ... could you elaborate? Could you show how we can do it without fit::protect and with? You can’t do it without fit::protect, unless you use boost::protect. >> >>> Is there a typo here >>> assert(lazy(f)(protect(lazy(g)(_1)))() == f(lazy(g)(_1))) ^ Shouldn't it be assert(lazy(f)(protect(lazy(g)),_1)() == f(lazy(g)(_1))) >> >> Nope, that is correct. > > It is incoherent with the example. So maybe the example is wrong > > auto lazy_apply = lazy(apply)(protect(lazy_id), _1);` > > Or I'm missing something In the semantic requirements it assumes only a unary function. I could add a binary version in the semantic requirements. >> >>> >>> *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/result.html*** <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/result.html***> >>> This adaptor converts explicitly the result of the call to the type. Have you considered `convert_to`? >> >> It also adds a `result_type` to the function. Its mainly used to annotate function with the result type, which can be useful for fit::fix or Boost.Variant visitors. The documentation could make this clearer. > > Yes, I know that knowing the result type allows to optimize visitors. What is the main intent? to force the conversion or to have a way to retrieve the result type of a function object? Both actually. > The name should convey the main intent. > We have std::result_of until C++14 and invoke_result since C++17 to get the result type. Those aren’t the same as they try to deduce the type. The result adaptor provides a way to know the result type without deduction. >> >>> >>> *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/reveal.html* <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/reveal.html*> >>> >>> as_failures, with_failures, .... /adaptors/ don't appear on the index. >> >> You mean the table of contents? Yea, for them to appear there they need to be moved to a different section, with a header for each section. > You have items in the index that don't have his own file, e.g. http://pfultz2.github.io/Fit/doc/html/include/boost/fit/placeholders.html#u… <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/placeholders.html#u…>, so you should be able to add to it anything without needed a file, isn't it? Yes, but these would go under the adaptors section, which they don’t belong. >>> *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/static.html*** <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/static.html***> >>> >>> What are the differences of this adaptor and the macro STATIC_FUNCTION? >> >> STATIC_FUNCTION just declares a function objects at namespace or global scope, which requires the function to be constexpr constructible. The `static_` adaptor is to declare an adaptor that does not have a constexpr constructor. > > It is weird the example don't show the specific case as it uses static_ at global global scope. Could you show another example that is not at the namesapce o global scope. The purpose is to use at global or namespace scope, but the example should be update to use `BOOST_FIT_STATIC_FUNCTION`. > > Why static_ couldn't declare its default constructor constexpr? > I believe the description is on the other sense, which is why it is confusing. static_ requires a default constructor but don't requires the constructor to be constexpr and don't provides one constexpr default constructor It does provide constexpr constructor. Which is why it is useful because you can constepxr initialize a function object without a constexpr constructor. > , but I suspect that if the default constructor is constexpr it should work also. IIUC, you are saying that if it is the case then it is better to use the macro BOOST_FIT_STATIC_FUNCTION. They both can be used together. Although `static_` can be used at class scope. >>> *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/unpack.html* <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/unpack.html*> >>> >>> Why name it unpack instead of apply like in C++17? >> >> First, it doesn’t have the same signature as std::apply. > > Because you curry the function? Kind of. It is an adaptor. It also can take multiple sequences. >> Secondly, its very confusing, as ‘apply' generally means function applications especially in boost. So I would like to avoid this confusion. > > We are doing a function application here, isn't it? Eventually yes, but so does all the other adaptors. It doesn’t mean the other adaptors should be named apply either. >> >>> Need to introduce the Sequence concept and how it is customized? >> >> Hmm that is probably a better way to define it. >> >>> unpack_sequence? How unpack_sequence is used by unpack? >>> >>> *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/unpack_sequence.html*** <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/unpack_sequence.htm…> >>> Why unpack_sequence, and not the tuple-like traits? >> >> Not every sequence could be defined with indices. > For example? fit::pack has no index-based access, or if the sequence is defined as: auto seq = [](auto f) { reuturn f(1, 2, 3); }; >> >>> Is unpack_sequence defined if the class defines the tuple-like traits? >> >> No because they are not sfinae-friendly. > Why? Could you elaborate? The standard mandates that they are not sfinae-friendly. See: https://stackoverflow.com/a/41708982/375343 <https://stackoverflow.com/a/41708982/375343> As such there is no way to know if a type implements the std tuple-like traits. >> >>> Aside the example, it is not defined what the user must define. >> >> That could probably use more explanation. >> >>> What the member function apply must return? >> >> The result of calling `f`. > > These things need to be defined in the documentation. > > When a user specialize unpack_sequence, what are the constraints of the parameter F. Should it be ConstCallable? It will always be a FunctionObject. >> >>> How the unpack_sequence parameter and the Sequence parameter of member function apply are related? >>> I don't understand >>> >>> template<class F, class Sequence> >>> constexpr static auto apply(F&& f, Sequence&& s) BOOST_FIT_RETURNS >>> ( >>> s(std::forward<F>(f)) >>> ); Is a Sequence a callable taking a Callable or there is a type here? Is there a missing return? >>> >>> I suspect it should be >>> >>> template<class F, class Sequence> >>> constexpr static auto apply(F&& f, Sequence&& s) BOOST_FIT_RETURNS >>> ( >>> std::forward<F>(f)(s0, ,, sk); >>> ); >>> If this is correct, does it means that unpack just forwards to unpack_sequence? >> >> That example, I guess is a little confusing. As the `Sequence` is a function like fit::pack, but yes unpack calls unpack_sequence to do the unpacking for a single sequence. > Please, fix it. >> >>> Does the default specialization make use of INVOKE? >> >> Its not needed, as the function passed to `unpack_sequence` will always have a call operator. > I was talking of what the *default* specialization for tuple does. For any specialization, INVOKE is not necessary. >>> *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/repeat.html* <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/repeat.html*> >>> >>> Add requirement on the function parameter that must be a Unary function such that f(f(x)) is well formed. >> >> True, but the first call to repeat doesn’t need to be unary. > And what it could be? You lost me. Its the parameters passed by the user. That is `repeat(n)(f)(1, 2)` will call `f(1, 2)` the first time, and every time after that it will call `f` with the result of `f`. >>> *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/arg.html*** <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/arg.html***> >>> What is the rational for the choice of been 1-based? >> >> This is to match how placeholders work. So arg<1> and _1 are the same number. > I was sure that you had a good reason:) I went back and forth on this, but hana uses the convention. >>> *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/decay.html* <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/decay.html*> >>> >>> Why not decay_copy? >> >> It doesn’t always copy, like when passing reference_wrapper. > > It copies the reference_wrapper, isn't it? Nope, it returns a reference to the object being wrapped. >> >>> >>> >>> *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/placeholders.html*** <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/placeholders.html***> >>> Wondering if it is not better to locate them in a placeholders namespace, so that we can avoid possible collisions with other placeholders. >>> >>> *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/placeholders.html#unamed-placeholder* <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/placeholders.html#u…> >>> >>> The same here >> >> Ah, it could cause collision if users do `using boost::fit`. > Would you move to a nested placeholders namespace? Yes, I added a issue. >>> *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/apply.html*** <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/apply.html***> >>> Confusion with std::apply. is this related to std::invoke? >> >> Its not like std::apply, its like hana::apply. > > I know that it is not like std::apply, hence the possible confusion. >> Of course, maybe I could rename this to fit::invoke, and then add a fit::apply, that only calls the call operator. > > I don't see any reason to use a different name when the function are curried. fit::apply is not curried. >>> *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/tap.html* <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/tap.html*> >>> >>> How this is related to the tee unix command? >> >> I am not that familiar with unix tee. > https://en.wikipedia.org/wiki/Tee_(command) <https://en.wikipedia.org/wiki/Tee_(command)> It is kind of similar, but its not saving a file. >>> *http://pfultz2.github.io/Fit/doc/html/doc/src/configurations.html***Which <http://pfultz2.github.io/Fit/doc/html/doc/src/configurations.html***Which> ones? >>> > There are none now. Are there some or should this section be removed? Yea, for some reason they dont show. I dont know if something happened with the boost conversion. You can see the pre-boost version of this page here: http://fit.readthedocs.io/en/latest/doc/src/configurations.html <http://fit.readthedocs.io/en/latest/doc/src/configurations.html> Also, I added issues for a lot of the points raised in the email here: https://github.com/pfultz2/Fit/issues <https://github.com/pfultz2/Fit/issues> Let me know if I missed anything. Thanks, Paul

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Re: [Boost-users] Fit review
by Andrea Bocci 09 Sep '17

09 Sep '17

Hi, maybe it's too late, but I hadn't seen this library before on the boost-users list. Would you consider a different name ? In the context of mathematical and statistical analysis, a "fit" is something else entirely - still related to "functions". Reading that "Fit is a header-only ... library that provides utilities for functions..." I was expecting something quite different ;-) Anyway, good job with library itself. Regards, .Andrea

2 1

Re: [Boost-users] [boost] Fit review - viboes
by P F 09 Sep '17

09 Sep '17

> On Sep 9, 2017, at 6:27 AM, Vicente J. Botet Escriba via Boost <boost(a)lists.boost.org> wrote: > > Hi, > > here it is my review. > > I believe that Boost.Fit should be*accepted*. Thanks for the review. > > > > *Design* > > The design is sound and clean. > > I have some concerns respect the the ConstFunctionObjects that I believe should merit an explanation on a rationale section. Why the library support only Const function objects? This is described in the FAQ, but maybe it should be moved to a rationale section. The main reasons are they are error prone, and in C++11 can’t be supported with constexpr. > > Wondering if some parts should be moved to Boost.TypeTraits or reused from there (is_callable). But would that imply a C++98 compatible trait? Of course, I don’t see a reason to dump every trait used in boost into Boost.TypeTraits. > > I'm missing the std::invoke function. What do you mean? std::invoke is provided by C++17. There is fit::apply, which will work like std::invoke except fit::apply also uses constexpr and is defined as a function object(so it can be passed to other functions). > > The_adaptor<> are not documented. Maybe in the definitions section I can go over how `foo(f)` is the same as `foo_adaptor<F>{f}`. > The utility of those classes is not documented. The are mainly useful for when you want to type-based transformations to functions. This is common when you need to pass a function as a template parameter(like with the comparator in std::map, the deleter in std::unique_ptr, or when using Boost.MultiIndex). > If the user can use those classes the documentaion must document them. I guess they are useful to build other adaptors. It is not clear whether the defined functions would use SFINAE or just fail when used with types that don't respect the requirements. While I'm generally for SFINAE, I understand that it will not be the case in order to improve the compile time. The goal is to be as transparent as possible. So if `foo(f)(x)` is equivalent to `f(x)`, then if `f(x)` causes substitution failure, then `foo(f)(x)` causes substitution failure. The same is true for constexpr and noexcept on compilers that support those well enough. > It is not clear if the functions can be final function objects or not. They can be. There is no such restriction mentioned for the `Callable` or `ConstCallable` concept. > *Implementation* > > Not seen in depth. > > It should use as much as possible Boost.Config and/or Boost.Predef Right now it uses sd-6 macros, but it could move to use Boost.Config(probably not Boost.Predef). > > Possible files contains details that could be shared in Boost or used from other Boost libraries > > https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/move.hpp - I believe Hana use something like this also to reduce the dependencies (compile footprint) > https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/forward.… <https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/forward.…> Well hana uses a static_cast. Here, I use a macro which uses a static_cast if possible, and then I fallback to a function on compilers that can’t handle the static_cast. > https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/noexcept… > https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/and.hpp - I believe Hana use something like this also to reduce the dependencies (compile footprint) Well, I dont know of a library in boost that implements the fast_and algorithm that works on gcc 4.6+ and msvc. > https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/compress… <https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/compress…> I dont know of a library that implements this. There is Boost.CompressedPair, but that implementation wouldn’t work at all for the Fit library. > https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/constexp… > https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/intrinsi… <https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/intrinsi…> This probably could be factored out in a separate boost library, which might be useful for other heavy metaprogramming libraries. > https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/pp.hpp > https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/remove_r… > https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/result_o… > https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/static_c… > https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/using.hpp > > It uses a lot of macros that make complex the understanding of what is behind. On the same file https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/compose.hpp and only on 169 lines > BOOST_FIT_INHERIT_CONSTRUCTOR, BOOST_FIT_RETURNS_CLASS, > BOOST_FIT_SFINAE_RESULT, BOOST_FIT_MANGLE_CAST, BOOST_FIT_DECLARE_STATIC_VAR, BOOST_FIT_NOEXCEPT_CONSTRUCTIBLE, > BOOST_FIT_ENABLE_IF_CONSTRUCTIBLE, BOOST_FIT_JOIN *Documentation* Some of those are documented. The others I could add some more comments in the code to what those do exactly. > > Quite good butthe description of the semantic of the provided functions would need some extra wording. Maybe a section that states that the semantic expression is part of the constraints on the types. What do you mean is part of the constraints on the type? > It takes too much pages to see what the library proposes. > For some functions we would need more information, examples. See below the detailed > > *Potential usefulness of the library* > > Very useful. > > *Did you try to use the library? With which compiler(s)? Did you have any problems?*** > Not tried yet. > > *How much effort did you put into your evaluation? A glance? A quick reading? In-depth study?*** > In-depth study of the documentation (about 5 h for this revision). > > *Are you knowledgeable about the problem domain?* > > In general, yes. > > *Were the concerns from the March 2016 review of Fit addressed?*** > I believe ;-) > > Best, > Vicente > > *Documentation:* > > In general: > > * Navigation only from the top of the page > > * Hyper links missing. > > * There is no link to real code from the examples. Most of the examples are a full running program that can be pasted in. > > > In particular: > > *http://pfultz2.github.io/Fit/doc/html/doc/src/gettingstarted.html* > > An explanation of the BOOST_FIT_LIFT limitations would be more than welcome. Good point. > > Typo: last right parenthesis in > > // Pipable sum > BOOST_FIT_STATIC_LAMBDA_FUNCTION(sum) = pipable([](auto x, auto y) > { > return x + y; > }); > > It is not clear if the following is correct in the body of a function > > autosum = pipable([](auto x, auto y) > { > return x + y; > }; That needs to be corrected. > > *http://pfultz2.github.io/Fit/doc/html/doc/src/example_print.html* > > I would suggest to use an heterogeneous tuple in the for_each_tupleexample. > > In addition use some kind of brackets to print the sequences and the tuples would help to identify what is been printed. I was trying to keep the example simple. However, with the print out its a little more confusing. > > > *http://pfultz2.github.io/Fit/doc/html/doc/src/example_overloading.html* > > Typo: > > Before > // Check that T has member function for operator* and ope After // Check that T has member function for operator* and opeerator-> > > I'm not sure the example is_derreferenceable is fair. Using is_detected, might be a little simpler, but it don’t think it would help overall. > > > *http://pfultz2.github.io/Fit/doc/html/doc/src/example_polymorphic_constructors.html* > > Maybe it is worth adding references to the proposals (P0318R0 and P0338R2) > > > *http://pfultz2.github.io/Fit/doc/html/doc/src/more_examples.html* > > Extension Methods > > It is not clear what numbers, filter and transform are in the example. I should add an implementation of those. > > I believe that the range proposal woul include the pipe operator. Although, there are some who don’t see the usefulness of it. > > My question is how both pipe operator overloads interact. How so? > > http://pfultz2.github.io/Fit/doc/html/doc/src/point_free.html > > typo > > Before > > |b(f)(x, y)| > > |after| > > > ||by(f)(x, y)|| > > > *http://pfultz2.github.io/Fit/doc/html/doc/src/definitions.html* > > It woul dbe great to have an example associated to each definition That is a good idea. > > Static Function Adaptor > > I would say "It has an additional requirement that the *class****function* is |DefaultConstructible|:" > > Decorator > I would say "The *resulting* Function Adaptor <http://pfultz2.github.io/Fit/doc/html/doc/src/definitions.html#function-ada…> may be an unspecified or private type.” Ok. > > Typo? > Some parts of the documentation provides > > > > *http://pfultz2.github.io/Fit/doc/html/doc/src/concepts.html* > ConstFunctionObject > > I would like to note that this concept is not representable using the Concept TS as it is quantifying universally on the Ts (args) parameters. > > The same applies to UnaryFunctionObject, BinaryFunctionObject > > Wondering if the documentation should use the term Concepts then. The purpose of the Concepts section is to document the type requirements. The current standard may not be able to check those type requirements in its current form, but there could be future versions of C++ that can check these type requirements. > > > The use of expresion "Is an object with ..." is confusing. What are we qualifying the type or the instance? This means the type is an object(ie scalar, array, union, or class). Of course, an array or union cannot have a call operator, so this only applies to classes and scalars that are pointers. > > Maybe it is worth defining FunctionObject. Trye, although I never use that concept, it would make sense for completeness sake. > > EvaluatableFunctionObject > > It is not clear why this kind of FunctionObjects is useful This mainly used by the `fit::eval` and `fit::apply_eval` functions. > > > Callable > > I believe we have moved to call this Invocable in the standard. But again, I believe that you want to quantify universally the arguments, isn't it? That is possible to check with the current C++(hence `is_callable`). This should be renamed to `Invocalbe` and `is_invocable`. > > Does your definition of INVOKE differs from the one on the standard? No, it shouldn’t, unless the standard doesn’t allow constexpr. > If yes, the differences should be mentioned. If not, the definition on the standard should be referenced. Would cppreference be acceptable? > > You use type T twice with different meaning > > "The type |T| satisfies |Callable| if" > > "if |f| is a pointer to member function of class |T|:" > > I believe that here the T are not the same. True, let me fix that. > > Are final function objects Callable, ConstCallable? Yes, why wouldn’t they be? > > > ConstCallable > The brief description is the same as the one for Callable > Is the definition of the second INVOKE different from the first one? No, it isn’t. The only difference is the f is of type `const T`. > > UnaryCallable > The name doesn't convey that it is *Const*Callable > > Metafunction and MetafunctionClass > it is not clear what those are, there is no brief description. I guess that this applies to f. > What do you mean by a type or a template? I see, that is a little confusing. These should follow the same definitions as in Boost.MPL. > > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/by.html* > > > It is not clear to me what > > by(p)(xs...) == p(xs)... mean > > > An example of `fit::by` without a function argument will be welcome. Good point. > > It is not clear how by_adaptor<Projection, F> and by_adaptor<Projection> can be used by the user? I could add an example using std::map. > Shouldn't those be hidden? No they shouldn’t be hidden. > > This is a genral remak, why F must be ConstCallable? For the same reason everything is ConstCallable. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/compose.html *The requirements don't state clearly the constraints on the input parameters of f and the result of g, except by the semantic expression. This is a general remark. I suspect that you mean the semantic expression must be well formed. But, is this SFINAE friendly or is this a requirement? It is sfinae-friendly. > Can both function be final function objects? **** In compose? Any of the functions can be final. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/conditional.html* > It is not clear what king of parameters this function could have (in particular in comparison with P0051). Does it accept function/data members pointers, final classes, references_wrappers, …? Yes, it takes any `ConstCallable` > > Typo "Proposal for C++ Proposal for" > P0051 original proposal uses overload_linearly/overload (as Boost.Hana) instead of conditional/match. Wondering if those names aren't more clear. I really hate the name overload_linearly. Its long and doesn’t describe what it does. > Why do we need to change the Boost.Hana names? Those names were chose before Boost.Hana. I use `conditional` because it was like a conditional block, especially when used with fit::if_. Perhaps, there is a better name. > There is also std::conditional :( Which really should’ve been called std::if_. > > Can more than 2 parameters be final function objects? Yes, of course. > > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/flip.html** > * > IIUC, F must not be BinaryCallable, but Callable with at least two arguments. True, let me update the documentation. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/implicit.html* > > Is implicit a StaticFunctionAdaptor? Yes. > Shouldn't StaticFunctionAdaptors have Functions as parameters? What do you mean? > I named the `auto_cast` function `explicitly` to do a explicit conversion. > > Other uses of this pattern I've see are to create a buffer able to store a specific struct > > struct S; > S* ptr = create_msg(); > > create_msg returns an class that is convertible to a T* and that allocates sizeof(T) bytes of memory. Ah yes, for that too. > > Why this pattern respect the DRY principle (we don't repeat S), I believe it abuses of implicit conversions. Well, there is a caveat when someone uses ``auto`, like in your example: auto ptr = create_msg(); There is a guard to prevent this, but it doesn’t work in C++17. > Anyway, I wanted just to share another use case for implicit. > > http://pfultz2.github.io/Fit/doc/html/include/boost/fit/indirect.html > Wondering if it could be worth adding some preconditions as I guess that the function call > > indirect(f)(xs...) > > will be undefined if f is null That is true if `f` is a pointer, but is not true for all dereference operators. > > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/infix.html** > * > > One of the asked infix operations is pow. However we would like to evaluate from right to left and have the higher precedence than * x pow ypow z===pow(x, pow(y,z)) > x * ypow z===x * pow(y,z) x pow y* z===pow(x,y) * zWith the proposed infix notation this should be written > x <pow> (y<pow> z)===x * pow(y,z) x * (y<pow> z)===x * pow(y,z) (x <pow> y)* z===pow(x,y) * z > and the following would be surprising > x <pow> y<pow> z===pow(pow(x, y, z) x * y<pow> z===pow(x * y, z) x <pow> y*z===pow(x, y * z) It would work better for swap or compare (proposed operator <=>) as these functions are not associative. I believe a note should prevent the users for such bad use cases, for which it is better to don't define the infix operator. That is a good example to talk about. I will add that. > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/lazy.html* Note p0356r1. It would be good to have a comparison in order either to improve the proposal or your library. That seems more related to fit::partial. > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/match.html* Same comments than for fit::conditional. What are ex typo "Proposal for C++ Proposal for" > Can more than 2 parameters be final function objects? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/mutable.html *Example of bad usage would be welcome.**Why Fit uses always const? **Why not use a reference to the function object instead? There is no way to safely manage the lifetime with a reference. > Is there a safe way to use MutableFunctionObjects with Fit? Yes, you can use `std::ref. > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/partial.html* Are there any constraints on the type of xs. Shouldn't them be MoveConstructibles? That is true, since it decays the parameters. > http://pfultz2.github.io/Fit/doc/html/include/boost/fit/pipable.html > Are there any constraints on the type of x. No. > Shouldn't it be MoveConstructible? No, it is not necessary. Pipable does not capture the parameters by value, since it is almost always used in the same expression(ie `x | f(y)`). > http://pfultz2.github.io/Fit/doc/html/include/boost/fit/protect.html It is not clear to me what this useful for. Could you elaborate? When you want `bind` or `lazy` to capture a bind expression instead of evaluating it. > Is there a typo here > assert(lazy(f)(protect(lazy(g)(_1)))() == f(lazy(g)(_1))) ^ Shouldn't it be assert(lazy(f)(protect(lazy(g)),_1)() == f(lazy(g)(_1))) Nope, that is correct. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/result.html*** > This adaptor converts explicitly the result of the call to the type. Have you considered `convert_to`? It also adds a `result_type` to the function. Its mainly used to annotate function with the result type, which can be useful for fit::fix or Boost.Variant visitors. The documentation could make this clearer. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/reveal.html* > > as_failures, with_failures, .... /adaptors/ don't appear on the index. You mean the table of contents? Yea, for them to appear there they need to be moved to a different section, with a header for each section. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/reverse_fold.html* > > reverse_fold is not right fold, as right fold is right associative, isn't it? True, it is right fold with the arguments flipped. > > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/rotate.html*** > Could you show a concrete use case? > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/static.html*** > > What are the differences of this adaptor and the macro STATIC_FUNCTION? STATIC_FUNCTION just declares a function objects at namespace or global scope, which requires the function to be constexpr constructible. The `static_` adaptor is to declare an adaptor that does not have a constexpr constructor. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/unpack.html* > > Why name it unpack instead of apply like in C++17? First, it doesn’t have the same signature as std::apply. Secondly, its very confusing, as ‘apply' generally means function applications especially in boost. So I would like to avoid this confusion. > Need to introduce the Sequence concept and how it is customized? Hmm that is probably a better way to define it. > unpack_sequence? How unpack_sequence is used by unpack? > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/unpack_sequence.html*** > Why unpack_sequence, and not the tuple-like traits? Not every sequence could be defined with indices. > Is unpack_sequence defined if the class defines the tuple-like traits? No because they are not sfinae-friendly. > Aside the example, it is not defined what the user must define. That could probably use more explanation. > What the member function apply must return? The result of calling `f`. > How the unpack_sequence parameter and the Sequence parameter of member function apply are related? > I don't understand > > template<class F, class Sequence> > constexpr static auto apply(F&& f, Sequence&& s) BOOST_FIT_RETURNS > ( > s(std::forward<F>(f)) > ); Is a Sequence a callable taking a Callable or there is a type here? Is there a missing return? > > I suspect it should be > > template<class F, class Sequence> > constexpr static auto apply(F&& f, Sequence&& s) BOOST_FIT_RETURNS > ( > std::forward<F>(f)(s0, ,, sk); > ); > If this is correct, does it means that unpack just forwards to unpack_sequence? That example, I guess is a little confusing. As the `Sequence` is a function like fit::pack, but yes unpack calls unpack_sequence to do the unpacking for a single sequence. > Does the default specialization make use of INVOKE? Its not needed, as the function passed to `unpack_sequence` will always have a call operator. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/capture.html*** > Please, could you show how it is more flexible than lambda captures in C++? You can’t capture by value or reference dependending if it is an lvalue when using lambda captures. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/if.html* > > What happens when the parameter is false_type? SFINAE? Essentially yes. There is no call operator when its false. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/limit.html*** > if a function object is overloaded with 2 and 3 parameters, would limit be useful or it is only useful when the number of parameters is fixed? Yes its still useful, as it only sets a max limit. > I believe this is answered in http://pfultz2.github.io/Fit/doc/html/doc/src/partialfunctions.html, however I believe it merits a clarification here. > > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/repeat.html* > > Add requirement on the function parameter that must be a Unary function such that f(f(x)) is well formed. True, but the first call to repeat doesn’t need to be unary. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/repeat_while.html* > The same here. > > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/arg.html*** > What is the rational for the choice of been 1-based? This is to match how placeholders work. So arg<1> and _1 are the same number. > Could you add a rationale in the doc? Yea. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/construct.html* > > Maybe add a reference to the factory proposal p03382. Do you have a link? > > What happens when the parameter is not a T is not constructible from the params? SFINAE? Yes. > > What happens when the parameter is not a MetafunctionClass? SFINAE? Yes. > > I believe Boost.Hana uses make instead of construct. That is a possible name. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/decay.html* > > Why not decay_copy? It doesn’t always copy, like when passing reference_wrapper. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/identity.html *is identity a function or a function object? do we need identity()(x)? It can be treated as a function. I should update the synopsis to use a function signature instead. > > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/placeholders.html*** > Wondering if it is not better to locate them in a placeholders namespace, so that we can avoid possible collisions with other placeholders. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/placeholders.html#unamed-placeholder* > > The same here Ah, it could cause collision if users do `using boost::fit`. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/function_param_limit.html*** > |function_param_limit is not a Metafunction. "|The|function_param_limit| metafunction …" It is a metafunction(doing ::type works), but its actually more like a type trait. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/is_callable.html*** > F must be Callable can not be a requirement ;-) > > Add reference to C++17 trait is_invocable. > > Wondering if we should have it in type_traits, if not already there. > > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/apply.html*** > Confusion with std::apply. is this related to std::invoke? Its not like std::apply, its like hana::apply. Of course, maybe I could rename this to fit::invoke, and then add a fit::apply, that only calls the call operator. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/function.html* > > "By default, all functions defined with|BOOST_FIT_STATIC_FUNCTION| use thereveal <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/reveal.html> adaptor to improve error messages." > > How to change this default? There isn’t a way. Perhaps I could add PP define to change it, but I wonder if its better to have some way to change it on a per-variable basis. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/lift.html*** > WhyBOOST_FIT_LIFT_CLASSdoesn't defines a instance as do BOOST_FIT_STATIC_FUNCTION? That maybe a better approach. Maybe I can call it BOOST_FIT_LIFT_FUNCTION. > > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/pack.html*** > How this is related with fit::capture? fit::capture uses fit::pack, but also does a pack_join to combine the pack and the parameters together. > > *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/tap.html* > > How this is related to the tee unix command? I am not that familiar with unix tee. > > *http://pfultz2.github.io/Fit/doc/html/doc/src/configurations.html***Which ones? > > > _______________________________________________ > Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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[gsoc] Change in Google Summer of Code admin
by Niall Douglas 08 Sep '17

08 Sep '17

Dear all, Google Summer of Code 2017 has ended with another successful summer of student coding with probably the highest calibre year we've ever seen. After four years as lead admin for Boost Summer of Code, my time has come to an end. I'll be making way for David Bellot, long time mentor at Boost GSoC and maintainer of Boost.uBLAS. Please join me in welcoming David as new lead admin. I'll be staying on as backup admin next summer to help David settle in. My time as Boost Summer of Code admin has certainly been eventful with lots of surprises, ups and downs. The fact these surprises did not turn into crises is due in large part to a few people in particular who went far beyond the call of duty: * Jon Kalb, who went to bat for the students repeatedly in multiple venues and finding tens of thousands of dollars when it was needed. * Boris Schäling, whom I replaced as lead admin and who acted as backup admin for some years, who also managed to arrange tens of thousands of dollars of sponsorship when it was needed most. * Bryce Adelstein Lelbach, for acting as backup admin these past few years. * Andrew Sutton, the lead GSoC admin before Boris, who gave such detailed and useful early advice and materials on how to best navigate the treacherous waters of Google Summer of Code! And finally to all the mentors who so generously volunteered their time, and to the students every single one of whom successfully finished their projects in my time as admin despite problems with sickness, deaths in close family etc. Some of those students have gone on to become mainstays of the C++ conference circuit, famous names in their own right. I'm sure they would have been so without Google Summer of Code, but I'd like to think that it helped bring them to Boost rather than them getting into C++ via elsewhere. Thank you students! Regards, Niall

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echo server modification causes undefined behaviour
by Peter Koukoulis 07 Sep '17

07 Sep '17

I'm a database developer and I'm using boost for the first time.I've copied the echo server & client example from the Boost website and modified it somewhat so that when I receive a SQL statement from the client I pass pass it onto a function that performs the db execution. Once executed Ireply back to the client how many rows were affected. The code works , if I send only a single request at a time from the synchronous client, so I modified the async server so that the read is a read_until.The change now crashes the server. Could somebody please help ?Attached is the code.

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[release] Boost 1.65.1
by Daniel James 07 Sep '17

07 Sep '17

Release 1.65.1 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 bug fixes for existing libraries. For details, including download links, see <http://www.boost.org/users/history/version_1_65_1.html> You can also download directly from: <https://dl.bintray.com/boostorg/release/1.65.1/> To install this release on your system, see <http://www.boost.org/doc/libs/release/more/getting_started/index.html> Thanks to everyone who participated in this release. Thanks, -- The Boost Release Team Vladimir Prus Rene Rivera Marshall Clow Eric Niebler Daniel James Beman Dawes

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[Multi_Index] Mixing composite keys with chained pointer value types
by Nick Gordon 07 Sep '17

07 Sep '17

I have a multi-index container that I'm using to fulfill two search cases. The objects are all derived from `Base`, which is a pure virtual class. To store the `Derived` objects I'm using unique_ptrs as the container value type. However, I need to store the objects uniquely on a composite of a member string, and an enum type used for runtime reflection without dynamic_cast-ing or typeid-ing. So, I want to use a composite key to be unique over both of these things. However, it doesn't compile (why else would I be posting). The minimum source code I can construct to fail using GCC 5.4.0 or Clang 3.9.1 with Boost 1.62 is attached in test.cpp, and the compilation error from my version of clang is attached as compilation-error.txt. I compile it with `clang++ --std=c++14 test.cpp`. I'm not familiar with how the library works, but my surface-level understanding is it seems that the chained_ptr is trying to act on the value type, but the operand being passed is actually one of the composite key expressions. I couldn't find much about how these two mechanisms interact. In my case it's not strictly necessary that I have this type-determining enum value, but it's cheaper than dynamic casting, and it makes my life simpler, because there are also many cases where we want to print the class name of the derived instance. There are other approaches, but I don't want to use them if I can get this working :) -Nick Gordon

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Delete and free all elements of ptr_vector
by Florian Lindner 07 Sep '17

07 Sep '17

Hello, in my project we have a simple ptr_vector that has a member function: void deleteElements () { for ( CONTENT_T * elem : _content ) { assertion ( elem != NULL ); delete ( elem ); } } I want to replace this ptr_vector with boost::ptr_vector. However, I haven't found a way to delete and free all pointers stored in the container. How can I do that? Thanks, Florian

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[Test] Can't build Boost Test 1.65.0 with Visual Studio 2013
by Kerry, Richard 07 Sep '17

07 Sep '17

I've just tried building Boost Test 1.65.0 with Visual Studio 2013 (ie msvc-12) and it doesn't seem to work, showing a compiler internal error. Can anyone advise what I might be doing wrong. Or whether a newer (or older) release fixes this issue. I've also tried 1.64.0 with an identical looking failure. Details below. Regards, Richard. I run : >b2 --with-test (as in the docs, though I'm not specifying address-model, link, --prefix or install. Having tried address-model and link as documented they appear to show the same fault). And then, after some messages, including "- test : building" (and nothing else listed as building), I get some messages starting: ...patience... ...found 1239 targets... ...updating 28 targets... compile-c-c++ bin.v2\libs\chrono\build\msvc-12.0\debug\link-static\threading-multi\chrono.obj chrono.cpp C:\Users\kerryr01\Downloads\Boost\boost_1_65_0\boost/type_traits/common_type.hpp(43) : fatal error C1001: An internal error has occurred in the compiler. (compiler file 'msc1.cpp', line 1325) To work around this problem, try simplifying or changing the program near the locations listed above. Please choose the Technical Support command on the Visual C++ Help menu, or open the Technical Support help file for more information Internal Compiler Error in C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\BIN\cl.exe. You will be prompted to send an error report to Microsoft later. call "C:\Users\kerryr01\AppData\Local\Temp\b2_msvc_12.0_vcvarsall_x86.cmd" >nul cl /Zm800 -nologo @"bin.v2\libs\chrono\build\msvc-12.0\debug\link-static\threading-multi\chrono.obj.rsp" ...failed compile-c-c++ bin.v2\libs\chrono\build\msvc-12.0\debug\link-static\threading-multi\chrono.obj... This is followed by a number of similar blocks of messages relating to: chrono.obj, thread_clock.obj, process_cpu_clocks.obj, cpu_timer.obj, auto_timers_construction.obj, execution_monitor.obj and others. [Blue line] Richard Kerry BNCS Engineer, SI SOL Telco & Media Vertical Practice T: +44 (0)20 3618 2669 M: +44 (0)7812 325518 4 Triton Square, Regent’s Place, London NW1 3HG richard.kerry(a)atos.net<mailto:richard.kerry@atos.net> [Atos logo] This e-mail and the documents attached are confidential and intended solely for the addressee; it may also be privileged. If you receive this e-mail in error, please notify the sender immediately and destroy it. As its integrity cannot be secured on the Internet, the Atos group liability cannot be triggered for the message content. Although the sender endeavours to maintain a computer virus-free network, the sender does not warrant that this transmission is virus-free and will not be liable for any damages resulting from any virus transmitted.</ Atos, Atos Consulting, Worldline and Canopy The Open Cloud Company are trading names used by the Atos group. The following trading entities are registered in England and Wales: Atos IT Services UK Limited (registered number 01245534), Atos Consulting Limited (registered number 04312380), Atos Worldline UK Limited (registered number 08514184) and Canopy The Open Cloud Company Limited (registration number 08011902). The registered office for each is at 4 Triton Square, Regent’s Place, London, NW1 3HG.The VAT No. for each is: GB232327983. This e-mail and the documents attached are confidential and intended solely for the addressee, and may contain confidential or privileged information. If you receive this e-mail in error, you are not authorised to copy, disclose, use or retain it. Please notify the sender immediately and delete this email from your systems. As emails may be intercepted, amended or lost, they are not secure. Atos therefore can accept no liability for any errors or their content. Although Atos endeavours to maintain a virus-free network, we do not warrant that this transmission is virus-free and can accept no liability for any damages resulting from any virus transmitted. The risks are deemed to be accepted by everyone who communicates with Atos by email.

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flat_(multi)map/set and Compare::is_transparent
by TONGARI J 06 Sep '17

06 Sep '17

Hi, Since C++14, the standard introduces transparent comparators for heteregeneous lookup, but seems that the Boost's flat counterparts don't take advantage of this yet. Is there any plan to support transparent comparators? Thanks.

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[Boost.Container] Boost.Container support for transparent comparators
by dariomt＠gmail.com 05 Sep '17

05 Sep '17

Hi, I see this trac ticket [1] with a feature request, and I'd like to know if there has been any progress on it. It doesn't look like it is in the latest release yet. Thank you! [1] https://svn.boost.org/trac10/ticket/11780

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